188 research outputs found
The mazEF toxin-antitoxin system as a novel antibacterial target in Acinetobacter baumannii
Although analysis of toxin-antitoxin (TA) systems can be instructive, to date, there is no information on the prevalence and identity of TA systems based on a large panel of Acinetobacter baumannii clinical isolates. The aim of the current study was to screen for functional TA systems among clinical isolates of A. baumannii and to identify the systems' locations. For this purpose, we screened 85 A. baumannii isolates collected from different clinical sources for the presence of the mazEF, relBE and higBA TA genes. The results revealed that the genes coding for the mazEF TA system were commonly present in all clinical isolates of A. baumannii. Reverse transcriptase-polymerase chain reaction analysis showed that transcripts were produced in the clinical isolates. Our findings showed that TA genes are prevalent, harboured by chromosomes and transcribed within A. baumannii. Hence, activation of the toxin proteins in the mazEF TA system should be investigated further as an effective antibacterial strategy against this bacterium
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Information retrieval evaluation in knowledge acquisition tasks
The Cranfield Paradigm is a widely adopted and the de-facto standard approach to the evaluation of IR systems. However, this approach does not inherently support situations in which the user is acquiring knowledge (is learning) during an information seeking session consisting of the submission of a sequence of queries into an information retrieval system. More specifically, during a situation in which the retrieval of a particular document at the beginning of a session can be considered not relevant (due to the user's lack of knowledge), while it can be considered relevant at a later point in the session (once the user acquired all required prerequisite knowledge). In this position paper, we reflect on the limitations of the Cranfield Paradigm in the context of knowledge acquisition tasks and propose several alternatives. These alternatives are based on the notion of evaluating a session consisting of a sequence of individual queries created to address a specific information need as part of a knowledge acquisition task
SURVEY IN IRAN OF CLARITHROMYCIN RESISTANCE IN HELICOBACTER PYLORI ISOLATES BY PCR-RFLP
The aims of this study were to assess primary resistance of H. pylori strains isolated from adult patients of Ilam, Iran to antibacterial agents (amoxicillin, clarithromycin, metronidazole and tetracycline) and detection of clarithromycin, azithromycin, clarithromycin, metronidazole and tetracycline resistance by disc diffusion. Fifty biopsies were taken from gastric mucosa of the antrum and body regions of adult patients by gastroscopy, and were cultured on Helicobacter pylori selective medium. The susceptibility of H. pylon strains showed that 44, 6, 6, 4 and 16 were resistance to metronidazole, amoxicillin, tetracycline, azithromycin, and clarithromycin, respectively. Polymerase chain reaction-restriction fragment length polymorphism analysis showed that all clarithromycin resistance isolates had A2143G mutation and PCR amplicons from these strains upon digestion by BsaI restriction enzyme resulted in 319 and 106 base pair fragments. Because most of physicians in Ilam do not use amoxicillin in triple therapy of H. pylon infection, isolates showed low rate of resistance to amoxicilli
The effect of hydro-alcoholic extract of celery (Apium graveolens) leaves on serum level of testosterone, FSH and LH in male rats
Background and Objective: Celery (Apium graveolens) is a plant from Apiaceae family with high nutritional and medicinal use.This plant has many phytoestrogens that can affect the pituitary-gonadal axis. The purpose of this study was to investigate the effect of hydro-alcoholic extract of celery leaves on serum level of testosterone, FSH and LH in male rats. Materials and Methods: In this experimental study, thirty-two male wistar rats were randomly divided into four groups of eight rats each. The control group did not receive anything. The sham group received distilled water (as a solvent), and the experimental groups received doses of 200 and 300 mg/kg/ BW of hydro-alcoholic extract of celery leaves for 20 days. The extract was gavaged once a day. One day after the last gavage, the rats were anaesthetized and blood samples were collected from the heart and then serum levels of testosterone, LH and FSH were measured. The data were analyzed using SPSS software and ANOVA test. Results: Concentration of LH in the treatment group with doses of 200 mg/kg (0.39±0.02 mIU/dl) reduced in comparison with control (0.67±0.01 mIU/dl) and sham (0.73±0.02 mIU/dl) groups (P0.05). Conclusion: The results indicated that the administration of 200 mg/kg doses of celery extract causes a significant reduction in serum LH concentration, but it has no effect on ganadotropin and testosterone hormones in highest doses used in this study. This finding may be due to the presence of flavonoid and antioxidant proporties of celery
Economic assessment of nature-based solutions as enablers of circularity in water systems
The transition from the current linear model of abstraction, use and discharge of water into recycle-reuse under the circular economy (CE) principles is momentous. An analysis of recent literature about the economic impact of linear to circular (L2C) transition is made. The review investigates the economic implications (i.e. cost-benefit) of deployment of enabling technologies, tools and methodologies within the circular water systems. The study is enhanced by presenting the results of our investigation into the policy impact (push-barriers) of L2C transition. As the vehicle for the L2C transition, nature-based solutions (NBS) and its economic and policy implications is discussed. A framework is proposed for the monetary assessment of the costs of investment in NBS technologies, infrastructure and education against the environmental and socio-economic benefits within the policy frameworks. This framework may build the early foundation for bridging the gap that exists for a systematic and objective economic impact (cost-benefit) analysis of L2C transition in the Water sector. This framework will lead to a generic multi-parametric cost model of NBS for Circularity Water Systems.Engineering and Physical Sciences Research Council (EPSRC); Horizon 2020 research and innovation program HYDROUS
QSPR Modeling using Catalan Solvent and Solute Parameters
A área de correlação quantitativa entre estrutura e propriedade (QSPR) pode beneficiar-se de descritores moleculares que representam interações intermoleculares. Catalan desenvolveu um método de escalas solvatocrômicas para solventes que pode ser explorado para esta finalidade. Neste trabalho, escalas de solvente de Catalan foram usadas como descritores moleculares para o desenvolvimento de modelos QSPR, e para o cálculo de novos descritores de soluto para uso posterior em QSPR. As escalas Catalan para o solvente e os descritores de soluto derivados foram recentemente comparados com o método de descritores de Abraham, em termos da qualidade do QSPR desenvolvido. Os parâmetros Catalan para solventes, que mostraram uma correlação modesta com os correspondentes descritores de Abraham, mostraram-se bem sucedidos para modelar temperatura de fusão, temperatura de ebulição, ponto de ignição, índice de refração, tensão superficial, densidade e parâmetro de solubilidade dos solventes, com médias geométricas dos desvios relativos (GMRD) de 7,1, 6,6, 4,9, 3,8, 9,1, 6,0 e 4,2%, respectivamente. Os descritores do soluto foram obtidos a partir das equações de regressão entre a solubilidade de um soluto em diferentes solventes com um GMRD total de 30,0%. Os descritores de soluto obtidos desta maneira superam o modelo de solvatação geral de Abraham no cálculo de solubilidade em meio aquoso de 27 solutos de várias famílias químicas. Os descritores Catalan podem ser considerados como um recurso valioso para modelagem QSPR. The field of quantitative structure-property relationship (QSPR) can greatly benefit from molecular descriptors that particularly represent the intermolecular interactions. Catalan has developed a set of solvatochromic scales for solvents, which could be exploited for this purpose. In this work, Catalan solvent scales were explored as molecular descriptors for the development of QSPR models, and for the calculation of new solute descriptors for further use in QSPR. Catalan solvent scales and the newly derived solute descriptors were compared with the commonly used set of Abraham descriptors in terms of the quality of the developed QSPRs. Catalan solvent parameters, which showed modest correlation with the corresponding Abraham descriptors, proved to be successful in modeling melting point, boiling point, flash point, refractive index, surface tension, density, and solubility parameter of the solvents with geometric mean relative deviations (GMRD) of 7.1, 6.6, 4.9, 3.8, 9.1, 6.0, and 4.2%, respectively. The solute descriptors were obtained from regression equations between a solute's solubility in different solvents with an overall GMRD of 30.0%. The solute descriptors obtained in this way outperformed Abraham general solvation model in the calculation of aqueous solubility for 27 solutes of broad chemical ranges. It was concluded that Catalan descriptors can be regarded as a valuable resource for QSPR modeling
Epidemiological alteration in pathogens found in ground meat in Iran: unexpected predominance of vancomycin-resistant Enterococcus faecalis
Colonization of the human and animal intestinal tract with potential pathogenic bacteria is correlated with the risk of contamination of food products. The current study analyzed the prevalence of Enterococcus faecalis and Escherichia coli O157H7 in ground meat in Ilam, Iran. Both index organisms were identified following standard food microbiological methods. For E. faecalis, the susceptibility to vancomycin was tested, and PCR was used to check for the vanA gene. E. faecalis was present in all 24 ground meat samples, with no E. coli O157H7 detected in samples. The analysis showed the presence of the vanA gene in 5/24 vancomycin resistant enterococci. In conclusion, this study for the first time demonstrates the presence of vancomycin-resistant enterococci in ground meat in Iran. This observation warrants further epidemiologic investigation and should be followed up in the future
Local contractors' awareness on competitiveness towards liberalisation and globalisation in the Malaysian construction industry
Globalisation gives the opportunity to contractors from a particular country to venture into various countries around the globe as the construction market is unlimitedly open. Due to this globalisation, the government has signed free trade agreements (FTA) as the result of the liberalisation process. Globalisation and liberalisation do not only provide opportunities and benefits to the local construction market, but also give challenges to local contractors in terms of competition with other local and foreign contractors. Yet, a question arises whether the local contractors in particular are aware with the competitive challenges they are facing against the foreign contractors or even amongst the local contractors themselves. This is because there are limited studies conducted which seek to identify the current levels of awareness on competitiveness among local contractors within the Malaysian construction industry. Hence, this paper emerges with the objectives of (1) identifying the current level of awareness of local contractors on competitiveness and (2) investigating the most important attributes of awareness of local contractors in the Malaysian construction industry. Questionnaire surveys were conducted on local Malaysian contractors involving 61 organisations from 112 venturing into overseas market. Data were analysed via Rasch analysis consisting of five method analysis which are the reliability and validity analysis, organisation misfit analysis, unidimensionality analysis, item misfit analysis and item measure order analysis. Findings from this paper reveal that most of the contractors have a moderate level of awareness on the competitiveness in the Malaysian construction industry. The findings of this study have been concluded as the local contractors acknowledge their competitors' strength and weaknesses when bidding for new projects and also aim to improve their competitiveness in competing with other local contractors locally. Recognition of this paper on the awareness of the importance of competitiveness by various local contractors in the Malaysian construction industry is in line with the Construction Industry Transformation Plan (CITP) 2016-2020 in addressing the Internationalisation Thrust with the aim to increase competitiveness of the domestic market, especially with the presence of foreign player
Characterization of antimicrobial resistance pattern and molecular analysis among extended spectrum β-lactamase-producing Escherichia coli
Background: Infection is a serious problem in medicine and appropriate antibiotic therapy is very important. Because of broad spectrum activity and low toxicity of β-lactam antibiotics, they are the most commonly used drugs. But, bacterial resistance to β-lactam antibiotics, has been considered as the global healthcare concern. The aim of study was to evaluate the antimicrobial resistance pattern and molecular characterization among ESBL-producing Escherichia coli isolated from patients with diarrhea admitted to a hospital in Ilam, Iran. Methods: Totally, fifty E. coli isolates were investigated. Confirmatory tests for phenotypic detection of ESBLs were performed. Molecular identification of the blaTEM and blaSHV genes was carried out by PCR method. To identify genetic relatedness among isolates, Randomly Amplified Polymorphic DNA (RAPD) analysis was performed. Results: The antibiotic susceptibility results showed that the most effective antibiotic was imipenem and minimum effect was related to gentamicin. Thirty-one isolates (62) were ESBL-producing organisms according to phenotypic method. The distribution of blaTEM and blaSHV genes among ESBL-producing isolates were 20 (64.5) and 6 (19.3), respectively. RAPD-PCR typing among isolates gave us eight different types. Twelve isolates were clustered in genotype A and all of them were ESBL-producer. Conclusion: The present study showed noticeable incidence of ESBL-producing E. coli isolated from outpatients and hospitalized patients with diarrhea. Therefore, it seems that constant supervision is crucial to monitor the ESBL-producing microorganisms in hospitals and community. © 2016 The Authors
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