105 research outputs found

    New technique for using SMES to limit fault currents in wind farm power systems

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    This paper introduces a new scheme, which uses a multifunctional superconducting device that can be used as an energy storage and as a fault current limiter. It is denoted as a superconducting magnetic energy storage - fault current limiter (SMES-FCL) and is modeled as a number of pancakes. It is connected to a wind turbine power system via tertiary transformer and power converters. A complete control scheme is built to achieve effective power transfer between the superconducting coil and the power system during normal operation to smooth the wind turbine output power. The fault current limiting function is implemented using a new technique that inserts a few pancakes from the whole SMES coil into the main electrical system during the fault and isolates the remaining pancakes. The number of pancakes used to limit the fault is quenched and operates as a resistive fault current limiter. The whole system including the wind turbine, the SMES-FCL model, and the interface circuit are implemented using PSCAD/EMTDC computer package. Also, the control scheme of SMES-FCL is built based on a feedback current signal to enable its operation into the two modes

    Estimating the Prevalence of Foodborne Pathogen Campylobacter jejuni in Chicken and Its Control via Sorghum Extracts

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    Campylobacter jejuni is a Gram-negative bacterium which is considered as the most reported cause of foodborne infection, especially for poultry species. The object of this work is to evaluate the occurrence of C. jejuni in chicken meat as well its control via three types of sorghum extracts (white sorghum (WS), yellow sorghum (YS), and red sorghum (RS)); antibacterial activity, antioxidant power, and cytotoxicity of sorghum extracts were also assessed. It was found that C. jejuni is very abundant in chicken meat, especially breast and thigh. WS extract showed more effectiveness than both yellow and red ones. Lyophilized WS extract offered high total phenolic compounds (TPCs) and total flavonoid compounds (TFCs) of 64.2 ± 0.8 mg gallic acid equivalent (GAE/g) and 33.9 ± 0.4 mg catechol equivalent (CE)/g, respectively. Concerning the antibacterial and antioxidant activities, WS showed high and significant antibacterial activity (p < 0.001); hence, WS displayed a minimum inhibitory concentration (MIC) of 6.25%, and revealed an inhibition zone of 7.8 ± 0.3 mm; it also showed an IC50 at a concentration of 34.6 μg/mL. In our study, different samples of chicken fillet were collected and inoculated with pathogenic C. jejuni and stored at 4 °C. Inoculated samples were treated with lyophilized WS extract at (2%, 4%, and 6%), the 2% treatment showed a full reduction in C. jejuni on the 10th day, the 4% treatment showed a full reduction in C. jejuni on the 8th day, while the 6% treatment showed a full reduction in C. jejuni on the 6th day. Additionally, 2%, 4%, and 6% WS extracts were applied on un-inoculated grilled chicken fillet, which enhanced its sensory attributes. In sum, WS extract is a promising natural preservative for chicken meat with accepted sensory evaluation results thanks to its high antibacterial and antioxidant potentials

    Fuzzy logic controller equilibrium base to enhance AGC system performance with renewable energy disturbances

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    Owing to the various sources of complexity in the electrical power system, such as integrating intermittent renewable energy resources and widely spread nonlinear power system components, which result in sudden changes in the power system operating conditions, the conventional PID controller fails to track such dynamic challenges to mitigate the frequency deviation problem. Thus, in this paper, a fuzzy PI controller is proposed to enhance the automatic generation control system (AGC) against step disturbance, dynamic disturbance, and wind energy disturbance in a single area system. The proposed controller is initialized by using Equilibrium Optimization and proved its superiority through comparison with a classical PI optimized base. Results show that the fuzzy PI controller can reduce the peak-to-peak deviation in the frequency by 30–59% under wind disturbance, compared to a classical PI optimized base. Moreover, a fuzzy PID controller is also proposed and EO initialized in this paper to compare with the PIDA optimized by several techniques in the two-area system. Results show that the fuzzy PID controller can reduce the peak-to-peak deviation in the frequency of area 1 by 30–50% and the deviation of frequency in area 2 by 13–48% under wave disturbance, compared to the classical PIDA optimized base

    Impact Of Covid-19 Lockdown On Smoking (Waterpipe And Cigarette) And Participants\u27 Bmi Across Various Sociodemographic Groups In Arab Countries In The Mediterranean Region

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    INTRODUCTION Tobacco smokers are at high risk of developing severe COVID-19. Lockdown was a chosen strategy to deal with the spread of infectious diseases; nonetheless, it influenced people\u27s eating and smoking behaviors. The main objective of this study is to determine the impact of the COVID-19 lockdown on smoking (waterpipe and cigarette) behavior and its associations with sociodemographic characteristics and body mass index. METHODS The data were derived from a large-scale retrospective cross-sectional study using a validated online international survey from 38 countries (n=37207) conducted between 17 April and 25 June 2020. The Eastern Mediterranean Region (WHO-EMR countries) data related to 10 Arabic countries that participated in this survey have been selected for analysis in this study. A total of 12433 participants were included in the analysis of this study, reporting their smoking behavior and their BMI before and during the COVID-19 lockdown. Descriptive and regression analyses were conducted to examine the association between smoking practices and the participant\u27s country of origin, sociodemographic characteristics, and BMI (kg/m2). RESULTS Overall, the prevalence rate of smoking decreased significantly during the lockdown from 29.8% to 23.5% (p\u3c0.05). The percentage of females who smoke was higher than males among the studied population. The highest smoking prevalence was found in Lebanon (33.2%), and the lowest was in Oman (7.9%). In Egypt, Kuwait, Lebanon, and Saudi Arabia, the data showed a significant difference in the education level of smokers before and during the lockdown (p\u3c0.05). Smokers in Lebanon had lower education levels than those in other countries, where the majority of smokers had a Bachelor\u27s degree. The findings show that the BMI rates in Jordan, Lebanon, Oman, and Saudi Arabia significantly increased during the lockdown (p\u3c0.05). The highest percentages of obesity among smokers before the lockdown were in Oman (33.3%), followed by Bahrain (28.4%) and Qatar (26.4%), whereas, during the lockdown, the percentage of obese smokers was highest in Bahrain (32.1%) followed by Qatar (31.3%) and Oman (25%). According to the logistic regression model, the odds ratio of smoking increased during the pandemic, whereas the odds ratio of TV watching decreased. This finding was statistically significant by age, gender, education level, country of residence, and work status. CONCLUSIONS Although the overall rates of smoking among the studied countries decreased during the lockdown period, we cannot attribute this change in smoking behavior to the lockdown. Smoking cessation services need to anticipate that unexpected disruptions, such as pandemic lockdowns, may be associated with changes in daily tobacco consumption. Public health authorities should promote the adoption of healthy lifestyles to reduce the long-term negative effects of the lockdown

    Correlates of low birth weight in term pregnancies: a retrospective study from Iran

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    <p>Abstract</p> <p>Background</p> <p>Low birth weight (LBW) is considered as a major multifaceted public health concern. Seventy-two percent of LBW infants are born in Asia. An estimation of 8% LBW infants has been reported for Eastern Mediterranean region including Iran. This study investigated contributory factors of LBW in singleton term births in Tehran, Iran. Tehran is a multicultural metropolitan area and a sample from the general population in Tehran could be regarded as a representative sample of urban population in Iran.</p> <p>Methods</p> <p>This was a retrospective study using data from 15 university maternity hospitals in Tehran, Iran. Data on all singleton term births in these hospitals were extracted from case records during a one calendar year. Study variables included: maternal age, maternal educational level, history of LBW deliveries, history of preterm labor, cigarette smoking during pregnancy, number of parities, chronic diseases and residential area (Tehran versus suburbs of Tehran). In order to examine the relationship between LBW and demographic and reproductive variables the adjusted logistic regression analysis was performed.</p> <p>Results</p> <p>In all, data for 3734 term pregnancies were extracted. The mean age of women was 25.7 (SD = 5.3) years and 5.2% of term births were LBW. In addition to association between LBW and maternal age, significant risk factors for LBW were: history of LBW deliveries [adjusted odds ratio (OR) = 2.53, 95% confidence interval (CI) = 1.06–6.03], smoking during pregnancy (OR = 4.64, 95% CI = 1.97–10.95) and chronic diseases (OR for hypertension = 3.70, 95% CI = 2.25–6.06, OR for others = 2.04, 95% CI = 1.09–3.83).</p> <p>Conclusion</p> <p>The findings indicate that in addition to maternal age, history of LBW deliveries; smoking during pregnancy and chronic diseases are significant determinants of LBW in this population. This is consistent with national and international findings indicating that maternal variables and risk behaviors during pregnancy play important roles on LBW.</p

    IAN Family Critically Regulates Survival and Development of T Lymphocytes

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    The IAN (immune-associated nucleotide-binding protein) family is a family of functionally uncharacterized GTP-binding proteins expressed in vertebrate immune cells and in plant cells during antibacterial responses. Here we show that all eight IAN family genes encoded in a single cluster of mouse genome are predominantly expressed in lymphocytes, and that the expression of IAN1, IAN4, and IAN5 is significantly elevated upon thymic selection of T lymphocytes. Gain-of-function experiments show that the premature overexpression of IAN1 kills immature thymocytes, whereas short hairpin RNA-mediated loss-of-function studies show that IAN4 supports positive selection. The knockdown of IAN5 perturbs the optimal generation of CD4/CD8 double-positive thymocytes and reduces the survival of mature T lymphocytes. We also show evidence suggesting that IAN4 and IAN5 are associated with anti-apoptotic proteins Bcl-2 and Bcl-xL, whereas IAN1 is associated with pro-apoptotic Bax. Thus, the IAN family is a novel family of T cell–receptor-responsive proteins that critically regulate thymic development and survival of T lymphocytes and that potentially exert regulatory functions through the association with Bcl-2 family proteins

    Genomic characterization of SARS-CoV-2 in Egypt: insights into spike protein thermodynamic stability

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    The overall pattern of the SARS-CoV-2 pandemic so far has been a series of waves; surges in new cases followed by declines. The appearance of novel mutations and variants underlie the rises in infections, making surveillance of SARS-CoV-2 mutations and prediction of variant evolution of utmost importance. In this study, we sequenced 320 SARS-CoV-2 viral genomes isolated from patients from the outpatient COVID-19 clinic in the Children’s Cancer Hospital Egypt 57357 (CCHE 57357) and the Egypt Center for Research and Regenerative Medicine (ECRRM). The samples were collected between March and December 2021, covering the third and fourth waves of the pandemic. The third wave was found to be dominated by Nextclade 20D in our samples, with a small number of alpha variants. The delta variant was found to dominate the fourth wave samples, with the appearance of omicron variants late in 2021. Phylogenetic analysis reveals that the omicron variants are closest genetically to early pandemic variants. Mutation analysis shows SNPs, stop codon mutation gain, and deletion/insertion mutations, with distinct patterns of mutations governed by Nextclade or WHO variant. Finally, we observed a large number of highly correlated mutations, and some negatively correlated mutations, and identified a general inclination toward mutations that lead to enhanced thermodynamic stability of the spike protein. Overall, this study contributes genetic and phylogenetic data, as well as provides insights into SARS-CoV-2 viral evolution that may eventually help in the prediction of evolving mutations for better vaccine development and drug targets

    Dietary Diversity in the Eastern Mediterranean Region Before and During the COVID-19 Pandemic: Disparities, Challenges, and Mitigation Measures

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    The COVID-19 pandemic has revealed the Eastern Mediterranean Region's food system's fragility posing severe challenges to maintaining healthy sustainable lifestyle. The aim of this cross-sectional study (N = 13,527 household's family members, mean age: 30.3 ±11.6, 80% women) is to examine the impact of the COVID-19 pandemic on food consumption patterns and household's dietary diversity in 10 Eastern Mediterranean countries. A food frequency questionnaire was used to investigate the consumption patterns along with the calculation of the Food Consumption Score (FCS), a proxy indicator of dietary diversity. Data collected on cooking attitudes, shopping and food stock explore the community mitigation measures. In the overall population, before and during the pandemic, most food groups were consumed less or equal to 4 times per week. As evident from our findings and considering that the pandemic may be better, but it's not over, small to moderate changes in food consumption patterns in relatively short time periods can become permanent and lead to substantial poor dietary diversity over time. While it is a priority to mitigate the immediate impact, one area of great concern is the long-term effects of this pandemic on dietary patterns and dietary diversity in Eastern Mediterranean households. To conclude, the COVID-19 crisis revealed the region's unpreparedness to deal with a pandemic. While the aggressive containment strategy was essential for most countries to help prevent the spread, it came at a high nutritional cost, driving poor dietary diversity.This research was funded by the Research Foundation Flanders (G047518N) and Flanders Innovation and Entrepreneurship (HBC.2018.0397). These funding sources had no role in the design of the study, the analysis and interpretation of the data or the writing of, nor the decision to publish the manuscript

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London
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