342 research outputs found

    A Predictive Model for Student Performance in Classrooms using Student Interactions with an eTextbook

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    With the rise of online eTextbooks and Massive Open Online Courses (MOOCs), a huge amount of data has been collected related to students’ learning. With the careful analysis of this data, educators can gain useful insights into their students’ performance and their behavior in learning a particular topic. This paper proposes a new model for predicting student performance based on an analysis of how students interact with an interactive online eTextbook. By being able to predict students’ performance early in the course, educators can easily identify students at risk and provide a suitable intervention. We considered two main issues: the prediction of good/bad performance and the prediction of the final exam grade. To build the proposed model, we evaluated the most popular classification and regression algorithms. Random Forest Regression and Multiple Linear Regression have been applied in Regression. While Logistic Regression, decision tree, Random Forest Classifier, K Nearest Neighbors, and Support Vector Machine have been applied in classification. Based on the findings of the experiments, the algorithm with the best result overall in classification was Random Forest Classifier with an accuracy equal to 91.7%, while in the regression it was Random Forest Regression with an R2 equal to 0.977

    Identifying Difficult exercises in an eTextbook Using Item Response Theory and Logged Data Analysis

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    The growing dependence on eTextbooks and Massive Open Online Courses (MOOCs) has led to an increase in the amount of students' learning data. By carefully analyzing this data, educators can identify difficult exercises, and evaluate the quality of the exercises when teaching a particular topic. In this study, an analysis of log data from the semester usage of the OpenDSA eTextbook was offered to identify the most difficult data structure course exercises and to evaluate the quality of the course exercises. Our study is based on analyzing students' responses to the course exercises. We applied item response theory (IRT) analysis and a latent trait mode (LTM) to identify the most difficult exercises .To evaluate the quality of the course exercises we applied IRT theory. Our findings showed that the exercises that related to algorithm analysis topics represented the most difficult exercises, and there existing six exercises were classified as poor exercises which could be improved or need some attention.Comment: 6 pages,5 figure

    Antioxidant and hepatoprotective effects of Astragalus echinops and Astragalus logopodioides ethanolic extracts on paracetamol-induced liver injury in rats

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    Background: Paracetamol (PCM) has an adequate safety profile when taken in normal doses. However, it could produce oxidative stress with liver injury when taken in an overdose. Plants of Astragalus genus (F. Fabaceae) are of wide-spread applications. Astragalus echinops (A. echinops) and Astragalus logopodioides (A. logopodioides) were tested for their potential hepatoprotective activities against liver injury induced by PCM in rats.Material and Methods: Seven groups of rats were used for determination of hepatoprotective activities of the extracts. The normal and hepatotoxic control groups received the vehicle while other groups were treated with silymarin (100 mg/ kg), A. echinops (250 and 500 mg/kg) and A. logopodioides (250 and 500 mg/ kg), respectively for seven days. Liver injury was induced on the 5th day by oral dosing of PCM (2g/kg) to all rats except those in normal control group. Moreover, the in vitro antioxidant activities of A. echinops and A. logopodioides extracts were tested using 2,2- diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging.Results: Hepatic enzyme markers as alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and glutamyl transferase and level of total bilirubin were significantly elevated, while total protein and albumin were declined significantly in PCM-exposed animals. The liver antioxidant markers like the activities of superoxide dismutase, catalase and glutathione peroxidase and the levels of reduced glutathione were significantly declined, while hepatic malondialdehyde levels were significantly increased in PCM alone-treated rats. Administration of A. echinops (250 and 500 mg/kg) and A. logopodioides (500 mg/ kg) extracts prior to PCM, significantly protected against the elevation in the serum activities of hepatic enzymes and bilirubin and reduced oxidative stress. The hepatoprotective effect of both extracts was further confirmed by histological findings in the liver tissue. In addition, both extracts displayed in vitro antioxidant activities in a concentration-dependent way.Conclusion: Our results suggest that both extracts protect the liver against oxidative damage and they could be used as effective hepatoprotectives against PCM induced liver injury.Keywords: Astragalus, Paracetamol, Hepatotoxicity, Hepatoprotective, DPPH, Antioxidan

    ANTIOXIDANT AND HEPATOPROTECTIVE EFFECTS OF ASTRAGALUS ECHINOPS AND ASTRAGALUS LOGOPODIOIDES ETHANOLIC EXTRACTS ON PARACETAMOL-INDUCED LIVER INJURY IN RATS

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    Background: Paracetamol (PCM) has an adequate safety profile when taken in normal doses. However, it could produce oxidative stress with liver injury when taken in an overdose. Plants of Astragalus genus (F. Fabaceae) are of wide-spread applications. Astragalus echinops (A. echinops) and Astragalus logopodioides (A. logopodioides) were tested for their potential hepatoprotective activities against liver injury induced by PCM in rats. Material and Methods: Seven groups of rats were used for determination of hepatoprotective activities of the extracts. The normal and hepatotoxic control groups received the vehicle while other groups were treated with silymarin (100 mg/ kg), A. echinops (250 and 500 mg/kg) and A. logopodioides (250 and 500 mg/ kg), respectively for seven days. Liver injury was induced on the 5th day by oral dosing of PCM (2g/kg) to all rats except those in normal control group. Moreover, the in vitro antioxidant activities of A. echinops and A. logopodioides extracts were tested using 2,2- diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging. Results: Hepatic enzyme markers as alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and glutamyl transferase and level of total bilirubin were significantly elevated, while total protein and albumin were declined significantly in PCM-exposed animals. The liver antioxidant markers like the activities of superoxide dismutase, catalase and glutathione peroxidase and the levels of reduced glutathione were significantly declined, while hepatic malondialdehyde levels were significantly increased in PCM alone-treated rats. Administration of A. echinops (250 and 500 mg/kg) and A. logopodioides (500 mg/ kg) extracts prior to PCM, significantly protected against the elevation in the serum activities of hepatic enzymes and bilirubin and reduced oxidative stress. The hepatoprotective effect of both extracts was further confirmed by histological findings in the liver tissue. In addition, both extracts displayed in vitro antioxidant activities in a concentration-dependent way. Conclusion: Our results suggest that both extracts protect the liver against oxidative damage and they could be used as effective hepatoprotectives against PCM induced liver injury

    Development of spiro-3-indolin-2-one containing compounds of antiproliferative and anti-SARS-CoV-2 properties

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    Abstract: A series of 1″-(alkylsulfonyl)-dispiro[indoline-3,2′-pyrrolidine-3′,3″-piperidine]-2,4″-diones 6a‒o has been synthesized through regioselective multi-component azomethine dipolar cycloaddition reaction of 1-(alkylsulfonyl)-3,5-bis(ylidene)-piperidin-4-ones 3a‒h. X-ray diffraction studies (6b‒d, h) confirmed the structures. The majority of the synthesized analogs reveal promising antiproliferation properties against a variety of human cancer cell lines (MCF7, HCT116, A431 and PaCa2) with good selectivity index towards normal cell (RPE1). Some of the synthesized agents exhibit potent inhibitory properties against the tested cell lines with higher efficacies than the standard references (sunitinib and 5-fluorouracil). Compound 6m is the most potent. Multi-targeted inhibitory properties against EGFR and VEGFR-2 have been observed for the synthesized agents. Flow cytometry supports the antiproliferation properties and shows the tested agents as apoptosis and necrosis forming. Vero cell viral infection model demonstrates the anti-SARS-CoV-2 properties of the synthesized agents. Compound 6f is the most promising (about 3.3 and 4.8 times the potency of the standard references, chloroquine and hydroxychloroquine). QSAR models explain and support the observed biological properties

    Distribution pattern of antibiotic resistance genes in Escherichia coli isolated from colibacillosis cases in broiler farms of Egypt

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    Background and Aim: Multidrug resistance (MDR) of Escherichia coli has become an increasing concern in poultry farming worldwide. However, E. coli can accumulate resistance genes through gene transfer. The most problematic resistance mechanism in E. coli is the acquisition of genes encoding broad-spectrum β-lactamases, known as extended-spectrum β-lactamases, that confer resistance to broad-spectrum cephalosporins. Plasmid-mediated quinolone resistance genes (conferring resistance to quinolones) and mcr-1 genes (conferring resistance to colistin) also contribute to antimicrobial resistance. This study aimed to investigate the prevalence of antimicrobial susceptibility and to detect β-lactamase and colistin resistance genes of E. coli isolated from broiler farms in Egypt. Materials and Methods: Samples from 938 broiler farms were bacteriologically examined for E. coli isolation. The antimicrobial resistance profile was evaluated using disk diffusion, and several resistance genes were investigated through polymerase chain reaction amplification. Results: Escherichia coli was isolated and identified from 675/938 farms (72%) from the pooled internal organs (liver, heart, lung, spleen, and yolk) of broilers. Escherichia coli isolates from the most recent 3 years (2018–2020) were serotyped into 13 serotypes; the most prevalent serotype was O125 (n = 8). The highest phenotypic antibiotic resistance profiles during this period were against ampicillin, penicillin, tetracycline, and nalidixic acid. Escherichia coli was sensitive to clinically relevant antibiotics. Twenty-eight selected isolates from the most recent 3 years (2018–2020) were found to have MDR, where the prevalence of the antibiotic resistance genes ctx, tem, and shv was 46% and that of mcr-1 was 64%. Integrons were found in 93% of the isolates. Conclusion: The study showed a high prevalence of E. coli infection in broiler farms associated with MDR, which has a high public health significance because of its zoonotic relevance. These results strengthen the application of continuous surveillance programs

    Determination of nitrogen dioxide, sulfur dioxide, ozone, and ammonia in ambient air using the passive sampling method associated with ion chromatographic and potentiometric analyses

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    Concentrations of nitrogen dioxide (NO2), sulfur dioxide (SO2), ozone (O3), and ammonia (NH3) were determined in the ambient air of Al-Ain city over a year using the passive sampling method associated with ion chromatographic and potentiometric detections. IVL samplers were used for collecting nitrogen and sulfur dioxides whereas Ogawa samplers were used for collecting ozone and ammonia. Five sites representing the industrial, traffic, commercial, residential, and background regions of the city were monitored in the course of this investigation. Year average concentrations of ≤59.26, 15.15, 17.03, and 11.88 μg/m3 were obtained for NO2, SO2, O3, and NH3, respectively. These values are lower than the maxima recommended for ambient air quality standards by the local environmental agency and the world health organization. Results obtained were correlated with the three meteorological parameters: humidity, wind speed, and temperature recorded during the same period of time using the paired t test, probability p values, and correlation coefficients. Humidity and wind speed showed insignificant effects on NO2, SO2, O3, and NH3 concentrations at 95% confidence level. Temperature showed insignificant effects on the concentrations of NO2 and NH3 while significant effects on SO2 and O3 were observed. Nonlinear correlations (R2 ≤ 0.722) were obtained for the changes in measured concentrations with changes in the three meteorological parameters. Passive samplers were shown to be not only precise (RSD ≤ 13.57) but also of low cost, low technical demand, and expediency in monitoring different locations

    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

    Novel Insights into the Diversity of Catabolic Metabolism from Ten Haloarchaeal Genomes

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    BACKGROUND: The extremely halophilic archaea are present worldwide in saline environments and have important biotechnological applications. Ten complete genomes of haloarchaea are now available, providing an opportunity for comparative analysis. METHODOLOGY/PRINCIPAL FINDINGS: We report here the comparative analysis of five newly sequenced haloarchaeal genomes with five previously published ones. Whole genome trees based on protein sequences provide strong support for deep relationships between the ten organisms. Using a soft clustering approach, we identified 887 protein clusters present in all halophiles. Of these core clusters, 112 are not found in any other archaea and therefore constitute the haloarchaeal signature. Four of the halophiles were isolated from water, and four were isolated from soil or sediment. Although there are few habitat-specific clusters, the soil/sediment halophiles tend to have greater capacity for polysaccharide degradation, siderophore synthesis, and cell wall modification. Halorhabdus utahensis and Haloterrigena turkmenica encode over forty glycosyl hydrolases each, and may be capable of breaking down naturally occurring complex carbohydrates. H. utahensis is specialized for growth on carbohydrates and has few amino acid degradation pathways. It uses the non-oxidative pentose phosphate pathway instead of the oxidative pathway, giving it more flexibility in the metabolism of pentoses. CONCLUSIONS: These new genomes expand our understanding of haloarchaeal catabolic pathways, providing a basis for further experimental analysis, especially with regard to carbohydrate metabolism. Halophilic glycosyl hydrolases for use in biofuel production are more likely to be found in halophiles isolated from soil or sediment

    Global economic burden of unmet surgical need for appendicitis

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    Background: There is a substantial gap in provision of adequate surgical care in many low-and middle-income countries. This study aimed to identify the economic burden of unmet surgical need for the common condition of appendicitis. Methods: Data on the incidence of appendicitis from 170 countries and two different approaches were used to estimate numbers of patients who do not receive surgery: as a fixed proportion of the total unmet surgical need per country (approach 1); and based on country income status (approach 2). Indirect costs with current levels of access and local quality, and those if quality were at the standards of high-income countries, were estimated. A human capital approach was applied, focusing on the economic burden resulting from premature death and absenteeism. Results: Excess mortality was 4185 per 100 000 cases of appendicitis using approach 1 and 3448 per 100 000 using approach 2. The economic burden of continuing current levels of access and local quality was US 92492millionusingapproach1and92 492 million using approach 1 and 73 141 million using approach 2. The economic burden of not providing surgical care to the standards of high-income countries was 95004millionusingapproach1and95 004 million using approach 1 and 75 666 million using approach 2. The largest share of these costs resulted from premature death (97.7 per cent) and lack of access (97.0 per cent) in contrast to lack of quality. Conclusion: For a comparatively non-complex emergency condition such as appendicitis, increasing access to care should be prioritized. Although improving quality of care should not be neglected, increasing provision of care at current standards could reduce societal costs substantially
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