MAT-715: SUSTAINABLE HIGH-VOLUME FLY ASH GROUTS FOR TWO-STAGE CONCRETE

Two-stage concrete (TSC) is a special type of concrete in which coarse aggregates are pre-placed in the formwork and subsequently injected with a grout. Beneficiating fly ash in TSC grouts increases TSC sustainability through the ecological use of large quantities of fly ash, reduced carbon-dioxide emissions associated with cement production, and enhancement of resource productivity of the concrete industry. Limited research has explored the effects of using high volume of fly ash as partial replacement for cement in TSC grout mixtures. Therefore, the flowability of grout mixtures incorporating various fly ash addition rates (i.e. 0%, 30%, 50% and 70%) was evaluated using the flow cone method and spread flow test. Correlations between the efflux time and spread flow for the grout mixtures were developed. Results show that increasing the fly ash addition reduced the grouts efflux time while increasing its spread flow. The optimum high-volume fly ash dosage for achieving high flowability and acceptable TSC compressive strength was identified

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

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

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

Feasibility of Artificial Insemination Network for Egyptian Buffalo Development

Literature reviews confirmed that Egypt has a comparative advantage in milk production rather than red meat production, particularly from buffalo. Furthermore, water resources are becoming increasingly scarce, limiting horizontal expansion in fodder acreage. Furthermore, there is fierce competition between food and feed demand on available agricultural land resources. As a result, horizontal expansion in dairy buffalo stock would be impossible. As a result, the only option for buffalo development in Egypt is vertical expansion through increased milk yield to meet the current deficit in domestic milk production. The Egyptian consumer prefers buffalo milk for its color taste and high content of total solids, particularly fat. Buffalo milk is more expensive than cow milk, and its production is increasing faster than cow milk production. The proposed genetic improvement of buffalo milk yield is being accelerated using an artificial insemination (AI) network. A recent study [1], provided evidence that the return of genetic investment in dairy buffalo would be feasible, (IRR = 19.71%) However, according to official statistics, Egypt has only two AI-centers for buffalo selected buffalo sires, serving four AI-units. As a result, the goal of this study was to assess the feasibility of establishing an AI-network in Egypt by estimating (NPV, IRR, and payback period) and its sensitivity to unfavorable changes that the proposed program may face. The study used a field survey data collected from an AI-unit of the buffaloes’ semen and an AI-Center for raising buffalo sires in Nile Delta. The findings showed that, while the Egyptian economy's average discount rate was 17.5 %, the estimated IRR for one AI-unit was around 35 % under the most likely scenario. A 10% decrease in semen price and a 10% increase in insemination costs would result in IRRs of approximately 28% and 31%, respectively. Under the most likely conditions, the estimated IRR for the AI-center was around 31%. 10% Decrease in Semen Price, and 10% increase in feed costs or in Sire’s price would result in 26%, 30% or 28% respectively. The lowest sale price of semen dose is thus the most effective variable on the IRR. Unfavorable changes, on the other hand, would keep investments with high incentives in establishing a feasible AI-Network for rapidly increasing the dairy buffalo milk yield

MAT-716: GREEN SIDEWALKS USING SUSTAINABLE TWO-STAGE CONCRETE

Two-stage concrete (TSC) is a special type of concrete, which has a high potential for use in sidewalk construction owing to its high volume stability. TSC is characterized by its high coarse aggregate content. Hence, using recycled solid waste materials as a coarse aggregate will increase TSC sustainability, while providing a cost-effective alternative to natural aggregates. Aggregates are pre-placed in TSC. Hence, water absorption by recycled concrete aggregates and the associated rheology problems do not exist in TSC. This study explores the performance of green TSC sidewalks incorporating recycled concrete aggregates (RCA) and crumb rubber from scrap tires. Mechanical properties of the proposed green TSC including compressive strength, modulus of elasticity, flexural strength and toughness, as well as durability to freeze-thaw cycles were investigated. Results show a slight reduction in TSC mechanical properties due to the use of RCA. Moreover, incorporating tire particles reduced TSC mechanical properties significantly, while improving its toughness and freeze-thaw resistance. Addition of recycled tire steel wires allowed to overcome the negative effects on the mechanical properties induced by crumb tire rubber. Therefore, recycling solid waste materials in TSC sidewalks can be an effective strategy to beneficiate such waste materials

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

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

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

A Database Study of Visual Outcomes and Intraoperative Complications of Postvitrectomy Cataract Surgery

PURPOSE: To analyze the visual outcomes and rate of intraoperative complications of phacoemulsification surgery after prior pars plana vitrectomy (PPV). DESIGN: Retrospective, multicenter database study. PARTICIPANTS: Eyes that underwent phacoemulsification between June 2005 and March 2015 at 8 sites in the United Kingdom. METHODS: Study eyes were classified as vitrectomized (prior PPV group) or nonvitrectomized (reference group) depending on the vitreous state at the time of cataract surgery. Eyes with multiple intraocular surgeries or history of ocular diseases known to cause cataract progression or increased risk of intraoperative complications during phacoemulsification were excluded. MAIN OUTCOME MEASURES: Logarithm of the minimum angle of resolution (logMAR) visual acuity (VA), rate of intraoperative complications, and time interval to cataract surgery. RESULTS: Eyes in the prior PPV group (n = 2221) had worse preoperative logMAR VA (0.96±0.60 vs. 0.62±0.52, P \u3c 0.0001), were from younger patients, and had longer axial lengths than the nonvitrectomized group (n = 136 533). At all postoperative time points measured up to 24 weeks, mean vision was poorer in the prior PPV group (0.41±0.47 vs. 0.17±0.29 at 4-12 weeks, P \u3c 0.0001) and a smaller proportion of eyes achieved postoperative VA ≤0.30 logMAR (Snellen, ≥20/40) (60.8% vs. 86.5% at 4-12 weeks, P \u3c 0.0001). The rate of posterior capsular rupture was not different between the prior PPV (1.5%) and the nonvitrectomized (1.7%) groups, but the incidences of zonular dialysis (1.3% vs. 0.6%) and dropped nuclear fragments (0.6% vs. 0.2%) were higher in the prior PPV group (P \u3c 0.0001). The mean time interval between PPV and cataract surgery was 399 days. CONCLUSIONS: We found a significant improvement in VA with postvitrectomy cataract surgery. However, compared with eyes without prior PPV, there was a worse mean postoperative vision of 0.2 logMAR units, a higher rate of zonular dialysis and dropped nuclear fragments, and a similar rate of posterior capsule rupture

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

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