902 research outputs found

    Examining the effects of mental workload and time pressure on cognitive task performance

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    In this research, I investigated ways to reliably measure the effects of time pressure on mental workload using physiological measurement techniques and subjective workload assessments, as well as the resultant effects on performance in a cognitively-demanding task. This task involved subjects solving mental arithmetic problems of varying difficulties to induce different workloads. Time pressure has not been systematically researched to the extent of mental workload, but has been observed to affect performance in two contrasting ways: 1) limiting performance in a manner similar to cognitive overload; and by 2) focusing cognitive activities to improve performance

    Impacts of Seawater Rise on Seawater Intrusion in the Nile Delta Aquifer, Egypt

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    Abstract Several investigations have recently considered the possible impacts of climate change and seawater level rise on seawater intrusion in coastal aquifers. All have revealed the severity of the problem and the significance of the landward movement of the dispersion zone under the condition of seawater level rise. Most of the studies did not consider the possible effects of the seawater rise on the inland movement of the shoreline and the associate changes in the boundary conditions at the seaside and the domain geometry. Such effects become more evident in flat, low land, coastal alluvial plans where large areas might be submerged with seawater under a relatively small increase in the seawater level. None of the studies combined the effect of increased groundwater pumping, due to the possible decline in precipitation and shortage in surface water resources, with the expected landward shift of the shore line. In this article, the possible effects of seawater level rise in the Mediterranean Sea on the seawater intrusion problem in the Nile Delta Aquifer are investigated using FEFLOW. The simulations are conducted in horizontal view while considering the effect of the shoreline landward shift using digital elevation models. In addition to the basic run (current conditions), six different scenarios are considered. Scenarios one, two, and three assume a 0.5 m seawater rise while the total pumping is reduced by 50%, maintained as per the current conditions and doubled, respectively. Scenarios four, five, and six assume a 1.0 m seawater rise and the total pumping is changed as in the first three scenarios. The shoreline is moved to account for the seawater rise and hence the study domain and the seaside boundary are modified accordingly. It is concluded that, large areas in the coastal zone of the Nile Delta will be submerged by seawater and the coast line will shift landward by several kilometers in the eastern and western sides of the Delta. Scenario six represents the worst case under which the volume of freshwater will be reduced to about 513 km 3 (billion m 3 )

    Healthcare financing in Egypt: a systematic literature review

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    Background: The Egyptian healthcare system has multiple stakeholders, including a wide range of public and private healthcare providers and several financing agents. This study sheds light on the healthcare system’s financing mechanisms and the flow of funds in Egypt. It also explores the expected challenges facing the system with the upcoming changes.// Methods: We conducted a systematic review of relevant papers through the PubMed and Scopus search engines, in addition to searching gray literature through the ISPOR presentations database and the Google search engine. Articles related to Egypt’s healthcare system financing from 2009 to 2019 were chosen for full-text review. Data were aggregated to estimate budgets and financing routes.// Results: We analyzed the data of 56 out of 454 identified records. Governmental health expenditure represented approximately one-third of the total health expenditure (THE). Total health expenditure as a percent of gross domestic product (GDP) was almost stagnant in the last 12 years, with a median of 5.5%. The primary healthcare financing source is out-of-pocket (OOP) expenditure, representing more than 60% of THE, followed by government spending through the Ministry of Finance, around 37% of THE. The pharmaceutical expenditure as a percent of THE ranged from 26.0 to 37.0%.// Conclusions: Although THE as an absolute number is increasing, total health expenditure as a percentage of GDP is declining. The Egyptian healthcare market is based mainly on OOP expenditures and the next period anticipates a shift toward more public spending after Universal Health Insurance gets implemented

    Oral Delivery of Psoralidin by Mucoadhesive Surface-Modified Bilosomes Showed Boosted Apoptotic and Necrotic Effects against Breast and Lung Cancer Cells

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    © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).This study aims to design and optimize chitosan-coated bilosomal formulations loaded with psoralidin (Ps-CS/BLs) with improved physicochemical properties, oral bioavailability, and boosted apoptotic and necrotic effects. In this regard, uncoated bilosomes loaded with Ps (Ps/BLs) were nanoformulated using the thin-film hydration technique using different molar ratios of phosphatidylcholine (PC), cholesterol (Ch), Span 60 (S60), and sodium deoxycholate (SDC) (1:0.4:0.2:0.125, 1:0.4:0.2:0.25, and 1:0.4:0.2:0.5, respectively). The best-optimized formulation with respect to size, PDI, zeta potential, and EE% was selected and then coated with chitosan at two different concentrations (0.125 and 0.25 w/v%), forming Ps-CS/BLs. The optimized Ps/BLs and Ps-CS/BLs showed a spherical shape and relatively homogenous size with negligible apparent agglomerations. Additionally, it was demonstrated that coating Ps/BLs with chitosan has significantly increased the particle size from 123.16 ± 6.90 in the case of Ps/BLs to 183.90 ± 15.93 nm in the case of Ps-CS/BLs. In addition, Ps-CS/BLs exhibited higher zeta potential (+30.78 ± 1.44 mV) as compared to Ps/BLs (−18.59 ± 2.13 mV). Furthermore, Ps-CS/BL showed enhanced entrapment efficiency (EE%) of 92.15 ± 7.20% as compared to Ps/BLs (68.90 ± 5.95%). Moreover, Ps-CS/BLs exhibited a more sustained release behavior of Ps compared to Ps/BLs over 48 h, and both formulations were best obeying the Higuchi diffusion model. More importantly, Ps-CS/BLs displayed the highest mucoadhesive efficiency% (74.89 ± 3.5%) as compared to Ps/BLs (26.78 ± 2.9%), indicating the ability of the designed nanoformulation to improve oral bioavailability and extend the residence time inside the gastrointestinal tract upon oral administration. Moreover, upon evaluating the apoptotic and necrotic effects of free Ps and Ps-CS/BLs on human breast cancer cell lines (MCF-7) and human lung adenocarcinoma cell lines (A549), there was a dramatic increase in the percentages of the apoptotic and necrotic cell compared to the control and free Ps. Our findings suggest the possible oral use of Ps-CS/BLs in hampering breast and lung cancers.Peer reviewe

    Study of the Urinary Ratio of 6 β-Hydroxycortisol/Cortisol as a Biomarker of CYP3A4 Activity in Egyptian Patients with Chronic Liver Diseases

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    The urinary ratio of 6 β-hydroxycortisol/cortisol (6 β-OHC/C) as a biomarker of CYP3A4 metabolizing activity has been studied in Egyptian patients with chronic liver cirrhosis associated with previous hepatic Schistosomiasis infection to determine any possible alteration in enzyme activity. The ratio of 6-β OHC/C was determined in morning urine samples collected from 8:00 a.m. to 12:00 p.m. in healthy adults (n = 36) and patients with liver cirrhosis (n = 57). The median age for control was 27 years (range: 18–50 years) and 50 years (range: 27–75 years) for patients. 6 β-OHC was detected in urine by ELIZA kits (Stabiligen, France). Patients with liver cirrhosis were categorized according to Child Pugh Classification into Child B (n = 28) and Child C (n = 29) classes. Cholestasis was observed in 9/28 of Child B class and 8/29 of Child C class of patients. The control subjects showed gender-related difference in the urinary ratio of 6 β-OHC/C. A significant reduction (P < 0.001) in 6 β-OHC/C ratio was observed only in Child C patients in comparison with control subjects. Regression analysis showed a significant correlation (P < 0.05) between 6 β-OHC/C ratio and serum albumin. The influence of cholestasis on the urinary ratio of 6-β OHC/C was observed on cirrhotic patients of Child B class. In conclusion, patients with chronic liver cirrhosis might have a reduction of metabolizing activity of CYP3A4 enzymes which could be identified by measuring the urinary ratio of 6 β-OHC/C. This reduction is more apparent in severe liver injury (Child C class). Therefore, it is important to understand the metabolic fate of drugs metabolized by 3A4 enzymes in patients with liver cirrhosis to avoid drug accumulation that might lead to development of drug toxicity

    Listening to Students’ and Teachers’ Voices: Online Teaching Practices Leading to EFL Learners ' Demotivation

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    This study was conducted in response to the online teaching practices which demotivate EFL learners in learning English from both the teachers' and students' perspectives so that it can provide an equal point of view. The study was done by distributing a questionnaire to 152 students of the State Islamic Madrasah in Tulungagung, East Java, Indonesia to find data related to those who experience demotivation in learning English and interviewing them in depth both directly and indirectly through voice notes in July to September 2022. The in-depth interview was also done to their English teachers. The result of qualitative data analysis revealed that students were demotivated, bored, and lazy during online learning because of two main factors, namely teachers, i.e., uninteresting teaching methods and techniques, lack of online teaching experience, teacher’s personality, and the usage of the online learning application. Meanwhile, the teachers perceive that their demotivating EFL teaching was resulted from students' learning loss, lack of students' learning involvement, and teachers' feeling insecure caused by some factors, namely the variety of online teaching methods, the accessibility of online learning media, family interference, and students' internal lack of motivation. Still, this demotivating online teaching and learning do not significantly implicate the students' achievement of English. These research results are pedagogically implemented to improve the quality of online teaching and learning English, mainly at the secondary levels

    Biomechanical analysis using FEA and experiments of metal plate and bone strut repair of a femur midshaft segmental defect

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    © 2018 Jason Coquim et al. This investigation assessed the biomechanical performance of the metal plate and bone strut technique for fixing recalcitrant nonunions of femur midshaft segmental defects, which has not been systematically done before. A finite element (FE) model was developed and then validated by experiments with the femur in 15 deg of adduction at a subclinical hip force of 1 kN. Then, FE analysis was done with the femur in 15 deg of adduction at a hip force of 3 kN representing about 4 x body weight for a 75 kg person to examine clinically relevant cases, such as an intact femur plus 8 different combinations of a lateral metal plate of fixed length, a medial bone strut of varying length, and varying numbers and locations of screws to secure the plate and strut around a midshaft defect. Using the traditional “high stiffness” femur-implant construct criterion, the repair technique using both a lateral plate and a medial strut fixed with the maximum possible number of screws would be the most desirable since it had the highest stiffness (1948 N/mm); moreover, this produced a peak femur cortical Von Mises stress (92 MPa) which was below the ultimate tensile strength of cortical bone. Conversely, using the more modern “low stiffness” femur-implant construct criterion, the repair technique using only a lateral plate but no medial strut provided the lowest stiffness (606 N/mm), which could potentially permit more in-line interfragmentary motion (i.e., perpendicular to the fracture gap, but in the direction of the femur shaft long axis) to enhance callus formation for secondary-type fracture healing; however, this also generated a peak femur cortical Von Mises stress (171 MPa) which was above the ultimate tensile strength of cortical bone

    Genotypic and Phenotypic Structure of the Population of Phytophthora infestans in Egypt Revealed the Presence of European Genotypes

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    Late blight disease of potato and tomato, caused by Phytophthora infestans, results in serious losses to Egyptian and global potato and tomato production. To understand the structure and dynamics of the Egyptian population of P. infestans, 205 isolates were collected from potato and tomato plants during three growing seasons in 2010–2012. The characterization was achieved by mating-type assay, metalaxyl sensitivity assay, and virulence pattern. Additionally, genotyping of 85 Egyptian isolates and 15 reference UK isolates was performed using 12 highly informative microsatellite (SSR) markers David E. L. Cooke and five effector (RxLR) genes. Mating-type testing showed that 58% (118 of 205) of the isolates belonged to mating type A1, 35% (71 isolates) to mating type A2, and the rest 8% (16 isolates) were self-fertile. The phenotype of metalaxyl response was represented as 45% resistant, 43% sensitive, and 12% as intermediate. Structure analysis grouped the 85 identified genotypes into two main clonal lineages. The first clonal lineage comprised 21 isolates belonging to A2 mating type and 8 self-fertile isolates. This clonal lineage was identified as Blue_13 or EU_13_A2. The second main clonal lineage comprised 55 isolates and was identified as EU_23_A1. A single isolate with a novel SSR genotype that formed a distinct genetic grouping was also identified. The effector sequencing showed good correspondence with the virulence data and highlighted differences in the presence and absence of loci as well as nucleotide polymorphism that affect gene function. This study indicated a changing population of P. infestans in Egypt and discusses the findings in the context of late blight management
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