Differences in instructional quality during the Covid-19 pandemic between Oman and Germany and the role of teacher competences

Introduction: School closures during the Covid-19 pandemic hit educational systems worldwide, forcing teachers to switch to digital learning settings. The presented study aims to (a) adapt and evaluate scales on instructional quality in digital settings, (b) describe instructional quality during the pandemic, and (c) to identify predictive teacher competences. Method: Data was assessed in a cross-sectional design via an online questionnaire conducted in Oman and Germany simultaneously. Results: Analyses of data from N = 284 teachers in Oman and Germany revealed mostly good psychometric parameters, differences in instructional quality between both countries, and positive relations between teachers’ competences and instructional quality. Conclusion: The present study contributes to instrument development and to the growing body of research, investigating teaching quality during the pandemic

Antioxidant, hypoglycemic and anti-diabetic activities of Ziziphus spina-christi (L) Willd (Rhamnacae) leaf extract

Purpose: To investigate the antioxidant, hypoglycemic and antidiabetic activities as well as the phenolic composition of Ziziphus spina-christi (ZSC)Methods: Eighty percent methanol extract (ZSC-1), as well as ethyl acetate (ZSC-2), n-butanol (ZSC-3) and aqueous (ZSC-4) fractions were administered orally to mice at doses of 250 and 500 mg/kg of body weight. The hypoglycemic and anti-diabetic activities of these fractions in the treated mice were evaluated after 7 and 15 days, using glibenclamide as a standard. Antioxidant activities in vitro were determined using stable free radical DPPH and ABTS radical scavenging techniques.Results: The strongest (p < 0.001) anti-diabetic activity (25.59 and 39.48 % after 7 and 15 days, respectively) was found following treatment with 500 mg/kg ZSC-3 fraction. Similarly, the highest (p > 0.001) hypoglycemic effect was achieved with 500 mg/kg ZSC-3 treatment (29.07 and 35.56 % after 7 and 15 days, respectively). ZSC-1 possessed the highest content of total flavonoids (36.2 mg/g) and total polyphenol (82.3 mg/g).Conclusion: Fraction ZSC-3 displayed potential hypoglycemic activity while ZSC-1, ZSC-2 and ZSC-3 possess remarkable DPPH scavenging ability equivalent to 89, 96 and 80.3 % of the activity of the standard drug respectively.Keywords: Ziziphus spina, Rhamnaceae, Hypoglycemic, Anti-diabetic, Flavonoids, Polypheno

CLOVE OR GREEN TEA ADMINISTRATION ANTAGONIZES KHAT HEPATOTOXICITY IN RATS

Objective: Khat consumption has become a common problem that affects the health aspects of life in Yemen and other parts in the world. The liver has been suspected to be particularly vulnerable to the harmful effects of khat use and until now khat hepatotoxicity effects are still controversial. This study was conducted to investigate the hepatoprotective effects of aqueous extracts of clove and green tea, as medicinal herbs with established antioxidant properties, against controversial hepatotoxicity effects of khat in rats. Methods: Rats received a daily oral dose of khat extract alone or in combination with green tea or clove extract for six weeks. To study the effects on liver cells, histopathology, routine liver function tests, malondialdehyde (MDA), total antioxidant capacity (TAC) and the activities of superoxide dismutase (SOD) and catalase (CAT) enzymes were investigated. Results: Khat administration showed marked liver injury; congestion in the portal vein with fibrous tissue proliferation, extended from the portal area and forming intralobular Porto-portal bridging fibrous septae. Besides significant routine liver function tests alterations, lipid peroxides elevation, and TAC reduction with significant inhibition of SOD and CAT activities. Conclusion: Combined administration of khat with clove or green tea protected hepatocytes via oxidative stress inhibition. They significantly counteracted the alterations in liver function tests, decreased lipid peroxidation and restored the antioxidant status to near normal levels. These results confirm khat hepatotoxicity and suggest that clove or green tea administration has strong hepatoprotective effects against khat induced hepatotoxicity in rats via antioxidant mediated mechanism.Â

Pollutant Removal from Highway Runoff Using Retention/Detention Units

Highway runoff contains total suspended solids, hydrocarbons, oil and greases, chloride, and other contaminants that are transported in solution and particulate forms to adjacent floodplains, roadside swales, and retention/detention ponds. Oil and grit chambers represent a type of retention/detention unit used for removing heavy particulates and adsorbed hydrocarbon particulates. Storage/sediment units also represent a type of retention/detention unit used for controlling peak flow and removing suspended solids. The aim of this study is to evaluate the effect of traffic volume and site characteristics on highway runoff quality. The study also aims to evaluate the performance of retention/detention units that collect runoff from the Prague-Brno and Prague-Plzeň highways, Czech Republic. The results of this study indicate no definitive relationship between average daily traffic and concentration of runoff constituents, though the site characteristics have a strong relation to some constituents. The results also show that retention/detention units are effective in treating organic compounds

Influencia de distintas fuentes de sílice en las propiedades físicas y mecánicas de materiales derivados del yeso

Gypsum plaster/silica composites prepared by dry blending (0.2-10 %) natural sand, silica fume or silica gel and subsequently hydrated. Their physical and mechanical properties, including normal consistency, setting time, apparent porosity, bulk density and compressive strength, were determined after hydration for 7- and 28-days. The results indicated that adding different forms of silica lowered the bulk density and increased the normal consistency, setting time, apparent porosity and, to some limited extent, compressive strength of the composites. This improvement in properties can be attributed to the existence of silica in the interstitial pores in the hardened plaster matrices. While most of the composites revealed only scant rises in compressive strength, their composition was beneficial in so far as it included either a readily available low-cost constituent (sand) or industrial by-products. Consequently, the formed plaster-silica composites are of economic value, contribute to a cleaner environment by minimizing waste and can be used for applications where high porosity, lightweight units are required or recommended for low-cost buildings.Se prepararon pastas compuestas de yeso y sílice mediante la mezcla en seco de yeso con distintas proporciones (0,2- 10 %) de arena natural, o gel o humo de sílice, procediéndose a continuación a su hidratación. A fin de determinar las propiedades físicas y mecánicas de las pastas, a los 7 y los 28 días de hidratación se hallaron su fluidez, tiempo de fraguado, porosidad aparente, densidad aparente y resistencia a la compresión. Los resultados obtenidos indican que al incorporar las distintas modalidades de sílice a la mezcla, disminuyó la densidad aparente y aumentaron la fluidez, el tiempo de fraguado, la porosidad aparente y, en menor medida, la resistencia a la compresión de las muestras. Se considera que esta mejora de las propiedades del material se debe a la presencia de sílice en los poros intersticiales de las matrices endurecidas de yeso. Aunque la resistencia a la compresión de la mayoría de las pastas ensayadas apenas aumentó, estas se beneficiaron de la presencia en su composición de elementos de bajo coste como la arena o los distintos subproductos industriales utilizados. Puede concluirse, por lo tanto, que los compuestos de yeso y sílice tienen valor económico y contribuyen a mejorar el medioambiente al valorizar residuos. Por otra parte, son apropiados para las aplicaciones en las que se necesitan o recomiendan elementos de alta porosidad y bajo peso, concretamente en las edificaciones bajas

Simulation: Early Detection of Brain Vessels Stroke by Applying Electromagnetic Waves Non-Invasively

Introduction: Early recognition of stroke with its two types Ischemic and Hemorrhagic, is one of the most crucial research points, commonly used methods are CT- (computerized tomography), and MRI- (Magnetic resonance imaging). These techniques cause a delay in the detection of the condition, which causes permanent disability. The main reason behind the fatal consequences of stroke is the delay of detection. Therefore, this research paper aims to early detection of the type of stroke without delay until the appropriate diagnosis of each type is made, and then the appropriate treatment without delay. Method: Using a non-invasive and fast technique to determine the stroke type by wave, we simulate and design a vessel containing a liquid as a laminar flow with the same density and velocity of blood, and it was surrounded by a Homogenized multi-turn coil consisting of (n) turns to represent the magnetic field, using specific frequency (HZ) with Electrical field in coil current (A) to see the changing in magnetic flux density (MFD), Depending on the changes in MFD, the flow of blood in laminar flow can be affected by clotting (Ischemic) or Hemorrhagic (cutting) in our vessel designed. We have built three different scenarios to apply the technique which are: First: Normal Scenario (where the blood in vessel has no problem), second: clotting (ischemic, where the vessel blocked in specific three position) and Third: Cutting (Hemorrhagic, where the vessel cut in certain nine positions). Results: This paper presents-through our own design-the studying of applying the electromagnetic waves on blood inside the vessel to detect the stroke type in our three scenarios (normal, ischemic three positions or hemorrhagic nine positions), Studying the magnetic field and laminar flow. This study covered in three areas. First: coil geometry analysis, Second: stationary, and Third: frequency domain. through the changes in Magnetic Flux Density -MFD- waves. The results were promising and distinct for distinguishing between the three scenarios which are normal, ischemic (3 positions) and hemorrhagic (9 positions) the results of MFD are: 0.09 to 3.3*10^-3, 0.08 to 3.15*10^-4, 0.15 to 6.2*10^-3 respectively

Polyphenolic content and antioxidant activity of some wild Saudi Arabian asteraceae plants

AbstractObjectiveTo study the antioxidant properties of crude extract of different Asteraceae plants.MethodsThe antioxidant properties of six extracts were evaluated using different antioxidant tests, including free radical scavenging, reducing power, metal chelation, superoxide anion radical scavenging, total antioxidant capacity and inhibition of lipid peroxidation activities.ResultsPicris cyanocarpa (P. cyanocarpa) and Anthemis deserti (A. deserti) had powerful antioxidant properties as radical scavenger, reducing agent and superoxide anion radical scavenger while Achillia fragrantissima (A. fragrantissima) and Artemissia monosperma (A. monosperma) were the most efficient as ion chelator (100% at 100, 200 and 400 μg/mL) A. fragrantissima and Rhantarium appoposum (R. appoposum) showed 100% inhibition on peroxidation of linoleic acid emulsion at 200 and 400 μg/mL, while butylatedhydroxy toluene and ascorbic acid showed 100 and 95% inhibition percentage at 400 μg/mL, respectively. Those various antioxidant activities were compared to standard antioxidants such as butylated hydroxyl toluene and ascorbic acid.ConclusionsIn most tests P. cyanocarpa and A. deserti had powerful antioxidant properties as radical scavenger, reducing agent and superoxide anion radical scavenger

Modelling of Highway Runoff Quantity and Quality

The stormwater Management Model (SWMM) is a well-known stormwater runoff-simulation model. It is a deterministic, spatially distributed model for calculation of runoff quantity and quality. The aim of this study was to predict highway runoff characteristics using data from different highway catchments. The SWMM was used in the simulation process and the predicted data was verified using monitoring data collected from Prague-Plzeň highway for both total suspended solids and organic compounds. The analyzed data indicated that the simulated TSS, BOD5 concentrations lie within the range of the measured data and both data sets are considered highly polluted with respect to the specification limits. The analyzed data also show that the first flush of runoff is the most polluted, and is responsible for contamination of retention and/or received waters