Connecting the dots: Understanding the interrelated impacts of type,quality and children's awareness of design features and the mathematics content learning goals in digital math games and related learning outcomes

This study focused on an examination of how type, quality and children's awareness of design features in digital math games, along with an awareness of the mathematics goals of the game, were related to learning outcomes. We conducted a parallel conversion mixed methods study with 45 students in Grades 3 and 4 (ages 9–10). Students participated in clinical interviews using three digital math games. The results suggest a moderated mediation relationship in which the quality of the design features moderated the mediating impact of children's awareness of the game's design features, specifically when the child was aware of the mathematics content learning goal (MCLG) of the game. These findings show how important it is that design features are of high quality in a digital math game, and how this is intertwined with children's awareness of the features and the MCLG. When these variables intertwined in just the right way, the interactions between the children and the digital math game afforded mathematical learning growth.     

Removal of Cd(II), Hg(II), and Pb(II) ions from aqueous solution using p(HEMA/chitosan) membranes

An interpenetration network (IPN) was synthesized from 2‐hydroxyethyl methacrylate (HEMA) and chitosan, p(HEMA/chitosan) via UV‐initiated photo‐polymerization. The selectivity to different heavy metal ions viz Cd(II), Pb(II), and Hg(II) to the IPN membrane has been investigated from aqueous solution using bare pHEMA membrane as a control system. Removal efficiency of metal ions from aqueous solution using the IPN membranes increased with increasing chitosan content and initial metal ions concentrations, and the equilibrium time was reached within 60 min. Adsorption of all the tested heavy metal ions on the IPN membranes was found to be pH dependent and maximum adsorption was obtained at pH 5.0. The maximum adsorption capacities of the IPN membrane for Cd(II), Pb(II), and Hg(II) were 0.063, 0.179, and 0.197 mmol/g membrane, respectively. The adsorption of the Cd(II), Hg(II), and Pb(II) metal ions on the bare pHEMA membrane was not significant. When the heavy metal ions were in competition, the amounts of adsorbed metal ions were found to be 0.035 mmol/g for Cd(II), 0.074 mmol/g for Hg(II), and 0.153 mmol/g for Pb(II), the IPN membrane is significantly selective for Pb(II) ions. The stability constants of IPN membrane–metal ions complexes were calculated by the method of Ruzic. The results obtained from the kinetics and isotherm studies showed that the experimental data for the removal of heavy metal ions were well described with the second‐order kinetic equations and the Langmuir isotherm model. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Reducing Dimensionality of Multi-regime Data for Failure Prognostics

Journal of Failure Analysis and Prevention - Over the last decade, the prognostics and health management literature has introduced many conceptual frameworks for remaining useful life predictions....     

Evaluation of the Chemical Composition and Antioxidant Activity of the Peel Oil of Citrus nobilis

Peel oil of Citrus nobilis (Lour) was analyzed for determining its chemical composition. Fourteen identified components accounted for 99.1% (GC) and 100.0% (FID) of the total oil. Major component of the oil was limonene (76.8%-GC and 86.2%-FID). Essential oil was also evaluated for its antioxidant activity in four complementary test systems namely; β-carotene/linoleic acid, DPPH radical scavenging, reducing power and metal chelating activities. In the first system, antioxidant activity increased with the increasing concentration. At 20.0 mg.ml^?1 concentration, antioxidant property of the oil was 96.8% ± 0.2 and as strong as the positive controls BHT and α-tocopherol. Scavenging effect of the oil was superior to the positive controls BHT and α-tocopherol at 1.5 mg.ml^?1 concentration (96.4% ± 0.1). Reducing power and chelating effect of the essential oil increased with the increasing concentration.     

Effects of crushed clay brick aggregate on mortar durability

This paper reports an experimental study that aimed to investigate the effects of recycled clay brick, used as a part of fine aggregate, on mortar durability. The brick, in crushed form, was from a local brick manufacturer that salvages its off-standard products. It was used to replace 10% and 20% (by weight) of the river sand in mortar. Effects of the brick replacement on the mortar flow, compressive strength, shrinkage, freeze–thaw resistance, and alkali–silica reaction potential were investigated. The results showed that as the brick replacement level increased, the mortar flowability reduced. The 10% and 20% brick replacements had no negative effect on the mortar compressive strength and very limited effect on the mortar shrinkage. The freeze–thaw resistance of the mortar was improved by the brick replacement. However, the use of crushed brick as aggregate appeared not to reduce potential alkali–silica reaction. The microscopy study revealed the alkali–silica reaction product and associated cracking in the mortar. Additional study indicated that the brick aggregate used in the study had pessimum proportion, 30%, for the alkali–silica reaction expansion.     

Phenolic composition,enzyme inhibitory,and antioxidant activity of <Emphasis Type="Italic">Bituminaria bituminosa</Emphasis>

This study aimed to evaluate the in vitro antioxidant and enzyme inhibitory activities of ethyl acetate, methanol, and water extracts of Bituminaria bituminosa. In phosphomolybdenum assay, the methanol extract showed the highest activity (166.78 μmol TEs/g dry plant). The water extract exhibited the highest scavenging activity on 1,1-diphenyl-2-picrylhydrazyl (DPPH^?) and 2,2-azino-bis (3-ethylbenzothiazloine-6-sulphonic acid) (ABTS^?+). In addition, it exhibited the highest activity in cupric ion reducing (CUPRAC) and ferric reducing antioxidant power (FRAP) assays (41.26 and 46.82 μmol TEs/g dry plant). The extracts did not show cholinesterase and tyrosinase inhibitory activity. However, α-glucosidase inhibition assay resulted in the superiority of water extract (1233.86 μmol ACEs/g dry plant). In the case of α-amylase inhibitory assay, the ethyl acetate extract showed the highest activity (53.65 μmol ACEs/g dry plant). The water extract exhibited the highest phenolic content (31.70 μmol GAEs/g dry plant). In contrast, the methanol extract was found rich in flavonoid compounds (5.29 μmol REs/g dry plant). The water extract contained considerable amounts of rosmarinic acid, luteolin, quercetin, and rutin. Therefore, it can be used as a source of new and alternative antioxidant and enzyme inhibitory agents.     

Gabapentin-induced coma in a patient with renal failure

We describe a 60-year-old woman who became comatose after a single dose of gabapentin for right-sided sciatalgia. The patient was improved by hemodialysis. Gabapentin toxicity should be considered when mental status changes develop in patients with renal failure after even a single dose.     

Evaluation of antioxidant activities of 3 edible mushrooms: Ramaria flava (Schaef.: Fr.) Quél., Rhizopogon roseolus (Corda) T.M. Fries., and Russula delica Fr.

The methanolic extracts of Ramaria flava, Rhizopogon roseolus, and Russula delica were analyzed for their antioxidant activities in different test systems including β-carotene/linoleic acid, 1.1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging, reducing power, and metal chelating activities in addition to their total phenolic and flavonoid contents. In the first case, methanol extract of R. roseolus showed the strongest activity. In DPPH system, the scavenging effects increased with the concentration. The reducing power of the mushroom also increased with concentration. Chelating effect was 96.75±0.28% for R. flava. In the case of total phenolic and flavonoid assays, R. flava found to have the highest phenolic content. Total flavonoid content of R. flava again found the superior to the other mushrooms. Experimental results indicate that the mushroom species evaluated here can be consumed safely. On the other hand, knowing the biological activity of these mushrooms will contribute to the establishment of conscious consumption.     

Screening of the antioxidant potentials of six Salvia species from Turkey

This study was designed to examine the in vitro antioxidant activities of the methanol extracts of six Salvia species [Salvia caespitosa Montbret & Aucher ex Bentham (ENDEMIC), Salvia hypargeia Fisch. & Mey. (ENDEMIC), Salvia euphratica subsp. euphratica Montbret & Aucher ex Bentham (ENDEMIC), Salvia sclarea L., Salvia candidissima subsp. candidissima Montbret & Aucher ex Bentham and Salvia aethiopis L.] from Turkey. The extracts were screened for their possible antioxidant activities by two complementary test systems, namely DPPH free radical-scavenging and β-carotene/linoleic acid systems. Non-polar subfractions of the methanol extracts of Salvia species studied did not show any antioxidant activity in both test systems. In the first case, the most active plant was S. euphratica subsp. euphratica, an endemic species, with an IC₅₀ value of 20.7 ± 1.22 μg/ml, followed by S. sclarea (IC₅₀ = 23.4 ± 0.97 μg/ml) among the polar subfractions. In the β-carotene/linoleic acid test system, polar extract of S. hypargeia was superior to the polar extracts of other Salvia species studied (69.2% ± 1.90%). This activity was followed by S. sclarea with 63.5% ± 4.24% inhibition rate. The inhibition rate of the synthetic antioxidant, buthylated hydroxytoluene (BHT), was also determined to be 96%. Since the polar extracts of Salvia species dealt with here exhibited excellent antioxidant activities when compared to BHT, it seems possible to keep perishable fat-containing food longer by direct addition of an extract of sage.     

Adsorption of heavy‐metal ions on poly(ethylene imine)‐immobilized poly(methyl methacrylate) microspheres

Poly(methyl methacrylate) (PMMA) microspheres carrying poly(ethylene imine) (PEI) were prepared for the removal of heavy‐metal ions (copper, cadmium, and lead) from aqueous solutions with different amounts of these ions (50–600 mg/L) and different pH values (3.0–7.0). Ester groups in the PMMA structures were converted to imine groups in a reaction with PEI as a metal‐chelating ligand in the presence of NaH. The adsorption of heavy‐metal ions on the unmodified PMMA microspheres was very low [3.6 μmol/g for Cu(II), 4.6 μmol/g for Cd(II), and 4.2 μmol/g for Pb(II)]. PEI immobilization significantly increased the heavy‐metal adsorption [0.224 mmol/g for Cu(II), 0.276 mmol/g for Cd(II), and 0.126 mmol/g for Pb(II)]. The affinity order of adsorption (in moles) was Cd(II) > Cu(II) > Pb(II). The adsorption of heavy‐metal ions increased with increasing pH and reached a plateau value around pH 5.5. Their adsorption behavior was approximately described with the Langmuir equation. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 197–205, 2001