How can self-regulated learning support the problem solving of third-grade students with mathematics anxiety?

The study compares 140 third-grade Israeli students (lower and higher achievers) who were either exposed to self-regulated learning (SRL) supported by metacognitive questioning (the MS group) or received no direct SRL support (the N_MS group). We investigated: (a) mathematical problem solving performance; (b) metacognitive strategy use in three phases of the problem-solving process; and (c) mathematics anxiety. Findings indicated that the MS students showed greater gains in mathematical problem solving performance than the N_MS students. They reported using metacognitive strategies more often, and showed a greater reduction in anxiety. In particular, the lower MS achievers showed these gains in the basic and complex tasks, in strategy use during the on-action phase of the problem solving process and a decrease in negative thoughts. The higher achievers showed greater improvement in transfer tasks and an increase in positive thoughts towards mathematics. Both the theoretical and practical implications of this study are discussed.     

Preparation,proton and carbon-13 structure determination,and fungicidal activity of chlorinated 1-arylamino-1H-pyrrole-2,5-diones

1-(2′,4′-dichloro)phenylamino-1H-pyrrole-2,5-dione and 1-(2′,4′,6′-trichloro)phenylamino-1H-pyrrole-2,5-dione were prepared via direct chlorination of 2-phenyl-3-oxo-6-hydroxy-2H-pyridazine. Both pmr and mass spectroscopy clearly showed that dichloro substitution occurred in the aromatic moiety and not in the vinylic region of the molecule. The former method showed that pyridiazine- to pyrrole-ring isomerization had occurred already at the level of dichlorination. The identical 2′,4′-dichlorophenyl and 2′,4′,6′-trichlorophenylpyr-rolediones were also prepared by reaction of maleic anhydride with the appropriate arylhydrazine. Similar 2′,4-dichlorophenyl and 2′,4′,6′-trichlorophenyl analogues were prepared using dichloromaleic anhydride. Cmr spectroscopic techniques were used for pyridazine-/pyrrole-ring stereochemical assignment of products derived from dichloromaleic anhydride. 1-(2′,4′-dichloro)phenylamino-1H-pyrrole-2,5-dione and the trichloro-phenyl analogue were shown to exhibit fungicidal activity in both in-vivo and in-vitro assays.     

It's Not Too Late to Conceptualize: Constructing a Generalized Subtraction Schema by Abstracting and Connecting Procedures

In this study, children were encouraged to abstract mathematical principles by making connections between procedures. Children from 2 sixth-grade classes (N = 58) were asked to solve and explain subtraction examples in 3 different number domains (whole numbers, fractions, and decimals), solve subtraction word problems, compare the procedures, and discuss subtraction principles. Forty percent of the children could identify procedural similarities and could abstract general subtraction principles. The rest of the children received more instruction. One group received individual abstraction and mapping instruction that encouraged them to generalize procedural steps and connect procedures. Another group received domain-specific instruction without connections between domains. The results show that following mapping instruction, children whose original instruction was mostly procedural could make connections and abstract principles, that is, construct a general subtraction schema. These children improved in conceptual knowledge and in solving transfer problems.     

Chemiluminescent optical fiber immunosensor for the detection of anti-West Nile virus IgG

An ELISA-based optical fiber methodology developed for the detection of anti-West Nile virus IgG antibodies in serum was compared to standard colorimetric and chemiluminescent ELISA based on microtiter plates. Colorimetric ELISA was the least sensitive, especially at high titer dilutions. The fiber-optic immunosensor based on the same ELISA immunological rationale was the most sensitive technique.