Gongju National University of Education

About: Gongju National University of Education is a education organization based out in Gongju, South Korea. It is known for research contribution in the topics: Functional equation & Quadratic equation. The organization has 37 authors who have published 96 publications receiving 558 citations.

The Challenges of Science Inquiry Teaching for Pre-Service Teachers in Elementary Classrooms: Difficulties on and under the Scene

Abstract: In the context of the emphasis on inquiry teaching in science education, this study looks into how pre-service elementary teachers understand and practise science inquiry teaching during field experience. By examining inquiry lesson preparation, practice, and reflections of pre-service elementary teachers, we attempt to understand the difficulties they encounter and what could result from those difficulties in their practice. A total of 16 seniors (fourth-year students) in an elementary teacher education program participated in this study. In our findings, we highlight three difficulties ‘on the lesson’ that are related to teaching practices that were missing in the classrooms: (1) developing children’s own ideas and curiosity, (2) guiding children in designing valid experiments for their hypotheses, (3) scaffolding children’s data interpretation and discussion and another three difficulties ‘under the lesson’ that are related to problems with the pre-service teachers’ conceptualization of the task: (4) tension between guided and open inquiry, (5) incomplete understanding of hypothesis, and (6) lack of confidence in science content knowledge. Based on these findings, we discuss how these difficulties are complexly related in the pre-service teachers’ understandings and action. Several suggestions for science teacher education for inquiry teaching, especially hypothesis-based inquiry teaching, are then explored.

Priors and Posteriors in Bayesian Timing of Divergence Analyses: The Age of Butterflies Revisited.

Abstract: The need for robust estimates of times of divergence is essential for downstream analyses, yet assessing this robustness is still rare. We generated a time-calibrated genus-level phylogeny of butterflies (Papilionoidea), including 994 taxa, up to 10 gene fragments and an unprecedented set of 12 fossils and 10 host-plant node calibration points. We compared marginal priors and posterior distributions to assess the relative importance of the former on the latter. This approach revealed a strong influence of the set of priors on the root age but for most calibrated nodes posterior distributions shifted from the marginal prior, indicating significant information in the molecular data set. Using a very conservative approach we estimated an origin of butterflies at 107.6 Ma, approximately equivalent to the latest Early Cretaceous, with a credibility interval ranging from 89.5 Ma (mid Late Cretaceous) to 129.5 Ma (mid Early Cretaceous). In addition, we tested the effects of changing fossil calibration priors, tree prior, different sets of calibrations and different sampling fractions but our estimate remained robust to these alternative assumptions. With 994 genera, this tree provides a comprehensive source of secondary calibrations for studies on butterflies.

Synthesis and photophysical properties of chlorins bearing 0-4 distinct meso-substituents.

Abstract: The presence of substituents at designated sites about the chlorin macrocycle can alter the spectral properties, a phenomenon that can be probed through synthesis. Prior syntheses have provided access to chlorins bearing distinct aryl substituents (individually or collectively) at the 5, 10, and 15-positions, but not the 20-position. A new Western half (5-phenyl-2,3,4,5-tetrahydro-1,3,3-trimethyldipyrrin) has been employed in condensation with an Eastern half (9-bromodipyrromethane-1-carboxaldehyde) followed by oxidative cyclization to give (5% yield) the zinc(II) 20-phenylchlorin. Condensation of the same Western half and a diaryl-substituted Eastern half provided (11% yield) the zinc(II) 5,10,20-triarylchlorin; demetalation with TFA followed by 15-bromination and Suzuki coupling gave the free base 5,10,15,20-tetraarylchlorin. Altogether, 10 new synthetic chlorins have been prepared. The near-UV (B) absorption band of the free base chlorins shifts bathochromically from 389 to 429 nm and that for the zinc chlorins from 398 to 420 nm as the number of meso-aryl rings is increased stepwise from 0–4. The long-wavelength (Qy) absorption band undergoes a bathochromic and hypochromic shift upon increase in number of meso-aryl groups. Regardless of the number and positions of the meso-aryl substituents (including “walking a phenyl group around the ring”), the respective fluorescence quantum yields (0.17 to 0.27) and singlet excited-state lifetimes (9.4 to 13.1 ns) are comparable among the free base chlorins and the same is true for the zinc chelates (0.057 to 0.080; 1.2 to 1.6 ns). Density functional theory calculations show that of the frontier molecular orbitals of the chlorin, the energy of the HOMO−1 is the most affected by meso-aryl substituents, undergoing progressive destabilization as the number of meso-aryl groups is increased. The availability of chlorins with 0–4 distinct meso-aryl substituents provides the individual stepping-stones to bridge the known unsubstituted chlorin and the meso-tetraarylchlorins.

The ownership perception gap: exploring teacher job satisfaction and its relationship to teachers’ and principals’ perception of decision-making opportunities

Abstract: Research has shown that when principals provide teachers with opportunities to participate in meaningful decision-making opportunities, it leads to teachers’ feeling a greater sense of ownership an...