Lifespan-Extending Effects of Royal Jelly and Its Related Substances on the Nematode Caenorhabditis elegans

One of the most important challenges in the study of aging is to discover compounds with longevity-promoting activities and to unravel their underlying mechanisms. Royal jelly (RJ) has been reported to possess diverse beneficial properties. Furthermore, protease-treated RJ (pRJ) has additional pharmacological activities. Exactly how RJ and pRJ exert these effects and which of their components are responsible for these effects are largely unknown. The evolutionarily conserved mechanisms that control longevity have been indicated. The purpose of the present study was to determine whether RJ and its related substances exert a lifespan-extending function in the nematode Caenorhabditis elegans and to gain insights into the active agents in RJ and their mechanism of action.We found that both RJ and pRJ extended the lifespan of C. elegans. The lifespan-extending activity of pRJ was enhanced by Octadecyl-silica column chromatography (pRJ-Fraction 5). pRJ-Fr.5 increased the animals' lifespan in part by acting through the FOXO transcription factor DAF-16, the activation of which is known to promote longevity in C. elegans by reducing insulin/IGF-1 signaling (IIS). pRJ-Fr.5 reduced the expression of ins-9, one of the insulin-like peptide genes. Moreover, pRJ-Fr.5 and reduced IIS shared some common features in terms of their effects on gene expression, such as the up-regulation of dod-3 and the down-regulation of dod-19, dao-4 and fkb-4. 10-Hydroxy-2-decenoic acid (10-HDA), which was present at high concentrations in pRJ-Fr.5, increased lifespan independently of DAF-16 activity.These results demonstrate that RJ and its related substances extend lifespan in C. elegans, suggesting that RJ may contain longevity-promoting factors. Further analysis and characterization of the lifespan-extending agents in RJ and pRJ may broaden our understanding of the gene network involved in longevity regulation in diverse species and may lead to the development of nutraceutical interventions in the aging process

Teacher professional knowledge and classroom management: on the relation of general pedagogical knowledge (GPK) and classroom management expertise (CME)

Due to the need for measurement instruments that allow an investigation of teachers' situational cognition and thus go beyond the limited scope of classical paper-and-pencil-tests, we ask how a specific video-based measurement of teachers' classroom management expertise can provide additional information when compared with an established paper-and-pencil-test that broadly covers mathematics teachers' general pedagogical knowledge. For this, we apply the general pedagogical knowledge test previously developed in the Teacher Education and Development Study-Mathematics (TEDS-M) comprising knowledge of structuring lessons ('structure'); motivating students and managing the classroom ('motivation/classroom management'); dealing with heterogeneous learning groups ('adaptivity'); and assessing students ('assessment'). Using test data of 188 novice teachers, advanced beginners, and expert teachers, we raise questions regarding the two tests' (1) structural relations, (2) expert-novice differences, and (3) predictive validity. Findings: (1a) classroom management expertise can be empirically separated from general pedagogical knowledge, although the two constructs are positively inter-correlated (medium effect size), (1b) classroom management expertise is more highly correlated with pedagogical knowledge of classroom management than with pedagogical knowledge of 'adaptivity', 'structure', and 'assessment', (1c) classroom management expertise is more highly correlated with procedural pedagogical knowledge (cognitive demand 'generate') than with declarative pedagogical knowledge (cognitive demands 'recall' and 'understand/analyze'), (2) novice teachers as well as advanced beginners are outperformed by expert teachers, and (3) classroom management expertise, compared with general pedagogical knowledge, is a stronger predictor for instructional quality aspects of classroom management as rated by students