An early childhood education reform with emphasis on intellectual education is currently underway in Germany, and project works pertaining to this reform are attracting attention as an approach to ...promote children’s competencies and as a way of implementing appropriate learning for early childhood. In this paper, the themes and activities of 53 project works related to natural sciences were analyzed, and the following findings were obtained.Approximately 60% of the themes were biological and about 40% were physical, chemical, and geological. The project works can be classified into 13 categories, such as “water,” “fire,” “energy,” “soil,” etc. Additionally, while children’s interests were the basis of the project themes, those regarding education for sustainable development (ESD) and Mathematik, Informatik, Naturwissenschaft, Technik (MINT) were set after support by teachers. The project works are characterized first by experiential activities that involve thoughts, feelings, and the five senses; second, they include free expressive activities; and finally, they develop activities that advocate personal lifestyles and social change. Given that the “process itself is the goal” of project works, there is value in participating in a certain situation or process, and this could be one way of “learning” in early childhood.
Main conclusion
The
Arabidopsis
ppGpp-overproducing mutant indicates a larger biomass than wild type by modulated amino-acid metabolism under nitrogen-limiting conditions.
The regulatory nucleotide, ...guanosine 3’, 5’-bis(pyrophosphate; ppGpp)—originally identified in
Escherichia coli
—controls gene expression and enzyme activities in the bacteria and plastids of plant cells. We recently reported that the ppGpp over-producing mutant of
Arabidopsis thaliana
had a larger shoot weight than wild type (WT), especially under nutrient-deficient conditions. However, the mechanisms behind the influence of ppGpp on plant growth and biomass remain elusive. To understand the impact of the ppGpp accumulation on plant growth, we characterized metabolic changes in the ppGpp-overproducing mutant upon transition from nitrogen-rich to nitrogen-limiting concentrations. We found that the fresh weight of the mutant was significantly larger than WT when the total nitrogen source (KNO
3
and NH
4
NO
3
) concentration was below 0.9 mM. When the nitrogen content in the medium decreased, aromatic and branched-chain amino acids increased in WT due to accelerated protein degradation and/or attenuated protein synthesis. These amino-acid levels in the ppGpp over-accumulating mutant decreased upon nitrogen deficiency. The results suggest that the ppGpp-overaccumulation affects amino-acid and protein homeostasis and facilitates growth under nitrogen-limiting conditions.
This study points out some characteristics of the nature experience including experiments in German forest kindergartens. The episodes were analyzed from the following aspects; (1) the content of the ...experiments, (2) the involvement of children in the experiments, and (3) encouragement by educators’ support.Through the analysis of the episodes, the following results were obtained: (1) the experiments had a wide variety of areas such as animals, plants, fungi, fire, air, water, soil, energy, and astral bodies; (2) first, children conducted experiments with their hands, and subsequently children inferred the result of the experiments or the reasons why the phenomena occurred; and (3) educators provided clear explanations of the experiments’ contents, which are correlated to the learning contents in elementary school.
The regulatory nucleotide, guanosine 3′,5′-bis(pyrophosphate) (ppGpp), originally identified in
Escherichia coli
, controls transcription, translation and enzyme activities in bacteria and plastids ...of plant cells. We recently reported that seedlings of the ppGpp over-producing mutant of
Arabidopsis thaliana
grown on agar-solidified medium showed larger biomass than those of wild type (WT), especially under nutrient-limiting conditions. However, the reproducibility of the phenotype on the soil is unknown. To better understand the impact of the ppGpp accumulation on plant growth on the soil, phenotypes of the Arabidopsis ppGpp-less and ppGpp-accumulating mutants were characterized on nitrogen-rich and nitrogen-limiting soil. We found that although fresh weight of the ppGpp-accumulating mutant was significantly larger than that of WT under nitrogen-limiting conditions, dry weights of the mutants were the same as that of WT, indicating that impact of the ppGpp accumulation on plant biomass relies on growth conditions. These results confirmed that artificial modulation of ppGpp-dependent plastidial stringent response could contribute to plant growth on soil in response to nitrogen availability.
Guanosine-tetraphosphate (ppGpp) is known as an alarmone that mediates bacterial stress responses. In plants, ppGpp is synthesized in chloroplasts from GTP and ATP and functions as a regulator of ...chloroplast gene expression to affect photosynthesis and plant growth. This observation indicates that ppGpp metabolism is closely related to chloroplast function, but the regulation of ppGpp and its role in chloroplast differentiation are not well understood. In rice, ppGpp directly inhibits plastidial guanylate kinase (GKpm), a key enzyme in GTP biosynthesis. GKpm is highly expressed during early leaf development in rice, and the GKpm-deficient mutant, virescent-2 (v2), develops chloroplast-deficient chlorotic leaves under low-temperature conditions. To examine the relationship between GTP synthesis and ppGpp homeostasis, we generated transgenic rice plants over-expressing RSH3, a protein known to act as a ppGpp synthase. When RSH3 was overexpressed in v2, the leaf chlorosis was more severe. Although the RSH3 overexpression in the wild type caused no visible effects, PAM fluorometer measurements indicated that photosynthetic rates were reduced in this line. This finding implies that the regulation of ppGpp synthesis in rice is involved in the maintenance of the GTP pool required to regulate plastid gene expression during early chloroplast biogenesis. We further investigated changes in the expressions of RelA/SpoT Homolog (RSH) genes encoding ppGpp synthases and hydrolases during the same period. Comparing the expression of these genes with the cellular ppGpp content suggests that the basal ppGpp level is determined by the antagonistic action of multiple RSH enzymatic activities during early leaf development in rice.
For the physical performance of female athletes, it is necessary to eliminate energy insufficiency that causes amenorrhea. In addition to female athlete triad (FAT), relative energy deficiency in ...sports (RED-S) was proposed, and as a result, there is osteoporosis, which is also considered as amenorrhea. In gynecology you can only treat amenorrhea, but as a sports doctor it is necessary to eliminate energy insufficiency and prevent osteoporosis. For prevention, an athlete needs an clinical index that you can understand yourself, and you should check your height/weight every month for growth period. The group without growth peak repeats fatigue fracture with high risk. It is more important rather than delayed menarche. The physical status during the growth periods evaluates the degree of obesity, but judgment is made by BMI at athlete, and when it decreases it is judged as abnormal in pediatrics. RED-S is more common not only for leaner athletes but also for ones with high skeletal muscle mass. RED-S affects various aspects, so that anemia and reduction of testosterone can also be used as an clinical indicator of RED-S.
