Refine
Has Fulltext
- no (147) (remove)
Year of publication
- 2018 (147) (remove)
Document Type
- Article (147) (remove)
Language
- German (147) (remove)
Keywords
- Grundschule (2)
- Kardinal Franz Ehrle (2)
- Prävention (2)
- prevention (2)
- (Verfahrens-)Gerechtigkeit (1)
- 3R-Prinzip (1)
- 3R-principles (1)
- Abscisic acid (1)
- Acquisition of arithmetical concepts (1)
- Adorno (1)
Institute
- Department Erziehungswissenschaft (15)
- Wirtschaftswissenschaften (14)
- Bürgerliches Recht (12)
- Department Psychologie (11)
- Zentrum für Lehrerbildung und Bildungsforschung (ZeLB) (11)
- Historisches Institut (10)
- Institut für Romanistik (8)
- Öffentliches Recht (7)
- WeltTrends e.V. Potsdam (6)
- Institut für Germanistik (5)
As our climate changes, plant mechanisms involved for dormancy release become increasingly important for commercial orchards. It is generally believed that abscisic acid (ABA) is a key hormone that responds to various environmental stresses which affects bud dormancy. For this reason, a multi-year study was initiated to obtain data on plant metabolites during winter rest and ontogenetic development in sweet cherry buds (Prunus avium L.). In this paper, we report on metabolites involved in ABA synthesis and catabolism and its effect on bud dormancy in the years 2014/15-2016/17. In previous work, the timings of the different phases of para-, endo-, ecodormancy and ontogenetic development for cherry flower buds of the cultivar ‘Summit’ were determined, based on classical climate chamber experiments and changes in the bud’s water content. Based on these time phases, we focused now on the different aspects of the ABA-metabolism. The results show that there is a continual synthesis of ABA about 5 weeks before leaf fall, and a degradation of ABA during ecodormancy and bud development until the phenological stage ‘open cluster’. This is confirmed by relating the ABA content to that of the total precursor carotenoids, neoxanthin and violaxanthin. The tentative monitoring of individual intermediate metabolites revealed that dihydroxyphaseic acid is the most abundant catabolite of ABA and ABA glucosyl ester is in terms of mass intensity, the most abundant ABA metabolite observed in this study. The results suggest that the direct route for ABA biosynthesis from farnesyl pyrophosphate may also be relevant in cherry flower buds.
The acquisition of basic arithmetic concepts of children at pre-school and primary-school age (about 4 to 8 years of age) can be described by a cognitive developmental model with 6 levels: (1) count number, (2) mental number line, (3) cardinality and decomposability, (4) class inclusion and embeddedness, (5) relationality, and (6) units in numbers (bundling and unbundling). In this paper, 3 studies for longitudinally testing the model are presented. In Studies 1 (N = 26; heterogeneous age) and 2 (N = 62; homogeneous age) it shows that the individual development of arithmetic concepts across 18 months (Study 1:4 points of measurement) respectively 17 months (Study 2:3 points of measurement before, at, and after entering primary school) follows the levels of the model. In Study 3 (N = 243) it shows that the acquisition of curricular mathematical competencies at the end of Grade 2 is better predicted by conceptual arithmetic understanding at the end of Grade 1 than by intelligence. The results substantiate the validity of the model und confirm the relevance of basic arithmetic concepts for mathematical learning at school with respective consequences for the remedial training of children with math learning difficulties and dyscalculia.
Arme Schweine
(2018)
Auf Hochtouren
(2018)
Automatisierungstechnik I
(2018)
Automatisierungstechnik II
(2018)