@article{HerzogEhlertFritz2017,
  author    = {Herzog, Moritz and Ehlert, Antje and Fritz, Annemarie},
  title     = {A Competency Model of Place Value Understanding in South African Primary School Pupils},
  series = {African Journal of Research in Mathematics, Science and Technology Education},
  volume    = {21},
  journal   = {African Journal of Research in Mathematics, Science and Technology Education},
  publisher = {Routledge, Taylor \& Francis Group},
  address   = {Abingdon},
  issn      = {1811-7295},
  doi       = {10.1080/18117295.2017.1279453},
  pages     = {37 -- 48},
  year      = {2017},
  abstract  = {Although the general development of mathematical abilities in primary school has been the focus of many researchers, the development of place value understanding has rarely been investigated to date. This is possibly due to the lack of conceptual approaches and empirical studies related to this topic. To fill this gap, a theory-driven and empirically validated model was developed that describes five sequential conceptual levels of place value understanding. The level sequence model gives us the ability to estimate general abilities and difficulties in primary school pupils in the development of a conceptual place value understanding. The level sequence model was tried and tested in Germany, and given that number words are very differently constructed in German and in the languages used in South African classrooms, this study aims to investigate whether this level sequence model can be transferred to South Africa. The findings based on the responses of 198 Grade 2-4 learners show that the English translation of the test items results in the same item level allocation as the original German test items, especially for the three basic levels. Educational implications are provided, in particular concrete suggestions on how place value might be taught according to the model and how to collect specific empirical data related to place value understanding.},
  language  = {en}
}
@article{HerzogEhlertFritz2017,
  author    = {Herzog, Moritz and Ehlert, Antje and Fritz, Annemarie},
  title     = {Kombinatorikaufgaben in der dritten Grundschulklasse},
  series = {Journal f{\"u}r Mathematik-Didaktik},
  volume    = {38},
  journal   = {Journal f{\"u}r Mathematik-Didaktik},
  publisher = {Springer},
  address   = {Heidelberg},
  issn      = {0173-5322},
  doi       = {10.1007/s13138-017-0118-8},
  pages     = {263 -- 289},
  year      = {2017},
  abstract  = {Seit einigen Jahren werden kombinatorische Aufgaben als eigenst{\"a}ndiges Thema im Mathematikunterricht der Grundschule behandelt, das diverse Lerngelegenheiten bereith{\"a}lt. Dies wirft Fragen zur Bearbeitungsweise sowie zu den Repr{\"a}sentationen der Sch{\"u}lerinnen und Sch{\"u}ler auf. In einer empirischen Studie (N = 548) wurden anhand von sechs Kombinatorikaufgaben Leistungen und Bearbeitungsweisen von Lernenden in der dritten Klasse erhoben. Besonderes Augenmerk wurde auf die verwendeten Darstellungen und den Abstraktionsgrad sowie den Einsatz von Makrostrategien gerichtet. Diese drei Faktoren wurden hinsichtlich ihres Einflusses auf die L{\"o}sungsg{\"u}te untersucht. Die Ergebnisse zeigen, dass nicht alle Sch{\"u}lerinnen und Sch{\"u}ler ohne Anleitung geeignete L{\"o}sungsans{\"a}tze zu kombinatorischen Problemen fanden. Die Darstellungsweise hatte einen vergleichsweise geringen Einfluss auf die L{\"o}sungsquote. Im Gegensatz dazu konnten unterschiedlich starke positive Zusammenh{\"a}nge zwischen Abstraktionsgrad bzw. Strategieeinsatz und L{\"o}sungserfolg nachgewiesen werden. Aus den Ergebnissen der Studie lassen sich Schl{\"u}sse {\"u}ber die Vermittlung und didaktische Aufbereitung des Themenfeldes Kombinatorik in der Grundschulmathematik ziehen.},
  language  = {de}
}
@article{FritzLongHerzogetal.2020,
  author    = {Fritz, Annemarie and Long, Caroline and Herzog, Moritz and Balzer, Lars and Ehlert, Antje and Henning, Elizabeth},
  title     = {Mismatch of the South African foundation phase curriculum demands and learners' current knowledge},
  series = {African journal of research in mathematics, science and technology education},
  volume    = {24},
  journal   = {African journal of research in mathematics, science and technology education},
  number    = {1},
  publisher = {Routledge, Taylor \& Francis Group},
  address   = {Abingdon},
  issn      = {1811-7295},
  doi       = {10.1080/18117295.2020.1724466},
  pages     = {10 -- 20},
  year      = {2020},
  abstract  = {Against the background of the low mathematical performance of South African learners in international panel studies, there is an urgent need to improve mathematical education. In particular, the curriculum and its structure raise questions. It is logical that the prescribed curricula should align with learners' developmental trajectories. Given the hierarchical structure of mathematics, the curricular requirements should pay attention to learners' current knowledge of mathematical concepts. The aim of this study was to compare the curricular requirements as defined by the CAPS with the conceptual current knowledge of South African learners. South African Grade 1 learners (N = 602) were assessed on a test of numeracy concepts, based on a theoretically informed and empirically validated model of developing mathematical proficiency. The content of the CAPS for Grade 1 was aligned to the model levels by two experts (Cohen's kappa = .753, p < 0.001). Results show that the curricular requirements go far beyond the current knowledge required to engage with these new concepts of the vast majority of South African Grade 1 learners. The mismatch may to some extent be responsible for the unsatisfactory results in international comparison studies. These results show that the intended curriculum is beyond the grasp of most South African Grade 1 learners. These children are unlikely to develop new arithmetic concepts based on their lack of required foundation knowledge. We therefore argue that the intended curriculum for Grade 1 should focus more on counting skills, ordinal relations between numbers and-most importantly-set-based number representations and part-part-whole relations.},
  language  = {en}
}
@misc{deVeraAlawiBackhausetal.2019,
  author    = {de Vera, Jean-Pierre Paul and Alawi, Mashal and Backhaus, Theresa and Baque, Mickael and Billi, Daniela and Boettger, Ute and Berger, Thomas and Bohmeier, Maria and Cockell, Charles and Demets, Rene and de la Torre Noetzel, Rosa and Edwards, Howell and Elsaesser, Andreas and Fagliarone, Claudia and Fiedler, Annelie and Foing, Bernard and Foucher, Frederic and Fritz, J{\"o}rg and Hanke, Franziska and Herzog, Thomas and Horneck, Gerda and H{\"u}bers, Heinz-Wilhelm and Huwe, Bj{\"o}rn and Joshi, Jasmin Radha and Kozyrovska, Natalia and Kruchten, Martha and Lasch, Peter and Lee, Natuschka and Leuko, Stefan and Leya, Thomas and Lorek, Andreas and Martinez-Frias, Jesus and Meessen, Joachim and Moritz, Sophie and Moeller, Ralf and Olsson-Francis, Karen and Onofri, Silvano and Ott, Sieglinde and Pacelli, Claudia and Podolich, Olga and Rabbow, Elke and Reitz, G{\"u}nther and Rettberg, Petra and Reva, Oleg and Rothschild, Lynn and Garcia Sancho, Leo and Schulze-Makuch, Dirk and Selbmann, Laura and Serrano, Paloma and Szewzyk, Ulrich and Verseux, Cyprien and Wadsworth, Jennifer and Wagner, Dirk and Westall, Frances and Wolter, David and Zucconi, Laura},
  title     = {Limits of life and the habitability of Mars},
  series = {Astrobiology},
  volume    = {19},
  journal   = {Astrobiology},
  number    = {2},
  publisher = {Liebert},
  address   = {New Rochelle},
  issn      = {1531-1074},
  doi       = {10.1089/ast.2018.1897},
  pages     = {145 -- 157},
  year      = {2019},
  abstract  = {BIOMEX (BIOlogy and Mars EXperiment) is an ESA/Roscosmos space exposure experiment housed within the exposure facility EXPOSE-R2 outside the Zvezda module on the International Space Station (ISS). The design of the multiuser facility supports-among others-the BIOMEX investigations into the stability and level of degradation of space-exposed biosignatures such as pigments, secondary metabolites, and cell surfaces in contact with a terrestrial and Mars analog mineral environment. In parallel, analysis on the viability of the investigated organisms has provided relevant data for evaluation of the habitability of Mars, for the limits of life, and for the likelihood of an interplanetary transfer of life (theory of lithopanspermia). In this project, lichens, archaea, bacteria, cyanobacteria, snow/permafrost algae, meristematic black fungi, and bryophytes from alpine and polar habitats were embedded, grown, and cultured on a mixture of martian and lunar regolith analogs or other terrestrial minerals. The organisms and regolith analogs and terrestrial mineral mixtures were then exposed to space and to simulated Mars-like conditions by way of the EXPOSE-R2 facility. In this special issue, we present the first set of data obtained in reference to our investigation into the habitability of Mars and limits of life. This project was initiated and implemented by the BIOMEX group, an international and interdisciplinary consortium of 30 institutes in 12 countries on 3 continents. Preflight tests for sample selection, results from ground-based simulation experiments, and the space experiments themselves are presented and include a complete overview of the scientific processes required for this space experiment and postflight analysis. The presented BIOMEX concept could be scaled up to future exposure experiments on the Moon and will serve as a pretest in low Earth orbit.},
  language  = {en}
}
@article{ShaydukHallmannRodriguezFernandezetal.2022,
  author    = {Shayduk, Roman and Hallmann, J{\"o}rg and Rodriguez-Fernandez, Angel and Scholz, Markus and Lu, Wei and B{\"o}senberg, Ulrike and M{\"o}ller, Johannes and Zozulya, Alexey and Jiang, Man and Wegner, Ulrike and Secareanu, Radu-Costin and Palmer, Guido and Emons, Moritz and Lederer, Max and Volkov, Sergey and Lindfors-Vrejoiu, Ionela and Schick, Daniel and Herzog, Marc and Bargheer, Matias and Madsen, Anders},
  title     = {Femtosecond x-ray diffraction study of multi-THz coherent phonons in SrTiO3},
  series = {Applied physics letters},
  volume    = {120},
  journal   = {Applied physics letters},
  number    = {20},
  publisher = {AIP Publishing},
  address   = {Melville},
  issn      = {0003-6951},
  doi       = {10.1063/5.0083256},
  pages     = {5},
  year      = {2022},
  abstract  = {We report generation of ultra-broadband longitudinal acoustic coherent phonon wavepackets in SrTiO3 (STO) with frequency components extending throughout the first Brillouin zone. The wavepackets are efficiently generated in STO using femtosecond infrared laser excitation of an atomically flat 1.6 nm-thick epitaxial SrRuO3 film. We use femtosecond x-ray diffraction at the European X-Ray Free Electron Laser Facility to study the dispersion and damping of phonon wavepackets. The experimentally determined damping constants for multi-THz frequency phonons compare favorably to the extrapolation of a simple ultrasound damping model over several orders of magnitude.},
  language  = {en}
}