Mathematik und Sprache : Tagungsband des AK Grundschule in der GDM 2017

Dieser Tagungsband dokumentiert die Ergebnisse der Jahrestagung des Arbeitskreises Grundschule in der Gesellschaft für Didaktik der Mathematik (GDM), die in diesem Jahr wieder in Bad Salzdetfurth stattfand. Vom 03. bis 05. November 2017 widmete sich der Arbeitskreis dem Thema „Mathematik und Sprache“. Sprachbildung in der Mathematik ist eine herausfordernde und langfristige Aufgabe für die Unterrichtspraxis sowie die mathematikdidaktische Forschungs- und Entwicklungsarbeit. Dieser Themenkomplex wurde im Rahmen von vier Hauptvorträgen aus verschiedenen Perspektiven beleuchtet und im Plenum diskutiert. Zusätzlich setzten sich acht Arbeitsgruppen mit den Themenfeldern ‚Arithmetik‘, ‚Geometrie‘, ‚Sachrechnen‘, ‚Daten, Häufigkeit und Wahrscheinlichkeit‘, ‚Lehrerfortbildung‘, ‚Kommunikation und Kooperation‘, ‚Lernen, Lehren und Forschen mit digitalen Medien‘ sowie ‚vorschulische Bildung‘ intensiv mit aktuellen Forschungs-und Praxisfragen auseinander. Zentrale Ergebnisse dieser Arbeitsgruppen sind in diesem Band ebenfalls dokumentiert.The Proceedings of the 2017 Conference of the Research Group on Primary Mathematics Education (Arbeitskreis Grundschule in der GDM) focus on language in mathematics education in primary school. Four invited talks addressed the main theme in plenum. Additionally, workings groups on the research areas arithmetic, geometry, modelling, data & probability, as well as groups on teacher education, ICT, and last not least early mathematics education offered discussions on current research issues

Exosomal release of L-plastin by breast cancer cells facilitates metastatic bone osteolysis

Bone metastasis from breast and prostate carcinomas is facilitated by activation of bone-resorbing osteoclasts. Using proteomics approaches, we have identified peroxiredoxin-4 (PRDX4) as a cancer-secreted mediator of osteoclastogenesis. We now report characterization of L-plastin in the conditioned media (CM) of MDA-MB-231 human breast cancer cells using immunoblotting and mass spectrometry. The osteoclastogenic potential of MDAMB-231 CM with siRNA-silenced L-plastin was significantly reduced. L-plastin was detected in cancer-derived exosomes, and inhibition of exosomal release significantly decreased the osteoclastogenic capacity of MDA-MB-231 CM. When added to osteoclast precursors primed with RANKL for 2 days, recombinant L-plastin induced calcium/NFATc1-mediated osteoclastogenesis to the levels similar to continuous treatment with RANKL. Using shRNA, we generated MDA-MB-231 cells lacking L-plastin, PRDX4, or both and injected these cell populations intratibially in CD-1 immunodeficient mice. Micro-CT and histomorphometric analysis demonstrated a complete loss of osteolysis when MDA-MB-231 cells lacking both L-plastin and PRDX4 were injected. A meta-analysis established an increase in L-plastin and PRDX4 mRNA expression in numerous human cancers, including breast and prostate carcinomas. This study demonstrates that secreted L-plastin and PRDX4 mediate osteoclast activation by human breast cancer cells

ABCC5 supports osteoclast formation and promotes breast cancer metastasis to bone

INTRODUCTION: Bone is the most common site of breast cancer metastasis, and complications associated with bone metastases can lead to a significantly decreased patient quality of life. Thus, it is essential to gain a better understanding of the molecular mechanisms that underlie the emergence and growth of breast cancer skeletal metastases. METHODS: To search for novel molecular mediators that influence breast cancer bone metastasis, we generated gene-expression profiles from laser-capture microdissected trephine biopsies of both breast cancer bone metastases and independent primary breast tumors that metastasized to bone. Bioinformatics analysis identified genes that are differentially expressed in breast cancer bone metastases compared with primary, bone-metastatic breast tumors. RESULTS: ABCC5, an ATP-dependent transporter, was found to be overexpressed in breast cancer osseous metastases relative to primary breast tumors. In addition, ABCC5 was significantly upregulated in human and mouse breast cancer cell lines with high bone-metastatic potential. Stable knockdown of ABCC5 substantially reduced bone metastatic burden and osteolytic bone destruction in mice. The decrease in osteolysis was further associated with diminished osteoclast numbers in vivo. Finally, conditioned media from breast cancer cells with reduced ABCC5 expression failed to induce in vitro osteoclastogenesis to the same extent as conditioned media from breast cancer cells expressing ABCC5. CONCLUSIONS: Our data suggest that ABCC5 functions as a mediator of breast cancer skeletal metastasis. ABCC5 expression in breast cancer cells is important for efficient osteoclast-mediated bone resorption. Hence, ABCC5 may be a potential therapeutic target for breast cancer bone metastasis

Beschreibungen als fachliche Wegweiser - Zu Beschreibungen von Materialhandlungen im Prozess der Strategieentwicklung

Tiedemann K, Rottmann T. Beschreibungen als fachliche Wegweiser - Zu Beschreibungen von Materialhandlungen im Prozess der Strategieentwicklung. In: Brandt B, Tiedemann K, eds. Mathematiklernen aus interpretativer Perspektive I: Aktuelle Themen, Arbeiten und Fragen. Empirische Studien zur Didaktik der Mathematik. Vol 34. Münster: Waxmann; 2019: 165-192

Learning Mathematics in the Family About Familial Support Systems for Children's Mathematics Learning in Everyday Reading and Playing Sessions

In research, politics and general public, one pays more and more attention to the family as a place of mathematics education in the early years. In this context, research findings show that, besides the mathematical content, the way in which families talk about mathematics and integrates it into their everyday lives, is important, too. This article focuses on support systems for mathematics learning which are established in the interactions between a child and its mother and which coins the child's mathematical development. Such support systems are interpreted from an interactionistic perspective and investigated by means of Interpretative Research on the basis of data from everyday reading and playing sessions. As the main qualitative-descriptive result, three different types of support systems are presented and delineated from each other. Thereby, on the one hand, the diversity of support systems for mathematical learning in the familial context becomes apparent and, on the other hand, the object of investigation is structured on a conceptual level so that a transfer to other contexts of research and practice is generally possible

Practices of Describing-About the Functions of Language in the Acquisition of the Jump Strategy

Tiedemann K. Praktiken des Beschreibens – Zu Funktionen der Sprache bei der Erarbeitung des Teilschrittverfahrens im Zahlenraum bis 100. Journal für Mathematik-Didaktik. 2020;41:11-41.Die Sprache ist im Zusammenhang des Mathematiklernens nicht erst in Leistungs-, sondern ganz wesentlich schon für die soziale Verständigung und die individuelle Bedeutungskonstruktion in Lernsituationen von Bedeutung. Im vorliegenden Beitrag werden Ergebnisse aus einer qualitativ-interpretativen Studie zum mündlichen Beschreiben von Materialhandlungen vorgestellt. Die zugrunde liegenden Daten stammen aus universitären Fördersituationen mit rechenschwachen Kindern, in denen anhand von Handlungen am Hunderter-Rechenrahmen die Strategie des Teilschrittverfahrens für den Aufgabentyp ZE ±E im Zahlenraum bis 100 zielgerichtet erarbeitet wird. Dabei werden die Kinder aufgefordert, ihr Materialhandeln zu beschreiben. Als Ergebnis der Studie zeigt sich, dass es dabei das Beschreiben gar nicht gibt. Vielmehr konnten drei Praktiken des Beschreibens unterschieden werden, die in der interaktionalen Erarbeitung des Teilschrittverfahrens unterschiedliche Funktionen erfüllen und im vorliegenden Beitrag anhand von Analysebeispielen vorgestellt werden: In den Fördersituationen wird mit Beschreibungen die Materialhandlung gesteuert und zielgerichtet ausgestaltet, das Charakteristische des Teilschrittverfahrens fokussiert und schließlich das Beschreiben selbst verdichtet.In the context of learning mathematics, language is not only relevant to mathematical performance, but to social interaction and individual construction of meaning, too. This article presents the findings of a qualitative-interpretative study that focuses on oral descriptions of physical actions on a number rack. The data was collected in the context of an university based intervention program where children with mathematical difficulties are supported to use the jump strategy on 2-digit additions and subtractions. Thereby, the children usually are encouraged to describe their physical actions on the number rack. The main result of the study is that there does not exist one single way of describing the physical actions. Rather, we could identify three different practices of describing which each have different functions with regard to developing the jump strategy and will be illustrated by analysis examples in this paper: Practices of describing are used for organizing the intended physical actions on the number rack, for focussing on the charateristic of the jump strategy, and for compressing the description itself

Mathematik in der Familie. Zur familialen Unterstützung früher mathematischer Lernprozesse in Vorlese- und Spielsituationen

Tiedemann K. Mathematik in der Familie. Zur familialen Unterstützung früher mathematischer Lernprozesse in Vorlese- und Spielsituationen. Münster: Waxmann; 2012

Biosynthesis of Dermatan Sulphate. Enzymatic mechanism and role of cytokines

Dermatan sulphate is a prominent feature of several different proteoglycans and occurs in almost every tissue of the body. It is an unbranched polymer containing the repeating disaccharide unit of N-acetylgalactosamine and D-glucuronic acid or L-iduronic acid. The polymer can be highly sulphated resulting in an unusual and largely unknown diversity in the chain. The unique step in dermatan sulphate synthesis is the conversion of glucuronic acid into iduronic acid, performed by the action of the dermatan sulphate C5-epimerase. This is followed by a subsequent C4-sulphation of the N-acetylgalactosamine unit by a 4-O-sulphotransferase. C5-epimerase and 4-O-sulphotransferase were quantitated in tissues producing dermatan/chondroitin sulphate of different structures. Varying amounts of enzyme activity corresponded to different amounts of iduronic acid and, in tissue devoid of iduronic acid no epimerase could be demonstrated. In contrast, adequate amounts of 4-sulphotransferase were detected indicating a regulating role for the C5-epimerase in dermatan sulphate synthesis. A possible mechanism to generate the varation in content and organisation of iduronic acid in dermatan sulphate is the influence of various cytokine expressions. To investigate this, fibroblasts were either treated with epidermal growth factor, transforming growth factor-ß and platelet derived growth factor-BB singly or in combination. This resulted in a profound change in proteoglycan production, where biglycan in particular was increased after treatment with a combination of cytokines. Furthermore, treatment with cytokines decreased the C5-epimerase activity, which resulted in a change in dermatan sulphate structure with an increased number of glucuronic acid residues. The 4-O-sulphotransferase and glycosaminoglycan chain length was unaffected. The co-polymeric structure of dermatan sulphate is essential for the interaction with matrix components such as cytokines, proteases and cell surface receptors. An increased knowledge of the structure and how its synthesis is regulated would create a greater understanding of tissue remodelling in physiological, as well as pathophysiological conditions