Appendix A. Origins of populations of Centaurea stoebe used in the experiment.

Origins of populations of Centaurea stoebe used in the experiment

Appendix C. Comparisons of life history traits of the three geo-cytotypes of C. stoebe from different eco-geographical regions.

Comparisons of life history traits of the three geo-cytotypes of C. stoebe from different eco-geographical regions

Appendix B. Eco-climatic niche space of populations of the three geo-cytotypes of C. stoebe.

Eco-climatic niche space of populations of the three geo-cytotypes of C. stoebe

reduction in biomass

Reduction in biomass of Centaurea stoebe and neighbouring communit

Species list of the native neighbour species from Europe and North America investigated in this study, their family and their functional group.

<p>Species list of the native neighbour species from Europe and North America investigated in this study, their family and their functional group.</p

REI

RE

Origin of <i>Centaurea stoebe</i> populations.

<p>Origin of <i>Centaurea stoebe</i> populations.</p

Performance of neighbouring community and <i>C</i>. <i>stoebe</i> in the presence of competition.

<p>In the presence of competition, biomass (g dry weight) of European and North American neighbouring community (EU-NC and NA-NC, respectively) (a), and biomass (b) of and proportion flowering (c) of European diploid (EU2x), European tetraploid (EU4x) and North American tetraploid (NA4x) <i>Centaurea stoebe</i>.</p

Community layout in containers.

<p>The arrangement of ten European (a) and ten North American (b) native neighbour plants and ten <i>Centaurea stoebe</i> in the interspecies competition containers; triangles are <i>C</i>. <i>stoebe</i>.</p

Justifications-on-demand as a device to promote shifts of attention associated with relational thinking in elementary arithmetic

Student responses to arithmetical questions that can be solved by using arithmetical structure can serve to reveal the extent and nature of relational, as opposed to computational thinking. Here, student responses to probes which require them to justify-on-demand are analysed using a conceptual framework which highlights distinctions between different forms of attention. We analyse a number of actions observed in students in terms of forms of attention and shifts between them: in the short-term (in the moment), medium-term (over several tasks), and long-term (over a year). The main factors conditioning students´ attention and its movement are identified and some didactical consequences are proposed.This study was funded by a Spanish national project of Research, Development and Innovation, identified by the code SEJ2006-09056, financed by the Spanish Ministry of Sciences and Technology and FEDER funds