Characterising patterns of engagement of different participants in a public STEM-based analysis project

An analysis project undertaken in the context of a historic visitor site is described. The project offered different types of opportunity for scientific working, and involved four distinct groups of participants. Two distinguishing features of the different groups of participants were their primary motivation for engagement with the activity, and their level of previous engagement with formal science education. Participants in different parts of the project were assessed as to their level of science capital (Archer et al., 2015). Drawing upon engagement theory, the observable behaviours were used as an indicator of engagement and then categorised according to Pearson's (2010) taxonomy. The analysis showed that learner engagement was exhibited at different levels by the different categories of participants, with higher levels of engagement exhibited by participants with a higher level of science capital. Although there was general correlation between the level of science capital and the proportion of higher engagement learning behaviours, one group of participants deviated from this trend. The findings indicate that the level of science capital is a key determinant of engagement and associated learning behaviours, but did not completely account for participants’ engagement in the science outreach activity

Pollination ecology and reproductive success in Jack-in-the Pulpit (Arisaema triphyllum) in Quebec (Canada)

International audienc

Pollination ecology and reproductive success in Jack-in-the Pulpit (Arisaema triphyllum) in Quebec (Canada)

International audienc

Metabolism of chlorobiphenyls by a variant biphenyl dioxygenase exhibiting enhanced activity toward dibenzofuran

International audienceThe biphenyl dioxygenase of Burkholderia xenovorans LB400 (BphAE(LB400)) catalyzes the dihydroxylation of biphenyl and of several polychlorinated biphenyls (PCBs) but it poorly oxidizes dibenzofuran. In this work we showed that BphAE(RR41), a variant which was previously found to metabolize dibenzofuran more efficiently than its parent BphAE(LB400), metabolized a broader range of PCBs than BphAE(LB400). Hence, BphAE(RR41) was able to metabolize 2,6,2',6'-, 3,4,3',5'- and 2,4,3',4'-tetrachlorobiphenyl that BphAE(LB400) is unable to metabolize. BphAE(RR41) was obtained by changing Thr335Phe336Asn338Ile341Leu409 of BphAE(LB400) to Ala335Met336Gln338Val341Phe409. Site-directed mutagenesis was used to create combinations of each substitution, in order to assess their individual contributions. Data show that the same Asn338Glu/Leu409Phe substitution that enhanced the ability to metabolize dibenzofuran resulted in a broadening of the PCB substrates range of the enzyme. The role of these substitutions on regiospecificities toward selected PCBs is also discussed