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In recent years, much of the emphasis for transformation of introductory STEM courses has focused on “active learning”, and while this approach has been shown to produce more equitable outcomes for students, the construct of “active learning” is somewhat ill-defined and is often used as a “catch-all” that can encompass a wide range of pedagogical techniques. Here we present an alternative approach for how to think about the transformation of STEM courses that focuses instead on what students should know and what they can do with that knowledge. This approach, known as three-dimensional learning (3DL), emerged from the National Academy’s “A Framework for K-12 Science Education”, which describes a vision for science education that centers the role of constructing productive causal accounts for phenomena. Over the past 10 years, we have collected data from introductory biology, chemistry, and physics courses to assess the impact of such a transformation on higher education courses. Here we report on an analysis of video data of class sessions that allows us to characterize these sessions as active, 3D, neither, or both 3D and active. We find that 3D classes are likely to also involve student engagement (i.e. be active), but the reverse is not necessarily true. That is, focusing on transformations involving 3DL also tends to increase student engagement, whereas focusing solely on student engagement might result in courses where students are engaged in activities that do not involve meaningful engagement with core ideas of the discipline.

The importance of improving STEM education is of perennial interest, and to this end, the education community needs ways to characterize transformation efforts. Three-dimensional learning (3DL) is one such approach to transformation, in which core ideas of the discipline, scientific practices, and crosscutting concepts are combined to support student development of disciplinary expertise. We have previously reported on an approach to the characterization of assessments, the Three-Dimensional Learning Assessment Protocol (3D-LAP), that can be used to identify whether assessments have the potential to engage students in 3DL. Here we present the development of a companion, the Three-Dimensional Learning Observation Protocol (3D-LOP), an observation protocol that can reliably distinguish between instruction that has potential for engagement with 3DL and instruction that does not. The 3D-LOP goes beyond other observation protocols, because it is intended not only to characterize the pedagogical approaches being used in the instructional environment, but also to identify whether students are being asked to engage with scientific practices, core ideas, and crosscutting concepts. We demonstrate herein that the 3D-LOP can be used reliably to code for the presence of 3DL; further, we present data that show the utility of the 3D-LOP in differentiating between instruction that has the potential to promote 3DL from instruction that does not. Our team plans to continue using this protocol to evaluate outcomes of instructional transformation projects. We also propose that the 3D-LOP can be used to support practitioners in developing curricular materials and selecting instructional strategies to promote engagement in three-dimensional instruction.

National STEM education reform efforts call for increased emphasis on science practices, such as modeling. We describe an activity where students read a scientific blog post relating human gametogenesis to disease and then during class develop a model explaining why defects in meiotic machinery cause this disease. This interactive activity was implemented in two sections of an introductory biology course, each exceeding 150 students. Overall, students responded positively to the activity, and based on follow-up exam questions addressing the main learning goals of the modeling activity, about 70 percent of students mastered the learning objectives associated with the modeling activity.

In recent years, much of the emphasis for transformation of introductory STEM courses has focused on \"active learning\", and while this approach has been shown to produce more equitable outcomes for students, the construct of \"active learning\" is somewhat ill-defined, and can encompass a wide range of pedagogical techniques. Here we present an alternative approach for how to think about the transformation of STEM courses that focuses instead on what students should know and what they can do with that knowledge. This approach, known as three-dimensional learning (3DL), emerged from the National Academy's \"A Framework for K-12 Science Education\", which describes a vision for science education that centers the role of constructing productive causal accounts for phenomena. Over the past 10 years, we have collected data from introductory biology, chemistry, and physics courses to assess the impact of such a transformation on higher education courses. Here we report on an analysis of video data of class sessions that allows us to characterize these sessions as active, 3D, neither, or both 3D and active. We find that 3D classes are likely to also involve student engagement (i.e. be active), but the reverse is not necessarily true. That is, focusing on transformations involving 3DL also tends to increase student engagement, whereas focusing solely on student engagement might result in courses where students are engaged in activities that do not involve meaningful engagement with core ideas of the discipline.Competing Interest StatementThe authors have declared no competing interest.

Information about the nitrogen fixing potential, diversity and sites of colonization of endophytic bacteria from rice are needed to expand our understanding of a new area of microbial ecology and plant microbe interactions and lay the foundations for future studies aimed at using biologically fixed nitrogen to replace nitrogen fertilizers. A collection of 142 bacteria isolated from mechanically-abraded, surface-sterilized rice roots was studied. Polymerase Chain Reaction (PCR) mediated gene amplification using degenerate primers derived from highly conserved regions of the nitrogenase nifD gene revealed 20 isolates harboring nifD gene sequences. Southern hybridization analysis confirmed the presence of nif genes in 19 of these isolates. The diazotrophic nature of these 19 isolates was confirmed using Acetylene Reduction Assays (ARA). Examination of genetic diversity using amplified ribosomal DNA restriction analysis (ARDRA) fingerprints and rep-PCR genomic fingerprints with Gelcompar software revealed 56 unique ARDRA fingerprints and 71 unique rep-PCR genomic fingerprints. Clusters of similar combined fingerprints, consisting of 37, 15, 12, and 9 non-diazotrophic bacteria, as well as two clusters each containing 4 diazotrophic bacteria, were found. Analysis of partial Small Subunit (SSU) ribosomal RNA (rRNA) gene sequences revealed the presence of isolates with similarity to strains from the alpha-, beta-, and gamma subdivisions of the Proteobacteria, and to members of the Bacillaceae and Microbacteriaceae. Many of the ARDRA fingerprints and/or SSU rRNA gene sequences of these bacteria were highly similar to those of other bacteria previously isolated from the rhizosphere of rice. Two isolates from the collection and Sinorhizobium meliloti , a control, were tagged with the biomarker gus or gfp, and the colonization of rice tissue was examined. In situ visualization of colonization of three week old inoculated rice seedlings revealed no endophytic colonization of rice tissue by these bacteria. However, clumps of bacteria, as well as individual cells, could be visualized on the surface of the roots. On very rare occasions an isolated epidermal cell filled with bacteria was observed.