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Graphing is an important practice for scientists and in K-16 science curricula. Graphs can be constructed using an array of software packages as well as by hand, with pen-and-paper. However, we have an incomplete understanding of how students' graphing practice vary by graphing environment; differences could affect how best to teach and assess graphing. Here we explore the role of two graphing environments in students' graphing practice. We studied 43 undergraduate biology students' graphing practice using either pen-and-paper (PP) (n = 21 students) or a digital graphing tool GraphSmarts (GS) (n = 22 students). Participants' graphs and verbal justifications were analyzed to identify features such as the variables plotted, number of graphs created, raw data versus summarized data plotted, and graph types (e.g., scatter plot, line graph, or bar graph) as well as participants' reasoning for their graphing choices. Several aspects of participant graphs were similar regardless of graphing environment, including plotting raw vs. summarized data, graph type, and overall graph quality, while GS participants were more likely to plot the most relevant variables. In GS, participants could easily make more graphs than in PP and this may have helped some participants show latent features of their graphing practice. Those students using PP tended to focus more on ease of constructing the graph than GS. This study illuminates how the different characteristics of the graphing environment have implications for instruction and interpretation of assessments of student graphing practices. [ABSTRACT FROM AUTHOR]

Physiology demands systems thinking: reasoning within and between levels of biological organization and across different organ systems. Many physiological mechanisms explain how structures and their properties interact at one level of organization to produce emergent functions at a higher level of organization. Current physiology principles, such as structure-function relations, selectively neglect mechanisms by not mentioning this term explicitly. We explored how students characterized mechanisms and functions to shed light on how students make sense of these terms. Students characterized mechanisms as 1) processes that occur at levels of organization lower than that of functions; and 2) as detailed events with many steps involved. We also found that students produced more variability in how they characterized functions compared with mechanisms: students characterized functions in relation to multiple levels of organization and multiple definitions. We interpret these results as evidence that students see mechanisms as holding a more narrow definition than used in the biological sciences, and that students struggle to coordinate and distinguish mechanisms from functions due to cognitive processes germane to learning in many domains. We offer the instructional suggestion that we scaffold student learning by affording students opportunities to relate and also distinguish between these terms so central to understanding physiology. [ABSTRACT FROM AUTHOR]

Summary: A recently described form of synaptic plasticity results in dynamic changes in the calcium permeability of synaptic AMPA receptors. Since the AMPA receptor GluR2 subunit confers calcium permeability, this plasticity is thought to occur through the dynamic exchange of synaptic GluR2-lacking and GluR2-containing receptors. To investigate the molecular mechanisms underlying this calcium-permeable AMPA receptor plasticity (CARP), we examined whether AMPA receptor exchange was mediated by subunit-specific protein-protein interactions. We found that two GluR2-interacting proteins, the PDZ domain-containing Protein interacting with C kinase (PICK1) and N-ethylmaleimide sensitive fusion protein (NSF), are specifically required for CARP. Furthermore, PICK1, but not NSF, regulates the formation of extrasynaptic plasma membrane pools of GluR2-containing receptors that may be laterally mobilized into synapses during CARP. These results demonstrate that PICK1 and NSF dynamically regulate the synaptic delivery of GluR2-containing receptors during CARP and thus regulate the calcium permeability of AMPA receptors at excitatory synapses. [Copyright &y& Elsevier]

The original version of this article unfortunately contained a mistake. The name of "Susan Maruca" is now corrected in the author group. [ABSTRACT FROM AUTHOR]

Recent emphasis on learning biology through scientific investigations has focused instruction on understanding and using scientific evidence. To unpack the complexities of evidentiary reasoning, here we present a novel laboratory investigation for teaching the Hardy Weinberg Equilibrium (HWE) in an introductory biology laboratory course that was informed by the Conceptual Analysis of Disciplinary Evidence (CADE) framework. This HWE laboratory investigation highlights evidentiary reasoning with scaffolding questions to target reasoning with and about scientific evidence and it provides students with detailed disciplinary knowledge underpinning their investigation and evidentiary reasoning. To indicate how CADE influenced instruction on evidentiary reasoning during the investigation, changes in one instructor's laboratory discussion questions before and after implementing CADE are provided. Also, our CADE-informed HWE laboratory investigation is compared to other published activities for engaging students with HWE. Findings show that with CADE, the instructor implemented more scaffolds for directing students to consider multiple aspects of evidentiary reasoning and encouraged students' epistemic considerations about the nature, scope and quality of scientific evidence. These changes suggest that CADE can be a practical pedagogical tool to inform improvements in HWE laboratory investigations and to help instructors develop and implement scaffolds to guide students' evidentiary reasoning during a scientific investigation. [ABSTRACT FROM AUTHOR]