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MassIVE MSV000097096 - Data for "Different tools for different trades: Contrasts in specialized metabolite chemodiversity and phylogenetic dispersion in fruit, leaves, and roots of the Neotropical shrubs Psychotria and Palicourea (Rubiaceae)":Subtitle
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Spatial cognition is central to human behavior, but the way people conceptualize space varies within and across groups for unknown reasons. Here, we found that adults from an indigenous Bolivian group used systematically different spatial reference frames on different axes, according to known differences in their discriminability: In both verbal and nonverbal tests, participants preferred allocentric (i.e., environment-based) space on the left-right axis, where spatial discriminations (like “b” versus “d”) are notoriously difficult, but the same participants preferred egocentric (i.e., body-based) space on the front-back axis, where spatial discrimination is relatively easy. The results (i) establish a relationship between spontaneous spatial language and memory across axes within a single culture, (ii) challenge the claim that each language group has a predominant spatial reference frame at a given scale, and (iii) suggest that spatial thinking and language may both be shaped by spatial discrimination abilities, as they vary across cultures and contexts.more » « less
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Symmetry is a foundational concept in inorganic chemistry, essential for understanding molecular properties and interactions. Yet, little is known about how instructors teach symmetry or what shapes their instructional and curricular choices. To investigate this, we analyzed classroom observations from fourteen inorganic chemistry instructors from various institutions, focusing on their use of student-centered practices and emphasis on symmetry content. We then conducted semi-structured interviews to explore the reasoning behind their decisions, using the Teacher-Centered Systemic Reform (TCSR) model to interpret influences from personal factors (e.g., teaching experience), teacher thinking (e.g., beliefs about teaching and learning), and contextual factors (e.g., classroom layout). Minute-by-minute analyses of teaching revealed four instructional profiles (student-centered, high-interactive, low-interactive, and instructor-centered) and four content profiles, ranging from an emphasis on symmetry fundamentals (e.g., symmetry elements and operations, point group assignment) to symmetry applications (e.g., spectroscopy, molecular orbitals, character tables). Three themes emerged: (1) instructional approaches and content emphasis vary substantially across instructors; (2) more student-centered instructors tend to focus on foundational symmetry concepts and skills, whereas more instructor-centered instructors tend to prioritize advanced applications; and (3) instructors’ beliefs and prior experiences, more than personal and contextual factors, drive instructional decisions for teaching symmetry.more » « less
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null (Ed.)Data continue to accrue indicating that experimental techniques may differ in their sensitivity to mobility and glassiness. In this work the Limited Mobility (LM) kinetic model is used to show that two metrics for tracking sample mobility yield quantitatively different results for the glass transition and mobile layer thickness in systems where free surfaces are present. Both LM metrics track the fraction of material that embodies mobile free volume; in one it is relative to that portion of the sample containing any kind (mobile and dormant) of free volume, and in the other it is relative to the overall sample. Without any kind of optimization, use of the latter metric leads to semi-quantitative agreement with experimental film results, both for the mobile layer thickness and the dependence of sample glass transition temperature on film thickness. Connecting the LM predictions with experiment also produces a semi-quantitative mapping between LM model length and temperature scales, and those of real systems.more » « less
