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It has been reported that students often leave the introductory physics classroom believing that physics is less connected to the real world than when they entered. In this paper we aim to complicate that narrative by considering students' experiences in an introductory physics for the life-sciences course that leverages students' disciplinary expertise in biology and chemistry as they learn physics. In a case study of three students, we probed the role of physics in their lives to challenge the typical interpretation of PER attitudinal and epistemological measures that aim to assess how students connect physics to their lives outside of the classroom. Although we find that our life-science students' rarely think of physics in their everyday lives, they make a variety of connections to the real world. We argue that in order to reflect students' rich disciplinary experiences, our understanding of how students connect physics to life outside the classroom needs to be nuanced or expanded., Comment: Published (2017 PERC Proceedings)

A common hope of many physics educators and researchers is that students leave the course with a stronger sense that physics is relevant to them than when they entered the course. Multiple survey measures have attempted to measure shifts in students' beliefs on the relevance of physics but frequently the results show a negative shift in students' beliefs and are often reported as a failure of students to "see the relevance." We challenge this interpretation by first operationalizing relevance as a construct by using existing theories on beliefs and attitudes. We utilize ecological systems theory to identify rich sites of relevance in students lives and present evidence to demonstrate the rich ways students are able to make relevant connections to physics. We then reflect on the implications of this expanded view on the limitations of past measures of relevance. We articulate how incorporating students' disciplinary ideas and expertise into the classroom can challenge previous deficit-framed narratives of students' abilities to find the relevance of physics., Comment: pre-print

Physics education research has probed for the relevance of physics in students' everyday lives. Attitudinal and epistemological surveys have asked students if they think of or use physics in their daily lives. We have previously documented how it is uncommon that our life science students describe using or even seeing physics in their daily life (Nair, 2018). This result was unsurprising and aligns with previous scholarship of students majoring in disciplines outside of physics; we have argued that it is optimistic for scholars to expect students with disciplinary homes outside of physics to see their experiences through a lens of physics. Methodologically, we searched for a contrasting case (Sam). Sam is majoring in the life sciences and articulates moments where she uses physics to reason through everyday phenomena. We explore the ways in which courses can support students like Sam to find physics relevant to their everyday experiences., Comment: pre-print

The mindset literature is a longstanding area of psychological research focused on beliefs about intelligence, response to challenge, and goals for learning (Dweck, 2000). However, the mindset literature's applicability to the context of college physics has not been widely studied. In this paper we narrow our focus toward students' descriptions of their responses to challenge in college physics. We ask the research questions, "can we see responses to challenge in college physics that resemble that of the mindset literature?" and "how do students express evidence of challenge and to what extent is such evidence reflective of challenges found in the mindset literature?" To answer these questions, we developed a novel coding scheme for interview dialogue around college physics challenge and students' responses to it. In this paper we present the development process of our coding scheme. We find that it is possible to see student descriptions of challenge that resemble the mindset literature's characterizations. However, college physics challenges are frequently different than those studied in the mindset literature. We show that, in the landscape of college physics challenges, mindset beliefs cannot always be considered to be the dominant factor in how students respond to challenge. Broadly, our coding scheme helps the field move beyond broad Likert-scale survey measures of students' mindset beliefs.

Contractile forces exerted on the surrounding extracellular matrix (ECM) lead to the alignment and stretching of constituent fibers within the vicinity of cells. As a consequence, the matrix reorganizes to form thick bundles of aligned fibers that enable force transmission over distances larger than the size of the cells. Contractile force-mediated remodeling of ECM fibers has bearing on a number of physiologic and pathophysiologic phenomena. In this work, we present a computational model to capture cell-mediated remodeling within fibrous matrices using finite element based discrete fiber network simulations. The model is shown to accurately capture collagen alignment, heterogeneous deformations, and long-range force transmission observed experimentally. The zone of mechanical influence surrounding a single contractile cell and the interaction between two cells are predicted from the strain-induced alignment of fibers. Through parametric studies, the effect of cell contractility and cell shape anisotropy on matrix remodeling and force transmission are quantified and summarized in a phase diagram. For highly contractile and elongated cells, we find a sensing distance that is ten times the cell size, in agreement with experimental observations., Comment: Accepted for publication in the Biophysical Journal

Cells can sense and respond to mechanical signals over relatively long distances across fibrous extracellular matrices. Here, we explore all of the key factors that influence long range force transmission in cell-populated collagen matrices: alignment of collagen fibers, responses to applied force, strain stiffening properties of the aligned fibers, aspect ratios of the cells, and the polarization of cellular contraction. A constitutive law accounting for mechanically-driven collagen fiber reorientation is proposed. We systematically investigate the range of collagen fiber alignment using both finite element simulations and analytical calculations. Our results show that tension-driven collagen fiber alignment plays a crucial role in force transmission. Small critical stretch for fiber alignment, large fiber stiffness and fiber strain hardening behavior enable long-range interaction. Furthermore, the range of collagen fiber alignment for elliptical cells with polarized contraction is much larger than that for spherical cells with diagonal contraction. A phase diagram showing the range of force transmission as a function of cell shape and polarization and matrix properties is presented. Our results are in good agreement with recent experiments, and highlight the factors that influence long-range force transmission, in particular tension-driven alignment of fibers. Our work has important relevance to biological processes including development, cancer metastasis and wound healing, suggesting conditions whereby cells communicate over long distances., Comment: Accepted for publication in the Biophysical Journal