SUMMARY The Arp2/3 complex nucleates branched actin, forming networks involved in lamellipodial protrusion, phagocytosis and cell adhesion. We derived primary bone marrow macrophages lacking Arp2/3 complex (Arpc2−/−) and directly tested its role in macrophage functions. Despite protrusion and actin assembly defects, Arpc2−/− macrophages competently phagocytose via FcR and chemotax towards CSF and CX3CL1. However, CR3 phagocytosis and fibronectin haptotaxis, both integrin-dependent processes, are disrupted. Integrin-responsive actin assembly and αM/β2 integrin localization are compromised in Arpc2−/− cells. Using an in vivo system to observe endogenous monocytes migrating toward full-thickness ear wounds we found that Arpc2−/− monocytes maintain cell speeds and directionality similar to control. Our work reveals that the Arp2/3 complex is not a general requirement for phagocytosis or chemotaxis, but is a critical driver of integrin-dependent processes. We demonstrate further that cells lacking Arp2/3 complex function in vivo remain capable of executing important physiological responses that require rapid directional motility.

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PurposeThis paper examines instructional coaching as a means to support teachers at all levels in primary and secondary schools in implementing new and innovative practices using the Universal Design for Learning (UDL) framework as a design guide.Design/methodology/approachThis mixed-methods study compared the impact of an instructional coaching intervention around the implementation of the UDL framework on educators versus the UDL implementation efforts of educators who did not receive the coaching intervention. Coached participants shared their experiences with the coaching cycle. These qualitative data were collected through teacher interviews, self-assessments, and observations. The data assisted in the interpretation of the quantitative findings from a quasi-experimental pre-test–post-test comparison group design.FindingsThe results of this study revealed positive outcomes for teachers in knowledge and application of UDL, although not at statistically significant levels. The qualitative data collected supported the positive gains and revealed that teachers valued and changed their practices from the use of coaching as they navigated the implementation of UDL in their learning environments.Research limitations/implicationsOne limitation to be noted includes the district site that participated in this study had used the UDL framework for several years and maintained high expectations for teachers to increase their UDL-aligned practices each year. Therefore, all teachers who participated in this study were under the same district evaluative expectations to participate in professional development at some level to increase proficiency with UDL implementation, whereas a district in the beginning stages of UDL implementation might serve as a better gauge of growth. Additionally, the control participants were self-identified and not randomly assigned.Originality/valueThis study is one of the first conducted that investigates the effect of instructional coaching on teachers' increased understanding and implementation of the UDL framework. This study examines instructional coaching as a stand-alone professional development in supporting teachers' use of UDL in design-inclusive classrooms. Written into US law, the UDL framework is a scientifically valid framework that supports teachers with the design of flexible and accessible classrooms for an increasingly diverse population of students.

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