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Mytilus edulisis a commercially and ecologically important species found along the east coast of the United States. Ecologically,M.edulisimproves water quality through filtration feeding and provides habitat formation and coastal protection through reef formation. Like many marine calcifiers, ocean warming, and acidification are a growing threat to these organisms—impacting their morphology and function. Museum collections are useful in assessing long-term environmental impacts on organisms in a natural multi-stressor environment, where acclimation and adaptation can be considered. Using the American Museum of Natural History collections ranging from the early 1900s until now, we show that shell porosity changes through time. Shells collected today are significantly more porous than shells collected in the 1960s and, at some sites, than shells collected from the early 1900s. The disparity between porosity changes matches well with the warming that occurred over the last 130 years in the north Atlantic suggesting that warming is causing porosity changes. However, more work is required to discern local environmental impacts and to fully identify porosity drivers. Since, porosity is known to affect structural integrity, porosity increasing through time could have negative consequences for mussel reef structural integrity and hence habitat formation and storm defenses. 

In this paper, we explore the stories teachers tell as they study and grapple with culturally responsive education in their science classrooms. This qualitative case study focuses primarily on “Stories from the Field”, a conversational routine at each professional learning group meeting where teachers shared observations, thoughts, and insights about their classroom, instruction, and school settings in the context of culturally responsive education. We found that teachers’ stories from the first year of the group surfaced themes of navigating systemic constraints and supports, connecting through science, and sensemaking and learning from developing and analyzing strategies for culturally responsive science teaching. This helped to shine a light on a critical aspect of our work exploring culturally responsive education and what that might look like in science classrooms through the stories that teachers tell. Our findings suggest that storytelling is a rich, descriptive vehicle for exploration and sensemaking amongst teachers in a professional learning group and an underused resource in studying culturally responsive education, especially in science. 

Teacher education programs are increasingly taking up commitments to prepare new teachers for equitable teaching. Despite best intentions, programs feel challenged to help candidates translate these commitments into classroom practice. Using a context-specific teacher education framework, we conducted a mixed-methods study of seven urban-focused programs to understand how they targeted preparation for urban contexts. We found that while programs offer multiple opportunities to learn about content embedded in context, fewer opportunities exist for candidates to practice in context, and that faculty play a critical bridging role in designing practice opportunities that are informed by program vision. 

Context. The degree of coupling between the gas and the magnetic field during the collapse of a core and the subsequent formation of a disk depends on the assumed dust size distribution. Aims. We study the impact of grain–grain coagulation on the evolution of magnetohydrodynamic (MHD) resistivities during the collapse of a prestellar core. Methods. We use a 1D model to follow the evolution of the dust size distribution, out-of-equilibrium ionisation state, and gas chemistry during the collapse of a prestellar core. To compute the grain–grain collisional rate, we consider models for both random and systematic, size-dependent, velocities. We include grain growth through grain–grain coagulation and ice accretion, but ignore grain fragmentation. Results. Starting with a Mathis-Rumpl-Nordsieck (MRN) size distribution (Mathis et al. 1977, ApJ, 217, 425), we find that coagulation in grain–grain collisions generated by hydrodynamical turbulence is not efficient at removing the smallest grains and, as a consequence, does not have a large effect on the evolution of the Hall and ambipolar diffusion MHD resistivities, which still drop significantly during the collapse like in models without coagulation. The inclusion of systematic velocities, possibly induced by the presence of ambipolar diffusion, increases the coagulation rate between small and large grains, removing small grains earlier in the collapse and therefore limiting the drop in the Hall and ambipolar diffusion resistivities. At intermediate densities ( n H ~ 10 8 cm −3 ), the Hall and ambipolar diffusion resistivities are found to be higher by 1 to 2 orders of magnitude in models with coagulation than in models where coagulation is ignored, and also higher than in a toy model without coagulation where all grains smaller than 0.1 μ m would have been removed in the parent cloud before the collapse. Conclusions. When grain drift velocities induced by ambipolar diffusion are included, dust coagulation happening during the collapse of a prestellar core starting from an initial MRN dust size distribution appears to be efficient enough to increase the MHD resistivities to the values necessary to strongly modify the magnetically regulated formation of a planet-forming disk. A consistent treatment of the competition between fragmentation and coagulation is, however, necessary before reaching firm conclusions.