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Biomolecular condensates are increasingly recognized as key regulators of chromatin organization, yet how their formation and properties arise from protein sequences remains incompletely understood. Cross-species comparisons can reveal both conserved functions and significant evolutionary differences. Here, we integrate in vitro reconstitution, molecular dynamics simulations, and cell-based assays to examine how Drosophila and human variants of Polyhomeotic (Ph)—a subunit of the PRC1 chromatin regulatory complex— drive condensate formation through their sterile alpha motif (SAM) oligomerization domains. We identify divergent interactions between SAM and the disordered linker connecting it to the rest of Ph. These interactions enhance oligomerization and modulate both the formation and properties of reconstituted condensates. Oligomerization influences condensate dynamics but minimally impacts condensate formation. Linker-SAM interactions also affect condensate formation in Drosophila and human cells and growth in Drosophila imaginal discs. Our findings show how evolutionary changes in disordered linkers can finetune condensate properties, providing insights into sequence-function relationships. 

Droplet breakup is a complex process involving interfacial instability and transport across a wide range of length and time scales. Fundamental studies of shock-droplet interaction provide valuable insight into the physical processes behind droplet breakup at high Weber and Reynolds numbers. Many high-speed applications such as liquid-fueled detonations and hypersonic hydrometeor impacts involve small droplets under high Weber numbers and/or unsteady conditions. The work presented here will explore deformation and hydrodynamics leading to breakup for small droplets (< 200μm) at high Weber numbers. An experimental campaign is presented whereby droplet deformation is measured at high temporal and spatial resolution. Small rapidly evaporating droplets (≈ 150μm) at Weber numbers in excess of 1000 are studied. High-speed (sub-microsecond image times) shadowgraphy provides measurement of the droplet deformation rate, acceleration, and breakup timing. DNS results are presented to further explore deformation rates for smaller droplets (≈ 5μm). Deformation rates are compared with existing models for both experimental and simulation cases. This ongoing work will provide additional data from which our understanding of complex droplet phenomena may be advanced and applied to physical systems. 

Atherosclerosis is a prominent cause of coronary artery disease and broader cardiovascular diseases, the leading cause of death worldwide. Angioplasty and stenting is a common treatment, but in-stent restenosis, where the artery re-narrows, is a frequent complication. Restenosis is detected through invasive procedures and is not currently monitored frequently for patients. Here, we report an implantable vascular bioelectronic device using a newly developed miniaturized strain sensor via microneedle printing methods. A capillary-based printing system achieves high-resolution patterning of a soft, capacitive strain sensor. Ink and printing parameters are evaluated to create a fully printed sensor, while sensor design and sensing mechanism are studied to enhance sensitivity and minimize sensor size. The sensor is integrated with a wireless vascular stent, offering a biocompatible, battery-free, wireless monitoring system compatible with conventional catheterization procedures. The vascular sensing system is demonstrated in an artery model for monitoring restenosis progression. Collectively, the artery implantable bioelectronic system shows the potential for wireless, real-time monitoring of various cardiovascular diseases and stent-integrated sensing/treatments. 

Although it is well known that motivational and cognitive resources influence secondary teachers’ instructional quality, less is known about the tertiary instructional factors that influence secondary teachers’ development of these resources. To address this gap, we report on factors that prospective secondary teachers attribute to their learning. We draw on survey responses of 70 prospective secondary teachers enrolled in mathematics courses for teachers using Mathematics of Doing, Understanding, Learning, and Educating for Secondary Schools (MODULE(S2)) materials in one of four content areas. We triangulate response themes with data from 300 prospective secondary teachers on their perceptions of instructional practices used in a mathematics course for teachers using the same suite of materials. Then, we compare these themes with literature documenting implementation of mathematics curricula in these courses. We argue that coordinating mathematics content, applications of mathematics to teaching practices, and tertiary instructional practices are key to success of these mathematics courses. 

Abstract Volumetric muscle loss (VML) results in permanent functional deficits and remains a substantial regenerative medicine challenge. A coordinated immune response is crucial for timely myofiber regeneration, however the immune response following VML has yet to be fully characterized. Here, we leveraged dimensionality reduction and pseudo-time analysis techniques to elucidate the cellular players underlying a functional or pathological outcome as a result of subcritical injury or critical VML in the murine quadriceps, respectively. We found that critical VML resulted in a sustained presence of M2-like and CD206^hiLy6C^hi‘hybrid’ macrophages whereas subcritical defects resolved these populations. Notably, the retained M2-like macrophages from critical VML injuries presented with aberrant cytokine production which may contribute to fibrogenesis, as indicated by their co-localization with fibroadipogenic progenitors (FAPs) in areas of collagen deposition within the defect. Furthermore, several T cell subpopulations were significantly elevated in critical VML compared to subcritical injuries. These results demonstrate a dysregulated immune response in critical VML that is unable to fully resolve the chronic inflammatory state and transition to a pro-regenerative microenvironment within the first week after injury. These data provide important insights into potential therapeutic strategies which could reduce the immune cell burden and pro-fibrotic signaling characteristic of VML. 

We study the Brillouin instability and the transverse mode instability in a combined computational model for fiber amplifiers. We find the optimal core diameter, which leads to the highest power threshold and output power. 

Vertical transmission of bacterial endosymbionts is accompanied by virtually irreversible gene loss that results in a progressive reduction in genome size. While the evolutionary processes of genome reduction have been well described in some terrestrial symbioses, they are less understood in marine systems where vertical transmission is rarely observed. The association between deep-sea vesicomyid clams and chemosynthetic Gammaproteobacteria is one example of maternally inherited symbioses in the ocean. Here, we assessed the contributions of drift, recombination and selection to genome evolution in two extant vesicomyid symbiont clades by comparing 15 representative symbiont genomes (1.017–1.586 Mb) to those of closely related bacteria and the hosts' mitochondria. Our analyses suggest that drift is a significant force driving genome evolution in vesicomyid symbionts, though selection and interspecific recombination appear to be critical for maintaining symbiont functional integrity and creating divergent patterns of gene conservation. Notably, the two symbiont clades possess putative functional differences in sulfide physiology, anaerobic respiration and dependency on environmental vitamin B12, which probably reflect adaptations to different ecological habitats available to each symbiont group. Overall, these results contribute to our understanding of the eco-evolutionary processes shaping reductive genome evolution in vertically transmitted symbioses.