Search for: All records

The Domain Name System (DNS) is a critical piece of Internet infrastructure with remarkably complex properties and uses, and accordingly has been extensively studied. In this study we contribute to that body of work by organizing and analyzing records maintained within the DNS as a bipartite graph. We find that relating names and addresses in this way uncovers a surprisingly rich structure. In order to characterize that structure, we introduce a new graph decomposition for DNS name-to-IP mappings, which we term elemental decomposition. In particular, we argue that (approximately) decomposing this graph into bicliques — maximally connected components — exposes this rich structure. We utilize large-scale censuses of the DNS to investigate the characteristics of the resulting decomposition, and illustrate how the exposed structure sheds new light on a number of questions about how the DNS is used in practice and suggests several new directions for future research. 

Patterning biomolecules in synthetic hydrogels offers routes to visualize and learn how spatially‐encoded cues modulate cell behavior (e.g., proliferation, differentiation, migration, and apoptosis). However, investigating the role of multiple, spatially defined biochemical cues within a single hydrogel matrix remains challenging because of the limited number of orthogonal bioconjugation reactions available for patterning. Herein, a method to pattern multiple oligonucleotide sequences in hydrogels using thiol‐yne photochemistry is introduced. Rapid hydrogel photopatterning of hydrogels with micron resolution DNA features (≈1.5 µm) and control over DNA density are achieved over centimeter‐scale areas using mask‐free digital photolithography. Sequence‐specific DNA interactions are then used to reversibly tether biomolecules to patterned regions, demonstrating chemical control over individual patterned domains. Last, localized cell signaling is shown using patterned protein–DNA conjugates to selectively activate cells on patterned areas. Overall, this work introduces a synthetic method to achieve multiplexed micron resolution patterns of biomolecules onto hydrogel scaffolds, providing a platform to study complex spatially‐encoded cellular signaling environments.