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Abstract We explore an interacting dark matter (IDM) model that allows for a fraction of dark matter (DM) to undergo velocity-independent scattering with baryons. In this scenario, structure on small scales is suppressed relative to the cold DM scenario. Using the effective field theory of large-scale structure, we perform the first systematic analysis of BOSS full-shape galaxy clustering data for the IDM scenario, and we find that this model ameliorates theS₈tension between large-scale structure and Planck data. Adding theS₈prior from the Dark Energy Survey (DES) to our analysis further leads to a mild ∼3σpreference for a nonvanishing DM–baryon scattering cross section, assuming ∼10% of DM is interacting and has a particle mass of 1 MeV. This result produces a modest ∼20% suppression of the linear power atk≲ 1hMpc⁻¹, consistent with other small-scale structure observations. Similar scale-dependent power suppression was previously shown to have the potential to resolveS₈tension between cosmological data sets. The validity of the specific IDM model explored here will be critically tested with upcoming galaxy surveys at the interaction level needed to alleviate theS₈tension. 

How knotted proteins fold has remained controversial since the identification of deeply knotted proteins nearly two decades ago. Both computational and experimental approaches have been used to investigate protein knot formation. Motivated by the computer simulations of Bölinger et al. [Bölinger D, et al. (2010)PLoS Comput Biol6:e1000731] for the folding of the $6_1$-knotted α-haloacid dehalogenase (DehI) protein, we introduce a topological description of knot folding that could describe pathways for the formation of all currently known protein knot types and predicts knot types that might be identified in the future. We analyze fingerprint data from crystal structures of protein knots as evidence that particular protein knots may fold according to specific pathways from our theory. Our results confirm Taylor’s twisted hairpin theory of knot folding for the $3_1$-knotted proteins and the $4_1$-knotted ketol-acid reductoisomerases and present alternative folding mechanisms for the $4_1$-knotted phytochromes and the $5_2$- and $6_1$-knotted proteins.