Lineage-specific amino acids define functional attributes of the protomer-protomer interfaces for the Rad51 and Dmc1 recombinases.

Most eukaryotes possess two Rad51/RecA family DNA recombinases that are thought to have arisen from an ancient gene duplication event: Rad51, which is expressed in both mitosis and meiosis; and Dmc1, which is only expressed in meiosis. To explore the evolutionary relationship between these recombinases, here, we present high-resolution CryoEM structures of Rad51 filaments and Dmc1 filaments bound to ssDNA, which reveal a pair of stacked interfacial aromatic amino acid residues that are nearly universally conserved in Rad51 but are absent from Dmc1. We use a combination of bioinformatics, genetic analysis of natural sequence variation, and deep mutational analysis to probe the functionally tolerated sequence space for these stacked aromatic residues.

Psychosocial Impact of Suspected Xylazine-Associated Skin Wounds Among People Using Fentanyl, Philadelphia, 2022 to 2023.

Background: The United States opioid crisis has been worsened by the emergence of fentanyl adulterated or associated with the veterinary sedative xylazine. Designated by the White House as an "emerging threat to the US" in 2023, xylazine use is associated with severe skin wounds.

Methods: This research explored beliefs, concerns, and treatment behaviors for skin wounds among 93 participants recruited outside of a Philadelphia, Pennsylvania harm reduction agency who reported past-6-month history of a skin wound via a cross-sectional survey administered August-September 2022 (group 1;  = 33).

Testing the relationship between preferences for infant-directed speech and vocabulary development: A multi-lab study.

From early on, infants show a preference for infant-directed speech (IDS) over adult-directed speech (ADS), and exposure to IDS has been correlated with language outcome measures such as vocabulary. The present multi-laboratory study explores this issue by investigating whether there is a link between early preference for IDS and later vocabulary size. Infants' preference for IDS was tested as part of the ManyBabies 1 project, and follow-up CDI data were collected from a subsample of this dataset at 18 and 24 months.

Elucidating nanostructural organization and photonic properties of butterfly wing scales using hyperspectral microscopy.

Biophotonic nanostructures in butterfly wing scales remain fascinating examples of biological functional materials, with intriguing open questions with regard to formation and evolutionary function. One particularly interesting butterfly species, (Lycaenidae: Theclinae), develops wing scales that contain three-dimensional photonic crystals that closely resemble a single gyroid geometry. Unlike most other gyroid-forming butterflies, develops discrete gyroid crystallites with a pronounced size gradient hinting at a developmental sequence frozen in time.