Abstract: The present disclosure provides CasX proteins, nucleic acids encoding the CasX proteins, and modified host cells comprising the CasX proteins and/or nucleic acids encoding same. CasX proteins are useful in a variety of applications, which are provided. The present disclosure provides CasX guide RNAs that bind to and provide sequence specificity to the CasX proteins, nucleic acids encoding the CasX guide RNAs, and modified host cells comprising the CasX guide RNAs and/or nucleic acids encoding same. CasX guide RNAs are useful in a variety of applications, which are provided. The present disclosure provides archaeal Cas9 polypeptides and nucleic acids encoding same, as well as their associated archaeal Cas9 guide RNAs and nucleic acids encoding same.

Abstract: A duct connection including a first flange configured to couple with a first duct and a slip fit attached to the first flange. The slip fit has a first portion extending from the first flange substantially perpendicular with respect to the first flange and a second portion extending from the first portion of the slip fit substantially parallel with respect to the first flange. The slip fit and the first flange form a receiving area structured such that a portion of a corresponding flange included on a second duct can slide into the receiving area.