Wavelet Inverse Neutron Scattering Study of Layered Metallic NiC-Ti Composites

Composites are prevalent in high technology devices such as aircraft, computers, automobiles and communications systems. They improve brittleness and provide a lower density which enhances mechanical strength. Electron and light manipulating composites will be used more and more in the future. It is necessary to have a capability of inspecting composites, both to assure production quality and as a baseline for later NDE. In this paper, we present a study using wavelet, inverse neutron optics and the grazing angle neutron spectrometer, GANS, at the Missouri University Research Reactor, MURR

The Cac2 subunit is essential for productive histone binding and nucleosome assembly in CAF-1

Nucleosome assembly following DNA replication controls epigenome maintenance and genome integrity. Chromatin assembly factor 1 (CAF-1) is the histone chaperone responsible for histone (H3-H4)2 deposition following DNA synthesis. Structural and functional details for this chaperone complex and its interaction with histones are slowly emerging. Using hydrogen-deuterium exchange coupled to mass spectrometry, combined with in vitro and in vivo mutagenesis studies, we identified the regions involved in the direct interaction between the yeast CAF-1 subunits, and mapped the CAF-1 domains responsible for H3-H4 binding. The large subunit, Cac1 organizes the assembly of CAF-1. Strikingly, H3-H4 binding is mediated by a composite interface, shaped by Cac1-bound Cac2 and the Cac1 acidic region. Cac2 is indispensable for productive histone binding, while deletion of Cac3 has only moderate effects on H3-H4 binding and nucleosome assembly. These results define direct structural roles for yeast CAF-1 subunits and uncover a previously unknown critical function of the middle subunit in CAF-1.</p