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The microwave SQUID multiplexer (umux) has enabled higher bandwidth or higher channel counts across a wide range of experiments in particle physics, astronomy, and spectroscopy. The large multiplexing factor coupled with recent commercial availability of microwave components and warm electronics readout systems make it an attractive candidate for systems requiring large cryogenic detector counts. Since the multiplexer is considered for both bolometric and calorimetric applications across several orders of magnitude of signal frequencies, understanding the bandwidth of the device and its interaction with readout electronics is key to appropriately designing and engineering systems. Here we discuss several important factors contributing to the bandwidth properties of umux systems, including the intrinsic device bandwidth, interactions with warm electronics readout systems, and aliasing. We present simulations and measurements of umux devices coupled with SLAC Microresonator RF (SMuRF) tone-tracking electronics and discuss several implications for future experimental design., Comment: Proceedings for Low Temperature Physics 2021, accepted for publication in Journal of Low Temperature Physics. 8 pages (including references), 5 figures

The biological degradation of acrylonitrile–dimethylaminoethyl methacrylate and acrylonitrile–acrylic acid copolymers has been studied by evaluating copolymer films in a continuous in vitro rumen system. The copolymer films were examined before and after modification by reaction with ethylene oxide gas. The degradation of the acrylonitrile–dimethylaminoethyl methacrylate copolymer followed a pattern similar to that occurring on thermal degradation. Modification by reaction with ethylene oxide gas, which induces CN conjugation, did not improve the resistance to degradation. The acrylonitrile–acrylic acid copolymer films disintegrated, but on prior modification by reaction with ethylene oxide they remained virtually unaltered. Modification of the acrylonitrile–acrylic acid copolymer results in crosslinking with an absence of CN conjugation, leading to improved resistance to biological degradation.

The spectrum, pathogenesis, and changing bacteriology of spontaneous abdominal aortic infections is presented. The classic presentation includes fever, positive blood cultures, and a pulsatile abdominal mass. However, most essential in the preoperative diagnosis is having a high index of suspicion. The bacteriologic spectrum is changing, with Salmonella now being the most common organism cultured. Principles of management include aggressive antibiotic therapy, excision of infected tissue, and extra-anatomic bypass. Long-term follow-up for late complications is important. With early recognition and aggressive combined medical and surgical management, increasing numbers of survivors are being reported.