A single cell atlas of frozen shoulder capsule identifies features associated with inflammatory fibrosis resolution

Frozen shoulder is a spontaneously self-resolving chronic inflammatory fibrotic human disease, which distinguishes the condition from most fibrotic diseases that are progressive and irreversible. Using single-cell analysis, we identify pro-inflammatory MERTKlowCD48+ macrophages and MERTK + LYVE1 + MRC1+ macrophages enriched for negative regulators of inflammation which co-exist in frozen shoulder capsule tissues. Micro-cultures of patient-derived cells identify integrin-mediated cell-matrix interactions between MERTK+ macrophages and pro-resolving DKK3+ and POSTN+ fibroblasts, suggesting that matrix remodelling plays a role in frozen shoulder resolution. Cross-tissue analysis reveals a shared gene expression cassette between shoulder capsule MERTK+ macrophages and a respective population enriched in synovial tissues of rheumatoid arthritis patients in disease remission, supporting the concept that MERTK+ macrophages mediate resolution of inflammation and fibrosis. Single-cell transcriptomic profiling and spatial analysis of human foetal shoulder tissues identify MERTK + LYVE1 + MRC1+ macrophages and DKK3+ and POSTN+ fibroblast populations analogous to those in frozen shoulder, suggesting that the template to resolve fibrosis is established during shoulder development. Crosstalk between MerTK+ macrophages and pro-resolving DKK3+ and POSTN+ fibroblasts could facilitate resolution of frozen shoulder, providing a basis for potential therapeutic resolution of persistent fibrotic diseases

Ho‘oponopono: A Radar Calibration CubeSat

To accurately identify and track objects over its territories, the US military must regularly monitor and calibrate its 80+ C-band radar tracking stations distributed around the world. Unfortunately, only two calibration satellites are currently in service, and both have been operating well past their operational lifetimes. Losing either satellite will result in a community of users that no longer has a reliable means of radar performance monitoring and calibration. This paper not only presents the first radar calibration satellite in a CubeSat form factor, but also demonstrates the ability of a university student team to address an urgent operational need at very low cost while simultaneously providing immense educational value. Our CubeSat is named Ho‘oponopono (“to make right” in Hawaiian), an appropriate name for a calibration satellite. The government-furnished payload suite consists of a C-band transponder, GPS unit, and associated antennas, all housed in a 3U CubeSat form factor. Ho‘oponopono was the basis for the University of Hawaii’s participation in the AFOSR University Nanosat-6 Program, a rigorous two-year satellite design and fabrication competition. Ho‘oponopono was also selected by NASA as a participant in its CubeSat Launch Initiative for an upcoming launch

Femtosecond-Iaser-based synthesis of ultrastable microwave signals from optical frequency references

We use femtosecond laser frequency combs to convert optical frequency references to the microwave domain, where we demonstrate the synthesis of lO-GHz signals having a fractional frequency instability of ~ 3 . 5 X 10-15 at a 1-s averaging time, limited by the optical reference. The residual instability and phase noise of the femtosecond-laser-based frequency synthesizers are 6.5X 10-16 at 1 sand - 98 dBc/Hz at a I-Hz offset from the lO-GHz carrier, respectively. The timing jitter of the microwave signals is 3.3 fs

Absolute frequency measurement of the neutral 40Ca optical frequency standard at 657 nm based on microkelvin atoms

We report an absolute frequency measurement of the optical clock transition at 657 nm in 40Ca with a relative uncertainty of 7.5 x 10-15 , one of the most accurate frequency measurements of a neutral atom optical transition to date. The frequency (455986240494135.8 ± 3.4) Hz was measured by stabilizing a diode laser system to a spectroscopic signal derived from an ensemble of 106 atoms cooled in two stages to a temperature of 10 flK. The measurement used a femtosecond-laser-based frequency comb to compare the Ca transition frequency with that of the single-ion 199Hg+ optical frequency standard at NIST. The Hg+ frequency was simultaneously calibrated relative to the NIST Cs fountain via the NIST time scale to yield an absolute value for the Ca transition frequency. The relative fractional instability between the two o~tical standards was 2 x 10-15 for 10 s of averagmg tIme and 2 x 10-1 for 2000 s