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Jeffrey Sherman

Publications and source records attributed to Jeffrey Sherman.

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Patient foundation model for risk stratification in low-risk overweight patients

Accurate risk stratification in patients with overweight or obesity is critical for guiding preventive care and allocating high-cost therapies such as GLP-1 receptor agonists. We present PatientTPP, a neural temporal point process (TPP) model trained on over 500,000 real-world clinical trajectories to learn patient representations from sequences of diagnoses, labs, and medications. We extend existing TPP modeling approaches to include static and numeric features and incorporate clinical knowledge for event encoding. PatientTPP representations support downstream prediction tasks, including classification of obesity-associated outcomes in low-risk individuals, even for events not explicitly modeled during training. In health economic evaluation, PatientTPP outperformed body mass index in stratifying patients by future cardiovascular-related healthcare costs, identifying higher-risk patients more efficiently. By modeling both the type and timing of clinical events, PatientTPP offers an interpretable, general-purpose foundation for patient risk modeling with direct applications to obesity-related care and cost targeting.

cs.LG

Photonic Generation and Free-Space Distribution of Millimeter Waves for Portable Optical Clocks

Robust and portable optical clocks promise to bring sub-picosecond timing instability to smaller form factors, offering possible performance improvements and new scenarios for positioning and navigation, radar technologies, and experiments probing fundamental physics. However, there are currently limited methods suitable for broadly disseminating the sub-picosecond timing signals or performing frequency comparison of these clocks--particularly over open-air paths. Established microwave time transfer techniques only offer nanosecond level time synchronization, whereas optical techniques have challenging pointing requirements and lack the capability of all-weather operation. In this paper, we explore optically derived millimeter-wave carriers as a time-frequency link for full utilization of the next generation of portable optical clocks. We introduce an architecture that synthesizes 90 GHz millimeter waves with a one second residual instability of 2x10^-15, averaging into the 10^-17 range. In addition, we demonstrate a first-of-its-kind 110 m phase-stabilized free-space frequency comparison link over a millimeter-wave band with a one second instability in the 10^-14 region. Technical and systematic uncertainties are investigated and characterized, providing a foundation for future time and frequency transfer experiments among distributed portable optical clocks.

physics.optics