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Objective: To validate externally the QUiPP App v.2 algorithms in an independent cohort of high‐risk asymptomatic women attending a preterm birth (PTB) surveillance clinic in Ireland. Methods: This was a retrospective, single‐center, observational study assessing discrimination and calibration of the QUiPP App v.2 at six predetermined clinical timepoints (PTB at < 30, < 34 and < 37 weeks of pregnancy and PTB within 1, 2 and 4 weeks of testing). Discrimination was assessed by estimating the area under the receiver‐operating‐characteristics curve (AUC) and sensitivity at fixed false‐positive rates of 5%, 10% and 20%. Model calibration was assessed to evaluate the concordance between expected and observed outcomes. P‐values < 0.05 were considered statistically significant. No adjustments for treatment effects were made. Results: Overall, 762 women with 1660 PTB surveillance clinic visits using the QUiPP App v.2 between 2019 and 2022 were analyzed. The study population included 142 (18.6%) patients who later experienced PTB. The QuiPP App's performance in the prediction of short‐term outcomes, such as birth within 1 week (AUC, 0.866 (95% CI, 0.755–0.955)), 2 weeks (AUC, 0.721 (95% CI, 0.569–0.854)) and 4 weeks (AUC, 0.775 (95% CI, 0.699–0.842)), and delivery at < 30 weeks (AUC, 0.747 (95% CI, 0.613–0.865)), was superior to its ability to predict longer‐term outcomes (PTB at < 37 weeks: AUC, 0.631 (95% CI, 0.596–0.668)). Calibration was generally good for low‐risk results, as the predicted risk in these patients tended to match the observed incidence. However, in women deemed to be at greater risk of PTB, the predicted probability superseded the observed incidence of PTB. Conclusions: The QUiPP App v.2 accurately discriminates women who are at short‐term risk of PTB. A 'treatment paradox' may influence calibration in high‐risk women. Further research is needed to ascertain if QuiPP treatment thresholds can be safely adjusted in women receiving prophylactic treatment to prevent PTB, and whether this improves the outcome. © 2024 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology. [ABSTRACT FROM AUTHOR]

Objective: Evaluate spectral scaling properties of scalp electroencephalogram (EEG) and electromyogram (EMG), optimal spacing of electrodes, and strategies for mitigating EMG. Methods: EEG was recorded referentially from 9 subjects with a 64 channel linear array (electrodes 3 mm apart) placed parasagittally or transversely on forehead or occiput, at rest with eyes open or closed, or with deliberate EMG. Temporal (PSDt) and spatial (PSDx) power spectral densities were calculated with one-dimensional fast Fourier transform (FFT) for comparison with earlier analyses of intracranial EEG. Results: Scaling of PSDt from scalp resembled that from pia: near-linear decrease in log power with increasing log frequency (1/f(alpha)). Scalp PSDx decreased non-linearly and more rapidly than PSDx from pia. Peaks in PSDt (especially 4-12 Hz) and PSDx (especially 0.1-0.4 cycles/cm) revealed departures from 1/f(alpha). EMG power in PSDt was more "white" than 1/f(alpha). Conclusions: Smearing by dura-skull-scalp distorts PSDx more than PSDt of scalp EEG from 1/f(alpha) scaling at the pia. Spatial spectral peaks suggest that optimal scalp electrode spacing might be similar to I cm to capture non-local EEG components having the texture of gyri. Mitigation of EMG by filtering is unsatisfactory. A criterion for measuring EMG may support biofeedback for training subjects to reduce their EMG. Significance: High-density recording and log-log spectral display of EEG provide a foundation for holist studies of global human brain function, as an alternative to network approaches that decompose EEG into localized, modular signals for correlation and coherence. (C) 2003 International Federation of Clinical Neurophysiology. Published by Elsevier Science Ireland Ltd. All rights reserved.

A model named “KIII” of the olfactory system con-tains an array of 64 coupled oscillators simulating the olfactorybulb (OB), with negative and positive feedback through low-passfilter lines from single oscillators simulating the anterior olfactorynucleus (AON) and prepyriform cortex (PC). It is implementedin C to run on Macintosh, IBM, or UNIX platforms. The outputcan be set by parameter optimization to point, limit cycle,quasi-periodic, or aperiodic (presumably chaotic) attractors. Thefirst three classes of solutions are stable under variations ofparameters and perturbations by input, but they are biologicallyunrealistic. Chaotic solutions simulate the properties of time-dependent densities of olfactory action potentials and EEG’s,but they transit into the basins of point, limit cycle, or quasi-periodic attractors after only a few seconds of simulated run time.Despite use of double precision arithmetic giving 64-bit words, theKIII model is exquisitely sensitive to changes in the terminal bitof parameters and inputs. The global stability decreases as thenumber of coupled oscillators in the OB is increased, indicatingthat attractor crowding reduces the size of basins in the model to???the size of the digitizing step (??? ). Chaotic solutions havingbiological verisimilitude are robustly stabilized by introducing low-level, additive noise from a random number generator at two biologically determined points: rectified, spatially incoherent noise on each receptor input line, and spatially coherent noise to the AON, a global control point receiving centrifugal inputs from various parts of the forebrain. Methods are presented for evaluating global stability in the high dimensional system from measurements of multiple chaotic outputs. Ranges of stability are shown for variations of connection weights (gains) in the KIII model. The system is devised for pattern classification.