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Abstract This paper, the second in a two‐part series, outlines a low‐cost, open‐source, pseudo‐randomization approach for measuring cutaneous reflexes during human walking. The protocol guides users through integrating an Arduino Uno microcontroller, a VICON data acquisition system, and an electrical stimulation device. A custom code was developed in C++, and steps are provided to guide users in downloading and integrating it with an Arduino. This setup provides researchers the ability to define key experimental parameters such as the number of gait cycles to include in quantifying the average time of the subject's walking gait cycle, the number of bins to partition the human walking gait cycle, and the number of stimuli per bin—all while maintaining real‐time stimulation capability. During a walking trial, the system is designed to (1) deliver stimuli pseudo‐randomly using instances when the foot makes initial contact with the treadmill surface and (2) deliver an even distribution of stimuli across all bins. Real‐time feedback mechanisms and data monitoring are enabled via an integrated Arduino and VICON framework, allowing researchers to conduct controlled, repeatable experiments that aim to measure cutaneous reflexes during human walking. This protocol provides a flexible and accessible solution for researchers aiming to investigate phase‐dependent modulation of reflexes during normal and perturbed walking conditions. Its modularity and integration with existing motion capture systems make it a powerful tool for both basic and clinical research within the fields of neuroscience, biomechanics, and gait rehabilitation. © 2025 Wiley Periodicals LLC. Basic Protocol 1: Integrating Arduino to VICON data acquisition and stimulator Basic Protocol 2: Downloading and running pseudo‐randomized Arduino code 

Abstract This paper, the first in a two‐part series focused on measuring cutaneous reflexes during human walking, provides a detailed step‐by‐step methodology for reliably eliciting cutaneous reflexes during human treadmill walking. The procedure addresses the technical challenges of eliciting reflexes from cutaneous nerves in a consistent and reproducible manner throughout the gait cycle. Building on approaches used in previous studies, we integrate practical guidance on equipment setup, electrode placement, configuration of a foot‐sensitive resistor for quantifying gait cycle parameters, and reflex measurements to enable successful implementation across laboratories with varying levels of expertise. The custom development and use of a pseudorandomized stimulation approach is a novel feature of our broader methodology and is described in detail in the second paper. The present protocol focuses on the experimental setup required to obtain high‐quality reflex measurements during walking, thereby providing the basis for advanced stimulation paradigms in human sensorimotor research. © 2025 Wiley Periodicals LLC. Basic Protocol: Evoking cutaneous reflexes during human walking using a pseudorandomized approach 

Abstract In this paper, we explore the power of the cosmic microwave background (CMB) polarization ( E -mode) data to corroborate four potential anomalies in CMB temperature data: the lack of large angular-scale correlations, the alignment of the quadrupole and octupole (Q–O), the point-parity asymmetry, and the hemispherical power asymmetry. We use CMB simulations with noise representative of three experiments—the Planck satellite, the Cosmology Large Angular Scale Surveyor (CLASS), and the LiteBIRD satellite—to test how current and future data constrain the anomalies. We find the correlation coefficients ρ between temperature and E -mode estimators to be less than 0.1, except for the point-parity asymmetry ( ρ = 0.17 for cosmic-variance-limited simulations), confirming that E -modes provide a check on the anomalies that is largely independent of temperature data. Compared to Planck component-separated CMB data ( smica ), the putative LiteBIRD survey would reduce errors on E -mode anomaly estimators by factors of ∼3 for hemispherical power asymmetry and point-parity asymmetry, and by ∼26 for lack of large-scale correlation. The improvement in Q–O alignment is not obvious due to large cosmic variance, but we found the ability to pin down the estimator value will be improved by a factor ≳100. Improvements with CLASS are intermediate to these. 

The Cosmology Large Angular Scale Surveyor (CLASS) is a telescope array observing the Cosmic Microwave Background (CMB) at frequency bands centered near 40, 90, 150, and 220 GHz. CLASS measures the CMB polarization on the largest angular scales to constrain the inflationary tensor-to-scalar ratio and the optical depth due to reionization. To achieve the long time-scale stability necessary for this measurement from the ground, CLASS utilizes a front-end, variable-delay polarization modulator on each telescope. Here we report on the improvements in stability afforded by front-end modulation using data across all four CLASS frequencies. Across one month of modulated linear polarization data in 2021, CLASS achieved median knee frequencies of 9.1, 29.1, 20.4, and 36.4 mHz for the 40, 90, 150, and 220 GHz observing bands. The knee frequencies are approximately an order of magnitude lower than achieved via CLASS pair-differencing orthogonal detector pairs without modulation. 

The Cosmology Large Angular Scale Surveyor (CLASS) is a polarization-sensitive telescope array located at an altitude of 5,200 m in the Chilean Atacama Desert. CLASS is designed to measure "E-mode" (even parity) and "B-mode" (odd parity) polarization patterns in the Cosmic Microwave Background (CMB) over large angular scales with the aim of improving our understanding of inflation, reionization, and dark matter. CLASS is currently observing with three telescopes covering four frequency bands: one at 40 GHz (Q); one at 90 GHz (W1); and one dichroic system at 150/220 GHz (G). In these proceedings, we discuss the updated design and in-lab characterization of new 90 GHz detectors. The new detectors include design changes to the transition-edge sensor (TES) bolometer architecture, which aim to improve stability and optical efficiency. We assembled and tested four new detector wafers, to replace four modules of the W1 focal plane. These detectors were installed into the W1 telescope, and will achieve first light in the austral winter of 2022. We present electrothermal parameters and bandpass measurements from in-lab dark and optical testing. From in-lab dark tests, we also measure a median NEP of 12.3 aW√ s across all four wafers about the CLASS signal band, which is below the expected photon NEP of 32 aW√ s from the field. We therefore expect the new detectors to be photon noise limited. 

Abstract The Cosmology Large Angular Scale Surveyor (CLASS) is a telescope array that observes the cosmic microwave background over 75% of the sky from the Atacama Desert, Chile, at frequency bands centered near 40, 90, 150, and 220 GHz. This paper describes the CLASS data pipeline and maps for 40 GHz observations conducted from 2016 August to 2022 May. We demonstrate how well the CLASS survey strategy, with rapid (∼10 Hz) front-end modulation, recovers the large-scale Galactic polarization signal from the ground: the mapping transfer function recovers ∼67% (85%) ofEEandBB(VV) power atℓ= 20 and ∼35% (47%) atℓ= 10. We present linear and circular polarization maps over 75% of the sky. Simulations based on the data imply the maps have a white noise level of $110\mu \mathrm{K}\mathrm{arcmin}$and correlated noise component rising at low-ℓasℓ^−2.4. The transfer-function-corrected low-ℓcomponent is comparable to the white noise at the angular knee frequencies ofℓ≈ 18 (linear polarization) andℓ≈ 12 (circular polarization). Finally, we present simulations of the level at which expected sources of systematic error bias the measurements, finding subpercent bias for the Λ cold dark matterEEpower spectra. Bias fromE-to-Bleakage due to the data reduction pipeline and polarization angle uncertainty approaches the expected level for anr= 0.01BBpower spectrum. Improvements to the instrument calibration and the data pipeline will decrease this bias. 

Abstract The Cosmology Large Angular Scale Surveyor (CLASS) observes the polarized cosmic microwave background (CMB) over the angular scales of 1° ≲ θ ≤ 90° with the aim of characterizing primordial gravitational waves and cosmic reionization. We report on the on-sky performance of the CLASS Q -band (40 GHz), W -band (90 GHz), and dichroic G -band (150/220 GHz) receivers that have been operational at the CLASS site in the Atacama desert since 2016 June, 2018 May, and 2019 September, respectively. We show that the noise-equivalent power measured by the detectors matches the expected noise model based on on-sky optical loading and lab-measured detector parameters. Using Moon, Venus, and Jupiter observations, we obtain power to antenna temperature calibrations and optical efficiencies for the telescopes. From the CMB survey data, we compute instantaneous array noise-equivalent-temperature sensitivities of 22, 19, 23, and 71 μ K cmb s for the 40, 90, 150, and 220 GHz frequency bands, respectively. These noise temperatures refer to white noise amplitudes, which contribute to sky maps at all angular scales. Future papers will assess additional noise sources impacting larger angular scales.