Amplitude Measurements Research Articles

Abstract 4136762: Association Between Circadian Rest/Activity Rhythms and Incident Dementia in Older Adults: The Atherosclerosis Risk in Communities (ARIC) Study

Introduction: Alterations in circadian rest/activity rhythms (RARs) are common among older adults. RARs can be derived from accelerometry data and are routinely used as proxy measures. Evidence suggests that altered (e.g., fragmented, delayed) RARs may be risk factors for dementia. However, results have been mixed. Using data from the ARIC Study, a community-based cohort, we assessed the association between RARs and incident dementia. Methods: ARIC participants without dementia who wore the Zio XT ECG Patch in 2016-17 for > 3 days were included. RARs were obtained from an accelerometer within the Zio XT ECG Patch and measures of interdaily stability (IS; consistency), intradaily variability (IV; fragmentation), and relative amplitude (RA; strength) were derived. Dementia cases were identified through 2020 using in-person and phone-based cognitive assessments, hospitalization discharge codes, or death certificates. Cox proportional hazards models were used. Results: Of the 2,183 participants (mean [SD] age 79 [4.5] years, 58% female, 24% identified as Black), 176 (8%) developed dementia. Median follow-up time was 3 years and mean Zio XT ECG Patch wear time was 12 days. After multivariable adjustment, lower RA and higher IV were associated with incident dementia (HRs [95% CIs] per 1-SD increment: 0.65 [0.56-0.76], 1.19 [1.02-1.38]). No significant association between IS and dementia was noted; however, there was an interaction by race (p=0.03). Stratified results were not significant, but effect estimates were in opposite directions: (HRs [95% CIs] per 1-SD increment in IS: 0.78 [0.59-1.02] in Black participants and 1.17 [0.96-1.41] in white participants, respectively). No interactions by sex or APOEε4 were noted (p>0.10). Conclusion: In this community-based cohort of older adults, weaker circadian rhythm strength and fragmentation were associated with dementia risk. The association between IS and dementia may differ by race; however, this needs to be further examined in future research. Overall, measures of circadian RARs may be risk factors for dementia. Additional research is warranted to determine whether they can be novel targets for dementia prevention.

Abstract Su203: Development of Bioimpedance for the Measurement of Ventilation During Cardiopulmonary Resuscitation

Introduction: Previous studies have shown that ventilation during cardiopulmonary resuscitation (CPR) produces better patient outcomes. However, research regarding ventilation during the early stages of basic life support CPR is limited. Prior studies showed that thoracic bioimpedance, recorded by the LifePak 12 defibrillator device, can be used to count ventilations with a tidal volume at least 250 mL during CPR. However, the relationship between thoracic bioimpedance and tidal volume has yet to be studied for the Phillips MRx device, excluding a large data set from ventilation studies. Hypothesis: Bioimpedance, measured by the Phillips MRx device has a linear relationship with tidal volume. Aims: To determine the relationship between bioimpedance measured by the Phillips MRx device and tidal volume in males and females. Methods: We conducted the study in a respiratory laboratory at a University Hospital. We asked 27 volunteers to breathe fixed volumes (250 mL, 300 mL, 400 mL, 600 mL, and 800 mL) delivered by a mechanical ventilator while recording bioimpedance simultaneously with the Philips MRx monitor-defibrillator through electrode pads placed on the chest. Six measurements of bioimpedance waveform amplitudes (Ohms) were taken at each tidal volume. Results: Of 27 volunteers, 11 were female and 16 were male. In the female sample set, a linear equation of y=0.003x + 0.837 with an R^2 value of 0.9995 was calculated. In the male sample set, a linear equation of Y=0.0016x +0.1039 with a R^2 value of 0.995 was calculated. Females had a higher median bioimpedance amplitude than men at each tidal volume, and a steeper linear regression slope. At the minimum threshold tidal volume used for counting ventilations (250 mL), the median bioimpedance amplitude was 0.5 (0.4, 0.6) ohm for males and the median bioimpedance amplitude was 0.8 (0.6, 1) ohm for females. Conclusion: As measured and recorded with the Philips MRx monitor-defibrillator, there is a linear relationship between tidal volume and thoracic bioimpedance. The linear models created in this study can be used in future studies to count ventilations during CPR using the Philips MRx device.

Effectiveness of auditory measures in the diagnosis of cochlear synaptopathy and noise-induced hidden hearing loss: a case–control study

Abstract Background Cochlear synaptopathy is a disorder where auditory perceptual impairments, such as speech perception in noise and tinnitus, may not be accurately reflected by audiometric thresholds, even if the audiogram appears normal. It is proposed that the connections between hair cells and the auditory nerve are more susceptible to sound and aging damage than the cochlea’s hair cells. Cochlear synaptopathy can be present in ears with normal audiograms and undamaged hair cells, leading to hidden hearing loss. This study aims to construct electrophysiological and behavioral auditory parameters associated with persons exposed to loudness and having normal audiograms and auditory complaints to identify hidden hearing loss. Results A case–control study was done with forty participants with a documented history of exposure to loud sounds and various auditory complaints, compared to a control group of forty persons who had all been confirmed to have normal audiograms. The chosen behavioral core tests comprised the speech intelligibility in noise test (SPIN), gaps detection in noise (GIN test), and pitch pattern sequence test (PPS). The electrophysiological measures utilized in the study were the auditory brainstem response test (ABR) and electrocochleography (ECochG). The SPIN, PPS, and GIN test results demonstrated statistically significant disparities between the control and case groups. The amplitude ratio of wave I to wave V in ABR and the ratio of EcochG AP to SP demonstrated a statistically significant variance between the two groups. The SPIN test exhibited the highest AUC, signifying its superior diagnostic capability in identifying hidden hearing loss. Conclusion The present study has shown that the SPIN, as a behavioral test, and the EcochG AP amplitude measure, as an electrophysiological test, provide the greatest auditory diagnostic capability for identifying cochlear synaptopathy. Wave I amplitude in the auditory brainstem response (ABR) and the SP/AP ratio in electrocochleography (EcochG) are promising non-behavioral measures of cochlear synaptopathy or hidden hearing loss.

Diagnostic significance of the method of computerized joint vibration analysis in studying the functional state of temporomandibular joints

polyetiology, progressive course and high frequency of relapses is one of the urgent problems of modern dentistry. Different conceptual approaches to the analysis of etiological and pathogenetic aspects of the development of dysfunctional TMJ disorders predetermine the increased interest in the search for highly informative diagnostic methods, especially at the stage of preclinical manifestations.Goal. Evaluation of possibilities of computerized joint vibration analysis method in diagnostics of TMJ functional state.Materials and methods. The study involved 42 people of both sexes with physiologic types of bite, preserved tooth rows, no signs of functional disorders in TMJ and masticatory muscles. The patients underwent clinical dental examination, «Hamburg test», selective grinding of teeth, and measurement of mouth opening amplitude. Joint vibration analysis was performed on the hardware-software complex «BioPAK» with registration of TMJ noise oscillations according to the following indices: «Total Integral», «High Integral», «Low Integral», «Ratio». A flow chart (Ishigaki S. et al., 1993) was used to interpret the numerical values. The functional state of TMJ was de-termined according to the flowchart using numerical parameters in accordance with the classification of TMJ disorders (Wilkes С.Н., 1989).Results. In patients with physiologic occlusion, according to joint vibration analysis, Me «Total Integral» of the right TMJ was 11.7 PaHz, left TMJ – 12.6 PaHz, [Q-25; Q-75] – [9.3; 15.1] PaHz and [10.5; 18.3] PaHz respectively, Me «High Integral» of the right TMJ – 1.3 PaHz, left TMJ – 1.4 PaHz, [Q-25; Q-75] – [1.0; 1.8] PaHz and [1.2; 2.1] PaHz respectively, with no statistically significant (p≤0.05) differences in the studied parameters between the right and left TMJ.Conclusions. The diagnosis of «structurally intact» TMJ, corresponding to stage I of the American classification of TMJ disorders (Wilkes S.N., 1989) in people with physiologic types of bite, is confirmed by the numerical values [Q-25; Q-75] of «Total Integral», «High Integral» (block diagram of S. Ishigaki et al., 1993), the degree of maximum mouth opening [43; 50] mm in the absence of pronounced signs of facial asymmetry.

Correlation models for next-generation amplitude and cumulative intensity measures using artificial neural networks

Various next-generation intensity measures (IMs) have emerged in recent years. For instance, filtered incremental velocity, FIV3, was shown to be efficient in predicting the collapse of structures, or average spectral acceleration, Saavg, shown to be well-correlated with a wide range of response, from initiation of structural damage yielding to structural collapse. Different ground motion models (GMMs) are available to predict the probabilistic distribution of these IMs, given a set of seismological parameters. Nonetheless, a few key correlation models are still missing in the literature, which are elemental for a more holistic approach to ground motion record selection. These models are vital when performing seismic hazard analysis and ground motion record selection using state-of-the-art approaches like the conditional spectrum or generalized conditional intensity measure (GCIM) methods. This study uses a single machine-learning-based generalized ground motion model (GGMM) to estimate all the IMs. The model is based on the Next-Generation Attenuation (NGA)-West2 database and was utilized to quantify the correlations between the residuals. Correlations were calculated for intra- and inter-event residuals, but only those for total residuals are presented here, given their utility. Since the calculation of residuals comes from the same GMM and the same database of ground motions, this produces more consistent correlation coefficients between all IMs. To facilitate the usage of these correlation coefficients, predictive models of the empirical data were developed using machine-learning-based techniques, namely artificial neural networks (ANNs). It was found that FIV3 is strongly correlated with Sa(~1 s) and itself across all periods and has a weak negative correlation with duration at short periods and near-zero correlation for longer periods. Also, a stronger negative correlation between Sa and significant duration was found, compared with other prominent existing models. Direct correlation models between Sa and Saavg are also proposed.

Change in grounding line location on the Antarctic Peninsula measured using a tidal motion offset correlation method

Abstract. The grounding line position of glaciers and ice shelves is an essential observation for the study of the Earth's ice sheets. However, in some locations, such as the Antarctic Peninsula, where many grounding lines have not been mapped since the 1990s, remote sensing of grounding line position remains challenging. Here we present a tidal motion offset correlation (TMOC) method for measuring the grounding line position of tidewater glaciers and ice shelves, based on the correlation between tide amplitude and synthetic aperture radar offset tracking measurements. We apply this method to the Antarctic Peninsula Ice Sheet to automatically delineate a new grounding line position for 2019–2020, with near complete coverage along 9300 km of coastline, updating the 20-year-old record. A comparison of the TMOC grounding line to contemporaneous interferometrically measured grounding line position shows the method has a mean seaward offset compared to interferometry of 185 m and a standard deviation of 295 m. Our results show that over the last 24 years there has been grounding line retreat at a number of fast-flowing ice streams on the Antarctic Peninsula, with the most retreat concentrated in the north-eastern sector, where grounding lines have retreated following the collapse of ice shelves. We observe a maximum grounding line retreat since 1996 of 16.3 ± 0.5 km on Hektoria Glacier, with other notable glaciers retreating by 9.3 ± 0.5, 9.1 ± 0.5 and 3.6 ± 0.5 km. Our results document dynamic change on Antarctic Peninsula glaciers and show the importance of using an updated grounding line location to delineate the boundary between floating and grounded ice.

Measurement of Electron Antineutrino Oscillation Amplitude and Frequency via Neutron Capture on Hydrogen at Daya Bay.

This Letter reports the first measurement of the oscillation amplitude and frequency of reactor antineutrinos at Daya Bay via neutron capture on hydrogen using 1958days of data. With over 3.6million signal candidates, an optimized candidate selection, improved treatment of backgrounds and efficiencies, refined energy calibration, and an energy response model for the capture-on-hydrogen sensitive region, the relative ν[over ¯]_{e} rates and energy spectra variation among the near and far detectors gives sin^{2}2θ_{13}=0.0759_{-0.0049}^{+0.0050} and Δm_{32}^{2}=(2.72_{-0.15}^{+0.14})×10^{-3} eV^{2} assuming the normal neutrino mass ordering, and Δm_{32}^{2}=(-2.83_{-0.14}^{+0.15})×10^{-3} eV^{2} for the inverted neutrino mass ordering. This estimate of sin^{2}2θ_{13} is consistent with and essentially independent from the one obtained using the capture-on-gadolinium sample at Daya Bay. The combination of these two results yields sin^{2}2θ_{13}=0.0833±0.0022, which represents an 8% relative improvement in precision regarding the Daya Bay full 3158-day capture-on-gadolinium result.

Empatica E4 Assessment of Child Physiological Measures of Listening Effort During Remote and In-Person Communication.

Telepractice is a growing service model that delivers aural rehabilitation to deaf and hard-of hearing children via telecommunications technology. Despite known benefits of telepractice, this delivery approach may increase patients' listening effort (LE) characterized as an allocation of cognitive resources toward an auditory task. The study tested techniques for collecting physiological measures of LE in normal-hearing (NH) children during remote (referred to as tele-) and in-person communication using the wearable Empatica E4 wristband. Participants were 10 children (age range: 9-12 years old) who came to two tele- and two in-person weekly sessions, order counterbalanced. During each session, the children heard a short passage read by the clinical provider, completed an auditory passage comprehension task, and self-rated their effort as a part of the larger study. Measures of electrodermal activity and blood volume pulse amplitude were collected from the child E4 wristband. No differences in child subjective, physiological measures of LE or passage comprehension scores were found between in-person sessions and telesessions. However, an effect of treatment duration on subjective and physiological measures of LE was identified. Children self-reported a significant increase in LE over time. However, their physiological measures demonstrated a trend indicating a decrease in LE. A significant association between subjective measures and the passage comprehension task was found suggesting that those children who reported more effort demonstrated a higher proportion of correct responses. The study demonstrated the feasibility of collection of physiological measures of LE in NH children during remote and in-person communication using the E4 wristband. The results suggest that measures of LE are multidimensional and may reflect different sources of, or cognitive responses to, increased listening demand. https://doi.org/10.23641/asha.27122064.

Analysis of difficult flotation mechanisms for coarse low-rank coal: Comparing fluidized-bed and mechanical flotation technologies

Efficient flotation of coarse low-rank coal is essential for enhancing energy utilization in the mineral processing industry. As the beneficiation equipment scales up, the precision of particle size classification before flotation decreases, leading to a higher coarse particle content in the feed, which poses significant challenges to traditional flotation processes. Recent advancements in fluidized bed flotation technology have demonstrated considerable advantages in the flotation of coarse-grained metallic minerals; however, its application to coarse low-rank coal remains relatively unexplored. This study investigates the potential of fluidized bed flotation technology for coarse low-rank coal, employing various analytical methods to elucidate difficult flotation mechanisms. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) were utilized to comprehensively characterize the surface morphology and chemical composition of coal samples. The influence of increasing particle size on flotation performance was systematically assessed through measurements of induction time and critical detachment amplitude. Comparative flotation experiments were conducted to evaluate the efficacy of traditional mechanical flotation against fluidized bed flotation technologies. Results indicate that the presence of cracks and oxygen-containing functional groups on the coal surface significantly enhances hydrophilicity, hindering flotation recovery rates. With increasing particle size, the induction time between particles and bubbles lengthens, while the critical detachment amplitude decreases, weakening the attachment and increasing detachment likelihood. Although high-efficiency collectors enhance coal particle hydrophobicity, they cannot fully mitigate the turbulence disrupting bubble-particle interactions in mechanical flotation. Conversely, fluidized bed flotation effectively minimizes turbulence interference, leading to an approximate 40 % increase in the recovery rate of coarse low-rank coal (0.25–1.00 mm) compared to traditional mechanical flotation. This study presents a novel technological approach for the efficient recovery of coarse low-rank coal, contributing to the clean utilization of low-rank coal resources.

Resonant frequencies of multi-layer building constructions: Estimation by measurement of acceleration amplitudes

The Austrian building regulation requirements for impact sound insulation are based on the weighted standardized impact sound pressure level as single-number specification. In recent years, it has become apparent that not only the single-number specification, but the extended frequency range and frequency characteristics of impact sound insulation of constructions can have noticeable influence on the perceived acoustic performance of a construction. Therefore, the Austrian Classification Standard ÖNORM B 8115-5: 2021-04 includes extended requirements on impact sound insulation. It provides two ways for verification of the sound insulation classes A to C. One way is the verification via the resonance frequency of multi-layer constructions. However, there exist as yet no standardized measurement methods for the estimation of the resonance frequency of multi-layer building constructions. In response, in course of this study a new measurement method for the estimation of the resonance frequencies of multi-layer constructions was developed. For this development acceleration measurements were carried out on both surfaces of particularly double-layer building constructions, that were excited with a rubber hammer. From these measurement results, in conjunction with an analytical model, it was possible to derive a measurement method for estimating the resonant frequency via the frequency characteristics of the acceleration amplitudes.

Fusional Vergence amplitude measurement among students of ISRA School of optometry, Isra University, Karachi campus

Purpose: To determine mean fusional vergence amplitudes FVA and the effect age and gender on FVA. Methodology: A cross sectional descriptive study was conducted among Isra School of optometry, Isra University, Karachi campus students from August 2023 to December 2023. A total of 120 students consisting of 43 males (35.8%) and 77 females (64.1%) were recruited using a convenient sampling technique. Inclusion criteria included subjects with 6/6 vision, no any ocular disease, strabismus and subjects with exophoria or esophoria. The age ranged from 18-27 years. Patients underwent ophthalmic procedure i.e. visual acuity for both distance and near and ophthalmoscopy was performed to check the clarity of the patient’s media. After assessing the ocular media, cover test was used to check the type of phoria. By using horizontal prism bars, Positive Fusion Vergence (PFV) and Negative Fusion Vergence (NFV) were recorded as break, and recovery points at near and distance. All the information was recorded in self-made Performa. Data was analyzed using SPSS. Result: Students were categorized into three age groups: Group 1 (18-21 years), Group 2 (22-24 years), and Group 3 (25-27 years). The data showed negative fusional divergence break-up and recovery points at distance and near, with mean values of 10.06±4.8 Δ and 7.3±4.7 Δ, respectively. Positive fusional convergence break-up and recovery points at distance and near had mean values of 10.95±6.11 Δ and 8.1±5.57 Δ, respectively. The result for negative divergence break and recovery point at distance were significant with p-value of 0.021 and 0.026, respectively Conclusion: This study concluded that the mean fusional vergence amplitudes FVA at near and distance are reduced while distance and near FV revealed no effects of age and gender. However, negative fusional break point and positive fusional recovery point were significantly affected by age.

Tip tilt and focus estimation based on LGS and downlink joint measurements for ground to GEO satellite optical communication link

Achieving high data rates in GEO Feeder optical uplinks faces challenges due to the fading nature of the channel induced by atmospheric turbulence. Adaptive optics pre-compensation using downlink measurements is a solution to mitigate the impact of the turbulence. However, the point-ahead angle anisoplanatism, inherent to the bidirectional link geometry, limits the uplink correction efficiency, leading to persistent signal fades and loss of information onboard the satellite. We recently proposed a new minimum mean square error method that improves the phase estimation at the PAA based on the downlink phase and log amplitude measurements, reducing the anisoplanatism impact on the coupled flux. Alternatively, a laser guide star can be used to measure the phase at the PAA. However, it is currently challenging to retrieve the tip, tilt, and focus modes, whose correction is essential to improve the link quality. In this article, we propose to combine both techniques to estimate the tip, tilt, and focus at the PAA by incorporating the LGS high-order measurements in the MMSE formalism. We develop the associated analytical reconstructor and evaluate the performance of the phase estimation and the gain on the coupled flux statistics aboard the GEO satellite, considering an idealized LGS system. The new estimator is shown to reduce the tip, tilt, and focus error variances by up to 70% of their initial value.

Nerve conduction velocity studies in diabetic peripheral neuropathy involving sural nerve—A meta-analysis

ABSTRACT Introduction: Diabetes mellitus (DM) poses a significant health burden globally, impacting millions due to its metabolic disruptions. Among its complications, diabetic peripheral neuropathy (DPN) is a prevalent concern, affecting sensory and motor nerves. While various diagnostic methods exist, discrepancies persist in prevalence estimates of DPN among diabetic populations. Objective: This meta-analysis aimed to assess the prevalence of DPN in individuals with DM, focusing on sural nerve conduction velocity (NCV) measurements. Additionally, the study explored how different evaluation techniques influenced prevalence estimates. Methods: A systematic literature search was conducted following PRISMA guidelines across multiple databases. Studies reporting sural nerve NCV measurements in diabetic patients were included. Data extraction, quality assessment, and statistical analyses were performed to synthesize findings. Results: Twenty-six studies met the inclusion criteria, providing insights into sural nerve NCV among diabetic individuals. Pooled analysis revealed a mean sural nerve NCV of 42.12 m/s (95% CI: 39.87-44.36), indicative of reduced conduction velocity in diabetic populations. Furthermore, sural nerve amplitude was significantly lower in diabetic individuals, with a pooled mean of 4.68 μV (95% CI: 3.11-6.25). Conclusion: Individuals with type 2 DM exhibit impaired sural nerve function, as evidenced by reduced NCV and amplitude measurements. Timely NCV assessment, alongside glycemic monitoring, is crucial for identifying and managing DPN to prevent further complications. Interventions addressing glycemic control, dietary regulation, and lifestyle modifications are recommended to mitigate the progression of neuropathy in diabetic populations.

3D reconstruction of vocal fold dynamics with laser high-speed videoendoscopy in children.

The objective of this study is to evaluate three-dimensional vertical motion of the superior surface of the vocal folds in vivo in (a) typically developing children as a function of vocal frequency variations and (b) a child with vocal nodules. A custom developed laser endoscope coupled with high-speed videoendoscopy was used to obtain 3D parameters from 2 healthy children, one child with vocal nodules, and 23 vocally healthy adults (females = 11, males = 12). Parameters of amplitude (mm), maximum opening/closing velocity (mm/s), and mean opening/closing velocity (mm/s) were computed for the lateral and vertical vibratory motion along the anterior, middle, and posterior sections of the vocal folds were computed. We provide for the first time, absolute measurements of vertical amplitude and maximum/ mean velocity during the opening and closing phases, in vivo in children. Overall, the vertical motion was larger in vocally normal children compared with the lateral motion, especially along the visible posterior section of the vocal folds and during low pitch phonation. The opening phase dynamics were consistently large along the posterior section in the child with vocal nodules. The study findings establish the feasibility of capturing 3D motion in a clinical setting and provide proof of concept for the application of the proposed 3D laser in the pediatric population. Future large sample size studies are needed to establish the diagnostic potential of examining the closing phase vertical motion to evaluate vibratory development in children with normal voice and investigating the opening phase vertical motion in children with nodules. N/A.

Validation of computer vision technology for analyzing bradykinesia in outpatient clinic videos of people with Parkinson's disease

BackgroundCurrent diagnosis and monitoring of Parkinson's disease (PD) is based on subjective clinical assessments. Objective measures of motor functioning could support clinical acumen. Computer vision (CV) technology is a promising contactless technique but requires further validation. AimTo investigate the performance of CV analysis of clinic-based videos of finger-tapping. Our goals were (i) to distinguish PD from healthy controls (HC), when compared to human raters, (ii) to measure the severity of bradykinesia, and (iii) detect ON/OFF medication state. MethodsVideos of thirty-one persons with PD and forty-nine HC were collected during clinical outpatient visits. Videos were analysed using CV to produce speed, amplitude, rhythm and composite bradykinesia measures. All videos were independently rated by three raters using the Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) and Modified Bradykinesia Rating Scale (MBRS). Twenty video pairs were conducted in ON and OFF states. Classification accuracy for PD/HC state and ON/OFF state were measured using the Area under Receiver Operating characteristic curve and a confusion matrix. CV and clinical measures were correlated using Spearman coefficients. ResultsCV classified disease state with higher accuracy than clinical raters (91 % sensitivity; 97 % specificity). CV measures of bradykinesia correlated significantly with clinical ratings: R = 0.740 for MDS-UPDRS, 0.715 for MBRS speed, 0.714 for amplitude and 0.504 for rhythm. CV classified ON/OFF state as accurately as clinical raters. DiscussionCV can provide a valid, objective and contactless bradykinesia assessment based on clinically collected videos, which offers promise as a new clinical outcome, including in remote settings.

Efficacy and speed of effect after the first dose of aspirin in children with congenital heart disease.

Many paediatric studies report that patients must be established on aspirin therapy for a minimum of 5 days to achieve adequate response. This is not always practical especially in critical settings. Prospective identification of patients that are unresponsive to aspirin sooner could potentially prevent thrombotic events. The aim of this study was to investigate prospectively if the first dose of aspirin is effective in decreasing platelet aggregation, and thromboxane formation and if this can be measured after 2 hours in paediatric cardiology patients. A secondary aim was to identify a cut-off for a novel marker of aspirin responsiveness the maximum amplitude with arachidonic acid, which could potentially dramatically reduce the blood volume required. Third, we aimed to prospectively identify potentially non-responsive patients by spiking a sample of their blood ex vivo with aspirin. The majority (92.3%) of patients were responsive, when measured 2 hours post first dose of aspirin. Non-response or inadequate response (7.7%) can also be identified at 2 hours after taking the first dose of aspirin. Additionally, we have shown a novel way to reduce blood sample volume requirements by measurement of the maximum amplitude with arachidonic acid as a marker of response, particularly for monitoring. These findings of rapid efficacy in the majority of patients offer assurance in a sound, practical way to attending clinicians, patients, and families.

Computational vibration mitigation using phase interpolation in digital holographic microscopy for overlay metrology

Digital holographic microscopy retrieves amplitude and phase information of an image which allows us to computationally correct for imperfections in the imaging optics. However, digital holographic microscopy is an interferometric technique that is inherently sensitive to undesired phase variations between object and reference beam. These phase variations lower the fringe contrast if they are integrated over a finite exposure time which leads to a reduced amplitude of the retrieved image. This results in significant errors in applications that rely on a stable and accurate amplitude measurement, such as optical overlay metrology in the semiconductor industry. We present experimental results on a computational vibration mitigation method for the application of overlay metrology using phase interpolation between a sequence of measured holograms and demonstrate its capability to improve metrology precision in an overlay metrology application that uses digital holographic microscopy.

Absorptive corrections to the electromagnetic form factor in high-energy elastic proton-proton scattering

Recently, it was noted that absorptive corrections to the electromagnetic form factor in high-energy proton-proton scattering are important for the theoretical interpretation of the p↑p and p↑A analyzing power AN(t) measurements with the Hydrogen Jet Target polarimeter (HJET) at RHIC. Here, a concise expression for the absorptive correction was derived within the eikonal approach. The resulting analysis reveals a systematic bias, nearly independent of the beam energy, in the experimental determination of the real-to-imaginary ratio ρ when absorption effects are overlooked in the data analysis. Quantification of this bias, as ρmeas=ρ+(0.036±0.016)bias, was achieved using a Regge fit applied to available proton-proton measurements of ρmeas(s) and σtotmeas(s). Considering the potential impact of such an effect on the experimentally determined AN(t), one may enhance consistency between the HJET and STAR measurements of the hadronic spin-flip amplitude. While the sign of the bias in the value of ρ aligns with the anticipated effective increase in the proton charge radius in pp scattering due to absorption, it amplifies the observed discrepancy between σtotmeas and ρmeas values at s=13 TeV as measured in the TOTEM experiment. Evaluation (using published TOTEM data) of the measured proton-proton dσ/dt dependence on the absorptive corrections indicated that possible soft photon corrections to the hadronic amplitude slope may be essential for such data analysis. Published by the American Physical Society 2024

Solution of Inverse Photoacoustic Problem for Semiconductors via Phase Neural Network

The inverse photoacoustic problem is an ill-posed mathematical physics problem. There are many methods of solving the inverse photoacoustic problem, from parameter reduction to the development of complex regularization algorithms. The idea of this work is that semiconductor physical properties are determined from phase characteristic measurements because phase measurements are more sensitive than amplitude measurements. To solve the inverse photoacoustic problem, the thermoelastic properties and thickness of the sample are estimated using a neural network approach. The neural network was trained on a large database of photoacoustic phases calculated from a theoretical Si n-type model in the range of 20 Hz to 20 kHz, to which random Gaussian noise was applied. It is shown that in solving the inverse photoacoustic problem, high accuracy and precision can be achieved by applying phase measurement and neural network approaches. This study showed that a multi-parameter inverse problem can be solved using phase networks.

Assessing the impact of engine and non-engine urban noises on the calls of urban frogs: a natural experiment

Urban noise can potentially disturb the acoustic signals of animals inhabiting urban areas. Although a wide variety of noises from different sources is common in cities, the impact of non-engine noise on animal calls is less studied. In a natural experiment, we evaluated the effect of different urban noises on the advertisement calls of urban frogs (Eleutherodactylus nitidus) in the metropolitan area of Puebla, Mexico. We recorded and analyzed 672 advertisement calls from 28 male frogs and the corresponding environmental noises from three distinct localities. Our analysis focused on four acoustic properties of the calls: inter-call interval, call duration, dominant frequency, and call amplitude. To standardize the amplitude measurements of sound pressure levels produced by noise and frog calls, we employed a practical approach using a reference signal for calibration. We treated the longitudinal data of different noises occurring before, during, and after advertisement calls as repeated measures within the urban locations. During our samplings, frogs called amidst spontaneous urban noises, including dog barking, fireworks, and vehicle engine sounds. Our results indicate that vehicle engine sounds and dog barking do not cause significant distortions in the calls of these urban frogs. However, we observed slight variations in the dominant frequency of calls, decreasing by 11 Hz, during and after fireworks. Given the observed plasticity of E. nitidus in response to noise, urban noises may not pose a severe problem for this urban frog.