Sensitivity to a Break in Interaural Correlation in Frequency-Gliding Noises

This study was to investigate whether human listeners are able to detect a binaurally uncorrelated arbitrary-noise fragment embedded in binaurally identical arbitrary-noise markers [a break in correlation, break in interaural correlation (BIAC)] in either frequency-constant (frequency-steady) or frequency-varied (unidirectionally frequency gliding) noise. Ten participants with normal hearing were tested in Experiment 1 for up-gliding, down-gliding, and frequency-steady noises. Twenty-one participants with normal hearing were tested in Experiment 2a for both up-gliding and frequency-steady noises. Another nineteen participants with normal hearing were tested in Experiment 2b for both down-gliding and frequency-steady noises. Listeners were able to detect a BIAC in the frequency-steady noise (center frequency = 400 Hz) and two types of frequency-gliding noises (center frequency: between 100 and 1,600 Hz). The duration threshold for detecting the BIAC in frequency-gliding noises was significantly longer than that in the frequency-steady noise (Experiment 1), and the longest interaural delay at which a duration-fixed BIAC (200 ms) in frequency-gliding noises could be detected was significantly shorter than that in the frequency-steady noise (Experiment 2). Although human listeners can detect a BIAC in frequency-gliding noises, their sensitivity to a BIAC in frequency-gliding noises is much lower than that in frequency-steady noise.

Measurement-based evaluation of Google/Apple Exposure Notification API for proximity detection in a commuter bus

We report on the results of a measurement study carried out on a commuter bus in Dublin, Ireland using the Google/Apple Exposure Notification (GAEN) API. This API is likely to be widely used by Covid-19 contact tracing apps. Measurements were collected between 60 pairs of Android handset locations and are publicly available. We find that the attenuation level reported by the GAEN API need not increase with distance between handsets, consistent with there being a complex radio environment inside a bus caused by the metal-rich environment. Changing the people sitting in a pair of seats can cause variations of ±10dB in the attenuation level reported by the GAEN API. Applying the rule used by the Swiss Covid-19 contact tracing app to trigger an exposure notification to our bus measurements we find that no exposure notifications would have been triggered despite the fact that all pairs of handsets were within 2m of one another for at least 15 mins. Applying an alternative threshold-based exposure notification rule can somewhat improve performance to a detection rate of 5% when an exposure duration threshold of 15 minutes is used, increasing to 8% when the exposure duration threshold is reduced to 10 mins. Stratifying the data by distance between pairs of handsets indicates that there is only a weak dependence of detection rate on distance.

Abstract 16374: Effect of Dapagliflozin According to Duration of Heart Failure: An Analysis of the DAPA-HF Trial

Introduction: The relationship between duration of heart failure (HF), patient characteristics, outcomes, and the effect of treatment is largely unknown. We investigated these questions in DAPA-HF. Hypothesis: We hypothesized that longer HF duration is associated with worse outcomes and that, compared with placebo, the benefit of the SGLT2 inhibitor, dapagliflozin, is consistent, irrespective of HF duration, in patients with HF and reduced ejection fraction (HFrEF). Methods: HF duration was categorised as 0-1, >1-2, >2-5 and >5 years. Outcomes were adjusted for prognostic variables and analysed using Cox regression. The primary endpoint was the composite of worsening HF or cardiovascular death. Treatment effect (dapagliflozin versus placebo) was examined within each duration category and by duration threshold. Results: The number patients in each category was: 1098 (0-1 year), 686 (>1-2 years), 1105 (>2-5 years) and 1855 (>5 years). Patients with longer-duration HF were older and more comorbid with worse quality of life. The primary outcome rate (per 100 person-years) increased with HF duration: 10.2 (95% CI 8.7-12.0) for the 0-1-year group, 10.6 (8.7-12.9) for >1-2 years, 15.5 (13.6-17.7) for >2-5 years and 15.9 (14.5-17.6) for >5 years. The adjusted hazard ratio was 0.98 (95% CI 0.75-1.27), 1.52 (1.22-1.89) and 1.60 (1.31-1.96) respectively, for >1-2, >2-5 and >5 years compared with 0-1 years. Similar trends were seen for all other outcomes. The benefit of dapagliflozin was consistent across HF duration for all outcomes and on threshold analysis (Figure). Conclusion: Patients with longer-duration HF had higher rates of worsening HF and death. The benefit of dapagliflozin was consistent irrespective of HF duration. Starting dapagliflozin has substantial benefits, even in patients with longstanding HFrEF.

A remote-sensing-based intensity–duration threshold, Faifa Mountains, Saudi Arabia

Construction of intensity–duration (ID) thresholds and early-warning and nowcasting systems for landslides (EWNSLs) are hampered by the paucity of temporal and spatial archival data. This work represents significant steps towards the development of a prototype EWNSL to forecast and nowcast landslides over the Faifa Mountains in the Red Sea Hills. The developed methodologies rely on readily available, temporal, archival Google Earth and Sentinel-1A imagery, precipitation measurements, and limited field data to construct an ID threshold for Faifa. The adopted procedures entail the generation of an ID threshold to identify the intensity and duration of precipitation events that cause landslides in the Faifa Mountains, and the generation of pixel-based ID curves to identify locations where movement is likely to occur. Spectral and morphologic variations in temporal Google Earth imagery following precipitation events were used to identify landslide-producing storms and generate the Faifa ID threshold (I =4.89D−0.65). Backscatter coefficient variations in radar imagery were used to generate pixel-based ID curves and identify locations where mass movement is likely to occur following landslide-producing storms. These methodologies accurately distinguished landslide-producing storms from non-landslide-producing ones and identified the locations of these landslides with an accuracy of 60 %.