On the effect of SNR and superdirective beamforming in speaker diarisation in meetings

This paper examines the effect of sensor performance on speaker diarisation in meetings and investigates the use of more advanced beamforming techniques, beyond the typically employed delay-sum beamformer, for mitigating the effects of poorer sensor performance. We present superdirective beamforming and investigate how different time difference of arrival (TDOA) smoothing and beamforming techniques influence the performance of state-of-the-art diarisation systems. We produced and transcribed a new corpus of meetings recorded in the instrumented meeting room using a high SNR analogue and a newly developed low SNR digital MEMS microphone array (DMMA.2). This research demonstrates that TDOA smoothing has a significant effect on the diarisation error rate and that simple noise reduction and beamforming schemes suffice to overcome audio signal degradation due to the lower SNR of modern MEMS microphones. Index Terms — Speaker diarisation in meetings, digital MEMS microphone array, time difference of arrival (TDOA), superdirective beamforming 1

Hartree-Fock-Bogoliubov Model and Simulation of Attractive and Repulsive Bose-Einstein Condensates

We describe a model of dynamic Bose-Einstein condensates near a Feshbach resonance that is computationally feasible under assumptions of spherical or cylindrical symmetry. Simulations in spherical symmetry approximate the experimentally measured time to collapse of an unstably attractive condensate only when the molecular binding energy in the model is correct, demonstrating that the quantum fluctuations and atom-molecule pairing included in the model are the dominant mechanisms during collapse. Simulations of condensates with repulsive interactions find some quantitative disagreement, suggesting that pairing and quantum fluctuations are not the only significant factors for condensate loss or burst formation. Inclusion of three-body recombination was found to be inconsequential in all of our simulations, though we do not consider recent experiments [1] conducted at higher densities

Thinning of superfluid films below the critical point

Experiments on $^4$He films reveal an attractive Casimir-like force at the bulk $\lambda$-point, and in the superfluid regime. Previous work has explained the magnitude of this force at the $\lambda$ transition and deep in the superfluid region but not the substantial attractive force immediately below the $\lambda$-point. Utilizing a simple mean-field calculation renormalized by critical fluctuations we obtain an effective Casimir force that is qualitatively consistent with the scaling function $\vartheta$ obtained by collapse of experimental data.Comment: 4 page

Beyond ‘witnessing’: children’s experiences of coercive control in domestic violence and abuse

Children’s experiences and voices are underrepresented in academic literature and professional practice around domestic violence and abuse. The project ‘Understanding Agency and Resistance Strategies’ addresses this absence, through direct engagement with children. We present an analysis from interviews with 21 children in the United Kingdom (12 girls and 9 boys, aged 8-18 years), about their experiences of domestic violence and abuse, and their responses to this violence. These interviews were analysed using interpretive interactionism. Three themes from this analysis are presented: a) ‘Children’s experiences of abusive control’, which explores children’s awareness of controlling behaviour by the adult perpetrator, their experience of that control, and its impact on them; b) ‘Constraint’, which explores how children experience the constraint associated with coercive control in situations of domestic violence, and c) ‘Children as agents’ which explores children’s strategies for managing controlling behaviour in their home and in family relationships. The paper argues that, in situations where violence and abuse occurs between adult intimate partners, children are significantly impacted, and can be reasonably described as victims of abusive control. Recognising children as direct victims of domestic violence and abuse would produce significant changes in the way professionals respond to them, by 1) recognising children’s experience of the impact of domestic violence and abuse; 2) recognising children’s agency, undermining the perception of them as passive ‘witnesses’ or ‘collateral damage’ in adult abusive encounters; and 3) strengthening professional responses to them as direct victims, not as passive witnesses to violence

Impact of dietary nitrate dose on resistance exercise performance

The purpose of this study was to assess whether various doses of BR supplementation can influence muscle performance during a battery of resistance exercises in healthy, resistance-trained males. In a double-blind, randomized crossover design, 18 males were randomly allocated to consume 4 x 70 ml of BR over four conditions: (1) 4 x 70 ml of nitrate-depleted BR for placebo (PL); (2) 1 x 70 ml of nitrate-rich BR and 3 x 70 ml of PL for a low nitrate dose (BR-LOW); (3) 2 x 70 ml of nitrate-rich BR and 2 x 70 ml of PL for a moderate nitrate dose (BR-MOD); and (4) 4 x 70 ml of nitrate-rich BR for an elevated nitrate dose (BR-HIGH). Participants reported to the laboratory 5 times over 5-wk. Following a 1 repetition max (1RM) and a familiarization to the exercise protocol, participants completed a warm up and then a protocol to assess explosive performance using a linear transducer and force plate during vertical countermovement jumps, and then back squat and bench press, in a randomized order. A resting blood sample was drawn for the determination of plasma nitrate and nitrite concentrations. A two way repeated measures ANOVA was used to determine statistical differences between blood and performance variables, and is currently in progress. These data could provide insight for dietary nitrate as an ergogenic aid and inform both supplementation guidelines and recommendations for enhancing resistance training performance in men

Observation of Spin Wave Soliton Fractals in Magnetic Film Active Feedback Rings

The manifestation of fractals in soliton dynamics has been observed for the first time. The experiment utilized self-generated spin wave envelope solitons in a magnetic film based active feedback ring. At high ring gain, the soliton that circulates in the ring breathes in a fractal pattern. The corresponding power frequency spectrum shows a comb structure, with each peak in the comb having its own comb, and so on, to finer and finer scales.Comment: 4 pages, 4 figure

Functional Assessment of the Dural Lymphatic Vessels Using Dynamic Contrast MRI in Multiple Sclerosis

BACKGROUND AND PURPOSE: The discovery of glymphatic function in the human brain has generated interest in waste clearance mechanisms in neurological disorders such as multiple sclerosis (MS). However, noninvasive in vivo functional assessment is currently lacking. This work studies the feasibility of a novel intravenous dynamic contrast MRI method to assess the dural lymphatics, a purported pathway contributing to glymphatic clearance. METHODS: This prospective study included 20 patients with MS (17 women; age = 46.4 [27, 65] years; disease duration = 13.6 [2.1, 38.0] years, expanded disability status score (EDSS) = 2.0 [0, 6.5]). Patients were scanned on a 3.0T MRI system using intravenous contrast-enhanced fluid-attenuated inversion recovery MRI. Signal in the dural lymphatic vessel along the superior sagittal sinus was measured to calculate peak enhancement, time to maximum enhancement, wash-in and washout slopes, and the area under the time-intensity curve (AUC). Correlation analysis was performed to examine the relationship between the lymphatic dynamic parameters and the demographic and clinical characteristics, including the lesion load and the brain parenchymal fraction (BPF). RESULTS: Contrast enhancement was detected in the dural lymphatics in most patients 2-3 min after contrast administration. BPF had a significant correlation with AUC (p \u3c .03), peak enhancement (p \u3c .01), and wash-in slope (p = .01). Lymphatic dynamic parameters did not correlate with age, BMI, disease duration, EDSS, or lesion load. Moderate trends were observed for correlation between patient age and AUC (p = .062), BMI and peak enhancement (p = .059), and BMI and AUC (p = .093). CONCLUSION: Intravenous dynamic contrast MRI of the dural lymphatics is feasible and may be useful in characterizing its hydrodynamics in neurological diseases

Functional Assessment of the Dural Lymphatic Vessels Using Dynamic Contrast MRI in Multiple Sclerosis

Background and purpose The discovery of glymphatic function in the human brain has generated interest in waste clearance mechanisms in neurological disorders such as multiple sclerosis (MS). However, noninvasive in vivo functional assessment is currently lacking. This work studies the feasibility of a novel intravenous dynamic contrast MRI method to assess the dural lymphatics, a purported pathway contributing to glymphatic clearance. Methods This prospective study included 20 patients with MS (17 women; age = 46.4 [27, 65] years; disease duration = 13.6 [2.1, 38.0] years, expanded disability status score (EDSS) = 2.0 [0, 6.5]). Patients were scanned on a 3.0T MRI system using intravenous contrast‐enhanced fluid‐attenuated inversion recovery MRI. Signal in the dural lymphatic vessel along the superior sagittal sinus was measured to calculate peak enhancement, time to maximum enhancement, wash‐in and washout slopes, and the area under the time‐intensity curve (AUC). Correlation analysis was performed to examine the relationship between the lymphatic dynamic parameters and the demographic and clinical characteristics, including the lesion load and the brain parenchymal fraction (BPF). Results Contrast enhancement was detected in the dural lymphatics in most patients 2–3 min after contrast administration. BPF had a significant correlation with AUC (p \u3c .03), peak enhancement (p \u3c .01), and wash‐in slope (p = .01). Lymphatic dynamic parameters did not correlate with age, BMI, disease duration, EDSS, or lesion load. Moderate trends were observed for correlation between patient age and AUC (p = .062), BMI and peak enhancement (p = .059), and BMI and AUC (p = .093). Conclusion Intravenous dynamic contrast MRI of the dural lymphatics is feasible and may be useful in characterizing its hydrodynamics in neurological diseases

VLBA Imaging of the OH Maser in IIIZw35

We present a parsec-scale image of the OH maser in the nucleus of the active galaxy IIIZw35, made using the Very Long Baseline Array at a wavelength of 18 cm. We detected two distinct components, with a projected separation of 50 pc (for D=110 Mpc) and a separation in Doppler velocity of 70 km/s, which contain 50% of the total maser flux. Velocity gradients within these components could indicate rotation of clouds with binding mass densities of ~7000 solar masses per cubic parsec, or total masses of more than 500,000 solar masses. Emission in the 1665-MHz OH line is roughly coincident in position with that in the 1667-MHz line, although the lines peak at different Doppler velocities. We detected no 18 cm continuum emission; our upper limit implies a peak apparent optical depth greater than 3.4, assuming the maser is an unsaturated amplifier of continuum radiation.Comment: 10 pages, 3 figure