I will leave you now and this loudspeaker will take my place

Notions of ‘presence’ and ‘liveness’ run through academic theories and popular conceptions of sound mediation generally, and mediation of voice in particular. This article looks at experimental video that engages with these questions, particularly around the notion of the ‘authentic’ voice and vocal ‘presence’. We will demonstrate how these different experimental approaches explore the interaction between voice, vocal technique and audio-visual technology, thus challenging and interrogating conventions of how the soundtrack represents the voice and (in conjunction with the moving image) the audio-visually mediated body. Presenting Anneke Kampman's work as an experimental practice-led research response to seminal theories of sound and the film soundtrack, we provide further context through engagement with key examples of earlier video art and sound art by Vladan Radovanović, Richard Serra, and Meredith Monk. Overall, the article intervenes by demonstrating how video art and sound art can address key theoretical questions concerning voice and body in a broader sound and moving image context, as well as adopting a sound-focussed approach to aesthetic analysis of video art

Undoing violent masculinity: Lynne Ramsay’s You were never really here (2018)

Reviewers described Lynne Ramsay’s You Were Never Really Here (2018) as a “Taxi Driver for a new century.” Certainly, its narrative of an inarticulate killer who is also the would-be saviour of a lost and damaged “little white girl” recalls that of Scorsese’s 1976 film., and the two films share a fragmented, hallucinatory quality. Yet what such comparisons miss is both the devastating critique of this culturally powerful narrative to be found in Ramsay’s film, and the connections it makes between this paradigmatic story of a failed and violent but ultimately sympathetic white masculinity and another: that of the traumatising mother who is responsible for the violence of her psychotic son. In this article, I explore the nature of Ramsay’s critique, arguing that her film both refuses and interrogates both of these readings of gender. Ramsay’s protagonist, like Scorsese’s, is a traumatised war veteran, but his identification is not with a fantasised and recuperative ideal masculinity but with its feminised victims: girl and mother. His tragedy is not that he fails in his rescue attempt, or that he is in thrall to the “death mother”, but that he believes that the means of this rescue might be masculinity

A cell culture model using rat coronary artery adventitial fibroblasts to measure collagen production

<p>Abstract</p> <p>Background</p> <p>We have developed a rat cell model for studying collagen type I production in coronary artery adventitial fibroblasts. Increased deposition of adventitial collagen type I leads to stiffening of the blood vessel, increased blood pressure, arteriosclerosis and coronary heart disease. Although the source and mechanism of collagen deposition is yet unknown, the adventitia appears to play a significant role. To demonstrate the application of our cell model, cultured adventitial fibroblasts were treated with sex hormones and the effect on collagen production measured.</p> <p>Methods</p> <p>Hearts (10–12 weeks) were harvested and the left anterior descending coronary artery (LAD) was isolated and removed. Tissue explants were cultured and cells (passages 2–4) were confirmed as fibroblasts using immunohistochemistry. Optimal conditions were determined for cell tissue harvest, timing, proliferation and culture conditions. Fibroblasts were exposed to 10^-7M testosterone or 10^-7M estrogen for 24 hours and either immunostained for collagen type I or subjected to ELISA.</p> <p>Results</p> <p>Results showed increased collagen staining in fibroblasts treated with testosterone compared to control and decreased staining with estrogen. ELISA results showed that testosterone increased collagen I by 20% whereas estrogen decreased collagen I by 15%.</p> <p>Conclusion</p> <p>Data demonstrates the usefulness of our cell model in studying the specific role of the adventitia apart from other blood vessel tissue in rat coronary arteries. Results suggest opposite effects of testosterone and estrogen on collagen synthesis in the rat coronary artery adventitial fibroblasts.</p

Fate of nitrate in seepage from a restored wetland receiving agricultural tailwater

Constructed and restored wetlands are a common practice to filter agricultural runoff, which often contains high levels of pollutants, including nitrate. Seepage waters from wetlands have potential to contaminate groundwater. This study used soil and water monitoring and hydrologic and nitrogen mass balances to document the fate and transport of nitrate in seepage and surface waters from a restored flow-through wetland adjacent to the San Joaquin River, California. A 39% reduction in NO3-N concentration was observed between wetland surface water inflows (12.87±6.43mgL-1; mean±SD) and outflows (7.87±4.69mgL-1). Redox potentials were consistently below the nitrate reduction threshold (~250mV) at most sites throughout the irrigation season. In the upper 10cm of the main flowpath, denitrification potential (DNP) for soil incubations significantly increased from 151 to 2437mgNO3-Nm-2d-1 when nitrate was added, but showed no response to carbon additions indicating that denitrification was primarily limited by nitrate. Approximately 72% of the water entering the wetland became deep seepage, water that percolated beyond 1-m depth. The wetland was highly effective at removing nitrate (3866kgNO3-N) with an estimated 75% NO3-N removal efficiency calculated from a combined water and nitrate mass balance. The mass balance results were consistent with estimates of NO3-N removed (5085kgNO3-N) via denitrification potential. Results indicate that allowing seepage from wetlands does not necessarily pose an appreciable risk for groundwater nitrate contamination and seepage can facilitate greater nitrate removal via denitrification in soil compared to surface water transport alone

Aperture-level simultaneous transmit and receive with digital phased arrays

While purely digital phased arrays were once discarded as simultaneous transmit and receive (STAR) capable platforms, this notion has recently been reconsidered. Previous work demonstrated that adaptive digital beamforming and digital self-interference cancellation (SIC) can enable transmitting and receiving subapertures in an array to operate simultaneously in the same frequency band. This approach, referred to as Aperture-Level Simultaneous Transmit and Receive (ALSTAR), uses only adaptive digital beamforming and digital SIC techniques. The ALSTAR architecture does not require custom radiators or analog canceling circuits that can increase front end losses and add significant size, weight, and cost to the array. This paper extends the previously proposed effective isotropic isolation (EII) metric to account for fixed dynamic range transmit and receive channels. An alternating optimization procedure that exploits the interdependence of the transmit and receive beamformers is proposed based on the symmetry of the EII metric, achieving higher EII than in previous work. This optimization procedure balances the goal of null-placement for interference and noise rejection with the goal of maintaining high transmit and receive gain. Simulated results are presented for a 50-element array that achieves 187.1 dB of EII in narrowband operation with 2500 W of transmit power. We explore the effectiveness of the architecture and proposed optimization methods by demonstrating the high EII achieved across the full scan space of the array at several transmit power levels. Results are also presented for a regularized version of the beamformer optimization problem that allows the designer to trade EII for array gain

Neural networks for real-time adaptive beamforming in simultaneous transmit and receive digital phased arrays: Student submission

Fully digital phased arrays have become more common as technology advancements have driven down their cost. However, adaptive beamforming techniques can lead to extremely high computational costs when faced with handling the many high-rate data streams created by fully digital arrays. In this work, we focus on the particular challenge of adaptive beamforming for transmit/receive isolation required by Aperture-Level Simultaneous Transmit and Receive (ALSTAR) phased array architectures. We propose that the adaptive transmit and receive beamformers required for a 10-element uniform linear ALSTAR array can be generated by a neural network. In our simulations, the neural network generated beamformers achieved 165.8 dB of effective isotropic isolation at broadside, a gain of 39.7 dB over the non-adaptive beamformers and a loss of only 1.3 dB with respect to the beamformers generated by the ground-truth adaptive beamforming algorithm. This work demonstrates that shallow neural networks are capable of accurately learning the complex input-to-output mapping described by the adaptive beamforming algorithm required for the ALSTAR architecture. We also show that the neural networks generate the required adaptive beamformers to a high precision with a reduced computational complexity (compared to the previously proposed adaptive beamforming algorithm). Because Field-Programmable Gate Array (FPGA) implementations of neural networks exist and can leverage their highly parallelizable structure, we also suggest that neural networks open a pathway to real-time adaptive beamforming in ALSTAR arrays. This is especially true as the FPGAs integrated into phased array platforms grow in size and performance

Characterization of SU-8 using terahertz time-domain spectroscopy

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An information-theoretic approach to partitioning simultaneous transmit and receive digital phased arrays

Dynamically reconfigurable digital phased array technology has become more common and advances in signal processing techniques have enabled digital self-interference cancellation sufficient for practical simultaneous transmit and receive applications. As systems implement these technologies, techniques for configuring arrays must be developed. In this work, we consider operating an array in an imaging mode and demonstrate the effectiveness of the Fisher Information of a point target\u27s estimated cross-range position in determining the optimal partitioning of an array into transmit and receive elements. We demonstrate that the partitions formed by optimizing the Fisher Information metric perform better than those that consider other metrics

Optimizing the Information- Theoretic Partitioning of Simultaneous Transmit and Receive Phased Arrays

© 2018 IEEE. Phased array technology has progressed towards fully digital architectures over recent years. This has significantly increased the agility of phased arrays, which in turn has created a need to determine how to optimally configure these arrays for dynamic missions. Previous work on assigning signals to antennas in phased arrays has focused on minimizing measures of the sidelobes in the beam patterns produced by thinning or interleaving the array using genetic algorithms (GAs). This work explores a novel application of the GA to optimize the resolution of a narrowband imaging array with respect to the transmit/receive antenna partition when considering self-interference in a simultaneous-transmit-and-receive operation. The results demonstrate the GA\u27s effectiveness at finding optimal or near-optimal array partitions without exhaustively exploring the impractically large search space