Publications by authors named "Leighton T"

Audible very-high frequency sound (VHFS) and ultrasound (US) have been rated more unpleasant than lower frequency sounds when presented to listeners at similar sensation levels (SLs). In this study, 17 participants rated the sensory unpleasantness of 14-, 16-, and 18-kHz tones and a 1-kHz reference tone. Tones were presented at equal subjective loudness levels for each individual, corresponding to levels of 10, 20, and 30 dB SL measured at 1 kHz.

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Hyperbaric oxygen therapy as a treatment for conditions like traumatic brain injury, posttraumatic stress disorder, and migraines would seem intuitive, given its effect on condition-related ischemia and inflammation. However, hyperbaric therapeutic impacts for these in acute and chronic, or prolonged symptoms are elusive. This narrative review of hyperbaric's utility provided in sections per disease renders first a review of conventional pathological mechanisms and then articulates hyperbaric treatment targets versus their respective impacts.

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The expansion and potential rupture of the swim bladder due to rapid decompression, a major cause of barotrauma injury in fish that pass through turbines and pumps, is generally assumed to be governed by Boyle's Law. In this study, two swim bladder expansion models are presented and tested in silico. One based on the quasi-static Boyle's Law, and a Modified Rayleigh Plesset Model (MRPM), which includes both inertial and pressure functions and was parametrised to be representative of a fish swim bladder.

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Deterrents that use acoustics to guide fish away from dangerous areas depend on the elicitation of avoidance in the target species. Acoustic deterrents select the optimum frequency based on an assumption that highest avoidance is likely to occur at the greatest sensitivity. However, such an assumption may be unfounded.

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Article Synopsis
  • Broadly protective coronavirus vaccines are essential for fighting off future versions of SARS-CoV-2 and other novel coronaviruses, helping to reduce the impact of potential outbreaks.
  • The Coronavirus Vaccines Research and Development (R&D) Roadmap (CVR) is a structured plan funded by major foundations, created through collaboration among experts, and outlines vital research areas and strategic goals.
  • Organized into five key topics, the CVR includes 20 goals and 86 R&D milestones, with 26 identified as high priority, to help direct funding and research efforts in making effective vaccines.
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Passive acoustic inversion techniques for measuring gas flux into the water column have the potential to be a powerful tool for the long-term monitoring and quantification of natural marine seeps and anthropogenic emissions. Prior inversion techniques have had limited precision due to lack of constraints on the initial amplitude of a bubble's excitation following its release into the water column ( ). is determined by observing the acoustic signal of bubbles released from sediment in a controlled experiment and its use is demonstrated by quantifying the flux from a volcanic CO seep offshore Panarea (Italy), improving the precision by 78%.

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Chronic wounds fail to progress through the normal stages of healing, with the largest remediable cause of chronicity being presence of a multi-species biofilm. Removal of biofilm from the wound environment is central to wound care. A device for mechanically removing biofilms from wounds has been devised.

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The Myasthenia Gravis Activities of Living (MG-ADL) scale is an 8-item patient-reported scale that measures myasthenia gravis (MG) symptoms and functional status. The objective of the current review is to summarize the psychometric properties of the MG-ADL and published evidence of MG-ADL use. A targeted literature review for published studies of the MG-ADL was conducted using a database and gray literature search.

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Acoustic bubble curtains have been marketed as relatively low cost and easily maintained behavioural deterrents for fisheries management. Their energy efficiency can be improved by reducing air flow and exploiting bubble resonance. In a series of three flume experiments, we: (1) investigated the reactions of carp to a low air flow bubble curtain, (2) compared the effectiveness of resonant versus non-resonant insonified bubble curtains (for the same volume flux of gas injected through the nozzles) to deter passage, and determined the stimuli responsible for eliciting deterrence, and (3) included the effect of visual cues generated by the bubble curtain.

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Direct oral anticoagulants (DOACs) are used to treat several conditions such as non-valvular atrial fibrillation, deep vein thrombosis, and pulmonary embolism. DOACs and other anticoagulants block crucial steps in the coagulation cascade and ultimately prevent clot formation. Generally, individuals initiated on an anticoagulant are predisposed to or have a propensity to form clots.

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The need to predict acoustic propagation through marine sediments that contain gas bubbles has become increasingly important for civil engineering and climate studies. There are relatively few in situ acoustic wave propagation studies of muddy intertidal sediments, in which bubbles of biogenic gas (generally methane, a potent greenhouse gas) are commonly found. We used a single experimental rig to conduct two in situ intertidal acoustical experiments to improve understanding of acoustic remote sensing of gassy sediments, eventually including gas bubble size distributions.

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Introduction: Myasthenia gravis (MG) is a rare, chronic, autoimmune disease, mediated by immunoglobulin G antibodies, which causes debilitating muscle weakness. As with most rare diseases, there is little patient-reported data with which to understand and address patient needs. This study explores the impact of MG in the real world from the patient perspective.

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Collective behaviour, such as shoaling in fish, benefits individuals through a variety of activities such as social information exchange and anti-predator defence. Human driven disturbance (e.g.

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In this study, we investigated the effects of an ultrasonically activated stream (UAS) on the removal of microbial contaminants from spinach leaves. The microbial loads on samples cleaned with and without UAS were enumerated using the cell culture method and compared against unwashed samples on day 0 and day 6 after cleaning. The effects of UAS cleaning on leaf quality were also examined through both macroscopic and microscopic inspection, as well as measurement of the electrolyte leakage rate.

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The ingestion of contaminated hay is detrimental to livestock wellbeing. In this study, the feasibility of using an ultrasonically activated stream (UAS) to clean bacterial contamination from hay was investigated. Hay samples were stained with SYTO-9 nucleic acid stain for the in-situ visualization of microbes on the surface using an episcopic differential interference contrast microscope coupled with epi-fluorescence.

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Background: Sterile service department decontamination procedures for surgical instruments struggle to demonstrate efficient removal of the hardiest infectious contaminants, such as prion proteins. A recently designed novel system, which uses a low pressure ultrasonically activated, cold water stream, has previously demonstrated efficient hard surface cleaning of several biological contaminants.

Aim: To test the efficacy of an ultrasonically activated stream for the removal of tissue proteins, including prion-associated amyloid, from surgical stainless steel surfaces.

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Behavioral guidance systems are commonly used in freshwater fish conservation. The biological relevance of sound to fish and recorded responses to human-generated noise supports the viability of the use of acoustics as an effective stimulus in such technologies. Relatively little information exists on the long-term responses and recovery of fish to repeated acoustic exposures.

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Underwater noise from commercial shipping throughout the oceans has been increasing over the past decades and the environmental impact of this noise remains an area of great uncertainty. This has led to the measurement of noise from commercial vessels in order to understand the impacts that these vessels may engender. Hydrofoils are used by ferries in various locations around the world and locally may be a significant contributing factor of the soundscape.

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In 2004, Leighton hypothesized that the acoustic calls emitted by humpback whales when feeding using bubble nets, may enhance the effectiveness of the net in confining prey (such as herring) by forming a "wall of sound" with a quiet zone within. Modelling of the acoustics of this phenomenon was previously restricted to 2D; this paper conducts a 3D model of the propagation of signals resembling those emitted by humpback whales when bubble netting, projected into an upward spiral bubble net which data to date suggest is the accurate form for the bubble net in 3D space. In this study, the feeding calls were analyzed in the time-frequency domain to extract acoustic information sufficient to allow modeling of the resulting spatial distribution of acoustic pressure and particle velocity, and how they vary over the duration of the call.

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Various adverse symptoms resulting from exposure to very high-frequency sound (VHFS) and ultrasound (US) have previously been reported. This study aimed to establish whether these symptoms are experienced under controlled laboratory conditions and are specific to VHFS/US. To do this, participants were exposed to VHFS/US (at frequencies between 13.

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Article Synopsis
  • Some individuals have attributed symptoms like nausea, dizziness, and headaches to ultrasound emitted from public devices, prompting this study to examine the effects of inaudible ultrasound compared to a sham (fake) exposure.
  • The study, conducted under double-blind conditions, tested a 20 kHz ultrasound tone that was below detectable levels for participants, revealing no direct symptoms caused by ultrasound but observing small nocebo effects linked to participants' expectations.
  • The findings did not replicate severe symptoms reported by the public, suggesting the results might be influenced by the sound pressure level, duration, or nature of the stimulus, and can't predict effects from higher volume or audible sounds.
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This editorial introduces a Special Issue of the Journal of the Acoustical Society of America, on "Ultrasound in Air." In this Special Issue, one paper covers ways of categorizing the ultrasonic regimes, and three papers cover human effects. One of those three, plus five others, constitute the six papers that report on the measured outputs of commercial devices.

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It is proposed that the ultrasound frequency spectrum should be divided into three bands in order to facilitate a more rational assessment of its health effects. Whilst statement of the frequencies at the borders of these bands facilitates their definition, it is recognized that these observables vary continuously with frequency and consequently these border frequencies should not be used to rule out the possibility of a given effect occurring. The lowest band, US(A), lies between 17.

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Recent work showing the presence of a new generation of ultrasound (US) sources in public places has reopened the debate about whether there are adverse effects of US on humans, and has identified weaknesses in standards and exposure guidelines. Systems that rely on very high-frequency sound (VHFS) and US include public-address voice-alarm (PAVA) systems (whose operational status is often monitored using tones at ∼20 kHz) and pest deterrents. In this study, sound pressure levels (SPLs) produced by 16 sources that were either publically available or installed in busy public spaces were measured.

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