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Ultrasonic haptic (UH) feedback employs mid-air ultrasound waves detectable by the palm of the hand. This interface demonstrates a novel opportunity to utilize non-visual input and output (I/O) functionalities in interactive applications, such as vehicle controls that allow the user to keep their eyes on the road. However, more work is needed to evaluate the useability of such an interface. In this study, 16 blindfolded participants completed tasks involving finding and counting UH buttons, associating buttons with audio cues, learning spatial arrangements, and determining button states. Results showed that users were generally successful with 2–4 arranged buttons and could associate them with audio cues with an average accuracy of 77.1%. Participants were also able to comprehend button spatial arrangements with 77.8% accuracy and engage in reconstruction tasks to prove user understanding. These results signify the capability of UH feedback to have real-world I/O functionality and serve to guide future exploration in this area. 

Mid-air ultrasonic feedback is a new form of haptic stimulation supporting mid-air, touch-free user interfaces. Functional implementation of ultrasonic haptic (UH) interfaces depend upon the ability to accurately distinguish between the intensity, shape, orientation, and movement of a signal. This user study (N = 15) investigates the ability to non-visually perceive two ultrasonic lines with varying lengths (3, 5, and 7 cm) and orientations (vertical and horizontal) using the palm of the hand. Key results showed that: (1) the orientation of the lines had no effect on a user’s accuracy when determining their relative lengths, (2) line length distinction significantly improved when the length difference was at least 4 cm, and (3) a clear learning curve was evident when evaluating a new user’s ability to perceive ultrasonic signals. The capabilities of UH technology identified and discussed within this study will help engineer user-friendly and functional mid-air haptic interfaces for future applications. 

Abstract Leptospirosis, the most widespread zoonotic disease in the world, is broadly understudied in multi-host wildlife systems. Knowledge gaps regardingLeptospiracirculation in wildlife, particularly in densely populated areas, contribute to frequent misdiagnoses in humans and domestic animals. We assessedLeptospiraprevalence levels and risk factors in five target wildlife species across the greater Los Angeles region: striped skunks (Mephitis mephitis), raccoons (Procyon lotor), coyotes (Canis latrans), Virginia opossums (Didelphis virginiana), and fox squirrels (Sciurus niger). We sampled more than 960 individual animals, including over 700 from target species in the greater Los Angeles region, and an additional 266 sampled opportunistically from other California regions and species. In the five target species seroprevalences ranged from 5 to 60%, and infection prevalences ranged from 0.8 to 15.2% in all except fox squirrels (0%).Leptospiraphylogenomics and patterns of serologic reactivity suggest that mainland terrestrial wildlife, particularly mesocarnivores, could be the source of repeated observed introductions ofLeptospirainto local marine and island ecosystems. Overall, we found evidence of widespreadLeptospiraexposure in wildlife across Los Angeles and surrounding regions. This indicates exposure risk for humans and domestic animals and highlights that this pathogen can circulate endemically in many wildlife species even in densely populated urban areas. 

Abstract Arctic staircases mediate the heat transport from the warm water of Atlantic origin to the cooler waters of the Arctic mixed layer. For this reason, staircases have received much due attention from the community, and their heat transport has been well characterized for systems in the absence of external forcing. However, the ocean is a dynamic environment with large-scale currents and internal waves being omnipresent, even in regions shielded by sea-ice. Thus, we have attempted to address the effects of background shear on fully developed staircases using numerical simulations. The code, which is pseudo-spectral, evolves the governing equations for a Boussinesq fluid with temperature and salinity in a shearing coordinate system. We find that—– unlike many other double-diffusive systems—the sheared staircase requires three-dimensional simulations to properly capture the dynamics. Our simulations predict shear patterns that are consistent with observations and show that staircases in the presence of external shear should be expected to transport heat and salt at least twice as efficiently as in the corresponding non-sheared systems. These findings may lead to critical improvements in the representation of micro-scale mixing in global climate models.