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1. Modulation of Boundary-Layer Stability and the Surface Energy Budget by a Local Flow in Central Alaska

   https://doi.org/10.1007/s10546-022-00737-2  

   Maillard, Julia ; Ravetta, François ; Raut, Jean-Christophe ; Fochesatto, Gilberto J. ; Law, Kathy S. ( August 2022 , Boundary-Layer Meteorology)

   The pre-ALPACA (Alaskan Layered Pollution And Chemical Analysis) 2019 winter campaign took place in Fairbanks, Alaska, in November–December 2019. One objective of the campaign was to study the life-cycle of surface-based temperature inversions and the associated surface energy budget changes. Several instruments, including a 4-component radiometer and sonic anemometer were deployed in the open, snow-covered University of Alaska Fairbanks (UAF) Campus Agricultural Field. A local flow from a connecting valley occurs at this site. This flow is characterized by locally elevated wind speeds (greater than 3 m s$$^{-1}$$${}^{-1}$) under clear-sky conditions and a north-westerly direction. It is notably different to the wind observed at the airport more than 3.5 km to the south-west. The surface energy budget at the UAF Field site exhibits two preferential modes. In the first mode, turbulent sensible heat and net longwave fluxes are close to 0 W m$$^{-2}$$${}^{-2}$, linked to the presence of clouds and generally low winds. In the second, the net longwave flux is around − 50 W m$$^{-2}$$${}^{-2}$and the turbulent sensible heat flux is around 15 W m$$^{-2}$$${}^{-2}$, linked to clear skies and elevated wind speeds. The development of surface-based temperature inversions at the field is hindered compared to the airport because the local flow sustains vertical mixing. In this secondmore »mode the residual of the surface energy budget is large, possibly due to horizontal temperature advection.

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2. Variability in locomotor dynamics reveals the critical role of feedback in task control

   https://doi.org/10.7554/eLife.51219  

   Uyanik, Ismail ; Sefati, Shahin ; Stamper, Sarah A ; Cho, Kyoung-A ; Ankarali, M Mert ; Fortune, Eric S ; Cowan, Noah J ( January 2020 , eLife)

   People come in different shapes and sizes, but most will perform similarly well if asked to complete a task requiring fine manual dexterity – such as holding a pen or picking up a single grape. How can different individuals, with different sized hands and muscles, produce such similar movements? One explanation is that an individual’s brain and nervous system become precisely tuned to mechanics of the body’s muscles and skeleton. An alternative explanation is that brain and nervous system use a more “robust” control policy that can compensate for differences in the body by relying on feedback from the senses to guide the movements. To distinguish between these two explanations, Uyanik et al. turned to weakly electric freshwater fish known as glass knifefish. These fish seek refuge within root systems, reed grass and among other objects in the water. They swim backwards and forwards to stay hidden despite constantly changing currents. Each fish shuttles back and forth by moving a long ribbon-like fin on the underside of its body. Uyanik et al. measured the movements of the ribbon fin under controlled conditions in the laboratory, and then used the data to create computer models of the brain and body ofmore »each fish. The models of each fish’s brain and body were quite different. To study how the brain interacts with the body, Uyanik et al. then conducted experiments reminiscent of those described in the story of Frankenstein and transplanted the brain from each computer model into the body of different model fish. These “brain swaps” had almost no effect on the model’s simulated swimming behavior. Instead, these “Frankenfish” used sensory feedback to compensate for any mismatch between their brain and body. This suggests that, for some behaviors, an animal’s brain does not need to be precisely tuned to the specific characteristics of its body. Instead, robust control of movement relies on many seemingly redundant systems that provide sensory feedback. This has implications for the field of robotics. It further suggests that when designing robots, engineers should prioritize enabling the robots to use sensory feedback to cope with unexpected events, a well-known idea in control engineering.« less
3. Context-aware Monitoring in Robotic Surgery

   Yasar, Mohammad Samin ; Evans, David ; Alemzadeh, Homa ( January 2019 , International Symposium on Medical Robotics)

   Robotic-assisted minimally invasive surgery (MIS) has enabled procedures with increased precision and dexterity, but surgical robots are still open loop and require surgeons to work with a tele-operation console providing only limited visual feedback. In this setting, mechanical failures, software faults, or human errors might lead to adverse events resulting in patient complications or fatalities. We argue that impending adverse events could be detected and mitigated by applying context-specific safety constraints on the motions of the robot. We present a context-aware safety monitoring system which segments a surgical task into subtasks using kinematics data and monitors safety constraints specific to each subtask. To test our hypothesis about context specificity of safety constraints, we analyze recorded demonstrations of dry-lab surgical tasks collected from the JIGSAWS database as well as from experiments we conducted on a Raven II surgical robot. Analysis of the trajectory data shows that each subtask of a given surgical procedure has consistent safety constraints across multiple demonstrations by different subjects. Our preliminary results show that violations of these safety constraints lead to unsafe events, and there is often sufficient time between the constraint violation and the safety-critical event to allow for a corrective action.
4. PacificORCA

   https://doi.org/10.7914/SN/7B_2019  

   Gaherty, Jim ; Eilon, Zach ; Forsyth, Don ; Ekström, Göran ( January 2019 )

   Abstract

   This project contributes to an international effort to strategically place temporary arrays of instruments across the Pacific Ocean basin that record the energy from earthquakes. Recent community advances in ocean bottom seismographs will be used to record unique datasets in locations where large gaps in coverage exist today. These data will allow us to infer deformation and variations in mantle temperature related to small-scale convection. As part of the international collaboration, all data will be openly available to scientists worldwide. The project supports the training of graduate and undergraduate students. This project will collect 12-15 months of broadband ocean bottom seismograph (OBS) data in two 30-station arrays in the central and southern Pacific. These arrays, deployed at two distinct plate ages (~30 Ma and ~120 Ma), will address specific critical questions on the dynamics of the oceanic asthenosphere, including its underlying state (temperature, presence of melt, water or other volatiles, and deformation mechanism). The arrays are designed to image the anisotropic velocity signature of small-scale convection, which has been invoked to explain the flattening of the age versus depth curve in old ocean plates, 140-200 km wavelength gravity lineations, and ubiquitous off-axis, non-plume volcanism observed at a variety of scales. Anisotropic surface wave and body wave tomographic models will be supplemented by shear wave splitting and attenuation measurements to obtain a multi-faceted understanding of the asthenosphere and base of the plates. Finally, the order-of-magnitude increases in path coverage for surface and body waves in the south-central Pacific will enable new advances in global tomography.
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5. The Impact of Climate and Weather on a Small Tourism Business: A wSWOT Case Study

   https://doi.org/10.1177/2515127419829399  

   Craig, Christopher A. ; Sayers, Elizabeth Petrun ; Feng, Song ; Kinghorn, Brent ( February 2019 , Entrepreneurship Education and Pedagogy)

   Climatic variability and shifting weather patterns, resulting in extreme weather events and natural disasters, pose risks to small businesses in the United States. This is particularly true in coastal regions of the southeast United States where extreme events such as hurricanes, flooding, and thunderstorms are projected to increase in frequency and intensity. Yet, the vast majority of small business owners do not have a disaster plan in place and an estimated 40% to 60% of small businesses that have experienced a natural disaster never reopen. This teaching case explores the impact of climatic trends and weather on one location of an outdoor tourism industry business in the coastal community of Virginia Beach, Virginia. The case draws from observed weather and sales data for the local small business. Students will draw from descriptive statistics, statistical analysis, and graphs to explore (a) long-term climatic trends for the business; (b) relationships between small business sales and local weather; and (c) strengths, weaknesses, opportunities, and threats relative to weather conditions and climate change. Instructors can give the body of this document to students. They can also make use of the supplemental teaching notes to assist them with teaching this case.