119 research outputs found

    Where’s the First Tee and What’s the Course Record?: The Pros and Cons of Using ADR in the PGA TOUR-LIV Golf Antitrust Suit

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    LIV Golf has taken the professional golfing world by storm. Started by golfing legend Greg Norman and funded by the Saudi Arabia Public Fund, LIV golf has brought a new league with a new format to golf, but it has also drawn its fair share of criticism due to its sources of funding. In response to the rise of LIV Golf, the PGA TOUR, professional golf’s principal league, announced it would suspend any player that signed a contract to play for LIV Golf. Recently, eleven LIV Golf players and LIV Golf itself have filed an antitrust suit against the PGA TOUR. Not only has this suit captured the interest of golf fans worldwide, but it also could serve as a blueprint for future antitrust lawsuits in the sports market

    The Efficacy and Optimization of Somatosensory Intracortical Microstimulation in Rats

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    Demand exists for brain-machine interfaces that offer a wide range of sensory feedback along with volitional motor control to individuals with limited control of natural sensory or motor function. As these sensorimotor devices are developed, it is necessary to improve the interaction between the prostheses and higher-level cortical structures. Optimizing these somatosensory stimulation parameters will require the use of a high-throughput experimental design. To address this, one Sprague-Dawley rat was trained to respond to auditory stimuli during a conditioned-avoidance behavior task and then implanted with a penetrating microelectrode array in the part of the somatosensory cortex corresponding to the left forelimb. After implantation, the task was repeated using electrical stimuli instead of auditory signals. Detection threshold data was collected from each electrode site to prove stimulation efficacy. The pulse rate of electrical stimulation was varied to optimize power usage by the neuroprosthesis while still achieving the lowest possible thresholds. Electrical impedance spectroscopy and cyclic voltammetry data were collected to monitor the performance of the electrode. Testing shows that auditory learning can be translated to somatosensory stimulation. As an aggregate, somatosensory detection thresholds are significantly different from those in the auditory cortex (Student’s t-test, p \u3c 0.0003). With these results in mind, future research can further optimize somatosensory intracortical microstimulation to provide more sensory feedback in motor prostheses

    Integrated seawater sampler and data acquisition system prototype : final report

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    This report documents the work performed by the Woods Hole Oceanographic Institution (WHOI) and the Battelle Memorial Institute from August 1988 to December 1992 in the NSF sponsored development of an Integrated Seawater Sampler and Data Acquisition Prototype. After a 6-month initial design study, a prototype underwater profiing unit was designed and constructed, containing the water acquisition subsystem, CTD and altimeter, control circuitry and batteries. A standard WHOI CTD was adapted for use in the underwater unit and was interfaced to the underwater controller which had a telemetry module connecting ít with a deck control unit. This enabled CTD data to be logged in normal fashion on shipboard while additional commands and diagnostics were sent over the telemetry link to command the underwater unit's water sampling process and receive diagnostic information on system performance. The water sampling subsystem consisted of 36 trays, each containing a plastic sample bag, the pump and control circuitry. The sample bags, initially sealed in a chemically clean environment, were opened by pumping the water out of the tray, thus forcing water into the bag by ambient pressure. The command system could select any bag, and control the water sampling procss from the surface with diagnostic information on system altitude, depth, orientation and cable tension displayed in real time for operator information. At sea tests confirmed the operation of the electrical and control system. Problems were encountered with the bags and seals which were partially solved by further post cruise efforts. However, the bag closing mechanism requires further development, and numerous small system improvements identified during the cruises need to be implemented to produce an operational water sampler. Finally, initial design tor a water sampler handling and storage unit and water extraction system were developed but not implemented. The detailed discussion of the prototype water sampler design, testing and evaluation, and new bag testing result are presented.Funding was provided by the National Science Foundation through Grant No. OCE8821977

    Micromechanical finite element modelling of thermo-mechanical fatigue for P91 steels

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    In this paper, the cyclic plasticity and fatigue crack initiation behaviour of a tempered martensite ferritic steel under thermo-mechanical fatigue conditions is examined by means of micromechanical finite element modelling. The crystal plasticity-based model explicitly reflects the microstructure of the material, measured by electronic backscatter diffraction. The predicted cyclic thermo-mechanical response agrees well with experiments under both in-phase and out-of-phase conditions. A thermo-mechanical fatigue indicator parameter, with stress triaxiality and temperature taken into account, is developed to predict fatigue crack initiation. In the fatigue crack initiation simulation, the out-of-phase thermo-mechanical response is identified to be more dangerous than in-phase response, which is consistent with experimental failure data. It is shown that the behaviour of thermo-mechanical fatigue can be effectively predicted at the microstructural level and this can lead to a more accurate assessment procedure for power plant components

    Improving Light and Soundscapes for Wildlife Use of Highway Crossing Structures

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    UC-ITS-2020-03Transportation and other agencies and organizations are increasingly planning and building under- and over-crossing structures for wildlife to traverse busy highways. However, if wildlife do not use these structures due to noise, light, and other factors, then the structures may have a low benefit to cost ratio. Several criteria are key for their success\u2014 sufficient safety and/or conservation need, cost, location, and anticipated use by wildlife. There is limited information in wildlife-crossing guidance on how wildlife biologists should advise designers, engineers, and architects on the use of structural and vegetation elements that could reduce noise and light disturbances. To address this problem, this study used field measurements and modeling of light and noise from traffic to inform and test the designs of two wildlife overcrossings. Wildlife-responsive designs were developed and tested for two crossings being considered or planned by California Department of Transportation in California. For the planned crossing of US 101 near the city of Agoura Hills (the Wallis-Annenberg crossing), the three designs consisted of noise/glare barriers; noise/glare barriers + berm; and noise/glare barriers + multiple berms. For the potential crossing of Interstate 15 south of Temecula, one design used noise/glare barriers of 3 different heights and the other had no barriers. Key limitations and opportunities for each design approach were identified. Creating \u201cdark and quiet paths\u201d using a combination of berms and noise/glare barriers could decrease disturbance in the crossing structure approach zones and increase the wildlife-responsiveness of the designs

    Flexibility of short-strand RNA in aqueous solution as revealed by molecular dynamics simulation:are A′-RNA and A-RNA distinct conformational structures?

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    We use molecular dynamics simulations to compare the conformational structure and dynamics of a 21-base pair RNA sequence initially constructed according to the canonical A-RNA and A'-RNA forms in the presence of counterions and explicit water. Our study aims to add a dynamical perspective to the solid-state structural information that has been derived from X-ray data for these two characteristic forms of RNA. Analysis of the three main structural descriptors commonly used to differentiate between the two forms of RNA namely major groove width, inclination and the number of base pairs in a helical twist over a 30 ns simulation period reveals a flexible structure in aqueous solution with fluctuations in the values of these structural parameters encompassing the range between the two crystal forms and more. This provides evidence to suggest that the identification of distinct A-RNA and A'-RNA structures, while relevant in the crystalline form, may not be generally relevant in the context of RNA in the aqueous phase. The apparent structural flexibility observed in our simulations is likely to bear ramifications for the interactions of RNA with biological molecules (e.g. proteins) and non-biological molecules (e.g. non-viral gene delivery vectors)

    Tree water dynamics in a drying and warming world

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    Disentangling the relative impacts of precipitation reduction and vapour pressure deficit (VPD) on plant water dynamics and determining whether acclimation may influence these patterns in the future is an important challenge. Here, we report sap flux density (FD), stomatal conductance (Gs), hydraulic conductivity (KL) and xylem anatomy in piñon pine (Pinus edulis) and juniper (Juniperus monosperma) trees subjected to five years of precipitation reduction, atmospheric warming (elevated VPD) and their combined effects. No acclimation occurred under precipitation reduction: lower Gs and FD were found for both species compared to ambient conditions. Warming reduced the sensibility of stomata to VPD for both species but resulted in the maintenance of Gs and FD to ambient levels only for piñon. For juniper, reduced soil moisture under warming negated benefits of stomatal adjustments and resulted in reduced FD, Gs and KL. Although reduced stomatal sensitivity to VPD also occurred under combined stresses, reductions in Gs, FD and KL took place to similar levels as under single stresses for both species. Our results show that stomatal conductance adjustments to high VPD could minimize but not entirely prevent additive effects of warming and drying on water use and carbon acquisition of trees in semi-arid regions.The Los Alamos Survival-Mortality (SUMO) Experiment was funded by the US Department of Energy, Office of Science, Biological and Environmental Research. C.G. and S.M. were supported by a Director’s Fellowship from the Los Alamos National Laboratory. A.V. was supported by a fellowship from Generalitat Valenciana (BEST/2016/289) and the project Survive-2 (CGL2015-69773-C2-2-P MINECO/FEDER) from the Spanish Government. CEAM is funded by Generalitat Valenciana

    A multi-scale crystal plasticity model for cyclic plasticity and low-cycle fatigue in a precipitate-strengthened steel at elevated temperature

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    peer-reviewedIn this paper, a multi-scale crystal plasticity model is presented for cyclic plasticity and low-cycle fatigue in a tempered martensite ferritic steel at elevated temperature. The model explicitly represents the geometry of grains, sub-grains and precipitates in the material, with strain gradient effects and kinematic hardening included in the crystal plasticity formulation. With the multiscale model, the cyclic behaviour at the sub-grain level is predicted with the effect of lath and precipitate sizes examined. A crystallographic, accumulated slip (strain) parameter, modulated by triaxiality, is implemented at the micro scale, to predict crack initiation in precipitate-strengthened laths. The predicted numbers of cycles to crack initiation agree well with experimental data. A strong dependence on the precipitate size is demonstrated, indicating a detrimental effect of coarsening of precipitates on fatigue at elevated temperature. (C) 2016 Elsevier Ltd. All rights reserved.ACCEPTEDpeer-reviewe

    Co-evolution of a broadly neutralizing HIV-1 antibody and founder virus

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    Current HIV-1 vaccines elicit strain-specific neutralizing antibodies. However, cross-reactive neutralizing antibodies arise in ~20% of HIV-1-infected individuals, and details of their generation could provide a roadmap for effective vaccination. Here we report the isolation, evolution and structure of a broadly neutralizing antibody from an African donor followed from time of infection. The mature antibody, CH103, neutralized ~55% of HIV-1 isolates, and its co-crystal structure with gp120 revealed a novel loop-based mechanism of CD4-binding site recognition. Virus and antibody gene sequencing revealed concomitant virus evolution and antibody maturation. Notably, the CH103-lineage unmutated common ancestor avidly bound the transmitted/founder HIV-1 envelope glycoprotein, and evolution of antibody neutralization breadth was preceded by extensive viral diversification in and near the CH103 epitope. These data elucidate the viral and antibody evolution leading to induction of a lineage of HIV-1 broadly neutralizing antibodies and provide insights into strategies to elicit similar antibodies via vaccination
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