91 research outputs found

    EFFECTS OF FOREIGN INTELLECTUAL PROPERTY RIGHTS ON U.S. BILATERAL EXPORTS OF BIOTECHNOLOGY RELATED AGRICULTURAL INPUTS

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    This paper examines the effect of foreign intellectual property right (IPR) systems and the policies that comprise them on U.S. exports of biotechnology related agricultural input industries. Policy components include the extent of patent coverage across industry sectors, enforcement mechanisms, provisions for loss of patent protection, memberships to other international patent agreements, and duration of patent protection. Extending the empirical and theoretical work of Smith (2002), this paper uses a gravity model to analyze how IPRs affect the market power and market expansion effects of exports to countries with differing abilities to imitate technology. The findings suggest that strengthening global IPRs grant a market power effect to U.S. exporters; strong IPRs reduce U.S. exports by awarding a temporary monopoly over the protected good. However, the analysis of the individual policy components of an IPR system reveal which components inhibit trade through market power effects and which components counterbalance it through market expansion effects, increasing the flow of trade and access to biotechnology related agricultural inputs.Research and Development/Tech Change/Emerging Technologies,

    Hydrogen Balmer Line Broadening in Solar and Stellar Flares

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    The broadening of the hydrogen lines during flares is thought to result from increased charge (electron, proton) density in the flare chromosphere. However, disagreements between theory and modeling prescriptions have precluded an accurate diagnostic of the degree of ionization and compression resulting from flare heating in the chromosphere. To resolve this issue, we have incorporated the unified theory of electric pressure broadening of the hydrogen lines into the non-LTE radiative transfer code RH. This broadening prescription produces a much more realistic spectrum of the quiescent, A0 star Vega compared to the analytic approximations used as a damping parameter in the Voigt profiles. We test recent radiative-hydrodynamic (RHD) simulations of the atmospheric response to high nonthermal electron beam fluxes with the new broadening prescription and find that the Balmer lines are over-broadened at the densest times in the simulations. Adding many simultaneously heated and cooling model loops as a "multithread" model improves the agreement with the observations. We revisit the three-component phenomenological flare model of the YZ CMi Megaflare using recent and new RHD models. The evolution of the broadening, line flux ratios, and continuum flux ratios are well-reproduced by a multithread model with high-flux nonthermal electron beam heating, an extended decay phase model, and a "hot spot" atmosphere heated by an ultrarelativistic electron beam with reasonable filling factors: 0.1%, 1%, and 0.1% of the visible stellar hemisphere, respectively. The new modeling motivates future work to understand the origin of the extended gradual phase emission.Comment: 31 pages, 13 figures, 2 tables, accepted for publication in the Astrophysical Journa

    Towards Space-like Photometric Precision from the Ground with Beam-Shaping Diffusers

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    We demonstrate a path to hitherto unachievable differential photometric precisions from the ground, both in the optical and near-infrared (NIR), using custom-fabricated beam-shaping diffusers produced using specialized nanofabrication techniques. Such diffusers mold the focal plane image of a star into a broad and stable top-hat shape, minimizing photometric errors due to non-uniform pixel response, atmospheric seeing effects, imperfect guiding, and telescope-induced variable aberrations seen in defocusing. This PSF reshaping significantly increases the achievable dynamic range of our observations, increasing our observing efficiency and thus better averages over scintillation. Diffusers work in both collimated and converging beams. We present diffuser-assisted optical observations demonstrating 6216+2662^{+26}_{-16}ppm precision in 30 minute bins on a nearby bright star 16-Cygni A (V=5.95) using the ARC 3.5m telescope---within a factor of \sim2 of Kepler's photometric precision on the same star. We also show a transit of WASP-85-Ab (V=11.2) and TRES-3b (V=12.4), where the residuals bin down to 18041+66180^{+66}_{-41}ppm in 30 minute bins for WASP-85-Ab---a factor of \sim4 of the precision achieved by the K2 mission on this target---and to 101ppm for TRES-3b. In the NIR, where diffusers may provide even more significant improvements over the current state of the art, our preliminary tests have demonstrated 13736+64137^{+64}_{-36}ppm precision for a KS=10.8K_S =10.8 star on the 200" Hale Telescope. These photometric precisions match or surpass the expected photometric precisions of TESS for the same magnitude range. This technology is inexpensive, scalable, easily adaptable, and can have an important and immediate impact on the observations of transits and secondary eclipses of exoplanets.Comment: Accepted for publication in ApJ. 30 pages, 20 figure

    The Implications of M Dwarf Flares on the Detection and Characterization of Exoplanets at Infrared Wavelengths

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    We present the results of an observational campaign which obtained high time cadence, high precision, simultaneous optical and IR photometric observations of three M dwarf flare stars for 47 hours. The campaign was designed to characterize the behavior of energetic flare events, which routinely occur on M dwarfs, at IR wavelengths to milli-magnitude precision, and quantify to what extent such events might influence current and future efforts to detect and characterize extrasolar planets surrounding these stars. We detected and characterized four highly energetic optical flares having U-band total energies of ~7.8x10^30 to ~1.3x10^32 ergs, and found no corresponding response in the J, H, or Ks bandpasses at the precision of our data. For active dM3e stars, we find that a ~1.3x10^32 erg U-band flare (delta Umax ~1.5 mag) will induce <8.3 (J), <8.5 (H), and <11.7 (Ks) milli-mags of a response. A flare of this energy or greater should occur less than once per 18 hours. For active dM4.5e stars, we find that a ~5.1x10^31 erg U-band flare (delta Umax ~1.6 mag) will induce <7.8 (J), <8.8 (H), and <5.1 (Ks) milli-mags of a response. A flare of this energy or greater should occur less than once per 10 hours. No evidence of stellar variability not associated with discrete flare events was observed at the level of ~3.9 milli-mags over 1 hour time-scales and at the level of ~5.6 milli-mags over 7.5 hour time-scales. We therefore demonstrate that most M dwarf stellar activity and flares will not influence IR detection and characterization studies of M dwarf exoplanets above the level of ~5-11 milli-mags, depending on the filter and spectral type. We speculate that the most energetic megaflares on M dwarfs, which occur at rates of once per month, are likely to be easily detected in IR observations with sensitivity of tens of milli-mags.Comment: Accepted in Astronomical Journal, 17 pages, 6 figure

    Kepler Flares II: The Temporal Morphology of White-Light Flares on GJ 1243

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    We present the largest sample of flares ever compiled for a single M dwarf, the active M4 star GJ 1243. Over 6100 individual flare events, with energies ranging from 102910^{29} to 103310^{33} erg, are found in 11 months of 1-minute cadence data from Kepler. This sample is unique for its completeness and dynamic range. We have developed automated tools for finding flares in short-cadence Kepler light curves, and performed extensive validation and classification of the sample by eye. From this pristine sample of flares we generate a median flare template. This template shows that two exponential cooling phases are present during the white-light flare decay, providing fundamental constraints for models of flare physics. The template is also used as a basis function to decompose complex multi-peaked flares, allowing us to study the energy distribution of these events. Only a small number of flare events are not well fit by our template. We find that complex, multi-peaked flares occur in over 80% of flares with a duration of 50 minutes or greater. The underlying distribution of flare durations for events 10 minutes and longer appears to follow a broken power law. Our results support the idea that sympathetic flaring may be responsible for some complex flare events.Comment: 12 pages, 9 figures, accepted for publication in Ap

    NEID Reveals that The Young Warm Neptune TOI-2076 b Has a Low Obliquity

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    TOI-2076 b is a sub-Neptune-sized planet (R=2.39±0.10RR=2.39 \pm 0.10 \mathrm{R_\oplus}) that transits a young (204±50MYr204 \pm 50 \mathrm{MYr}) bright (V=9.2V = 9.2) K-dwarf hosting a system of three transiting planets. Using spectroscopic observations with the NEID spectrograph on the WIYN 3.5 m Telescope, we model the Rossiter-McLaughlin effect of TOI-2076 b, and derive a sky-projected obliquity of λ=315+16\lambda=-3_{-15}^{+16\:\circ}. Using the size of the star (R=0.775±0.015RR=0.775 \pm0.015 \mathrm{R_\odot}), and the stellar rotation period (Prot=7.27±0.23P_{\mathrm{rot}}=7.27\pm0.23 days), we estimate a true obliquity of ψ=189+10\psi=18_{-9}^{+10\:\circ} (ψ<34\psi < 34^\circ at 95% confidence), demonstrating that TOI-2076 b is on a well-aligned orbit. Simultaneous diffuser-assisted photometry from the 3.5 m Telescope at Apache Point Observatory rules out flares during the transit. TOI-2076 b joins a small but growing sample of young planets in compact multi-planet systems with well-aligned orbits, and is the fourth planet with an age 300\lesssim 300 Myr in a multi-transiting system with an obliquity measurement. The low obliquity of TOI-2076 b and the presence of transit timing variations in the system suggest the TOI-2076 system likely formed via convergent disk migration in an initially well-aligned disk.Comment: Submitted to ApJL, 13 pages, 4 figures, 3 table
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