2,293 research outputs found

    Factors that support Indigenous involvement in multi-actor environmental stewardship

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    Regional, multi-actor environmental collaborations bring together diverse parties to achieve environmental protection and stewardship outcomes. Involving a range of participants helps involve alternative forms of knowledge, expertise, and perspectives; it may also present greater challenges in reaching agreements, particularly when both Indigenous and non-Indigenous parties are involved. The authors conduct a cross-case study of 39 regional partnerships involving Indigenous nations from the Great Lakes basin of North America with the aim of determining the factors that enable Indigenous partners to remain engaged in multi-actor collaborations. Six characteristics influenced Indigenous nations’ willingness to remain engaged: respect for Indigenous knowledges, control of knowledge mobilization, intergenerational involvement, self-determination, continuous cross-cultural education, and early involvement. Being attentive of these factors can help partnerships achieve their environmental goals by keeping important partners at the table

    Radiative DD^* Decay Using Heavy Quark and Chiral Symmetry

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    The implications of chiral SU(3)L×SU(3)RSU(3)_L \times SU(3)_R symmetry and heavy quark symmetry for the radiative decays D0D0γD^{*0}\to D^0\gamma, D+D+γD^{*+}\to D^+\gamma, and DsDsγD_s^*\to D_s\gamma are discussed. Particular attention is paid to SU(3)SU(3) violating contributions of order mq1/2m_q^{1/2}. Experimental data on these radiative decays provide constraints on the DDπD^* D\pi coupling.Comment: 9 pages plus 3 pages of figures in POSTSCRIPT file appended to TeX file (uses harvmac.tex and tables.tex), UCSD/PTH 92-31, CALT-68-1816, EFI-92-45, CERN-TH.6650/9

    Long-lived space observatories for astronomy and astrophysics

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    NASA's plan to build and launch a fleet of long-lived space observatories that include the Hubble Space Telescope (HST), the Gamma Ray Observatory (GRO), the Advanced X Ray Astrophysics Observatory (AXAF), and the Space Infrared Telescope Facility (SIRTF) are discussed. These facilities are expected to have a profound impact on the sciences of astronomy and astrophysics. The long-lived observatories will provide new insights about astronomical and astrophysical problems that range from the presence of planets orbiting nearby stars to the large-scale distribution and evolution of matter in the universe. An important concern to NASA and the scientific community is the operation and maintenance cost of the four observatories described above. The HST cost about 1.3billion(1984dollars)tobuildandisestimatedtorequire1.3 billion (1984 dollars) to build and is estimated to require 160 million (1986 dollars) a year to operate and maintain. If HST is operated for 20 years, the accumulated costs will be considerably more than those required for its construction. Therefore, it is essential to plan carefully for observatory operations and maintenance before a long-lived facility is constructed. The primary goal of this report is to help NASA develop guidelines for the operations and management of these future observatories so as to achieve the best possible scientific results for the resources available. Eight recommendations are given

    Detection of Potential Transit Signals in the First Three Quarters of Kepler Mission Data

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    We present the results of a search for potential transit signals in the first three quarters of photometry data acquired by the Kepler Mission. The targets of the search include 151,722 stars which were observed over the full interval and an additional 19,132 stars which were observed for only 1 or 2 quarters. From this set of targets we find a total of 5,392 detections which meet the Kepler detection criteria: those criteria are periodicity of the signal, an acceptable signal-to-noise ratio, and a composition test which rejects spurious detections which contain non-physical combinations of events. The detected signals are dominated by events with relatively low signal-to-noise ratio and by events with relatively short periods. The distribution of estimated transit depths appears to peak in the range between 40 and 100 parts per million, with a few detections down to fewer than 10 parts per million. The detected signals are compared to a set of known transit events in the Kepler field of view which were derived by a different method using a longer data interval; the comparison shows that the current search correctly identified 88.1% of the known events. A tabulation of the detected transit signals, examples which illustrate the analysis and detection process, a discussion of future plans and open, potentially fruitful, areas of further research are included

    Enskog Theory for Polydisperse Granular Mixtures. I. Navier-Stokes order Transport

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    A hydrodynamic description for an ss-component mixture of inelastic, smooth hard disks (two dimensions) or spheres (three dimensions) is derived based on the revised Enskog theory for the single-particle velocity distribution functions. In this first portion of the two-part series, the macroscopic balance equations for mass, momentum, and energy are derived. Constitutive equations are calculated from exact expressions for the fluxes by a Chapman-Enskog expansion carried out to first order in spatial gradients, thereby resulting in a Navier-Stokes order theory. Within this context of small gradients, the theory is applicable to a wide range of restitution coefficients and densities. The resulting integral-differential equations for the zeroth- and first-order approximations of the distribution functions are given in exact form. An approximate solution to these equations is required for practical purposes in order to cast the constitutive quantities as algebraic functions of the macroscopic variables; this task is described in the companion paper.Comment: 36 pages, to be published in Phys. Rev.

    Recent Decisions

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    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

    The influence of yeast strain on the oxidative stability of beer

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    Funder: SABMiller PlcFunder: University of Nottingham; Id: http://dx.doi.org/10.13039/501100000837Flavour stability, or instability, relates to the rate of flavour change through the shelf‐life of packaged beer. There are several control points in the production of beer where flavour stability may be altered. These include fermentation and the influence of yeast is key. Greater insight into the yeast traits which contribute to flavour stability may help yeast strain selection in the future. Knowledge of the key phenotypes may also lead to improved yeast handing or monitoring practices. In this study, 11 yeast strains, previously characterised according to their sensitivity to oxidative stresses (induced by menadione and hydrogen peroxide) were screened using miniature (100 mL) fermentations and the oxidative stability of the resultant green beer assessed using Electron Paramagnetic Resonance Spectroscopy. The selection of strains with high resistance to multiple oxidative stresses was shown to be a good indicator that yeast would produce a more oxidatively stable beer, although the mechanisms determining this are unknown. The relevance of selecting yeast based on their oxidative sensitivity, their potential to remove metals and sulphur dioxide production are discussed. © 2021 The Authors. Journal of the Institute of Brewing published by John Wiley & Sons Ltd on behalf of The Institute of Brewing & Distillin

    A low-mass planet candidate orbiting Proxima Centauri at a distance of 1.5 AU

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    Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).Our nearest neighbor, Proxima Centauri, hosts a temperate terrestrial planet. We detected in radial velocities evidence of a possible second planet with minimum mass m c sin i c = 5.8 ± 1.9 M ⊕ and orbital period P c = 5.21 - 0.22 + 0.26 years. The analysis of photometric data and spectro-scopic activity diagnostics does not explain the signal in terms of a stellar activity cycle, but follow-up is required in the coming years for confirming its planetary origin. We show that the existence of the planet can be ascertained, and its true mass can be determined with high accuracy, by combining Gaia astrometry and radial velocities. Proxima c could become a prime target for follow-up and characterization with next-generation direct imaging instrumentation due to the large maximum angular separation of ~1 arc second from the parent star. The candidate planet represents a challenge for the models of super-Earth formation and evolution.Peer reviewedFinal Published versio

    1,1-Bis[4-(trifluoro­meth­yl)phen­yl]germetane

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    The inter­nal C—Ge—C bond angle in the germacyclo­butane ring of the title compound, C17H14F6Ge or [Ge(C3H6)(C7H4F3)2], is 77.8 (3)°. The –CF3 groups display rotational disorder [occupancies 0.604 (14):0.396 (14) and 0.410 (6):0.411 (6):0.179 (3)] and the germacyclo­butane ring also shows disorder [occupancies 0.604 (14):0.396 (14)]
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