801 research outputs found

    With Love: Attempting to Instill the Lasting Value of Humanity While Teaching During a Global Pandemic

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    Given the onslaught of COVID-19, the University of Minnesota suspended in-person instruction, forcing instructors to engage multiple forms of distance learning. This essay describes how two graduate instructors in social studies teacher education shifted their pedagogical focus from one course’s content to the ways in which their students would experience their online instruction. The instructors’ overarching goal was to model for their pre-service teachers what they hoped would be the pedagogical imperatives in those pre-service teachers’ future classrooms: the centering of humanity, the ability to balance grace with high expectations, and the willingness to reflect and learn on their own

    Personality factors and self-reported political news consumption predict susceptibility to political fake news

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    17 USC 105 interim-entered record; under temporary embargo.The existence of fake news on social media is likely to influence important issues such as elections, attitudes toward public policy, and health care decisions. Studies have shown that individual differences predict participants’ ability to discern real and fake news. The present study examined whether personality factors and news consumption predict an individual’s political news discernment. Participants (N = 353) judged the accuracy of true and false political news headlines, completed a personality inventory, and reported how many hours they obtained political news from various sources in a typical week. Regression analyses revealed that greater levels of agreeableness, conscientiousness, open-mindedness, lower levels of extraversion, and fewer hours of news consumption were related to better news discernment. Participants also showed a bias toward headlines consistent with their self-reported political ideology, and this bias was related to consumption of ideologically biased news sources. These results extend those that have identified individual differences in news discernment, demonstrating that personality factors and news consumption are related to the ability to discern between true and false political news.U.S. Government affiliation is unstated in article text

    Evolution of circular, non-equatorial orbits of Kerr black holes due to gravitational-wave emission: II. Inspiral trajectories and gravitational waveforms

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    The inspiral of a ``small'' (μ1100M\mu \sim 1-100 M_\odot) compact body into a ``large'' (M1057MM \sim 10^{5-7} M_\odot) black hole is a key source of gravitational radiation for the space-based gravitational-wave observatory LISA. The waves from such inspirals will probe the extreme strong-field nature of the Kerr metric. In this paper, I investigate the properties of a restricted family of such inspirals (the inspiral of circular, inclined orbits) with an eye toward understanding observable properties of the gravitational waves that they generate. Using results previously presented to calculate the effects of radiation reaction, I assemble the inspiral trajectories (assuming that radiation reacts adiabatically, so that over short timescales the trajectory is approximately geodesic) and calculate the wave generated as the compact body spirals in. I do this analysis for several black hole spins, sampling a range that should be indicative of what spins we will encounter in nature. The spin has a very strong impact on the waveform. In particular, when the hole rotates very rapidly, tidal coupling between the inspiraling body and the event horizon has a very strong influence on the inspiral time scale, which in turn has a big impact on the gravitational wave phasing. The gravitational waves themselves are very usefully described as ``multi-voice chirps'': the wave is a sum of ``voices'', each corresponding to a different harmonic of the fundamental orbital frequencies. Each voice has a rather simple phase evolution. Searching for extreme mass ratio inspirals voice-by-voice may be more effective than searching for the summed waveform all at once.Comment: 15 pages, 11 figures, accepted for publication in PRD. This version incorporates referee's comments, and is much less verbos

    Improving sheep feedlot management

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    This paper summarise six studies undertaken by the Sheep CRC to elucidate certain aspects of confinement feeding of sheep. A review of confinement feeding highlighted the variability of growth rate and feed conversion of sheep and revealed that little is known about the use of sorghum for feeding sheep. The review indicated that the main factors responsible for variation of growth rate and feed conversion were adaptation to grain and feeding system, including the preparation and presentation of feed. The importance of social and physiological adaptation to grain feeding was confirmed. Factors identified as responsible for safe induction and uniform growth rates included prior exposure to grain as lambs, gradual introduction of grain and, when concentrate was provided ad libitum from the first day, the use of either virginiamycin, a pelleted feed, a total mixed ration or a step-wise increase of high-starch grain components. Separate feeding of hay and grain resulted in performance comparable with that of a pelleted diet and that of a total mixed ration. Sorghum-based concentrate diets resulted in growth rates and carcase weights similar to that for winter cereal grains or pellets. Steam flaking or expanding of sorghum had no significant effect on growth rates or carcase weights. These results can be used to determine the profitability of various feedlotting options

    Improving sheep feedlot management

    Get PDF
    This paper summarise six studies undertaken by the Sheep CRC to elucidate certain aspects of confinement feeding of sheep. A review of confinement feeding highlighted the variability of growth rate and feed conversion of sheep and revealed that little is known about the use of sorghum for feeding sheep. The review indicated that the main factors responsible for variation of growth rate and feed conversion were adaptation to grain and feeding system, including the preparation and presentation of feed. The importance of social and physiological adaptation to grain feeding was confirmed. Factors identified as responsible for safe induction and uniform growth rates included prior exposure to grain as lambs, gradual introduction of grain and, when concentrate was provided ad libitum from the first day, the use of either virginiamycin, a pelleted feed, a total mixed ration or a step-wise increase of high-starch grain components. Separate feeding of hay and grain resulted in performance comparable with that of a pelleted diet and that of a total mixed ration. Sorghum-based concentrate diets resulted in growth rates and carcase weights similar to that for winter cereal grains or pellets. Steam flaking or expanding of sorghum had no significant effect on growth rates or carcase weights. These results can be used to determine the profitability of various feedlotting options

    Electrical testing of the full-scale model of the NSTX HHFW antenna array

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    The 30 MHz high harmonic fast wave (HHFW) antenna array for NSTX consists of 12 current straps, evenly spaced in the toroidal direction. Each pair of straps is connected as a half-wave resonant loop and will be driven by one transmitter, allowing rapid phase shift between transmitters. A decoupling network using shunt stub tuners has been designed to compensate for the mutual inductive coupling between adjacent current straps, effectively isolating the six transmitters from one another. One half of the array, consisting of six full-scale current strap modules, three shunt stub decouplers, and powered by three phase-adjustable rf amplifiers had been built for electrical testing at ORNL. Low power testing includes electrical characterization of the straps, operation and performance of the decoupler system, and mapping of the rf fields in three dimensions

    Comparing Formulations of Generalized Quantum Mechanics for Reparametrization-Invariant Systems

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    A class of decoherence schemes is described for implementing the principles of generalized quantum theory in reparametrization-invariant `hyperbolic' models such as minisuperspace quantum cosmology. The connection with sum-over-histories constructions is exhibited and the physical equivalence or inequivalence of different such schemes is analyzed. The discussion focuses on comparing constructions based on the Klein-Gordon product with those based on the induced (a.k.a. Rieffel, Refined Algebraic, Group Averaging, or Spectral Analysis) inner product. It is shown that the Klein-Gordon and induced products can be simply related for the models of interest. This fact is then used to establish isomorphisms between certain decoherence schemes based on these products.Comment: 21 pages ReVTe

    Anisotropic splitting of intersubband spin plasmons in quantum wells with bulk and structural inversion asymmetry

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    In semiconductor heterostructures, bulk and structural inversion asymmetry and spin-orbit coupling induce a k-dependent spin splitting of valence and conduction subbands, which can be viewed as being caused by momentum-dependent crystal magnetic fields. This paper studies the influence of these effective magnetic fields on the intersubband spin dynamics in an asymmetric n-type GaAs/AlGaAs quantum well. We calculate the dispersions of intersubband spin plasmons using linear response theory. The so-called D'yakonov-Perel' decoherence mechanism is inactive for collective intersubband excitations, i.e., crystal magnetic fields do not lead to decoherence of spin plasmons. Instead, we predict that the main signature of bulk and structural inversion asymmetry in intersubband spin dynamics is a three-fold, anisotropic splitting of the spin plasmon dispersion. The importance of many-body effects is pointed out, and conditions for experimental observation with inelastic light scattering are discussed.Comment: 8 pages, 6 figure
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