11,278 research outputs found

    Exploring the Experiences and Perceptions of 21st Century Leadership Academy Participants

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    The 21st Century Leadership Academy grew out of an effort by the Council of Technology Teacher Education’s (CTTE) Leadership Development Committee to prepare future leaders for the field of Technology & Engineering Education (TEE). Efforts by Drs. Roger Hill (University of Georgia) and Bill Havice (Clemson University) led to the creation, and subsequent implementation, of this leadership academy with support from CTTE (later renamed the Council on Technology & Engineering Teacher Education [CTETE]) and the International Technology & Engineering Education Association (ITEEA). Initially, participation in the leadership academy was focused on early-career university faculty but recruitment was later expanded to include individuals with related professional experience (e.g., graduate students, tenured faculty members, etc.) and, as of January 2021, more than 80 individuals have participated in the academy. This study reports an investigation into the experiences and perceptions of the academy alums with an additional focus on their professional involvement, how participation may have influenced these activities, and suggestions they had for future cohorts. In addition, our investigation provides suggestions for future similar leadership training efforts that could be applied in a variety of fields. Our efforts, as researchers, aim to present the shared experience as navigated by the cohort participants. Although individual takeaways vary, overall themes such as networking and collaboration underscore the experience of participants in each cohort year. While participants consider themselves active in the field of Technology & Engineering Education, few of them are serving in leadership roles within CTETE or ITEEA

    N-body Gravity and the Schroedinger Equation

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    We consider the problem of the motion of NN bodies in a self-gravitating system in two spacetime dimensions. We point out that this system can be mapped onto the quantum-mechanical problem of an N-body generalization of the problem of the H2+_{2}^{+} molecular ion in one dimension. The canonical gravitational N-body formalism can be extended to include electromagnetic charges. We derive a general algorithm for solving this problem, and show how it reduces to known results for the 2-body and 3-body systems.Comment: 15 pages, Latex, references added, typos corrected, final version that appears in CQ

    Carbonyl­chlorido(1-methyl­sulfanylpenta-1,3-dien-1-yl-5-yl­idene)bis­(triphenyl­phosphane)osmium(II)

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    The crystal structure of the title compound, [Os(C6H7S)Cl(C18H15P)2(CO)], confirms the formulation as an osmabenzene. There is a slightly distorted octa­hedral coordination environment at the OsII ion, with the triphenyl­phosphane ligands mutually trans and the chloride cis to the carbon bearing the –SMe substituent. Within the metallacyclic ring, the C—C distances are appropriate for aromatic bonds and the two Os—C distances are shorter than typical Os—C single bonds. The maximum deviation from the least-squares plane through the osmabenzene ring occurs for the carbon bearing the SMe substituent [0.1037 (18) Å]

    Tracing the Bipolar Outflow from Orion Source I

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    Using CARMA, we imaged the 87 GHz SiO v=0 J=2-1 line toward Orion-KL with 0.45 arcsec angular resolution. The maps indicate that radio source I drives a bipolar outflow into the surrounding molecular cloud along a NE--SW axis, in agreement with the model of Greenhill et al. (2004). The extended high velocity outflow from Orion-KL appears to be a continuation of this compact outflow. High velocity gas extends farthest along a NW--SE axis, suggesting that the outflow direction changes on time scales of a few hundred years.Comment: 4 pages, 4 figures; accepted for publication in Ap J Letter

    Helix 11 Dynamics Is Critical for Constitutive Androstane Receptor Activity

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    SummaryThe constitutive androstane receptor (CAR) transactivation can occur in the absence of exogenous ligand and this activity is enhanced by agonists TCPOBOP and meclizine. We use biophysical and cell-based assays to show that increased activity of CAR(TCPOBOP) relative to CAR(meclizine) corresponds to a higher affinity of CAR(TCPOBOP) for the steroid receptor coactivator-1. Additionally, steady-state fluorescence spectra suggest conformational differences between CAR(TCPOBOP):RXR and CAR(meclizine):RXR. Hydrogen/deuterium exchange (HDX) data indicate that the CAR activation function 2 (AF-2) is more stable in CAR(TCPOBOP):RXR and CAR(meclizine):RXR than in CAR:RXR. HDX kinetics also show significant differences between CAR(TCPOBOP):RXR and CAR(meclizine):RXR. Unlike CAR(meclizine):RXR, CAR(TCPOBOP):RXR shows a higher overall stabilization that extends into RXR. We identify residues 339–345 in CAR as an allosteric regulatory site with a greater magnitude reduction in exchange kinetics in CAR(TCPOBOP):RXR than CAR(meclizine):RXR. Accordingly, assays with mutations on CAR at leucine-340 and leucine-343 confirm this region as an important determinant of CAR activity

    Prediction of the Aerothermodynamic Environment of the Huygens Probe

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    An investigation of the aerothermodynamic environment of the Huygens entry probe has been conducted. A Monte Carlo simulation of the trajectory of the probe during entry into Titan's atmosphere was performed to identify a worst-case heating rate trajectory. Flowfield and radiation transport computations were performed at points along this trajectory to obtain convective and radiative heat-transfer distributions on the probe's heat shield. This investigation identified important physical and numerical factors, including atmospheric CH4 concentration, transition to turbulence, numerical diffusion modeling, and radiation modeling, which strongly influenced the aerothermodynamic environment

    Integrated stratigraphy of the Waitakian-Otaian Stage boundary stratotype, Early Miocene, New Zealand

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    The base of the type section of the Otaian Stage at Bluecliffs, South Canterbury, is recognised as the stratotype for the boundary between the Waitakian and Otaian Stages. Principal problems with the boundary are the restriction of existing bioevent proxies to shelf and upper slope environments and its uncertain age. These topics are addressed by a multidisplinary study of a 125 m section about the boundary, which examines its lithostratigraphy, depositional setting, biostratigraphy, correlation, and geochronology. The lower siltstone lithofacies (0-38.5 m) was deposited at upper bathyal depths (200-600 m) in a marginal basin which was partially sheltered from fully oceanic circulation by a submarine high and islands. The site was covered by cool-temperate water and was probably adjacent to the Subtropical Convergence. This unit is succeeded by the banded lithofacies (38.5-106 m) and the upper siltstone lithofacies (basal 19 m studied). Paleodepth probably declined up-sequence, but deposition at shelf depths is not definitely indicated. A cyclic pattern of abundance spikes in benthic and planktonic foraminifera commences 9 m above base and extends to 73 m in the banded lithofacies. Oxygen isotope excursions (up to 2.08%) in Euuvigerina miozea and Cibicides novozelandicus are greatest within the interval containing the abundance spikes. The stage boundary occurs in the banded lithofacies at the highest abundance spike (73 m). Although condensed intervals might affect the completeness of the section, they are not associated with sedimentary discontinuities, and we consider that the section is suitable as a biostratigraphic reference. Spores, pollens, dinoflagellates, calcareous nannofossils, foraminifera, bryozoans, and ostracods are preserved near the boundary, but molluscs principally occur higher, in the shallower upper siltstone lithofacies. Siliceous microfossils are rare. There is considerable scope for further biostratigraphic research. The primary event marking the boundary at 73 m is the appearance of the benthic foraminifer Ehrenbergina marwicki. This is a distinctive and widely distributed event but is restricted to shelf and upper bathyal environments. Supplementary events in planktonic foraminifera and calcareous nannofossils were researched. Highest occurrences of Globigerina brazieri and G. euapertura are recorded at 47 and 58 m. There is a marked decline in relative abundance of Paragloborotalia spp. at 62 m. Helicosphaera carteri becomes more abundant than H. euphratis between 56 and 87 m. These events are not exact proxies for the boundary but they may usefully indicate proximity to it. They occur in the interval of prominent spikes in foraminiferal abundance. The Waitakian-Otaian boundary is dated at 21.7 Ma by strontium isotopes. Stable primary remanence could not be determined in a pilot paleomagnetic study of Bluecliffs specimens. However, specimens trended towards reversed polarity, and remagnetisation great circle analysis will allow directions to be calculated in future collections
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