456 research outputs found

    Pre-breeding Strategies

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    Design and Implementation of a Studio-Based General Chemistry Course

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    Most students taking general chemistry courses do not intend to pursue careers in chemistry; in fact, they are more likely to end up in positions where they fund, write, or vote for chemical research and policies. Our profession continues to ask how we can teach students scientific reasoning skills and chemical understanding in general chemistry that they are able to take beyond the classroom into their everyday lives. The emerging answer at this university is the studio teaching method, which incorporates the “best teaching and learning practices†recommended by chemical education research within an integrated lecture–lab technology-intensive environment. The design, implementation, and pedagogical rationale of studio general chemistry are described

    Natural drivers of multidecadal Arctic sea ice variability over the last millennium

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    This is the final version. Available from Nature Research via the DOI in this record.The climate varies due to human activity, natural climate cycles, and natural events external to the climate system. Understanding the different roles played by these drivers of variability is fundamental to predicting near-term climate change and changing extremes, and to attributing observed change to anthropogenic or natural factors. Natural drivers such as large explosive volcanic eruptions or multidecadal cycles in ocean circulation occur infrequently and are therefore poorly represented within the observational record. Here we turn to the first high-latitude annually-resolved and absolutely dated marine record spanning the last millennium, and the Paleoclimate Modelling Intercomparison Project (PMIP) Phase 3 Last Millennium climate model ensemble spanning the same time period, to examine the influence of natural climate drivers on Arctic sea ice. We show that bivalve oxygen isotope data are recording multidecadal Arctic sea ice variability and through the climate model ensemble demonstrate that external natural drivers explain up to third of this variability. Natural external forcing causes changes in sea-ice mediated export of freshwater into areas of active deep convection, affecting the strength of the Atlantic Meridional Overturning Circulation (AMOC) and thereby northward heat transport to the Arctic. This in turn leads to sustained anomalies in sea ice extent. The models capture these positive feedbacks, giving us improved confidence in their ability to simulate future sea ice in in a rapidly evolving Arctic.Natural Environment Research Council (NERC)Natural Environment Research Council (NERC)Natural Environment Research Council (NERC)Leverhulme TrustAustralian Research CouncilEuropean Union’s Horizon 202

    The Grizzly, September 21, 1993

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    Israel and PLO Reach Peace Agreement • The Quilt: To Remember, To Educate, To Celebrate • Russian TV Crew Filming at Ursinus • New Reimert Policies for \u2793-\u2794 • Jurassic Park: It\u27s Only a Movie • Bernie Bernie Headflap Wins the Battle Again! • The Newly Roomie Game • A Unique Affair Awaits Us: Javapalooza \u2793 to Entertain Ursinus • Ursinus Needs AIDS Policy • More Than a Number • The New Wismer? Or a Police State? • Field Hockey Struggles Early • Men\u27s X-Country Starts off 2-0 • Lady Bears Search for Consistencyhttps://digitalcommons.ursinus.edu/grizzlynews/1318/thumbnail.jp

    Flaring Behavior of the Quasar 3C~454.3 across the Electromagnetic Spectrum

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    We analyze the behavior of the parsec-scale jet of the quasar 3C~454.3 during pronounced flaring activity in 2005-2008. Three major disturbances propagated down the jet along different trajectories with Lorentz factors Γ>\Gamma>10. The disturbances show a clear connection with millimeter-wave outbursts, in 2005 May/June, 2007 July, and 2007 December. High-amplitude optical events in the RR-band light curve precede peaks of the millimeter-wave outbursts by 15-50 days. Each optical outburst is accompanied by an increase in X-ray activity. We associate the optical outbursts with propagation of the superluminal knots and derive the location of sites of energy dissipation in the form of radiation. The most prominent and long-lasting of these, in 2005 May, occurred closer to the black hole, while the outbursts with a shorter duration in 2005 Autumn and in 2007 might be connected with the passage of a disturbance through the millimeter-wave core of the jet. The optical outbursts, which coincide with the passage of superluminal radio knots through the core, are accompanied by systematic rotation of the position angle of optical linear polarization. Such rotation appears to be a common feature during the early stages of flares in blazars. We find correlations between optical variations and those at X-ray and γ\gamma-ray energies. We conclude that the emergence of a superluminal knot from the core yields a series of optical and high-energy outbursts, and that the mm-wave core lies at the end of the jet's acceleration and collimation zone.Comment: 57 pages, 23 figures, 8 tables (submitted to ApJ
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