3,039 research outputs found

    Beyond Heroes & Role Models: Using Biographies to Develop Young Change Agents

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    Reading, writing, and discussing biographies provide unique opportunities for teachers and students. Critical thinking can be developed through questioning, predicting, and analyzing various biographical mediums--texts, photographs and illustrations, book reviews, websites, films, news articles, etc.--to learn more about an individual\u27s life experiences and choices. Decision making skills can be enhanced when students juxtapose their perceptions of heroes and role models to that of a change agent, even considering how their own life experiences and choices may be contributing to larger actions of change. In this article, the authors discuss six biographies that could be used with young people in the elementary classroom to study change agents. The authors carefully selected and organized their literary choices into four categories: (1) familiar historical figures, (2) familiar living persons, (3) less familiar figures, and finally (4) students and teachers themselves--because they can act as change agents today on a local and personal level

    Quantum Error Correction of Observables

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    A formalism for quantum error correction based on operator algebras was introduced in [1] via consideration of the Heisenberg picture for quantum dynamics. The resulting theory allows for the correction of hybrid quantum-classical information and does not require an encoded state to be entirely in one of the corresponding subspaces or subsystems. Here, we provide detailed proofs for the results of [1], derive a number of new results, and we elucidate key points with expanded discussions. We also present several examples and indicate how the theory can be extended to operator spaces and general positive operator-valued measures.Comment: 22 pages, 1 figure, preprint versio

    Scalable Bayesian inference for self-excitatory stochastic processes applied to big American gunfire data

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    The Hawkes process and its extensions effectively model self-excitatory phenomena including earthquakes, viral pandemics, financial transactions, neural spike trains and the spread of memes through social networks. The usefulness of these stochastic process models within a host of economic sectors and scientific disciplines is undercut by the processes' computational burden: complexity of likelihood evaluations grows quadratically in the number of observations for both the temporal and spatiotemporal Hawkes processes. We show that, with care, one may parallelize these calculations using both central and graphics processing unit implementations to achieve over 100-fold speedups over single-core processing. Using a simple adaptive Metropolis-Hastings scheme, we apply our high-performance computing framework to a Bayesian analysis of big gunshot data generated in Washington D.C. between the years of 2006 and 2019, thereby extending a past analysis of the same data from under 10,000 to over 85,000 observations. To encourage wide-spread use, we provide hpHawkes, an open-source R package, and discuss high-level implementation and program design for leveraging aspects of computational hardware that become necessary in a big data setting.Comment: Submitted to Statistics and Computin

    Scaffolding Classroom Discourse in an Election Year: Keeping a Cool Mood in a Heated Season

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    Certainly, teaching about politics can be daunting, especially as the political climate in the United States becomes increasingly partisan as a result of heated political rhetoric amplified through a variety of media outlets. However, elementary teachers can help students develop the respectful dispositions they will need as young adults living in an increasingly pluralistic society. These dispositions can be fostered only if teachers are willing to engage their young learners in discussions of politics as part of the curriculum. In this article, the authors discuss ways in which teachers can promote political tolerance and respect during coverage of a presidential election, a high-profile event that social studies educators Mary Haas and Margaret Laughlin describe as the quintessential example of teaching social studies. Here, the authors also describe instructional strategies designed specifically for the upper elementary grades, although they note ways in which teachers can adapt these strategies for younger learners as well

    On the surprising effectiveness of a simple matrix exponential derivative approximation, with application to global SARS-CoV-2

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    The continuous-time Markov chain (CTMC) is the mathematical workhorse of evolutionary biology. Learning CTMC model parameters using modern, gradient-based methods requires the derivative of the matrix exponential evaluated at the CTMC's infinitesimal generator (rate) matrix. Motivated by the derivative's extreme computational complexity as a function of state space cardinality, recent work demonstrates the surprising effectiveness of a naive, first-order approximation for a host of problems in computational biology. In response to this empirical success, we obtain rigorous deterministic and probabilistic bounds for the error accrued by the naive approximation and establish a "blessing of dimensionality" result that is universal for a large class of rate matrices with random entries. Finally, we apply the first-order approximation within surrogate-trajectory Hamiltonian Monte Carlo for the analysis of the early spread of SARS-CoV-2 across 44 geographic regions that comprise a state space of unprecedented dimensionality for unstructured (flexible) CTMC models within evolutionary biology

    Science lives: School choices and ‘natural tendencies’

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    An analysis of 12 semi-structured interviews with university-based scientists and non-scientists illustrates their life journeys towards, or away from, science and the strengths and impact of life occurrences leading them to choose science or non-science professions. We have adopted narrative approaches and used Mezirow's transformative learning theory framework. The areas of discussion from the result have stressed on three main categories that include ‘smooth transition’, ‘incremental wavering transition' and ‘transformative transition’. The article concludes by discussing the key influences that shaped initial attitudes and direction in these people through natural inclination, environmental inspirations and perceptions of science

    Modelled hydraulic redistribution by sunflower (Helianthus annuus L.) matches observed data only after including night-time transpiration

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    Author Posting. © The Author(s), 2013. This is the author's version of the work. It is posted here by permission of John Wiley & Sons for personal use, not for redistribution. The definitive version was published in Plant, Cell & Environment 37 (2014): 899-910, doi:10.1111/pce.12206.The movement of water from moist to dry soil layers through the root systems of plants, referred to as hydraulic redistribution (HR), occurs throughout the world and is thought to influence carbon and water budgets and ecosystem functioning. The realized hydrologic, biogeochemical, and ecological consequences of HR depend on the amount of redistributed water, while the ability to assess these impacts requires models that correctly capture HR magnitude and timing. Using several soil types and two eco-types of sunflower (Helianthus annuus L.) in split-pot experiments, we examined how well the widely used HR modeling formulation developed by Ryel et al. (2002) matched experimental determination of HR across a range of water potential driving gradients. H. annuus carries out extensive nighttime transpiration, and though over the last decade it has become more widely recognized that nighttime transpiration occurs in multiple species and many ecosystems, the original Ryel et al. (2002) formulation does not include the effect of nighttime transpiration on HR. We developed and added a representation of nighttime transpiration into the formulation, and only then was the model able to capture the dynamics and magnitude of HR we observed as soils dried and nighttime stomatal behavior changed, both influencing HR.This work was supported by a NOAA Climate and Global Change Postdoctoral Fellowship to RBN, administered by the University Corporation for Atmospheric Research, by a grant from the Andrew W. Mellon Foundation to NMH, and by DOE Terrestrial Ecosystem Science grant ER65389 to ZGC and RBN.2014-10-2

    Development of Readout Interconnections for the Si-W Calorimeter of SiD

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    The SiD collaboration is developing a Si-W sampling electromagnetic calorimeter, with anticipated application for the International Linear Collider. Assembling the modules for such a detector will involve special bonding technologies for the interconnections, especially for attaching a silicon detector wafer to a flex cable readout bus. We review the interconnect technologies involved, including oxidation removal processes, pad surface preparation, solder ball selection and placement, and bond quality assurance. Our results show that solder ball bonding is a promising technique for the Si-W ECAL, and unresolved issues are being addressed.Comment: 8 pages + title, 6 figure

    Defining forgiveness: Christian clergy and general population perspectives.

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    The lack of any consensual definition of forgiveness is a serious weakness in the research literature (McCullough, Pargament &amp; Thoresen, 2000). As forgiveness is at the core of Christianity, this study returns to the Christian source of the concept to explore the meaning of forgiveness for practicing Christian clergy. Comparisons are made with a general population sample and social science definitions of forgiveness to ensure that a shared meaning of forgiveness is articulated. Anglican and Roman Catholic clergy (N = 209) and a general population sample (N = 159) completed a postal questionnaire about forgiveness. There is agreement on the existence of individual differences in forgiveness. Clergy and the general population perceive reconciliation as necessary for forgiveness while there is no consensus within psychology. The clergy suggests that forgiveness is limitless and that repentance is unnecessary while the general population suggests that there are limits and that repentance is necessary. Psychological definitions do not conceptualize repentance as necessary for forgiveness and the question of limits has not been addressed although within therapy the implicit assumption is that forgiveness is limitless.</p
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