2,033 research outputs found

    Murder in America: a history

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    (print) ix, 399 p., [8] p. of plates : ill. ; 24 cmAcknowledgments -- Introduction: the historian as detective. p.1 -- 1. The British background. p.9 -- 2. The colonial era, 1607-1776. p.33 -- 3. The American Revolution and the early Republic, 1776-1829. p.67 -- 4. The antebellum decades and the Civil War, 1829-1865. p.92 -- 5. The Civil War to World War I, 1865-1917. p.146 -- 6. World War I to World War II, 1917-1941. p.214 -- 7. World War II to the Vietnam War, 1941-1963. p.249 -- 8. The Sixties, 1963-1974. p.268 -- 9. Murder in contemporary America, 1974 to the present: a historical perspective. p.304 -- Select bibliography. p.355 -- Index. p.36

    Octopus arms exhibit exceptional flexibility

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    © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Kennedy, E. B. L., Buresch, K. C., Boinapally, P., & Hanlon, R. T. Octopus arms exhibit exceptional flexibility. Scientific Reports, 10(1), (2020): 20872. doi:10.1038/s41598-020-77873-7.The octopus arm is often referred to as one of the most flexible limbs in nature, yet this assumption requires detailed inspection given that this has not been measured comprehensively for all portions of each arm. We investigated the diversity of arm deformations in Octopus bimaculoides with a frame-by-frame observational analysis of laboratory video footage in which animals were challenged with different tasks. Diverse movements in these hydrostatic arms are produced by some combination of four basic deformations: bending (orally, aborally; inward, outward), torsion (clockwise, counter-clockwise), elongation, and shortening. More than 16,500 arm deformations were observed in 120 min of video. Results showed that all eight arms were capable of all four types of deformation along their lengths and in all directions. Arms function primarily to bring the sucker-lined oral surface in contact with target surfaces. Bending was the most common deformation observed, although the proximal third of the arms performed relatively less bending and more shortening and elongation as compared with other arm regions. These findings demonstrate the exceptional flexibility of the octopus arm and provide a basis for investigating motor control of the entire arm, which may aid the future development of soft robotics.We gratefully acknowledge funding from Grant N00014-19-1-2445 from the Office of Naval Research, Tom McKenna and Marc Steinberg, Program Managers. We also thank the staff of the Marine Resources Center at MBL for assistance with water quality measurements, seawater system maintenance, and collection of food items for octopuses

    A Statement on the Appropriate Role for Research and Development in Climate Policy

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    This statement is issued by a group of economists and scientists which met at Stanford University on October 18, 2008 to discuss the role of research and development (R&D) in developing effective policies for addressing the adverse potential consequences of climate change. We believe that climate change is a serious issue that governments need to address. We also believe that research and development needs to be a central part of governments’ strategies for responding to this challenge. Solutions to manage long-term risks will require the development and global deployment of a range of technologies for energy supply and end-use, land-use, agriculture and adaptation that are not currently commercial. A key potential benefit of focused scientific and technological research and development investment is that it could dramatically reduce the cost of restricting greenhouse gas emissions by encouraging the development of more affordable, better performing technologies.

    Holonomy and parallel transport for Abelian gerbes

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    In this paper we establish a one-to-one correspondence between S1S^1-gerbes with connections, on the one hand, and their holonomies, for simply connected manifolds, or their parallel transports, in the general case, on the other hand. This result is a higher-order analogue of the familiar equivalence between bundles with connections and their holonomies for connected manifolds. The holonomy of a gerbe with group S1S^1 on a simply connected manifold MM is a group morphism from the thin second homotopy group to S1S^1, satisfying a smoothness condition, where a homotopy between maps from [0,1]2[0,1]^2 to MM is thin when its derivative is of rank ≤2\leq 2. For the non-simply connected case, holonomy is replaced by a parallel transport functor between two monoidal Lie groupoids. The reconstruction of the gerbe and connection from its holonomy is carried out in detail for the simply connected case. Our approach to abelian gerbes with connections holds out prospects for generalizing to the non-abelian case via the theory of double Lie groupoids.Comment: Final version. Improved readibility (hopefully). LaTeX, 60 pages, 14 figures. To appear in Advances in Mathematic

    Variable- and person-centered approaches to examining construct-relevant multidimensionality in writing self-efficacy

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    Self-efficacy is an essential component of students’ motivation and success in writing. There have been great advancements in our theoretical understanding of writing self-efficacy over the past 40 years; however, there is a gap in how we empirically model the multidimensionality of writing self-efficacy. The purpose of the present study was to examine the multidimensionality of writing selfefficacy, and present validity evidence for the adapted Self-Efficacy for Writing Scale (SEWS) through a series of measurement model comparisons and person-centered approaches. Using a sample of 1,466 8th–10th graders, results showed that a bifactor exploratory structural equation model best represented the data, demonstrating that the SEWS exhibits both construct-relevant multidimensionality and the presence of a global theme. Using factor scores derived from this model, we conducted latent profile analysis to further establish validity of the measurement model and examine how students disaggregate into groups based on their response trends of the SEWS. Three profiles emerged, differentiated by global writing self-efficacy, with substantively varying factor differences among the profiles. Concurrent, divergent, and discriminant validity evidence was established through a series of analyses that assessed predictors and outcomes of the profiles (e.g., demographics, standardized writing assessments, and grades). Theoretical and practical implications and avenues for future research are discussed. Supplement attached below
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