4,856 research outputs found

    Getting to know you: Accuracy and error in judgments of character

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    Character judgments play an important role in our everyday lives. However, decades of empirical research on trait attribution suggest that the cognitive processes that generate these judgments are prone to a number of biases and cognitive distortions. This gives rise to a skeptical worry about the epistemic foundations of everyday characterological beliefs that has deeply disturbing and alienating consequences. In this paper, I argue that this skeptical worry is misplaced: under the appropriate informational conditions, our everyday character-trait judgments are in fact quite trustworthy. I then propose a mindreading-based model of the socio-cognitive processes underlying trait attribution that explains both why these judgments are initially unreliable, and how they eventually become more accurate

    Effects of Lightning on Trees: A Predictive Model Based on in situ Electrical Resistivity

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    The effects of lightning on trees range from catastrophic death to the absence of observable damage. Such differences may be predictable among tree species, and more generally among plant life history strategies and growth forms. We used field‐collected electrical resistivity data in temperate and tropical forests to model how the distribution of power from a lightning discharge varies with tree size and identity, and with the presence of lianas. Estimated heating density (heat generated per volume of tree tissue) and maximum power (maximum rate of heating) from a standardized lightning discharge differed 300% among tree species. Tree size and morphology also were important; the heating density of a hypothetical 10 m tall Alseis blackiana was 49 times greater than for a 30 m tall conspecific, and 127 times greater than for a 30 m tall Dipteryx panamensis. Lianas may protect trees from lightning by conducting electric current; estimated heating and maximum power were reduced by 60% (±7.1%) for trees with one liana and by 87% (±4.0%) for trees with three lianas. This study provides the first quantitative mechanism describing how differences among trees can influence lightning–tree interactions, and how lianas can serve as natural lightning rods for trees

    The comparative biology of skeletal metastasis

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    Bone metastasis, a very common sequelae of cancer, is often associated with great morbidity. Understanding the biology of bone metastases may lead to therapeutic interventions to target the metastases. In addition to replacing bone marrow elements, the presence of tumour cells in bone modulates the normal bone remodelling process. Some tumours result in primarily osteolytic bone lesions, whereas others are associated with osteoblastic bone lesions. In either case, the resulting changes in the bone structure result in weakened bone that induces pain and is predisposed to fracture. The mechanisms through which cancer cells modulate bone remodelling are not clearly defined, but ongoing research using a variety of animal models will hopefully provide clues to prevent or slow the progress of bone metastases.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73390/1/j.1476-5829.2003.00023.x.pd

    Impact of an improved neutrino energy estimate on outflows in neutron star merger simulations

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    Binary neutron star mergers are promising sources of gravitational waves for ground-based detectors such as Advanced LIGO. Neutron-rich material ejected by these mergers may also be the main source of r-process elements in the Universe, while radioactive decays in the ejecta can power bright electromagnetic post-merger signals. Neutrino-matter interactions play a critical role in the evolution of the composition of the ejected material, which significantly impacts the outcome of nucleosynthesis and the properties of the associated electromagnetic signal. In this work, we present a simulation of a binary neutron star merger using an improved method for estimating the average neutrino energies in our energy-integrated neutrino transport scheme. These energy estimates are obtained by evolving the neutrino number density in addition to the neutrino energy and flux densities. We show that significant changes are observed in the composition of the polar ejecta when comparing our new results with earlier simulations in which the neutrino spectrum was assumed to be the same everywhere in optically thin regions. In particular, we find that material ejected in the polar regions is less neutron rich than previously estimated. Our new estimates of the composition of the polar ejecta make it more likely that the color and timescale of the electromagnetic signal depend on the orientation of the binary with respect to an observer's line-of-sight. These results also indicate that important observable properties of neutron star mergers are sensitive to the neutrino energy spectrum, and may need to be studied through simulations including a more accurate, energy-dependent neutrino transport scheme.Comment: 19p, 17 figures, Accepted by Phys.Rev.

    Evidence for quantum confinement in the photoluminescence of porous Si and SiGe

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    We have used anodization techniques to process porous surface regions in p-type Czochralski Si and in p-type Si0.85Ge0.15 epitaxial layers grown by molecular beam epitaxy. The SiGe layers were unrelaxed before processing. We have observed strong near-infrared and visible light emission from both systems. Analysis of the radiative and nonradiative recombination processes indicate that the emission is consistent with the decay of excitons localized in structures of one or zero dimensions

    Adaptive Management and Quail Conservation on Rangelands in the American West

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    Adaptive management has been and is being practiced with the goal of sustaining populations of wild quails on large areas of rangelands in the American West. Because the current land use practices throughout most of the eastern two-thirds of the United States largely do not promote early-successional vegetation communities, rangelands contain the largest remaining blocks of contiguous (unfragmented) habitat for the northern bobwhite (Colinus virginianus) and the other 5 species of quails found in the western states. Many wildlife professionals on both private and public rangelands are practicing a diverse array of quail habitat and population management actions that could be considered a form of adaptive management—an iterative process used to make decisions in the context of uncertainty. Though this “learning by doing” approach is not always formally labeled adaptive management, these wildlife professionals intuitively recognize the value of the process in sustaining populations of wild quails. We support our assertions about adaptive management with 4 case study examples of adaptive management projects that promote quail conservation—including quail hunting—on both private and public rangelands in the American West. By discussing these scenarios within an adaptive management framework, we hope to highlight current and future opportunities for adaptive management in quail conservation on rangelands and to discuss where adaptive management may be improved or no longer be appropriate
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