5,384 research outputs found

    Integrating Two Epistemological Goals: Why Shouldn’t We Give It Another Chance?

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    As Beller, Bender, and Medin (in press) pointed out in their target article, in the contemporary study of culture in psychology, anthropology is virtually invisible. In this commentary, I traced this invisibility to a root conflict in epistemological goals of the two disciplines: Whereas anthropologists value rich description of specific cultures, psychologists aspire to achieve theoretical simplicity. To anthropologists, then, to understand culture is to articulate symbolic systems that are at work in a given location at a given time. In contrast, to psychologists, to understand culture amounts to identifying socio‐cultural variables that moderate psychological effects. These divergent epistemological goals dictate both theoretical perspectives and empirical approaches in both disciplines. Yet, the two goals are both valid and in fact complementary. A renewed effort toward integration of the two goals may enrich both disciplines.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/92388/1/j.1756-8765.2012.01201.x.pd

    Heavy-Baryon Spectroscopy from Lattice QCD

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    We use a four-dimensional lattice calculation of the full-QCD (quantum chromodynamics, the non-abliean gauge theory of the strong interactions of quarks and gluons) path integrals needed to determine the masses of the charmed and bottom baryons. In the charm sector, our results are in good agreement with experiment within our systematics, except for the spin-1/2 Ξcc\Xi_{cc}, for which we found the isospin-averaged mass to be Ξcc\Xi_{cc} to be 3665±17±14−78+03665\pm17\pm14^{+0}_{-78} MeV. We predict the mass of the (isospin-averaged) spin-1/2 Ωcc\Omega_{cc} to be 3763±19±26−79+133763\pm19\pm26^{+13}_{-79} {MeV}. In the bottom sector, our results are also in agreement with experimental observations and other lattice calculations within our statistical and systematic errors. In particular, we find the mass of the Ωb\Omega_b to be consistent with the recent CDF measurement. We also predict the mass for the as yet unobserved Ξbâ€Č\Xi^\prime_b to be 5955(27) MeV.Comment: Invited talk at Conference of Computational Physics 2009. 3 page

    General non-Markovian dynamics of open quantum systems

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    We present a general theory of non-Markovian dynamics for open quantum systems. We explore the non-Markovian dynamics by connecting the exact master equations with the non-equilibirum Green functions. Environmental back-actions are fully taken into account. The non-Markovian dynamics consists of non-exponential decays and dissipationless oscillations. Non-exponential decays are induced by the discontinuity in the imaginary part of the self-energy corrections. Dissipationless oscillations arise from band gaps or the finite band structure of spectral densities. The exact analytic solutions for various non-Markovian environments show that the non-Markovian dynamics can be largely understood from the environmental-modified spectra of the open systems.Comment: 6 pages, 2 figure

    Difficult birth is the main contributor to birth‐related fracture and accidents to other neonatal fractures

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    Aim Specific birth-related fractures have been studied; underestimates might be a problem. We aimed to assess all fractures diagnosed as birth-related as well as other neonatal fractures. Methods A population-based study on all infants born in Sweden 1997-2014; data were retrieved from the Swedish Health Registers (10th version of International Classification of Diseases. Outcome measures were birth-related fractures (ICD-10 P-codes) and other neonatal fractures (ICD-10 S-codes). Results The overall fracture incidence was 2.9 per 1000 live birth (N = 5336); 92.6% had P-codes and 7.4% (S-codes). Some birth-related fractures were diagnosed beyond the neonatal period. Other neonatal fractures could have been birth-related. Clavicle fracture (88.8%) was associated with adverse maternal and infant anthropometrics and birth complications. The few neonates with rib fractures all had concomitant clavicle fracture. For skull fractures, a minor part was birth-related and most were associated with accidents. Half of the long bone fractures were associated with accidents. Birth-related femur fractures were associated with bone fragility risk factors. Five infants with abuse diagnoses had fractures: skull (4), long bone (2) and rib (1). Conclusion Birth-related and other neonatal fractures are rarely diagnosed. Difficult birth is the main contributor to birth-related fracture and accidents to other neonatal fractures.Peer reviewe

    IL-17A induces Pendrin expression and chloride-bicarbonate exchange in human bronchial epithelial cells

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    The epithelium plays an active role in the response to inhaled pathogens in part by responding to signals from the immune system. Epithelial responses may include changes in chemokine expression, increased mucin production and antimicrobial peptide secretion, and changes in ion transport. We previously demonstrated that interleukin-17A (IL-17A), which is critical for lung host defense against extracellular bacteria, significantly raised airway surface pH in vitro, a finding that is common to a number of inflammatory diseases. Using microarray analysis of normal human bronchial epithelial (HBE) cells treated with IL-17A, we identified the electroneutral chloride-bicarbonate exchanger Pendrin (SLC26A4) as a potential mediator of this effect. These data were verified by real-time, quantitative PCR that demonstrated a time-dependent increase in Pendrin mRNA expression in HBE cells treated with IL-17A up to 48 h. Using immunoblotting and immunofluorescence, we confirmed that Pendrin protein expression is increased in IL-17 treated HBE cells and that it is primarily localized to the mucosal surface of the cells. Functional studies using live-cell fluorescence to measure intracellular pH demonstrated that IL-17A induced chloride-bicarbonate exchange in HBE cells that was not present in the absence of IL-17A. Furthermore, HBE cells treated with short interfering RNA against Pendrin showed substantially reduced chloride-bicarbonate exchange. These data suggest that Pendrin is part of IL-17A-dependent epithelial changes and that Pendrin may therefore be a therapeutic target in IL-17A-dependent lung disease. © 2014 Adams et al

    Rendezvous on a Line by Location-Aware Robots Despite the Presence of Byzantine Faults

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    A set of mobile robots is placed at points of an infinite line. The robots are equipped with GPS devices and they may communicate their positions on the line to a central authority. The collection contains an unknown subset of "spies", i.e., byzantine robots, which are indistinguishable from the non-faulty ones. The set of the non-faulty robots need to rendezvous in the shortest possible time in order to perform some task, while the byzantine robots may try to delay their rendezvous for as long as possible. The problem facing a central authority is to determine trajectories for all robots so as to minimize the time until the non-faulty robots have rendezvoused. The trajectories must be determined without knowledge of which robots are faulty. Our goal is to minimize the competitive ratio between the time required to achieve the first rendezvous of the non-faulty robots and the time required for such a rendezvous to occur under the assumption that the faulty robots are known at the start. We provide a bounded competitive ratio algorithm, where the central authority is informed only of the set of initial robot positions, without knowing which ones or how many of them are faulty. When an upper bound on the number of byzantine robots is known to the central authority, we provide algorithms with better competitive ratios. In some instances we are able to show these algorithms are optimal

    Approaching Conformality with Ten Flavors

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    We present first results for lattice simulations, on a single volume, of the low-lying spectrum of an SU(3) Yang-Mills gauge theory with ten light fermions in the fundamental representation. Fits to the fermion mass dependence of various observables are found to be globally consistent with the hypothesis that this theory is within or just outside the strongly-coupled edge of the conformal window, with mass anomalous dimension consistent with 1 over the range of scales simulated. We stress that we cannot rule out the possibility of spontaneous chiral-symmetry breaking at scales well below our infrared cutoff. We discuss important systematic effects, including finite-volume corrections, and consider directions for future improvement.Comment: 7 pages, 3 figures. Submitted to Physical Review Letters. v2: corrected global fits. v3: corrected estimation of confidence interval
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