2,183 research outputs found

    Dilemmatic Deliberations In Kierkegaard’s Fear and Trembling

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    My central claim in this paper is that Kierkegaard’s Fear and Trembling is governed by the basic aim to articulate a real dilemma, and to elicit its proper recognition as such. I begin by indicating how Kierkegaard’s works are shaped in general by this aim, and what the aim involves. I then show how the dilemmaticstructure of Fear and Trembling is obscured in a recent dispute between Michelle Kosch and John Lippitt regarding the basic aims and upshot of the book. Finally, I consider two critical questions: Why does Kierkegaard present his dilemmatic reasoning in the form of a “dialectical lyric”? And why does he write a book that aims only to articulate a dilemma, and not also to resolve it

    The Υ(1S)\Upsilon(1S) leptonic decay using the principle of maximum conformality

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    In the paper, we study the Υ(1S)\Upsilon(1S) leptonic decay width Γ(Υ(1S)+)\Gamma(\Upsilon(1S)\to \ell^+\ell^-) by using the principle of maximum conformality (PMC) scale-setting approach. The PMC adopts the renormalization group equation to set the correct momentum flow of the process, whose value is independent to the choice of the renormalization scale and its prediction thus avoids the conventional renormalization scale ambiguities. Using the known next-to-next-to-next-to-leading order perturbative series together with the PMC single scale-setting approach, we do obtain a renormalization scale independent decay width, ΓΥ(1S)e+e=1.2620.175+0.195\Gamma_{\Upsilon(1S) \to e^+ e^-} = 1.262^{+0.195}_{-0.175} keV, where the error is squared average of those from αs(MZ)=0.1181±0.0011\alpha_s(M_{Z})=0.1181\pm0.0011, mb=4.93±0.03m_b=4.93\pm0.03 GeV and the choices of factorization scales within ±10%\pm 10\% of their central values. To compare with the result under conventional scale-setting approach, this decay width agrees with the experimental value within errors, indicating the importance of a proper scale-setting approach.Comment: 6 pages, 4 figure

    Propagation characteristics and identification of type I cracks by the extended finite element method combined with modal analysis

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    Extended finite element frame based on Abaqus is applied to research the crack propagation problem of two-dimensional long rectangular thin plate. Presuppose type I crack with different horizontal locations and longitudinal dimensions, the propagation characteristics of the edge crack is discussed with the objects of structural flexibility of the thin plate, crack propagation length and plastic zone of crack tip etc. The results indicate that the horizontal location of the initial crack has a small influence on the crack propagation characteristics, and it only affects the local flexibility of the thin plate as well as the dimension and shape of plastic zone of crack tip. The longitudinal dimension of the initial crack obviously nonlinear influence on various parameters of the crack propagation characteristics. In view of the disastrous consequence of crack propagation, the vibration characteristics of the thin plate with different crack dimensions and crack locations are discussed based on the experiment and simulation modal analysis on the thin plate, thus providing basis for prior estimation and control for crack generation and propagation

    The heavy quarkonium inclusive decays using the principle of maximum conformality

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    The next-to-next-to-leading order (NNLO) pQCD correction to the inclusive decays of the heavy quarkonium ηQ\eta_Q (QQ being cc or bb) has been done in the literature within the framework of nonrelativistic QCD. One may observe that the NNLO decay width still has large conventional renormalization scale dependence due to its weaker pQCD convergence, e.g. about (34%+4%)(^{+4\%}_{-34\%}) for ηc\eta_c and (9%+0.0)(^{+0.0}_{-9\%}) for ηb\eta_b, by varying the scale within the range of [mQ,4mQ][m_Q, 4m_Q]. The principle of maximum conformality (PMC) provides a systematic way to fix the αs\alpha_s-running behavior of the process, which satisfies the requirements of renormalization group invariance and eliminates the conventional renormalization scheme and scale ambiguities. Using the PMC single-scale method, we show that the resultant PMC conformal series is renormalization scale independent, and the precision of the ηQ\eta_Q inclusive decay width can be greatly improved. Taking the relativistic correction O(αsv2)\mathcal{O}(\alpha_{s}v^2) into consideration, the ratios of the ηQ\eta_{Q} decays to light hadrons or γγ\gamma\gamma are: RηcNNLOPMC=(3.930.24+0.26)×103R^{\rm NNLO}_{\eta_c}|_{\rm{PMC}}=(3.93^{+0.26}_{-0.24})\times10^3 and RηbNNLOPMC=(22.850.87+0.90)×103R^{\rm NNLO}_{\eta_b}|_{\rm{PMC}}=(22.85^{+0.90}_{-0.87})\times10^3, respectively. Here the errors are for Δαs(MZ)=±0.0011\Delta\alpha_s(M_Z) = \pm0.0011. As a step forward, by applying the Padeˊ\acute{e} approximation approach (PAA) over the PMC conformal series, we obtain approximate NNNLO predictions for those two ratios, e.g. RηcNNNLOPAA+PMC=(5.660.55+0.65)×103R^{\rm NNNLO}_{\eta_c}|_{\rm{PAA+PMC}} =(5.66^{+0.65}_{-0.55})\times10^3 and RηbNNNLOPAA+PMC=(26.021.17+1.24)×103R^{\rm NNNLO}_{\eta_b}|_{\rm{PAA+PMC}}=(26.02^{+1.24}_{-1.17})\times10^3. The RηcNNNLOPAA+PMCR^{\rm NNNLO}_{\eta_c}|_{\rm{PAA+PMC}} ratio agrees with the latest PDG value Rηcexp=(5.31.4+2.4)×103R_{\eta_c}^{\rm{exp}}=(5.3_{-1.4}^{+2.4})\times10^3, indicating the necessity of a strict calculation of NNNLO terms.Comment: 10 pages, 4 figure

    Scale-free resilience of real traffic jams

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    The concept of resilience can be realized in natural and engineering systems, representing the ability of system to adapt and recover from various disturbances. Although resilience is a critical property needed for understanding and managing the risks and collapses of transportation system, an accepted and useful definition of resilience for urban traffic as well as its statistical property under perturbations is still missing. Here we define city traffic resilience based on the spatio-temporal clusters of congestion in real traffic, and find that the resilience follows a scale free distribution in two-dimensional city road networks and one-dimensional highways, with different exponents, but similar exponents in different days and different cities. The traffic resilience is also revealed to have a novel scaling relation between the cluster size of the spatio-temporal jam and its recovery duration, independent of microscopic details. Our findings of universal traffic resilience can provide indication towards better understanding and designing these complex engineering systems under internal and external disturbances. Comment: 6 pages, 4 figure Document type: Articl

    The FOXO Transcription Factor Controls Insect Growth and Development by Regulating Juvenile Hormone Degradation in the Silkworm, \u3cem\u3eBombyx mori\u3c/em\u3e

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    Forkhead box O (FOXO) functions as the terminal transcription factor of the insulin signaling pathway and regulates multiple physiological processes in many organisms, including lifespan in insects. However, how FOXO interacts with hormone signaling to modulate insect growth and development is largely unknown. Here, using the transgene-based CRISPR/Cas9 system, we generated and characterized mutants of the silkworm Bombyx mori FOXO (BmFOXO) to elucidate its physiological functions during development of this lepidopteran insect. The BmFOXO mutant (FOXO-M) exhibited growth delays from the first larval stage and showed precocious metamorphosis, pupating at the end of the fourth instar (trimolter) rather than at the end of the fifth instar as in the wild-type (WT) animals. However, different from previous reports on precocious metamorphosis caused by juvenile hormone (JH) deficiency in silkworm mutants, the total developmental time of the larval period in the FOXO-M was comparable with that of the WT. Exogenous application of 20-hydroxyecdysone (20E) or of the JH analog rescued the trimolter phenotype. RNA-seq and gene expression analyses indicated that genes involved in JH degradation but not in JH biosynthesis were up-regulated in the FOXO-M compared with the WT animals. Moreover, we identified several FOXO-binding sites in the promoter of genes coding for JH-degradation enzymes. These results suggest that FOXO regulates JH degradation rather than its biosynthesis, which further modulates hormone homeostasis to control growth and development in B. mori. In conclusion, we have uncovered a pivotal role for FOXO in regulating JH signaling to control insect development
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