44,332 research outputs found

    Real photons produced from photoproduction in pppp collisions

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    We calculate the production of real photons originating from the photoproduction in relativistic pppp collisions. The Weizsa¨\ddot{\mathrm{a}}cker-Williams approximation in the photoproduction is considered. Numerical results agree with the experimental data from Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC). We find that the modification of the photoproduction is more prominent in large transverse momentum region.Comment: 2 figure

    Guanxi and the organization of Chinese new year festivals in England

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    This article explores how Chinese diaspora communities use guanxi, a unique Chinese interpretation of personal relationships, in the organization of Chinese New Year (CNY) festivals in England. A case-study approach that incorporated mixed qualitative methods was used to investigate the interactions and interrelationships between the ethnic Chinese communities involved in the organization of CNY festivals in five English cities. The article argues that Chinese diaspora communities use their guanxi to establish collaboration at CNY festivals. However, the process of organizing CNY festivals has also exposed divisions among Chinese communities. The article proposes that guanxi has important implications for the relationships among Chinese diaspora communities in the context of CNY festivals. Although it facilitates collaboration and promotes solidarity among Chinese communities, it may also intensify competition for power. Diaspora festivals in general are a neglected area of research and this article is the first to study the organization of Chinese New Year festivals in detail

    Photometric and Spectroscopic Observations of the Algol Type Binary V Triangle

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    Time-series, multi-color photometry and high-resolution spectra of the short period eclipsing binary V Tri were obtained by observations. The completely covered light and radial velocity curves of the binary system are presented. All times of light minima derived from both photoelectric and CCD photometry were used to calculate the orbital period and new ephemerides of the eclipsing system. The analysis of OCO-C diagram reveals that the orbital period is 0.58520481 days0.58520481\ days, decreasing at a rate of $dP/dt=-7.80\times10^{-8} d\ yr^{-1} .Themasstransferbetweenthetwocomponentsandthelighttimetraveleffectduetoathirdbodycouldbeusedtoexplaintheperioddecrease.However,asemidetachedconfigurationwiththelessmasscomponentfillingandtheprimarynearlyfillingeachoftheirRochelobeswasderivedfromthesynthesisofthelightandradialvelocitycurvesbyusingthe2015versionoftheWilsonDevinneycode.Weconsidertheperioddecreasetobethenonconservativemasstransferfromthesecondarycomponenttotheprimaryandthemasslossofthesystem,whichwasthoughttobeanEBtypewhileitshouldbeanEAtype(semidetachedAlgoltype)fromourstudy.Themasses,radiiandluminositiesoftheprimaryandsecondaryare. The mass transfer between the two components and the light time-travel effect due to a third body could be used to explain the period decrease. However, a semidetached configuration with the less-mass component filling and the primary nearly filling each of their Roche lobes was derived from the synthesis of the light and radial velocity curves by using the 2015 version of the Wilson-Devinney code. We consider the period decrease to be the nonconservative mass transfer from the secondary component to the primary and the mass loss of the system, which was thought to be an EB type while it should be an EA type (semi-detached Algol-type) from our study. The masses, radii and luminosities of the primary and secondary are 1.60\pm0.07 M_\odot,, 1.64\pm0.02 R_\odot,, 14.14\pm0.73 L_\odotand and 0.74\pm0.02 M_\odot,, 1.23\pm0.02 R_\odot,, 1.65\pm0.05 L_\odot$, respectively.Comment: 11 pages, 6 figures, Accepted for publication by A

    Beyond relativistic mean-field studies of low-lying states in neutron-deficient krypton isotopes

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    Neutron-deficient krypton isotopes are of particular interest due to the coexistence of oblate and prolate shapes in low-lying states and the transition of ground-state from one dominate shape to another as a function of neutron number. A detailed interpretation of these phenomena in neutron-deficient Kr isotopes requires the use of a method going beyond a mean-field approach that permits to determine spectra and transition probabilities. The aim of this work is to provide a systematic calculation of low-lying state in the even-even 68-86Kr isotopes and to understand the shape coexistence phenomenon and the onset of large collectivity around N=40 from beyond relativistic mean-field studies. The starting point of our method is a set of relativistic mean-field+BCS wave functions generated with a constraint on triaxial deformations (beta, gamma). The excitation energies and electric multipole transition strengths of low-lying states are calculated by solving a five-dimensional collective Hamiltonian (5DCH) with parameters determined by the mean-field wave functions. To examine the role of triaxiality, a configuration mixing of both particle number (PN) and angular momentum (AM) projected axially deformed states is also carried out within the exact generator coordinate method (GCM) based on the same energy density functional. The energy surfaces, the excitation energies of 0^+_2, 2^+_1, 2^+_2 states, as well as the E0 and E2 transition strengths are compared with the results of similar 5DCH calculations but with parameters determined by the non-relativistic mean-field wave functions, as well as with the available data...Comment: 23 pages, 10 figure

    The structure of electronic polarization and its strain dependence

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    The \phi(\kpp)\sim \kpp relation is called polarization structure. By density functional calculations, we study the polarization structure in ferroelectric perovskite PbTiO3_3, revealing (1) the \kpp point that contributes most to the electronic polarization, (2) the magnitude of bandwidth, and (3) subtle curvature of polarization dispersion. We also investigate how polarization structure in PbTiO3_3 is modified by compressive inplane strains. The bandwidth of polarization dispersion in PbTiO3_3 is shown to exhibit an unusual decline, though the total polarization is enhanced. As another outcome of this study, we formulate an analytical scheme for the purpose of identifying what determine the polarization structure at arbitrary \kpp points by means of Wannier functions. We find that \phi(\kpp) is determined by two competing factors: one is the overlaps between neighboring Wannier functions within the plane {\it perpendicular} to the polarization direction, and the other is the localization length {\it parallel} to the polarization direction. Inplane strain increases the former while decreases the latter, causing interesting non-monotonous effects on polarization structure. Finally, polarization dispersion in another paradigm ferroelectric BaTiO3_3 is discussed and compared with that of PbTiO3_3.Comment: 5 Figure

    Gaps below strange star crusts

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    The gap caused by a strong electric field between the quark surface and nuclear crust of a strange star is studied in an improved model including gravity and pressure as well as electrostatic forces. The transition from gap to crust is followed in detail. The properties of the gap are investigated for a wide range of parameters assuming both color-flavor locked and non color-flavor locked strange star cores. The maximally allowed crust density is generally lower than that of neutron drip. Finite temperature is shown to increase the gap width, but the effect is significant only at extreme temperatures. Analytical approximations are derived and shown to provide useful fits to the numerical results.Comment: 12 pages incl. 14 figures. To appear in Physical Review

    Abdominal obesity and the prevalence of diabetes and intermediate hyperglycaemia in Chinese adults

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    Objective: To assess the association of indicators of general and abdominal obesity with the prevalence of type 2 diabetes (T2DM) and intermediate hyperglycaemia (IHG) in the Chinese population. Methods: We used data of 50 905 adults aged 18¿79 years in the 2002 China National Nutrition and Health Survey. Recommended Chinese cut-off values were used for BMI (24 kg/m2) and waist circumference (WC; 85 cm in men, 80 cm in women). Optimal cut-offs for waist:height ratio (WHtR) were determined from analyses of receiver-operating characteristic (ROC) curves. Results: The prevalence of T2DM and IHG was 2?6% and 1?9% respectively. ROC curve analyses indicated 0?5 as the optimal cut-off value for WHtR in both sexes. High BMI, WC and WHtR were all associated with the prevalence of glucose tolerance abnormalities, with the highest prevalence ratio (PR) for high WHtR (men: PR52?85, 95% CI 2?54, 3?21; women: PR53?10, 95% CI 2?74, 3?51). When combining BMI and WHtR, in men either a high BMI or a high WHtR alone was associated with increased risk. Among women, a high BMI without a concomitant high WHtR was not associated with increased glucose tolerance abnormalities risk, whereas a high WHtR was associated with risk irrespective of BMI. Conclusions: Among the Chinese adult population measures of central obesity are better predictors of glucose tolerance abnormalities prevalence than BMI. AWHtR cutoff point of 0?5 for both men and women can be considered as optimum for predicting (pre-) diabetes and may be a useful tool for screening and health education

    On Mitigation of Side-Channel Attacks in 3D ICs: Decorrelating Thermal Patterns from Power and Activity

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    Various side-channel attacks (SCAs) on ICs have been successfully demonstrated and also mitigated to some degree. In the context of 3D ICs, however, prior art has mainly focused on efficient implementations of classical SCA countermeasures. That is, SCAs tailored for up-and-coming 3D ICs have been overlooked so far. In this paper, we conduct such a novel study and focus on one of the most accessible and critical side channels: thermal leakage of activity and power patterns. We address the thermal leakage in 3D ICs early on during floorplanning, along with tailored extensions for power and thermal management. Our key idea is to carefully exploit the specifics of material and structural properties in 3D ICs, thereby decorrelating the thermal behaviour from underlying power and activity patterns. Most importantly, we discuss powerful SCAs and demonstrate how our open-source tool helps to mitigate them.Comment: Published in Proc. Design Automation Conference, 201

    ZIKV infection activates the IRE1-XBP1 and ATF6 pathways of unfolded protein response in neural cells.

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    BACKGROUND: Many viruses depend on the extensive membranous network of the endoplasmic reticulum (ER) for their translation, replication, and packaging. Certain membrane modifications of the ER can be a trigger for ER stress, as well as the accumulation of viral protein in the ER by viral infection. Then, unfolded protein response (UPR) is activated to alleviate the stress. Zika virus (ZIKV) is a mosquito-borne flavivirus and its infection causes microcephaly in newborns and serious neurological complications in adults. Here, we investigated ER stress and the regulating model of UPR in ZIKV-infected neural cells in vitro and in vivo. METHODS: Mice deficient in type I and II IFN receptors were infected with ZIKV via intraperitoneal injection and the nervous tissues of the mice were assayed at 5 days post-infection. The expression of phospho-IRE1, XBP1, and ATF6 which were the key markers of ER stress were analyzed by immunohistochemistry assay in vivo. Additionally, the nuclear localization of XBP1s and ATF6n were analyzed by immunohistofluorescence. Furthermore, two representative neural cells, neuroblastoma cell line (SK-N-SH) and astrocytoma cell line (CCF-STTG1), were selected to verify the ER stress in vitro. The expression of BIP, phospho-elF2α, phospho-IRE1, and ATF6 were analyzed through western blot and the nuclear localization of XBP1s was performed by confocal immunofluorescence microscopy. RT-qPCR was also used to quantify the mRNA level of the UPR downstream genes in vitro and in vivo. RESULTS: ZIKV infection significantly upregulated the expression of ER stress markers in vitro and in vivo. Phospho-IRE1 and XBP1 expression significantly increased in the cerebellum and mesocephalon, while ATF6 expression significantly increased in the mesocephalon. ATF6n and XBP1s were translocated into the cell nucleus. The levels of BIP, ATF6, phospho-elf2α, and spliced xbp1 also significantly increased in vitro. Furthermore, the downstream genes of UPR were detected to investigate the regulating model of the UPR during ZIKV infection in vitro and in vivo. The transcriptional levels of atf4, gadd34, chop, and edem-1 in vivo and that of gadd34 and chop in vitro significantly increased. CONCLUSION: Findings in this study demonstrated that ZIKV infection activates ER stress in neural cells. The results offer clues to further study the mechanism of neuropathogenesis caused by ZIKV infection
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