864 research outputs found

    Development of the Magnetic Excitations of Charge-Stripe Ordered La(2-x)Sr(x)NiO(4) on Doping Towards Checkerboard Charge Order

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    The magnetic excitation spectrums of charge stripe ordered La(2-x)Sr(x)NiO(4) x = 0.45 and x = 0.4 were studied by inelastic neutron scattering. We found the magnetic excitation spectrum of x = 0.45 from the ordered Ni^2+ S = 1 spins to match that of checkerboard charge ordered La(1.5)Sr(0.5)NiO(4). The distinctive asymmetry in the magnetic excitations above 40 meV was observed for both doping levels, but an additional ferromagnetic mode was observed in x = 0.45 and not in the x = 0.4. We discuss the origin of crossover in the excitation spectrum between x = 0.45 and x = 0.4 with respect to discommensurations in the charge stripe structure.Comment: 4 Figures. To be appear in the J. Kor. Phys. Soc. as a proceedings paper from the ICM 2012 conferenc

    Radiation-induced myeloid leukaemia in CBA/H mice: a non-immunogenic malignant disease in syngeneic mice.

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    In vivo growth characteristics of myeloid leukaemia induced by whole-body irradiation of CBA/H male mice were examined in the strain of origin by procedures expected to enhance or depress immunological responses. Syngeneic growth in vivo (survival time and frequency of takes) was not modified by attempted active immunization with radiation-inactivated cells or by sublethal whole-body irradiation of recipients before inoculation of small numbers of clonogenic cells. Since the growth stimuli involved in in vivo repair of severely damaged normal haemopoietic tissue also did not modify the growth of the radiation-induced leukaemia cells in syngeneic passage, their growth in vivo in the irradiated primary hosts can be regarded as autonomous by the stage at which leukaemia was diagnosed. Challenge inocula in the "immunization" experiments were 1-9 clonogenic cells from 4 different passaged lines and in the whole-body radiation experiments, 1-10(3) clonogenic cells derived from 11 different primary hosts and 4 different passaged lines

    Homophobia and national collective narcissism in populist Poland

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    Opposition to sexual minority rights in Poland is among the highest in the EU. Populist political actors in the country repeatedly scapegoat gays and lesbians, presenting them as a threat to the Polish nation and its shared norms and values, particularly those derived from religion. Building upon previous research which shows how discourse constructing homosexuality as a threat to the nation has been used by social and political actors to legitimize homophobic rhetoric and behaviour, our paper aims to show whether nationalism – understood here as national collective narcissism – predicts prejudice towards gays and lesbians at the level of individual beliefs

    Is attending a mental process?

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    The nature of attention has been the topic of a lively research programme in psychology for over a century. But there is widespread agreement that none of the theories on offer manage to fully capture the nature of attention. Recently, philosophers have become interested in the debate again after a prolonged period of neglect. This paper contributes to the project of explaining the nature of attention. It starts off by critically examining Christopher Mole’s prominent “adverbial” account of attention, which traces the failure of extant psychological theories to their assumption that attending is a kind of process. It then defends an alternative, process-based view of the metaphysics of attention, on which attention is understood as an activity and not, as psychologists seem to implicitly assume, an accomplishment. The entrenched distinction between accomplishments and activities is shown to shed new light on the metaphysics of attention. It also provides a novel diagnosis of the empirical state of play

    Integrin beta 1 coordinates survival and morphogenesis of the embryonic lineage upon implantation and pluripotency transition

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    At implantation, the embryo establishes contacts with the maternal endometrium. This stage is associated with a high incidence of preclinical pregnancy losses. While the maternal factors underlying uterine receptivity have been investigated, the signals required by the embryo for successful peri-implantation development remain elusive. To explore these, we studied integrin beta 1 signaling, as embryos deficient for this receptor degenerate at implantation. We demonstrate that the coordinated action of pro-survival signals and localized actomyosin suppression via integrin beta 1 permits the development of the embryo beyond implantation. Failure of either process leads to developmental arrest and apoptosis. Pharmacological stimulation through fibroblast growth factor 2 (FGF2) and insulin-like growth factor 1 (IGF1), coupled with ROCK-mediated actomyosin inhibition, rescues the deficiency of integrin beta 1, promoting progression to post-implantation stages. Mutual exclusion between integrin beta 1 and actomyosin seems to be conserved in the human embryo, suggesting the possibility that these mechanisms could also underlie the transition of the human epiblast from pre- to post-implantation

    Magnetic excitations of the charge stripe electrons below half doping in La2−xSrxNiO4 (x = 0.45, 0.4)

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    The low energy magnetic excitation spectrum of charge stripe ordered La2−xSrxNiO4, x = 0.4 and x = 0.45 were studied by neutron scattering. Two excitation modes are observed in both materials, one from the ordered magnetic moments, and a second mode consistent with pseudo-onedimensional antiferromagnetic excitations of the charge stripe electrons (q-1D). The dispersion of the q-1D excitation follows the same relation as in x = 1/3 composition, with even spectral weight in the two counter-propagating branches of the x = 0.4, however in the x = 0.45 only one dispersion branch has any measurable spectral weight. The evolution of the q-1D excitations on doping to the checkerboard charge ordered phase is discussed
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