1,707 research outputs found

    Constructing our identities: Identity Expression amongst lesbian women attending university

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    Issues of marginalisation have been central to studies on lesbian women, and can affect the expression of sexuality. The university is a site that can potentially provide a physical and relational space that facilitates the negotiation of identities within the context of institutional policies that protect LGBTI people. This article examines data collected from 3 focus group discussions with 11 lesbian women attending university. Using queer theory, this article explores how policy shifts have affected identity expression; identification with ‘categories’ of lesbianism; the intersections of sexual identity with other social markers; and the interplay of space and identity expression. The results of the study indicated new emerging ways of viewing and expressing lesbian identity. The intersection of identity with policies, Westernisation, privilege, and power, as well as an increase in LGBTI consciousness and access to information, has allowed for wider expressions of sexuality that attempt to break gender binaries

    Geometric Phase: a Diagnostic Tool for Entanglement

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    Using a kinematic approach we show that the non-adiabatic, non-cyclic, geometric phase corresponding to the radiation emitted by a three level cascade system provides a sensitive diagnostic tool for determining the entanglement properties of the two modes of radiation. The nonunitary, noncyclic path in the state space may be realized through the same control parameters which control the purity/mixedness and entanglement. We show analytically that the geometric phase is related to concurrence in certain region of the parameter space. We further show that the rate of change of the geometric phase reveals its resilience to fluctuations only for pure Bell type states. Lastly, the derivative of the geometric phase carries information on both purity/mixedness and entanglement/separability.Comment: 13 pages 6 figure

    Suppression of static stripe formation by next-neighbor hopping

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    We show from real-space Hartree-Fock calculations within the extended Hubbard model that next-nearest neighbor (t') hopping processes act to suppress the formation of static charge stripes. This result is confirmed by investigating the evolution of charge-inhomogeneous corral and stripe phases with increasing t' of both signs. We propose that large t' values in YBCO prevent static stripe formation, while anomalously small t' in LSCO provides an additional reason for the appearance of static stripes only in these systems.Comment: 4 pages, 5 figure

    Cross-border and domestic minority acquisitions and financial constraints: Reaping big benefits from small shareholders

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    Research Question/Issue Do the motivations of cross-border minority acquisitions differ from those of domestic minority acquisitions? We examine and compare the underlying motivations for and consequences of domestic and cross-border minority acquisitions by analyzing data from transactions that took place across 31 countries over a 13-year period. Research Findings/Insights Using a sample of 11,926 domestic and cross-border minority acquisitions, we show that the interplay of financing and country-level governance motives is the main driver of such deals in both settings. We find that financially constrained firms are more likely to engage in both domestic and cross-border minority acquisitions, even in the face of higher information asymmetry and transaction costs that international transactions entail. In the wake of either domestic or cross-border deals, financially constrained firms' long-term debt increases; their short-term debt, cash holdings, and equity decrease. The greater likelihood of minority acquisitions of financially constrained firms is explained by the degree of corporate governance institutions in the country in which the targeted firm is based and by differences in levels of creditor and shareholder protections between the home countries of the targeted and acquiring firms involved. Our results remain robust after controlling for alternative explanations such as the contracting motive, the gravity model of foreign transactions, economic development levels, and differences in tax and exchange rates. Theoretical/Academic Implications Our results extend prior literature on mergers and acquisitions that have focused solely on control transfers or domestic deals. We provide empirical evidence for the importance of jointly considering financing and governance motivations in seeking to explain domestic and cross-border minority acquisitions and their consequences in alleviating financial constraints. We provide new evidence on how firm- and country-level characteristics interact to affect minority acquisitions. Practitioner/Policy Implications Our results offer valuable insights for business policy by highlighting how firms can circumvent financial constraints through partial integration, especially in cross-border settings. The results also offer evidence of beneficial ex post outcomes for targeted firms' leverage and liquidity. In terms of public policy, the results show that minority shareholder protections improve the equity market and provide a positive externality to the debt market through a certification effect

    Relativistic treatment of harmonics from impurity systems in quantum wires

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    Within a one particle approximation of the Dirac equation we investigate a defect system in a quantum wire. We demonstrate that by minimally coupling a laser field of frequency omega to such an impurity system, one may generate harmonics of multiples of the driving frequency. In a multiple defect system one may employ the distance between the defects in order to tune the cut-off frequency.Comment: 9 pages Latex, 8 eps figures, section added, numerics improve

    alpha'-exact entropies for BPS and non-BPS extremal dyonic black holes in heterotic string theory from ten-dimensional supersymmetry

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    We calculate near-horizon solutions for four-dimensional 4-charge and five-dimensional 3-charge black holes in heterotic string theory from the part of the ten-dimensional tree-level effective action which is connected to gravitational Chern-Simons term by supersymmetry. We obtain that the entropies of large black holes exactly match the alpha'-exact statistical entropies obtained from microstate counting (D=4) and AdS/CFT correspondence (D=5). Especially interesting is that we obtain agreement for both BPS and non-BPS black holes, contrary to the case of R^2-truncated (four-derivative) actions (D-dimensional N=2 off-shell supersymmetric or Gauss-Bonnet) were used, which give the entropies agreeing (at best) just for BPS black holes. The key property of the solutions, which enabled us to tackle the action containing infinite number of terms, is vanishing of the Riemann tensor \bar{R}_{MNPQ} obtained from torsional connection defined with \bar{\Gamma} = \Gamma - H/2. Morover, if every monomial of the remaining part of the effective action would contain at least two Riemanns \bar{R}_{MNPQ}, it would trivially follow that our solutions are exact solutions of the full heterotic effective action in D=10. The above conjecture, which appeared (in this or stronger form) from time to time in the literature, has controversial status, but is supported by the most recent calculations of Richards (arXiv:0807.3453 [hep-th]). Agreement of our results for the entropies with the microscopic ones supports the conjecture. As for small black holes, our solutions in D=5 still have singular horizons.Comment: 28 pages; v2: minor changes, references added; v3: extended discussion on small black holes in sec. 5.4, more references added, accepted in JHE

    Human Blood Lipoprotein Predictions from <sup>1</sup>H NMR Spectra:Protocol, Model Performances, and Cage of Covariance

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    Lipoprotein subfractions are biomarkers for the early diagnosis of cardiovascular diseases. The reference method, ultracentrifugation, for measuring lipoproteins is time-consuming, and there is a need to develop a rapid method for cohort screenings. This study presents partial least-squares regression models developed using 1H nuclear magnetic resonance (NMR) spectra and concentrations of lipoproteins as measured by ultracentrifugation on 316 healthy Danes. This study explores, for the first time, different regions of the 1H NMR spectrum representing signals of molecules in lipoprotein particles and different lipid species to develop parsimonious, reliable, and optimal prediction models. A total of 65 lipoprotein main and subfractions were predictable with high accuracy, Q2 of >0.6, using an optimal spectral region (1.4-0.6 ppm) containing methylene and methyl signals from lipids. The models were subsequently tested on an independent cohort of 290 healthy Swedes with predicted and reference values matching by up to 85-95%. In addition, an open software tool was developed to predict lipoproteins concentrations in human blood from standardized 1H NMR spectral recordings

    X-boson cumulant approach to the periodic Anderson model

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    The Periodic Anderson Model (PAM) can be studied in the infinite U limit by employing the Hubbard X operators to project out the unwanted states. We have already studied this problem employing the cumulant expansion with the hybridization as perturbation, but the probability conservation of the local states (completeness) is not usually satisfied when partial expansions like the Chain Approximation (CHA) are employed. Here we treat the problem by a technique inspired in the mean field approximation of Coleman's slave-bosons method, and we obtain a description that avoids the unwanted phase transition that appears in the mean-field slave-boson method both when the chemical potential is greater than the localized level Ef at low temperatures (T) and for all parameters at intermediate T.Comment: Submited to Physical Review B 14 pages, 17 eps figures inserted in the tex

    Effect of Holstein phonons on the optical conductivity of gapped graphene

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    We study the optical conductivity of a doped graphene when a sublattice symmetry breaking is occurred in the presence of the electron-phonon interaction. Our study is based on the Kubo formula that is established upon the retarded self-energy. We report new features of both the real and imaginary parts of the quasiparticle self-energy in the presence of a gap opening. We find an analytical expression for the renormalized Fermi velocity of massive Dirac Fermions over broad ranges of electron densities, gap values and the electron-phonon coupling constants. Finally we conclude that the inclusion of the renormalized Fermi energy and the band gap effects are indeed crucial to get reasonable feature for the optical conductivity.Comment: 12 pages, 4 figures. To appear in Eur. Phys. J.
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