1,387 research outputs found

    Ethnic ties, organized opposition and voter defection in authoritarian elections

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    Existing studies of ethnic voting mainly focus on democratic elections. In electoral autocracies, politically subordinate ethnicity can help citizens coordinate against the incumbent. However, we argue that collective action will be constrained when the group grows large, as it becomes costly for its members to form common behavioural norms and carry out effective sanctions through shared ethnic ties under authoritarian repression. Drawing on unique historical surveys in Taiwan, we study how Taiwanese ethnicity and local ethnic demography jointly induced voters’ defection against the hegemonic KMT regime. We find that the pro-defection or anti-incumbent effect of Taiwanese ethnicity fell as the share of Taiwanese citizens in a township increased. However, the relative size of the Taiwanese group no longer undermined pro-defection ethnic voting after the KMT lifted the ban on opposition parties. Our results illustrate that formal organizations play a critical role in sustaining the informational salience of ethnicity in the elections

    On the Circular Orbit Approximation for Binary Compact Objects In General Relativity

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    One often-used approximation in the study of binary compact objects (i.e., black holes and neutron stars) in general relativity is the instantaneously circular orbit assumption. This approximation has been used extensively, from the calculation of innermost circular orbits to the construction of initial data for numerical relativity calculations. While this assumption is inconsistent with generic general relativistic astrophysical inspiral phenomena where the dissipative effects of gravitational radiation cause the separation of the compact objects to decrease in time, it is usually argued that the timescale of this dissipation is much longer than the orbital timescale so that the approximation of circular orbits is valid. Here, we quantitatively analyze this approximation using a post-Newtonian approach that includes terms up to order ({Gm/(rc^2)})^{9/2} for non-spinning particles. By calculating the evolution of equal mass black hole / black hole binary systems starting with circular orbit configurations and comparing them to the more astrophysically relevant quasicircular solutions, we show that a minimum initial separation corresponding to at least 6 (3.5) orbits before plunge is required in order to bound the detection event loss rate in gravitational wave detectors to < 5% (20%). In addition, we show that the detection event loss rate is > 95% for a range of initial separations that include all modern calculations of the innermost circular orbit (ICO).Comment: 10 pages, 12 figures, revtex

    Fibrosis Evaluation by Transient Elastography in Patients With Long-Term Sustained HCV Clearance

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    BACKGROUND: Reversibility of advanced fibrosis after HCV-clearance is an important goal of therapy. OBJECTIVES: Measuring liver stiffness (LS) by transient elastography (TE) might be helpful in this setting. PATIENTS AND METHODS: We evaluated 104 patients with biopsy-proven chronic hepatitis C (CHC) and sustained virological response (SVR) after Peg-Interferon (IFN) plus ribavirin since at least 18 months. HCV-eradication was confirmed searching for serum HCV-RNA (TMA® sensitivity > 5-10 IU/ml). Data from literature reported the best LS cut-off values for different stages of liver fibrosis were 7.1 kPa for Metavir stage 2 (F2), 9.5 kPa for F3 and 12.5 for cirrhosis (F4). RESULTS: TE was not reliable in four SVR obese patients. Metavir-stage of biopsy was F0-1 in 28, F2 in 47, F3 in 17 and F4 in eight patients. The median interval elapsed since achieving SVR was 36 months (range: 18-77, SD¬¬:18). Stratifying patients according to the histological stage assessed before treatment, a clear-cut gradient of LS values was observed from F0-1: median: 3.8 kPa (range: 3.5-4.9) to F2: 4.6 kPa (3.8-6.0), F3: 6.2 kPa (4.8-8.6) and F4: 8.4 kPa (6.2-9.2) (P = 0.001). Overall, 86 patients had lower values of LS than the expected LS values according to Metavir-stage. At multivariate logistic analysis γ-GT and histological steatosis were independently associated with persistence of higher values of LS. CONCLUSION: Long term responders to IFN-based therapies have lower LS values than those who are untreated and still viraemic. High levels of γ-GT and liver steatosis, all markers of insulin resistance, may hamper reduction of liver stiffness after HCV-clearance

    SC-to-AFM transition in CeCo(In1-xCdx)5: De Haas-van Alphen Measurements

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    The results of de-Haas-van-Alphen (dHvA) measurements on Cd doped CeCoIn5 in the high magnetic field paramagnetic phase are reported. The replacement of trivalent In by divalent Cd is known to induce an antiferromagnetic order coexisting with superconductivity in this heavy fermion superconductor. We find a small but systematic change in the dHvA frequencies with Cd doping, reflecting the chemical potential shift due to the removal of conduction electrons. The frequencies and effective masses are close to those found in the undoped compound. We observe no abrupt change in the electron Fermi surface (FS) volume in the high field paramagnetic phase for x \u3e x c corresponding to the onset of antiferromagnetic ordering at zero magnetic field in CeCo(In1xCdx)5. Our results show that no significant change of the Fermi surface volume occurs to cause the AFM onset inside the SC state in CeCoIn5 with Cd doping. Only slight changes causing the Band 15 electron FS to be more cylindrical are observed making nesting more likely. © Published under licence by IOP Publishing Ltd

    Oxidation of DJ-1 Induced by 6-Hydroxydopamine Decreasing Intracellular Glutathione

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    DJ-1, the causative gene of a familial form of Parkinson's disease (PD), has been reported to undergo preferential oxidation of the cysteine residue at position 106 (Cys-106) under oxidative stress; however, details of the molecular mechanisms are not well known. In the present study, mechanisms of DJ-1 oxidation induced by 6-hydroxydopamine (6-OHDA) were investigated by using SH-SY5Y cells. The treatment of these cells with 6-OHDA caused an obvious acidic spot sift of DJ-1 due to its oxidation. However, when catalase, which is an hydrogen peroxide (H2O2)-removing enzyme, was added during the treatment, it failed to prevent the oxidation induced by 6-OHDA, suggesting that electrophilic p-quinone formed from 6-OHDA, but not H2O2, was responsible for the DJ-1 oxidation. Benzoquinone, another electrophilic p-quinone, also induced DJ-1 oxidation. The intracellular glutathione (GSH) levels were significantly decreased by 6-OHDA, irrespective of the presence or absence of catalase. The inhibition of GSH synthesis by buthionine sulfoximine resulted in a decrease in GSH levels and enhancement of DJ-1 oxidation. The pretreatment of cells with N-acetyl-cysteine prevented the loss of intracellular GSH and subsequently DJ-1 oxidation induced by 6-OHDA. Collectively, these results suggest that electrophilic p-quinone formed from 6-OHDA induces DJ-1 oxidation by decreasing intracellular GSH

    High Magnetic Field NMR Studies of LiVGe2_2O6_6, a quasi 1-D Spin S=1S = 1 System

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    We report 7^{7}Li pulsed NMR measurements in polycrystalline and single crystal samples of the quasi one-dimensional S=1 antiferromagnet LiVGe2_2O6_6, whose AF transition temperature is TN24.5T_{\text{N}}\simeq 24.5 K. The field (B0B_0) and temperature (TT) ranges covered were 9-44.5 T and 1.7-300 K respectively. The measurements included NMR spectra, the spin-lattice relaxation rate (T11T_1^{-1}), and the spin-phase relaxation rate (T21T_2^{-1}), often as a function of the orientation of the field relative to the crystal axes. The spectra indicate an AF magnetic structure consistent with that obtained from neutron diffraction measurements, but with the moments aligned parallel to the c-axis. The spectra also provide the TT-dependence of the AF order parameter and show that the transition is either second order or weakly first order. Both the spectra and the T11T_1^{-1} data show that B0B_0 has at most a small effect on the alignment of the AF moment. There is no spin-flop transition up to 44.5 T. These features indicate a very large magnetic anisotropy energy in LiVGe2_2O6_6 with orbital degrees of freedom playing an important role. Below 8 K, T11T_1^{-1} varies substantially with the orientation of B0B_0 in the plane perpendicular to the c-axis, suggesting a small energy gap for magnetic fluctuations that is very anisotropic.Comment: submitted to Phys. Rev.

    Observation of coherent many-body Rabi oscillations

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    A two-level quantum system coherently driven by a resonant electromagnetic field oscillates sinusoidally between the two levels at frequency Ω\Omega which is proportional to the field amplitude [1]. This phenomenon, known as the Rabi oscillation, has been at the heart of atomic, molecular and optical physics since the seminal work of its namesake and coauthors [2]. Notably, Rabi oscillations in isolated single atoms or dilute gases form the basis for metrological applications such as atomic clocks and precision measurements of physical constants [3]. Both inhomogeneous distribution of coupling strength to the field and interactions between individual atoms reduce the visibility of the oscillation and may even suppress it completely. A remarkable transformation takes place in the limit where only a single excitation can be present in the sample due to either initial conditions or atomic interactions: there arises a collective, many-body Rabi oscillation at a frequency N0.5ΩN^0.5\Omega involving all N >> 1 atoms in the sample [4]. This is true even for inhomogeneous atom-field coupling distributions, where single-atom Rabi oscillations may be invisible. When one of the two levels is a strongly interacting Rydberg level, many-body Rabi oscillations emerge as a consequence of the Rydberg excitation blockade. Lukin and coauthors outlined an approach to quantum information processing based on this effect [5]. Here we report initial observations of coherent many-body Rabi oscillations between the ground level and a Rydberg level using several hundred cold rubidium atoms. The strongly pronounced oscillations indicate a nearly complete excitation blockade of the entire mesoscopic ensemble by a single excited atom. The results pave the way towards quantum computation and simulation using ensembles of atoms

    Spacial and temporal dynamics of the volume fraction of the colloidal particles inside a drying sessile drop

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    Using lubrication theory, drying processes of sessile colloidal droplets on a solid substrate are studied. A simple model is proposed to describe temporal dynamics both the shape of the drop and the volume fraction of the colloidal particles inside the drop. The concentration dependence of the viscosity is taken into account. It is shown that the final shapes of the drops depend on both the initial volume fraction of the colloidal particles and the capillary number. The results of our simulations are in a reasonable agreement with the published experimental data. The computations for the drops of aqueous solution of human serum albumin (HSA) are presented.Comment: Submitted to EPJE, 7 pages, 8 figure

    Symmetry and topology in antiferromagnetic spintronics

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    Antiferromagnetic spintronics focuses on investigating and using antiferromagnets as active elements in spintronics structures. Last decade advances in relativistic spintronics led to the discovery of the staggered, current-induced field in antiferromagnets. The corresponding N\'{e}el spin-orbit torque allowed for efficient electrical switching of antiferromagnetic moments and, in combination with electrical readout, for the demonstration of experimental antiferromagnetic memory devices. In parallel, the anomalous Hall effect was predicted and subsequently observed in antiferromagnets. A new field of spintronics based on antiferromagnets has emerged. We will focus here on the introduction into the most significant discoveries which shaped the field together with a more recent spin-off focusing on combining antiferromagnetic spintronics with topological effects, such as antiferromagnetic topological semimetals and insulators, and the interplay of antiferromagnetism, topology, and superconductivity in heterostructures.Comment: Book chapte

    Highly Parallel and Short-Acting Amplification with Locus-Specific Primers to Detect Single Nucleotide Polymorphisms by the DigiTag2 Assay

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    The DigiTag2 assay enables analysis of a set of 96 SNPs using Kapa 2GFast HotStart DNA polymerase with a new protocol that has a total running time of about 7 hours, which is 6 hours shorter than the previous protocol. Quality parameters (conversion rate, call rate, reproducibility and concordance) were at the same levels as when genotype calls were acquired using the previous protocol. Multiplex PCR with 192 pairs of locus-specific primers was available for target preparation in the DigiTag2 assay without the optimization of reaction conditions, and quality parameters had the same levels as those acquired with 96-plex PCR. The locus-specific primers were able to achieve sufficient (concentration of target amplicon ≥5 nM) and specific (concentration of unexpected amplicons <2 nM) amplification within 2 hours, were also able to achieve detectable amplifications even when working in a 96-plex or 192-plex form. The improved DigiTag2 assay will be an efficient platform for screening an intermediate number of SNPs (tens to hundreds of sites) in the replication analysis after genome-wide association study. Moreover, highly parallel and short-acting amplification with locus-specific primers may thus facilitate widespread application to other PCR-based assays
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