2,363 research outputs found

    Towards smaller family size in Egypt, Morocco and Turkey: overall change over time or socio-economic compositional effect?

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    The whole region of the South and East Mediterranean exhibits a profound fertility transition with marked differences in the pace of fertility declines among the countries. The authors choose three representative countries: Egypt, Morocco and Turkey. Determinants of the propensity towards smaller family size are investigated as scrutinizing the development in the pattern of third births, which represents the critical step in the transitional process for these countries. The authors are particularly interested in verifying whether the decline of higher-order births is significantly driven by an overall societal change over time or by compositional change over different socio-economic segments of the female population. Evidence is found that overall societal changes have mainly driven the decline in large family size, though, to a much lesser extent, compositional changes are important too.Egypt, Morocco, Turkey, childbearing, family size, fertility decline

    Constraint on energy-momentum squared gravity from neutron stars and its cosmological implications

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    Deviations from the predictions of general relativity due to energy-momentum squared gravity (EMSG) are expected to become pronounced in the high density cores of neutron stars. We derive the hydrostatic equilibrium equations in EMSG and solve them numerically to obtain the neutron star mass-radius relations for four different realistic equations of state. We use the existing observational measurements of the masses and radii of neutron stars to constrain the free parameter, α,\alpha , that characterizes the coupling between matter and spacetime in EMSG. We show that 1038cm3/erg<α<+1037cm3/erg-10^{-38}\,\mathrm{cm^{3}/erg}<\alpha <+10^{-37}\,\mathrm{cm^{3}/erg}. Under this constraint, we discuss what contributions EMSG can provide to the physics of neutron stars, in particular, their relevance to the so called \textit{hyperon puzzle} in neutron stars. We also discuss how EMSG alters the dynamics of the early universe from the predictions of the standard cosmological model. We show that EMSG leaves the standard cosmology safely unaltered back to t104t\sim 10^{-4} seconds at which the energy density of the universe is 1034ergcm3\sim 10^{34}\,\mathrm{erg\,cm^{-3}}.Comment: 17 pages, 7 figures, 1 table; matches the version to appear in PR

    Genistein-induced mir-23b expression inhibits the growth of breast cancer cells

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    Aim of the study: Genistein, an isoflavonoid, plays roles in the inhibition of protein tyrosine kinase phosphorylation, induction of apoptosis, and cell differentiation in breast cancer. This study aims to induce cellular stress by exposing genistein to determine alterations of miRNA expression profiles in MCF-7 cells. Material and methods: XTT assay and trypan blue dye exclusion assays were performed to examine the cytotoxic effects of genistein treatment. Expressions of miRNAs were quantified using Real-Time Online RT-PCR. Results: The IC50 dose of genistein was 175 μM in MCF-7 cell, line and the cytotoxic effect of genistein was detected after 48 hours. miR-23b was found to be up-regulated 56.69 fold following the treatment of genistein. It was found that miR-23b was up-regulated for MCF-7 breast cancer cells after genistein treatment. Conclusions: Up-regulated ex-expression of miR-23b might be a putative biomarker for use in the therapy of breast cancer patients. miR-23b up-regulation might be important in terms of response to genistein. © 2015, Termedia Publishing House Ltd. All rights reserved

    Rabi flopping between ground and Rydberg states with dipole-dipole atomic interactions

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    We demonstrate Rabi flopping of small numbers of 87Rb\rm{^{87}Rb} atoms between ground and Rydberg states with n43n\le 43. Coherent population oscillations are observed for single atom flopping, while the presence of two or more atoms decoheres the oscillations. We show that these observations are consistent with van der Waals interactions of Rydberg atoms.Comment: 4 pages, 6 figure

    Spectral-discrete solitons and localization in frequency space

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    We report families of discrete optical solitons in frequency space, or spectral-discrete solitons existing in a dispersive Raman medium, where individual side-bands are coupled by coherence. The associated time-domain patterns correspond to either trains of ultrashort pulses, or weakly modulated waves. We describe the physics behind the spectral localization and study soliton bifurcations, stability and dynamics.Comment: 4 pages, 4 figures, submitted to Opt. Let

    Fast Ground State Manipulation of Neutral Atoms in Microscopic Optical Traps

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    We demonstrate Rabi flopping at MHz rates between ground hyperfine states of neutral 87^{87}Rb atoms that are trapped in two micron sized optical traps. Using tightly focused laser beams we demonstrate high fidelity, site specific Rabi rotations with crosstalk on neighboring sites separated by 8μm8 \mu\rm m at the level of 10310^{-3}. Ramsey spectroscopy is used to measure a dephasing time of 870μs870 \mu\rm s which is \approx 5000 times longer than the time for a π/2\pi/2 pulse.Comment: 4 pages, 4 figure

    Coherent Quantum Optical Control with Subwavelength Resolution

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    We suggest a new method for quantum optical control with nanoscale resolution. Our method allows for coherent far-field manipulation of individual quantum systems with spatial selectivity that is not limited by the wavelength of radiation and can, in principle, approach a few nanometers. The selectivity is enabled by the nonlinear atomic response, under the conditions of Electromagnetically Induced Transparency, to a control beam with intensity vanishing at a certain location. Practical performance of this technique and its potential applications to quantum information science with cold atoms, ions, and solid-state qubits are discussed.Comment: 4 pages, 2 figures. V2: changes in presentation (text, figures, tables) and new references - final version as published in Phys. Rev. Lett
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