1,720 research outputs found

    Open borders and global distributive justice

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    In this article, I examine how open borders can serve the idea of global distributive justice by asking how or how not the existing practices of immigration to rich countries may contribute to global economic redistribution. There are two observations. First, migration is not the redistributive option that anyone has an equal access. In order to make use of migration as a means of global redistribution, rich countries need to provide a chance to migrate to those who cannot afford movement by themselves. Second, as long as brain-drain problems happen, what the perspective of global distributive justice requires is the compensation for some educational cost of raising professionals or some control of their movement. Immigration admissions largely focusing on getting highly skilled professionals may not serve the idea of global redistribution

    A general approach to high-yield biosynthesis of chimeric RNAs bearing various types of functional small RNAs for broad applications.

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    RNA research and therapy relies primarily on synthetic RNAs. We employed recombinant RNA technology toward large-scale production of pre-miRNA agents in bacteria, but found the majority of target RNAs were not or negligibly expressed. We thus developed a novel strategy to achieve consistent high-yield biosynthesis of chimeric RNAs carrying various small RNAs (e.g. miRNAs, siRNAs and RNA aptamers), which was based upon an optimal noncoding RNA scaffold (OnRS) derived from tRNA fusion pre-miR-34a (tRNA/mir-34a). Multi-milligrams of chimeric RNAs (e.g. OnRS/miR-124, OnRS/GFP-siRNA, OnRS/Neg (scrambled RNA) and OnRS/MGA (malachite green aptamer)) were readily obtained from 1 l bacterial culture. Deep sequencing analyses revealed that mature miR-124 and target GFP-siRNA were selectively released from chimeric RNAs in human cells. Consequently, OnRS/miR-124 was active in suppressing miR-124 target gene expression and controlling cellular processes, and OnRS/GFP-siRNA was effective in knocking down GFP mRNA levels and fluorescent intensity in ES-2/GFP cells and GFP-transgenic mice. Furthermore, the OnRS/MGA sensor offered a specific strong fluorescence upon binding MG, which was utilized as label-free substrate to accurately determine serum RNase activities in pancreatic cancer patients. These results demonstrate that OnRS-based bioengineering is a common, robust and versatile strategy to assemble various types of small RNAs for broad applications

    Stationary-state electronic distribution in quantum dots

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    We wish to draw an attention to a non-gibbsian behavior of zero-dimensional semiconductor nanostructures, which appears to be manifested in experiments by an effect of incomplete depopulation from electronic excited states or by an effect of up-conversion of electronic level occupation after preparing the system in the ground state of electronic excitation. In the present work the effect is interpreted with help of electron-LO-phonon interaction, which is supposed to play a role in these structures in the form of multiple-scattering of electron on the optical phonons. Quantum kinetic equation describing the process of electronic ralaxation with the inclusion of electronic multiple scattering on phonons is considered. The multiple electron scattering interpretation of the effect is supported by pointing out a considerable degree of agreement between the theoretical picture presented and a rather extensive amount of existing experimental data.Comment: 8 pages, 3 figure

    Phase separation in the vicinity of the surface of κ\kappa-(BEDT-TTF)2_2Cu[N(CN)2_2]Br by fast cooling

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    Partial suppression of superconductivity by fast cooling has been observed in the organic superconductor κ\kappa-(BEDT-TTF)2_2Cu[N(CN)2_2]Br by two means: a marked sample size effect on the magnetic susceptibility and direct imaging of insulating regions by scanning microregion infrared reflectance spectroscopy. Macroscopic insulating regions are found in the vicinity of the crystalline surface after fast cooling, with diameters of 50--100 μ\mum and depths of a few μ\mum. The very large in-plane penetration depth reported to date (\sim 24--100 μ\mum) can be explained by the existence of the insulating regions.Comment: Several rhetoric alternations to avoid misleadings. 6 pages, 3 figures. to be publihsed in Phys. Rev.

    Nanoscale Infrared Imaging Analysis of Carbonaceous Chondrites to Understand Organic-Mineral Interactions During Aqueous Alteration

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    Organic matter in carbonaceous chondrites is distributed in fine-grained matrix. To understand pre- and postaccretion history of organic matter and its association with surrounding minerals, microscopic techniques are mandatory. Infrared (IR) spectroscopy is a useful technique, but the spatial resolution of IR is limited to a few micrometers, due to the diffraction limit. In this study, we applied the high spatial resolution IR imaging method to CM2 carbonaceous chondrites Murchison and Bells, which is based on an atomic force microscopy (AFM) with its tip detecting thermal expansion of a sample resulting from absorption of infrared radiation. We confirmed that this technique permits 30 nm spatial resolution organic analysis for the meteorite samples. The IR imaging results are consistent with the previously reported association of organic matter and phyllosilicates, but our results are at much higher spatial resolution. This observation of heterogeneous distributions of the functional groups of organic matter revealed its association with minerals at 30 nm spatial resolution in meteorite samples by IR spectroscopy

    Swelling Behavior of Polybutadiene Networks in Nematic Liquid Crystal Solvents (STATES AND STRUCTURES-Polymer Condensed States) .

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    Degree of equilibrium swelling (Q) of polybutadiene networks in four nematic liquid crystals (LCs) has been investigated as a function of temperature by cross-polarized microscopy. Phase behavior of the LCs in the networks has also been observed. It has been found that the nematic-to-isotropic phase transition temperatures of the LCs in the networks (TNI g) are slightly (ca. 1K) lower than the ones of the corresponding pure LCs (TNI o), and that the depression degrees of TNI in each system are comparable in spite of large differences in Q between every system. In the temperature regions of TNI g<T<TNI o where the LC phases inside and outside gel are different, Q is almost constant against temperature change
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