Open borders and global distributive justice

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.

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

Field-induced staggered magnetic moment in the quasi-two-dimensional organic Mott insulator κ\kappa-(BEDT-TTF)2_{2}Cu[N(CN)2_{2}]Cl

We investigated the magnetism under a magnetic field in the quasi-two-dimensional organic Mott insulator $\kappa$-(BEDT-TTF)$_{2}$Cu[N(CN)$_{2}$]Cl through magnetization and $^{13}$C-NMR measurements. We found that in the nominally paramagnetic phase (i.e., above N\'eel temperature) the field-induced local moments have a staggered component perpendicular to the applied field. As a result, the antiferromagnetic transition well defined at a zero field becomes crossover under a finite field. This unconventional behavior is qualitatively reproduced by the molecular-field calculation for Hamiltonian including the exchange, Dzyaloshinsky-Moriya (DM), and Zeeman interactions. This calculation also explains other unconventional magnetic features in $\kappa$-(BEDT-TTF)$_{2}$Cu[N(CN)$_{2}$]Cl reported in the literature. The present results highlight the importance of the DM interaction in field-induced magnetism in a nominally paramagnetic phase, especially in low-dimensional spin systems.Comment: 11 pages, 12 figures, selected for Editors' Suggestion

Stationary-state electronic distribution in quantum dots

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

Partial suppression of superconductivity by fast cooling has been observed in the organic superconductor $\kappa$-(BEDT-TTF)$_2$Cu[N(CN)$_2$]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 $\mu$m and depths of a few $\mu$m. The very large in-plane penetration depth reported to date ($\sim$ 24--100 $\mu$m) 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

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

Self-referenced continuous-variable quantum key distribution protocol

We introduce a new continuous-variable quantum key distribution (CV-QKD) protocol, self-referenced CV-QKD, that eliminates the need for transmission of a high-power local oscillator between the communicating parties. In this protocol, each signal pulse is accompanied by a reference pulse (or a pair of twin reference pulses), used to align Alice's and Bob's measurement bases. The method of phase estimation and compensation based on the reference pulse measurement can be viewed as a quantum analog of intradyne detection used in classical coherent communication, which extracts the phase information from the modulated signal. We present a proof-of-principle, fiber-based experimental demonstration of the protocol and quantify the expected secret key rates by expressing them in terms of experimental parameters. Our analysis of the secret key rate fully takes into account the inherent uncertainty associated with the quantum nature of the reference pulse(s) and quantifies the limit at which the theoretical key rate approaches that of the respective conventional protocol that requires local oscillator transmission. The self-referenced protocol greatly simplifies the hardware required for CV-QKD, especially for potential integrated photonics implementations of transmitters and receivers, with minimum sacrifice of performance. As such, it provides a pathway towards scalable integrated CV-QKD transceivers, a vital step towards large-scale QKD networks.Comment: 14 pages, 10 figures. Published versio