Intervalley coupling by quantum dot confinement potentials in monolayer transition metal dichalcogenides

Monolayer transition metal dichalcogenides (TMDs) offer new opportunities for realizing quantum dots (QDs) in the ultimate two-dimensional (2D) limit. Given the rich control possibilities of electron valley pseudospin discovered in the monolayers, this quantum degree of freedom can be a promising carrier of information for potential quantum spintronics exploiting single electrons in TMD QDs. An outstanding issue is to identify the degree of valley hybridization, due to the QD confinement, which may significantly change the valley physics in QDs from its form in the 2D bulk. Here we perform a systematic study of the intervalley coupling by QD confinement potentials on extended TMD monolayers. We find that the intervalley coupling in such geometry is generically weak due to the vanishing amplitude of the electron wavefunction at the QD boundary, and hence valley hybridization shall be well quenched by the much stronger spin-valley coupling in monolayer TMDs and the QDs can well inherit the valley physics of the 2D bulk. We also discover sensitive dependence of intervalley coupling strength on the central position and the lateral length scales of the confinement potentials, which may possibly allow tuning of intervalley coupling by external controlsComment: 17 pages, 14 figure

Exchange Rate Regimes, Trade, and the Wage Comovements

The introduction of exchange rate regimes into the standard Ricardian model of trade implies stronger positive nominal wage comovements between trading countries that fix their bilateral exchange rates. Panel regression results based on data from OECD countries from 1973 to 2010 suggest that countries in the European Monetary Union (EMU) experienced stronger positive wage comovements with their main trade partners. In comparison, the positive wage comovements between countries engaged in non-currency-union pegs were weaker. When we restrict the regression to the subsample of the EMU countries, we find a significant increase in wage comovements after these countries joined the EMU in 1999 compared to the pre-euro era.

Feedback Control of Nuclear Spin Bath of a Single Hole Spin in a Quantum Dot

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Exchange Rate Regimes and Nominal Wage Comovements in a Dynamic Ricardian Model

We construct a dynamic Ricardian model of trade with money and nominal exchange rate. The model implies that the nominal wages of the trading countries are more likely to exhibit stronger positive comovements when the countries fix their bilateral exchange rates. Panel regression results based on data from OECD countries from 1973 to 2012 suggest that countries in the European Monetary Union (EMU) experienced stronger positive wage comovements with their main trade partners. When we restrict the regression to the subsample of the EMU countries, we find a significant increase in wage comovements after these countries joined the EMU in 1999 compared to the pre-euro era. In comparison, when the sample is restricted to the non-EMU countries, we find no evidence that non-currency union pegs affected the wage comovements

ARPC4 gene silencing inhibits T24 cell invasion and metastasis via a mechanism involving Arp2/3/cofilin-1 signaling pathway

Purpose: To study the influence of ARPC4 gene silencing on human urinary bladder cancer (T24) cell proliferation, invasiveness and migration, and the mechanism(s) involved.Methods: Short interfering RNA (siRNA) ARPC4 silencing fragment was transfected into T24 cells. Transfection efficiency was measured with qRT-PCR. Cell proliferation, invasiveness and migratory potential were determined with CCK-8, Transwell invasion assay, and immunofluorescence assay,respectively. Protein expressions of ARPC4 and cofilin-1 were assayed using Western blotting.Results: Short interfering RNA (siRNA) silencing of ARPC4 gene led to the downregulation of mRNA and protein expressions of ARPC4 (t = 14.898, p < 0.05; t = 7.686, p < 0.05). It also significantly downregulated cofilin-1 protein, while inhibiting proliferative capacity, invasiveness and pseudopodiaformation capacity of T24 cells (t = 8.042, p < 0.05).Conclusion: The results obtained suggest that ARPC4 gene silencing inhibits T24 cell invasion and metastasis via a mechanism involving regulation of the Arp2/3/cofilin-1 signaling route. This provides new leads for gene therapy. Keywords: ARPC4, Bladder carcinoma, Gene silencing, Invasiveness, Cell proliferatio