Interaction of topological solitons with defects: using a nontrivial metric

By including potential into the flat metric, we study interaction of sine-Gordon soliton with potentials. We will show numerically that while the soliton-barrier system shows fully classical behaviour, the soliton-well system demonstrates non-classical behaviour. In particular, solitons with low velocities are trapped in the well and emit energy radiation.Comment: 10 pages, 11 figure

Nonperiodic Flux to Voltage Conversion of an Arithmetic Series Array of dc SQUIDs

A theoretical study on the voltage response function of a series array of dc SQUIDs is presented in which the elementary dc SQUID loops vary in size and, possibly, in orientation. Such series arrays of two-junction SQUIDs possess voltage response functions vs. external magnetic field B that differ substantially from those of corresponding regular series arrays with identical loop-areas, while maintaining a large voltage swing as well as a low noise level. Applications include the design of current amplifiers and quantum interference filters.Comment: 3 pages, 3 figure

A Case of Bowen’s Disease and Small-Cell Lung Carcinoma: Long-Term Consequences of Chronic Arsenic Exposure in Chinese Traditional Medicine

Chronic arsenic toxicity occurs primarily through inadvertent ingestion of contaminated water and food or occupational exposure, but it can also occur through medicinal ingestion. This case features a 53-year-old lifetime nonsmoker with chronic asthma treated for 10 years in childhood with Chinese traditional medicine containing arsenic. The patient was diagnosed with Bowen’s disease and developed extensive-stage small-cell carcinoma of the lung 10 years and 47 years, respectively, after the onset of arsenic exposure. Although it has a long history as a medicinal agent, arsenic is a carcinogen associated with many malignancies including those of skin and lung. It is more commonly associated with non–small-cell lung cancer, but the temporal association with Bowen’s disease in the absence of other chemical or occupational exposure strongly points to a causal role for arsenic in this case of small-cell lung cancer. Individuals with documented arsenic-induced Bowen’s disease should be considered for more aggressive screening for long-term complications, especially the development of subsequent malignancies

Observation of Ising-like critical fluctuations in frustrated Josephson junction arrays with modulated coupling energies

We report the results of ac sheet conductance measurements performed on fully frustrated square arrays of Josephson junctions whose coupling energy is periodically modulated in one of the principal lattice directions. Such systems are predicted to exhibit two distinct transitions: a low-temperature Ising-like transition triggered by the proliferation of domain walls and a high-temperature transition driven by the vortex unbinding mechanism of the Beresinskii-Kosterlitz-Thouless (BKT) theory. Both the superfluid and dissipative components of the conductance are found to exhibit features which unambiguously demonstrate the existence of a double transition whose properties are consistent with the Ising-BKT scenario.Comment: To be published in Physica C (Proceedings of the 2nd European Conference in School Format 'Vortex Matter in Superconductors'

Experimentally realizable characterizations of continuous variable Gaussian states

Measures of entanglement, fidelity and purity are basic yardsticks in quantum information processing. We propose how to implement these measures using linear devices and homodyne detectors for continuous variable Gaussian states. In particular, the test of entanglement becomes simple with some prior knowledge which is relevant to current experiments.Comment: 4 pages, This paper supersedes quant-ph/020315

Regulation of sertoli-germ cell adherens junction dynamics via changes in protein-protein interactions of the N-cadherin-β-catenin protein complex which are possibly mediated by c-Src and myotubularin-related protein 2: An in vivo study using an androgen suppression model

Using a well characterized model of cell-cell actin-based adherens junction (AJ) disruption by suppressing the intratesticular testosterone level in adult rats with testosterone-estradiol implants, we have confirmed earlier findings that Sertoli-germ cell AJ dynamics are regulated by the activation of kinases via putative signaling pathways but with some unexpected findings as follows. First, the loss of germ cells from the seminiferous epithelium during androgen suppression was associated with a surge in myotubularin-related protein 2 (MTMR2, a lipid phosphatase, in which adult MTMH2-/- mice were recently shown to be azoospermic because of the loss of cell adhesion function between germ and Sertoli cells); kinases: phosphatidylinositol 3-kinase, c-Src, and C-terminal Src kinase; adaptors: α-actinin, vinculin, afadin, and p130 Crk-associated protein; and AJ-integral membrane proteins at the ectoplasmic specialization (ES, a testis-specific cell-cell actin-based AJ type) site: N-cadherin, β-catenin, integrin β1, and nectin 3. Second, MTMR2, instead of structurally interacting with phosphatidylinositol 3-kinase, a protein and lipid kinase, was shown to associate only with c-Src, a nonreceptor protein tyrosine kinase, as demonstrated by both coimmunoprecipitation and fluorescent microscopy at the site of apical ES, but none of the kinases, adaptors, and AJ-infegral proteins that were examined. Collectively, these results suggest that the MTMR2/c-Src is an important phosphatase/kinase protein pair in AJ dynamics in the testis. Because c-Src is known to associate with the cadherin/catenin protein complex at the ES in the testis, we next sought to investigate any changes in the protein-protein interactions of this protein complex during androgen suppression-induced germ cell loss. Indeed, there was a loss of N-cadherin and β-catenin association, accompanied by a surge in Tyr phosphorylation of β-catenin, during germ cell loss from the epithelium. Third, and perhaps the most important of all, during natural recovery of the epithelium after removal of testosterene-estradiol implants when spermatids were reattaching to Sertoli cells, an increase in N-cadherin and β-catenin association was detected with a concomitant loss in the increased Tyr phosphorylation in β-catenin. In summary, these results illustrate that the cadherin/catenin is a crucial cell adhesion complex that regulates AJ dynamics in the testis, and its functionality is likely modulated by the MTMR2/c-Src protein complex.postprin