A Multichannel Spatial Compressed Sensing Approach for Direction of Arrival Estimation

The final publication is available at http://link.springer.com/chapter/10.1007%2F978-3-642-15995-4_57ESPRC Leadership Fellowship EP/G007144/1EPSRC Platform Grant EP/045235/1EU FET-Open Project FP7-ICT-225913\"SMALL

Characterization of the 4-canonical birationality of algebraic threefolds

In this article we present a 3-dimensional analogue of a well-known theorem of E. Bombieri (in 1973) which characterizes the bi-canonical birationality of surfaces of general type. Let $X$ be a projective minimal 3-fold of general type with $\mathbb{Q}$-factorial terminal singularities and the geometric genus $p_g(X)\ge 5$. We show that the 4-canonical map $\phi_4$ is {\it not} birational onto its image if and only if $X$ is birationally fibred by a family $\mathscr{C}$ of irreducible curves of geometric genus 2 with $K_X\cdot C_0=1$ where $C_0$ is a general irreducible member in $\mathscr{C}$.Comment: 25 pages, to appear in Mathematische Zeitschrif

Exploration of Strange Electromagnetics in Carbon Films

Results of magnetic force microscopy (MFM), dc SQUID magnetization, reversed Josephson effect (RJE), and resistance measurements in thin carbon arc (CA) films are presented. The observation of a RJE induced voltage as well as its rf frequency, input amplitude, and temperature dependence reveals the existence of Josephson Junction arrays. Oscillating behavior of the DC SQUID magnetization reminiscent of the Fraunhofer-like behavior of superconducting (SC) critical current in the range of 10000 Oe has been observed. The dc SQUID magnetization measurement indicates a possible elementary 102 nm SC loop; this is compared to MFM direct observations of magnetic clusters with a median size of 165 nm. All these data are consistent with the existence of a high temperature SC-like phase or fluctuations up to 650 K. It is proposed to expose such CA film to energetic particle (neutron or ion) bombardment to verify this hypothesis. Such bombardment would change both the structure of film and consequently the experimental measurements. In addition such bombardment-induced changes will provide a basis for particle detectors utilizing the Josephson effect.Comment: 18 pages, 7 figure

Retraction Notice of the Article: The DYRK-family kinase Pom1 phosphorylates the F-BAR protein Cdc15 to prevent division at cell poles

Division site positioning is critical for both symmetric and asymmetric cell divisions. In many organisms, positive and negative signals cooperate to position the contractile actin ring for cytokinesis. In rod-shaped fission yeast Schizosaccharomyces pombe cells, division at midcell is achieved through positive Mid1/anillin-dependent signaling emanating from the central nucleus and negative signals from the dual-specificity tyrosine phosphorylation-regulated kinase family kinase Pom1 at the cell poles. In this study, we show that Pom1 directly phosphorylates the F-BAR protein Cdc15, a central component of the cytokinetic ring. Pom1-dependent phosphorylation blocks Cdc15 binding to paxillin Pxl1 and C2 domain protein Fic1 and enhances Cdc15 dynamics. This promotes ring sliding from cell poles, which prevents septum assembly at the ends of cells with a displaced nucleus or lacking Mid1. Pom1 also slows down ring constriction. These results indicate that a strong negative signal from the Pom1 kinase at cell poles converts Cdc15 to its closed state, destabilizes the actomyosin ring, and thus promotes medial septation

One-pot Synthesis of Soluble Nanoscale CIGS Photoactive Functional Materials

Promising alternatives for solar energy utilization are thin film technologies involving various new materials. This contribution describes an easy and inexpensive synthetic method that can be used to prepare soluble nanoscale triphenyl phosphine-coordinated CIGS (TPP-CIGS) photoactive functional materials. This complex is stable in the solid state under the irradiation of the ambient light, but its solution becomes a little bit unstable under the illumination of the low intensity laser

Spectral properties of a generalized chGUE

We consider a generalized chiral Gaussian Unitary Ensemble (chGUE) based on a weak confining potential. We study the spectral correlations close to the origin in the thermodynamic limit. We show that for eigenvalues separated up to the mean level spacing the spectral correlations coincide with those of chGUE. Beyond this point, the spectrum is described by an oscillating number variance centered around a constant value. We argue that the origin of such a rigid spectrum is due to the breakdown of the translational invariance of the spectral kernel in the bulk of the spectrum. Finally, we compare our results with the ones obtained from a critical chGUE recently reported in the literature. We conclude that our generalized chGUE does not belong to the same class of universality as the above mentioned model.Comment: 12 pages, 3 figure

Combined CI+MBPT calculations of energy levels and transition amplitudes in Be, Mg, Ca, and Sr

Configuration interaction (CI) calculations in atoms with two valence electrons, carried out in the V(N-2) Hartree-Fock potential of the core, are corrected for core-valence interactions using many-body perturbation theory (MBPT). Two variants of the mixed CI+MBPT theory are described and applied to obtain energy levels and transition amplitudes for Be, Mg, Ca, and Sr

Azido Groups Hamper Glycan Acceptance by Carbohydrate Processing Enzymes

Azido sugars have found frequent use as probes of biological systems in approaches ranging from cell surface metabolic labeling to activity-based proteomic profiling of glycosidases. However, little attention is typically paid to how well azide-substituted sugars represent the parent molecule, despite the substantial difference in size and structure of an azide compared to a hydroxyl. To quantitatively assess how well azides are accommodated, we have used glycosidases as tractable model enzyme systems reflecting what would also be expected for glycosyltransferases and other sugar binding/modifying proteins. In this vein, specificity constants have been measured for the hydrolysis of a series of azidodeoxy glucosides and N-acetylhexosaminides by a large number of glycosidases produced from expressed synthetic gene and metagenomic libraries. Azides at secondary carbons are not significantly accommodated, and thus, associated substrates are not processed, while those at primary carbons are productively recognized by only a small subset of the enzymes and often then only very poorly. Accordingly, in the absence of careful controls, results obtained with azide-modified sugars may not be representative of the situation with the natural sugar and should be interpreted with considerable caution. Azide incorporation can indeed provide a useful tool to monitor and detect glycosylation, but careful consideration should go into the selection of sites of azide substitution; such studies should not be used to quantitate glycosylation or to infer the absence of glycosylation activity.Bio-organic Synthesi