Stable gauged maps

We give an introduction to moduli stacks of gauged maps satisfying a stability conditition introduced by Mundet and Schmitt, and the associated integrals giving rise to gauged Gromov-Witten invariants. We survey various applications to cohomological and K-theoretic Gromov-Witten invariants.Comment: Survey for the 2015 AMS Summer Institute on Algebraic Geometry. Split off from the more technical paper "Properness for scaled gauged maps" [arXiv:1606.01383]. There is still substantial overlap between the two papers. This version has minor correction

Experiment K-6-06. Morphometric and EM analyses of tibial epiphyseal plates from Cosmos 1887 rats

Light and electron microscopy studies were carried out on decalcified tibial epiphyseal plates of rats flown aboard Cosmos 1887 (12.5d flight plus 53.5h recovery). Analysis of variance showed that the proliferative zone of flight animals was significantly higher than that of synchronous controls, while the hypertrophic/calcification zone was significantly reduced. Flight animals had more cells than synchronous controls in the proliferative zone, and less in the hypertrophic/calcification region. The total number of cells, however, was significantly higher in flight animals. No differences were found for perimeter or shape factor of growth plates, but area was significantly lower in flight animals in comparison to synchronous controls. Collagen fibrils in flight animals were shorter and wider than in synchronous controls. The time required for a cell to cycle through the growth plate is 2 to 3 days, so most of the cells and matrix present were formed after the animals had returned to 1 g, and probably represent stages of recovery from microgravity exposure, which in itself is an interesting question

Ion condensation on charged patterned surfaces

We study ion condensation onto a patterned surface of alternating charges. The competition between self-energy and ion-surface interactions leads to the formation of ionic crystalline structures at low temperatures. We consider different arrangements of underlying ionic crystals, including single ion adsorption, as well as the formation of dipoles at the interface between charged domains. Molecular dynamic simulation illustrates existence of single and mixed phases. Our results contribute to understanding pattern recognition, and molecular separation and synthesis near patterned surfaces.Comment: 3 figure

Design and implementation of a compliant robot with force feedback and strategy planning software

Force-feedback robotics techniques are being developed for automated precision assembly and servicing of NASA space flight equipment. Design and implementation of a prototype robot which provides compliance and monitors forces is in progress. Computer software to specify assembly steps and makes force feedback adjustments during assembly are coded and tested for three generically different precision mating problems. A model program demonstrates that a suitably autonomous robot can plan its own strategy

Tunable entanglement distillation of spatially correlated down-converted photons

We report on a new technique for entanglement distillation of the bipartite continuous variable state of spatially correlated photons generated in the spontaneous parametric down-conversion process (SPDC), where tunable non-Gaussian operations are implemented and the post-processed entanglement is certified in real-time using a single-photon sensitive electron multiplying CCD (EMCCD) camera. The local operations are performed using non-Gaussian filters modulated into a programmable spatial light modulator and, by using the EMCCD camera for actively recording the probability distributions of the twin-photons, one has fine control of the Schmidt number of the distilled state. We show that even simple non-Gaussian filters can be finely tuned to a ~67% net gain of the initial entanglement generated in the SPDC process.Comment: 12 pages, 6 figure

Roles of Candida albicans Mig1 and Mig2 in glucose repression, pathogenicity traits, and SNF1 essentiality.

Metabolic adaptation is linked to the ability of the opportunistic pathogen Candida albicans to colonize and cause infection in diverse host tissues. One way that C. albicans controls its metabolism is through the glucose repression pathway, where expression of alternative carbon source utilization genes is repressed in the presence of its preferred carbon source, glucose. Here we carry out genetic and gene expression studies that identify transcription factors Mig1 and Mig2 as mediators of glucose repression in C. albicans. The well-studied Mig1/2 orthologs ScMig1/2 mediate glucose repression in the yeast Saccharomyces cerevisiae; our data argue that C. albicans Mig1/2 function similarly as repressors of alternative carbon source utilization genes. However, Mig1/2 functions have several distinctive features in C. albicans. First, Mig1 and Mig2 have more co-equal roles in gene regulation than their S. cerevisiae orthologs. Second, Mig1 is regulated at the level of protein accumulation, more akin to ScMig2 than ScMig1. Third, Mig1 and Mig2 are together required for a unique aspect of C. albicans biology, the expression of several pathogenicity traits. Such Mig1/2-dependent traits include the abilities to form hyphae and biofilm, tolerance of cell wall inhibitors, and ability to damage macrophage-like cells and human endothelial cells. Finally, Mig1 is required for a puzzling feature of C. albicans biology that is not shared with S. cerevisiae: the essentiality of the Snf1 protein kinase, a central eukaryotic carbon metabolism regulator. Our results integrate Mig1 and Mig2 into the C. albicans glucose repression pathway and illuminate connections among carbon control, pathogenicity, and Snf1 essentiality

Dual regimes of ion migration in high repetition rate femtosecond laser inscribed waveguides

Ion migration in high repetition rate femtosecond laser inscribed waveguides is currently being reported in different optical glasses. For the first time we discuss and experimentally demonstrate the presence of two regimes of ion migration found in laser written waveguides. Regime-I, corresponds to the initial waveguide formation mainly via light element migration (in our case atomic weight < 31u), whereas regime-II majorly corresponds to the movement of heavy elements. This behavior brings attention to a problem which has never been analyzed before and that affects laser written active waveguides in which active ions migrate changing their local spectroscopic properties. The migration of active ions may in fact detune the pre-designed optimal values of active photonic devices. This paper experimentally evidences this problem and provides solutions to avert it.Comment: 4 pages, 5 figure

Charge reversal of colloidal particles

A theory is presented for the effective charge of colloidal particles in suspensions containing multivalent counterions. It is shown that if colloids are sufficiently strongly charged, the number of condensed multivalent counterion can exceed the bare colloidal charge leading to charge reversal. Charge renormalization in suspensions with multivalent counterions depends on a subtle interplay between the solvation energies of the multivalent counterions in the bulk and near the colloidal surface. We find that the effective charge is {\it not} a monotonically decreasing function of the multivalent salt concentration. Furthermore, contrary to the previous theories, it is found that except at very low concentrations, monovalent salt hinders the charge reversal. This conclusion is in agreement with the recent experiments and simulations

Enhanced Charge Carrier Transport in 2D Perovskites by Incorporating Single-Walled Carbon Nanotubes or Graphene

Two-dimensional (2D) organic-inorganic (hybrid) perovskites are considered promising candidates to replace conventional three-dimensional (3D) perovskites for solar cell applications as they have good resistance against moisture and UV light. However, the use of 2D perovskite is associated with a significant decrease in power efficiency resulting from their low photogenerated charge carrier density and poor charge transport. To improve power efficiency in 2D perovskites, highly crystalline films (near-single-crystal quality) of 2D perovskite need to be synthesized where the alignment of the inorganic perovskite components is controlled to have vertical alignment with respect to the contacts to improve charge transport. In this work, we explored strategies to overcome this limitation by integrating 2D perovskite with single-walled carbon nanotubes or graphene to enable more efficient extraction of charge carriers toward electric contacts. Longer carrier lifetimes were achieved after the incorporation of the carbon nanostructures in the films, and at the cell level, power efficiency increased by 2-fold