4,679 research outputs found

    On compression of Bruhat-Tits buildings

    Full text link
    We obtain an analog of the compression of angles theorem in symmetric spaces for Bruhat--Tits buildings of the type AA. More precisely, consider a pp-adic linear space VV and the set Lat(V)Lat(V) of all lattices in VV. The complex distance in Lat(V)Lat(V) is a complete system of invariants of a pair of points of Lat(V)Lat(V) under the action of the complete linear group. An element of a Nazarov semigroup is a lattice in the duplicated linear space VVV\oplus V. We investigate behavior of the complex distance under the action of the Nazarov semigroup on the set Lat(V)Lat(V).Comment: 6 page

    Uniform thin film based polymer separators for rechargeable Li-ion batteries

    Get PDF
    Battery separator’s main function is to prevent physical contact of the electrodes while permitting ions to flow freely. They itself does not participate in any cell reactions, however, its properties significantly determine the performance and safety of the batteries. For high energy and power densities, the separator is required to be very thin and highly porous, while it adversely affects the safety and cycle life of the battery as a result of the reduced mechanical strength. The safety requirement is a top priority for rechargeable Li-ion batteries, especially these used in hybrid electric vehicles and power tools. Battery separators need to have excellent porosity, as well as low cost, lightness and durability

    Filarial antigenemia and Loa loa night blood microfilaremia in an area without bancroftian filariasis in the democratic republic of Congo

    Get PDF
    Implementation of mass drug administration for lymphatic filariasis (LF) has been delayed in central Africa because of incomplete mapping and coendemic loiasis. We mapped two regions in eastern Democratic Republic of Congo that were suspected to have LF. Night blood samples were collected from 2,724 subjects in 30 villages. Filarial antigenemia rates by card test exceeded 1% in 28 villages (range = 0–14%). Prevalence rates for large sheathed microfilariae (Mf) ranged from 4% to 40%; Mansonella perstans rates ranged from 22% to 98%. Large Mf were exclusively Loa loa by microscopy, and only 1 of 337 samples tested by quantitative polymerase chain reaction (qPCR) was positive for Wuchereria bancrofti DNA. Filarial antigen positivity was strongly associated with high L. loa Mf counts. Periodicity studies revealed atypical patterns, with no significant diurnal periodicity in some individuals. Thus, methods routinely used for LF mapping may not be reliable in areas in central Africa that are highly endemic for loiasis

    Cell-Instructive Surface Gradients of Photoresponsive Amyloid-like Fibrils

    Get PDF
    [Image: see text] Gradients of bioactive molecules play a crucial role in various biological processes like vascularization, tissue regeneration, or cell migration. To study these complex biological systems, it is necessary to control the concentration of bioactive molecules on their substrates. Here, we created a photochemical strategy to generate gradients using amyloid-like fibrils as scaffolds functionalized with a model epitope, that is, the integrin-binding peptide RGD, to modulate cell adhesion. The self-assembling β-sheet forming peptide (CKFKFQF) was connected to the RGD epitope via a photosensitive nitrobenzyl linker and assembled into photoresponsive nanofibrils. The fibrils were spray-coated on glass substrates and macroscopic gradients were generated by UV-light over a centimeter-scale. We confirmed the gradient formation using matrix-assisted laser desorption ionization mass spectroscopy imaging (MALDI-MSI), which directly visualizes the molecular species on the surface. The RGD gradient was used to instruct cells. In consequence, A549 adapted their adhesion properties in dependence of the RGD-epitope density

    Testing Hardy nonlocality proof with genuine energy-time entanglement

    Full text link
    We show two experimental realizations of Hardy ladder test of quantum nonlocality using energy-time correlated photons, following the scheme proposed by A. Cabello \emph{et al.} [Phys. Rev. Lett. \textbf{102}, 040401 (2009)]. Unlike, previous energy-time Bell experiments, these tests require precise tailored nonmaximally entangled states. One of them is equivalent to the two-setting two-outcome Bell test requiring a minimum detection efficiency. The reported experiments are still affected by the locality and detection loopholes, but are free of the post-selection loophole of previous energy-time and time-bin Bell tests.Comment: 5 pages, revtex4, 6 figure

    Modular Invariance and Characteristic Numbers

    Full text link
    We show that a general miraculous cancellation formula, the divisibility of certain characteristic numbers and some other topologiclal results are con- sequences of the modular invariance of elliptic operators on loop spaces. Previously we have shown that modular invariance also implies the rigidity of many elliptic operators on loop spaces.Comment: 14 page

    Quantitative Chevalley-Weil theorem for curves

    Get PDF
    The classical Chevalley-Weil theorem asserts that for an \'etale covering of projective varieties over a number field K, the discriminant of the field of definition of the fiber over a K-rational point is uniformly bounded. We obtain a fully explicit version of this theorem in dimension 1.Comment: version 4: minor inaccuracies in Lemma 3.4 and Proposition 5.2 correcte

    Star Formation and Feedback in Dwarf Galaxies

    Full text link
    We examine the star formation history and stellar feedback effects of dwarf galaxies under the influence of extragalactic ultraviolet radiation. We consider the dynamical evolution of gas in dwarf galaxies using a one-dimensional, spherically symmetric, Lagrangian numerical scheme to compute the effects of radiative transfer and photoionization. We include a physically-motivated star formation recipe and consider the effects of feedback. Our results indicate that star formation in the severe environment of dwarf galaxies is a difficult and inefficient process. For intermediate mass systems, such as the dSphs around the Galaxy, star formation can proceed with in early cosmic epochs despite the intense background UV flux. Triggering processes such as merger events, collisions, and tidal disturbance can lead to density enhancements, reducing the recombination timescale, allowing gas to cool and star formation to proceed. However, the star formation and gas retention efficiency may vary widely in galaxies with similar dark matter potentials, because they depend on many factors, such as the baryonic fraction, external perturbation, IMF, and background UV intensity. We suggest that the presence of very old stars in these dwarf galaxies indicates that their initial baryonic to dark matter content was comparable to the cosmic value. This constraint suggests that the initial density fluctuation of baryonic matter may be correlated with that of the dark matter. For the more massive dwarf elliptical galaxies, the star formation efficiency and gas retention rate is much higher. Their mass to light ratio is regulated by star formation feedback, and is expected to be nearly independent of their absolute luminosity. The results of our theoretical models reproduce the observed M/LMvM/L-M_v correlation.Comment: 35 pages, 13 figure

    An Exact Black Hole Entropy Bound

    Get PDF
    We show that a Rademacher expansion can be used to establish an exact bound for the entropy of black holes within a conformal field theory framework. This convergent expansion includes all subleading corrections to the Bekenstein-Hawking term.Comment: 6 pages, Latex, v2 minor re-wording, additional reference, to appear in Phyical Review D (title changed in journal
    corecore