1,071 research outputs found

    Echinocyte Shapes: Bending, Stretching and Shear Determine Spicule Shape and Spacing

    Get PDF
    We study the shapes of human red blood cells using continuum mechanics. In particular, we model the crenated, echinocytic shapes and show how they may arise from a competition between the bending energy of the plasma membrane and the stretching/shear elastic energies of the membrane skeleton. In contrast to earlier work, we calculate spicule shapes exactly by solving the equations of continuum mechanics subject to appropriate boundary conditions. A simple scaling analysis of this competition reveals an elastic length which sets the length scale for the spicules and is, thus, related to the number of spicules experimentally observed on the fully developed echinocyte.Comment: Revtex, 27 pages, 8 figures; some minor change

    A Study on understanding the use of a process color-based color communication systems to print synthetic colors accurately and consistently

    Get PDF
    The study is intended to provide a better understanding on the use of process color-based color communication systems such as those provided by Focoltone, Trumatch, and Pantone, in order to print synthetic colors as accurately and as consistently as possible. Using Focoltone\u27s system, an investigation was done on the materials and documentation, as provided by the Focoltone kit. The available information, as provided by Focoltone, was supplemented by the author\u27s interpretation of Focoltone\u27s specifications. From the author\u27s understanding of Focoltone specifications, a set of procedures were outlined that would contribute towards the accurate and consistent reproduction of synthetic colors on a press run. The study concludes that the use of standard film dots, as specified by Focoltone, to reproduce the reference colors on the swatchbook, is question able because the dot gain characteristics of press run(s) used to print Focoltone\u27s swatchbooks differ significantly from that of industry average values obtained from FIPP. Moreover, as each production press would exhibit its own dot gain characteristics, the use of a standard film dot in the printing process would not contribute to an accurate reproduction of color. Instead, the study recommends that procedures have to be established that: 1. Enable the conversion of standard film dot area specifications into custom film dot specifications to suit the particular press run\u27s dot gain characteristics. This procedure requires the availability of the plate/press curve of the printing process used to print the swatchbook, and that of the production press, as established in a fingerprint press run. 2. Ensure that the graphic reproduction process, from film to plate to press, is implemented in standardized conditions and manner, and that process control of SID be established, so that deviations from desired SID and dot gain are minimized. This way, the synthetic colors, using process color-based color communication systems, can be as printed as accurately, with reference to the reference color swatches, and as consistently throughout the press run

    Going Green with IT: A Study of Energy Consumption by Home and School Information Technology Systems in the College of Information at the University of North Texas

    Get PDF
    This paper addresses the strategies introduced by the College of Information at the University of North Texas to monitor and begin implementing approaches to enable the college to move toward the university???s strategic goal of becoming a climate-neutral, ???Green University??? [3]. Data based on monitoring selected office and home inventories of information technology equipment were used to generate estimated production-level use and standby (vampire) consumption of electrical energy. Sample-based estimations and projections regarding 2008 to 2009 progress indicate that that the College of Information at the University of North Texas has made extensive progress over one year in reducing the energy consumed by its information technology systems. New computer and printer systems have greater processing power and capabilities but consume no more power than the ones they replace, when in full operation. The computer systems consume one-half to one-third (and in some cases oneseventh) the power of the previous systems when in 'sleep???, 'hibernate' or 'shut down' states that qualify for the standard definition of consuming stand by power. The authors estimate that these actions have brought the college at least halfway toward its five-year goal of becoming climate neutral, during the first year of the initiative

    Integer Quantization of the Chern-Simons Coefficient in a Broken Phase

    Full text link
    We consider a spontaneously broken nonabelian topologically massive gauge theory in a broken phase possessing a residual nonabelian symmetry. Recently there has been some question concerning the renormalization of the Chern-Simons coefficient in such a broken phase. We show that, in this broken vacuum, the renormalized ratio of the Chern-Simons coupling to the gauge coupling is shifted by 1/4Ï€1/4\pi times an integer, preserving the usual integer quantization condition on the bare parameters.Comment: 9 pages LaTeX, two figures available upon reques

    Synthesis and Characterization of Ruthenium Amidinate Complexes as Precursors for Vapor Deposition

    Get PDF
    Three new ruthenium amidinate complexes were prepared: tris(diisopropylacetamidinato)-ruthenium(III), Ru(iPrNC(Me)NiPr)3 4; bis(diisopropyl-acetamidinato)ruthenium(II) dicarbonyl, Ru(iPrNC(Me)NiPr)2(CO)2 5; and bis(ditert- butylacetamidinato)ruthenium(II) dicarbonyl, Ru(tBuNC(Me)NtBu)2(CO)2 6. They have been synthesized and characterized by 1H NMR, TG and X-ray structure analysis. These three complexes were found to be monomeric and air stable. Compound 6 was found to have sufficient volatility and thermal stability for use in chemical vapor deposition (CVD) and atomic layer deposition (ALD) of ruthenium metal films.Chemistry and Chemical Biolog

    Remarks on the thermodynamics and the vacuum energy of a quantum Maxwell gas on compact and closed manifolds

    Full text link
    The quantum Maxwell theory at finite temperature at equilibrium is studied on compact and closed manifolds in both the functional integral- and Hamiltonian formalism. The aim is to shed some light onto the interrelation between the topology of the spatial background and the thermodynamic properties of the system. The quantization is not unique and gives rise to inequivalent quantum theories which are classified by {\theta}-vacua. Based on explicit parametrizations of the gauge orbit space in the functional integral approach and of the physical phase space in the canonical quantization scheme, the Gribov problem is resolved and the equivalence of both quantization schemes is elucidated. Using zeta-function regularization the free energy is determined and the effect of the topology of the spatial manifold on the vacuum energy and on the thermal gauge field excitations is clarified. The general results are then applied to a quantum Maxwell gas on a n-dimensional torus providing explicit formulae for the main thermodynamic functions in the low- and high temperature regimes, respectively.Comment: 41 page

    The effects of estrogen, its antagonist ICI 182, 780, and interferon-tau on the expression of estrogen receptors and integrin alphaV beta 3 on cycle day 16 in bovine endometrium

    Get PDF
    We have shown previously that downregulation of intercaruncular stromal integrin α(v)β(3 )in bovine endometrium on day 16 of the estrous cycle coincided with the antibody recognition of estrogen receptors (ER) in the luminal epithelium. In pregnancy, these changes were not observed. Our hypothesis was that on day 16 of the estrous cycle, estrogen from the dominant follicle causes a reduction in integrin α(v)β(3 )and affects ERα in the luminal epithelium. The pregnancy recognition protein, interferon-τ (IFN-τ), may prevent downregulation of integrin α(v)β(3 )and suppress ERα expression in the luminal epithelium. On days 14 to 16, heifers received uterine infusions of the anti-estrogen ICI 182, 780, estradiol 17β, IFN-τ or the saline control. On day 16, reproductive tracts were collected for analysis of integrin α(v)β(3 )and ERα. Estrogen receptor α immunoreactivity was largely restricted to the luminal epithelium in control animals. Using anti-ERα recognizing the amino terminus, estrogen-treated animals showed reactivity in the stroma, shallow and deep glands and myometrium as is typical of estrus, whereas ICI 182, 870 treated heifers showed little or no reactivity. In contrast, carboxyl terminus-directed antibodies showed a widespread distribution of ERα with reactivity detected in the uterine epithelium, stroma and myometrium of both estrogen and ICI 182, 780 treated animals. Heifers treated with IFN-τ had low ERα reactivity overall. Control and IFN-τ treated heifers had lower intercaruncular stromal expression of integrin α(v)β(3 )in comparison to estrogen and ICI 182, 780 treatments. Overall, the results suggest that on day 16 of the estrous cycle, estrogen effects on integrin α(v)β(3 )are indirect and do not directly involve ERα in the luminal epithelium. During pregnancy, interferon-tau may block ERα in the luminal epithelium but likely does not rescue integrin α(v)β(3 )expression

    Desmoplastic small round cell tumor of the stomach mimicking a gastric cancer in a child

    Get PDF
    Intra-abdominal desmoplastic small round cell tumor (DSRCT) is a highly malignant tumor of uncertain histogenesis. Here we report a case of DSRCT involving the stomach, initially misdiagnosed as gastric cancer. A 12-year-old boy presented with upper abdominal pain developed 1 month prior. On gastroscopy, a 7-cm mass was noted involving the esophago-gastric junction to the fundus, and positron emission tomography showed multiple hot uptakes suggesting distant metastasis. Gastroscopic biopsy showed poorly differentiated malignant cells. We diagnosed as stage IV gastric cancer and treated with 6 cycles of chemotherapy. Laparotomy revealed a huge gastric mass along with peritoneal disseminations. Palliative proximal gastrectomy was performed. Pathological examination revealed transmural involvement of DSRCT, and t(11;22)(p12;q12) was demonstrated on fluorescence in situ hybridization test. The chemotherapeutic regimen was changed and the patient underwent 8 additional cycles of post-operative chemotherapy. The patient is now alive and the residual tumor shows no significant changes after chemotherapy
    • …
    corecore