658 research outputs found

    Three New Species of the Genus Kisaura (Trichoptera, Philopotamidae) from Indian Himalaya

    No full text
    Иллюстрированное описание Kisaura malickyi sp. n. и K. bhagati sp. n. из Уттараханда и K. kanchenjungaensis sp. n. из Сиккима.Kisaura malickyi sp. n., K. bhagati sp. n. from Uttarakhand, and K. kanchenjungaensis sp. n. from Sikkim are described and illustrated in this paper

    The topology of the Fermi surface of Bi2212 from angle resolved photoemission

    Full text link
    We present a study of the topology of the normal state Fermi surface (FS) of the high Tc superconductor Bi2212 using angle-resolved photoemission. We present FS mapping experiments, recorded using unpolarised radiation with high (E,k) resolution, and an extremely dense sampling of k-space. In addition, synchrotron radiation-based ARPES has been used to prove the energy independence of the FS as seen by photoemission. We resolve the current controversy regarding the normal state FS in Bi2212. The true picture is simple, self-consistent and robust: the FS is hole-like, with the form of rounded tubes centred on the corners of the Brillouin zone. Two further types of features are also clearly observed: shadow FSs, and diffraction replicas of the main FS caused by passage of the photoelectrons through the modulated Bi-O planes.Comment: M2S-HTSC-VI conference paper (4 pages, 3 eps. figures), using Elsevier style espcrc2.st

    Stock prices, exchange rates and causality in Malaysia: a note

    Get PDF
    This article contributes to the debate on stock prices and exchange rates in Malaysia. It examines causal relations using a new Granger non-causality test proposed by Toda and Yamamoto (Journal of Econometrics, 66, 225-50, 1995). Among the findings of interest, there is a feedback interaction between exchange rates and stock prices for the pre-crisis period. The results also reveal that exchange rates lead stock prices for the crisis period. In a financially liberalized environment, exchange rates stability is important for stock market well-being

    Evolution of density perturbations in double exponential quintessence models

    Full text link
    In this work we investigate the evolution of matter density perturbations for quintessence models with a self-interaction potential that is a combination of exponentials. One of the models is based on the Einstein theory of gravity, while the other is based on the Brans-Dicke scalar tensor theory. We constrain the parameter space of the models using the determinations for the growth rate of perturbations derived from data of the 2-degree Field Galaxy Redshift Survey.Comment: 5 pages, 3 eps figure

    A biophotonic approach to measure pH in small volumes in vitro: quantifiable differences in metabolic flux around the cumulus-oocyte-complex (COC)

    Get PDF
    Unfertilised eggs (oocytes) release chemical biomarkers into the medium surrounding them. This provides an opportunity to monitor cell health and development during assisted reproductive processes if detected in a non-invasive manner. Here we report the measurement of pH using an optical fibre probe, OFP1, in 5 μL drops of culture medium containing single mouse cumulus-oocyte-complexes (COCs). This allowed for the detection of statistically significant differences in pH between COCs in culture medium with no additives and those incubated with either a chemical (cobalt chloride) or hormonal treatment (follicle stimulating hormone); both of which serve to induce the release of lactic acid into the medium immediately surrounding the COC. Importantly, OFP1 was shown to be cell-safe with no inherent cell toxicity or light-induced phototoxicity indicated by negative DNA damage staining. Pre-measurement photobleaching of the probe reduced fluorescence signal variability, providing improved measurement precision (0.01 - 0.05 pH units) compared to previous studies. This optical technology presents a promising platform for the measurement of pH and the detection of other extracellular biomarkers to assess cell health during assisted reproduction. This article is protected by copyright. All rights reserved.Hanna J. McLennan, Avishkar Saini, Georgina M. Sylvia, Erik P. Schartner, Kylie R. Dunning, Malcolm S. Purdey, Tanya M. Monro, Andrew D. Abell, Jeremy G. Thompso

    Constraining the dark energy with galaxy clusters X-ray data

    Full text link
    The equation of state characterizing the dark energy component is constrained by combining Chandra observations of the X-ray luminosity of galaxy clusters with independent measurements of the baryonic matter density and the latest measurements of the Hubble parameter as given by the HST key project. By assuming a spatially flat scenario driven by a "quintessence" component with an equation of state px=ωρxp_x = \omega \rho_x we place the following limits on the cosmological parameters ω\omega and Ωm\Omega_{\rm{m}}: (i) 1ω0.55-1 \leq \omega \leq -0.55 and Ωm=0.320.014+0.027\Omega_{\rm m} = 0.32^{+0.027}_{-0.014} (1σ\sigma) if the equation of state of the dark energy is restricted to the interval 1ω<0-1 \leq \omega < 0 (\emph{usual} quintessence) and (ii) ω=1.290.792+0.686\omega = -1.29^{+0.686}_{-0.792} and Ωm=0.310.034+0.037\Omega_{\rm{m}} = 0.31^{+0.037}_{-0.034} (1σ1\sigma) if ω\omega violates the null energy condition and assume values <1< -1 (\emph{extended} quintessence or ``phantom'' energy). These results are in good agreement with independent studies based on supernovae observations, large-scale structure and the anisotropies of the cosmic background radiation.Comment: 6 pages, 4 figures, LaTe

    On exact solutions for quintessential (inflationary) cosmological models with exponential potentials

    Full text link
    We first study dark energy models with a minimally-coupled scalar field and exponential potentials, admitting exact solutions for the cosmological equations: actually, it turns out that for this class of potentials the Einstein field equations exhibit alternative Lagrangians, and are completely integrable and separable (i.e. it is possible to integrate the system analytically, at least by quadratures). We analyze such solutions, especially discussing when they are compatible with a late time quintessential expansion of the universe. As a further issue, we discuss how such quintessential scalar fields can be connected to the inflationary phase, building up, for this class of potentials, a quintessential inflationary scenario: actually, it turns out that the transition from inflation toward late-time exponential quintessential tail admits a kination period, which is an indispensable ingredient of this kind of theoretical models. All such considerations have also been done by including radiation into the model.Comment: Revtex4, 10 figure

    iNOS activity is critical for the clearance of Burkholderia mallei from infected RAW 264.7 murine macrophages

    Get PDF
    Burkholderia mallei is a facultative intracellular pathogen that can cause fatal disease in animals and humans. To better understand the role of phagocytic cells in the control of infections caused by this organism, studies were initiated to examine the interactions of B. mallei with RAW 264.7 murine macrophages. Utilizing modified kanamycin-protection assays, B. mallei was shown to survive and replicate in RAW 264.7 cells infected at multiplicities of infection (moi) of ≤ 1. In contrast, the organism was efficiently cleared by the macrophages when infected at an moi of 10. Interestingly, studies demonstrated that the monolayers only produced high levels of TNF-α, IL-6, IL-10, GM-CSF, RANTES and IFN-β when infected at an moi of 10. In addition, nitric oxide assays and inducible nitric oxide synthase (iNOS) immunoblot analyses revealed a strong correlation between iNOS activity and clearance of B. mallei from RAW 264.7 cells. Furthermore, treatment of activated macrophages with the iNOS inhibitor, aminoguanidine, inhibited clearance of B. mallei from infected monolayers. Based upon these results, it appears that moi significantly influence the outcome of interactions between B. mallei and murine macrophages and that iNOS activity is critical for the clearance of B. mallei from activated RAW 264.7 cells

    Differential cross section and recoil polarization measurements for the gamma p to K+ Lambda reaction using CLAS at Jefferson Lab

    Full text link
    We present measurements of the differential cross section and Lambda recoil polarization for the gamma p to K+ Lambda reaction made using the CLAS detector at Jefferson Lab. These measurements cover the center-of-mass energy range from 1.62 to 2.84 GeV and a wide range of center-of-mass K+ production angles. Independent analyses were performed using the K+ p pi- and K+ p (missing pi -) final-state topologies; results from these analyses were found to exhibit good agreement. These differential cross section measurements show excellent agreement with previous CLAS and LEPS results and offer increased precision and a 300 MeV increase in energy coverage. The recoil polarization data agree well with previous results and offer a large increase in precision and a 500 MeV extension in energy range. The increased center-of-mass energy range that these data represent will allow for independent study of non-resonant K+ Lambda photoproduction mechanisms at all production angles.Comment: 22 pages, 16 figure

    Measurement of the nuclear multiplicity ratio for Ks0K^0_s hadronization at CLAS

    Full text link
    The influence of cold nuclear matter on lepto-production of hadrons in semi-inclusive deep inelastic scattering is measured using the CLAS detector in Hall B at Jefferson Lab and a 5.014 GeV electron beam. We report the Ks0K_s^0 multiplicity ratios for targets of C, Fe, and Pb relative to deuterium as a function of the fractional virtual photon energy zz transferred to the Ks0K_s^0 and the transverse momentum squared pT2p_{T}^2 of the Ks0K_s^0. We find that the multiplicity ratios for Ks0K^0_s are reduced in the nuclear medium at high zz and low pT2p_{T}^2, with a trend for the Ks0K^0_s transverse momentum to be broadened in the nucleus for large pT2p_{T}^2.Comment: Submitted to Phys. Lett.
    corecore