Sample records for wimp line sensitivity

  1. Development of Bubble Chambers with Sensitivity to WIMPs

    SciTech Connect

    Bond, Leonard J.; Collar, J. I.; Ely, James H.; Flake, Matthew; Hall, Jason M.; Jordan, David V.; Nakazawa, Dante; Raskin, Aza; Sonnenschein, Andrew; Sullivan, Kelly O.

    2005-05-01

    Bubble nucleation in moderately superheated liquids can be triggered by nuclear recoils from WIMPs. This phenomenon is the basis for superheated droplet detectors. The droplet technique is currently limited by insensitivity to spin-independent interactions, due to lack of heavy elements in the usual target liquids, and sensitivity to contamination of the gel by alpha emitters. As an alternative, we have developed a new type of homogeneous bubble chamber, which can contain heavy liquids, including CF3Br, CF3I, and C3F8. Detectors of this type may be scalable to large size at modest cost and could have very low backgrounds. We discuss results obtained with a 12 ml prototype and plans for a 1 liter chamber.

  2. Development of Bubble Chambers with Sensitivity to WIMPs

    SciTech Connect

    Bond, Leonard J.; Collar, J. I.; Ely, James H.; Flake, Matthew; Hall, Jason M.; Jordan, David V.; Nakazawa, Dante; Raskin, Aza; Sonnenschein, Andrew; O'Sullivan, Kevin

    2005-01-10

    Bubble nucleation in moderately superheated liquids can be triggered by nuclear recoils from WIMPs. This phenomenon is the basis for superheated droplet detectors. The droplet technique is currently limited by insensitivity to spin-independent interactions, due to lack of heavy elements in the usual target liquids, and sensitivity to contamination of the gel by alpha emitters. As an alternative, we have developed a new type of homogeneous bubble chamber, which can contain heavy liquids, including CF3Br, CF3I, and C3F8. Detectors of this type may be scalable to large size at modest cost and could have very low backgrounds. We discuss results obtained with a 12 ml prototype and plans for a 1 liter chamber.

  3. Sensitivity of the EDELWEISS WIMP search to spin-dependent interactions

    NASA Astrophysics Data System (ADS)

    EDELWEISS Collaboration; Benoit, A.; Bergé, L.; Blümer, J.; Broniatowski, A.; Censier, B.; Chabert, L.; Chapellier, M.; Chardin, G.; Collin, S.; de Jésus, M.; Deschamps, H.; di Stefano, P.; Dolgorouky, Y.; Drain, D.; Dumoulin, L.; Eitel, K.; Fesquet, M.; Fiorucci, S.; Gascon, J.; Gerbier, G.; Goldbach, C.; Gros, M.; Gumbsheimer, R.; Horn, M.; Juillard, A.; de Lesquen, A.; Luca, M.; Mallet, J.; Marnieros, S.; Mosca, L.; Navick, X.-F.; Nollez, G.; Pari, P.; Razeti, M.; Sanglard, V.; Schoeffel, L.; Stern, M.; Villar, V.

    2005-06-01

    The EDELWEISS Collaboration is searching for WIMP dark matter using natural Ge cryogenic detectors. The whole data set of the first phase of the experiment contains a fiducial exposure of 4.8 kg?day on 73Ge, the naturally present (7.8%), high-spin Ge isotope. The sensitivity of the experiment to the spin-dependent WIMP-nucleon interactions is evaluated using the model-independent framework proposed by Tovey et al. [Phys. Lett. B 488 (2000) 17]. It is shown that the EDELWEISS sensitivity for the WIMP-neutron coupling is competitive when compared with results of other spin-sensitive WIMP dark matter experiments. The current experimental limits lie however two orders of magnitude higher than the most optimistic SUSY models.

  4. Critical revision of the ZEPLIN-I sensitivity to WIMP interactions

    NASA Astrophysics Data System (ADS)

    Benoit, A.; Chapellier, M.; Chardin, G.; Dumoulin, L.; Eitel, K.; Gascon, J.; Gerbier, G.; Goldbach, C.; Jochum, J.; de Lesquen, A.; Nollez, G.; Pröbst, F.; Seidel, W.

    2006-06-01

    The ZEPLIN Collaboration has recently published its first result presenting a maximum sensitivity of 1.1×10 picobarn for a WIMP mass of ?60 GeV. The analysis is based on a discrimination method using the different time distribution of scintillation light generated in electron recoil and nuclear recoil interactions. We show that the methodology followed both for the calibration of the ZEPLIN-I detector response and for the estimation of the discrimination power is not reliable enough to claim any background discrimination at the present stage. The ZEPLIN-I sensitivity appears then to be in the order of 10-3 picobarn, three orders of magnitude above the claimed 1.1×10 picobarn.

  5. A high efficiency veto to increase the sensitivity of ZEPLIN-III, a WIMP detector

    SciTech Connect

    Barnes, E. J. [School of Physics and Astronomy, University of Edinburgh, Edinburgh, EH9 3JZ (United Kingdom)

    2009-09-08

    An active veto detector to complement the ZEPLIN-III two phase Xenon, direct dark matter device is described. The proposed design consists of 52 plastic scintillator segments, individually read out by high efficiency photomultipliers, coupled to a Gd loaded passive polypropylene shield. Experimental work was performed to determine the plastic scintillator characteristics which were used to inform a complete end-to-end Monte Carlo simulation of the expected performance of the new instrument, both operating alone and as an active veto detector for ZEPLIN-III. The veto device will be capable of tagging over 65% of coincident nuclear recoil events in the energy range of interest in ZEPLIN-III, and over 12% for gamma ray rejection, while contributing no significant additional background. In addition it will also provide valuable diagnostic capabilities. The inclusion of the veto to ZEPLIN-III will aid to significantly improve the sensitivity to spin independent WIMP-nucleon cross sections below 10{sup -8} pb.

  6. 3.5 keV X-ray line from nearly-degenerate WIMP dark matter decays

    NASA Astrophysics Data System (ADS)

    Chiang, Cheng-Wei; Yamada, Toshifumi

    2014-09-01

    The unidentified emission line at the energy of ~3.5 keV observed in X-rays from galaxy clusters may originate from a process involving a dark matter particle. On the other hand, a weakly interacting massive particle (WIMP) has been an attractive dark matter candidate, due to its well-understood thermal production mechanism and its connection to physics at the TeV scale. In this paper, we pursue the possibility that the 3.5 keV X-ray arises from a late time decay of a WIMP dark matter into another WIMP dark matter, both of which have the mass of O(100) GeV and whose mass splitting is about 3.5 keV. We focus on the simplest case where there are two Majorana dark matter particles and two charged scalars that couple with a standard model matter particle. By assuming a hierarchical structure in the couplings of the two dark matter particles and two charged scalars, it is possible to explain the 3.5 keV line and realize the WIMP dark matter scenario at the same time. Since the effective coupling of the two different Majorana dark matter particles and one photon violates CP symmetry, the model always contains a new source of CP violation, so the model's connection to the physics of electric dipole moments is discussed. The model's peculiar signatures at the LHC are also studied. We show the prospect of detecting the charged scalars through a detailed collider simulation.

  7. Feature Sensitive Hole Filling with Crest Lines

    Microsoft Academic Search

    Mingxi Zhao; Lizhuang Ma; Zhihong Mao; Zhong Li

    2006-01-01

    Feature sensitive hole filling is important for many computer graphics and geometric modeling applications. In this paper,\\u000a we address the problem of reconstructing the salient features when filling holes in mesh. It respects fine shape features\\u000a and works well on various types of shapes, including natural mesh and mechanical parts. For representing salient surface features,\\u000a we adopt crest lines. The

  8. Latest results from the EDELWEISS WIMP search

    NASA Astrophysics Data System (ADS)

    Marnieros, S.; Benoit, A.; Bergé, L.; Broniatowski, A.; Censier, B.; Chabert, L.; Chambon, B.; Chapellier, M.; Chardin, G.; Charvin, P.; Jésus, M. De; Stefano, P. Di; Drain, D.; Dumoulin, L.; Fesquet, M.; Fiorucci, S.; Gascon, J.; Gerbier, G.; Gerlic, E.; Goldbach, C.; Goyot, M.; Gros, M.; Hadjout, J. P.; Hervé, S.; Juillard, A.; Kikuchi, C.; de Lesquen, A.; Mallet, J.; Martineau, O.; Mosca, L.; Navick, X. F.; Nollez, G.; Pari, P.; Riccio, C.; Sanglard, V.; Stern, M.; Vagneron, L.; Villard, V.; EDELWEISS Collaboration

    2004-03-01

    The latest results obtained by the EDELWEISS Weakly Interacting Massive Particles (WIMP) direct detection experiment using three heat-and-ionization 320 g germanium bolometers are presented. Presently, the most sensitive WIMP direct detection experiment for WIMP mass >30 GeV, EDELWEISS-I is testing a range of SUSY models compatible with the accelerator constraints. The status and main characteristics of EDELWEISS-II, involving in a first stage 28 germanium bolometers, and able to accommodate up to 120 detectors, will be briefly presented.

  9. Neutrinos from WIMP annihilations

    E-print Network

    Mattias Blennow

    2007-10-08

    We make an improved analysis on the flow of neutrinos originating from WIMP annihilations inside the Sun and the Earth. We treat both neutrino interaction and oscillation effects in a consistent framework. Our numerical simulations are performed in an event based setting, which is useful for both theoretical studies and for creating neutrino telescope Monte Carlos. We find that the flow of muon-type neutrinos is enhanced or suppressed depending on the dominant WIMP annihilation channel.

  10. WIMP Dark Matter Limit-Direct Detection Data and Sensitivity Plots from the Cryogenic Dark Matter Search II and the University of California at Santa Barbara

    DOE Data Explorer

    Expectations for non-baryonic dark matter are founded principally in Big Bang nucleosynthesis calculations, which indicate that the missing mass of the universe is not likely to be baryonic. The supersymmetric standard model (SUSY) offers a promising framework for expectations of particle species which could satisfy the observed properties of dark matter. WIMPs are the most likely SUSY candidate for a dark matter particle. The High Energy Physics Group at University of California, Santa Barbara, is part of the CDMSII Collaboration and have provided the Interactive Plotter for WIMP Dark Matter Limit-Direct Detection Data on their website. They invite other collaborations working on dark matter research to submit datasets and, as a result, have more than 150 data sets now available for use with the plotting tool. The published source of the data is provided with each data set.

  11. Isolation of two chloroethylnitrosourea-sensitive Chinese hamster cell lines

    SciTech Connect

    Hata, H.; Numata, M.; Tohda, H.; Yasui, A.; Oikawa, A. (Tohoku Univ., Sendai (Japan))

    1991-01-01

    1-((4-Amino-2-methylpyrimidin-5-yl)methyl)-3-(2-chloroethyl)-3- nitrosourea hydrochloride (ACNU), a cancer chemotherapeutic bifunctional alkylating agent, causes chloroethylation of DNA and subsequent DNA strand cross-linking through an ethylene bridge. We isolated and characterized two ACNU-sensitive mutants from mutagenized Chinese hamster ovary cells and found them to be new drug-sensitive recessive Chinese hamster mutants. Both mutants were sensitive to various monofunctional alkylating agents in a way similar to that of the parental cell lines CHO9. One mutant (UVS1) was cross-sensitive to UV and complemented the UV sensitivity of all Chinese hamster cell lines of 7 established complementation groups. Since UV-induced unscheduled DNA synthesis was very low, a new locus related to excision repair is thought to be defective in this cell line. Another ACNU-sensitive mutant, CNU1, was slightly more sensitive to UV than the parent cell line. CNU1 was cross-sensitive to 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea and slightly more sensitive to mitomycin C. No increased accumulation of ACNU and a low level of UV-induced unscheduled DNA synthesis in this cell as compared with the parental cell line suggest that there is abnormality in a repair response of this mutant cell to some types of DNA cross-links.

  12. Magneto-induced Line Broadening of Magneto-sensitive Lines in Solar Magnetized Atmospheres

    Microsoft Academic Search

    Zhong-Quan Qu; Shuai Wang; Cheng-Lin Xu; Xiao-Yu Zhang; Ming-Guo Sun; Chun-Lan Jin

    2005-01-01

    We analyze the spectral line broadening of those magneto-sensitive lines in solar magnetized atmospheres. The broadening at the line wings is due to the increase of the effective width of energy levels involved in Zeeman splitting, and the broadening at the line core also originated in Zeeman splitting under the condition that the Zeeman components are mixed. Therefore, the magneto-induced

  13. Improved Detection Sensitivity of Line-Scanning Optical Coherence Microscopy

    PubMed Central

    Chen, Yu; Huang, Shu-Wei; Zhou, Chao; Potsaid, Benjamin; Fujimoto, James G.

    2012-01-01

    Optical coherence microscopy (OCM) is a promising technology for high-resolution cellular-level imaging in human tissues. Line-scanning OCM is a new form of OCM that utilizes line-field illumination for parallel detection. In this study, we demonstrate improved detection sensitivity by using an achromatic design for line-field generation. This system operates at 830-nm wavelength with 82-nm bandwidth. The measured axial resolution is 3.9 ?m in air (corresponding to ~2.9 ?m in tissue), and the transverse resolutions are 2.1 ?m along the line-field illumination direction and 1.7 ?m perpendicular to line illumination direction. The measured sensitivity is 98 dB with 25 line averages, resulting in an imaging speed of ~2 frames/s (516 lines/s). Real-time, cellular-level imaging of scattering tissues is demonstrated using human-colon specimens. PMID:22685379

  14. Investigation of Magnetically Sensitive FeH Lines

    NASA Astrophysics Data System (ADS)

    Wende, S.; Reiners, A.; Seifahrt, A.; Shulyak, D.; Kochukhov, O.

    2011-12-01

    M-type stars exhibit strong magnetic fields towards decreasing effective temperatures. The measurement of these fields is complicated due to missing indicators. Molecular FeH lines provide an excellent means to determine magnetic field strengths from the Zeeman broadening of magnetically sensitive lines. Our aim is the investigation of possible dependencies of the amount of sensitivity to magnetic fields from rotational quantum number, branch, and the projection of the total angular momentum onto the internuclear axis (?). We also compare results from computations with those from observations. We use high resolution CRIRES spectra of the two M dwarfs GJ1002 (M5.5 inactive) and GJ1224 (M4.5 active). Individual lines are fitted by Gaussians and the obtained line depths and widths from the active and inactive star can be compared with each other. In this way, magnetically sensitive lines can be detected. For test purposes, we do the same with computed spectra of FeH. One with zero magnetic field and the other with a 2 kG magnetic field vector used in the disc integration (i.e. pure radial at the disc center). We found, in agreement with theory, that lines with high ? show strong sensitivity to magnetic fields. No obvious correlation with branch or J was found, which was also expected for lines formed in intermediate Hund's case. The computations agreed in general well with the observations, but in many cases the individual splitting of certain lines can be very different to observations.

  15. WIMP physics with ensembles of direct-detection experiments

    NASA Astrophysics Data System (ADS)

    Peter, Annika H. G.; Gluscevic, Vera; Green, Anne M.; Kavanagh, Bradley J.; Lee, Samuel K.

    2014-12-01

    The search for weakly-interacting massive particle (WIMP) dark matter is multi-pronged. Ultimately, the WIMP-dark-matter picture will only be confirmed if different classes of experiments see consistent signals and infer the same WIMP properties. In this work, we review the ideas, methods, and status of direct-detection searches. We focus in particular on extracting WIMP physics (WIMP interactions and phase-space distribution) from direct-detection data in the early discovery days when multiple experiments see of order dozens to hundreds of events. To demonstrate the essential complementarity of different direct-detection experiments in this context, we create mock data intended to represent the data from the near-future Generation 2 experiments. We consider both conventional supersymmetry-inspired benchmark points (with spin-independent and -dependent elastic cross sections just below current limits), as well as benchmark points for other classes of models (inelastic and effective-operator paradigms). We also investigate the effect on parameter estimation of loosening or dropping the assumptions about the local WIMP phase-space distribution. We arrive at two main conclusions. Firstly, teasing out WIMP physics with experiments depends critically on having a wide set of detector target materials, spanning a large range of target nuclear masses and spin-dependent sensitivity. It is also highly desirable to obtain data from low-threshold experiments. Secondly, a general reconstruction of the local WIMP velocity distribution, which will only be achieved if there are multiple experiments using different target materials, is critical to obtaining a robust and unbiased estimate of the WIMP mass.

  16. Combined limits on WIMPs from the CDMS and EDELWEISS experiments

    NASA Astrophysics Data System (ADS)

    Ahmed, Z.; Akerib, D. S.; Armengaud, E.; Arrenberg, S.; Augier, C.; Bailey, C. N.; Balakishiyeva, D.; Baudis, L.; Bauer, D. A.; Benoît, A.; Bergé, L.; Blümer, J.; Brink, P. L.; Broniatowski, A.; Bruch, T.; Brudanin, V.; Bunker, R.; Cabrera, B.; Caldwell, D. O.; Censier, B.; Chapellier, M.; Chardin, G.; Charlieux, F.; Cooley, J.; Coulter, P.; Cox, G. A.; Cushman, P.; Daal, M.; Defay, X.; de Jesus, M.; Dejongh, F.; di Stefano, P. C. F.; Dolgorouki, Y.; Domange, J.; Dumoulin, L.; Dragowsky, M. R.; Eitel, K.; Fallows, S.; Figueroa-Feliciano, E.; Filippini, J.; Filosofov, D.; Fourches, N.; Fox, J.; Fritts, M.; Gascon, J.; Gerbier, G.; Gironnet, J.; Golwala, S. R.; Gros, M.; Hall, J.; Hennings-Yeomans, R.; Henry, S.; Hertel, S. A.; Hervé, S.; Holmgren, D.; Hsu, L.; Huber, M. E.; Juillard, A.; Kamaev, O.; Kiveni, M.; Kluck, H.; Kos, M.; Kozlov, V.; Kraus, H.; Kudryavtsev, V. A.; Leman, S. W.; Liu, S.; Loaiza, P.; Mahapatra, R.; Mandic, V.; Marnieros, S.; Martinez, C.; McCarthy, K. A.; Mirabolfathi, N.; Moore, D.; Nadeau, P.; Navick, X.-F.; Nelson, H.; Nones, C.; Ogburn, R. W.; Olivieri, E.; Pari, P.; Pattavina, L.; Paul, B.; Phipps, A.; Pyle, M.; Qiu, X.; Rau, W.; Reisetter, A.; Ricci, Y.; Robinson, M.; Rozov, S.; Saab, T.; Sadoulet, B.; Sander, J.; Sanglard, V.; Schmidt, B.; Schnee, R. W.; Scorza, S.; Seitz, D. N.; Semikh, S.; Serfass, B.; Sundqvist, K. M.; Tarka, M.; Torrento-Coello, A. S.; Vagneron, L.; Verdier, M.-A.; Walker, R. J.; Wikus, P.; Yakushev, E.; Yellin, S.; Yoo, J.; Young, B. A.; Zhang, J.

    2011-07-01

    The CDMS and EDELWEISS collaborations have combined the results of their direct searches for dark matter using cryogenic germanium detectors. The total data set represents 614kg·days equivalent exposure. A straightforward method of combination was chosen for its simplicity before data were exchanged between experiments. The results are interpreted in terms of limits on spin-independent weakly interacting, massive particle (WIMP)-nucleon cross section. For a WIMP mass of 90GeV/c2, where this analysis is most sensitive, a cross section of 3.3×10-44cm2 is excluded at 90% C.L. At higher WIMP masses, the combination improves the individual limits, by a factor 1.6 above 700GeV/c2. Alternative methods of combining the data provide stronger constraints for some ranges of WIMP masses and weaker constraints for others.

  17. Positive tone camp resists sensitive to I-line irradiation

    SciTech Connect

    Slater, S.; Blakeney, A. [OCG Microelectronic Materials Inc., E. Providence, RI (United States); Schultz, R.; Muenzel, N.; Mertesdorf, C.; Thomas-Schacht, H. [Microelectronic Materials Inc., Basel (Switzerland)

    1993-12-31

    Chemically amplified resist materials have been the subject of numerous studies in recent years in attempts to develop and commercialize high resolution photoresists. The majority of these studies have dealt with deep UV exposure. Few chemically amplified I-line resists (mostly negative resists) have been developed and commercialized. This paper will describe and compare the chemistry and lithographic effects of a series of I-line sensitive photoacid generators in polymer matrixes developed for Deep UV lithography. The results will also be compared to state of the art DNQ/novolac based I-line resists.

  18. Differential Sensitivity in the Survival of Oligodendrocyte Cell Lines to

    E-print Network

    Bongarzone, Ernesto R.

    Differential Sensitivity in the Survival of Oligodendrocyte Cell Lines to Overexpression of Myelin in oligodendrocyte survival by overexpression studies in vitro and in vivo. The classic and sr proteolipids are targeted to different cellular com- partments in the oligodendrocyte, suggesting different cellular

  19. Investigation of magnetically sensitive FeH lines

    E-print Network

    Wende, Sebastian; Seifahrt, Andreas; Shulyak, Denis; Kochukhov, Oleg

    2010-01-01

    M-type stars exhibit strong magnetic fields towards decreasing effective temperatures. The measurement of these fields is complicated due to missing indicators. Molecular FeH lines provide an excellent means to determine magnetic field strengths from the Zeeman broadening of magnetically sensitive lines. Our aim is the investigation of possible dependencies of the amount of sensitivity to magnetic fields from rotational quantum number, branch, and the projection of the total angular momentum onto the internuclear axis ({\\Omega}). We also compare results from com-putations with those from observations. We use high resolution CRIRES spectra of the two M dwarfs GJ1002 (M5.5 inactive) and GJ1224 (M4.5 active). Individual lines are fitted by Gaussians and the obtained line depths and widths from the active and inactive star can be compared with each other. In this way, magnetically sensitive lines can be detected. For test purposes, we do the same with computed spectra of FeH. One with zero magnetic field and the ...

  20. 47 CFR 69.713 - Common line, traffic-sensitive, and tandem-switched transport services.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...Common line, traffic-sensitive, and tandem-switched transport services. 69...Common line, traffic-sensitive, and tandem-switched transport services. (a...The traffic-sensitive components of tandem-switched transport services, as...

  1. The WIMP Forest: Indirect Detection of a Chiral Square

    SciTech Connect

    Bertone, Gianfranco; Jackson, C.B.; Shaughnessy, Gabe; Tait, Tim M.P.; Vallinotto, Alberto

    2009-04-01

    The spectrum of photons arising from WIMP annihilation carries a detailed imprint of the structure of the dark sector. In particular, loop-level annihilations into a photon and another boson can in principle lead to a series of lines (a WIMP forest) at energies up to the WIMP mass. A specific model which illustrates this feature nicely is a theory of two universal extra dimensions compactified on a chiral square. Aside from the continuum emission, which is a generic prediction of most dark matter candidates, we find a 'forest' of prominent annihilation lines that, after convolution with the angular resolution of current experiments, leads to a distinctive (2-bump plus continuum) spectrum, which may be visible in the near future with the Fermi Gamma-Ray Space Telescope (formerly known as GLAST).

  2. Post-WIMP user interfaces

    Microsoft Academic Search

    Andries Van Dam

    1997-01-01

    arge set of software-engineering tools for building WIMP interfaces. Ifind it rather surprising that the third generation ofWIMP user interfaces has been so dominant for morethan two decades; they are apparently sufficiently goodfor conventional desktop tasks that the field is stuckcomfortably in a rut.I argue in this essay that the status quo does not suffice---that the newer forms of computing

  3. Probing WIMP particle physics and astrophysics with direct detection and neutrino telescope data

    NASA Astrophysics Data System (ADS)

    Kavanagh, Bradley J.; Fornasa, Mattia; Green, Anne M.

    2015-05-01

    With positive signals from multiple direct detection experiments, it will, in principle, be possible to measure the mass and cross sections of weakly interacting massive particle (WIMP) dark matter. Recent work has shown that, with a polynomial parametrization of the WIMP speed distribution, it is possible to make an unbiased measurement of the WIMP mass, without making any astrophysical assumptions. However, direct detection experiments are not sensitive to low-speed WIMPs and, therefore, any model-independent approach will lead to a bias in the cross section. This problem can be solved with the addition of measurements of the flux of neutrinos from the Sun. This is because the flux of neutrinos produced from the annihilation of WIMPs which have been gravitationally captured in the Sun is sensitive to low-speed WIMPs. Using mock data from next-generation direct detection experiments and from the IceCube neutrino telescope, we show that the complementary information from IceCube on low-speed WIMPs breaks the degeneracy between the cross section and the speed distribution. This allows unbiased determinations of the WIMP mass and spin-independent and spin-dependent cross sections to be made, and the speed distribution to be reconstructed. We use two parametrizations of the speed distribution: binned and polynomial. While the polynomial parametrization can encompass a wider range of speed distributions, this leads to larger uncertainties in the particle physics parameters.

  4. Improved exclusion limits from the EDELWEISS WIMP search

    NASA Astrophysics Data System (ADS)

    Benoit, A.; Bergé, L.; Broniatowski, A.; Chabert, L.; Chambon, B.; Chapellier, M.; Chardin, G.; Charvin, P.; de Jésus, M.; di Stefano, P.; Drain, D.; Dumoulin, L.; Gascon, J.; Gerbier, G.; Gerlic, E.; Goldbach, C.; Goyot, M.; Gros, M.; Hadjout, J. P.; Hervé, S.; Juillard, A.; de Lesquen, A.; Loidl, M.; Mallet, J.; Marnieros, S.; Martineau, O.; Mirabolfathi, N.; Mosca, L.; Navick, X.-F.; Nollez, G.; Pari, P.; Riccio, C.; Sanglard, V.; Stern, M.; Vagneron, L.; EDELWEISS Collaboration

    2002-10-01

    The EDELWEISS experiment has improved its sensitivity for the direct search for WIMP dark matter. In the recoil energy range relevant for WIMP masses below 10 TeV/ c2, no nuclear recoils were observed in the fiducial volume of a heat-and-ionization cryogenic Ge detector operated in the low-background environment of the Laboratoire Souterrain de Modane in the Fréjus Tunnel, during an effective exposure of 7.4 kg d. This result is combined with the previous EDELWEISS data to derive a limit on the cross-section for spin-independent interaction of WIMPs and nucleons as a function of WIMP mass, using standard nuclear physics and astrophysical assumptions. This limit excludes at more than 99.8% CL a WIMP candidate with a mass of 44 GeV/ c2 and a cross-section of 5.4×10 -6 pb, as reported by the DAMA Collaboration. A first sample of supersymmetric models are also excluded at 90% CL.

  5. Improved exclusion limits from the EDELWEISS WIMP search

    NASA Astrophysics Data System (ADS)

    EDELWEISS Collaboration; Benoit, A.; Bergé, L.; Broniatowski, A.; Chabert, L.; Chambon, B.; Chapellier, M.; Chardin, G.; Charvin, P.; de Jésus, M.; di Stefano, P.; Drain, D.; Dumoulin, L.; Gascon, J.; Gerbier, G.; Gerlic, E.; Goldbach, C.; Goyot, M.; Gros, M.; Hadjout, J. P.; Hervé, S.; Juillard, A.; de Lesquen, A.; Loidl, M.; Mallet, J.; Marnieros, S.; Martineau, O.; Mirabolfathi, N.; Mosca, L.; Navick, X.-F.; Nollez, G.; Pari, P.; Riccio, C.; Sanglard, V.; Stern, M.; Vagneron, L.

    2002-10-01

    The EDELWEISS experiment has improved its sensitivity for the direct search for WIMP dark matter. In the recoil energy range relevant for WIMP masses below 10 TeV/c2, no nuclear recoils were observed in the fiducial volume of a heat-and-ionization cryogenic Ge detector operated in the low-background environment of the Laboratoire Souterrain de Modane in the Fréjus Tunnel, during an effective exposure of /7.4 kgd. This result is combined with the previous EDELWEISS data to derive a limit on the cross-section for spin-independent interaction of WIMPs and nucleons as a function of WIMP mass, using standard nuclear physics and astrophysical assumptions. This limit excludes at more than /99.8% CL a WIMP candidate with a mass of 44 GeV/c2 and a cross-section of 5.4×10-6 pb, as reported by the DAMA Collaboration. A first sample of supersymmetric models are also excluded at 90% CL.

  6. Spin-Dependent WIMP Limits from a Bubble Chamber

    NASA Astrophysics Data System (ADS)

    Behnke, , E.; Collar, , J. I.; Cooper, , P. S.; Crum, , K.; Crisler, , M.; Hu, , M.; Levine, , I.; Nakazawa, , D.; Nguyen, , H.; Odom, , B.; Ramberg, , E.; Rasmussen, , J.; Riley, , N.; Sonnenschein, , A.; Szydagis, , M.; Tschirhart, R.

    2008-02-01

    Bubble chambers were the dominant technology used for particle detection in accelerator experiments for several decades, eventually falling into disuse with the advent of other techniques. We report here on a new application for these devices. We operated an ultraclean, room-temperature bubble chamber containing 1.5 kilograms of superheated CF3I, a target maximally sensitive to spin-dependent and -independent weakly interacting massive particle (WIMP) couplings. An extreme intrinsic insensitivity to the backgrounds that commonly limit direct searches for dark matter was measured in this device under operating conditions leading to the detection of low-energy nuclear recoils like those expected from WIMPs. Improved limits on the spin-dependent WIMP-proton scattering cross section were extracted during our experiments, excluding this type of coupling as a possible explanation for a recent claim of particle dark-matter detection.

  7. Spin-dependent WIMP limits from a bubble chamber.

    PubMed

    Behnke, E; Collar, J I; Cooper, P S; Crum, K; Crisler, M; Hu, M; Levine, I; Nakazawa, D; Nguyen, H; Odom, B; Ramberg, E; Rasmussen, J; Riley, N; Sonnenschein, A; Szydagis, M; Tschirhart, R

    2008-02-15

    Bubble chambers were the dominant technology used for particle detection in accelerator experiments for several decades, eventually falling into disuse with the advent of other techniques. We report here on a new application for these devices. We operated an ultraclean, room-temperature bubble chamber containing 1.5 kilograms of superheated CF3I, a target maximally sensitive to spin-dependent and -independent weakly interacting massive particle (WIMP) couplings. An extreme intrinsic insensitivity to the backgrounds that commonly limit direct searches for dark matter was measured in this device under operating conditions leading to the detection of low-energy nuclear recoils like those expected from WIMPs. Improved limits on the spin-dependent WIMP-proton scattering cross section were extracted during our experiments, excluding this type of coupling as a possible explanation for a recent claim of particle dark-matter detection. PMID:18276885

  8. Light WIMPs and Equivalent Neutrinos

    NASA Astrophysics Data System (ADS)

    Steigman, Gary; Nollett, Kenneth M.

    Very light WIMPs (?), thermal relics that annihilate late in the early Universe, change the energy and entropy densities at BBN and at recombination. BBN, in combination with the CMB, can remove some of the degeneracies among light WIMPs and equivalent neutrinos, constraining the existence and properties of each. Depending on the nature of the light WIMP (Majorana or Dirac fermion, real or complex scalar) the joint BBN + CMB analyses set lower bounds to m? in the range 0.5 - 5 MeV (m?/me ?1 - 10), and they identify best fit values for m? in the range 5 - 10 MeV. The joint BBN + CMB analysis finds a best fit value for the number of equivalent neutrinos, ?N? ? 0.65, nearly independent of the nature of the WIMP. In the absence of a light WIMP (m? ?20 MeV), Neff = 3.05(1 + ?N?/3). In this case, there is excellent agreement between BBN and the CMB, but the joint fit reveals ?N? = 0.40 ± 0.17, disfavoring standard big bang nucleosynthesis (SBBN) (?N? = 0) at ? 2.4 ?, as well as a sterile neutrino (?N? = 1) at ? 3.5 ?. The best BBN + CMB joint fit disfavors the absence of dark radiation (?N? = 0 at ? 95% confidence), while allowing for the presence of a sterile neutrino (?N? = 1 at ?1 ?). For all cases considered here, the lithium problem persists. These results, presented at the TAUP 2013 Conference, are based on Nollett & Steigman [14].

  9. Delay-Line Three-Dimensional Position Sensitive Radiation Detection

    NASA Astrophysics Data System (ADS)

    Jeong, Manhee

    High-resistivity silicon(Si) in large volumes and with good charge carrier transport properties has been produced and achieved success as a radiation detector material over the past few years due to its relatively low cost as well as the availability of well-established processing technologies. One application of that technology is in the fabrication of various position-sensing topologies from which the incident radiation's direction can be determined. We have succeeded in developing the modeling tools for investigating different position-sensing schemes and used those tools to examine both amplitude-based and time-based methods, an assessment that indicates that fine position-sensing can be achieved with simpler readout designs than are conventionally deployed. This realization can make ubiquitous and inexpensive deployment of special nuclear materials (SNM) detecting technology becomes more feasible because if one can deploy position-sensitive semiconductor detectors with only one or two contacts per side. For this purpose, we have described the delay-line radiation detector and its optimized fabrication. The semiconductor physics were simulated, the results from which guided the fabrication of the guard ring structure and the detector electrode, both of which included metal-field-plates. The measured improvement in the leakage current was confirmed with the fabricated devices, and the structures successfully suppressed soft-breakdown. We also demonstrated that fabricating an asymmetric strip-line structure successfully minimizing the pulse shaping and increases the distance through which one can propagate the information of the deposited charge distribution. With fabricated delay-line detectors we can acquire alpha spectra (Am-241) and gamma spectra (Ba-133, Co-57 and Cd-109). The delay-line detectors can therefore be used to extract the charge information from both ion and gamma-ray interactions. Furthermore, standard charge-sensitive circuits yield high SNR pulses. The detectors and existing electronics can therefore be used to yield imaging instruments for neutron and gamma-rays, in the case of silicon. For CZT, we would prefer to utilize current sensing to be able to clearly isolate the effects of the various charge-transport non-idealities, the full realization of which awaits the fabrication of the custom-designed TIA chip.

  10. Direct WIMP searches with XENON100 and XENON1T

    NASA Astrophysics Data System (ADS)

    Alfredo Davide, Ferella

    2015-05-01

    The XENON100 experiment is the second phase of the XENON direct Dark Matter search program. It consists of an ultra-low background double phase (liquid-gas) xenon filled time projection chamber with a total mass of 161 kg (62 in the target region and 99 in the active shield), installed at the Laboratori Nazionali del Gran Sasso (LNGS). Here the results from the 224.6 live days of data taken between March 2011 and April 2012 are reported. The experiment set one of the most stringent limits on the WIMP-nucleon spin-independent cross section to date (2 × 10-45 cm2 for a 55 Gev/c2 WIMP mass at 90 % confidence level) and the most stringent on the spin-dependent WIMP-neutron interaction (3.5 × 10-40 for a 45 GeV/c2 WIMP mass). With the same dataset, XENON100 excludes also solar axion coupling to electrons at gAe > 7.7 × 10-12 for a mass of mAxion <1 keV/c2 and galactic axion couplings by gAe > 1 × 10-12 at a mass range of mAxion = 5-10 keV/c2 (both 90 % C.L.). Moreover an absolute spectral comparison between simulated and measured nuclear recoil distributions of light and charge signals from a 241AmBe source demonstrates a high level of detector and systematics understanding. Finally, the third generation of the XENON experiments, XENON1T, is the first tonne scale direct WIMP search experiment currently under construction. The commissioning phase of XENON1T is expected to start in early 2015 followed, a few months after, by the first science run. The experiment will reach sensitivities on the WIMP-nucleon spin-independent cross section down to 2 ×10-47 cm2 after two years of data taking.

  11. Event rates for WIMP detection

    SciTech Connect

    Vergados, J. D. [University of Ioannina, Ioannina, Gr 45110 (Greece); Moustakidis, Ch. C.; Oikonomou, V. [Department of Theoretical Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece)

    2006-11-28

    The event rates for the direct detection of dark matter for various types of WIMPs are presented. In addition to the neutralino of SUSY models, we considered other candidates (exotic scalars as well as particles in Kaluza-Klein and technicolour theories) with masses in the TeV region. Then one finds reasonable branching ratios to excited states. Thus the detection of the WIMP can be made not only by recoil measurements, by measuring the de-excitation {gamma}-rays as well.

  12. Preliminary results of a WIMP search with EDELWEISS-II cryogenic detectors

    E-print Network

    E. Armengaud; for the EDELWEISS collaboration

    2010-11-10

    The EDELWEISS-II experiment uses cryogenic heat-and-ionization detectors in order to detect the rare interactions from possible WIMP dark matter particles on Germanium nuclei. Recently, new-generation detectors with an interleaved electrode geometry were developped and validated, enabling an outstanding rejection of gamma-rays and surface interactions. We present here preliminary results of a one-year WIMP search carried out with ten of such detectors in the Laboratoire Souterrain de Modane. A sensitivity to the spin-independent WIMP-nucleon cross-section of 5 \\times 10-8 pb was achieved using a 322 kg

  13. Dark matter in the solar system II: WIMP annihilation rates in the Sun

    E-print Network

    Annika H. G. Peter

    2009-02-09

    We calculate the annihilation rate of weakly interacting massive particles (WIMPs) in the Sun as a function of their mass and elastic scattering cross section. One byproduct of the annihilation, muon neutrinos, may be observed by the next generation of neutrino telescopes. Previous estimates of the annihilation rate assumed that any WIMPs from the Galactic dark halo that are captured in the Sun by elastic scattering off solar nuclei quickly reach thermal equilibrium in the Sun. We show that the optical depth of the Sun to WIMPs and the gravitational forces from planets both serve to decrease the annihilation rate below these estimates. While we find that the sensitivity of upcoming km^3-scale neutrino telescopes to ~100 GeV WIMPs is virtually unchanged from previous estimates, the sensitivity of these experiments to ~10 TeV WIMPs may be an order of magnitude less than the standard calculations would suggest. The new estimates of the annihilation rates should guide future experiment design and improve the mapping from neutrino event rates to WIMP parameter space.

  14. Characterization of UV radiation sensitive frog cell lines

    Microsoft Academic Search

    Smith-Stein

    1983-01-01

    Twenty-one subclones of nine frog cell isolates were tested for sensitivity to a panel of DNA damaging agents. Two clones were identified which had a greater than wild type level of sensitivity to UV radiation but had a wild type level of sensitivity to the other agents. These clones were the haploid RRP602-7 and the diploid RRP802-1. RRP802-1 was found

  15. Assessing Alternatives for Directional Detection of a WIMP Halo

    E-print Network

    Craig J. Copi; Lawrence M. Krauss; David Simmons-Duffin; Steven R. Stroiney

    2005-08-30

    The future of direct terrestrial WIMP detection lies on two fronts: new, much larger low background detectors sensitive to energy deposition, and detectors with directional sensitivity. The former can large range of WIMP parameter space using well tested technology while the latter may be necessary if one is to disentangle particle physics parameters from astrophysical halo parameters. Because directional detectors will be quite difficult to construct it is worthwhile exploring in advance generally which experimental features will yield the greatest benefits at the lowest costs. We examine the sensitivity of directional detectors with varying angular tracking resolution with and without the ability to distinguish forward versus backward recoils, and compare these to the sensitivity of a detector where the track is projected onto a two-dimensional plane. The latter detector regardless of where it is placed on the Earth, can be oriented to produce a significantly better discrimination signal than a 3D detector without this capability, and with sensitivity within a factor of 2 of a full 3D tracking detector. Required event rates to distinguish signals from backgrounds for a simple isothermal halo range from the low teens in the best case to many thousands in the worst.

  16. WIMP identification through a combined measurement of axial and scalar couplings

    E-print Network

    Bertone, G; Collar, J I; Odom, B

    2007-01-01

    We study the prospects for detecting Weakly Interacting Massive Particles (WIMPs), in a number of phenomenological scenarios, with a detector composed of a target simultaneously sensitive to both spin-dependent and spin-independent couplings, as is the case of COUPP (Chicagoland Observatory for Underground Particle Physics). First, we show that sensitivity to both couplings optimizes chances of initial WIMP detection. Second, we demonstrate that in case of detection, comparison of the signal on two complementary targets, such as in COUPP CF3I and C4F10 bubble chambers, allows a significantly more precise determination of the dark matter axial and scalar couplings. This strategy would provide crucial information on the nature of the WIMPs, and possibly allow discrimination between neutralino and Kaluza-Klein dark matter.

  17. WIMP identification through a combined measurement of axial and scalar couplings

    E-print Network

    G. Bertone; D. G. Cerdeno; J. I. Collar; B. Odom

    2007-07-23

    We study the prospects for detecting Weakly Interacting Massive Particles (WIMPs), in a number of phenomenological scenarios, with a detector composed of a target simultaneously sensitive to both spin-dependent and spin-independent couplings, as is the case of COUPP (Chicagoland Observatory for Underground Particle Physics). First, we show that sensitivity to both couplings optimizes chances of initial WIMP detection. Second, we demonstrate that in case of detection, comparison of the signal on two complementary targets, such as in COUPP CF3I and C4F10 bubble chambers, allows a significantly more precise determination of the dark matter axial and scalar couplings. This strategy would provide crucial information on the nature of the WIMPs, and possibly allow discrimination between neutralino and Kaluza-Klein dark matter.

  18. Model-independent WIMP Characterisation using ISR

    E-print Network

    Christoph Bartels; Olaf Kittel; Ulrich Langenfeld; Jenny List

    2012-03-01

    The prospects of measuring the parameters of WIMP dark matter in a model independent way at the International Linear Collider are investigated. The signal under study is direct WIMP pair production with associated initial state radiation. The analysis is performed in full simulation of the ILD detector concept. With an integrated luminosity of L = 500 fb-1 and realistic beam polarizations the helicity structure of the WIMP couplings to electrons can be determined, and the masses and cross sections can be measured to the percent level. The systematic uncertainties are dominated by the polarization measurement and the luminosity spectrum.

  19. Isolation of uv-sensitive clones from mouse cell lines by lederberg style replica plating

    Microsoft Academic Search

    Toshio Kuroki; Shigeyo Y. Miyashita

    1977-01-01

    Seven uv-sensitive clones were isolated from the mouse cell lines, FM3A and L5178Y, using Lederberg style replica plating. The uv-sensitive clones were found at a frequency of 1 in 886 clones of FM3A and of 6 in 420 clones of L5178Y, after treatment with N-methyl-N'-nitro-N-nitrosoguanidine, but no uv-sensitive clones were obtained in the untreated controls. The Do values of freshly

  20. Search for Light WIMPs Captured in the Sun Using Contained Events in Super-Kamiokande

    NASA Astrophysics Data System (ADS)

    Choi, K.

    Super-Kamiokande can search for dark matter by detecting neutrinos and muons which are produced by WIMP pair annihilations occurring inside the Sun. The huge gravity and hydrogen-rich composition of the Sun combined with high sensitivity of Super-Kamiokande for low energy (few GeV) neutrinos allow us good sensitivity to light (few GeV to few 10 GeV) WIMP dark matter, especially for spin-dependent coupling ones. In this analysis, we increased signal acceptance by using fully-contained and partially-contained neutrino events added to up-going muons in Super-Kamiokande. We performed least-squares fitting to use energy, direction and flavor information. We used 3903 days of Super-Kamiokande I-IV data to find the allowed contribution of WIMP-induced neutrino events added to large background of atmospheric neutrino events. As a result, we found no signal observed and the null result is interpreted as upper limit on the spin-dependent WIMP-proton elastic scattering cross-section for ?? ? bb¯ and ?? ? ?+?- WIMPannihilation channels. We set current best limit for WIMP mass below 100 GeV.

  1. Sensitivity analysis of TRV in TCSC compensated transmission lines during fault clearing by line CB

    Microsoft Academic Search

    A. Parvizi; M. Rostami; A. Majzoob Ghadiri

    2008-01-01

    Thyristor controlled series capacitors (TCSC) are effective devices for transmission lines power delivery enhancement in power systems. Before installation of TCSCs, it is necessary to study side effects of their integration in power system. One of these studies is the effect of series compensation on transient recovery voltage (TRV) of line circuit breaker when clearing a fault. The amplitude and

  2. WIMP abundance and lepton (flavour) asymmetry

    SciTech Connect

    Stuke, Maik; Schwarz, Dominik J. [Fakultät für Physik, Universität Bielefeld, Postfach 100131, 33501 Bielefeld (Germany); Starkman, Glenn, E-mail: mstuke@physik.uni-bielefeld.de, E-mail: dschwarz@physik.uni-bielefeld.de, E-mail: glenn.starkman@case.edu [CERCA/ISO, Department of Physics, Case Western Reserve University, Cleveland, OH 44106-7079 (United States)

    2012-03-01

    We investigate how large lepton asymmetries affect the evolution of the early universe at times before big bang nucleosynthesis and in particular how they influence the relic density of WIMP dark matter. In comparison to the standard calculation of the relic WIMP abundance we find a decrease, depending on the lepton flavour asymmetry. We find an effect of up to 20 per cent for lepton flavour asymmetries l{sub f} = O(0.1)

  3. Low-Background Detector Development at EFI: WIMPs, Axions, Neutrinos, and Other Sneaky Beasts

    SciTech Connect

    Collar, Juan (University of Chicago) [University of Chicago

    2003-12-03

    I will review the status of several experimental efforts at University of Chicago aiming at the detection of astrophysical exotica: a bubble chamber using CF3I and CF3Br dedicated to WIMP searches, the CAST experiment at CERN (looking for solar axions) and R&D towards a detector sensitive to very low-energy nuclear recoils from coherent neutrino scattering.

  4. Improved WIMP-search reach of the CDMS II germanium data

    E-print Network

    R. Agnese; A. J. Anderson; M. Asai; D. Balakishiyeva; D. Barker; R. Basu Thakur; D. A. Bauer; J. Billard; A. Borgland; M. A. Bowles; D. Brandt; P. L. Brink; R. Bunker; B. Cabrera; D. O. Caldwell; R. Calkins; D. G. Cerdeño; H. Chagani; Y. Chen; J. Cooley; B. Cornell; C. H. Crewdson; P. Cushman; M. Daal; P. C. F. Di Stefano; T. Doughty; L. Esteban; S. Fallows; E. Figueroa-Feliciano; G. L. Godfrey; S. R. Golwala; J. Hall; H. R. Harris; S. A. Hertel; T. Hofer; D. Holmgren; L. Hsu; M. E. Huber; D. Jardin; A. Jastram; O. Kamaev; B. Kara; M. H. Kelsey; A. Kennedy; M. Kiveni; K. Koch; A. Leder; B. Loer; E. Lopez Asamar; P. Lukens; R. Mahapatra; V. Mandic; K. A. McCarthy; N. Mirabolfathi; R. A. Moffatt; S. M. Oser; K. Page; W. A. Page; R. Partridge; M. Pepin; A. Phipps; K. Prasad; M. Pyle; H. Qiu; W. Rau; P. Redl; A. Reisetter; Y. Ricci; H. E. Rogers; T. Saab; B. Sadoulet; J. Sander; K. Schneck; R. W. Schnee; S. Scorza; B. Serfass; B. Shank; D. Speller; D. Toback; S. Upadhyayula; A. N. Villano; B. Welliver; J. S. Wilson; D. H. Wright; X. Yang; S. Yellin; J. J. Yen; B. A. Young; J. Zhang

    2015-04-22

    CDMS II data from the 5-tower runs at the Soudan Underground Laboratory were reprocessed with an improved charge-pulse fitting algorithm. Two new analysis techniques to reject surface-event backgrounds were applied to the 612 kg days germanium-detector WIMP-search exposure. An extended analysis was also completed by decreasing the 10 keV analysis threshold to $\\sim$5 keV, to increase sensitivity near a WIMP mass of 8 GeV/$c^2$. After unblinding, there were zero candidate events above a deposited energy of 10 keV and 6 events in the lower-threshold analysis. This yielded minimum WIMP-nucleon spin-independent scattering cross-section limits of $1.8 \\times 10^{-44}$ and $1.18 \\times 10 ^{-41}$ cm$^2$ at 90\\% confidence for 60 and 8.6 GeV/$c^2$ WIMPs, respectively. This improves the previous CDMS II result by a factor of 2.4 (2.7) for 60 (8.6) GeV/$c^2$ WIMPs.

  5. Sensitization assays: monocyte-derived dendritic cells versus a monocytic cell line (THP-1).

    PubMed

    Tietze, Corinna; Blomeke, Brunhilde

    2008-01-01

    Dendritic cells (DCs) play a critical role in the skin sensitization process of contact allergens. Many efforts have been made to develop in vitro sensitization tests that employ DCs, but more recently protocols were introduced that use cell lines other than DCs. The potential of the cell line THP-1 compared to monocyte-derived DCs (MoDCs) was evaluated using a known potent sensitizer 2,4-dinitrochlorobenzene (DNCB) and the terpenoid ascaridol (1,4-epodioxy-p-menth-2-ene), an ingredient present in oxidized tea tree oil. Activation of these cells was studied by estimation of the CD86 and CD54 cell surface expression. Overall, comparable results were found. The expression of CD86 was augmented by ascaridol in THP-1 and MoDCs, while the expression of CD54 was not reproducibly increased. These results encourage the further development of THP-1 cells as a short-term model for sensitization testing. PMID:18569603

  6. Selective breeding of two rat lines differing in sensitivity to GHB and baclofen

    Microsoft Academic Search

    Giancarlo Colombo; Carla Lobina; Roberta Agabio; Giuliana Brunetti; Giacomo Diaz; Martino Littera; Samuele Melis; Marialaura Pani; Roberta Reali; Salvatore Serra; Giovanni Vacca; Mauro A. M Carai; Gian Luigi Gessa

    2001-01-01

    Two Wistar-derived rat lines, one sensitive (GHB-S) and the other resistant (GHB-R) to the anesthetic effect of ?-hydroxybutyric acid (GHB), have been selectively bred. GHB-S and GHB-R rats were also sensitive and resistant, respectively, to the anesthetic effect of baclofen, the prototype GABAB receptor agonist, suggesting that they may be useful to elucidate not only the role of endogenous GHB

  7. Sensitivity of different cell lines to phototoxic effect of disulfonated chloroaluminium phthalocyanine.

    PubMed

    Kolarova, H; Lenobel, R; Kolar, P; Strnad, M

    2007-10-01

    Photodynamic therapy (PDT) is a treatment for cancer involving three key components: sensitizer, light and tissue oxygen. A sensitizer is a chemical compound that can be excited by light of a specific wavelength. Phthalocyanine ClAlPcS(2), belonging among the promising second generation of sensitizers, was evaluated as an inducer of photodamage on NIH3T3 (mouse fibroblasts), B16 (mouse melanoma), MCF7 (human breast adenocarcinoma) and G361 (human melanoma) cell lines. A semiconductor laser was used as a source for evocation of the photodynamic effect. We report the influence of various concentrations of the sensitizer in combination with laser irradiation on the photodamage of cells. Viability of cells was determined by means of molecular probes (Calcein AM and ethidium homodimer) for fluorescence microscopy. The quantitative changes of cell viability in relation to sensitizer concentrations and laser irradiation were proved by fluorometric measurement. We detected phototoxicity evoked by laser irradiated sensitizer in all studied cell lines. In addition, the viability studies showed that G361 melanoma cells and MCF7 breast adenocarcinoma cells were more sensitive than NIH3T3 mouse fibroblasts and B16 mouse melanoma to photodynamic damage induced by ClAlPcS(2). PMID:17923379

  8. SENSITIVE AND RESISTANT LINES OF SNAPBEAN (PHASEOLUS VULGARIS L.) II. DAILY WATER USE.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Experiments were conducted to determine the relative growth, yield and selected physiological responses of ozone resistant (R331) and sensitive (S156) lines of snapbean Phaseolus vulgaris to a range of chronic Ozone exposures. Plants were grown in mini-greenhouses in the field which allow 90% of ful...

  9. Tips for improving equipment test sensitivity demonstrated at IEEE's Live-Line Maintenance Conference

    Microsoft Academic Search

    R. Smock; D. Vernola

    1980-01-01

    Utilities learned how to make their equipment testing more sensitive and how to eliminate stray currents in test measurements at IEEE's Live-Line Maintenance Conference. The test methods demonstrated are commonly used by manufacturers for laboratory certification. The conference included demonstrations of the hot stick, the conductive suit, and the bucket truck. (DCK)

  10. In-line interferometer for direction-sensitive displacement measurements by optical feedback detection

    Microsoft Academic Search

    Alvarado Tarun; Julius Jecong; Caesar Saloma

    2005-01-01

    We demonstrate a compact in-line interferometer for direction-sensitive displacement measurement by optical feedback detection with a semiconductor laser (SL) light source. Two reflected beams from a semitransparent reference mirror and a reflecting test object interfere in the SL medium, causing a variation in its output power. The reference mirror is located between the SL output facet and the test object.

  11. SENSITIZATION OF HUMAN OSTEOSARCOMA CELL LINE 143B WITH CALCITRIOL FOR CISPLATIN THERAPY

    E-print Network

    Bhamidi Lakshmi, Surya Kameshwari Priyanka

    2012-08-31

    is pretreatment of OS cells with calcitriol would sensitize them for cisplatin therapy leading to decrease in concentration for IC50. Secondary objective was to evaluate the effect of calcitriol on migration and invasion of OS cell lines, and the role of matrix...

  12. RFI shielding and mitigation techniques for a sensitive search for the 327 MHz line of Deuterium

    E-print Network

    Ellingson, Steven W.

    RFI shielding and mitigation techniques for a sensitive search for the 327 MHz line of Deuterium the amelioration of RFI is the major challenge for the "Deuterium array". Locally generated RFI both from the array of prime importance for the search. Since almost all the RFI comes from the horizon the station array has

  13. The Cancer Cell Line Encyclopedia enables predictive modelling of anticancer drug sensitivity.

    PubMed

    Barretina, Jordi; Caponigro, Giordano; Stransky, Nicolas; Venkatesan, Kavitha; Margolin, Adam A; Kim, Sungjoon; Wilson, Christopher J; Lehár, Joseph; Kryukov, Gregory V; Sonkin, Dmitriy; Reddy, Anupama; Liu, Manway; Murray, Lauren; Berger, Michael F; Monahan, John E; Morais, Paula; Meltzer, Jodi; Korejwa, Adam; Jané-Valbuena, Judit; Mapa, Felipa A; Thibault, Joseph; Bric-Furlong, Eva; Raman, Pichai; Shipway, Aaron; Engels, Ingo H; Cheng, Jill; Yu, Guoying K; Yu, Jianjun; Aspesi, Peter; de Silva, Melanie; Jagtap, Kalpana; Jones, Michael D; Wang, Li; Hatton, Charles; Palescandolo, Emanuele; Gupta, Supriya; Mahan, Scott; Sougnez, Carrie; Onofrio, Robert C; Liefeld, Ted; MacConaill, Laura; Winckler, Wendy; Reich, Michael; Li, Nanxin; Mesirov, Jill P; Gabriel, Stacey B; Getz, Gad; Ardlie, Kristin; Chan, Vivien; Myer, Vic E; Weber, Barbara L; Porter, Jeff; Warmuth, Markus; Finan, Peter; Harris, Jennifer L; Meyerson, Matthew; Golub, Todd R; Morrissey, Michael P; Sellers, William R; Schlegel, Robert; Garraway, Levi A

    2012-03-29

    The systematic translation of cancer genomic data into knowledge of tumour biology and therapeutic possibilities remains challenging. Such efforts should be greatly aided by robust preclinical model systems that reflect the genomic diversity of human cancers and for which detailed genetic and pharmacological annotation is available. Here we describe the Cancer Cell Line Encyclopedia (CCLE): a compilation of gene expression, chromosomal copy number and massively parallel sequencing data from 947 human cancer cell lines. When coupled with pharmacological profiles for 24 anticancer drugs across 479 of the cell lines, this collection allowed identification of genetic, lineage, and gene-expression-based predictors of drug sensitivity. In addition to known predictors, we found that plasma cell lineage correlated with sensitivity to IGF1 receptor inhibitors; AHR expression was associated with MEK inhibitor efficacy in NRAS-mutant lines; and SLFN11 expression predicted sensitivity to topoisomerase inhibitors. Together, our results indicate that large, annotated cell-line collections may help to enable preclinical stratification schemata for anticancer agents. The generation of genetic predictions of drug response in the preclinical setting and their incorporation into cancer clinical trial design could speed the emergence of 'personalized' therapeutic regimens. PMID:22460905

  14. The Cancer Cell Line Encyclopedia enables predictive modeling of anticancer drug sensitivity

    PubMed Central

    Barretina, Jordi; Caponigro, Giordano; Stransky, Nicolas; Venkatesan, Kavitha; Margolin, Adam A.; Kim, Sungjoon; Wilson, Christopher J.; Lehár, Joseph; Kryukov, Gregory V.; Sonkin, Dmitriy; Reddy, Anupama; Liu, Manway; Murray, Lauren; Berger, Michael F.; Monahan, John E.; Morais, Paula; Meltzer, Jodi; Korejwa, Adam; Jané-Valbuena, Judit; Mapa, Felipa A.; Thibault, Joseph; Bric-Furlong, Eva; Raman, Pichai; Shipway, Aaron; Engels, Ingo H.; Cheng, Jill; Yu, Guoying K.; Yu, Jianjun; Aspesi, Peter; de Silva, Melanie; Jagtap, Kalpana; Jones, Michael D.; Wang, Li; Hatton, Charles; Palescandolo, Emanuele; Gupta, Supriya; Mahan, Scott; Sougnez, Carrie; Onofrio, Robert C.; Liefeld, Ted; MacConaill, Laura; Winckler, Wendy; Reich, Michael; Li, Nanxin; Mesirov, Jill P.; Gabriel, Stacey B.; Getz, Gad; Ardlie, Kristin; Chan, Vivien; Myer, Vic E.; Weber, Barbara L.; Porter, Jeff; Warmuth, Markus; Finan, Peter; Harris, Jennifer L.; Meyerson, Matthew; Golub, Todd R.; Morrissey, Michael P.; Sellers, William R.; Schlegel, Robert; Garraway, Levi A.

    2012-01-01

    The systematic translation of cancer genomic data into knowledge of tumor biology and therapeutic avenues remains challenging. Such efforts should be greatly aided by robust preclinical model systems that reflect the genomic diversity of human cancers and for which detailed genetic and pharmacologic annotation is available1. Here we describe the Cancer Cell Line Encyclopedia (CCLE): a compilation of gene expression, chromosomal copy number, and massively parallel sequencing data from 947 human cancer cell lines. When coupled with pharmacologic profiles for 24 anticancer drugs across 479 of the lines, this collection allowed identification of genetic, lineage, and gene expression-based predictors of drug sensitivity. In addition to known predictors, we found that plasma cell lineage correlated with sensitivity to IGF1 receptor inhibitors; AHR expression was associated with MEK inhibitor efficacy in NRAS-mutant lines; and SLFN11 expression predicted sensitivity to topoisomerase inhibitors. Altogether, our results suggest that large, annotated cell line collections may help to enable preclinical stratification schemata for anticancer agents. The generation of genetic predictions of drug response in the preclinical setting and their incorporation into cancer clinical trial design could speed the emergence of “personalized” therapeutic regimens2. PMID:22460905

  15. Drug-Resistant Urothelial Cancer Cell Lines Display Diverse Sensitivity Profiles to Potential Second-Line Therapeutics.

    PubMed

    Vallo, Stefan; Michaelis, Martin; Rothweiler, Florian; Bartsch, Georg; Gust, Kilian M; Limbart, Dominik M; Rödel, Franz; Wezel, Felix; Haferkamp, Axel; Cinatl, Jindrich

    2015-06-01

    Combination chemotherapy with gemcitabine and cisplatin in patients with metastatic urothelial cancer of the bladder frequently results in the development of acquired drug resistance. Availability of cell culture models with acquired resistance could help to identify candidate treatments for an efficient second-line therapy. Six cisplatin- and six gemcitabine-resistant cell lines were established. Cell viability assays were performed to evaluate the sensitivity to 16 different chemotherapeutic substances. The activity of the drug transporter ATP-binding cassette transporter, subfamily B, member 1 (ABCB1, a critical mediator of multidrug resistance in cancer) was evaluated using fluorescent ABCB1 substrates. For functional assessment, cells overexpressing ABCB1 were generated by transduction with a lentiviral vector encoding for ABCB1, while zosuquidar was used for selective inhibition. In this study, 8 of 12 gemcitabine- or cisplatin-resistant cell lines were cross-resistant to carboplatin, 5 to pemetrexed, 4 to methotrexate, 3 to oxaliplatin, 5-fluorouracil, and paclitaxel, and 2 to cabazitaxel, larotaxel, docetaxel, topotecan, doxorubicin, and mitomycin c, and 1 of 12 cell lines was cross-resistant to vinflunine and vinblastine. In one cell line with acquired resistance to gemcitabine (TCC-SUP(r)GEMCI(20)), cross-resistance seemed to be mediated by ABCB1 expression. Our model identified the vinca alkaloids vinblastine and vinflunine, in Europe an already approved second-line therapeutic for metastatic bladder cancer, as the most effective compounds in urothelial cancer cells with acquired resistance to gemcitabine or cisplatin. These results demonstrate that this in vitro model can reproduce clinically relevant results and may be suitable to identify novel substances for the treatment of metastatic bladder cancer. PMID:26055179

  16. Drug-Resistant Urothelial Cancer Cell Lines Display Diverse Sensitivity Profiles to Potential Second-Line Therapeutics12

    PubMed Central

    Vallo, Stefan; Michaelis, Martin; Rothweiler, Florian; Bartsch, Georg; Gust, Kilian M.; Limbart, Dominik M.; Rödel, Franz; Wezel, Felix; Haferkamp, Axel; Cinatl, Jindrich

    2015-01-01

    Combination chemotherapy with gemcitabine and cisplatin in patients with metastatic urothelial cancer of the bladder frequently results in the development of acquired drug resistance. Availability of cell culture models with acquired resistance could help to identify candidate treatments for an efficient second-line therapy. Six cisplatin- and six gemcitabine-resistant cell lines were established. Cell viability assays were performed to evaluate the sensitivity to 16 different chemotherapeutic substances. The activity of the drug transporter ATP-binding cassette transporter, subfamily B, member 1 (ABCB1, a critical mediator of multidrug resistance in cancer) was evaluated using fluorescent ABCB1 substrates. For functional assessment, cells overexpressing ABCB1 were generated by transduction with a lentiviral vector encoding for ABCB1, while zosuquidar was used for selective inhibition. In this study, 8 of 12 gemcitabine- or cisplatin-resistant cell lines were cross-resistant to carboplatin, 5 to pemetrexed, 4 to methotrexate, 3 to oxaliplatin, 5-fluorouracil, and paclitaxel, and 2 to cabazitaxel, larotaxel, docetaxel, topotecan, doxorubicin, and mitomycin c, and 1 of 12 cell lines was cross-resistant to vinflunine and vinblastine. In one cell line with acquired resistance to gemcitabine (TCC-SUPrGEMCI20), cross-resistance seemed to be mediated by ABCB1 expression. Our model identified the vinca alkaloids vinblastine and vinflunine, in Europe an already approved second-line therapeutic for metastatic bladder cancer, as the most effective compounds in urothelial cancer cells with acquired resistance to gemcitabine or cisplatin. These results demonstrate that this in vitro model can reproduce clinically relevant results and may be suitable to identify novel substances for the treatment of metastatic bladder cancer. PMID:26055179

  17. Phosphoproteomics data classify hematological cancer cell lines according to tumor type and sensitivity to kinase inhibitors

    PubMed Central

    2013-01-01

    Background Tumor classification based on their predicted responses to kinase inhibitors is a major goal for advancing targeted personalized therapies. Here, we used a phosphoproteomic approach to investigate biological heterogeneity across hematological cancer cell lines including acute myeloid leukemia, lymphoma, and multiple myeloma. Results Mass spectrometry was used to quantify 2,000 phosphorylation sites across three acute myeloid leukemia, three lymphoma, and three multiple myeloma cell lines in six biological replicates. The intensities of the phosphorylation sites grouped these cancer cell lines according to their tumor type. In addition, a phosphoproteomic analysis of seven acute myeloid leukemia cell lines revealed a battery of phosphorylation sites whose combined intensities correlated with the growth-inhibitory responses to three kinase inhibitors with remarkable correlation coefficients and fold changes (> 100 between the most resistant and sensitive cells). Modeling based on regression analysis indicated that a subset of phosphorylation sites could be used to predict response to the tested drugs. Quantitative analysis of phosphorylation motifs indicated that resistant and sensitive cells differed in their patterns of kinase activities, but, interestingly, phosphorylations correlating with responses were not on members of the pathway being targeted; instead, these mainly were on parallel kinase pathways. Conclusion This study reveals that the information on kinase activation encoded in phosphoproteomics data correlates remarkably well with the phenotypic responses of cancer cells to compounds that target kinase signaling and could be useful for the identification of novel markers of resistance or sensitivity to drugs that target the signaling network. PMID:23628362

  18. Resistance to cisplatin does not affect sensitivity of human ovarian cancer cell lines to mifepristone cytotoxicity

    PubMed Central

    Freeburg, Elizabeth M; Goyeneche, Alicia A; Seidel, Erin E; Telleria, Carlos M

    2009-01-01

    Background The prototypical antiprogestin mifepristone exhibits potent growth inhibition activity towards ovarian cancer cells in vitro and in vivo. The aim of this research was to establish whether mifepristone is capable of inhibiting cell proliferation and inducing apoptotic cell death regardless of the degree of sensitivity ovarian cancer cells exhibit to cisplatin. Methods OV2008, OV2008/C13, A2780, A2780/CP70, Caov-3, and SK-OV-3 cell lines exhibiting a range of sensitivities to cisplatin were used. Growth inhibition, cell viability, and sub-diploid DNA content in response to treatment with escalating doses of either mifepristone or cisplatin were assessed by microcapillary cytometry. Apoptotic cell death was evaluated by measuring genomic DNA fragmentation and cleavage of caspase-3 and poly (ADP ribose) polymerase (PARP). Results The sensitivities to cisplatin manifested by the cell lines were OV2008 > A2780 > Caov-3 > SK-OV-3 > OV2008/C13 > A2780/CP70. Mifepristone inhibited the growth of all six cell lines in a dose-related manner with IC50s ranging from ~6–12 ?M and without significant correlation with the relative sensitivities the cells displayed for cisplatin. Moreover, at the highest concentration studied, mifepristone triggered apoptotic death in all six cell lines as evidenced by the increase in sub-diploid fragmented DNA content and cleavage of caspase-3 and of its downstream substrate PARP. Conclusion Mifepristone is cytotoxic towards ovarian cancer cells independent of the sensitivity exhibited by the cells to cisplatin, displaying cytostatic effects at lower concentrations and lethal effects at higher concentrations. Mifepristone monotherapy emerges as a valuable therapeutic alternative for platinum-resistant ovarian cancers. PMID:19222856

  19. Folate depletion increases sensitivity of solid tumor cell lines to 5-fluorouracil and antifolates.

    PubMed

    Backus, H H; Pinedo, H M; Wouters, D; Padrón, J M; Molders, N; van Der Wilt, C L; van Groeningen, C J; Jansen, G; Peters, G J

    2000-09-15

    Cancer cell lines in standard cell culture medium or in animal models are surrounded by an environment with relatively high folate (HF) levels, compared with folate levels in human plasma. In the present study we adapted 4 colon cancer (C26-A, C26-10, C26-G and WiDr) and 3 squamous cell carcinoma of the head and neck (HNSCC) cell lines (11B, 14C and 22B) to culture medium with low folate (LF) levels (2.5, 1.0 and 0.5 nM, respectively) and investigated whether folate depletion had an effect on sensitivity to antifolates and which mechanisms were involved. All LF cell lines showed a higher sensitivity to 5-fluorouracil (5-FU) alone or in combination with leucovorin (LV) (2-5-fold), to the thymidylate synthase (TS) inhibitors, AG337 (2-7-fold), ZD1694 (3-49-fold), ZD9331 (3-40-fold), LY231514 (2-21-fold) or GW1843U89 (4-29-fold) or to the dihydrofolate reductase (DHFR) inhibitor PT523 (2-50-fold) compared with their HF variants cultured in standard medium containing up to 8 microM folic acid. LV could only increase sensitivity to 5-FU in HNSCC cell lines 14C and 14C/F. The differences in sensitivity could partially be explained by a 2-7-fold increased transport activity of the reduced folate carrier (RFC) in LF cell lines, whereas no significant change in folylpolyglutamate synthetase (FPGS) activity was observed. Furthermore, the protein expression and catalytic activity of the target enzyme TS were up to 7-fold higher in HF colon cancer cells compared with the LF variants (p < 0.05). Although the TS protein expression in LF HNSCC cells was also lower than in HF variants, the TS catalytic activity and FdUMP binding sites were up to 3-fold higher (p < 0.05). Thus, changes in TS levels were associated with differences in sensitivity. These results indicate that folate depletion was associated with changes in TS and RFC levels which resulted in an increase in sensitivity to 5-FU and antifolates. The folate levels in LF medium used in this study are more representative for folate levels in human plasma and therefore these data could be more predictive for the activity of 5-FU and antifolates in a clinical setting than results obtained from cell lines cultured in HF medium or in animal models. PMID:10956384

  20. Spectrometer sensitivity calibration in the extreme uv by means of branching ratios of magnetic dipole lines

    SciTech Connect

    Denne, B.; Hinnov, E.

    1984-04-01

    Relative intensity measurements of various line pairs resulting from magnetic dipole transitions within the configurations s/sup 2/p/sup 2/ and s/sup 2/p/sup 4/, in conjunction with calculated transition probabilities, have been used to determine the wavelength dependence of the sensitivity of a grazing incidence spectrometer, in the range 400 to 1000 A. Emissions from Cr XIX, Fe XXI, Ni XXI and XXIII, Cu XXIV, and Zr XXVII ions in PLT tokamak discharges were used for this purpose. Absolute sensitivity of the spectrometer at selected wavelengths had been determined by the traditional hydrogen, helium, carbon, and oxygen electric-dipole line pairs from the same discharges. Similar attempts to use transitions in the s/sup 2/p/sup 3/ configurations in Cr XVIII, Zr XXVI, and Mo XXVIII ions resulted in significant discrepancies that are ascribed to uncertainties in the corresponding calculated transition probabilities.

  1. Induction of resistance to hexadecylphosphocholine in the highly sensitive human epidermoid tumour cell line KB

    Microsoft Academic Search

    E. A. M. Fleer; D. Berkovic; U. Grunwald; W. Hiddemann

    1996-01-01

    Hexadecylphosphocholine (HePC, Miltefosine) is a representative of the group of alkyl-lysophosphocholines showing remarkable antitumoral activity in in vitro experiments and in experimental animal tumour models. The epidermoid tumour cell line KB, which is highly sensitive to HePC (half-maximal growth inhibiting concentration, ic50: 1.2 ?M; half lethal concentration, lc50: 2.8 ?M), was slowly adapted to increasing concentrations of HePC. After 14

  2. Differential sensitivities of glioblastoma cell lines towards metabolic and signaling pathway inhibitions.

    PubMed

    Kennedy, Colin R; Tilkens, Sarah B; Guan, Hong; Garner, Justine A; Or, Penelope M Y; Chan, Andrew M

    2013-08-19

    In glioblastoma multiforme (GBM), the activation of the phosphatidylinositol 3-kinase (PI3-K) pathway is known to promote aerobic glycolysis. The relative sensitivity of GBM towards PI3-K and metabolic inhibitors was examined in a panel of human GBM lines. We observed differential sensitivities towards oligomycin, an ATP synthase inhibitor that suppresses oxidative phosphorylation (OXPHOS). GBMs that were sensitive to oligomycin have greater intrinsic oxygen consumption. They also failed to undergo adaptive glycolytic switches in response to oligomycin, as reflected in the failure to activate AMPK?. On the other hand, GBM lines that were less sensitive to oligomycin could be rendered non-viable when simultaneously treated with the glycolysis inhibitor, 2-Deoxyglucose (2DG). Furthermore, inhibiting either PI3-K pathway or glycolysis was effective in suppressing cell migration. Inhibiting OXPHOS alone did not have any significant effects on cell motility. However, both oligomycin and 2DG acted synergistically in suppressing cell migration. We conclude that while there was less synergy by the combined inhibition of PI3-K and glycolysis, the simultaneous targeting of glycolysis and OXPHOS is highly effective in blocking GBM tumorigenic phenotypes. PMID:23523615

  3. Alterations in root proteome of salt-sensitive and tolerant barley lines under salt stress conditions.

    PubMed

    Mostek, Agnieszka; Börner, Andreas; Badowiec, Anna; Weidner, Stanis?aw

    2015-02-01

    Salinity is one of the most important abiotic stresses causing a significant reduction of crop plants yield. To gain a better understanding of salinity tolerance mechanisms in barley (Hordeum vulgare), we investigated the changes in root proteome of salt-sensitive (DH14) and tolerant (DH187) lines in response to salt-stress. The seeds of both barley lines were germinating in water or in 100mM NaCl for 6 days. The root proteins were separated by two-dimensional gel electrophoresis. To identify proteins regulated in response to salt stress, MALDI-TOF/TOF mass spectrometry was applied. It was demonstrated that the sensitive and tolerant barley lines respond differently to salt stress. Some of the identified proteins are well-documented as markers of salinity resistance, but several proteins have not been detected in response to salt stress earlier, although they are known to be associated with other abiotic stresses. The most significant differences concerned the proteins that are involved in signal transduction (annexin, translationally-controlled tumor protein homolog, lipoxygenases), detoxification (osmotin, vacuolar ATP-ase), protein folding processes (protein disulfide isomerase) and cell wall metabolism (UDP-glucuronic acid decarboxylase, ?-d-glucan exohydrolase, UDP-glucose pyrophosphorylase). The results suggest that the enhanced salinity tolerance of DH187 line results mainly from an increased activity of signal transduction mechanisms eventually leading to the accumulation of stress protective proteins and cell wall structure changes. PMID:25462980

  4. Confirmation of quantitative trait loci for ethanol sensitivity and neurotensin receptor density in crosses derived from the inbred High and Low Alcohol Sensitive selectively bred rat lines

    Microsoft Academic Search

    Richard A. Radcliffe; Pequita Bludeau; William Asperi; Tina Fay; X-S Deng; V. Gene Erwin; Richard A. Deitrich

    2006-01-01

    Rationale  Genetically influenced alcohol sensitivity is thought to be an important risk factor for the development of alcoholism. An effective first step for identifying genes that mediate variation in alcohol sensitivity is through quantitative trait loci (QTL) mapping in model organisms.Objective  Fourteen provisional QTLs related to alcohol sensitivity were previously mapped in an F2 derived from the IHAS1 and ILAS1 rat lines.

  5. Line-robust statistics for continuous gravitational waves: safety in the case of unequal detector sensitivities

    E-print Network

    David Keitel; Reinhard Prix

    2015-01-16

    The multi-detector F-statistic is close to optimal for detecting continuous gravitational waves (CWs) in Gaussian noise. However, it is susceptible to false alarms from instrumental artefacts, for example quasi-monochromatic disturbances ('lines'), which resemble a CW signal more than Gaussian noise. In a recent paper [Keitel et al 2014, PRD 89 064023], a Bayesian model selection approach was used to derive line-robust detection statistics for CW signals, generalising both the F-statistic and the F-statistic consistency veto technique and yielding improved performance in line-affected data. Here we investigate a generalisation of the assumptions made in that paper: if a CW analysis uses data from two or more detectors with very different sensitivities, the line-robust statistics could be less effective. We investigate the boundaries within which they are still safe to use, in comparison with the F-statistic. Tests using synthetic draws show that the optimally-tuned version of the original line-robust statistic remains safe in most cases of practical interest. We also explore a simple idea on further improving the detection power and safety of these statistics, which we however find to be of limited practical use.

  6. WIMP Search by DAMA at Gran Sasso

    E-print Network

    Bernabei, R; Belli, P; Cappella, F; Cerulli, R; Dai Chang Jiang; He, H L; Ignesti, G; Incicchitti, A; Kuang Hao Huai; Ma, J M; Montecchia, F; Nozzoli, F; Prosperi, D

    2002-01-01

    DAMA is searching for rare processes by developing and using several kinds of radiopure scintillators: in particular, NaI(Tl), liquid Xenon and CaF$_2$(Eu). Here only the results released so far on the WIMP annual modulation signature are summarized and compared with results from other experiments, including the recent re-analysis of CDMS-I data. Next perspectives are also shortly addressed.

  7. Low mass stellar evolution with WIMP capture and annihilation

    E-print Network

    Pat Scott; Joakim Edsjö; Malcolm Fairbairn

    2007-11-07

    Recent work has indicated that WIMP annihilation in stellar cores has the potential to contribute significantly to a star's total energy production. We report on progress in simulating the effects of WIMP capture and annihilation upon stellar structure and evolution near supermassive black holes, using the new DarkStars code. Preliminary results indicate that low-mass stars are the most influenced by WIMP annihilation, which could have consequences for upcoming observational programs.

  8. Position- and time-sensitive single photon detector with delay-line readout

    NASA Astrophysics Data System (ADS)

    Czasch, A.; Milnes, J.; Hay, N.; Wicking, W.; Jagutzki, O.

    2007-10-01

    We have developed an image intensifier tube with delay-line anode for time- and position-sensitive detection of single photons. By combining two well-approved techniques, the helical-wire delay-line readout for single particle detection and the production capability for large-format sealed photo-multiplier tubes with microchannel-plates, it is possible to build single photon sensors with 40 and 75 mm diameter. Applications are found wherever precise time tagging (< 1 ns) in combination with high position resolution (1000×1000 pixel) for single photon detection is of equal importance. Due to the low background this technique is especially suited for imaging at very low light intensity or for "3d" imaging and timing applications such as fluorescence microscopy or coincident photon detection experiments. We present the performance of prototype detectors with 75 mm low-noise S-20 and 40 mm S-20 red-enhanced photo-cathodes.

  9. Limits on the spin-dependent WIMP-nucleon cross-sections from the first science run of the ZEPLIN-III experiment

    E-print Network

    V. N. Lebedenko; H. M. Araujo; E. J. Barnes; A. Bewick; R. Cashmore; V. Chepel; D. Davidge; J. Dawson; T. Durkin; B. Edwards; C. Ghag; V. Graffagnino; M. Horn; A. S. Howard; A. J. Hughes; W. G. Jones; M. Joshi; G. E. Kalmus; A. G. Kovalenko; A. Lindote; I. Liubarsky; M. I. Lopes; R. Luscher; K. Lyons; P. Majewski; A. StJ. Murphy; F. Neves; J. Pinto da Cunha; R. Preece; J. J. Quenby; P. R. Scovell; C. Silva; V. N. Solovov; N. J. T. Smith; P. F. Smith; V. N. Stekhanov; T. J. Sumner; C. Thorne; R. J. Walker

    2009-01-27

    We present new experimental constraints on the WIMP-nucleon spin-dependent elastic cross-sections using data from the first science run of ZEPLIN-III, a two-phase xenon experiment searching for galactic dark matter WIMPs based at the Boulby mine. Analysis of $\\sim$450 kg$\\cdot$days fiducial exposure revealed a most likely signal of zero events, leading to a 90%-confidence upper limit on the pure WIMP-neutron cross-section of $\\sigma_n=1.8\\times 10^{-2}$ pb at 55 GeV/$c^2$ WIMP mass. Recent calculations of the nuclear spin structure based on the Bonn CD nucleon-nucleon potential were used for the odd-neutron isotopes $^{129}$Xe and $^{131}$Xe. These indicate that the sensitivity of xenon targets to the spin-dependent WIMP-proton interaction is much lower than implied by previous calculations, whereas the WIMP-neutron sensitivity is impaired only by a factor of $\\sim$2.

  10. Can Heavy WIMPs Be Captured by the Earth?

    E-print Network

    Andrew Gould; S. M. Khairul Alam

    1999-11-16

    If weakly interacting massive particles (WIMPs) in bound solar orbits are systematically driven into the Sun by solar-system resonances (as Farinella et al. have shown is the case for many Earth-crossing asteroids), then the capture of high-mass WIMPs by the Earth would be affected dramatically because high-mass WIMPs are captured primarily from bound orbits. WIMP capture would be eliminated for M_x>630 GeV and would be highly suppressed for M_x>~150 GeV. Annihilation of captured WIMPs and anti-WIMPs is expected to give rise to neutrinos coming from the Earth's center. The absence of such a neutrino signal has been used to place limits on WIMP parameters. At present, one does not know if typical WIMP orbits are in fact affected by these resonances. Until this question is investigated and resolved, one must (conservatively) assume that they are. Hence, limits on high-mass WIMP parameters are significantly weaker than previously believed.

  11. Murine leukemia P388 vinorelbine-resistant cell lines are sensitive to vinflunine.

    PubMed

    Aggarwal, Ashish; Kruczynski, Anna; Frankfurter, Anthony; Correia, John J; Lobert, Sharon

    2008-08-01

    The work presented here was initiated to explore the mechanisms underlying vinorelbine resistance in two previously established murine leukemia P388 cell lines (N.63 and N2.5). IC(50) measurements demonstrated that the vinorelbine-resistant cell line N.63 was sensitive to both vinblastine and vinflunine. In addition, vinorelbine-resistant cell line N2.5 retained sensitivity to vinflunine. We used flow cytometry with propidium iodide to measure G2/M arrest in response to drug treatment. Annexin V labeling was used as a marker of apoptosis and JC-1 dye labeling as a marker of mitochondrial membrane depolarization to explore differential responses that might help explain the absence of cross resistance to vinflunine. At equipotent (10X IC(50)) doses, after 8 h of drug treatment, vinflunine induced G2/M arrest in a significantly larger fraction of vinorelbine- resistant cells compared to vinorelbine. At the same drug doses, at 16 h after initiation of drug treatment, vinflunine induced a statistically significant greater apoptotic response and mitochondrial depolarization. The mitochondrial depolarization at 16 h was confirmed by Western blotting that showed release of cytochrome c. Comparison of apoptotic and mitochondrial depolarization responses in vinorelbine-resistant cells upon exposure to vinorelbine, vinblastine and vinflunine demonstrated the following pattern of drug activity: vinflunine > vinblastine > vinorelbine, confirming the importance of a antimitotic-induced mitochondria-mediated pathways in these P388 cell lines. We conclude that vinflunine may be preferred for treatment of specific cancers compared to other vinca alkaloids due to its enhanced effects on apoptotic pathways that follow G2/M arrest. PMID:18071633

  12. New limits on spin-independent and spin-dependent couplings of low-mass WIMP dark matter with a germanium detector at a threshold of 220 eV

    SciTech Connect

    Lin, S. T.; Li, H. B.; Lin, S. K.; Wong, H. T.; Lin, C. W.; Lin, F. K.; Wang, J. J.; Wang, Y. R.; Wu, S. C. [Institute of Physics, Academia Sinica, Taipei 115, Taiwan (China); Li, X.; Fang, B. B.; He, D.; Yue, Q. [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Deniz, M. [Institute of Physics, Academia Sinica, Taipei 115, Taiwan (China); Department of Physics, Middle East Technical University, Ankara 06531 (Turkey); Li, J. [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Institute of High Energy Physics, Chinese Academy of Science, Beijing 100039 (China); Ruan, X. C.; Zhou, Z. Y. [Department of Nuclear Physics, Institute of Atomic Energy, Beijing 102413 (China); Singh, V.; Soma, A. K. [Institute of Physics, Academia Sinica, Taipei 115, Taiwan (China); Department of Physics, Banaras Hindu University, Varanasi 221005 (India)

    2009-03-15

    An energy threshold of (220{+-}10) eV was achieved at an efficiency of 50% with a four-channel ultralow-energy germanium detector, each with an active mass of 5 g. This provides a unique probe to weakly interacting massive particles (WIMP) dark matter with mass below 10 GeV. With a data acquisition live time of 0.338 kg-day at the Kuo-Sheng Laboratory, constraints on WIMPs in the galactic halo were derived. The limits improve over previous results on both spin-independent WIMP-nucleon and spin-dependent WIMP-neutron cross-sections for WIMP mass between 3 and 6 GeV. Sensitivities for full-scale experiments are projected. This detector technique makes the unexplored sub-keV energy window accessible for new neutrino and dark matter experiments.

  13. Method for Increasing Sensitivity of the Distance Protection on a 330 KV Double-Circuit Transmission Line

    NASA Astrophysics Data System (ADS)

    Brinkis, K.; Vanzovich, E.; Drozd, D.; Mutule, A.

    2010-01-01

    Possibilities of increasing the distance protection (DP) sensitivity are considered for a double-circuit transmission line connected to a substation busbar only with one circuit-breaker in each phase. The DP sensitivity can be increased on such a line using mutual connections of the phase wires along its whole length. The minimal (optimal) number of the connections is found by the proposed calculation method.

  14. JF-305, a pancreatic cancer cell line is highly sensitive to the PARP inhibitor olaparib

    PubMed Central

    YANG, XUELI; NDAWULA, CHARLES; ZHOU, HAIYAN; GONG, XIAOHAI; JIN, JIAN

    2015-01-01

    Poly(ADP-ribose) polymerase-1 (PARP-1) is a DNA nick sensor involved in the base excision repair (BER) pathway. Olaparib, a PARP inhibitor, has demonstrated antitumor activity in homologous recombination (HR)-deficient cancers. To extend this specific therapy to other types of carcinomas, a panel of 11 different cancer cells were screened in the present study. JF-305, a pancreatic cancer cell line of Chinese origin, demonstrated sensitivity to the PARP inhibitor 6(5H)-phenanthridinone. In the present study, 3 ?M olaparib conferred a cell survival rate of 25% following four days of treatment. The colony formation efficiency was 83% at 10 nM, and dropped to 12% at 1 ?M following seven days of treatment. Furthermore, olaparib induced cell cycle arrest in the S and G2/M phases prior to the initiation of apoptosis. Although the incidence of double-strand breaks (DSBs) was increased in the olaparib-treated JF-305 cells, the RAD51 foci were well formed at the sites of ?-H2AX recruitment, indicating an activated HR mechanism. Furthermore, tumor growth was reduced by 49.8% following 22 days of consecutive administration of 10 mg/kg olaparib in the JF-305 xenograft mouse model. In summary, the JF-305 cell line was sensitive to olaparib and provided a prospective model for the preclinical assessment of PARP inhibitors in the therapy of pancreatic cancer. PMID:25621047

  15. Establishment of three cell lines from Chinese giant salamander and their sensitivities to the wild-type and recombinant ranavirus.

    PubMed

    Yuan, Jiang-Di; Chen, Zhong-Yuan; Huang, Xing; Gao, Xiao-Chan; Zhang, Qi-Ya

    2015-01-01

    Known as lethal pathogens, Ranaviruses have been identified in diseased fish, amphibians (including Chinese giant salamander Andrias davidianus, the world's largest amphibian) and reptiles, causing organ necrosis and systemic hemorrhage. Here, three Chinese giant salamander cell lines, thymus cell line (GSTC), spleen cell line (GSSC) and kidney cell line (GSKC) were initially established. Their sensitivities to ranaviruses, wild-type Andrias davidianus ranavirus (ADRV) and recombinant Rana grylio virus carrying EGFP gene (rRGV-EGFP) were tested. Temporal transcription pattern of ranavirus major capsid protein (MCP), fluorescence and electron microscopy observations showed that both the wild-type and recombinant ranavirus could replicate in the cell lines. PMID:26070783

  16. A Novel Delay-Line Anode Design for Position and Time Sensitive Read-Out of MCP-Based Detectors

    NASA Astrophysics Data System (ADS)

    Spillmann, U.; Jagutzki, O.; Spielberger, L.; Dörner, R.; Mergel, V.; Ullmann-Pfleger, K.; Schmidt-Böcking, H.

    We have developed a novel delay-line anode design based on L/2 shifted maeander-lines for the readout of open-faced and sealed MCP-based detectors. In combination with the sealed detector (image intensifier) we are able to provide position and time sensitive single photon detection from near UV to near IR.

  17. Characterization of a new malignant human T-cell line (PFI-285) sensitive to ascorbic acid.

    PubMed

    Helgestad, J; Pettersen, R; Storm-Mathisen, I; Schjerven, L; Ulrich, K; Smeland, E B; Egeland, T; Sørskaard, D; Brøgger, A; Hovig, T

    1990-01-01

    A new malignant human T-cell line-labelled PFI-285-has been isolated from a boy with malignant lymphoma. Morphologically, the cells had characteristics of malignant lymphoid cells. The cells presented surface antigens as early cortical lymphocytes and proliferated non-adherently as single cells, independent of T-cell growth factor (IL-2), in liquid culture. The cells had undetectable levels of receptors for IL-2, were not clonogenic in soft agar, but did form tumors in nude mice. Their establishment and continuous growth in vitro was dependent on the number of cells inoculated and on the growth medium used. Cytogenetic alteration, HTLV-1 or reverse transcriptase activity were not detected. The production of known T-cell derived lymphokines such as IL-2, B-cell growth factor(s), alpha-interferon or granulocyte/macrophage colony stimulating or inhibiting factor(s) was not detected. The cells had 5-8% natural killer (NK)-cell activity against NK-cell sensitive target cells (K562) and were not sensitive for NK cells. A most unusual characteristic was the pronounced sensitivity of the cells to ascorbic acid. Concentrations down to 50 mumol/l killed the cells within hours. PMID:2307225

  18. Towards One Tonne Direct WIMP Detectors: Have we got what it takes?

    E-print Network

    R. J. Gaitskell

    2001-06-12

    Experimentally have we got what it takes to pursue the direct observation of WIMP interactions down to sensitivities of a few events /100 kg/year? For a Ge target with a low energy threshold (5) orders of magnitude spread in the possible interaction rates for models consistent with existing Cosmology and Accelerator bounds. Some theorists, but certainly not all, are able to generate models, that lead to interaction rates at the few /kg/day that would be implied by the current DAMA annual modulation signal. All theorists demonstrate models that generate much lower interaction rates. This paper takes an unashamed experimentalist`s view of the issues that arise when looking forward to constructing 1 tonne WIMP detectors.

  19. Gene and microRNA expression reveals sensitivity to paclitaxel in laryngeal cancer cell line

    PubMed Central

    Xu, Cheng-Zhi; Xie, Jin; Jin, Bin; Chen, Xin-Wei; Sun, Zhen-Feng; Wang, Bao-Xing; Dong, Pin

    2013-01-01

    Paclitaxel is a widely used chemotherapy drug for advanced laryngeal cancer patients. However, the fact that there are 20-40% of advanced laryngeal cancer patients do not response to paclitaxel makes it necessary to figure out potential biomarkers for paclitaxel sensitivity prediction. In this work, Hep2, a laryngeal cancer cell line, untreated or treated with lower dose of paclitaxel for 24 h, was applied to DNA microarray chips for gene and miR expression profile analysis. Expression of eight genes altered significantly following paclitaxel treatment, which was further validated by quantitative real-time PCR. Four up-regulated genes were ID2, BMP4, CCL4 and ACTG2, in which ID2 and BMP4 were implicated to be involved in several drugs sensitivity. While the down-regulated four genes, MAPK4, FASN, INSIG1 and SCD, were mainly linked to the endoplasmic reticulum and fatty acid biosynthesis, these two cell processes that are associated with drug sensitivity by increasing evidences. After paclitaxel treatment, expression of 49 miRs was significantly altered. Within these miRs, the most markedly expression-changed were miR-31-star, miR-1264, miR-3150b-5p and miR-210. While the miRs putatively modulated the mRNA expression of the most significantly expression-altered genes were miR-1264, miR-130a, miR-27b, miR-195, miR-1291, miR-214, miR-1277 and miR-1265, which were obtained by miR target prediction and miRNA target correlation. Collectively, our study might provide potential biomarkers for paclitaxel sensitivity prediction and drug resistance targets in laryngeal cancer patients. PMID:23826416

  20. Evaluation of the drug sensitivity and expression of 16 drug resistance-related genes in canine histiocytic sarcoma cell lines.

    PubMed

    Asada, Hajime; Tomiyasu, Hirotaka; Goto-Koshino, Yuko; Fujino, Yasuhito; Ohno, Koichi; Tsujimoto, Hajime

    2015-07-01

    Canine histiocytic sarcoma (HS) is an aggressive tumor type originating from histiocytic cell lineages. This disease is characterized by poor response to chemotherapy and short survival time. Therefore, it is of critical importance to identify and develop effective antitumor drugs against HS. The objectives of this study were to examine the drug sensitivities of 10 antitumor drugs. Using a real-time RT-PCR system, the mRNA expression levels of 16 genes related to drug resistance in 4 canine HS cell lines established from dogs with disseminated HS were determined and compared to 2 canine lymphoma cell lines (B-cell and T-cell). These 4 canine HS cell lines showed sensitivities toward microtubule inhibitors (vincristine, vinblastine and paclitaxel), comparable to those in the canine B-cell lymphoma cell line. Moreover, it was shown that P-gp in the HS cell lines used in this study did not have enough function to efflux its substrate. Sensitivities to melphalan, nimustine, methotrexate, cytarabine, doxorubicin and etoposide were lower in the 4 HS cell lines than in the 2 canine lymphoma cell lines. The data obtained in this study using cultured cell lines could prove helpful in the developing of advanced and effective chemotherapies for treating dogs that are suffering from HS. PMID:25715778

  1. Evaluation of the drug sensitivity and expression of 16 drug resistance-related genes in canine histiocytic sarcoma cell lines

    PubMed Central

    ASADA, Hajime; TOMIYASU, Hirotaka; GOTO-KOSHINO, Yuko; FUJINO, Yasuhito; OHNO, Koichi; TSUJIMOTO, Hajime

    2015-01-01

    Canine histiocytic sarcoma (HS) is an aggressive tumor type originating from histiocytic cell lineages. This disease is characterized by poor response to chemotherapy and short survival time. Therefore, it is of critical importance to identify and develop effective antitumor drugs against HS. The objectives of this study were to examine the drug sensitivities of 10 antitumor drugs. Using a real-time RT-PCR system, the mRNA expression levels of 16 genes related to drug resistance in 4 canine HS cell lines established from dogs with disseminated HS were determined and compared to 2 canine lymphoma cell lines (B-cell and T-cell). These 4 canine HS cell lines showed sensitivities toward microtubule inhibitors (vincristine, vinblastine and paclitaxel), comparable to those in the canine B-cell lymphoma cell line. Moreover, it was shown that P-gp in the HS cell lines used in this study did not have enough function to efflux its substrate. Sensitivities to melphalan, nimustine, methotrexate, cytarabine, doxorubicin and etoposide were lower in the 4 HS cell lines than in the 2 canine lymphoma cell lines. The data obtained in this study using cultured cell lines could prove helpful in the developing of advanced and effective chemotherapies for treating dogs that are suffering from HS. PMID:25715778

  2. Parallel Dipole Line System: A Novel Magnetic Trap and High Sensitivity Hall system

    NASA Astrophysics Data System (ADS)

    Gunawan, Oki; Virgus, Yudistira; Tai, Kong Fai

    2015-03-01

    A system that could trap cylindrical objects such as semiconductor nanowires provides a route towards self-assembled fabrication of bottom-up nanowire integrated circuit. We show that such a trap can be realized using a simple parallel dipole line (PDL) system which can be experimentally realized using diametrically-magnetized magnets with a diamagnetic rod as the trapped object. This system produces a fascinating 1D camelback potential profile at the center plane and yields a new technique for magnetic susceptibility measurement for the trapped rod. This system also yields a surprising application for a high sensitivity Hall measurement system which plays a decisive role in extracting low carrier mobility in earth abundant kesterite solar cell.

  3. In-line interferometer for direction-sensitive displacement measurements by optical feedback detection

    SciTech Connect

    Tarun, Alvarado; Jecong, Julius; Saloma, Caesar

    2005-12-01

    We demonstrate a compact in-line interferometer for direction-sensitive displacement measurement by optical feedback detection with a semiconductor laser (SL) light source. Two reflected beams from a semitransparent reference mirror and a reflecting test object interfere in the SL medium, causing a variation in its output power. The reference mirror is located between the SL output facet and the test object. The performance of the interferometer is investigated numerically and experimentally to determine its optimal operating conditions. We have verified the operating conditions where the behavior of the SL output power profile could indicate accurately the displacement magnitude and direction of the moving test object. The profile behavior is robust against variations in optical feedback and scale of the interferometer configuration.

  4. Nonlinear Quantitative Radiation Sensitivity Prediction Model Based on NCI-60 Cancer Cell Lines

    PubMed Central

    Zhang, Chunying; Girard, Luc; Das, Amit; Chen, Sun; Zheng, Guangqiang

    2014-01-01

    We proposed a nonlinear model to perform a novel quantitative radiation sensitivity prediction. We used the NCI-60 panel, which consists of nine different cancer types, as the platform to train our model. Important radiation therapy (RT) related genes were selected by significance analysis of microarrays (SAM). Orthogonal latent variables (LVs) were then extracted by the partial least squares (PLS) method as the new compressive input variables. Finally, support vector machine (SVM) regression model was trained with these LVs to predict the SF2 (the surviving fraction of cells after a radiation dose of 2?Gy ?-ray) values of the cell lines. Comparison with the published results showed significant improvement of the new method in various ways: (a) reducing the root mean square error (RMSE) of the radiation sensitivity prediction model from 0.20 to 0.011; and (b) improving prediction accuracy from 62% to 91%. To test the predictive performance of the gene signature, three different types of cancer patient datasets were used. Survival analysis across these different types of cancer patients strongly confirmed the clinical potential utility of the signature genes as a general prognosis platform. The gene regulatory network analysis identified six hub genes that are involved in canonical cancer pathways. PMID:25032244

  5. Short-term selection for acute ethanol tolerance and sensitization from an F2 population derived from the high and low alcohol-sensitive selectively bred rat lines.

    PubMed

    Radcliffe, Richard A; Bludeau, Pequita; Deng, Xin-Sheng; Erwin, V Gene; Deitrich, Richard A

    2007-12-01

    Previous studies have identified quantitative trait loci (QTL) in the inbred high and low alcohol-sensitive rat (IHAS1 and ILAS1) strains. The original development of the strains involved selection for ethanol sensitivity based on duration of the loss of the righting reflex (LORR) after a standard dose of ethanol. This paper confirms some of these QTL using a short-term selection procedure based on the difference between the blood ethanol level at LORR and regain of the righting response. An F(2) population of rats was developed by a reciprocal cross of IHAS1 and ILAS1 rats. Selection for five generations was carried out using delta-blood ethanol concentration (dBEC) as the selection trait, where dBEC=BECLR (BEC at loss of righting reflex)-BECRR (BEC at regain of righting reflex). The lines were labeled tolerant (TOL) or sensitive (SENS). Approximately one-third of the offspring for each generation in each line were genotyped using DNA markers that had been previously found to be linked to QTL on chromosomes 1, 2, 5, 12, and 13. By the fifth generation of selection, the lines showed a very large difference in dBEC, BECRR, and duration of LORR; BECLR showed little segregation during the selection, and latency to lose the righting reflex showed none. IHAS allele frequency increased in the SENS line for markers on chromosomes 1, 5, 12, and 13 while ILAS allele frequency increased in the TOL line. These results were in good agreement with the two previous QTL studies. On chromosome 2, the selection resulted in an accumulation of ILAS alleles in both lines. This study provides independent confirmation of the location of QTL on chromosomes 1, 5, 12, and 13 for ethanol sensitivity. It also suggests that genetic differences in duration of LORR are mediated primarily by the dBEC phenotype. PMID:18047909

  6. Glucosensing in an immortalized adrenomedullary chromaffin cell line: role of ATP-sensitive K+ channels.

    PubMed

    Piskuric, Nikol A; Brown, Stephen T; Zhang, Min; Nurse, Colin A

    2008-11-01

    Using an immortalized adrenal chromaffin cell line (MAH cells), we investigated the cellular mechanisms underlying sensitivity to glucose-free solution (aglycemia) using ratiometric Ca2+ imaging and whole-cell recording. Though few cells (< 15%) responded to aglycemia with an increase in intracellular-free Ca2+ concentration ([Ca2+]i), in most cells (approximately 75%), aglycemia caused > 50% suppression of the Delta[Ca2+]i induced by the depolarizing stimulus, high (10 mM) K+. Moreover, in normal K+, the average aglycemia-induced rise in Cai2+ as well as the proportion of aglycemia-responsive cells increased in the presence of the K(ATP) channel blocker, glibenclamide. During membrane potential (Vm) measurements, aglycemia induced either hyperpolarization (6/20), depolarization (4/20) or no change in Vm. RT-PCR and Western blotting confirmed the presence of K(ATP) channel subunits Kir6.2 and SUR1 in MAH cells. These findings suggest a dual inhibitory and excitatory action of aglycemia in MAH cells, where activation of K(ATP) channels effectively inhibits or blunts the Delta[Ca2+]i due to the excitatory effect. Thus, this cell line appears as an attractive model for studying the molecular mechanisms of glucosensing. PMID:18786611

  7. Inhibition of geranylgeranylation mediates sensitivity to CHOP-induced cell death of DLBCL cell lines

    SciTech Connect

    Ageberg, Malin, E-mail: Malin.Ageberg@med.lu.se [Division of Hematology and Transfusion Medicine, Lund University, BMC C14, 221 84 Lund (Sweden)] [Division of Hematology and Transfusion Medicine, Lund University, BMC C14, 221 84 Lund (Sweden); Rydstroem, Karin, E-mail: Karin.Rydstom@skane.se [Department of Oncology, Skanes University Hospital, Allmaenmott, Onkologiska kliniken i Lund, 221 85 Lund (Sweden)] [Department of Oncology, Skanes University Hospital, Allmaenmott, Onkologiska kliniken i Lund, 221 85 Lund (Sweden); Linden, Ola, E-mail: Ola.Linden@skane.se [Department of Oncology, Skanes University Hospital, Allmaenmott, Onkologiska kliniken i Lund, 221 85 Lund (Sweden)] [Department of Oncology, Skanes University Hospital, Allmaenmott, Onkologiska kliniken i Lund, 221 85 Lund (Sweden); Linderoth, Johan, E-mail: Johan.Linderoth@skane.se [Department of Oncology, Skanes University Hospital, Allmaenmott, Onkologiska kliniken i Lund, 221 85 Lund (Sweden)] [Department of Oncology, Skanes University Hospital, Allmaenmott, Onkologiska kliniken i Lund, 221 85 Lund (Sweden); Jerkeman, Mats, E-mail: Mats.Jerkeman@skane.se [Department of Oncology, Skanes University Hospital, Allmaenmott, Onkologiska kliniken i Lund, 221 85 Lund (Sweden)] [Department of Oncology, Skanes University Hospital, Allmaenmott, Onkologiska kliniken i Lund, 221 85 Lund (Sweden); Drott, Kristina, E-mail: Kristina.Drott@med.lu.se [Division of Hematology and Transfusion Medicine, Lund University, BMC C14, 221 84 Lund (Sweden)] [Division of Hematology and Transfusion Medicine, Lund University, BMC C14, 221 84 Lund (Sweden)

    2011-05-01

    Prenylation is a post-translational hydrophobic modification of proteins, important for their membrane localization and biological function. The use of inhibitors of prenylation has proven to be a useful tool in the activation of apoptotic pathways in tumor cell lines. Rab geranylgeranyl transferase (Rab GGT) is responsible for the prenylation of the Rab family. Overexpression of Rab GGTbeta has been identified in CHOP refractory diffuse large B cell lymphoma (DLBCL). Using a cell line-based model for CHOP resistant DLBCL, we show that treatment with simvastatin, which inhibits protein farnesylation and geranylgeranylation, sensitizes DLBCL cells to cytotoxic treatment. Treatment with the farnesyl transferase inhibitor FTI-277 or the geranylgeranyl transferase I inhibitor GGTI-298 indicates that the reduction in cell viability was restricted to inhibition of geranylgeranylation. In addition, treatment with BMS1, a combined inhibitor of farnesyl transferase and Rab GGT, resulted in a high cytostatic effect in WSU-NHL cells, demonstrated by reduced cell viability and decreased proliferation. Co-treatment of BMS1 or GGTI-298 with CHOP showed synergistic effects with regard to markers of apoptosis. We propose that inhibition of protein geranylgeranylation together with conventional cytostatic therapy is a potential novel strategy for treating patients with CHOP refractory DLBCL.

  8. Prodigiosin down-regulates survivin to facilitate paclitaxel sensitization in human breast carcinoma cell lines

    SciTech Connect

    Ho, T.-F. [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Department of Medical Technology, Central Taiwan University of Science and Technology, Taichung, Taiwan (China); Peng, Y.-T.; Chuang, S.-M.; Lin, S.-C.; Feng, B.-L. [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Lu, C.-H. [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China); Department of Obstetrics and Gynecology, Taichung Veterans General Hospital, Taichung, Taiwan (China); Yu, W.-J. [Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan (China); Chang, J.-S. [Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan (China); Sustainable Environment Research Center, National Cheng Kung University, Tainan, Taiwan (China)], E-mail: changjs@mail.ncku.edu.tw; Chang, C.-C. [Institute of Biomedical Sciences, National Chung Hsing University, Taichung, Taiwan (China)], E-mail: chia_che@dragon.nchu.edu.tw

    2009-03-01

    Prodigiosin is a bacterial metabolite with potent anticancer activity, which is attributed to its proapoptotic effect selectively active in malignant cells. Still, the molecular mechanisms whereby prodigiosin induces apoptosis remain largely unknown. In particular, the role of survivin, a vital inhibitor of apoptosis, in prodigiosin-induced apoptosis has never been addressed before and hence was the primary goal of this study. Our results showed that prodigiosin dose-dependently induced down-regulation of survivin in multiple breast carcinoma cell lines, including MCF-7, T-47D and MDA-MB-231. This down-regulation is mainly regulated at the level of transcription, as prodigiosin reduced the levels of both survivin mRNA and survivin promoter activity but failed to rescue survivin expression when proteasome-mediated degradation is abolished. Importantly, overexpression of survivin rendered cells more resistant to prodigiosin, indicating an essential role of survivin down-regulation in prodigiosin-induced apoptosis. In addition, we found that prodigiosin synergistically enhanced cell death induced by paclitaxel, a chemotherapy drug known to up-regulate survivin that in turn confers its own resistance. This paclitaxel sensitization effect of prodigiosin is ascribed to the lowering of survivin expression, because prodigiosin was shown to counteract survivin induction by paclitaxel and, notably, the sensitization effect was severely abrogated in cells that overexpress survivin. Taken together, our results argue that down-regulation of survivin is an integral component mediating prodigiosin-induced apoptosis in human breast cancer cells, and further suggest the potential of prodigiosin to sensitize anticancer drugs, including paclitaxel, in the treatment of breast cancer.

  9. The Sensitivity of West African Squall Line Water Budgets to Land Cover

    NASA Technical Reports Server (NTRS)

    Mohr, Karen I.; Baker, R. David; Tao, Wei-Kuo; Famiglietti, James S.; Starr, David OC. (Technical Monitor)

    2001-01-01

    This study used a two-dimensional coupled land/atmosphere (cloud-resolving) model to investigate the influence of land cover on the water budgets of squall lines in the Sahel. Study simulations used the same initial sounding and one of three different land covers, a sparsely vegetated semi-desert, a grassy savanna, and a dense evergreen broadleaf forest. All simulations began at midnight and ran for 24 hours to capture a full diurnal cycle. In the morning, the latent heat flux, boundary layer mixing ratio, and moist static energy in the boundary layer exhibited notable variations among the three land covers. The broadleaf forest had the highest latent heat flux, the shallowest, moistest, slowest growing boundary layer, and significantly more moist static energy per unit area than the savanna and semi-desert. Although all simulations produced squall lines by early afternoon, the broadleaf forest had the most intense, longest-lived squall lines with 29% more rainfall than the savanna and 37% more than the semi-desert. The sensitivity of the results to vegetation density, initial sounding humidity, and grid resolution was also assessed. There were greater differences in rainfall among land cover types than among simulations of the same land cover with varying amounts of vegetation. Small changes in humidity were equivalent in effect to large changes in land cover, producing large changes in the condensate and rainfall. Decreasing the humidity had a greater effect on rainfall volume than increasing the humidity. Reducing the grid resolution from 1.5 km to 0.5 km decreased the temperature and humidity of the cold pools and increased the rain volume.

  10. Sensitivity analysis of oxygen absorption lines in the 1.26-1.27 micron spectral band

    NASA Astrophysics Data System (ADS)

    Edwards, W. C.; Prasad, N.; Browell, E. V.

    2009-12-01

    In the Decadal Survey prepared by the National Research Council (Reference: Earth Science and Applications from Space: National Imperatives for the Next Decade and Beyond), the ASCENDS mission (Active Sensing of CO2 Emissions over Nights, Days and Seasons), requires simultaneous laser remote sensing of CO2 and O2 in order to convert CO2 atmospheric concentrations to mixing ratios. As the mission is envisioned, the CO2 mixing ratio needs to be measured to a precision of 0.5 percent of background or better (slightly less than 2 ppm) at 100-km horizontal length scale overland and at 200-km scale over open oceans. While the O2 measurement could be made at 0.765 µm (the oxygen A band), the absorption cross section is substantially higher and the scattering is lower in the 1.26-1.27 µm wavelength band, and as such it is anticipated that better accuracies could be accomplished. Hence, NASA Langley Research Center is developing oxygen lidar technology in the 1.26-1.27 micron band for surface pressure measurements. One or more wavelengths for differential absorption lidar operation have to be carefully chosen to eliminate ambient influences on them. The model optical depth calculation is very sensitive to knowledge of the transmitted wavelengths and to the choice of Voigt input parameters. Uncertainties in atmospheric profiles of temperature, pressure and relative humidity can cause ~0.5 % errors in model optical depths. In order to select candidate wavelengths in the 1.26 micron spectral band, wavelength uncertainties due to temperature and pressure have to be determined. Uncertainties at line center and offset wavelengths have to be known precisely to reduce uncertainties in oxygen concentration measurements from airborne and space based platforms. In this paper, based on HITRAN database and absorption line measurements, we evaluate systematic relative errors and their sources of pressure shift and atmospheric temperature influences for selected O2 lines suitable for making high precision measurements.

  11. 47 CFR 69.713 - Common line, traffic-sensitive, and tandem-switched transport services.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...traffic-sensitive, and tandem-switched transport services. 69.713 Section 69...traffic-sensitive, and tandem-switched transport services. (a) Scope. This paragraph...traffic-sensitive components of tandem-switched transport services, as described in §§...

  12. Sensitivities of human glioma cell lines to interferons and double-stranded RNAs individually and in synergistic combinations

    Microsoft Academic Search

    Robbin S. Dick; Howard R. Hubbell

    1987-01-01

    The antiproliferative effects of human interferons (IFNs) and double-stranded RNAs (dsRNAs) were studied in five human glioma cell lines. Dose response curves were generated over a 72 hour treatment period. The concentration of interferon or double-stranded RNA necessary to produce a 50% antiproliferative response (GI50) was calculated by linear regression analysis. Two cell lines were more sensitive to IFN-ß than

  13. Sensitive quantitative analysis of murine LINE1 DNA methylation using high resolution melt analysis

    PubMed Central

    Newman, Michelle; Blyth, Benjamin J.; Hussey, Damian J.; Jardine, Daniel; Ormsby, Rebecca J.

    2012-01-01

    We present here the first high resolution melt (HRM) assay to quantitatively analyze differences in murine DNA methylation levels utilizing CpG methylation of Long Interspersed Elements-1 (LINE1 or L1). By calculating the integral difference in melt temperature between samples and a methylated control, and biasing PCR primers for unmethylated CpGs, the assay demonstrates enhanced sensitivity to detect changes in methylation in a cell line treated with low doses of 5-aza-2’-deoxycytidine (5-aza). The L1 assay was confirmed to be a good marker of changes in DNA methylation of L1 elements at multiple regions across the genome when compared with total 5-methyl-cytosine content, measured by Liquid Chromatography-Mass Spectrometry (LC-MS). The assay design was also used to detect changes in methylation at other murine repeat elements (B1 and Intracisternal-A-particle Long-terminal Repeat elements). Pyrosequencing analysis revealed that L1 methylation changes were non-uniform across the CpGs within the L1-HRM target region, demonstrating that the L1 assay can detect small changes in CpG methylation among a large pool of heterogeneously methylated DNA templates. Application of the assay to various tissues from Balb/c and CBA mice, including previously unreported peripheral blood (PB), revealed a tissue hierarchy (from hypermethylated to hypomethylated) of PB > kidney > liver > prostate > spleen. CBA mice demonstrated overall greater methylation than Balb/c mice, and male mice demonstrated higher tissue methylation compared with female mice in both strains. Changes in DNA methylation have been reported to be an early and fundamental event in the pathogenesis of many human diseases, including cancer. Mouse studies designed to identify modulators of DNA methylation, the critical doses, relevant time points and the tissues affected are limited by the low throughput nature and exorbitant cost of many DNA methylation assays. The L1 assay provides a high throughput, inexpensive and sensitive screening tool for identifying and characterizing DNA methylation changes to L1 elements at multiple regions across the genome. PMID:22274612

  14. High-count-rate operation of a TFTR position-sensitive x-ray detector with delay-line readouts

    NASA Astrophysics Data System (ADS)

    Hsuan, H.; Bitter, M.; von Goeler, S.; Harder, J. A.; Hill, K. W.; Lemunyan, G.

    1990-10-01

    X-ray spectra obtained with position-sensitive detectors which use delay-line readout systems are subject to distortions at count rates comparable to the inverse of the temporal length of the delay line. These distortions are due to the simultaneous existence of pulses from different photons on the delay line. High incident rates up to several MHz can be obtained on the detectors of the TFTR crystal spectrometer under certain conditions. This paper describes improvements which can be obtained by an interarrival time discriminator circuit.

  15. The cytokine-dependent MUTZ-3 cell line as an in vitro model for the screening of contact sensitizers.

    PubMed

    Azam, Philippe; Peiffer, Jean-Luc; Chamousset, Delphine; Tissier, Marie-Hélène; Bonnet, Pierre-Antoine; Vian, Laurence; Fabre, Isabelle; Ourlin, Jean-Claude

    2006-04-01

    Langerhans cells (LC) are key mediators of contact allergenicity in the skin. However, no in vitro methods exist which are based on the activation process of LC to predict the sensitization potential of chemicals. In this study, we have evaluated the performances of MUTZ-3, a cytokine-dependent human monocytic cell line, in its response to sensitizers. First, we compared undifferentiated MUTZ-3 cells with several standard human cells such as THP-1, KG-1, HL-60, K-562, and U-937 in their response to the strong sensitizer DNCB and the irritant SDS by monitoring the expression levels of HLA-DR, CD54, and CD86 by flow cytometry. Only MUTZ-3 and THP-1 cells show a strong and specific response to sensitizer, while other cell lines showed very variable responses. Then, we tested MUTZ-3 cells against a wider panel of sensitizers and irritants on a broader spectrum of cell surface markers (HLA-DR, CD40, CD54, CD80, CD86, B7-H1, B7-H2, B7-DC). Of these markers, CD86 proved to be the most reliable since it detected all sensitizers, including benzocaine, a classical false negative in local lymph node assay (LLNA) but not irritants. We confirmed the MUTZ-3 response to DNCB by real-time PCR analysis. Taken together, our data suggest that undifferentiated MUTZ-3 cells may represent a valuable in vitro model for the screening of potential sensitizers. PMID:16039684

  16. Sensitivity to voltage-independent inhibition determined by pore-lining region of the acetylcholine receptor.

    PubMed Central

    Francis, M M; Choi, K I; Horenstein, B A; Papke, R L

    1998-01-01

    Some noncompetitive inhibitors (e.g., ganglionic blockers) exhibit selectivity for the inhibition of neuronal nicotinic acetylcholine receptors (nAChRs). This study characterizes the mechanism of selective long-term inhibition of neuronal and muscle-neuronal chimeric nAChRs by bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate (bis-TMP-10 or BTMPS), a bifunctional form of the potent ganglionic blocker tetramethylpiperidine. Long-term inhibition of neuronal nAChRs by bis-TMP-10 has been previously demonstrated to arise, at least in part, from the binding of the bis compound to neuronal beta-subunits. In this study, long-term inhibition is demonstrated to be dependent upon the presence of sequence element(s) within the pore-lining second transmembrane domain (tm2) of neuronal beta-subunits; however, the inhibitor binding site itself does not appear to be contained within the segment of the channel pore influenced by the membrane electric field. Specifically, our results imply that bis-TMP-10 interacts with an activation-sensitive element, the availability of which may be regulated by a sequence in the tm2 domain. Furthermore, we demonstrate a compound length requirement for long-term inhibition that would be consistent with binding to multiple sites located on the extracellular portion of the receptor. PMID:9591658

  17. In-line prediction of drug release profiles for pH-sensitive coated pellets.

    PubMed

    Pomerantsev, Alexey L; Rodionova, Oxana Ye; Melichar, Michael; Wigmore, Anthony J; Bogomolov, Andrey

    2011-11-21

    A new method for the prediction of the drug release profiles during a running pellet coating process from in-line near infrared (NIR) measurements has been developed. The NIR spectra were acquired during a manufacturing process through an immersion probe. These spectra reflect the coating thickness that is inherently connected with the drug release. Pellets sampled at nine process time points from thirteen designed laboratory-scale coating batches were subjected to the dissolution testing. In the case of the pH-sensitive Acryl-EZE coating the drug release kinetics for the acidic medium has a sigmoid form with a pronounced induction period that tends to grow along with the coating thickness. In this work the autocatalytic model adopted from the chemical kinetics has been successfully applied to describe the drug release. A generalized interpretation of the kinetic constants in terms of the process and product parameters has been suggested. A combination of the kinetic model with the multivariate Partial Least Squares (PLS) regression enabled prediction of the release profiles from the process NIR data. The method can be used to monitor the final pellet quality in the course of a coating process. PMID:21968477

  18. DARWIN: dark matter WIMP search with noble liquids

    E-print Network

    Laura Baudis; for the DARWIN Consortium

    2012-01-11

    DARWIN (dark matter wimp search with noble liquids) is a design study for a next-generation, multi-ton dark matter detector in Europe. Liquid argon and/or liquid xenon are the target media for the direct detection of dark matter candidates in the form of weakly interacting massive particles (WIMPs). Light and charge signals created by particle interactions in the active detector volume are observed via the time projection chamber technique. DARWIN is to probe the spin-independent, WIMP-nucleon cross section down 1e-48 cm2 and to measure WIMP-induced nuclear recoil spectra with high-statistics, should they be discovered by an existing or near-future experiment. After a brief introduction, I will describe the project, selected R&D topics, expected backgrounds and the physics reach.

  19. Morphometric and Colorimetrie Analyses of Human Tumor Cell Line Growth and Drug Sensitivity in Soft Agar Culture1

    Microsoft Academic Search

    M. C. Alle; C. M. Pacula-Co; M. L. Hursey; L. R. Rubinstein; M. R. Boy

    1991-01-01

    Previous studies have demonstrated the suitability of image analysis of tetrazolium-stained colonies to assess growth and drug sensitivity of human tumor cells cultivated in soft agar culture. In the present study, the potential utility of colorimetrie analysis to expedite experimental drug evaluations using human tumor cell lines was investigated. The same culture dishes were assessed by image analysis and by

  20. Converting cell lines representing hematological malignancies from glucocorticoid-resistant to glucocorticoid-sensitive: signaling pathway interactions.

    PubMed

    Garza, Anna S; Miller, Aaron L; Johnson, Betty H; Thompson, E Brad

    2009-05-01

    Mitogen-activated protein kinases (MAPKs), protein kinase A (PKA) and mTOR pathways modulate the apoptotic effects of glucocorticoids (GCs) in human lymphoblastic leukemia CEM cells. We now show that manipulation of these pathways converts several cell lines, representing other lymphoid malignancies, from GC-resistant to GC-sensitive. Basal levels of phosphorylated JNK and ERK were elevated in the GC-resistant cells. Treatments that directly or indirectly reduced phosphorylated JNK and ERK resulted in Dex sensitivity in five resistant lymphoid cell lines. Sensitivity to GC-driven apoptosis correlated with GC-dependent increases in phosphorylated and total glucocorticoid receptor, and in increased levels of the pro-apoptotic protein Bim. PMID:19012965

  1. Sensitivity of malignant rhabdoid tumor cell lines to PD 0332991 is inversely correlated with p16 expression

    SciTech Connect

    Katsumi, Yoshiki; Iehara, Tomoko; Miyachi, Mitsuru; Yagyu, Shigeki; Tsubai-Shimizu, Satoko; Kikuchi, Ken; Tamura, Shinichi; Kuwahara, Yasumichi; Tsuchiya, Kunihiko; Kuroda, Hiroshi; Sugimoto, Tohru [Department of Pediatrics, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, Kawaramachi-hirokoji, Kamigyo-ku, Kyoto 602-8566 (Japan)] [Department of Pediatrics, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, Kawaramachi-hirokoji, Kamigyo-ku, Kyoto 602-8566 (Japan); Houghton, Peter J. [Molecular Pharmacology, St. Jude Children's Research Hospital, 332 N. Lauderdale St. Memphis, TN 38105-2794 (United States)] [Molecular Pharmacology, St. Jude Children's Research Hospital, 332 N. Lauderdale St. Memphis, TN 38105-2794 (United States); Hosoi, Hajime, E-mail: hhosoi@koto.kpu-m.ac.jp [Department of Pediatrics, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, Kawaramachi-hirokoji, Kamigyo-ku, Kyoto 602-8566 (Japan)] [Department of Pediatrics, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, Kawaramachi-hirokoji, Kamigyo-ku, Kyoto 602-8566 (Japan)

    2011-09-16

    Highlights: {yields} PD 0332991 (PD) could suppress four of five malignant rhabdoid tumor (MRT) cell lines. {yields} The sensitivity of the MRT cell lines to PD was inversely correlated with p16 expression (r = 0.951). {yields} p16 expression in MRT could be used to predict its sensitivity to PD. {yields} PD may be an attractive agent for patients with MRT whose tumors express low levels of p16. -- Abstract: Malignant rhabdoid tumor (MRT) is a rare and highly aggressive neoplasm of young children. MRT is characterized by inactivation of integrase interactor 1 (INI1). Cyclin-dependent kinase 4 (CDK4), which acts downstream of INI1, is required for the proliferation of MRT cells. Here we investigated the effects of PD 0332991 (PD), a potent inhibitor of CDK4, against five human MRT cell lines (MP-MRT-AN, KP-MRT-RY, G401, KP-MRT-NS, KP-MRT-YM). In all of the cell lines except KP-MRT-YM, PD inhibited cell proliferation >50%, (IC{sub 50} values 0.01 to 0.6 {mu}M) by WST-8 assay, and induced G1-phase cell cycle arrest, as shown by flow cytometry and BrdU incorporation assay. The sensitivity of the MRT cell lines to PD was inversely correlated with p16 expression (r = 0.951). KP-MRT-YM cells overexpress p16 and were resistant to the growth inhibitory effect of PD. Small interfering RNA against p16 significantly increased the sensitivity of KP-MRT-YM cells to PD (p < 0.05). These results suggest that p16 expression in MRT could be used to predict its sensitivity to PD. PD may be an attractive agent for patients with MRT whose tumors express low levels of p16.

  2. Sensitivity of the curve-to-growth technique utilized in rocket experiments to determine the line shape of solar He I resonance lines

    NASA Technical Reports Server (NTRS)

    Wu, C. Y. R.; Ogawa, H. S.

    1986-01-01

    The sensitivity of the curve-of-growth (COG) technique utilized in rocket measurements to determine the line profiles of the solar He I resonance emissions is theoretically examined with attention to the possibility of determining the line core shape using this technique. The line at 584.334 A is chosen as an illustration. Various possible source functions of the solar line have been assumed in the computation of the integrated transmitted intensity. A recent observational data set obtained by the present researchers is used as the constraint of the computation. It is confirmed that the COG technique can indeed provide a good measurement of the solar line width. However, to obtain detailed knowledge of the solar profile at line center and in the core region, (1) it is necessary to be able to carry out relative solar flux measurements with a 1-percent or better precision, and (2) it must be possible to measure the He gas pressure in the absorption cell to lower than 0.1 mtorr. While these numbers apply specifically to the present geometry, the results are readily scaled to other COG measurements using other experimental parameters.

  3. 'PSA-SPN' - A Parameter Sensitivity Analysis Method Using Stochastic Petri Nets: Application to a Production Line System

    SciTech Connect

    Labadi, Karim [EPMI-ECS, 13 Bld de l'Hautil, 95092 Cergy-Pontoise Cedex (France); Saggadi, Samira [INRIA Rennes, DIONYSOS, Bretagne Atlantique, Campus Universitaire de Beaulieu, 35042 Rennes (France); Amodeo, Lionel [UTT-ICD, Universite de Technologie de Troyes, 12 rue Marie Curie, BP2060, 10010 Troyes (France)

    2009-03-05

    The dynamic behavior of a discrete event dynamic system can be significantly affected for some uncertain changes in its decision parameters. So, parameter sensitivity analysis would be a useful way in studying the effects of these changes on the system performance. In the past, the sensitivity analysis approaches are frequently based on simulation models. In recent years, formal methods based on stochastic process including Markov process are proposed in the literature. In this paper, we are interested in the parameter sensitivity analysis of discrete event dynamic systems by using stochastic Petri nets models as a tool for modelling and performance evaluation. A sensitivity analysis approach based on stochastic Petri nets, called PSA-SPN method, will be proposed with an application to a production line system.

  4. Highly Sensitive Fetal Goat Tongue Cell Line for Detection and Isolation of Foot-and-Mouth Disease Virus ?

    PubMed Central

    Brehm, K. E.; Ferris, N. P.; Lenk, M.; Riebe, R.; Haas, B.

    2009-01-01

    A fetal goat cell line (ZZ-R 127) supplied by the Collection of Cell Lines in Veterinary Medicine of the Friedrich Loeffler Institute was examined for susceptibility to infection by foot-and-mouth disease (FMD) virus (FMDV) and by two other viruses causing clinically indistinguishable vesicular conditions, namely, the viruses of swine vesicular disease and vesicular stomatitis. Primary bovine thyroid (BTY) cells are generally the most sensitive cell culture system for FMDV detection but are problematic to produce, particularly for laboratories that infrequently perform FMD diagnostic tests and for those in countries where FMD is endemic that face problems in sourcing thyroid glands from FMD-negative calves. Strains representing all seven serotypes of FMDV could be isolated in ZZ-R 127 cells with a sensitivity that was considerably higher than that of established cell lines and within 0.5 log of that for BTY cells. The ZZ-R 127 cell line was found to be a sensitive, rapid, and convenient tool for the isolation of FMDV and a useful alternative to BTY cells for FMD diagnosis. PMID:19656987

  5. BBN and the CMB constrain neutrino coupled light WIMPs

    NASA Astrophysics Data System (ADS)

    Nollett, Kenneth M.; Steigman, Gary

    2015-04-01

    In the presence of a light weakly interacting massive particle (WIMP) with mass m??30 MeV , there are degeneracies among the nature of the WIMP (fermion or boson), its couplings to the standard model particles (to electrons, positrons, and photons, or only to neutrinos), its mass m?, and the number of equivalent (additional) neutrinos, ? N?. These degeneracies cannot be broken by the cosmic microwave background (CMB) constraint on the effective number of neutrinos, Neff. However, since big bang nucleosynthesis (BBN) is also affected by the presence of a light WIMP and equivalent neutrinos, complementary BBN and CMB constraints can help to break some of these degeneracies. In a previous paper [K. M. Nollett and G. Steigman, Phys. Rev. D 89, 083508 (2014)] the combined BBN and Planck [P. A. R. Ade et al. (Planck Collaboration), Astron. Astrophys. 571, A16 (2014)] CMB constraints were used to explore the allowed ranges for m?, ? N?, and Neff in the case where the light WIMPs annihilate electromagnetically (EM) to photons and/or e± pairs. In this paper the BBN predictions for the primordial abundances of deuterium and 4He (along with 3He and 7Li) in the presence of a light WIMP that only couples (annihilates) to neutrinos [either standard model (SM) only or both SM and equivalent] are calculated. Recent observational estimates of the relic abundances of D and 4He are used to limit the light WIMP mass, the number of equivalent neutrinos, the effective number of neutrinos, and the present Universe baryon density (?Bh2 ). Allowing for a neutrino coupled light WIMP and ? N? equivalent neutrinos, the combined BBN and CMB data provide lower limits to the WIMP mass that depend very little on the nature of the WIMP (Majorana or Dirac fermion, real or complex scalar boson), with a best fit m??35 MeV , equivalent to no light WIMP at all. The analysis here excludes all neutrino coupled WIMPs with masses below a few MeV, with specific limits varying from 4 to 9 MeV depending on the nature of the WIMP. In the absence of a light WIMP (either EM or neutrino coupled), BBN alone prefers ? N? =0.50 ±0.23 , favoring neither the absence of equivalent neutrinos (? N?=0 ), nor the presence of a fully thermalized sterile neutrino (? N?=1 ). This result is consistent with the CMB constraint, Neff=3.30 ±0.27 [1], constraining "new physics" between BBN and recombination. Combining the BBN and CMB constraints gives ? N? =0.35 ±0.16 and Neff=3.40 ±0.16 . As a result, while BBN and the CMB combined require ? N? ?0 at ˜98 % confidence, they disfavor ? N? ?1 at >99 % confidence. Adding the possibility of a neutrino-coupled light WIMP extends the allowed range slightly downward for ? N? and slightly upward for Neff simultaneously, while leaving the best-fit values unchanged.

  6. Cerebellar GABA A receptor binding and function in vitro in two rat lines developed for high and low alcohol sensitivity

    Microsoft Academic Search

    M. Uusi-Oukari; E. R. Korpi

    1989-01-01

    TheBmax of the [3H]muscimol binding in the cerebellum of ethanol-naive alcohol-sensitive ANT (Alcohol Non-Tolerant) rats was only about 70% of that in the alcohol-insensitive AT (Alcohol Tolerant) rats. There were no line differences in the muscimol binding to cerebrocortical and hippocampal membranes. In the alcohol-sensitive rats, the cerebellar [3H]muscimol binding (5 nM) negatively correlated with the ethanol-induced motor-impairment measured in

  7. Electrophoresis 1994, 15, 225-221 Field programming for uniform sensitivity in on-line detection in electrophoresis 225 Jason B. Shear

    E-print Network

    Zare, Richard N.

    Electrophoresis 1994, 15, 225-221 Field programming for uniform sensitivity in on-line detection in electrophoresis 225 Jason B. Shear Rajeev Dadoo Richard N. Zare Field programming to achieve uniform sensitivity for on-line detection in electrophoresis Department Of Chemistry, Stanford University, Stanford, CA Under

  8. Sensitivity of different cell lines to phototoxic effect of disulfonated chloroaluminium phthalocyanine

    Microsoft Academic Search

    H. Kolarova; R. Lenobel; P. Kolar; M. Strnad

    2007-01-01

    Photodynamic therapy (PDT) is a treatment for cancer involving three key components: sensitizer, light and tissue oxygen. A sensitizer is a chemical compound that can be excited by light of a specific wavelength. Phthalocyanine ClAlPcS2, belonging among the promising second generation of sensitizers, was evaluated as an inducer of photodamage on NIH3T3 (mouse fibroblasts), B16 (mouse melanoma), MCF7 (human breast

  9. Establishment of a feline T-lymphoblastoid cell line highly sensitive for replication of feline immunodeficiency virus

    Microsoft Academic Search

    Takayuki Miyazawa; Tetsuya Furuya I; Shin-ichi Itagaki; Yukinobu Tohya; Eiji Takahashi; Takeshi Mikami I

    1989-01-01

    Summary Interleukin-2 dependent feline T-lymphoblastoid cells designated as MYA-1 cells were established. The cells were free from exogenous retroviruses and sensitive for replication of feline immunodeficiency virus (FIV). FIV can grow more efficiently in MYA-1 cells than in feline primary peripheral blood mononuclear cells. This line of cells will be useful not only for isolation and propagation of FIV, but

  10. A major QTL for acute ethanol sensitivity in the alcohol tolerant and non-tolerant selected rat lines.

    PubMed

    Radcliffe, R A; Erwin, V G; Bludeau, P; Deng, X; Fay, T; Floyd, K L; Deitrich, R A

    2009-08-01

    The Alcohol Tolerant and Alcohol Non-Tolerant rats (AT, ANT) were selectively bred for ethanol-induced ataxia as measured on the inclined plane. Here we report on a quantitative trait locus (QTL) study in an F(2) intercross population derived from inbred AT and ANT (IAT, IANT) and a follow-up study of congenics that were bred to examine one of the mapped QTLs. Over 1200 F(2) offspring were tested for inclined plane sensitivity, acute tolerance on the inclined plane, duration of the loss of righting reflex (LORR) and blood ethanol at regain of the righting reflex (BECRR). F(2) rats that were in the upper and lower 20% for inclined plane sensitivity were genotyped with 78 SSLP markers. Significant QTLs for inclined plane sensitivity were mapped on chromosomes 8 and 20; suggestive QTLs were mapped on chromosomes 1, 2 and 3. Highly significant QTLs for LORR duration (LOD = 12.4) and BECRR (LOD = 5.7) were mapped to the same locus on chromosome 1. Breeding and testing of reciprocal congenic lines confirmed the chromosome 1 LORR/BECRR QTL. A series of recombinant congenic sub-lines were bred to fine-map this QTL. Current results have narrowed the QTL to an interval of between 5 and 20 Mb. We expect to be able to narrow the interval to less than 5 Mb with additional genotyping and continued breeding of recombinant sub-congenic lines. PMID:19500156

  11. Sensitivity of Malignant Rhabdoid Tumor cell lines to PD 0332991 is inversely correlated with p16 expression

    PubMed Central

    Katsumi, Yoshiki; Iehara, Tomoko; Miyachi, Mitsuru; Yagyu, Shigeki; Tsubai-Shimizu, Satoko; Kikuchi, Ken; Tamura, Shinichi; Kuwahara, Yasumichi; Tsuchiya, Kunihiko; Kuroda, Hiroshi; Sugimoto, Tohru; Houghton, Peter J.; Hosoi, Hajime

    2011-01-01

    Malignant rhabdoid tumor (MRT) is a rare and highly aggressive neoplasm of young children. MRT is characterized by inactivation of integrase interactor 1 (INI1). Cyclin-dependent kinase 4 (CDK4), which acts downstream of INI1, is required for the proliferation of MRT cells. Here we investigated the effects of PD 0332991 (PD), a potent inhibitor of CDK4, against five human MRT cell lines (MP-MRT-AN, KP-MRT-RY, G401, KP-MRT-NS, KP-MRT-YM). In all of the cell lines except KP-MRT-YM, PD inhibited cell proliferation > 50 %, (IC50 values 0.01 to 0.6 µM) by WST-8 assay, and induced G1-phase cell cycle arrest, as shown by flow cytometry and BrdU incorporation assay. The sensitivity of the MRT cell lines to PD was inversely correlated with p16 expression (r = 0.951). KP-MRT-YM cells overexpress p16 and were resistant to the growth inhibitory effect of PD. Small interfering RNA against p16 significantly increased the sensitivity of KP-MRT-YM cells to PD (p < 0.05). These results suggest that p16 expression in MRT could be used to predict its sensitivity to PD. PD may be an attractive agent for patients with MRT whose tumors express low levels of p16. PMID:21871868

  12. Sensitivity of malignant rhabdoid tumor cell lines to PD 0332991 is inversely correlated with p16 expression.

    PubMed

    Katsumi, Yoshiki; Iehara, Tomoko; Miyachi, Mitsuru; Yagyu, Shigeki; Tsubai-Shimizu, Satoko; Kikuchi, Ken; Tamura, Shinichi; Kuwahara, Yasumichi; Tsuchiya, Kunihiko; Kuroda, Hiroshi; Sugimoto, Tohru; Houghton, Peter J; Hosoi, Hajime

    2011-09-16

    Malignant rhabdoid tumor (MRT) is a rare and highly aggressive neoplasm of young children. MRT is characterized by inactivation of integrase interactor 1 (INI1). Cyclin-dependent kinase 4 (CDK4), which acts downstream of INI1, is required for the proliferation of MRT cells. Here we investigated the effects of PD 0332991 (PD), a potent inhibitor of CDK4, against five human MRT cell lines (MP-MRT-AN, KP-MRT-RY, G401, KP-MRT-NS, KP-MRT-YM). In all of the cell lines except KP-MRT-YM, PD inhibited cell proliferation >50%, (IC(50) values 0.01 to 0.6 ?M) by WST-8 assay, and induced G1-phase cell cycle arrest, as shown by flow cytometry and BrdU incorporation assay. The sensitivity of the MRT cell lines to PD was inversely correlated with p16 expression (r=0.951). KP-MRT-YM cells overexpress p16 and were resistant to the growth inhibitory effect of PD. Small interfering RNA against p16 significantly increased the sensitivity of KP-MRT-YM cells to PD (p<0.05). These results suggest that p16 expression in MRT could be used to predict its sensitivity to PD. PD may be an attractive agent for patients with MRT whose tumors express low levels of p16. PMID:21871868

  13. Search for gamma-ray spectral lines with the Fermi Large Area Telescope and dark matter implications

    NASA Astrophysics Data System (ADS)

    Ackermann, M.; Ajello, M.; Albert, A.; Allafort, A.; Baldini, L.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Bissaldi, E.; Bloom, E. D.; Bonamente, E.; Bottacini, E.; Brandt, T. J.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Casandjian, J. M.; Cecchi, C.; Charles, E.; Chaves, R. C. G.; Chekhtman, A.; Chiang, J.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Conrad, J.; Cutini, S.; D'Ammando, F.; de Angelis, A.; de Palma, F.; Dermer, C. D.; Digel, S. W.; Di Venere, L.; Drell, P. S.; Drlica-Wagner, A.; Essig, R.; Favuzzi, C.; Fegan, S. J.; Ferrara, E. C.; Focke, W. B.; Franckowiak, A.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Germani, S.; Giglietto, N.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Gomez-Vargas, G. A.; Grenier, I. A.; Guiriec, S.; Gustafsson, M.; Hadasch, D.; Hayashida, M.; Hill, A. B.; Horan, D.; Hou, X.; Hughes, R. E.; Inoue, Y.; Izaguirre, E.; Jogler, T.; Kamae, T.; Knödlseder, J.; Kuss, M.; Lande, J.; Larsson, S.; Latronico, L.; Longo, F.; Loparco, F.; Lovellette, M. N.; Lubrano, P.; Malyshev, D.; Mayer, M.; Mazziotta, M. N.; McEnery, J. E.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Moiseev, A. A.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nakamori, T.; Nemmen, R.; Nuss, E.; Ohsugi, T.; Okumura, A.; Omodei, N.; Orienti, M.; Orlando, E.; Ormes, J. F.; Paneque, D.; Perkins, J. S.; Pesce-Rollins, M.; Piron, F.; Pivato, G.; Rainò, S.; Rando, R.; Razzano, M.; Razzaque, S.; Reimer, A.; Reimer, O.; Romani, R. W.; Sánchez-Conde, M.; Schulz, A.; Sgrò, C.; Siegal-Gaskins, J.; Siskind, E. J.; Snyder, A.; Spandre, G.; Spinelli, P.; Suson, D. J.; Tajima, H.; Takahashi, H.; Thayer, J. G.; Thayer, J. B.; Tibaldo, L.; Tinivella, M.; Tosti, G.; Troja, E.; Uchiyama, Y.; Usher, T. L.; Vandenbroucke, J.; Vasileiou, V.; Vianello, G.; Vitale, V.; Winer, B. L.; Wood, K. S.; Wood, M.; Yang, Z.; Zaharijas, G.; Zimmer, S.

    2013-10-01

    Weakly interacting massive particles (WIMPs) are a theoretical class of particles that are excellent dark matter candidates. WIMP annihilation or decay may produce essentially monochromatic ? rays detectable by the Fermi Large Area Telescope (LAT) against the astrophysical ?-ray emission of the Galaxy. We have searched for spectral lines in the energy range 5-300 GeV using 3.7 years of data, reprocessed with updated instrument calibrations and an improved energy dispersion model compared to the previous Fermi-LAT Collaboration line searches. We searched in five regions selected to optimize sensitivity to different theoretically motivated dark matter density distributions. We did not find any globally significant lines in our a priori search regions and present 95% confidence limits for annihilation cross sections of self-conjugate WIMPs and decay lifetimes. Our most significant fit occurred at 133 GeV in our smallest search region and had a local significance of 3.3 standard deviations, which translates to a global significance of 1.5 standard deviations. We discuss potential systematic effects in this search, and examine the feature at 133 GeV in detail. We find that the use both of reprocessed data and of additional information in the energy dispersion model contributes to the reduction in significance of the linelike feature near 130 GeV relative to significances reported in other works. We also find that the feature is narrower than the LAT energy resolution at the level of 2 to 3 standard deviations, which somewhat disfavors the interpretation of the 133 GeV feature as a real WIMP signal.

  14. The relationship between powdery mildew ( Sphaerotheca fuliginea ) resistance and leaf chlorosis sensitivity in cucumber ( Cucumis sativus ) studied in single seed descent lines

    Microsoft Academic Search

    S. Zijlstra; R. C. Jansen; S. P. C. Groot

    1995-01-01

    The genetic relation between powdery mildew resistance and sensitivity for leaf chlorosis of glasshouse cucumber was investigated. The powdery mildew resistant, leaf chlorosis sensitive hybrid variety ‘Profito’ was crossed with the powdery mildew susceptible, non chlorosis sensitive hybrid variety ‘Corona’. Forty four F6 inbred lines of this cross, produced by single seed descent, were tested for powdery mildew resistance (PMR)

  15. Low ATM protein expression and depletion of p53 correlates with olaparib sensitivity in gastric cancer cell lines.

    PubMed

    Kubota, Eiji; Williamson, Christopher T; Ye, Ruiqiong; Elegbede, Anifat; Peterson, Lars; Lees-Miller, Susan P; Bebb, D Gwyn

    2014-01-01

    Small-molecule inhibitors of poly (ADP-ribose) polymerase (PARP) have shown considerable promise in the treatment of homologous recombination (HR)-defective tumors, such as BRCA1- and BRCA2-deficient breast and ovarian cancers. We previously reported that mantle cell lymphoma cells with deficiency in ataxia telangiectasia mutated (ATM) are sensitive to PARP-1 inhibitors in vitro and in vivo. Here, we report that PARP inhibitors can potentially target ATM deficiency arising in a solid malignancy. We show that ATM protein expression varies between gastric cancer cell lines, with NUGC4 having significantly reduced protein levels. Significant correlation was found between ATM protein expression and sensitivity to the PARP inhibitor olaparib, with NUGC4 being the most sensitive. Moreover, reducing ATM kinase activity using a small-molecule inhibitor (KU55933) or shRNA-mediated depletion of ATM protein enhanced olaparib sensitivity in gastric cancer cell lines with depletion or inactivation of p53. Our results demonstrate that ATM is a potential predictive biomarker for PARP-1 inhibitor activity in gastric cancer harboring disruption of p53, and that combined inhibition of ATM and PARP-1 is a rational strategy for expanding the utility of PARP-1 inhibitors to gastric cancer with p53 disruption. PMID:24841718

  16. DARWIN: dark matter WIMP search with noble liquids

    E-print Network

    Laura Baudis

    2010-12-21

    DARWIN (DARk matter WImp search with Noble liquids) is an R&D and design study towards the realization of a multi-ton scale dark matter search facility in Europe, based on the liquid argon and liquid xenon time projection chamber techniques. Approved by ASPERA in late 2009, DARWIN brings together several European and US groups working on the existing ArDM, XENON and WARP experiments with the goal of providing a technical design report for the facility by early 2013. DARWIN will be designed to probe the spin-independent WIMP-nucleon cross section region below 10-47cm^2 and to provide a high-statistics measurement of WIMP interactions in case of a positive detection in the intervening years. After a brief introduction, the DARWIN goals, components, as well as its expected physics reach will be presented.

  17. A New Solar System Population of WIMP Dark Matter

    E-print Network

    Thibault Damour; Lawrence M. Krauss

    1998-12-29

    Perturbations due to the planets combined with the non-Coulomb nature of the gravitational potential in the Sun imply that WIMPs that are gravitationally captured by scattering in surface layers of the Sun can evolve into orbits that no longer intersect the Sun. For orbits with a semi-major axis $ solar system for $ > 10^9$ years, leading to a previously unanticipated population intersecting Earth's orbit. For WIMPs detectable in the next generation of detectors, this population can provide a complementary signal, in the keV range, to that of galactic halo dark matter.

  18. The Magnetic Sensitivity of the Ba II D1 and D2 Lines of the Fraunhofer Spectrum

    E-print Network

    Luca Belluzzi; Javier Trujillo Bueno; Egidio Landi Degl'Innocenti

    2007-04-30

    The physical interpretation of the spectral line polarization produced by the joint action of the Hanle and Zeeman effects offers a unique opportunity to obtain empirical information about hidden aspects of solar and stellar magnetism. To this end, it is important to achieve a complete understanding of the sensitivity of the emergent spectral line polarization to the presence of a magnetic field. Here we present a detailed theoretical investigation on the role of resonance scattering and magnetic fields on the polarization signals of the Ba II D1 and D2 lines of the Fraunhofer spectrum, respectively at 4934 \\AA\\ and 4554 \\AA. We adopt a three-level model of Ba II, and we take into account the hyperfine structure that is shown by the $^{135}$Ba and $^{137}$Ba isotopes. Despite of their relatively small abundance (18%), the contribution coming from these two isotopes is indeed fundamental for the interpretation of the polarization signals observed in these lines. We consider an optically thin slab model, through which we can investigate in a rigorous way the essential physical mechanisms involved (resonance polarization, Zeeman, Paschen-Back and Hanle effects), avoiding complications due to radiative transfer effects. We assume the slab to be illuminated from below by the photospheric solar continuum radiation field, and we investigate the radiation scattered at 90 degrees, both in the absence and in the presence of magnetic fields, deterministic and microturbulent. We show in particular the existence of a differential magnetic sensitivity of the three-peak Q/I profile that is observed in the D2 line in quiet regions close to the solar limb, which is of great interest for magnetic field diagnostics.

  19. Glass frit overcoated silver grid lines for nano-crystalline dye sensitized solar cells

    Microsoft Academic Search

    Won Jae Lee; Easwaramoorthi Ramasamy; Dong Yoon Lee; Jae Sung Song

    2006-01-01

    Nano-crystalline dye sensitized solar cells (nc-DSSC) are promising alternative to expensive conventional solar cells. Relatively low efficiency in large size cell is also one of the factors that delayed the entry of this type cells in commercial market. Performance of large size DSSCs is always poor than small size cells because of high resistive losses associated with transparent conductive glass

  20. DarkSide-50: A WIMP Search with a Two-phase Argon TPC

    NASA Astrophysics Data System (ADS)

    Meyers, P. D.; Agnes, P.; Alton, D.; Arisaka, K.; Back, H. O.; Baldin, B.; Biery, K.; Bonfini, G.; Bossa, M.; Brigatti, A.; Brodsky, J.; Budano, F.; Cadonati, L.; Calaprice, F.; Canci, N.; Candela, A.; Cao, H.; Cariello, M.; Cavalcante, P.; Chavarria, A.; Chepurnov, A.; Cocco, A. G.; Crippa, L.; DAngelo, D.; D'Incecco, M.; Davini, S.; De Deo, M.; Derbin, A.; Di Eusanio, F.; Di Pietro, G.; Edkins, E.; Empl, A.; Fan, A.; Fiorillo, G.; Fomenko, K.; Forster, G.; Franco, D.; Gabriele, F.; Galbiati, C.; Goretti, A.; Grandi, L.; Gromov, M.; Guan, M.; Guardincerri, Y.; Hackett, B.; Herner, K.; Humble, P.; Hungerford, E. V.; Ianni, Al.; Ianni, An.; Joliet, C.; Keeter, K.; Kendziora, C.; Kidner, S.; Kobychev, V.; Koh, G.; Korablev, D.; Korga, G.; Kurlej, A.; Li, P.; Loer, B.; Lombardi, P.; Love, C.; Ludhova, L.; Luitz, S.; Ma, Y.; Machulin, I.; Mandarano, A.; Mari, S.; Maricic, J.; Martoff, C. J.; Meregaglia, A.; Meroni, E.; Meyers, P. D.; Milincic, R.; Montanari, D.; Montuschi, M.; Monzani, M. E.; Mosteiro, P.; Mount, B.; Muratova, V.; Musico, P.; Nelson, A.; Okounkova, M.; Orsini, M.; Ortica, F.; Pagani, L.; Pallavicini, M.; Pantic, E.; Papp, L.; Parmeggiano, S.; Parsells, R.; Pelczar, K.; Pelliccia, N.; Perasso, S.; Perfetto, F.; Pocar, A.; Pordes, S.; Qian, H.; Randle, K.; Ranucci, G.; Razeto, A.; Reinhold, B.; Romani, A.; Rossi, B.; Rossi, N.; Rountree, S. D.; Sablone, D.; Saggese, P.; Saldanha, R.; Sands, W.; Segreto, E.; Semenov, D.; Shields, E.; Skorokhvatov, M.; Smirnov, O.; Sotnikov, A.; Suvarov, Y.; Tartaglia, R.; Tatarowicz, J.; Testera, G.; Tonazzo, A.; Unzhakov, E.; Vogelaar, R. B.; Wada, M.; Wang, H.; Wang, Y.; Watson, A.; Westerdale, R.; Wojcik, M.; Wright, A.; Xu, J.; Yang, C.; Yoo, J.; Zavatarelli, S.; Zuzel, G.

    DarkSide-50 is a two phase argon TPC for direct dark matter detection which is installed at the Gran Sasso underground laboratory, Italy. DarkSide-50 has a 50-kg active volume and will make use of underground argon low in 39Ar. The TPC is installed inside an active neutron veto made with boron-loaded high radiopurity liquid scintillator. The neutron veto is installed inside a 1000 m3 water Cherenkov muon veto. The DarkSide-50 TPC and cryostat are assembled in two radon-free clean rooms to reduce radioactive contaminants. The overall design aims for a background free exposure after selection cuts are applied. The expected sensitivity for WIMP-nucleon cross section is of the order of 10-45 cm2 for WIMP masses around 100 GeV/c2. The commissioning and performance of the detector are described. Details of the low-radioactivity underground argon and other unique features of the projects are reported.

  1. Dynamics of WIMPs in the solar system and implications for direct and indirect detection

    E-print Network

    Annika H. G. Peter; Scott Tremaine

    2008-10-14

    Semi-analytic treatments of the evolution of orbits of weakly interacting massive particles (WIMPs) in the solar system suggest that the WIMPs bound to the solar system may enhance the direct detection rate relative to that of the unbound population by up to a factor of order unity, and boost the flux of neutrinos from WIMP annihilation in the Earth by up to two orders of magnitude. To test these important but uncertain results, we perform a suite of numerical orbit integrations to explore the properties of the bound WIMP population as a function of the WIMP mass and the scattering cross section with baryonic matter. For regions of WIMP parameter space presently allowed by experiments, we find that (i) the bound WIMP population enhances the direct detection rate by at most ~1% relative to the rate from unbound halo WIMPs; (ii) it is unlikely that planned km^3-scale neutrino telescopes will detect neutrinos from WIMP annihilation in the Earth; (iii) the event rate from neutrinos produced by WIMP annihilation in the Sun may be much smaller than implied by the usual calculations, which assume that WIMPs scattered onto bound orbits are rapidly thermalized in the Sun.

  2. A tumorigenic murine Sertoli cell line that is temperature-sensitive for differentiation.

    PubMed

    Boekelheide, K; Lee, J W; Hall, S J; Rhind, N R; Zaret, K S

    1993-10-01

    The Sertoli cell is the epithelial cell within the seminiferous tubule responsible for supporting germ cells. Most current in vitro studies of Sertoli cell function use primary cultures because of the limited number of available Sertoli cell lines. In addition, few in vivo models of Sertoli cell malignancy have been described. In this study, a tumorigenic Sertoli cell line was developed by infection of isolated murine Sertoli cells by simian virus 40 tsA255; the ts mutation causes the inactivation of the large T antigen at elevated temperatures. A cloned Sertoli cell line, called S14-1, demonstrated temperature-dependent growth in soft agar and formed tumors in nude mice. Electron microscopy of the S14-1-derived tumor revealed extensive basal intercellular junctions and tubulobulbarlike processes supporting its Sertoli cell origin. Cytogenetic analysis showed that S14-1 cells were aneuploid with an average of 70 chromosomes per cell. At the nonpermissive (40 C) temperature, S14-1 cells in vitro demonstrated a reduced growth rate, enhanced secretion of transferrin, and increased expression of sulfated glycoprotein-2 messenger RNA, indicating the cells manifested increased differentiation following large T antigen inactivation. The murine S14-1 Sertoli cell line should be useful for both in vitro studies of Sertoli cell function and in vivo studies of Sertoli cell malignancy. PMID:8214009

  3. Integrated Cantilever-Based Flow Sensors with Tunable Sensitivity for In-Line Monitoring of Flow Fluctuations in Microfluidic Systems

    PubMed Central

    Noeth, Nadine; Keller, Stephan Sylvest; Boisen, Anja

    2014-01-01

    For devices such as bio-/chemical sensors in microfluidic systems, flow fluctuations result in noise in the sensor output. Here, we demonstrate in-line monitoring of flow fluctuations with a cantilever-like sensor integrated in a microfluidic channel. The cantilevers are fabricated in different materials (SU-8 and SiN) and with different thicknesses. The integration of arrays of holes with different hole size and number of holes allows the modification of device sensitivity, theoretical detection limit and measurement range. For an average flow in the microliter range, the cantilever deflection is directly proportional to the flow rate fluctuations in the microfluidic channel. The SiN cantilevers show a detection limit below 1 nL/min and the thinnest SU-8 cantilevers a detection limit below 5 nL/min. Finally, the sensor is applied for in-line monitoring of flow fluctuations generated by external pumps connected to the microfluidic system. PMID:24366179

  4. A sensitive and robust method for automated on-line monitoring of enzymatic activities in water and water resources.

    PubMed

    Ryzinska-Paier, G; Lendenfeld, T; Correa, K; Stadler, P; Blaschke, A P; Mach, R L; Stadler, H; Kirschner, A K T; Farnleitner, A H

    2014-01-01

    The realisation of a novel concept for automated on-line monitoring of enzymatic activities in water was successfully demonstrated by long-term field testing at two remote Austrian ground water resources. The ?-D-glucuronidase (GLUC) activity was selected as a representative enzymatic model parameter for the on-line determination. But the device can be adapted for any enzymatic reaction with diagnostic relevance for microbial water quality monitoring, as demonstrated for the ?-D-galactosidase activity. Automated filtration of volumes up to 5 litres supports sensitive quantification of enzymatic activities. Internet-based data transfer, using internal control parameters for verification and a dynamic determination of the limit of quantification, enabled robust enzymatic on-line monitoring during a 2-year period. A proportion of 5,313 out of 5,506 GLUC activity measurements (96.5%) could be positively verified. Hydrological (discharge, gauge, turbidity, temperature, pH, electric conductivity, spectral absorbance coefficient at 254 nm) as well as microbiological parameters (Escherichia coli, coliforms) were concurrently determined to characterise the investigated ground water resources. The enzymatic on-line measurements closely reflected the different hydrological conditions and contamination patterns of the test sites. Contrary to expectations, GLUC did not qualify as a proxy-parameter for the occurrence of cultivation-based E. coli contamination and warrants further detailed investigations on its indication capacity as a rapid means for microbial faecal pollution detection in such aquatic habitats. Microbial on-line monitoring is likely to become more important in the future, complementing existing surveillance strategies for water safety management. Further perspectives on the application of such analytical on-line technologies, such as their connection with event-triggered sampling and standardised diagnostics, are discussed. PMID:24647204

  5. Increased caspase-2 activity is associated with induction of apoptosis in IFN-beta sensitive melanoma cell lines.

    PubMed

    Kamiya, Takafumi; Okabayashi, Tamaki; Yokota, Shin-Ichi; Kan, Yuji; Ogino, Jiro; Yamashita, Toshiharu; Fujii, Nobuhiro; Jimbow, Kowichi

    2010-05-01

    Interferon (IFN) is believed to be one of the most effective anti-melanoma agents. Specifically, IFN-beta has the ability to induce apoptosis of melanoma cells. Induction of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has also been suggested to have a critical role in IFN-beta-induced apoptosis. To characterize the signaling pathway involved in IFN-beta-induced apoptosis, we analyzed the biological effects of IFN-beta on the cell death and caspase activation of melanoma cells. IFN-sensitive cell lines, MM418, SK-mel-23, and SK-mel-118, showed increased apoptotic populations correlated with the activation of caspase-2 and caspase-3 by IFN-beta. IFN-beta-induced apoptosis was significantly suppressed by inhibitors for caspase-2 or caspase-3, but not by inhibitors for caspase-8 or caspase-9 in these cell lines. TRAIL expression was observed in IFN-beta-treated cells of SK-mel-23 and SK-mel-118, but not in those cells of MM418, which showed massive IFN-beta-induced apoptosis and resistance to exogenous TRAIL-mediated apoptosis. G361 was resistant to IFN-beta-induced apoptosis but sensitive to exogenous TRAIL-mediated apoptosis. Furthermore, IFN-beta pretreatment significantly increased the sensitivity against exogenous TRAIL-mediated apoptosis and activation of caspase-2 in G361. These results suggested that caspase-2 activation is commonly associated with induction of IFN-beta-induced apoptosis in IFN-beta-sensitive melanoma cells. PMID:20187765

  6. Searching for super-WIMPs in leptonic heavy meson decays

    E-print Network

    Y. G. Aditya; Kristopher J. Healey; Alexey A. Petrov

    2012-01-04

    We study constraints on the models of bosonic super-weakly interacting particle (super-WIMP) dark matter (DM) with DM masses $m_X \\sim \\mathcal{O}(1 - 100)$ keV from leptonic decays $M\\rightarrow \\ell \\bar{\

  7. Optimizing line intercept sampling and estimation for feral swine damage levels in ecologically sensitive wetland plant communities.

    PubMed

    Thomas, Jacob F; Engeman, Richard M; Tillman, Eric A; Fischer, Justin W; Orzell, Steve L; Glueck, Deborah H; Felix, Rodney K; Avery, Michael L

    2013-03-01

    Ecological sampling can be labor intensive, and logistically impractical in certain environments. We optimize line intercept sampling and compare estimation methods for assessing feral swine damage within fragile wetland ecosystems in Florida. Sensitive wetland sites, and the swine damage within them, were mapped using GPS technology. Evenly spaced parallel transect lines were simulated across a digital map of each site. The length of each transect and total swine damage under each transect were measured and percent swine damage within each site was estimated by two methods. The total length method (TLM) combined all transects as a single long transect, dividing the sum of all damage lengths across all transects by the combined length of all transect lines. The equal weight method (EWM) calculated the damage proportion for each transect line and averaged these proportions across all transects. Estimation was evaluated using transect spacings of 1, 3, 5, 10, 15, and 20 m. Based on relative root mean squared error and relative bias measures, the TLM produced higher quality estimates than EWM at all transect spacings. Estimation quality decreased as transect spacing increased, especially for TLM. Estimation quality also increased as the true proportion of swine damage increased. Diminishing improvements in estimation quality as transect spacings decreased suggested 5 m as an optimal tradeoff between estimation quality and labor. An inter-transect spacing of 5 m with TLM estimation appeared an optimal starting point when designing a plan for estimating swine damage, with practical, logistical, economic considerations determining final design details. PMID:22707203

  8. Identification and characterization of a Ca2+-calmodulin-sensitive cyclic nucleotide phosphodiesterase in a human lymphoblastoid cell line.

    PubMed Central

    Epstein, P M; Moraski, S; Hachisu, R

    1987-01-01

    This study examines the pattern and regulatory properties of cyclic nucleotide phosphodiesterases in a human lymphoblastoid B-cell line (RPMI 8392) established from a patient with acute lymphocytic leukaemia. In this cell line, phosphodiesterase activity measured at 0.25 microM-cyclic AMP is approx. 7-fold greater than that in isolated human peripheral-blood lymphocytes, and 16% of the phosphodiesterase activity in RPMI 8392 cells is associated with particulate fractions. Phosphodiesterase activity in crude fractions of this cell line is reproducibly stimulated by about 60-80% by Ca2+-calmodulin. In the presence of 20 nM-calmodulin, half-maximal stimulation occurs at 0.7 microM-Ca2+. The cytosolic phosphodiesterase activity of RPMI 8392 cells is separated into two forms by DEAE-Sephacel chromatography. The first form is eluted at approx. 0.2 M-sodium acetate, catalyses the hydrolysis of both cyclic AMP and cyclic GMP, and is stimulated 3-fold by Ca2+-calmodulin. This form exhibits non-linear kinetics for cyclic AMP in the absence of calmodulin, with extrapolated Km values of 0.8 and 4 microM, and non-linear kinetics in the presence of calmodulin, with extrapolated Km values of 0.5 and 1 microM. The Vmax. values are increased approx. 3-fold by calmodulin. The second form is eluted at approx. 0.6 M-sodium acetate, is specific for cyclic AMP, and insensitive to stimulation by Ca2+-calmodulin. The Ca2+-calmodulin-sensitive phosphodiesterase from the DEAE-Sephacel column can be adsorbed to a calmodulin-Sepharose affinity column and eluted with EGTA. This enzymic activity can also be immunoprecipitated by a monoclonal antibody directed against a calmodulin-bovine heart phosphodiesterase complex. This study documents the existence of Ca2+-calmodulin-sensitive phosphodiesterase in a cultured lymphoblastoid cell line derived from a leukaemic patient. PMID:2820385

  9. Transmission-line tunnel diode oscillator: A sensitive, fast, and flexible low-temperature detection system

    SciTech Connect

    Brisson, J.G.; Silvera, I.F.

    1986-11-01

    Tunnel diode oscillators (TDO's) excel in high-resolution measurement of inductive and capacitive transducers at cryogenic temperatures. The transmission-line tunnel diode oscillator (TLTDO) discussed here combines the ease of construction of a discrete element TDO with the quick response times and immunity to stray reactances of the reentrant cavity TDO. Theory and design of four TLTDO's are discussed. Two characteristic response times for TDO's are discussed.

  10. Response of sensitive human ataxia and resistant T-1 cell lines to accelerated heavy ions

    SciTech Connect

    Tobias, C.A.; Blakely, E.A.; Chang, P.Y.; Lommel, L.; Roots, R.

    1983-07-01

    The radiation dose responses of fibroblast from a patient with Ataxia telangiectasis (AT-2SF) and an established line of human T-1 cells were studied. Nearly monoenergetic accelerated neon and argon ions were used at the Berkeley Bevalac with various residual range values. The LET of the particles varied from 30 keV/..mu..m to over 1000 keV/..mu..m. All Ataxia survival curves were exponential functions of the dose. Their radiosensitivity reached peak values at 100 to 200 keV/..mu..m. Human T-1 cells have effective sublethal damage repair as has been evidenced by split dose experiments, and they are much more resistant to low LET than to high LET radiation. The repair-misrepair model has been used to interpret these results. We have obtained mathematical expressions that describe the cross sections and inactivation coefficients for both human cell lines as a function of the LET and the type of particle used. The results suggest either that high-LET particles induce a greater number of radiolesions per track or that heavy-ions at high LET induce lesions that kill cells more effectively and that are different from those produced at low LET. We assume that the lesions induced in T-1 and Ataxia cells are qualitatively similar and that each cell line attempts to repair these lesions. The result in most irradiated Ataxia cells, however, is either lethal misrepair or incomplete repair leading to cell death. 63 references, 10 figures, 1 table.

  11. Organization of actin cytoskeleton during meiosis I in a wheat thermo-sensitive genic male sterile line.

    PubMed

    Xu, Chenguang; Liu, Zetao; Zhang, Liping; Zhao, Changping; Yuan, Shaohua; Zhang, Fengting

    2013-02-01

    BS366 is a thermo-sensitive male sterile line of wheat (Triticum aestivum L.) for two-line hybrid breeding, which exhibits aberrant meiotic cytokinesis under low temperature. Through transcriptome analysis, a possible regulatory role for plant actin cytoskeleton was suggested. However, the organization of actin cytoskeleton in meiosis has been poorly understood so far. Here, fixed microsporocytes during meiosis were labeled with tetramethylrhodamine isothiocyanate-phalloidin and 4',6-diamidino-2-phenylindole. Quantities of fluorescent micrographs were captured using a confocal microscope, including the transient state from metaphase to telophase. We observed that actin filaments were abundant in typical kariokinetic spindle, central spindle (parallel microtubules or actin fibers between two separated chromosomes in anaphase), and phragmoplast. Interestingly, we identified the Chinese lantern-shaped actin phragmoplast in wheat meiosis for the first time. Under low temperature, phragmoplast actin filaments were chaotic and normal cell plate failed to form. These data provide new insights into the organization of actin filaments during male meiosis of plant and support a role of actin cytoskeleton in bringing about thermo-sensitive male sterility in wheat. PMID:22350736

  12. Medullary lateral line units of rudd, Scardinius erythrophthalmus, are sensitive to Kármán vortex streets.

    PubMed

    Klein, Adrian; Winkelnkemper, Jan; Dylda, Evelyn; Bleckmann, Horst

    2015-07-01

    We investigated the responses of medullary lateral line units of the rudd, Scardinius erythrophthalmus, to bulk water flow (7 cm s(-1)) and to water flow that contained vortices shed by an upstream half cylinder (diameter 1, 2, and 3 cm). Thirty-five percent of the medullary units either increased or decreased their discharge rate with the increasing cylinder diameter. In some units, the spike patterns revealed the vortex shedding frequency, i.e., in these units the amplitude of spike train frequency spectra was similar or identical to the vortex shedding frequency. PMID:26018072

  13. NQR Line Broadening Due to Crystal Lattice Imperfections and Its Relationship to Shock Sensitivity

    NASA Astrophysics Data System (ADS)

    Caulder, S. M.; Buess, M. L.; Garroway, A. N.; Miller, P. J.

    2004-07-01

    The hydrodynamic hot spot model is used to explain the difference between shock sensitive and shock insensitive explosives. Among the major factors that influence the shock sensitivity of energetic compounds are the quality and particle size of the energetic crystals used to formulate the cast plastic bonded explosive. As do all energetic compounds, RDX and HMX exhibit internal crystal defects the magnitude and type of which depend on the manufacturing process used to synthesize and re-crystallize the energetic compound. Nuclear Quadrupole Resonance (NQR) spectroscopy was used to determine the crystal quality of RDX, HMX and CL-20 obtained from various manufacturers. The NQR experimental results are discussed. Cast plastic bonded explosives were made using the RDX and HMX obtained from the various manufacturers and subsequently subjected to the NOL large-scale gap test (LSGT). The results of the LSGT are discussed and correlated with the NQR results. A relationship between the crystal defect density and shock initiation pressure of the plastic bonded explosive is developed and discussed.

  14. High-sensitivity determination of tyrosine-phosphorylated peptides by on-line enzyme reactor and electrospray ionization mass spectrometry.

    PubMed Central

    Amankwa, L. N.; Harder, K.; Jirik, F.; Aebersold, R.

    1995-01-01

    We describe a simple, fast, sensitive, and nonisotopic bioanalytical technique for the detection of tyrosine-phosphorylated peptides and the determination of sites of protein tyrosine phosphorylation. The technique employs a protein tyrosine phosphatase micro enzyme reactor coupled on-line to either capillary electrophoresis or liquid chromatography and electrospray ionization mass spectrometry instruments. The micro enzyme reactor was constructed by immobilizing genetically engineered, metabolically biotinylated human protein tyrosine phosphatase beta onto the inner surface of a small piece of a 50-microns inner diameter, 360-microns outer diameter fused silica capillary or by immobilization of the phosphatase onto 40-90-microns avidin-activated resins. By coupling these reactors directly to either a capillary electrophoresis column or a liquid chromatography column, we were able to rapidly perform enzymatic dephosphorylation and separation of the reaction products. Detection and identification of the components of the reaction mixture exiting these reactors were done by mass analysis with an on-line electrospray ionization mass spectrometer. Tyrosine-phosphorylated peptides, even if present in a complex peptide mixture, were identified by subtractive analysis of peptide patterns generated with or without phosphatase treatment. Two criteria, namely a phosphatase-induced change in hydropathy and charge, respectively, and a change in molecular mass by 80 Da, were used jointly to identify phosphopeptides. We demonstrate that, with this technique, low picomole amounts of a tyrosine-phosphorylated peptide can be detected in a complex peptide mixture generated by proteolysis of a protein and that even higher sensitivities can be realized if more sensitive detection systems are applied. PMID:7539661

  15. Lentivirus-mediated RNAi silencing targeting ABCC2 increasing the sensitivity of a human nasopharyngeal carcinoma cell line against cisplatin

    PubMed Central

    Xie, Si Ming; Fang, Wei Yi; Liu, Zhen; Wang, Shuang Xi; Li, Xin; Liu, Teng Fei; Xie, Wei Bing; Yao, Kai Tai

    2008-01-01

    Background High resistance to drug is taken as a characteristic of human tumors, which is usually mediated by multidrug resistance-associated genes. ABCC2, an ATP-binding cassette multidrug resistance transporter, is found to be expressed in a variety of human cancers. In this study the effect of a RNAi construct targeting ABCC2 on the chemosensitivity of NPC cell line CNE2 against cisplatin was investigated. Methods Lentiviral vectors were constructed to allow an efficient expression of anti-ABCC2 siRNA. The effective target sequence comprised nucleotides 1707–1727 of the human ABCC2 mRNA. The cell clones expressing the construct were picked and expanded, followed by identification using qRT-PCR and western blot method. As control, lentiviral vector containing invalid RNAi sequence was transfected to CNE2 cells. In vitro, cellular accumulation of cisplatin was detected by HPLC. The capacity of cellular growth and sensitivity of cells against cisplatin were detected by MTT assay. In vivo, the sensitivity of the tumor tissues against cisplatin were evaluated by transplanted CNE2 nude mice model. Results Two CNE2 cell clones with reduced expression of targeted ABCC2 mRNA and protein for more than 70% by qRT-PCR and western blot were established, and no differences were shown in proliferation rates compared to control CNE2 cells by growth curves analysis. In vitro the accumulation of intracellular cisplatin in these CNE2 cell clones with reduced expression of ABCC2 increased markedly, accompanied by increased sensitivity against cisplatin. In vivo, the growth of CNE2 solid tumors with a stably transfected anti-ABCC2 siRNA construct was significantly inhibited by cisplatin in transplanted nude mice model. Conclusion Our investigation demonstrated that lentivirus-mediated RNAi silencing targeting ABCC2 might reverse the ABCC2-related drug resistance of NPC cell line CNE2 against cisplatin. PMID:18834541

  16. Identification of Proteins Sensitive to Thermal Stress in Human Neuroblastoma and Glioma Cell Lines

    PubMed Central

    Xu, Guilian; Stevens, Stanley M.; Kobiessy, Firas; Brown, Hilda; McClung, Scott; Gold, Mark S.; Borchelt, David R.

    2012-01-01

    Heat-shock is an acute insult to the mammalian proteome. The sudden elevation in temperature has far-reaching effects on protein metabolism, leads to a rapid inhibition of most protein synthesis, and the induction of protein chaperones. Using heat-shock in cells of neuronal (SH-SY5Y) and glial (CCF-STTG1) lineage, in conjunction with detergent extraction and sedimentation followed by LC-MS/MS proteomic approaches, we sought to identify human proteins that lose solubility upon heat-shock. The two cell lines showed largely overlapping profiles of proteins detected by LC-MS/MS. We identified 58 proteins in detergent insoluble fractions as losing solubility in after heat shock; 10 were common between the 2 cell lines. A subset of the proteins identified by LC-MS/MS was validated by immunoblotting of similarly prepared fractions. Ultimately, we were able to definitively identify 3 proteins as putatively metastable neural proteins; FEN1, CDK1, and TDP-43. We also determined that after heat-shock these cells accumulate insoluble polyubiquitin chains largely linked via lysine 48 (K-48) residues. Collectively, this study identifies human neural proteins that lose solubility upon heat-shock. These proteins may represent components of the human proteome that are vulnerable to misfolding in settings of proteostasis stress. PMID:23145051

  17. Protein Profiles Reveal Diverse Responsive Signaling Pathways in Kernels of Two Maize Inbred Lines with Contrasting Drought Sensitivity

    PubMed Central

    Yang, Liming; Jiang, Tingbo; Fountain, Jake C.; Scully, Brian T.; Lee, Robert D.; Kemerait, Robert C.; Chen, Sixue; Guo, Baozhu

    2014-01-01

    Drought stress is a major factor that contributes to disease susceptibility and yield loss in agricultural crops. To identify drought responsive proteins and explore metabolic pathways involved in maize tolerance to drought stress, two maize lines (B73 and Lo964) with contrasting drought sensitivity were examined. The treatments of drought and well water were applied at 14 days after pollination (DAP), and protein profiles were investigated in developing kernels (35 DAP) using iTRAQ (isobaric tags for relative and absolute quantitation). Proteomic analysis showed that 70 and 36 proteins were significantly altered in their expression under drought treatments in B73 and Lo964, respectively. The numbers and levels of differentially expressed proteins were generally higher in the sensitive genotype, B73, implying an increased sensitivity to drought given the function of the observed differentially expressed proteins, such as redox homeostasis, cell rescue/defense, hormone regulation and protein biosynthesis and degradation. Lo964 possessed a more stable status with fewer differentially expressed proteins. However, B73 seems to rapidly initiate signaling pathways in response to drought through adjusting diverse defense pathways. These changes in protein expression allow for the production of a drought stress-responsive network in maize kernels. PMID:25334062

  18. Generalization of the slip line field theory for temperature sensitive visco-plastic materials

    NASA Astrophysics Data System (ADS)

    Paesold, Martin; Peters, Max; Regenauer-Lieb, Klaus; Veveakis, Manolis; Bassom, Andrew

    2015-04-01

    Geological processes can be a combination of various effects such as heat production or consumption, chemical reactions or fluid flow. These individual effects are coupled to each other via feedbacks and the mathematical analysis becomes challenging due to these interdependencies. Here, we concentrate solely on thermo-mechanical coupling and a main result of this work is that the coupling can depend on material parameters and boundary conditions and the coupling is more or less pronounced depending on theses parameters. The transitions from weak to strong coupling can be studied in the context of a bifurcation analysis. classically, Material instabilities in solids are approached as material bifurcations of a rate-independent, isothermal, elasto-plastic solid. However, previous research has shown that temperature and deformation rate are important factors and are fully coupled with the mechanical deformation. Early experiments in steel revealed a distinct pattern of localized heat dissipation and plastic deformation known as heat lines. Further, earth materials, soils, rocks and ceramics are known to be greatly influenced by temperature with strain localization being strongly affected by thermal loading. In this work, we provide a theoretical framework for the evolution of plastic deformation for such coupled systems, with a two-pronged approach to the prediction of localized failure. First, slip line field theory is employed to predict the geometry of the failure patterns and second, failure criteria are derived from an energy bifurcation analysis. The bifurcation analysis is concerned with the local energy balance of a material and compares the effects of heat diffusion terms and heat production terms where the heat production is due to mechanical processes. Commonly, the heat is produced locally along the slip lines and if the heat production outweighs diffusion the material is locally weakened which eventually leads to failure. The effect of diffusion and heat production is captured by a dimensionless quantity, the Gruntfest number, and only if the Gruntfest number is larger than a critical value localized failure occurs. This critical Gruntfest number depends on boundary conditions such as temperature or pressure and hence this critical value gives rise to localization criteria. We find that the results of this approach agree with earlier contributions to the theory of plasticity but gives the advantage of a unified framework which might prove useful in numerical schemes for visco-plasticity.

  19. Sensitivity to noise and ergodicity of an assembly line of cellular automata that classifies density.

    PubMed

    Mendonça, J Ricardo G

    2011-03-01

    We investigate the sensitivity of the composite cellular automaton of  H. Fuk? [Phys. Rev. E 55, R2081 (1997)] to noise and assess the density classification performance of the resulting probabilistic cellular automaton (PCA) numerically. We conclude that the composite PCA performs the density classification task reliably only up to very small levels of noise. In particular, it cannot outperform the noisy Gacs-Kurdyumov-Levin automaton, an imperfect classifier, for any level of noise. While the original composite CA is nonergodic, analyses of relaxation times indicate that its noisy version is an ergodic automaton, with the relaxation times decaying algebraically over an extended range of parameters with an exponent very close (possibly equal) to the mean-field value. PMID:21517459

  20. Sensitivity to noise and ergodicity of an assembly line of cellular automata that classifies density

    NASA Astrophysics Data System (ADS)

    Mendonça, J. Ricardo G.

    2011-03-01

    We investigate the sensitivity of the composite cellular automaton of H. Fuk? [Phys. Rev. EPNASA61539-375510.1103/PhysRevE.55.R2081 55, R2081 (1997)] to noise and assess the density classification performance of the resulting probabilistic cellular automaton (PCA) numerically. We conclude that the composite PCA performs the density classification task reliably only up to very small levels of noise. In particular, it cannot outperform the noisy Gacs-Kurdyumov-Levin automaton, an imperfect classifier, for any level of noise. While the original composite CA is nonergodic, analyses of relaxation times indicate that its noisy version is an ergodic automaton, with the relaxation times decaying algebraically over an extended range of parameters with an exponent very close (possibly equal) to the mean-field value.

  1. Position and time sensitive photon counting detector with image charge delay-line readout

    NASA Astrophysics Data System (ADS)

    Czasch, Achim; Dangendorf, Volker; Milnes, James; Schössler, Sven; Lauck, Ronald; Spillmann, Uwe; Howorth, Jon; Jagutzki, Ottmar

    2007-09-01

    We have developed single photon counting image intensifier tubes combining position and time information read-out with at least 500x500 pixels and sub-nanosecond time resolution. This image intensifier type uses a resistive screen instead of a phosphor screen and the image charge pickup anode is placed outside the sealed tube. We present a novel delay-line anode design which allows for instance detecting simultaneously arriving pairs of photons. Due to the very low background this technique is suited for applications with very low light intensity and especially if a precise time tagging for each photon is required. We show results obtained with several anode types on a 25 mm image intensifier tube and a 40 mm open-face MCP detector and discuss the performance in neutron radiography, e.g. for homeland security, and the prospects for applications like Fluorescence Life-time Imaging Microscopy (FLIM), astronomy and X-ray polarimetry.

  2. Heavy superheated droplet detectors as a probe of spin-independent WIMP dark matter existence

    NASA Astrophysics Data System (ADS)

    Giuliani, F.; Morlat, T.; Girard, T. A.

    2007-03-01

    At present, application of Superheated Droplet Detectors (SDDs) in WIMP dark matter searches has been limited to the spin-dependent sector, owing to the general use of fluorinated refrigerants which have high spin sensitivity. Given their recent demonstration of a significant constraint capability with relatively small exposures and the relative economy of the technique, we consider the potential impact of heavy versions of such devices on the spin-independent sector. Limits obtainable from a CF3I-loaded SDD are estimated on the basis of the radiopurity levels and backgrounds already achieved by the SIMPLE and PICASSO experiments. With 34 kgd exposure, equivalent to the current CDMS, such a device may already probe to below 10-6pb in the spin-independent cross section.

  3. Cultural differences in on-line sensitivity to emotional voices: comparing East and West

    PubMed Central

    Liu, Pan; Rigoulot, Simon; Pell, Marc D.

    2015-01-01

    Evidence that culture modulates on-line neural responses to the emotional meanings encoded by vocal and facial expressions was demonstrated recently in a study comparing English North Americans and Chinese (Liu et al., 2015). Here, we compared how individuals from these two cultures passively respond to emotional cues from faces and voices using an Oddball task. Participants viewed in-group emotional faces, with or without simultaneous vocal expressions, while performing a face-irrelevant visual task as the EEG was recorded. A significantly larger visual Mismatch Negativity (vMMN) was observed for Chinese vs. English participants when faces were accompanied by voices, suggesting that Chinese were influenced to a larger extent by task-irrelevant vocal cues. These data highlight further differences in how adults from East Asian vs. Western cultures process socio-emotional cues, arguing that distinct cultural practices in communication (e.g., display rules) shape neurocognitive activity associated with the early perception and integration of multi-sensory emotional cues. PMID:26074808

  4. Klotho sensitizes human lung cancer cell line to cisplatin via PI3k/Akt pathway.

    PubMed

    Wang, Yan; Chen, Lei; Huang, Guochang; He, Dongmei; He, Juan; Xu, Wei; Zou, Chunying; Zong, Feng; Li, Yan; Chen, Bo; Wu, Shuanshuan; Zhao, Weihong; Wu, Jianqing

    2013-01-01

    Klotho was first identified in 1997 and has been considered as an anti-aging gene. Emerging evidence demonstrates that klotho has a close relationship with cancers, including lung cancer, breast cancer, etc, by inhibiting the proliferation and promoting apoptosis of cancer cells. Cisplatin has been the most widely used drug in the first-line chemotherapy. However, the increase in cisplatin-resistant cancer cells has become a major obstacle in clinical management of cancers. In our study, we for the first time demonstrated that klotho could attenuate the resistance of lung cancer to cisplatin based chemotherapy and the apoptosis of the resistant cells with klotho overexpression was markedly increased. However, klotho knockdown cells showed enhanced resistance to chemotherapy. Further analysis showed that inhibition of PI3K/Akt pathway with specific inhibitor (LY294002) attenuated the promotive effects on cancer growth following interfering with klotho shRNA. Moreover, we demonstrated that klotho modulated the resistance to cisplatin in a xenograft nude mice model. These observations suggested that klotho could improve the resistance of lung cancer cells to chemotherapy and may serve as a potential target for the gene therapy of lung cancers resistant to cisplatin based chemotherapy. PMID:23437382

  5. Cultural differences in on-line sensitivity to emotional voices: comparing East and West.

    PubMed

    Liu, Pan; Rigoulot, Simon; Pell, Marc D

    2015-01-01

    Evidence that culture modulates on-line neural responses to the emotional meanings encoded by vocal and facial expressions was demonstrated recently in a study comparing English North Americans and Chinese (Liu et al., 2015). Here, we compared how individuals from these two cultures passively respond to emotional cues from faces and voices using an Oddball task. Participants viewed in-group emotional faces, with or without simultaneous vocal expressions, while performing a face-irrelevant visual task as the EEG was recorded. A significantly larger visual Mismatch Negativity (vMMN) was observed for Chinese vs. English participants when faces were accompanied by voices, suggesting that Chinese were influenced to a larger extent by task-irrelevant vocal cues. These data highlight further differences in how adults from East Asian vs. Western cultures process socio-emotional cues, arguing that distinct cultural practices in communication (e.g., display rules) shape neurocognitive activity associated with the early perception and integration of multi-sensory emotional cues. PMID:26074808

  6. WIMP Dark Matter Direct-Detection Searches in Noble Gases

    E-print Network

    Laura Baudis

    2014-08-19

    Cosmological observations and the dynamics of the Milky Way provide ample evidence for an invisible and dominant mass component. This so-called dark matter could be made of new, colour and charge neutral particles, which were non-relativistic when they decoupled from ordinary matter in the early universe. Such weakly interacting massive particles (WIMPs) are predicted to have a non-zero coupling to baryons and could be detected via their collisions with atomic nuclei in ultra-low background, deep underground detectors. Among these, detectors based on liquefied noble gases have demonstrated tremendous discovery potential over the last decade. After briefly introducing the phenomenology of direct dark matter detection, I will review the main properties of liquefied argon and xenon as WIMP targets and discuss sources of background. I will then describe existing and planned argon and xenon detectors that employ the so-called single- and dual-phase detection techniques, addressing their complementarity and science reach.

  7. Sensitivity of human lung adenocarcinoma cell lines to targeted inhibition of BET epigenetic signaling proteins

    PubMed Central

    Lockwood, William W.; Zejnullahu, Kreshnik; Bradner, James E.; Varmus, Harold

    2012-01-01

    Bromodomain and extra terminal domain (BET) proteins function as epigenetic signaling factors that associate with acetylated histones and facilitate transcription of target genes. Inhibitors targeting the activity of BET proteins have shown potent antiproliferative effects in hematological cancers through the suppression of c-MYC and downstream target genes. However, as the epigenetic landscape of a cell varies drastically depending on lineage, transcriptional coactivators such as BETs would be expected to have different targets in cancers derived from different cells of origin, and this may influence the activity and mechanism of action of BET inhibitors. To test this hypothesis, we treated a panel of lung adenocarcinoma (LAC) cell lines with the BET inhibitor JQ1 and found that a subset is acutely susceptible to BET inhibition. In contrast to blood tumors, we show that LAC cells are inhibited by JQ1 through a mechanism independent of c-MYC down-regulation. Through gene expression profiling, we discovered that the oncogenic transcription factor FOSL1 and its targets are suppressed by JQ1 in a dose-dependant manner. Knockdown of BRD4 also decreased FOSL1 levels, and inhibition of FOSL1 phenocopied the effects of JQ1 treatment, suggesting that loss of this transcription factor may be partly responsible for the cytotoxic effects of BET inhibition in LAC cells, although ectopic expression of FOSL1 alone did not rescue the phenotype. Together, these findings suggest that BET inhibitors may be useful in solid tumors and that cell-lineage–specific differences in transcriptional targets of BETs may influence the activity of inhibitors of these proteins in different cancer types. PMID:23129625

  8. Sensitivity of human lung adenocarcinoma cell lines to targeted inhibition of BET epigenetic signaling proteins.

    PubMed

    Lockwood, William W; Zejnullahu, Kreshnik; Bradner, James E; Varmus, Harold

    2012-11-20

    Bromodomain and extra terminal domain (BET) proteins function as epigenetic signaling factors that associate with acetylated histones and facilitate transcription of target genes. Inhibitors targeting the activity of BET proteins have shown potent antiproliferative effects in hematological cancers through the suppression of c-MYC and downstream target genes. However, as the epigenetic landscape of a cell varies drastically depending on lineage, transcriptional coactivators such as BETs would be expected to have different targets in cancers derived from different cells of origin, and this may influence the activity and mechanism of action of BET inhibitors. To test this hypothesis, we treated a panel of lung adenocarcinoma (LAC) cell lines with the BET inhibitor JQ1 and found that a subset is acutely susceptible to BET inhibition. In contrast to blood tumors, we show that LAC cells are inhibited by JQ1 through a mechanism independent of c-MYC down-regulation. Through gene expression profiling, we discovered that the oncogenic transcription factor FOSL1 and its targets are suppressed by JQ1 in a dose-dependant manner. Knockdown of BRD4 also decreased FOSL1 levels, and inhibition of FOSL1 phenocopied the effects of JQ1 treatment, suggesting that loss of this transcription factor may be partly responsible for the cytotoxic effects of BET inhibition in LAC cells, although ectopic expression of FOSL1 alone did not rescue the phenotype. Together, these findings suggest that BET inhibitors may be useful in solid tumors and that cell-lineage-specific differences in transcriptional targets of BETs may influence the activity of inhibitors of these proteins in different cancer types. PMID:23129625

  9. A Sensitive Sensor Cell Line for the Detection of Oxidative Stress Responses in Cultured Human Keratinocytes

    PubMed Central

    Hofmann, Ute; Priem, Melanie; Bartzsch, Christine; Winckler, Thomas; Feller, Karl-Heinz

    2014-01-01

    In the progress of allergic and irritant contact dermatitis, chemicals that cause the generation of reactive oxygen species trigger a heat shock response in keratinocytes. In this study, an optical sensor cell line based on cultured human keratinocytes (HaCaT cells) expressing green fluorescent protein (GFP) under the control of the stress-inducible HSP70B' promoter were constructed. Exposure of HaCaT sensor cells to 25 ?M cadmium, a model substance for oxidative stress induction, provoked a 1.7-fold increase in total glutathione and a ?300-fold induction of transcript level of the gene coding for heat shock protein HSP70B'. An extract of Arnica montana flowers resulted in a strong induction of the HSP70B' gene and a pronounced decrease of total glutathione in keratinocytes. The HSP70B' promoter-based sensor cells conveniently detected cadmium-induced stress using GFP fluorescence as read-out with a limit of detection of 6 ?M cadmium. In addition the sensor cells responded to exposure of cells to A. montana extract with induction of GFP fluorescence. Thus, the HaCaT sensor cells provide a means for the automated detection of the compromised redox status of keratinocytes as an early indicator of the development of human skin disorders and could be applied for the prediction of skin irritation in more complex in vitro 3D human skin models and in the development of micro-total analysis systems (?TAS) that may be utilized in dermatology, toxicology, pharmacology and drug screenings. PMID:24967604

  10. A sensitive sensor cell line for the detection of oxidative stress responses in cultured human keratinocytes.

    PubMed

    Hofmann, Ute; Priem, Melanie; Bartzsch, Christine; Winckler, Thomas; Feller, Karl-Heinz

    2014-01-01

    In the progress of allergic and irritant contact dermatitis, chemicals that cause the generation of reactive oxygen species trigger a heat shock response in keratinocytes. In this study, an optical sensor cell line based on cultured human keratinocytes (HaCaT cells) expressing green fluorescent protein (GFP) under the control of the stress-inducible HSP70B' promoter were constructed. Exposure of HaCaT sensor cells to 25 µM cadmium, a model substance for oxidative stress induction, provoked a 1.7-fold increase in total glutathione and a ~300-fold induction of transcript level of the gene coding for heat shock protein HSP70B'. An extract of Arnica montana flowers resulted in a strong induction of the HSP70B' gene and a pronounced decrease of total glutathione in keratinocytes. The HSP70B' promoter-based sensor cells conveniently detected cadmium-induced stress using GFP fluorescence as read-out with a limit of detection of 6 µM cadmium. In addition the sensor cells responded to exposure of cells to A. montana extract with induction of GFP fluorescence. Thus, the HaCaT sensor cells provide a means for the automated detection of the compromised redox status of keratinocytes as an early indicator of the development of human skin disorders and could be applied for the prediction of skin irritation in more complex in vitro 3D human skin models and in the development of micro-total analysis systems (µTAS) that may be utilized in dermatology, toxicology, pharmacology and drug screenings. PMID:24967604

  11. MultiNotch MS3 Enables Accurate, Sensitive, and Multiplexed Detection of Differential Expression across Cancer Cell Line Proteomes

    PubMed Central

    2015-01-01

    Multiplexed quantitation via isobaric chemical tags (e.g., tandem mass tags (TMT) and isobaric tags for relative and absolute quantitation (iTRAQ)) has the potential to revolutionize quantitative proteomics. However, until recently the utility of these tags was questionable due to reporter ion ratio distortion resulting from fragmentation of coisolated interfering species. These interfering signals can be negated through additional gas-phase manipulations (e.g., MS/MS/MS (MS3) and proton-transfer reactions (PTR)). These methods, however, have a significant sensitivity penalty. Using isolation waveforms with multiple frequency notches (i.e., synchronous precursor selection, SPS), we coisolated and cofragmented multiple MS2 fragment ions, thereby increasing the number of reporter ions in the MS3 spectrum 10-fold over the standard MS3 method (i.e., MultiNotch MS3). By increasing the reporter ion signals, this method improves the dynamic range of reporter ion quantitation, reduces reporter ion signal variance, and ultimately produces more high-quality quantitative measurements. To demonstrate utility, we analyzed biological triplicates of eight colon cancer cell lines using the MultiNotch MS3 method. Across all the replicates we quantified 8?378 proteins in union and 6?168 proteins in common. Taking into account that each of these quantified proteins contains eight distinct cell-line measurements, this data set encompasses 174?704 quantitative ratios each measured in triplicate across the biological replicates. Herein, we demonstrate that the MultiNotch MS3 method uniquely combines multiplexing capacity with quantitative sensitivity and accuracy, drastically increasing the informational value obtainable from proteomic experiments. PMID:24927332

  12. MultiNotch MS3 enables accurate, sensitive, and multiplexed detection of differential expression across cancer cell line proteomes.

    PubMed

    McAlister, Graeme C; Nusinow, David P; Jedrychowski, Mark P; Wühr, Martin; Huttlin, Edward L; Erickson, Brian K; Rad, Ramin; Haas, Wilhelm; Gygi, Steven P

    2014-07-15

    Multiplexed quantitation via isobaric chemical tags (e.g., tandem mass tags (TMT) and isobaric tags for relative and absolute quantitation (iTRAQ)) has the potential to revolutionize quantitative proteomics. However, until recently the utility of these tags was questionable due to reporter ion ratio distortion resulting from fragmentation of coisolated interfering species. These interfering signals can be negated through additional gas-phase manipulations (e.g., MS/MS/MS (MS3) and proton-transfer reactions (PTR)). These methods, however, have a significant sensitivity penalty. Using isolation waveforms with multiple frequency notches (i.e., synchronous precursor selection, SPS), we coisolated and cofragmented multiple MS2 fragment ions, thereby increasing the number of reporter ions in the MS3 spectrum 10-fold over the standard MS3 method (i.e., MultiNotch MS3). By increasing the reporter ion signals, this method improves the dynamic range of reporter ion quantitation, reduces reporter ion signal variance, and ultimately produces more high-quality quantitative measurements. To demonstrate utility, we analyzed biological triplicates of eight colon cancer cell lines using the MultiNotch MS3 method. Across all the replicates we quantified 8,378 proteins in union and 6,168 proteins in common. Taking into account that each of these quantified proteins contains eight distinct cell-line measurements, this data set encompasses 174,704 quantitative ratios each measured in triplicate across the biological replicates. Herein, we demonstrate that the MultiNotch MS3 method uniquely combines multiplexing capacity with quantitative sensitivity and accuracy, drastically increasing the informational value obtainable from proteomic experiments. PMID:24927332

  13. Reduced metabotropic glutamate receptor 5 in the Flinders Sensitive Line of rats, an animal model of depression: An autoradiographic study

    PubMed Central

    Kova?evi?, Tomislav; Skelin, Ivan; Minuzzi, Luciano; Rosa-Neto, Pedro; Diksic, Mirko

    2013-01-01

    Depression is a brain disorder and there is still only a partial understanding of its underlying pathophysiology. Antidepressant medications with a fast onset have not yet been developed. In addition to the monoaminergic systems, the brain glutaminergic system has been implicated in the etiology of depression. Animal studies of depression have gained importance because they permit a more invasive manipulation of the subjects than human studies. In the present study, we measured the densities of the brain regional metabotropic glutaminergic receptor 5 (mGluR5) in the Flinders Sensitive Line (FSL) rat model of depression and two groups of control rats, the Flinders Resistant Line (FRL) and Sprague Dawley (SPD), the parent strain for both the FSL and FRL rats. The FSL rats showed lower densities of mGluR5 in many brain regions compared to either the SPD and/or FRL rats. In addition, the densities in the FRL rats were larger than in the SPD rats, suggesting possible problems in using FRL rats as controls. The presented data suggest that mGluR5 is lower in animal models of depression which could be related to the cognitive and emotional dysfunctions in the FSL rat model of depression and could be relevant to a better understanding of depression in humans. PMID:22310150

  14. Sensitive simultaneous determination of three sulfanilamide artificial sweeters by capillary electrophoresis with on-line preconcentration and contactless conductivity detection.

    PubMed

    Yang, Lirong; Zhou, ShengJi; Xiao, Yuezhou; Tang, Yufeng; Xie, Tianyao

    2015-12-01

    A sensitive method followed by capillary electrophoresis with on-line perconcentration and capacitively coupled contactless conductivity detection (CE-C(4)D) was evaluated as a novel approach for the determination of three sulfanilamide artificial sweeteners (acesulfame-K, sodium saccharin and sodium cyclamate) in beverages. The on-line preconcentration technique, namely field-amplified sample injection, coupled with CE-C(4)D were successfully developed and optimized. The separation was achieved within 10min under the following conditions: an uncoated fused-silica capillary (45cm×50?m i.d., Leff=40cm), 20mmolL(-1) HAc as running buffer, separation voltage of -12kV, electrokinetic injection of -11kV×8s. The detection limits of acesulfame-K, sodium saccharin and sodium cyclamate were 4.4, 6.7 and 8.8?gL(-1), respectively. The relative standard deviation varied in the range of 3.0-5.0%. Results of this study show a great potential method for the fast screening of these artificial sweeteners contents in commercial beverages. PMID:26041216

  15. Specific down-regulation of XIAP with RNA interference enhances the sensitivity of canine tumor cell-lines to TRAIL and doxorubicin

    PubMed Central

    Spee, Bart; Jonkers, Martijn DB; Arends, Brigitte; Rutteman, Gerard R; Rothuizen, Jan; Penning, Louis C

    2006-01-01

    Background Apoptosis resistance occurs in various tumors. The anti-apoptotic XIAP protein is responsible for inhibiting apoptosis by reducing caspase-3 activation. Our aim is to evaluate whether RNA inhibition against XIAP increases the sensitivity of canine cell-lines for chemotherapeutics such as TRAIL and doxorubicin. We used small interfering RNA's (siRNA) directed against XIAP in three cell-lines derived from bile-duct epithelia (BDE), mammary carcinoma (P114), and osteosarcoma (D17). These cell-lines represent frequently occurring canine cancers and are highly comparable to their human counterparts. XIAP down-regulation was measured by means of quantitative PCR (Q-PCR) and Western blotting. The XIAP depleted cells were treated with a serial dilution of TRAIL or doxorubicin and compared to mock- and nonsense-treated controls. Viability was measured with a MTT assay. Results All XIAP siRNA treated cell-lines showed a mRNA down-regulation over 80 percent. Western blot analysis confirmed mRNA measurements. No compensatory effect of IAP family members was seen in XIAP depleted cells. The sensitivity of XIAP depleted cells for TRAIL was highest in BDE cells with an increase in the ED50 of 14-fold, compared to mock- and nonsense-treated controls. The sensitivity of P114 and D17 cell-lines increased six- and five-fold, respectively. Doxorubicin treatment in XIAP depleted cells increased sensitivity in BDE cells more than eight-fold, whereas P114 and D17 cell-lines showed an increase in sensitivity of three- and five-fold, respectively. Conclusion XIAP directed siRNA's have a strong sensitizing effect on TRAIL-reduced cell-viability and a smaller but significant effect with the DNA damaging drug doxorubicin. The increase in efficacy of chemotherapeutics with XIAP depletion provides the rationale for the use of XIAP siRNA's in insensitive canine tumors. PMID:16953886

  16. Studies of variation in inherent sensitivities to radiation, 5-fluorouracil and methotrexate in a series of human and murine tumor cell lines in vitro

    SciTech Connect

    Bellamy, A.S.; Whelan, R.D.H.; Hill, B.T.

    1984-01-01

    Clinical studies have reported reduced response rates to subsequent chemotherapy in certain tumors recurring after radiotherapy. These authors have investigated whether there are any correlations between radiation and drug responses in vitro using a range of murine and human tumor cell lines. They have compared sensitivities to X-irradiation and to 24 hr exposures to two widely used antitumor drugs, methotrexate and 5-fluorouracil. The 4 murine lines selected showed a range of radiation responses with Do values of 0.48-0.76 Gy. Methotrexate sensitivities also exhibited an 800-fold difference which appeared to correlate inversely with radiation response. Sensitivity to 5-FU was less variable in these cells and was unrelated to radiation response. In contrast, in the human lines tested, no correlations were observed between drug sensitivities and radiation response. The six lines tested showed a range of radiation responses with Do values of 0.66-1.59 Gy. Methotrexate sensitivities ranged only over a 150-fold concentration but, contrasting with data from the murine cells, no correlation with radiation response was apparent. Similarly, no correlations between response to 5-fluorouracil and radiation or 5-fluorouracil and methotrexate were noted, which is inconsistent with results using murine cells.

  17. Sensitivity of an Epstein-Barr Virus-Positive Tumor Line, Daudi, to Alpha Interferon Correlates with Expression of a GC-Rich Viral Transcript

    Microsoft Academic Search

    YANNING GAO; SHAO-AN XUE; BEVERLY E. GRIFFIN

    1999-01-01

    The exquisite sensitivity of the Burkitt's lymphoma (BL)-derived cell line Daudi to type I interferons has not previously been explained. Here we show that expression of an Epstein-Barr virus (EBV) transcript, designated D-HIT (Y. Gao et al., J. Virol. 71:84-94, 1997), correlates with the sensitivity of different Daudi cell isolates (or that of other EBV-carrying cells, where known) to alpha

  18. Conditionally immortalized brain capillary endothelial cell lines established from a transgenic mouse harboring temperature-sensitive simian virus 40 large T-antigen gene

    Microsoft Academic Search

    Ken-ichi Hosoya; Kazuhiro Tetsuka; Katsuhiko Nagase; Masatoshi Tomi; Shigeki Saeki; Sumio Ohtsuki; Tetsuya Terasaki; Nobuaki Yanai; Masuo Obinata; Akihiko Kikuchi; Hitomi Takanaga

    2000-01-01

    Five immortalized brain capillary endothelial cell lines (TM-BBB1-5) were established from 3 transgenic mice harboring temperature-sensitive\\u000a simian virus 40 large T-antigen gene (Tg mouse). These cell lines expressed active large T-antigen and grew well at 33°C with\\u000a a doubling time of about 20 to 30 hours. TM-BBBs also grew at 37°C but not at 39°C. However, growth was restored when

  19. Glial cell-line-derived neurotrophic factor expression in skin alters the mechanical sensitivity of cutaneous nociceptors.

    PubMed

    Albers, Kathryn M; Woodbury, C Jeffrey; Ritter, Amy M; Davis, Brian M; Koerber, H Richard

    2006-03-15

    Neurons classified as nociceptors are dependent on nerve growth factor (NGF) during embryonic development, but a large subpopulation lose this dependence during embryonic and postnatal times and become responsive to the transforming growth factor beta family member, glial cell line-derived growth factor (GDNF). To elucidate the functional properties of GDNF-dependent nociceptors and distinguish them from nociceptors that retain NGF dependence, the cellular and physiologic properties of sensory neurons of wild-type and transgenic mice that overexpress GDNF in the skin (GDNF-OE) were analyzed using a skin, nerve, dorsal root ganglion, and spinal cord preparation, immunolabeling, and reverse transcriptase-PCR assays. Although an increase in peripheral conduction velocity of C-fibers in GDNF-OE mice was measured, other electrophysiological properties, including resting membrane potential and somal action potentials, were unchanged. We also show that isolectin B4 (IB4)-positive neurons, many of which are responsive to GDNF, exhibited significantly lower thresholds to mechanical stimulation relative to wild-type neurons. However, no change was observed in heat thresholds for the same population of cells. The increase in mechanical sensitivity was found to correlate with significant increases in acid-sensing ion channels 2A and 2B and transient receptor potential channel A1, which are thought to contribute to detection of mechanical stimuli. These data indicate that enhanced expression of GDNF in the skin can change mechanical sensitivity of IB4-positive nociceptive afferents and that this may occur through enhanced expression of specific types of channel proteins. PMID:16540576

  20. Chronic treatment with the phosphodiesterase type 5 inhibitors sildenafil and tadalafil display anxiolytic effects in Flinders Sensitive Line rats.

    PubMed

    Liebenberg, Nico; Harvey, Brian H; Brand, Linda; Wegener, Gregers; Brink, Christiaan B

    2012-09-01

    There are conflicting results from behavioural studies regarding whether the activation or inhibition of the cGMP-nitric oxide (NO) pathway induces anxiolytic-like behaviour. Sildenafil, an inhibitor of cGMP-selective phosphodiesterase-5, increases anxiety acutely, but previous evidence suggests that its chronic administration may be anxiolytic, and could involve a cholinergic interaction. We used the Flinders Sensitive Line (FSL) rat, a genetic model of depression that presents with increased anxiety- and depression-like behaviour, to investigate the action of chronic treatment with the PDE5 inhibitors sildenafil or tadalafil, with/without atropine on social interaction behaviour, a correlate for anxiety. Fluoxetine was used as positive control, with validation performed using Flinders Resistant Line (FRL) rats. In order to relate behavioural changes to brain penetration, we determined the concentration of sildenafil in cortex and hippocampus of rats following the schedule above using LC-MS/MS. FSL rats displayed significantly reduced social interactive behaviour than FRL rats, while sildenafil, tadalafil, and fluoxetine significantly reversed these deficits. Atropine did not exert effects on social interactive behaviour, nor did it modulate the effects of sildenafil or tadalafil. Sildenafil was present in cortex and hippocampus regions in lower nanomolar concentrations after chronic treatment, in agreement with the binding to PDE5 required for pharmacological effects. This study emphasizes the complicated regulation of anxiety by the cGMP-NO system, and provides supporting evidence for an anxiolytic action after the chronic activation of this pathway. As far as we know this is also the first report to formally demonstrate that sildenafil effectively crosses the blood-brain barrier to elicit central effects. PMID:22359075

  1. Identification of expression signatures predictive of sensitivity to the Bcl-2 family member inhibitor ABT-263 in small cell lung carcinoma and leukemia/lymphoma cell lines.

    PubMed

    Tahir, Stephen K; Wass, John; Joseph, Mary K; Devanarayan, Viswanath; Hessler, Paul; Zhang, Haichao; Elmore, Steve W; Kroeger, Paul E; Tse, Christin; Rosenberg, Saul H; Anderson, Mark G

    2010-03-01

    ABT-263 inhibits the antiapoptotic proteins Bcl-2, Bcl-x(L), and Bcl-w and has single-agent efficacy in numerous small cell lung carcinoma (SCLC) and leukemia/lymphoma cell lines in vitro and in vivo. It is currently in clinical trials for treating patients with SCLC and various leukemia/lymphomas. Identification of predictive markers for response will benefit the clinical development of ABT-263. We identified the expression of Bcl-2 family genes that correlated best with sensitivity to ABT-263 in a panel of 36 SCLC and 31 leukemia/lymphoma cell lines. In cells sensitive to ABT-263, expression of Bcl-2 and Noxa is elevated, whereas expression of Mcl-1 is higher in resistant cells. We also examined global expression differences to identify gene signature sets that correlated with sensitivity to ABT-263 to generate optimal signature sets predictive of sensitivity to ABT-263. Independent cell lines were used to verify the predictive power of the gene sets and to refine the optimal gene signatures. When comparing normal lung tissue and SCLC primary tumors, the expression pattern of these genes in the tumor tissue is most similar to sensitive SCLC lines, whereas normal tissue is most similar to resistant SCLC lines. Most of the genes identified using global expression patterns are related to the apoptotic pathway; however, all but Bcl-rambo are distinct from the Bcl-2 family. This study leverages global expression data to identify key gene expression patterns for sensitivity to ABT-263 in SCLC and leukemia/lymphoma and may provide guidance in the selection of patients in future clinical trials. PMID:20179162

  2. Mechanisms of collateral sensitivity to fluorouracil of a cis-diamminedichloroplatinum(II)-resistant human non-small lung cancer cell line.

    PubMed Central

    Sugimoto, Y.; Ohe, Y.; Nishio, K.; Ohmori, T.; Morikage, T.; Fujiwara, Y.; Saijo, N.

    1992-01-01

    A cisplatin(CDDP)-resistant subline of a human lung cancer cell line, PC-7/CDDP, was 4.7-fold more resistant to CDDP than the parent line in a colony-forming assay. The sensitivity of this cell line to anthracyclines, vinca-alkaloid, etoposide, mitomycin C, and bleomycin was similar to that of the parental line, PC-7. However, PC-7/CDDP exhibited 4-fold higher sensitivity to fluorouracil (FUra). Possible mechanisms associated with the collateral sensitivity to FUra were studied in PC-7/CDDP cells. The sensitivity of both cell lines to FUra did not correlate with the effect of FUra on RNA. On the other hand, FUra induced a greater reduction in dTTP pools and more single strand breaks in PC-7/CDDP than in PC-7 cells. These results suggest that the pathway for de novo deoxyribonucleotide synthesis may be a target for FUra in PC-7/CDDP cells. However, inhibition of thymidylate synthase after FUra treatment did not correlate with the DNA-directed activity of FUra. Based on the above findings, the decreased salvage synthesis of dTTP was considered a possible mechanism of the greater reduction of dTTP pools in PC-7/CDDP cells. However, the activity of dThd kinase was the same in both cell lines. In the presence of physiological concentrations of exogenous dThd in the serum, uptake of dThd was less in PC-7/CDDP cells than that in PC-7 cells. Our data suggest that FUra-induced cytotoxicity in PC-7/CDDP cells is associated with the inhibition of dTTP synthesis and that the decreased uptake of dThd is a possible mechanism of the collateral sensitivity to FUra in PC-7/CDDP cells. PMID:1319727

  3. Gefitinib upregulates death receptor 5 expression to mediate rmhTRAIL-induced apoptosis in Gefitinib-sensitive NSCLC cell line

    PubMed Central

    Yan, Dong; Ge, Yang; Deng, Haiteng; Chen, Wenming; An, Guangyu

    2015-01-01

    Background Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) triggers apoptosis in tumor cells, but when used alone, it is not effective in the treatment of TRAIL-resistant tumors. Some studies have shown that gefitinib interacts with recombinant mutant human TRAIL (rmhTRAIL) to induce high levels of apoptosis in gefitinib-responsive bladder cancer cell lines; however, the molecular mechanisms underlying the anticancer effects are not fully understood. Several reports have shown that the death receptor 5 (DR5) plays an important role in sensitizing cancer cells to apoptosis induced by TRAIL. Therefore, we investigated the effects of the combination of drugs and the expression of the DR5 to analyze the growth of a gefitinib-responsive non-small cell lung cancer cell line PC9, which was treated with rmhTRAIL and gefitinib individually or in combination. Methods Human PC9 non-small cell lung cancer cells harboring an epidermal growth factor receptor mutation were used as a model for the identification of the therapeutic effects of gefitinib alone or in combination with rmhTRAIL, and cytotoxicity was assessed by MTT assays. Cell cycle and apoptosis were investigated using flow cytometry. Moreover, the effects of drugs on DR5, BAX, FLIP, and cleaved-caspase3 proteins expressions were analyzed using Western blot analyses. Finally, quantitative polymerase chain reaction analysis was carried out to assess whether rmhTRAIL and gefitinib modulate the expression of genes related to drug activity. Results Gefitinib and rmhTRAIL synergistically interact to inhibit cell proliferation, and apoptosis assessment demonstrated that associations of drug increased the apoptotic index. rmhTRAIL when used alone downregulated DR5 and upregulated BAX, FLIP, and cleaved-caspase3 proteins expressions. However, results obtained in Western blot analyses demonstrated that the combined treatment-induced cell apoptosis was achieved involving upregulated DR5, cleaved-caspase3, and BAX proteins expression and downregulated FLIP protein expression. Moreover, quantitative polymerase chain reaction showed that gefitinib modulated the expression of targets related to rmhTRAIL activity. Conclusion These results indicate that epidermal growth factor receptor inhibitors enhance rmhTRAIL antitumor activity in the gefitinib-responsive PC9 cell line, and upregulated DR5 expression plays a critical role in activating caspase-signaling apoptotic pathway. PMID:26170696

  4. Direct WIMP detection in directional experiments

    SciTech Connect

    Vergados, J. D. [Theoretical Physics Division, University of Ioannina, Ioannina, Gr 451 10 (Greece); Institute of Theoretical Physics, University of Tuebingen, Tuebingen (Germany); Faessler, Amand [Institute of Theoretical Physics, University of Tuebingen, Tuebingen (Germany)

    2007-03-01

    The recent WMAP data have confirmed that exotic dark matter together with the vacuum energy (cosmological constant) dominate in the flat Universe. Thus the direct dark matter search, consisting of detecting the recoiling nucleus, is central to particle physics and cosmology. Modern particle theories naturally provide viable cold dark matter candidates with masses in the GeV-TeV region. Supersymmetry provides the lightest supersymmetric particle (LSP), theories in extra dimensions the lightest Kaluza-Klein particle (LKP) etc. Unfortunately, however, in nuclear recoil measurements the interesting signal cannot be easily distinguished from the background. So, to minimize the background problems, one should exploit characteristic signatures of the reaction, such as the modulation effect and, in directional experiments, the correlation of the event rates with the sun's motion. In standard nondirectional experiments the modulation is small, less than two per cent and the location of the maximum depends on the unknown particle's mass. In directional experiments, in addition to the forward-backward asymmetry due to the sun's motion, one expects a larger modulation, which depends on the direction of observation. We study such effects both in the case of a light and a heavy target. Furthermore, since it now appears that the planned experiments may be only partly directional, in the sense that they can only detect the line of the recoiling nucleus, but not the sense of direction on it, we study which of the above mentioned interesting features, if any, will persist in these less ambitious experiments.

  5. WIMP diffusion in the solar system including solar depletion and its effect on Earth capture rates

    E-print Network

    Johan Lundberg; Joakim Edsjo

    2004-01-08

    Weakly Interacting Massive Particles (WIMPs) can be captured by the Earth, where they eventually sink to the core, annihilate and produce e.g. neutrinos that can be searched for with neutrino telescopes. The Earth is believed to capture WIMPs not dominantly from the Milky Way halo directly, but instead from a distribution of WIMPs that have diffused around in the solar system due to gravitational interactions with the planets in the solar system. Recently, doubts have been raised about the lifetime of these WIMP orbits due to solar capture. We here investigate this issue by detailed numerical simulations. Compared to earlier estimates, we find that the WIMP velocity distribution is significantly suppressed below about 70 km/s which results in a suppression of the capture rates mainly for heavier WIMPs (above ~100 GeV). At 1 TeV and above the reduction is almost a factor of 10. We apply these results to the case where the WIMP is a supersymmetric neutralino and find that, within the Minimal Supersymmetric Standard Model (MSSM), the annihilation rates, and thus the neutrino fluxes, are reduced even more than the capture rates. At high masses (above ~1 TeV), the suppression is almost two orders of magnitude. This suppression will make the detection of neutrinos from heavy WIMP annihilations in the Earth much harder compared to earlier estimates.

  6. Supersymmetry with radiatively-driven naturalness: implications for WIMP and axion searches

    E-print Network

    Kyu Jung Bae; Howard Baer; Vernon Barger; Michael R. Savoy; Hasan Serce

    2015-03-13

    By insisting on naturalness in both the electroweak and QCD sectors of the MSSM, the portrait for dark matter production is seriously modified from the usual WIMP miracle picture. In SUSY models with radiatively-driven naturalness (radiative natural SUSY or RNS) which include a DFSZ-like solution to the strong CP and SUSY mu problems, dark matter is expected to be an admixture of both axions and higgsino-like WIMPs. The WIMP/axion abundance calculation requires simultaneous solution of a set of coupled Boltzmann equations which describe quasi-stable axinos and saxions. In most of parameter space, axions make up the dominant contribution of dark matter although regions of WIMP dominance also occur. We show the allowed range of PQ scale f_a and compare to the values expected to be probed by the ADMX axion detector in the near future. We also show WIMP detection rates which are suppressed from usual expectations because now WIMPs comprise only a fraction of the total dark matter. Nonetheless, ton-scale noble liquid detectors should be able to probe the entirety of RNS parameter space. Indirect WIMP detection rates are less propitious since they are reduced by the square of the depleted WIMP abundance.

  7. Altered local field potential activity and serotonergic neurotransmission are further characteristics of the Flinders sensitive line rat model of depression.

    PubMed

    Voget, Mareike; Rummel, Julia; Avchalumov, Yosef; Sohr, Reinhard; Haumesser, Jens K; Rea, Ellis; Mathé, Aleksander A; Hadar, Ravit; van Riesen, Christoph; Winter, Christine

    2015-09-15

    A significant portion of patients suffering from major depression remains refractory to available antidepressant treatment strategies. This highlights the need for a better understanding of the underlying neuropathology in order to develop rationale-based treatments. Here we aimed to further characterize neurobiological abnormalities of the Flinders Sensitive Line (FSL) rat model of depression. Biochemically, in FSL rats we mainly found increased levels of serotonin in most cortical and subcortical brain regions when compared to controls. Using electrophysiological measurements, in FSL rats we found decreased alpha, beta and low gamma oscillatory activity in the medial prefrontal cortex and nucleus accumbens and decreased alpha and beta as well as increased low gamma oscillatory activity in the subthalamicus nucleus when compared to controls. In summary, we show distinct neurochemical properties in combination with particular oscillatory activity patterns for brain areas thought to be pathophysiologically relevant for depression. Our data contribute to the further understanding of neurobiological alterations in the FSL rat model of depression that could provide a basis for research into future therapeutic strategies. PMID:26025511

  8. New beam line for time-of-flight medium energy ion scattering with large area position sensitive detector

    SciTech Connect

    Linnarsson, M. K.; Hallen, A. [KTH Royal Institute of Technology, School of Information and Communication Technology, Integrated Circuits and Devices, P.O. Box E229, SE-16440 Kista-Stockhom (Sweden); Astroem, J.; Primetzhofer, D.; Legendre, S.; Possnert, G. [Uppsala University, Angstroem Laboratory, Department of Physics, Ion Physics, P.O. Box 534, SE-751 21 Uppsala (Sweden)

    2012-09-15

    A new beam line for medium energy ion mass scattering (MEIS) has been designed and set up at the Angstroem laboratory, Uppsala University, Sweden. This MEIS system is based on a time-of-flight (ToF) concept and the electronics for beam chopping relies on a 4 MHz function generator. Repetition rates can be varied between 1 MHz and 63 kHz and pulse widths below 1 ns are typically obtained by including beam bunching. A 6-axis goniometer is used at the target station. Scattering angle and energy of backscattered ions are extracted from a time-resolved and position-sensitive detector. Examples of the performance are given for three kinds of probing ions, {sup 1}H{sup +}, {sup 4}He{sup +}, and {sup 11}B{sup +}. Depth resolution is in the nanometer range and 1 and 2 nm thick Pt layers can easily be resolved. Mass resolution between nearby isotopes can be obtained as illustrated by Ga isotopes in GaAs. Taking advantage of the large size detector, a direct imaging (blocking pattern) of crystal channels are shown for hexagonal, 4H-SiC. The ToF-MEIS system described in this paper is intended for use in semiconductor and thin film areas. For example, depth profiling in the sub nanometer range for device development of contacts and dielectric interfaces. In addition to applied projects, fundamental studies of stopping cross sections in this medium energy range will also be conducted.

  9. New beam line for time-of-flight medium energy ion scattering with large area position sensitive detector.

    PubMed

    Linnarsson, M K; Hallén, A; Åström, J; Primetzhofer, D; Legendre, S; Possnert, G

    2012-09-01

    A new beam line for medium energy ion mass scattering (MEIS) has been designed and set up at the A?ngstro?m laboratory, Uppsala University, Sweden. This MEIS system is based on a time-of-flight (ToF) concept and the electronics for beam chopping relies on a 4 MHz function generator. Repetition rates can be varied between 1 MHz and 63 kHz and pulse widths below 1 ns are typically obtained by including beam bunching. A 6-axis goniometer is used at the target station. Scattering angle and energy of backscattered ions are extracted from a time-resolved and position-sensitive detector. Examples of the performance are given for three kinds of probing ions, (1)H(+), (4)He(+), and (11)B(+). Depth resolution is in the nanometer range and 1 and 2 nm thick Pt layers can easily be resolved. Mass resolution between nearby isotopes can be obtained as illustrated by Ga isotopes in GaAs. Taking advantage of the large size detector, a direct imaging (blocking pattern) of crystal channels are shown for hexagonal, 4H-SiC. The ToF-MEIS system described in this paper is intended for use in semiconductor and thin film areas. For example, depth profiling in the sub nanometer range for device development of contacts and dielectric interfaces. In addition to applied projects, fundamental studies of stopping cross sections in this medium energy range will also be conducted. PMID:23020419

  10. New beam line for time-of-flight medium energy ion scattering with large area position sensitive detector

    NASA Astrophysics Data System (ADS)

    Linnarsson, M. K.; Hallén, A.; Åström, J.; Primetzhofer, D.; Legendre, S.; Possnert, G.

    2012-09-01

    A new beam line for medium energy ion mass scattering (MEIS) has been designed and set up at the Ångström laboratory, Uppsala University, Sweden. This MEIS system is based on a time-of-flight (ToF) concept and the electronics for beam chopping relies on a 4 MHz function generator. Repetition rates can be varied between 1 MHz and 63 kHz and pulse widths below 1 ns are typically obtained by including beam bunching. A 6-axis goniometer is used at the target station. Scattering angle and energy of backscattered ions are extracted from a time-resolved and position-sensitive detector. Examples of the performance are given for three kinds of probing ions, 1H+, 4He+, and 11B+. Depth resolution is in the nanometer range and 1 and 2 nm thick Pt layers can easily be resolved. Mass resolution between nearby isotopes can be obtained as illustrated by Ga isotopes in GaAs. Taking advantage of the large size detector, a direct imaging (blocking pattern) of crystal channels are shown for hexagonal, 4H-SiC. The ToF-MEIS system described in this paper is intended for use in semiconductor and thin film areas. For example, depth profiling in the sub nanometer range for device development of contacts and dielectric interfaces. In addition to applied projects, fundamental studies of stopping cross sections in this medium energy range will also be conducted.

  11. Goodbye to WIMPs: A Scalable Interface for ALMA Operations

    NASA Astrophysics Data System (ADS)

    Schwarz, J.; Pietriga, E.; Schilling, M.; Grosbol, P.

    2011-07-01

    The operators of the ALMA Observatory will monitor and control more than 50 mm/submm radio antennas and their associated instrumentation from an operations site that is separated from this hardware by 35-50 km. Software that enables them to identify trouble spots and react to failures quickly in this environment will be critical to the safe and efficient functioning of the observatory. Early commissioning of ALMA uses a operator interface implemented with a standard window, icon, menu, pointing device (WIMP) toolkit. Early experience indicates that this paradigm will not scale well as the number of antennas approaches its full complement. Operators lose time as they manipulate overlapping or tabbed windows to drill-down to detailed diagnostic data, losing a feeling for "where they are" in the process. The WIMP model reaches its limits when there is so much information to present to users that they cannot focus on details while maintaining a view from above. To simplify the operators' tasks and let them concentrate on the real issues at hand rather than continually re-organizing their use of screen space, we are replacing the existing top-level interface with a multi-scale interface that takes advantage of semantic zooming, dynamic network visualization and other advanced filtering, navigation and visualization features. Following the first of several planned participatory design workshops, we have developed prototypes to show how users' needs can be met with the kinds of navigation that become possible when the restrictions of the WIMP model are lifted. Cycles of design and implementation coupled with active user feedback will characterize this project up through deployment.

  12. Differential Mitochondrial Electron Transport through the Cyanide-Sensitive and Cyanide-Insensitive Pathways in Isonuclear Lines of Cytoplasmic Male Sterile, Male Fertile, and Restored Petunia1

    PubMed Central

    Connett, Marie B.; Hanson, Maureen R.

    1990-01-01

    Three pairs of isonuclear lines of cytoplasmic male sterile (CMS) and fertile Petunia cells (Petunia hybrida [Hook] Vilm. and Petunia parodii L.S.M.) grown in suspension culture were examined for sensitivity to inhibitors of respiratory electron transport at time-points after transfer into fresh media. Cells from CMS lines differed from cells of fertile lines in their utilization of the cyanide-insensitive oxidase pathway. Under our culture regime, after approximately 3 days of culture cells from the CMS lines exhibited much lower cyanide-insensitive, salicylhydroxamic acid-sensitive respiration than cells from the fertile lines. This respiratory difference was shown to be specific to the mitochondrial alternative oxidase pathway by using other characteristic inhibitors of mitochondrial electron transport in experiments with isolated mitochondria. Immature anthers from CMS plants also showed lower alternative oxidase activity relative to anthers from male fertile plants, but no such difference was detected in leaf tissue, ovary or perianth tissue, or anthers collected just prior to anthesis. A cell line from a fertile plant carrying a nuclear fertility restorer gene and the CMS cytoplasm exhibited increased activity of the alternative pathway compared with the CMS lines. PMID:16667667

  13. Search for low-mass WIMPs with EDELWEISS-II heat-and-ionization detectors

    NASA Astrophysics Data System (ADS)

    Armengaud, E.; Augier, C.; Benoît, A.; Bergé, L.; Bergmann, T.; Blümer, J.; Broniatowski, A.; Brudanin, V.; Censier, B.; Chapellier, M.; Charlieux, F.; Couëdo, F.; Coulter, P.; Cox, G. A.; Domange, J.; Drillien, A. A.; Dumoulin, L.; Eitel, K.; Filosofov, D.; Fourches, N.; Gascon, J.; Gerbier, G.; Gironnet, J.; Gros, M.; Henry, S.; Heuermann, G.; Hervé, S.; Juillard, A.; Kleifges, M.; Kluck, H.; Kozlov, V.; Kraus, H.; Kudryavtsev, V. A.; Le Sueur, H.; Loaiza, P.; Marnieros, S.; Menshikov, A.; Navick, X.-F.; Nones, C.; Olivieri, E.; Pari, P.; Paul, B.; Robinson, M.; Rozov, S.; Sanglard, V.; Schmidt, B.; Siebenborn, B.; Tcherniakhovski, D.; Torrento-Coello, A. S.; Vagneron, L.; Walker, R. J.; Weber, M.; Yakushev, E.; Zhang, X.

    2012-09-01

    We report on a search for low-energy (E<20keV) WIMP-induced nuclear recoils using data collected in 2009-2010 by EDELWEISS from four germanium detectors equipped with thermal sensors and an electrode design (ID) which allows to efficiently reject several sources of background. The data indicate no evidence for an exponential distribution of low-energy nuclear recoils that could be attributed to WIMP elastic scattering after an exposure of 113kg·d. For weakly interacting massive particles (WIMPs) of mass 10 GeV, the observation of one event in the WIMP search region results in a 90% C.L. limit of 1.0×10-5pb on the spin-independent WIMP-nucleon scattering cross-section, which constrains the parameter space associated with the findings reported by the CoGeNT, DAMA and CRESST experiments.

  14. Search for pseudoscalar-mediated WIMPs in $t \\rightarrow c$ transitions with missing energy

    E-print Network

    Jia, Lian-Bao

    2015-01-01

    The recent astronomical observation confirms a spatially extended excess of $\\sim$1-3 GeV gamma rays from the region surrounding the Galactic Center, and it is suggested that the excess is due to dark matter, e.g. WIMPs (weakly interacting massive particles) of $35\\sim 51$ GeV annihilating to $b\\bar b$ pairs. Inevitably, models about WIMPs must undergo the tests of astronomical observation, accelerator and direct detection. In this work, considering the pseudoscalar-mediated WIMP model and assuming the mass of WIMP around 5-60 GeV, we suggest to test the model in the $t\\to c$ decays with missing energy. With the reasonable inputs, the branching ratio $\\mathcal {B}_{t\\rightarrow c \\bar{\\chi} \\chi}$ is derived of order $10^{-8} - 10^{-6}$, thus careful studies in the future on top-physics may help to gain a better understanding of WIMPs.

  15. Development of an in vitro skin sensitization test using human cell lines; human Cell Line Activation Test (h-CLAT) II. An inter-laboratory study of the h-CLAT

    Microsoft Academic Search

    H. Sakaguchi; T. Ashikaga; M. Miyazawa; Y. Yoshida; Y. Ito; K. Yoneyama; M. Hirota; H. Itagaki; H. Toyoda; H. Suzuki

    2006-01-01

    Recent regulatory changes have placed a major emphasis on in vitro safety testing and alternative models. In regard to skin sensitization tests, dendritic cells (DCs) derived from human peripheral blood have been considered in the development of new in vitro alternatives. Human cell lines have been also reported recently. In our previous study, we suggested that measuring CD86 and\\/or CD54

  16. Comparative In Vitro Sensitivities of Human Immune Cell Lines, Vaginal and Cervical Epithelial Cell Lines, and Primary Cells to Candidate Microbicides Nonoxynol 9, C31G, and Sodium Dodecyl Sulfate

    Microsoft Academic Search

    Fred C. Krebs; Shendra R. Miller; Bradley J. Catalone; Raina Fichorova; Deborah Anderson; Daniel Malamud; Mary K. Howett; Brian Wigdahl

    2002-01-01

    In experiments to assess the in vitro impact of the candidate microbicides nonoxynol 9 (N-9), C31G, and sodium dodecyl sulfate (SDS) on human immune and epithelial cell viability, cell lines and primary cell populations of lymphocytic and monocytic origin were generally shown to be equally sensitive to exposures ranging from 10 min to 48 h. However, U-937 cells were more

  17. Procedure of bidirectional selective outbreeding for production of two rat lines differing in sensitivity to the sedative\\/hypnotic effect of ?-hydroxybutyric acid

    Microsoft Academic Search

    Carla Lobina; Giancarlo Colombo; Giuliana Brunetti; Giacomo Diaz; Samuele Melis; Marialaura Pani; Salvatore Serra; Giovanni Vacca; Gian Luigi Gessa; Mauro A. M. Carai

    2001-01-01

    The exogenous administration of ?-hydroxybutyric acid (GHB), a constituent of the mammalian brain where it likely functions as a neurotransmitter or a neuromodulator, exerts a number of pharmacological effects, including sedation and hypnosis. The present paper describes a procedure for selective breeding of two rat lines which markedly differ in sensitivity to the sedative\\/hypnotic effect of GHB. Selective breeding originated

  18. The effects of 6-mercaptopurine nucleotide derivatives on the growth and survival of 6-mercaptopurine-sensitive and -resistant cell culture lines

    Microsoft Academic Search

    H P Johnston; P Hawley; S E White; I Gibson; D M Tidd

    1985-01-01

    6-Mercaptopurine (MP)-sensitive and -resistant cell culture lines were used to further characterize the apparent ability of MP nucleotide derivatives to overcome resistance to the parent drug. 6-Mercaptopurine-9-beta-D-ribofuranoside 5'-monophosphate [MPRP], bis(6-mercaptopurine-9-beta-D-ribofuranoside)-5', 5\\

  19. Next-generation sequencing of paired tyrosine kinase inhibitor-sensitive and -resistant EGFR mutant lung cancer cell lines identifies spectrum of DNA changes associated with drug resistance

    PubMed Central

    Jia, Peilin; Jin, Hailing; Meador, Catherine B.; Xia, Junfeng; Ohashi, Kadoaki; Liu, Lin; Pirazzoli, Valentina; Dahlman, Kimberly B.; Politi, Katerina; Michor, Franziska; Zhao, Zhongming; Pao, William

    2013-01-01

    Somatic mutations in kinase genes are associated with sensitivity of solid tumors to kinase inhibitors, but patients with metastatic cancer eventually develop disease progression. In EGFR mutant lung cancer, modeling of acquired resistance (AR) with drug-sensitive cell lines has identified clinically relevant EGFR tyrosine kinase inhibitor (TKI) resistance mechanisms such as the second-site mutation, EGFR T790M, amplification of the gene encoding an alternative kinase, MET, and epithelial–mesenchymal transition (EMT). The full spectrum of DNA changes associated with AR remains unknown. We used next-generation sequencing to characterize mutational changes associated with four populations of EGFR mutant drug-sensitive and five matched drug-resistant cell lines. Comparing resistant cells with parental counterparts, 18–91 coding SNVs/indels were predicted to be acquired and 1–27 were lost; few SNVs/indels were shared across resistant lines. Comparison of two related parental lines revealed no unique coding SNVs/indels, suggesting that changes in the resistant lines were due to drug selection. Surprisingly, we observed more CNV changes across all resistant lines, and the line with EMT displayed significantly higher levels of CNV changes than the other lines with AR. These results demonstrate a framework for studying the evolution of AR and provide the first genome-wide spectrum of mutations associated with the development of cellular drug resistance in an oncogene-addicted cancer. Collectively, the data suggest that CNV changes may play a larger role than previously appreciated in the acquisition of drug resistance and highlight that resistance may be heterogeneous in the context of different tumor cell backgrounds. PMID:23733853

  20. A Search for WIMP Dark Matter using an Optimized Chi-square Technique on the Final Data from the Cryogenic Dark Matter Search Experiment (CDMS II)

    NASA Astrophysics Data System (ADS)

    Manungu Kiveni, Joseph

    During the last two decades, cosmology has become a precision observational science thanks (in part) to the incredible number of experiments performed to better understand the composition of the universe. The large amount of data accumulated strongly indicates that the bulk of the universe's matter is in the form of non-baryonic matter that does not interact electromagnetically. Combined evidence from the dynamics of galaxies and galaxy clusters confirms that most of the mass in the universe is not composed of any known form of matter. Measurements of the cosmic microwave background, big bang nucleosynthesis and many other experiments indicate that ˜80% of the matter in the universe is dark, non-relativistic and cold. The dark matter resides in the halos surrounding galaxies, galaxy clusters and other large-scale structures. Weakly Interacting Massive Particles (WIMPs) are well motivated class of dark matter candidates that arise naturally in supersymmetric extensions to the Standard Model of particles physics, and can be produced as non-relativistic thermal relics in the early universe with about the right density to account for the missing mass. The Cryogenic Dark Matter Search (CDMS) experiment seeks to directly detect the keV-scale energy deposited by WIMPs in the galactic halo when they scatter from nuclei in the crystalline detectors made of germanium and silicon. These detectors, called Z-sensitive Ionization and Phonon detectors (ZIPs) are operated at ˜ 45 mK and simultaneously measure the ionization and the (athermal) phonons produced by particle interactions. The ratio of ionization and phonon energies allows discrimination of a low rate of nuclear recoils (expected for WIMPs) from an overwhelming rate of electron recoils (expected for most backgrounds). Phonon-pulse shape and timing enables further suppression of lower-rate interactions at the detector surfaces. This dissertation describes the results of a WIMP search using CDMS II data sets accumulated at the Soudan Underground Laboratory in Minnesota. Results from the original analysis of these data were published in 2009; two events were observed in the signal region with an expected leakage of 0.9 events. Further investigation revealed an issue with the ionization-pulse reconstruction algorithm leading to a software upgrade and a subsequent reanalysis of the data. As part of the reanalysis, I performed an advanced discrimination technique to better distinguish (potential) signal events from backgrounds using a 5-dimensional chi-square method. This data-analysis technique combines the event information recorded for each WIMP-search event to derive a background-discrimination parameter capable of reducing the expected background to less than one event, while maintaining high efficiency for signal events. Furthermore, optimizing the cut positions of this 5-dimensional chi-square parameter for the 14 viable germanium detectors yields an improved expected sensitivity to WIMP interactions relative to previous CDMS results. This dissertation describes my improved (and optimized) discrimination technique and the results obtained from a blind application to the reanalyzed CDMS II WIMP-search data. This analysis achieved the best expected sensitivity of the three techniques developed for the reanalysis and so was chosen as the primary timing analysis whose limit will be quoted in a on-going publication paper which is currently in preparation. For this analysis, a total raw exposure of 612.17 kg-days are analyzed for this work. No candidate events was observed, and a corresponding upper limit on the WIMP-nucleon scattering cross section as a function of WIMP mass is defined. These data set a 90% upper limit on spin-independent WIMP-nucleon elastic-scattering cross section of 3.19 × 10-44 cm2 for a WIMP mass of 60 GeV c 2. Combining this result with all previous CDMS II data gives an upper limit of 1.96 ×10-44 cm2 for a WIMP of mass 60 GeV/c2 (a factor of 2 better than the original analysis). At the moment this analysis is being written, the WIMP-search results ob

  1. Short-term selection for acute ethanol tolerance and sensitization from an F 2 population derived from the high and low alcohol-sensitive selectively bred rat lines

    Microsoft Academic Search

    Richard A. Radcliffe; Pequita Bludeau; Xin-Sheng Deng; V. Gene Erwin; Richard A. Deitrich

    2007-01-01

    Previous studies have identified quantitative trait loci (QTL) in the inbred high and low alcohol-sensitive rat (IHAS1 and ILAS1) strains. The original development of the strains involved selection for ethanol sensitivity based on duration of the loss of the righting reflex (LORR) after a standard dose of ethanol. This paper confirms some of these QTL using a short-term selection procedure

  2. WIMP Dark Matter and the QCD Equation of State

    E-print Network

    Mark Hindmarsh; Owe Philipsen

    2005-01-25

    Weakly Interacting Massive Particles (WIMPs) of mass m freeze out at a temperature T_f ~ m/25, i.e. in the range 400 MeV -- 40 GeV for a particle in the typical mass range 10 -- 1000 GeV. The WIMP relic density, which depends on the effective number of relativistic degrees of freedom at T_f, may be measured to better than 1% by Planck, warranting comparable theoretical precision. Recent theoretical and experimental advances in the understanding of high temperature QCD show that the quark gluon plasma departs significantly from ideal behaviour up to temperatures of several GeV, necessitating an improvement of the cosmological equation of state over those currently used. We discuss how this increases the relic density by approximately 1.5 -- 3.5% in benchmark mSUGRA models, with an uncertainly in the QCD corrections of 0.5 -- 1 %. We point out what further work is required to achieve a theoretical accuracy comparable with the expected observational precision, and speculate that the effective number of degrees of freedom at T_f may become measurable in the foreseeable future.

  3. Mitotic Slippage and Expression of Survivin Are Linked to Differential Sensitivity of Human Cancer Cell-Lines to the Kinesin-5 Inhibitor Monastrol

    PubMed Central

    Hershfinkel, Michal; Gheber, Larisa

    2015-01-01

    The mitotic Kinesin-5 motor proteins crosslink and slide apart antiparallel spindle microtubules, thus performing essential functions in mitotic spindle dynamics. Specific inhibition of their function by monastrol-like small molecules has been examined in clinical trials as anticancer treatment, with only partial success. Thus, strategies that improve the efficiency of monastrol-like anticancer drugs are required. In the current study, we examined the link between sensitivity to monastrol and occurrence of mitotic slippage in several human cell-lines. We found that the rank of sensitivity to monastrol, from most sensitive to least sensitive, is: AGS>HepG2>Lovo>Du145?HT29. We show correlation between the sensitivity of a particular cell-line to monastrol and the tendency of the same cell-line to undergo mitotic slippage. We also found that in the monastrol resistant HT29 cells, prolonged monastrol treatments increase mRNA and protein levels of the chromosomal passenger protein survivin. In contrast, survivin levels are not increased by this treatment in the monastrol-sensitive AGS cells. We further show that over-expression of survivin in the monastrol-sensitive AGS cells reduces mitotic slippage and increases resistance to monastrol. Finally, we show that during short exposure to monastrol, Si RNA silencing of survivin expression reduces cell viability in both AGS and HT29 cells. Our data suggest that the efficiency of anti-cancer treatment with specific kinesin-5 inhibitors may be improved by modulation of expression levels of survivin. PMID:26035434

  4. Prediction of doxorubicin sensitivity in breast tumors based on gene expression profiles of drug-resistant cell lines correlates with patient survival.

    PubMed

    Györffy, Balázs; Serra, Violeta; Jürchott, Karsten; Abdul-Ghani, Rula; Garber, Mitch; Stein, Ulrike; Petersen, Iver; Lage, Hermann; Dietel, Manfred; Schäfer, Reinhold

    2005-11-17

    Up to date clinical tests for predicting cancer chemotherapy response are not available and individual markers have shown little predictive value. We hypothesized that gene expression patterns attributable to chemotherapy-resistant cells can predict response and cancer prognosis. We contrasted the expression profiles of 13 different human tumor cell lines of gastric (EPG85-257), pancreatic (EPP85-181), colon (HT29) and breast (MCF7 and MDA-MB-231) origin and their counterparts resistant to the topoisomerase inhibitors daunorubicin, doxorubicin or mitoxantrone. We interrogated cDNA arrays with 43 000 cDNA clones ( approximately 30 000 unique genes) to study the expression pattern of these cell lines. We divided gene expression profiles into two sets: we compared the expression patterns of the daunorubicin/doxorubicin-resistant cell lines and the mitoxantrone-resistant cell lines independently to the parental cell lines. For identifying predictive genes, the Prediction Analysis for Mircorarrays algorithm was used. The analysis revealed 79 genes best correlated with doxorubicin resistance and 70 genes with mitoxantrone resistance. In an independent classification experiment, we applied our model of resistance for predicting the sensitivity of 44 previously characterized breast cancer samples. The patient group characterized by the gene expression profile similar to those of doxorubicin-sensitive cell lines exhibited longer survival (49.7+/-26.1 months, n=21, P=0.034) than the resistant group (32.9+/-18.7 months, n=23). The application of gene expression signatures derived from doxorubicin-resistant and -sensitive cell lines allowed to predict effectively clinical survival after doxorubicin monotherapy. Our approach demonstrates the significance of in vitro experiments in the development of new strategies for cancer response prediction. PMID:16044152

  5. Evaluation of the skin sensitization potential of chemicals using expression of co-stimulatory molecules, CD54 and CD86, on the naive THP-1 cell line.

    PubMed

    Yoshida, Y; Sakaguchi, H; Ito, Y; Okuda, M; Suzuki, H

    2003-04-01

    It has been known that dendritic cells (DCs) including Langerhans cells (LCs) play a critical role in the skin sensitization process. Many attempts have been made to develop in vitro sensitization tests that employ DCs derived from peripheral blood mononuclear cells (PBMC-DC) or CD34+ hematopoietic progenitor cells (CD34+ HPC) purified from cord blood or bone marrow. However, the use of the DCs in in vitro methods has been difficult due to the nature of these cells such as low levels in the source and/or donor-to-donor variability. In our studies, we employed the human monocytic leukemia cell line, THP-1, in order to avoid some of these difficulties. At the start, we examined whether treatment of the cells with various cytokines could produce DCs from THP-1. Treatment of THP-1 cells with cytokines such as GM-CSF, IL-4, TNF-alpha, and/or PMA did induce some phenotypic changes in THP-1 cells that were characteristic of DCs. Subsequently, responses to a known sensitizer, dinitrochlorobenzene (DNCB), and a non-sensitizer, dimethyl sulfoxide (DMSO) or sodium lauryl sulfate (SLS), on the expression of co-stimulatory molecules, CD54 and CD86, were examined between the naive cells and the cytokine-treated cells. Interestingly, the naive THP-1 cells responded only to DNCB and the response to the sensitizer was more distinct than cytokine-treated THP-1 cells. Similar phenomena were also observed in the human myeloid leukemia cell line, KG-1. Furthermore, with treatment of DNCB, naive THP-1 cells showed augmented expression of HLA, CD80 and secretion of IL-1 beta. The response of THP-1 cells to a sensitizer was similar to that of LCs/DCs. Upon demonstrating the differentiation of monocyte cells in our system, we then evaluated a series of chemicals, including known sensitizers and non-sensitizers, for their potential to augment CD54 and CD86 expression on naive THP-1 cells. Indeed, known sensitizers such as PPD and 2-MBT significantly augmented CD54 and CD86 expression in a dose-dependent manner while non-sensitizers, such as SLS and methyl salicylate (MS), did not. To note, the metal allergens such as (NH(4))(2)[PtCl(4)], NiSO(4) and CoSO(4) augmented significantly only CD54 expression. Taking advantage of a cultured cell line, measurement of the co-stimulatory molecules, CD54 and CD86, on naive THP-1 cells following chemical exposure shows promise for the development of a simple, short-term in vitro sensitization test. PMID:12650676

  6. Cytoskeletal Regulation Dominates Temperature-Sensitive Proteomic Changes of Hibernation in Forebrain of 13-Lined Ground Squirrels

    PubMed Central

    Hindle, Allyson G.; Martin, Sandra L.

    2013-01-01

    13-lined ground squirrels, Ictidomys tridecemlineatus, are obligate hibernators that transition annually between summer homeothermy and winter heterothermy – wherein they exploit episodic torpor bouts. Despite cerebral ischemia during torpor and rapid reperfusion during arousal, hibernator brains resist damage and the animals emerge neurologically intact each spring. We hypothesized that protein changes in the brain underlie winter neuroprotection. To identify candidate proteins, we applied a sensitive 2D gel electrophoresis method to quantify protein differences among forebrain extracts prepared from ground squirrels in two summer, four winter and fall transition states. Proteins that differed among groups were identified using LC-MS/MS. Only 84 protein spots varied significantly among the defined states of hibernation. Protein changes in the forebrain proteome fell largely into two reciprocal patterns with a strong body temperature dependence. The importance of body temperature was tested in animals from the fall; these fall animals use torpor sporadically with body temperatures mirroring ambient temperatures between 4 and 21°C as they navigate the transition between summer homeothermy and winter heterothermy. Unlike cold-torpid fall ground squirrels, warm-torpid individuals strongly resembled the homeotherms, indicating that the changes observed in torpid hibernators are defined by body temperature, not torpor per se. Metabolic enzymes were largely unchanged despite varied metabolic activity across annual and torpor-arousal cycles. Instead, the majority of the observed changes were cytoskeletal proteins and their regulators. While cytoskeletal structural proteins tended to differ seasonally, i.e., between summer homeothermy and winter heterothermy, their regulatory proteins were more strongly affected by body temperature. Changes in the abundance of various isoforms of the microtubule assembly and disassembly regulatory proteins dihydropyrimidinase-related protein and stathmin suggested mechanisms for rapid cytoskeletal reorganization on return to euthermy during torpor-arousal cycles. PMID:23951209

  7. Modulation of reconstituted ATP-sensitive K+ channels by GTP-binding proteins in a mammalian cell line

    PubMed Central

    Sánchez, Jorge A; Gonoi, Tohru; Inagaki, Nobuya; Katada, Toshiaki; Seino, Susumu

    1998-01-01

    The action of GTP-binding proteins on ATP-sensitive potassium (KATP) channels was investigated. KATP channels were expressed in a mammalian cell line (COS-1 cells) by cotransfecting vectors carrying the sulphonylurea receptor (SUR1) and BIR (Kir6.2), a member of the inward rectifier K+ channel family. G proteins were also tested on KATP channels composed of an isoform of SUR1, SUR2A, in combination with Kir6.2.The ? and ?? subunits of the GTP binding protein Gi were tested separately in inside-out patches under continuous recording. G?-i1 increases the activity of SUR1-Kir6.2 and SUR2A-Kir6.2 channels by 200 and by 30 %, respectively.G?-i2 does not increase the activity of SUR1-Kir6.2 channels, but increases the activity of SUR2A-Kir6.2 channels by 30 %.Control experiments showed that GTP?S, a specific activator of G proteins, and heat- inactivated G?-i1 do not increase the single channel activity.No effects of the other subunits (??) from either Gi1 or Gi2 on the single channel activity were observed.The protein kinase C inhibitors H7 and an inhibitory peptide (FARKGALRQKNV) had no effect on the modulatory action of G?-i1 on SUR1-Kir6.2 channels.We conclude that both types of reconstituted KATP channels are modulated by G proteins. PMID:9518695

  8. Osmotic Stress Regulates Mineralocorticoid Receptor Expression in a Novel Aldosterone-Sensitive Cortical Collecting Duct Cell Line

    E-print Network

    Paris-Sud XI, Université de

    EBP, Renal Cell Line, Targeted Oncogenesis, Tis11b Grant Support: This work was supported by grants from established by targeted oncogenesis a novel immortalized cortical collecting duct (CCD) cell line and examined

  9. Dark matter in the Solar System. III. The distribution function of WIMPs at the Earth from gravitational capture

    SciTech Connect

    Peter, Annika H. G. [Department of Physics, Princeton University, Princeton, New Jersey 08544 (United States) and California Institute of Technology, Mail Code 105-24, Pasadena, California 91125 (United States)

    2009-05-15

    In this last paper in a series of three on weakly interacting massive particle (WIMP) dark matter in the Solar System, we focus on WIMPs bound to the system by gravitationally scattering off of planets. We present simulations of WIMP orbits in a toy solar system consisting of only the Sun and Jupiter. As previous work suggested, we find that the density of gravitationally captured WIMPs at the Earth is small and largely insensitive to the details of elastic scattering in the Sun. However, we find that the density of gravitationally captured WIMPs may be affected by external Galactic gravitational fields. If such fields are unimportant, the density of gravitationally captured WIMPs at the Earth should be similar to the maximum density of WIMPs captured in the Solar System by elastic scattering in the Sun. Using standard assumptions about the halo WIMP distribution function, we find that the gravitationally captured WIMPs contribute negligibly to direct detection event rates. While these WIMPs do dominate the annihilation rate of WIMPs in the Earth, the resulting event rate in neutrino telescopes is too low to be observed in next-generation neutrino telescopes.

  10. Dark matter in the solar system III: The distribution function of WIMPs at the Earth from gravitational capture

    E-print Network

    Annika H. G. Peter

    2009-02-09

    In this last paper in a series of three on weakly interacting massive particle (WIMP) dark matter in the solar system, we focus on WIMPs bound to the system by gravitationally scattering off of planets. We present simulations of WIMP orbits in a toy solar system consisting of only the Sun and Jupiter. As previous work suggested, we find that the density of gravitationally captured WIMPs at the Earth is small and largely insensitive to the details of elastic scattering in the Sun. However, we find that the density of gravitationally captured WIMPs may be affected by external Galactic gravitational fields. If such fields are unimportant, the density of gravitationally captured WIMPs at the Earth should be similar to the maximum density of WIMPs captured in the solar system by elastic scattering in the Sun. Using standard assumptions about the halo WIMP distribution function, we find that the gravitationally captured WIMPs contribute negligibly to direct detection event rates. While these WIMPs do dominate the annihilation rate of WIMPs in the Earth, the resulting event rate in neutrino telescopes is too low to be observed in next-generation neutrino telescopes.

  11. Comparative in vitro sensitivities of human immune cell lines, vaginal and cervical epithelial cell lines, and primary cells to candidate microbicides nonoxynol 9, C31G, and sodium dodecyl sulfate.

    PubMed

    Krebs, Fred C; Miller, Shendra R; Catalone, Bradley J; Fichorova, Raina; Anderson, Deborah; Malamud, Daniel; Howett, Mary K; Wigdahl, Brian

    2002-07-01

    In experiments to assess the in vitro impact of the candidate microbicides nonoxynol 9 (N-9), C31G, and sodium dodecyl sulfate (SDS) on human immune and epithelial cell viability, cell lines and primary cell populations of lymphocytic and monocytic origin were generally shown to be equally sensitive to exposures ranging from 10 min to 48 h. However, U-937 cells were more sensitive to N-9 and C31G after 48 h than were primary monocyte-derived macrophages. Cytokine activation of monocytes and lymphocytes had no effect on cell viability following exposure to these microbicidal compounds. Primary and passaged vaginal epithelial cultures and cell lines differed in sensitivity to N-9 and C31G but not SDS. These studies provide a foundation for in vitro experiments in which cell lines of human immune and epithelial origin can be used as suitable surrogates for primary cells to further investigate the effects of microbicides on cell metabolism, membrane composition, and integrity and the effects of cell type, proliferation, and differentiation on microbicide sensitivity. PMID:12069993

  12. Ecdysteroids Sensitize MDR and Non-MDR Cancer Cell Lines to Doxorubicin, Paclitaxel, and Vincristine but Tend to Protect Them from Cisplatin

    PubMed Central

    Sipos, Péter; Dér, Katalin; Csábi, József; Miklos, Walter; Berger, Walter; Zalatnai, Attila; Amaral, Leonard; Molnár, Joseph; Szabó-Révész, Piroska

    2015-01-01

    Ecdysteroids, analogs of the insect molting hormone, are known for their various mild, nonhormonal bioactivities in mammals. Previously, we reported that less-polar ecdysteroids can modulate the doxorubicin resistance of a multidrug resistant (MDR) mouse lymphoma cell line expressing the human ABCB1 transporter. Here, we describe the ability of 20-hydroxyecdysone (1) and its mono- (2) and diacetonide (3) derivatives to sensitize various MDR and non-MDR cancer cell lines towards doxorubicin, paclitaxel, vincristine, or cisplatin. Drug IC50 values with or without ecdysteroid were determined by MTT assay. Compound 3 significantly sensitized all cell lines to each chemotherapeutic except for cisplatin, whose activity was decreased. In order to overcome solubility and stability issues for the future in vivo administration of compound 3, liposomal formulations were developed. By means of their combination index values obtained via checkerboard microplate method, a formulation showed superior activity to that of compound 3 alone. Because ecdysteroids act also on non-ABCB1 expressing (sensitive) cell lines, our results demonstrate that they do not or not exclusively exert their adjuvant anticancer activity as ABCB1 inhibitors, but other mechanisms must be involved, and they opened the way towards their in vivo bioactivity testing against various cancer xenografts.

  13. A New WIMP Population in the Solar System and New Signals for Dark-Matter Detectors

    E-print Network

    Thibault Damour; Lawrence M. Krauss

    1998-12-29

    We describe in detail how perturbations due to the planets can cause a sub-population of WIMPs captured by scattering in surface layers of the Sun to evolve to have orbits which no longer intersect the Sun. We argue that such WIMPs, if their orbit has a semi-major axis less than 1/2 of Jupiter's, can persist in the solar system for cosmological timescales. This leads to a new, previously unanticipated WIMP population intersecting the Earth's orbit. The WIMP-nucleon cross sections required for this population to be significant are precisely those in the range predicted for SUSY dark matter, lying near the present limits obtained by direct underground dark matter searches using cyrogenic detectors. Thus, if a WIMP signal is observed in the next generation of detectors, a potentially measurable signal due to this new population must exist. This signal, lying in the keV range for Germanium detectors, would be complementary to that of galactic halo WIMPs. A comparison of event rates, anisotropies, and annual modulations would not only yield additional confirmation that any claimed signal is indeed WIMP-based, but would also allow one to gain information on the nature of the underlying dark matter model.

  14. Higher Levels of c-Met Expression and Phosphorylation Identify Cell Lines With Increased Sensitivity to AMG-458, a Novel Selective c-Met Inhibitor With Radiosensitizing Effects

    SciTech Connect

    Li Bo; Torossian, Artour [Department of Radiation Oncology, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, Tennessee (United States)] [Department of Radiation Oncology, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, Tennessee (United States); Sun, Yunguang [Department of Radiation Oncology, Kimmel Cancer Center, Jefferson Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania (United States)] [Department of Radiation Oncology, Kimmel Cancer Center, Jefferson Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania (United States); Du, Ruihong [Department of Radiation Oncology, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, Tennessee (United States)] [Department of Radiation Oncology, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, Tennessee (United States); Dicker, Adam P. [Department of Radiation Oncology, Kimmel Cancer Center, Jefferson Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania (United States)] [Department of Radiation Oncology, Kimmel Cancer Center, Jefferson Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania (United States); Lu Bo, E-mail: bo.lu@jefferson.edu [Department of Radiation Oncology, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, Tennessee (United States); Department of Radiation Oncology, Kimmel Cancer Center, Jefferson Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania (United States)

    2012-11-15

    Purpose: c-Met is overexpressed in some non-small cell lung cancer (NSCLC) cell lines and tissues. Cell lines with higher levels of c-Met expression and phosphorylation depend on this receptor for survival. We studied the effects of AMG-458 on 2 NSCLC cell lines. Methods and Materials: 3-(4,5-Dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl) -2H-tetrazolium assays assessed the sensitivities of the cells to AMG-458. Clonogenic survival assays illustrated the radiosensitizing effects of AMG-458. Western blot for cleaved caspase 3 measured apoptosis. Immunoblotting for c-Met, phospho-Met (p-Met), Akt/p-Akt, and Erk/p-Erk was performed to observe downstream signaling. Results: AMG-458 enhanced radiosensitivity in H441 but not in A549. H441 showed constitutive phosphorylation of c-Met. A549 expressed low levels of c-Met, which were phosphorylated only in the presence of exogenous hepatocyte growth factor. The combination of radiation therapy and AMG-458 treatment was found to synergistically increase apoptosis in the H441 cell line but not in A549. Radiation therapy, AMG-458, and combination treatment were found to reduce p-Akt and p-Erk levels in H441 but not in A549. H441 became less sensitive to AMG-458 after small interfering RNA knockdown of c-Met; there was no change in A549. After overexpression of c-Met, A549 became more sensitive, while H441 became less sensitive to AMG-458. Conclusions: AMG-458 was more effective in cells that expressed higher levels of c-Met/p-Met, suggesting that higher levels of c-Met and p-Met in NSCLC tissue may classify a subset of tumors that are more sensitive to molecular therapies against this receptor.

  15. Gene expression changes induced by skin sensitizers in the KeratinoSens™ cell line: Discriminating Nrf2-dependent and Nrf2-independent events.

    PubMed

    Emter, Roger; van der Veen, Jochem W; Adamson, Greg; Ezendam, Janine; van Loveren, Henk; Natsch, Andreas

    2013-12-01

    The KeratinoSens™ assay is an in vitro screen for the skin sensitization potential of chemicals. It is based on a luciferase reporter gene under the control of the antioxidant response element of the aldoketoreductase gene AKR1C2. The transferability, reproducibility, and predictivity of the KeratinoSens™ assay have been investigated in detail and it is currently under assessment at the European Center for Validation of Alternatives to animal testing (ECVAM). Here we investigate the sensitizer-induced gene expression in the KeratinoSens™ cell line at the mRNA level and discriminate Nrf2-dependent and Nrf2-independent events by using siRNA to better characterize this test system at the molecular level. The results show that (i) the sensitizer-induced luciferase signal in KeratinoSens™ cells is completely dependent on Nrf2. The same holds true for the luciferase induction observed for the false positive chemical Tween80, indicating that the false positive result is not due to recruitment of an alternative transcription factor. (ii) Luciferase induction parallels the induction of endogenous Nrf2-dependent genes, indicating that the luciferase signal is representative for the sensitizer-induced Nrf2-response. (iii) The induction by sensitizers of additional genetic markers related to heat shock proteins and cellular stress could be reproduced in the KeratinoSens™ cell line and they were shown to be Nrf2-independent. These results confirm that the KeratinoSens™ cell line is a rapid and adequate screening tool to assess the sensitizer-induced Nrf2-response in keratinocytes. PMID:24055896

  16. Activity of a trinuclear platinum complex in human ovarian cancer cell lines sensitive and resistant to cisplatin: cytotoxicity and induction and gene-specific repair of DNA lesions

    PubMed Central

    Colella, G; Pennati, M; Bearzatto, A; Leone, R; Colangelo, D; Manzotti, C; Daidone, M G; Zaffaroni, N

    2001-01-01

    A collateral sensitivity or a very modest cross-resistance to BBR 3464 was found in 2 ovarian cancer cell lines with experimentally induced resistance to cisplatin. Loss of mismatch repair proteins (hMLH1, hPMS2) or overexpression of nucleotide excision repair proteins (ERCC1) was not detrimental for the cellular sensitivity to BBR 3464. Moreover, interesting differences in the kinetics of formation and removal of DNA lesions at the single-gene (N- ras) level were observed between BBR 3464 and CDDP. © 2001 Cancer Research Campaign www.bjcancer.com PMID:11355952

  17. Gravitationally Induced Particle Production and its Impact on the WIMP Abundance

    E-print Network

    I. Baranov; J. A. S. Lima

    2015-05-11

    A large set of independent astronomical observations have provided a strong evidence for nonbaryonic dark matter in the Universe. One of the most investigated candidates is an unknown long-lived Weakly Interacting Massive Particle (WIMP) which was in thermal equilibrium with the primeval plasma. Here we investigate the WIMP abundance based on the relativistic kinetic treatment for gravitationally induced particle production recently proposed in the literature (Lima \\& Baranov, Phys. Rev. D {\\bf 90}, 043515, 2014). The new evolution equation is deduced and solved both numerically and also through a semi-analytical approach. The predictions of the WIMP observables are discussed and compared with the ones obtained in the standard approach.

  18. Gravitationally Induced Particle Production and its Impact on the WIMP Abundance

    E-print Network

    Baranov, I

    2015-01-01

    A large set of independent astronomical observations have provided a strong evidence for nonbaryonic dark matter in the Universe. One of the most investigated candidates is an unknown long-lived Weakly Interacting Massive Particle (WIMP) which was in thermal equilibrium with the primeval plasma. Here we investigate the WIMP abundance based on the relativistic kinetic treatment for gravitationally induced particle production recently proposed in the literature (Lima \\& Baranov, Phys. Rev. D {\\bf 90}, 043515, 2014). The new evolution equation is deduced and solved both numerically and also through a semi-analytical approach. The predictions of the WIMP observables are discussed and compared with the ones obtained in the standard approach.

  19. Relationship between Resolution, Line Edge Roughness, and Sensitivity in Chemically Amplified Resist of Post-Optical Lithography Revealed by Monte Carlo and Dissolution Simulations

    NASA Astrophysics Data System (ADS)

    Saeki, Akinori; Kozawa, Takahiro; Tagawa, Seiichi

    2009-07-01

    The simultaneous achievement of high resolution and low line width (edge) roughness (LWR, LER) at acceptable sensitivity (RLS) in chemically-amplified resist (CAR) is in strong demand to realize the mass production of ultra-small electric circuit using extreme ultraviolet. We performed Monte Carlo and dissolution simulations of positive-tone CAR of electron beam lithography to clarify this RLS formation. The trade-off RLS relationship was successfully reproduced and discussed in terms of non-scaling law of exposed line width. It was demonstrated that LER follows the inverse of square root of exposure dose at moderate acid diffusion length.

  20. Theoretical direct WIMP detection rates for transitions to excited states

    E-print Network

    Vergados, J D; Savvidy, K G

    2013-01-01

    The recent WMAP and Planck data have confirmed that exotic dark matter together with the vacuum energy (cosmological constant) dominate in the flat Universe. Many extensions of the standard model provide dark matter candidates, in particular Weakly Interacting Massive Particles (WIMPs). %Supersymmetry provides a natural dark matter candidate, the lightest supersymmetric particle (LSP). Thus the direct dark matter detection is central to particle physics and cosmology. Most of the research on this issue has hitherto focused on the detection of the recoiling nucleus. In this paper we study transitions to the excited states, possible in some nuclei, which have sufficiently low lying excited states. Good examples are the first excited states of I-127 and Xe-129. %focusing on the first excited state at 50 keV of Iodine A=127. We find appreciable branching ratios for the inelastic scattering mediated by the spin cross sections. %find that the transition rate to this excited state is about 5 %percent of the transiti...

  1. Event categories in the EDELWEISS WIMP search experiment

    NASA Astrophysics Data System (ADS)

    Benoit, A.; Bergé, L.; Broniatowski, A.; Chambon, B.; Chapellier, M.; Chardin, G.; Charvin, P.; De Jésus, M.; Di Stefano, P.; Drain, D.; Dumoulin, L.; Garoche, P.; Gascon, J.; Goldbach, C.; Gros, M.; Juillard, A.; de Lesquen, A.; L'Hôte, D.; Mallet, J.; Mangin, J.; Marnieros, S.; Mirabolfathi, N.; Miramonti, L.; Mosca, L.; Navick, X.-F.; Nollez, G.; Pari, P.; Pécourt, S.; Simon, E.; Stern, M.; Torre, J.-P.

    2000-04-01

    Four categories of events have been identified in the EDELWEISS-I dark matter experiment using germanium cryogenic detectors measuring simultaneously charge and heat signals. These categories of events are interpreted as electron and nuclear interactions occurring in the volume of the detector, and electron and nuclear interactions occurring close to the surface of the detectors (within /~10-20 ?m of the surface). We discuss the hypothesis that low energy surface nuclear recoils, which seem to have been unnoticed by previous WIMP searches, may provide an interpretation of the anomalous events recorded by the UKDMC and Saclay NaI experiments. The present analysis points to the necessity of taking into account surface nuclear and electron recoil interactions for a reliable estimate of background rejection factors.

  2. The Temperature-Sensitive Ion Channel TRPV2 is Endogenously Expressed and Functional in the Primary Sensory Cell Line F-11

    Microsoft Academic Search

    Florian Bender; Michael Mederos y Schnitzler; Yanzhang Li; Ailing Ji; Eberhard Weihe; Thomas Gudermann; Martin Schäfer

    2005-01-01

    In sensory neurons heat is transduced by a subfamily of TRP channels sharing sequence homology with the capsaicin-sensitive vanilloid receptor subtype 1 (TRPV1), but differing in their thermal response thresholds. To identify a neuronal cell line endogenously expressing noxious heat-transducing ion channels, we examined F-11 cells, a hybridoma derived from rat dorsal root ganglia and mouse neuroblastoma. Using RT-PCR, transcripts

  3. Prediction of preservative sensitization potential using surface marker CD86 and\\/or CD54 expression on human cell line, THP1

    Microsoft Academic Search

    Hitoshi Sakaguchi; Masaaki Miyazawa; Yukiko Yoshida; Yuichi Ito; Hiroyuki Suzuki

    2007-01-01

    Preservatives are important components in many products, but have a history of purported allergy. Several assays [e.g., guinea\\u000a pig maximization test (GPMT), local lymph node assay (LLNA)] are used to evaluate allergy potential of preservatives. We recently\\u000a developed the human Cell Line Activation Test (h-CLAT), an in vitro skin sensitization test using human THP-1 cells. This\\u000a test evaluates the augmentation

  4. High IGF-IR activity in triple-negative breast cancer cell lines and tumorgrafts correlates with sensitivity to anti-IGF-IR therapy

    PubMed Central

    Litzenburger, Beate C.; Creighton, Chad J.; Tsimelzon, Anna; Chan, Bonita T.; Hilsenbeck, Susan G.; Wang, Tao; Carboni, Joan M.; Gottardis, Marco M.; Huang, Fei; Chang, Jenny C.; Lewis, Michael T.; Rimawi, Mothaffar F.; Lee, Adrian V.

    2010-01-01

    Purpose We previously reported an IGF gene expression signature, based upon genes induced or repressed by IGF-I, which correlated with poor prognosis in breast cancer. We tested if the IGF signature was affected by anti-IGF-IR inhibitors, and if the IGF signature correlated with response to a dual anti-IGF-IR/InsR inhibitor BMS-754807. Experimental Design An IGF gene expression signature was examined in human breast tumors and cell lines, and changes noted following treatment of cell lines or xenografts with anti-IGF-IR antibodies or tyrosine kinase inhibitors. Sensitivity of cells to BMS-754807 was correlated with levels of the IGF signature. Human primary tumorgrafts were analyzed for the IGF signature and IGF-IR levels and activity, and MC1 tumorgrafts treated with BMS-754807 and chemotherapy. Results The IGF gene expression signature was reversed in three different models (cancer cell lines or xenografts) treated with three different anti-IGF-IR therapies. The IGF signature was present in triple-negative breast cancers (TNBC) and TNBC cell lines. TNBC cell lines were especially sensitive to BMS-754807, and sensitivity was significantly correlated to expression of the IGF gene signature. The TNBC primary human tumorgraft MC1 showed high levels of both IGF-IR expression and activity, and IGF gene signature score. Treatment of MC1 with BMS-754807 showed growth inhibition and in combination with docetaxel tumor regression occurred until no tumor was palpable. Regression was associated with reduced proliferation, increased apoptosis, and mitotic catastrophe. Conclusion These studies provide a clear biological rationale to test anti-IGF-IR/InsR therapy in combination with chemotherapy in patients with TNBC. PMID:21177763

  5. First results of the EDELWEISS-II WIMP search using Ge cryogenic detectors with interleaved electrodes

    NASA Astrophysics Data System (ADS)

    Armengaud, E.; Augier, C.; Benoît, A.; Bergé, L.; Besida, O.; Blümer, J.; Broniatowski, A.; Chantelauze, A.; Chapellier, M.; Chardin, G.; Charlieux, F.; Collin, S.; Defay, X.; de Jesus, M.; di Stefano, P.; Dolgorouki, Y.; Domange, J.; Dumoulin, L.; Eitel, K.; Gascon, J.; Gerbier, G.; Gros, M.; Hannawald, M.; Hervé, S.; Juillard, A.; Kluck, H.; Kozlov, V.; Lemrani, R.; Loaiza, P.; Lubashevskiy, A.; Marnieros, S.; Navick, X.-F.; Olivieri, E.; Pari, P.; Paul, B.; Rozov, S.; Sanglard, V.; Scorza, S.; Semikh, S.; Torrento-Coello, A. S.; Vagneron, L.; Verdier, M.-A.; Yakushev, E.; EDELWEISS Collaboration

    2010-04-01

    The EDELWEISS-II Collaboration has performed a direct search for WIMP dark matter with an array of ten 400 g heat-and-ionization cryogenic detectors equipped with interleaved electrodes for the rejection of near-surface events. Six months of continuous operation at the Laboratoire Souterrain de Modane have been achieved. The observation of one nuclear recoil candidate above 20 keV in an effective exposure of 144 kg?d is interpreted in terms of limits on the cross-section of spin-independent interactions of WIMPs and nucleons. A cross-section of 1.0×10-7 pb is excluded at 90% CL for a WIMP mass of 80 GeV/c2. This result demonstrates for the first time the very high background rejection capabilities of these simple and robust detectors in an actual WIMP search experiment.

  6. The histone deacetylase inhibitor valproic acid sensitizes diffuse large B-cell lymphoma cell lines to CHOP-induced cell death.

    PubMed

    Ageberg, Malin; Rydström, Karin; Relander, Thomas; Drott, Kristina

    2013-01-01

    Epigenetic code modifications by histone deacetylase inhibitors (HDACis) have recently been proposed as potential new therapies for hematological malignancies. Diffuse large B-cell lymphoma (DLBCL) is the most common form of aggressive lymphoma. At present, standard first line treatment for DLBCL patients is the antracycline-based chemotherapy regimen CHOP (cyclophosphamide, doxorubicin, vincristine and prednisone) combined with the monoclonal anti-CD20 antibody rituximab (R-CHOP). Since only 50-60% of patients reach a long-time cure by this treatment, there is an urgent need for novel treatment strategies to increase the response and long-term remission to initial R-CHOP therapy. In this study, we investigated the effect of the HDAC inhibitor valproic acid (VPA) on DLBCL cell lines. To elucidate the effects of VPA on chemo-sensitivity, we used a cell-line based model of CHOP-refractory DLBCL. All five DLBCL cell lines treated with VPA alone or in combination with CHOP showed decreased viability and proliferation. The VPA-induced sensitization of DLBCL cells to cytotoxic treatment resulted in increased number of apoptotic cell as judged by annexin V-positivity and the presence of cleaved caspase-3. In addition, pretreatment with VPA resulted in a significantly increased DNA-damage as compared to CHOP alone. In summary, HDAC inhibitors such as VPA, are promising therapeutic agents in combination with R-CHOP for patients with DLBCL. PMID:23573362

  7. Halo-Independent analysis of direct dark matter detection data for any WIMP interaction

    E-print Network

    Graciela B. Gelmini

    2014-11-04

    The halo independent comparison of direct dark matter detection data eliminates the need to make any assumption on the uncertain local dark matter distribution and is complementary to the usual data comparison which required assuming a dark halo model for our galaxy. The method, initially proposed for WIMPs with spin-independent contact interactions, has been generalized to any other interaction and applied to recent data on "Light WIMPs".

  8. Characterization of Murine Thymic Stromal-Cell Lines Immortalized by Temperature-Sensitive Simian Virus 40 Large T or Adenovirus 5 E1a

    PubMed Central

    Larsson, Lena; Timms, Emma; Blight, Kenneth; Restall, Deborah E.; Jat, Parmjit S.; Fisher, Amanda G.

    1991-01-01

    The heterogeneity of thymic stromal cells is probably related to their role in providing different microenvironments where T cells can develop. We have immortalized thymic stromal elements using recombinant retroviral constructs containing a temperature-sensitive simian virus 40 (SV40tsA58) large-T antigen gene or the adenovirus 5 E1a region linked to the gene coding for resistance to G418. Cell lines containing the thermolabile large T antigen encoded by SV40 proliferate at the permissive temperature of 33°C and arrest growth when transferred to the nonpermissive temperature of 39°C. At the nonpermissive temperature, ts-derived cell lines are shown to alter their phenotype but remain metabolically active, as indicated by the inducible expression of class I and class II MHC antigens. Here we describe the generation of a total of 84 thymic stromal-cell lines, many of which show distinct morphologic, phenotypic, and functional properties consistent with fibroblastoid, epithelial, or monocytoid origins. Several E1a and SV40tsA58-derived cell lines generated exhibit the epithelial characteristic of desmosome formation and, in addition, two of these lines (15.5 and 15.18) form multicellular complexes (rosettes) when incubated with unfractionated thymocytes from syngeneic mice. A single line (14.5) displays very strong nonspecific esterase activity, suggesting it may represent a macrophagelike cell type. We describe the generation of stromal cell lines with different properties, which is consistent with the heterogeneity found in the thymic microenvironment. In addition to documenting this diversity, these cell lines may be useful tools for studying T-cell development in vitro and give access to model systems in which stromal-thymocyte interactions can be examined. PMID:1668372

  9. Supersymmetry with radiatively-driven naturalness: implications for WIMP and axion searches

    E-print Network

    Bae, Kyu Jung; Barger, Vernon; Savoy, Michael R; Serce, Hasan

    2015-01-01

    By insisting on naturalness in both the electroweak and QCD sectors of the MSSM, the portrait for dark matter production is seriously modified from the usual WIMP miracle picture. In SUSY models with radiatively-driven naturalness (radiative natural SUSY or RNS) which include a DFSZ-like solution to the strong CP and SUSY mu problems, dark matter is expected to be an admixture of both axions and higgsino-like WIMPs. The WIMP/axion abundance calculation requires simultaneous solution of a set of coupled Boltzmann equations which describe quasi-stable axinos and saxions. In most of parameter space, axions make up the dominant contribution of dark matter although regions of WIMP dominance also occur. We show the allowed range of PQ scale f_a and compare to the values expected to be probed by the ADMX axion detector in the near future. We also show WIMP detection rates which are suppressed from usual expectations because now WIMPs comprise only a fraction of the total dark matter. Nonetheless, ton-scale noble liq...

  10. An Analysis of the LUX First WIMP Search Run Using Effective Field Theory Techniques

    NASA Astrophysics Data System (ADS)

    Larsen, Nicole; LUX Collaboration

    2014-09-01

    The LUX (Large Underground Xenon) experiment is a dark matter direct detection experiment located 4850 feet underground at the Sanford Underground Research Facility in Lead, SD. During Summer 2013, LUX collected 10065 kg-days of WIMP search data, ultimately reporting a minimum cross-section limit for spin-independent WIMP-nucleon elastic scattering of 7.6 × 10-46 cm2 for 33 GeV-mass WIMPs. Direct detection experiments typically characterize WIMP-nucleon interactions in terms of spin-independent (SI) and spin-dependent (SD) couplings. However, Fitzpatrick et al. show that the total set of effective field theory operators allowed by basic symmetry considerations result in additional qualitatively distinct nuclear responses for WIMP-nucleon interactions. These new operators can also interfere with the standard SI and SD operators, potentially enhancing or suppressing them, and should therefore be taken into consideration to ensure that direct detection experiments do not leave any gaps in the theoretical parameter space being probed. Here I discuss recent work toward using the LUX 2013 WIMP search dataset to set limits on these new operators.

  11. Radiation Sensitivity, H2AX Phosphorylation, and Kinetics of Repair of DNA Strand Breaks in Irradiated Cervical Cancer Cell Lines

    Microsoft Academic Search

    Judit P. Banath; Susan H. MacPhail; Peggy L. Olive

    2004-01-01

    Six human cervical cancer cell lines (five human papillomavirus (HPV) positive, one HPV negative) for induction and rejoining of DNA strand breaks and for kinetics of formation and loss of serine 139 phosphorylated histone H2AX (H2AX). X-rays induced the same level of DNA breakage for all cell lines. By 8 hours after 20 Gy, <2% of the initial single-strand breaks

  12. Molecular analysis of ethyl methanesulfonate-induced mutations at the hprt gene in the ethyl methanesulfonate-sensitive Chinese hamster cell line EM-C11 and its parental line CHO9.

    PubMed

    Op het Veld, C W; Zdzienicka, M Z; Vrieling, H; Lohman, P H; van Zeeland, A A

    1994-06-01

    The Chinese hamster cell line EM-C11 has been shown to be 5 times more sensitive than its parental line CHO9, but not hypermutable, after treatment with ethyl methanesulfonate. Ethyl methanesulfonate-induced mutational spectra were determined at the hprt locus to investigate whether the same adducts are responsible for mutation induction in both cell lines. The mutational spectra for EM-C11 and CHO9 show an important difference. GC-->AT transitions were found in both cell lines at similar frequencies; however, the spectrum of CHO9 contains a class of AT-->GC transitions, which seems to be replaced by a group of deletions in EM-C11. Since the ethyl methanesulfonate-induced mutation frequency for both lines is the same at equal exposure, it is hypothesized that the lesions leading to AT-->GC transitions in CHO9 are responsible for the deletions in EM-C11. This phenomenon might be explained if the responsible adduct(s) in CHO9 is bypassed resulting in replication errors, while blocking DNA synthesis in EM-C11 causing the observed increase in cell death. In surviving EM-C11 cells, DNA strand exchanges might have occurred at the position of stalled replication forks, leading to gross molecular changes. The adduct probably responsible for the AT-->GC transitions in CHO9 and the deletions in EM-C11 is 3-ethyladenine. PMID:8187089

  13. Thiol-sensitive mast cell lines derived from mouse bone marrow respond to a mast cell growth-enhancing activity different from both IL-3 and IL-4.

    PubMed

    Hültner, L; Moeller, J; Schmitt, E; Jäger, G; Reisbach, G; Ring, J; Dörmer, P

    1989-05-15

    A series of permanent IL-3-dependent cell lines have been established from normal BALB/c or C3H bone marrow using alpha-thioglycerol-supplemented culture medium and PWM-stimulated spleen cell-conditioned medium as a source of IL-3. The cell lines and derivatives cloned in agar resembled "mucosal type" mast cells with respect to phenotypic and functional properties. In this report we demonstrate that in vitro growth of these mast cell lines was not only dependent on IL-3 and synergistically enhanced by IL-4, but in addition regulated by alpha-thioglycerol which could be replaced by 2-ME or cysteamine. We show that these thiol-sensitive mast cell lines respond to a mast cell growth enhancing activity (MEA) present in spleen cell-conditioned medium and acting in concert with IL-3. Partially purified MEA was not able to stimulate the growth of IL-3-dependent 32Dcl.23 cells, IL-2-dependent CTLL-2 cells or the mouse T cell line F4/4K.6 (L3T4+) adapted to grow in purified IL-4. Moreover, 11B11 hybridoma-derived anti-IL-4 mAb specifically neutralizing mouse Il-4 were unable to abolish the bioactivity of MEA. PWM, CSF-1, GM-CSF, IL-1, IL-2, IL-5, IL-6, IL-7, IFN-gamma, TGF-alpha, TNF-alpha, NGF, or EPO did not substitute for MEA in our standard proliferation assay. PMID:2785556

  14. Molecular Mechanism for the Thermo-Sensitive Phenotype of CHO-MT58 Cell Line Harbouring a Mutant CTP:Phosphocholine Cytidylyltransferase

    PubMed Central

    Marton, Lívia; Nagy, Gergely N.; Ozohanics, Olivér; Lábas, Anikó; Krámos, Balázs; Oláh, Julianna; Vékey, Károly; Vértessy, Beáta G.

    2015-01-01

    Control and elimination of malaria still represents a major public health challenge. Emerging parasite resistance to current therapies urges development of antimalarials with novel mechanism of action. Phospholipid biosynthesis of the Plasmodium parasite has been validated as promising candidate antimalarial target. The most prevalent de novo pathway for synthesis of phosphatidylcholine is the Kennedy pathway. Its regulatory and often also rate limiting step is catalyzed by CTP:phosphocholine cytidylyltransferase (CCT). The CHO-MT58 cell line expresses a mutant variant of CCT, and displays a thermo-sensitive phenotype. At non-permissive temperature (40°C), the endogenous CCT activity decreases dramatically, blocking membrane synthesis and ultimately leading to apoptosis. In the present study we investigated the impact of the analogous mutation in a catalytic domain construct of Plasmodium falciparum CCT in order to explore the underlying molecular mechanism that explains this phenotype. We used temperature dependent enzyme activity measurements and modeling to investigate the functionality of the mutant enzyme. Furthermore, MS measurements were performed to determine the oligomerization state of the protein, and MD simulations to assess the inter-subunit interactions in the dimer. Our results demonstrate that the R681H mutation does not directly influence enzyme catalytic activity. Instead, it provokes increased heat-sensitivity by destabilizing the CCT dimer. This can possibly explain the significance of the PfCCT pseudoheterodimer organization in ensuring proper enzymatic function. This also provide an explanation for the observed thermo-sensitive phenotype of CHO-MT58 cell line. PMID:26083347

  15. Molecular Mechanism for the Thermo-Sensitive Phenotype of CHO-MT58 Cell Line Harbouring a Mutant CTP:Phosphocholine Cytidylyltransferase.

    PubMed

    Marton, Lívia; Nagy, Gergely N; Ozohanics, Olivér; Lábas, Anikó; Krámos, Balázs; Oláh, Julianna; Vékey, Károly; Vértessy, Beáta G

    2015-01-01

    Control and elimination of malaria still represents a major public health challenge. Emerging parasite resistance to current therapies urges development of antimalarials with novel mechanism of action. Phospholipid biosynthesis of the Plasmodium parasite has been validated as promising candidate antimalarial target. The most prevalent de novo pathway for synthesis of phosphatidylcholine is the Kennedy pathway. Its regulatory and often also rate limiting step is catalyzed by CTP:phosphocholine cytidylyltransferase (CCT). The CHO-MT58 cell line expresses a mutant variant of CCT, and displays a thermo-sensitive phenotype. At non-permissive temperature (40°C), the endogenous CCT activity decreases dramatically, blocking membrane synthesis and ultimately leading to apoptosis. In the present study we investigated the impact of the analogous mutation in a catalytic domain construct of Plasmodium falciparum CCT in order to explore the underlying molecular mechanism that explains this phenotype. We used temperature dependent enzyme activity measurements and modeling to investigate the functionality of the mutant enzyme. Furthermore, MS measurements were performed to determine the oligomerization state of the protein, and MD simulations to assess the inter-subunit interactions in the dimer. Our results demonstrate that the R681H mutation does not directly influence enzyme catalytic activity. Instead, it provokes increased heat-sensitivity by destabilizing the CCT dimer. This can possibly explain the significance of the PfCCT pseudoheterodimer organization in ensuring proper enzymatic function. This also provide an explanation for the observed thermo-sensitive phenotype of CHO-MT58 cell line. PMID:26083347

  16. Effects of a new antioestrogen, idoxifene, on cisplatin- and doxorubicin-sensitive and -resistant human ovarian carcinoma cell lines.

    PubMed Central

    Sharp, S. Y.; Rowlands, M. G.; Jarman, M.; Kelland, L. R.

    1994-01-01

    Pyrrolidino-4-iodotamoxifen (idoxifene) is a new non-steroidal antioestrogen currently undergoing phase I clinical evaluation. Using idoxifene and tamoxifen and two additional analogues of tamoxifen (3-hydroxytamoxifen and 4-iodotamoxifen) and the imidazole-based calmodulin inhibitor, calmidazolium, a strong positive correlation (r2 > 0.95) was observed between cytotoxicity and inhibition of calmodulin-dependent cyclic AMP phosphodiesterase (e.g. mean IC50 across four human ovarian carcinoma cell lines of 4.5 microM for idoxifene and 6.3 microM for tamoxifen). Using two parent human ovarian carcinoma cell lines (41M and CH1; both oestrogen receptor negative) in which acquired resistance to doxorubicin or cisplatin has been generated, we have determined the ability of idoxifene to overcome resistance in these lines. At a non-toxic concentration of 2 microM, idoxifene appeared at least as effective as the clinically used multidrug resistance modifiers verapamil and tamoxifen in overcoming doxorubicin resistance in two acquired resistant cell lines shown to overexpress the P-170 efflux glycoprotein. Non-cross-resistance between cisplatin and idoxifene was observed in two acquired resistant cell lines possessing contrasting mechanisms of resistance to cisplatin (41McisR6 reduced drug transport and CH1cisR6 resistance mediated at the level of DNA). In one of four cell lines (CH1), synergism between idoxifene and cisplatin was observed by median effect analysis. However, with the 41M and its 6-fold cisplatin-resistant variant, antagonism was observed. These observations made by median effect analysis appeared to be unrelated to platinum uptake or removal of platinum-induced DNA interstrand cross-links. These in vitro data suggest that idoxifene may be usefully combined with doxorubicin in the clinical setting, but caution should be exercised in combining it with cisplatin in the treatment of certain tumours. Images Figure 3 PMID:8080723

  17. The Sensitivity of Tropical Squall Lines (GATE and TOGA COARE) to Surface Fluxes: Cloud Resolving Model Simulations

    NASA Technical Reports Server (NTRS)

    Wang, Yansen; Tao, Wei-Kuo; Simpson, Joanne; Lang, Stephen

    1999-01-01

    Two tropical squall lines from TOGA COARE and GATE were simulated using a two-dimensional cloud-resolving model to examine the impact of surface fluxes on tropical squall line development and associated precipitation processes. The important question of how CAPE in clear and cloudy areas is maintained in the tropics is also investigated. Although the cloud structure and precipitation intensity are different between the TOGA COARE and GATE squall line cases, the effects of the surface fluxes on the amount of rainfall and on the cloud development processes are quite similar. The simulated total surface rainfall amount in the runs without surface fluxes is about 67% of the rainfall simulated with surface fluxes. The area where surface fluxes originated was categorized into clear and cloudy regions according to whether there was cloud in the vertical column. The model results indicated that the surface fluxes from the large clear air environment are the dominant moisture source for tropical squall line development even though the surface fluxes in the cloud region display a large peak. The high-energy air from the boundary layer in the clear area is what feeds the convection while the CAPE is removed by the convection. The surface rainfall was only reduced 8 to 9% percent in the simulations without surface fluxes in the cloud region. Trajectory and water budget analysis also indicated that most moisture (92%) was from the boundary layer of the clear air environment.

  18. Evaluation of the sensitivity of three sublethal cytotoxicity assays in human HepG2 cell line using

    E-print Network

    Paris-Sud XI, Université de

    ,4-DAT, 17-EE, H2O2, 4-OP, sodium bromate, sodium chlorate, sodium nitrate) was evaluated on the human) Keywords: water contaminants; cytotoxicity assays; HepG2 cell line; RNA synthesis; alamar blue; ATP synthesis assay (RNA), luminometric ATP assay (ATP), fluorometric Alamar blue assay (AB)]. Among all

  19. SK2 encodes the apamin-sensitive Ca 2+-activated K + channels in the human leukemic T cell line, Jurkat

    Microsoft Academic Search

    Heike Jäger; John P. Adelman; Stephan Grissmer

    2000-01-01

    T cells express two different types of voltage-independent Ca2+-activated K+ channels with small (SK) and intermediate (IK) conductance that serve important roles in the activation of T lymphocytes. In contrast to the IK channels from T lymphocytes which are upregulated upon mitogen stimulation, SK channels of Jurkat T cells, a human leukemic T cell line, are constitutively expressed even in

  20. BRAFV600E Mutation Is Associated with Preferential Sensitivity to Mitogen-Activated Protein Kinase Kinase Inhibition in Thyroid Cancer Cell Lines

    PubMed Central

    Leboeuf, Rebecca; Baumgartner, Jacqueline E.; Benezra, Miriam; Malaguarnera, Roberta; Solit, David; Pratilas, Christine A.; Rosen, Neal; Knauf, Jeffrey A.; Fagin, James A.

    2008-01-01

    Context: Mutually exclusive mutations of RET, RAS, or BRAF are present in about 70% of papillary thyroid carcinomas, whereas only the latter two are seen in poorly differentiated and anaplastic cancers. Although the signal output common to these oncoproteins is ERK, a recent report showed that only BRAF mutations consistently predicted responsiveness to MAPK kinase (MEK) inhibitors. Objectives: Here we investigated whether sensitivity to MEK inhibition was determined by oncogene status in 13 human thyroid cancer cell lines: four with BRAF mutations, four RAS, one RET/PTC1, and four wild type. Results: Growth of BRAF (+) cells was inhibited by the MEK antagonist PD0325901 with an IC50 of less than 5 nm. By contrast, RAS, RET/PTC1, or wild-type cells had IC50 of 4 nm to greater than 1000nm. Sensitivity was not predicted by coexisting mutations in PIK3CA or by PTEN status. Similar effects were obtained with the MEK inhibitor AZD6244. PD0325901 induced a sustained G1/S arrest in BRAF (+) but not BRAF (?) lines. PD0325901 was equipotent at inhibiting pERK1/2 after 2 h, regardless of genetic background, but pERK rebounded at 24 h in most lines. MEK inhibitor resistance was associated with partial refractoriness of pERK to further inhibition by the compounds. AZD6244 was more potent at inhibiting growth of NPA (BRAF +) than Cal62 (KRAS +) xenografts. Conclusion: Thyroid cancers with BRAF mutation are preferentially sensitive to MEK inhibitors, whereas tumors with other MEK-ERK effector pathway gene mutations have variable responses, either because they are only partially dependent on ERK and/or because feedback responses elicit partial refractoriness to MEK inhibition. PMID:18381570

  1. PAMELA, DAMA, INTEGRAL and Signatures of Metastable Excited WIMPs

    E-print Network

    Douglas P. Finkbeiner; Tracy Slatyer; Neal Weiner; Itay Yavin

    2009-06-25

    Models of dark matter with ~ GeV scale force mediators provide attractive explanations of many high energy anomalies, including PAMELA, ATIC, and the WMAP haze. At the same time, by exploiting the ~ MeV scale excited states that are automatically present in such theories, these models naturally explain the DAMA/LIBRA and INTEGRAL signals through the inelastic dark matter (iDM) and exciting dark matter (XDM) scenarios, respectively. Interestingly, with only weak kinetic mixing to hypercharge to mediate decays, the lifetime of excited states with delta xenon, silicon, and argon targets, can push this limit significantly lower. We also consider the possibility that the DAMA excitation occurs from a metastable state into the XDM state, which decays via e+e- emission, which allows lighter states to explain the INTEGRAL signal due to the small kinetic energies required. Such models yield dramatic signals from down-scattering, with spectra peaking at high energies, sometimes as high as ~1 MeV, well outside the usual search windows. Such signals would be visible at future Ar and Si experiments, and may be visible at Ge and Xe experiments. We also consider other XDM models involving ~ 500 keV metastable states, and find they can allow lighter WIMPs to explain INTEGRAL as well.

  2. WIMP dark matter from gravitino decays and leptogenesis

    NASA Astrophysics Data System (ADS)

    Buchmüller, W.; Domcke, V.; Schmitz, K.

    2012-06-01

    The spontaneous breaking of B-L symmetry naturally accounts for the small observed neutrino masses via the seesaw mechanism. We have recently shown that the cosmological realization of B-L breaking in a supersymmetric theory can successfully generate the initial conditions of the hot early universe, i.e. entropy, baryon asymmetry and dark matter, if the gravitino is the lightest superparticle (LSP). This implies relations between neutrino and superparticle masses. Here we extend our analysis to the case of very heavy gravitinos which are motivated by hints for the Higgs boson at the LHC. We find that the nonthermal production of 'pure' wino or higgsino LSPs, i.e. weakly interacting massive particles (WIMPs), in heavy gravitino decays can account for the observed amount of dark matter while simultaneously fulfilling the constraints imposed by primordial nucleosynthesis and leptogenesis within a range of LSP, gravitino and neutrino masses. For instance, a mass of the lightest neutrino of 0.05 eV would require a higgsino mass below 900 GeV and a gravitino mass of at least 10 TeV.

  3. COUPP - a search for dark matter with a continuously sensitive bubble chamber

    SciTech Connect

    Collar, Juan,; Crum, Keith; Mishra, Smriti; Nakazawa, Dante; Odom, Brian; Rasmussen, Julia; Riley, Nathan; Szydagis, Matthew; /Chicago U.; Behnke, Ed; Levine, Ilan; Vander Werf, Nate; /Indiana U., South Bend; Cooper, Peter; Crisler, Mike; Hu, Martin; Ramberg, Erik; Sonnenschein, Andrew; Tschirhart, Robert; /Fermilab

    2007-01-01

    We propose to construct and operate a 60-kg room temperature CF{sub 3}I bubble chamber as a prototype dark matter (WIMP) detector. Operating in weakly-superheated mode, the chamber will be sensitive to WIMP induced nuclear recoils above 10 keV, while rejecting background electron recoils at a level approaching 10{sup 10}. We would first commission and operate this chamber in the MINOS near detector hall with the goal to demonstrate stable operation and measure internal contamination and any other backgrounds. This chamber, or an improved version, would then be relocated to an appropriate deep underground site such as the Soudan Mine. This detector will have unique sensitivity to spin-dependent WIMP-nucleon couplings, and even in this early stage of development will attain competitive sensitivity to spin-independent couplings.

  4. Calculations of H2O microwave line broadening in collisions with He atoms: sensitivity to potential energy surfaces.

    PubMed

    Green, S; DeFrees, D J; McLean, A D

    1991-01-15

    Broadening parameters for three microwave lines of water at 22.2, 183.3, and 380.2 GHz, in a bath of helium atoms, are calculated using accurate molecular scattering S matrices obtained from two theoretical potentials presented by Palma et al., J. Chem. Phys. 89, 1401 (1988). For the 22 GHz line results are in substantial agreement with values presented in that work, indicating the accuracy of approximate methods used there. The present work improves the potential energy surfaces, computed from perturbation theory (MP4) and variational interacting correlated fragments (ICF1) wave functions, by correcting them for basis set superposition error (BSSE), and recomputes the line broadening using a different procedure for fitting computed energy points. In addition, the entire set of calculations are repeated with a quite different basis set for orbital expansion to establish the reliability of the potential energy surface. We show that adjustments for superposition error are essential, and that broadening cross sections computed from the new surfaces are changed 10%-30% from the old, significantly improving agreement with experiment. The MP4 BSSE adjusted surface appears to be the most accurate, giving room temperature broadenings of 8.9, 11.8, and 10.0 angstroms2 compared with experimental determinations of 12.2 +/- 1.2, 11.9, and 11.2 angstroms2 for the 22, 183, and 380 GHz lines, respectively. Thus, computed line to line variation is larger than observed. The ICF1 BSSE adjusted results for pressure broadening cross section parallel those from the MP4 BSSE calculations but are about 10% smaller. We believe our computed results are stable with respect to basis set for orbital expansion and that the scattering calculations are accurate. Any theoretical inadequacy has been pinpointed to too few points on the potential energy surface resulting in an inadequate description of the angle dependence. It is not clear whether the present discrepancy between computation and experiment stems from this or from errors in the experimental values, although we show some indication that additional information on the surface might decrease the computed broadenings, worsening agreement with experiment. PMID:11538204

  5. The development of a sensitive method to study volatile organic compounds in gaseous emissions of lung cancer cell lines

    E-print Network

    Maroly, Anupam

    2005-08-29

    emissions in selected cancer cell lines and identification of volatile organic compounds (VOCs) in them. Disadvantages of earlier studies were that the measurements were not real time or state specific so that molecular identification was often... used to study styrene in urine and blood [37]. Techniques used Many different detection and concentration techniques apart from P&T or GC-MS have used in lung cancer studies. Each has their own advantages and disadvantages. Some of the more...

  6. Lentivirus-mediated RNAi silencing targeting ABCC2 increasing the sensitivity of a human nasopharyngeal carcinoma cell line against cisplatin

    Microsoft Academic Search

    Si Ming Xie; Wei Yi Fang; Zhen Liu; Shuang Xi Wang; Xin Li; Teng Fei Liu; Wei Bing Xie; Kai Tai Yao

    2008-01-01

    BACKGROUND: High resistance to drug is taken as a characteristic of human tumors, which is usually mediated by multidrug resistance-associated genes. ABCC2, an ATP-binding cassette multidrug resistance transporter, is found to be expressed in a variety of human cancers. In this study the effect of a RNAi construct targeting ABCC2 on the chemosensitivity of NPC cell line CNE2 against cisplatin

  7. Dark matter production in the early Universe: Beyond the thermal WIMP paradigm

    NASA Astrophysics Data System (ADS)

    Baer, Howard; Choi, Ki-Young; Kim, Jihn E.; Roszkowski, Leszek

    2015-02-01

    Increasingly stringent limits from LHC searches for new physics, coupled with lack of convincing signals of weakly interacting massive particle (WIMP) in dark matter searches, have tightly constrained many realizations of the standard paradigm of thermally produced WIMPs as cold dark matter. In this article, we review more generally both thermally and non-thermally produced dark matter (DM). One may classify DM models into two broad categories: one involving bosonic coherent motion (BCM) and the other involving WIMPs. BCM and WIMP candidates need, respectively, some approximate global symmetries and almost exact discrete symmetries. Supersymmetric axion models are highly motivated since they emerge from compelling and elegant solutions to the two fine-tuning problems of the Standard Model: the strong CP problem and the gauge hierarchy problem. We review here non-thermal relics in a general setup, but we also pay particular attention to the rich cosmological properties of various aspects of mixed SUSY/axion dark matter candidates which can involve both WIMPs and BCM in an interwoven manner. We also review briefly a panoply of alternative thermal and non-thermal DM candidates.

  8. The effects of QCD equation of state on the relic density of WIMP dark matter

    NASA Astrophysics Data System (ADS)

    Drees, Manuel; Hajkarim, Fazlollah; Rossi Schmitz, Ernany

    2015-06-01

    Weakly Interactive Massive Particles (WIMPs) are the most widely studied candidate particles forming the cold dark matter (CDM) whose existence can be inferred from a wealth of astrophysical and cosmological observations. In the framework of the minimal cosmological model detailed measurements on the cosmic microwave background by the PLANCK collaboration fix the scaled CDM relic density to ?ch2=0.1193±0.0014, with an error of less than 1.5%. In order to fully exploit this observational precision, theoretical calculations should have a comparable or smaller error. In this paper we use recent lattice QCD calculations to improve the description of the thermal plasma. This affects the predicted relic density of ``thermal WIMPs'', which once were in chemical equilibrium with Standard Model particles. For WIMP masses between 3 and 15 GeV, where QCD effects are most important, our predictions differ from earlier results by up to 9% (12%) for pure S-wave (P-wave) annihilation. We use these results to compute the thermally averaged WIMP annihilation cross section that reproduces the correct CDM relic density, for WIMP masses between 0.1 GeV and 10 TeV.

  9. Fibulin-3 negatively regulates ALDH1 via c-MET suppression and increases ?-radiation-induced sensitivity in some pancreatic cancer cell lines.

    PubMed

    Kim, In-Gyu; Lee, Jae-Ha; Kim, Seo-Yoen; Kim, Jeong-Yul; Cho, Eun-Wie

    2014-10-24

    Fibulin-3 (FBLN-3) has been postulated to be either a tumor suppressor or promoter depending on the cell type, and hypermethylation of the FBLN-3 promoter is often associated with human disease, especially cancer. We report that the promoter region of the FBLN-3 was significantly methylated (>95%) in some pancreatic cancer cell lines and thus FBLN-3 was poorly expressed in pancreatic cancer cell lines such as AsPC-1 and MiaPaCa-2. FBLN-3 overexpression significantly down-regulated the cellular level of c-MET and inhibited hepatocyte growth factor-induced c-MET activation, which were closely associated with ?-radiation resistance of cancer cells. Moreover, we also showed that c-MET suppression or inactivation decreased the cellular level of ALDH1 isozymes (ALDH1A1 or ALDH1A3), which serve as cancer stem cell markers, and subsequently induced inhibition of cell growth in pancreatic cancer cells. Therefore, forced overexpression of FBLN-3 sensitized cells to cytotoxic agents such as ?-radiation and strongly inhibited the stemness and epithelial to mesenchymal transition (EMT) property of pancreatic cancer cells. On the other hand, if FBLN3 was suppressed in FBLN-3-expressing BxPC3 cells, the results were opposite. This study provides the first demonstration that the FBLN-3/c-MET/ALDH1 axis in pancreatic cancer cells partially modulates stemness and EMT as well as sensitization of cells to the detrimental effects of ?-radiation. PMID:25451256

  10. Comparison of primary human fibroblasts and keratinocytes with immortalized cell lines regarding their sensitivity to sodium dodecyl sulfate in a neutral red uptake cytotoxicity assay.

    PubMed

    Olschläger, Veronika; Schrader, Andreas; Hockertz, Stefan

    2009-01-01

    Cell lines present a valuable tool for in vitro assessment of skin damage caused by application of cosmeticals or pharmaceuticals. They form a reproducible test system under controllable test conditions and, in many cases, can be used as alternatives to animal testing in order to assess the compatibility of drugs or cosmetics and human skin. Yet, it can not necessarily be assumed that the behavior of cultured cells, when treated with different substances, is exactly consistent with the behavior of cells being part of a live organism. Becoming immortal, cells exhibit changes in genotype and/or phenotype, possibly resulting in modified reactions to external influences. Therefore, to obtain results close to in vivo studies, it seems apparent to use primary cells for testing that have not yet undergone any modifications. To compare the properties of primary fibroblasts (Normal Human Dermal Fibroblasts, NHDF) and primary keratinocytes (Normal Human Epidermal Keratinocytes, NHEK) with those of immortal cell lines (3T3 (ACC 173) Swiss albino mouse fibroblasts and HaCaT (human, adult, low calcium, high temperature, human adult skin keratinocytes) cells), their sensitivities in cytotoxicity assays have been assessed. While both fibroblast cell cultures showed similar sensitivities towards sodium dodecyl sulfate (SDS), primary keratinocytes died at SDS concentrations about three times lower than the immortal HaCaT cells. PMID:19402346

  11. H2 Lyman and Werner band lines and their sensitivity for a variation of the proton-electron mass ratio in the gravitational potential of white dwarfs

    NASA Astrophysics Data System (ADS)

    Salumbides, E. J.; Bagdonaite, J.; Abgrall, H.; Roueff, E.; Ubachs, W.

    2015-06-01

    Recently we published an accurate analysis of molecular hydrogen absorption in the photospheres of the white dwarf stars GD133 and GD29-38, previously observed with the Cosmic Origins Spectrograph aboard the Hubble Space Telescope. Constraints were derived on a possible dependence of the proton-electron mass ratio on gravitational fields that are 10 000 times stronger than at the Earth's surface. Here we present further details of that study, in particular a re-evaluation of the spectrum of the B^1? _u^+ - X^1? _g^+ (v^' },v^' ' }) Lyman bands relevant for the prevailing temperatures (12 000-14 000 K) of the photospheres. The emphasis is on the calculation of so-called Ki-coefficients, that represent the sensitivity of each individual line to a possible change in the proton-electron mass ratio. Such calculations were performed by semi-empirical methods and by ab initio methods providing accurate and consistent values. A full listing is provided for the molecular physics data on the Lyman bands (wavelengths ?i, line oscillator strengths fi, radiative damping rates ?i, and sensitivity coefficients Ki) as required for the analyses of H2-spectra in hot dwarf stars. A similar listing of the molecular physics parameters for the C^1?_u - X^1? _g^+ (v^' },v^' ' }) Werner bands is provided for future use in the analysis of white dwarf spectra.

  12. Cytotoxic salan-titanium(IV) complexes: high activity toward a range of sensitive and drug-resistant cell lines, and mechanistic insights.

    PubMed

    Manna, Cesar M; Braitbard, Ori; Weiss, Esther; Hochman, Jacob; Tshuva, Edit Y

    2012-04-01

    The cytotoxicities of highly efficient salan-Ti(IV) complexes toward a range of cell lines, including drug-resistant cells, are reported along with preliminary mechanistic insights. Five salan-Ti(IV) complexes were investigated toward eight different human and murine cancer-derived cell lines, including colon, ovarian, lung, cervical, pancreatic, leukemic, skin, and breast. The salan complexes are more active toward the cells analyzed than cisplatin and the known titanium compound (bzac)(2) Ti(OiPr)(2) , and no cell line resistant to the salan complexes was identified. Moreover, the salan-Ti(IV) complexes are highly active toward both cisplatin-sensitive (A2780) and cisplatin-resistant (A2780CisR) human ovarian cancer cell lines. Similarly, the salan complexes are cytotoxic toward multi-drug-resistant (ABCB1-expressing) mouse lymphoma cell lines HU-1 and HU-2. Importantly, minimal or no activity was observed toward primary murine cells (bone marrow, heart, liver, kidney, spleen, and lung), supporting selectivity for cancer cells. Additionally, the salan complexes maintain high cytotoxicity for up to 24 h following exposure to cell culture medium, whereas reference complexes (bzac)(2) Ti(OiPr)(2) and Cp(2) TiCl(2) rapidly lose much of their activity upon exposure to medium, within ~1 h. The upregulation of p53 followed by cell-cycle arrest in G(1) phase is likely one mechanism of action of the salan complexes. Taken together, the results indicate that these compounds are selectively toxic to cancer cells and are able to circumvent two independent mechanisms of drug resistance, thus expanding the scope of their potential medicinal utility. PMID:22262543

  13. A combination of positive dielectrophoresis driven on-line enrichment and aptamer-fluorescent silica nanoparticle label for rapid and sensitive detection of Staphylococcus aureus.

    PubMed

    Shangguan, Jingfang; Li, Yuhong; He, Dinggeng; He, Xiaoxiao; Wang, Kemin; Zou, Zhen; Shi, Hui

    2015-06-15

    Staphylococcus aureus (S. aureus) is an important human pathogen that causes several diseases ranging from superficial skin infections to life-threatening diseases. Here, a method combining positive dielectrophoresis (pDEP) driven on-line enrichment and aptamer-fluorescent silica nanoparticle label has been developed for the rapid and sensitive detection of S. aureus in microfluidic channels. An aptamer, having high affinity to S. aureus, is used as the molecular recognition tool and immobilized onto chloropropyl functionalized fluorescent silica nanoparticles through a click chemistry approach to obtain S. aureus aptamer-nanoparticle bioconjugates (AptS.aureus/FNPs). The pDEP driven on-line enrichment technology was used for accumulating the AptS.aureus/FNP labeled S. aureus. After incubating with S. aureus, the mixture of AptS.aureus/FNP labeled S. aureus and AptS.aureus/FNPs was directly introduced into the pDEP-based microfluidic system. By applying an AC voltage in a pDEP frequency region, the AptS.aureus/FNP labelled S. aureus moved to the electrodes and accumulated in the electrode gap, while the free AptS.aureus/FNPs flowed away. The signal that came from the AptS.aureus/FNP labelled S. aureus in the focused detection areas was then detected. Profiting from the specificity of aptamer, signal amplification of FNP label and pDEP on-line enrichment, this assay can detect as low as 93 and 270 cfu mL(-1)S. aureus in deionized water and spiked water samples, respectively, with higher sensitivities than our previously reported AptS.aureus/FNP based flow cytometry. Moreover, without the need for separation and washing steps usually required for FNP label involved bioassays, the total assay time including sample pretreatment was within 2 h. PMID:25963028

  14. Supersymmetry and dark matter post LHC8: Why we may expect both axion and WIMP detection

    SciTech Connect

    Baer, Howard [Dep't of Physics and Astronomy, University of Oklahoma, Norman, OK 73019 (United States)

    2014-01-01

    In the post-LHC8 era, it is perceived that what is left of SUSY model parameter space is highly finetuned in the EW sector (EWFT). We discuss how conventional measures overestimate EWFT in SUSY theory. Radiatively-driven natural SUSY (RNS) models maintain the SUSY GUT paradigm with low EWFT at 10% level, but are characterized by light higgsinos ~100–300 GeV and a thermal underabundance of WIMP dark matter. Implementing the SUSY DFSZ solution to the strong CP problem explains the small ? parameter but indicates dark matter should be comprised mainly of axions with a small admixture of higgsino-like WIMPs. While RNS might escape LHC14 searches, we would expect ultimately direct detection of both WIMPs and axions. An e?e? collider with ?(s)~500–600 GeV should provide a thorough search for the predicted light higgsinos.

  15. Results on low mass WIMPs using an upgraded CRESST-II detector

    NASA Astrophysics Data System (ADS)

    Angloher, G.; Bento, A.; Bucci, C.; Canonica, L.; Erb, A.; von Feilitzsch, F.; Iachellini, N. Ferreiro; Gorla, P.; Gütlein, A.; Hauff, D.; Huff, P.; Jochum, J.; Kiefer, M.; Kister, C.; Kluck, H.; Kraus, H.; Lanfranchi, J.-C.; Loebell, J.; Münster, A.; Petricca, F.; Potzel, W.; Pröbst, F.; Reindl, F.; Roth, S.; Rottler, K.; Sailer, C.; Schäffner, K.; Schieck, J.; Schmaler, J.; Scholl, S.; Schönert, S.; Seidel, W.; von Sivers, M.; Stodolsky, L.; Strandhagen, C.; Strauss, R.; Tanzke, A.; Uffinger, M.; Ulrich, A.; Usherov, I.; Wawoczny, S.; Willers, M.; Wüstrich, M.; Zöller, A.

    2014-12-01

    The CRESST-II cryogenic dark matter search aims for the detection of WIMPs via elastic scattering off nuclei in CaWO crystals. We present results from a low-threshold analysis of a single upgraded detector module. This module efficiently vetoes low energy backgrounds induced by -decays on inner surfaces of the detector. With an exposure of 29.35 kg live days collected in 2013 we set a limit on spin-independent WIMP-nucleon scattering which probes a new region of parameter space for WIMP masses below 3 GeV/c, previously not covered in direct detection searches. A possible excess over background discussed for the previous CRESST-II phase 1 (from 2009 to 2011) is not confirmed.

  16. Downregulation of c-Met expression does not enhance the sensitivity of gastric cancer cell line MKN-45 to gefitinib.

    PubMed

    Ma, Jin-An; Hu, Chunhong; Li, Wenjuan; Ren, Jing; Zou, Fangwen; Zhou, Dongai; Zou, Wen; Wei, Yajun; Zhou, Ying

    2015-03-01

    The aim of the present study was to investigate the effect of downregulation of the c?Met gene on signal transduction and apoptosis in gastric cancer MKN?45 cells; furthermore, the study aimed to determine whether altered c?Met gene expression affected MKN?45 sensitivity to gefitinib. Three c?Met?specific small interfering RNAs (siRNAs) were synthesized and transfected into MKN?45 cells. Messenger RNA (mRNA) and protein levels of c?Met and its downstream signaling molecules [phosphoinositide 3?kinase (PI3K) and AKT] were examined using reverse transcription polymerase chain reaction and western blot analysis 48 h following transfection. Cell apoptosis was evaluated using Annexin?V/propidium iodide double staining and fluorescence?activated cell sorting analysis. An MTT assay was performed in order to measure the 50% inhibitory concentration (IC50) of gefitinib on MKN?45 cells. The results of the present study demonstrated that 48 h post?transfection with c?Met siRNA, MKN?45 cells showed significantly downregulated expression of c?Met mRNA and protein as well as an increased rate of apoptosis (P<0.05). In addition, following c?Met siRNA transfection mRNA and protein levels of PI3K and AKT were not significantly altered in MKN?45 cells (P>0.05); however, a marked decrease in the expression levels of phosphorylated (p)?PI3K and p?AKT was observed (P<0.05). Furthermore, the IC50 of gefitinib in MKN?45 cells was not significantly decreased. In conclusion, knockdown of the c?Met gene promoted gastric cancer cell apoptosis and inhibited downstream p?PI3K and p?AKT; however, the sensitivity of MKN?45 cells to gefitinib was not increased. PMID:25395073

  17. Heating, moisture, and water budgets of tropical and midlatitude squall lines - Comparisons and sensitivity to longwave radiation

    NASA Technical Reports Server (NTRS)

    Tao, W.-K.; Simpson, J.; Sui, C.-H.; Ferrier, B.; Lang, S.; Scala, J.; Chou, M.-D.; Pickering, K.

    1993-01-01

    A 2D time-dependent and nonhydrostatic numerical cloud model is presently used to estimate the heating, moisture, and water budgets in the convective and stratiform regions for both a tropical and a midlatitude squall line. The model encompasses a parameterized, three-class ice phase microphysical scheme and longwave radiative transfer process. It is noted that the convective region plays an important role in the generation of stratiform rainfall for both cases. While a midlevel minimum in the moisture profile for the tropical case is due to vertical eddy transport in the convective region, the contribution to the heating budget by the cloud-scale fluxes is minor; by contrast, the vertical eddy heat-flux is relatively important for the midlatitude case due to the stronger vertical velocities present in the convective cells.

  18. Exclusion Limits on the WIMP: Nucleon Cross-section from the Cryogenic Dark Matter Search

    NSDL National Science Digital Library

    Abusaidi, R.

    2000-01-01

    From University of California-Berkeley's Center for Particle Astrophysics, this paper entitled "Exclusion Limits on the WIMP-Nucleon Cross-section from the Cryogenic Dark Matter Search" is a collaboration of the Cryogenic Dark Matter Search (CDMS). The CDMS consists of "looking for dark matter in the form of Weakly Interacting Massive Particles, or WIMPs. One attempt to solve the dark matter problem hypothesizes the existence of an undiscovered particle that was in thermal equilibrium with the very early universe." This paper delves into aspects of solving the dark matter problem.

  19. Use of the human monocytic leukemia THP-1 cell line and co-incubation with microsomes to identify and differentiate hapten and prohapten sensitizers.

    PubMed

    Chipinda, Itai; Ruwona, Tinashe B; Templeton, Steven P; Siegel, Paul D

    2011-02-27

    Consumer and medical products can contain leachable chemical allergens which can cause skin sensitization. Recent efforts have been directed at the development of non-animal based tests such as in vitro cell activation assays for the identification of skin sensitizers. Prohapten identification by in vitro assays is still problematic due to the lack of prohapten bioactivation. The present study evaluated the effect of hapten and prohapten exposure on cell surface markers expression (CD86, CD54 and CD40) in the human monocytic leukemia, THP-1, cell line. Upregulation of activation and costimulatory markers are key events in the allergic sensitization process and have been reported to serve as indicators of skin sensitization. Cells were exposed to the prohaptens benzo(a)pyrene (BaP), 7,12-dimethylbenz(a)anthracene (DMBA), carvone oxime (COx), cinnamic alcohol (CA) and isoeugenol (IEG) at concentrations ranging from 1 to 10 ?M for 24 and 48 h. The direct-binding haptens dinitrochlorobenzene (DNCB), benzoquinone (BQ), hydroxylethyl acrylate (HEA) and benzylbromide (BB) were used as positive controls. Cells were also exposed to the irritants sodium dodecyl sulfate (SDS) and sulfanilamide (SFA). Bioactivation of prohaptens was achieved by adding aroclor-induced rat liver microsomes (S9) to the cell cultures. Consistent upregulation of surface expressions of CD86, CD54 (ICAM-1) and CD40 was observed in THP-1 cells treated with direct-acting haptens (±S9) or prohapten (+S9). Upregulation of these markers was not observed after exposure to skin irritants or prohaptens in the absence of exogenously added S9. In conclusion, modification of in vitro cell culture assays to include co-incubation with microsomes enhances identification of prohaptens and allows them to be clearly distinguished from direct-binding haptens. PMID:21163322

  20. Anion exchange chromatography for the determination of 5-methyl-2'-deoxycytidine: application to cisplatin-sensitive and cisplatin-resistant ovarian cancer cell lines.

    PubMed

    Iglesias, Tamara; Espina, Marta; Montes-Bayón, María; Sierra, Luisa María; Blanco-González, Elisa

    2015-03-01

    Epigenetic alterations are increasingly implicated in the initiation and progression of cancer. Genome-wide (global) hypomethylation seems to occur in early neoplasia and is a feature of genomic DNA derived from solid tumour tissues like ovarian cancer. Thus, analytical methods that provide sensitive and quantitative information about cytosine methylation in DNA are currently required. In this work, we compare two different anion-exchange columns for the separation of methylated cytosine from the other DNA nucleotides: a silica-based (Tracer Extrasil SAX) column and a polystyrene/divinyl benzene-based (Mono-Q™) column. Under the optimised conditions, linearity range, precision and detection limits of the developed high-performance liquid chromatography (HPLC) method were evaluated and compared using conventional ultraviolet (UV) absorbance detection at 270 nm. Good separation of the five target nucleotides, including 5-methyl-2'-deoxycytidine monophosphate (5mdCMP) and 2'-deoxycytidine monophosphate (dCMP) was achieved on the Mono-Q™ column with a gradient elution of ammonium acetate buffer (1 M, pH 6.9) at a flow rate of 1 mL min(-1). The coupling of this column to inductively coupled plasma mass spectrometry (ICP-MS) permitted also phosphorous ((31)P) specific detection of the nucleotides. Both detection systems offered adequate analytical performance characteristics, with detection limits of 30 and 40 ?g L(-1) for 5mdCMP by HPLC-UV and HPLC-ICP-MS, respectively. However, the latter method allowed the determination of the global DNA methylation level (%) without the need for external calibration. Different genomic DNA samples were analysed including calf thymus DNA and DNA from two human cancer cell lines (adenocarcinoma epithelial A549 and ovarian carcinoma A2780) using the proposed strategy. In the line A2780, the cisplatin-sensitive and cisplatin-resistant variants were analysed, finding no significant differences in the methylation percentage after treatment with cisplatin. PMID:25142048

  1. Automated and sensitive analysis of 28-epihomobrassinolide in Arabidopsis thaliana by on-line polymer monolith microextraction coupled to liquid chromatography-mass spectrometry.

    PubMed

    Wang, Xin; Ma, Qiao; Li, Min; Chang, Cuilan; Bai, Yu; Feng, Yuqi; Liu, Huwei

    2013-11-22

    By on-line solid phase microextraction with polymer monolith coupled to liquid chromatography-mass spectrometry (SPME-LC-MS), an automated and sensitive method for analysis of the endogenous 28-epihomobrassinolide (28-epihomoBR) in Arabidopsis thaliana was developed in this work. Firstly, a poly(methacrylic acid-co-ethylene dimethacrylate) (poly(MAA-co-EDMA)) monolith was prepared in the capillary and applied in in-tube SPME. Polyethylene glycol (PEG) was used as porogen to adjust the specific surface area and hydrophobicity of the target monolith to get satisfactory permeability, high mechanical strength and good stability. The optimized monolith was then served as extraction medium for analysis of the derivatized 28-epihomoBR in plant samples with the cleanup of matrix and enrichment of desired analyte at the same time. Good linearity was obtained in the linear range of 5-500 ng/L with the coefficient of determination (R(2)) of 0.9996. The limit of detection (S/N=3) of 28-epihomoBR was found to be 2.0 ng/L and the limit of quantification (S/N=10) was 5.0 ng/L. Using this method, the endogenous 0.101 ng/g (FW) 28-epihomoBR was successfully detected from only 400mg A. thaliana samples with satisfactory recovery (80.3-92.1%) and reproducibility (RSD 6.8-9.6%). Comparing with other sample pretreatment methods, this automated on-line SPME-LC-MS method is rapid, sensitive, reproducible and laborsaving. PMID:23915641

  2. Peroxyacetyl nitrate-induced oxidative and calcium signaling events leading to cell death in ozone-sensitive tobacco cell-line

    PubMed Central

    Yukihiro, Masaru; Hiramatsu, Takuya; Bouteau, Francois; Kadono, Takashi; Kawano, Tomonori

    2012-01-01

    It has long been concerned that some secondary air pollutants such as smog components, ozone (O3) and peroxyacetyl nitrate (PAN), are highly phytotoxic even at low concentrations. Compared with the biology of O3, we largely lack the information on the toxicity model for PAN at the cellular signaling levels. Here, we studied the cell-damaging impact of PAN using suspension culture of smog-sensitive tobacco variety (Bel-W3). The cells were exposed to freshly synthesized PAN and the induced cell death was assessed under microscope after staining with Evans blue. Involvement of reactive oxygen species (ROS) in PAN toxicity was suggested by PAN-dependently increased intracellular H2O2 and also by the cell-protective effects of ROS scavengers and related inhibitors. Calcium chelator also lowered the level of PAN-induced cell death, indicating that Ca2+ is also involved. Using a transgenic cell line expressing aequorin, an increase in cytosolic Ca2+ concentration responsive to the pulse of PAN, but sensitive to Ca2+ channel blockers, was recorded, indicating that Ca2+ channels are activated by PAN or PAN-derived signals. Above data show some similarity between the signaling mechanisms responsive to O3 and PAN. PMID:22301977

  3. Insulin-like Growth Factor 1 Differentially Affects Lithium Sensitivity of Lymphoblastoid Cell Lines from Lithium Responder and Non-responder Bipolar Disorder Patients.

    PubMed

    Milanesi, Elena; Hadar, Adva; Maffioletti, Elisabetta; Werner, Haim; Shomron, Noam; Gennarelli, Massimo; Schulze, Thomas G; Costa, Marta; Del Zompo, Maria; Squassina, Alessio; Gurwitz, David

    2015-07-01

    Bipolar disorder (BD) is a chronic psychiatric illness with an unknown etiology. Lithium is considered the cornerstone in the management of BD, though about 50-60 % of patients do not respond sufficiently to chronic treatment. Insulin-like growth factor 1 (IGF1) has been identified as a candidate gene for BD susceptibility, and its low expression has been suggested as a putative biomarker for lithium unresponsiveness. In this study, we examined the in vitro effects of insulin-like growth factor 1 (IGF-1) on lithium sensitivity in lymphoblastoid cell lines (LCLs) from lithium responder (R) and non-responder (NR) bipolar patients. Moreover, we evaluated levels of microRNA let-7c, a small RNA predicted to target IGF1. We found that exogenous IGF-1 added to serum-free media increased lithium sensitivity selectively in LCLs from NR BD patients. However, no significant differences were observed when comparing let-7c expression in LCLs from R vs. NR BD patients. Our data support a key role for IGF-1 in lithium resistance/response in the treatment of bipolar disorder. PMID:25740013

  4. Quantitative analysis of the effect of tubulin isotype expression on sensitivity of cancer cell lines to a set of novel colchicine derivatives

    PubMed Central

    2010-01-01

    Background A maximum entropy approach is proposed to predict the cytotoxic effects of a panel of colchicine derivatives in several human cancer cell lines. Data was obtained from cytotoxicity assays performed with 21 drug molecules from the same family of colchicine compounds and correlate these results with independent tubulin isoform expression measurements for several cancer cell lines. The maximum entropy method is then used in conjunction with computed relative binding energy values for each of the drug molecules against tubulin isotypes to which these compounds bind with different affinities. Results We have found by using our analysis that ??I and ??III tubulin isoforms are the most important isoforms in establishing predictive response of cancer cell sensitivity to colchicine derivatives. However, since ??I tubulin is widely distributed in the human body, targeting it would lead to severe adverse side effects. Consequently, we have identified tubulin isotype ??III as the most important molecular target for inhibition of microtubule polymerization and hence cancer cell cytotoxicity. Tubulin isotypes ??I and ??II are concluded to be secondary targets. Conclusions The benefit of being able to correlate expression levels of specific tubulin isotypes and the resultant cell death effect is that it will enable us to better understand the origin of drug resistance and hence design optimal structures for the elimination of cancer cells. The conclusion of the study described herein identifies tubulin isotype ??III as a target for optimized chemotherapy drug design. PMID:20509970

  5. A Sensitive and Rapid Assay for Investigating Vertical Transmission of Hepatitis B Virus via Male Germ Line Using EGFP Vector as Reporter

    PubMed Central

    Ahmed, Mohamed Morsi M.; Huang, Tian-Hua; Xie, Qing-Dong

    2008-01-01

    Hepatitis B virus (HBV) constitutes a serious menace to man. DNA recombination and sequencing, interspecific in vitro fertilization, single-embryo PCR and RT-PCR were employed to establish a sensitive and rapid assay for exploring the vertical transmission of viruses via male germ line. Plasmid pIRES2-EGFP-HBs which expressed enhanced green fluorescent protein as reporter for the expression of hepatitis B virus S gene was successfully constructed and confirmed by PCR, EcoR I and Sal I digestion, and DNA sequencing. After exposure to the plasmid, human spermatozoa were used to fertilize with zona-free hamster ova. Two-cell embryos were collected and classified into group A with green fluorescence and group B without green fluorescence under fluorescence microscope. The results showed that HBs DNA positive bands were detected in the embryos with green fluorescence (PCR and RT-PCR) and positive control (PCR) indicating expression of pIRES2-EGFP-HBs, and not observed in the embryos without green fluorescence and negative controls (PCR and RT-PCR) indicating no pIRES2-EGFP-HBs in the cells. The advantages and application foreground of this assay for study on vertical transmission of viruses such as HCV, HIV, HPV, and SARS via germ line were discussed. PMID:18670607

  6. Low Energy Nuclear Recoil Response in Xenon Gas for Low Mass Dark Matter WIMP Search 

    E-print Network

    Sofka, Clement James

    2014-04-16

    neutralino, seems to fit perfectly into both particle physics and cosmology. First estimates from a Minimal Supersymmetric Standard Model (MSSM) placed the WIMP in the mass range of O(10) - O(10^(3)) GeV/c^(2). However, there is mounting evidence in recent...

  7. Impacts of WIMP dark matter upon stellar evolution: main-sequence stars

    E-print Network

    Pat Scott; Malcolm Fairbairn; Joakim Edsjö

    2008-10-30

    The presence of large amounts of WIMP dark matter in stellar cores has been shown to have significant effects upon models of stellar evolution. We present a series of detailed grids of WIMP-influenced stellar models for main sequence stars, computed using the DarkStars code. We describe the changes in stellar structure and main sequence evolution which occur for masses ranging from 0.3 to 2.0 solar masses and metallicities from Z = 0.0003-0.02, as a function of the rate of energy injection by WIMPs. We then go on to show what rates of energy injection can be obtained using realistic orbital parameters for stars near supermassive black holes, including detailed considerations of dark matter halo velocity and density profiles. Capture and annihilation rates are strongly boosted when stars follow elliptical rather than circular orbits, causing WIMP annihilation to provide up to 100 times the energy of hydrogen fusion in stars at the Galactic centre.

  8. The Physics Case for Axions, WIMPs, WISPs and Other Weird Stuff

    E-print Network

    Joerg Jaeckel

    2008-09-18

    We argue that there exists an excellent `physics case' motivating the search for axions, WIMPs, WISPs and other phenomena testable at low energies. This physics case arises from both experimental and observational evidence as well as the desire to test theoretical model building.

  9. The Physics Case for Axions, WIMPs, WISPs and Other Weird Stuff

    E-print Network

    Jaeckel, Joerg

    2008-01-01

    We argue that there exists an excellent `physics case' motivating the search for axions, WIMPs, WISPs and other phenomena testable at low energies. This physics case arises from both experimental and observational evidence as well as the desire to test theoretical model building.

  10. Determining Properties of WIMP Dark Matter with Direct Detection Experiments as Model Independently as Possible

    E-print Network

    Peters, Achim

    Determining Properties of WIMP Dark Matter with Direct Detection Experiments as Model Independently) are one of the leading candidates for Dark Matter. Currently, the most promising method to detect and their couplings on nucleons from direct Dark Matter detection experiments are essential. In this talk I

  11. DHFR-mediated effects of methotrexate in medulloblastoma and osteosarcoma cells: The same outcome of treatment with different doses in sensitive cell lines

    PubMed Central

    NERADIL, JAKUB; PAVLASOVA, GABRIELA; SRAMEK, MARTIN; KYR, MICHAL; VESELSKA, RENATA; STERBA, JAROSLAV

    2015-01-01

    Although methotrexate (MTX) is the most well-known antifolate included in many standard therapeutic regimens, substantial toxicity limits its wider use, particularly in pediatric oncology. Our study focused on a detailed analysis of MTX effects in cell lines derived from two types of pediatric solid tumors: medulloblastoma and osteosarcoma. The main aim of this study was to analyze the effects of treatment with MTX at concentrations comparable to MTX plasma levels in patients treated with high-dose or low-dose MTX. The results showed that treatment with MTX significantly decreased proliferation activity, inhibited the cell cycle at S-phase and induced apoptosis in Daoy and Saos-2 reference cell lines, which were found to be MTX-sensitive. Furthermore, no difference in these effects was observed following treatment with various doses of MTX ranging from 1 to 40 ?M. These findings suggest the possibility of achieving the same outcome with the application of low-dose MTX, an extremely important result, particularly for clinical practice. Another important aspect of treatment with high-dose MTX in clinical practice is the administration of leucovorin (LV) as an antidote to reduce MTX toxicity in normal cells. For this reason, the combined application of MTX and LV was also included in our experiments; however, this application of MTX together with LV did not elicit any detectable effect. The expression analysis of genes involved in the mechanisms of resistance to MTX was a final component of our study, and the results helped us to elucidate the mechanisms of the various responses to MTX among the cell lines included in our study. PMID:25739012

  12. DHFR-mediated effects of methotrexate in medulloblastoma and osteosarcoma cells: the same outcome of treatment with different doses in sensitive cell lines.

    PubMed

    Neradil, Jakub; Pavlasova, Gabriela; Sramek, Martin; Kyr, Michal; Veselska, Renata; Sterba, Jaroslav

    2015-05-01

    Although methotrexate (MTX) is the most well-known antifolate included in many standard therapeutic regimens, substantial toxicity limits its wider use, particularly in pediatric oncology. Our study focused on a detailed analysis of MTX effects in cell lines derived from two types of pediatric solid tumors: medulloblastoma and osteosarcoma. The main aim of this study was to analyze the effects of treatment with MTX at concentrations comparable to MTX plasma levels in patients treated with high-dose or low-dose MTX. The results showed that treatment with MTX significantly decreased proliferation activity, inhibited the cell cycle at S-phase and induced apoptosis in Daoy and Saos-2 reference cell lines, which were found to be MTX-sensitive. Furthermore, no difference in these effects was observed following treatment with various doses of MTX ranging from 1 to 40 µM. These findings suggest the possibility of achieving the same outcome with the application of low-dose MTX, an extremely important result, particularly for clinical practice. Another important aspect of treatment with high-dose MTX in clinical practice is the administration of leucovorin (LV) as an antidote to reduce MTX toxicity in normal cells. For this reason, the combined application of MTX and LV was also included in our experiments; however, this application of MTX together with LV did not elicit any detectable effect. The expression analysis of genes involved in the mechanisms of resistance to MTX was a final component of our study, and the results helped us to elucidate the mechanisms of the various responses to MTX among the cell lines included in our study. PMID:25739012

  13. First measurement of the Head-Tail directional nuclear recoil signature at energies relevant to WIMP dark matter searches

    E-print Network

    S. Burgos; E. Daw; J. Forbes; C. Ghag; M. Gold; C. Hagemann; V. A. Kudryavtsev; T. B. Lawson; D. Loomba; P. Majewski; D. Muna; A. StJ. Murphy; G. G. Nicklin; S. M. Paling; A. Petkov; S. J. S. Plank; M. Robinson; N. Sanghi; D. P. Snowden-Ifft; N. J. C. Spooner; J. Turk; E. Tziaferi

    2008-09-10

    We present first evidence for the so-called Head-Tail asymmetry signature of neutron-induced nuclear recoil tracks at energies down to 1.5 keV/amu using the 1m^3 DRIFT-IIc dark matter detector. This regime is appropriate for recoils induced by Weakly Interacting Massive Particle (WIMPs) but one where the differential ionization is poorly understood. We show that the distribution of recoil energies and directions induced here by Cf-252 neutrons matches well that expected from massive WIMPs. The results open a powerful new means of searching for a galactic signature from WIMPs.

  14. Line selection and sensitivity analysis for oxygen sensing in the 1.26-1.27 micron spectral band for the ASCENDS mission

    NASA Astrophysics Data System (ADS)

    Prasad, N.; Browell, E. V.; Zaccheo, T. S.; Karpowicz, B.

    2010-12-01

    The National Research Council’s (NRC) Decadal Survey (DS) of Earth Science and Applications from Space has identified the Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) as an important atmospheric science mission. The CO2 mixing ratio needs to be measured to a precision of 0.5 percent of background or better (slightly less than 2 ppm) at 100-km horizontal resolution overland and 200-km resolution over oceans. To meet this goal, the ASCENDS mission requires simultaneous laser remote sensing of CO2 and O2 in order to convert CO2 column number densities to average column CO2 mixing ratios (XCO2). As such, the CO2 column number density and the O2 column number density will be utilized to derive the average XCO2 column. NASA Langley Research Center, working with its partners, is developing O2 lidar technology in the 1.26-1.27-?m band for surface pressure measurements. To obtain XCO2 with LAS technique the simultaneous measurement of the CO2 column number density, the O2 column number density for converting the CO2 column number density to XCO2 and the total path length of the measurement are required. The O2 LAS operating at 1.26 ?m will be used to convert CO2 number density to mixing ratio. The 1.26-?m spectral band was chosen due to architectural advantage from wavelengths being close to 1.57-?m CO2 LAS column measurements and the favorable spectroscopic characteristics of the O2 absorption line parameters. Furthermore, the surface and atmospheric scattering characteristics from aerosols and thin clouds are nearly the same as for 1.26-?m O2 measurements and the 1.57-?m CO2 measurements. One or more "on-line" wavelengths in the 1.26-?m O2 absorption band have to be carefully chosen to eliminate ambient influences on them when used in conjunction with the integrated path differential absorption (IPDA) technique. The O2 model optical depth calculation is very sensitive to knowledge of the transmitted wavelengths and to the choice of Voigt input parameters. Uncertainties in atmospheric profiles of temperature, pressure and relative humidity can cause ~0.5 % errors in model optical depths. Uncertainties at line center and offset wavelengths of the candidate on-line wavelengths have to be precisely known to reduce uncertainties in O2 concentration measurements from airborne and space based platforms. In this paper, we evaluate systematic relative errors related to uncertainties in O2 absorption line pressure shifts and atmospheric temperature for selected O2 absorption lines suitable for making high precision O2 and XCO2 measurements based on HITRAN database and O2 absorption line measurements.

  15. Isolation of INS-1-derived cell lines with robust ATP-sensitive K+ channel-dependent and -independent glucose-stimulated insulin secretion.

    PubMed

    Hohmeier, H E; Mulder, H; Chen, G; Henkel-Rieger, R; Prentki, M; Newgard, C B

    2000-03-01

    The biochemical mechanisms involved in regulation of insulin secretion are not completely understood. The rat INS-1 cell line has been used to gain insight in this area because it secretes insulin in response to glucose concentrations in the physiological range. However, the magnitude of the response is far less than that seen in freshly isolated rat islets. In the current study, we have stably transfected INS-1 cells with a plasmid containing the human proinsulin gene. After antibiotic selection and clonal expansion, 67% of the resultant clones were found to be poorly responsive to glucose in terms of insulin secretion (< or =2-fold stimulation by 15 mmol/l compared with 3 mmol/l glucose), 17% of the clones were moderately responsive (2- to 5-fold stimulation), and 16% were strongly responsive (5- to 13-fold stimulation). The differences in responsiveness could not be ascribed to differences in insulin content. Detailed analysis of one of the strongly responsive lines (832/13) revealed that its potent response to glucose (average of 10-fold) was stable over 66 population doublings (approximately 7.5 months of tissue culture) with half-maximal stimulation at 6 mmol/l glucose. Furthermore, in the presence of 15 mmol/l glucose, insulin secretion was potentiated significantly by 100 pmol/l isobutylmethylxanthine (320%), 1 mmol/l oleate/palmitate (77%), and 50 nmol/l glucagon-like peptide 1 (60%), whereas carbachol had no effect. Glucose-stimulated insulin secretion was also potentiated by the sulfonylurea tolbutamide (threefold at 3 mmol/l glucose and 50% at 15 mmol/l glucose) and was abolished by diazoxide, which demonstrates the operation of the ATP-sensitive K+ channel (K(ATP)) in 832/13 cells. Moreover, when the K(ATP) channel was bypassed by incubation of cells in depolarizing K+ (35 mmol/l), insulin secretion was more effectively stimulated by glucose in 832/13 cells than in parental INS-1 cells, which demonstrates the presence of a K(ATP) channel-independent pathway of glucose sensing. We conclude that clonal selection of INS-1 cells allows isolation of cell lines that exhibit markedly enhanced and stable responsiveness to glucose and several of its known potentiators. These lines may be attractive new vehicles for studies of beta-cell function. PMID:10868964

  16. Differential effects of all-trans-retinoic acid, docosahexaenoic acid, and hexadecylphosphocholine on cisplatin-induced cytotoxicity and apoptosis in a cisplantin-sensitive and resistant human embryonal carcinoma cell line

    Microsoft Academic Search

    Hetty Timmer-Bosscha; Elisabeth G. E. de Vries; C. Meijer; J. Wolter Oosterhuis; Nanno H. Mulder

    1998-01-01

    Apart from modulation of tumor-cell drug sensitivity, induction of differentiation might be an alternative in the treatment\\u000a of tumors resistant to cytotoxic drugs. In this report the capacity to induce differentiation and to modulate the cis-diamminedichloroplatinum(II)\\u000a (CDDP) sensitivity of all-trans-retinoic acid (RA), docosahexaenoic acid (DCHA), and hexadecylphosphocholine (HePC) is examined in human germ-cell tumor cell\\u000a lines. In the embryonal carcinoma

  17. Development of an in vitro skin sensitization test using human cell lines: the human Cell Line Activation Test (h-CLAT). I. Optimization of the h-CLAT protocol.

    PubMed

    Ashikaga, T; Yoshida, Y; Hirota, M; Yoneyama, K; Itagaki, H; Sakaguchi, H; Miyazawa, M; Ito, Y; Suzuki, H; Toyoda, H

    2006-08-01

    The aim of this study is to optimize the experimental conditions for an in vitro skin sensitization test using the human cell lines THP-1 and U-937. As regards pre-culturing time, the expression of CD86 on DNCB-treated THP-1 cells tended to be higher after 48h and 72h pre-culture compared with other time points evaluated. Next, we investigated the effect of chemical treatment time, and found that induction of CD86 expression on THP-1 cells by DNCB reached a plateau after 24h. Augmentation of CD86 expression is often observed when cells are treated with a subtoxic dose of allergens. To determine the appropriate dose of test samples, the cytotoxicity of test samples to THP-1 and U-937 cells was assessed with MTT assay, and the 50% inhibitory concentration (IC50) of each test sample was calculated. Based on the cytotoxicity assay data, four concentrations in the range between toxic and non-toxic were selected (0.1x, 0.5x, 1x and 2x IC50). Several kinds of antibodies were tested for staining THP-1 and U-937 cells treated with allergens/non-allergens (e.g., DNCB, Ni/SLS), and suitable antibodies for staining CD86 and CD54 were selected. We confirmed that the working dilutions of the selected CD86 and CD54 antibodies were appropriate for use in our method. The effect of an FcR blocking procedure was also evaluated. The mean fluorescence intensity (MFI value) was decreased by the FcR blocking procedure, which indicated that non-specific staining was blocked. Therefore, this procedure should be included in the method. Based on our findings, the protocol for this assay was optimized and the experimental conditions to be used in a future validation study were identified. We propose to call this kind of in vitro skin sensitization test h-CLAT, which is short for human Cell Line Activation Test. PMID:16311011

  18. PI3K/Akt inhibition and down-regulation of BCRP re-sensitize MCF7 breast cancer cell line to mitoxantrone chemotherapy

    PubMed Central

    Komeili-Movahhed, Tahereh; Fouladdel, Shamileh; Barzegar, Elmira; Atashpour, Shekoufeh; Hossein Ghahremani, Mohammad; Nasser Ostad, Seyed; Madjd, Zahra; Azizi, Ebrahim

    2015-01-01

    Objective(s): Multidrug resistance (MDR) of cancer cells is a major obstacle to successful chemotherapy. Overexpression of breast cancer resistance protein (BCRP) is one of the major causes of MDR. In addition, it has been shown that PI3K/Akt signaling pathway involves in drug resistance. Therefore, we evaluated the effects of novel approaches including siRNA directed against BCRP and targeted therapy against PI3K/Akt signaling pathway using LY294002 (LY) to re-sensitize breast cancer MCF7 cell line to mitoxantrone (MTX) chemotherapy. Materials and Methods: Anticancer effects of MTX, siRNA, and LY alone and in combination were evaluated in MCF7 cells using MTT cytotoxicity assay and flow cytometry analysis of cell cycle distribution and apoptosis induction. Results: MTT and apoptosis assays showed that both MTX and LY inhibited cell proliferation and induced apoptosis in MCF7 cells. Results indicated that inhibition of BCRP by siRNA or PI3K/Akt signaling pathway by LY significantly increased sensitivity of MCF7 cells to antiproliferation and apoptosis induction of MTX. Furthermore, MTX showed G2/M arrest, whereas LY induced G0/G1 arrest in cell cycle distribution of MCF7 cells. Combination of siRNA or LY with MTX chemotherapy significantly increased accumulation of MCF7 cells in the G2/M phase of cell cycle. Conclusion: Combination of MTX chemotherapy with BCRP siRNA and PI3K/Akt inhibition can overcome MDR in breast cancer cells. This study furthermore suggests that novel therapeutic approaches are needed to enhance anticancer effects of available drugs in breast cancer.

  19. Molecular basis for sensitivity and acquired resistance to gefitinib in HER2-overexpressing human gastric cancer cell lines derived from liver metastasis

    PubMed Central

    Yokoyama, H; Ikehara, Y; Kodera, Y; Ikehara, S; Yatabe, Y; Mochizuki, Y; Koike, M; Fujiwara, M; Nakao, A; Tatematsu, M; Nakanishi, H

    2006-01-01

    Gastric cancer metastasised to the liver was found to overexpress HER2 at a significantly higher incidence than primary gastric cancers. The purpose of the present study was to investigate the possibility of molecular therapy targeting HER2 overexpression in gastric cancer liver metastasis. We developed three new HER2-overexpressing gastric cancer cell lines (GLM-1, GLM-2, GLM-4) without epidermal growth factor receptor (EGFR) mutations derived from such liver metastasis, two of which had HER2 gene amplifications. All these GLM series of cell lines were highly sensitive to gefitinib in vitro, a specific inhibitor of EGFR tyrosine kinase (Iressa) rather than anti-HER2 antibody trastuzumab (Herceptin), whereas most of the HER2 low-expressing counterparts were not. In these HER2-overexpressing GLM series, protein kinase B (Akt), but not extracellular signal-regulated kinase 1/2 (ERK1/2), was constitutively phosphorylated, and gefitinib efficiently inhibited this Akt phosphorylation, induced strong apoptosis in vitro and exhibited antitumour activity in tumour xenografts in nude mice. This gefitinib-mediated antitumour effect in xenograft was significantly potentiated by trastuzumab treatment. On the other hand, gefitinib-resistant cells (GLM-1R) exhibited increased EGFR expression, followed by constitutive activation of mitogen-activated protein kinase (MAPK) pathway. These results suggest that the antitumour effect of gefitinib is due to the effective inhibition of HER2-driven constitutive activation of phosphatidylinositol-3-kinase (PI3K)/Akt pathway, and that the acquired resistance to gefitinib is due to the constitutive activation of Ras/MAPK pathway in compensation for PI3K/Akt pathway. Gastric cancer liver metastasis with HER2 overexpression would be a potential molecular target for gefitinib and trastuzumab. PMID:17088902

  20. Resting Glutamate Levels and Rapid Glutamate Transients in the Prefrontal Cortex of the Flinders Sensitive Line Rat: A Genetic Rodent Model of Depression

    PubMed Central

    Hascup, Kevin N; Hascup, Erin R; Stephens, Michelle L; Glaser, Paul EA; Yoshitake, Takashi; Mathé, Aleksander A; Gerhardt, Greg A; Kehr, Jan

    2011-01-01

    Despite the numerous drugs targeting biogenic amines for major depressive disorder (depression), the search for novel therapeutics continues because of their poor response rates (?30%) and slow onset of action (2–4 weeks). To better understand role of glutamate in depression, we used an enzyme-based microelectrode array (MEA) that was selective for glutamate measures with fast temporal (2?Hz) and high spatial (15 × 333??m) resolution. These MEAs were chronically implanted into the prefrontal cortex of 3- to 6-month-old and 12- to 15-month-old Flinders Sensitive Line (FSL) and control Flinders Resistant Line (FRL) rats, a validated genetic rodent model of depression. Although no changes in glutamate dynamics were observed between 3 and 6 months FRL and FSL rats, a significant increase in resting glutamate levels was observed in the 12- to 15-month-old FSL rats compared with the 3- to 6-month-old FSL and age-matched FRL rats on days 3–5 post-implantation. Our MEA also recorded, for the first time, a unique phenomenon in all the four rat groups of fluctuations in resting glutamate, which we have termed glutamate transients. Although these events lasted only for seconds, they did occur throughout the testing paradigm. The average concentration of these glutamate-burst events was significantly increased in the 12- to 15-month-old FSL rats compared with 3- to 6-month-old FSL and age-matched FRL rats. These studies lay the foundation for future studies of both tonic and phasic glutamate signaling in rat models of depression to better understand the potential role of glutamate signaling in depression. PMID:21525860

  1. Dark matter in the solar system I: The distribution function of WIMPs at the Earth from solar capture

    E-print Network

    Annika H. G. Peter

    2009-02-09

    The next generation of dark matter (DM) direct detection experiments and neutrino telescopes will probe large swaths of dark matter parameter space. In order to interpret the signals in these experiments, it is necessary to have good models of both the halo DM streaming through the solar system and the population of DM bound to the solar system. In this paper, the first in a series of three on DM in the solar system, we present simulations of orbits of DM bound to the solar system by solar capture in a toy solar system consisting of only the Sun and Jupiter, assuming that DM consists of a single species of weakly interacting massive particle (WIMP). We describe how the size of the bound WIMP population depends on the WIMP mass, spin-independent cross section, and spin-dependent cross section. Using a standard description of the Galactic DM halo, we find that the maximum enhancement to the direct detection event rate, consistent with current experimental constraints on the WIMP-nucleon cross section, is < 1% relative to the event rate from halo WIMPs, while the event rate from neutrinos from WIMP annihilation in the center of the Earth is unlikely to meet the threshold of next-generation, km^3-sized (IceCube, KM3NeT) neutrino telescopes.

  2. Development of Nano-Liposomal Formulations of Epidermal Growth Factor Receptor Inhibitors and their Pharmacological Interactions on Drug-Sensitive and Drug-Resistant Cancer Cell Lines

    NASA Astrophysics Data System (ADS)

    Trummer, Brian J.

    A rapidly expanding understanding of molecular derangements in cancer cell function has led to the development of selective, targeted chemotherapeutic agents. Growth factor signal transduction networks are frequently activated in an aberrant fashion, particularly through the activity of receptor tyrosine kinases (RTK). This has spurred an intensive effort to develop receptor tyrosine kinase inhibitors (RTKI) that are targeted to specific receptors, or receptor subfamilies. Chapter 1 reviews the pharmacology, preclinical, and clinical aspects of RTKIs that target the epidermal growth factor receptor (EGFR). EGFR inhibitors demonstrate significant success at inhibiting phosphorylation-based signaling pathways that promote cancer cell proliferation. Additionally RTKIs have physicochemical and structural characteristics that enable them to function as inhibitors of multi-drug resistance transport proteins. Thus EGFR inhibitors and other RTKIs have both on-target and off-target activities that could be beneficial in cancer therapy. However, these agents exert a number of side effects, some of which arise from their hydrophobic nature and large in vivo volume of distribution. Side effects of the EGFR inhibitor gefitinib include skin rash, severe myelotoxicity when combined with certain chemotherapeutic agents, and impairment of the blood brain barrier to xenobiotics. Weighing the preclinical and clinical observations with the EGFR inhibitors, we developed the primary overall hypothesis of this research: that drug-carrier formulations of RTKIs such as the EGFR inhibitors could be developed based on nanoparticulate liposomal carriers. Theoretically, this carrier strategy would ameliorate toxicity and improve the biodistribution and tumor selectivity of these agents. We hypothesized specifically that liposomal formulations could shift the biodistribution of EGFR inhibitors such as gefitinib away from skin, bone marrow, and the blood brain barrier, and toward solid tumors, due to leaky tumor vasculature and the resulting Enhanced Permeability and Retention (EPR) phenomenon. In Chapter 2 we report that both gefitinib and the structurally similar EGFR inhibitor erlotinib display environment-dependent fluorescence properties. Peak excitation was 345 nm, and the emission peak ranged from 365 to 476 nm, depending upon the polarity of the environment and physical state of the drug. The fluorescence was negligible in aqueous solution, but intense in organic solvents or membrane bilayers. The environment-sensitive fluorescence properties of these drugs enabled rapid evaluation of numerous parameters affecting liposomal drug incorporation and performance. Up to 4-6 mol% of gefitinib could be incorporated in the liposome bilayer, based upon hydrophobic interactions with membrane bilayers. In contrast, 40-60 mol% could be loaded into the aqueous core of pre-formed liposomes at high efficiency, using a remote loading procedure. A stable formulation consisting of distearoylphosphatidylcholine: polyethylene glycol-distereoylphosphatidylethanolamine: cholesterol (DSPC:PEGDSPE:Chol, 9:1:5 mol:mol:mol) and containing drug at 50-60 mol% gefitinib (L-GEF) showed minimal leakage in serum-containing medium over 24 h at 37°C, which should be sufficient to improve biodistribution in vivo. Chapter 3 investigated the pharmacological activity of liposome-encapsulated gefitinib, alone and in combination with several prevalent anticancer agents. Experiments with MCF7 breast cancer cell lines demonstrated that liposome encapsulated gefitinib formulation (L-GEF) had a 2-fold higher IC50 (concentration of drug resulting in half-maximal growth inhibition) than free gefitinib. Lower in vitro potency would be consistent with delayed drug release from the carrier. Therapeutic effects were investigated in combination with the cytotoxic agents paclitaxel and doxorubicin. The drug-resistant MCF7R cell line was 23-fold more resistant to paclitaxel than the parental, drug-sensitive MCF7S cell line, and MCF7R was 12-fold more resistant than MCF7S to doxorubicin. A conce

  3. Depth-Sensitivity Relation (DSR) for Underground Laboratories

    Microsoft Academic Search

    D.-M. Mei; A. Hime; S. R. Elliott; V. M. Gehman; K. Kazkaz

    2006-01-01

    Muon-induced background can limit the sensitivity of next generation experiments searching for neutrinoless double beta decay and WIMP dark matter. We have established the DSR based upon the muon and muon-induced fast neutron fluxes and spectra for a number of underground laboratories. Our results indicate that the muon-induced neutron elastic and inelastic scattering processes create a significant background for germanium-based

  4. Tests on NaI(Tl) crystals for WIMP search at the Yangyang Underground Laboratory

    NASA Astrophysics Data System (ADS)

    Kim, K. W.; Kang, W. G.; Oh, S. Y.; Adhikari, P.; So, J. H.; Kim, N. Y.; Lee, H. S.; Choi, S.; Hahn, I. S.; Jeon, E. J.; Joo, H. W.; Kim, B. H.; Kim, H. J.; Kim, Y. D.; Kim, Y. H.; Lee, J. K.; Leonard, D. S.; Li, J.; Olsen, S. L.; Park, H. S.

    2015-03-01

    Among the direct searches for WIMP-type dark matter, the DAMA experiment is unique in that it has consistently reported a positive signal for an annual-modulation signal with a large (9.3?) statistical significance. This result is controversial because if it is interpreted as a signature for WIMP interactions, it conflicts with other direct search experiments that report null signals in the regions of parameter space that are allowed by the DAMA observation. This necessitates an independent verification of the origin of the observed modulation signal using the same technique as that employed by the DAMA experiment, namely low-background NaI(Tl) crystal detectors. Here, we report first results of a program of NaI(Tl) crystal measurements at the Yangyang Underground Laboratory aimed at producing NaI(Tl) crystal detectors with lower background levels and higher light yields than those used for the DAMA measurements.

  5. Out-of-equilibrium Baryogenesis and SuperWIMP Dark Matter

    E-print Network

    Arcadi, Giorgio; Nardecchia, Marco

    2013-01-01

    The experimental fact that the energy density in Dark Matter and in Baryons is of the same order is one of the most puzzling in cosmology. In this letter we suggest a new mechanism able to explain this coincidence in the context of out-of-equilibrium baryogenesis with DM production "\\`a la" SuperWIMP starting from the same initial particle. We then discuss two simple implementations of this scenario within supersymmetric models with gravitino DM.

  6. Reevaluation of spin-dependent WIMP-proton interactions as an explanation of the DAMA data

    E-print Network

    Eugenio Del Nobile; Graciela B. Gelmini; Andreea Georgescu; Ji-Haeng Huh

    2015-07-10

    We reexamine the interpretation of the annual modulation signal observed by the DAMA experiment as due to WIMPs with a spin-dependent coupling mostly to protons. We consider both axial-vector and pseudo-scalar couplings, and elastic as well as endothermic and exothermic inelastic scattering. We conclude that the DAMA signal is in strong tension with null results of other direct detection experiments, particularly PICASSO and KIMS.

  7. Limits on WIMP cross-sections from the NAIAD experiment at the Boulby Underground Laboratory

    Microsoft Academic Search

    G. J. Alner; H. M. Araújo; G. J. Arnison; J. C. Barton; A. Bewick; C. Bungau; B. Camanzi; M. J. Carson; D. Davidge; G. J. Davies; E. Daw; J. V. Dawson; C. Duffy; T. J. Durkin; T. Gamble; S. P. Hart; R. Hollingworth; G. J. Homer; A. S. Howard; I. Ivaniouchenkov; W. G. Jones; M. K. Joshi; J. Kirkpatrick; V. A. Kudryavtsev; T. B. Lawson; V. Lebedenko; M. J. Lehner; P. K. Lightfoot; I. Liubarsky; R. Lüscher; J. E. McMillan; B. Morgan; A. Murphy; G. Nicklin; A. Nickolls; S. M. Paling; R. M. Preece; J. J. Quenby; J. W. Roberts; M. Robinson; N. J. T. Smith; P. F. Smith; N. J. C. Spooner; T. J. Sumner; D. R. Tovey; E. Tziaferi

    2005-01-01

    The NAIAD experiment (NaI Advanced Detector) for WIMP dark matter searches at the Boulby Underground Laboratory (North Yorkshire, UK) ran from 2000 until 2003. A total of 44.9 kg×years of data collected with 2 encapsulated and 4 unencapsulated NaI(Tl) crystals with high light yield were included in the analysis. We present final results of this analysis carried out using pulse

  8. The Effects of QCD Equation of State on the Relic Density of WIMP Dark Matter

    E-print Network

    Drees, Manuel; Schmitz, Ernany Rossi

    2015-01-01

    Weakly Interactive Massive Particles (WIMPs) are the most widely studied candidate particles forming the cold dark matter (CDM) whose existence can be inferred from a wealth of astrophysical and cosmological observations. In the framework of the minimal cosmological model detailed measurements on the cosmic microwave background by the PLANCK collaboration fix the scaled CDM relic density to $\\Omega_{c}h^2=0.1193\\pm0.0014$, with an error of less than 1.5%. In order to fully exploit this observational precision, theoretical calculations should have a comparable or smaller error. In this paper we use recent lattice QCD calculations to improve the description of the thermal plasma. This affects the predicted relic density of "thermal WIMPs", which once were in chemical equilibrium with Standard Model particles. For WIMP masses between 3 and 15 GeV, where QCD effects are most important, our predictions differ from earlier results by up to 9% (12%) for pure S-wave (P-wave) annihilation. We use these results to comp...

  9. Nuclear ?-terms and Scalar-Isoscalar WIMP-Nucleus Interactions from Lattice QCD

    E-print Network

    S. R. Beane; S. D. Cohen; W. Detmold; H. -W. Lin; M. J. Savage

    2015-03-18

    It has been argued that the leading scalar-isoscalar WIMP-nucleus interactions receive parametrically enhanced contributions in the context of nuclear effective field theories. These contributions arise from meson-exchange currents (MECs) and potentially modify the impulse approximation estimates of these interactions by 10--60%. We point out that these MECs also contribute to the quark mass dependence of nuclear binding energies, that is, nuclear \\sigma-terms. In this work, we use recent lattice QCD calculations of the binding energies of the deuteron, He-3 and He-4 at pion masses near 500 MeV and 800 MeV, combined with the experimentally determined binding energies at the physical point, to provide approximate determinations of the \\sigma-terms for these light nuclei. For each nucleus, we find that the deviation of the corresponding nuclear \\sigma-term from the single-nucleon estimate is at the few percent level, in conflict with the conjectured enhancement. As a consequence, lattice QCD calculations currently indicate that the cross sections for scalar-isoscalar WIMP-nucleus interactions arising from fundamental WIMP interactions with quarks do not suffer from significant uncertainties due to enhanced meson-exchange currents.

  10. Secluded WIMPs, QED with massive photons, and the galactic center gamma-ray excess

    E-print Network

    Fortes, E C F S; Stecker, F W

    2015-01-01

    We propose to investigate a secluded WIMP dark matter model consisting of neutral fermions as the dark matter candidate and a Proca-Wentzel (PW) field as a mediator. In the model that we consider here, dark matter WIMPs interact with standard model (SM) particles only through the PW field of ~ MeV -- multi-GeV mass particles. The interactions occur via an U(1)' mediator, V_{\\mu}', which couples to the SM by kinetic mixing with U(1) hypercharge bosons, B_{\\mu}. One important difference between our model and other such models in the literature is the absence of an extra singlet scalar, so that the parameter with dimension of mass M^2_V is not related to a spontaneous symmetry breaking. The mass scale of the mediator and the absence of the singlet scalar can lead to interesting astrophysical signatures. We show that the GeV-energy gamma-ray excess in the galactic center region, as derived from Fermi-LAT Gamma-ray Space Telescope data, can be attributed to such secluded dark matter WIMPs, given parameters of the ...

  11. Secluded WIMPs, QED with massive photons, and the galactic center gamma-ray excess

    E-print Network

    E. C. F. S. Fortes; V. Pleitez; F. W. Stecker

    2015-05-05

    We propose to investigate a secluded WIMP dark matter model consisting of neutral fermions as the dark matter candidate and a Proca-Wentzel (PW) field as a mediator. In the model that we consider here, dark matter WIMPs interact with standard model (SM) particles only through the PW field of ~ MeV -- multi-GeV mass particles. The interactions occur via an U(1)' mediator, V_{\\mu}', which couples to the SM by kinetic mixing with U(1) hypercharge bosons, B_{\\mu}. One important difference between our model and other such models in the literature is the absence of an extra singlet scalar, so that the parameter with dimension of mass M^2_V is not related to a spontaneous symmetry breaking. This QED based model is also renormalizable. The mass scale of the mediator and the absence of the singlet scalar can lead to interesting astrophysical signatures. The dominant annihilation channels are different from those usually considered in previous work. We show that the GeV-energy gamma-ray excess in the galactic center region, as derived from Fermi-LAT Gamma-ray Space Telescope data, can be attributed to such secluded dark matter WIMPs, given parameters of the model that are consistent with the cosmological dark matter density.

  12. Neutrinos from WIMP annihilation in the Sun : Implications of a self-consistent model of the Milky Way's dark matter halo

    E-print Network

    Susmita Kundu; Pijushpani Bhattacharjee

    2012-05-21

    Upper limits on the spin-independent (SI) as well as spin-dependent (SD) elastic scattering cross sections of WIMPs with protons, imposed by the Super-Kamiokande (S-K) upper limit on the neutrino flux from WIMP annihilation in the Sun, and their compatibility with the "DAMA-compatible" regions of the WIMP parameter space within which the annual modulation signal observed by the DAMA/LIBRA experiment is compatible with the null results of other direct detection experiments, are studied within the frame work of a self-consistent model of the finite-size dark matter (DM) halo of the Galaxy, the parameters of which are determined by a fit to the rotation curve data of the Galaxy. We find that the S-K implied upper limits on the WIMP-proton elastic cross section as a function of WIMP mass impose stringent restrictions on the branching fractions of the various WIMP annihilation channels. For SI interaction, while the S-K upper limits are consistent with the DAMA-compatible region of the WIMP parameter space if the WIMPs annihilate dominantly to $\\bbarb$\\ and/or $\\cbarc$, portions of the DAMA-compatible region can be excluded if WIMP annihilations to $\\tautau$ and $\

  13. Tricyclic Antidepressant Amitriptyline-induced Glial Cell Line-derived Neurotrophic Factor Production Involves Pertussis Toxin-sensitive G?i/o Activation in Astroglial Cells.

    PubMed

    Hisaoka-Nakashima, Kazue; Miyano, Kanako; Matsumoto, Chie; Kajitani, Naoto; Abe, Hiromi; Okada-Tsuchioka, Mami; Yokoyama, Akinobu; Uezono, Yasuhito; Morioka, Norimitsu; Nakata, Yoshihiro; Takebayashi, Minoru

    2015-05-29

    Further elaborating the mechanism of antidepressants, beyond modulation of monoaminergic neurotransmission, this study sought to elucidate the mechanism of amitriptyline-induced production of glial cell line-derived neurotrophic factor (GDNF) in astroglial cells. Previous studies demonstrated that an amitriptyline-evoked matrix metalloproteinase (MMP)/FGF receptor (FGFR)/FGFR substrate 2? (FRS2?)/ERK cascade is crucial for GDNF production, but how amitriptyline triggers this cascade remains unknown. MMP is activated by intracellular mediators such as G proteins, and this study sought to clarify the involvement of G protein signaling in amitriptyline-evoked GDNF production in rat C6 astroglial cells (C6 cells), primary cultured rat astrocytes, and normal human astrocytes. Amitriptyline-evoked GDNF mRNA expression and release were inhibited by pertussis toxin (PTX), a G?i/o inhibitor, but not by NF449, a G?s inhibitor, or YM-254890, a G?q inhibitor. The activation of the GDNF production cascade (FGFR/FRS2?/ERK) was also inhibited by PTX. Deletion of G??1 and G?i3 by RNAi demonstrated that these G proteins play important roles in amitriptyline signaling. G protein activation was directly analyzed by electrical impedance-based biosensors (CellKey(TM) assay), using a label-free (without use of fluorescent proteins/probes or radioisotopes) and real time approach. Amitriptyline increased impedance, indicating G?i/o activation that was suppressed by PTX treatment. The impedance evoked by amitriptyline was not affected by inhibitors of the GDNF production cascade. Furthermore, FGF2 treatment did not elicit any effect on impedance, indicating that amitriptyline targets PTX-sensitive G?i/o upstream of the MMP/FGFR/FRS2?/ERK cascade. These results suggest novel targeting for the development of antidepressants. PMID:25869129

  14. USE OF A MURINE EMBRYONIC STEM CELL LINE THAT IS SENSITIVE TO HIGH GLUCOSE ENVIRONMENT TO MODEL NEURAL TUBE DEVELOPMENT IN DIABETIC PREGNANCY

    PubMed Central

    Sanders, Kaitlyn; Jung, Jin Hyuk; Loeken, Mary R.

    2014-01-01

    Background Neural tube defects (NTDs) are significantly increased by maternal diabetes. Embryonic stem cells (ESC) that can differentiate into neuroepithelium and can sense supraphysiological glucose concentrations would be very valuable to simulate the effects of maternal diabetes on molecular and cellular processes during neural tube formation. Methods LG-ESC, a recently established ESC line that expresses the glucose transporter, Scl2a2, and is sensitive to elevated glucose concentrations, were grown for up to 8 days in a 3-dimensional culture to form neural cysts (NC). We tested whether high glucose media inhibits expression of Pax3, a gene that is required for neural tube closure and whose expression is inhibited in embryos of diabetic mice, and inhibits formation of NC. Results Pax3 expression was detected after 4 days of culture and increased with time. Pax3 expression was inhibited by high glucose media, but not if cells had been cultured in low glucose media for the first 4 days of culture. Pax7, which is also expressed in dorsal neural tube, was not detected. Pax6, which is expressed in the ventral neural tube, was detected only after 8 days of culture, but was not inhibited by high glucose. High glucose media did not inhibit formation of NC. Conclusions LG-ESC can be used as a model of embryonic exposure to a diabetic environment during neural tube development. While high glucose exposure inhibits expression of a gene required for neural tube closure, it may not inhibit all of the processes involved in formation of a neural tube-like structure. PMID:25124397

  15. In vitro cross-resistance and collateral sensitivity in seven resistant small-cell lung cancer cell lines: preclinical identification of suitable drug partners to taxotere, taxol, topotecan and gemcitabin.

    PubMed Central

    Jensen, P. B.; Holm, B.; Sorensen, M.; Christensen, I. J.; Sehested, M.

    1997-01-01

    The acquisition of drug-resistant tumour cells is the main problem in the medical treatment of a range of malignant diseases. In recent years, three new classes of anti-cancer agents, each with a novel mechanism of action, have been brought forward to clinical trials. These are the topoisomerase I (topo I) poisons topotecan and irinotecan, which are both camptothecin derivatives, the taxane tubulin stabilizers taxol and taxotere and, finally, the antimetabolite gemcitabin, which is active in solid tumours. The process of optimizing their use in a combination with established agents is very complex, with numerous possible drug and schedule regimens. We describe here how a broad panel of drug-resistant small-cell lung cancer (SCLC) cell lines can be used as a model of tumour heterogeneity to aid in the selection of non-cross-resistant regimens. We have selected low-fold (3-10x) drug-resistant sublines from a classic (NCI-H69) and a variant (OC-NYH) SCLC cell line. The resistant cell lines include two sublines with different phenotypes towards alkylating agents (H69/BCNU and NYH/CIS), two sublines with different phenotypes against topo I poisons (NYH/CAM and NYH/TPT) and three multidrug resistant (MDR) sublines (H69/DAU, NYH/VM, and H69/VP) with combinations of mdr1 and MRP overexpression as well as topoisomerase II (topo II) down-regulation or mutation. Sensitivity to 20 established and new agents was measured in a standardized clonogenic assay. Resistance was highly drug specific. Thus, none of the cell lines was resistant to all drugs. In fact, all resistant cell lines exhibited patterns of collateral sensitivity to various different classes of drugs. The most intriguing pattern was collateral sensitivity to gemcitabin in two cell lines and to ara-C in five drug-resistant cell lines, i.e. in all lines except the lines resistant to topo I poisons. Next, all sensitivity patterns in the nine cell lines were compared by correlation analysis. A high correlation coefficient (CC) for a given pair of compounds indicates a similar pattern in response in the set of cell lines. Such data corroborate the view that there is cross-resistance among the drugs. A numerically low coefficient indicates that the two drugs are acting in different ways, suggesting a lack of cross-resistance between the drugs, and a negative correlation coefficient implies that two drugs exhibit collateral sensitivity. The most negative CCs (%) to the new drug leads were: taxotere-carmustine (BCNU) (-75), taxol-cisplatin (-58), ara-C-taxol (-25), gemcitabin-doxorubicin (-32), camptotecin-VM26 (-41) and topotecan-VP16 (-17). The most negative correlations to the clinically important agent VP-16 were: cisplatin (-70); BCNU (-68); camptothecin (-38); bleomycin (-33), gemcitabin (-32); ara-C (-21); topotecan (-17); melphalan (-3); and to the other main drug in SCLC treatment cisplatin were: doxorubicin (-70); VP-16 (-70); VM-26 (-69); mAMSA (-64); taxotere (-58); taxol (-58). Taxol and taxotere were highly correlated (cross-resistant) to VP-16 (0.76 and 0.81 respectively) and inversely correlated to cisplatin (both -0.58). Similarly, camptothecin and topotecan were correlated to cisplatin but inversely correlated to VP-16 and other topo II poisons. From the sensitivity data, we conclude that collateral sensitivity and lack of cross-resistance favours a cisplatin-taxane or topo I-topo II poison combination, whereas patterns of cross-resistance suggest that epipodophyllotoxin-taxane or topo I poison-cisplatin combinations may be disadvantageous. PMID:9062409

  16. Phase-sensitive optical coherence tomography at up to 370,000 lines per second using buffered Fourier domain mode-locked lasers

    Microsoft Academic Search

    Desmond C. Adler; Robert Huber; James G. Fujimoto

    2007-01-01

    Buffered Fourier domain mode-locked (FDML) lasers are demonstrated for dynamic phase-sensitive optical coherence tomography (OCT) and 3D OCT phase microscopy. Systems are operated at sweep speeds of 42, 117, and 370 kHz, and displacement sensitivities of 39, 52, and 102 pm are achieved, respectively. Sensitivities are comparable to spectrometer-based OCT phase microscopy systems, but much faster acquisition speeds are possible.

  17. Sensitive sequential-injection system for the determination of 2-phenylbenzimidazole-5-sulphonic acid in human urine samples using on-line solid-phase extraction coupled with fluorimetric detection

    Microsoft Academic Search

    M. T Vidal; A Chisvert; A Salvador

    2003-01-01

    2-Phenylbenzimidazole-5-sulphonic acid (PBS) is an UV-filter contained in many cosmetics as a sunscreen. A direct, selective and sensitive method to determine traces of PBS is presented. The on-line separation of this compound from urine matrix was directly coupled with fluorimetric detection in a sequential-injection system. The separation was performed using a SAX microcolumn in which the analyte was retained and

  18. Gene profiles of a human bronchial epithelial cell line after in vitro exposure to respiratory (non-)sensitizing chemicals: Identification of discriminating genetic markers and pathway analysis

    Microsoft Academic Search

    Sandra Verstraelen; Inge Nelissen; Jef Hooyberghs; Hilda Witters; Greet Schoeters; Paul Van Cauwenberge; Rosette Van Den Heuvel

    2009-01-01

    Respiratory sensitization is a concern for occupational and environmental health in consumer product development. Despite international regulatory requirements there is no established protocol for the identification of chemical respiratory sensitizers. New tests should be based on mechanistic understanding and should be preferentially restricted to in vitro assays. The major goal of this study was to investigate the alterations in gene

  19. The relationship between CD86/CD54 expression and THP-1 cell viability in an in vitro skin sensitization test--human cell line activation test (h-CLAT).

    PubMed

    Sakaguchi, Hitoshi; Ashikaga, Takao; Miyazawa, Masaaki; Kosaka, Nanae; Ito, Yuichi; Yoneyama, Katsurako; Sono, Sakiko; Itagaki, Hiroshi; Toyoda, Hidekazu; Suzuki, Hiroyuki

    2009-04-01

    Recent regulations for cosmetics in Europe prohibit animal testing for evaluating the sensitization potential of chemicals to improve animal welfare. Yet, there is not an acceptable Organization for Economic Co-operation and Development non-animal skin sensitization test method. Several in vitro skin sensitization methods that focus on the activation of Langerhans cells, including human cell lines, are being evaluated as possible alternatives. In our previous study, we optimized our human cell line activation test (h-CLAT) using THP-1 cells (monocytic leukemia cell line) and conducted an inter-laboratory study. We found that measuring CD86/CD54 expression may be useful for predicting skin sensitization. The aim of this study was to confirm the relationship between CD86/CD54 expression and THP-1 cell viability in the h-CLAT. In this study, 21 allergens (e.g., dinitrochlorobenzene, p-phenylenediamine, Ni) and 8 non-allergens (e.g., SLS, lactic acid) were evaluated. For each chemical, more than 10 concentrations that gave a predicted cell viability range of 20-95% were used. The data showed that expression patterns of CD86/CD54 differed depending on chemical. For most allergens, cytotoxicity (65-90% cell viability) was needed for enhancement of CD86/CD54 expression. The criteria of "CD86 > or = 150 or CD54 > or = 200" resulted in an accuracy of 93%, which confirms appropriate cut-off criteria for h-CLAT. Furthermore, a good correlation was observed between EC3 of local lymph node assay and EC150(CD86) or EC200(CD54) of h-CLAT (12 or 16 chemicals, respectively), which would provide a useful estimate of allergic potency. These findings suggest that h-CLAT would be a good robust in vitro skin sensitization test. PMID:18204907

  20. The Search for Milky Way Halo Substructure WIMP Annihilations Using the GLAST LAT

    SciTech Connect

    Wai, Larry; /SLAC

    2007-02-05

    The GLAST LAT Collaboration is one among several experimental groups, covering a wide range of approaches, pursuing the search for the nature of dark matter. The GLAST LAT has the unique ability to find new sources of high energy gamma radiation emanating directly from WIMP annihilations in situ in the universe. Using it's wide band spectral and full sky spatial capabilities, the GLAST LAT can form ''images'' in high energy gamma-rays of dark matter substructures in the gamma-ray sky. We describe a preliminary feasibility study for indirect detection of milky way dark matter satellites using the GLAST LAT.

  1. WIMP-less dark matter and meson decays with missing energy

    SciTech Connect

    McKeen, David [Enrico Fermi Institute and Department of Physics, University of Chicago, 5640 South Ellis Avenue, Chicago, Illinois 60637 (United States)

    2009-06-01

    WIMP-less dark matter [J. L. Feng and J. Kumar, Phys. Rev. Lett. 101, 231301 (2008).] offers an attractive framework in which dark matter can be very light. We investigate the implications of such scenarios on invisible decays of bottomonium states for dark matter with a mass less than around 5 GeV. We relate these decays to measurements of nucleon-dark matter elastic scattering. We also investigate the effect that a coupling to s quarks has on flavor changing b{yields}s processes involving missing energy.

  2. Improved Limits on Spin-Dependent WIMP-Proton Interactions from a Two Liter CF$_3$I Bubble Chamber

    E-print Network

    E. Behnke; J. Behnke; S. J. Brice; D. Broemmelsiek; J. I. Collar; P. S. Cooper; M. Crisler; C. E. Dahl; D. Fustin; J. Hall; J. H. Hinnefeld; M. Hu; I. Levine; E. Ramberg; T. Shepherd; A. Sonnenschein; M. Szydagis

    2011-03-07

    Data from the operation of a bubble chamber filled with 3.5 kg of CF$_{3}$I in a shallow underground site are reported. An analysis of ultrasound signals accompanying bubble nucleations confirms that alpha decays generate a significantly louder acoustic emission than single nuclear recoils, leading to an efficient background discrimination. Three dark matter candidate events were observed during an effective exposure of 28.1 kg-day, consistent with a neutron background. This observation provides the strongest direct detection constraint to date on WIMP-proton spin-dependent scattering for WIMP masses $>20$ GeV/c$^{2}$.

  3. Improved Limits on Spin-Dependent WIMP-Proton Interactions from a Two Liter CF3I Bubble Chamber

    NASA Astrophysics Data System (ADS)

    Behnke, E.; Behnke, J.; Brice, S. J.; Broemmelsiek, D.; Collar, J. I.; Cooper, P. S.; Crisler, M.; Dahl, C. E.; Fustin, D.; Hall, J.; Hinnefeld, J. H.; Hu, M.; Levine, I.; Ramberg, E.; Shepherd, T.; Sonnenschein, A.; Szydagis, M.

    2011-01-01

    Data from the operation of a bubble chamber filled with 3.5 kg of CF3I in a shallow underground site are reported. An analysis of ultrasound signals accompanying bubble nucleations confirms that alpha decays generate a significantly louder acoustic emission than single nuclear recoils, leading to an efficient background discrimination. Three dark matter candidate events were observed during an effective exposure of 28.1kgday, consistent with a neutron background. This observation provides strong direct detection constraints on weakly interacting massive particle (WIMP)-proton spin-dependent scattering for WIMP masses >20GeV/c2.

  4. Improved limits on spin-dependent WIMP-proton interactions from a two liter CF3I bubble chamber.

    PubMed

    Behnke, E; Behnke, J; Brice, S J; Broemmelsiek, D; Collar, J I; Cooper, P S; Crisler, M; Dahl, C E; Fustin, D; Hall, J; Hinnefeld, J H; Hu, M; Levine, I; Ramberg, E; Shepherd, T; Sonnenschein, A; Szydagis, M

    2011-01-14

    Data from the operation of a bubble chamber filled with 3.5 kg of CF3I in a shallow underground site are reported. An analysis of ultrasound signals accompanying bubble nucleations confirms that alpha decays generate a significantly louder acoustic emission than single nuclear recoils, leading to an efficient background discrimination. Three dark matter candidate events were observed during an effective exposure of 28.1??kg? day, consistent with a neutron background. This observation provides strong direct detection constraints on weakly interacting massive particle (WIMP)-proton spin-dependent scattering for WIMP masses >20??GeV/c2. PMID:21405218

  5. First results of the EDELWEISS WIMP search using a 320 g heat-and-ionization Ge detector

    NASA Astrophysics Data System (ADS)

    EDELWEISS Collaboration; Benoit, A.; Bergé, L.; Broniatowski, A.; Chambon, B.; Chapellier, M.; Chardin, G.; Charvin, P.; De Jésus, M.; Di Stefano, P.; Drain, D.; Dumoulin, L.; Gascon, J.; Gerbier, G.; Goldbach, C.; Goyot, M.; Gros, M.; Hadjout, J. P.; Juillard, A.; de Lesquen, A.; Loidl, M.; Mallet, J.; Marnieros, S.; Martineau, O.; Mirabolfathi, N.; Mosca, L.; Miramonti, L.; Navick, X.-F.; Nollez, G.; Pari, P.; Stern, M.; Vagneron, L.

    2001-07-01

    The EDELWEISS Collaboration has performed a direct search for WIMP dark matter using a 320 g heat-and-ionization cryogenic Ge detector operated in a low-background environment in the Laboratoire Souterrain de Modane. No nuclear recoils are observed in the fiducial volume in the 30-200 keV energy range during an effective exposure of 4.53 kgday. Limits for the cross-section for the spin-independent interaction of WIMPs and nucleons are set in the framework of the Minimal Supersymmetric Standard Model (MSSM). The central value of the signal reported by the experiment DAMA is excluded at 90% CL.

  6. Phase-sensitive optical coherence tomography at up to 370,000 lines per second using buffered Fourier domain mode-locked lasers

    NASA Astrophysics Data System (ADS)

    Adler, Desmond C.; Huber, Robert; Fujimoto, James G.

    2007-03-01

    Buffered Fourier domain mode-locked (FDML) lasers are demonstrated for dynamic phase-sensitive optical coherence tomography (OCT) and 3D OCT phase microscopy. Systems are operated at sweep speeds of 42, 117, and 370 kHz, and displacement sensitivities of 39, 52, and 102 pm are achieved, respectively. Sensitivities are comparable to spectrometer-based OCT phase microscopy systems, but much faster acquisition speeds are possible. An additional factor of sqrt 2 improvement in noise performance is observed for differential phase measurements, which is important for Doppler OCT. Dynamic measurements of piezoelectric transducer motion and static 3D OCT phase microscopy are demonstrated. Buffered FDML lasers provide excellent displacement sensitivities at extremely high sweep speeds.

  7. Phase-sensitive optical coherence tomography at up to 370,000 lines per second using buffered Fourier domain mode-locked lasers.

    PubMed

    Adler, Desmond C; Huber, Robert; Fujimoto, James G

    2007-03-15

    Buffered Fourier domain mode-locked (FDML) lasers are demonstrated for dynamic phase-sensitive optical coherence tomography (OCT) and 3D OCT phase microscopy. Systems are operated at sweep speeds of 42, 117, and 370 kHz, and displacement sensitivities of 39, 52, and 102 pm are achieved, respectively. Sensitivities are comparable to spectrometer-based OCT phase microscopy systems, but much faster acquisition speeds are possible. An additional factor of sqrt 2 improvement in noise performance is observed for differential phase measurements, which is important for Doppler OCT. Dynamic measurements of piezoelectric transducer motion and static 3D OCT phase microscopy are demonstrated. Buffered FDML lasers provide excellent displacement sensitivities at extremely high sweep speeds. PMID:17308582

  8. Carbamoylation of Glutathione Reducíaseand Changes in Cellular and Chromosome Morphology in a Rat Cell Line Resistant to Nitrogen Mustards but Collaterally Sensitive to Nitrosoureas1

    Microsoft Academic Search

    Kenneth D. Tew; Gregg Kyle; Alfred Johnson; Ann L. Wang

    A Walker 256 rat carcinoma cell line (WR) with acquired resistance to nitrogen mustards has been found to lack cross- resistance to nitrosoureas. Although total cellular glutathione pools were similar in the parent (WS) and resistant cell lines (WS, 2.5 x 10~6;WR, 2.0 x 10~6mol\\/mg protein), glutathione reduc- tase activity was 3.98 in WR compared to 8.67 nmol reduced nicotinamide

  9. On-line complexation\\/cloud point preconcentration for the sensitive determination of dysprosium in urine by flow injection inductively coupled plasma-optical emission spectrometry

    Microsoft Academic Search

    Claudia Ortega; Soledad Cerutti; Roberto A. Olsina; María F. Silva; Luis D. Martinez

    2003-01-01

    An on-line dysprosium preconcentration and determination system based on the hyphenation of cloud point extraction (CPE) to flow injection analysis (FIA) associated with ICP-OES was studied. For the preconcentration of dysprosium, a Dy(III)-2-(5-bromo-2-pyridylazo)-5-diethylaminophenol complex was formed on-line at pH 9.22 in the presence of nonionic micelles of PONPE-7.5. The micellar system containing the complex was thermostated at 30 °C in

  10. Silicon photonic crystal microarrays for high throughput label-free detection of lung cancer cell line lysates with sensitivity and specificity

    NASA Astrophysics Data System (ADS)

    Chakravarty, Swapnajit; Lai, Wei-Cheng; Zou, Yi; Gemmill, Robert M.; Chen, Ray T.

    2013-03-01

    Detection of biomolecules on microarrays based on label-free on-chip optical biosensors is very attractive since this format avoids complex chemistries caused by steric hindrance of labels. Application areas include the detection of cancers and allergens, and food-borne pathogens to name a few. We have demonstrated photonic crystal microcavity biosensors with high sensitivity down to 1pM concentrations (67pg/ml). High sensitivities were achieved by slow light engineering which reduced the radiation loss and increased the stored energy in the photonic crystal microcavity resonance mode. Resonances with high quality factor Q~26,760 in liquid ambient, coupled with larger optical mode volumes allowed enhanced interaction with the analyte biomolecules which resulted in sensitivities down to 10 cells per micro-liter to lung cancer cell lysates. The specificity of detection was ensured by multiplexed detections from multiple photonic crystal microcavities arrayed on the arms of a multimode interference power splitter. Specific binding interactions and control experiments were performed simultaneously at the same instant of time with the same 60 microliter sample volume. Specificity is further ensured by sandwich assay methods in the multiplexed experiment. Sandwich assay based amplification increased the sensitivity further resulting in the detection of lung cancer cell lysates down to concentrations of 2 cells per micro-liter. The miniaturization enabled by photonic crystal biosensors coupled with waveguide interconnected layout thus offers the potential of high throughput proteomics with high sensitivity and specificity.

  11. PoS(idm2008)116 WIMP neutrinos from the Sun and the Earth (15'+5')

    Microsoft Academic Search

    MATTIAS BLENNOW; JOAKIM EDSJÖ; TOMMY OHLSSON

    We discuss the propagation treatment of the indirect dark matter detection using WIMP annihi- lations in the Sun and the Earth. In particular, we focus on tr eating neutrino interactions and oscillations in a consistent framework, including tau neut rino regeneration and a full three-flavor neutrino oscillation framework. We also discuss the equivalence of using a Monte Carlo approach -

  12. Gene profiles of a human alveolar epithelial cell line after in vitro exposure to respiratory (non-)sensitizing chemicals: Identification of discriminating genetic markers and pathway analysis

    Microsoft Academic Search

    Sandra Verstraelen; Inge Nelissen; Jef Hooyberghs; Hilda Witters; Greet Schoeters; Paul Van Cauwenberge; Rosette Van Den Heuvel

    2009-01-01

    There are currently no accepted biological prediction models for assessing the potential of a substance to cause respiratory sensitization. New tests should be based on mechanistic understanding and should be preferentially restricted to in vitro assays. The major goal of this study was to investigate the alterations in gene expression of human alveolar epithelial (A549) cells after exposure to respiratory

  13. High Sensitivity CW-Cavity Ring Down Spectroscopy of five 13 isotopologues of carbon dioxide in the 1.26-1.44 m region (I): Line positions

    E-print Network

    Boyer, Edmond

    1 High Sensitivity CW-Cavity Ring Down Spectroscopy of five 13 CO2 isotopologues of carbon dioxide, Tomsk, Russia 12/11/2009 Key words: Carbon dioxide, CO2, Cavity Ring Down Spectroscopy, effective;2 Abstract The absorption spectrum of highly enriched 13 C carbon dioxide has been investigated by CW

  14. Generated using version 3.2 of the official AMS LATEX template Summer season squall line simulations: Sensitivity of gravity1

    E-print Network

    Alexander, M. Joan

    simulations: Sensitivity of gravity1 waves to physics parameterization and implications for their2.stephan@colorado.edu 1 #12;ABSTRACT6 Gravity waves have important effects on the middle atmosphere circulation, and those of gravity wave momentum flux above the storm irrespective of the19 convective details that coarse resolution

  15. HMOX1 and NQO1 genes are upregulated in response to contact sensitizers in dendritic cells and THP-1 cell line: role of the Keap1/Nrf2 pathway.

    PubMed

    Ade, Nadège; Leon, Fanny; Pallardy, Marc; Peiffer, Jean-Luc; Kerdine-Romer, Saadia; Tissier, Marie-Hélène; Bonnet, Pierre-Antoine; Fabre, Isabelle; Ourlin, Jean-Claude

    2009-02-01

    Electrophilicity is one of the most common features of skin contact sensitizers and is necessary for protein haptenation. The Keap1 (Kelch-like ECH-associated protein 1)/Nrf2 -signaling pathway is dedicated to the detection of electrophilic stress in cells leading to the upregulation of genes involved in protection or neutralization of chemical reactive species. Signals provided by chemical stress could play an important role in dendritic cell activation and the aim of this work was to test whether contact sensitizers were specific activators of the Keap1/Nrf2 pathway. CD34-derived dendritic cells (CD34-DC) and the THP-1 myeloid cell line were treated by a panel of sensitizers (Ni, 1-chloro 2,4-dinitrobenzene, cinnamaldehyde, 7-hydroxycitronellal, 1,4-dihydroquinone, alpha-methyl-trans-cinnamaldehyde, 2-4-tert-(butylbenzyl)propionaldehyde or Lilial, and 1,4-phenylenediamine), irritants (sodium dodecyl sulfate, benzalkonium chloride), and a nonsensitizer molecule (chlorobenzene). Three well-known Nrf2 activators (tert-butylhydroquinone, lipoic acid, sulforaphane) were also tested. Expression of hmox1 and nqo1 was measured using real-time PCR and cellular accumulation of Nrf2 was assessed by Western blot. Our results showed an increased expression at early time points of hmox1 and nqo1 mRNAs in response to sensitizers but not to irritants. Accumulation of the Nrf2 protein was also observed only with chemical sensitizers. A significant inhibition of the expression of hmox1 and nqo1 mRNAs and CD86 expression was found in 1-chloro 2,4-dinitrobenzene-treated THP-1 cells preincubated with N-acetyl cysteine, a glutathione precursor. Altogether, these data suggested that the Keap1/Nrf2-signaling pathway was activated by electrophilic molecules including sensitizers in dendritic cells and in the THP-1 cell line. Monitoring of this pathway may provide new biomarkers (e.g., Nrf2, hmox1) for the detection of the sensitization potential of chemicals. PMID:19033392

  16. Increased sensitivity of HPV-positive head and neck cancer cell lines to x-irradiation ± Cisplatin due to decreased expression of E6 and E7 oncoproteins and enhanced apoptosis.

    PubMed

    Ziemann, Frank; Arenz, Andrea; Preising, Stefanie; Wittekindt, Claus; Klussmann, Jens P; Engenhart-Cabillic, Rita; Wittig, Andrea

    2015-01-01

    Squamous cell carcinoma of the head and neck region (HNSCC), which is related to an infection with human papilloma virus (HPV), responds better to simultaneous radio-chemotherapy with Cisplatin based regimens than HPV-negative tumors. The underlying molecular mechanisms for this clinical observation are not fully understood. Therefore, the response of four HPV-positive (HPV+) (UM-SCC-47, UM-SCC-104, 93-VU-147T, UPCI:SCC152) and four HPV-negative (HPV-) (UD-SCC-1, UM-SCC-6, UM-SCC-11b, UT-SCC-33) HNSCC cell lines to x-irradiation ± Cisplatin incubation in terms of clonogenic survival, cell cycle progression, protein expression (cyclin A2, cyclin E2, E6, E7, p53) and induction of apoptosis, was investigated. HPV+ cells were more radio- and chemosensitive and were more effectively sensitized to x-irradiation by simultaneous Cisplatin incubation than HPV- cell lines. HPV+ cell lines revealed an increased and prolonged G2/M arrest after irradiation, whereas Cisplatin induced a blockage of cells in S phase. In comparison to irradiation only, addition of Cisplatin significantly enhanced apoptosis especially in HPV+ cell lines. While irradiation alone increased the amount of HPV E6 and E7 proteins, both were down-regulated by Cisplatin incubation either alone or in combination with x-rays, which however did not increase the expression of endogenous p53. Our results demonstrate that cell cycle deregulation together with downregulation of HPV E6 and E7 proteins facilitating apoptosis after Cisplatin incubation promote the enhanced sensitivity of HPV+ HNSCC cells to simultaneous radio-chemotherapy. Combined effects of irradiation and Cisplatin appear to be relevant in mediating the enhanced therapeutic response of HPV-related HNSCC and are indicative of the benefit of combined modality approaches in future treatment optimization strategies. PMID:26045983

  17. Increased sensitivity of HPV-positive head and neck cancer cell lines to x-irradiation ± Cisplatin due to decreased expression of E6 and E7 oncoproteins and enhanced apoptosis

    PubMed Central

    Ziemann, Frank; Arenz, Andrea; Preising, Stefanie; Wittekindt, Claus; Klussmann, Jens P; Engenhart-Cabillic, Rita; Wittig, Andrea

    2015-01-01

    Squamous cell carcinoma of the head and neck region (HNSCC), which is related to an infection with human papilloma virus (HPV), responds better to simultaneous radio-chemotherapy with Cisplatin based regimens than HPV-negative tumors. The underlying molecular mechanisms for this clinical observation are not fully understood. Therefore, the response of four HPV-positive (HPV+) (UM-SCC-47, UM-SCC-104, 93-VU-147T, UPCI:SCC152) and four HPV-negative (HPV-) (UD-SCC-1, UM-SCC-6, UM-SCC-11b, UT-SCC-33) HNSCC cell lines to x-irradiation ± Cisplatin incubation in terms of clonogenic survival, cell cycle progression, protein expression (cyclin A2, cyclin E2, E6, E7, p53) and induction of apoptosis, was investigated. HPV+ cells were more radio- and chemosensitive and were more effectively sensitized to x-irradiation by simultaneous Cisplatin incubation than HPV- cell lines. HPV+ cell lines revealed an increased and prolonged G2/M arrest after irradiation, whereas Cisplatin induced a blockage of cells in S phase. In comparison to irradiation only, addition of Cisplatin significantly enhanced apoptosis especially in HPV+ cell lines. While irradiation alone increased the amount of HPV E6 and E7 proteins, both were down-regulated by Cisplatin incubation either alone or in combination with x-rays, which however did not increase the expression of endogenous p53. Our results demonstrate that cell cycle deregulation together with downregulation of HPV E6 and E7 proteins facilitating apoptosis after Cisplatin incubation promote the enhanced sensitivity of HPV+ HNSCC cells to simultaneous radio-chemotherapy. Combined effects of irradiation and Cisplatin appear to be relevant in mediating the enhanced therapeutic response of HPV-related HNSCC and are indicative of the benefit of combined modality approaches in future treatment optimization strategies.

  18. Hsp90 inhibitor NVP-AUY922 enhances the radiation sensitivity of lung cancer cell lines with acquired resistance to EGFR-tyrosine kinase inhibitors.

    PubMed

    Hashida, Shinsuke; Yamamoto, Hiromasa; Shien, Kazuhiko; Ohtsuka, Tomoaki; Suzawa, Ken; Maki, Yuho; Furukawa, Masashi; Soh, Junichi; Asano, Hiroaki; Tsukuda, Kazunori; Miyoshi, Shinichiro; Kanazawa, Susumu; Toyooka, Shinichi

    2015-03-01

    Acquired resistance to epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) is a critical issue that needs to be overcome in the treatment of patients with non-small cell lung cancer (NSCLC) harboring EGFR activating mutations. EGFR and AKT are client proteins of the 90-kDa heat shock protein (Hsp90). Therefore, it was hypothesized that the use of Hsp90 inhibitors might allow the resistance to EGFR-TKIs to be overcome. Furthermore, Hsp90 inhibitors are known to function as radiosensitizers in various types of cancer. In the present study, we evaluated the radiosensitizing effect of the novel Hsp90 inhibitor, NVP-AUY922 (AUY), on NSCLC cell lines harboring EGFR activating mutations and showing acquired resistance to EGFR-TKIs via any of several mechanisms. We used HCC827 and PC-9, which are NSCLC cell lines harboring EGFR exon 19 deletions, and gefitinib-resistant sublines derived from the same cell lines with T790M mutation, MET amplification or stem-cell like properties. AUY was more effective against the gefitinib-resistant sublines with T790M mutation and MET amplification than against the parental cell lines, although the subline with stem cell-like properties showed more than a 10-fold higher resistance to AUY than the parental cell line. AUY exerted a significant radiosensitizing effect on the parental cell line and the MET-amplified subline through inducing G2/M arrest and inhibition of non-homologous end joining (NHEJ). In contrast, the radiosensitizing effect of AUY was limited on the subline with stem cell-like properties, in which it did not induce G2/M arrest or inhibition of NHEJ. In conclusion, combined inhibition of Hsp90 plus radiation was effective, and therefore a promising treatment alternative for overcoming major EGFR-TKI resistance, such as that induced by T790M mutation or MET amplification. However, other approaches are required to overcome minor resistance to EGFR-TKIs, such as that observed in cells with stem cell-like properties. PMID:25607753

  19. The Role of Cytidine Deaminase and GATA1 Mutations in the Increased Cytosine Arabinoside Sensitivity of Down Syndrome Myeloblasts and Leukemia Cell Lines

    Microsoft Academic Search

    Yubin Ge; Tanya L. Jensen; Mark L. Stout; Robin M. Flatley; Patrick J. Grohar; Yaddanapudi Ravindranath; Larry H. Matherly; Jeffrey W. Taub

    2004-01-01

    Myeloblasts from Down syndrome (DS) children with acute myeloid leukemia (AML) are significantly more sensitive in vitro to 1--D-arabino- furanosylcytosine (ara-C) and generate higher 1--D-arabinofuranosylcy- tosine 5-triphosphate (ara-CTP) than non-DS AML myeloblasts. Semi- quantitative reverse transcription-PCR analyses demonstrated that transcripts for cytidine deaminase (CDA) were 2.7-fold lower in DS than for non-DS myeloblasts. In contrast, transcripts of cystathionine--syn- thase and

  20. A novel method using Autographa californica multiple nucleopolyhedrovirus for increasing the sensitivity of insecticide through calcium influx in insect cell line.

    PubMed

    Licznar, Patricia; List, Olivier; Goven, Delphine; Nna, Rolande Ndong; Lapied, Bruno; Apaire-Marchais, Véronique

    2014-01-01

    Due to an intensive use of chemical insecticides, resistance mechanisms to insecticides together with adverse effects on non-target organisms have been largely reported. Improvement in pest control strategy represents an urgent need to optimize efficiency in the control of pest insects. In this context, a novel method based on the use of insect specific virus applied in combination with chemical insecticide, which could lead to sensitization of the insect target to insecticides is described. Insect virus, the baculovirus Autographa californica multiple nucleopolyhedrovirus (AcMNPV), applied onto Sf9 cells induces an increase of intracellular calcium concentration via extracellular calcium influx. Co-application of AcMNPV with chlorpyrifos-ethyl onto Sf9 cells expressing the key enzyme acetylcholinesterase (AChE), known to be targeted by organophosphate insecticides, increases 1.5-fold the sensitivity of AChE to the insecticide. This effect is correlated with intracellular calcium concentration rise since AcMNPV-induced potentiating insecticide effect is counteracted by pretreatment with the calcium channel blocker, cadmium chloride. Increasing insecticide target sensitivity through intracellular calcium modulation by using insect virus co-applied with a chemical insecticide is a very promising strategy allowing optimization of insecticide treatment while reducing the concentration of insecticides used. PMID:24140515

  1. Expression of two 50 kDa proteins is associated with sensitivity towards etherlipid analogues in the human leukaemia cell line HL 60

    Microsoft Academic Search

    D. Berkovic; W. Hiddemann; J. Kuduz; E. A. M. Fleer

    1997-01-01

    Hexadecylphosphocholine (HePC) is a new etherphospholipid derived substance with pronounced antineoplastic activity. So far the mode of action of this compound has not been resolved. Therefore, we decided to approach this problem by generating HePC resistant sublines of susceptible cells. The human leukaemia cell line HL 60 was successfully adapted to high concentrations of HePC over a period of 14

  2. Asparagine-linked oligosaccharides in murine tumor cells: comparison of a WGA-resistant (WGAr) nonmetastatic mutant and a related WGA-sensitive (WGAs) metastatic line

    PubMed Central

    1984-01-01

    MDW40, a wheat germ agglutinin-resistant (WGAr) mutant of the highly metastatic tumor cell line called MDAY-D2, is restricted to local growth at the subcutaneous site of inoculation. The WGAr tumor cells acquire metastatic ability by fusing spontaneously with a normal host cell followed by chromosome segregation, a process accompanied by reversion of the WGAr phenotype (i.e., WGAs). Since lectin-resistant mutant cell lines often have oligosaccharide alterations that may affect membrane function and consequently metastatic capacity, we compared the major Asn-linked glycopeptides in WGAr and WGAs cell lines. [2-3H]mannose-labeled glycopeptides were separated into four fractions on a DEAE-cellulose column and then further fractionated on a concanavalin A-Sepharose column. Glycopeptide structures were determined by: (a) sequential exoglycosidase digestion followed by chromatography on lectin/agarose and Bio-Gel P-4 columns and (b) proton nuclear magnetic resonance analysis. The metastatic WGAs cells had a sialylated poly-N-acetyllactosamine-containing glycopeptide which was absent in the nonmetastatic mutant cell line. Unique to the mutant was a neutral triantennary class of glycopeptide lacking sialic acid and galactose; the WGAr lesion therefore appeared to be a premature truncation of the antennae of the poly-N-acetyllactosamine-containing glycopeptide found in the WGAs cells. High mannose glycopeptides containing five to nine mannose residues constituted a major class in both WGAr and WGAs cells. Lysates of both wild-type and mutant cells had similar levels of galactosyltransferase activity capable of adding galactose to the N-acetylglucosamine-terminated glycopeptide isolated from mutant cells; the basis of the WGAr lesion remains to be determined. PMID:6547960

  3. Direct Search for Spin-Dependent WIMPS with CaF2 Detector

    NASA Astrophysics Data System (ADS)

    Hazama, R.; Ogawa, I.; Mukaida, K.; Ajimura, S.; Hirano, Y.; Ichihara, K.; Ishikawa, Y.; Itamura, M.; Katsuki, A.; Kishimoto, K.; Matsuoka, K.; Miyawaki, H.; Nitta, T.; Sakai, H.; Shiomi, S.; Suzuki, N.; Tanaka, Y.; Tatewaki, Y.; Tomii, S.; Umehara, S.; Yokoyama, D.; Yoshida, S.; Kishimoto, T.

    2008-04-01

    A CaF2 scintillator complex system (ELEGANT VI) is developed to search for the axial-vector coupled dark matter (WIMPs) and study the neutrino-less double beta decay of 48Ca. Active light guides of pure CaF2 crystals which are on both sides of the central CaF2(Eu) crystal act as a 4? active shield, combined with surrounding CsI(Tl) scintillators. The whole system is in operation at the underground laboratory (Oto Cosmo Observatory) located in Nara. In this article recent several improvements and our current status of the investigation are described, especially putting emphasis on the radioactive impurities of CaF2 crystal and development of flash scaler/trigger system with FPGA (Field Programmable Gate Array) to do a single photon counting and a noise-cut via photon time distribution.

  4. SUSY Implications from WIMP Annihilation into Scalars at the Galactic Centre

    E-print Network

    Tony Gherghetta; Benedict von Harling; Anibal D. Medina; Michael A. Schmidt; Timothy Trott

    2015-05-10

    An excess in gamma-rays emanating from the galactic centre has recently been observed in the Fermi-LAT data. This signal can be interpreted as resulting from WIMP annihilation, with the spectrum well-fit by dark matter annihilating dominantly into either bottom-quark or Higgs pairs. Supersymmetric models provide a well-motivated framework to study the implications of this signal in these channels. With a neutralino dark matter candidate, the gamma-ray excess cannot be easily accommodated in the minimal supersymmetric model, which in any case requires tuning below the percent level to explain the observed Higgs mass. Instead we are naturally led to consider the next-to-minimal model with a singlet superfield. This not only allows for the annihilation channel into bottom-quark pairs to be implemented, but also provides new possibilities for annihilation into Higgs-pseudoscalar pairs. We show that the fit to the gamma-ray excess for the Higgs-pseudoscalar channel can be just as good as for annihilation into bottom-quark pairs. Moreover, in the parameter range of interest, the next-to-minimal supersymmetric model solves the mu-problem and can explain the 125 GeV Higgs mass with improved naturalness. We also consider an extension by adding a right-handed neutrino superfield with the right-handed sneutrino acting as a dark matter candidate. Interestingly, this allows for the annihilation into pseudoscalar pairs which also provide a good fit to the gamma-ray excess. Furthermore, in the case of a neutralino LSP, the late decay of a sneutrino NLSP can non-thermally produce the observed relic abundance. Finally, the WIMP annihilation into scalar pairs allows for the possibility of detecting the Higgs or pseudoscalar decay into two photons, providing a smoking-gun signal of the model.

  5. Final results of the EDELWEISS-II WIMP search using a 4-kg array of cryogenic germanium detectors with interleaved electrodes

    NASA Astrophysics Data System (ADS)

    Armengaud, E.; Augier, C.; Benoît, A.; Bergé, L.; Blümer, J.; Broniatowski, A.; Brudanin, V.; Censier, B.; Chardin, G.; Chapellier, M.; Charlieux, F.; Coulter, P.; Cox, G. A.; Defay, X.; de Jesus, M.; Dolgorouki, Y.; Domange, J.; Dumoulin, L.; Eitel, K.; Filosofov, D.; Fourches, N.; Gascon, J.; Gerbier, G.; Gironnet, J.; Gros, M.; Henry, S.; Hervé, S.; Juillard, A.; Kluck, H.; Kozlov, V.; Kraus, H.; Kudryavtsev, V. A.; Loaiza, P.; Marnieros, S.; Navick, X.-F.; Nones, C.; Olivieri, E.; Pari, P.; Pattavina, L.; Paul, B.; Robinson, M.; Rozov, S.; Sanglard, V.; Schmidt, B.; Scorza, S.; Semikh, S.; Torrento-Coello, A. S.; Vagneron, L.; Verdier, M.-A.; Walker, R. J.; Yakushev, E.; EDELWEISS Collaboration

    2011-08-01

    The EDELWEISS-II Collaboration has completed a direct search for WIMP dark matter with an array of ten 400-g cryogenic germanium detectors in operation at the Laboratoire Souterrain de Modane. The combined use of thermal phonon sensors and charge collection electrodes with an interleaved geometry enables the efficient rejection of ?-induced radioactivity as well as near-surface interactions. A total effective exposure of 384 kg d has been achieved, mostly coming from fourteen months of continuous operation. Five nuclear recoil candidates are observed above 20 keV, while the estimated background is 3.0 events. The result is interpreted in terms of limits on the cross-section of spin-independent interactions of WIMPs and nucleons. A cross-section of 4.4×10 pb is excluded at 90%CL for a WIMP mass of 85 GeV. New constraints are also set on models where the WIMP-nucleon scattering is inelastic.

  6. Final results of the EDELWEISS-II WIMP search using a 4-kg array of cryogenic germanium detectors with interleaved electrodes

    NASA Astrophysics Data System (ADS)

    EDELWEISS Collaboration; Armengaud, E.; Augier, C.; Benoît, A.; Bergé, L.; Blümer, J.; Broniatowski, A.; Brudanin, V.; Censier, B.; Chardin, G.; Chapellier, M.; Charlieux, F.; Coulter, P.; Cox, G. A.; Defay, X.; de Jesus, M.; Dolgorouki, Y.; Domange, J.; Dumoulin, L.; Eitel, K.; Filosofov, D.; Fourches, N.; Gascon, J.; Gerbier, G.; Gironnet, J.; Gros, M.; Henry, S.; Hervé, S.; Juillard, A.; Kluck, H.; Kozlov, V.; Kraus, H.; Kudryavtsev, V. A.; Loaiza, P.; Marnieros, S.; Navick, X.-F.; Nones, C.; Olivieri, E.; Pari, P.; Pattavina, L.; Paul, B.; Robinson, M.; Rozov, S.; Sanglard, V.; Schmidt, B.; Scorza, S.; Semikh, S.; Torrento-Coello, A. S.; Vagneron, L.; Verdier, M.-A.; Walker, R. J.; Yakushev, E.

    2011-08-01

    The EDELWEISS-II Collaboration has completed a direct search for WIMP dark matter with an array of ten 400-g cryogenic germanium detectors in operation at the Laboratoire Souterrain de Modane. The combined use of thermal phonon sensors and charge collection electrodes with an interleaved geometry enables the efficient rejection of ? -induced radioactivity as well as near-surface interactions. A total effective exposure of 384 kg?d has been achieved, mostly coming from fourteen months of continuous operation. Five nuclear recoil candidates are observed above 20 keV, while the estimated background is 3.0 events. The result is interpreted in terms of limits on the cross-section of spin-independent interactions of WIMPs and nucleons. A cross-section of 4.4 × 10 - 8 pb is excluded at 90%CL for a WIMP mass of 85 GeV. New constraints are also set on models where the WIMP-nucleon scattering is inelastic.

  7. Volume-sensitive release of organic osmolytes in the human lung epithelial cell line A549: role of the 5-lipoxygenase.

    PubMed

    Holm, Jacob Bak; Grygorczyk, Ryszard; Lambert, Ian Henry

    2013-07-01

    Pathophysiological conditions challenge cell volume homeostasis and perturb cell volume regulatory mechanisms leading to alterations of cell metabolism, active transepithelial transport, cell migration, and death. We report that inhibition of the 5-lipoxygenase (5-LO) with AA861 or ETH 615-139, the cysteinyl leukotriene 1 receptor (CysLT?) with the antiasthmatic drug Zafirlukast, or the volume-sensitive organic anion channel (VSOAC) with DIDS blocks the release of organic osmolytes (taurine, meAIB) and the concomitant cell volume restoration following hypoosmotic swelling of human type II-like lung epithelial cells (A549). Reactive oxygen species (ROS) are produced in A549 cells upon hypotonic cell swelling by a diphenylene iodonium-sensitive NADPH oxidase. The swelling-induced taurine release is suppressed by ROS scavenging (butylated hydroxytoluene, N-acetyl cysteine) and potentiated by H?O?. Ca²? mobilization with ionomycin or ATP stimulates the swelling-induced taurine release whereas calmodulin inhibition (W7) inhibits the release. Chelation of the extracellular Ca²? (EGTA) had no effect on swelling-induced taurine release but prevented ATP-induced stimulation. H?O?, ATP, and ionomycin were unable to stimulate the taurine release in the presence of AA861 or Zafirlukast, placing 5-LO and CysLT? as essential elements in the swelling-induced activation of VSOAC with ROS and Ca²? as potent modulators. Inhibition of tyrosine kinases (genistein, cucurbitacin) reduces volume-sensitive taurine release, adding tyrosine kinases (Janus kinase) as regulators of VSOAC activity. Caspase-3 activity during hypoxia is unaffected by inhibition of 5-LO/CysLT? but reduced when swelling-induced taurine loss via VSOAC is prevented by DIDS excess extracellular taurine, indicating a beneficial role of taurine under hypoxia. PMID:23485709

  8. Selective sensitivity to wasabi-derived 6-(methylsulfinyl)hexyl isothiocyanate of human breast cancer and melanoma cell lines studied in vitro.

    PubMed

    Nomura, Takahiro; Shinoda, Shoko; Yamori, Takao; Sawaki, Saeko; Nagata, Ikuko; Ryoyama, Kazuo; Fuke, Yoko

    2005-01-01

    Recently, attention has focused on the anticancer properties of an aromatic component 6-(methylsulfinyl)hexyl isothiocyanate (6-MITC) in a typical Japanese spice, wasabi. In this paper, anticancer activity of 6-MITC in vitro was studied by using a human cancer cell (HCC) panel. 6-MITC directly affected the cells in the HCC panel and inhibited their growth in culture. The mean concentration required to inhibit 50% of control cell growth was 3.9 microM, which is a sufficiently low dosage for practical use. The suppression influenced not only the cell growth, but also the survival of these cells. The mean concentration to suppress cells to a 50% survival was 43.7 microM. The reduction activity of 6-MITC was differential, and it suppressed specific cells. These severely suppressed cell lines included breast cancer and melanoma cell lines. For example, one melanoma line was seriously damaged at a concentration of 0.3 microM of 6-MITC. Compared with other MITCs (2-MITC, 4-MITC and 8-MITC), 6-MITC showed the most effective suppression and with the most specific manner of the cells mentioned above. A "COMPARE" analysis using a computerized algorithm, which was based on the HCC database, suggested that the suppression mechanism of 6-MITC is unique and may be different from that of other known chemicals. The actual mechanism may not a simple one but may involve multiple pathways. On account of its sufficiently small size, 6-MITC is a new possible candidate for controlling cancer cells. PMID:15829375

  9. Thymidylate synthase level as the main predictive parameter for sensitivity to 5-fluorouracil, but not for folate-based thymidylate synthase inhibitors, in 13 nonselected colon cancer cell lines.

    PubMed

    van Triest, B; Pinedo, H M; van Hensbergen, Y; Smid, K; Telleman, F; Schoenmakers, P S; van der Wilt, C L; van Laar, J A; Noordhuis, P; Jansen, G; Peters, G J

    1999-03-01

    Thymidylate synthase (TS), a critical enzyme in the de novo synthesis of thymidylate, is an important target for fluoropyrimidines and folate-based TS inhibitors. In a panel of 13 nonselected human colon cancer cell lines, we evaluated the role of TS levels in sensitivity to 5-fluorouracil (5FU) and four folate-based TS inhibitors that have been introduced recently into the clinic: ZD1694 (Tomudex, Raltitrexed, TDX), GW1843U89 (GW), LY231514 (LY), and AG337 (Thymitaq, AG). Because the latter compounds have different transport and polyglutamylation characteristics, we also related these parameters with drug sensitivity, measured by the sulforhodamine B assay after 72 h of drug exposure. For 5FU, the IC50s varied from 0.8 to 43.0 microM. Leucovorin (LV) potentiated the activity of 5FU in only 4 of 13 cell lines. Sensitivity to folate-based TS inhibitors was variable; IC50s were in the range of: 5.3-59.0 nM TDX; 11.0-1570 nM LY; and 0.5-8.9 nM GW. Eleven of 13 cell lines had an IC50 for AG between 1.3 and 5.3 microM. Two cell lines were resistant to AG, Colo201 and SW1116, with IC50s of 27 and 29 microM, respectively. TS catalytic activity (conversion of dUMP to dTMP) varied from 62 to 777 pmol/h/10(6) cells. The number of FdUMP binding sites varied from 32 to 231 fmol/10(6) cells. Regression analysis showed a significant relation between TS catalytic activity and IC50s for 5FU and 5FU/LV. Kis for FdUMP showed a significant Spearman rank correlation with the IC50s of AG and GW. The role of antifolate transport, accumulation, and polyglutamylation was determined with [3H]methotrexate (MTX) as a reference compound. [3H]MTX influx via the reduced folate carrier varied from 18.6 to 150 fmol/10(6) cells/min. Folylpolyglutamate synthetase (FPGS) activity showed a range from 47 to 429 pmol/10(6) cells/h. A total of 24 h of [3H]MTX accumulation showed a 20-fold variation, from 1.2 to 21.8 pmol/10(6) cells. FPGS levels showed a Spearman rank positive correlation with cytotoxicity to TDX. In conclusion, in a heterogeneous nonselected human colon cancer cell line panel, the best predictor for sensitivity to 5FU and 5FU/LV was TS activity. Multiple sensitivity determinants were of importance for antifolate TS inhibitors, including FPGS activity and TS enzyme kinetics. PMID:10100718

  10. Neutrinos from WIMP annihilation in the Sun: Implications of a self-consistent model of the Milky Way's dark matter halo

    NASA Astrophysics Data System (ADS)

    Kundu, Susmita; Bhattacharjee, Pijushpani

    2012-06-01

    Upper limits on the spin-independent as well as spin-dependent elastic scattering cross sections of low mass (˜2-20GeV) weakly interacting massive particles (WIMPs ) with protons, imposed by the upper limit on the neutrino flux from WIMP annihilation in the Sun given by the Super-Kamiokande (S-K) experiment, and their compatibility with the “DAMA-compatible” regions of the WIMP parameter space—the regions of the WIMP mass versus cross-section parameter space within which the annual modulation signal observed by the DAMA/LIBRA experiment is compatible with the null results of other direct-detection experiments—are studied within the framework of a self-consistent model of the finite-size dark matter halo of the Galaxy. The halo model includes the gravitational influence of the observed visible matter of the Galaxy on the phase-space distribution function of the WIMPs constituting the Galaxy’s dark matter halo in a self-consistent manner. Unlike in the “standard halo model” used in earlier analyses, the velocity distribution of the WIMPs in our model is non-Maxwellian, with a high-velocity cutoff determined self-consistently by the model itself. The parameters of the model are determined from a fit to the rotation curve data of the Galaxy. We find that, for our best-fit halo model, for spin-independent interaction, while the S-K upper limits do not place additional restrictions on the DAMA-compatible region of the WIMP parameter space if the WIMPs annihilate dominantly to b¯b and/or c¯c, portions of the DAMA-compatible region can be excluded if WIMP annihilations to ?+?- and ??¯ occur at larger than 35% and 0.4% levels, respectively. For spin-dependent interaction, on the other hand, the restrictions on the possible annihilation channels are much more stringent: they rule out the entire DAMA region if WIMPs annihilate to ?+?- and ??¯ final states at greater than ˜0.05% and 0.0005% levels, respectively, and/or to b¯b and c¯c at greater than ˜0.5% levels. The very latest results from the S-K Collaboration [T. Tanaka , Astrophys. J. 742, 78 (2011)ASJOAB0004-637X10.1088/0004-637X/742/2/78] make the above constraints on the branching fractions of various WIMP annihilation channels even more stringent by roughly a factor of 3-4.

  11. Genetic inactivation of the Fanconi anemia gene FANCC identified in the hepatocellular carcinoma cell line HuH-7 confers sensitivity towards DNA-interstrand crosslinking agents

    PubMed Central

    2010-01-01

    Background Inactivation of the Fanconi anemia (FA) pathway through defects in one of 13 FA genes occurs at low frequency in various solid cancer entities among the general population. As FA pathway inactivation confers a distinct hypersensitivity towards DNA interstrand-crosslinking (ICL)-agents, FA defects represent rational targets for individualized therapeutic strategies. Except for pancreatic cancer, however, the prevalence of FA defects in gastrointestinal (GI) tumors has not yet been systematically explored. Results A panel of GI cancer cell lines was screened for FA pathway inactivation applying FANCD2 monoubiquitination and FANCD2/RAD51 nuclear focus formation and a newly identified FA pathway-deficient cell line was functionally characterized. The hepatocellular carcinoma (HCC) line HuH-7 was defective in FANCD2 monoubiquitination and FANCD2 nuclear focus formation but proficient in RAD51 focus formation. Gene complementation studies revealed that this proximal FA pathway inactivation was attributable to defective FANCC function in HuH-7 cells. Accordingly, a homozygous inactivating FANCC nonsense mutation (c.553C > T, p.R185X) was identified in HuH-7, resulting in partial transcriptional skipping of exon 6 and leading to the classic cellular FA hypersensitivity phenotype; HuH-7 cells exhibited a strongly reduced proliferation rate and a pronounced G2 cell cycle arrest at distinctly lower concentrations of ICL-agents than a panel of non-isogenic, FA pathway-proficient HCC cell lines. Upon retroviral transduction of HuH-7 cells with FANCC cDNA, FA pathway functions were restored and ICL-hypersensitivity abrogated. Analyses of 18 surgical HCC specimens yielded no further examples for genetic or epigenetic inactivation of FANCC, FANCF, or FANCG in HCC, suggesting a low prevalence of proximal FA pathway inactivation in this tumor type. Conclusions As the majority of HCC are chemoresistant, assessment of FA pathway function in HCC could identify small subpopulations of patients expected to predictably benefit from individualized treatment protocols using ICL-agents. PMID:20509860

  12. Depth-Sensitivity Relation (DSR) for Underground Laboratories

    SciTech Connect

    Mei, D.-M.; Hime, A.; Elliott, S. R.; Gehman, V. M. [P-23, H803, Los Alamos National Laboratory, Los Alamos, NM 87544 (United States); Kazkaz, K. [Physics Department, University of Washington, Seattle, WA 98195 (United States)

    2006-07-11

    Muon-induced background can limit the sensitivity of next generation experiments searching for neutrinoless double beta decay and WIMP dark matter. We have established the DSR based upon the muon and muon-induced fast neutron fluxes and spectra for a number of underground laboratories. Our results indicate that the muon-induced neutron elastic and inelastic scattering processes create a significant background for germanium-based dark matter and double beta decay experiments, unless such experiments are staged deep underground. We use the measured neutron elastic and inelastic scattering processes with a segmented CLOVER (germanium) detector on the surface to test our model predictions.

  13. Depth-Sensitivity Relation (DSR) for Underground Laboratories

    NASA Astrophysics Data System (ADS)

    Mei, D.-M.; Hime, A.; Elliott, S. R.; Gehman, V. M.; Kazkaz, K.

    2006-07-01

    Muon-induced background can limit the sensitivity of next generation experiments searching for neutrinoless double beta decay and WIMP dark matter. We have established the DSR based upon the muon and muon-induced fast neutron fluxes and spectra for a number of underground laboratories. Our results indicate that the muon-induced neutron elastic and inelastic scattering processes create a significant background for germanium-based dark matter and double beta decay experiments, unless such experiments are staged deep underground. We use the measured neutron elastic and inelastic scattering processes with a segmented CLOVER (germanium) detector on the surface to test our model predictions.

  14. Suppression of HSP70 expression sensitizes NSCLC cell lines to TRAIL-induced apoptosis by upregulating DR4 and DR5 and downregulating c-FLIP-L expressions.

    PubMed

    Zhuang, Hongqin; Jiang, Weiwei; Zhang, Xiangyu; Qiu, Fan; Gan, Ziyi; Cheng, Wei; Zhang, Jing; Guan, Shengwen; Tang, Bo; Huang, Qilai; Wu, Xinhua; Huang, Xiaofeng; Jiang, Wenhui; Hu, Qingang; Lu, Min; Hua, Zi-Chun

    2013-02-01

    Many cancer cell types are resistant to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis. Here, we examined whether HSP70 suppression by small interfering RNA (siRNA) sensitized non-small cell lung cancer (NSCLC) cells to TRAIL-induced apoptosis and the underlying mechanisms. We demonstrated that HSP70 suppression by siRNA sensitized NSCLC cells to TRAIL-induced apoptosis by upregulating the expressions of death receptor 4 (DR4) and death receptor 5 (DR5) through activating NF-?B, JNK, and, subsequently, p53, consequently significantly amplifying TRAIL-mediated caspase-8 processing and activity, cytosolic translocation of cytochrome c, and cell death. Consistently, the pro-apoptotic proteins Bad and Bax were upregulated, while the anti-apoptotic protein Bcl-2 was downregulated. The luciferase activity of the DR4 promoter was blocked by a NF-?B pathway inhibitor BAY11-7082, suggesting that NF-?B activation plays an important role in the transcriptional upregulation of DR4. Additionally, HSP70 suppression inhibited the phosphorylation of ERK, AKT, and PKC, thereby downregulating c-FLIP-L. A549 xenografts in mice receiving HSP70 siRNA showed TRAIL-induced cell death and increased DR4/DR5 levels and reduced tumor growth. The combination of psiHSP70 gene therapy with TRAIL also significantly increased the survival benefits induced by TRAIL therapy alone. Interestingly, HSP27 siRNA and TRAIL together could not suppress tumor growth or prolong the survival of tumor-bearing mice significantly, although the combination could efficiently induce the apoptosis of A549 cells in vitro. Our findings suggest that HSP70 suppression or downregulation might be promising to overcome TRAIL resistance in cancer. PMID:22948392

  15. RNA silencing of integrin-linked kinase increases the sensitivity of the A549 lung cancer cell line to cisplatin and promotes its apoptosis.

    PubMed

    Zhao, Xiaozhen; Xu, Zhenye; Wang, Zhongqi; Wu, Zhonghua; Gong, Yabin; Zhou, Lijuan; Xiang, Yi

    2015-07-01

    The expression of integrin-linked kinase (ILK) has been reported to be involved in the regulation of integrin-mediated processes, including cancer cell proliferation, migration and invasion. Previous studies have demonstrated that inhibition of ILK may be an underlying approach for treating cancer. However, whether the knock down of ILK affects growth and apoptosis of lung cancer cells remains to be elucidated. Importantly, whether downregulation of ILK increases the sensitivity of lung cancer cells to cisplatin and amplifies cell apoptosis also remains to be elucidated. In the present study, ILK downregulation was mediated by lentivirus-mediated RNA interference. The expression levels of associated genes were determined by reverse-transcription quantitative polymerase chain reaction and western blotting. Cell proliferation was evaluated using a modified 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and clone formation assay. The cell cycle and apoptosis were analyzed using flow cytometry. The current data revealed that lentivirus-mediated ILK gene silencing alone inhibited A549 cell proliferation and promotes cell cycle arrest, however, had no detectable effect on cell apoptosis. However, combined treatment with lentivirus-mediated ILK interference and cisplatin chemotherapy induced significantly more cell apoptosis than mono-chemotherapy or knockdown. The increased cell apoptosis and proliferation inhibition were attributed to abnormal downstream protein expression of ILK, including phospho-glycogen synthase kinase 3?, p-AKT, activator protein-1, ?-catenin, cyclin D1 and matrix metalloproteinase-9. ILK inhibition may suppress the proliferation of A549 and increase A549 sensitivity to cisplatin. The combined treatment of ILK gene knockdown and chemotherapy has the potential to improve anticancer efficacy. PMID:25760437

  16. RNA silencing of integrin-linked kinase increases the sensitivity of the A549 lung cancer cell line to cisplatin and promotes its apoptosis

    PubMed Central

    ZHAO, XIAOZHEN; XU, ZHENYE; WANG, ZHONGQI; WU, ZHONGHUA; GONG, YABIN; ZHOU, LIJUAN; XIANG, YI

    2015-01-01

    The expression of integrin-linked kinase (ILK) has been reported to be involved in the regulation of integrin-mediated processes, including cancer cell proliferation, migration and invasion. Previous studies have demonstrated that inhibition of ILK may be an underlying approach for treating cancer. However, whether the knock down of ILK affects growth and apoptosis of lung cancer cells remains to be elucidated. Importantly, whether downregulation of ILK increases the sensitivity of lung cancer cells to cisplatin and amplifies cell apoptosis also remains to be elucidated. In the present study, ILK downregulation was mediated by lentivirus-mediated RNA interference. The expression levels of associated genes were determined by reverse-transcription quantitative polymerase chain reaction and western blotting. Cell proliferation was evaluated using a modified 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and clone formation assay. The cell cycle and apoptosis were analyzed using flow cytometry. The current data revealed that lentivirus-mediated ILK gene silencing alone inhibited A549 cell proliferation and promotes cell cycle arrest, however, had no detectable effect on cell apoptosis. However, combined treatment with lentivirus-mediated ILK interference and cisplatin chemotherapy induced significantly more cell apoptosis than mono-chemotherapy or knockdown. The increased cell apoptosis and proliferation inhibition were attributed to abnormal downstream protein expression of ILK, including phospho-glycogen synthase kinase 3?, p-AKT, activator protein-1, ?-catenin, cyclin D1 and matrix metalloproteinase-9. ILK inhibition may suppress the proliferation of A549 and increase A549 sensitivity to cisplatin. The combined treatment of ILK gene knockdown and chemotherapy has the potential to improve anticancer efficacy. PMID:25760437

  17. Limits on spin-independent couplings of WIMP dark matter with a p-type point-contact germanium detector.

    PubMed

    Li, H B; Liao, H Y; Lin, S T; Liu, S K; Singh, L; Singh, M K; Soma, A K; Wong, H T; Wu, Y C; Zhao, W; Asryan, G; Chuang, Y C; Deniz, M; Fang, J M; Hsu, C L; Huang, T R; Kiran Kumar, G; Lee, S C; Li, J; Li, J M; Li, Y J; Li, Y L; Lin, C W; Lin, F K; Liu, Y F; Ma, H; Ruan, X C; Shen, Y T; Singh, V; Tang, C J; Tseng, C H; Xu, Y; Yang, S W; Yu, C X; Yue, Q; Zeng, Z; Zeyrek, M; Zhou, Z Y

    2013-06-28

    We report new limits on a spin-independent weakly interacting massive particle (WIMP)-nucleon interaction cross section using 39.5 kg days of data taken with a p-type point-contact germanium detector of 840 g fiducial mass at the Kuo-Sheng Reactor Neutrino Laboratory. Crucial to this study is the understanding of the selection procedures and, in particular, the bulk-surface events differentiation at the sub-keV range. The signal-retaining and background-rejecting efficiencies were measured with calibration gamma sources and a novel n-type point-contact germanium detector. Part of the parameter space in the cross section versus WIMP-mass implied by various experiments is probed and excluded. PMID:23848861

  18. Search for inelastic WIMP nucleus scattering on 129Xe in data from the XMASS-I experiment

    NASA Astrophysics Data System (ADS)

    Uchida, H.; Abe, K.; Hieda, K.; Hiraide, K.; Hirano, S.; Ichimura, K.; Kishimoto, Y.; Kobayashi, K.; Moriyama, S.; Nakagawa, K.; Nakahata, M.; Ogawa, H.; Oka, N.; Sekiya, H.; Shinozaki, A.; Suzuki, Y.; Takeda, A.; Takachio, O.; Umemoto, D.; Yamashita, M.; Yang, B. S.; Tasaka, S.; Liu, J.; Martens, K.; Hosokawa, K.; Miuchi, K.; Murata, A.; Onishi, Y.; Otsuka, Y.; Takeuchi, Y.; Kim, Y. H.; Lee, K. B.; Lee, M. K.; Lee, J. S.; Fukuda, Y.; Itow, Y.; Masuda, K.; Nishitani, Y.; Takiya, H.; Kim, N. Y.; Kim, Y. D.; Kusaba, F.; Nishijima, K.; Fujii, K.; Murayama, I.; Nakamura, S.

    2014-06-01

    A search for inelastic scattering of weakly interacting massive particles (WIMPs) on the isotope ^{129}Xe was done in data taken with the single-phase liquid-xenon detector XMASS at the Kamioka Observatory. Using a restricted volume containing 41 kg of liquid xenon at the very center of our detector, we observed no significant excess of events in 165.9 live days of data. Our background reduction allowed us to derive our limits without explicitly subtracting the remaining events that are compatible with background expectations. As an example, we derive for a 50 GeV WIMP an upper limit of 3.2 pb at the 90% confidence level for its inelastic cross section on ^{129}Xe nuclei.

  19. [Enhanced sensitivity to cytosine arabinoside by combined stimulation of steel factor and GM-CSF in a factor-dependent leukemic cell line, MO7e--in terms of a possible clinical application to AML treatment].

    PubMed

    Gotoh, A; Kawanishi, Y; Kurosawa, K; Miyazawa, K; Ohtaka, M; Aizawa, S; Kimura, Y; Yoshikawa, O; Toyama, K

    1993-07-01

    In normal hematopoiesis, granulocyte macrophage-colony stimulating factor (GM-CSF) is known to stimulate the proliferation and differentiation of myelo-monocytoid lineage, while Steel factor (SLF) has been supposed to support the proliferation of more primitive hematopoietic progenitors including stem cells. We investigated the stimulatory effect of SLF and GM-CSF in twelve cases of acute myeloid leukemia (AML) cells in vitro by MTT assay. In 10 out of 12 cases, SLF or GM-CSF stimulated the proliferation of leukemic cells in short term liquid culture. In 7 out of these 10 cases, the leukemic cells responded to both cytokines. To investigate the possibility of the clinical application of these cytokines by combination with cell cycle-specific anti-tumor reagents, we assessed the effects of SLF and GM-CSF on the modulation of the cell cycle and sensitivity against cytosine arabinoside (ara-C) in a human factor-dependent leukemic cell line, MO7e. Flow cytometric analysis revealed the effect of cell recruitment into the cell cycle in the quiescent MO7e cells by exposure to these cytokines. The drug-sensitivity test using the MTT assay system demonstrated that pre-treatment with each cytokine enhanced sensitivity of ara-C. Furthermore, by combination of SLF and GM-CSF, the ara-C sensitivity was significantly wore graty enhanced than by each cytokine alone. These data suggest that combined pre-treatment with SLF and GM-CSF may provide new benefits for cure-oriented chemotherapy of AML followed by bone marrow transplantation or peripheral blood stem cell transplantation. PMID:7689660

  20. Limits on WIMP dark matter using scintillating CaWO 4 cryogenic detectors with active background suppression

    Microsoft Academic Search

    G. Angloher; C. Bucci; P. Christ; C. Cozzini; F. von Feilitzsch; D. Hauff; S. Henry; Th. Jagemann; J. Jochum; H. Kraus; B. Majorovits; J. Ninkovic; F. Petricca; W. Potzel; F. Probst; Y. Ramachers; M. Razeti; W. Rau; W. Seidel; M. Stark; L. Stodolsky; A. J. B. Tolhurst; W. Westphal; H. Wulandari

    2005-01-01

    We present first significant limits on WIMP dark matter by the phonon-light technique, where combined phonon and light signals from a scintillating cryogenic detector are used. Data from early 2004 with two 300g CRESST-II prototype detector modules are presented, with a net exposure of 20.5kg days. The modules consist of a CaWO4 scintillating “target” crystal and a smaller cryogenic light

  1. First measurement of the head–tail directional nuclear recoil signature at energies relevant to WIMP dark matter searches

    Microsoft Academic Search

    S. Burgos; E. Daw; J. Forbes; C. Ghag; M. Gold; C. Hagemann; V. A. Kudryavtsev; T. B. Lawson; D. Loomba; P. Majewski; D. Muna; A. St J. Murphy; G. G. Nicklin; S. M. Paling; A. Petkov; S. J. S. Plank; M. Robinson; N. Sanghi; D. P. Snowden-Ifft; N. J. C. Spooner; J. Turk; E. Tziaferi

    2009-01-01

    We present first evidence for the so-called head–tail directional signature of neutron-induced nuclear recoil tracks at energies down to 1.5keV\\/amu using the DRIFT-IIc dark matter detector. This regime is appropriate for recoils induced by Weakly Interacting Massive Particle (WIMPs) but one where the differential ionization is poorly understood. We show that the distribution of recoil energies and directions induced here

  2. Sensitivity of grounding line dynamics to viscoelastic deformation of the solid Earth: Inferences from a fully coupled ice sheet - solid Earth model

    NASA Astrophysics Data System (ADS)

    Konrad, H.; Sasgen, I.; Thoma, M.; Klemann, V.; Grosfeld, K.; Martinec, Z.

    2013-12-01

    The interactions of ice sheets with the sea level and the solid Earth are important factors for the stability of the ice shelves and the tributary inland ice (e.g. Thomas and Bentley, 1978; Gomez et al, 2012). First, changes in ice extent and ice thickness induce viscoelastic deformation of the Earth surface and Earth's gravity field. In turn, global and local changes in sea level and bathymetry affect the grounding line and, subsequently, alter the ice dynamic behaviour. Here, we investigate these feedbacks for a synthetic ice sheet configuration as well as for the Antarctic ice sheet using a three-dimensional thermomechanical ice sheet and shelf model, coupled to a viscoelastic solid-Earth and gravitationally self-consistent sea-level model. The respective ice sheet undergoes a forcing from rising sea level, warming ocean, and/or changing surface mass balance. The coupling is realized by exchanging ice thickness, Earth surface deformation, and sea level periodically. We apply several sets of viscoelastic Earth parameters to our coupled model, e.g. simulating a low-viscous upper mantle present at the Antarctic Peninsula (Ivins et al., 2011). Special focus of our study lies on the evolution of Earth surface deformation and local sea level changes, as well as on the accompanying grounding line evolution. N. Gomez, D. Pollard, J. X. Mitrovica, P. Huybers, and P. U. Clark 2012. Evolution of a coupled marine ice sheet-sea level model, J. Geophys. Res., 117, F01013, doi:10.1029/2011JF002128. E. R. Ivins, M. M. Watkins, D.-N. Yuan, R. Dietrich, G. Casassa, and A. Rülke 2011. On-land ice loss and glacial isostatic adjustment at the Drake Passage: 2003-2009, J. Geophys. Res. 116, B02403, doi: 10.1029/2010JB007607 R. H. Thomas and C. R. Bentley 1978. A model for Holocene retreat of the West Antarctic Ice Sheet, Quaternary Research, 10 (2), pages 150-170, doi: 10.1016/0033-5894(78)90098-4.

  3. Enhanced one-loop corrections to WIMP annihilation and their thermal relic density in the coannihilation region

    NASA Astrophysics Data System (ADS)

    Drees, Manuel; Gu, Jie

    2013-03-01

    We consider quantum corrections to coannihilation processes of weakly interacting massive particles (WIMPs) due to the exchange of light bosons in the initial state (“Sommerfeld corrections”). We work at the one-loop level, i.e. we assume that these corrections can be treated perturbatively. Coannihilation is important if there is at least one additional new particle with mass close to the lightest WIMP, which is a dark matter candidate. In this case the exchange of a (relatively light) boson in the initial state can change the identity of the annihilating particles. The corrections we are interested in factorize, as in the case of WIMP self-annihilation treated previously, but they can mix different tree-level amplitudes. Moreover, even small mass splittings between the external particles and those in the loop can change the relevant loop functions significantly. We find exact analytical expressions for these functions and illustrate the effects by considering the cases of wino- or Higgsino-like neutralinos as examples.

  4. Design and synthesis of pH-sensitive polyamino-ester magneto-dendrimers: Surface functional groups effect on viability of human prostate carcinoma cell lines DU145.

    PubMed

    Dayyani, Nahid; Khoee, Sepideh; Ramazani, Ali

    2015-06-15

    Novel pH-sensitive, biocompatible and biodegradable magneto-dendrimers with OH and/or NH2 functional groups based on poly amino-ester were synthesized for delivery of anti-cancer drugs. Magnetite nanoparticles (MNPs) were synthesized by the co-precipitation method and their surfaces were modified by 3-aminopropyl triethoxysilane. The first and second generations of the magneto-dendrimer with hydroxyl end groups were produced by sequential acrylation and Michael addition reactions using the required amounts of acryloyl chloride and diethanolamine, respectively. The dendrimer containing amino functional surface groups up to second generation was synthesized by the same method using the necessary amounts of acryloyl chloride and ethylenediamine. These dendrimers were fully characterized by the Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), dynamic light scattering (DLS) and zeta potential analysis, vibrating-sample magnetometer (VSM), scanning electron microscope (SEM), transmission electron microscopy (TEM) and selected area electron diffraction (SAED). In-vitro release profiles of the drug-loaded magnetic nanoparticles and their cytotoxicity assay were investigated at two pHs (7.4 and 5.8). The hydrolytic degradation behavior of magneto-dendrimers was evaluated in PBS buffer. Our research suggests that magneto-dendrimers having amine or hydroxyl functional groups could be considered as the suitable nanocarriers for therapy applications. PMID:26021708

  5. IRE1 inhibition perturbs the unfolded protein response in a pancreatic ?-cell line expressing mutant proinsulin, but does not sensitize the cells to apoptosis

    PubMed Central

    2014-01-01

    Background The Akita mutation (C96Y) in the insulin gene results in early onset diabetes in both humans and mice. Expression of mutant proinsulin (C96Y) causes endoplasmic reticulum (ER) stress in pancreatic ?-cells and consequently the cell activates the unfolded protein response (UPR). Since the proinsulin is terminally misfolded ER stress is irremediable and chronic activation of the UPR eventually activates apoptosis in some cells. Here we analyzed the IRE1-dependent activation of genes in response to misfolded proinsulin production in an inducible mutant proinsulin (C96Y) insulinoma cell line. Results The IRE1 endoribonuclease inhibitors 4?8c and MKC-3946 prevented the splicing of the XBP1 mRNA in response to ER stress caused by mutant proinsulin production. Microarray expression analysis and qPCR validation of select genes revealed that maximal upregulation of many UPR genes in response to mutant proinsulin production required IRE1, although most were still increased above control. Interestingly, neither degradation of misfolded proinsulin via ER-associated degradation (ERAD), nor apoptosis induced by prolonged misfolded proinsulin expression were affected by inhibiting IRE1. Conclusions Although maximal induction of most UPR genes requires IRE1, inhibition of IRE1 does not affect ERAD of misfolded proinsulin or predispose pancreatic ?-cells expressing misfolded proinsulin to chronic ER stress-induced apoptosis. PMID:25011481

  6. An enhanced and sensitive autocrine stimulation by transforming growth factor-alpha is acquired in the brain metastatic variant of a human non-small-cell lung cancer cell line.

    PubMed Central

    Fang, K.

    1996-01-01

    Transforming growth factor-alpha (TGF-alpha)-mediated autocrine regulation in human non-small-cell lung cancer (NSCLC) cells NCI-H226 and its brain metastatic variant H226Br were compared. An enhanced TGF-alpha-induced dose-dependent mitogenic responsiveness in H226Br cells was observed. Neutralising antibody that binds TGF-alpha inhibits H226Br cell growth more effectively than NCI-H226 cell growth. Binding assay with 125I-labelled epidermal growth factor (EGF) revealed that H226Br has two types of EGF receptors (EGFRs), whereas the parental cell line, NCI-H226, has only one. H226Br cells contain twice as many EGFRs as H226 cells, as proved by Scatchard analysis and immune kinase assay. Northern analysis indicated that there is more EGFR transcript in H226Br than in NCI-H226, indicating a transcriptional EGFR gene elevation during metastasis progression. The level of accumulated immunoactive TGF-alpha is lower in the conditioned medium of H226Br than in that of NCI-H226. demonstrating down-regulation of TGF-alpha transcript. The accumulated data suggest an elevated and sensitive autocrine modulation by TGF-alpha and EGFR in immortalising the brain metastatic variant cells that were derived from a human NSCLC squamous cell line. Images Figure 4 Figure 5 Figure 6 Figure 7 PMID:8956792

  7. Implications of CoGeNT and DAMA for light WIMP dark matter

    SciTech Connect

    Fitzpatrick, A. Liam [Department of Physics, Boston University, Boston, Massachusetts 02215 (United States); Hooper, Dan [Particle Astrophysics, Fermi National Accelerator Laboratory, Batavia, Illinois 60563 (United States); Department of Astronomy and Astrophysics, University of Chicago, Chicago, Illinois 60637 (United States); Zurek, Kathryn M. [Michigan Center for Theoretical Physics and Department of Physics, University of Michigan, Ann Arbor, Michigan 48109 (United States)

    2010-06-01

    In this paper, we study the recent excess of low energy events observed by the CoGeNT Collaboration, and discuss the possibility that these events originate from the elastic scattering of a light (m{sub DM{approx}}5-10 GeV) weakly interacting massive particle (WIMP). We find that such a dark matter candidate may also be capable of generating the annual modulation reported by DAMA, without conflicting with the null results from other experiments, such as XENON10. The regions implied by CoGeNT and DAMA are also near those required to produce the two observed CDMS events. A dark matter interpretation of the CoGeNT and DAMA observations favors a region of parameter space that is especially attractive within the context of asymmetric dark matter models. In such models, the cosmological dark matter density arises from the baryon asymmetry of the Universe, naturally leading to the expectation that m{sub DM{approx}}1-10 GeV. We also discuss neutralino dark matter from extended supersymmetric frameworks, such as the next-to-minimal supersymmetric standard model. Lastly, we explore the implications of such a dark matter candidate for indirect searches, and find very encouraging prospects for experiments attempting to detect neutrino or gamma ray annihilation products.

  8. Constraints on WIMP and Sommerfeld-enhanced dark matter annihilation from HESS observations of the galactic center

    SciTech Connect

    Abazajian, Kevork N.; Harding, J. Patrick, E-mail: kevork@uci.edu, E-mail: hard0923@umd.edu [Center for Cosmology, Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States)

    2012-01-01

    We examine the constraints on models of weakly interacting massive particle (WIMP) dark matter from the recent observations of the Galactic Center by the High Energy Spectroscopic System (HESS) telescope. We analyze canonical WIMP annihilation into Standard Model particle final states, including b b-bar , t t-bar and W{sup +}W{sup ?}. The constraints on annihilation into b b-bar is within an order of magnitude of the thermal cross section at ? 3 TeV, while the ?{sup +}?{sup ?} channel is within a factor of ? 2 of thermal. We also study constraints on Sommerfeld-enhanced dark matter annihilation models, and find that the gamma-ray observational constraints here rule out all of the parameter space consistent with dark matter annihilation interpretations of PAMELA and the Fermi-LAT e{sup +}e{sup ?} spectrum, in specific classes of models, and strongly constrains these interpretations in other classes. The gamma-ray constraints we find are more constraining on these models, in many cases, than current relic density, cosmic microwave background, halo shape and naturalness constraints.

  9. Limits on spin-independent wimp-nucleon interactions from the two-tower run of the cryogenic dark matter search

    SciTech Connect

    Akerib, D.S.; Attisha, M.J.; Bailey, C.N.; Baudis, L.; Bauer, Daniel A.; Brink, P.L.; Brusov, P.P.; Bunker, R.; Cabrera, B.; Caldwell, D.O.; Chang, C.L.; Cooley, J.; Crisler, M.B.; Cushman, P.; Daal, M.; Dixon, R.; Dragowsky, M.R.; Driscoll, D.D.; Duong, L.; Ferril, R.; Filippini, J.; /Brown U. /Case Western Reserve U. /Fermilab /LBL, Berkeley

    2005-09-01

    We report new results from the Cryogenic Dark Matter Search (CDMS II) at the Soudan Underground Laboratory. Two towers, each consisting of six detectors, were operated for 74.5 live days, giving spectrum-weighted exposures of 34 kg-d for germanium and 12 kg-d for silicon targets after cuts, averaged over recoil energies 10-100 keV for a WIMP mass of 60GeV/c{sup 2}. A blind analysis was conducted, incorporating improved techniques for rejecting surface events. No WIMP signal exceeding expected backgrounds was observed. When combined with our previous results from Soudan, the 90% C.L. upper limit on the spin-independent WIMP-nucleon cross section is 1.6 x 10{sup -43} cm{sup 2} from Ge, and 3 x 10{sup -42} cm{sup 2} from Si, for a WIMP mass of 60GeV/c{sup 2}. The combined limit from Ge (Si) is a factor of 2.5 (10) lower than our previous results, and constrains predictions of supersymmetric models.

  10. Development of bubble chambers with enhanced stability and sensitivity to low-energy nuclear recoils

    NASA Astrophysics Data System (ADS)

    Bolte, W. J.; Collar, J. I.; Crisler, M.; Hall, J.; Holmgren, D.; Nakazawa, D.; Odom, B.; O'Sullivan, K.; Plunkett, R.; Ramberg, E.; Raskin, A.; Sonnenschein, A.; Vieira, J. D.

    2007-07-01

    The viability of using Bubble Chambers as dark matter particle detectors is considered. Techniques leading to the enhanced chamber stability needed for this new application are described in detail. Prototype trials show that sensitivity to the low-energy nuclear recoils induced by Weakly Interacting Massive Particles (WIMP) is possible in conditions of extreme insensitivity to minimum ionizing backgrounds. An understanding of detector response is demonstrated using existing theoretical models. We briefly comment on the prospects for detection of supersymmetric dark matter with large CF3I chambers.

  11. Climate Sensitivity

    NASA Astrophysics Data System (ADS)

    Hansen, J.

    2007-12-01

    Discussion of climate sensitivity requires careful definition of forcings, feedbacks and response times, indeed, foggy definitions have produced flawed assessments of climate sensitivity. The best information available on climate sensitivity comes from insightful interpretation of the Earth's history aided by quantitative information from climate models and understanding of climate processes. Climate sensitivity is a strong function of time scale, in part because of the nature of climate feedbacks. Unfortunately for humanity, the preponderance of feedbacks on the century time scale appears to be positive. The chief implication is the need for a sharp reversal in the trend of human-made climate forcing, if we are to avoid creating a planet that is dramatically different than the one on which civilization developed.

  12. Non-thermal Dark Matter Production from the Electroweak Phase Transition: Multi-TeV WIMPs and "Baby-Zillas"

    E-print Network

    Adam Falkowski; Jose Miguel No

    2012-11-23

    Particle production at the end of a first-order electroweak phase transition may be rather generic in theories beyond the standard model. Dark matter may then be abundantly produced by this mechanism if it has a sizable coupling to the Higgs field. For an electroweak phase transition occuring at a temperature T_EW ~ 50-100 GeV, non-thermally generated dark matter with mass M_X > TeV will survive thermalization after the phase transition, and could then potentially account for the observed dark matter relic density in scenarios where a thermal dark matter component is either too small or absent. Dark matter in these scenarios could then either be multi-TeV WIMPs whose relic abundace is mostly generated at the electroweak phase transition, or "Baby-Zillas" with mass M_GUT >> M_X >> v_EW that never reach thermal equilibrium in the early universe.

  13. Non-thermal dark matter production from the electroweak phase transition: multi-TeV WIMPs and "baby-zillas"

    NASA Astrophysics Data System (ADS)

    Falkowski, Adam; No, Jose M.

    2013-02-01

    Particle production at the end of a first-order electroweak phase transition may be rather generic in theories beyond the standard model. Dark matter may then be abundantly produced by this mechanism if it has a sizable coupling to the Higgs field. For an electroweak phase transition occuring at a temperature T EW 50-100 GeV, non- thermally generated dark matter with mass M X > TeV will survive thermalization after the phase transition, and could then potentially account for the observed dark matter relic density in scenarios where a thermal dark matter component is either too small or absent. Dark matter in these scenarios could then either be multi-TeV WIMPs whose relic abundace is mostly generated at the electroweak phase transition, or " Baby-Zillas" with mass M GUT ? M X ? {v_{EW}} that never reach thermal equilibrium in the early universe.

  14. Measure Lines

    ERIC Educational Resources Information Center

    Crissman, Sally

    2011-01-01

    One tool for enhancing students' work with data in the science classroom is the measure line. As a coteacher and curriculum developer for The Inquiry Project, the author has seen how measure lines--a number line in which the numbers refer to units of measure--help students not only represent data but also analyze it in ways that generate…

  15. Sensitive Electroscopes

    Microsoft Academic Search

    Charles Lukens

    1932-01-01

    Three electroscopes are described whose electrodes are: (I) a single fiber repelled from a forked wire, (II) a Schonland electrode hollowed to increase the sensitivity, (III) a Schonland electrode, also hollowed, but with the mirror hung on a single gold leaf suspension and rotating on a nearly vertical axis. The deflections produced by the emission of an ? particle, as

  16. Limits on Spin-independent Couplings of Light Dark Matter WIMPs with a p-type Point-contact Germanium Detector

    NASA Astrophysics Data System (ADS)

    Lin, S. T.; Wong, H. T.

    New limits on spin-independent WIMP-nucleon coupling using 39.5 kg-days of data taken with a p-type point-contact germanium detector with fiducial mass of 840 g at the Kuo-Sheng Reactor Neutrino Laboratory (KSNL) is presented. Charactering and understanding the anomalous surface behaviour is of particular significance to this study. The slow rise-time of surface events is identified via software pulse shape analysis techniques. In addition, the signal-retaining and background-rejecting efficiencies are implied to clarify the actual bulk and surface events in the mixed regime at sub-keV range. Both efficiencies are evaluated with calibration sources and a novel n-type point-contact germanium detector. Efficiencies-corrected background spectra from the low-background facility at KSNL are derived. Part of the parameter space in cross-section versus WIMP-mass is probed and excluded.

  17. Sensitivity, block sensitivity, and `block sensitivity of boolean functions

    E-print Network

    Kenyon, Claire

    Sensitivity, block sensitivity, and `­block sensitivity of boolean functions Claire Kenyon LRI, bat for Communications Research, 805 Bunn Drive, Princeton, NJ 08540. E­mail: kutin@idaccr.org Sensitivity is one of the simplest, and block sensitivity one of the most useful, invariants of a boolean function. Nisan [8

  18. Query-sensitive ray shooting

    Microsoft Academic Search

    Joseph S. B. Mitchell; David M. Mountt; Subhash Suri

    1994-01-01

    Ray (segment) shooting is the problem of determining the rst intersection between a ray (directed line segment) and a collection of polygonal or polyhedral obstacles. In order to process queries eciently, the set of obstacle polyhedra is usually preprocessed into a data structure. In this paper we propose a query-sensitive data structure for ray shooting, which means that the performance

  19. Zip Line

    NSDL National Science Digital Library

    WGBH

    2010-01-01

    In this design challenge activity, learners build a device to carry a Ping-Pong ball from the top of a zip line to the bottom in four seconds (or less!). Learners follow the design process to build the carrier that slides quickly down a zip line string, figure out how to keep something balanced, and identify ways to reduce friction.

  20. Potential animal model of multiple chemical sensitivity with cholinergic supersensitivity

    Microsoft Academic Search

    David H. Overstreet; Claudia S. Miller; David S. Janowsky; Roger W. Russell

    1996-01-01

    Multiple Chemical Sensitivity (MCS) is a clinical phenomenon in which individuals, after acute or intermittent exposure to one or more chemicals, commonly organophosphate pesticides (OPs), become overly sensitive to a wide variety of chemically-unrelated compounds, which can include ethanol, caffeine and other psychotropic drugs. The Flinders Sensitive Line (FSL) rats were selectively bred to be more sensitive to the OP

  1. Bosonic super-WIMPs as keV-scale dark matter

    SciTech Connect

    Pospelov, Maxim [Department of Physics and Astronomy, University of Victoria, Victoria, British Colombia, V8P 1A1 (Canada); Perimeter Institute for Theoretical Physics, Waterloo, Ontario, N2J 2W9 (Canada); Ritz, Adam [Department of Physics and Astronomy, University of Victoria, Victoria, British Colombia, V8P 1A1 (Canada); Voloshin, Mikhail [William I. Fine Theoretical Physics Institute, University of Minnesota, Minneapolis, Minnesota 55455 (United States); Institute of Theoretical and Experimental Physics, Moscow, 117218 (Russian Federation)

    2008-12-01

    We consider models of light superweakly interacting cold dark matter, with O(10-100) keV mass, focusing on bosonic candidates such as pseudoscalars and vectors. We analyze the cosmological abundance, the {gamma} background created by particle decays, the impact on stellar processes due to cooling, and the direct-detection capabilities in order to identify classes of models that pass all the constraints. In certain models, variants of photoelectric (or axioelectric) absorption of dark matter in direct-detection experiments can provide a sensitivity to the superweak couplings to the standard model which is superior to all existing indirect constraints. In all models studied, the annual modulation of the direct-detection signal is at the currently unobservable level of O(10{sup -5})

  2. Number Line

    NSDL National Science Digital Library

    Clarity Innovations, Inc.

    2013-11-22

    This iOS app helps students to visualize number sentences and create models for addition, subtractions, multiplication, and division. The number line can be adjusted to represent multiples of numbers from one to one hundred.

  3. HMOX1 and NQO1 Genes are Upregulated in Response to Contact Sensitizers in Dendritic Cells and THP1 Cell Line: Role of the Keap1\\/Nrf2 Pathway

    Microsoft Academic Search

    Nadege Ade; Fanny Leon; Marc Pallardy; Jean-Luc Peiffer; Saadia Kerdine-Romer; Marie-Helene Tissier; Pierre-Antoine Bonnet; Isabelle Fabre; Jean-Claude Ourlin

    2009-01-01

    Electrophilicity is one of the most common features of skin contact sensitizers and is necessary for protein haptenation. The Keap1 (Kelch-like ECH-associated protein 1)\\/Nrf2 -signaling pathway is dedicated to the detection of electrophilic stress in cells leading to the upregulation of genes involved in protection or neutralization of chemical reactive species. Signals provided by chemical stress could play an important

  4. Differential Activation of the c-Jun N-Terminal Kinase Pathway in Arsenite-Induced Apoptosis and Sensitization of Chemically Resistant Compared to Susceptible B-Lymphoma Cell Lines

    Microsoft Academic Search

    Donna E. Muscarella; Stephen E. Bloom

    2002-01-01

    Various forms of inorganic arsenic are significant environmen- tal contaminants that have multiple effects on cells, including the induction of apoptotic cell death. Induction of apoptosis in lym- phoid cells can mediate immunotoxicity following exposure to chemicals. However, the mechanisms regulating the sensitivity of B-lymphocytes to arsenic-induced apoptosis are not understood. Therefore, we investigated the involvement of key mitogen-acti- vated

  5. An assessment of the sensitivity of a low pressure time projection chamber to the direction of WIMP-induced nuclear recoils/

    E-print Network

    Henderson, Shawn Wesley

    2013-01-01

    Direct directional detection of dark matter could provide an unambiguous observation of dark matter due to the predicted directional anisotropy of dark matter particles in the galactic reference frame. The Dark Matter Time ...

  6. Relationship between constitutive nuclear factor-kappaB (NF-?B) and inhibitor kappaB-alpha (I?B-?) in an interferon-?-sensitive human Burkitt lymphoma cell line

    Microsoft Academic Search

    Pramod C. Rath

    2005-01-01

    The human Burkitt lymphoma Daudi cell line expresses constitutively active nuclear factor kappaB (NF-?B) in the nucleus in spite of high levels of inhibitor kappaB-alpha (I?B-?) in the cytoplasm. The antiproliferative response of these cells to interferon-? (IFN-?) correlated with the inhibition of the constitutive NF-?B activity by the cytokine. The present study shows that IFN-? caused an increase in

  7. The local dark matter phase-space density and impact on WIMP direct detection

    SciTech Connect

    Catena, Riccardo [Institut für Theoretische Physik, Friedrich-Hund-Platz 1, 37077 Göttingen (Germany); Ullio, Piero, E-mail: riccardo.catena@theorie.physik.uni-goettingen.de, E-mail: ullio@sissa.it [SISSA and INFN, Sezione di Trieste, Via Bonomea, 265, 34136 Trieste (Italy)

    2012-05-01

    We present a new determination of the local dark matter phase-space density. This result is obtained implementing, in the limit of isotropic velocity distribution and spherical symmetry, Eddington's inversion formula, which links univocally the dark matter distribution function to the density profile, and applying, within a Bayesian framework, a Markov Chain Monte Carlo algorithm to sample mass models for the Milky Way against a broad and variegated sample of dynamical constraints. We consider three possible choices for the dark matter density profile, namely the Einasto, NFW and Burkert profiles, finding that the velocity dispersion, which characterizes the width in the distribution, tends to be larger for the Burkert case, while the escape velocity depends very weakly on the profile, with the mean value we obtain being in very good agreement with estimates from stellar kinematics. The derived dark matter phase-space densities differ significantly — most dramatically in the high velocity tails — from the model usually taken as a reference in dark matter detection studies, a Maxwell-Boltzmann distribution with velocity dispersion fixed in terms of the local circular velocity and with a sharp truncation at a given value of the escape velocity. We discuss the impact of astrophysical uncertainties on dark matter scattering rates and direct detection exclusion limits, considering a few sample cases and showing that the most sensitive ones are those for light dark matter particles and for particles scattering inelastically. As a general trend, regardless of the assumed profile, when adopting a self-consistent phase-space density, we find that rates are larger, and hence exclusion limits stronger, than with the standard Maxwell-Boltzmann approximation. Tools for applying our result on the local dark matter phase-space density to other dark matter candidates or experimental setups are provided.

  8. Evaluation of the neutron background in an HPGe target for WIMP direct detection when using a reactor neutrino detector as a neutron veto system

    SciTech Connect

    Ji, Xiangpan; Xu, Ye, E-mail: xuye76@nankai.edu.cn; Lin, Junsong; Feng, Yulong; Li, Haolin [Nankai University, School of Physics (China)

    2013-11-15

    A direct WIMP (weakly interacting massive particle) detector with a neutron veto system is designed to better reject neutrons. The experimental configuration is studied in this paper involves 984 Ge modules placed inside a reactor-neutrino detector. The neutrino detector is used as a neutron veto device. The neutron background for the experimental design is estimated using the Geant4 simulation. The results show that the neutron background can decrease to O(0.01) events per year per tonne of high-purity germanium and it can be ignored in comparison with electron recoils.

  9. High Voltage Lines: Hazard at a Distance.

    ERIC Educational Resources Information Center

    Marino, Andrew A.; Becker, Robert O.

    1978-01-01

    It appears that a variety of biological organisms, including man, are sensitive to both long and short-term exposure to the extra low frequency electric and magnetic fields produced by high voltage lines. (BB)

  10. On the sensitivity of CTA to gamma-ray boxes from multi-TeV dark matter

    E-print Network

    Alejandro Ibarra; Anna S. Lamperstorfer; Sergio López Gehler; Miguel Pato; Gianfranco Bertone

    2015-03-23

    Collider, direct and indirect searches for dark matter have typically little or no sensitivity to weakly interacting massive particles (WIMPs) with masses above a few TeV. This rather unexplored regime can however be probed through the search for distinctive gamma-ray spectral features produced by the annihilation of WIMPs at very high energies. Here we present a dedicated search for gamma-ray boxes -- sharp spectral features that cannot be mimicked by astrophysical sources -- with the upcoming Cherenkov Telescope Array (CTA). Using realistic projections for the instrument performance and detailed background modelling, a profile likelihood analysis is implemented to derive the expected upper limits and sensitivity reach after 100 h of observations towards a $2^\\circ\\times2^\\circ$ region around the Galactic centre. Our results show that CTA will be able to probe gamma-ray boxes down to annihilation cross sections of $10^{-27}-10^{-26}\\,\\text{cm}^3\\text{/s}$ up to tens of TeV. We also identify a number of concrete particle physics models providing thermal dark matter candidates that can be used as target benchmarks in future search campaigns. This constitutes a golden opportunity for CTA to either discover or rule out multi-TeV thermal dark matter in a corner of parameter space where all other experimental efforts are basically insensitive.

  11. Pi Line

    NSDL National Science Digital Library

    2011-01-19

    This lesson from Illuminations asks students to measure the diameter and circumference of various circular objects, plot the measurements on a graph, and relate the slope of the line to Ï?, the ratio of circumference to diameter. A student activity sheet is included. The material is appropriate for grades 9-12 and should require 1 class period to complete.

  12. Murine double minute 2 siRNA and wild-type p53 gene therapy enhances sensitivity of the SKOV3/DDP ovarian cancer cell line to cisplatin chemotherapy in vitro and in vivo.

    PubMed

    Gu, Junlian; Tang, Yufeng; Liu, Yanan; Guo, Hua; Wang, Yue; Cai, Lu; Li, Yang; Wang, Bo

    2014-02-28

    SKOV3/DDP cells urgently require an efficient therapy to improve drug resistance. Here we show a critical role for cisplatin combined with gene therapy, using transfection of a p53 gene/MDM2-siRNA plasmid, in improving cisplatin sensitivity of SKOV3/DDP cells with a strong inhibition of tumor cell growth in vitro and in vivo. The effects may be associated with enhancement of intracellular platinum accumulation via decreased MDR1/P-gp and improvement of apoptotic resistance via increased P53, PUMA and NOXA expression. The combined therapy may efficiently inhibit cell invasion and migration via deceased HIF-1, VEGF, MMP-9 and MMP-2 to suppress malignant progression. These results indicate that cisplatin chemotherapy combined with targeting the MDM2/p53 axis is an attractive strategy to treat SKOV3/DDP cancer. PMID:24161623

  13. Familial melanoma associated with dominant ultraviolet radiation sensitivity

    SciTech Connect

    Ramsay, R.G.; Chen, P.; Imray, F.P.; Kidson, C.; Lavin, M.F.; Hockey, A.

    1982-07-01

    Sensitivity to ultraviolet radiation was studied in lymphoblastoid cell lines derived from 32 members of two families with histories of multiple primary melanomas in several generations. As assayed by colony formation in agar or by trypan blue exclusion following irradiation, cellular sensitivity showed a bimodal distribution. All persons with melanoma or multiple moles were in the sensitive group, while some family members exhibited responses similar to those of controls. Cells from four cases of sporadic melanoma showed normal levels of sensitivity. The data are consistent with a dominantly inherited ultraviolet light sensitivity associated with these examples of familial melanoma. Spontaneous and ultraviolet light-induced sister chromatid exchange frequencies were similar to those in control cell lines. No defect in excision repair was detected in any of the above cell lines, but the sensitive group showed postirradiation inhibition of DNA replication intermediate between controls and an excision-deficient xeroderma pigmentosum cell line.

  14. Line Defaults Modify Line/Shipping/Accounting

    E-print Network

    Shull, Kenneth R.

    Line Defaults and Modify Line/Shipping/Accounting NUFinancials Supply Chain FMS815 03/31/2010 --rkw, vlr Line Defaults & Modify Line/Shipping/Accounting © 2010 Northwestern University FMS815­ Job Aid Page 1 of 5 This job aid describes how and when to use Line Defaults and Modify Line/Shipping/Accounting

  15. Line Scanners Basic line-scanner principle

    E-print Network

    Giger, Christine

    to the ground coordinate system · NB: satellite line scanners · line scanners are especially popularLine Scanners #12;Principle · Basic line-scanner principle #12;Principle · Sensor · single CCD line oriented perpendicular to the scanning (=flight) direction, often called "pushbroom scanner" · Scanning

  16. Silencing of Taxol-Sensitizer Genes in Cancer Cells: Lack of Sensitization Effects

    PubMed Central

    Huang, Shang-Lang; Chao, Chuck C.-K.

    2015-01-01

    A previous genome-wide screening analysis identified a panel of genes that sensitize the human non-small-cell lung carcinoma cell line NCI-H1155 to taxol. However, whether the identified genes sensitize other cancer cells to taxol has not been examined. Here, we silenced the taxol-sensitizer genes identified (acrbp, atp6v0d2, fgd4, hs6st2, psma6, and tubgcp2) in nine other cancer cell types (including lung, cervical, ovarian, and hepatocellular carcinoma cell lines) that showed reduced cell viability in the presence of a sub-lethal concentration of taxol. Surprisingly, none of the genes studied increased sensitivity to taxol in the tested panel of cell lines. As observed in H1155 cells, SKOV3 cells displayed induction of five of the six genes studied in response to a cell killing dose of taxol. The other cell types were much less responsive to taxol. Notably, four of the five inducible taxol-sensitizer genes tested (acrbp, atp6v0d2, psma6, and tubgcp2) were upregulated in a taxol-resistant ovarian cancer cell line. These results indicate that the previously identified taxol-sensitizer loci are not conserved genetic targets involved in inhibiting cell proliferation in response to taxol. Our findings also suggest that regulation of taxol-sensitizer genes by taxol may be critical for acquired cell resistance to the drug. PMID:26086592

  17. Characterization of Nuclear Recoils in High Pressure Xenon Gas: Towards a Simultaneous Search for WIMP Dark Matter and Neutrinoless Double Beta Decay

    NASA Astrophysics Data System (ADS)

    Renner, J.; Gehman, V. M.; Goldschmidt, A.; Oliveira, C. A. B.; Nygren, D.

    Xenon has recently been the medium of choice in several large scale detectors searching for WIMP dark matter and neutrinoless double beta decay. Though present-day large scale experiments use liquid xenon, the gas phase o_ers advantages favorable to both types of searches such as improved intrinsic energy resolution and fewer fluctuations in the partition of deposited energy between scintillation and ionization channels. We recently constructed a high pressure xenon gas TPC as a prototype for the NEXT (Neutrino Experiment with a Xenon TPC) neutrinoless double beta decay experiment and have demonstrated the feasibility of 0.5% FWHM energy resolution at the 136Xe double beta Q-value with 3-D tracking capabilities. We now present results from this prototype on the simultaneous observation of scintillation and ionization produced by nuclear recoils at approximately 14 bar pressure. The recoils were produced by neutrons of approximately 2-6 MeV emitted from a radioisotope plutonium-beryllium source, and primary scintillation (S1) and electroluminescent photons produced by ionization (S2) were observed. We discuss the potential of gaseous xenon to distinguish between electron and nuclear recoils through the ratio of these two signals S2/S1. From these results combined with the possibility of using columnar recombination to sense nuclear recoil directionality at high pressures we envision a dual-purpose, ton-scale gaseous xenon detector capable of a combined search for WIMP dark matter and neutrinoless double beta decay. This work has been performed within the context of the NEXT collaboration.

  18. Polar Lines

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Context image for PIA03597 Polar Lines

    This linear features near the South Polar Cap appeared during the height of southern summer.

    Image information: VIS instrument. Latitude 79.7S, Longitude 249.1E. 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  19. The DRIFT Dark Matter Project: Directionality, Sensitivity, and Environmental Backgrounds 

    E-print Network

    Plank, Steven J S

    2008-01-01

    It is now largely accepted that dark matter, and more specifically, Weakly Interacting Massive Particles (WIMPs), constitute the majority of the mass in our Universe. Within this thesis are presented: (i) an overview of ...

  20. How Sensitively Timed Are Sensitive Periods?

    ERIC Educational Resources Information Center

    Zener, Rita Schaefer

    2003-01-01

    Reviews Maria Montessori's view of sensitive periods and examines the kinds of help needed from adults: an open mind, specific help from a prepared learning environment, and challenges presented at the right time. Stresses the universality of sensitive periods and their connection to brain development. Focuses on the unconscious nature and…

  1. In vitro screening for aryl hydrocarbon receptor agonistic activity in 200 pesticides using a highly sensitive reporter cell line, DR-EcoScreen cells, and in vivo mouse liver cytochrome P450-1A induction by propanil, diuron and linuron.

    PubMed

    Takeuchi, Shinji; Iida, Mitsuru; Yabushita, Hisatoshi; Matsuda, Tadashi; Kojima, Hiroyuki

    2008-12-01

    The aryl hydrocarbon receptor (AhR) is a ligand-dependent transcription factor that regulates genes involved in xenobiotic metabolism, cellular proliferation and differentiation. In this study, we have developed a highly sensitive AhR-mediated reporter cell line, DR-EcoScreen cells, which are mouse hepatoma Hepa1c1c7 cells stably transfected with a reporter plasmid containing seven copies of dioxin-responsive element. Using these DR-EcoScreen cells, we performed the reporter gene assay and characterized the AhR agonistic activities of 200 pesticides (29 organochlorines, 11 diphenyl ethers, 56 organophosphorus pesticides, 12 pyrethroids, 22 carbamates, 12 acid amides, 7 triazines, 6 ureas, and 45 others). Eleven of the 200 pesticides (acifluorfen-methyl, bifenox, chlorpyrifos, isoxathion, quinalphos, chlorpropham, diethofencarb, propanil, diuron, linuron, and prochloraz) showed AhR-mediated transcriptional activity. In particular, three herbicides (propanil, diuron, and linuron) have a common chemical structure and showed more potent agonistic activity than other pesticides. To investigate the in vivo effects, we examined the gene expression of AhR-inducible cytochrome P450 1As (CYP1As) in the liver of female C57BL/6 mice intraperitoneally injected with these three herbicides (300 mg kg(-1)) by quantitative RT-PCR, resulting in induction of significant high levels of CYP1A1 and CYP1A2 mRNAs. This indicates that propanil, diuron and linuron possess AhR-mediated transactivation effect in vivo as well as in vitro. Through the present study, we demonstrated that DR-EcoScreen cells are useful for sensitive, rapid and simple identification of AhR agonists among a large number of environmental chemicals. PMID:18835618

  2. Proposed animal neurosensitization model for multiple chemical sensitivity in studies with formalin

    Microsoft Academic Search

    Barbara A. Sorg; James R. Willis; Thomas C. Nowatka; Catherine Ulibarri; Ronald E. See; Hal H. Westberg

    1996-01-01

    A potentially promising line of animal research relevant to multiple chemical sensitivity (MCS) is that of sensitization in the central nervous system (CNS), particularly limbic pathways in the brain. Sensitization is the progressive and enduring enhancement in behavioral and neurochemical responses that occurs after repeated exposure to psychostimulants or environmental stressors. Since the onset and progression of sensitization has many

  3. Pressure Sensitive Paints

    NASA Technical Reports Server (NTRS)

    Liu, Tianshu; Bencic, T.; Sullivan, J. P.

    1999-01-01

    This article reviews new advances and applications of pressure sensitive paints in aerodynamic testing. Emphasis is placed on important technical aspects of pressure sensitive paint including instrumentation, data processing, and uncertainty analysis.

  4. Sensitivity versus block sensitivity of Boolean functions

    E-print Network

    Virza, Madars

    2010-01-01

    Determining relationship between sensitivity and block sensitivity of Boolean functions is of interest for computational complexity theory. We construct a sequence of Boolean functions with bs(f) = 1/2 (s(f))^2+ 1/2 s(f). The best known separation previously was bs(f) = 1/2 (s(f))^2 due to Rubinstein (1995). We also report results of computer search for functions with at most 12 variables.

  5. Delay-line readout for multicell detectors

    NASA Astrophysics Data System (ADS)

    Ditta, J.; Kuroda, K.; Nemoz, C.; Sillou, D.

    1986-09-01

    A simple delay-line readout method has been tested with a position-sensitive photomultiplier. Position accuracies of the reconstruction by means of a time-to-amplitude convertor are quite comparable to those obtained by a conventional centroid method using a number of analog-to-digital convertors. In this way, a simple and economic solution can be conceived for the readout of not only position-sensitive photomultipliers, but also arrays of different kinds of position detectors.

  6. [Subjective sensitivity to noise].

    PubMed

    Belojevi?, G

    1991-01-01

    It is likely that individual variations in subjectively estimated noise sensitivity influence different social and psychophysiological reactions of people exposed to noise. Subjective noise sensitivity might be a relatively stable personal characteristic. A correlation have been found between high sensitiveness to noise and some medical symptoms (sleep disturbance, nervousness, depression), and worse work performance in noisy environments. An introvert person with neurotic symptoms is more frequently found in people highly sensitive to noise. Testing for subjective sensitivity to noise might be helpful in professional selection and orientation for noisy work-places as well as in housing advising. PMID:1792583

  7. Mass sensitivity of multilayer thin film resonant BAW sensors

    Microsoft Academic Search

    G. Wingqvist; V. Yantchev; I. Katardjiev

    2008-01-01

    A systematic study of the mass sensitivity and its dependence on the material's properties and thicknesses in composite multilayer Thin Film Bulk Acoustic Resonators (FBAR) is presented. The Mason transmission line model has been employed in combination with the acoustic energy balance principle for the determination of the FBAR mass sensitivity. The results have been experimentally verified. Further, the mass

  8. Personal Time Line

    NSDL National Science Digital Library

    Eric Muller

    2003-01-01

    In this activity, learners work in groups to create a time line representing significant moments in their lives. Learners use scientific suffixes and prefixes to label their time lines, modeling the Geologic Time Line (i.e. Mesozoic, Paleozoic).

  9. Work accommodation for people with multiple chemical sensitivity

    Microsoft Academic Search

    Pamela Reed Gibson; Amanda Lindberg

    2007-01-01

    Multiple chemical sensitivity (MCS) is a term used to describe allergic?like reactions to chemicals that represent everyday exposures in industrialized countries. It is sometimes associated with electromagnetic sensitivity, and both conditions are most likely engendered by environmental exposures. Prevalence studies suggest that chemical sensitivity affects 12–15% of the US population and that it crosses age, socio?economic status and racial lines.

  10. First-Line Treatment for Tuberculosis (TB), Drug Resistant TB -- A Visual Tour

    MedlinePLUS

    ... Content Area First-Line Treatment of TB for Drug-Sensitive TB Tuberculosis, which results from an infection ... Click here to see how these drugs work . Drug-Resistant TB—A Visual Tour First-Line Treatment ...

  11. Nuclear spin-dependent interactions: searches for WIMP, axion and topological defect dark matter, and tests of fundamental symmetries

    NASA Astrophysics Data System (ADS)

    Stadnik, Y. V.; Flambaum, V. V.

    2015-03-01

    We calculate the proton and neutron spin contributions for nuclei using semi-empirical methods, as well as a novel hybrid ab initio/semi-empirical method, for interpretation of experimental data. We demonstrate that core-polarisation corrections to ab initio nuclear shell model calculations generally reduce discrepancies in proton and neutron spin expectation values from different calculations. We derive constraints on the spin-dependent P,T-violating interaction of a bound proton with nucleons, which for certain ranges of exchanged pseudoscalar boson masses improve on the most stringent laboratory limits by several orders of magnitude. We derive a limit on the CPT and Lorentz-invariance-violating parameter GeV, which improves on the most stringent existing limit by a factor of 8, and we demonstrate sensitivities to the parameters and at the level - GeV, which is a one order of magnitude improvement compared to the corresponding existing sensitivities. We extend previous analysis of nuclear anapole moment data for Cs to obtain new limits on several other CPT and Lorentz-invariance-violating parameters: GeV, , GeV and.

  12. Flash Mob Project Creates Awareness of Environmental Sensitivities: Making "Multiple Chemical Sensitivity" a Household Name

    ERIC Educational Resources Information Center

    Smith, Melva Gail

    2011-01-01

    Having severe Asthma and trying to maintain a social life isn't easy, but when one adds the disability of Multiple Chemical Sensitivity (MCS) to the combination, the challenges become even tougher. As a dancer with both Asthma and MCS, the author was forced to give up the sport for 15 years before finding a group of line dancers that were…

  13. Multiple Chemical Sensitivity: Toxicological and Sensitivity Mechanisms

    Microsoft Academic Search

    Martin L. Pall

    Cases of multiple chemical sensitivity (MCS) are reported to be initiated by seven classes of chemicals. Each of the seven acts along a specific pathway, indirectly producing increases in NMDA activity in the mammalian body. Members of each of these seven classes have their toxicant responses lowered by NMDA antagonists, showing that the NMDA response is important for the toxic

  14. Fabrics Protect Sensitive Skin from UV Rays

    NASA Technical Reports Server (NTRS)

    2009-01-01

    Late Johnson Space Center engineer Dr. Robert Dotts headed a team to develop cool suits for children suffering from life-threatening sun sensitivities. Dotts hoped to develop ultraviolet-blocking technology in a fabric that -- unlike in a bulky space suit -- could remain comfortable, light, and breathable in the sun and heat. The team worked with SPF 4 US LLC (SPF) of Madison, Wisconsin to design ultraviolet-blocking cool suits, which protect sun-sensitive patients and enable them to experience life outdoors safely. Using knowledge gained during the NASA collaboration, SPF created an entire line of ultraviolet-blocking apparel.

  15. In-line Sagnac interferometer current sensor

    Microsoft Academic Search

    J. Blake; P. Tantaswadi; R. T. de Carvalho

    1996-01-01

    The authors demonstrate for the first time a near shot noise limited in-line Sagnac interferometer current sensor. It is shown to have a number of advantages over the optical current sensors based on polarimetric Faraday and Faraday\\/Sagnac loop interferometer topologies, including lower sensitivity to environmental disturbances, less demanding optical components, and easy installation.

  16. Easy Observation of Infrared Spectral Lines

    ERIC Educational Resources Information Center

    Cortel, Adolf

    2012-01-01

    The spectra of some chemical elements display intense infrared (IR) lines that can be used more effectively than the ones in the visible region for identification purposes. A simple setup, based on the IR sensitivity of a handycam in nightshot mode, is described to record the visible as well as the IR spectra from decorative bulbs or salts on the…

  17. The Language of Lines.

    ERIC Educational Resources Information Center

    Breig-Allen, Cheryl; Hill, Janet; Geismar-Ryan, Lori; Cadwell, Louise Boyd

    1998-01-01

    Describes a project about lines in the environment used with 2- and 3-year olds and based on the Reggio Emilia approach. Activities included making tracks with riding toys, drawing lines on papers, seeing cloud lines, and making lines with yarn and Cuisenaire rods. Shows how young children's observations and ongoing discoveries can uncover their…

  18. Abstract Line Designs

    ERIC Educational Resources Information Center

    Nevinskas, Nancy

    2011-01-01

    In this article, the author describes a unit on the exploration of line. The unit was composed of two individual line lessons. In the first lesson, students were introduced to line as an element of design. They were asked to describe different types of lines, and look for them in art reproductions. The second lesson in the unit involved painting…

  19. Nuclear spin-dependent interactions: Searches for WIMP, Axion and Topological Defect Dark Matter, and Tests of Fundamental Symmetries

    E-print Network

    Y. V. Stadnik; V. V. Flambaum

    2015-01-22

    We calculate the proton and neutron spin contributions for nuclei using semi-empirical methods, as well as a novel hybrid \\emph{ab initio}/semi-empirical method, for interpretation of experimental data. We demonstrate that core-polarisation corrections to \\emph{ab initio} nuclear shell model calculations generally reduce discrepancies in proton and neutron spin expectation values from different calculations. We derive constraints on the spin-dependent P,T-violating interaction of a bound proton with nucleons, which for certain ranges of exchanged pseudoscalar boson masses improve on the most stringent laboratory limits by several orders of magnitude. We derive a limit on the CPT and Lorentz-invariance-violating parameter $|\\tilde{b}_{\\perp}^p| < 7.6 \\times 10^{-33}$ GeV, which improves on the most stringent existing limit by a factor of 8, and demonstrate sensitivities to the parameters $\\tilde{d}_{\\perp}^p$ and $\\tilde{g}_{ D\\perp}^p$ at the level $\\sim 10^{-29} - 10^{-28}$ GeV, which is a one order of magnitude improvement compared to the corresponding existing sensitivities. We extend previous analysis of nuclear anapole moment data for Cs to obtain new limits on several other CPT and Lorentz-invariance-violating parameters: $\\left|b_0^p \\right| < 7 \\times 10^{-8}$ GeV, $\\left|d_{00}^p \\right| < 8 \\times 10^{-8}$, $\\left|b_0^n \\right| < 3 \\times 10^{-7}$ GeV and $\\left|d_{00}^n \\right| < 3 \\times 10^{-7}$.

  20. Tuned cavity magnetometer sensitivity.

    SciTech Connect

    Okandan, Murat; Schwindt, Peter

    2009-09-01

    We have developed a high sensitivity (sensitivity levels.

  1. Are Psychopaths Morally Sensitive?

    ERIC Educational Resources Information Center

    Maxwell, Bruce; Le Sage, Leonie

    2009-01-01

    Philosophical and psychological opinion is divided over whether moral sensitivity, understood as the ability to pick out a situation's morally salient features, necessarily involves emotional engagement. This paper seeks to offer insight into this question. It reasons that if moral sensitivity does draw significantly on affective capacities of…

  2. Vaginal erotic sensitivity

    Microsoft Academic Search

    Heli Alzate; Maria Ladi Londono

    1984-01-01

    Vaginal erotic sensitivity was investigated in a group of 48 coitally experienced volunteers by means of systematic digital stimulation of both vaginal walls. It was found that 45 subjects reported erotic sensitivity located in most cases on the upper anterior wall, and of those, 30 (66. 7%) either reached orgasm or requested to stop stimulation short of orgasm. This study

  3. The potential effectiveness of nanoparticles as radio sensitizers for radiotherapy

    PubMed Central

    Babaei, Mohammad; Ganjalikhani, Maryam

    2014-01-01

    Introduction: Application of nanoparticles as radio sensitizer is a promising field to improve efficiency of radiotherapy. Methods: This study was conducted to review nano radio sensitizers. PubMed, Ovid Medline, Science Direct, Scopus, ISI web of knowledge, and Springer databases were searched from 2000 to May 2013 to identify relevant studies. Search was restricted to English language. Results: We included any study that evaluated nanoparticles, volunteer of radio enhancement at radiotherapy on animals or cell lines. Nanoparticles can increase radio sensitivity of tumor cells. This effect was shown in vivo and in vitro, at kilovltage or megavoltage energies, in 24 reviewed studies. Focus of studies was on gold nanoparticles. Radio sensitizing effects of nanoparticles depend on nanoparticles’ size, type, concentration, intracellular localization, used irradiation energy and tested cell line. Conclusion: Literature suggests potency of nanoparticles for increasing cell radio sensitivity. Reviewed results are promising and warrant future clinical trials. PMID:24790894

  4. A study of eigenvalue sensitivity for hydrodynamic stability operators

    NASA Technical Reports Server (NTRS)

    Schmid, Peter J.; Henningson, Dan S.; Khorrami, Mehdi R.; Malik, Mujeeb R.

    1993-01-01

    The eigenvalue sensitivity for hydrodynamic stability operators is investigated. Classical matrix perturbation techniques as well as the concept of epsilon-pseudospectra are applied to show that parts of the spectrum are highly sensitive to small perturbations. Applications are drawn from incompressible plane Couette flow, trailing line vortex flow, and compressible Blasius boundary-layer flow. Parameter studies indicate a monotonically increasing effect of the Reynolds number on the sensitivity. The phenomenon of eigenvalue sensitivity is due to the nonnormality of the operators and their discrete matrix analogs and may be associated with large transient growth of the corresponding initial value problem.

  5. Determination of transient stability constrained line flow limits: an application of linearized techniques for the transient energy function method

    Microsoft Academic Search

    V. Vittal; Jolene LeAnne Gleason

    1989-01-01

    An effort is made to determine how line flow changes affect the robustness of the power system using the energy margin sensitivities to power generation shifts and power flow distribution factors. A method to obtain stability constrained line flow limits is proposed. The major difference between this research work and other research in transient energy function sensitivity techniques for line

  6. Transgenic Campanula carpatica plants with reduced ethylene sensitivity.

    PubMed

    Sriskandarajah, Sridevy; Mibus, Heiko; Serek, Margrethe

    2007-06-01

    Fertile transgenic Campanula carpatica Jacq. plants with flowers, which had reduced sensitivity to ethylene were obtained by Agrobacterium tumefaciens that mediated transformation. The construct used for transformation contained the etr1-1 gene from Arabidopsis thaliana under control of the flower specific fbp1-promoter from petunia. More than 100 flowering T0 lines were tested for their ethylene sensitivity using 2 microl l(-1) ethylene. The tolerance level to ethylene varied among the lines. While control plants stopped flowering within 3 days of exposure to ethylene, one of the transformed lines flowered for up to 27 days. The presence and the expression pattern of the transgene in various tissues were studied by polymerase chain reaction (PCR) and reverse transcription (RT)-PCR techniques. The expression of etr1-1 was significant in flowers and buds. Transgenic lines did not differ morphologically from control plants. The selected transgenic T0 lines, which were re-established from in vitro cultures showed the same degree of tolerance to exogenous ethylene, confirming the stability of the transgene in in vitro cultures. The rooting ability of the transgenic plants was not affected by the presence of etr1-1. T1 progeny were produced by crossing the transgenic line, which showed the most significant reduction in ethylene sensitivity with a control plant, and the analysis of the T1 plants showed 1:1 segregation in terms of ethylene sensitivity and the presence of the transgene. PMID:17221226

  7. Contact sensitization in children.

    PubMed

    Manzini, B M; Ferdani, G; Simonetti, V; Donini, M; Seidenari, S

    1998-01-01

    Our study concerns contact sensitization in children, the frequency of which is still debated in the literature, even though specific reports are increasing. During a 7 year period (1988-1994) 670 patients, 6 months to 12 years of age, were patch tested with the European standard series, integrated with 24 haptens, at the same concentrations as for adults. We observed positive results in 42% of our patients. Thimerosal, nickel sulfate, Kathon CG, fragrance mix, neomycin, wool alcohols, and ammoniated mercury induced most of the positive responses. The highest sensitization rate was found in children from 0 to 3 years of age. Comments on main positive haptens are reported. Seventy-seven percent of our sensitized patients were atopics, suggesting that atopy represents a predisposing factor for contact hypersensitivity. Patch testing represents a useful diagnostic procedure for the definition of childhood eczematous dermatitis and for the identification of agents inducing contact sensitization which is frequently associated with atopic dermatitis. PMID:9496796

  8. Performance-Sensitive Debt

    E-print Network

    Manso, Gustavo

    This article studies performance-sensitive debt (PSD), the class of debt obligations whose interest payments depend on some measure of the borrower’s performance. We demonstrate that the existence of PSD obligations cannot ...

  9. Sensitivity to wild vegetation.

    PubMed

    Menz, J; Winkelmann, R K

    1987-03-01

    74 patients suspected of having allergic contact dermatitis to wild vegetation were patch tested with either extracts of 13 plants of the family Compositae and 7 other weeds or trees. Anthemis cotula (dog fennel) and Xanthium strumarium (cocklebur) gave the most frequent positive results, demonstrating a change of frequency in sensitivity compared to the 1950s, when Ambrosia artemisiifolia (ragweed) was recognized as the most frequently sensitizing weed. The reasons for these changes of incidence and clinical patterns are examined. PMID:3581826

  10. The Line Sequence Diagram

    Microsoft Academic Search

    Calvin R. Srock

    1966-01-01

    This paper describes the symbols and techniques used to construct and apply a line sequence diagram. A line sequence diagram, as the name implies, describes the sequence of operations for an electrical control circuit.

  11. Peripheral arterial line - infants

    MedlinePLUS

    PAL - infants; Art line - infants ... an "art line." This article addresses PALs in babies. Why is a PAL used? Doctors and nurses use a PAL to watch your baby's blood pressure. A PAL can also be use ...

  12. Racing line optimization

    E-print Network

    Xiong, Ying, S.M. Massachusetts Institute of Technology

    2010-01-01

    Although most racers are good at controlling their cars, world champions are always talented at choosing the right racing line while others mostly fail to do that. Optimal racing line selection is a critical problem in car ...

  13. Double Line Image Rotation.

    PubMed

    Ashtari, Amir Hossein; Nordin, Md Jan; Kahaki, Seyed Mostafa Mousavi

    2015-11-01

    This paper proposes a fast algorithm for rotating images while preserving their quality. The new approach rotates images based on vertical or horizontal lines in the original image and their rotated equation in the target image. The proposed method is a one-pass method that determines a based-line equation in the target image and extracts all corresponding pixels on the base-line. Floating-point multiplications are performed to calculate the base-line in the target image, and other line coordinates are calculated using integer addition or subtraction and logical justifications from the base-line pixel coordinates in the target image. To avoid a heterogeneous distance between rotated pixels in the target image, each line rotates to two adjacent lines. The proposed method yields good performance in terms of speed and quality according to the results of an analysis of the computation speed and accuracy. PMID:26054069

  14. High-resolution line-scanning optical coherence microscopy.

    PubMed

    Chen, Yu; Huang, Shu-Wei; Aguirre, Aaron D; Fujimoto, James G

    2007-07-15

    An optical coherence microscopy system based on line illumination and detection is demonstrated. The system uses a Linnik-type interferometer illuminated by a broadband Ti:sapphire laser and detected by a high-speed, line-scan CCD camera. This approach is less sensitive to incoherent scattering and sample motion than full-field imaging. Spatial resolutions of approximately 2 microm x approximately 3 microm(transverse x axial) are achieved. The sensitivity of the system is 93 dB with averaging over 30 line scans. En face real time, cellular-level imaging of biological tissues is demonstrated at approximately 2 frames/s. PMID:17632613

  15. Points, Lines, and Planes

    NSDL National Science Digital Library

    Mrs. Neubert

    2011-08-18

    This lesson will define the important basics of Geometry: Points, Lines, and Planes Let's take notes on our first lesson! Click on the link below to get started: Points, Lines, and Planes Now, here is an activity to check your understanding: Points, Lines and Planes Activity OK! Now, here is a quiz to really see if you got it: Points, Lines, and Planes Quiz! Good Job! Now, your homework can be found on your Canvas account or my website calendar on ...

  16. Mechanisms of multiple chemical sensitivity

    Microsoft Academic Search

    Chris Winder

    2002-01-01

    Sensitivity to chemicals is a toxicological concept, contained in the dose–response relationship. Sensitivity also includes the concept of hypersensitivity, although controversy surrounds the nature of effects from very low exposures. The term multiple chemical sensitivity has been used to describe individuals with a debilitating, multi-organ sensitivity following chemical exposures. Many aspects of this condition extend the nature of sensitivity to

  17. Some nonrealizable line diagrams

    Microsoft Academic Search

    Rudi Penne

    1994-01-01

    We superimpose weaving patterns on planar line arrangements, and we face the question when they can be realized by lines in 3-space. Using the combinatorial type of the given lines in the plane we derive a class of nonrealizable weavings.

  18. Service Based Product Lines

    Microsoft Academic Search

    Alberto Sillitti; Tullio Vernazza; Giancarlo Succi

    Product lines are sets of products designed to solve complex problems that a single tool is not able to approach because of the complexity. Moreover product lines are scalable: customers can buy only components that they need to work at present. Future enhancement could be done with little training effort due to the homogeneity of products inside a product line.

  19. Epitaxy and line tension

    NASA Astrophysics Data System (ADS)

    Mederos, L.; Quintana, A.; Navascués, G.

    1985-01-01

    The line tension concept is used to generalize the classical theory of heterogeneous nucleation. The theory is applied to study the impingement flux-temperature diagram of nucleation. The epitaxial nucleation zone at the diagram can be drastically modified depending on the sign of the line tension. Line tension also gives place to a new zone of no nucleation due to spreading effects.

  20. Linear Pose Estimation from Points or Lines Adnan Ansar and Kostas Daniilidis, Member, IEEE

    E-print Network

    Abstract--Estimation of camera pose from an image of n points or lines with known correspondence estimation problem for both n points and n lines. We then analyze the sensitivity of our solutions to image noise and show that the sensitivity analysis can be used as a conservative predictor of error for our

  1. CRIRES spectroscopy and empirical line-by-line identification of FeH molecular absorption in an M dwarf

    NASA Astrophysics Data System (ADS)

    Wende, S.; Reiners, A.; Seifahrt, A.; Bernath, P. F.

    2010-11-01

    Molecular FeH provides a large number of sharp and isolated absorption lines that can be used to measure radial velocity, rotation, or magnetic field strength with high accuracy. Our aim is to provide an FeH atlas for M-type stars in the spectral region from 986 nm to 1077 nm (Wing-Ford band). To identify these lines in CRIRES spectra of the magnetically inactive, slowly rotating, M5.5 dwarf GJ1002, we calculated model spectra for the selected spectral region with theoretical FeH line data. In general this line list agrees with the observed data, but several individual lines differ significantly in position or in line strength. After identification of as many as possible FeH lines, we corrected the line data for position and line strength to provide an accurate atlas of FeH absorption lines for use in high precision spectroscopy of low mass stars. For all lines, we used a Voigt function to obtain their positions and equivalent widths. Identification with theoretical lines was done by hand. For confirmation of the identified lines, we used statistical methods, cross-correlation techniques, and line intensities. Eventually, we were able to identify FeH lines from the (0,0), (1,0), (1,1), (2,1), (2,2), (3,2), and (4,3) vibrational bands in the observed spectra and correct the positions of the lines if necessary. The deviations between theoretical and observed positions follow a normal distribution approximately around zero. In order to empirically correct the line strength, we determined Teff, instrumental broadening (rotational broadening) and a van der Waals enhancement factor for the FeH lines in GJ1002. We also give the scaling factors for the Einstein A values to correct the line strengths. With the identified lines, we derived rotational temperatures from the line intensities for GJ1002. We conclude that FeH lines can be used for a wide variety of applications in astrophysics. With the identified lines it will be possible for example to characterize magnetically sensitive or very temperature sensitive lines, which can be used to investigate M-type stars. Data were taken at ESO Telescopes under the program 79.D-0357(A).Full Table 4 and FeH atlas are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/viz-bin/qcat?J/A+A/523/A58

  2. Scrubber lining betterment

    SciTech Connect

    Cmiel, R. (TX (US))

    1990-01-01

    This article is intended to provide guidance in the selection, qualification, and application of corrosion-resistant coatings and linings in electrical generating plants with emphasis on flue gas desulfurization (FGD) scrubber maintenance. Guidance is included here especially for those facing a lining project. This article describes scrubber outlet duct vinyl ester lining installation at San Miguel Electric. This lining is also being used in scrubber waste slurry thickeners and in the scrubber absorber vessel to overcoat existing flakeglass linings providing useful life extension.

  3. Line of Best Fit

    NSDL National Science Digital Library

    Roberts, Donna

    When data is displayed with a scatter plot, it is often useful to attempt to represent that data with the equation of a straight line for purposes of predicting values that may not be displayed on the plot. Such a straight line is called the "line of best fit." In this activity, students discover the relationship between the fat grams and the total calories in fast food by graphing the given data, estimate the line of best fit using a strand of spaghetti, calculate the slope of that line, and translate it into an equation. Then, they use that equation to predict information not originally included in the scatter plot.

  4. Fiber-optic hydrophone with increased sensitivity

    NASA Astrophysics Data System (ADS)

    Guo, Ke; Zhang, Min; Liao, Yanbiao; Lai, Shurong; Wang, Zehan; Tang, Jin

    2006-08-01

    This article is about some results of the research for increasing the phase-shift sensitivity of fiber-optic hydrophone. Many factors that affect the sensitivity are discussed, including the structure of the hydrophone sensor, the substrate of the fiber and the composite structure of the fiber. The framework of the hydrophone sensor is enwound by the fiber of the reference arm of the interferometer; out of this an inner lining is used with the fiber of the signal arm enwound on it. The fiber has a composite structure. From inner to exterior there are the core, the cladding and the substrate. The thickness of the substrate has an effect on the phase-shift sensitivity of the hydrophone. Outside the sensor we spread a kind of elastic material that is sound non-transparent. This material can protect the fiber of the signal arm. It can also be regarded as the substrate of the fiber, so the thickness of the material can affect the phase-shift sensitivity of the hydrophone. The theory analysis and the experiment measurement have been made in detail in this article. And the result is that 1mm of Teflon can raise the phase-shift sensitivity by 10dBrad/Pa.

  5. Environmental Sensitivity and Paranormal Experiences 

    E-print Network

    Massullo, Brandon

    2008-12-03

    ) these environmentally sensitive individuals are also significantly more likely to report paranormal experiences than non-sensitives. The current study set out to test the hypothesis that environmentally sensitive individuals will report more past paranormal experiences...

  6. Allergic sensitization: screening methods.

    PubMed

    Ladics, Gregory S; Fry, Jeremy; Goodman, Richard; Herouet-Guicheney, Corinne; Hoffmann-Sommergruber, Karin; Madsen, Charlotte B; Penninks, André; Pomés, Anna; Roggen, Erwin L; Smit, Joost; Wal, Jean-Michel

    2014-01-01

    Experimental in silico, in vitro, and rodent models for screening and predicting protein sensitizing potential are discussed, including whether there is evidence of new sensitizations and allergies since the introduction of genetically modified crops in 1996, the importance of linear versus conformational epitopes, and protein families that become allergens. Some common challenges for predicting protein sensitization are addressed: (a) exposure routes; (b) frequency and dose of exposure; (c) dose-response relationships; (d) role of digestion, food processing, and the food matrix; (e) role of infection; (f) role of the gut microbiota; (g) influence of the structure and physicochemical properties of the protein; and (h) the genetic background and physiology of consumers. The consensus view is that sensitization screening models are not yet validated to definitively predict the de novo sensitizing potential of a novel protein. However, they would be extremely useful in the discovery and research phases of understanding the mechanisms of food allergy development, and may prove fruitful to provide information regarding potential allergenicity risk assessment of future products on a case by case basis. These data and findings were presented at a 2012 international symposium in Prague organized by the Protein Allergenicity Technical Committee of the International Life Sciences Institute's Health and Environmental Sciences Institute. PMID:24739743

  7. Sensitive skin: an overview.

    PubMed

    Berardesca, E; Farage, M; Maibach, H

    2013-02-01

    Sensitive skin is a condition of subjective cutaneous hyper-reactivity to environmental factors. Subjects experiencing this condition report exaggerated reactions when their skin is in contact with cosmetics, soaps and sun screens, and they often report worsening after exposure to dry and cold climate. Although no sign of irritation is commonly detected, itching, burning, stinging and a tight sensation are constantly present. Generally substances that are not commonly considered irritants are involved in this abnormal response.Sensitive skin and subjective irritation are widespread but still far from being completely defined and understood. A correlation between sensitive skin and constitutional anomalies and/or other triggering factors such as occupational skin diseases or chronic exposure to irritants has been hypothesized. Recent findings suggest that higher sensitivity can be due to different mechanisms. Hyper-reactors may have a thinner stratum corneum with a reduced corneocyte area causing a higher transcutaneous penetration of water-soluble chemicals. Alterations in vanilloid receptors and changes in neuronal transmission have been described. Monitoring skin parameters such as barrier function, proclivity to irritation, corneocyte size and sensorial transmission can also be useful to identify regional differences in skin sensitivity. PMID:22928591

  8. COS FUV Sensitivity

    NASA Astrophysics Data System (ADS)

    Keyes, Charles

    2009-07-01

    DESCRIPTION: This activity confirms COS sensitivity versus wavelength over the entire observable spectrum for all FUV gratings and central wavelength settings. Obtain quicklook sensitivity visit early in SMOV. Later, after wavelength calibration is verified, perform a precise-centering acquisition and observe an appropriate HST flux standard star {chosen from the HST prime standard and FASTEX lists} with the PSA. {A limited BOA characterization is obtained in Visit 13 using primary standard GD153.} No off aperture-center observations are performed in this activity {see COS32, program 11490, for off-center characterizations}. Spectra will be obtained to meet a Poisson S/N criterion of 30 per sensitivity extraction bin or higher; substantially higher S/N characterization will be utilized in routine Cycle 17 calibration.

  9. Wide-Band Low-Noise Charge Sensitive Preamplifier

    Microsoft Academic Search

    T. V. Blalock

    1966-01-01

    This paper presents the design considerations and experimental characteristics of a transistorized charge-sensitive preamplifier that has a noise line-width significantly lower than that of the best vacuum-tube preamplifiers, and a high gain-bandwidth product which allows stabilization of the charge gain against detector capacitance fluctuations over a wide range of pulse-shaping time-constants. The open-loop gain of both the input charge-sensitive section

  10. Transgenic Campanula carpatica plants with reduced ethylene sensitivity

    Microsoft Academic Search

    Sridevy Sriskandarajah; Heiko Mibus; Margrethe Serek

    2007-01-01

    Fertile transgenic Campanula carpatica Jacq. plants with flowers, which had reduced sensitivity to ethylene were obtained by Agrobacterium tumefaciens that mediated transformation. The construct used for transformation contained the etr1-1 gene from Arabidopsis thaliana under control of the flower specific fbp1-promoter from petunia. More than 100 flowering T0 lines were tested for their ethylene sensitivity using 2 ?l l?1 ethylene. The tolerance

  11. Improved spatial frequency response in silver halide sensitized gelatin holograms

    Microsoft Academic Search

    A. Beléndez; C. Neipp; I. Pascual

    1998-01-01

    We report what we believe to be the best results obtained to date with regard to the spatial frequency response of silver halide sensitized gelatin (SHSG) holograms. A very high diffraction efficiency, as high as 91% (after allowing for reflection), and an almost flat spatial frequency response between 800 lines\\/mm and 2800 lines\\/mm have been achieved using the new BB-640

  12. Gene expression differences in mice divergently selected for methamphetamine sensitivity

    Microsoft Academic Search

    Abraham A. Palmer; Miguel Verbitsky; Rathi Suresh; Helen M. Kamens; Cheryl L. Reed; Na Li; Carrie S. McKinnon; John K. Belknap; T. Conrad Gilliam; Tamara J. Phillips

    2005-01-01

    In an effort to identify genes that may be important for drug-abuse liability, we mapped behavioral quantitative trait loci (bQTL) for sensitivity to the locomotor stimulant effect of methamphetamine (MA) using two mouse lines that were selectively bred for high MA-induced activity (HMACT) or low MA-induced activity (LMACT). We then examined gene expression differences between these lines in the nucleus

  13. Linear Polarization Measurements of Chromospheric Emission Lines

    NASA Astrophysics Data System (ADS)

    Sheeley, N. R., Jr.; Keller, C. U.

    2003-09-01

    We have used the Zurich Imaging Stokes Polarimeter (ZIMPOL I) with the McMath-Pierce 1.5 m main telescope on Kitt Peak to obtain linear polarization measurements of the off-limb chromosphere with a sensitivity better than 1×10-5. We found that the off-disk observations require a combination of good seeing (to show the emission lines) and a clean heliostat (to avoid contamination by scattered light from the Sun's disk). When these conditions were met, we obtained the following principal results:1. Sometimes self-reversed emission lines of neutral and singly ionized metals showed linear polarization caused by the transverse Zeeman effect or by instrumental cross talk from the longitudinal Zeeman effect in chromospheric magnetic fields. Otherwise, these lines tended to depolarize the scattered continuum radiation by amounts that ranged up to 0.2%.2. Lines previously known to show scattering polarization just inside the limb (such as the Na I ?5889 D2 and the He I ?5876 D3 lines) showed even more polarization above the Sun's limb, with values approaching 0.7%.3. The O I triplet at ?7772, ?7774, and ?7775 showed a range of polarizations. The ?7775 line, whose maximum intrinsic polarizability, Pmax, is less than 1%, revealed mainly Zeeman contributions from chromospheric magnetic fields. However, the more sensitive ?7772 (Pmax=19%) and ?7774 (Pmax=29%) lines had relatively strong scattering polarizations of approximately 0.3% in addition to their Zeeman polarizations. At times of good seeing, the polarization spectra resolve into fine structures that seem to be chromospheric spicules.

  14. Mapping global sensitivity of cellular network dynamics: sensitivity heat maps

    E-print Network

    Rand, David

    Mapping global sensitivity of cellular network dynamics: sensitivity heat maps and a global and aid in the design of experiments. Here, I tackle this by developing new techniques for sensitivity analysis. In particular, I show how to globally analyse the sensitivity of a complex system by means of two

  15. Neutral line chaos and phase space structure

    NASA Technical Reports Server (NTRS)

    Burkhart, Grant R.; Speiser, Theodore W.; Martin, Richard F., Jr.; Dusenbery, Paul B.

    1991-01-01

    Phase space structure and chaos near a neutral line are studied with numerical surface-of-section (SOS) techniques and analytic methods. Results are presented for a linear neutral line model with zero crosstail electric field. It was found that particle motion can be divided into three regimes dependening on the value of the conserved canonical momentum, Py, and the conserved Hamiltonian, h. The phase space structure, using Poincare SOS plots, is highly sensitive to bn = Bn/B0 variations, but not to h variations. It is verified that the slow motion preserves the action, Jz, as evaluated by Sonnerup (1971), when the period of the fast motion is smaller than the time scale of the slow motion. Results show that the phase space structure and particle chaos depend sensitively upon Py and bn, but are independent of h.

  16. X-ray line spectropolarimetry as a new diagnostic of anisotropic plasma sources

    Microsoft Academic Search

    Alla S. Shlyaptseva; Victor L. Kantsyrev; Nick D. Ouart; Dmitry A. Fedin; Safeia Hamasha; Stephanie B. Hansen

    2004-01-01

    The results of theoretical and experimental studies of anisotropic plasma sources are reported. They are based on x-ray line spectropolarimetry, a powerful new tool for investigating anisotropy of high-temperature plasmas. It is based on theoretical modeling of polarization-sensitive x-ray line spectra recorded simultaneously by two spectrometers with different sensitivities to polarization. The difference in these polarization-sensitive spectra is used to

  17. Integrative “Omic” Analysis for Tamoxifen Sensitivity through Cell Based Models

    PubMed Central

    Weng, Liming; Ziliak, Dana; LaCroix, Bonnie; Geeleher, Paul; Huang, R. Stephanie

    2014-01-01

    It has long been observed that tamoxifen sensitivity varies among breast cancer patients. Further, ethnic differences of tamoxifen therapy between Caucasian and African American have also been reported. Since most studies have been focused on Caucasian people, we sought to comprehensively evaluate genetic variants related to tamoxifen therapy in African-derived samples. An integrative “omic” approach developed by our group was used to investigate relationships among endoxifen (an active metabolite of tamoxifen) sensitivity, SNP genotype, mRNA and microRNA expressions in 58 HapMap YRI lymphoblastoid cell lines. We identified 50 SNPs that associate with cellular sensitivity to endoxifen through their effects on 34 genes and 30 microRNA expression. Some of these findings are shared in both Caucasian and African samples, while others are unique in the African samples. Among gene/microRNA that were identified in both ethnic groups, the expression of TRAF1 is also correlated with tamoxifen sensitivity in a collection of 44 breast cancer cell lines. Further, knock-down TRAF1 and over-expression of hsa-let-7i confirmed the roles of hsa-let-7i and TRAF1 in increasing tamoxifen sensitivity in the ZR-75-1 breast cancer cell line. Our integrative omic analysis facilitated the discovery of pharmacogenomic biomarkers that potentially affect tamoxifen sensitivity. PMID:24699530

  18. Sensitive, specific polymorphism discovery

    E-print Network

    Cai, Long

    sequence differences between drug-sensitive strains and drug-resistant derivatives. Bacteria are enormously tuberculosis, which might differ in their resistance to various drugs. We expected to find genetic variation of a mutant strain resistant to a particular antibiotic. One would expect to find only one mutation

  19. High-Sensitivity Spectrophotometry.

    ERIC Educational Resources Information Center

    Harris, T. D.

    1982-01-01

    Selected high-sensitivity spectrophotometric methods are examined, and comparisons are made of their relative strengths and weaknesses and the circumstances for which each can best be applied. Methods include long path cells, noise reduction, laser intracavity absorption, thermocouple calorimetry, photoacoustic methods, and thermo-optical methods.…

  20. UNITEC SENS-IT

    EPA Science Inventory

    The UniTec Sens-It is a small gas-sensing device that can measure volatile organic compounds (VOCs). This sensor is used to measure VOCs in applications such as urban air quality, roadside pollution, and (solid waste) landfill monitoring. This operating procedure explains what yo...

  1. Naegleria fowleri: Trimethoprim Sensitivity

    Microsoft Academic Search

    Lubor Cerva

    1980-01-01

    Trimethoprim in a concentration of 4 micrograms per milliliter of Bacto-Casitone (Difco) medium inhibits the growth of nonvirulent Naegleria fowleri isolates. The growth of virulent strains is unaffected even with 400 micrograms of the drug per milliliter of medium. Differences in sensitivity constitute the possibility of a simple selection of environmental isolates. The pathogenicity and virulence of Naegleria species may

  2. Analytical sensitivities and energies of thermal-neutron-capture gamma rays

    USGS Publications Warehouse

    Duffey, D.; El-Kady, A.; Senftle, F.E.

    1970-01-01

    A table of the analytical sensitivities of the principal lines in the thermal-neutron-capture gamma ray spectrum has been compiled for most of the elements. In addition a second table of the full-energy, single-escape, and double-escape peaks has been compiled according to energy for all significant lines above 3 MeV. Lines that contrast well with adjacent lines are noted as prominent. The tables are useful for spectral interpretation and calibration. ?? 1970.

  3. In-Line Sagnac Interferometer Current Sensor

    Microsoft Academic Search

    Prinya Tantaswadi

    1995-01-01

    We demonstrate for the first time a near shot noise limited in-line Sagnac interferometer current sensor. It is shown to have a number of advantages over the optical current sensors based on polarimetric Faraday and Faraday\\/Sagnac loop interferometer topologies, including lower sensitivity to environmental disturbances, less demanding optical components, and easy installation. Our contributions to the field of fiber-optic current

  4. High energy beam lines

    NASA Astrophysics Data System (ADS)

    Marchetto, M.; Laxdal, R. E.

    2014-01-01

    The ISAC post accelerator comprises an RFQ, DTL and SC-linac. The high energy beam lines connect the linear accelerators as well as deliver the accelerated beams to two different experimental areas. The medium energy beam transport (MEBT) line connects the RFQ to the DTL. The high energy beam transport (HEBT) line connects the DTL to the ISAC-I experimental stations (DRAGON, TUDA-I, GPS). The DTL to superconducting beam (DSB) transport line connects the ISAC-I and ISAC-II linacs. The superconducting energy beam transport (SEBT) line connects the SC linac to the ISAC-II experimental station (TUDA-II, HERACLES, TIGRESS, EMMA and GPS). All these lines have the function of transporting and matching the beams to the downstream sections by manipulating the transverse and longitudinal phase space. They also contain diagnostic devices to measure the beam properties.

  5. On-line surfactant monitoring

    SciTech Connect

    Mullen, K.I.; Neal, E.E.; Soran, P.D.; Smith, B. [Los Alamos National Lab., NM (United States). Chemical Science and Technology Div.

    1995-04-01

    This group has developed a process to extract metal ions from dilute aqueous solutions. The process uses water soluble polymers to complex metal ions. The metal/polymer complex is concentrated by ultrafiltration and the metals are recovered by a pH adjustment that frees the metal ions. The metal ions pass through the ultrafiltration membrane and are recovered in a concentrated form suitable for reuse. Surfactants are present in one of the target waste streams. Surfactants foul the costly ultrafiltration membranes. It was necessary to remove the surfactants before processing the waste stream. This paper discusses an on-line device the authors fabricated to monitor the process stream to assure that all the surfactant had been removed. The device is inexpensive and sensitive to very low levels of surfactants.

  6. FBG tread wear detecting lines

    NASA Astrophysics Data System (ADS)

    Li, Weilai; Dai, Xin; Liu, Jie; Pan, Jianjun; Wang, Qin; Zhang, Yanxiao

    2012-02-01

    FBG strain sensing technology is used to dynamically detect tread wear of railway train wheels. Dozens of FBG track strain sensors are installed as lines along railway tracks in crosstie sections. Train wheels one by one roll on the track and load the sensors, groups of strain peak are taken. The strain curve of defective wheel appears a gap or with serration. By means of strain pulse processing program, tread wear and wheel health condition are obtained. FBG strain gauge is employed to increase the measuring sensitivity. Protecting methods for sensors and fiber are adopted to keep them surviving from harsh application environment. The examples of detecting results are given to show the validity of this FBG application.

  7. Impact of Genomic Methylation on Radiation Sensitivity of Colorectal Carcinoma

    SciTech Connect

    Hofstetter, Barbara [Department of Radiation Oncology, Zurich University Hospital, University of Zuerich (Switzerland); Niemierko, Andrzej [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Forrer, Christian [Department of Radiation Oncology, Zurich University Hospital, University of Zuerich (Switzerland); Benhattar, Jean [Department of Pathology, Centre Hospitalier Universitaire Vaudois, Lausanne (Switzerland); Albertini, Veronica [Laboratory of Experimental Oncology, Oncology Institute of Southern Switzerland, Bellinzona (Switzerland); Pruschy, Martn [Department of Radiation Oncology, Zurich University Hospital, University of Zuerich (Switzerland); Bosman, Fred T. [Department of Pathology, Centre Hospitalier Universitaire Vaudois, Lausanne (Switzerland); Catapano, Carlo V. [Laboratory of Experimental Oncology, Oncology Institute of Southern Switzerland, Bellinzona (Switzerland); Ciernik, I. Frank, E-mail: ilja.ciernik@usz.c [Center for Clinical Research, Zurich University Hospital, University of Zurich, Zuerich (Switzerland)

    2010-04-15

    Purpose: To investigate the influence of demethylation with 5-aza-cytidine (AZA) on radiation sensitivity and to define the intrinsic radiation sensitivity of methylation deficient colorectal carcinoma cells. Methods and Materials: Radiation sensitizing effects of AZA were investigated in four colorectal carcinoma cell lines (HCT116, SW480, L174 T, Co115), defining influence of AZA on proliferation, clonogenic survival, and cell cycling with or without ionizing radiation. The methylation status for cancer or DNA damage response-related genes silenced by promoter methylation was determined. The effect of deletion of the potential target genes (DNMT1, DNMT3b, and double mutants) on radiation sensitivity was analyzed. Results: AZA showed radiation sensitizing properties at >=1 {mu}mol/l, a concentration that does not interfere with the cell cycle by itself, in all four tested cell lines with a sensitivity-enhancing ratio (SER) of 1.6 to 2.1 (confidence interval [CI] 0.9-3.3). AZA successfully demethylated promoters of p16 and hMLH1, genes associated with ionizing radiation response. Prolonged exposure to low-dose AZA resulted in sustained radiosensitivity if associated with persistent genomic hypomethylation after recovery from AZA. Compared with maternal HCT116 cells, DNMT3b-defcient deficient cells were more sensitive to radiation with a SER of 2.0 (CI 0.9-2.1; p = 0.03), and DNMT3b/DNMT1-/- double-deficient cells showed a SER of 1.6 (CI 0.5-2.7; p = 0.09). Conclusions: AZA-induced genomic hypomethylation results in enhanced radiation sensitivity in colorectal carcinoma. The mediators leading to sensitization remain unknown. Defining the specific factors associated with radiation sensitization after genomic demethylation may open the way to better targeting for the purpose of radiation sensitization.

  8. Series Transmission Line Transformer

    DOEpatents

    Buckles, Robert A. (Livermore, CA); Booth, Rex (Livermore, CA); Yen, Boris T. (El Cerrito, CA)

    2004-06-29

    A series transmission line transformer is set forth which includes two or more of impedance matched sets of at least two transmissions lines such as shielded cables, connected in parallel at one end ans series at the other in a cascading fashion. The cables are wound about a magnetic core. The series transmission line transformer (STLT) which can provide for higher impedance ratios and bandwidths, which is scalable, and which is of simpler design and construction.

  9. Lines and Slope

    NSDL National Science Digital Library

    Math Forum

    2007-12-12

    At this math site students learn to draw a line and find its slope. Includes information about solving equations; graphing points; calculating slope; learning the formula for slope; using slope; horizontal, vertical, parallel, and perpendicular lines; slope-intercept form; lines with a right slope; and right y-intercept. A glossary of terms, links to other sites, and suggestions of how to use the material can also be found.

  10. Nematostatics of triple lines.

    PubMed

    Rey, Alejandro D

    2003-01-01

    The Landau-de Gennes model for nematic liquid crystal bulk and interfaces has been extended to nematic triple lines involving the intersection of two isotropic fluids and one nematic liquid crystalline phase. A complete set of bulk, interface, and triple line force and torque balance equations has been formulated. The triple line force and torque balance equations have linear, interfacial, and bulk contributions. The bulk contributions appear as junction integrals, the surface contributions as junctions sums, and the line contributions as gradients of stresses. Reduction of dimensionality from three to one dimensional creates the following effects: (a) bulk terms enter interfacial balances as surface jumps and line balances as junction integrals, and (b) surface terms enter linear balances as junction sums. Line stress and torque equations are derived using classical liquid crystal models. The correspondence between line stress and line torque and their surface and bulk analogs is established. The triple line force and torque balance equations are use to analyze the contact angle in a nematic lens lying at the interface between two isotropic fluids, when the preferred surface orientation is tangential. The effect of anisotropy and long range elasticity on triple line phases is established. Under weak anchoring the contact angle is shown to be a function of the anchoring energy at the nematic-isotropic interface, while under strong anchoring conditions the contact angle is a function of the Peach-Koehler force that originates from bulk long range elasticity and acts on the triple line. The use of the complete set of balance equations removes the classical inconsistency in force balances at a contact line by properly taking into account long range (bulk gradient elasticity) and anisotropic (interfacial anchoring elasticity) effects. PMID:12636516

  11. Interactive Fraction Number Lines

    NSDL National Science Digital Library

    Michael Green

    2012-05-25

    In this lesson students make models of fractions, including a human number line. Using a number line, students develop conceptual understanding of fractions. Students use the number line to represent and compare fractions less than one. The activities are engaging and include full participation/engagement of all students. The fractions are limited to positive fractions less than one with a denominator of 2 or 4 including 0 and 1 whole.

  12. Submillimeter CO Line Emission from Orion

    NASA Astrophysics Data System (ADS)

    Wilson, T. L.; Muders, D.; Kramer, C.; Henkel, C.

    2001-08-01

    Images of an 8 square arcmin region around the Orion KL source have been made in the J=7-6 (806 GHz) and J=4-3 (461 GHz) lines of CO with angular resolutions of 13" and 18". These data were taken employing on-the-fly mapping and position switching techniques. Our J=7-6 data set is the largest image of Orion with the highest sensitivity and resolution obtained so far in this line. Most of the extended emission arises from a photon dominated region (PDR), but 8% is associated with the Orion ridge. For the prominent Orion KL outflow, we produced ratios of the integrated intensities of our J=7-6 and 4-3 data to the J=2-1 line of CO. Large velocity gradient (LVG) models fit the outflow ratios better than PDR models. The LVG models give H2 densities of ~105 cm-3. The CO outflow is probably heated by shocks. In the Orion S outflow, the CO line intensities are lower than for Orion KL. The 4-3/2-1 line ratio is 1.3 for the blueshifted wing and 0.8 for the redshifted wing. The line ratios in the Orion S outflow and jet features are consistent with both PDR and LVG models. Emission in the jet feature extending 2' to the SW of Orion S was detected in the J=4-3 but not the J=7-6 line; the average 4-3/2-1 line ratio is ~1. Comparisons of the intensities of the J=7-6 and J=4-3 lines from the Orion Bar with PDR models show that the ratios exceed predictions by a factor of 2. Either clumping or additional heating by mechanisms, such as shocks, may be the cause of this discrepancy.

  13. Interplanetary Magnetic Field Lines

    NSDL National Science Digital Library

    Mendez, J.

    This web page, authored and curated by David P. Stern, provides information and a graphical exercise for students regarding the interaction between magnetic field lines and a plasma. The activity involves tracing a typical interplanetary magnetic field line, dragged out of a location on the Sun by the radial flow of the solar wind. This illustrates the way magnetic field lines are "frozen to the plasma" and the wrapping of field lines due to the rotation of the sun. This is part of the work "The Exploration of the Earth's Magnetosphere". A Spanish translation is available.

  14. Central line infections - hospitals

    MedlinePLUS

    Central line-associated bloodstream infection; CLABSI; Peripherally inserted central catheter - infection; PICC - infection; Central venous catheter - infection; CVC - infection; Central venous device - infection

  15. Argon I Lines Produced in a Hollow Cathode Source, 332 nm to 5865 nm

    Microsoft Academic Search

    W. Whaling; W. H. C. Anderson; M. T. Carle

    We report precision measurements by Fourier transform spectroscopy of the vacuum wavenumber, line width, and rela- tive signal strength of 928 lines in the Ar I spectrum. Wavelength in air and classi- fication of the transition are supplied for each line. A comparison of our results with other precision measurements illustrates the sensitivity of Ar I wavelengths to condi- tions

  16. Kinematic sensitivity of robot manipulators

    NASA Technical Reports Server (NTRS)

    Vuskovic, Marko I.

    1989-01-01

    Kinematic sensitivity vectors and matrices for open-loop, n degrees-of-freedom manipulators are derived. First-order sensitivity vectors are defined as partial derivatives of the manipulator's position and orientation with respect to its geometrical parameters. The four-parameter kinematic model is considered, as well as the five-parameter model in case of nominally parallel joint axes. Sensitivity vectors are expressed in terms of coordinate axes of manipulator frames. Second-order sensitivity vectors, the partial derivatives of first-order sensitivity vectors, are also considered. It is shown that second-order sensitivity vectors can be expressed as vector products of the first-order sensitivity vectors.

  17. Monochromatic neutrino lines from sneutrino dark matter

    E-print Network

    Arina, Chiara; Silk, Joseph

    2015-01-01

    We investigate the possibility of observing monochromatic neutrino lines originating from annihilation of dark matter. We analyse several astrophysical sources with overdensities of dark matter that can amplify the signal. As a case study, we consider mixed left and right handed sneutrino dark matter. We demonstrate that in the physically viable region of the model, one can obtain a prominent monochromatic neutrino line. We propose a search strategy to observe these neutrino lines in future generations of neutrino telescopes that is especially sensitive to dwarf spheroidal galaxies. We demonstrate that the presence of massive black holes in the cores of dwarfs as well as of more massive galaxies substantially boosts any putative signal. In particular, dark matter in dwarf galaxies spiked by IMBH provides a powerful means of probing low annihilation cross-sections well below $10^{-26} \\rm cm^3 s^{-1}$ that are otherwise inaccessible by any future direct detection or collider experiment.

  18. Monochromatic neutrino lines from sneutrino dark matter

    E-print Network

    Chiara Arina; Suchita Kulkarni; Joseph Silk

    2015-06-26

    We investigate the possibility of observing monochromatic neutrino lines originating from annihilation of dark matter. We analyse several astrophysical sources with overdensities of dark matter that can amplify the signal. As a case study, we consider mixed left and right handed sneutrino dark matter. We demonstrate that in the physically viable region of the model, one can obtain a prominent monochromatic neutrino line. We propose a search strategy to observe these neutrino lines in future generations of neutrino telescopes that is especially sensitive to dwarf spheroidal galaxies. We demonstrate that the presence of massive black holes in the cores of dwarfs as well as of more massive galaxies substantially boosts any putative signal. In particular, dark matter in dwarf galaxies spiked by IMBH provides a powerful means of probing low annihilation cross-sections well below $10^{-26} \\rm cm^3 s^{-1}$ that are otherwise inaccessible by any future direct detection or collider experiment.

  19. Control of Retinal Sensitivity

    PubMed Central

    Normann, Richard A.; Werblin, Frank S.

    1974-01-01

    Rods and cones in Necturus respond with graded hyperpolarization to test flashes spanning about 3.5 log units of intensity. Steady background levels hyperpolarize the rods, and the rod responses become progressively smaller as background level is increased. In cones, higher background levels reduce the effectiveness of test flashes, so higher ranges of test intensities are required to elicit the full range of graded responses. When backgrounds are terminated, cones return rapidly, but rods return slowly to the dark potential level. The effects of backgrounds on both rods and cones can be observed at intensities that cause negligible bleaching as determined by retinal densitometry. During dark adaptation, changes are observed in the rods and cones that are similar to those produced by backgrounds. Receptor sensitivities, derived from these results, show that rods saturate, cones obey Weber's law, and sensitization during dark adaptation follows a two-phase time-course. PMID:4359063

  20. Scaling in sensitivity analysis

    USGS Publications Warehouse

    Link, W.A.; Doherty, P.F., Jr.

    2002-01-01

    Population matrix models allow sets of demographic parameters to be summarized by a single value 8, the finite rate of population increase. The consequences of change in individual demographic parameters are naturally measured by the corresponding changes in 8; sensitivity analyses compare demographic parameters on the basis of these changes. These comparisons are complicated by issues of scale. Elasticity analysis attempts to deal with issues of scale by comparing the effects of proportional changes in demographic parameters, but leads to inconsistencies in evaluating demographic rates. We discuss this and other problems of scaling in sensitivity analysis, and suggest a simple criterion for choosing appropriate scales. We apply our suggestions to data for the killer whale, Orcinus orca.

  1. COS NUV Spectroscopic Sensitivity

    NASA Astrophysics Data System (ADS)

    Aloisi, Alessandra

    2009-07-01

    This activity confirms COS sensitivity versus wavelength over the entire observable spectrum for all NUV gratings and central wavelength settings. Perform a precise-centering acquisition and observe an appropriate HST flux standard star {chosen from the HST prime standard and FASTEX lists} with the PSA. A limited BOA characterization is also obtained {see also program 11476, activity COS16}. A quick spot check of the sensitivities with the PSA is also executed immediately after the NUV alignment {but at least 7 days after that}. No off aperture-center observations are performed in this activity {see program 11477, activity COS17, for off-center characterizations}. Spectra will be obtained to meet a Poisson S/N criterion of 20 per resolution element in the central wavelength of the setting; higher S/N characterization will be utilized in routine Cycle 17 calibration.

  2. On line tying

    Microsoft Academic Search

    M. Gibons; D. S. Spicer

    1981-01-01

    We discuss the claim frequently found in the solar physics literature that line tying in the photosphere is capable of stabilizing certain classes of both ideal and resistive MHD instabilities. Our approach is to present a picture of the physical origins of line tying and how resistive effects will affect it.

  3. Electric Field Lines

    NSDL National Science Digital Library

    Reddy, B. Surendranath

    This applet displays the electric field lines of force around one or two charged particle. The charged particle can be positive or negative. The magnitude of charge can be varied and the change in the electric field lines of force can be viewed. This is part of a large collection of physics and math applets by the author Surendrenath Reddy.

  4. Fraction Number Line

    NSDL National Science Digital Library

    2010-01-01

    Using this interactive fraction number line, students can identify and locate equivalent fractions as well as compare fractions. They can move the mouse to the left or right and "mark" fractions on the number line. A section called "Which is Larger?" provides examples of fraction pairs to compare.

  5. Transmission line: design manual

    Microsoft Academic Search

    Farr

    1980-01-01

    The purpose of this manual is to outline the various requirements for, and the procedures to be followed in the design of power transmission lines by the Bureau of Reclamation, US Department of the Interior. Numerous design studies, which have been made on specific aspects of transmission line design, are included with explanations of their applications. Information is presented concerning

  6. Coolant line hydrometer

    Microsoft Academic Search

    M. D. Barber; W. G. Kipp

    1987-01-01

    This patent describes a hydrometer unit for connection in an automobile coolant flow line comprising: a tubular fitting adapted to be connected to the coolant flow line; a coolant receiving chamber means connected to the tubular fitting for receiving coolant from the tubular fitting; and indicating float elements contained within the coolant receiving chamber means and adapted to rise therein

  7. Tangent Lines without Calculus

    ERIC Educational Resources Information Center

    Rabin, Jeffrey M.

    2008-01-01

    This article presents a problem that can help high school students develop the concept of instantaneous velocity and connect it with the slope of a tangent line to the graph of position versus time. It also gives a method for determining the tangent line to the graph of a polynomial function at any point without using calculus. (Contains 1 figure.)

  8. Airborne Fraunhofer Line Discriminator

    NASA Technical Reports Server (NTRS)

    Gabriel, F. C.; Markle, D. A.

    1969-01-01

    Airborne Fraunhofer Line Discriminator enables prospecting for fluorescent materials, hydrography with fluorescent dyes, and plant studies based on fluorescence of chlorophyll. Optical unit design is the coincidence of Fraunhofer lines in the solar spectrum occurring at the characteristic wavelengths of some fluorescent materials.

  9. Tree Lines: Discussion

    Microsoft Academic Search

    P. G. Jarvis; J. Grace; N. Hutchings; J. L. Monteith; W. J. Shuttleworth; D. Fowler; J. Corlett; J. Thomas

    1989-01-01

    Trees do not generally grow in places where the mean temperature of the warmest month is less than about 10 ^circ C. At their limit, trees are often short and crooked, the condition known as krummholz; and the transition from tall forest to dwarf shrubby vegetation is often abrupt, forming a distinct tree line. Tree lines fluctuate with climatic change.

  10. Hybrid assembly line design

    Microsoft Academic Search

    B. Rekiek; A. Delchambre

    2001-01-01

    This paper presents a method to address the multiple objective hybrid assembly line balancing problem. The aim is to assign a set of tasks to stations and select equipment to perform each of them. The goal is to minimize the total cost of the line by integrating design (station space, equipment cost, etc.) and operation issues (cycle time, precedence constraints

  11. Multiple chemical sensitivity (MCS)

    Microsoft Academic Search

    Christian Wolf

    1996-01-01

    Multiple Chemical Sensitivity (MCS) is a systemic disorder causing central nervous, irritative and gastrointestinal symptoms,\\u000a and can be included in the category of “idiopathic environmental intolerance” (IEI). This term describes phenomena with multiple,\\u000a recurrent symptoms associated with various environmental factors that are tolerated by most people without problems. Those\\u000a advocating these concepts attribute the symptoms to exogenous substances. Those opposing

  12. LISA Telescope Sensitivity Analysis

    NASA Technical Reports Server (NTRS)

    Waluschka, Eugene; Krebs, Carolyn (Technical Monitor)

    2002-01-01

    The Laser Interferometer Space Antenna (LISA) for the detection of Gravitational Waves is a very long baseline interferometer which will measure the changes in the distance of a five million kilometer arm to picometer accuracies. As with any optical system, even one with such very large separations between the transmitting and receiving, telescopes, a sensitivity analysis should be performed to see how, in this case, the far field phase varies when the telescope parameters change as a result of small temperature changes.

  13. Sensitivity testing and analysis

    SciTech Connect

    Neyer, B.T.

    1991-01-01

    New methods of sensitivity testing and analysis are proposed. The new test method utilizes Maximum Likelihood Estimates to pick the next test level in order to maximize knowledge of both the mean, {mu}, and the standard deviation, {sigma} of the population. Simulation results demonstrate that this new test provides better estimators (less bias and smaller variance) of both {mu} and {sigma} than the other commonly used tests (Probit, Bruceton, Robbins-Monro, Langlie). A new method of analyzing sensitivity tests is also proposed. It uses the Likelihood Ratio Test to compute regions of arbitrary confidence. It can calculate confidence regions, for {mu}, {sigma}, and arbitrary percentiles. Unlike presently used methods, such as the program ASENT which is based on the Cramer-Rao theorem, it can analyze the results of all sensitivity tests, and it does not significantly underestimate the size of the confidence regions. The new test and analysis methods will be explained and compared to the presently used methods. 19 refs., 12 figs.

  14. Heat sensitive immunoliposomes

    SciTech Connect

    Sullivan, S.M.

    1985-01-01

    Heat sensitive immunoliposomes were prepared with derivatized antibody. The liposomes are able to bind specifically to target cells and to release their encapsulated contents upon brief heating. Monoclonal anti-H2K/sup K/ was covalently derivatized with palmitoyl-N-hydroxysuccinimide. The palmitoyl antibody was injected at a controlled rate into a suspension of fused unilamellar dipalmitoylphosphati-dylcholine liposomes maintained at a constant temperature. Injection of palmitoyl antibody into a liposome suspension containing 50 mM carboxyfluorescein at 41/sup 0/C resulted in simultaneous antibody incorporation and entrapment of dye. The immunoliposomes were able to release entrapped dye upon heating. Furthermore, this ability was retained when the immunoliposomes were found to the target cells. /sup 3/H-Uridine was entrapped in the heat sensitive immunoliposomes to examine the cellular uptake properties of entrapped contents upon release. The release of uridine from bound heat sensitive immunoliposomes exhibited very similar properties to those obtained for carboxyfluorescein release. The rate of uridine uptake for immunoliposome released uridine was 5 fold greater than bare liposome released uridine and 10 fold greater than that obtained for free uridine. Nucleoside uptake inhibitors were able to inhibit uptake of free uridine and uridine released from immunoliposomes showing the release to be extracellular and uridine uptake was mediated by the nucleoside transporter. These results show that a high local concentration of nucleosides released from immunoliposomes bound to their respective target cell can enhance cellular uptake thus promoting efficient drug delivery.

  15. CDF's Higgs sensitivity status

    SciTech Connect

    Junk, Tom; /Illinois U., Urbana

    2005-10-01

    The combined sensitivity of CDF's current Standard Model Higgs boson searches is presented. The expected 95% CL limits on the production cross section times the relevant Higgs boson branching ratios are computed for the W{sup {+-}}H {yields} {ell}{sup {+-}}{nu}b{bar b}, ZH {yields} {nu}{bar {nu}}b{bar b}, gg {yields} H {yields} W{sup +}W{sup -} W{sup {+-}}H {yields} W{sup {+-}}W{sup +}W{sup -} channels as they stand as of the October 2005, using results which were prepared for Summer 2005 conferences and a newer result form the gg {yields} H {yields} W{sup +}W{sup -} channel. Correlated and uncorrelated systematic uncertainties are taken into account, and the luminosity requirements for 95% CL exclusion, 3{sigma} evidence, and 5{sigma} discovery are computed for median experimental outcomes. A list of improvements required to achieve the sensitivity to a SM Higgs boson as quantified in the Higgs Sensitivity Working Group's report is provided.

  16. Interference and Sensitivity Analysis

    PubMed Central

    VanderWeele, Tyler J.; Tchetgen Tchetgen, Eric J.; Halloran, M. Elizabeth

    2014-01-01

    Causal inference with interference is a rapidly growing area. The literature has begun to relax the “no-interference” assumption that the treatment received by one individual does not affect the outcomes of other individuals. In this paper we briefly review the literature on causal inference in the presence of interference when treatments have been randomized. We then consider settings in which causal effects in the presence of interference are not identified, either because randomization alone does not suffice for identification, or because treatment is not randomized and there may be unmeasured confounders of the treatment-outcome relationship. We develop sensitivity analysis techniques for these settings. We describe several sensitivity analysis techniques for the infectiousness effect which, in a vaccine trial, captures the effect of the vaccine of one person on protecting a second person from infection even if the first is infected. We also develop two sensitivity analysis techniques for causal effects in the presence of unmeasured confounding which generalize analogous techniques when interference is absent. These two techniques for unmeasured confounding are compared and contrasted. PMID:25620841

  17. New perylene derivative dyes for dye-sensitized solar cells

    Microsoft Academic Search

    Ceylan Zafer; Mahmut Kus; Gulsah Turkmen; Haluk Dincalp; Serafettin Demic; Baha Kuban; Yildirim Teoman; Siddik Icli

    2007-01-01

    We have studied the influence of the spacer alkyl chain length of perylenemonoimide (PMI) dyes on the device performance in dye-sensitized solar cells (DSSCs). We observed that the dyes with longer and brunched alkyl chains exhibit higher efficiencies in DSSCs. In line with these statements we now report the highest efficiency obtained under standard conditions for a perylene imide derivative

  18. Sensitivity to Number: Reply to Gebuis and Gevers

    ERIC Educational Resources Information Center

    de Hevia, Maria Dolores

    2011-01-01

    Past research showing a bias towards the larger non-symbolic number by adults and children in line bisection tasks (de Hevia & Spelke, 2009) has been challenged by Gebuis and Gevers, suggesting that area subtended by the stimulus and not number is responsible for the biases. I review evidence supporting the idea that although sensitivity to number…

  19. Calibrating Noise to Sensitivity in Private Data Analysis

    Microsoft Academic Search

    Cynthia Dwork; Frank McSherry; Kobbi Nissim; Adam Smith

    2006-01-01

    We continue a line of research initiated in (10, 11) on privacy- preserving statistical databases. Consider a trusted server that holds a database of sensitive information. Given a query function f mapping databases to reals, the so-called true answer is the result of applying f to the database. To protect privacy, the true answer is perturbed by the addition of

  20. Personalized chemotherapy profiling using cancer cell lines from selectable mice

    PubMed Central

    Kamiyama, Hirohiko; Rauenzahn, Sherri; Shim, Joong Sup; Karikari, Collins A.; Feldmann, Georg; Hua, Li; Kamiyama, Mihoko; Schuler, F. William; Lin, Ming-Tseh; Beaty, Robert M.; Karanam, Balasubramanyam; Liang, Hong; Mullendore, Michael E.; Mo, Guanglan; Hidalgo, Manuel; Jaffee, Elizabeth; Hruban, Ralph H.; Jinnah, H. A.; Roden, Richard B. S.; Jimeno, Antonio; Liu, Jun O.; Maitra, Anirban; Eshleman, James R.

    2013-01-01

    Purpose High-throughput chemosensitivity testing of low-passage cancer cell lines can be used to prioritize agents for personalized chemotherapy. However, generating cell lines from primary cancers is difficult, because contaminating stromal cells overgrow the malignant cells. Experimental Design We produced a series of hypoxanthine phosphoribosyl transferase (hprt)-null immunodeficient mice. During growth of human cancers in these mice, hprt-null murine stromal cells replace their human counterparts. Results Pancreatic and ovarian cancers explanted from these mice were grown in selection media to produce pure human cancer cell lines. We screened one cell line with a 3,131-drug panel and identified seventy-seven FDA approved drugs with activity, including two novel drugs to which the cell line was uniquely sensitive. Xenografts of this carcinoma were selectively responsive to both drugs. Conclusion Chemotherapy can be personalized using patient-specific cell lines derived in biochemically selectable mice. PMID:23340293

  1. PORTION OF A LINE (AT LEFT) AND B LINE (AT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    PORTION OF A LINE (AT LEFT) AND B LINE (AT RIGHT) ON GENTLE TERRACE SLOPE. A LINE POLE 75A (LEFT FOREGROUND) HAS ORIGINAL GLASS PIN-TYPE INSULATORS AND INTACT COMMUNICATION LINE CROSS ARM. VIEW TO WEST-SOUTHWEST. - Mystic Lake Hydroelectric Facility, Electric Transmission A Line, Along West Rosebud Creek, Fishtail, Stillwater County, MT

  2. Coherent soliton communication lines

    NASA Astrophysics Data System (ADS)

    Yushko, O. V.; Redyuk, A. A.; Fedoruk, M. P.; Turitsyn, S. K.

    2014-11-01

    The data transmission in coherent fiber-optical communication lines using solitons with a variable phase is studied. It is shown that nonlinear coherent structures (solitons) can be applied for effective signal transmission over a long distance using amplitude and optical-phase keying of information. The optimum ratio of the pulse width to the bit slot at which the spectral efficiency (transmitted bits per second and hertz) is maximal is determined. It is shown that soliton fiber-optical communication lines can ensure data transmission at a higher spectral efficiency as compared to traditional communication lines and at a high signal-to-noise ratio.

  3. Coherent soliton communication lines

    SciTech Connect

    Yushko, O. V., E-mail: olesya.yushko@gmail.com; Redyuk, A. A.; Fedoruk, M. P.; Turitsyn, S. K. [Novosibirsk State University (Russian Federation)

    2014-11-15

    The data transmission in coherent fiber-optical communication lines using solitons with a variable phase is studied. It is shown that nonlinear coherent structures (solitons) can be applied for effective signal transmission over a long distance using amplitude and optical-phase keying of information. The optimum ratio of the pulse width to the bit slot at which the spectral efficiency (transmitted bits per second and hertz) is maximal is determined. It is shown that soliton fiber-optical communication lines can ensure data transmission at a higher spectral efficiency as compared to traditional communication lines and at a high signal-to-noise ratio.

  4. Vertical Line Test

    NSDL National Science Digital Library

    2010-01-01

    In this activity, students try to connect given points on a graph in a way that they will pass the vertical line test. If the points can't be made to pass the vertical line test, the student must adjust the points so they will pass the test. This activity allows students to explore the vertical line test for functions. This activity includes supplemental materials, including background information about the topics covered, a description of how to use the application, and exploration questions for use with the java applet.

  5. Explanation of the activity sensitivity of Mn I 5394.7 Å

    E-print Network

    N. Vitas; B. Viticchiè; R. J. Rutten; A. Vögler

    2008-11-21

    There is a long-standing controversy concerning the reason why the Mn I 5394.7 A line in the solar irradiance spectrum brightens more at larger activity than most other photospheric lines. The claim that this activity sensitivity is caused by spectral interlocking to chromospheric emission in Mg II h & k is disputed. Classical one-dimensional modeling is used for demonstration; modern three-dimensional MHD simulation for verification and analysis. The Mn I 5394.7 A line thanks its unusual sensitivity to solar activity to its hyperfine structure. This overrides the thermal and granular Doppler smearing through which the other, narrower, photospheric lines lose such sensitivity. We take the nearby Fe I 5395.2 A line as example of the latter and analyze the formation of both lines in detail to demonstrate and explain granular Doppler brightening. We show that this affects all narrow lines. Neither the chromosphere nor Mg II h & k play a role, nor is it correct to describe the activity sensitivity of Mn I 5394.7 A through plage models with outward increasing temperature contrast. The Mn I 5394.7 A line represents a proxy diagnostic of strong-field magnetic concentrations in the deep solar photosphere comparable to the G band and the blue wing of H-alpha, but not a better one than these. The Mn I lines are more promising as diagnostic of weak fields in high-resolution Stokes polarimetry.

  6. Dye Sensitized Solar Cells

    PubMed Central

    Wei, Di

    2010-01-01

    Dye sensitized solar cell (DSSC) is the only solar cell that can offer both the flexibility and transparency. Its efficiency is comparable to amorphous silicon solar cells but with a much lower cost. This review not only covers the fundamentals of DSSC but also the related cutting-edge research and its development for industrial applications. Most recent research topics on DSSC, for example, applications of nanostructured TiO2, ZnO electrodes, ionic liquid electrolytes, carbon nanotubes, graphene and solid state DSSC have all been included and discussed. PMID:20480003

  7. New protection method for HVDC lines including cables

    Microsoft Academic Search

    H. Takeda; H. Ayakawa; N. Tsumenaga; M. Sanpei

    1995-01-01

    For the third project of the Hokkaido-Honshu HVDC Link in Japan, called the HVDC Link III project (rated at 250 kVdc-1,200 A-300 MW), the authors developed an HVDC transmission line protection method based on a new working principle that allows high-speed and highly sensitive detection of faults, enhancing reliability in the supply of electric power. In general, increasing the sensitivity

  8. Characterisation of CVD diamond dosimeters in on-line configuration

    Microsoft Academic Search

    M. Bruzzi; M. Bucciolini; G. A. P Cirrone; G. Cuttone; S. Mazzocchi; S. Pirollo; S. Sciortino

    2000-01-01

    The high sensitivity and the nearly tissue equivalence of diamond make it a material suitable as detector for on-line dosimetry. The tremendous development of the CVD diamond technology allows to employ polycrystalline diamond films with controlled dimensions and a potential low cost as on-line radiation dosimeters. In this paper a characterisation and a comparison of the response of two “detector-grade”

  9. Characterization and isolation of some genes of the shikimate pathway in sensitive and resistant Centaurea jacea plants after ozone exposure

    Microsoft Academic Search

    A. Francini; C. Nali; E. Pellegrini; G. Lorenzini

    2008-01-01

    Centaurea jacea has been suggested as a potential bioindicator for ozone, but little is known about its intraspecific variation in sensitivity, especially at molecular level. The effects of ozone (200ppb, 5h) on sensitive and resistant lines of Centaurea have been investigated at the end of fumigation. Sensitive plants showed characteristic symptoms of injury in the form of diffuse discoloration stipples

  10. Effects of gamma-butyrolactone, amphetamine, and haloperidol in mice differing in sensitivity to alcohol

    Microsoft Academic Search

    Bruce C. Dudek; Richard J. Fanelli

    1980-01-01

    Gamma-butyrolactone (GBL) induced longer loss of righting reflex in mice (LS-line) selectively bred for greater sensitivity to ethanol than in less sensitive SS-line mice. GBL also induced a three-fold greater increase of brain dopamine levels in LS than in SS mice. Among three inbred strains, GBL-induced loss of righting reflex was greater in BALB\\/c, and greater in DBA\\/2 than in

  11. Power line detection system

    DOEpatents

    Latorre, Victor R. (Tracy, CA); Watwood, Donald B. (Tracy, CA)

    1994-01-01

    A short-range, radio frequency (RF) transmitting-receiving system that provides both visual and audio warnings to the pilot of a helicopter or light aircraft of an up-coming power transmission line complex. Small, milliwatt-level narrowband transmitters, powered by the transmission line itself, are installed on top of selected transmission line support towers or within existing warning balls, and provide a continuous RF signal to approaching aircraft. The on-board receiver can be either a separate unit or a portion of the existing avionics, and can also share an existing antenna with another airborne system. Upon receipt of a warning signal, the receiver will trigger a visual and an audio alarm to alert the pilot to the potential power line hazard.

  12. Line, Shape, Color.

    ERIC Educational Resources Information Center

    Greenman, Geri

    2002-01-01

    Describes an art project used with beginning high school art students that teaches them about continuous line drawing. Explains that the students create portraits of themselves, or another student, using glue, black construction paper, and chalk. (CMK)

  13. Complex Line Integrals I

    NSDL National Science Digital Library

    Moore, Lang

    Created by Lang More of the Connected Curriculum Project, the purpose of this module is to investigate the behavior of complex line integrals. This is one lesson within a much larger set of learning modules hosted by Duke University.

  14. Camera sensitivity study

    NASA Astrophysics Data System (ADS)

    Schlueter, Jonathan; Murphey, Yi L.; Miller, John W. V.; Shridhar, Malayappan; Luo, Yun; Khairallah, Farid

    2004-12-01

    As the cost/performance Ratio of vision systems improves with time, new classes of applications become feasible. One such area, automotive applications, is currently being investigated. Applications include occupant detection, collision avoidance and lane tracking. Interest in occupant detection has been spurred by federal automotive safety rules in response to injuries and fatalities caused by deployment of occupant-side air bags. In principle, a vision system could control airbag deployment to prevent this type of mishap. Employing vision technology here, however, presents a variety of challenges, which include controlling costs, inability to control illumination, developing and training a reliable classification system and loss of performance due to production variations due to manufacturing tolerances and customer options. This paper describes the measures that have been developed to evaluate the sensitivity of an occupant detection system to these types of variations. Two procedures are described for evaluating how sensitive the classifier is to camera variations. The first procedure is based on classification accuracy while the second evaluates feature differences.

  15. Surveillance Metrics Sensitivity Study

    SciTech Connect

    Bierbaum, R; Hamada, M; Robertson, A

    2011-11-01

    In September of 2009, a Tri-Lab team was formed to develop a set of metrics relating to the NNSA nuclear weapon surveillance program. The purpose of the metrics was to develop a more quantitative and/or qualitative metric(s) describing the results of realized or non-realized surveillance activities on our confidence in reporting reliability and assessing the stockpile. As a part of this effort, a statistical sub-team investigated various techniques and developed a complementary set of statistical metrics that could serve as a foundation for characterizing aspects of meeting the surveillance program objectives. The metrics are a combination of tolerance limit calculations and power calculations, intending to answer level-of-confidence type questions with respect to the ability to detect certain undesirable behaviors (catastrophic defects, margin insufficiency defects, and deviations from a model). Note that the metrics are not intended to gauge product performance but instead the adequacy of surveillance. This report gives a short description of four metrics types that were explored and the results of a sensitivity study conducted to investigate their behavior for various inputs. The results of the sensitivity study can be used to set the risk parameters that specify the level of stockpile problem that the surveillance program should be addressing.

  16. Surveillance metrics sensitivity study.

    SciTech Connect

    Hamada, Michael S. (Los Alamos National Laboratory); Bierbaum, Rene Lynn; Robertson, Alix A. (Lawrence Livermore Laboratory)

    2011-09-01

    In September of 2009, a Tri-Lab team was formed to develop a set of metrics relating to the NNSA nuclear weapon surveillance program. The purpose of the metrics was to develop a more quantitative and/or qualitative metric(s) describing the results of realized or non-realized surveillance activities on our confidence in reporting reliability and assessing the stockpile. As a part of this effort, a statistical sub-team investigated various techniques and developed a complementary set of statistical metrics that could serve as a foundation for characterizing aspects of meeting the surveillance program objectives. The metrics are a combination of tolerance limit calculations and power calculations, intending to answer level-of-confidence type questions with respect to the ability to detect certain undesirable behaviors (catastrophic defects, margin insufficiency defects, and deviations from a model). Note that the metrics are not intended to gauge product performance but instead the adequacy of surveillance. This report gives a short description of four metrics types that were explored and the results of a sensitivity study conducted to investigate their behavior for various inputs. The results of the sensitivity study can be used to set the risk parameters that specify the level of stockpile problem that the surveillance program should be addressing.

  17. Density sensitive hashing.

    PubMed

    Jin, Zhongming; Li, Cheng; Lin, Yue; Cai, Deng

    2014-08-01

    Nearest neighbor search is a fundamental problem in various research fields like machine learning, data mining and pattern recognition. Recently, hashing-based approaches, for example, locality sensitive hashing (LSH), are proved to be effective for scalable high dimensional nearest neighbor search. Many hashing algorithms found their theoretic root in random projection. Since these algorithms generate the hash tables (projections) randomly, a large number of hash tables (i.e., long codewords) are required in order to achieve both high precision and recall. To address this limitation, we propose a novel hashing algorithm called density sensitive hashing (DSH) in this paper. DSH can be regarded as an extension of LSH. By exploring the geometric structure of the data, DSH avoids the purely random projections selection and uses those projective functions which best agree with the distribution of the data. Extensive experimental results on real-world data sets have shown that the proposed method achieves better performance compared to the state-of-the-art hashing approaches. PMID:24158526

  18. Modeling sensitive elasmobranch habitats

    NASA Astrophysics Data System (ADS)

    Pennino, M. Grazia; Muñoz, Facundo; Conesa, David; López-Quílez, Antonio; Bellido, José Marí; a

    2013-10-01

    Basic information on the distribution and habitat preferences of ecologically important species is essential for their management and protection. In the Mediterranean Sea there is increasing concern over elasmobranch species because their biological (ecological) characteristics make them highly vulnerable to fishing pressure. Their removal could affect the structure and function of marine ecosystems, inducing changes in trophic interactions at the community level due to the selective elimination of predators or prey species, competitors and species replacement. In this study Bayesian hierarchical spatial models are used to map the sensitive habitats of the three most caught elasmobranch species (Galeus melastomus, Scyliorhinus canicula, Etmopterus spinax) in the western Mediterranean Sea, based on fishery-dependent bottom trawl data. Results show that habitats associated with hard substrata and sandy beds, mainly in deep waters and with a high seabed gradient, have a greater probability registering the presence of the studied species than those associated with muddy shallow waters. Temperature and chlorophyll-? concentration show a negative relationship with S. canicula occurrence. Our results identify some of the sensitive habitats for elasmobranchs in the western Mediterranean Sea (GSA06 South), providing essential and easy-to-use interpretation tools, such as predictive distribution maps, with the final aim of improving management and conservation of these vulnerable species.

  19. Contour Lines and Elevation

    NSDL National Science Digital Library

    Stephen J Reynolds

    This animation features a static image of a contour surface on the left and an oblique 3-D view of the same area. Upon starting the animation, by clicking adjacent arrows, a surface of water begins to rise. By examining the views in both windows, a simulated flood shows how contour lines trace out equal elevations and how concave/convex undulations in the contour lines would be represented in 3-D. The animation can be paused and rewound to stress important points.

  20. ccsd00003900, ON SYMMETRIC SENSITIVITY

    E-print Network

    ccsd­00003900, version 1 ­ 14 Jan 2005 ON SYMMETRIC SENSITIVITY Benoît CADRE and Pierre JACOB UMR, 34095 Montpellier cedex 5, FRANCE Abstract We de#28;ne the concept of symmetric sensitivity with respect sensitive map may diverge from a positive quantity independent of the initial points. We study

  1. Sensitivity study: SO2 retrieval

    E-print Network

    Oxford, University of

    ) (SUMMER) WAVELENGHT (µm) Transmittance RR ON GROUND TIR CAMERA FOR VOLCANIC PLUME DETECTION: SENSITIVITY,volcanic ash, O3). · The sensitivity study on BIRD camera shows the ability to retrieve from 0.5 to 1 g/m2. In this work a sensitivity study on sulphur dioxide and volcanic ash retrieval using on ground TIR camera

  2. A line confusion limited millimeter survey of Orion KL

    NASA Astrophysics Data System (ADS)

    Tercero, B.; Cernicharo, J.; Pardo, J. R.; Goicoechea, J. R.

    2011-05-01

    We perform a sensitive (line confusion limited), single-side band spectral survey towards Orion KL with the IRAM 30m telescope, covering the following frequency ranges: 80-115.5 GHz, 130-178 GHz, and 197-281 GHz. We detect more than 14 400 spectral features of which 10 040 have been identified up to date and attributed to 43 different molecules, including 148 isotopologues and lines from vibrationally excited states. In the 2 mm and 1.3 mm windows, the features weaker than 0.1 K have not yet been systematically analyzed, except when searching for isotopic species with good laboratory frequencies. We thus expect to considerably increase the number of both identified and unidentified lines. We note that the number of U lines was initially much larger. Identification of some isotopologues of most abundant species allowed us to reduce the number of U-lines at a rate of ˜ 500 lines per year. We used standard procedures to identify lines above 0.2 K including all possible contributions (taking into account the energy of the transition and the line strength) from different species. Thanks to the wide frequency coverage of our survey, many rotational lines were observed for each species, hence it is possible to estimate the contribution of a given molecule to the intensity of a spectral feature where several lines from different species are blended.

  3. Transmission line capital costs

    SciTech Connect

    Hughes, K.R.; Brown, D.R.

    1995-05-01

    The displacement or deferral of conventional AC transmission line installation is a key benefit associated with several technologies being developed with the support of the U.S. Department of Energy`s Office of Energy Management (OEM). Previous benefits assessments conducted within OEM have been based on significantly different assumptions for the average cost per mile of AC transmission line. In response to this uncertainty, an investigation of transmission line capital cost data was initiated. The objective of this study was to develop a database for preparing preliminary estimates of transmission line costs. An extensive search of potential data sources identified databases maintained by the Bonneville Power Administration (BPA) and the Western Area Power Administration (WAPA) as superior sources of transmission line cost data. The BPA and WAPA data were adjusted to a common basis and combined together. The composite database covers voltage levels from 13.8 to 765 W, with cost estimates for a given voltage level varying depending on conductor size, tower material type, tower frame type, and number of circuits. Reported transmission line costs vary significantly, even for a given voltage level. This can usually be explained by variation in the design factors noted above and variation in environmental and land (right-of-way) costs, which are extremely site-specific. Cost estimates prepared from the composite database were compared to cost data collected by the Federal Energy Regulatory Commission (FERC) for investor-owned utilities from across the United States. The comparison was hampered because the only design specifications included with the FERC data were voltage level and line length. Working within this limitation, the FERC data were not found to differ significantly from the composite database. Therefore, the composite database was judged to be a reasonable proxy for estimating national average costs.

  4. Stimuli Sensitive Amphiphilic Dendrimers

    PubMed Central

    Rajasekhar Reddy, R; Raghupathi, Krishna R.; Torres, Diego Amado

    2013-01-01

    In the past decade, there has been an increasing interest in supramolecular systems that can undergo physical or chemical tranformations upon encountering a specific stimulus. Micelle-forming amphiphilic systems based on polymers and dendrimers are particularly preferred over small molecule amphiphiles, due to their ability to sequester and release a vast library of hydrophobic guest molecules at micromolar polymer or dendrimer concentrations. Here we review a relatively underexplored, yet rapidly advancing, field of amphiphilic systems based on dendritic architechture that exhibit stimuli sensitive behaviour. In particular, we will be focusing on stimuli such as temperature, pH, enzymatic and non-enzymatic proteins. These stimuli-responsive systems offer a unique opportunity in the field of drug delivery and sensing. PMID:24039387

  5. N inventory sensitivity to organic matter remineralization

    NASA Astrophysics Data System (ADS)

    Landolfi, Angela; Kriest, Iris; Koeve, Wolfgang; Oschlies, Andreas

    2014-05-01

    Nitrogen (N) is an essential element for the maintenance of marine biological production. The inventory of marine N is sensitive to the ratio of oxic versus suboxic remineralization of organic matter. Net N loss may occur when significant portions of newly fixed organic material is remineralized under suboxic conditions via denitrification. In the current ocean, this potential N loss is restricted to limited regions. However, numerous climate-sensitive factors that affect the sinking and decay rate of organic matter may impact on the balance between oxic remineralization and suboxic reminerlization of organic matter via denitrification and, conditions for net N loss might emerge in the future. Here we use a biogeochemical ocean model, coupled off-line within the Transport Matrix Method (TMM) framework with transport fields taken from the ECCO configuration of the MIT General Circulation Model, to investigate how changes in the depth and rate of remineralization of organic matter affect the ratio of oxic versus suboxic remineralization and impact on the N inventory. We find a high sensitivity of the marine N invenotry to changes in the depth remineralization scale and to rates of suboxic remineralization of organic matter.

  6. Pharmacogenetics: detecting sensitive populations.

    PubMed Central

    Shields, P G

    1994-01-01

    Risk assessment models strive to predict risks to humans from toxic agents. Safety factors and assumptions are incorporated into these models to allow a margin of error. In the case of cancer, substantial evidence shows that the carcinogenic process is a multistage process driven by the interaction of exogenous carcinogenic exposures, genetic traits, and other endogenous factors. Current risk assessment models fail to consider genetic predispositions that make people more sensitive or resistant to exogenous exposures and endogenous processes. Several cytochrome P450 enzymes, responsible for metabolically activating carcinogens and medications, express wide interindividual variation whose genetic coding has now been identified as polymorphic and linked to cancer risk. For example, a restriction fragment-length polymorphism for cytochrome P4501A1, which metabolizes polycyclic aromatic hydrocarbons, and cytochrome P4502E1, which metabolizes N-nitrosamines and benzene, is linked to lung cancer risk. Cytochrome P4502D6, responsible for metabolizing many clinically important medications, also is linked to lung cancer risk. The frequency for each of these genetic polymorphisms vary among different ethnic and racial groups. In addition to inherited factors for the detection of sensitive populations, determining the biologically effective doses for carcinogenic exposures also should quantitatively and qualitatively enhance the risk assessment process. Levels of carcinogen-DNA adducts reflect the net effect of exposure, absorption, metabolic activation, detoxification, and DNA repair. These effects are genetically predetermined, inducibility notwithstanding. The combination of adduct and genotyping assays provide an assessment of risk that reflects recent exogenous exposure as well as one's lifetime ability to activate and detoxify carcinogens. PMID:7737047

  7. Unveiling the nature of dark matter with high redshift 21 cm line experiments

    NASA Astrophysics Data System (ADS)

    Evoli, C.; Mesinger, A.; Ferrara, A.

    2014-11-01

    Observations of the redshifted 21 cm line from neutral hydrogen will open a new window on the early Universe. By influencing the thermal and ionization history of the intergalactic medium (IGM), annihilating dark matter (DM) can leave a detectable imprint in the 21 cm signal. Building on the publicly available 21cmFAST code, we compute the 21 cm signal for a 10 GeV WIMP DM candidate. The most pronounced role of DM annihilations is in heating the IGM earlier and more uniformly than astrophysical sources of X-rays. This leaves several unambiguous, qualitative signatures in the redshift evolution of the large-scale (k simeq 0.1 Mpc-1) 21 cm power amplitude: (i) the local maximum (peak) associated with IGM heating can be lower than the other maxima; (ii) the heating peak can occur while the IGM is in emission against the cosmic microwave background (CMB); (iii) there can be a dramatic drop in power (a global minimum) corresponding to the epoch when the IGM temperature is comparable to the CMB temperature. These signatures are robust to astrophysical uncertainties, and will be easily detectable with second generation interferometers. We also briefly show that decaying warm dark matter has a negligible role in heating the IGM.

  8. 3.5 keV Galactic Emission Line as a Signal from the Hidden Sector

    E-print Network

    Ning Chen; Zuowei Liu; Pran Nath

    2014-08-07

    An emission line with energy of $E\\sim 3.5$ keV has been observed in galaxy clusters by two experiments. The emission line is consistent with the decay of a dark matter particle with a mass of $\\sim 7$ keV. In this work we discuss the possibility that the dark particle responsible for the emission is a real scalar ($\\rho$) which arises naturally in a $U(1)_X$ Stueckelberg of MSSM. In the MSSM Stueckelberg extension $\\rho$ couples only to other scalars carrying a $U(1)_X$ quantum number. Under the assumption that there exists a vectorlike leptonic generation carrying both $SU(2)_L\\times U(1)_Y$ and $U(1)_X$ quantum numbers, we compute the decay of the $\\rho$ into two photons via a triangle loop involving scalars. The relic density of the $\\rho$ arises via the decay $H^0\\to h^0+ \\rho$ at the loop level involving scalars, and via the annihilation processes of the vectorlike scalars into $\\rho + h^0$. It is shown that the galactic data can be explained within a multicomponent dark matter model where the 7 keV dark matter is a subdominant component constituting only $(1-10)$\\% of the matter relic density with the rest being supersymmetric dark matter such as the neutralino. Thus the direct detection experiments remain viable searches for WIMPs. The fact that the dark scalar $\\rho$ with no interactions with the standard model particles arises from a Stueckelberg extension of a hidden $U(1)_X$ implies that the 3.5 KeV galactic line emission is a signal from the hidden sector.

  9. PARTICLES AND FIELDS: On ?c line shape in charmonium transitions

    NASA Astrophysics Data System (ADS)

    Ping, Rong-Gang

    2009-08-01

    The line shapes to observe ?c in charmonium transitions, i.e., ? (2S), J/? ? ??c, are investigated. The ?c line shapes in exclusive decays or by observing the inclusive photon spectrum are given. The sensitivities to measure the ?c resonance parameters are also evaluated. With more than two thousand ?c events observed, the precision of the ?c decay width measurement will be improved by better than 3%. However, the uncertainties associated with the ?c modified line shapes will dominate the systematic errors and this will prohibit precision mass and width measurements.

  10. Balancing data sharing requirements for analyses with data sensitivity

    USGS Publications Warehouse

    Jarnevich, C.S.; Graham, J.J.; Newman, G.J.; Crall, A.W.; Stohlgren, T.J.

    2007-01-01

    Data sensitivity can pose a formidable barrier to data sharing. Knowledge of species current distributions from data sharing is critical for the creation of watch lists and an early warning/rapid response system and for model generation for the spread of invasive species. We have created an on-line system to synthesize disparate datasets of non-native species locations that includes a mechanism to account for data sensitivity. Data contributors are able to mark their data as sensitive. This data is then 'fuzzed' in mapping applications and downloaded files to quarter-quadrangle grid cells, but the actual locations are available for analyses. We propose that this system overcomes the hurdles to data sharing posed by sensitive data. ?? 2006 Springer Science+Business Media B.V.

  11. An oscillator design using low g-sensitivity, low phase noise STW devices

    Microsoft Academic Search

    MARK S. CAVIN; RODOLFO C. ALMAR

    1995-01-01

    Focuses upon results of integrating surface transverse wave (STW) technology into an oscillator product line. Phase noise of <-100 dBc\\/Hz at 100 Hz, noise floor of <-180 dBc\\/Hz, and g-sensitivity of <5×10-10 per g have been achieved at 1 GHz using STW technology. Select units have exhibited g-sensitivities below 1×10 -10 per g. These 1\\/f and g-sensitivity results represent state

  12. NK sensitivity of neuroblastoma cells determined by a highly sensitive coupled luminescent method

    SciTech Connect

    Ogbomo, Henry [Institut fuer Medizinische Virologie, Zentrum der Hygiene, Klinikum der J.W. Goethe-Universitaet Paul Ehrlich Str. 40 60596 Frankfurt (Germany); Hahn, Anke [Institut fuer Medizinische Virologie, Zentrum der Hygiene, Klinikum der J.W. Goethe-Universitaet Paul Ehrlich Str. 40 60596 Frankfurt (Germany); Geiler, Janina [Institut fuer Medizinische Virologie, Zentrum der Hygiene, Klinikum der J.W. Goethe-Universitaet Paul Ehrlich Str. 40 60596 Frankfurt (Germany); Michaelis, Martin [Institut fuer Medizinische Virologie, Zentrum der Hygiene, Klinikum der J.W. Goethe-Universitaet Paul Ehrlich Str. 40 60596 Frankfurt (Germany); Doerr, Hans Wilhelm [Institut fuer Medizinische Virologie, Zentrum der Hygiene, Klinikum der J.W. Goethe-Universitaet Paul Ehrlich Str. 40 60596 Frankfurt (Germany); Cinatl, Jindrich [Institut fuer Medizinische Virologie, Zentrum der Hygiene, Klinikum der J.W. Goethe-Universitaet Paul Ehrlich Str. 40 60596 Frankfurt (Germany)]. E-mail: Cinatl@em.uni-frankfurt.de

    2006-01-06

    The measurement of natural killer (NK) cells toxicity against tumor or virus-infected cells especially in cases with small blood samples requires highly sensitive methods. Here, a coupled luminescent method (CLM) based on glyceraldehyde-3-phosphate dehydrogenase release from injured target cells was used to evaluate the cytotoxicity of interleukin-2 activated NK cells against neuroblastoma cell lines. In contrast to most other methods, CLM does not require the pretreatment of target cells with labeling substances which could be toxic or radioactive. The effective killing of tumor cells was achieved by low effector/target ratios ranging from 0.5:1 to 4:1. CLM provides highly sensitive, safe, and fast procedure for measurement of NK cell activity with small blood samples such as those obtained from pediatric patients.

  13. Lung HelpLine and Tobacco QuitLine

    MedlinePLUS

    ... for ENews Home > About Us Lung HelpLine and Tobacco QuitLine You Ask. We Answer. Talk to our ... at the American Lung Association Lung HelpLine and Tobacco QuitLine. Our service is free and available as ...

  14. Line Bisector Variability in the Sun as a Star

    NASA Astrophysics Data System (ADS)

    Giampapa, Mark; Bertello, Luca

    2015-01-01

    We utilize spectra obtained with the Integrated Sunlight Spectrometer (ISS) instrument of the NSO SOLIS facility on Kitt Peak, AZ to perform a preliminary study of the variability of line asymmetries in the Mn I line at 539.5 nm and the nearby Fe I line at 539.3 nm, respectively. We derive the line bisector for these photospheric features from daily spectra of the Sun as a star acquired since January 2007, and characterize the variability of a measure of bisector amplitude with the solar cycle. A simple two-component model of the solar magnetic field is investigated as a possible origin for the variation in line depth with time of the magnetically sensitive Mn I feature.

  15. Harry: Between the Lines 

    E-print Network

    Kurz, R.; White, T.

    1982-01-01

    I 5. ; ..v^-rr>.>-'- j??!*f fefi ( -??;r' ,, ;rl&.i:-??t**rK&d t ? -?, .- 'c-y. ~ :'y$???M .'??. ??.v-'-/i / ' , *? I te / - 5- MAGNUM FORCE: HARRY Between The Lines by Ruth Kurz Seeing Harry, instead of The Callahan... Image. (1973) Special thanks to Teri White for the original "first time"*scene. Further thanks JL MW AW DMc A production of AD NAUSEUM PRESS 3613 West Park Road Cleveland, Ohio 44111 MAGNUM FORCE: HARRY Between The Lines by ruth kurz ' "I...

  16. Bonneville upgrades lines

    SciTech Connect

    Not Available

    1993-08-30

    A stretch of Bonneville Power Administration transmission line between Spokane and the Grand Coulee Dam is an 82-mile bottleneck as it is the last 115-kv section of [open quotes]road[close quotes] along a 500-kv transmission [open quotes]highway[close quotes]. Soon the administration will change all that. A number of independent and utility powerplants have been proposed in Idaho, Montana and the Spokane, Wash., area during the 1990s. As the operators will need to move their power, Bonneville is planning to build a $144-million, 500-kv line to upgrade the 115-kv section. The agency is planning to use its existing right-of-way.

  17. Political Money Line

    NSDL National Science Digital Library

    For those Internauts interested on where the money that flows to U.S. political campaigns (Congressional and Presidential) comes from, the Political Money Line (formerly FECInfo) site is an excellent places to start. Political Money Line, provided by Tony Raymond, a former employee of the FEC, is a site that allows users to query FEC data for individual contributors (by name and zip code), which candidates have the most cash, detailed information about PACs (Political Action Committees), and which candidates have contributed the most money to their own campaigns, among other data. Raymond claims simply to make FEC data easier to use; his site is in no way affiliated with FEC.

  18. 8.EE Two Lines

    NSDL National Science Digital Library

    This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: Consider the graph below showing two lines, $L1$ and $L2$. Find the two corresponding linear equations. Find points other than the ones given in the gr...

  19. Pipe Line Control

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The array of tanks, pipes and valves in the photo below is a petroleum tank farm in Georgia, part of a petrochemical pipe line system that moves refined petroleum products from Texas and Louisiana to the mid-Eastern seaboard. The same pipes handle a number of different products, such as gasoline, kerosene, jet fuel or fuel oil. The fluids are temporarily stored in tanks, pumped into the pipes in turn and routed to other way stations along the pipe line. The complex job of controlling, measuring and monitoring fuel flow is accomplished automatically by a computerized control and communications system which incorporates multiple space technologies.

  20. Line-Follower Challenge

    NSDL National Science Digital Library

    GK-12 Program, Computational Neurobiology Center,

    Student groups are challenged to program robots with light sensors to follow a black line. Learning both the logic and skills behind programming robots for this challenge helps students improve their understanding of how robots "think" and widens their appreciation for the complexity involved in programming LEGO® MINDSTORMS® NXT robots to do what appears to be a simple task. They test their ideas for approaches to solve the problem and ultimately learn a (provided) working programming solution. They think of real-world applications for line-follower robots that use sensor input. A PowerPoint® presentation and pre/post quizzes are provided.