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1

Estimate for GLAST LAT Milky Way Dark Matter WIMP Line Sensitivity  

SciTech Connect

The LAT Dark Matter and New Physics Working group has been developing approaches for the indirect astrophysical detection of annihilation of dark matter. Our work has assumed that a significant component of dark matter is a new type of Weakly Interacting Massive Particle (WIMP). The annihilation of two WIMPs usually results in the production of many high energy gamma rays (>1 GeV) that can be well measured in the GLAST LAT if present. There is also the possibility to observe {gamma} lines from annihilation into {gamma}{gamma} and or {gamma}Z final states. In popular SUSY theories these line decays occur at the 10{sup -4} to 10{sup -2} branching fraction level. Estimates of LAT sensitivity (at 5{sigma} above background) and upper limits (upper limit at the 95% confidence level) to these WIMP lines will be presented. These sensitivities are given in photons/cm2/sec/sr and so do not depend on the WIMP models. However, they do depend on the diffuse background model. The latter is derived from GALPROP[1] based on EGRET and other data in the EGRET energy range. We use extrapolations, provided by the GALPROP team to the higher energy range of 150 GeV explored in the preliminary line sensitivity study presented here. Comparison with theory depends upon the WIMP model (e.g., line energy and 1 or 2 lines), the DM halo model, and other astrophysics backgrounds. Thus estimates of the ability of the LAT to actually observe WIMP lines can vary over orders of magnitude depending upon which models are chosen.

Edmonds, Y.; Baltz, E.; Bloom, E.; Cohen-Tanugi, J.; Godfrey, G.; Wai, L.; Wang, P.; /SLAC /KIPAC, Menlo Park; Scargle, J.; /NASA, Ames; Conrad, J.; /Royal Inst. Tech., Stockholm

2007-11-02

2

Estimate for GLAST LAT Milky Way Dark Matter WIMP Line Sensitivity  

SciTech Connect

The LAT Dark Matter and New Physics Working group has been developing approaches for the indirect astrophysical detection of annihilation of dark matter. Our work has assumed that a significant component of dark matter is a new type of Weakly Interacting Massive Particle (WIMP). The annihilation of two WIMPs usually results in the production of many high energy gamma rays (>1 GeV) that can be well measured in the GLAST LAT if present. There is also the possibility to observe {gamma} lines from annihilation into {gamma}{gamma} and or {gamma}Z final states. In popular SUSY theories these line decays occur at the 10-4 to 10-2 branching fraction level. Estimates of LAT sensitivity (at 5{sigma} above background) and upper limits (upper limit at the 95% confidence level) to these WIMP lines will be presented. These sensitivities are given in photons/cm2/sec/sr and so do not depend on the WIMP models. However, they do depend on the diffuse background model. The latter is derived from GALPROP based on EGRET and other data in the EGRET energy range. We use extrapolations, provided by the GALPROP team to the higher energy range of 150 GeV explored in the preliminary line sensitivity study presented here. Comparison with theory depends upon the WIMP model (e.g., line energy and 1 or 2 hues), the DM halo model, and other astrophysics backgrounds. Thus estimates of the ability of the LAT to actually observe WIMP lines can vary over orders of magnitude depending upon which models are chosen.

Edmonds, Y.; Baltz, E.; Bloom, E.; Cohen-Tanugi, J.; Godfrey, G.; Wai, L.; Wang, P. [Stanford Linear Accelerator Center, 2575 Sand Hill Rd, Menlo Park, CA 94025 (United States)]|[Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94309 (United States); Scargle, J. [NASA Ames Research Center, Moffet Field, California 94035 (United States); Conrad, J. [Royal Institute of Technology (KTH), AlbaNova University Centre, SE-10691 Stockholm (Sweden)

2007-07-12

3

Positron line radiation from halo WIMP annihilations as a dark matter signature  

NASA Technical Reports Server (NTRS)

We suggest a new signature for dark matter annihilation in the halo: high energy positron line radiation. Because the cosmic ray positron spectrum falls rapidly with energy, e+'s from halo WIMP annihilations can be a significant, clean signal for very massive WIMP's (approx. greater than 30 GeV). In the case that the e+e- annihilation channel has an appreciable branch, the e+ signal should be above background in a future detector, such as have been proposed for ASTROMAG, and of potential importance as a dark matter signature. A significant e+e- branching ratio can occur for neutralinos or Dirac neutrinos. High-energy, continuum positron radiation may also be an important signature for massive neutralino annihilations, especially near or above the threshold of the W+W- and ZoZo annihilation channels.

Turner, Michael S.; Wilczek, Frank

1989-01-01

4

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

E-print Network

The unidentified emission line at the energy of $\\sim$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.

Cheng-Wei Chiang; Toshifumi Yamada

2014-07-28

5

Expected Sensitivity to Galactic/Solar Axions and Bosonic Super-WIMPs based on the Axio-electric Effect in Liquid Xenon Dark Matter Detectors  

E-print Network

We present systematic case studies to investigate the sensitivity of axion searches by liquid xenon detectors, using the axio-electric effect (analogue of the photoelectric effect) on xenon atoms. Liquid xenon is widely considered to be one of the best target media for detection of WIMPs (Weakly Interacting Massive Particles which may form the galactic dark matter) using nuclear recoils. Since these detectors also provide an extremely low radioactivity environment for electron recoils, very weakly-interacting low-mass particles ( 10^-33 (for mass 1 keV/c^2) or > 10^-27 (for mass 100 keV/c^2).

K. Arisaka; P. Beltrame; C. Ghag; J. Kaidi; K. Lung; A. Lyashenko; R. D. Peccei; P. Smith; K. Ye

2013-01-23

6

The granulation sensitivity of helioseismology lines  

Microsoft Academic Search

The sensitivity of the Ni I 676.78 nm Global Oscillation Network Group line and the K I 769.9 nm resonance line to the temperature fluctuations present in the solar granulation are discussed. The temperature contrasts due to granulation are probably small in the upper photosphere where the cores of these two helioseismology lines are formed. However, the cores are sensitive

R. J. Rutten; J. H. M. J. Bruls; M. T. Gomez; G. Severino

1988-01-01

7

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.

8

WIMP physics with ensembles of direct-detection experiments  

NASA Astrophysics Data System (ADS)

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.

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

2014-12-01

9

Improved Detection Sensitivity of Line-Scanning Optical Coherence Microscopy  

PubMed Central

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

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

2012-01-01

10

Sites of ozone sensitivity in diverse maize inbred lines  

Technology Transfer Automated Retrieval System (TEKTRAN)

Tropospheric ozone (O3) is an air pollutant that costs ~$14-26 billion in global crop losses and is projected to worsen in the future. Potential sites of O3 sensitivity in maize were tested by growing 200 inbred lines, including the nested association mapping population founder lines, under ambient...

11

The WIMP Forest: Indirect Detection of a Chiral Square  

E-print Network

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).

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

2009-04-08

12

Post-WIMP user interfaces  

Microsoft Academic Search

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

Andries Van Dam

1997-01-01

13

Nano-booms — A new class of WIMP detectors  

NASA Astrophysics Data System (ADS)

Weakly Interacting Massive Particles (WIMPs) can constitute a large fraction of the dark matter (DM) in the universe. The importance of coherent scattering and detection of annual modulation effect (AME), diurnal modulation effect (DME) and direction sensitive AME was documented. In particular, DAMA/NaI and DAMA/LIBRA have released data collected during 14 annual cycles, which support in model independent way, the presence of DM particles in the galactic halo. There is a clear evidence of AME signature in DAMA data. Recently, positive hints have also been reported by CoGeNT on AME signature in Ge, while CREST-II and CDMS-Si have published some events in excess of estimated background; these events are compatible with WIMP-like candidates. If these results would be analyzed all together in some WIMP scenario, one could derive: MDM < 10 GeV/c2. Current generation of detectors is far from being optimal or in some cases even reliable when MDM approaches 5 GeV/c2. We propose a detector, which can detect the direction of incoming WIMPs. This paper focus on a particular implementation of the new class of nano-explosive DM detectors. The local heating ignites an explosion, which release chemical energy stored in such a nano-grain. Use of two component nano-explosive permits to amplify the bolometric effect due to WIMP-candidates. The energy available becomes 100,000-fold larger than the energy initially deposited by DM candidate. This leads to a sonic-boom, which can be detected remotely. This new class of nano-explosive detectors may be especially important in detection of WIMPs with very low mass, say MDM = O(5 GeV/c2). We describe a configuration, which leads to explosive-triode, and permits detection of the direction of incoming WIMPs.

Drukier, A. K.; Fagaly, R. L.; Bielski, R.

2014-07-01

14

Radiation sensitivity of Merkel cell carcinoma cell lines  

SciTech Connect

Merkel cell carcinoma (MCC), being a small cell carcinoma, would be expected to be sensitive to radiation. Clinical analysis of patients at our center, especially those with macroscopic disease, would suggest the response is quite variable. We have recently established a number of MCC cell lines from patients prior to radiotherapy, and for the first time are in a position to determine their sensitivity under controlled conditions. Some of the MCC lines grew as suspension cultures and could not be single cell cloned; therefore, it was not possible to use clonogenic survival for all cell lines. A tetrazolium based (MTT) assay was used for these lines, to estimate cell growth after {gamma} irradiation. Control experiments were conducted on lymphoblastoid cell lines (LCL) and the adherent MCC line, MCC13, to demonstrate that the two assays were comparable under the conditions used. We have examined cell lines from MCC, small cell lung cancer (SCLC), malignant melanomas, Epstein Barr virus (EBV) transformed lymphocytes (LCL), and skin fibroblasts for their sensitivity to {gamma} irradiation using both clonogenic cell survival and MTT assays. The results show that the tumor cell lines have a range of sensitivities, with melanoma being more resistant (surviving fraction at 2 Gy (SF2) 0.57 and 0.56) than the small cell carcinoma lines, MCC (SF2 range 0.21-0.45, mean SF2 0.30, n = 8) and SCLC (SF2 0.31). Fibroblasts were the most sensitive (SF2 0.13-0.20, mean 0.16, n = 5). The MTT assay, when compared to clonogenic assay for the MCC13 adherent line and the LCL, gave comparable results under the conditions used. Both assays gave a range of SF2 values for the MCC cell lines, suggesting that these cancers would give a heterogeneous response in vivo. The results with the two derivative clones of MCC14 (SF2 for MCC14/1 0.38, MCC14/2 0.45) would further suggest that some of them may develop resistance during clonogenic evolution. 25 refs., 3 figs., 1 tab.

Leonard, J.H.; Ramsay, J.R.; Birrell, G.W. [Queensland Institute of Medical Research (Australia)] [and others] [Queensland Institute of Medical Research (Australia); and others

1995-07-30

15

Light WIMPs in the Sun: Constraints from helioseismology  

SciTech Connect

We calculate solar models including dark matter (DM) weakly interacting massive particles (WIMPs) of mass 5-50 GeV and test these models against helioseismic constraints on sound speed, convection-zone depth, convection-zone helium abundance, and small separations of low-degree p-modes. Our main conclusion is that both direct detection experiments and particle accelerators may be complemented by using the Sun as a probe for WIMP DM particles in the 5-50 GeV mass range. The DM most sensitive to this probe has suppressed annihilations and a large spin-dependent elastic scattering cross section. For the WIMP cross section parameters explored here, the lightest WIMP masses <10 GeV are ruled out by constraints on core sound speed and low-degree frequency spacings. For WIMP masses 30-50 GeV, the changes to the solar structure are confined to the inner 4% of the solar radius and so do not significantly affect the solar p-modes. Future helioseismology observations, most notably involving g-modes, and future solar neutrino experiments may be able to constrain the allowable DM parameter space in a mass range that is of current interest for direct detection.

Cumberbatch, Daniel T. [Astroparticle Theory and Cosmology Group, Department of Physics and Astronomy, University of Sheffield, Hicks Building, Hounsfield Road, Sheffield, S3 7RH (United Kingdom); Guzik, Joyce A. [Los Alamos National Laboratory, XTD-2 Mail Stop T086, Los Alamos, New Mexico 87545-2345 (United States); Silk, Joseph [Physics Department, University of Oxford, Oxford, OX1 3RH (United Kingdom); Watson, L. Scott [Sandia National Laboratories, PO Box 5800 Mail Stop 0431, Albuquerque, New Mexico 87185 (United States); West, Stephen M. [Royal Holloway, University of London, Egham, TW20 0EX (United Kingdom); Rutherford Appleton Laboratory, Chilton, Didcot, OX11 0QX (United Kingdom)

2010-11-15

16

WIMP Searches with Liquid Xenon: the XENON10 Experiment  

Microsoft Academic Search

The XENON experiment searches for Weakly Interacting Massive Particles (WIMPs) with liquid xenon (LXe) as the active target. The detector is a 3-D position sensitive Time Projection Cham- ber optimized to simultaneously measure the ionization and scintillation produced by a recoil event down to energies of 16 keV. The distinct ratio of the two signals for nuclear recoils arising from

Laura Baudis

2005-01-01

17

Radiation sensitivity of merkel cell carcinoma cell lines  

Microsoft Academic Search

Purpose: Merkel cell carcinoma (MCC), being a small cell carcinoma, would be expected to be sensitive to radiation. Clinical analysis of patients at our center, especially those with macroscopic disease, would suggest the response is quite variable. We have recently established a number of MCC cell lines from patients prior to radiotherapy, and for the first time are in a

J. Helen Leonard; Jonathan R. Ramsay; John H. Kearsley; Geoff W. Birrell

1995-01-01

18

Differential Sensitivity in the Survival of Oligodendrocyte Cell Lines to  

E-print Network

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

Bongarzone, Ernesto R.

19

Event rates for WIMP detection  

SciTech Connect

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.

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

20

DNA methylation and sensitivity to antimetabolites in cancer cell lines.  

PubMed

The prediction of the cellular direction of metabolic pathways toward either DNA synthesis or DNA methylation is crucial for determining the susceptibility of cancers to anti-metabolites such as fluorouracil (5-FU). We genotyped the methylenetetrahydrofolate reductase (MTHFR) gene in NCI-60 cancer cell lines, and identified the methylation status of 24 tumor suppressor genes using methylation-specific multiplex ligation-dependent probe amplification. The susceptibility of the cancer cell lines to seven antimetabolites was then determined. Cells homozygous for CC at MTHFR-A1298C were significantly more sensitive to cyclocytidine, cytarabine (AraC) and floxuridine than those with AA or AC (p=0.0215, p=0.0166, and p=0.0323, respectively), and carried more methylated tumor suppressor genes (p=0.0313). Among the 12 tumor suppressor genes which were methylated in >25% of cancer cell lines, the methylation status of TIMP3, APC and IGSF4 significantly correlated with sensitivity to pyrimidine synthesis inhibitors. In particular, cells with methylated TIMP3 had reduced mRNA levels and were significantly more sensitive to aphidicolin-glycinate, AraC and 5-FU than cells with unmethylated TIMP3. We speculate that MTHFR-A1298C homozygous CC might direct the methylation rather than the synthesis of DNA, and result in the methylation of several tumor suppressor genes such as TIMP3. These genes could be useful biological markers for predicting the efficacy of antimetabolites. PMID:18202788

Sasaki, Shin; Kobunai, Takashi; Kitayama, Joji; Nagawa, Hirokazu

2008-02-01

21

Temperature-Sensitive Variants of an Established Myoblast Line  

PubMed Central

Upon reaching confluency, mononucleated myoblasts fuse into multinucleated myotubes and concomitantly accumulate various characteristic muscle proteins, including myosin, actin, and several enzymes. We have approached the problem of determining the relationship between morphological and biochemical differentiation of muscle cells by isolating a series of temperature-sensitive clones from the established myoblast line, L6. Twelve phenotypically variant clones were isolated from mutagenized populations of myoblasts. These fell into five classes, distinguishing conditional growth variants from conditional developmental variants. The phenotype of these strains, at least for the more extensively studied ones, was stable for more than 80 generations. Synthesis of characteristic proteins such as myosin, glycogen phosphorylase (EC 2.4.1.1), and phosphocreatine kinase (EC 2.7.3.2) has been studied in two conditional developmental mutants. One mutant, E3, fuses into myotubes at 37° but not at 40°; the other, H6, does not fuse into myotubes at 37° but does so at 40°. At permissive temperatures the enzymes accumulated in mutant cells with the same time course as in the parent cell line. Myosin accumulated in strain E3 but not in strain H6. At nonpermissive temperatures neither fusion into myotubes nor accumulation of any of the proteins occured in the cells of these two variant lines. PMID:4510285

Loomis, W. F.; Wahrmann, J. P.; Luzzati, D.

1973-01-01

22

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

E-print Network

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.

Annika H. G. Peter

2009-02-09

23

Direct search for WIMP dark matter  

E-print Network

We will review the experimental aspects of the direct search for WIMP dark matter. In thin search, one looks in a terrestrial target for nuclear recoils produced by the impacts with WIMPs from the galatic halo. After describing the different search strategies and review the currently running experiments and the prospects of future experiments

J. Gascon

2005-04-11

24

WIMP astronomy and particle physics with liquid-noble and cryogenic direct-detection experiments  

E-print Network

Once weakly-interacting massive particles (WIMPs) are unambiguously detected in direct-detection experiments, the challenge will be to determine what one may infer from the data. Here, I examine the prospects for reconstructing the local speed distribution of WIMPs in addition to WIMP particle-physics properties (mass, cross sections) from next-generation cryogenic and liquid-noble direct-detection experiments. I find that the common method of fixing the form of the velocity distribution when estimating constraints on WIMP mass and cross sections means losing out on the information on the speed distribution contained in the data and may lead to biases in the inferred values of the particle-physics parameters. I show that using a more general, empirical form of the speed distribution can lead to good constraints on the speed distribution. Moreover, one can use Bayesian model-selection criteria to determine if a theoretically-inspired functional form for the speed distribution (such as a Maxwell-Boltzmann distribution) fits better than an empirical model. The shape of the degeneracy between WIMP mass and cross sections and their offset from the true values of those parameters depends on the hypothesis for the speed distribution, which has significant implications for consistency checks between direct-detection and collider data. In addition, I find that the uncertainties on theoretical parameters depends sensitively on the upper end of the energy range used for WIMP searches. Better constraints on the WIMP particle-physics parameters and speed distribution are obtained if the WIMP search is extended to higher energy (~ 1 MeV).

Annika H. G. Peter

2012-01-18

25

Identification of transporters associated with Etoposide sensitivity of stomach cancer cell lines and methotrexate sensitivity of breast cancer cell lines by quantitative targeted absolute proteomics.  

PubMed

Membrane transporter proteins may influence the sensitivity of cancer cells to anticancer drugs that can be recognized as substrates. The purpose of this study was to identify proteins that play a key role in the drug sensitivity of stomach and breast cancer cell lines by measuring the absolute protein expression levels of multiple transporters and other membrane proteins and examining their correlation to drug sensitivity. Absolute protein expression levels of 90 membrane proteins were examined by quantitative targeted absolute proteomics using liquid chromatography-linked tandem mass spectrometry. Among them, 11 and 14 membrane proteins, including transporters, were present in quantifiable amounts in membrane fraction of stomach cancer and breast cancer cell lines, respectively. In stomach cancer cell lines, the protein expression level of multidrug resistance-associated protein 1 (MRP1) was inversely correlated with etoposide sensitivity. MK571, an MRP inhibitor, increased both the cell-to-medium ratio of etoposide and the etoposide sensitivity of MRP1-expressing stomach cancer cell lines. In breast cancer cell lines, the protein expression level of reduced folate carrier 1 (RFC1) was directly correlated with methotrexate (MTX) sensitivity. Initial uptake rate and steady-state cell-to-medium ratio of [(3)H]MTX were correlated with both RFC1 expression level and MTX sensitivity. These results suggest that MRP1 modulates the etoposide sensitivity of stomach cancer cell lines and RFC1 modulates the MTX sensitivity of breast cancer cell lines. Our results indicate that absolute quantification of multiple membrane proteins could be a useful strategy for identification of candidate proteins involved in drug sensitivity. PMID:23197647

Obuchi, Wataru; Ohtsuki, Sumio; Uchida, Yasuo; Ohmine, Ken; Yamori, Takao; Terasaki, Tetsuya

2013-02-01

26

Soft collinear effective theory for heavy WIMP annihilation  

NASA Astrophysics Data System (ADS)

In a large class of models for Weakly Interacting Massive Particles (WIMPs), the WIMP mass M lies far above the weak scale m W . This work identifies universal Sudakov-type logarithms ˜ ? log2(2 M/m W ) that spoil the naive convergence of perturbation theory for annihilation processes. An effective field theory (EFT) framework is presented, allowing the systematic resummation of these logarithms. Another impact of the large separation of scales is that a long-distance wavefunction distortion from electroweak boson exchange leads to observable modifications of the cross section. Careful accounting of momentum regions in the EFT allows the rigorous disentanglement of this so-called Sommerfeld enhancement from the short-distance hard annihilation process. The WIMP is described as a heavy-particle field, while the electroweak gauge bosons are treated as soft and collinear fields. Hard matching coefficients are computed at renormalization scale ? ˜ 2 M , then evolved down to ? ˜ m W , where electroweak symmetry breaking is incorporated and the matching onto the relevant quantum mechanical Hamiltonian is performed. The example of an SU(2) W triplet scalar dark matter candidate annihilating to line photons is used for concreteness, allowing the numerical exploration of the impact of next-to-leading order corrections and log resummation. For M ? 3 TeV, the resummed Sommerfeld enhanced cross section is reduced by a factor of ˜ 3 with respect to the treelevel fixed order result.

Bauer, Martin; Cohen, Timothy; Hill, Richard J.; Solon, Mikhail P.

2015-01-01

27

Assessing Alternatives for Directional Detection of a WIMP Halo  

E-print Network

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.

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

2005-08-30

28

The solar activity sensitivity of Mn I lines  

Microsoft Academic Search

The MnI 5394.7 ûA line is the only spectral line originating in the solar photosphere for which it has been established that it tracks solar magnetic activity in its line-center brightness in the disk-averaged \\

Robert J. Rutten

29

WIMP abundance and lepton (flavour) asymmetry  

SciTech Connect

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)

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

30

Search for Low-Mass WIMPs with SuperCDMS  

E-print Network

We report a first search for weakly interacting massive particles (WIMPs) using the background rejection capabilities of SuperCDMS. An exposure of 577 kg-days was analyzed for WIMPs with mass < 30 GeV/c2, with the signal region blinded. Eleven events were observed after unblinding. We set an upper limit on the spin-independent WIMP-nucleon cross section of 1.2e-42 cm2 at 8 GeV/c2. This result is in tension with WIMP interpretations of recent experiments and probes new parameter space for WIMP-nucleon scattering for WIMP masses < 6 GeV/c2.

R. Agnese; A. J. Anderson; M. Asai; D. Balakishiyeva; R. Basu Thakur; D. A. Bauer; J. Beaty; J. Billard; A. Borgland; M. A. Bowles; D. Brandt; P. L. Brink; R. Bunker; B. Cabrera; D. O. Caldwell; D. G. Cerdeno; H. Chagani; Y. Chen; M. Cherry; J. Cooley; B. Cornell; C. H. Crewdson; P. Cushman; M. Daal; D. DeVaney; P. C. F. Di Stefano; E. Do Couto E Silva; T. Doughty; L. Esteban; S. Fallows; E. Figueroa-Feliciano; G. L. Godfrey; S. R. Golwala; J. Hall; S. Hansen; H. R. Harris; S. A. Hertel; B. A. Hines; T. Hofer; D. Holmgren; L. Hsu; M. E. Huber; A. Jastram; O. Kamaev; B. Kara; M. H. Kelsey; S. Kenany; A. Kennedy; M. Kiveni; K. Koch; A. Leder; B. Loer; E. Lopez Asamar; R. Mahapatra; V. Mandic; C. Martinez; K. A. McCarthy; N. Mirabolfathi; R. A. Moffatt; R. H. Nelson; L. Novak; K. Page; R. Partridge; M. Pepin; A. Phipps; M. Platt; K. Prasad; M. Pyle; H. Qiu; W. Rau; P. Redl; A. Reisetter; R. W. Resch; Y. Ricci; M. Ruschman; T. Saab; B. Sadoulet; J. Sander; R. L. Schmitt; K. Schneck; R. W. Schnee; S. Scorza; D. N. Seitz; B. Serfass; B. Shank; D. Speller; A. Tomada; S. Upadhyayula; A. N. Villano; B. Welliver; D. H. Wright; S. Yellin; J. J. Yen; B. A. Young; J. Zhang

2014-03-12

31

NEWS : a new spherical gas detector for very low mass WIMP detection  

E-print Network

The main characteristics of a new concept of spherical gaseous detectors, with some details on its operation are first given. The very low energy threshold of such detector has led to investigations of its potential performance for dark matter particle searches, in particular low mass WIMP's : original methods for energy and fiducial volume calibration and background rejection are described and preliminary results obtained with a low radioactivity prototype operated in Laboratoire Souterrain de Modane ("Frejus" lab) are presented. Typical expected sensitivities in cross section for low mass WIMP's are also shown, and other applications briefly discussed.

G. Gerbier; I. Giomataris; P. Magnier; A. Dastgheibi; M. Gros; D. Jourde; E. Bougamont; X. F. Navick; T. Papaevangelou; J. Galan; J. Derre; I. Savvidis; G. Tsiledakis

2014-01-30

32

Relationship of SR2508 sensitizer enhancement ratio to cellular glutathione levels in human tumor cell lines  

Microsoft Academic Search

We have recently demonstrated that intracellular elevation of glutathione (GSH) by oxothiazolidine 4-carboxylate lessens SR-2508 hypoxic cell radiosensitization in Chinese hamster cells. This observation, coupled with the fact that GSH depletion potentiates SR-2508 hypoxic radiosensitization, prompted a study of human tumor cell lines whose inherent GSH levels are high compared to normal human cell lines or rodent cell lines. Sensitizer

James B. Mitchell; Theodore L. Phillips; William Degraff; James Carmichael; Rajesh K. Rajpal; Angelo Russo

1986-01-01

33

A delay line with highly linear thermal sensitivity for smart temperature sensor  

Microsoft Academic Search

A highly linear thermal sensitivity delay line for smart temperature sensor is presented. The proposed delay line is a current starved inverter chain. A simple bias current source circuit is incorporated with the delay line to generate a current inversely proportional to temperature based on the transconductance characteristics of a MOS device at the vicinity of the zero temperature coefficient

Nguyen Thanh Trung; Kwansu Shon; Soo-Won Kim

2007-01-01

34

WIMP Velocity Impact on Direct Dark Matter Searches  

E-print Network

We examine the effect of some uncertainties in the input astrophysical parameters on direct detection searches for WIMPs in the Galactic halo. We concentrate on the possible WIMP annual modulation signal recently reported by the DAMA Collaboration. We find that allowing for a reasonable uncertainty in a WIMP Maxwellian velocity distribution leads to significantly relaxed constraints on the WIMP mass as compared to the original DAMA analysis.

Michal Brhlik; Leszek Roszkowski

1999-03-24

35

Comparisons of the five analytic reference lines of the horizontal lip position: their consistency and sensitivity.  

PubMed

One-hundred ten lateral facial profiles were judged to be attractive and were selected from 1000 Taiwanese pupils by a panel of four men and three women from different educational backgrounds. The 110 in the attractive group were analyzed by using five analytic reference lines: Ricketts E line, Holdaway's H line, Steiner's S1 line, Burstone's B line, and Sushner's S2 line. Comparisons of the "consistency" (the smaller coefficient of variation the better the consistency) and the "sensitivity" (the power to differentiate the attractive lateral facial profiles from the unattractive ones) of the five analytic lines were performed. The B line was found to be best in terms of both consistency and sensitivity. From the point of view of convenience, the E line is of great value because its anterior location makes it convenient for the clinician to use. However, the B line appears best from the perspective of the value of reference. This study found that those analytic reference lines that do not transverse an anatomic landmark of the nose most likely have poor consistency and sensitivity. This finding is consistent with the idea that the nose should be taken into consideration when a line is to be used as a reference for beauty on the lateral facial profile. PMID:8213657

Hsu, B S

1993-10-01

36

Halofuginone enhances the radiation sensitivity of human tumor cell lines.  

PubMed

Transforming growth factor beta (TGF-beta) is implicated in radiation-induced fibrosis of normal tissues in patients receiving radiotherapy. Inhibiting the TGF-beta signaling pathway by various means has been shown to reduce radiation-induced fibrosis in pre-clinical studies. The present study evaluated the effects of interfering with the TGF-beta signaling pathway on the radiosensitivity of selected human tumor cell lines using the plant-derived alkaloid, halofuginone. Halofuginone treatment inhibited cell growth, halted cell cycle progression, decreased radiation-induced DNA damage repair, and decreased TGF-beta receptor II protein levels, leading to increased cellular radiosensitization. These data further support the goal of manipulating the TGF-beta pathway to achieve a positive increase in the therapeutic gain in clinical radiotherapy. PMID:19713035

Cook, John A; Choudhuri, Rajani; Degraff, William; Gamson, Janet; Mitchell, James B

2010-03-01

37

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

E-print Network

RFI shielding and mitigation techniques for a sensitive search for the 327 MHz line of Deuterium and from nearby sites has been reduced by extensive shielding and in some cases the removal of consumer from RFI plays an important role in achieving the required sensitivity. #12;MIT Haystack Observatory

Ellingson, Steven W.

38

Abstract We have shown that Werner syndrome (WRN) fibroblast cell lines are unusually sensitive to the DNA-  

E-print Network

Abstract We have shown that Werner syndrome (WRN) fibroblast cell lines are unusually sensitive peroxide. The fu- sion of 4NQO-sensitive WRN and 4NQO-resistant con- trol fibroblast cell lines generated establish the recessive na- ture of 4NQO sensitivity in WRN cell lines and provide a cellular assay for WRN

Monnat, Ray

39

Searches for WIMP Annihilation with GLAST  

SciTech Connect

We describe signatures for WIMP annihilation in the gamma ray sky which can be observed by the GLAST mission, scheduled for launch in 2007. We review the search regions, which range from galactic substructure in the Milky Way all the way out to cosmological sources.

Wai, L.; /SLAC; ,

2005-06-21

40

Differentiating hidden sector dark matter from light WIMPs with Germanium detectors  

E-print Network

Light WIMP dark matter and hidden sector dark matter have been proposed to explain the DAMA, CoGeNT and CRESST-II data. Both of these approaches feature spin independent elastic scattering of dark matter particles on nuclei. Light WIMP dark matter invokes a single particle species which interacts with ordinary matter via contact interactions. By contrast hidden sector dark matter is typically multi-component and is assumed to interact via the exchange of a massless mediator. Such hidden sector dark matter thereby predicts a sharply rising nuclear recoil spectrum, $dR/dE_R \\sim 1/E_R^2$ due to this dynamics, while WIMP dark matter predicts a spectrum which depends sensitively on the WIMP mass, $m_\\chi$. We compare and contrast these two very different possible origins of the CoGeNT low energy excess. In the relevant energy range, the recoil spectra predicted by these two theories approximately agree provided $m_\\chi \\simeq 8.5$ GeV - close to the value favoured from fits to the CoGeNT and CDMS low energy data. Forthcoming experiments including C-4, CDEX, and the MAJORANA demonstrator, are expected to provide reasonably precise measurements of the low energy Germanium recoil spectrum, including the annual modulation amplitude, which should differentiate between these two theoretical possibilities.

R. Foot

2012-11-14

41

A line voltage regulator\\/conditioner for harmonic-sensitive load isolation  

Microsoft Academic Search

A technique is presented for the isolation of harmonic-sensitive loads from harmonic-producing loads, such as rectifiers and power converters. The solution, referred to as a line voltage regulator\\/conditioner (LVRC), utilizes a combination of a series and a parallel active power filter. The series filter isolates the sensitive loads on the output side of the LVRC from the nonlinear, distortion-producing loads

Steven Moran

1989-01-01

42

A comparison of heat and radiation sensitivity of three human glioma cell lines  

SciTech Connect

Three human glioma cell lines were tested for radiation and hyperthermia sensitivity and compared to the responses of a normal human fibroblast cell line. The radiation response of the glioma cell lines exhibited a large shoulder on the radiation survival curve indicating radioresistance when compared to the more radiosensitive fibroblast cell line. The hyperthermia response for the glioma cell lines was qualitatively similar to responses reported for other cell lines. When compared to normal human fibroblasts the glioma cells were found to be more sensitive to hyperthermia than the normal fibroblasts indicating hyperthermia may be a promising method or adjunct to radiotherapy in the treatment of resistant glioma cells or tumors. The results also show that both the radiation and thermal response is influenced by cell culture conditions and growth status. Two of the cell lines grown to confluency and treated in confluency showed an increased radiation resistance at low doses and the cell lines showed decreased resistance at high doses compared to cells plated to confluency. An increased thermal resistance, especially at the lower heating temperatures, was also observed for cells grown to confluency. Measurements of residual glucose in the culture medium at the time of irradiation was about the same for the two culture methods (55%-65%). Cell cycle analysis showed that the differences were not related to changes in cell cycle distribution.

Raaphorst, G.P.; Feeley, M.M.; Da Silva, V.F.; Danjoux, C.E.; Gerig, L.H. (Ottawa Regional Cancer Centre, Ontario (Canada))

1989-09-01

43

Reactivation of death receptor 4 (DR4) expression sensitizes medulloblastoma cell lines to TRAIL  

Microsoft Academic Search

Object Apoptosis, a key cellular response to therapeutic agents is often inactivated in tumor cells. In this study, we evaluated\\u000a the expression of the tumor necrosis family of death receptors, DR4 and DR5, in medulloblastoma tumor samples and cell lines to determine if epigenetic modulation of gene expression could sensitize\\u000a tumor cell lines to TRAIL-mediated apoptosis. Methods Human medulloblastoma samples

Dolly G. Aguilera; Chandra M. Das; Neeta D. Sinnappah-Kang; Celine Joyce; Pete H. Taylor; Sijin Wen; Martin Hasselblatt; Werner Paulus; Greg Fuller; Johannes E. Wolff; Vidya Gopalakrishnan

2009-01-01

44

Kinetic decoupling of WIMPs: analytic expressions  

E-print Network

We present a general expression for the values of the average kinetic energy and of the temperature of kinetic decoupling of a WIMP, valid for any cosmological model. We show an example of the usage of our solution when the Hubble rate has a power-law dependence on temperature, and we show results for the specific cases of kination cosmology and low- temperature reheating cosmology.

Visinelli, Luca

2015-01-01

45

Comparative sensitivity of three mosquito cell lines for isolation of dengue viruses*  

PubMed Central

Comparative studies were carried out on three mosquito cell lines (C6/36 clone of Aedes albopictus, AP-61 from A. pseudoscutellaris, and TRA-284 from Toxorhynchites amboinensis) to determine their sensitivity to dengue virus isolation, growth, and handling characteristics for immunofluorescent testing. Virus isolation rates from human sera were the highest in the TRA-284-SF (a line adapted to serum-free medium), followed by the TRA-284 parental line and AP-61. Virus isolation was the lowest in the C6/36 line. All 3 cell lines were comparable in terms of ease of handling, but C6/36 cells were preferable for detecting infected cells by the direct fluorescent antibody test (DFAT) because of frequent cell clumping in the AP-61 and TRA-284 lines. Early detection of viral antigen of all 4 serotypes in the infected cells by DFAT was dependent upon the virus titre in the serum. The AP-61 and TRA-284-SF cells were the best for early detection and identification of viral antigen. Similarly, both AP-61 and TRA-284 cells were more resistant than C6/36 cells to toxic effects of human sera. Based on the economy of using the serum-free medium, their higher sensitivity for dengue virus isolation, and their ease of handling, it is recommended that the TRA-284-SF cell line be used for routine dengue virus isolation in laboratories with cell culture capability. PMID:2861916

Kuno, G.; Gubler, D. J.; Vélez, M.; Oliver, A.

1985-01-01

46

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

E-print Network

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...

Bhamidi Lakshmi, Surya Kameshwari Priyanka

2012-08-31

47

3-Bromopyruvate induces necrotic cell death in sensitive melanoma cell lines  

SciTech Connect

Clinicians successfully utilize high uptake of radiolabeled glucose via PET scanning to localize metastases in melanoma patients. To take advantage of this altered metabolome, 3-bromopyruvate (BrPA) was used to overcome the notorious resistance of melanoma to cell death. Using four melanoma cell lines, BrPA triggered caspase independent necrosis in two lines, whilst the other two lines were resistant to killing. Mechanistically, sensitive cells differed from resistant cells by; constitutively lower levels of glutathione, reduction of glutathione by BrPA only in sensitive cells; increased superoxide anion reactive oxygen species, loss of outer mitochondrial membrane permeability, and rapid ATP depletion. Sensitive cell killing was blocked by N-acetylcysteine or glutathione. When glutathione levels were reduced in resistant cell lines, they became sensitive to killing by BrPA. Taken together, these results identify a metabolic-based Achilles' heel in melanoma cells to be exploited by use of BrPA. Future pre-clinical and clinical trials are warranted to translate these results into improved patient care for individuals suffering from metastatic melanoma.

Qin, J.-Z.; Xin, H. [Oncology Institute, Cardinal Bernardin Cancer Center, Loyola University of Chicago Medical Center (United States)] [Oncology Institute, Cardinal Bernardin Cancer Center, Loyola University of Chicago Medical Center (United States); Nickoloff, B.J., E-mail: bnickol@lumc.edu [Oncology Institute, Cardinal Bernardin Cancer Center, Loyola University of Chicago Medical Center (United States)

2010-05-28

48

BBN and the CMB constrain light, electromagnetically coupled WIMPs  

NASA Astrophysics Data System (ADS)

In the presence of a light weakly interacting massive particle (WIMP; m??30 MeV), there are degeneracies among the nature of the WIMP (fermion or boson), its couplings to the standard-model particles (electromagnetic or to neutrinos only), the WIMP mass m?, and the number of equivalent neutrinos beyond the standard model ?N? (including possible sterile neutrinos). These degeneracies cannot be broken by the cosmic microwave background (CMB) constraint on the effective number of neutrinos, Neff. However, big bang nucleosynthesis (BBN) is affected by the presence of a light WIMP and equivalent neutrinos, so the combination of BBN and CMB constraints can help to break some of these degeneracies. Here, the BBN predictions for the primordial abundances of deuterium and He4 (along with He3 and Li7) in the presence of a light WIMP and equivalent neutrinos are explored, and the most recent estimates of their observationally determined relic abundances are used to limit the light-WIMP mass, the number of equivalent neutrinos, and the present Universe baryon density (?Bh2). These constraints are explored here for Majorana and Dirac fermion WIMPs, as well as for real and complex scalar WIMPs that couple to electrons, positrons, and photons. In a separate paper, this analysis is repeated for WIMPs that couple only to the standard-model neutrinos, and the constraints for the two cases are contrasted. In the absence of a light WIMP, but allowing for ?N? equivalent neutrinos, the combined BBN and CMB constraints favor Neff=3.46±0.17, ?Bh2=0.0224±0.0003, and ?N?=0.40±0.17 (all at a 68% C.L.). In this case, standard BBN (?N?=0) is disfavored at ˜98% confidence, and the presence of one sterile neutrino (?N?=1) is disfavored at ?99% confidence. Allowing for a light WIMP and ?N? equivalent neutrinos together, the combined BBN and CMB data provide lower limits to the WIMP masses (m??0.5-5 MeV) that depend on the nature of the WIMP, favor m?˜8 MeV (with small variations depending on the WIMP type) slightly over standard BBN, and loosen the constraints on the allowed number of equivalent neutrinos, ?N?=0.65-0.35+0.46. As a result, while ?N?=0 is still disfavored at ˜95% confidence when there is a light WIMP, ?N?=1 is now allowed.

Nollett, Kenneth M.; Steigman, Gary

2014-04-01

49

Azelaic acid was sensitizing effect in the chemotherapeutic treatment of several melanoma cell lines.  

PubMed

Chemotherapy for melanoma results in low response and must be reinforced with sensitizer compounds. We believed that azelaic acid (AZA) could modulate melanomas' resistance to antineoplastics. Therefore we tried to compare in vitro treatment with antineoplastics alone versus AZA treatment followed by antineoplastics. We carried out MTT assays to evaluate the cytotoxicity of melphalan, lomustine (CCNU), fotemustine, and 4-Hydroxyanisole (4-HA) on three melanoma lines (B16F10, SK-MEL-28, and SK-MEL-1), and the modulating effect of pretreatment with AZA (1 mM). AZA showed a dose-dependent antineoplastic activity on the three lines. Melphalan was the most active drug followed by CCNU, fotemustine, and 4-HA. The most sensitive line was B16F10 and the least sensitive was SK-meL-1. Previous treatment with AZA of B16F10 reinforced the effect of melphalan (2.5 times), CCNU (10 times), and fotemustine (14 times); whereas for SK-MEL-28 and SK-MEL-1, only the cytotoxicity of CCNU and fotemustine increased. An antagonist effect was produced by 4-HA on all three lines. We concluded that AZA enhances in vitro cytotoxicity of CCNU and fotemustine. PMID:9125756

Rodriguez-Vicente, J; Vicente-Ortega, V; Canteras-Jordana

1996-12-01

50

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

PubMed Central

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

2013-01-01

51

A quantitative proteomics-based signature of platinum sensitivity in ovarian cancer cell lines.  

PubMed

Although DNA encodes the molecular instructions that underlie the control of cell function, it is the proteins that are primarily responsible for implementing those instructions. Therefore quantitative analyses of the proteome would be expected to yield insights into important candidates for the detection and treatment of disease. We present an iTRAQ (isobaric tag for relative and absolute quantification)-based proteomic analysis of ten ovarian cancer cell lines and two normal ovarian surface epithelial cell lines. We profiled the abundance of 2659 cellular proteins of which 1273 were common to all 12 cell lines. Of the 1273, 75 proteins exhibited elevated expression and 164 proteins had diminished expression in the cancerous cells compared with the normal cell lines. The iTRAQ expression profiles allowed us to segregate cell lines based upon sensitivity and resistance to carboplatin. Importantly, we observed no substantial correlation between protein abundance and RNA expression or epigenetic DNA methylation data. Furthermore, we could not discriminate between sensitivity and resistance to carboplatin on the basis of RNA expression and DNA methylation data alone. The present study illustrates the importance of proteomics-based discovery for defining the basis for the carboplatin response in ovarian cancer and highlights candidate proteins, particularly involved in cellular redox regulation, homologous recombination and DNA damage repair, which otherwise could not have been predicted from whole genome and expression data sources alone. PMID:25406946

Fan, Gaofeng; Wrzeszczynski, Kazimierz O; Fu, Cexiong; Su, Gang; Pappin, Darryl J; Lucito, Robert; Tonks, Nicholas K

2015-02-01

52

Wearable Line-of-Sight Detection System Utilizing Dye-Sensitized Photovoltaic Devices  

Microsoft Academic Search

This paper demonstrates the preliminary results of our novel line-of-sight (LOS) detection systems utilizing dye-sensitized photovoltaic devices. Detection of LOS has a variety of applications, such as communication tools for elderly or disabled people, assisting drivers, effective location of traffic signs, etc. To realize such promising applications, the LOS detecting system that does not restrict users' activities and is free

T. Shigeoka; N. Miki

2007-01-01

53

New class of biological detectors for WIMPs  

NASA Astrophysics Data System (ADS)

Weakly Interacting Massive Particles (WIMPs) may constitute a large fraction of the matter in the Universe. There are excess events in the data of DAMA/LIBRA, CoGeNT, CRESST-II, and recently CDMS-Si, which could be consistent with WIMP masses of approximately 10 GeV/c2. However, for MDM > 10 GeV/c2 null results of the CDMS-Ge, XENON, and LUX detectors may be in tension with the potential detections for certain dark matter scenarios and assuming a certain light response. We propose the use of a new class of biological dark matter (DM) detectors to further examine this light dark matter hypothesis, taking advantage of new signatures with low atomic number targets. Two types of biological DM detectors are discussed here: DNA-based detectors and enzymatic reactions (ER) based detectors. In the case of DNA-based detectors, we discuss a new implementation. In the case of ER detectors, there are four crucial phases of the detection process: (a) change of state due to energy deposited by a particle; (b) amplification due to the release of energy derived from the action of an enzyme on its substrate; (c) sustainable but nonexplosive enzymatic reaction; (d) self-termination due to the denaturation of the enzyme, when the temperature is raised. This paper provides information of how to design as well as optimize these four processes.

Drukier, A. K.; Cantor, Ch.; Chonofsky, M.; Church, G. M.; Fagaly, R. L.; Freese, K.; Lopez, A.; Sano, T.; Savage, C.; Wong, W. P.

2014-07-01

54

Isolation and preliminary characterization of u. v. -sensitive mutants from the human cell line EUE  

SciTech Connect

Five u.v. light-sensitive clones were isolated in the EUE cell line by means of a modified form of the original 5-bromodeoxyuridine (BUdR)-light method worked out by Puck and Kao for the isolation of nutritional mutants. A cell population was mutagenized with ethylmethanesulfonate. After the expression time, cells were u.v.-irradiated and incubated with BUdR to label excision patches in repair proficient cells. A subsequent irradiation with black light caused DNA strand breakage in BUdR-substituted cells. During BUdR treatment, hydroxyurea and a fluorochrome (Hoechst 33258) were added to possibly enhance the analogue incorporation into DNA and to increase the photolability of BUdR containing sequences, respectively. Out of 192 colonies selected with this method, 38 were isolated and tested for their u.v.-sensitivity. Five of them showed significant, reproducible differences with respect to the parental line. As a partial characterization, the five u.v.-sensitive clones were assayed for unscheduled (/sup 3/H)thymidine incorporation after exposure to u.v. light, by means of liquid scintillation spectrometry and autoradiography. In all clones. DNA repair synthesis was significantly decreased with respect to the parental line.

Fiorio, R.; Frosina, G.; Abbondandolo, A.

1983-01-01

55

Differential sensitivities to lactate transport inhibitors of breast cancer cell lines.  

PubMed

The tumour microenvironment is known to be acidic due to high glycolytic rates of tumour cells. Monocarboxylate transporters (MCTs) play a role in extracellular acidification, which is widely known to be involved in tumour progression. Recently, we have described the upregulation of MCT1 in breast carcinomas and its association with poor prognostic variables. Thus, we aimed to evaluate the effect of lactate transport inhibition in human breast cancer cell lines. The effects of ?-cyano-4-hydroxycinnamate, quercetin and lonidamine on cell viability, metabolism, proliferation, apoptosis, migration and invasion were assessed in a panel of different breast cancer cell lines. MCT1, MCT4 and CD147 were differently expressed among the breast cancer cell lines and, as expected, different sensitivities were observed for the three inhibitors. Interestingly, in the most sensitive cell lines, lactate transport inhibition induced a decrease in cell proliferation, migration and invasion, as well as an increase in cell death. Results were validated by silencing MCT1 expression using siRNA. The results obtained here support targeting of lactate transport as a strategy to treat breast cancer, with a special emphasis on the basal-like subtype, which so far does not have a specific molecular therapy. PMID:24174370

Morais-Santos, Filipa; Miranda-Gonçalves, Vera; Pinheiro, Sílvia; Vieira, André F; Paredes, Joana; Schmitt, Fernando C; Baltazar, Fátima; Pinheiro, Céline

2014-02-01

56

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

PubMed

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

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

2015-02-01

57

Isolation and characterization of a variant myoblast cell line that is temperature sensitive for differentiation.  

PubMed Central

A new variant rat myogenic cell line, ts485, was isolated by subcloning the cell line ts3b2 (H. T. Nguyen, R. M. Medford, and B. Nadal-Ginard, Cell 34:281-293, 1983). Unlike the progenitor cell line, ts485 was thermosensitive for differentiation. Experiments with conditioned medium suggested that diffusible extracellular factors were not involved in dictating the differential phenotypes of ts485 cells cultured at the permissive and nonpermissive temperatures. Temperature shift experiments performed on cultures of ts485 cells indicated that the temperature-sensitive lesion was in a factor active during the growth phase and required to trigger a cascade of events leading to terminal differentiation. Images PMID:3043175

Akhurst, R J; Flavin, N B; Worden, J

1988-01-01

58

Nuclear structure aspects of spin-independent WIMP scattering off xenon  

E-print Network

We study the structure factors for spin-independent WIMP scattering off xenon based on state-of-the-art large-scale shell-model calculations, which are shown to yield a good spectroscopic description of all experimentally relevant isotopes. Our results are based on the leading scalar one-body currents only. At this level and for the momentum transfers relevant to direct dark matter detection, the structure factors are in very good agreement with the phenomenological Helm form factors used to give experimental limits for WIMP-nucleon cross sections. In contrast to spin-dependent WIMP scattering, the spin-independent channel, at the one-body level, is less sensitive to nuclear structure details. In addition, we explicitly show that the structure factors for inelastic scattering are suppressed by ~ 10^{-4} compared to the coherent elastic scattering response. This implies that the detection of inelastic scattering will be able to discriminate clearly between spin-independent and spin-dependent scattering. Finally, we provide fits for all calculated structure factors.

L. Vietze; P. Klos; J. Menéndez; W. C. Haxton; A. Schwenk

2014-12-05

59

Nuclear structure aspects of spin-independent WIMP scattering off xenon  

E-print Network

We study the structure factors for spin-independent WIMP scattering off xenon based on state-of-the-art large-scale shell-model calculations, which are shown to yield a good spectroscopic description of all experimentally relevant isotopes. Our results are based on the leading scalar one-body currents only. At this level and for the momentum transfers relevant to direct dark matter detection, the structure factors are in very good agreement with the phenomenological Helm form factors used to give experimental limits for WIMP-nucleon cross sections. In contrast to spin-dependent WIMP scattering, the spin-independent channel, at the one-body level, is less sensitive to nuclear structure details. In addition, we explicitly show that the structure factors for inelastic scattering are suppressed by ~ 10^{-4} compared to the coherent elastic scattering response. This implies that the detection of inelastic scattering will be able to discriminate clearly between spin-independent and spin-dependent scattering. Finall...

Vietze, L; Menéndez, J; Haxton, W C; Schwenk, A

2014-01-01

60

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

E-print Network

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 [KPPLS2014], 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.

David Keitel; Reinhard Prix

2014-09-09

61

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

NASA Astrophysics Data System (ADS)

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 Phys. Rev. D 89 064023), a Bayesian model selection approach was used to derive line-robust detection statistics for CW signals, generalizing both the F-statistic and the F-statistic consistency veto technique and yielding improved performance in line-affected data. Here we investigate a generalization 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.

Keitel, David; Prix, Reinhard

2015-02-01

62

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

E-print Network

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.

David Keitel; Reinhard Prix

2015-01-16

63

The moment of truth for WIMP Dark Matter  

E-print Network

We know that dark matter constitutes 85% of all the matter in the Universe, but we do not know of what it is made. Amongst the many Dark Matter candidates proposed, WIMPs (weakly interacting massive particles) occupy a special place, as they arise naturally from well motivated extensions of the standard model of particle physics. With the advent of the Large Hadron Collider at CERN, and a new generation of astroparticle experiments, the moment of truth has come for WIMPs: either we will discover them in the next five to ten years, or we will witness the inevitable decline of WIMP paradigm.

Gianfranco Bertone

2010-11-15

64

High-Sensitivity Broadband Spectral Line Surveys of Star Forming Regions with the CSO  

NASA Astrophysics Data System (ADS)

Spectral line surveys are powerful tools for astrochemistry because they circumvent the one-line-at-a-time approach that has historically hampered new molecule identification. Until recently, line surveys were typically motivated by the need to characterize the major components of interstellar clouds, i.e. the so-called ``interstellar weeds." Previously reported surveys therefore often do not provide the sensitivity levels required for identification of new molecules with weak spectral signatures. The goal of our recent observations with the Caltech Submillimeter Observatory (CSO) is to shift the focus of spectral line surveys away from the interstellar weeds and toward detection of new interstellar molecules. We have obtained broadband, high-sensitivity spectra toward several star forming regions with the new ?=1 mm receiver at the CSO. When used with the facility AOS's, this receiver affords 4 GHz of DSB spectral coverage for each LO setting. We have employed a stepped frequency-offset approach to allow for full spectral deconvolution. The noise temperature of this receiver is ˜100 K (SSB), resulting in spectral RMS levels that far surpass those reported in similar previous studies. Our initial observations targeted the Orion and Sagittarius B2(N-LMH) hot cores and a collection of Class 0 sources. We have now completed our coverage of these initial targets, and upcoming observing time has been allocated for similar surveys of the hot cores W51 e1/e2 and G34.3+0.2. We have fully deconvolved 28 GHz of spectra on Orion with RMS levels of T_A^*˜20 mK. Our coverage on Sgr was more limited, yielding ˜8 GHz of fully-deconvolved spectra to the same RMS level. In this talk, we will report on the data analysis for the Orion and Sgr observations, discuss our progress on line surveys of other star-forming regions, and discuss the implications of these results in the context of recent hot core astrochemical models.

Weaver, Susanna L. Widicus; Sumner, Matthew C.; Rice, Frank; Zmuidzinas, Jonas; Blake, Geoffrey A.

2009-06-01

65

ERCC1 mutations in UV-sensitive Chinese hamster ovary (CHO) cell lines.  

PubMed

In mammalian nucleotide excision repair (NER), the ERCC1 protein is known to act as a complex with ERCC4 (XPF) protein, which is necessary for stability of ERCC1, and this complex introduces an incision on the 5' side of a damaged site in DNA. ERCC1 also binds to XPA protein to make a large protein complex at the site of DNA damage. Since no human disease associated with ERCC1 has been identified, Chinese hamster ovary (CHO) cell lines defective in ERCC1 are a unique source for characterization of ERCC1 deficiency in mammalian cells. We have isolated the full length ERCC1 cDNA from a wild-type CHO cell line and analyzed mutations in two CHO cell lines which fall into complementation group 1 of UV-sensitive rodent cell lines. One cell line, 43-3B, has a missense mutation at the 98th residue (V98E). The in vitro translated mutant protein of 43-3B is unable to bind to XPA protein. Although the mutant protein is able to bind to XPF protein in vitro, the mutant protein is highly unstable in vivo. These defects presumably cause the NER deficiency of this cell line. Another mutant, UV-4, has an insertion mutation in the middle of the coding sequence, resulting in a truncated protein due to a nonsense codon arising from the frameshift. Thus, these two mutant cell lines are deficient in the function of the ERCC1 gene for NER. PMID:9653453

Hayashi, T; Takao, M; Tanaka, K; Yasui, A

1998-06-01

66

Relationships between resistance to cisplatin and antifolates in sensitive and resistant tumour cell lines.  

PubMed

Possible relationships between tumour resistance to cisplatin and the folate-based thymidylate synthase (TS) inhibitors, CB3717 and ZD1694 (tomudex), have been investigated in vitro using a panel of tumour cell lines (predominantly human ovarian), either parental or possessing acquired resistance to cisplatin or ZD1694. Across eight parent human tumour cell lines, ZD1694 was the most potent drug (mean IC50 of 1.9 x 10(-8) M), being over 250 times as potent as its prototype CB3717 (mean IC50 of 4.8 x 10(-6) M). In five pairs of acquired cisplatin-resistant human tumour cell lines (three ovarian, one cervical and one testicular) which encompass all of the main known mechanisms of platinum drug resistance, ZD1694, CB3717 and the DHFR inhibitor, methotrexate, all exhibited non-cross-resistance. The cervical line, HX/155cisR, showed collateral sensitivity to ZD1694, CB3717, 5-fluorouracil (FUra) and fluorodeoxyuridine (FdUrd). One cell line, A2780cisR, showed a low level of cross-resistance to FUra (resistance factor, RF, of 1.5) and FdUrd (RF of 3.8). A2780cisR, in common with two other cisplatin-resistant lines, did not possess elevated TS activity compared with its parent. Cisplatin retained activity in four acquired ZD1694-resistant cell lines (encompassing reduced folate transport, elevated TS and defective polyglutamation mechanisms of resistance). Furthermore, combinations of ZD1694 with each of the platinum-based drugs, cisplatin, carboplatin and the recently introduced orally administrable, JM216, all showed additive growth inhibitory effects by median effect analysis. These data suggest that the tumour inhibitory properties of the recently introduced highly potent TS inhibitor, ZD1694, and cisplatin, and, moreover, their respective mechanisms of resistance, do not overlap. Therefore, these drugs may be considered for combination in the clinic. PMID:7646933

Kelland, L R; Kimbell, R; Hardcastle, A; Aherne, G W; Jackman, A L

1995-06-01

67

Variable intrinsic sensitivity of human tumor cell lines to raltitrexed (Tomudex) and folylpolyglutamate synthetase activity.  

PubMed

The cytotoxic effects of Tomudex (TX) were investigated on a panel of 15 human tumor cell lines expressing a spontaneous sensitivity to the tested agent. We determined the basal cellular amount of relevant cellular factors potentially related to the cytotoxic efficacy of or resistance to TX. We selected thymidylate synthase (TS) as the target for TX, basal reduced folates (RF), because RF may compete with TX for a common site on the TS molecule. We also tested folylpolyglutamate synthetase (FPGS) because this is the enzyme which transforms the drug into its active polyglutamated form. Results were as follows. There was a wide inter-cell line variability in IC50 values for TX and there were marked differences between cell lines for all tested biochemical parameters. No link was observed between basal cellular TS activity and TX cytotoxic efficacy. There was an inverse relationship between reduced folate cellular content and TX IC50 values; this relationship did not, however, reach statistical significance. The only significant relationship was found between basal cellular FPGS activity and TX IC50r = -0.56, p = 0.03. Tumor cells with a relatively high FPGS activity were more sensitive to TX cytotoxic effects and vice versa. Along with previous results which showed that acquired resistance to TX is accompanied by a decrease in FPGS activity, the present data are strongly indicative of a prominent role played by FPGS activity in the intrinsic sensitivity to TX. Means to up-regulate FPGS activity with pharmacological or tumor-specific genetic approaches are recommended so as to optimize TX antitumor activity. PMID:10477170

Chéradame, S; Chazal, M; Fischel, J L; Formento, P; Renée, N; Milano, G

1999-06-01

68

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

NASA Astrophysics Data System (ADS)

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.

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

2007-10-01

69

Measurement and Modeling of Density-Sensitive Lines of Fe XIII in the Extreme Ultraviolet  

SciTech Connect

We present an analysis of the spectral emission of Fe XIII near 200 {angstrom}. High resolution spectra were recorded at two densities ({approx} x 10{sup 11} and {approx} 10{sup 13} cm{sup -3}) in the laboratory and compared to collisional radiative model calculations based on the CHIANTI data base as well as to models using atomic data from distorted-wave and R-matrix calculations. The Fe XIII lines in this wavelength range are sensitive indicators of plasma density below {approx} 10{sup 11} cm{sup -3}. The laboratory data thus test the calculations in the astrophysically high-density limit. Significant differences between the measurements and models were found for several line ratios. Differences in the wavelengths employed in the different models also changed the agreement with the measurements. Best agreement was found in the comparisons with CHIANTI.

Yamamoto, N; Kato, T; Beiersdorfer, P; Lepson, J K

2008-01-17

70

The magnetic sensitivity of the Stokes I Profile of the 15260 A line of Mn I  

SciTech Connect

The near-IR line of Mn I at 15262.7 A has recently been proposed as a new tool for diagnosing the magnetic field strength and magnetic energy density associated with unresolved magnetic structures, due to the enhanced sensitivity of the Stokes I profile. In this paper, the behavior of the line, focusing on the properties of the Stokes I profile, is analyzed in detail with the aid of state-of-the-art magneto-hydrodynamical simulations of the solar surface convection. The line is synthesized taking into account that the splitting and the strength of the Zeeman components have to be calculated under the framework of the Paschen-Back theory via the numerical diagonalization of the total Hamiltonian, including the hyperfine and Zeeman contributions. The peak ratio and separation of the blue and red lobes of the emergent Stokes I profile are shown to be correlated with the magnetic field strength when no smearing is taken into account, while the correlation slightly degrades when diffraction and stray-light contamination is accounted for. We also analyze the dependence of the first two line moments with the magnetic field, showing that the first and second moments can be used to trace the velocity and the magnetic field strength, respectively. This correlation is still maintained for ground-based observations.

Asensio Ramos, A. [Instituto de AstrofIsica de Canarias, 38205, La Laguna, Tenerife (Spain)], E-mail: aasensio@iac.es

2009-01-01

71

DARWIN: dark matter WIMP search with noble liquids  

E-print Network

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.

Laura Baudis; for the DARWIN Consortium

2012-01-11

72

DARWIN: dark matter WIMP search with noble liquids  

E-print Network

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.

Baudis, Laura

2012-01-01

73

Towards an Er-doped Si nanocrystal sensitized waveguide laser the thin line between gain and loss  

E-print Network

and lasers that can be pumped with low-power broadband light sources. Er excitation via Si nanocrystals must1 Towards an Er-doped Si nanocrystal sensitized waveguide laser ­ the thin line between gain

Polman, Albert

74

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

PubMed Central

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.

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

2015-01-01

75

Temperature-sensitive adult liver cell line dependent on glucocorticoid for differentiation.  

PubMed Central

A clonal rat adult hepatocyte cell line (RALA255-10G) was shown to be temperature sensitive (ts) for growth and differentiation. Glucocorticoid was necessary to maintain the maximal levels of differentiated functions in these cells. The RALA255-10G cell line was established by transforming primary adult hepatocytes with simian virus 40 tsA255 virus that is temperature sensitive for maintenance of transformation. At the permissive temperature (33 degrees C), RALA255-10G cells showed characteristics of malignant transformation, synthesized low levels of albumin and transferrin, and contained low levels of functional receptors for glucagon. At the nonpermissive temperature (40 degrees C), these cells regain the normal differentiated phenotype, and the levels of these three hepatic functions were increased. Induction of albumin and transferrin production by RALA255-10G cells at 40 degrees C was shown to be the result of the increase in the biosynthesis of these proteins. Furthermore, the albumin and transferrin produced by these cells were immunologically and electrophoretically indistinguishable from authentic rat albumin and transferrin. Glucocorticoid, which reduced the growth rate and saturation density of RALA255-10G cells at 33 degrees C, was absolutely required by these cells to synthesize albumin at both temperatures. This hormone also enhanced transferrin production and glucagon response. Our data indicate that glucocorticoid hormone is one of the factors that maintain adult hepatocytes in a differentiated state. Images PMID:6877237

Chou, J Y

1983-01-01

76

Identification of Cellular Defect in UVS1, a UV-sensitive Chinese Hamster Ovary Mutant Cell Line  

Microsoft Academic Search

UVS1 is an intermediately UV-sensitive Chinese hamster ovary mutant originally isolated by its hypersensitivity to an anticancer drug, l-((4- amino-2-methyl-5-pyrimidinyl)methyl)-3-(2-chloroethyl)-3-nitrosourea hydrochloride. By cell fusion analysis, UVS1 complemented the UV sen sitivity of the mouse lymphoma cell line US31 from the eighth comple mentation group of UV-sensitive rodent cell lines. By enzyme-linked im- munosorbent assay we found that within 3 h

Masayuki Ninnala; Hiroaki Hata; Tadahiro Shiomi; Tsukasa Matsunaga; Toshio Mori; Osanni Nikaido; Akira Yasui; Atsushi Oikawa

77

BIM induction of apoptosis triggered by EGFR-sensitive and resistance cell lines of non-small-cell lung cancer  

Microsoft Academic Search

We sought to improve the understanding of oncogene-dependent and independent non-small-cell lung cancer (NSCLC), which could\\u000a provide insight into mechanism of sensitivity and\\/or resistance to tyrosine kinase inhibitors or chemotherapeutics. NSCLC\\u000a cell lines with different EGFR genotypes were used in this study; MTT assay and flow cytometry were applied to study the sensitivities\\u000a of these cell lines to gefitinib and

Zhanxia LiSongwen; Songwen Zhou; Ling Zhang; Chunxia Su; Jinqin Hang; Yinmin Zhao; Bo Su; Caicun Zhou

2011-01-01

78

The flinders sensitive line rat model of depression--25 years and still producing.  

PubMed

Approximately 25 years have passed since the first publication suggesting the Flinders sensitive line (FSL) rat as an animal model of depression. At least 6 years of research on these rats was completed before that seminal paper, and there has been a steady stream of publications (130+) over the years. The present review will focus on several issues not previously covered in earlier reviews, summarize the several lines of ongoing investigations, and propose a novel mechanism that accounts for a number of previously unexplained observations. A key observation in the FSL rat relates to the antidepressant (AD)-like effects of known and putative antidepressants. The FSL rat typically exhibits an AD-like effect in behavioral tests for AD-like activity following chronic (14 days) treatment, although some studies have found AD-like effects after fewer days of treatment. In other observations, exaggerated swim test immobility in the FSL rat has been found to have a maternal influence, as shown by cross-fostering studies and observations of maternal behavior; the implications of this finding are still to be determined. Ongoing or recently completed studies have been performed in the laboratories of Marko Diksic of Canada, Aleksander Mathé of Sweden, Gregers Wegener of Denmark, Brian Harvey of South Africa, Paul Pilowsky and Rod Irvine of Australia, and Gal Yadid of Israel. Jennifer Loftis of Portland, Oregon, and Lynette Daws of San Antonio, Texas, have been working with the FSL rats in the United States. A puzzling feature of the FSL rat is its sensitivity to multiple chemicals, and its greater sensitivity to a variety of drugs with different mechanisms of action. It has been recently shown that each of these drugs feeds through G protein-coupled receptors to potassium-gated channels. Thus, an abnormality in the potassium channel could underlie the depressed-like behavior of the FSL rats. PMID:23319547

Overstreet, David H; Wegener, Gregers

2013-01-01

79

Application of Time Projection Chambers with GEMs and Pixels to WIMP Searches and Fast Neutron Detection  

NASA Astrophysics Data System (ADS)

We present work on the detection of neutral particles via nuclear recoils in gas-?lled Time Projection Chambers (TPCs). We employ Gas Electron Multipliers (GEMs) to amplify the signal and silicon pixel electronics to detect the avalanche charge. These technologies allow ionization in the target gas to be detected with low noise, improved position and time resolution, and high efficiency. We review experimental results obtained in previous years, and report on ongoing simulation studies and construction of the ?rst prototype at the University of Hawaii. We also present prospects of using such detectors to perform direction-sensitive searches for WIMP dark matter and fast neutron from ?ssionable material.

Yamaoka, J.; Feng, H.; Garcia-Sciveres, M.; Jaegle, I.; Kadyk, J.; Nguyen, Y.; Rosen, M.; Ross, S.; Thorpe, T.; Vahsen, S.

80

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

NASA Astrophysics Data System (ADS)

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.

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

81

SYSTEMATIC ASSESSMENT OF ANALYTICAL METHODS FOR DRUG SENSITIVITY PREDICTION FROM CANCER CELL LINE DATA*  

PubMed Central

Large-scale pharmacogenomic screens of cancer cell lines have emerged as an attractive pre-clinical system for identifying tumor genetic subtypes with selective sensitivity to targeted therapeutic strategies. Application of modern machine learning approaches to pharmacogenomic datasets have demonstrated the ability to infer genomic predictors of compound sensitivity. Such modeling approaches entail many analytical design choices; however, a systematic study evaluating the relative performance attributable to each design choice is not yet available. In this work, we evaluated over 110,000 different models, based on a multifactorial experimental design testing systematic combinations of modeling factors within several categories of modeling choices, including: type of algorithm, type of molecular feature data, compound being predicted, method of summarizing compound sensitivity values, and whether predictions are based on discretized or continuous response values. Our results suggest that model input data (type of molecular features and choice of compound) are the primary factors explaining model performance, followed by choice of algorithm. Our results also provide a statistically principled set of recommended modeling guidelines, including: using elastic net or ridge regression with input features from all genomic profiling platforms, most importantly, gene expression features, to predict continuous-valued sensitivity scores summarized using the area under the dose response curve, with pathway targeted compounds most likely to yield the most accurate predictors. In addition, our study provides a publicly available resource of all modeling results, an open source code base, and experimental design for researchers throughout the community to build on our results and assess novel methodologies or applications in related predictive modeling problems. PMID:24297534

Jang, In Sock; Neto, Elias Chaibub; Guinney, Justin; Friend, Stephen H.; Margolin, Adam A.

2014-01-01

82

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

PubMed

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

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

2013-01-01

83

Evaluation of the neutron background in CsI target for WIMP direct detection when using a reactor neutrino detector as a neutron veto system  

NASA Astrophysics Data System (ADS)

A direct Weakly Interacting Massive Particle (WIMP) detector with a neutron veto system is designed to better reject neutrons. An experimental configuration is studied in the present paper: a WIMP detectors with CsI(Na) target is placed inside a reactor neutrino detector. The neutrino detector is used as a neutron veto device. The neutron background for the experimental design has been estimated using the Geant4 simulation. The results show that the neutron background can decrease to O(0.01) events per year per tonne of CsI(Na). We calculate the sensitivity to spin-independent WIMP-nucleon elastic scattering. An exposure of 1 tonne year could reach a cross-section of about 3 pb.

Xu, Ye; Ji, Xiangpan; Li, Haolin; Feng, Yulong

2014-04-01

84

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

SciTech Connect

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.

Tarun, Alvarado; Jecong, Julius; Saloma, Caesar

2005-12-01

85

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

SciTech Connect

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.

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

86

Decreased in vivo ?2 adrenoceptor binding in the Flinders Sensitive Line rat model of depression.  

PubMed

Depression is a debilitating heterogenous disorder and the underlying mechanisms remain elusive. Alterations in monoaminergic neurotransmission, including noradrenergic, have been implicated in the etiology of depression. Although depression is difficult to model in animals, the availability of animal models with face, predictive and construct validity permits more in-depth investigations resulting in a greater understanding of the disease. We investigated the role of noradrenaline (NA) and ?2 adrenoceptors in vivo in a genetic model of depression, the Flinders Sensitive Line (FSL) rat. We determined baseline differences in NA receptor volume of distribution to ?2 adrenoceptors in FSL, in comparison with two routinely used controls, Flinders Resistant Line (FRL) and Sprague-Dawley (SD) rats using positron emission tomography (PET) imaging and the carbon-11 labeled radioligand yohimbine. We demonstrate a 42-47% reduction in the binding of the tracer in the cortex, striatum, cerebellum, thalamus and pons of FSL rats compared to the two control groups. Our results suggest that the behavioral deficits expressed in the FSL depression model are associated with functional over-activity of the NA system. PMID:25576372

Landau, Anne M; Phan, Jenny-Ann; Iversen, Peter; Lillethorup, Thea P; Simonsen, Mette; Wegener, Gregers; Jakobsen, Steen; Doudet, Doris J

2015-04-01

87

Altered neuroendocrine response and gastric dysmotility in the Flinders Sensitive Line rat.  

PubMed

In the search for animal models that can replicate some features of functional dyspepsia (FD) patients, we turned our interest to the Flinders Sensitive Line (FSL) rat. Gastric motility disturbances prevalent in FD patients as well as urine corticosterone and plasma prolactin were measured following buspirone challenge. Flinders Resistant Line (FRL) rat was used as control. The results show that the FSL rats have a disturbed gastric motility, reflected as both an increased gastric accommodation rate and gastric volume during gastric distension as well as a delayed gastric emptying, the latter possibly as a consequence of the former. Lipid administration resulted in a significant increase in maximal gastric volume only in the FRL rats. Both the corticosterone response to buspirone and the 24-h urinary output of corticosterone were normal in FSL rats. Similar to FD patients, the FSL rat showed supersensitivity to buspirone in the increase in prolactin release. Although FSL rats show some features similar to a subset of FD patients, the increased gastric accommodation contrasts to the reduced accommodation often seen in FD patients. Further studies are warranted to determine the relevance of this rat strain as a model for FD. PMID:15787937

Mattsson, H; Arani, Z; Astin, M; Bayati, A; Overstreet, D H; Lehmann, A

2005-04-01

88

Proteomics study of changes in soybean lines resistant and sensitive to Phytophthora sojae  

PubMed Central

Background Phytophthora sojae causes soybean root and stem rot, resulting in an annual loss of 1-2 billion US dollars in soybean production worldwide. A proteomic technique was used to determine the effects on soybean hypocotyls of infection with P. sojae. Results In the present study, 46 differentially expressed proteins were identified in soybean hypocotyls infected with P. sojae, using two-dimensional electrophoresis and matrix-assisted laser desorption/ionization tandem time of flight (MALDI-TOF/TOF). The expression levels of 26 proteins were significantly affected at various time points in the tolerant soybean line, Yudou25, (12 up-regulated and 14 down-regulated). In contrast, in the sensitive soybean line, NG6255, only 20 proteins were significantly affected (11 up-regulated and 9 down-regulated). Among these proteins, 26% were related to energy regulation, 15% to protein destination and storage, 11% to defense against disease, 11% to metabolism, 9% to protein synthesis, 4% to secondary metabolism, and 24% were of unknown function. Conclusion Our study provides important information on the use of proteomic methods for studying protein regulation during plant-oomycete interactions. PMID:21899734

2011-01-01

89

Effects of chemically modified tetracyclines (CMTs) in sensitive, multidrug resistant and apoptosis resistant leukaemia cell lines  

PubMed Central

Recently discovered chemically modified tetracyclines (CMTs) have shown in vitro and in vivo anti-proliferative and anti-tumour activities. Here, we evaluated in vitro the anti-proliferative and apoptotic activity of six different dedimethylamino chemically modified tetracyclines (CMT-1, CMT-3, CMT-5, CMT-6, CMT-7 and CMT-8) in sensitive and multidrug resistant myeloid leukaemia cells (HL60 and HL60R) in vitro. Three of these compounds (CMT-5, CMT-6, CMT-7) showed low cytotoxic activity both in sensitive and in resistant cells, CMT-3 was endowed with a high anti-proliferative activity only in sensitive cells and was moderately effective as apoptosis inducing agent, with an activity similar to that shown by doxycycline. On the contrary, CMT-1 and CMT-8 were very effective as programmed cell death inducing agents. The apoptotic pathway activated by these compounds involved the activation of caspases, especially caspase-9 and, for CMT-1, also the activation of Fas. Interestingly CMT-8, but not CMT-1, was able to induce apoptosis in multidrug resistant HL60R and in Fas-ligand resistant HUT78B1 cell lines. These properties, together with others previously described (e.g. anti-metastatic and anti-osteolytic activities), suggest that CMT-8 may have important applications in the clinical management of cancer. The comparative analysis of structure-activity relationship of CMT-8 and doxycycline suggests that the C-5 hydroxy moiety may play an important role in conferring activity in multidrug resistant cells. These findings appear to support the hypothesis that CMT-8 may represent an interesting lead for the development of a new class of potent apoptosis inducer agents active in multidrug resistant and Fas-ligand resistant malignancies. PMID:11350867

Tolomeo, Manlio; Grimaudo, Stefania; Milano, Salvatore; La Rosa, Marzia; Ferlazzo, Viviana; Di Bella, Gloria; Barbera, Caterina; Simoni, Daniele; D'Agostino, Pietro; Cillari, Enrico

2001-01-01

90

Pancreatic cancer cell lines deficient in argininosuccinate synthetase are sensitive to arginine deprivation by arginine deiminase  

PubMed Central

Eukaryotic cells can synthesize the non-essential amino acid arginine from aspartate and citrulline using the enzyme argininosuccinate synthetase (ASS). It has been observed that ASS is under-expressed in various types of cancers ASS, for which arginine become auxotrophic. Arginine deiminase (ADI) is a prokaryotic enzyme that metabolizes arginine to citrulline and has been found to inhibit melanoma and hepatoma cancer cells deficient of ASS. We tested the hypothesis that pancreatic cancers have low ASS expression and therefore arginine deprivation by ADI will inhibit cell growth. ASS expression was examined in 47 malignant and 20 non-neoplastic pancreatic tissues as well as a panel of human pancreatic cancer cell lines. Arginine deprivation was achieved by treatment with a recombinant form of ADI formulated with polyethylene glycol (PEG-ADI). Effects on caspase activation, cell growth and cell death were examined. Furthermore, the effect of PEG-ADI on the in vivo growth of pancreatic xenografts was examined. Eighty-seven percent of the tumors lacked ASS expression; 5 of 7 cell lines similarly lacked ASS expression. PEG-ADI specifically inhibited growth of those cell lines lacking ASS. PEG-ADI treatment induced caspase activation and induction of apoptosis. PEG-ADI was well tolerated in mice despite complete elimination of plasma arginine; tumor growth was inhibited by ?50%. Reduced expression of ASS occurs in pancreatic cancer and predicts sensitivity to arginine deprivation achieved by PEG-ADI treatment. Therefore, these findings suggest that arginine deprivation by ADI could provide a beneficial strategy for the treatment of pancreatic cancer, a malignancy in which new therapy is desperately needed. PMID:18661517

Bowles, Tawnya L.; Kim, Randie; Galante, Joseph; Parsons, Colin M.; Virudachalam, Subbulakshmi; Kung, Hsing-Jien; Bold, Richard J.

2009-01-01

91

DARWIN: dark matter WIMP search with noble liquids  

E-print Network

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.

Laura Baudis

2010-12-21

92

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

PubMed Central

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

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

2012-01-01

93

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

PubMed Central

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

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

1998-01-01

94

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

NASA Astrophysics Data System (ADS)

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.

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

1990-10-01

95

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

E-print Network

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.

Annika H. G. Peter; Scott Tremaine

2008-06-12

96

TOWARDS AN ER-DOPED SI NANOCRYSTAL SENSITIZED WAVEGUIDE LASER THE THIN LINE BETWEEN GAIN AND LOSS  

E-print Network

to fabricating integrated waveguide amplifiers and lasers that can be pumped with low-power broadband lightTOWARDS AN ER-DOPED SI NANOCRYSTAL SENSITIZED WAVEGUIDE LASER ­ THE THIN LINE BETWEEN GAIN AND LOSS emission of Er ions. This combination promises to enable the fabrication of a broadband pumped integrated

Kik, Pieter

97

The CDF and its sensitivity analysis of stochastic structure with stochastic excitation by advanced stratified line sampling  

NASA Astrophysics Data System (ADS)

For the stochastic structure with stochastic excitation, an advanced stratified line sampling (SLS) method is presented to obtain the cumulative distribution function (CDF) of the structural response and its sensitivity. The advanced stratified line sampling method introduces a set of middle failure subsets firstly. And for each subset, the conventional line sampling can be used to obtain the corresponding value of the response's CDF. At the same time, the sensitivity estimations of each failure subset can also be computed by modifying the important direction and corresponding reliability coefficients. The properties of CDF sensitivity are proved while the performance function is linear with normal random variables. After two simple examples are used to demonstrate the properties of CDF sensitivity and the feasibility of the presented method, the method employed to analyze the CDF and corresponding sensitivity of root bending moment (RBM) responses for the stochastic BAH is wing with gust excitation to a square-edged gust and to a Dryden gust. The results show that the parameters of the second and the fifth order modals exert more influence on the CDF of response than the other ones, and the presented SLS method can more significantly reduce the computational cost compared with Monte Carlo simulation (MCS).

Song, ShuFang; Lu, ZhenZhou; Zhang, WeiWei; Ye, ZhengYin

2013-08-01

98

Vasohibin 2 Decreases the Cisplatin Sensitivity of Hepatocarcinoma Cell Line by Downregulating p53  

PubMed Central

Hepatocellular carcinoma (HCC) is a prevalent problem worldwide. Chemotherapy, especially cisplatin (CDDP)-based systemic chemotherapy, is the best option for advanced liver cancer. However, CDDP resistance is becoming common and hindering the clinical application of CDDP. Meanwhile, no consensus has been reached regarding the chemotherapeutic use of vasohibin 2 (VASH2), which promotes the angiogenesis and proliferation of cancer cells. In this work, a tissue microarray was used to observe VASH2 and its possible role in cancer treatment. Results showed that VASH2 was highly expressed in HCC tissues and was significantly correlated with cancer differentiation. To further investigate the efficacy and mechanism of the combination of VASH2 with anti-cancer drugs in liver cancer cells, we stably built VASH2 overexpression and knockdown cell lines. We found that VASH2 can influence the CDDP sensitivity and that the cell overexpression of VASH2 had a higher cell viability and lower apoptosis rate after CDDP exposure. We also observed that VASH2 overexpression downregulated wild-type p53, as well as suppressed the expression of the pro-apoptotic protein BCL2-associated X protein (Bax) and cleaved caspase-3 (CC-3) after treatment by CDDP. Conversely, the knockdown of VASH2 significantly inhibited these effects. In an in vivo chemosensitivity study, nude mice were subcutaneously injected with tumor cells and received CDDP treatment through intraperitoneal administration every 3 days. We found that VASH2 knockdown markedly limited the tumor growth and enhanced the CDDP toxicity and apoptosis of tumor cells. Western blot analysis revealed that tumor cells with downregulated VASH2 had a higher expression of wild-type p53, Bax, and CC-3 than control cells. Overall, our results indicated the novel roles of VASH2 in the chemoresistance of hepatocarcinoma cells to CDDP and suggested that VASH2 may be a promising anticancer target. PMID:24595063

Han, Bei; Gu, Yuqing; Xue, Xiaofeng; Sun, Jie; Ge, Qianqian; Miao, Yi; Qian, Zhuyin

2014-01-01

99

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

SciTech Connect

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.

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

100

Dye sensitized photovoltaic miniaturized solar cells, used as optical sensors for line of sight detection  

NASA Astrophysics Data System (ADS)

Dye sensitized photovoltaic devices have been studied as transparent and low-cost solar cells. Our group have miniaturized the cells and used them as transparent optical sensors. This paper reports the design and fabrication of the cells and avoids the cross talk among cells, which was found recently and such effect provokes hardware instability. We use these optical sensors as an eye tracking device. The sensor array detects the difference in the intensity of light reflected from the pupil and the sclera and then determines the pupil position. Each sensor consists of two electrodes and electrolyte; hence our device conformed by only four semi-circular shaped sensors on eyeglasses can detect the view angle in both horizontal and vertical directions. Manufacturing process gives us freedom to easily re-arrange, add or remove sensors. In our prior work we had good performance in stand-alone configuration. We used specialized equipment from National Instruments for our measurements. However we found that: A cell is not 100% independent from the others, is affected by the absence or presence of light at the neighbour cells. When our device is connected to other electronic devices (for data processing), all cells have the same voltage among them; therefore, all cells behave the same way when any of them is affected by light. The root cause is, due to all sensors were interconnected via a micro channel and filled with electrolyte, due to its conductive properties, electrolyte does neither need electrodes nor physical paths to conduct electricity, so it creates a liquid wire between sensors, hence the gap between them become inexistent, consequently when our device is connected to other electronic devices, due to this unique channel and by sharing a common electronic ground, this connection provokes the voltage to be the same among all sensors in the array. Our device becomes four separate voltage lines in a parallel circuit. The device was also in short circuit provoked by some overlapping paths, despite that such paths were in different layers and separated by an adhesive film of 100pm thickness, such thickness was not large enough to creates a successful dielectric to isolate the paths.

Cesar, Cortes Torres Carlos; Sampei, Kota; Miho, Ogawa; Masataka, Ozawa; Norihisa, Miki

2014-11-01

101

Polarization-sensitive spectral-domain optical coherence tomography using a multi-line single camera spectrometer.  

PubMed

We describe a polarization sensitive spectral domain optical coherence tomography technique based on a single camera spectrometer that includes a multiplexed custom grating, camera lenses, and a high-speed three-line CCD camera. Two orthogonally polarized beams could be separately taken by two lines of the camera as a result of vertically different incident angles. The system could provide the imaging capabilities of a full camera speed and increased measurable depth. The proposed optical coherence tomography system could make a distinction between the normal muscle and cancerous tissue from the chest of a DSred GFP mouse and the OCT images were compared with those of in vivo confocal microscopy. PMID:21164725

Song, Cheol; Ahn, MyoungKi; Gweon, DaeGab

2010-11-01

102

A DNA repair defect in a radiation-sensitive clone of a human bladder carcinoma cell line.  

PubMed Central

DNA repair was measured in an ionising radiation-sensitive mutant of a human bladder carcinoma cell line. No difference in the rate or extent of double-strand break rejoining was found using the techniques of neutral filter elution and pulsed-field gel electrophoresis. In contrast, significant differences in repair fidelity, measured by plasmid reconstitution, were found. The parent line had a repair fidelity of 84.7% compared with 58.9% for S40b (P = 0.0003). It is suggested that repair fidelity can be an important determinant of radiosensitivity in human tumour cells. PMID:1616851

Powell, S. N.; Whitaker, S. J.; Edwards, S. M.; McMillan, T. J.

1992-01-01

103

The Research of H? Mixed Sensitivity Method for line-of-sight Stabilization for Carrier-Based theodolite  

Microsoft Academic Search

In view of the requirements of isolating disturbances and stabilizing optical axis of Carrier-Based theodolite, A two-axis stabilizated platform system with the rate gyro was designed, The expressions of line-of-sight add-angle velocity begotten by ship-swaying is introduced, The principles of selection of weighting of functions are brought, and adopting H? Mixed Sensitivity Method in the velocity Stabilization-loop.

Cai Li Hua; Gao Hui Bin; Zhang Shu Mei

2010-01-01

104

A fast time-to-digital converter for position-sensitive radiation detectors with delay line readouts  

Microsoft Academic Search

A fast time-to-digital converter (TDC) has been developed for use with position-sensitive radiation detectors having delay line readouts. The device is recommended for detector applications where high position resolution and low distortion are required at high rates. The device has 2 ns time resolution, less than 0.1% differential nonlinearity, and a recovery time of 70 ns. When used with a

Joseph A. Harder

1998-01-01

105

A fast time-to-digital converter for position-sensitive radiation detectors with delay line readouts  

Microsoft Academic Search

A fast time-to-digital converter (TDC) has been developed for use with position-sensitive radiation detectors having delay line readouts. The device is recommended for detector applications where high position resolution and low distortion are required at high rates. The device has 2 ns time resolution, less than 0.1% differential nonlinearity, and a recovery time of 70 ns. When used with a

Joseph A. Harder

1988-01-01

106

An intermediate framework between WIMP, FIMP, and EWIP dark matter  

SciTech Connect

WIMP (Weakly Interacting Massive Particle), FIMP (Feebly interacting Massive Particle) and EWIP (Extremely Weakly Interacting Particle) dark matter are different theoretical frameworks that have been postulated to explain the dark matter. In this paper we examine an intermediate scenario that combines features from these three frameworks. It consists of a weakly interacting particle — à la WIMP — that does not reach thermal equilibrium in the early Universe — à la FIMP — and whose relic density is determined by the reheating temperature of the Universe — à la EWIP. As an example, an explicit realization of this framework, based on the singlet scalar model of dark matter, is analyzed in detail. In particular, the relic density is studied as a function of the parameters of the model, and the new viable region within this intermediate scenario is determined. Finally, it is shown that this alternative framework of dark matter allows for arbitrarily heavy dark matter particles and that it suggests a connection between dark matter and inflation.

Yaguna, Carlos E., E-mail: carlos.yaguna@uni-muenster.de [Institut für Theoretische Physik, Universität Münster, Wilhelm-Klemm-Straße 9, D-48149 Münster (Germany)

2012-02-01

107

Cosmological radio emission induced by WIMP Dark Matter  

SciTech Connect

We present a detailed analysis of the radio synchrotron emission induced by WIMP dark matter annihilations and decays in extragalactic halos. We compute intensity, angular correlation, and source counts and discuss the impact on the expected signals of dark matter clustering, as well as of other astrophysical uncertainties as magnetic fields and spatial diffusion. Bounds on dark matter microscopic properties are then derived, and, depending on the specific set of assumptions, they are competitive with constraints from other indirect dark matter searches. At GHz frequencies, dark matter sources can become a significant fraction of the total number of sources with brightness below the microJansky level. We show that, at this level of fluxes (which are within the reach of the next-generation radio surveys), properties of the faint edge of differential source counts, as well as angular correlation data, can become an important probe for WIMPs.

Fornengo, N.; Regis, M. [Dipartimento di Fisica Teorica, Università di Torino, via P. Giuria 1, I-10125 Torino (Italy); Lineros, R.; Taoso, M., E-mail: fornengo@to.infn.it, E-mail: rlineros@ific.uv.es, E-mail: regis@to.infn.it, E-mail: mtaoso@phas.ubc.ca [IFIC, CSIC-Universidad de Valencia, Ed. Institutos, Apdo. Correos 22085, E-46071 Valencia (Spain)

2012-03-01

108

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

PubMed

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

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

109

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

PubMed Central

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

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

110

Mutation in CSA creates a new photoperiod-sensitive genic male sterile line applicable for hybrid rice seed production.  

PubMed

Rice is a major staple food worldwide. Making hybrid rice has proved to be an effective strategy to significantly increase grain yield. Current hybrid rice technologies rely on male sterile lines and have been used predominantly in indica cultivars. However, intrinsic problems exist in the implementation of these technologies, such as limited germplasms and unpredictable conversions from sterility to fertility in the field. Here, we describe a photoperiod-controlled male sterile line, carbon starved anther (csa), which contains a mutation in an R2R3 MYB transcription regulator of pollen development. This mutation was introduced into indica and japonica rice, and it rendered male sterility under short-day conditions and male fertility under long-day conditions in both lines. Furthermore, F(1) plants of csa and a restorer line JP69 exhibited heterosis (hybrid vigor), suggesting the feasibility of using this mutation to create hybrid rice. The csa-based photoperiod-sensitive male sterile line allows the establishment of a stable two-line hybrid system, which promises to have a significant impact on agriculture. PMID:23256151

Zhang, Hui; Xu, Chenxi; He, Yi; Zong, Jie; Yang, Xijia; Si, Huamin; Sun, Zongxiu; Hu, Jianping; Liang, Wanqi; Zhang, Dabing

2013-01-01

111

Data analysis on XENON100 detector searching for WIMP  

NASA Astrophysics Data System (ADS)

The XENON100 detector is a dual-phase xenon time projection chamber (LXeTPC) installed underground at the Laboratori Nazionali del Gran Sasso (Italy) and used to search for dark matter in the form of weakly interacting massive particles (WIMPs) by simultaneously measuring the scintillation and ionization signals produced by nuclear recoils. The 62 kg LXeTPC is instrumented by 178 PMTs and surrounded by a 99 kg Lxe active veto with 64 PMTs. XENON100 has set the most stringent limits on WIMP-nucleon interaction cross section to date, above 7E-45cm^2 at 90% C.L., and continues to accrue blinded data towards a first robust discovery. We present the analysis techniques developed for the experiment and detail data selection procedures, quality cuts and efficiencies, as well the unblinding procedures for the experiment. Finally the methods for establishing presence of signal or for establishing a limit on interaction cross-section for WIMPs with matter are described.

Rizzo, Alfio

2012-03-01

112

Dark Matter; Modification of f(R) or Wimps Miracle  

E-print Network

The identity of dark matter is one of the key outstanding problems in both particle and astrophysics. In this thesis, I review some candidates of dark matter, especially WIMPs (weakly interacting massive particles) which is one of the best candidate so it is called that WIMPs miracle. In addition of this, there are also some theories of modification of gravity, by changing the law of gravity, it could be possible that the dark matter observations are explained. Until the dark matter particle is detected, there is some room for uncertainty. So we should consider every part of the problem and solve it. Dark matter problem is covering a large area so every possibility is important. So f(R) gravity is also reviewed in this thesis and some theories are considered as a possible solution of dark matter problem. Finally we highlight that, even in the case of WIMPs or another particles solution, f(R) gravity is also can be used for this problem. However, last words will be said by experiments.

A. Övgün

2013-01-23

113

Can WIMP Dark Matter overcome the Nightmare Scenario?  

E-print Network

Even if new physics beyond the Standard Model (SM) indeed exists, the energy scale of new physics might be beyond the reach at the Large Hadron Collider (LHC) and the LHC could find only the Higgs boson but nothing else. This is the so-called "nightmare scenario". On the other hand, the existence of the dark matter has been established from various observations. One of the promising candidates for thermal relic dark matter is a stable and electric charge-neutral Weakly Interacting Massive Particle (WIMP) with the mass below the TeV scale. In the nightmare scenario, we introduce a WIMP dark matter singlet under the SM gauge group, which only couples to the Higgs doublet at the lowest order, and investigate a possibility that such WIMP dark matter can be a clue to overcome the nightmare scenario via various phenomenological tests such as the dark matter relic abundance, the direct detection experiments for the dark matter particle, and the production of the dark matter particle at the LHC.

Shinya Kanemura; Shigeki Matsumoto; Takehiro Nabeshima; Nobuchika Okada

2010-05-31

114

Improved phase sensitivity in spectral domain phase microscopy using line-field illumination and self phase-referencing  

PubMed Central

We report a quantitative phase microscope based on spectral domain optical coherence tomography and line-field illumination. The line illumination allows self phase-referencing method to reject common-mode phase noise. The quantitative phase microscope also features a separate reference arm, permitting the use of high numerical aperture (NA > 1) microscope objectives for high resolution phase measurement at multiple points along the line of illumination. We demonstrate that the path-length sensitivity of the instrument can be as good as 41 pm/Hz, which makes it suitable for nanometer scale study of cell motility. We present the detection of natural motions of cell surface and two-dimensional surface profiling of a HeLa cell. PMID:19550464

Yaqoob, Zahid; Choi, Wonshik; Oh, Seungeun; Lue, Niyom; Park, Yongkeun; Fang-Yen, Christopher; Dasari, Ramachandra R.; Badizadegan, Kamran; Feld, Michael S.

2010-01-01

115

Polarization-sensitive spectral-domain optical coherence tomography using a single line scan camera  

Microsoft Academic Search

Polarization-sensitive optical coherence tomography can be used to measure the birefringence of biological tissue such as the human retina. Previous measurements with a time-domain polarization-sensitive optical coherence tomography system revealed that the birefringence of the human retinal nerve fiber layer is not constant, but varies as a function of location around the optic nerve head. Here we present a spectral-domain

Barry Cense; Mircea Mujat; Teresa C. Chen; B. H. Park; Johannes F. de Boer

2007-01-01

116

Relationships between resistance to cisplatin and antifolates in sensitive and resistant tumour cell lines  

Microsoft Academic Search

Possible relationships between tumour resistance to cisplatin and the folate-based thymidylate synthase (TS) inhibitors, CB3717 and ZD1694 (tomudex), have been investigated in vitro using a panel of tumour cell lines (predominantly human ovarian), either parental or possessing acquired resistance to cisplatin or ZD1694. Across eight parent human tumour cell lines, ZD1694 was the most potent drug (mean ic50 of 1.9

L. R. Kelland; R. Kimbell; A. Hardcastle; G. W. Aherne; A. L. Jackman

1995-01-01

117

In vivo and in vitro chemotherapy sensitivity testing for human kidney tumor lines: a comparative study  

SciTech Connect

In vivo and in vitro chemosensitivity testing has been applied to kidney carcinoma tumor lines. Serially transplantable tumors were implanted subcutaneously in nude mice and the animals were treated with cytostatic drugs. The results of this in vivo assay were compared with the results obtained with the subrenal capsule assay, the DNA precursor assay (/sup 3/H-thymidine), and the colony-formation assay, utilizing the same tumor line in each case. Higher rates of resistant tumors were found in the in vivo assays than in the in vitro assays. The SRC assay and the DNA assay had the highest predictive value, as judged from comparison with the results obtained with the source tumor (human kidney carcinoma tumor line).

Kurth, K.H.; Romijn, J.C.; Kappendijk, M.; Weissglas, M.G.; van Dongen, J.W.

1988-01-01

118

Effect of Berry Extracts and Bioactive Compounds on Fulvestrant (ICI 182,780) Sensitive and Resistant Cell Lines  

PubMed Central

Fulvestrant (ICI 182,780; ICI) is approved for the treatment of advanced metastatic breast cancer that is unresponsive to other endocrine therapies. Berries are frequently consumed for their antioxidant, anti-inflammatory, and anticancer potential. In this study, we tested the efficacy of two berry extracts (Jamun-EJAE and red raspberry-RRE) and their bioactive compounds (Delphinidin-Del and Ellagic acid-EA) to inhibit cell proliferation with or without a sublethal dose of ICI in various breast cancer cell lines. ICI-sensitive (LCC1, ZR75-1, and BT474) and -resistant (LCC9, ZR75-1R) cells were subjected to treatment with berry extracts alone (0.1–100??g/mL) or with a sub-lethal dose of ICI (sensitive; 1??M for resistant cells). Extracts and Del enhanced the effect of ICI in sensitive ZR75-1 and BT474 cells primarily in an additive fashion (measured by relative index (RI)~1). In ZR75-1R cells, both EJAE and RRE synergistically enhanced the effects of ICI (15–50%; P < 0.05; RI > 1). EA, in doses tested, did not have any significant effects on any of the cell lines. Finally, we found that the extracts were more effective at lower, physiologically relevant concentrations than at higher experimental doses. PMID:23346406

Woode, Denzel R.; Aiyer, Harini S.; Sie, Nicole; Zwart, Alan L.; Li, Liya; Seeram, Navindra P.; Clarke, Robert

2012-01-01

119

OZONE SENSITIVE AND RESISTANT LINES OF SNAP BEAN. I. PHOTOSYNTHESIS AND CHLOROPHYLL FLUORESCENCE  

Technology Transfer Automated Retrieval System (TEKTRAN)

Widespread areas of crop production are at risk for damage at ambient ozone (O3) concentrations. Past research has not determined the plant mechanisms that cause differences in O3 sensitivity. Therefore, a study was undertaken to examine the effects of O3 on three snap bean (Phaseolus vulgaris) ge...

120

TERRA Expression Levels Do Not Correlate with Telomere Length and Radiation Sensitivity in Human Cancer Cell Lines  

PubMed Central

Mammalian telomeres are transcribed into long non-coding telomeric repeat-containing RNA (TERRA) molecules that seem to play a role in the maintenance of telomere stability. In human cells, CpG-island promoters drive TERRA transcription and are regulated by methylation. It was suggested that the amount of TERRA may be related to telomere length. To test this hypothesis we measured telomere length and TERRA levels in single clones isolated from five human cell lines: HeLa (cervical carcinoma), BRC-230 (breast cancer), AKG and GK2 (gastric cancers), and GM847 (SV40 immortalized skin fibroblasts). However, these two parameters did not correlate with each other. Moreover, cell survival to ?-rays did not show a significant variation among the clones, suggesting that, in this cellular system, the intra-population variability in telomere length and TERRA levels does not influence sensitivity to ionizing radiation. This conclusion was supported by the observation that in a cell line in which telomeres were greatly elongated by the ectopic expression of telomerase, TERRA expression levels and radiation sensitivity were similar to the parental HeLa cell line. PMID:23717814

Smirnova, Alexandra; Gamba, Riccardo; Khoriauli, Lela; Vitelli, Valerio; Nergadze, Solomon G.; Giulotto, Elena

2013-01-01

121

Collateral sensitivity to cold stress and differential BCL-2 family expression in new daunomycin-resistant lymphoblastoid cell lines.  

PubMed

The acquisition of a multidrug-resistant (MDR) phenotype by tumor cells is one of the main causes of chemotherapy failure in cancer, and, usually, is due to the increased expression of P-glycoprotein (MDR-1, P-gp, ABCB1), a pump that expels chemotherapeutics from the cell and/or regulates apoptosis. Thus, it is fundamental to find drugs or stress stimuli with a capacity to induce apoptosis in such cells and to identify the mechanisms involved. We address this matter in human cells and establish new daunomycin (DNM)-resistant cell lines (IM-9R) by exposing the parental lymphoblastic cells (IM-9) to increasing doses of the anti-neoplastic drug, daunomycin. The resistance level of IM-9R cell lines, MDR-1 expression and functionality, collateral sensitivity and Bcl-2 and caspases protein expression are analyzed. As a result, we show for the first time that, unlike the parental cells, human lymphoblastic resistant cells exhibit collateral sensitivity to cold stress, confirming that this phenomenon is not exclusive to murine leukemic cells, but a broader one associated with the acquisition of drug resistance. Furthermore, the new resistant cell lines undergo a significant increase in active caspase-3 and -9 levels and drastic changes in Bcl-2 family protein expression during the process of MDR phenotype acquisition. PMID:25498972

Cerezo, David; Cánovas, Manuel; García-Peñarrubia, Pilar; Martín-Orozco, Elena

2015-02-01

122

DIFFERENTIAL CYTOTOXIC SENSITIVITY IN MOUSE AND HUMAN CELL LINES EXPOSED TO ORGANOPHOSPHATE INSECTICIDES  

EPA Science Inventory

Cell lines were used to examine the differential interspecies response (i.e., species selectivity) to organophosphates (OPs). aseline activities of the major target esterase i.e., cholinesterase (ChE), carboxylesterase (CbxE), neurotoxic esterase (NTE) were assayed in mouse and v...

123

Wearable Line-Of-Sight Detection System Using Dye-Sensitized Photovoltaic Devices  

Microsoft Academic Search

Detection of line-of-sight (LOS) has a variety of applications, such as communication tools for elderly or disabled people, assisting drivers, and effective location of traffic signs. To realize such promising applications, the LOS detecting system that does not restrict users' activities and is free from mental stress from the equipment is strongly demanded. In this paper, we propose a novel

T. Shigeoka; N. Miki

2007-01-01

124

Hybridization approach to in-line and off-axis (electron) holography for superior resolution and phase sensitivity  

NASA Astrophysics Data System (ADS)

Holography - originally developed for correcting spherical aberration in transmission electron microscopes - is now used in a wide range of disciplines that involve the propagation of waves, including light optics, electron microscopy, acoustics and seismology. In electron microscopy, the two primary modes of holography are Gabor's original in-line setup and an off-axis approach that was developed subsequently. These two techniques are highly complementary, offering superior phase sensitivity at high and low spatial resolution, respectively. All previous investigations have focused on improving each method individually. Here, we show how the two approaches can be combined in a synergetic fashion to provide phase information with excellent sensitivity across all spatial frequencies, low noise and an efficient use of electron dose. The principle is also expected to be widely to applications of holography in light optics, X-ray optics, acoustics, ultra-sound, terahertz imaging, etc.

Ozsoy-Keskinbora, C.; Boothroyd, C. B.; Dunin-Borkowski, R. E.; van Aken, P. A.; Koch, C. T.

2014-11-01

125

Hybridization approach to in-line and off-axis (electron) holography for superior resolution and phase sensitivity.  

PubMed

Holography--originally developed for correcting spherical aberration in transmission electron microscopes--is now used in a wide range of disciplines that involve the propagation of waves, including light optics, electron microscopy, acoustics and seismology. In electron microscopy, the two primary modes of holography are Gabor's original in-line setup and an off-axis approach that was developed subsequently. These two techniques are highly complementary, offering superior phase sensitivity at high and low spatial resolution, respectively. All previous investigations have focused on improving each method individually. Here, we show how the two approaches can be combined in a synergetic fashion to provide phase information with excellent sensitivity across all spatial frequencies, low noise and an efficient use of electron dose. The principle is also expected to be widely to applications of holography in light optics, X-ray optics, acoustics, ultra-sound, terahertz imaging, etc. PMID:25387480

Ozsoy-Keskinbora, C; Boothroyd, C B; Dunin-Borkowski, R E; van Aken, P A; Koch, C T

2014-01-01

126

Hybridization approach to in-line and off-axis (electron) holography for superior resolution and phase sensitivity  

PubMed Central

Holography - originally developed for correcting spherical aberration in transmission electron microscopes - is now used in a wide range of disciplines that involve the propagation of waves, including light optics, electron microscopy, acoustics and seismology. In electron microscopy, the two primary modes of holography are Gabor's original in-line setup and an off-axis approach that was developed subsequently. These two techniques are highly complementary, offering superior phase sensitivity at high and low spatial resolution, respectively. All previous investigations have focused on improving each method individually. Here, we show how the two approaches can be combined in a synergetic fashion to provide phase information with excellent sensitivity across all spatial frequencies, low noise and an efficient use of electron dose. The principle is also expected to be widely to applications of holography in light optics, X-ray optics, acoustics, ultra-sound, terahertz imaging, etc. PMID:25387480

Ozsoy-Keskinbora, C.; Boothroyd, C. B.; Dunin-Borkowski, R. E.; van Aken, P. A.; Koch, C. T.

2014-01-01

127

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

Microsoft Academic Search

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

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

2009-01-01

128

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

PubMed Central

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

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

2014-01-01

129

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

E-print Network

States, more deaths are attributed to lung cancer than breast, prostate, and colon cancers combined. It is estimated that 169,400 new cases were diagnosed in 2002 and 154,900 deaths were attributed to lung cancer [1] [2]. According to studies by World... THE DEVELOPMENT OF A SENSITIVE METHOD TO STUDY VOLATILE ORGANIC COMPOUNDS IN GASEOUS EMISSIONS OF LUNG CANCER CELL LINES A Thesis by ANUPAM MAROLY Submitted to the Office of Graduate Studies of Texas A&M University in partial...

Maroly, Anupam

2005-08-29

130

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

PubMed

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

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

131

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

SciTech Connect

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.

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

1983-07-01

132

A high sensitive two-line detector with large dynamic range for intravenous coronary angiography  

NASA Astrophysics Data System (ADS)

The medical community is highly interested in methods for non-invasive imaging of coronary arteries. One method under development is dichromography. This method allows imaging of small fast moving objects like the coronary arteries including distal parts and sidebranches after intravenous injection of contrast material. Two images with monochromatic X-rays at energies just below and above the K-edge of iodine at 33.17 keV are simultaneously taken. After logarithmic subtraction coronary arteries down to 0.7 mm diameter with extremely low iodine concentrations of 10 mg/ml become visible. At the Hamburger Synchrotronstrahlungslabor HASYLAB at DESY in Hamburg, Germany the system NIKOS was developed for dichromography. In this system the detector is one of the main components. This two-line detector is an ionization chamber for the two energies. The two gaps are separated by the drift cathode. A Frisch-grid for shielding the ions in a distance of 3 mm defines the conversion room. The 336 anode strips per line with a length of 56 mm in the direction of the beam are connected to the frontend electronics. The parameters of the current version of the detector in one setting are: noise equivalent of 7.6 photons, dynamic range of 300 000 : 1, readout time for the two lines (672 pixels) 0.18 ms.

Lohmann, M.; Besch, H. J.; Dix, W.-R.; Dünger, O.; Jung, M.; Menk, R. H.; Reime, B.; Schildwächter, L.

1998-12-01

133

Relationships between Signaling Pathway Usage and Sensitivity to a Pathway Inhibitor: Examination of Trametinib Responses in Cultured Breast Cancer Lines  

PubMed Central

Cellular signaling pathways involving mTOR, PI3K and ERK have dominated recent studies of breast cancer biology, and inhibitors of these pathways have formed a focus of numerous clinical trials. We have chosen trametinib, a drug targeting MEK in the ERK pathway, to address two questions. Firstly, does inhibition of a signaling pathway, as measured by protein phosphorylation, predict the antiproliferative activity of trametinib? Secondly, do inhibitors of the mTOR and PI3K pathways synergize with trametinib in their effects on cell proliferation? A panel of 30 human breast cancer cell lines was chosen to include lines that could be classified according to whether they were ER and PR positive, HER2 over-expressing, and “triple negative”. Everolimus (targeting mTOR), NVP-BEZ235 and GSK2126458 (both targeting PI3K/mTOR) were chosen for combination experiments. Inhibition of cell proliferation was measured by IC50 values and pathway utilization was measured by phosphorylation of signaling kinases. Overall, no correlation was found between trametinib IC50 values and inhibition of ERK signaling. Inhibition of ERK phosphorylation was observed at trametinib concentrations not affecting proliferation, and sensitivity of cell proliferation to trametinib was found in cell lines with low ERK phosphorylation. Evidence was found for synergy between trametinib and either everolimus, NVP-BEZ235 or GSK2126458, but this was cell line specific. The results have implications for the clinical application of PI3K/mTOR and MEK inhibitors. PMID:25170609

Leung, Euphemia Y.; Kim, Ji Eun; Askarian-Amiri, Marjan; Rewcastle, Gordon W.; Finlay, Graeme J.; Baguley, Bruce C.

2014-01-01

134

Correlation between potassium channel expression and sensitivity to drug-induced cell death in tumor cell lines.  

PubMed

Plasma membrane (PM) and mitochondrial (mt) ion channels - particularly potassium channels - became oncological targets soon after the discovery that they are involved both in the regulation of proliferation and apoptosis. Some members of the Kv Shaker family, namely Kv1.1, Kv1.3, Kv1.5 and Kv11.1 (Herg), and the intermediate-conductance calcium-activated potassium KCa3.1 (IK) channels have been shown to contribute to apoptosis in various cell lines. Kv1.3, Kv1.5 and IK are located in the plasma membrane but also in the mitochondrial inner membrane, where they participate in apoptotic signalling. Interestingly, an altered protein expression of some of the channels mentioned above has been reported in neoplastic cell lines/tissues, but a systematic quantification addressing the protein expression of the above potassium channels in tumor cell lines of different origin has not been carried out yet. In the present study we investigated whether expression of specific potassium channels, at the mRNA and protein level, can be correlated with cell sensitivity to various apoptotic stimuli, including chemotherapeutic drugs, in a panel of cancer cell lines. The results show correlation between the protein expression of the Kv1.1 and Kv1.3 channels and susceptibility to death upon treatment with staurosporine, C2-ceramide and cisplatin. Furthermore, we investigated the correlation between Kv channel expression and sensitivity to three distinct membrane-permeant Kv1.3 inhibitors, since these drugs have recently been shown to be able to induce apoptosis and also reduce tumor volume in an in vivo model. Higher protein expression of Kv1.3 significantly correlated with lower cell survival upon treatment with clofazimine, one of the Kv1.3 inhibitors. These results suggest that expression of Kv1.1 and Kv1.3 sensitizes tumour cells of various origins to cytotoxins. Data reported in this work regarding potassium channel protein expression in different cancer cell lines may be exploited for pharmacological manipulation aiming to affect proliferation/apoptosis of cancer cells. PMID:23701546

Leanza, Luigi; O'Reilly, Paul; Doyle, Anne; Venturini, Elisa; Zoratti, Mario; Szegezdi, Eva; Szabo, Ildiko

2014-01-01

135

democrite-00023778,version1-11Apr2005 DIRECT SEARCH FOR WIMP DARK MATTER  

E-print Network

democrite-00023778,version1-11Apr2005 DIRECT SEARCH FOR WIMP DARK MATTER J. GASCON Institut de the experimental aspects of the direct search for WIMP dark matter. In this search, one looks in a terrestrial observations is that our Galaxy could be immersed in a halo of heavy Dark Matter particles of a fundamentally

Paris-Sud XI, Université de

136

Goodbye to WIMPs: A Scalable Interface for ALMA Operations  

NASA Astrophysics Data System (ADS)

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.

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

2011-07-01

137

A Search for WIMP Dark Matter Using the First Five-Tower Run of the Cryogenic Dark Matter Search  

E-print Network

A Search for WIMP Dark Matter Using the First Five-Tower Run of the Cryogenic Dark Matter Search;A Search for WIMP Dark Matter Using the First Five-Tower Run of the Cryogenic Dark Matter Search Copyright 2008 by Jeffrey Peter Filippini #12;1 Abstract A Search for WIMP Dark Matter Using the First Five

California at Berkeley, University of

138

A Neutron Sensitive Microchannel Plate Detector with Cross Delay Line Readout  

SciTech Connect

Microchannel plates containing neutron absorbing elements such as boron and gadolinium in the bulk glass are used as the sensing element in high spatial resolution, high rate neutron imaging systems. In this paper we describe one such device, using both 10B and natural Gd, which employs cross delay line signal readout, with time-of-flight capability. This detector has a measured spatial resolution under 40 m FWHM, thermal neutron efficiency of 19%, and has recorded rates in excess of 500 kHz. A physical and functional description is presented, followed by a discussion of measurements of detector performance and a brief survey of some practical applications.

Berry, Kevin D [ORNL; Bilheux, Hassina Z [ORNL; Crow, Lowell [ORNL; Diawara, Yacouba [ORNL; Feller, W Bruce [Nova Scientific, Inc., Sturbridge, MA; Iverson, Erik B [ORNL; Martin, Adrian [Sensor Sciences, LLC; Robertson, Lee [ORNL

2012-01-01

139

Dark matter search by exclusive studies of X-rays following WIMPs nuclear interactions  

E-print Network

It is shown that weakly interacting massive particles (WIMPs), which are possible cold dark matter candidates, can be studied by exclusive measurements of X-rays following WIMPs nuclear interactions. Inner-shell atomic electrons are ionized through WIMP-nuclear interaction, and then mono-energetic X-rays are emitted when they are filled by outer-shell electrons. The number of inner-shell holes amounts to as large as one per five nuclear recoils for K-shell and several per recoil for L-shell in the case of medium heavy target nuclei interacting with 100-300 GeV WIMPs. Then the K and L X-ray peaks show up in the 5-50 keV region. Consequently exclusive studies of the X-rays in coincidence with the nuclear recoils and the ionization electrons are found to provide excellent opportunities to detect WIMPs such as the Lightest Super Symmetric Particles (LSP)

H. Ejiri; Ch. C. Moustakidis; J. D. Vergados

2006-03-14

140

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

E-print Network

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 x 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 shape discrimination. No signal associated with nuclear recoils from WIMP interactions was observed in any run with any crystal. This allowed us to set upper limits on the WIMP-nucleon spin-independent and WIMP-proton spin-dependent cross-sections. The NAIAD experiment has so far imposed the most stringent constraints on the spin-dependent WIMP-proton cross-section.

The UK Dark Matter Collaboration

2005-04-17

141

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

PubMed

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

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

2013-02-01

142

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

PubMed Central

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

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

2012-01-01

143

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

PubMed Central

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

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

2014-01-01

144

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

NASA Astrophysics Data System (ADS)

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.

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

2007-09-01

145

Extended Source Gamma-Ray Emission from WIMP Annihilation in the Sagittarius Dwarf Elliptical Galaxy (SULI paper)  

SciTech Connect

The proximity of the dark matter dominated Sagittarius Dwarf Elliptical Galaxy (position (l,b) = 5.6{sup o}, -14{sup o}) allows it to act as an ideal laboratory for the exploration of extended gamma-ray emission from Weakly Interacting Massive Particle (WIMP) annihilation processes in a dark matter-dominated system. Since the matter in our universe is predominantly dark, exploring such processes as WIMP annihilation will lead to a better understanding of cosmology. In order to study this gamma-ray emission, a model for the diffuse background gamma-radiation in the dwarf galaxy's region is extracted from the Energetic Gamma Ray Experiment Telescope (EGRET) data. After validating this model and comparing it to the EGRET diffuse model, the background model is added to effective bleeding-contamination from external point sources and multiple models for the signal-above-background emission. Various models of this emission are tested: (a) no source located in region, (b) unidentified point source 3EG J1847-3219 from the Third EGRET Catalog responsible for the emission and (c) extended emission resulting from WIMP annihilation responsible for the signal above background. These models are created through the employment of Monte Carlo simulation methods, utilizing the response functions of the EGRET instrument to simulate the point spread function, energy dispersion and effects of variable effective area depending on angle of incidence. Energy spectra for point sources are generated from the best predictions of spectral indices listed in the Third EGRET Catalog and the spectrum for the extended dark matter source is generated from Pythia high energy annihilation simulations. Hypothesis testing is conducted to assess the goodness-of-fit of these models to the data taken by EGRET. Additionally, we hope to expand our analysis by employing the response functions of the imminent Gamma Ray Large Area Space Telescope (GLAST) to our models. This extension should highlight the sensitivity disparities between GLAST and EGRET and show GLAST's potential enhancement of this analysis. This process will allow for forecasting of extended WIMP annihilation emission signatures for the GLAST detector.

Vasu-Devan, Vidya; /Columbia U. /SLAC

2006-01-04

146

Epigenetics-related genes in prostate cancer: Expression profile in prostate cancer tissues, androgen-sensitive and -insensitive cell lines  

PubMed Central

Epigenetic changes have been suggested to drive prostate cancer (PCa) development and progression. Therefore, in this study, we aimed to identify novel epigenetics-related genes in PCa tissues, and to examine their expression in metastatic PCa cell lines. We analyzed the expression of epigenetics-related genes via a clustering analysis based on gene function in moderately and poorly differentiated PCa glands compared to normal glands of the peripheral zone (prostate proper) from PCa patients using Whole Human Genome Oligo Microarrays. Our analysis identified 12 epigenetics-related genes with a more than 2-fold increase or decrease in expression and a p-value <0.01. In moderately differentiated tumors compared to normal glands of the peripheral zone, we found the genes, TDRD1, IGF2, DICER1, ADARB1, HILS1, GLMN and TRIM27, to be upregulated, whereas TNRC6A and DGCR8 were found to be downregulated. In poorly differentiated tumors, we found TDRD1, ADARB and RBM3 to be upregulated, whereas DGCR8, PIWIL2 and BC069781 were downregulated. Our analysis of the expression level for each gene in the metastatic androgen-sensitive VCaP and LNCaP, and -insensitive PC3 and DU-145 PCa cell lines revealed differences in expression among the cell lines which may reflect the different biological properties of each cell line, and the potential role of each gene at different metastatic sites. The novel epigenetics-related genes that we identified in primary PCa tissues may provide further insight into the role that epigenetic changes play in PCa. Moreover, some of the genes that we identified may play important roles in primary PCa and metastasis, in primary PCa only, or in metastasis only. Follow-up studies are required to investigate the functional role and the role that the expression of these genes play in the outcome and progression of PCa using tissue microarrays. PMID:23135352

SHAIKHIBRAHIM, ZAKI; LINDSTROT, ANDREAS; OCHSENFAHRT, JACQUELINE; FUCHS, KERSTIN; WERNERT, NICOLAS

2012-01-01

147

Epigenetics-related genes in prostate cancer: expression profile in prostate cancer tissues, androgen-sensitive and -insensitive cell lines.  

PubMed

Epigenetic changes have been suggested to drive prostate cancer (PCa) development and progression. Therefore, in this study, we aimed to identify novel epigenetics-related genes in PCa tissues, and to examine their expression in metastatic PCa cell lines. We analyzed the expression of epigenetics-related genes via a clustering analysis based on gene function in moderately and poorly differentiated PCa glands compared to normal glands of the peripheral zone (prostate proper) from PCa patients using Whole Human Genome Oligo Microarrays. Our analysis identified 12 epigenetics-related genes with a more than 2-fold increase or decrease in expression and a p-value <0.01. In modera-tely differentiated tumors compared to normal glands of the peripheral zone, we found the genes, TDRD1, IGF2, DICER1, ADARB1, HILS1, GLMN and TRIM27, to be upregulated, whereas TNRC6A and DGCR8 were found to be downregulated. In poorly differentiated tumors, we found TDRD1, ADARB and RBM3 to be upregulated, whereas DGCR8, PIWIL2 and BC069781 were downregulated. Our analysis of the expression level for each gene in the metastatic androgen-sensitive VCaP and LNCaP, and -insensitive PC3 and DU-145 PCa cell lines revealed differences in expression among the cell lines which may reflect the different biological properties of each cell line, and the potential role of each gene at different metastatic sites. The novel epigenetics-related genes that we identified in primary PCa tissues may provide further insight into the role that epigenetic changes play in PCa. Moreover, some of the genes that we identified may play important roles in primary PCa and metastasis, in primary PCa only, or in metastasis only. Follow-up studies are required to investigate the functional role and the role that the expression of these genes play in the outcome and progression of PCa using tissue microarrays. PMID:23135352

Shaikhibrahim, Zaki; Lindstrot, Andreas; Ochsenfahrt, Jacqueline; Fuchs, Kerstin; Wernert, Nicolas

2013-01-01

148

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

E-print Network

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.

Annika H. G. Peter

2009-02-09

149

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

PubMed Central

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

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

2014-01-01

150

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

PubMed

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

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

2014-01-01

151

Variation in Drug Sensitivity of Malignant Mesothelioma Cell Lines with Substantial Effects of Selenite and Bortezomib, Highlights Need for Individualized Therapy  

PubMed Central

Background Malignant mesothelioma cells have an epithelioid or sarcomatoid morphology, both of which may be present in the same tumor. The sarcomatoid phenotype is associated with worse prognosis and heterogeneity of mesothelioma cells may contribute to therapy resistance, which is often seen in mesothelioma. This study aimed to investigate differences in sensitivity between mesothelioma cell lines to anti-cancer drugs. We studied two novel drugs, selenite and bortezomib and compared their effect to four conventional drugs. We also investigated the immunoreactivity of potential predictive markers for drug sensitivity; Pgp, MRP-1, ERCC1, RRM1, TS, xCT and proteasome 20S subunit. Materials and methods We treated six mesothelioma cell lines with selenite, bortezomib, carboplatin, pemetrexed, doxorubicin or gemcitabine as single agents and in combinations. Viability was measured after 24 and 48 hours. Immunocytochemistry was used to detect predictive markers. Results As a single agent, selenite was effective on four out of six cell lines, and in combination with bortezomib yielded the greatest response in the studied mesothelioma cell lines. Cells with an epithelioid phenotype were generally more sensitive to the different drugs than the sarcomatoid cells. Extensive S-phase arrest was seen in pemetrexed-sensitive cell lines. MRP-1 predicted sensitivity of cell lines to treatment with carboplatin and xCT predicted pemetrexed effect. Conclusions The observed heterogeneity in sensitivity of mesothelioma cell lines with different morphology highlights the need for more individualized therapy, requiring development of methods to predict drug sensitivity of individual tumors. Selenite and bortezomib showed a superior effect compared to conventional drugs, motivating clinical testing of these agents as future treatment regime components for patients with malignant mesothelioma. PMID:23840376

Szulkin, Adam; Nilsonne, Gustav; Mundt, Filip; Wasik, Agata M.; Souri, Pega; Hjerpe, Anders; Dobra, Katalin

2013-01-01

152

A Meta-Analysis Approach for Characterizing Pan-Cancer Mechanisms of Drug Sensitivity in Cell Lines  

PubMed Central

Understanding the heterogeneous drug response of cancer patients is essential to precision oncology. Pioneering genomic analyses of individual cancer subtypes have begun to identify key determinants of resistance, including up-regulation of multi-drug resistance (MDR) genes and mutational alterations of drug targets. However, these alterations are sufficient to explain only a minority of the population, and additional mechanisms of drug resistance or sensitivity are required to explain the remaining spectrum of patient responses to ultimately achieve the goal of precision oncology. We hypothesized that a pan-cancer analysis of in vitro drug sensitivities across numerous cancer lineages will improve the detection of statistical associations and yield more robust and, importantly, recurrent determinants of response. In this study, we developed a statistical framework based on the meta-analysis of expression profiles to identify pan-cancer markers and mechanisms of drug response. Using the Cancer Cell Line Encyclopaedia (CCLE), a large panel of several hundred cancer cell lines from numerous distinct lineages, we characterized both known and novel mechanisms of response to cytotoxic drugs including inhibitors of Topoisomerase 1 (TOP1; Topotecan, Irinotecan) and targeted therapies including inhibitors of histone deacetylases (HDAC; Panobinostat) and MAP/ERK kinases (MEK; PD-0325901, AZD6244). Notably, our analysis implicated reduced replication and transcriptional rates, as well as deficiency in DNA damage repair genes in resistance to TOP1 inhibitors. The constitutive activation of several signaling pathways including the interferon/STAT-1 pathway was implicated in resistance to the pan-HDAC inhibitor. Finally, a number of dysregulations upstream of MEK were identified as compensatory mechanisms of resistance to the MEK inhibitors. In comparison to alternative pan-cancer analysis strategies, our approach can better elucidate relevant drug response mechanisms. Moreover, the compendium of putative markers and mechanisms identified through our analysis can serve as a foundation for future studies into these drugs. PMID:25036042

Wang, Kendric; Shrestha, Raunak; Wyatt, Alexander W.; Reddy, Anupama; Lehár, Joseph; Wang, Yuzhou

2014-01-01

153

Limits on spin-dependent wimp-nucleon interactions from the cryogenic dark matter search  

SciTech Connect

The Cryogenic Dark Matter Search (CDMS) is an experiment to detect weakly interacting massive particles (WIMPs) based on their interactions with Ge and Si nuclei. We report the results of an analysis of data from the first two runs of CDMS at the Soudan Underground Laboratory in terms of spin-dependent WIMP-nucleon interactions on {sup 73}Ge and {sup 29}Si. These data exclude new regions of spin-dependent WIMP-nucleon interaction parameter space, including regions relevant to spin-dependent interpretations of the annual modulation signal reported by the DAMA/NaI experiment.

Akerib, D.S.; Armel-Funkhouser, M.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.; DeJongh, F.; Dixon, R.; Dragowsky, M.R.; Driscoll, D.D.; Duong, L.; /Case Western Reserve U. /UC, Berkeley /Brown U.

2005-09-01

154

[Adenosine triphosphate-dependence of volume sensitive chloride current in LNCaP cell line of human prostate cancer].  

PubMed

Although sensitivity to intracellular ATP is considered to be one of the hallmarks of swelling activated Cl- current (I(Cl,swell)) involved in regulatory volume decrease (RVD) following hypotonic stress, the type and manner of such sensitivity seems to vary in different cell types. Here by using whole-cell patch-clamp recording we investigated ATP sensitivity of I(Cl,swell) in LNCaP human prostate cancer cell line. Suppression of endogenous ATP production with metabolic inhibitors (oligomycin, iodoacetate and rotenone) during cell dialysis with ATP- and Mg2+-free pipette solution did not prevent I(Cl,swell) in response to hypotonic exposure. However, supplementing this solution with 5 mM Na-ATP led to the development of I(Cl,swell) with nearly 305 higher density and less pronounced voltage-dependent inactivation (manifested mainly by the increase of non-inactivated current component) at positive potentials. On the contrary, inclusion of 1 mM Mg2+ in the patch pipette resulted in even smaller I(Cl,swell) (30% lower density compared to Mg2+-free conditions), which inactivated completely on prolonged depolarization. The presence of 5 mM Mg-ATP in the pipette did not affect I(Cl,swell) density. Neither intervention significantly altered the rate of I(Cl,swell) development in response to hypotonicity. We conclude that intracellular ATP, a positive modulator of I(Cl,swell)-carrying volume-regulated anion channel (VRAC) in LNCaP cells most likely acts via binding rather than hydrolysis and/or phosphorylation reactions, whereas intracellular Mg2+ is VRAC inhibitor. PMID:15801200

Lazarenko, P M; Pohoriela, N Kh; Shuba, Ia M

2005-01-01

155

DNA microarray reveals ZNF195 and SBF1 are potential biomarkers for gemcitabine sensitivity in head and neck squamous cell carcinoma cell lines.  

PubMed

Gemcitabine is a potential chemotherapy drug for treatment of head and neck squamous cell carcinoma (HNSCC), however, the poor or partial response of HNSCC patients to gemcitabine demonstrated the urgent need for gemcitabine biomarkers to improve the therapy. In present work, 10 HNSCC cell lines were employed to figure out the biomarkers for gemcitabine sensitivity. The sensitivities of these 10 cell lines to gemcitabine and the basal expression of these cell lines was investigated, the correlation between gemcitabine response (IC50 dose) and gene expression was investigated by Pearson correlation and FDR estimation. The top seven positive genes responsible for gemcitabine sensitivity were validated by qPCR in these 10 HNSCC cell lines, while only two genes (SBF1 and ZNF195) were expression-correlated to gemcitabine response. Furthermore, ZNF195 expression was closely associated with gemcitabine sensitivity in the subsequent independent validation in cell lines from various types of cancer. Our work might provide potential biomarkers for gemcitabine sensitivity in HNSCC and various type of cancer. PMID:24817947

Zhu, Min-Hui; Ji, Shun-Long; Zhang, Cai-Yun; Cui, Long; Xiong, Lei; Zheng, Hong-Liang

2014-01-01

156

DNA microarray reveals ZNF195 and SBF1 are potential biomarkers for gemcitabine sensitivity in head and neck squamous cell carcinoma cell lines  

PubMed Central

Gemcitabine is a potential chemotherapy drug for treatment of head and neck squamous cell carcinoma (HNSCC), however, the poor or partial response of HNSCC patients to gemcitabine demonstrated the urgent need for gemcitabine biomarkers to improve the therapy. In present work, 10 HNSCC cell lines were employed to figure out the biomarkers for gemcitabine sensitivity. The sensitivities of these 10 cell lines to gemcitabine and the basal expression of these cell lines was investigated, the correlation between gemcitabine response (IC50 dose) and gene expression was investigated by Pearson correlation and FDR estimation. The top seven positive genes responsible for gemcitabine sensitivity were validated by qPCR in these 10 HNSCC cell lines, while only two genes (SBF1 and ZNF195) were expression-correlated to gemcitabine response. Furthermore, ZNF195 expression was closely associated with gemcitabine sensitivity in the subsequent independent validation in cell lines from various types of cancer. Our work might provide potential biomarkers for gemcitabine sensitivity in HNSCC and various type of cancer. PMID:24817947

Zhu, Min-Hui; Ji, Shun-Long; Zhang, Cai-Yun; Cui, Long; Xiong, Lei; Zheng, Hong-Liang

2014-01-01

157

Improvement of the antiproliferative effect of rapamycin on tumor cell lines by poly (monomethylitaconate)-based pH-sensitive, plasma stable liposomes.  

PubMed

pH-responsive polymers produce liposomes with pH-sensitive property which can release their encapsulated drug under mild acidic conditions found inside the cellular endosomes, inflammatory tissues and cancerous cells. The aim of this study was preparing pH-sensitive and plasma stable liposomes in order to enhance the selectivity and antiproliferative effect of Rapamycin. In the present study we used PEG-poly (monomethylitaconate)-CholC6 (PEG-PMMI-CholC6) copolymer and Oleic acid (OA) to induce pH-sensitive property in Rapamycin liposomes. pH-sensitive liposomal formulations bearing copolymer PEG-PMMI-CholC6 and OA were characterized in regard to physicochemical stability, pH-responsiveness and stability in human plasma. The ability of pH-sensitive liposomes in enhancing the cytotoxicity of Rapamycin was evaluated in vitro by using colon cancer cell line (HT-29) and compared with its cytotoxicity on human umbilical vein endothelial cell (HUVEC) line. Both formulations were found to release their contents under mild acidic conditions rapidly. However, unlike OA-based liposomes, the PEG-PMMI-CholC6 bearing liposomes preserved their pH-sensitivity in plasma. Both types of pH-sensitive Rapamycin-loaded liposomes exhibited high physicochemical stability and could deliver antiproliferative agent into HT-29 cells much more efficiently in comparison with conventional liposomes. Conversely, the antiproliferative effect of pH-sensitive liposomes on HUVEC cell line was less than conventional liposomes. This study showed that both OA and PEG-PMMI-CholC6-based vesicles could submit pH-sensitive property, however, only PEG-PMMI-CholC6-based liposomes could preserve pH-sensitive property after incubation in plasma. As a result pH-sensitive PEG-PMMI-CholC6-based liposomal formulation can improve the selectivity, stability and antiproliferative effect of Rapamycin. PMID:24394948

Ghanbarzadeh, Saeed; Arami, Sanam; Pourmoazzen, Zhaleh; Khorrami, Arash

2014-03-01

158

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

E-print Network

to the detection of relatively higher mass WIMPs because of detector threshold limits, background effects, or a lack of fundamental understanding of very low energy nuclear recoils (nuclear recoil energies...

Sofka, Clement James

2014-04-16

159

A sensitive WST-8-based bioassay for PEGylated granulocyte colony stimulating factor using the NFS-60 cell line.  

PubMed

Abstract Context: Granulocyte colony stimulating factor (G-CSF) has been commonly used to treat neutropenia caused by chemotherapy, radiotherapy, and organ transplants. Improved in vitro efficacy of G-CSF has already been observed by conjugating it to polyethylene glycol (PEG). Objective: The in vivo bioassay using tetrazolium dye with the NFS-60 cell line has been recommended for G-CSF but no such monographs are available for PEGylated G-CSF in pharmacopeias. In the present study, the assay recommended for G-CSF was evaluated for its suitability to PEGylated G-CSF. Materials and methods: The generally used MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium]-based assay was compared with a bioassay employing a water-soluble tetrazolium dye, WST-8 [2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium], using NFS-60 cells at a concentration of 7?×?10(5)?cells/ml against 800?IU/ml of PEGylated G-CSF at 24, 48, 72, and 72?h time points to determine the efficacy of PEGylated G-CSF. Further, the optimized WST-8 dye-based assay was used to test the potency of various commercially available PEGylated G-CSF preparations. Results: The results demonstrated enhanced sensitivity of the WST-8-based assay over the conventional MTS-based assay for determining the potency of PEGylated G-CSF using the NFS-60 cell line. Conclusion: Our study demonstrates the potential application of WST-8-based bioassays for other biotherapeutic proteins of human and veterinary interest. PMID:25423580

Tiwari, Krishna; Wavdhane, Madan; Haque, Shafiul; Govender, Thavendran; Kruger, Hendrik G; Mishra, Maheshwari K; Chandra, Ramesh; Tiwari, Dileep

2014-11-25

160

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

PubMed

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

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

2012-09-01

161

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

NASA Astrophysics Data System (ADS)

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.

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

2012-09-01

162

High Sensitivity CW-Cavity Ring Down Spectroscopy of 12 near 1.35 m (II): New observations and Line intensities modeling  

E-print Network

High Sensitivity CW-Cavity Ring Down Spectroscopy of 12 CO2 near 1.35 m (II): New observations, China (c) Laboratory of Theoretical Spectroscopy, Institute of Atmospheric Optics SB RAS, 1: Carbon dioxide, CO2, Cavity Ring Down Spectroscopy, line intensities, Global modelling, HITRAN, HITEMP

Boyer, Edmond

163

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

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

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

164

HSP90 inhibition downregulates thymidylate synthase and sensitizes colorectal cancer cell lines to the effect of 5FU-based chemotherapy  

PubMed Central

Cell cycle progression and DNA synthesis are essential steps in cancer cell growth. Thymidylate synthase (TS) is a therapeutic target for 5FU. We tested the hypothesis that HSP90 transcriptional and functional inhibition can inhibit cell cycle progression, downregulate TS levels and sensitize colorectal cancer (CRC) cell lines to the effects of 5FU. Treatment with ganetespib (50nM) for 24 hours inhibited cyclin D1 and pRb at the transcriptional and translational levels and induced p21, leading to G0/G1 cell cycle arrest in both CRC cell lines (HCT-116 and HT-29). This was associated with downregulation of E2F1 and its target gene TS. In addition, ganetespib inhibited PI3K/Akt and ERK signalling pathways. Similar effects were observed with HSP90 knockdown in both cell lines. Ganetespib sensitized CRC cell lines to the effects of oxaliplatin and 5FU. Similar effects were also observed in tumors from animals treated with ganetespib, oxaliplatin and 5FU. In this study, we present in vitro and animal data supporting that the targeting of HSP90 decreases CRC cell survival and proliferation. Ganetespib sensitizes CRC cell lines to the effects of 5FU-based chemotherapy. Combining HSP90 inhibitors with chemotherapy is a rational approach for future drug development in CRC. PMID:25296971

Nagaraju, Ganji Purnachandra; Alese, Olatunji B.; Landry, Jerome; Diaz, Roberto; El-Rayes, Bassel F

2014-01-01

165

HSP90 inhibition downregulates thymidylate synthase and sensitizes colorectal cancer cell lines to the effect of 5FU-based chemotherapy.  

PubMed

Cell cycle progression and DNA synthesis are essential steps in cancer cell growth. Thymidylate synthase (TS) is a therapeutic target for 5FU. We tested the hypothesis that HSP90 transcriptional and functional inhibition can inhibit cell cycle progression, downregulate TS levels and sensitize colorectal cancer (CRC) cell lines to the effects of 5FU. Treatment with ganetespib (50 nM) for 24 hours inhibited cyclin D1 and pRb at the transcriptional and translational levels and induced p21, leading to G0/G1 cell cycle arrest in both CRC cell lines (HCT-116 and HT-29). This was associated with downregulation of E2F1 and its target gene TS. In addition, ganetespib inhibited PI3K/Akt and ERK signalling pathways. Similar effects were observed with HSP90 knockdown in both cell lines. Ganetespib sensitized CRC cell lines to the effects of oxaliplatin and 5FU. Similar effects were also observed in tumors from animals treated with ganetespib, oxaliplatin and 5FU. In this study, we present in vitro and animal data supporting that the targeting of HSP90 decreases CRC cell survival and proliferation. Ganetespib sensitizes CRC cell lines to the effects of 5FU-based chemotherapy. Combining HSP90 inhibitors with chemotherapy is a rational approach for future drug development in CRC. PMID:25296971

Nagaraju, Ganji Purnachandra; Alese, Olatunji B; Landry, Jerome; Diaz, Roberto; El-Rayes, Bassel F

2014-10-30

166

Cytoskeletal regulation dominates temperature-sensitive proteomic changes of hibernation in forebrain of 13-lined ground squirrels.  

PubMed

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

Hindle, Allyson G; Martin, Sandra L

2013-01-01

167

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

PubMed Central

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

Hindle, Allyson G.; Martin, Sandra L.

2013-01-01

168

LUX likelihood and limits on spin-independent and spin-dependent WIMP couplings with LUXCalc  

E-print Network

We present LUXCalc, a new utility for calculating likelihoods and deriving WIMP-nucleon coupling limits from the recent results of the LUX direct search dark matter experiment. After a brief review of WIMP-nucleon scattering, we derive, for the first time, LUX limits on the spin-dependent WIMP-nucleon couplings over a broad range of WIMP masses, under standard assumptions on the relevant astrophysical parameters. We find that, under these and other common assumptions, LUX excludes the entire spin-dependent parameter space consistent with a dark matter interpretation of DAMA's anomalous signal, the first time a single experiment has been able to do so. We also revisit the case of spin-independent couplings, and demonstrate good agreement between our results and the published LUX results. Finally, we derive constraints on the parameters of an effective dark matter theory in which a spin-1 mediator interacts with a fermionic WIMP and Standard Model fermions via axial-vector couplings. A detailed appendix describ...

Savage, Christopher; White, Martin; Williams, Anthony G

2015-01-01

169

Omega 3 fatty acids increase the chemo-sensitivity of B-CLL-derived cell lines EHEB and MEC-2 and of B-PLL-derived cell line JVM-2 to anti-cancer drugs doxorubicin, vincristine and fludarabine  

PubMed Central

Background B-Cell chronic lymphocytic leukemia (CLL) is the most common form of leukemia in the United States. Clinical treatment of CLL is often limited due to drug resistance and severe therapy-induced toxicities. We hypothesized that the omega 3 (n-3) fatty acids, eicosapentaenoic acid (EPA) and/or docosahexaenoic acid (DHA), would increase the sensitivity of malignant B-lymphocytes to anti-cancer drugs doxorubicin, vincristine and/or fludarabine in vitro and that increased sensitivity is achieved by alterations in cell-cycle progression leading to growth inhibition and/or enhanced cell death. We further postulate that enhanced sensitivity is dependent on the formation of lipid peroxides and to the generation of reactive oxygen species (ROS). Methods In the present study, B-CLL-derived leukemic cell lines EHEB and MEC-2 and the B-Prolymphocytic leukemic-derived (PLL) cell line JVM-2 were tested for in vitro sensitivity against doxorubicin, vincristine or fludarabine in the presence or absence of vehicle, arachidonic acid (omega 6), EPA or DHA. Cell cycle analysis and Annexin-V assays were performed to determine cell cycle progression and % apoptotic cells, respectively. Assays for malondialdehyde, a measure of lipid peroxidation, and DCF fluorescence assays, a measure of intracellular ROS, were performed to determine if enhanced sensitivity of cells to the drugs by n-3 was dependent on the formation of ROS. Results Our results indicated that: 1) EPA and DHA differentially sensitized B-leukemic cell lines EHEB, JVM-2 and MEC-2 to doxorubicin, vincristine and fludarabine in vitro; 2) n-3 alone and with drug treatment increased cell death and induced G2/M arrest in a cell-type specific manner; 3) lipid peroxidation increased in the presence of n-3; 4) there was higher lipid peroxidation in MEC-2 cells in presence of DHA and doxorubicin than with either alone; 5) n-3 increased generation of ROS in MEC-2, and 6) the addition of vitamin-E abrogated the increase in ROS generation and chemo-sensitivity of MEC-2 to doxorubicin by DHA. Conclusion N-3’s are promising chemo-sensitizing agents for the treatment of CLL. Selective enhancement of chemo-sensitivity of EHEB, JVM-2 and MEC-2 to drugs by n-3 that is not dependent on increased lipid peroxidation and ROS generation indicates alternative mechanisms by which n-3 enhances chemo-sensitivity. PMID:23497075

2013-01-01

170

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

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.

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

171

Isolation and characterization of a Chinese hamster ovary mutant cell line with altered sensitivity to vaccinia virus killing.  

PubMed Central

The Chinese hamster ovary (CHO) cell line is nonpermissive for vaccinia virus, and translation of viral intermediate genes was reported to be blocked (A. Ramsey-Ewing and B. Moss, Virology 206:984-993, 1995). However, cells are readily killed by vaccinia virus. A vaccinia virus-resistant CHO mutant, VV5-4, was isolated by retroviral insertional mutagenesis. Parental CHO cells, upon infection with vaccinia virus, die within 2 to 3 days, whereas VV5-4 cells preferentially survive this cytotoxic effect. The survival phenotype of VV5-4 is partial and in inverse correlation with the multiplicity of infection used. In addition, viral infection fails to shut off host protein synthesis in VV5-4. VV5-4 was used to study the relationship of progression of the virus life cycle and cell fate. We found that in parental CHO cells, vaccinia virus proceeds through expression of viral early genes, uncoating, viral DNA replication, and expression of intermediate and late promoters. In contrast, we detect only expression of early genes and uncoating in VV5-4 cells, whereas viral DNA replication appears to be blocked. Consistent with the cascade regulation model of viral gene expression, we detect little intermediate- and late-gene expression in VV5-4 cells. Since vaccinia virus is known to be cytolytic, isolation of this mutant therefore demonstrates a new mode of the cellular microenvironment that affects progression of the virus life cycle, resulting in a different cell fate. This process appears to be mediated by a general mechanism, since VV5-4 is also resistant to Shope fibroma virus and myxoma virus killing. On the other hand, VV5-4 remains sensitive to cowpox virus killing. To examine the mechanism of VV5-4 survival, we investigated whether apoptosis is involved. DNA laddering and staining of apoptotic nuclei with Hoechst 33258 were observed in both CHO and VV5-4 cells infected with vaccinia virus. We concluded that the cellular pathway, which blocks viral DNA replication and allows VV5-4 to survive, is independent of apoptosis. This mutant also provides evidence that an inductive signal for apoptosis upon vaccinia virus infection occurs prior to viral DNA replication. PMID:8676492

Bair, C H; Chung, C S; Vasilevskaya, I A; Chang, W

1996-01-01

172

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)

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.

Saeki, Akinori; Kozawa, Takahiro; Tagawa, Seiichi

2009-07-01

173

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

SciTech Connect

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{sup +}e{sup ?} collider with ?(s)?500–600 GeV should provide a thorough search for the predicted light higgsinos.

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

2014-06-24

174

Limits on spin-dependent WIMP-nucleon cross-sections from the XENON10 experiment  

E-print Network

XENON10 is an experiment to directly detect weakly interacting massive particle (WIMPs), which may comprise the bulk of the non-baryonic dark matter in our Universe. We report new results for spin-dependent WIMP-nucleon interactions with 129-Xe and 131-Xe from 58.6 live-days of operation at the Laboratori Nazionali del Gran Sasso (LNGS). Based on the non-observation of a WIMP signal in 5.4 kg of fiducial liquid xenon mass, we exclude previously unexplored regions in the theoretically allowed parameter space for neutralinos. We also exclude a heavy Majorana neutrino with a mass in the range of 10 GeV -2 TeV as a dark matter candidate under standard assumptions for its density and distribution in the galactic halo.

J. Angle; E. Aprile; F. Arneodo; L. Baudis; A. Bernstein; A. Bolozdynya; P. Brusov; L. C. C. Coelho; C. E. Dahl; L. DeViveiros; A. D. Ferella; L. M. P. Fernandes; S. Fiorucci; R. J. Gaitskell; K. L. Giboni; R. Gomez; R. Hasty; L. Kastens; J. Kwong; J. A. M. Lopes; N. Madden; A. Manalaysay; A. Manzur; D. N. McKinsey; M. E. Monzani; K. Ni; U. Oberlack; J. Orboeck; G. Plante; R. Santorelli; J. M. F. dos Santos; P. Shagin; T. Shutt; P. Sorensen; S. Schulte; C. Winant; M. Yamashita; for the XENON10 Collaboration

2008-09-10

175

The XENON10 WIMP Search Experiment at the Gran Sasso Underground Laboratory  

E-print Network

XENON10 is a new direct dark matter detection experiment using liquid xenon as target for weakly interacting, massive particles (WIMPs). A two-phase (liquid/gas) time projection chamber with 15 kg fiducial mass has been installed in a low-background shield at the Gran Sasso Underground Laboratory in July 2006. After initial performance tests with various calibration sources, the science data run started on August 24, 2006. The detector has been running stably since then, and a full analysis of more than 75 live days of WIMP search data is now in progress. We present first results on gamma and neutron calibration runs, as well as a preliminary analysis of a subset of the WIMP search data.

Laura Baudis

2007-03-08

176

Standard Model anatomy of WIMP dark matter direct detection II: QCD analysis and hadronic matrix elements  

E-print Network

Models of Weakly Interacting Massive Particles (WIMPs) specified at the electroweak scale are systematically matched to effective theories at hadronic scales where WIMP-nucleus scattering observables are evaluated. Anomalous dimensions and heavy quark threshold matching conditions are computed for the complete basis of lowest-dimension effective operators involving quarks and gluons. The resulting QCD renormalization group evolution equations are solved. The status of relevant hadronic matrix elements is reviewed and phenomenological illustrations are given, including details for the computation of the universal limit of nucleon scattering with heavy $SU(2)_W\\times U(1)_Y$ charged WIMPs. Several cases of previously underestimated hadronic uncertainties are isolated. The results connect arbitrary models specified at the electroweak scale to a basis of $n_f=3$ flavor QCD operators. The complete basis of operators and Lorentz invariance constraints through order $v^2/c^2$ in the nonrelativistic nucleon effective theory are derived.

Richard J. Hill; Mikhail P. Solon

2014-09-29

177

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

NASA Astrophysics Data System (ADS)

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.

Baer, Howard

2014-06-01

178

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

NASA Astrophysics Data System (ADS)

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.

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

179

Limits on spin-dependent WIMP-nucleon cross sections from 225 live days of XENON100 data  

E-print Network

We present new experimental constraints on the elastic, spin-dependent WIMP-nucleon cross section using recent data from the XENON100 experiment, operated in the Laboratori Nazionali del Gran Sasso in Italy. An analysis of 224.6 live days x 34 kg of exposure acquired during 2011 and 2012 revealed no excess signal due to axial-vector WIMP interactions with 129-Xe and 131-Xe nuclei. This leads to the most stringent upper limits on WIMP-neutron cross sections for WIMP masses above 6 GeV, with a minimum cross section of 3.5 x 10^{-40} cm^2 at a WIMP mass of 45 GeV, at 90% confidence level.

XENON100 collaboration; E. Aprile; M. Alfonsi; K. Arisaka; F. Arneodo; C. Balan; L. Baudis; B. Bauermeister; A. Behrens; P. Beltrame; K. Bokeloh; A. Brown; E. Brown; G. Bruno; R. Budnik; J. M. R. Cardoso; W. -T. Chen; B. Choi; A. P. Colijn; H. Contreras; J. P. Cussonneau; M. P. Decowski; E. Duchovni; S. Fattori; A. D. Ferella; W. Fulgione; F. Gao; M. Garbini; C. Ghag; K. -L. Giboni; L. W. Goetzke; C. Grignon; E. Gross; W. Hampel; F. Kaether; A. Kish; J. Lamblin; H. Landsman; R. F. Lang; M. Le Calloch; D. Lellouch; C. Levy; K. E. Lim; Q. Lin; S. Lindemann; M. Lindner; J. A. M. Lopes; K. Lung; T. Marrodan Undagoitia; F. V. Massoli; A. J. Melgarejo Fernandez; Y. Meng; M. Messina; A. Molinario; K. Ni; U. Oberlack; S. E. A. Orrigo; E. Pantic; R. Persiani; G. Plante; N. Priel; A. Rizzo; S. Rosendahl; J. M. F. dos Santos; G. Sartorelli; J. Schreiner; M. Schumann; L. Scotto Lavina; P. R. Scovell; M. Selvi; P. Shagin; H. Simgen; A. Teymourian; D. Thers; O. Vitells; H. Wang; M. Weber; C. Weinheimer

2013-01-29

180

Limits on spin-dependent WIMP-nucleon cross sections from 225 live days of XENON100 data.  

PubMed

We present new experimental constraints on the elastic, spin-dependent WIMP-nucleon cross section using recent data from the XENON100 experiment, operated in the Laboratori Nazionali del Gran Sasso in Italy. An analysis of 224.6 live days×34 kg of exposure acquired during 2011 and 2012 revealed no excess signal due to axial-vector WIMP interactions with 129Xe and 131Xe nuclei. This leads to the most stringent upper limits on WIMP-neutron cross sections for WIMP masses above 6 GeV/c², with a minimum cross section of 3.5×10(-40) cm² at a WIMP mass of 45 GeV/c², at 90% confidence level. PMID:23889382

Aprile, E; Alfonsi, M; Arisaka, K; Arneodo, F; Balan, C; Baudis, L; Bauermeister, B; Behrens, A; Beltrame, P; Bokeloh, K; Brown, A; Brown, E; Bruno, G; Budnik, R; Cardoso, J M R; Chen, W-T; Choi, B; Colijn, A P; Contreras, H; Cussonneau, J P; Decowski, M P; Duchovni, E; Fattori, S; Ferella, A D; Fulgione, W; Gao, F; Garbini, M; Ghag, C; Giboni, K-L; Goetzke, L W; Grignon, C; Gross, E; Hampel, W; Kaether, F; Kish, A; Lamblin, J; Landsman, H; Lang, R F; Le Calloch, M; Lellouch, D; Levy, C; Lim, K E; Lin, Q; Lindemann, S; Lindner, M; Lopes, J A M; Lung, K; Marrodán Undagoitia, T; Massoli, F V; Melgarejo Fernandez, A J; Meng, Y; Messina, M; Molinario, A; Ni, K; Oberlack, U; Orrigo, S E A; Pantic, E; Persiani, R; Plante, G; Priel, N; Rizzo, A; Rosendahl, S; dos Santos, J M F; Sartorelli, G; Schreiner, J; Schumann, M; Scotto Lavina, L; Scovell, P R; Selvi, M; Shagin, P; Simgen, H; Teymourian, A; Thers, D; Vitells, O; Wang, H; Weber, M; Weinheimer, C

2013-07-12

181

In-line phase-sensitive amplification of QPSK signal using multiple quasi-phase matched LiNbO? waveguide.  

PubMed

Phase-sensitive amplifiers (PSA) using periodically poled (PPLN) LiNbO? waveguides are promising as low-noise optical amplifiers. However, it is difficult to realize in-line operation for multi-level phase modulated signals using a PPLN based PSA with the conventional configuration. In this paper, we report a PPLN based in-line PSA that can regenerate quadrature phase shift keying (QPSK) signals. Multi-stage frequency mixing in a multiple quasi-phase matched LiNbO?waveguide allows carrier phase recovery from a QPSK signal. Non-degenerate parametric amplification enables the phase-sensitive amplification of a QPSK signal. Amplitude and phase regeneration is examined utilizing gain saturation and phase squeezing capability. PMID:25401814

Asobe, Masaki; Umeki, Takeshi; Takenouchi, Hirokazu; Miyamoto, Yutaka

2014-11-01

182

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

Microsoft Academic Search

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

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

2007-01-01

183

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

E-print Network

Among the direct search experiments for WIMP dark matter, the DAMA experiment observed an annual modulation signal interpreted as WIMP interactions with 9.2$\\sigma$ significance. However, this result is contradictory with other direct search experiments reporting null signals in the same parameter space allowed by the DAMA observation, necessitating clarification of the origin of the modulation signal observed using the NaI(Tl) crystals of the DAMA experiment independently. Here, we report the first results of NaI(Tl) crystal measurement at the Yangyang Underground Laboratory to grow ultra-low-background NaI(Tl) crystal detectors.

Kim, K W; 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

2014-01-01

184

Camptothecin analog (CPT-11)-sensitive human pancreatic tumor cell line QGP-1N shows resistance to SN-38, an active metabolite of CPT-11.  

PubMed

In the course of our study to determine the cross-sensitivity between CPT-11 and its active metabolite, SN-38, we found a SN-38-resistant human pancreatic tumor cell line, QGP-1N, which shows sensitivity to CPT-11. The IC50 of SN-38 was 152 times greater for QGP-1N than for SUIT-2, also a human pancreatic tumor cell line, whose IC50 of CPT-11 was similar to that for QGP-1N. The uptakes of CPT-11 and SN-38 and the intracellular conversion of CPT-11 to SN-38 could not explain the difference in sensitivity. DNA synthesis of QGP-1N cells was inhibited by CPT-11 which did not affect that of SUIT-2, while SN-38 inhibited the DNA synthesis of SUIT-2 at lower concentrations than that of QGP-1N. The inhibition test of topoisomerase I catalytic activity by CPT-11 or SN-38 revealed no difference in the biochemical properties of the topoisomerase I enzymes to the compounds between these two cell lines. These results indicate that CPT-11 should have its own inhibitory effect on DNA synthesis through a yet unknown mechanism in QGP-1N cells, although SN-38 plays an essential role in the antitumor activity of CPT-11 in SUIT-2 cells. In some cases, the antitumor effect of CPT-11 might be consequent not only on SN-38 but also on CPT-11 itself. PMID:1329748

Takeda, S; Shimazoe, T; Kuga, H; Sato, K; Kono, A

1992-10-15

185

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

PubMed

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

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

2013-01-01

186

The transformation of the photo-thermo sensitive genic male-sterile line 261S of rice via an expression vector containing the anti-Waxy gene.  

PubMed

Transgenic photo-thermo sensitive genic male sterility Oryza sativa L. cv. "261S" plants with the anti-Waxy gene were successfully obtained using an Agrobacterium tumefaciens-mediated co-transformation method. Marker-free homozygous transgenic lines with the anti-Waxy gene were obtained. The setting seed rates of the transgenic plants via self-pollination or via crossing with the restorer line WX99075 rice and the 1000-grain weight of the transgenic plants and the F2 hybrid seeds obtained by crossing the transgenic or non-transgenic plants with the restorer line WX99075 rice, and the number of panicles of the transgenic plants and yields of the F2 hybrid rice, were analysed. Quality indexes of the transgenic plants and of the F2 hybrid seeds were analysed. Our researches results indicate that hybrid female and hybrid descendant edibility could be improved via the introduction of the anti-Waxy gene, but the grain yields of the reserve seeds via self-pollination of the transgenic photo-thermo sensitive genic sterile lines and of the hybrid rice were not affected. PMID:23853508

Yang, Rui; Zhou, Yongguo; Cao, Yueqin; Yin, Zhongming; Yang, Lijun; Li, Jianyue

2013-06-01

187

Hormone Resistance in Two MCF-7 Breast Cancer Cell Lines is Associated with Reduced mTOR Signaling, Decreased Glycolysis, and Increased Sensitivity to Cytotoxic Drugs  

PubMed Central

The mTOR pathway is a key regulator of multiple cellular signaling pathways and is a potential target for therapy. We have previously developed two hormone-resistant sub-lines of the MCF-7 human breast cancer line, designated TamC3 and TamR3, which were characterized by reduced mTOR signaling, reduced cell volume, and resistance to mTOR inhibition. Here, we show that these lines exhibit increased sensitivity to carboplatin, oxaliplatin, 5-fluorouracil, camptothecin, doxorubicin, paclitaxel, docetaxel, and hydrogen peroxide. The mechanisms underlying these changes have not yet been characterized but may include a shift from glycolysis to mitochondrial respiration. If this phenotype is found in clinical hormone-resistant breast cancers, conventional cytotoxic therapy may be a preferred option for treatment. PMID:25232533

Leung, Euphemia Yee; Kim, Ji Eun; Askarian-Amiri, Marjan; Joseph, Wayne R.; McKeage, Mark J.; Baguley, Bruce C.

2014-01-01

188

hMena+11a Isoform Serves as a Marker of Epithelial Phenotype and Sensitivity to EGFR Inhibition in Human Pancreatic Cancer Cell Lines  

PubMed Central

Purpose hMena, member of the Ena/VASP protein family, is a cytoskeletal protein that is involved in the regulation of cell motility and adhesion. The aim of this study was to determine whether or not the expression of hMena isoforms correlated with sensitivity to EGFR tyrosine kinase inhibitors and could serve as markers with potential clinical use. Experimental design Human pancreatic ductal adenocarcinoma (PDAC) cell lines were characterized for in vitro sensitivity to erlotinib, expression of HER family receptors, markers of epithelial to mesenchymal transition (EMT), and expression of hMena and its isoform hMena+11a. The effects of EGF and erlotinib on hMena expression as well as the effect of hMena knock-down on cell proliferation were also evaluated. Results hMena was detected in all of the pancreatic tumor cell lines tested as well as in the majority of the human tumor samples [primary (92%) and metastatic (86%)]. Intriguingly, in vitro hMena+11a isoform was specifically associated with an epithelial phenotype, EGFR dependency and sensitivity to erlotinib. In epithelial BxPC3 cells EGF upregulated hMena/hMena+11a and erlotinib downregulated expression. hMena knock-down reduced cell proliferation and MAPK and AKT activation in BxPC3 cells and promoted the growth inhibitory effects of erlotinib. Conclusions Collectively, our data indicate that the hMena+11a isoform is associated with an epithelial phenotype and identifies EGFR dependent cell lines that are sensitive to the EGFR inhibitor erlotinib. The availability of anti-hMena+11a specific probes may offer a new tool in pancreatic cancer management if these results can be verified prospectively in cancer patients. PMID:18676769

Pino, Maria S.; Balsamo, Michele; Di Modugno, Francesca; Mottolese, Marcella; Alessio, Massimo; Melucci, Elisa; Milella, Michele; McConkey, David J.; Philippar, Ulrike; Gertler, Frank B.; Natali, Pier Giorgio; Nistico, Paola

2008-01-01

189

Exclusion limits on spin dependent WIMP-nucleon couplings from the SIMPLE experiment  

E-print Network

The SIMPLE experiment is reanalyzed within the context of the WIMP model independent framework of Tovey et. al.. The results are compared with those of the UK NAIAD and NaF experiments as recently reported by the Tokyo group, together with those of the latest UK NAIAD results in 2003, and further constrain the allowed parameter space.

F. Giuliani; TA Girard

2003-11-26

190

Model-independent Limits from Spin-dependent WIMP Dark Matter Experiments  

E-print Network

Spin-dependent WIMP searches have traditionally presented results within an odd group approximation and by suppressing one of the spin-dependent interaction cross sections. We here elaborate on a model-independent analysis in which spin-dependent interactions with both protons and neutrons are simultaneously considered. Within this approach, equivalent current limits on the WIMP-nucleon interaction at WIMP mass of 50 GeV/c$^{2}$ are either $\\sigma_{p}\\leq0.7$ pb, $\\sigma_{n}\\leq0.2$ pb or $|a_{p}|\\leq0.4$, $|a_{n}|\\leq0.7$ depending on the choice of cross section or coupling strength representation. These limits become less restrictive for either larger or smaller masses; they are less restrictive than those from the traditional odd group approximation regardless of WIMP mass. Combination of experimental results are seen to produce significantly more restrictive limits than those obtained from any single experiment. Experiments traditionally considered spin-independent are moreover found to severely limit the spin-dependent phase space. The extension of this analysis to the case of positive signal experiments is explored.

F. Giuliani; TA Girard

2005-02-25

191

ON METEORS, EARTHWORMS AND WIMPS SARA BILLEY, KRZYSZTOF BURDZY, SOUMIK PAL, AND BRUCE E. SAGAN  

E-print Network

ON METEORS, EARTHWORMS AND WIMPS SARA BILLEY, KRZYSZTOF BURDZY, SOUMIK PAL, AND BRUCE E. SAGAN of the graph holds mass Mx t 0 at time t. When a "meteor hits" x at time t, the mass Mx t of the soil present) left at x just after a meteor hit. Meteor hits are modeled as independent Poisson processes, one

Sagan, Bruce

192

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

E-print Network

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

Peters, Achim

193

The Pressure of Misalignment Axions: a Difference from WIMPs in Galaxy Formation?  

E-print Network

Two populations of axions can contribute to cold dark matter: the classical field produced via the misalignment mechanism, and the modes produced in the decay of strings. The classical field has extra pressure, as compared to WIMPs, which could have observable consequences in non-linear galaxy formation.

Sacha Davidson

2014-10-18

194

Analysis of mRNA profiles after MEK1/2 inhibition in human pancreatic cancer cell lines reveals pathways involved in drug sensitivity.  

PubMed

Mutationally activated KRAS, detected in approximately 90% of pancreatic ductal adenocarcinomas (PDA), has proven an intractable pharmacologic target to date. Consequently, efforts to treat KRAS-mutated cancers are focused on targeting RAS-regulated signaling pathways. In mouse models, expression of BRAF(V600E) combined with dominant-negative TP53 elicits PDA, and pharmacologic blockade of mitogen-activated protein/extracellular signal-regulated kinase (MEK) inhibits proliferation of human PDA-derived cell lines. To better understand the role of RAF?MEK?ERK signaling on PDA cell proliferation, we assessed the consequences of MEK inhibition on global patterns of mRNA expression and tumor cell proliferation in a panel of human PDA-derived cell lines. This analysis revealed that RAF?MEK?ERK signaling regulates mRNAs involved in cell-cycle control as well as regulators of the immune system. Linear regression analysis of relative drug sensitivity and mRNA expression revealed mRNAs and pathways correlating with relative drug sensitivity of the cell lines. Mice carrying orthotopically implanted pancreas tumors that were treated with MEK inhibitor displayed reduced tumor growth, concomitant with a reduction of cells in S phase. Furthermore, analysis of tumor mRNA expression revealed PDA cell lines to display similar baseline and MEK inhibitor mRNA expression profiles in vitro and in vivo. Among the proteins subject to downregulation following MEK inhibition, we identified c-MYC as a key driver of cell proliferation downstream of RAF?MEK?ERK signaling. Indeed, in some PDA cell lines, RNA interference-mediated silencing of c-MYC expression had antiproliferative effects similar to that of MEK inhibition, thereby highlighting the importance of c-MYC in key aspects of pancreatic cancer cell maintenance. PMID:22833572

Gysin, Stephan; Paquette, Jesse; McMahon, Martin

2012-12-01

195

Targeting of Rad51-dependent homologous recombination: implications for the radiation sensitivity of human lung cancer cell lines  

PubMed Central

The aim of the present work was to study the role of Rad51-dependent homologous recombination in the radiation response of non-small-cell lung cancer (NSCLC) cell lines. A dose- and time-dependent increase in the formation of Rad51 and ?-H2AX foci with a maximum at about 4 and 1?h after irradiation, followed by a decrease, has been found. The relative fraction of cells with persisting Rad51 foci was 20–30% in radioresistant and 60–80% in radiosensitive cell lines. In comparison, a higher fraction of residual Dsb was evident in cell lines with nonfunctional p53. Transfection with As-Rad51 significantly downregulates radiation-induced formation of Rad51 foci and increases apoptosis, but did not influence the rejoining of DNA double-strand breaks. Interestingly, wortmannin, a well-known inhibitor of nonhomologous end-joining, also inhibits Rad51 foci formation. In general, there was no correlation between the clonogenic survival at 2?Gy and the percentage of initial Rad51 or ?-H2AX foci after ionising radiation (IR). The most reliable predictive factor for radiosensitivity of NSCLC cell lines was the relative fraction of Rad51 foci remaining at 24?h after IR. Although most of the Rad51 foci are co-localised with ?-H2AX foci, no correlation of the relative fraction of persisting ?-H2AX foci and SF2 is evident. PMID:15785736

Sak, A; Stueben, G; Groneberg, M; Böcker, W; Stuschke, M

2005-01-01

196

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

E-print Network

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.

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

197

High resolution-sensitivity characterization of polycyclic aromatic hydrocarbon-DNA adducts using fluorescence line narrowing spectrometry  

Microsoft Academic Search

The application of fluorescence line narrowing spectrometry (FLNS) to the investigation of polar polycyclic aromatic hydrocarbon (PAH) metabolites and their corresponding DNA adducts is demonstrated. The selectivity is shown through the successful resolution of all components in separate mixtures of similar but distinct derivatives of benzo(a)pyrene, benz(a)anthracene, and chrysene. The separate mixtures were composed of six metabolites, five DNA adducts,

1988-01-01

198

3-methyladenine-DNA-glycosylase and O6-alkyl guanine-DNA-alkyltransferase activities and sensitivity to alkylating agents in human cancer cell lines.  

PubMed Central

The activities and the expression of 3-methyladenine glycosylase (3-meAde gly) and O6-alkylguanine-DNA-alkyltransferase (O6 ATase) were investigated in ten human cancer cell lines. Both 3-meAde gly and O6 ATase activities were variable among different cell lines. mRNA levels of the O6 ATase gene, appeared to be related to the content of O6 ATase in different cell lines, whereas no apparent correlation was found between mRNA of 3-meAde gly and the enzyme activity. No correlation was found between the activity of the two enzymes and the sensitivity to alkylating agents of different structures such as CC-1065, tallimustine, dimethylsulphate (DMSO), N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), cis-diamminedichloroplatinum (cDDP) and melphalan (L-PAM). The most striking finding of this study is that a correlation exists between the activity of O6 ATase and 3-meAde gly in the various cell lines investigated (P<0.01), suggesting a common mechanism of regulation of two DNA repair enzymes. Images Figure 2 PMID:8611396

Damia, G.; Imperatori, L.; Citti, L.; Mariani, L.; D'Incalci, M.

1996-01-01

199

Different vimentin expression in two clones derived from a human colocarcinoma cell line (LoVo) showing different sensitivity to doxorubicin.  

PubMed Central

We selected two clones, isolated from the human colocarcinoma cell line LoVo, showing a sensitivity to doxorubicin similar to (LoVo clone 5) or three times lower than (LoVo clone 7) the parental cell line. Since vimentin was atypically expressed in a human breast carcinoma cell line made resistant to doxorubicin, we looked at vimentin expression in these two clones with spontaneously different sensitivity to the drug. For comparison we used the parental cell line LoVo WT and LoVo/DX made resistant pharmacologically. mRNA for vimentin was undetectable by Northern blot analysis in LoVo WT and in LoVo clone 5, while expression of this gene was high in LoVo clone 7 and in LoVo/DX. This increase in mRNA levels was not related to an amplification of DNA, as suggested by Southern blot analysis. Immunofluorescence and immunocytochemistry findings confirmed, at protein level, the mRNA data. In LoVo clones 5 and 7, there were respectively 8.6% and 71% vimentin-positive cells, although the two clones showed similar expression of multidrug resistance gene 1 (mdr-1) and accumulated intracellular doxorubicin at similar levels. Similarly, drug efflux was the same for both clones. Our results show for the first time that cells resistant to doxorubicin express vimentin independently of the mdr glycoprotein. However when cells from clone 5 were transfected with human vimentin cDNA, they did not become resistant, indicating that vimentin can be considered as a marker of resistance in these cells but does not give rise to a resistant phenotype by itself. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:7880731

Conforti, G.; Codegoni, A. M.; Scanziani, E.; Dolfini, E.; Dasdia, T.; Calza, M.; Caniatti, M.; Broggini, M.

1995-01-01

200

Epigenetic regulation of the ABCB1 gene in drug-sensitive and drug-resistant lymphoid tumour cell lines obtained from canine patients.  

PubMed

Multidrug resistance (MDR) is a major obstacle in the treatment of cancer. Overexpression of P-glycoprotein (P-gp), encoded by the ABCB1 (MDR1) gene, is an important factor in determining the MDR phenotype of a tumour. Although recent studies have revealed the epigenetic transcriptional regulation of the human ABCB1 gene, such regulation of this gene has not been examined in dogs. The aim of the current study was to evaluate differences in epigenetic regulation of the ABCB1 gene, between drug-sensitive and drug-resistant canine lymphoid tumour cell lines. In two drug-sensitive cell lines, GL-1 and CLBL-1, ABCB1 mRNA expression was significantly lower than in two drug-resistant cell lines, UL-1 and Ema, using real-time quantitative polymerase chain reaction (QPCR). Bisulphite sequencing and real-time methylation-specific PCR revealed that the CpG island present in the upstream region of exon 2 was hypermethylated in GL-1 and CLBL-1, but hypomethylated in UL-1 and Ema. Chromatin immunoprecipitation and QPCR revealed that histone H3 acetylation in the same CpG island was significantly increased in UL-1 and Ema compared to GL-1 and CLBL-1. Treatment with 5-aza 2'-deoxycytidine or trichostatin A increased ABCB1 mRNA expression in GL-1 and CLBL-1. DNA methylation and histone H3 acetylation were shown to be involved in ABCB1 gene expression and associated with an MDR phenotype in these canine lymphoid tumour cell lines. PMID:24332606

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

2014-01-01

201

Evaluation of the sensitizing potential of antibiotics in vitro using the human cell lines THP-1 and MUTZ-LC and primary monocyte?derived dendritic cells  

SciTech Connect

Since the 7th amendment to the EU cosmetics directive foresees a complete ban on animal testing, alternative in vitro methods have been established to evaluate the sensitizing potential of small molecular weight compounds. To find out whether these novel in vitro assays are also capable to predict the sensitizing potential of small molecular weight drugs, model compounds such as beta-lactams and sulfonamides – which are the most frequent cause of adverse drug reactions – were co-incubated with THP-1, MUTZ-LC, or primary monocyte?derived dendritic cells for 48 h and subsequent expression of selected marker genes (IL-8, IL-1?, CES1, NQO1, GCLM, PIR and TRIM16) was studied by real time PCR. Benzylpenicillin and phenoxymethylpenicillin were recognized as sensitizing compounds because they are capable to induce the mRNA expression of these genes in moDCs and, except for IL-8, in THP-1 cells but not in MUTZ-LC. Ampicillin stimulated the expression of some marker genes in moDCs and THP-1 cells. SMX did not affect the expression of these genes in THP-1, however, in moDCs, at least PIR was enhanced and there was an increase of the release of IL-8. These data reveal that novel in vitro DC based assays might play a role in the evaluation of the allergenic potential of novel drug compounds, but these systems seem to lack the ability to detect the sensitizing potential of prohaptens that require metabolic activation prior to sensitization and moDCs seem to be superior with regard to the sensitivity compared with THP-1 and MUTZ-3 cell lines. -- Highlights: ? We tested the sensitizing potential of small molecular weight drugs in vitro. ? In vitro assays were performed with moDCs and THP-1 cells. ? Beta-lactam antibiotics can be recognized as sensitizing compounds. ? They affect the expression of metabolic enzymes, cytokines and transcription factors. ? Sulfamethoxazole has no measurable effect on THP-1 cells and moDCs.

Sebastian, Katrin, E-mail: ksebastian@ukaachen.de [Department of Dermatology and Allergology, RWTH Aachen University Hospital, D-52074 Aachen (Germany)] [Department of Dermatology and Allergology, RWTH Aachen University Hospital, D-52074 Aachen (Germany); Ott, Hagen [Department of Dermatology and Allergology, RWTH Aachen University Hospital, D-52074 Aachen (Germany)] [Department of Dermatology and Allergology, RWTH Aachen University Hospital, D-52074 Aachen (Germany); Zwadlo-Klarwasser, Gabriele [IZKF (BIOMAT), RWTH Aachen University Hospital, D-52074 Aachen (Germany)] [IZKF (BIOMAT), RWTH Aachen University Hospital, D-52074 Aachen (Germany); Skazik-Voogt, Claudia; Marquardt, Yvonne; Czaja, Katharina; Merk, Hans F.; Baron, Jens Malte [Department of Dermatology and Allergology, RWTH Aachen University Hospital, D-52074 Aachen (Germany)] [Department of Dermatology and Allergology, RWTH Aachen University Hospital, D-52074 Aachen (Germany)

2012-08-01

202

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

PubMed

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

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

2014-10-24

203

Establishment of a Bombyx mori nucleopolyhedrovirus (BmNPV) hyper-sensitive cell line from the silkworm e21 strain.  

PubMed

Baculoviral expression systems, including those of Autographa californica multiple nucleopolyhedrovirus Bombyx mori nucleopolyhedrovirus (BmNPV), are used for recombinant protein production. Four B. mori-derived (BmN4, Bm5, Bmc140, and Bme21) cell lines were infected with recombinant BmNPV viruses expressing firefly luciferase or EGFP as reporters under the control of a viral polyhedrin promoter. Bme21 exhibited significantly higher (100-fold) luciferase activity than BmN4 and Bm5. With the EGFP reporter protein, Bme21 cells showed a marked increase in the ratio of EGFP-positive cells, reaching 90 % on day 4 post-infection, while Bm5 and BmN4 cells had a slow increase in the ratio of their EGFP-positive population. The viral titer in a supernatant of Bme21 cell culture increased faster than those of Bm5 and BmN4 cells. This susceptibility indicates that the Bme21 cell line is useful for large-scale protein expression using BmNPV. PMID:22714272

Lee, Jae Man; Kawakami, Naoya; Mon, Hiroaki; Mitsunobu, Hitoshi; Iiyama, Kazuhiro; Ninaki, Satoshi; Maenaka, Katsumi; Park, Enoch Y; Kusakabe, Takahiro

2012-10-01

204

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

E-print Network

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.

Annika H. G. Peter

2009-02-09

205

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

PubMed

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

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

2015-03-01

206

High resolution-sensitivity characterization of polycyclic aromatic hydrocarbon-DNA adducts using fluorescence line narrowing spectrometry  

SciTech Connect

The application of fluorescence line narrowing spectrometry (FLNS) to the investigation of polar polycyclic aromatic hydrocarbon (PAH) metabolites and their corresponding DNA adducts is demonstrated. The selectivity is shown through the successful resolution of all components in separate mixtures of similar but distinct derivatives of benzo(a)pyrene, benz(a)anthracene, and chrysene. The separate mixtures were composed of six metabolites, five DNA adducts, each metabolite and its corresponding DNA adduct, and six metabolites and two DNA adducts. The broad applicability of FLNS is demonstrated through applications to the analysis of globin adducts, PAH metabolites in urine, and real samples, and to the investigation of carcinogenic metabolic pathways. 98 refs., 31 figs., 5 tabs.

Cooper, R.S.

1988-07-01

207

Development and characterization of a cell line from Pacific herring, Clupea harengus pallasi, sensitive to both naphthalene cytotoxicity and infection by viral hemorrhagic septicemia virus.  

PubMed

A cell line, PHL, has been successfully established from newly hatched herring larvae. The cells are maintained in growth medium consisting of Leibovitz's L-15 supplemented with 15% fetal bovine serum (FBS), and have been cryopreserved and maintain viability after thawing. These cells retain a diploid karotype after 65 population doublings. PHL are susceptible to infection by the North American strain of viral hemorrhagic septicemia (VHS) virus, and are sensitive to the cytotoxic effects of naphthalene, a common environmental contaminant. Naphthalene is a component of crude and refined oil, and may be found in the marine environment following acute events such as oil spills. In addition, chronic sources of naphthalene contamination include offshore drilling and petroleum contamination from areas such as docks and marinas that have creosote-treated docks and pilings and also receive constant small inputs of petroleum products. This cell line should be useful for investigations of the toxicity of naphthalene and other petroleum components to juvenile herring. In addition, studies of the VHS virus will be facilitated by the availability of a susceptible cell line from an alternative species. PMID:10813363

Ganassin, R C; Sanders, S M; Kennedy, C J; Joyce, E M; Bols, N C

1999-01-01

208

A novel way of constraining WIMPs annihilations in the Sun: MeV neutrinos  

SciTech Connect

Annihilation of dark matter particles accumulated in the Sun would produce a flux of high-energy neutrinos whose prospects of detection in neutrino telescopes and detectors have been extensively discussed in the literature. However, for annihilations into Standard Model particles, there would also be a flux of neutrinos in the MeV range from the decays at rest of muons and positively charged pions. These low-energy neutrinos have never been considered before and they open the possibility to also constrain dark matter annihilation in the Sun into e{sup +}e{sup ?}, ?{sup +}?{sup ?} or light quarks. Here we perform a detailed analysis using the recent Super-Kamiokande data in the few tens of MeV range to set limits on the WIMP-nucleon scattering cross section for different annihilation channels and computing the evaporation rate of WIMPs from the Sun for all values of the scattering cross section in a consistent way.

Bernal, Nicolás [Bethe Center for Theoretical Physics and Physikalisches Institut, Universität Bonn, Nußallee 12, D-53115 Bonn (Germany); Martín-Albo, Justo; Palomares-Ruiz, Sergio, E-mail: nicolas@th.physik.uni-bonn.de, E-mail: justo.martin-albo@ific.uv.es, E-mail: sergio.palomares.ruiz@ific.uv.es [Instituto de Física Corpuscular (IFIC), CSIC-Universitat de València, Apartado de Correos 22085, E-46071 València (Spain)

2013-08-01

209

Preliminary Limits on the WIMP-Nucleon Cross Section from the Cryogenic Dark Matter Search (CDMS)  

E-print Network

We are conducting an experiment to search for WIMPs, or weakly-interacting massive particles, in the galactic halo using terrestrial detectors. This generic class of hypothetical particles, whose properties are similar to those predicted by extensions of the standard model of particle physics, could comprise the cold component of non-baryonic dark matter. We describe our experiment, which is based on cooled germanium and silicon detectors in a shielded low-background cryostat. The detectors achieve a high degree of background rejection through the simultaneous measurement of the energy in phonons and ionization. Using exposures on the order of one kilogram-day from initial runs of our experiment, we have achieved (preliminary) upper limits on the WIMP-nucleon cross section that are comparable to much longer runs of other experiments.

DS Akerib; PD Barnes Jr; DA Bauer; PL Brink; B Cabrera; DO Caldwell; RM Clarke; A Da Silva; AK Davies; BL Dougherty; KD Irwin; RJ Gaitskell; SR Golwala; EE Haller; J Jochum; WB Knowlton; V Kuzminov; SW Nam; V Novikov; MJ Penn; TA Perera; RR Ross; B Sadoulet; RW Schnee; T Shutt; A Smith; AH Sonnenschein; AL Spadafora; WK Stockwell; S Yellin; BA Young

1997-12-30

210

Optimal detectors for WIMP and 0–? ?? searches: Identical high-pressure xenon gas TPCs?  

Microsoft Academic Search

A time projection chamber (TPC) filled with high-pressure gaseous xenon (HPXe)—instead of liquid xenon (LXe)—appears likely to offer both superior energy resolution for the 0–? ?? decay search in 136Xe and superior ?-background rejection in the search for WIMPs. An augmentation to maximize the primary scintillation detection efficiency of the 0–? ?? decay detector design will realize an optimum design

David Nygren

2007-01-01

211

Optimal detectors for WIMP and 0 nu betabeta searches: Identical high-pressure xenon gas TPCs?  

Microsoft Academic Search

A time projection chamber (TPC) filled with high-pressure gaseous xenon (HPXe)---instead of liquid xenon (LXe)---appears likely to offer both superior energy resolution for the 0 nu betabeta decay search in 136Xe and superior gamma-background rejection in the search for WIMPs. An augmentation to maximize the primary scintillation detection efficiency of the 0 nu betabeta decay detector design will realize an

David Nygren

2007-01-01

212

Hypotonic stimulation induced Ca2+ release from IP3-sensitive internal stores in a green monkey kidney cell line.  

PubMed

1. Hypotonic stimulation (180 +/- 5 mosmol l-1) increased [Ca2+]i in fura-2-loaded Green monkey kidney cells (COS-7 cells) and depolarized the membrane. 2. COS-7 cells were depolarized up to -3.5 +/- 4.4 mV from a resting membrane potential of -35.2 +/- 2.3 mV in response to hypotonic stimulation, when the patch electrode was filled with a 160 mM KCl-0.5 mM EGTA-based intracellular medium. 3. The increase in [Ca2+]i induced by hypotonic stimulation was divided into two phases. One was transient and oscillatory, and observed in Ca(2+)-free medium; the other was persistent, blocked by 100 microM La3+, and observed only in Ca(2+)-containing medium. 4. The increase in [Ca2+]i in Ca(2+)-free medium was blocked by pretreatment with 10 microM thapsigargin. The increase in [Ca2+]i induced by 10 microM thapsigargin was reduced after hypotonic stimulation which induced an increase in [Ca2+]i in Ca(2+)-free medium. 5. The increase in [Ca2+]i in Ca(2+)-free medium was not affected by treatment with 5 mM caffeine or 1-10 microM ryanodine. Neither caffeine nor ryanodine induced an increase in [Ca2+]i. 6. Adenosine 5'-O-2-thiodiphosphate (ADP-beta-S; a P2Y receptor agonist) induced an increase in [Ca2+]i in Ca(2+)-free medium and caused phosphoinositide breakdown in COS-7 cells. Exposure to 10 microM ADP-beta-S blocked the increase in [Ca2+]i induced in the Ca(2+)-free medium by hypotonic stimulation. The results of summary points 4, 5, and 6 suggest that the increase in [Ca2+]i induced by hypotonic stimulation is due to Ca2+ release from inositol 1,4,5-trisphosphate (IP3)-sensitive internal stores. 7. The hypotonic stimulation-activated hydrolysis of phosphoinositides was decreased by pertussis toxin (PTX) in a dose-dependent manner. 8. These observations strongly suggest that hypotonic stimulation induced an increase in [Ca2+]i in Ca(2+)-free medium through activation of cascades using PTX-sensitive guanine nucleotide binding protein (G protein) and IP3. PMID:8782102

Ishii, T; Hashimoto, T; Ohmori, H

1996-06-01

213

Hypotonic stimulation induced Ca2+ release from IP3-sensitive internal stores in a green monkey kidney cell line.  

PubMed Central

1. Hypotonic stimulation (180 +/- 5 mosmol l-1) increased [Ca2+]i in fura-2-loaded Green monkey kidney cells (COS-7 cells) and depolarized the membrane. 2. COS-7 cells were depolarized up to -3.5 +/- 4.4 mV from a resting membrane potential of -35.2 +/- 2.3 mV in response to hypotonic stimulation, when the patch electrode was filled with a 160 mM KCl-0.5 mM EGTA-based intracellular medium. 3. The increase in [Ca2+]i induced by hypotonic stimulation was divided into two phases. One was transient and oscillatory, and observed in Ca(2+)-free medium; the other was persistent, blocked by 100 microM La3+, and observed only in Ca(2+)-containing medium. 4. The increase in [Ca2+]i in Ca(2+)-free medium was blocked by pretreatment with 10 microM thapsigargin. The increase in [Ca2+]i induced by 10 microM thapsigargin was reduced after hypotonic stimulation which induced an increase in [Ca2+]i in Ca(2+)-free medium. 5. The increase in [Ca2+]i in Ca(2+)-free medium was not affected by treatment with 5 mM caffeine or 1-10 microM ryanodine. Neither caffeine nor ryanodine induced an increase in [Ca2+]i. 6. Adenosine 5'-O-2-thiodiphosphate (ADP-beta-S; a P2Y receptor agonist) induced an increase in [Ca2+]i in Ca(2+)-free medium and caused phosphoinositide breakdown in COS-7 cells. Exposure to 10 microM ADP-beta-S blocked the increase in [Ca2+]i induced in the Ca(2+)-free medium by hypotonic stimulation. The results of summary points 4, 5, and 6 suggest that the increase in [Ca2+]i induced by hypotonic stimulation is due to Ca2+ release from inositol 1,4,5-trisphosphate (IP3)-sensitive internal stores. 7. The hypotonic stimulation-activated hydrolysis of phosphoinositides was decreased by pertussis toxin (PTX) in a dose-dependent manner. 8. These observations strongly suggest that hypotonic stimulation induced an increase in [Ca2+]i in Ca(2+)-free medium through activation of cascades using PTX-sensitive guanine nucleotide binding protein (G protein) and IP3. Images Figure 1 PMID:8782102

Ishii, T; Hashimoto, T; Ohmori, H

1996-01-01

214

Phorbol esters rapidly stimulate amiloride-sensitive Na+/H+ exchange in a human leukemic cell line  

PubMed Central

The human, leukemic cell line, HL-60, undergoes differentiation in response to tumor-promoting phorbol esters. Recent studies have implicated stimulation of a Na+/H+ antiporter as an initial event in cellular differentiation and/or proliferation. The effects of phorbol esters on Na+-dependent H+ efflux from HL-60 cells were studied by pH- stat titration. Tumor-promoting phorbol diesters, but not the inactive parent alcohol, stimulated Na+-dependent H+ efflux in a rapid (within 1 min at 37 degrees C) and reversible manner. Stimulation was dependent on the concentration of extracellular sodium; lithium could substitute for sodium, but choline could not. Stimulation was dependent on the activity of extracellular protons and was inhibited completely by amiloride. The concentrations of phorbol diesters at which we observed half-maximal stimulation of Na+-dependent H+ efflux are very similar to the Kd reported in the literature for binding of these phorbol diesters to the phorbol ester receptor and the Km for phorbol diester activation of protein kinase C. Overall characterization of basal and phorbol ester-stimulated H+ efflux indicate that stimulation of a Na+/H+ antiporter constitutes a primary event in phorbol ester interaction with HL-60 cells. PMID:6330130

1984-01-01

215

Rapid and sensitive on-line solid phase extraction-ultra high performance liquid chromatography-electrospray-tandem mass spectrometry analysis of pesticides in surface waters.  

PubMed

A simple, fast and sensitive method has been developed for the determination of 37 LC-amenable pesticides in surface water samples. On-line solid phase extraction (SPE) coupled to ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS. was employed for pre-concentration and analysis of all compounds in 16min. SPE parameters were evaluated in order to increase sample throughput and detectability. Thus, injected sample volume, sample loading flow, carryover effects and reusability of the cartridges employed were studied, observing that 70 extractions can be performed with the same cartridge. Validation parameters were performed and good linearity (R(2)>0.99 in all cases) and precision (interday relative standard deviation values were lower than 14%) were obtained. Limits of detection (LOD) and limits of quantification (LOQ) were lower than 6.0 and 18.0ngL(-1) applying an injection sample volume of 1.5mL, respectively, with exception of thifensulfuron methyl, whose limits were 10.0 and 33.0ngL(-1), respectively. On-line SPE recoveries were evaluated for three concentration levels (0.01, 0.03, 0.10 and 0.20?gL(-1)) and acceptable values were found. The on-line SPE method was also compared with off-line SPE. Matrix effects were observed for majority of compounds and standard addition method was selected for analysis of real water samples. Finally, surface water samples were analyzed and, in all cases, the pesticide concentrations were below than the allowable limit in water for human consumption. PMID:23885668

Hurtado-Sánchez, M C; Romero-González, R; Rodríguez-Cáceres, M I; Durán-Merás, I; Frenich, A Garrido

2013-08-30

216

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

PubMed

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

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

2013-11-22

217

On-line SPE-Nano-LC-Nanospray-MS for rapid and sensitive determination of perfluorooctanoic acid and perfluorooctane sulfonate in river water.  

PubMed

An instrumental set up including on-line solid-phase extraction, nano-liquid chromatography, and nanospray mass spectrometry is constructed to improve the sensitivity for quantitation of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) in surface water. Sample volumes of 1000 microL are loaded onto a microbore 1.0-mm i.d. x 5 mm, 5 microm Kromasil C(18) enrichment column by a carrier solution consisting of 10mM ammonium acetate in acetonitrile-water (10:90, v/v) at a flow rate of 250 microL/min, providing on-line analyte enrichment and sample clean-up. Backflushed elution onto a 0.1-mm i.d. x 150 mm, 3.5 microm Kromasil C(18) analytical column is conducted using an acetonitrile-10mM ammonium acetate solvent gradient from 30% to 70% acetonitrile. Water samples are added with internal standard (perfluoroheptanoic acid) and filtrated prior to injection. The mass limits of detection of PFOA and PFOS are 0.5 and 1 pg, respectively, corresponding to concentration limits of detection of 500 pg/L and 1 ng/L, respectively. The total time spent on sample preparation, chromatography, and detection is approximately 12 min per sample. The method was employed for the determination of PFOS and PFOA in urban river water. PMID:17462129

Wilson, Steven Ray; Malerød, Helle; Holm, Anders; Molander, Paal; Lundanes, Elsa; Greibrokk, Tyge

2007-03-01

218

Neuropeptide S alters anxiety, but not depression-like behaviour in Flinders Sensitive Line rats: a genetic animal model of depression.  

PubMed

Neuropeptide S (NPS) and its receptor (NPSR) have been implicated in the mediation of anxiolytic-like behaviour in rodents. However, little knowledge is available regarding the NPS system in depression-related behaviours, and whether NPS also exerts anxiolytic effects in an animal model of psychopathology. Therefore, the aim of this work was to characterize the effects of NPS on depression- and anxiety-related parameters, using male and female rats in a well-validated animal model of depression: the Flinders Sensitive Line (FSL), their controls, the Flinders Resistant Line (FRL), and Sprague-Dawley (SD) rats. We found that FSL showed greater immobility in the forced swim test (FST) than FRL, confirming their phenotype. However, NPS did not affect depression-related behaviour in any rat line. No significant differences in baseline anxiety levels between the FSL and FRL strains were observed, but FSL and FRL rats displayed less anxiety-like behaviour compared to SD rats. NPS decreased anxiety-like behaviour on the elevated plus-maze in all strains. The expression of the NPSR in the amygdala, periventricular hypothalamic nucleus, and hippocampus was equal in all male strains, although a trend towards reduced expression within the amygdala was observed in FSL rats compared to SD rats. In conclusion, NPS had a marked anxiolytic effect in FSL, FRL and SD rats, but did not modify the depression-related behaviour in any strain, in spite of the significant differences in innate level between the strains. These findings suggest that NPS specifically modifies anxiety behaviour but cannot overcome/reverse a genetically mediated depression phenotype. PMID:21708052

Wegener, Gregers; Finger, Beate C; Elfving, Betina; Keller, Kirsten; Liebenberg, Nico; Fischer, Christina W; Singewald, Nicolas; Slattery, David A; Neumann, Inga D; Mathé, Aleksander A

2012-04-01

219

WIMP-less dark matter and meson decays with missing energy  

SciTech Connect

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.

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

2009-06-01

220

Establishment and characterization of a colonic epithelial cell line MCE301 from transgenic mice harboring temperature-sensitive simian virus 40 large T-antigen gene.  

PubMed

We produced an immortalized colonic epithelial cell line, MCE301, using fetal mice transgenic for the temperature-sensitive simian virus 40 large T-antigen gene. MCE301 cells showed epithelial-like morphology and maintained tight connections with neighboring cells. The cells grew at a permissive temperature (33 degrees C), but the growth of the cells was significantly prevented at the nonpermissive temperature (39 degrees C). The cells expressed large T-antigen at 33 degrees C but not at 39 degrees C. MCE301 cells were not transformed, as judged by the absence of anchorage-independent growth in soft agar gel and lack of tumor formation in nude mice. Electron microscopic studies showed that the cells formed microvilli-like structures on the cell surface and junctional complexes such as tight junctions and desmosomes between the cells. The cells expressed cytosketal (acidic cytokeratins and actin), basement membrane (laminin and collagen type IV) and junctional complex proteins (ZO-1 and desmoplakin I + II), as judged by specific antibodies. Fetal bovine serum, epidermal growth factor, insulin-like growth factor and insulin significantly increased the cell growth at 33 degrees C. Moreover, MCE301 cells expressed colonic mucin Muc2 mRNA as demonstrated by reverse transcriptase-polymerase chain reaction, indicating that the cells originate from mucus-secreting cells. Alkaline phosphatase, a brush border-associated enzyme, was detected in the cells. Sodium butyrate (2 mM), an inducer of cellular differentiation, markedly elevated alkaline phosphatase activity. Thus, the present mouse colonic epithelial cell line MCE301 possessing these unique characteristics should provide a useful in vitro model of colonic epithelium. PMID:11235898

Tabuchi, Y; Ohta, S; Arai, Y; Kawahara, M; Ishibashi, K; Sugiyama, N; Horiuchi, T; Furusawa, M; Obinata, M; Fuse, H; Takeguchi, N; Asano, S

2000-10-01

221

Limits on light WIMPs with a germanium detector at 177 eVee threshold at the China Jinping Underground Laboratory  

E-print Network

The China Dark Matter Experiment reports results on light WIMP dark matter searches at the China Jinping Underground Laboratory with a germanium detector array with a total mass of 20 g. The physics threshold achieved is 177 eVee ("ee" represents electron equivalent energy) at 50% signal efficiency. With 0.784 kg-days of data, exclusion region on spin-independent coupling with the nucleon is derived, improving over our earlier bounds at WIMP mass less than 4.6 GeV.

S. K. Liu; Q. Yue; K. J. Kang; J. P. Cheng; H. T. Wong; Y. J. Li; S. T. Lin; J. P. Chang; N. Chen; Q. H. Chen; Y. H. Chen; Y. C. Chuang; Z. Deng; Q. Du; H. Gong; X. Q. Hao; H. J. He; Q. J. He; H. X. Huang; T. R. Huang; H. Jiang; H. B. Li; J. M. Li; J. Li; J. Li; X. Li; X. Q. Li; X. Y. Li; Y. L. Li; H. Y. Liao; F. K. Lin; L. C. Lü; H. Ma; S. J. Mao; J. Q. Qin; J. Ren; J. Ren; X. C. Ruan; M. B. Shen; L. Singh; M. K. Singh; A. K. Soma; J. Su; C. J. Tang; C. H. Tseng; J. M. Wang; L. Wang; Q. Wang; S. Y. Wu; Y. C. Wu; Y. C. Wu; Z. Z. Xianyu; R. Q. Xiao; H. Y. Xing; F. Z. Xu; Y. Xu; X. J. Xu; T. Xue; C. W. Yang; L. T. Yang; S. W. Yang; N. Yi; C. X. Yu; H. Yu; X. Z. Yu; X. H. Zeng; Z. Zeng; L. Zhang; Y. H. Zhang; M. G. Zhao; W. Zhao; Z. Y. Zhou; J. J. Zhu; W. B. Zhu; X. Z. Zhu; Z. H. Zhu

2014-03-21

222

Search for inelastic WIMP nucleus scattering on $^{129}$Xe in data from the XMASS-I experiment  

E-print Network

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 LXe at the very center of our detector we observed no significant excess in 165.9 days of data and derived for e.g. a 50 GeV WIMP an upper limit for its inelastic cross section on $^{129}$Xe nuclei of 3.2 pb at the 90% confidence level.

Uchida, H; 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

2014-01-01

223

GENIUS and the Genius TF: A New Observatory for WIMP Dark Matter and Neutrinoless Double Beta Decay  

NASA Astrophysics Data System (ADS)

The GENIUS proposal is described and some of it's physics potential is outlined. Also in the light of the contradictive results from the DAMA and CDMS experiments the Genius TF, a new experimental setup is proposed. The Genius TF could probe the DAMA evidence region using the WIMP nucleus recoil signal and WIMP annual modulation signature simultaneously. Besides that it can prove the long term feasibility of the detector technique to be implemented into the GENIUS setup and will in this sense be a first step towards the realization of the GENIUS experiment.

Klapdor-Kleingrothaus, H. V.; Majorovits, B.

224

Blocks to herpes simplex virus type 1 replication in a cell line, tsBN2, encoding a temperature-sensitive RCC1 protein.  

PubMed

Circularization of the herpes simplex virus type 1 (HSV-1) genome is thought to be an important early event during the lytic cycle. Previous studies from another laboratory using a cell line, tsBN2, that carries a temperature-sensitive mutation in the gene encoding the regulator of chromatin condensation 1 (RCC1) indicated that functional RCC1 was required for HSV-1 genome circularization and subsequent viral DNA synthesis. Here, HSV-1 infection of tsBN2 cells has been re-examined by utilizing both wild-type HSV-1 and a derivative that enables a direct demonstration of circularization. At the non-permissive temperature, when RCC1 was absent, both circularization and viral DNA synthesis were reduced, but not abolished. However, no infectious progeny virus was detected under these conditions. An impairment in the cleavage of concatemeric DNA and the failure to express at least one capsid protein indicated that HSV-1 replication is also blocked at a late stage in the absence of RCC1. This conclusion was supported by a temperature-upshift experiment, which demonstrated a role for RCC1 at times later than 6 h post-infection. Finally, a virus constitutively expressing beta-galactosidase produced the protein in a reduced number of cells when RCC1 was inactivated, suggesting that genome delivery to the nucleus or the initial stages of gene expression may also be affected. PMID:17251553

Strang, Blair L; Stow, Nigel D

2007-02-01

225

H$_2$ Lyman and Werner band lines and their sensitivity for a variation of the proton-electron mass ratio in the gravitational potential of white dwarfs  

E-print Network

Recently an accurate analysis of absorption spectra of molecular hydrogen, observed with the Cosmic Origins Spectrograph aboard the Hubble Space Telescope, in the photosphere of white dwarf stars GD133 and GD29-38 was published in a Letter [Phys. Rev. Lett. 113, 123002 (2014)], yielding a constraint on a possible dependence of the proton-electron mass ratio on a gravitational field of strength 10,000 times that at the Earth's surface. In the present paper further details of that study are presented, in particular a re-evaluation of the spectrum of the $B^1\\Sigma_u^+ - X^1\\Sigma_g^+ (v',v'')$ Lyman bands relevant for the prevailing temperatures (12,000 - 14,000 K) of the photospheres. An emphasis is on the calculation of so-called $K_i$-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 ...

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

2014-01-01

226

RNAi-mediated knockdown of the c-jun gene sensitizes radioresistant human nasopharyngeal carcinoma cell line CNE-2R to radiation.  

PubMed

This study aimed to investigate the effect of RNA interference (RNAi)-mediated downregulation of the expression of the c-jun gene (a proto-oncogene) on the radiosensitivity of a radioresistant human nasopharyngeal carcinoma cell line (CNE-2R) and to validate its potential as an anticancer target. A lentiviral vector with c-jun small hairpin RNA (shRNA) was constructed and transfected into CNE-2R cells. The gene silencing efficiency of these recombinants was confirmed by RT-PCR and western blotting. Radiosensitivity, cell proliferation, cell cycle profile and apoptosis were assessed using colony formation assay, CCK-8 assay and flow cytometry, respectively. The lentiviral shRNA efficiently knocked down the expression of c-jun at both the mRNA and protein levels (P<0.05). c-jun-downregulated CNE-2R cells exhibited significantly decreased cell proliferation and enhanced radiosensitivity compared to the control group (P<0.05), and the effects were likely due to G2/M phase arrest and enhanced cell apoptosis. These data provide evidence that c-jun may be involved in the radioresistance of nasopharyngeal carcinoma (NPC) and knockdown of the c-jun gene may be a potential strategy to enhance the radiation sensitivity of NPC. PMID:25571870

Guo, Si-Yan; Zhu, Xiao-Dong; Ge, Lian-Ying; Qu, Song; Li, Ling; Su, Fang; Guo, Ya

2015-03-01

227

A convenient and sensitive method for haloacetic acid analysis in tap water by on-line field-amplified sample-stacking CE-ESI-MS.  

PubMed

In this study, we propose a simple strategy based on flow injection and field-amplified sample-stacking CE-ESI-MS/MS to analyze haloacetic acids (HAAs) in tap water. Tap water was passed through a desalination cartridge before field-amplified sample-stacking CE-ESI-MS/MS analysis to reduce sample salinity. With this treatment, the signals of the HAAs increased 300- to 1400-fold. The LODs for tap water analysis were in the range of 10 to 100 ng/L, except for the LOD of monochloroacetic acid (1 ?g/L in selected-ion monitoring mode detection). The proposed method is fast, convenient, and sensitive enough to perform on-line analysis of five HAAs in the tap water of Taipei City. Four HAAs, including trichloroacetic acid, dichloroacetic acid, dibromoacetic acid, and monobromoacetic acid, were detected at concentrations of approximately 1.74, 1.15, 0.16, and 0.15 ppb, respectively. PMID:24019225

Hung, Sih-Hua; Her, Guor-Rong

2013-11-01

228

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)

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

Trummer, Brian J.

229

Dark Matter Spin-Dependent Limits for WIMP Interactions on 19-F by PICASSO  

E-print Network

The PICASSO experiment at SNOLAB reports new results for spin-dependent WIMP interactions on $^{19}$F using the superheated droplet technique. A new generation of detectors and new features which enable background discrimination via the rejection of non-particle induced events are described. First results are presented for a subset of two detectors with target masses of $^{19}$F of 65 g and 69 g respectively and a total exposure of 13.75 $\\pm$ 0.48 kgd. No dark matter signal was found and for WIMP masses around 24 GeV/c$^2$ new limits have been obtained on the spin-dependent cross section on $^{19}$F of $\\sigma_F$ = 13.9 pb (90% C.L.) which can be converted into cross section limits on protons and neutrons of $\\sigma_p$ = 0.16 pb and $\\sigma_n$ = 2.60 pb respectively (90% C.L). The obtained limits on protons restrict recent interpretations of the DAMA/LIBRA annual modulations in terms of spin-dependent interactions.

S. Archambault; F. Aubin; M. Auger; E. Behnke; B. Beltran; K. Clark; X. Dai; A. Davour; J. Farine; R. Faust; M. -H. Genest; G. Giroux; R. Gornea; C. Krauss; S. Kumaratunga; I. Lawson; C. Leroy; L. Lessard; C. Levy; I. Levine; R. MacDonald; J. -P. Martin; P. Nadeau; A. Noble; M. -C. Piro; S. Pospisil; T. Shepherd; N. Starinski; I. Stekl; C. Storey; U. Wichoski; V. Zacek

2009-11-10

230

A new analysis method for WIMP searches with dual-phase liquid Xe TPCs  

NASA Astrophysics Data System (ADS)

A new data analysis method based on physical observables for WIMP dark matter searches with noble liquid Xe dual-phase TPCs is presented. Traditionally, the nuclear recoil energy from a scatter in the liquid target has been estimated by means of the initial prompt scintillation light (S1) produced at the interaction vertex. The ionization charge (C2), or its secondary scintillation (S2), is combined with the primary scintillation in log10(S2/S1) vs. S1 only as a discrimination parameter against electron recoil background. Arguments in favor of C2 as the more reliable nuclear recoil energy estimator than S1 are presented. The new phase space of log10(S1/C2) vs. C2 is introduced as more efficient for nuclear recoil acceptance and exhibiting superior energy resolution. This is achieved without compromising the discrimination power of the LXe TPC, nor its 3D event reconstruction and fiducialization capability, as is the case for analyses that exploit only the ionization channel. Finally, the concept of two independent energy estimators for background rejection is presented: E2 as the primary (based on C2) and E1 as the secondary (based on S1). log10(E1/E2) vs. E2 is shown to be the most appropriate phase space in which to evaluate WIMP signal candidates.

Arisaka, K.; Beltrame, P.; Ghag, C.; Lung, K.; Scovell, P. R.

2012-09-01

231

Characterization of a UV-resistant strain, UVr-10, established from a human clonal cell line, RSb, with high sensitivity to UV, 4NQO, MNNG and interferon.  

PubMed

Characterization was performed of a UV-resistant variant strain. UVr-10, derived from a human clonal cell line, RSb, with high sensitivity not only to the lethal effect of 254-nm far-ultraviolet (UV) irradiation but also to the effects of 4-nitroquinoline 1-oxide (4NQO) and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), and to the cell proliferation inhibition (CPI) effect of human leukocyte interferon (HuIFN-alpha) preparations. Colony-formation assays confirmed the increased resistance of UVr-10 cells to both UV and 4NQO, but no increased resistance to MNNG. The marked recovery from the inhibition of the total cellular DNA synthesis of UVr-10 cells, estimated by [methyl-3H]thymidine ([3H]dThd) uptake into the cellular DNA materials, was seen during 6 h after UV irradiation or 4NQO treatment even under the conditions without the recovery uptake into those of the parent RSb cells, but not during 6 h after MNNG treatment. Comparative studies on the activity of DNA repair synthesis between UVr-10 and RSb cells, by measuring the extent of UV-, 4NQO- or MNNG-induced unscheduled DNA synthesis (UDS) and DNA repair replication, revealed an increased activity of UVr-10 cells to UV and 4NQO but no significant increase of the activity to MNNG. These results suggest that increased DNA repair activities of a UVr-10 cell line may account for its becoming resistant to the lethal effect of UV and 4NQO. Concerning the CPI effect of HuIFN-alpha, UVr-10 cells showed increased resistance. Further, the DNA synthesis activity of UVr-10 cells was not so inhibited by HuIFN-alpha exposure as that of RSb cells. However, HuIFN-alpha-exposed UVr-10 cells showed more enhanced levels of activity of pppA(2'p5'A)n synthetase (2-5A synthetase) than the exposed RSb, thus suggesting that HuIFN-alpha could exert enough intracellular effect even in UVr-10 cells. The implication of the increased resistance of UVr-10 cells to the effects of UV, 4NQO and HuIFN-alpha, but not to those of MNNG, is discussed. PMID:6818478

Suzuki, N; Nishimaki, J; Kuwata, T

1982-12-01

232

Arctic land hydrothermal sensitivity under warming: Idealized off-line evaluation of a physical terrestrial scheme in a global climate model  

NASA Astrophysics Data System (ADS)

A series of idealized one-dimensional off-line sensitivity experiments for the Arctic hydroclimate under a transitional warming environment were conducted to investigate the impact of different internal mechanisms and external forcing (excessive water input) in a physical terrestrial scheme, Minimal Advanced Treatments of Surface Interaction and Runoff (MATSIRO), used in a global climate model. The scheme has freeze/thaw processes and was run with the column depth greater than 50 m. The inclusion of the top organic layers and the physically based parameterization of soil hydrothermal properties led to a realistic seasonal amplitude of a subsurface thermal regime and mitigated the warming and deepening of the maximum active layer thickness (ALT). After a 6-K warming over 100 years, ALT increases by 67% (from 9.6 to 16 cm) with the top organic layers and increases by more than a factor of 2 for the default mineral layers (122% from 45 cm to 1.0 m). With the more realistic thermal property profile, the physically based parameterizations projected ALT after the 100-year warming to be about a half of what the original parameterization did (2.0 against 3.5 m). Finer soil layer thickness near the surface had impacts on the near-surface wetness and the energy and water exchange between the atmosphere and also showed greater tolerance to the misconfiguration of porosity profile, whose global-scale distribution is poorly known for global climate model applications. With much wetter forcing, water infiltration kept the soil close to the saturation, degradation of the frozen state proceeded faster, and the adaptation back to a drier condition occurred on a decadal time scale.

Saito, Kazuyuki

2008-11-01

233

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

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

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

1997-01-01

234

Gene expression patterns that predict sensitivity to epidermal growth factor receptor tyrosine kinase inhibitors in lung cancer cell lines and human lung tumors  

Microsoft Academic Search

BACKGROUND: Increased focus surrounds identifying patients with advanced non-small cell lung cancer (NSCLC) who will benefit from treatment with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKI). EGFR mutation, gene copy number, coexpression of ErbB proteins and ligands, and epithelial to mesenchymal transition markers all correlate with EGFR TKI sensitivity, and while prediction of sensitivity using any one of

Justin M Balko; Anil Potti; Christopher Saunders; Arnold Stromberg; Eric B Haura; Esther P Black

2006-01-01

235

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

Microsoft Academic Search

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

Chih-Yuan Tseng; Jonathan Y Mane; Philip Winter; Lorelei Johnson; Torin Huzil; Elzbieta Izbicka; Richard F Luduena; Jack A Tuszynski

2010-01-01

236

Search for inelastic WIMP nucleus scattering on $^{129}$Xe in data from the XMASS-I experiment  

E-print Network

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 LXe at the very center of our detector we observed no significant excess of events in 165.9 days of data. Our background reduction allowed us to derive our limits without explicitly subtracting the remaining events which are compatible with background expectations and derive for e.g. a 50 GeV WIMP an upper limit for its inelastic cross section on $^{129}$Xe nuclei of 3.2 pb at the 90% confidence level.

H. Uchida; K. Abe; K. Hieda; K. Hiraide; S. Hirano; K. Ichimura; Y. Kishimoto; K. Kobayashi; S. Moriyama; K. Nakagawa; M. Nakahata; H. Ogawa; N. Oka; H. Sekiya; A. Shinozaki; Y. Suzuki; A. Takeda; O. Takachio; D. Umemoto; M. Yamashita; B. S. Yang; S. Tasaka; J. Liu; K. Martens; K. Hosokawa; K. Miuchi; A. Murata; Y. Onishi; Y. Otsuka; Y. Takeuchi; Y. H. Kim; K. B. Lee; M. K. Lee; J. S. Lee; Y. Fukuda; Y. Itow; K. Masuda; Y. Nishitani; H. Takiya; N. Y. Kim; Y. D. Kim; F. Kusaba; K. Nishijima; K. Fujii; I. Murayama; S. Nakamura

2014-01-19

237

Discovery of underground argon with low level of radioactive 39Ar and possible applications to WIMP dark matter detectors  

E-print Network

We report on the first measurement of 39Ar in argon from underground natural gas reservoirs. The gas stored in the US National Helium Reserve was found to contain a low level of 39Ar. The ratio of 39Ar to stable argon was found to be argon (39Ar/Ar=8x10-16). The total quantity of argon currently stored in the National Helium Reserve is estimated at 1000 tons. 39Ar represents one of the most important backgrounds in argon detectors for WIMP dark matter searches. The findings reported demonstrate the possibility of constructing large multi-ton argon detectors with low radioactivity suitable for WIMP dark matter searches.

C. Galbiati; R. Purtschert

2007-12-03

238

Discovery of underground argon with low level of radioactive 39Ar and possible applications to WIMP dark matter detectors.  

NASA Astrophysics Data System (ADS)

We report on the first measurement of 39Ar in argon from underground natural gas reservoirs. The gas stored in the US National Helium Reserve was found to contain a low level of 39Ar. The ratio of 39Ar to stable argon was found to be <4x10-17 (84% C.L.), less than 5% the value in atmospheric argon (39Ar/Ar=8x10-16). The total quantity of argon currently stored in the National Helium Reserve is estimated at 1000 tons. 39Ar represents one of the most important backgrounds in argon detectors for WIMP dark matter searches. The findings reported demonstrate the possibility of constructing large multi-ton argon detectors with low radioactivity suitable for WIMP dark matter searches.

Galbiati, Cristiano

2008-04-01

239

Discovery of underground argon with low level of radioactive 39Ar and possible applications to WIMP dark matter detectors  

NASA Astrophysics Data System (ADS)

We report on the first measurement of 39Ar in argon from underground natural gas reservoirs. The gas stored in the US National Helium Reserve was found to contain a low level of 39Ar. The ratio of 39Ar to stable argon was measured to be ?4×10-17 (84% C.L.), less than 5% the value in atmospheric argon ( 39Ar/Ar=8×10-16). The total quantity of argon currently stored in the National Helium Reserve is estimated at 1000 tons. 39Ar represents one of the most important backgrounds in argon detectors for WIMP dark matter searches. The findings reported demonstrate the possibility of constructing large multi-ton argon detectors with low radioactivity suitable for WIMP dark matter searches.

Acosta-Kane, D.; Acciarri, R.; Amaize, O.; Antonello, M.; Baibussinov, B.; Baldo Ceolin, M.; Ballentine, C. J.; Bansal, R.; Basgall, L.; Bazarko, A.; Benetti, P.; Benziger, J.; Burgers, A.; Calaprice, F.; Calligarich, E.; Cambiaghi, M.; Canci, N.; Carbonara, F.; Cassidy, M.; Cavanna, F.; Centro, S.; Chavarria, A.; Cheng, D.; Cocco, A. G.; Collon, P.; Dalnoki-Veress, F.; de Haas, E.; Di Pompeo, F.; Fiorillo, G.; Fitch, F.; Gallo, V.; Galbiati, C.; Gaull, M.; Gazzana, S.; Grandi, L.; Goretti, A.; Highfill, R.; Highfill, T.; Hohman, T.; Ianni, Al.; Ianni, An.; LaCava, A.; Laubenstein, M.; Lee, H. Y.; Leung, M.; Loer, B.; Loosli, H. H.; Lyons, B.; Marks, D.; McCarty, K.; Meng, G.; Montanari, C.; Mukhopadhyay, S.; Nelson, A.; Palamara, O.; Pandola, L.; Pietropaolo, F.; Pivonka, T.; Pocar, A.; Purtschert, R.; Rappoldi, A.; Raselli, G.; Resnati, F.; Robertson, D.; Roncadelli, M.; Rossella, M.; Rubbia, C.; Ruderman, J.; Saldanha, R.; Schmitt, C.; Scott, R.; Segreto, E.; Shirley, A.; Szelc, A. M.; Tartaglia, R.; Tesileanu, T.; Ventura, S.; Vignoli, C.; Visnjic, C.; Vondrasek, R.; Yushkov, A.

2008-03-01

240

Discovery of underground argon with a low level of radioactive 39Ar and possible applications to WIMP dark matter detectors  

NASA Astrophysics Data System (ADS)

We report on the first measurement of 39Ar in argon from underground natural gas reservoirs. The gas stored in the US National Helium Reserve was found to contain a low level of 39Ar. The ratio of 39Ar to stable argon was found to be <=4×10-17 (84% C.L.), less than 5% the value in atmospheric argon (39Ar/Ar=8×10-16). The total quantity of argon currently stored in the National Helium Reserve is estimated at 1000 tons. 39Ar represents one of the most important backgrounds in argon detectors for WIMP dark matter searches. The findings reported demonstrate the possibility of constructing large multi-ton argon detectors with low radioactivity suitable for WIMP dark matter searches.

Galbiati, C.; Acosta-Kane, D.; Acciarri, R.; Amaize, O.; Antonello, M.; Baibussinov, B.; Ceolin, M. B.; Ballentine, C. J.; Bansal, R.; Basgall, L.; Bazarko, A.; Benetti, P.; Benziger, J.; Burgers, A.; Calaprice, F.; Calligarich, E.; Cambiaghi, M.; Canci, N.; Carbonara, F.; Cassidy, M.; Cavanna, F.; Centro, S.; Chavarria, A.; Cheng, D.; Cocco, A. G.; Collon, P.; Dalnoki-Veress, F.; de Haas, E.; Di Pompeo, F.; Fiorillo, G.; Fitch, F.; Gallo, V.; Gaull, M.; Gazzana, S.; Grandi, L.; Goretti, A.; Highfill, R.; Highfill, T.; Hohman, T.; Ianni, A.; Ianni, A.; La Cava, A.; Laubenstein, M.; Lee, H. Y.; Leung, M.; Loer, B.; Loosli, H. H.; Lyons, B.; Marks, D.; McCarty, K.; Meng, G.; Montanari, C.; Mukhopadhyay, S.; Nelson, A.; Palamara, O.; Pandola, L.; Pietropaolo, F.; Pivonka, T.; Pocar, A.; Purtschert, R.; Rappoldi, A.; Raselli, G.; Resnati, F.; Robertson, D.; Roncadelli, M.; Rossella, M.; Rubbia, C.; Ruderman, J.; Saldanha, R.; Schmitt, C.; Scott, R.; Segreto, E.; Shirley, A.; Szelc, A. M.; Tartaglia, R.; Tesileanu, T.; Ventura, S.; Vignoli, C.; Visnjic, C.; Vondrasek, R.; Yushkov, A.

2008-07-01

241

Limits on spin-independent couplings of WIMP dark matter with a p-type point-contact germanium detector.  

PubMed

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

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

242

Limits on WIMP dark matter using scintillating CaWO 4 cryogenic detectors with active background suppression  

Microsoft Academic Search

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

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

243

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

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

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

2003-01-01

244

Selection and characterization of BCR-ABLpositive cell lines with differential sensitivity to the tyrosine kinase inhibitor STI571: diverse mechanisms of resistance  

Microsoft Academic Search

Targeting the tyrosine kinase activity of Bcr-Abl with STI571 is an attractive thera- peutic strategy in chronic myelogenous leukemia (CML). A few CML cell lines and primary progenitors are, however, resis- tant to this compound. We investigated the mechanism of this resistance in clones of the murine BaF\\/3 cells trans- fected with BCR-ABL and in 4 human cell lines from

Francois Xavier Mahon; Michael W. N. Deininger; Beate Schultheis; Jerome Chabrol; Josy Reiffers; John M. Goldman; Junia V. Melo

2000-01-01

245

The XENON100 Dark Matter Experiment: Initial Performance and Projected Sensitivity  

NASA Astrophysics Data System (ADS)

The XENON Dark Matter Project aims at the direct detection of WIMPs (Weakly Interacting Massive Particles) with dual phase (liquid/gas) xenon time projection chambers (LXeTPCs). Following the successful performance of the XENON10 detector, which has shown in 2007 the best sensitivity to spin-independent coupling of WIMPs to matter, we have designed and completed the construction of a new TPC with an active LXe shield, containing a total of 150 kg of xenon. The detector, mounted in the same passive shield used for XENON10 at the Gran Sasso Underground Laboratory, is currently undergoing gamma calibration. Based on a similar design as XENON10, XENON100 features an increase in fiducial target mass of a factor of 10, with an overall background rate about 100 times lower. We report on the status of this development and discuss the projected sensitivity reach for dark matter detection.

Aprile, Elena

2008-04-01

246

Effect of Galium verum aqueous extract on growth, motility and gene expression in drug-sensitive and -resistant laryngeal carcinoma cell lines.  

PubMed

Galium verum, also known as Lady's Bedstraw, is a herbaceous perennial plant of the family Rubiaceae, native to Europe and Asia and used in traditional medicine as an anticancer medicine. It is used as a decoction in most traditional recipes, applied externally as well as internally. We produced a Galium verum decoction and applied it in vitro to chemosensitive (Hep-2 and HLaC79) and chemoresistant, P-glycoprotein-overexpressing (Hep2-Tax, HLaC79-Tax) laryngeal carcinoma cell lines. It could be demonstrated that Galium aqueous extract is cytotoxic for all cell lines. A detailed spheroid-based 3D invasion analysis of Hep2 and Hep2-Tax in semisolid collagen gels and on different extracellular matrix coatings was performed, which showed an inhibition of invasion by sublethal concentrations of Galium decoction and proved to be even more pronounced in the more aggressively invading chemoresistant Hep2-Tax cell line. Gelatinolytic activity of MMP-2 was downregulated in three of the four cell lines. Angiogenesis (endothelial tube formation) in contrast, was not affected by Galium aqueous extract. Gene expression array on HLaC79 and Hep2 cell lines treated with Galium decoction vs. untreated controls revealed no unique pathway activation patterns in these cells. Results are discussed with respect to the use of herbal drugs as a preventive and/or a concomitant therapeutic approach in head and neck cancer. PMID:24366449

Schmidt, Marianne; Scholz, Claus-Juergen; Gavril, Georgiana-Luminita; Otto, Clemens; Polednik, Christine; Roller, Jeanette; Hagen, Rudolf

2014-03-01

247

Evidence for Serpentine as a novel antioxidant by a redox sensitive HABP1 overexpressing cell line by inhibiting its nuclear translocation of NF-?B.  

PubMed

Herbal antioxidants are gradually gaining importance as dietary supplements considering the growing implications of oxidative stress in most degenerative diseases and aging. Thus, continuous attempts are made to search for novel herbal molecules with antioxidative properties, using chemical methods predominantly with the need arising for cell based assays. We have generated a stable cell line F-HABP07, by constitutively overexpressing human Hyaluronan Binding Protein1 (HABP1) in murine fibroblasts which accumulates in the mitochondria leading to excess ROS generation without any external stimuli. In the present study, we demonstrated the nuclear translocation of p65 subunit of NF-?B in F-HABP07 cells, an important signature of ROS induced signalling cascade providing us an opportunity to use it as a screening system for ROS scavengers. Using known antioxidants on our designer cell line, we have demonstrated a dose dependant reduction in ROS generation and observed inhibition of p65 subunit of NF-?B nuclear translocation, increase in glutathione content and down-regulation of apoptotic marker Bax establishing its antioxidant biosensing capacity. With the help of this cell line, we for the first time demonstrated serpentine, one of the active components from the roots of Rauwolfia serpentina (a traditional medicinal plant), to be a novel non-cytotoxic antioxidant. The authenticity of this cell line screening system based discovery was validated using standard chemical assays thus, opening up new therapeutic avenues for this herbal compound and the use of this designer cell line. PMID:21815883

Dutta, Shubhra; Chowdhury, Anindya Roy; Srivastava, S K; Ghosh, Ilora; Datta, Kasturi

2011-11-01

248

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

1 High Sensitivity CW-Cavity Ring Down Spectroscopy of five 13 CO2 isotopologues of carbon dioxide Spectroscopy, Institute of Atmospheric Optics, SB, Russian Academy of Science, 1, Akademicheckii av., 634055, Tomsk, Russia 12/11/2009 Key words: Carbon dioxide, CO2, Cavity Ring Down Spectroscopy, effective

Boyer, Edmond

249

Optimal detectors for WIMP and 0 ? ?? searches: Identical high-pressure xenon gas TPCs?  

NASA Astrophysics Data System (ADS)

A time projection chamber (TPC) filled with high-pressure gaseous xenon (HPXe)—instead of liquid xenon (LXe)—appears likely to offer both superior energy resolution for the 0-? ?? decay search in 136Xe and superior ?-background rejection in the search for WIMPs. An augmentation to maximize the primary scintillation detection efficiency of the 0-? ?? decay detector design will realize an optimum design for both purposes. In this scenario an attractive synergy exists: two identical HPXe TPCs differing only in isotopic content will provide significantly more robust evidence for the existence of either signal if present. A simple analysis of important factors that limit energy resolution leads to the conclusion that the optimal design for either next-generation search at the few hundred kg level is the same HPXe-based TPC. A careful measurement of the scintillation and ionization responses of HPXe to nuclear and electronic recoils is needed to test the claim of HPXe superiority to LXe for the combined goals.

Nygren, David

2007-11-01

250

A New Analysis Method for WIMP searches with Dual-Phase Liquid Xe TPCs  

E-print Network

A new data analysis method based on physical observables for WIMP dark matter searches with noble liquid Xe dual-phase TPCs is presented. Traditionally, the nuclear recoil energy from a scatter in the liquid target has been estimated by means of the initial prompt scintillation light (S1) produced at the interaction vertex. The ionization charge (C2), or its secondary scintillation (S2), is combined with the primary scintillation in Log(S2/S1) vs. S1 only as a discrimination parameter against electron recoil background. Arguments in favor of C2 as the more reliable nuclear recoil energy estimator than S1 are presented. The new phase space of Log(S1/C2) vs. C2 is introduced as more e?cient for nuclear recoil acceptance and exhibiting superior energy resolution. This is achieved without compromising the discrimination power of the LXe TPC, nor its 3D event reconstruction and ?ducialization capability, as is the case for analyses that exploit only the ionization channel. Finally, the concept of two independent e...

Arisaka, Katsushi; Ghag, Chamkaur; Lung, Kevin; Scovell, Paul Robert

2012-01-01

251

Pre-launch estimates for GLAST sensitivity to dark matter annihilation signals  

SciTech Connect

We investigate the sensitivity of the Gamma-ray Large Area Space Telescope (GLAST) for indirectly detecting weakly interacting massive particles (WIMPs) through the {gamma}-ray signal that their pair annihilation produces. WIMPs are among the favorite candidates for explaining the compelling evidence that about 80% of the mass in the Universe is non-baryonic dark matter (DM). They are serendipitously motivated by various extensions of the standard model of particle physics such as supersymmetry and universal extra dimensions (UED). With its unprecedented sensitivity and its very large energy range (20 MeV to more than 300 GeV) the main instrument on board the GLAST satellite, the Large Area Telescope (LAT), will open a new window of discovery. As our estimates show, the LAT will be able to detect an indirect DM signature for a large class of WIMP models given a cuspy profile for the DM distribution. Using the current state of the art Monte Carlo and event reconstruction software developed within the LAT collaboration, we present preliminary sensitivity studies for several possible sources inside and outside the Galaxy. We also discuss the potential of the LAT to detect UED via the electron/positron channel. Diffuse background modeling and other background issues that will be important in setting limits or seeing a signal are presented.

Baltz, E A; Berenji, B; Bloom, E; Chiang, J; Cohen-Tanugi, J; Edmonds, Y; Godfrey, G [Stanford Linear Accelerator Center (SLAC), Kavli Institute for Particle Astrophysics and Cosmology (KIPAC), Menlo Park, CA 94025 (United States)] [Stanford Linear Accelerator Center (SLAC), Kavli Institute for Particle Astrophysics and Cosmology (KIPAC), Menlo Park, CA 94025 (United States); Bertone, G [Institut d'Astrophysique de Paris, 98bis Boulevard Arago, F-75014 Paris (France)] [Institut d'Astrophysique de Paris, 98bis Boulevard Arago, F-75014 Paris (France); Bergstroem, L; Bringmann, T; Conrad, J; Edsjoe, J [Physics Department, Stockholm University, Albanova, SE-10691 Stockholm (Sweden)] [Physics Department, Stockholm University, Albanova, SE-10691 Stockholm (Sweden); Hughes, R E [The Ohio State University, Columbus, OH 43210 (United States)] [The Ohio State University, Columbus, OH 43210 (United States); Johnson, R P [Santa Cruz Institute for Particle Physics, University of California, Santa Cruz, CA 95064 (United States)] [Santa Cruz Institute for Particle Physics, University of California, Santa Cruz, CA 95064 (United States); Lionetto, A; Morselli, A [INFN Roma Tor Vergata, via della Ricerca Scientifica 1, Roma (Italy)] [INFN Roma Tor Vergata, via della Ricerca Scientifica 1, Roma (Italy); Moiseev, A A [CRESST and AstroParticle Physics Laboratory, NASA/GSFC, Greenbelt, MD 20771 (United States)] [CRESST and AstroParticle Physics Laboratory, NASA/GSFC, Greenbelt, MD 20771 (United States); Moskalenko, I V [Hansen Experimental Physics Laboratory and Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305 (United States)] [Hansen Experimental Physics Laboratory and Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305 (United States); Nuss, E [LPTA, University of Montpellier, CNRS/IN2P3, Montpellier (France)] [LPTA, University of Montpellier, CNRS/IN2P3, Montpellier (France); Ormes, J F, E-mail: conrad@physto.se [University of Denver, Denver, CO 80208 (United States); and others

2008-07-15

252

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

E-print Network

-line detection zone, udet,is inversely pro- portional to the elapsed time between the start of the separation and detection, rdet: Accordingly, the time available for measurement as ana- lyte molecules pass through is achieved when the excitation intensity results in approximately 70O h photoalteration of the ana- lyte

Zare, Richard N.

253

A new matrix metalloproteinase inhibitor SI27 induces apoptosis in several human myeloid leukemia cell lines and enhances sensitivity to TNF alpha-induced apoptosis  

Microsoft Academic Search

MMP inhibitors are used clinically for the stabilization of tumor growth, thus prolonging survival in cancer patients. However, their role in the treatment of hematopoietic malignancies remains unclear. In the present study, we investigated the effects of a new MMP inhibitor, SI-27, in hematopoietic malignancies. SI-27 alone induces apoptosis in several human myeloid leukemia cell lines such as U937, NB4,

Y Nakamura; K Sato; N Wakimoto; F Kimura; A Okuyama; K Motoyoshi

2001-01-01

254

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

PubMed

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

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

255

Role of Dephosphorylation in Accumulation of 1-ß-D-Arabinofuranosylcytosine S'Triphosphate in Human Lymphoblastic Cell Lines with Reference to Their Drug Sensitivity  

Microsoft Academic Search

After a 3-day exposure to 0.1 ¡ÍM 1-\\/8-D-arabinofuranosylcy- tosine (ara-C) in culture, growth was inhibited to 5.6% in MOLT- 4F, 25% in Raji, and 91 % in Daudi cells compared with control. Growth inhibition was more profound when exposure time was extended up to 7 days. Inhibition of DNA synthesis varied with sensitivity to ara-C. Plateau levels of ¡ntracellular1-\\/?-o-arabi- nofuranosylcytosine

Ikuo Abe; Sachiko Saito; Katsuyoshi Hori; Maroh Suzuki; Haruo Sato

256

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

PubMed

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

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

2014-01-01

257

A ras GTPase-activating protein-binding protein, TaG3BP, associated with the modulation of male fertility in a thermo-sensitive cytoplasmic male sterile wheat line.  

PubMed

Hybrid wheat development may contribute to higher, more stable yield and could result in greater food security for much of the world's growing population. YS type thermo-sensitive cytoplasmic male sterile (TCMS) wheat lines were developed for use in hybrid wheat breeding in China. To investigate the molecular mechanism of modulation of male fertility in the YS-type TCMS wheat lines, a ras GTPase-activating protein-binding protein (TaG3BP) was examined. The deduced amino acid sequence encoded by TaG3BP was conserved in the sequenced genomes of Embryophyte. TaG3BP expression in the anthers of YS-type TCMS lines taken at the critical fertility reversion stage of pollen development from male fertile anthers was higher than that from male-sterile anthers, either by quantitative real-time PCR or by western blot analysis. Sequence analysis on the cDNA and genomic DNA of TaG3BP in three kinds of K-type CMS wheat lines and their maintainers indicated that there were no significant difference between the genes or in their 5' flanking sequences. The TaG3BP expression revealed by quantitative real-time RT-PCR was lower in the young spikes of these CMS lines than that of their maintainers. This indicates that TaG3BP expression is associated with the modulation, from male-sterile to fertile, of the TCMS wheat line, and TaG3BP might be a key factor in the pathway responsible for the fertility reversion. PMID:22076104

Zhou, Linlin; Song, Guoqi; He, Beiru; Hu, Yin-Gang

2011-12-01

258

Behavioral, physiological, and neuroendocrine stress responses and differential sensitivity to diazepam in two Wistar rat lines selectively bred for high- and low-anxiety-related behavior.  

PubMed

Two Wistar rat lines, selectively bred for high-anxiety-related behavior (HAB) and low-anxiety-related behavior (LAB) in the elevated plus-maze test, were tested for the susceptibility of their behavioral characteristics to anxiolytic treatment and for their endocrine and physiological reactivity to different stressors. Injection of 1 mg/kg diazepam failed to affect line differences in coping strategy but resulted in a marked (20-fold) decrease in plus-maze anxiety in HAB rats; whereas, the anxiolytic effect was less pronounced in LAB animals. Biotelemetrical measurements revealed that HAB and LAB rats do not significantly differ in their baseline body temperature, locomotor activity, food and water intake, or in stress-induced alterations of the diurnal rhythms in these parameters. However, line differences were found in acute changes in body temperature and locomotor activity following stress exposure, LAB rats responding with a greater, albeit shorter, increase in body temperature and activity than HAB animals. Basal ACTH and corticosterone plasma levels as well as pituitary reactivity to intravenously administered CRH (40 ng/kg) were similar in both lines, although, especially in response to plus-maze exposure, HAB rats tended toward higher ACTH secretion than LAB rats. These data confirm that animals with high or low basal levels of anxiety may be a promising model for studying the mechanisms of action of anxiolytic substances. Nevertheless, the endocrine findings support the notion that the reactivity of the hypothalamo-pituitary-adrenocortical system and anxiety-related behavior can be regulated independently. PMID:9778660

Liebsch, G; Linthorst, A C; Neumann, I D; Reul, J M; Holsboer, F; Landgraf, R

1998-11-01

259

NMR spectroscopy analysis of phosphorus metabolites and the effect of adriamycin on these metabolite levels in an adriamycin-sensitive and -resistant human small cell lung carcinoma cell line.  

PubMed Central

31P nuclear magnetic resonance (NMR) spectra of cells and of cell extract revealed high levels of phosphorylcholine (PC) and phosphocreatine (PCr) in an adriamycin-resistant human small cell lung carcinoma cell line (GLC4/ADR) and the adriamycin-sensitive parental cell line (GLC4). PCr levels in extracts of GLC4/ADR were increased compared to extracts of GLC4. We estimated that 11% of the total intracellular ATP is not bound to Mg2+ in both cell lines. This value corresponded to an intracellular free Mg2+ of 0.30 mM. The effects of different adriamycin concentrations, 0.05, 1 and 30 microM for GLC4 and 1, 30 and 200 microM for GLC4/ADR, on the phosphorus metabolite levels in continuously perfused cells were monitored. Significant differences between GLC4 and GLC4/ADR included: (a) a strong increase in the beta ATP level in the presence of 30 microM adriamycin in GLC4 only, followed by a fast decrease after 5 h of perfusion. (b) a less dramatic increase in the PC level in GLC4/ADR and an unchanged ATP level in the presence of increasing adriamycin concentrations. (c) an increased GPC level in GLC4/ADR in the presence of adriamycin. The changes in PC and GPC levels in the presence of adriamycin suggested that the phospholipid turnover was increased in GLC4/ADR and could be stimulated in the presence of adriamycin. In both cell lines, PCr levels decreased faster than the ATP levels after adriamycin treatment. Thus, biochemical markers for adriamycin resistance can be detected with NMR spectroscopy. However, more studies are necessary to obtain parameters to distinguish drug-sensitive from drug-resistant tumours in patients by NMR spectroscopy. PMID:1847646

de Jong, S.; Mulder, N. H.; de Vries, E. G.; Robillard, G. T.

1991-01-01

260

Volume-sensitive release of organic osmolytes in the human lung epithelial cell line A549: role of the 5-lipoxygenase.  

PubMed

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

Holm, Jacob Bak; Grygorczyk, Ryszard; Lambert, Ian Henry

2013-07-01

261

Transformation of temperature-sensitive growth mutant of BHK21 cell line to wild-type phenotype with hamster and mouse DNA.  

PubMed

A temperature-sensitive (ts) mutant, tsBN2, which was derived from BHK21 and is defective in the regulatory mechanism for chromosome condensation, was transformed to the temperature-resistant (ts+) phenotype by means of DNA-mediated gene transfer with hamster and mouse DNA. Treatment of mouse DNA with the restriction enzymes EcoRI, HindIII, PstI and SalI, but not with XhoI, almost completely abolished the transforming activity. A fluctuation test, originally devised by Luria and Delbrück, was used to estimate the reversion and transformation frequencies of tsBN2 cultures. PMID:6318373

Kai, R; Sekiguchi, T; Yamashita, K; Sekiguchi, M; Nishimoto, T

1983-11-01

262

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

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

2010-01-01

263

Yondelis® (ET-743, Trabectedin) sensitizes cancer cell lines to CD95-mediated cell death: new molecular insight into the mechanism of action.  

PubMed

Trabectedin, a naturally occurring substance isolated from the Caribbean marine invertebrate Ecteinascidia turbinata, is the active compound of the antitumor drug Yondelis®. The mechanism of action of Trabectedin has been attributed to interactions with the minor groove of the DNA double helix, thereby affecting transcription of different genes involved in DNA repair and thus facilitating lethal DNA strand breaks. Nevertheless, the existence of other clinically important molecular mechanisms has not yet been fully explored. In this paper we demonstrate how Yondelis®, apart from activating the caspase-8-dependent cascade of apoptosis, sensitizes cancer cells to Fas-mediated cell death at achievable concentrations similar to those found in the plasma of patients. In addition we show that the facilitated apoptosis activated through the Fas death receptor, is associated with a significant increase of membrane Fas/FasL, as well as the modulation of accessory proteins regulating this route, such as FLIP (L) or Akt. Thus, our results propose that the sensitization of the death receptor pathway is an essential mechanism amplifying the cytotoxic properties of Yondelis® that could explain the hepatotoxicity observed in patients treated with this drug. Finally, we also show how the use of dexamethasone as a prophylactic agent that protects against hepatotoxicity induced by Yondelis® may also inhibit some of the cytotoxic properties described in this work. The study of this important mechanism of action should set up the basis for reassessing clinical therapy with Yondelis® in order to improve antitumor treatment outcome. PMID:21371453

Martínez-Serra, Jordi; Maffiotte, Elena; Martín, Javier; Bex, Teresa; Navarro-Palou, María; Ros, Teresa; Plazas, Joana M; Vögler, Oliver; Gutiérrez, Antonio; Amat, Juan Carlos; Ramos, Rafael; Saus, Carlos; Ginés, Jordi; Alemany, Regina; Diaz, Matias; Besalduch, Joan

2011-05-11

264

Limits on light WIMPs from the CDEX-1 experiment with a p-type point-contact germanium detector at the China Jingping Underground Laboratory  

E-print Network

We report results of a search for light Dark Matter WIMPs with CDEX-1 experiment at the China Jinping Underground Laboratory, based on 53.9 kg-days of data from a p-type point-contact germanium detector enclosed by a NaI(Tl) crystal scintillator as anti-Compton detector. The event rate and spectrum above the analysis threshold of 475 eVee are consistent with the understood background model. Part of the allowed regions for WIMP-nucleus coherent elastic scattering at WIMP mass of 6-20 GeV are probed and excluded. Independent of interaction channels, this result contradicts the interpretation that the anomalous excesses of the CoGeNT experiment are induced by Dark Matter, since identical detector techniques are used in both experiments.

Q. Yue; W. Zhao; K. J. Kang; J. P. Cheng; Y. J. Li; S. T. Lin; J. P. Chang; N. Chen; Q. H. Chen; Y. H. Chen; Y. C. Chuang; Z. Deng; Q. Du; H. Gong; X. Q. Hao; H. J. He; Q. J. He; H. X. Huang; T. R. Huang; H. Jiang; H. B. Li; J. M. Li; J. Li; J. Li; X. Li; X. Y. Li; Y. L. Li; H. Y. Liao; F. K. Lin; S. K. Liu; L. C. Lv; H. Ma; S. J. Mao; J. Q. Qin; J. Ren; J. Ren; X. C. Ruan; M. B. Shen; L. Singh; M. K. Singh; A. K. Soma; J. Su; C. J. Tang; C. H. Tseng; J. M. Wang; L. Wang; Q. Wang; H. T. Wong; S. Y. Wu; Y. C. Wu; Y. C. Wu; Z. Z. Xianyu; R. Q. Xiao; H. Y. Xing; F. Z. Xu; Y. Xu; X. J. Xu; T. Xue; L. T. Yang; S. W. Yang; N. Yi; C. X. Yu; H. Yu; X. Z. Yu; X. H. Zeng; Z. Zeng; L. Zhang; Y. H. Zhang; M. G. Zhao; Z. Y. Zhou; J. J. Zhu; W. B. Zhu; X. Z. Zhu; Z. H. Zhu

2014-04-19

265

Measurement of the quenching and channeling effects in a CsI crystal used for a WIMP search  

E-print Network

We have studied channeling effects in a Cesium Iodide (CsI) crystal that is similar in composition to the ones being used in a search for Weakly Interacting Massive Particles (WIMPs) dark matter candidates, and measured its energy-dependent quenching factor, the relative scintillation yield for electron and nuclear recoils. The experimental results are reproduced with a GEANT4 simulation that includes a model of the scintillation efficiency as a function of electronic stopping power. We present the measured and simulated quenching factors and the estimated effects of channeling.

Lee, J H; Seong, I S; Kim, B H; Kim, J H; Li, J; Park, J W; Lee, J K; Kim, K W; Bhang, H; Kim, S C; Choi, Seonho; Choi, J H; Joo, H W; Lee, S J; Olsen, S L; Myung, S S; Kim, S K; Kim, Y D; Kang, W G; So, J H; Kim, H J; Lee, H S; Hahn, I S; Leonard, D S; Li, Y J; Yue, Q; Li, X R

2015-01-01

266

Measurement of the quenching and channeling effects in a CsI crystal used for a WIMP search  

E-print Network

We have studied channeling effects in a Cesium Iodide (CsI) crystal that is similar in composition to the ones being used in a search for Weakly Interacting Massive Particles (WIMPs) dark matter candidates, and measured its energy-dependent quenching factor, the relative scintillation yield for electron and nuclear recoils. The experimental results are reproduced with a GEANT4 simulation that includes a model of the scintillation efficiency as a function of electronic stopping power. We present the measured and simulated quenching factors and the estimated effects of channeling.

J. H. Lee; G. B. Kim; I. S. Seong; B. H. Kim; J. H. Kim; J. Li; J. W. Park; J. K. Lee; K. W. Kim; H. Bhang; S. C. Kim; Seonho Choi; J. H. Choi; H. W. Joo; S. J. Lee; S. L. Olsen; S. S. Myung; S. K. Kim; Y. D. Kim; W. G. Kang; J. H. So; H. J. Kim; H. S. Lee; I. S. Hahn; D. S. Leonard; J. Li; Y. J. Li; Q. Yue; X. R. Li

2015-02-12

267

Improved Limits on Spin-Dependent WIMP-Proton Interactions from a Two Liter CF{sub 3}I Bubble Chamber  

SciTech Connect

Data from the operation of a bubble chamber filled with 3.5 kg of CF{sub 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 strong direct detection constraints on weakly interacting massive particle (WIMP)-proton spin-dependent scattering for WIMP masses >20 GeV/c{sup 2}.

Behnke, E.; Behnke, J.; Hinnefeld, J. H.; Levine, I.; Shepherd, T. [Indiana University South Bend, South Bend, Indiana (United States); Brice, S. J.; Broemmelsiek, D.; Cooper, P. S.; Crisler, M.; Hall, J.; Hu, M.; Ramberg, E.; Sonnenschein, A. [Fermi National Accelerator Laboratory, Batavia, Illinois (United States); Collar, J. I.; Dahl, C. E.; Fustin, D.; Szydagis, M. [Enrico Fermi Institute, KICP and Department of Physics, University of Chicago, Chicago, Illinois (United States)

2011-01-14

268

Molecular cloning of the cDNA of human X chromosomal gene (CCG1) which complements the temperature-sensitive G1 mutants, tsBN462 and ts13, of the BHK cell line.  

PubMed Central

The tsBN462 cell line, a temperature-sensitive (ts) mutant isolated from the hamster cell line, BHK21/13 has a ts defect in G1 progression and belongs to the same complementation group as the ts13 cell line. We cloned human cDNA which can complement both tsBN462 and ts13 mutations, from the cDNA library of the secondary ts+ transformant (K-1-1) of tsBN462 cells using, as a probe, the isolated human X chromosomal genomic DNA. The cloned DNA is 5.3 kb long and has an open reading frame of 4662 bp, encoding a protein of 178,768 daltons. The putative protein is hydrophilic with a tandem repeat of 120 amino acids in the C-terminal region. An amino acid sequence (PPKKKRRV), similar to the consensus sequence for the nuclear translocation signal, is located immediately before the tandem repeat of amino acids. Images PMID:3169001

Sekiguchi, T; Miyata, T; Nishimoto, T

1988-01-01

269

Phenotypic characterization, karyotype analysis and in vitro tamoxifen sensitivity of new ER-negative vulvar carcinoma cell lines, UM-SCV-1A and UM-SCV-1B.  

PubMed

Two cell lines (University of Michigan squamous carcinoma of the vulva UM-SCV-1A and UM-SCV-1B) were established from the primary tumor and a malignant pleural effusion of a 62-year-old woman. Both tumor specimens grew vigorously in vitro and could be passaged after only 14 and 10 days in culture, respectively. Both cell lines undergo 3 population doublings in 4 days, reaching saturation densities of 5 x 10(5) cells/cm2, and have been carried through more than 30 in vitro passages. In nude mice the cultured cells initially formed tumors but these regressed 2-3 weeks after inoculation. The regressing mouse tumors consisted of poorly differentiated squamous carcinoma surrounded by an inflammatory lymphoid infiltrate. The UM-SCV-1 cell lines express membrane antigens typically displayed by squamous-cell carcinomas. These include the HLA class-1 light chain beta 2-microglobulin, pemphigus, pemphigoid, and the alpha 6 beta 4 integrin defined by the UM-A9 monoclonal antibody (MAb). In contrast to the A431 vulvar carcinoma, these tumor lines do not have amplified expression of the epidermal growth factor (EGF) receptor. Although tissue from the primary tumor contained low levels of estrogen receptor activity, no receptor activity was detected in the cell lines. Nevertheless, both lines were sensitive to growth inhibition by tamoxifen. This effect was not reversible by estradiol, indicating an estrogen-receptor-independent mechanism. The tumors were both hypotetraploid, contained the same chromosome rearrangements and had stable karyotypes in vitro. Each contained inv(1)(p36.3q32.1), del(4)(q12), dic(4;11)(q12;p11.2), i(5p), der(6)t(3;6)(q25.1;p21.1), several rearrangements involving chromosomes 8 and 14, + i(13), i(18p), a dicentric t(11;19), and 2 or 3 unidentified markers. Since the karyotypes of both tumors were the same, no major karyotypic change was associated with metastatic spread. These paired primary and metastatic SCC lines from an unusually aggressive vulvar carcinoma provide an in vitro model for analysis of the biological basis of this tumor's behavior. PMID:2335395

Grénman, S E; Van Dyke, D L; Worsham, M J; England, B; McClatchey, K D; Hopkins, M; Babu, V R; Grénman, R; Carey, T E

1990-05-15

270

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)

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.

Konrad, H.; Sasgen, I.; Thoma, M.; Klemann, V.; Grosfeld, K.; Martinec, Z.

2013-12-01

271

High-specificity and high-sensitivity genotoxicity assessment in a human cell line: validation of the GreenScreen HC GADD45a-GFP genotoxicity assay.  

PubMed

The battery of genetic toxicity tests required by most regulatory authorities includes both bacterial and mammalian cell assays and identifies practically all genotoxic carcinogens. However, the relatively high specificity of the Salmonella mutagenicity assay (Ames test) is offset by the low specificity of the established mammalian cell assays, which leads to difficulties in the interpretation of the biological relevance of results. This paper describes a new high-throughput assay that links the regulation of the human GADD45a gene to the production of Green Fluorescent Protein (GFP). A study of 75 well-characterised genotoxic and non-genotoxic compounds with diverse mechanisms of DNA-damage induction (including aneugens) reveals that the assay responds positively to all classes of genotoxic damage with both high specificity and high sensitivity. The current micro-well assay format does not include metabolic activation, but a separate low-throughput protocol demonstrates a successful proof-of-principle for an S9 metabolic activation assay with the model pro-mutagen cyclophosphamide. The test should be of value both as a tool in the selection of candidate compounds for further development, where additional data may be required because of conflicting information from the in vitro test battery, or in product development areas where the use of animals is to be discontinued. As a microplate assay however, it has the qualities of high throughput and low compound use that will facilitate its application in early screening for genotoxic liability. PMID:16781187

Hastwell, Paul W; Chai, Li-Leng; Roberts, Kevin J; Webster, Thomas W; Harvey, James S; Rees, Robert W; Walmsley, Richard M

2006-09-01

272

Suppression of telomere-binding protein TPP1 resulted in telomere dysfunction and enhanced radiation sensitivity in telomerase-negative osteosarcoma cell line.  

PubMed

Mammalian telomeres are protected by the shelterin complex that contains the six core proteins POT1, TPP1, TIN2, TRF1, TRF2 and RAP1. TPP1, formerly known as TINT1, PTOP, and PIP1, is a key factor that regulates telomerase recruitment and activity. In addition to this, TPP1 is required to mediate the shelterin assembly and stabilize telomere. Previous work has found that TPP1 expression was elevated in radioresistant cells and that overexpression of TPP1 led to radioresistance and telomere lengthening in telomerase-positive cells. However, the exact effects and mechanism of TPP1 on radiosensitivity are yet to be precisely defined in the ALT cells. Here we report on the phenotypes of the conditional deletion of TPP1 from the human osteosarcoma U2OS cells using ALT pathway to extend the telomeres.TPP1 deletion resulted in telomere shortening, increased apoptosis and radiation sensitivity enhancement. Together, our findings show that TPP1 plays a vital role in telomere maintenance and protection and establish an intimate relationship between TPP1, telomere and cellular response to ionizing radiation, but likely has the specific mechanism yet to be defined. PMID:24513288

Qiang, Weiguang; Wu, Qinqin; Zhou, Fuxiang; Xie, Conghua; Wu, Changping; Zhou, Yunfeng

2014-03-01

273

Constraints on WIMP annihilation for contracted dark matter in the inner Galaxy with the Fermi-LAT  

SciTech Connect

We derive constraints on parameters of generic dark matter candidates by comparing theoretical predictions with the gamma-ray emission observed by the Fermi-LAT from the region around the Galactic Center. Our analysis is conservative since it simply requires that the expected dark matter signal does not exceed the observed emission. The constraints obtained in the likely case that the collapse of baryons to the Galactic Center is accompanied by the contraction of the dark matter are strong. In particular, we find that for b b-bar and ?{sup +}?{sup ?} or W{sup +}W{sup ?} dark matter annihilation channels, the upper limits on the annihilation cross section imply that the thermal cross section is excluded for a Weakly Interacting Massive Particle (WIMP) mass smaller than about 700 and 500 GeV, respectively. For the ?{sup +}?{sup ?} channel, where the effect of the inverse Compton scattering is important, depending on models of the Galactic magnetic field the exclusion of the thermal cross-section is for a WIMP mass smaller than about 150 to 400 GeV. The upper limits on the annihilation cross section of dark matter particles obtained are two orders of magnitude stronger than without contraction. In the latter case our results are compatible with the upper limits from the Galactic halo analysis reported by the Fermi-LAT collaboration for the case in which the same conservative approach without modeling of the astrophysical background is employed.

Gómez-Vargas, Germán A.; Huh, Ji-Haeng; Peiró, Miguel; Cerdeño, David G.; Muñoz, Carlos [Departamento de Física Teórica, Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049 Madrid (Spain); Sánchez-Conde, Miguel A. [SLAC National Accelerator Laboratory and Kavli Intitute for Particle Astrophysics and Cosmology, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Prada, Francisco [Instituto de Física Teórica UAM-CSIC, Campus de Cantoblanco UAM, 28049 Madrid (Spain); Morselli, Aldo [Istituto Nazionale di Fisica Nucleare, Sez. Roma Tor Vergata, Via della Ricerca Scientifica, 00133 Roma (Italy); Klypin, Anatoly [Astronomy Department, New Mexico State University, Astronomy building, Las Cruces NM (United States); Mambrini, Yann, E-mail: germanarturo.gomez@uam.es, E-mail: masc@stanford.edu, E-mail: jhhuh@physics.ucla.edu, E-mail: miguel.peiro@uam.es, E-mail: fprada@iaa.es, E-mail: aldo.morselli@roma2.infn.it, E-mail: klypin@nmsu.edu, E-mail: davidg.cerdeno@uam.es, E-mail: yann.mambrini@th.u-psud.fr, E-mail: carlos.munnoz@uam.es [Laboratoire de Physique Théorique Université Paris-Sud, F-91405 Orsay (France)

2013-10-01

274

The seminoma cell line TCam-2 is sensitive to HDAC inhibitor depsipeptide but tolerates various other chemotherapeutic drugs and loss of NANOG expression.  

PubMed

Seminomas and embryonal carcinomas (EC) are both type II germ cell tumor (GCT) entities and develop from the same precursor lesion (carcinoma-in situ, CIS). However, they show significant differences in growth behavior, differentiation potential, and gene expression. Although ECs are prone to differentiate into all three germ layers and give rise to the non-seminomatous GCT entities teratoma, choriocarcinoma, and yolk-sac tumor, differentiation of seminomas to these entities is only rarely observed. This might reflect the ability of seminomas to actively inhibit differentiation processes evoked by environmental cues. Also, it is not known why CIS gives rise to seminoma in some patients and to non-seminoma in the others. Here, we treated the seminoma-like cell line TCam-2 with the HDAC-inhibitor Depsipeptide, the global demethylating agent 5-aza-2'-deocycytidine, all-trans retinoic acid and the monaminooxidase inhibitor Tranylcipromine and also used knock down approaches to reduce expression of the pluripotency marker NANOG and/or the inhibitor of primordial germ cell differentiation TFAP2C. We found that TCam-2 cells induce apoptosis when treated with Depsipeptide (> 10 nM) but are resistant to treatments with 5-aza-2'-deocycytidine, all-trans retinoic acid and Tranylcipromine, highlighting Depsi as a treatment option for seminomas. We show that TCam-2 cells up-regulate endoderm- and throphectoderm-associated genes after down-regulation of NANOG expression; however, morphologically no indications of differentiation could be found. Instead, we observed up-regulation of OCT3/4 and SOX17 in TCam-2-NANOG knockdown and speculate that this compensates for the loss of the NANOG protein. Hence, NANOG is not a primary target gene responsible for the inhibition of differentiation in seminomas. PMID:21987446

Nettersheim, Daniel; Gillis, Ad; Biermann, Katharina; Looijenga, Leendert H J; Schorle, Hubert

2011-12-01

275

Limits on spin-independent wimp-nucleon interactions from the two-tower run of the cryogenic dark matter search  

SciTech Connect

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.

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

276

WIMPs search by scintillators possible strategy for annual modulation search with large-mass highly-radiopure NaI(Tl)  

E-print Network

The DAMA experiments are running deep underground in the Gran Sasso National Laboratory. Several interesting results have been achieved so far. Here a maximum likelihood method to search for the WIMP annual modulation signature is discussed and applied to a set of preliminary test data collected with large mass highly radiopure NaI(Tl) detectors. Various related technical arguments are briefly addressed.

Bernabei, R; Belli, P; Dai Chang Jiang; Ding, L K; Incicchitti, A; Kuang Hao Huai; Ma, J M; Montecchia, F; Nicolantonio, W D; Prosperi, D

1999-01-01

277

Durham, July 14 2009 Aldo Morselli, INFN Roma Tor Vergata 15th Patras Workshop on Axions, WIMPs and WISPs, Durham 13-17 July 2009 Aldo Morselli  

E-print Network

Durham, July 14 2009 Aldo Morselli, INFN Roma Tor Vergata 15th Patras Workshop on Axions, WIMPs and WISPs, Durham 13-17 July 2009 Aldo Morselli INFN Roma Tor Vergata Search for Dark matter in the sky in the Fermi, Atic and Pamela era #12;Durham, July 14 2009 Aldo Morselli, INFN Roma Tor Vergata 2 #12;Durham

Morselli, Aldo

278

Understanding copper sensitivity in zebrafish (Danio rerio) through the intracellular localization of copper transporters in a hepatocyte cell-line ZFL and the tissue expression profiles of copper transporters.  

PubMed

Zebrafish (Danio rerio) is a freshwater fish species of Cyprinidae known for its copper (Cu) intolerance, yet the underlying mechanisms of the sensitivity remain unclear. In this study, we examined the highly conserved molecular machineries in the copper handling system, namely ATOX1, ATP7A, ATP7B, and CTR1, by profiling their gene expression patterns among tissues before and after acute waterborne Cu exposure, and investigating their intracellular localization patterns using a zebrafish hepatocyte cell line, ZFL. We found that ATP7B was weak in its response toward Cu exposure to elicit its copper efflux function. Tissue distribution of these Cu transporters, however, revealed a distinct expression profile compared with mammals and other fish, particularly ATP7A, which unlike ATP7B was highly expressed in the liver, while ATP7B, not ATP7A, was specifically expressed in the intestine. ATOX1 transcript expression was also found to be significantly up-regulated with acute waterborne Cu, in contrast to the decreased expression found in other fish. A possible explanation for the Cu sensitivity in zebrafish is discussed. PMID:24658744

Leung, King Pong; Chen, Dongshi; Chan, King Ming

2014-05-01

279

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

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

Fang, K.

1996-01-01

280

BRCA1 overexpression sensitizes cancer cells to lovastatin via regulation of cyclin D1-CDK4-p21WAF1/CIP1 pathway: analyses using a breast cancer cell line and tumoral xenograft model.  

PubMed

It is well established that statins display potent anticancer activity in several types of proliferating tumor cells. However, how to promote the sensitivity of statins to mammary cancer is yet to be completely deciphered. The purpose of this study was to investigate whether breast cancer susceptibility gene 1 (BRCA1) overexpression sensitizes mammary cancer cells to statins. MCF-7 cells, which have only one wild-type BRCA1 allele, were transfected with pcDNA3-beta-HA-hsBRCA1 plasmids via liposomes to reconstitute BRCA1 overexpression human breast cancer cell line, and tumoral xenografts with BRCA1 overexpression were subsequently established in BALB/c nude mice. Then, the inhibitory activity of lovastatin on cancer cells and tumoral xenografts, and the underlying mechanism involving in cell-cycle regulatory proteins were analyzed. The proliferative ability of MCF-7 cells treated with lovastatin was reduced compared to normal, and further decreased in the presence of excess BRCA1, detected by methyl thiazolyl tetrazolium and flow cytometry techniques in vitro or by 5-bromodeoxyuridine incorporation in vivo. Additionally, the mRNA and protein expression of cyclin D1, cyclin-dependent kinase 4 (CDK4) and retinoblastoma protein (pRb), was further down-regulated under exposure to lovastatin in condition of BRCA1 overexpression, but the expression of p21WAF1/CIP1, a cyclin-dependent kinase inhibitor (CDKI), was further up-regulated, both in vitro and in vivo detected with quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot analysis. Moreover, we found the further reduced volume of tumoral xenografts treated with lovastatin in the presence of BRCA1 overexpression. Our results suggest that BRCA1 overexpression sensitizes cancer cells to lovastatin via regulation of cyclin D1-CDK4-p21WAF1/CIP1 pathway, which will provide an innovative experimental framework to study control of breast cancer cell proliferation. PMID:18695886

Yu, Xiaoping; Luo, Yuanqiong; Zhou, Yong; Zhang, Qianyong; Wang, Jian; Wei, Na; Mi, Mantian; Zhu, Jundong; Wang, Bin; Chang, Hui; Tang, Yong

2008-09-01

281

Annual modulation sensitivity in cold dark matter searches  

E-print Network

The sensitivity of experiments looking for annual modulated signals is discussed and analyzed. The choice of energy intervals for rate integration and enhancing the signal-to-noise ratio of the predicted WIMP signal is addressed. Special emphasis is placed on quantifying the minimum required exposure, MT, under experimental conditions. The difficulty reduces to establish the proper separation between the rate due to the unmodulated part of the WIMP signal and the rate of spurious background present in any experiment. The problem is solved by placing an upper bound to the unmodulated part of the signal using the best exclusion plot. We find that the lowest backgrounds achieved result in exposures in the range MT ~ 5 - 100 kg yr for masses m_{\\chi} > 100 GeV depending on the energy threshold of the detector. While our results are valid for Ge and NaI detectors, the formulae derived apply to other elements as well. Prescriptions are given to estimate exposures for higher background experiments.

F. Hasenbalg

1998-06-15

282

Sensitive Teeth  

MedlinePLUS

... tooth). When the dentin is exposed, cold or hot temperature or pressure can affect these nerve branches. This ... symptom. Less often, the teeth are sensitive to hot temperatures. If a single tooth becomes sensitive to heat, ...

283

Gluten Sensitivity  

MedlinePLUS

... Restaurant Certified Products Educational Bulletins Local Branches Gluten Sensitivity What is it? Individuals who experience distress when ... following a gluten-free diet may have gluten sensitivity (GS), instead of celiac disease (CD). These individuals ...

284

The novel sensitive and high throughput determination of cefepime in mouse plasma by SCX-LC/MS/MS method following off-line microElution 96-well solid-phase extraction to support systemic antibiotic programs.  

PubMed

A sensitive and high throughput off-line microElution 96-well solid-phase extraction (SPE) followed by strong cation exchange (SCX) liquid chromatography with tandem mass spectrometry (LC/MS/MS) quantification for determination of cefepime has been developed and validated in mouse plasma. Using the chemical analog, ceftazidime as an internal standard (IS), the linear range of the method for the determination of cefepime in mouse plasma was 4-2048 ng/mL with the lower limit of quantitation level (LLOQ) of 4 ng/mL. The inter- and intra-assay precision and accuracy of the method were below 9.05% and ranged from 95.6 to 113%, respectively, determined by quality control (QC) samples at five concentration levels including LLOQ. After microElution SPE, 71.1% of cefepime was recovered. The application of the validated assay for the determination of cefepime in mouse pharmacokinetics (PK) samples after intravenous (IV) and subcutaneous (SC) doses was demonstrated. PMID:20400382

Bu, Wei; Sexton, Holly; Fan, Xiaoqing; Torres, Patricia; Houston, Paul; Heyman, Irwin; Liu, Liang

2010-06-01

285

$B_s \\to ?^+ ?^-$ and the upward-going muon flux from the WIMP annihilation in the sun or the earth  

E-print Network

We consider the upward-going muon flux due to the WIMP annihilations in the cores of the sun and the earth, including the upper bound on the branching ratio for $B_s \\to \\mu^+ \\mu^-$ decay. We find that the constraint from $B_s \\to \\mu^+ \\mu^-$ is very strong in most parameter space, and exclude the supergravity parameter space regions where the expected upward-going muon fluxes are within the expected reach of AMANDA II.

Seungwon Baek; Yeong Gyun Kim; P. Ko

2005-06-13

286

A genetic rat model of depression, Flinders Sensitive Line, has a lower density of 5-HT1A receptors, but a higher density of 5-HT1B receptors, compared to control rats  

PubMed Central

Deficiencies in brain serotonergic neurotransmission, which is in part associated with the alteration of brain serotonin (5-HT) receptors, have been proposed as part of a neurochemical imbalance in affective disorders, including depression. The drugs used for the treatment of these disorders generally act through and/or on the serotonergic system. Different animal models of depression have provided researchers with tools to obtain a better understanding of drug actions and possibilities to obtain insight into the neurochemical bases of these disorders. The measurements of the 5-HT1A and 5-HT1B receptor densities in a rat model of depression, Flinders Sensitive Line (FSL) rats, and comparisons with Sprague-Dawley (SPD) and Flinders Resistant Line (FRL) rats, are reported here. The receptor sites were quantified by autoradiography in more than twenty-five distinct brain regions known to have relatively large densities of respective sites. Some brain regions (e.g., dental gyrus, septal nucleus) were divided into several parts, according to previously known subdivisions, because of a substantial heterogeneity of these receptors. The densities in the FSL rats (“depressed” rats) were compared statistically to those in the SPD rats. In addition, comparisons were made to the densities in the FRL rats (rats not showing depressive symptoms). Comparisons were performed with the SPD and FRL rats because both of these strains have been used as control animals in studies of FSL rats. The results show that the densities of 5-HT1A receptors are not significantly different between the FSL and SPD rats, but they are significantly different from the FRL rats. 5-HT1A receptor density is significantly higher in the FRL rats than the SPD rats. The 5-HT1B receptors were significantly greater in the FSL rats than in either the SPD or FRL rats. In addition, the FRL rats have 5-HT1B receptor densities significantly lower in many brain regions than the SPD rats. The data presented here, in addition to previously reported differences in regional synthesis between these strains and the effect of acute citalopram on synthesis, suggest that SPD rats are likely a more appropriate control than FRL rats, when studies of FSL rats are performed with drugs acting directly or indirectly on, or through, the brain serotonergic system. However, comparisons, particularly of neurochemical and/or biological parameters in FRL rats, may reveal new insight into the alterations of 5-HT neurotransmission in this animal model of depression and possibly human depression, as well as the elevation of symptoms with treatments. The data also suggest that there could be a different fraction of 5-HT1A receptors in high and low affinity states in these strains, as well as the possibility of different intracellular signalling. PMID:19121358

Nishi, Kyoko; Kanemaru, Kazuya; Diksic, Mirko

2008-01-01

287

Sensitive Periods  

PubMed Central

This chapter reviews sensitive periods in human brain development based on the literature on children raised in institutions. Sensitive experiences occur when experiences are uniquely influential for the development of neural circuitry. Because in humans, we make inferences about sensitive periods from evaluations of complex behaviors, we underestimate the occurrence of sensitive periods at the level of neural circuitry. Although we are most interested in complex behaviors, such as IQ or attachment or externalizing problems, many different sensitive periods at the level of circuits probably underlie these complex behaviors. Results from a number of studies suggest that across most, but not all, domains of development, institutional rearing limited to the first 4–6 months of life is associated with no significant increase risk for long-term adverse effects relative to non-institutionalized children. Beyond that, evidence for sensitive periods is less compelling, meaning that “the earlier the better” rule for enhanced caregiving is a reasonable conclusion at the current state of the science. PMID:25125708

Zeanah, Charles H.; Gunnar, Megan R.; McCall, Robert B.; Kreppner, Jana M.; Fox, Nathan A.

2010-01-01

288

Measure Lines  

ERIC Educational Resources Information Center

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…

Crissman, Sally

2011-01-01

289

The local dark matter phase-space density and impact on WIMP direct detection  

SciTech Connect

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.

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

290

Case for a 700+GeV WIMP: Cosmic ray spectra from PAMELA, Fermi, and ATIC  

NASA Astrophysics Data System (ADS)

Multiple lines of evidence indicate an anomalous injection of high-energy e+e- in the galactic halo. The recent e+ fraction spectrum from the payload for antimatter matter exploration and light-nuclei astrophysics (PAMELA) shows a sharp rise up to 100 GeV. The Fermi gamma-ray space telescope has found a significant hardening of the e+e- cosmic-ray spectrum above 100 GeV, with a break, confirmed by HESS at around 1 TeV. The advanced thin ionization calorimeter (ATIC) has also detected a similar excess, falling back to the expected spectrum at 1 TeV and above. Excess microwaves towards the galactic center in the WMAP data are consistent with hard synchrotron radiation from a population of 10-100 GeV e+e- (the WMAP “Haze”). We argue that dark matter annihilations can provide a consistent explanation of all of these data, focusing on dominantly leptonic modes, either directly or through a new light boson. Normalizing the signal to the highest energy evidence (Fermi and HESS), we find that similar cross sections provide good fits to PAMELA and the Haze, and that both the required cross section and annihilation modes are achievable in models with Sommerfeld-enhanced annihilation. These models naturally predict significant production of gamma rays in the galactic center via a variety of mechanisms. Most notably, there is a robust inverse-Compton scattered (ICS) gamma-ray signal arising from the energetic electrons and positrons, detectable at Fermi/GLAST energies, which should provide smoking gun evidence for this production.

Cholis, Ilias; Dobler, Gregory; Finkbeiner, Douglas P.; Goodenough, Lisa; Weiner, Neal

2009-12-01

291

An assessment of the sensitivity of a low pressure time projection chamber to the direction of WIMP-induced nuclear recoils/  

E-print Network

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 ...

Henderson, Shawn Wesley

2013-01-01

292

Zip Line  

NSDL National Science Digital Library

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.

Wgbh

2010-01-01

293

Sensitivity, block sensitivity, and `block sensitivity of boolean functions  

E-print Network

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

Kenyon, Claire

294

Shapely Lines  

NSDL National Science Digital Library

This activity gives students practice drawing straight lines with a ruler and looking for and categorizing shapes, for example, by the number of sides in polygons. The Teachers' Notes page includes suggestions for implementation, discussion questions and ideas for extension.

2010-06-01

295

Number Line  

NSDL National Science Digital Library

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.

Clarity Innovations, Inc.

2013-11-22

296

Number Line  

NSDL National Science Digital Library

In this brief article the numerous uses of the number line are detailed: counting, measurement, addition, subtraction, decimals, and fractions. The article contains visual representations of the some of the concepts and links to related topics.

2012-08-27

297

Wimps Need Not Apply.  

ERIC Educational Resources Information Center

A corporate leader argues that higher education leaders must be prepared to manage change, and suggests focusing on results, communicating straight and openly, and delegating responsibility. An institutionwide communication program and greater efficiency are key elements in management change. (MSE)

Walsh, Michael H.

1991-01-01

298

Stochastic resonance in visual sensitivity.  

PubMed

It is well known from psychophysical studies that stochastic resonance, in its simplest threshold paradigm, can be used as a tool to measure the detection sensitivity to fine details in noise contaminated stimuli. In the present manuscript, we report simulation studies conducted in the similar threshold paradigm of stochastic resonance. We have estimated the contrast sensitivity in detecting noisy sine-wave stimuli, with varying area and spatial frequency, as a function of noise strength. In all the cases, the measured sensitivity attained a peak at intermediate noise strength, which indicate the occurrence of stochastic resonance. The peak sensitivity exhibited a strong dependence on area and spatial frequency of the stimulus. We show that the peak contrast sensitivity varies with spatial frequency in a nonmonotonic fashion and the qualitative nature of the sensitivity variation is in good agreement with human contrast sensitivity function. We also demonstrate that the peak sensitivity first increases and then saturates with increasing area, and this result is in line with the results of psychophysical experiments. Additionally, we also show that critical area, denoting the saturation of contrast sensitivity, decreases with spatial frequency and the associated maximum contrast sensitivity varies with spatial frequency in a manner that is consistent with the results of psychophysical experiments. In all the studies, the sensitivities were elevated via a nonlinear filtering operation called stochastic resonance. Because of this nonlinear effect, it was not guaranteed that the sensitivities, estimated at each frequency, would be in agreement with the corresponding results of psychophysical experiments; on the contrary, close agreements were observed between our results and the findings of psychophysical investigations. These observations indicate the utility of stochastic resonance in human vision and suggest that this paradigm can be useful in psychophysical studies. PMID:25398687

Kundu, Ajanta; Sarkar, Sandip

2014-11-15

299

Establishment and Application of in Vitro Membrane Potential Assays in Cell Lines with Endogenous or Recombinant Expression of ATP-Sensitive Potassium Channels (Kir6.2\\/SUR1) Using a Fluorescent Probe Kit  

Microsoft Academic Search

The flow of current through the adenosine triphosphate (ATP)-sensitive potassium channel (KATP) of the isoform Kir6.2\\/SUR1 regulates the resting membrane potential in the pancreatic &bgr;-cell. In combination with the cellular glucose metabolism, it is an important minute-to-minute regulator of insulin secretion and whole-body glucose homeostasis. The same KATP isoform is further reported to be present in glucagon-secreting &agr;-cells, intestinal L-cells,

Per Arkhammar; Philip Wahl; Berit Gerlach; Tinna Fremming; John B. Hansen

2004-01-01

300

Differential Sensitivity of A 2A and Especially D 2 Receptor Trafficking to Cocaine Compared with Lipid Rafts in Cotransfected CHO Cell Lines. Novel Actions of Cocaine Independent of the DA Transporter  

Microsoft Academic Search

The effects of low and high concentrations of cocaine have been studied in vitro on the trafficking of plasma membrane A2A and D2 immunoreactivities in previously characterized A2A-D2 CHO cell lines. Receptor double immunofluorescence staining was performed with D2 and A2A antibodies, planar lipid rafts immunolabeling with biotinylated cholera toxin subunit B and membrane invaginations with an\\u000a anti-caveolin-1 antibody. A

Susanna Genedani; Chiara Carone; Diego Guidolin; Monica Filaferro; Daniel Marcellino; Kjell Fuxe; Luigi Francesco Agnati

2010-01-01

301

O6-methylguanine-DNA methyltransferase (MGMT) transfectants of a 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU)-sensitive colon cancer cell line selectively repopulate heterogenous MGMT+/MGMT- xenografts after BCNU and O6-benzylguanine plus BCNU.  

PubMed

To evaluate the role of O6-alkylguanine-DNA alkyltransferase (AGT) in colon tumor chloroethylnitrosourea (CENU) resistance, AGT-deficient VACO 8 cells were transfected with a vector containing or lacking the human O6-methylguanine-DNA methyltransferase (MGMT) cDNA. VACO 8MGMT (V8MGMT) sublines possessed high levels of AGT activity in cell culture and were > 10-fold resistant to the CENU 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU). V8MGMT cells, VACO 8neo cells, and mixtures of both were grown as xenografts in nude mice. MGMT expression in VACO 8 xenografts reflected the percentage of V8MGMT cells present in the tumor inoculum. Xenografts originally containing 0-10% V8MGMT cells were sensitive to BCNU, although partial resistance was observed as the percentage of V8MGMT cells increased. Tumors containing 30-100% V8MGMT cells were completely resistant to BCNU with no regressions and no growth delays. Pretreatment with O6-benzylguanine (BG) depleted tumor AGT activity for at least 6 h and sensitized xenografts containing 1 and 100% V8MGMT cells to BCNU. After BCNU or BG + BCNU, xenografts growing from inoculums containing as low as 0.1% V8MGMT cells had high AGT activities similar to that found in V8MGMT xenografts, with the majority of the cells expressing MGMT. These results provide evidence that MGMT expression influences both intrinsic and acquired colon tumor CENU resistance, that selective expansion of AGT+ colon tumor cells commonly occurs after CENU exposure, and that BG is effective in sensitizing colon tumors to CENUs, even when only a small fraction of the cells in a heterogeneous tumor express MGMT. PMID:9354444

Phillips, W P; Willson, J K; Markowitz, S D; Zborowska, E; Zaidi, N H; Liu, L; Gordon, N H; Gerson, S L

1997-11-01

302

Assembly Line  

NSDL National Science Digital Library

In this activity, learners work individually to assemble a product and then work in teams to design, construct, test, and redesign an assembly line process whose product must meet specific quality control criteria. Learners reflect and compare the two approaches. Note: Page 14 is not in the correct position. It should actually be between pages 2 and 3.

Ieee

2014-05-22

303

Pi Line  

NSDL National Science Digital Library

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 ÃÂ, 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.

2011-01-19

304

Washing Line  

NSDL National Science Digital Library

Children can use this interactive applet to practice counting and ordering numbers up to 24 in groups of 10 at a time. An empty clothesline appears along with 9 number cards and a mystery card. Students drag the numbers onto the line in the correct sequence and then determine the mystery number. After the first round, 1 - 10, users may select from three ranges, starting at 1, 7, or 15.

2009-01-01

305

High Voltage Lines: Hazard at a Distance.  

ERIC Educational Resources Information Center

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)

Marino, Andrew A.; Becker, Robert O.

1978-01-01

306

Gravitational-wave sensitivity curves  

NASA Astrophysics Data System (ADS)

There are several common conventions in use by the gravitational-wave community to describe the amplitude of sources and the sensitivity of detectors. These are frequently confused. We outline the merits of and differences between the various quantities used for parameterizing noise curves and characterizing gravitational-wave amplitudes. We conclude by producing plots that consistently compare different detectors. Similar figures can be generated on-line for general use at http://rhcole.com/apps/GWplotter.

Moore, C. J.; Cole, R. H.; Berry, C. P. L.

2015-01-01

307

Sensitivity Analysis in Engineering  

NASA Technical Reports Server (NTRS)

The symposium proceedings presented focused primarily on sensitivity analysis of structural response. However, the first session, entitled, General and Multidisciplinary Sensitivity, focused on areas such as physics, chemistry, controls, and aerodynamics. The other four sessions were concerned with the sensitivity of structural systems modeled by finite elements. Session 2 dealt with Static Sensitivity Analysis and Applications; Session 3 with Eigenproblem Sensitivity Methods; Session 4 with Transient Sensitivity Analysis; and Session 5 with Shape Sensitivity Analysis.

Adelman, Howard M. (compiler); Haftka, Raphael T. (compiler)

1987-01-01

308

DMTPC: A dark matter detector with directional sensitivity  

E-print Network

By correlating nuclear recoil directions with the Earth's direction of motion through the Galaxy, a directional dark matter detector can unambiguously detect Weakly Interacting Massive Particles (WIMPs), even in the presence ...

Battat, James

309

Sensitivity of an astronomical infrared heterodyne spectrometer  

NASA Technical Reports Server (NTRS)

The factors determining the sensitivity of a real astronomical heterodyne spectrometer are described. The deviation from the ideal heterodyne system for line detection is described in terms of a series of degradation factors. A discussion of degradation due to a low local oscillator power and to line profile detection is presented. Representative values for the degradation factors are given. Even with a total degradation of not less than 30, the heterodyne spectrometer is still found to be a highly sensitive tool in IR astronomy.

Kostiuk, T.; Mumma, M. J.; Abbas, M. M.; Buhl, D.

1976-01-01

310

Sensitivity of breast cancer cell lines to recombinant thiaminase I  

Microsoft Academic Search

Purpose  We have previously shown that the expression of the thiamine transporter THTR2 is decreased sevenfold in breast cancer, which\\u000a may leave breast cancer cells vulnerable to acute thiamine starvation. This concept was supported by the observation that\\u000a MDA231 breast cancer xenografts demonstrated growth inhibition in mice fed a thiamine-free diet.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  We purified recombinant Bacillus thiaminolyticus thiaminase I enzyme, which digests

Shuqian Liu; Noel R. Monks; Jeremiah W. Hanes; Tadhg P. Begley; Hui Yu; Jeffrey A. Moscow

2010-01-01

311

[Reproduction of the metapneumovirus in different cell lines].  

PubMed

The reproduction of the metapneumovirus was comparatively studied in 19 human and animal cell lines. The most sensitive transplanted cell lines were found to be human Chang Conjunctiva (clone 1-5C4) and animal cell lines of feline kidney CRFK. PMID:23012979

Isaeva, E I; Kozulina, I S; Podcherniaeva, R Ia; Grinkevich, O M

2012-01-01

312

High sensitivity radon emanation measurements.  

PubMed

The presented radon detection technique employs miniaturized ultra-low background proportional counters. (222)Rn samples are purified, mixed with a counting gas and filled into a counter using a special glass vacuum line. The absolute sensitivity of the system is estimated to be 40 microBq (20 (222)Rn atoms). For emanation investigations two metal sealed stainless steel vessels and several glass vials are available. Taking into account their blank contributions, measurements at a minimum detectable activity of about 100 microBq can be performed. PMID:19249216

Zuzel, G; Simgen, H

2009-05-01

313

Geometric sensitivity of ClearPET™ Neuro  

NASA Astrophysics Data System (ADS)

ClearPET™ Neuro is a small-animal positron emission tomography (PET) scanner dedicated to brain studies on rats and primates. The design of ClearPET™ Neuro leads to a specific geometric sensitivity, characterized by inhomogeneous and, depending on the measurement setup, even incomplete data. With respect to reconstruction techniques, homogeneous and complete data sets are a 'must' for analytical reconstruction methods, whereas iterative methods take the geometrical sensitivity into account during the reconstruction process. Nevertheless, here a homogeneous geometric sensitivity over the field of view is highly desirable. Therefore, this contribution aims at studying the impact of different scanner geometries and measurement setups on the geometric sensitivity. A data set of coincident events is computed for certain settings that contains each possible crystal combination once. The lines of response are rebinned into normalizing sinograms and backprojected into sensitivity images. Both, normalizing sinograms and sensitivity images mirror the geometric sensitivity and therefore, provide information which setting enables most complete and homogeneous data sets. An optimal measurement setup and scanner geometry in terms of homogeneous geometric sensitivity is found by analyzing the sensitivity images.

Gundlich, Brigitte; Weber, Simone

2007-02-01

314

Focus Sensitive Coordination  

E-print Network

This thesis investigates the role of the Focus Sensitive Operators (FSOs) even and also when found inside of a coordination. Coordinations of this form are called Focus Sensitive Coordinations (FSC) and include or even, ...

Hulsey, Sarah McNearney

2008-01-01

315

Pressure Sensitive Paints  

NASA Technical Reports Server (NTRS)

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.

Liu, Tianshu; Bencic, T.; Sullivan, J. P.

1999-01-01

316

Delay-line readout for multicell detectors  

NASA Astrophysics Data System (ADS)

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.

Ditta, J.; Kuroda, K.; Nemoz, C.; Sillou, D.

1986-09-01

317

Personal Time Line  

NSDL National Science Digital Library

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).

Muller, Eric

2003-01-01

318

STP Sensitivity to Initial Conditions Program  

NSDL National Science Digital Library

The STP Sensitivity to Initial Conditions program shows 11 particles in a line with the same velocity. You can perturb the system slightly and observe how sensitive the trajectory is to a small change. The default perturbation strength is 1.00001. STP SensitivityToInitialConditions is part of a suite of Open Source Physics programs that model aspects of Statistical and Thermal Physics (STP). The program is distributed as a ready-to-run (compiled) Java archive. Double-clicking the stp_SensitivityToInitialConditions.jar file will run the program if Java is installed on your computer. Additional programs can be found by searching ComPADRE for Open Source Physics, STP, or Statistical and Thermal Physics.

Gould, Harvey; Tobochnik, Jan; Christian, Wolfgang; Cox, Anne

2009-03-13

319

White paper: Chemical sensitivity: history and phenomenology.  

PubMed

Nearly everyone has heard something about chemical sensitivity, either from personal experience with someone who has the condition or from the media. The television series Northern Exposure recently featured a chemically sensitive attorney who lived in a geodesic dome in Alaska, and L.A. Law depicted the struggles of a Persian Gulf veteran with chemical sensitivities who lost his case against the Veterans Administration, but may appeal later in the season. Television news programs and the printed media have showcased patients living spartan existences in remote areas or in aluminum foil-lined rooms. Our views of the illness no doubt are colored by our own personal experiences of it. While some discount or make jokes about chemical sensitivity or these patients, physicians who have seen a number of them are discovering that many appear to be credible individuals with prior good work records who say they became ill following an identifiable exposure to chemicals. PMID:7778099

Miller, C S

1994-01-01

320

Abstract Line Designs  

ERIC Educational Resources Information Center

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…

Nevinskas, Nancy

2011-01-01

321

The Language of Lines.  

ERIC Educational Resources Information Center

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…

Breig-Allen, Cheryl; Hill, Janet; Geismar-Ryan, Lori; Cadwell, Louise Boyd

1998-01-01

322

Easy Observation of Infrared Spectral Lines  

ERIC Educational Resources Information Center

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…

Cortel, Adolf

2012-01-01

323

Gamma ray lines from dark matter annihilation  

SciTech Connect

If direct annihilation of dark matter particles into a pair of photons occurs in the galactic halo, a narrow {gamma}-ray line can be discovered at future {gamma}-ray detectors sensitive to the GeV region. The signals predicted by different dark matter candidates are analyzed. 16 refs., 3 figs.

Giudice, G.F.

1989-08-01

324

Line Scanners Basic line-scanner principle  

E-print Network

bit #12;Example · Leica ADS80 #12;Comparison to frame sensor · Three-line · 3 rays/strip for every% overlap · 4 for 80% overlap #12;Comparison to frame sensor · Three-line · parallax angle given by interior orientation · Frame · parallax angle depending on base length #12;Comparison to frame sensor · Three

Giger, Christine

325

Fabrics Protect Sensitive Skin from UV Rays  

NASA Technical Reports Server (NTRS)

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.

2009-01-01

326

Flash Mob Project Creates Awareness of Environmental Sensitivities: Making "Multiple Chemical Sensitivity" a Household Name  

ERIC Educational Resources Information Center

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…

Smith, Melva Gail

2011-01-01

327

Mentoring Emotionally Sensitive Individuals.  

ERIC Educational Resources Information Center

Mentoring individuals who are gifted, talented, and creative, but somewhat emotionally sensitive is a challenging and provocative arena. Several reasons individuals experience heightened sensitivity include: lack of nurturing, abuse, alcoholism in the family, low self-esteem, unrealistic parental expectations, and parental pressure to achieve.…

Shaughnessy, Michael F.; Self, Elizabeth

328

Tuned cavity magnetometer sensitivity.  

SciTech Connect

We have developed a high sensitivity (sensitivity levels.

Okandan, Murat; Schwindt, Peter

2009-09-01

329

Sense and Sensitivities  

NSDL National Science Digital Library

A Java applet that illustrates the utility of the sensitivity and complementary sensitivity functions for linear control system design. Sketch a reference input and disturbance input with the mouse, and select a sensor noise level. Then drag open-loop system poles and zeros with the mouse to track the reference while rejecting the disturbance and noise. Includes an audio introduction with suggested exercises.

Kahn, Seth

2010-11-30

330

Wimp/Neutralino Direct Detection  

E-print Network

The most popular candidate for non baryonic dark matter is the neutralino. More than twenty experiments are dedicated to its direct detection. This review describes the most competitive and promising experiments with different detection techniques. The most recent results are presented with some prospects for the near future.

M. De Jesus

2004-02-02

331

WIMP Dark Matter and Baryogenesis  

E-print Network

In the present universe visible and dark matter contribute comparable energy density although they have different properties. This coincidence can be elegantly explained if the dark matter relic density, originating from a dark matter asymmetry, is fully determined by the baryon asymmetry. Thus the dark matter mass is not arbitrary, rather becomes predictive. We realize this scenario in baryon(lepton) number conserving models where two or more neutral singlet scalars decay into two or three baryonic(leptonic) dark matter scalars, and also decay into quarks(leptons) through other on-shell and/or off-shell exotic scalar bilinears. The produced baryon(lepton) asymmetries in the dark matter scalar and in the standard model quarks(leptons) are thus equal and opposite. The dark matter mass can be predicted in a range from a few GeV to a few TeV depending on the baryon(lepton) numbers of the decaying scalars and the dark matter scalar. The dark matter scalar can interact with the visible matter through the exchange of the standard model Higgs boson, opening a window for the dark matter direct detection experiments. These models also provide testable predictions in the searches for the exotic scalar bilinears at LHC.

Pei-Hong Gu; Manfred Lindner; Utpal Sarkar; Xinmin Zhang

2010-09-14

332

Points, Lines, and Planes  

NSDL National Science Digital Library

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 ...

Neubert, Mrs.

2011-08-18

333

Interactive sensitivity analysis in transportation plan evaluation  

Microsoft Academic Search

An experimental technique for exploring the sensitivity of transportation plan evaluations to forecasting and community value uncertainties is described. Three kinds of uncertainty — goal-achievement impacts, costs, and goal-weights — are included. Within a cost-effectiveness evaluation framework, an “on-line” capability for interactively and iteratively testing plan comparisons is outlined. A series of user-oriented computer instructions is developed to test plan

Darwin G. Stuart

1974-01-01

334

Emission and Absorption Lines  

NSDL National Science Digital Library

This webpage from the University of California, Riverside offers an explanation of emission and absorption lines. A diagram, with descriptive text, shows how light from a star can produce each type of line. Also, an image of solar absorption lines is provided.

Wudka, Jose

2007-12-20

335

Basic Line Plots  

NSDL National Science Digital Library

Line plots are a useful way to display data especially change over time. In this lesson, students learn basic line plot analysis using authentic NASA wind speed data from two locations. In the extensions sections, there is an opportunity to build upon basic line plot analysis skills and opportunities for further assessment.

336

The potential effectiveness of nanoparticles as radio sensitizers for radiotherapy  

PubMed Central

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

Babaei, Mohammad; Ganjalikhani, Maryam

2014-01-01

337

Method for rapid isolation of sensitive mutants  

DOEpatents

Sensitive mammalian cell mutants are rapidly isolated using flow cytometry. A first population of clonal spheroids is established to contain both normal and mutant cells. The population may be naturally occurring or may arise from mutagenized cells. The first population is then flow sorted by size to obtain a second population of clonal spheroids of a first uniform size. The second population is then exposed to a DNA-damaging agent that is being investigated. The exposed second population is placed in a growth medium to form a third population of clonal spheroids comprising spheroids of increased size from the mammalian cells that are resistant to the DNA-damaging agent and spheroids of substantially the first uniform size formed from the mammalian cells that are sensitive to the DNA-damaging agent. The third population is not flow sorted to differentiate the spheroids formed from resistant mammalian cells from spheroids formed from sensitive mammalian cells. The spheroids formed from sensitive mammalian cells are now treated to recover viable sensitive cells from which a sensitive cell line can be cloned. 15 figs.

Freyer, J.P.

1997-07-29

338

Sensitivity of photoacoustic microscopy  

PubMed Central

Building on its high spatial resolution, deep penetration depth and excellent image contrast, 3D photoacoustic microscopy (PAM) has grown tremendously since its first publication in 2005. Integrating optical excitation and acoustic detection, PAM has broken through both the optical diffusion and optical diffraction limits. PAM has 100% relative sensitivity to optical absorption (i.e., a given percentage change in the optical absorption coefficient yields the same percentage change in the photoacoustic amplitude), and its ultimate detection sensitivity is limited only by thermal noise. Focusing on the engineering aspects of PAM, this Review discusses the detection sensitivity of PAM, compares the detection efficiency of different PAM designs, and summarizes the imaging performance of various endogenous and exogenous contrast agents. It then describes representative PAM applications with high detection sensitivity, and outlines paths to further improvement. PMID:25302158

Yao, Junjie; Wang, Lihong V.

2014-01-01

339

Building a Zip Line  

NSDL National Science Digital Library

A zip line is a way to glide from one point to another while hanging from a cable. Design and create a zip line that is safe for a hard-boiled egg. After designing a safety egg harness, connect the harness to fishing line or wire connected between two chairs of different heights using a paper clip. Learn to improve your zip line based on data. Attach a motion sensor at the bottom of your zip line and display a graph to show how smooth a ride your egg had!

2012-07-19

340

Slope of a Line  

NSDL National Science Digital Library

The purpose of this project is to provide resources for practicing graphing a line in slope-intercept form. Work through each step and make sure you do the assessment at the end. [Utah State Algebra 1 Core Curriculum - Standard II, Objectives 1-3.] S tep 1: Watch the video. Slope-Intercept Video Step 2: Click on the link to practice graphing lines. Try at least 10 different equations. Do more if you want to. Graphing Lines Practice Step 3: Learn a little bit more about graphs of lines. Use this link to focus more on the equations of veertical and horizontal line. Answer the questions ...

Edwards, Mr.

2010-10-26

341

Line of Best Fit  

NSDL National Science Digital Library

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.

2012-08-13

342

Collective Phase Sensitivity  

E-print Network

The collective phase response to a macroscopic external perturbation of a population of interacting nonlinear elements exhibiting collective oscillations is formulated for the case of globally-coupled oscillators. The macroscopic phase sensitivity is derived from the microscopic phase sensitivity of the constituent oscillators by a two-step phase reduction. We apply this result to quantify the stability of the macroscopic common-noise induced synchronization of two uncoupled populations of oscillators undergoing coherent collective oscillations.

Yoji Kawamura; Hiroya Nakao; Kensuke Arai; Hiroshi Kori; Yoshiki Kuramoto

2008-07-08

343

Estimating Sensitivity Indices from Computer Simulator Output  

E-print Network

An overview is given of statistical methodology for estimating sensitivity indices, including moment-based, quadrature-based, and process-based estimators of global sensitivity indices. The paper, together with the on-line Supplementary material, derives the specific formulae needed for the computation of process-based Bayesian and empirical Bayesian global sensitivity indices for a broad class of regression plus stationary Gaussian process models using the Gaussian, Bohman, or cubic correlation functions. It is shown how to restrict the parameter space for the compactly supported Bohman and cubic correlation functions so that (at least) a given proportion of the training data correlation entries are zero. This feature is important in the situation where the set of training data is large. Formulae are given in a form suitable for computation, and the estimation methods are illustrated and compared via examples. AMS Subject Classification: 62K05

Joshua Svenson A; Thomas Santner; Angela Dean B; Hyejung Moon D

344

Dark Matter Searches With GLAST  

SciTech Connect

Indirect detection of particle dark matter relies upon pair annihilation of Weakly Interaction Massive Particles (WIMPs), which is complementary to the well known techniques of direct detection (WIMP-nucleus scattering) and collider production (WIMP pair production). Pair annihilation of WIMPs results in the production of gamma-rays, neutrinos, and anti-matter. Of the various experiments sensitive to indirect detection of dark matter, the Gamma-ray Large Area Space Telescope (GLAST) may play the most crucial role in the next few years. After launch in late 2007, The GLAST Large Area Telescope (LAT) will survey the gamma-ray sky in the energy range of 20MeV-300GeV. By eliminating charged particle background above 100 MeV, GLAST may be sensitive to as yet to be observed Milky Way dark matter subhalos, as well as WIMP pair annihilation spectral lines from the Milky Way halo. Discovery of gamma-ray signals from dark matter in the Milky Way would not only demonstrate the particle nature of dark matter; it would also open a new observational window on galactic dark matter substructure. Location of new dark matter sources by GLAST would dramatically alter the experimental landscape; ground based gamma ray telescopes could follow up on the new GLAST sources with precision measurements of the WIMP pair annihilation spectrum.

Wai, Lawrence; /SLAC; Nuss, E.

2007-02-05

345

Dark Matter Searches with GLAST  

E-print Network

Indirect detection of particle dark matter relies upon pair annihilation of Weakly Interaction Massive Particles (WIMPs), which is complementary to the well known techniques of direct detection (WIMP-nucleus scattering) and collider production (WIMP pair production). Pair annihilation of WIMPs results in the production of gamma-rays, neutrinos, and anti-matter. Of the various experiments sensitive to indirect detection of dark matter, the Gamma-ray Large Area Space Telescope (GLAST) may play the most crucial role in the next few years. After launch in late 2007, The GLAST Large Area Telescope (LAT) will survey the gamma-ray sky in the energy range of 20MeV-300GeV. By eliminating charged particle background above 100 MeV, GLAST may be sensitive to as yet to be observed Milky Way dark matter subhalos, as well as WIMP pair annihilation spectral lines from the Milky Way halo. Discovery of gamma-ray signals from dark matter in the Milky Way would not only demonstrate the particle nature of dark matter; it would also open a new observational window on galactic dark matter substructure. Location of new dark matter sources by GLAST would dramatically alter the experimental landscape; ground based gamma ray telescopes could follow up on the new GLAST sources with precision measurements of the WIMP pair annihilation spectrum.

Lawrence Wai; GLAST LAT Collaboration

2007-01-31

346

Line Orientation Adaptation: Local or Global?  

PubMed Central

Prolonged exposure to an oriented line shifts the perceived orientation of a subsequently observed line in the opposite direction, a phenomenon known as the tilt aftereffect (TAE). Here we consider whether the TAE for line stimuli is mediated by a mechanism that integrates the local parts of the line into a single global entity prior to the site of adaptation, or the result of the sum of local TAEs acting separately on the parts of the line. To test between these two alternatives we used the fact the TAE transfers almost completely across luminance contrast polarity [1]. We measured the TAE using adaptor and test lines that (1) either alternated in luminance polarity or were of a single polarity, and (2) either alternated in local orientation or were of a single orientation. We reasoned that if the TAE was agnostic to luminance polarity and was parts-based, we should obtain large TAEs using alternating-polarity adaptors with single-polarity tests. However we found that (i) TAEs using one-alternating-polarity adaptors with all-white tests were relatively small, increased slightly for two-alternating-polarity adaptors, and were largest with all-white or all-black adaptors. (ii) however TAEs were relatively large when the test was one-alternating polarity, irrespective of the adaptor type. (iii) The results with orientation closely mirrored those obtained with polarity with the difference that the TAE transfer across orthogonal orientations was weak. Taken together, our results demonstrate that the TAE for lines is mediated by a global shape mechanism that integrates the parts of lines into whole prior to the site of orientation adaptation. The asymmetry in the magnitude of TAE depending on whether the alternating-polarity lines was the adaptor or test can be explained by an imbalance in the population of neurons sensitive to 1st-and 2nd-order lines, with the 2nd-order lines being encoded by a subset of the mechanisms sensitive to 1st-order lines. PMID:24023677

Gheorghiu, Elena; Bell, Jason; Kingdom, Frederick A. A.

2013-01-01

347

Allergic sensitization: screening methods  

PubMed Central

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

2014-01-01

348

Directed line liquids  

SciTech Connect

This thesis is devoted to the study of ensembles of dense directed lines. These lines are principally to be thought of as polymers, though they also have the morphology of flux lines in high temperature superconductors, strings of colloidal spheres in electrorheological fluids and the world lines of quantum mechanical bosons. The authors discuss how directed polymer melts, string-like formations in electrorheological and ferro-fluids, flux lines in high temperature superconductors and the world lines of quantum mechanical bosons all share similar descriptions. They study a continuous transition in all of these systems, and then study the critical mixing properties of binary mixtures of directed polymers through the renormalization group. They predict the exponents for a directed polymer blend consolute point and a novel two-phase superfluid liquid-gas critical point.

Kamien, R.D.

1992-01-01

349

Infant Allergies and Food Sensitivities  

MedlinePLUS

... Sensitivities Ages & Stages Listen Infant Allergies and Food Sensitivities Article Body Human breast milk typically does not ... your pediatrician about your family’s medical history. Food Sensitivities A few mothers notice minor reactions to other ...

350

Interactive Fraction Number Lines  

NSDL National Science Digital Library

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.

Green, Michael

2012-05-25

351

COS FUV Sensitivity  

NASA Astrophysics Data System (ADS)

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.

Keyes, Charles

2009-07-01

352

Interplanetary Magnetic Field Lines  

NSDL National Science Digital Library

This web page 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.

Stern, David

2005-04-27

353

Cherenkov Telescope Array Sensitivity  

NASA Astrophysics Data System (ADS)

The Cherenkov Telescope Array (CTA) will provide unprecedented capabilities in the gamma-ray regime, from a few tens of GeV up to at least 100 TeV. The goal of CTA is to improve the sensitivity over the whole energy range covered by current ground-based telescopes by a factor of between 5 and 10, depending on the energy, to extend the range of energies observed, with significantly improved energy and angular resolution over previous instruments. Plans for the layout of the array and the estimated sensitivity, derived from Monte Carlo, will be presented.

Humensky, Brian; Grube, Jeff

2014-08-01

354

Developments in sensitivity theory  

SciTech Connect

A review of recent developments in sensitivity theory is presented with an emphasis on (a) extensions to new areas such as thermal hydraulics, reactor depletion, multi-constraint and extrema problems, and (b) recent mathematical refinements to and extensions of the basic theory. The diverse new areas of application are discussed from a unified theoretical viewpoint based on nonlinear functional analysis. Several new applications of sensitivity theory are presented for problems in constrained reactor physics calculations, irradiation experiment analysis, reactor burnup calculations, and transient thermal-hydraulic analysis. Future directions of the research are suggested.

Cacuci, D.G.; Greenspan, E.; Marable, J.H.; Williams, M.L.

1980-01-01

355

Strain monitoring averts line failure in Rockies  

SciTech Connect

The case history of a landslide in the U.S. Rocky Mountains shows that the potential for pipeline monitoring in geologically sensitive areas, those subject to landslides and subsidence, for example. A properly installed monitoring system monitored by the pipeline operator, Western Gas Supply Co. (West Gas), Denver, provided an early warning of increasing line strains. The problem was complicated by rugged topography which is described here. Stability analysis was the key technique utilized in the process.

Miller, B.; Bukovansky, M.

1987-08-10

356

Mapping global sensitivity of cellular network dynamics: sensitivity heat maps  

E-print Network

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

Rand, David

357

High-Sensitivity Spectrophotometry.  

ERIC Educational Resources Information Center

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.…

Harris, T. D.

1982-01-01

358

Sensitization of stainless steel  

NASA Technical Reports Server (NTRS)

The objective of this experiment is to determine the corrosion rates of 18-8 stainless steels that have been sensitized at various temperatures and to show the application of phase diagrams. The laboratory instructor will assign each student a temperature, ranging from 550 C to 1050 C, to which the sample will be heated. Further details of the experimental procedure are detailed.

Nagy, James P.

1990-01-01

359

Sensitive hydrogen leak detector  

DOEpatents

A sensitive hydrogen leak detector system is described which uses passivation of a stainless steel vacuum chamber for low hydrogen outgassing, a high compression ratio vacuum system, a getter operating at 77.5 K and a residual gas analyzer as a quantitative hydrogen sensor. 1 fig.

Myneni, G.R.

1999-08-03

360

The Emotionally Sensitive Adolescent.  

ERIC Educational Resources Information Center

This paper provides a list of signs, symptoms, and indicators of emotionally sensitive adolescents includes clinging behavior, withdrawn behavior, shy/inhibited behavior, represses anger, poor reaction to criticism, makes self-disparaging statements, low self-esteem, "can't forgive self or others," ruined by a small critical comment, exploding…

Shaughnessy, Michael F.; Lehtonen, Kimmo

361

Developments in sensitivity theory  

Microsoft Academic Search

A review of recent developments in sensitivity theory is presented with an emphasis on (a) extensions to new areas such as thermal hydraulics, reactor depletion, multi-constraint and extrema problems, and (b) recent mathematical refinements to and extensions of the basic theory. The diverse new areas of application are discussed from a unified theoretical viewpoint based on nonlinear functional analysis. Several

D. G. Cacuci; E. Greenspan; J. H. Marable; M. L. Williams

1980-01-01

362

Airborne Fraunhofer Line Discriminator  

NASA Technical Reports Server (NTRS)

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.

Gabriel, F. C.; Markle, D. A.

1969-01-01

363

Coolant line hydrometer  

Microsoft Academic Search

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

M. D. Barber; W. G. Kipp

1987-01-01

364

Transmission Line Security Monitor  

ScienceCinema

The Transmission Line Security Monitor is a multi-sensor monitor that mounts directly on high-voltage transmission lines to detect, characterize and communicate terrorist activity, human tampering and threatening conditions around support towers. For more information about INL's critical infrastructure protection research, visit http://www.facebook.com/idahonationallaboratory.

None

2013-05-28

365

Tangent Lines without Calculus  

ERIC Educational Resources Information Center

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.)

Rabin, Jeffrey M.

2008-01-01

366

CLE: Coronal line synthesis  

NASA Astrophysics Data System (ADS)

CLE, written in Fortran 77, synthesizes Stokes profiles of forbidden lines such as Fe XIII 1074.7nm, formed in magnetic dipole transitions under coronal conditions. The lines are assumed to be optically thin, excited by (anisotropic) photospheric radiation and thermal particle collisions.

Judge, Philip G.; Casini, Roberto

2014-07-01

367

Transmission Line Security Monitor  

SciTech Connect

The Transmission Line Security Monitor is a multi-sensor monitor that mounts directly on high-voltage transmission lines to detect, characterize and communicate terrorist activity, human tampering and threatening conditions around support towers. For more information about INL's critical infrastructure protection research, visit http://www.facebook.com/idahonationallaboratory.

None

2011-01-01

368

Submillimeter CO Line Emission from Orion  

E-print Network

Images of an 8 square minute 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 H_2 densities of ~10^5 per ccm. 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 blue shifted wing and 0.8 for the red shifted wing. 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. The line ratios in the Orion S outflow and jet features are consistent with both PDR and LVG models. 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.

T. L. Wilson; D. Muders; C. Kramer; C. Henkel

2001-07-16

369

Kinematic sensitivity of robot manipulators  

NASA Technical Reports Server (NTRS)

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.

Vuskovic, Marko I.

1989-01-01

370

New sensitizers for PDT  

NASA Astrophysics Data System (ADS)

For a number of well-defined reasons, research into the development of alternative photosensitizers to PhotofrinTM, for use in Photodynamic Therapy, continues. The efforts described in this paper cover the study of a number of sensitizers absorbing at different wavelengths, which may have selective applications in the field of photomedicine. In one approach, the use of tetraazoporphyrins (porphyrazines) as sensitizers is studied. Although related tetramacrocyclic systems such as porphyrins and phthalocyanines have been, and continue to be, well studied in this field, porphyrazines have, to-date, received little attention. In a second study, purpurins are examined as possible alternatives to PhotofrinTM. In a recent study, tissue distribution properties of tin etiopurpurin dichloride, as a function of time, were examined. Results indicate that this purpurin continues to show promise for applications in PDT.

Morgan, Alan R.; Garbo, Greta M.; Krivak, T.; Mastroianni, Marta; Petousis, Nikolaos H.; St Clair, T.; Weisenberger, M.; van Lier, Johan E.

1991-06-01

371

COS NUV Spectroscopic Sensitivity  

NASA Astrophysics Data System (ADS)

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.

Aloisi, Alessandra

2009-07-01

372

Contact sensitivity to emulsifiers.  

PubMed

Common emulsifiers were tested in over 1,200 patients with eczema. Triethanolamine stearate tested at 5% in petrolatum caused irritant reactions in 9.5% of the patients. On the other hand, non-ionic emulsifying agents tested at 10-20% produced irritation in only a few cases. Allergic reactions were found in 2.1% of those tested. Lanette, sorbitan sesquioleate, the Spans, polyoxyethylene oxypropylene stearate, polyoxyethylene sorbitol lanolin derivative, and triethanolamine stearate each elicited allergic reactions in 0.3-0.7% of the cases. The Tweens caused an allergy in only two cases, but glycerol monostearate caused no reaction at all. Five out of six patients sensitive to sorbitan sesquioleate reacted positively to the Spans as well. The patients allergic to one or more emulsifiers were also sensitive to several other substances included in our routine test series with the exception of four patients who reacted only to the emulsifying agents. PMID:1021350

Hannuksela, M; Kousa, M; Pirilä, V

1976-08-01

373

Selective Calcium Sensitivity in Immature Glioma Cancer Stem Cells  

PubMed Central

Tumor-initiating cells are a subpopulation in aggressive cancers that exhibit traits shared with stem cells, including the ability to self-renew and differentiate, commonly referred to as stemness. In addition, such cells are resistant to chemo- and radiation therapy posing a therapeutic challenge. To uncover stemness-associated functions in glioma-initiating cells (GICs), transcriptome profiles were compared to neural stem cells (NSCs) and gene ontology analysis identified an enrichment of Ca2+ signaling genes in NSCs and the more stem-like (NSC-proximal) GICs. Functional analysis in a set of different GIC lines regarding sensitivity to disturbed homeostasis using A23187 and Thapsigargin, revealed that NSC-proximal GICs were more sensitive, corroborating the transcriptome data. Furthermore, Ca2+ drug sensitivity was reduced in GICs after differentiation, with most potent effect in the NSC-proximal GIC, supporting a stemness-associated Ca2+ sensitivity. NSCs and the NSC-proximal GIC line expressed a larger number of ion channels permeable to potassium, sodium and Ca2+. Conversely, a higher number of and higher expression levels of Ca2+ binding genes that may buffer Ca2+, were expressed in NSC-distal GICs. In particular, expression of the AMPA glutamate receptor subunit GRIA1, was found to associate with Ca2+ sensitive NSC-proximal GICs, and decreased as GICs differentiated along with reduced Ca2+ drug sensitivity. The correlation between high expression of Ca2+ channels (such as GRIA1) and sensitivity to Ca2+ drugs was confirmed in an additional nine novel GIC lines. Calcium drug sensitivity also correlated with expression of the NSC markers nestin (NES) and FABP7 (BLBP, brain lipid-binding protein) in this extended analysis. In summary, NSC-associated NES+/FABP7+/GRIA1+ GICs were selectively sensitive to disturbances in Ca2+ homeostasis, providing a potential target mechanism for eradication of an immature population of malignant cells. PMID:25531110

Marinescu, Voichita Dana; Segerman, Anna; Schmidt, Linnéa; Hermansson, Annika; Dirks, Peter; Forsberg-Nilsson, Karin; Westermark, Bengt; Uhrbom, Lene; Linnarsson, Sten; Nelander, Sven; Andäng, Michael

2014-01-01

374

Photoionization, line emission diagnostics  

NASA Astrophysics Data System (ADS)

Photoionization models for AGN, including Seyfert and LINERs are discussed. These photoionization models can be used to derive emission-line diagnostics for AGN that can determine the properties of the AGN and surrounding ISM, including the relative AGN contribution to the EUV radiation field, the hardness of the AGN radiation field, the ionization state of the gas, and the metallicity of the narrow-line region. It is shown how the AGN emission-line diagnostics are expected to change with redshift. Finally, latest application of these models by the author to wide integral field spectroscopy to separate starburst and AGN contributions in composite galaxies are presented.

Kewley, Lisa

2014-07-01

375

Automated spectral line identification  

NASA Astrophysics Data System (ADS)

Software has been developed to automate the intricate and tedious process of stellar line identification. A set of unknown stellar wavelengths and intensities is compared with a master multiplet list composed of the Revised Multiplet Table plus extensions. Potential identifications are evaluated on the basis of several criteria including Cowley's wavelength coincidence statistics, wavelength displacement, and the orderly filling of the associated multiplet. All data for each unknown stellar line are displayed and the user interactively decides on the best identification(s). To aid in this process another identification of a similar star can be simultaneously displayed. Comparisons with line identifications by Bidelman and by Adelman show virtually complete agreement.

Gulliver, Austin F.; Stadel, Joachim G.

1990-05-01

376

Flow line sampler  

DOEpatents

An on-line product sampling apparatus and method for measuring product samples from a product stream (12) in a flow line (14) having a sampling aperture (11), includes a sampling tube (18) for containing product samples removed from flow line (14). A piston (22) removes product samples from the product stream (12) through the sampling aperture (11) and returns samples to product stream (12). A sensor (20) communicates with sample tube (18), and senses physical properties of samples while the samples are within sample tube (18). In one embodiment, sensor (20) comprises a hydrogen transient nuclear magnetic resonance sensor for measuring physical properties of hydrogen molecules.

Nicholls, Colin I. (San Antonio, TX)

1992-07-14

377

Interference and Sensitivity Analysis  

PubMed Central

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

VanderWeele, Tyler J.; Tchetgen Tchetgen, Eric J.; Halloran, M. Elizabeth

2014-01-01

378

Unveiling the nature of dark matter with high redshift 21 cm line experiments  

NASA Astrophysics Data System (ADS)

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.

Evoli, C.; Mesinger, A.; Ferrara, A.

2014-11-01

379

Analytical sensitivities and energies of thermal-neutron-capture gamma rays  

USGS Publications Warehouse

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.

Duffey, D.; El-Kady, A.; Senftle, F.E.

1970-01-01

380

Ultrahigh-sensitivity new super-HARP camera  

NASA Astrophysics Data System (ADS)

NHK led the world in developing a high-sensitivity Super-HARP pickup tube using the avalanche multiplication effect. The authors have now developed an improved version (2/3- inch, with electromagnetic focusing and electromagnetic deflection) which is eight times more sensitive and has much better lag characteristics. The handy New Super-HARP color camera which uses this newly-developed pickup tube has higher sensitivity than human vision (2000 lux, F/110 equivalent), negligible low lag, and a limiting resolution of over 700 TV lines. It will be a powerful tool in emergency news gathering at night, the production of scientific programs, and other applications.

Kubota, Misao; Kato, Tsutomu; Suzuki, Shiro; Maruyama, Hirotaka; Tanioka, Kenkichi; Sameshima, Kenji; Makishima, Tatsuo; Tsuji, Kazutaka; Hirai, Tadaaki

1996-03-01

381

Folly Island Tidal Lines  

USGS Multimedia Gallery

Lines of debris from tidal action on Folly Island. Folly Island, a preserve owned by the Maine Coast Heritage Trust, is about 7 acres. It is located in Bartlett Narrows, along the western coast of Mount Desert Island....

382

Folly Island Tidal Lines  

USGS Multimedia Gallery

Lines of debris from tidal action on Folly Island. Folly Island, a preserve owned by the Maine Coast Heritage Trust, is about 7 acres. It is located in Bartlett Narrows, along the western coast of Mount Desert Island....

383

Complex Line Integrals I  

NSDL National Science Digital Library

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.

Moore, Lang

384

Drawing Electric Field Lines  

NSDL National Science Digital Library

The panel on the left displays an equipotential plot. The contours represent points at the exact same potential. Draw the electric field lines for this potential by dragging the pencil (at its tip) after clicking the "draw on" button.

Wolfgang Christian

385

Power line detection system  

DOEpatents

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. 4 figs.

Latorre, V.R.; Watwood, D.B.

1994-09-27

386

Power line detection system  

DOEpatents

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.

Latorre, Victor R. (Tracy, CA); Watwood, Donald B. (Tracy, CA)

1994-01-01

387

Line, Shape, Color.  

ERIC Educational Resources Information Center

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)

Greenman, Geri

2002-01-01

388

Decimal Number Line  

NSDL National Science Digital Library

This interactive Flash applet helps students explore place value and develop number sense within whole numbers, integers and decimals. It allows a child or teacher to select an interval in the given number line and show that interval divided into ten equal parts but on a larger scale, which can then be repeated. Users may choose the size of the interval between markers on the first number line and the starting number of that line, as well as whether to hide or show individual number lines and the numbers on them. This applet lends itself well for use on an interactive white board. A pdf guide to this collection of teaching applets is cataloged separately.

2006-01-01

389

Identify with Lines  

NSDL National Science Digital Library

In this application students determine the fractional value that is represented on the number line. Students use the number line to determine both the numerator and the denominator of the fraction. Beneath the application is a detailed explanation of the parts of a fraction; students may also receive an explanation by clicking on the "Explain" button. This resource is part of the Visual Fractions website which is cataloged separately.

Richard E. Rand

2013-01-01

390

Number Line Bars  

NSDL National Science Digital Library

Teachers and students can use this interactive Java applet to model and carry out arithmetic operations on the number line. Users manipulate the size, position, and direction of color bars to represent addition, subtraction, multiplication and division with whole numbers, integers and fractions. Options include the ability to zoom in and out, change the colors of the bars, and adjust the step size of the bars and number line increments.

2000-01-01

391

The diffuse interstellar lines  

NASA Astrophysics Data System (ADS)

The history of the diffuse interstellar absorption lines will be briefly reviewed. The existence of the unidentified carriers of the diffuse line absorption indicates that there may be an important component of the interstellar medium which has not been recognised. A review of a recent ULO survey of the diffuse features at 5780, 5797, 6283 and 6614 A° will be described and the bearing of the results of the survey on suggestions for carriers will be discussed.

McNally, D.

392

Multidimensional polarization sensitivity in damselfishes.  

PubMed

Using electroretinogram recording and microspectrophotometry we investigated spectral sensitivity and ultraviolet polarization sensitivity in three species of coral reef fishes commonly known as damselfishes. Here we show that three species of damselfishes (three-spot damselfish, Dascyllus trimaculatus; blacktail damselfish, D. melanurus; and blue-green chromis, Chromis viridis) have four classes of cone photoreceptors (lambda(max) ranges: ultraviolet 357-367 nm; short wavelength-sensitive 469-478 nm; medium wavelength-sensitive 482-493 nm; long wavelength-sensitive 512-524 nm; rods 499-500 nm). The three species shared similar combined spectral sensitivity but surprisingly complicated and varied polarization sensitivity. Damselfish examined in this study have three and four channel polarization sensitivity, the most complex polarization sensitivity recorded for any vertebrate. Such capacity could play an important role in mediating a conspecific visual communication network utilizing polarized light signals in the coral reef environment. PMID:12664097

Hawryshyn, C W; Moyer, H D; Allison, W T; Haimberger, T J; McFarland, W N

2003-03-01

393

Nasca Lines, Peru  

NASA Technical Reports Server (NTRS)

The Nasca Lines are located in the Pampa region of Peru, the desolate plain of the Peruvian coast 400 km south of Lima. The Lines were first spotted when commercial airlines began flying across the Peruvian desert in the 1920's. Passengers reported seeing 'primitive landing strips' on the ground below. The Lines were made by removing the iron-oxide coated pebbles which cover the surface of the desert. When the gravel is removed, they contrast with the light color underneath. In this way the lines were drawn as furrows of a lighter color. On the pampa, south of the Nasca Lines, archaeologists have now uncovered the lost city of the line-builders, Cahuachi. It was built nearly two thousand years ago and was mysteriously abandoned 500 years later. This ASTER sub-image covers an area of 14 x 18 km, was acquired on December 22, 2000, and is located at 14.7 degrees south latitude and 75.1 degrees west longitude.

The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

2001-01-01

394

An X-Ray Line from eXciting Dark Matter  

E-print Network

The eXciting Dark Matter (XDM) model was proposed as a mechanism to efficiently convert the kinetic energy (in sufficiently hot environments) of dark matter into e+e- pairs. The standard scenario invokes a doublet of nearly degenerate DM states, and a dark force to mediate a large upscattering cross section between the two. For heavy ($\\sim TeV$) DM, the kinetic energy of WIMPs in large (galaxy-sized or larger) halos is capable of producing low-energy positrons. For lighter dark matter, this is kinematically impossible, and the unique observable signature becomes an X-ray line, arising from $\\chi \\chi \\rightarrow \\chi^* \\chi^*$, followed by $\\chi^* \\rightarrow \\chi \\gamma$. This variant of XDM is distinctive from other DM X-ray scenarios in that it tends to be most present in more massive, hotter environments, such as clusters, rather than nearby dwarfs, and has different dependencies from decaying models. We find that it is capable of explaining the recently reported X-ray line at 3.56 keV. For very long lifetimes of the excited state, primordial decays can explain the signal without the presence of upscattering. Thermal models freeze-out as in the normal XDM setup, via annihilations to the light boson $\\phi$. For suitable masses the annihilation $\\chi \\chi \\rightarrow \\phi \\phi$ followed by $\\phi \\rightarrow SM$ can explain the reported gamma-ray signature from the galactic center. Direct detection is discussed, including the possibility of explaining DAMA via the "Luminous" dark matter approach. Quite generally, the proximity of the 3.56 keV line to the energy scale of DAMA motivates a reexamination of electromagnetic explanations. Other signals, including lepton jets and the modification of cores of dwarf galaxies are also considered.

Douglas P. Finkbeiner; Neal Weiner

2014-03-03

395

Baroreceptor sensitivity in supine man following inhalation of amyl nitrite  

SciTech Connect

This study compares baroreceptor sensitivity derived from high-fidelity central aortic blood pressure (BP) measurements following amyl nitrite inhalation (ANI) during BP fall and recovery in seven male subjects undergoing diagnostic catheterization for chest pain syndrome. Continuous beat-by-beat plots of BP va pulse interval revealed that all subjects exhibited a counter-clockwise loop with varying degrees of hysteresis. Baroreceptor sensitivity was derived from the slope of a linear plot of systolic BP vs pulse interval and central aortic BP. When baroreceptor sensitivities were compared during BP fall and recovery, the mean values did not differ for the group; however, the slope of regression lines differed in six of the seven subjects. In summary, this study: describes the use of hi-fi central aortic pressure recordings in assessments of baroreceptor sensitivity which avoids the influence of local BP wave reflections in determining baroreceptor sensitivity, and demonstrates the complex nature of the baroreceptor responses to ANI.

Rubal, B.J.; Moody, J.M.; Bailey, S.R. (Brooke Army Medical Center, Fort Sam Houston, TX (United States) Univ. of Texas, San Antonio (United States))

1991-03-15

396

Line Lengths and Starch Scores.  

ERIC Educational Resources Information Center

Investigates readability of different line lengths in advertising body copy, hypothesizing a normal curve with lower scores for shorter and longer lines, and scores above the mean for lines in the middle of the distribution. Finds support for lower scores for short lines and some evidence of two optimum line lengths rather than one. (SKC)

Moriarty, Sandra E.

1986-01-01

397

Fuzzy adaptive bacterial foraging congestion management using sensitivity based optimal active power re-scheduling of generators  

Microsoft Academic Search

This paper presents a new method of fuzzy adaptive bacterial foraging (FABF) based congestion management (CM) for the first time by optimal rescheduling of active powers of generators selected based on the generator sensitivity to the congested line. In the proposed method, generators are selected based on their sensitivity to the congested line to utilize the generators efficiently and optimal

Ch Venkaiah; D. M. Vinod Kumar

2011-01-01

398

Line transients with corona  

SciTech Connect

This paper investigates the effect of corona on the electromagnetic transients along high voltage overhead lines. A method is presented to simulate the line by dividing it into a number of sections connected in cascade. For {ital n} line sections, the number of the unknown variables is 2{ital n} + 1. The method allows any waveform of the exciting voltage function, as well as any impedance loading condition. The corona is represented by voltage-dependent shunt current sources. A systematic way for writing a sufficient number of differential equations is shown. For their solution, a digital computer subroutine based on the Runge--Kutta--Verner method was used. An artificial frequency-dependent damping by means of linear resistors was used to suppress the Gibb's oscillations in the solution. The proposed method is applied to study the transients on a 40 km high voltage line with 30-ft flat phase spacing and a single 1.4 inch ACSR conductor per phase. The exciting voltage has a double-exponential impulse waveform. Solutions are given for three values of resistive loads Z{sub {ital c}}2Z{sub {ital c}} and Z{sub {ital c}}/2, where Z{sub {ital c}} is the line surge impedance. The results of two interesting cases of inductive and capacitive loads are also given. Physical interpretations for the different solutions are given. Also, the current-voltage duality between inductive and capacitive loads is recognized. The corona was found to attenuate and distort the travelling waves. For example, during one wave excursion, the reduction of the current wave peaks can reach values as high as 8.5%. The effect is more noticeable in the current than in the voltage waves. As expected, it increases also with the line corona losses. The effect of the increase of the line effective capacitance due to the corona discharge is also demonstrated.

Saied, M.M.; Safar, Y.A.; Salama, M.H. (Kuwait Univ. (Kuwait))

1987-01-01

399

Performance studies of boron lined proportional counters for reactor applications  

NASA Astrophysics Data System (ADS)

Boron lined proportional counters of standard cylindrical geometry were developed and characterized for reactor applications. It is observed that the life of boron lined proportional counters is significantly lower if irradiated in high neutron flux keeping the HV bias 'ON' compared to the irradiation with HV bias 'OFF'. When operated in gamma radiation, the boron lined proportional counters suffer count rate loss and underestimate the neutron flux. The loss in the count rate in gamma radiation is attributed to the space charge effect. The space charge effect is theoretically calculated for a known gamma radiation. The estimated values compared well with the experimentally observed values. Neutron sensitivity is estimated by modeling the boron lined proportional counters in FLUKA Monte-Carlo simulation code. The estimated neutron sensitivity values are comparable to the experimental and theoretical values.

Dighe, P. M.; Das, D.

2015-01-01

400

Density sensitive hashing.  

PubMed

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

Jin, Zhongming; Li, Cheng; Lin, Yue; Cai, Deng

2014-08-01

401

Low Complexity Turbo Equalisation for Power Line Communications  

Microsoft Academic Search

Due to the highly dispersive nature of the power line channel, there has been a strong trend towards the use of orthogonal frequency division multiplexing (OFDM) modulation for wideband power line communications (PLC). However, OFDM modulation has the drawbacks of high peak-to-average power ratio and increased sensitivity to carrier synchronisation errors. On the other hand, single-carrier (SC) modulation techniques do

Bamidele Adebisi; Carlos López Giovaneli; Bahram Honary; Mohammad Mowlavi

2007-01-01

402

A Serial Analysis of Gene Expression (SAGE) Database Analysis of Chemosensitivity: Comparing Solid Tumors with Cell Lines and Comparing Solid Tumors from Different Tissue Origins  

Microsoft Academic Search

Drug sensitivity and resistance has been most extensively studied in cell lines carried in tissue culture. Furthermore, cell lines have been widely used in testing new anticancer agents, despite the widely recognized observation that cell lines are more sensitive to cytotoxic drugs than are their corresponding solid tumors. We used the Serial Analysis of Gene Expression (SAGE) database to identify

Wilfred D. Stein; Thomas Litman; Tito Fojo; Susan E. Bates

2004-01-01

403

Tunable line node semimetals  

NASA Astrophysics Data System (ADS)

Weyl semimetals are examples of a new class of topological states of matter, which are gapless in the bulk with protected surface states. Their low-energy sector is characterized by massless chiral fermions, which are robust against translationally invariant perturbations. A variant of these systems has two nondegenerate bands touching along lines rather than points. A proposal to realize such a phase involves alternating layers of topological insulators and magnetic insulators, where the magnetization lies perpendicular to the symmetry axis of the heterostructure. The shape, size, and the dispersion in the vicinity of the nodal lines varies with the strength of the magnetization, offering a new knob to control the properties of the system. In this paper, we map out the evolution of the nodal lines and the dependence of the conductivity on magnetization and identify signatures of the low-energy sector in quantum oscillation measurements.

Phillips, Michael; Aji, Vivek

2014-09-01

404

Treating sensitivity during tooth whitening.  

PubMed

The most common side effect of tooth whitening is tooth sensitivity. There are a number of materials and techniques for reducing sensitivity. This article focuses on potassium nitrate applied either by brushing before initiating whitening or by application via a tray during whitening to reduce sensitivity. A detailed step-by-step procedure for managing hypersensitive patients is described. PMID:17039676

Haywood, Van B

2005-09-01

405

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

406

High resolution RGB color line scan camera  

NASA Astrophysics Data System (ADS)

A color line scan camera family which is available with either 6000, 8000 or 10000 pixels/color channel, utilizes off-the-shelf lenses, interfaces with currently available frame grabbers, includes on-board pixel by pixel offset correction, and is configurable and controllable via RS232 serial port for computer controlled or stand alone operation is described in this paper. This line scan camera is based on an available 8000 element monochrome line scan camera designed by AOA for OEM use. The new color version includes improvements such as better packaging and additional user features which make the camera easier to use. The heart of the camera is a tri-linear CCD sensor with on-chip color balancing for maximum accuracy and pinned photodiodes for low lag response. Each color channel is digitized to 12 bits and all three channels are multiplexed together so that the resulting camera output video is either a 12 or 8 bit data stream at a rate of up to 24Megpixels/sec. Conversion from 12 to 8 bit, or user-defined gamma, is accomplished by on board user-defined video look up tables. The camera has two user-selectable operating modes; lows speed, high sensitivity mode or high speed, reduced sensitivity mode. The intended uses of the camera include industrial inspection, digital archiving, document scanning, and graphic arts applications.

Lynch, Theodore E.; Huettig, Fred

1998-04-01

407

Identification of Cr-tolerant lines in a rice ( Oryza sativa ) DH population  

Microsoft Academic Search

Identification of Cr-tolerant lines in a rice DH population was conducted based on the modified weighted function analysis.\\u000a The significant difference was found between the two parents and among DH population lines, with lines 117, 101 and parent\\u000a ZYQ8 showing the high Cr tolerance, lines 41 and 49 showing Cr sensitivity. A dramatic difference also existed in Cr accumulation\\u000a of

Boyin Qiu; Weihui Zhou; Dawei Xue; Fanrong Zeng; Shafaqat Ali; Guoping Zhang

2010-01-01

408

Line-Follower Challenge  

NSDL National Science Digital Library

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.

GK-12 Program, Computational Neurobiology Center,

409

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.

410

Lightning proof transmission lines  

SciTech Connect

Lightning is prone to strike electrical transmission and distribution lines. Design of protection is difficult. Failure to design for the worst case conditions cost U.S.A. utilities 20 million annually. These costs can be prevented. During the past 16 years, LEC, Inc. has developed and proven a system that prevents strikes as well as insulator flashover from nearby strikes. LEC's Dual Dissipator System, presented in this paper, replaces the need for the static line for lightning considerations, eliminating the need for lightning arrestors. The insulation requirements transformers and switchgear can be reduced which reduce original costs.

Carpenter, R.B. Jr.; Drabkin, M. (Lightning Elimination Associates, Santa Fe Springs, CA (USA))

1988-01-01

411

Sensitivity limits of an infrared heterodyne spectrometer for astrophysical applications  

NASA Technical Reports Server (NTRS)

A discussion and an evaluation of the degradation in sensitivity are given for a heterodyne spectrometer employing a HgCdTe photodiode mixer and tunable diode lasers. The minimum detectable source brightness is considered as a function of the mixer parameters, transmission coefficient of the beam splitter, and local oscillator emission powers. The degradation in the minimum detectable line source brightness that results from the bandwidth being a fraction of the line width is evaluated and plotted as a function of the wavelength and bandwidth for various temperature to mass ratios. It is shown that the minimum achievable degradation in the sensitivity of a practical astronomical heterodyne spectrometer is about 30. Estimates of SNRs with which IR line emission from astronomical sources of interest may be detected are given.

Abbas, M. M.; Mumma, M. J.; Kostiuk, T.; Buhl, D.

1976-01-01

412

Sensitivity limits of an infrared heterodyne spectrometer for astrophysical applications  

NASA Technical Reports Server (NTRS)

A discussion and an evaluation of the degradation in sensitivity is given for a heterodyne spectrometer employing a HgCdTe photodiode mixer and tunable diode lasers. The minimum detectable source brightness is considered as a function of the mixer parameters, transmission coefficient of the beam splitter, and local oscillator emission powers. The degradation in the minimum detectable line source brightness which results from the bandwidth being a function of the line width is evaluated and plotted as a function of the wavelength and bandwidth for various temperature to mass ratios. It is shown that the minimum achievable degradation in the sensitivity of a practical astronomical heterodyne spectrometer is approximately 30. Estimates of signal-to-noise ratios with which infrared line emission from astronomical sources of interest may be detected are given.

Abbas, M. M.; Mumma, M. J.; Kostiuk, T.; Buhl, D.

1975-01-01

413

Gossypium accessions resistant to Rotylenchulus reniformis vary in sensitivity to the herbicide fluometuron  

Technology Transfer Automated Retrieval System (TEKTRAN)

Reniform nematode (Rotylenchulus reniformis) resistance is being transferred to Upland cotton (Gossypium hirsutum) from its distant relatives. Anecdotal observations of fluometuron damage to LONREN lines with resistance from G. longicalyx raised concerns about introducing herbicide sensitivity from ...

414

Off-line Handwriting Text Line Segmentation : A Review  

Microsoft Academic Search

Summary Text line segmentation is an essential pre-processing stage for off-line handwriting recognition in many Optical Character Recognition (OCR) systems. It is an important step because inaccurately segmented text lines will cause errors in the recognition stage. Text line segmentation of the handwritten documents is still one of the most complicated problems in developing a reliable OCR. The nature of

Zaidi Razak; Khansa Zulkiflee; Mohd Yamani Idna Idris; Emran Mohd Tamil; Mohd Noorzaily Mohamed Noor; Rosli Salleh; Mohd Yaakob; Zulkifli Mohd Yusof; Mashkuri Yaacob

2008-01-01

415

Straight Line Graphs  

ERIC Educational Resources Information Center

In this article, the author shares one effective lesson idea on straight line graphs that he applied in his lower ability Y9 class. The author wanted something interesting for his class to do, something that was fun and engaging with direct feedback, and something that worked because someone else had tried it before. In a word, the author admits…

Krueger, Tom

2010-01-01

416

Glue-Line Insects.  

ERIC Educational Resources Information Center

Presents an activity for fourth- and fifth-grade students in which they create a realistic or imaginative insect of their choice following a brief slide presentation on insects. Explains that the activity combines the use of line, shape, and color and takes two 40-minute class periods. (CMK)

Dugas, Christine

2001-01-01

417

Microwave spectral line listing  

NASA Technical Reports Server (NTRS)

The frequency, intensity, and identification of 9615 spectral lines belonging to 75 molecules are tabulated in order of increasing frequency. Measurements for all 75 molecules were made in the frequency range from 26500 to 40000 MHz by a computer controlled spectrometer. Measurements were also made in the 18000 to 26500 MHz range for some of the molecules.

White, W. F., Jr.

1975-01-01

418

Magnetic field line Hamiltonian  

SciTech Connect

The basic properties of the Hamiltonian representation of magnetic fields in canonical form are reviewed. The theory of canonical magnetic perturbation theory is then developed and applied to the time evolution of a magnetic field embedded in a toroidal plasma. Finally, the extension of the energy principle to tearing modes, utilizing the magnetic field line Hamiltonian, is outlined.

Boozer, A.H.

1985-02-01

419

Zip Line Zoo  

NSDL National Science Digital Library

In this activity, learners build a stuffed-animal zip line. Learners hold a cord against a wall, hook a cute stuffed animal onto it, let the animal slide down, and records its travel time. Use this activity to explore gravity, practice measuring distances and angles, and analyze rates.

Math, Bedtime

2014-06-23

420

Investigating the Line  

NSDL National Science Digital Library

In the related activity called "Colors Collide or Combine," learners are intrigued by the apparent "line" that forms where colors from M&M coatings meet but do not mix. In this activity, learners investigate whether this non-mixing property is unique to M&M's and find that it happens whenever similar liquids come together.

Kessler, James H.; Galvan, Patricia M.

2007-01-01

421

Use of EUV scatterometry for the characterization of line profiles and line roughness on photomasks  

NASA Astrophysics Data System (ADS)

Scatterometry is a versatile metrology for characterizing periodic structures, regarding critical dimension (CD) and other profile properties. With respect to small feature sizes on future lithography photomasks, the short wavelength of extreme ultraviolet (EUV) radiation is advantageous since it minimizes diffraction phenomena and increases the sensitivity to roughness. The advantage of the short wavelength can also be used for investigations of DUV photomasks. For EUV masks, only EUV radiation provides direct information on at-wavelength mask performance. The intensity of the measured diffraction orders carries information about the absorber line profile like top CD, sidewall angle, height, and top corner radius. It is shown that it is feasible to derive information on the absorber line profile in periodic areas of lines and spaces by means of rigorous numerical modeling with the finite element method (FEM). We demonstrate the determination of line profile parameters for chrome on glass (CoG) and EUV masks. EUV Reflectometry on CoG masks is successfully used to determine absorber line heights. A good correlation (0.2 nm rms) between CD values determined using EUV scatterometry and CD-SEM is demonstrated for an EUV mask. A clear correlation between diffuse scatter intensity and CD uniformity, respectively line roughness, is also obtained.

Scholze, Frank; Laubis, Christian

2008-04-01

422

Climate sensitivity of Abrahamsenbreen (northern Spitsbergen)  

NASA Astrophysics Data System (ADS)

The climate sensitivity of Abrahamsenbreen, a 20 km long surge-type glacier in northern Spitsbergen, is studied with a simple glacier model. A scheme to describe the surges is included, which makes it possible to account for the effect of surges on the total mass budget of the glacier. A climate reconstruction back to 1300 AD, based on ice-core data from Lomonosovfonna and climate records from Longyearbyen, is used to drive the model. The model is calibrated by requesting that it produces the correct late-Holocene maximum glacier length and simulates the observed magnitude of the 1978-surge. We make a comparison of the glacier evolution with and without regular surges. The main effect of a surge is to lower the mean surface elevation and to increase the ablation area, thereby causing a negative perturbation of the mass budget. When the surging mechanism is switched off, long-term mean glacier length increases by typically 10%. Abrahamsenbreen is strongly out of balance with the current climate. If climatic conditions will remain as they were for the period 1989-2010, the glacier will ultimately shrink to a length of 8 km (but this will take hundreds of years). For a climate change scenario involving a 2 m per year rise of the equilibrium line from now onwards, we predict that in the year 2100 Abrahamsenbreen will be about 14 km long. Because of the very small bed slope, Abrahamsenbreen is sensitive to small perturbations in the equilibrium-line altitude E. For a decrease of E of only 60 m, the glacier would steadily grow into the Woodfjorddalen until after 2000 years it would reach the Woodfjord and calving could slow down the advance. Our study once more underlines the extreme sensitivity of the large and gently sloping Svalbard glaciers to climate change.

Oerlemans, Johannes; Van Pelt, Ward

2014-05-01

423

A Quantitative Transmission Line Experiment  

ERIC Educational Resources Information Center

Describes modifications of a commercially available strip-type transmission line, which makes possible reproducible measurements of standing waves on the line. Experimental data yield values for the characteristic impedance, phase velocity and line wavelength of radiation in the transmission line, and the dielectric constant of material in the…

Johnston, D. C.; Silbernagel, B. G.

1969-01-01

424

Non-LTE Formation of Ba II Resonance Lines  

NASA Astrophysics Data System (ADS)

We investigate the formation of the resonance lines of ionized Barium in the Solar atmosphere. We have constructed atomic model of Ba II, which includes 40 energy levels, 99 bound-bound and 39 bound-free transitions. Using the numerical solution of radiative transfer equation together with the statistical equilibrium equations we calculate emergent profiles of the Ba II 4554 A resonance line under different conditions. Line profiles are calculated in both standard 1D and 3D atmospheric models in LTE and non-LTE approximations. We found that non-LTE effects are very important for this line. Main NLTE mechanisms are the resonance line scattering and photon losses. In 1D the line shape is most sensitive to the following parameters: Barium abundance, collisional strengths and macroturbulent velocity. Sensitivity to the uncertainties in oscillator strengths is not so high. Taking precise theoretical values of collisional strengths by Barklem & O'Mara (1998) we found the best agreement with observations for the abundance close to the "classical" value of 2.13. In 3D calculated profiles are in a good agreement with the observations. In 1D the agreement is worse. Thus it is critical for the modelling of Ba II lines to use the 3D non-LTE radiative transfer.

Olshevsky, V. L.; Shchukina, N. G.

2006-08-01

425

Printed circuit dispersive transmission line  

DOEpatents

A printed circuit dispersive transmission line structure is disclosed comprising an insulator, a ground plane formed on one surface of the insulator, a first transmission line formed on a second surface of the insulator, and a second transmission line also formed on the second surface of the insulator and of longer length than the first transmission line and periodically intersecting the first transmission line. In a preferred embodiment, the transmission line structure exhibits highly dispersive characteristics by designing the length of one of the transmission line between two adjacent periodic intersections to be longer than the other. 5 figures.

Ikezi, H.; Lin-Liu, Y.R.; DeGrassie, J.S.

1991-08-27

426

On Spectropolarimetric Measurements with Visible Lines  

NASA Astrophysics Data System (ADS)

The ability of new instruments for providing accurate inferences of vector magnetic fields and line-of-sight velocities of the solar plasma depends a great deal on the sensitivity to these physical quantities of the spectral lines chosen to be measured. Recently, doubts have been raised about visible Stokes profiles to provide a clear distinction between weak fields and strong ones filling a small fraction of the observed area. The goal of this paper is to give qualitative and quantitative arguments that help in settling the debate since several instruments that employ visible lines are either operating or planned for the near future. The sensitivity of the Stokes profiles is calculated through the response functions (RFs), for e.g., by Ruiz Cobo & Del Toro Iniesta. Both theoretical and empirical evidences are gathered in favor of the reliability of visible Stokes profiles. The RFs are also used for estimating the uncertainties in the physical quantities due to noise in observations. A useful formula has been derived that takes into account the measurement technique (number of polarization measurements, polarimetric efficiencies, and number of wavelength samples), the model assumptions (number of free parameters and the filling factor), and the radiative transfer (RFs). We conclude that a scenario with a weak magnetic field can reasonably be distinguished with visible lines from another with a strong field but a similar Stokes V amplitude, provided that the Milne-Eddington approximation is good enough to describe the solar atmosphere and the polarization signal is at least 3 or 4 times larger than the typical rms noise of 10-3 I c reached in the observations.

del Toro Iniesta, J. C.; Orozco Suárez, D.; Bellot Rubio, L. R.

2010-03-01

427

Stratospheric Airship Design Sensitivity  

NASA Astrophysics Data System (ADS)

The concept of a stratospheric or high altitude powered platform has been around almost as long as stratospheric free balloons. Airships are defined as Lighter-Than-Air (LTA) vehicles with propulsion and steering systems. Over the past five (5) years there has been an increased interest by the U. S. Department of Defense as well as commercial enterprises in airships at all altitudes. One of these interests is in the area of stratospheric airships. Whereas DoD is primarily interested in things that look down, such platforms offer a platform for science applications, both downward and outward looking. Designing airships to operate in the stratosphere is very challenging due to the extreme high altitude environment. It is significantly different than low altitude airship designs such as observed in the familiar advertising or tourism airships or blimps. The stratospheric airship design is very dependent on the specific application and the particular requirements levied on the vehicle with mass and power limits. The design is a complex iterative process and is sensitive to many factors. In an effort to identify the key factors that have the greatest impacts on the design, a parametric analysis of a simplified airship design has been performed. The results of these studies will be presented.

Smith, Ira Steve; Fortenberry, Michael; Noll, . James; Perry, William

2012-07-01

428

Balancing data sharing requirements for analyses with data sensitivity  

USGS Publications Warehouse

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.

Jarnevich, C.S.; Graham, J.J.; Newman, G.J.; Crall, A.W.; Stohlgren, T.J.

2007-01-01

429

Geometric Properties of Central Catadioptric Line Images and  

E-print Network

to determine the image of the absolute conic encoding the camera's intrinsic parameters. The sensitivity catadioptric system can be fully calibrated from an image of three or more lines. The image of the absolute to as catadioptric image formation. Central catadioptric systems use specific optic-lens arrangements in order

Barreto, Joao

430

Context-Sensitive Auto-Sanitization in Web Templating Languages Using Type Qualifiers  

E-print Network

Context-Sensitive Auto-Sanitization in Web Templating Languages Using Type Qualifiers Mike Samuel backwards compatibility, per- formance and formal security through a context-sensitive auto- sanitization results. The predominant first-line of defense against scripting vul- nerabilities is sanitization

Song, Dawn

431

Drill string transmission line  

DOEpatents

A transmission line assembly for transmitting information along a downhole tool comprising a pin end, a box end, and a central bore traveling between the pin end and the box end, is disclosed in one embodiment of the invention as including a protective conduit. A transmission line is routed through the protective conduit. The protective conduit is routed through the central bore and the ends of the protective conduit are routed through channels formed in the pin end and box end of the downhole tool. The protective conduit is elastically forced into a spiral or other non-linear path along the interior surface of the central bore by compressing the protective conduit to a length within the downhole tool shorter than the protective conduit.

Hall, David R. (Provo, UT); Hall, Jr., H. Tracy (Provo, UT); Pixton, David S. (Lehi, UT); Bradford, Kline (Orem, UT); Fox, Joe (Spanish Fork, UT)

2006-03-28

432

Coolant line hydrometer  

SciTech Connect

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 individually as a function of the specific gravity of the coolant. The coolant receiving chamber means includes a closure cap which when connected to the tubular fitting forms a coolant receiving chamber, retaining means for retaining the indicating float elements within the coolant receiving chamber, a viewing window member of a substantially clear material through which the float elements can be visually observed within the coolant receiving chamber means, and air venturi means located within the coolant receiving chamber means for automatically removing air which may collect within the coolant chamber means.

Barber, M.D.; Kipp, W.G.

1987-03-17

433

Education-line  

NSDL National Science Digital Library

This working paper archive, part of the Electronic Libraries Programme (eLib) (discussed in the September 20, 1996 Scout Report), and managed by the British Education Index at the University of Leeds (UK), currently contains over 200 pre-prints in the areas of education and training. Users can search the collection by keywords, an inverted word index, or the BEI thesaurus, which contains hypertext connections to automatically-generated searches for broader and narrower terms, as well as the terms selected. The collection can also be browsed (most recent Education-line documents). Full text of each preprint is available and bibliographic information including number of pages, abstract, level, age group, document type, and related subjects are available for selected preprints. Although still a "pilot service" at this time, Education-line promises to become a major source of education and training working papers.

434

Kalanchoe blossfeldiana plants expressing the Arabidopsis etr1-1 allele show reduced ethylene sensitivity.  

PubMed

Transgenic Kalanchoe blossfeldiana Poelln. with reduced ethylene sensitivity in flowers was obtained by Agrobacterium tumefaciens-mediated transformation using the plasmid pBEO210 containing the mutant ethylene receptor gene etr1-1 from Arabidopsis thaliana under the control of the flower-specific fbp1-promoter from Petunia. Three ethylene-resistent T0 lines, 300, 324 and 331, were selected and analyzed for postharvest-performance and morphological characteristics. Line 324 was found to be infertile and only slightly less ethylene-sensitive than control-plants, but lines 300 and 331 had significantly increased ethylene-resistance and were fertile. These two lines were analyzed for copy-number of the etr1-1 gene by Southern blotting and were crossed with the ethylene-sensitive cultivar 'Celine' to create T1 progeny. Line 300 contains two T-DNA copies per nucleus, one of which is rearranged, and these are unlinked according to segregation data from the crossing to 'Celine' and PCR-analysis of progeny plants. For control plants all flowers were closed after 2 days at 2 microl l(-1 )ethylene, but for line 300 only 33% were closed after 10 days. Line 331 contains three T-DNA copies per nucleus and is more sensitive to ethylene than line 300. In the line 300 the etr1-1 gene was found by RT-PCR to be expressed in petals and stamens but not in carpels and sepals. Both lines 300 and 331, and their progeny, appear morphologically and physiologically identical to control plants except for the higher ethylene resistance. Line 300 and its progeny with only one T-DNA copy have very low ethylene sensitivity and may be useful in future breeding. PMID:18080125

Sanikhani, Mohsen; Mibus, Heiko; Stummann, Bjarne M; Serek, Margrethe

2008-04-01

435

Line formation in solar granulation VI. [C I], C I, CH and C2 lines and the photospheric C abundance  

E-print Network

The solar photospheric carbon abundance has been determined from [C I], C I, CH vibration-rotation, CH A-X electronic and C2 Swan electronic lines by means of a time-dependent, 3D, hydrodynamical model of the solar atmosphere. Departures from LTE have been considered for the C I lines. These turned out to be of increasing importance for stronger lines and are crucial to remove a trend in LTE abundances with the strengths of the lines. Very gratifying agreement is found among all the atomic and molecular abundance diagnostics in spite of their widely different line formation sensitivities. The mean of the solar carbon abundance based on the four primary abundance indicators ([C I], C I, CH vibration-rotation, C_2 Swan) is log C = 8.39 +/- 0.05, including our best estimate of possible systematic errors. Consistent results also come from the CH electronic lines, which we have relegated to a supporting role due to their sensitivity to the line broadening. The new 3D based solar C abundance is significantly lower than previously estimated in studies using 1D model atmospheres.

M. Asplund; N. Grevesse; A. J. Sauval; C. Allende Prieto; R. Blomme

2004-10-28

436

Mapping Magnetic Field Lines  

NSDL National Science Digital Library

This is an activity about electromagnetism. Learners will use a compass to map the magnetic field lines surrounding a coil of wire that is connected to a battery. This activity requires a large coil or spool of wire, a source of electricity such as 3 D-cell batteries or an AC to DC power adapter, alligator-clipped wire, and magnetic compasses. This is the third lesson in the second session of the Exploring Magnetism teachers guide.

437

Four in a Line  

NSDL National Science Digital Library

This strategy game has simple rules but can be a challenge. Players start with an empty hexagonal grid. On each turn, a player initials one empty hexagon on the grid. The first with exactly four hexagons in a line wins. Children develop geometry, logical thinking and spatial visualization skills as they play this game. Includes easier and harder variations. Available as a downloadable pdf and in Spanish.

Terc

2010-01-01

438

Visualizing Magnetic Field Lines  

NSDL National Science Digital Library

In this activity, students take the age old concept of etch-a-sketch a step further. Using iron filings, students begin visualizing magnetic field lines. To do so, students use a compass to read the direction of the magnet's magnetic field. Then, students observe the behavior of iron filings near that magnet as they rotate the filings about the magnet. Finally, students study the behavior of iron filings suspended in mineral oil which displays the magnetic field in three dimensions.

VU Bioengineering RET Program, School of Engineering,

439

Redesigning line structures  

Microsoft Academic Search

Electric Power Research Institute (EPRI)-sponsored research will study structural damage to power-transmission structures and test design strength as a way to lower costs while optimizing system reliability. If existing designs are found to be too conservative, utilities can lower their capital costs. The transmission-line mechanical research facility (TLMRF) will have a two-mile system to test tower and conductor transmission, another