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1

Development of Bubble Chambers with Sensitivity to WIMPs  

SciTech Connect

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

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

2005-05-01

2

Extending the Sensitivity to the Detection of WIMP Dark Matter with an Improved Understanding of the Limiting Neutron Backgrounds  

SciTech Connect

The Cryogenic Dark Matter Search (CDMS) uses position-sensitive Germanium and Silicon crystals in the direct detection of Weakly Interacting Massive Particles (WIMPs) believed to constitute most of the dark matter in the Universe. WIMP interactions with matter being rare, identifying and eliminating known backgrounds is critical for detection. Event-by-event discrimination by the detectors rejects the predominant gamma and beta backgrounds while Monte Carlo simulations help estimate, and subtract, the contribution from the neutrons. This thesis describes the effort to understand neutron backgrounds as seen in the two stages of the CDMS search for WIMPs. The first stage of the experiment was at a shallow site at the Stanford Underground Facility where the limiting background came from high-energy neutrons produced by cosmic-ray muon interactions in the rock surrounding the cavern. Simulations of this background helped inform the analysis of data from an experimental run at this site and served as input for the background reduction techniques necessary to set new exclusion limits on the WIMP-nucleon cross-section, excluding new parameter space for WIMPs of masses 8-20 GeV/c{sup 2}. This thesis considers the simulation methods used as well as how various event populations in the data served as checks on the simulations to allow them to be used in the interpretation of the WIMP-search data. The studies also confirmed the presence of a limiting neutron background at the shallow site, necessitating the move to the 713-meter deep Soudan Underground Facility. Similar computer-based studies helped quantify the neutron background seen at the deeper site and informed the analysis of the data emerging from the first physics run of the experiment at Soudan. In conjunction with the WIMP-search and calibration data, the simulations confirmed that increased depth considerably reduced the neutron backgrounds seen, greatly improving the sensitivity to WIMP detection. The data run set an upper limit of 4 x 10{sup -43} on the WIMP-nucleon cross section for a WIMP mass of 60 GeV/c{sup 2} . Upper limits to the rate of background neutrons have also been determined.

Kamat, Sharmila; /Case Western Reserve U.

2005-01-01

3

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

SciTech Connect

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

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

2009-09-08

4

Leptophilic Effective WIMPs  

E-print Network

Effective WIMP models are minimal extensions of the standard model that explain the relic density of dark matter by the ``WIMP miracle.'' In this paper we consider the phenomenology of effective WIMPs with trilinear couplings to leptons and a new ``lepton partner'' particle. The observed relic abundance fixes the strength of the cubic coupling, so the parameters of the models are defined by the masses of the WIMP and lepton partner particles. This gives a simple parameter space where collider and direct detection experiments can be compared under well-defined physical minimality assumptions. The most sensitive collider probe is the search for leptons + MET, while the most sensitive direct detection channel is scattering from nuclei arising from loop diagrams. Collider and direct detection searches are highly complementary: colliders give the only meaningful constraint when dark matter is its own antiparticle, while direct detection is generally more sensitive if the dark matter is not its own antiparticle.

Spencer Chang; Ralph Edezhath; Jeffrey Hutchinson; Markus Luty

2014-02-28

5

Leptophilic Effective WIMPs  

E-print Network

Effective WIMP models are minimal extensions of the standard model that explain the relic density of dark matter by the ``WIMP miracle.'' In this paper we consider the phenomenology of effective WIMPs with trilinear couplings to leptons and a new ``lepton partner'' particle. The observed relic abundance fixes the strength of the cubic coupling, so the parameters of the models are defined by the masses of the WIMP and lepton partner particles. This gives a simple parameter space where collider and direct detection experiments can be compared under well-defined physical minimality assumptions. The most sensitive collider probe is the search for leptons + MET, while the most sensitive direct detection channel is scattering from nuclei arising from loop diagrams. Collider and direct detection searches are highly complementary: colliders give the only meaningful constraint when dark matter is its own antiparticle, while direct detection is generally more sensitive if the dark matter is not its own antiparticle.

Chang, Spencer; Hutchinson, Jeffrey; Luty, Markus

2014-01-01

6

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

2014-07-02

7

Effective WIMPs  

E-print Network

The 'WIMP miracle' for the relic abundance of thermal dark matter motivates weak scale dark matter with renormalizable couplings to standard model particles. We study minimal models with such couplings that explain dark matter as a thermal relic. The models contain a singlet dark matter particle with cubic renormalizable couplings between standard model particles and 'partner' particles with the same gauge quantum numbers as the standard model particle. The dark matter has spin 0, 1/2, or 1, and may or may not be its own antiparticle. Each model has 3 parameters: the masses of the dark matter and standard model partners, and the cubic coupling. Requiring the correct relic abundance gives a 2-dimensional parameter space where collider and direct detection constraints can be directly compared. We focus on the case of dark matter interactions with colored particles. We find that collider and direct detection searches are remarkably complementary for these models. Direct detection limits for the cases where the d...

Chang, Spencer; Hutchinson, Jeffrey; Luty, Markus

2014-01-01

8

Probing light WIMPs with directional detection experiments  

E-print Network

The CoGeNT and CRESST WIMP direct detection experiments have recently observed excesses of nuclear recoil events, while the DAMA/LIBRA experiment has a long standing annual modulation signal. It has been suggested that these excesses may be due to light mass, m_chi ~ 5-10 GeV, WIMPs. The Earth's motion with respect to the Galactic rest frame leads to a directional dependence in the WIMP scattering rate, providing a powerful signal of the Galactic origin of any recoil excess. We investigate whether direct detection experiments with directional sensitivity have the potential to observe this anisotropic scattering rate with the elastically scattering light WIMPs proposed to explain the observed excesses. We find that the number of recoils required to detect an anisotropic signal from light WIMPs at 5 sigma significance varies from 7 to more than 190 over the set of target nuclei and energy thresholds expected for directional detectors. Smaller numbers arise from configurations where the detector is only sensitive to recoils from the highest speed, and hence most anisotropic, WIMPs. However, the event rate above threshold is very small in these cases, leading to the need for large experimental exposures to accumulate even a small number of events. To account for this sensitivity to the tail of the WIMP velocity distribution, whose shape is not well known, we consider two exemplar halo models spanning the range of possibilities. We also note that for an accurate calculation the Earth's orbital speed must be averaged over. We find that the exposures required to detect 10 GeV WIMPs at a WIMP-proton cross-section of 10^-4 pb are of order 10^3 kg day for a 20 keV energy threshold, within reach of planned directional detectors. Lower WIMP masses require higher exposures and/or lower energy thresholds for detection.

Ben Morgan; Anne M. Green

2012-08-24

9

Expected sensitivity to galactic/solar axions and bosonic super-WIMPs based on the axio-electric effect in liquid xenon dark matter detectors  

NASA Astrophysics Data System (ADS)

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 (< 100 keV/c2), such as the hypothetical axion, could be detected as well - in this case using the axio-electric effect. Future ton-scale liquid Xe detectors will be limited in sensitivity only by irreducible neutrino background (pp-chain solar neutrino and the double beta decay of 136Xe) in the mass range between 1 and 100 keV/c2. Assuming one ton-year of exposure, galactic axions (as non-relativistic dark matter) could be detected if the axio-electric coupling gAe is greater than 10-14 at 1 keV/c2 axion mass (or 10-13 at 100 keV/c2). Below a few keV/c2, and independent of the mass, a solar axion search would be sensitive to a coupling gAe˜10-12. This limit will set a stringent upper bound on axion mass for the DFSZ and KSVZ models for the mass ranges mA<0.1 eV/c2 and <10 eV/c2, respectively. Vector-boson dark matter could also be detected for a coupling constant ?'/?>10-33 (for mass 1 keV/c2) or >10-27 (for mass 100 keV/c2).

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

2013-04-01

10

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

DOE Data Explorer

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

11

Median recoil direction as a WIMP directional detection signal  

SciTech Connect

Direct detection experiments have reached the sensitivity to detect dark matter weakly interacting massive particles (WIMPs). Demonstrating that a putative signal is due to WIMPs, and not backgrounds, is a major challenge, however. The direction dependence of the WIMP scattering rate provides a potential WIMP 'smoking gun'. If the WIMP distribution is predominantly smooth, the Galactic recoil distribution is peaked in the direction opposite to the direction of Solar motion. Previous studies have found that, for an ideal detector, of order 10 WIMP events would be sufficient to reject isotropy, and rule out an isotropic background. We examine how the median recoil direction could be used to confirm the WIMP origin of an anisotropic recoil signal. Specifically, we determine the number of events required to confirm the direction of solar motion as the median inverse recoil direction at 95% confidence. We find that for zero background 31 events are required, a factor of {approx}2 more than are required to simply reject isotropy. We also investigate the effect of a nonzero isotropic background. As the background rate is increased the number of events required increases, initially fairly gradually and then more rapidly, once the signal becomes subdominant. We also discuss the effect of features in the speed distribution at large speeds, as found in recent high resolution simulations, on the median recoil direction.

Green, Anne M. [School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD (United Kingdom); Morgan, Ben [Department of Physics, University of Warwick, Coventry, CV4 7AL (United Kingdom)

2010-03-15

12

Dust Sensitivity of Absorption-Line Indices  

E-print Network

We investigate the effects of dust extinction on integrated absorption-line indices that are widely used to derive constraints on the ages and metallicities of composite stellar systems. Typically, absorption-line studies have been performed on globular clusters or elliptical galaxies, which are mostly dust-free systems. However, many recent studies of integrated stellar populations have focused on spiral galaxies which may contain significant amounts of dust. It is almost universally assumed that the effects of dust extinction on absorption-line measurements are entirely negligible given the narrow baseline of the spectral features, but no rigorous study has yet been performed to verify this conjecture. In this analysis, we explore the sensitivity of the standard set of Lick absorption-line indices, the higher-order Balmer line indices, the 4000 A break, the near-IR calcium triplet indices, and the Rose indices to dust absorption according to population synthesis models that incorporate a multi-component model for the line and continuum attenuation due to dust. The latter takes into account the finite lifetime of stellar birth clouds. While dust does not greatly affect the line-index measurements for single stellar populations, its effect can be significant for the 4000 A break or when there is a significant amount of current star formation.

Lauren A. MacArthur

2004-12-20

13

The WIMP Paradigm: Current Status  

SciTech Connect

The WIMP paradigm is the glue that joins together much of the high energy and cosmic frontiers. It postulates that most of the matter in the Universe is made of weakly-interacting massive particles, with implications for a broad range of experiments and observations. I will review the WIMP paradigm's underlying motivations, its current status in view of rapid experimental progress on several fronts, and recent theoretical variations on the WIMP paradigm theme.

Feng, Jonathan (University of California, Irvine) [University of California, Irvine

2011-03-23

14

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

15

The WIMP Forest: Indirect Detection of a Chiral Square  

SciTech Connect

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).

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

2009-04-01

16

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

17

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

18

Spin-dependent WIMP limits from a bubble chamber.  

PubMed

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

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

2008-02-15

19

Spin-Dependent WIMP Limits from a Bubble Chamber  

NASA Astrophysics Data System (ADS)

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

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

2008-02-01

20

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

E-print Network

With positive signals from multiple direct detection experiments it will, in principle, be possible to measure the mass and cross sections of weakly-interacting massive particle (WIMP) dark matter. Recent work has shown that, with a polynomial parameterisation of the WIMP speed distribution, it is possible to make an unbiased measurement of the WIMP mass, without making any astrophysical assumptions. However, direct detection experiments are not sensitive to low-speed WIMPs and, therefore, any model-independent approach will lead to a bias in the cross section. This problem can be solved with the addition of measurements of the flux of neutrinos from the Sun. This is because the flux of neutrinos produced from the annihilation of WIMPs which have been gravitationally captured in the Sun is sensitive to low-speed WIMPs. Using mock data from next-generation direct detection experiments and from the IceCube neutrino telescope, we show that the complementary information from IceCube on low-speed WIMPs breaks the ...

Kavanagh, Bradley J; Green, Anne M

2014-01-01

21

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

E-print Network

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

E. Armengaud; for the EDELWEISS collaboration

2010-11-10

22

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

23

Mouse lines selected for genetic differences in diazepam sensitivity  

Microsoft Academic Search

Selective breeding techniques were used to alter allelic frequencies responsible for diazepam sensitivity and resistance.\\u000a We used the rotarod test to determine the duration of diazepam-induced neurologic deficit in genetically heterogeneous mice.\\u000a Males were more sensitive than females in the initial population. We then selectively bred for diazepam resistance and sensitivity.\\u000a A significant difference between the lines was apparent in

E. J. Gallaher; L. E. Hollister; S. E. Gionet; J. C. Crabbe

1987-01-01

24

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

25

WIMP Annihilation and Cooling of Neutron Stars  

E-print Network

We study the effect of WIMP annihilation on the temperature of a neutron star. We shall argue that the released energy due to WIMP annihilation inside the neutron stars, might affect the temperature of stars older than 10 million years, flattening out the temperature at $\\sim 10^4$ K for a typical neutron star.

Chris Kouvaris

2007-08-17

26

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

27

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.

28

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

2011-03-26

29

Towards Direct Detection of WIMPs with the Cryogenic Dark Matter Search  

SciTech Connect

The Cryogenic Dark Matter Search (CDMS) is carrying out a direct detection search for Weakly Interacting Massive Particles (WIMPs), one of the favored candidates for dark matter. Our latest data has placed some of the most stringent limits on the WIMP-nucleon spin-independent cross section of 6.6x10{sup -44} cm{sup 2} for 60 GeV WIMPs at the 90% confidence level. This paper describes our experiment and our latest results; the status of SuperCDMS Soudan, a new experiment at the Soudan mine in Minnesota that will achieve a sensitivity of 5x10{sup -45} cm{sup 2} our plans for SuperCDMS SNOLAB, a 100 kg experiment with a projected sensitivity of 3x10{sup -46} cm{sup 2}; and GEODM, a ton-scale experiment at DUSEL with a projected sensitivity of 2x10{sup -47} cm{sup 2}.

Figueroa-Feliciano, E. [Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

2010-02-10

30

In-line phase sensitive amplifier based on PPLN waveguides.  

PubMed

We demonstrate a ?(2)-based in-line PSA with a carrier-recovery and phase-locking system for a phase shift keying (PSK) signal. By doubling the signal phase using a wavelength conversion technique, the carrier was recovered from a PSK signal. The carrier phase was synchronized to a local oscillator using optical injection locking. Phase sensitive amplification with a wide phase sensitive dynamic range of 20 dB was achieved using degenerate parametric amplification in a periodically poled LiNbO(3) (PPLN) waveguide. The phase regeneration effect was examined for a degraded signal by means of constellation analyses and bit-error rate measurements. The in-line PSA also operated successfully as a repeater amplifier in a 160 km fiber link without a power penalty. Finally, we demonstrate the regeneration of non-linear impairments induced by fiber non-linearity. PMID:23736428

Umeki, Takeshi; Asobe, Masaki; Takenouchi, Hirokazu

2013-05-20

31

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

32

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

33

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

2014-02-28

34

Bleaching induced tooth sensitivity: do the existing enamel craze lines increase sensitivity? A clinical study.  

PubMed

The aim of this clinical study was to evaluate whether or not an association exists between the presence of enamel craze lines and the prevalence of tooth sensitivity (TS) after in-office bleaching. Subjects that met the inclusion criteria (N = 23) were screened to detect the existence of enamel craze lines. In total, 460 teeth were subjected to bleaching where 49% of them presented enamel craze lines. After bleaching (15% hydrogen peroxide), the subjects were asked to rate the level of TS by answering a self-administered questionnaire. The majority of subjects (91%) experienced TS at the first day of bleaching. The TS prevalence decreased gradually to 22% at second day, to 17% at third day, and to 9% at fourth day. After the fourth day, no subject reported TS. While 15% of teeth with craze lines presented TS, 11% of teeth with no craze lines also showed TS. A positive but weak correlation (r = 0.214) was found between the existence of enamel craze lines and TS. In this clinical study, higher incidence of TS was found with the use of 15% hydrogen peroxide bleaching agent compared to the previous studies. Patients who would undergo in-office bleaching should be informed that tooth sensitivity is a very often side effect but it may disappear within 1 week. PMID:23479310

Özcan, Mutlu; Abdin, Sam; Sipahi, Cumhur

2014-07-01

35

Searching for WIMP Recoils in Ancient Mica  

NASA Astrophysics Data System (ADS)

We are exploring the possibility of using mica to set limits on weakly interacting massive particles (WIMPs). Mica is a solid state nuclear track detector capable of recording the keV/amu recoil atoms produced in WIMP-nucleus collisions. One way to apply this idea is to look for fossil tracks in mica as old as 1 billion years. The mica is used as a detector and as a target. To carry out this experiment we select mica which is very old and found very deep underground (to reduce background from muon induced recoils). Then we choose a target atom within the mica, typically Iron or heavier. Given the flux of WIMPs, their interaction cross section with the target nucleus, and a WIMP mass we can calculate the number of recoils produced inside the mica during its lifetime. The damage caused by the recoil is stored and can be revealed by placing the mica in a suitable etchant. The WIMP-recoil etch pits must be separated from a background of etch pits caused by the recoiling daughters of Uranium and Thorium after alpha decay which produce etch pits of comparable size. We believe this is possible using an atomic force microscope to measure the etch pit depths. By limiting the amount of WIMP-recoils we observe we can set limits on the WIMP masses and interaction cross sections. For reasonable values for the age of mica and target concentrations we can hope to set limits which are several orders of magnitude better than current limits. The status of this search will be reported.

Snowden-Ifft, D. P.; Price, P. B.

1993-05-01

36

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

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false Common line, traffic-sensitive, and tandem-switched...COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES (CONTINUED) ACCESS CHARGES Pricing Flexibility § 69.713 Common line, traffic-sensitive, and...

2010-10-01

37

Delay-Line Three-Dimensional Position Sensitive Radiation Detection  

NASA Astrophysics Data System (ADS)

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

Jeong, Manhee

38

Soft Collinear Effective Theory for Heavy WIMP Annihilation  

E-print Network

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 $\\sim \\alpha \\log^2 (2\\,M/m_W)$ 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 wave-function distortion from electroweak boson exchange leads to observable modifications of the cross section. Careful accounting of momentum regions in the EFT allows the rigorously disentanglement of this so-called Sommerfeld enhancement from the short distance hard annihilation process. The WIMP is modeled as a heavy-particle field, while the light, energetic, final-state electroweak gauge bosons are treated as soft and collinear fields. Hard matching coefficients are computed at renormalization scale $\\mu \\sim 2\\,M$, then evolved down to $\\mu \\sim m_W$, 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 $M \\simeq 3$ TeV, the resummed Sommerfeld enhanced cross section is reduced by a factor of $\\sim 3$ with respect to the tree-level fixed order result.

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

2014-09-25

39

Oh to Be Rid of Administrative Wimps!  

ERIC Educational Resources Information Center

Contemporary university administrators are usually wimps, and timidity in facing easily enraged campus radicals only invites outrageous demands which, in turn, subvert intellectual life. This must be changed. For much of human history leaders had to display physical valor and this trait should be restored to the college administrator job…

Weissberg, Robert

2007-01-01

40

Isolation of two chloroethylnitrosourea-sensitive Chinese hamster cell lines  

Microsoft Academic Search

1-((4-Amino-2-methylpyrimidin-5-yl)methyl)-3-(2-chloroethyl)-3- nitrosourea hydrochloride (ACNU), a cancer chemotherapeutic bifunctional alkylating agent, causes chloroethylation of DNA and subsequent DNA strand cross-linking through an ethylene bridge. We isolated and characterized two ACNU-sensitive mutants from mutagenized Chinese hamster ovary cells and found them to be new drug-sensitive recessive Chinese hamster mutants. Both mutants were sensitive to various monofunctional alkylating agents in a way similar

H. Hata; M. Numata; H. Tohda; A. Yasui; A. Oikawa

1991-01-01

41

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

42

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

E-print Network

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

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

2009-01-27

43

New limits on low-mass WIMP dark matter with sub-keV germanium detector  

NASA Astrophysics Data System (ADS)

The current goals of the TEXONO research program are on the development of germanium detectors with sub-keV sensitivities to realize experiments on neutrino magnetic moments, neutrino-nucleus coherent scattering, as well as WIMP dark matter searches. A threshold of 220 eV was achieved with prototype detectors at the Kuo-Sheng Neutrino Laboratory. New limits were placed for the couplings of low-mass WIMPs with matter. Data are being taken with a 500 g Point Contact Germanium detector, where a threshold of ~350 eV was demonstrated. The dark matter program will evolve into a dedicated experiment at an underground laboratory under construction in Sichuan, China.

Wong, Henry T.

2010-01-01

44

New class of biological detectors for WIMPs  

E-print Network

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 d...

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

2014-01-01

45

Changes in gene expression profile in two multidrug resistant cell lines derived from a same drug sensitive cell line.  

PubMed

Resistance to chemotherapy is one of the most relevant aspects of treatment failure in cancer. Cell lines are used as models to study resistance. We analyzed the transcriptional profile of two multidrug resistant (MDR) cell lines (Lucena 1 and FEPS) derived from the same drug-sensitive cell K562. Microarray data identified 130 differentially expressed genes (DEG) between K562 vs. Lucena 1, 1932 between K562 vs. FEPS, and 1211 between Lucena 1 versus FEPS. The NOTCH pathway was affected in FEPS with overexpression of NOTCH2 and HEY1. The highly overexpressed gene in MDR cell lines was ABCB1, and both presented the ABCB1 promoter unmethylated. PMID:24996974

Moreira, Miguel Angelo Martins; Bagni, Carolina; de Pinho, Marcos Barcelos; Mac-Cormick, Thaís Messias; dos Santos Mota, Mateus; Pinto-Silva, Flávio Eduardo; Daflon-Yunes, Nathalia; Rumjanek, Vivian Mary

2014-08-01

46

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

Code of Federal Regulations, 2013 CFR

...CONTINUED) ACCESS CHARGES Pricing Flexibility § 69.713 Common line, traffic-sensitive...paragraph governs requests for pricing flexibility with respect to the following services... (1) To obtain Phase I pricing flexibility, as specified in §...

2013-10-01

47

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

Code of Federal Regulations, 2011 CFR

...CONTINUED) ACCESS CHARGES Pricing Flexibility § 69.713 Common line, traffic-sensitive...paragraph governs requests for pricing flexibility with respect to the following services... (1) To obtain Phase I pricing flexibility, as specified in §...

2011-10-01

48

New Signatures and Sources for the Detection of WIMP Dark Matter in the Solar System  

E-print Network

I first outline new results on the angular modulation of WIMP dark matter scattering on targets in terrestrial laboratories, based on our uncertainties of the WIMP halo distribution, I then outline an exciting new result which indicates that for the high end of allowed SUSY WIMP scattering cross sections there exists a new distribution of WIMP dark matter in our solar system which could produce a dramatically different signal from halo WIMP dark matter in terrestrial detectors.

Lawrence M. Krauss

1998-07-14

49

A sensitive submillimetre survey of broad absorption-line quasars  

NASA Astrophysics Data System (ADS)

Using the Submillimetre Common-User Bolometer Array on the JCMT, we have carried out a submillimetre (submm) survey of broad absorption-line quasars (BALQs). The sample has been chosen to match, in redshift and optical luminosity, an existing benchmark 850-?m sample of radio-quiet quasars, allowing a direct comparison of the submm properties of BAL quasars relative to the parent radio-quiet population. We reach a submm limit 1? ~ 1.5 mJy at 850 ?m, allowing a more rigorous measure of the submm properties of BAL quasars than previous studies. Our submm photometry complements extensive observations at other wavelengths, in particular X-rays with Chandra and infrared with Spitzer. To compare the 850-?m flux distribution of BALQs with that of the non-BAL quasar benchmark sample, we employ a suite of statistical methods, including survival analysis and a novel Bayesian derivation of the underlying flux distribution. Although there are no strong grounds for rejecting the null hypothesis that BALQs on the whole have the same submm properties as non-BAL quasars, we do find tentative evidence (1-4 per cent significance from a Kolmogorov-Smirnov test and survival analysis) for a dependence of submm flux on the equivalent width of the characteristic CIV BAL. If this effect is real - submm activity is linked to the absorption strength of the outflow - it has implications either for the evolution of active galactic nuclei (AGNs) and their connection with star formation in their host galaxies, or for unification models of AGNs.

Priddey, Robert S.; Gallagher, S. C.; Isaak, K. G.; Sharp, R. G.; McMahon, R. G.; Butner, H. M.

2007-01-01

50

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

E-print Network

Improved phase sensitivity in spectral domain phase microscopy using line-field illumination. R. Dasari, and M. S. Feld, "Fourier phase microscopy for investigation of biological structures-field illumination. The line illumination allows self phase-referencing method to reject common-mode phase noise

Fang-Yen, Christopher

51

Understanding WIMP-baryon interactions with direct detection: A Roadmap  

E-print Network

We study prospects of dark-matter direct-detection searches for probing non-relativistic effective theory for WIMP-baryon scattering. We simulate a large set of noisy recoil-energy spectra for different scattering scenarios (beyond the standard momentum-independent contact interaction), for Generation 2 and futuristic experiments. We analyze these simulations and quantify the probability of successfully identifying the operator governing the scattering, if a WIMP signal is observed. We find that the success rate depends on a combination of factors: the WIMP mass, the mediator mass, the type of interaction, and the experimental energy window. For example, for a 20 GeV WIMP, Generation 2 is only likely to identify the right operator if the interaction is Coulomb-like, and is unlikely to do so in any other case. For a WIMP with a mass of 200 GeV or higher, success is almost guaranteed. We also find that, regardless of the scattering model and the WIMP parameters, a single Generation 2 experiment is unlikely to successfully discern the momentum dependence of the underlying operator on its own, but prospects improve drastically when experiments with different target materials and energy windows are analyzed jointly. Furthermore, we examine the quality of parameter estimation and degeneracies in the multi-dimensional parameter space of the effective theory. We find in particular that the resulting WIMP mass estimates can be severely biased if data are analyzed assuming the standard (momentum-independent) operator while the actual operator has momentum-dependence. Finally, we evaluate the ultimate reach of direct detection, finding that the prospects for successful operator selection prior to reaching the irreducible backgrounds are excellent, if the signal is just below the current limits, but slim if Generation 2 does not report WIMP detection.

Vera Gluscevic; Annika H. G. Peter

2014-06-26

52

Understanding WIMP-baryon interactions with direct detection: a roadmap  

NASA Astrophysics Data System (ADS)

We study prospects of dark-matter direct-detection searches for probing non-relativistic effective theory for WIMP-baryon scattering. We simulate a large set of noisy recoil-energy spectra for different scattering scenarios (beyond the standard momentum-independent contact interaction), for Generation 2 and futuristic experiments. We analyze these simulations and quantify the probability of successfully identifying the operator governing the scattering, if a WIMP signal is observed. We find that the success rate depends on a combination of factors: the WIMP mass, the mediator mass, the type of interaction, and the experimental energy window. For example, for a 20 GeV WIMP, Generation 2 is only likely to identify the right operator if the interaction is Coulomb-like, and is unlikely to do so in any other case. For a WIMP with a mass of 200 GeV or higher, success is almost guaranteed. We also find that, regardless of the scattering model and the WIMP parameters, a single Generation 2 experiment is unlikely to successfully discern the momentum dependence of the underlying operator on its own, but prospects improve drastically when experiments with different target materials and energy windows are analyzed jointly. Furthermore, we examine the quality of parameter estimation and degeneracies in the multi-dimensional parameter space of the effective theory. We find in particular that the resulting WIMP mass estimates can be severely biased if data are analyzed assuming the standard (momentum-independent) operator while the actual operator has momentum-dependence. Finally, we evaluate the ultimate reach of direct detection, finding that the prospects for successful operator selection prior to reaching the irreducible backgrounds are excellent, if the signal is just below the current limits, but slim if Generation 2 does not report WIMP detection.

Gluscevic, Vera; Peter, Annika H. G.

2014-09-01

53

Limits on the Spin-Dependent WIMP-Nucleon Cross Sections from the First Science Run of the ZEPLIN-III Experiment  

SciTech Connect

We present new experimental constraints on the WIMP-nucleon spin-dependent elastic cross sections using data from the first science run of ZEPLIN-III, a two-phase xenon experiment searching for galactic dark matter weakly interacting massive particles based at the Boulby mine. Analysis of approx450 kgcentre dotdays fiducial exposure allow us to place a 90%-confidence upper limit on the pure WIMP-neutron cross section of sigma{sub n}=1.9x10{sup -2} pb at 55 GeV/c{sup 2} WIMP mass. Recent calculations of the nuclear spin structure based on the Bonn charge-dependent nucleon-nucleon potential were used for the odd-neutron isotopes {sup 129}Xe and {sup 131}Xe. These indicate that the sensitivity of xenon targets to the spin-dependent WIMP-proton interaction could be much lower than implied by previous calculations, whereas the WIMP-neutron sensitivity is impaired only by a factor of approx2.

Lebedenko, V. N.; Bewick, A.; Currie, A.; Davidge, D.; Dawson, J.; Horn, M.; Howard, A. S.; Jones, W. G.; Joshi, M.; Liubarsky, I.; Lyons, K.; Quenby, J. J.; Sumner, T. J.; Thorne, C.; Walker, R. J. [Blackett Laboratory, Imperial College London, London (United Kingdom); Araujo, H. M.; Edwards, B. [Blackett Laboratory, Imperial College London, London (United Kingdom); Particle Physics Department, Rutherford Appleton Laboratory, Chilton (United Kingdom); Barnes, E. J.; Ghag, C.; Murphy, A. StJ. [School of Physics and Astronomy, SUPA University of Edinburgh, Edinburgh (United Kingdom)

2009-10-09

54

Detecting Dark Matter annihilation lines with Fermi  

SciTech Connect

Dark matter constitutes one of the most intriguing but so far unresolved issues in physics today. In many extensions of the Standard Model the existence of a stable Weakly Interacting Massive Particle (WIMP) is predicted. The WIMP is an excellent dark matter particle candidate and one of the most interesting scenarios include an annihilation of two WIMPs into two gamma-rays. If the WIMPs are assumed to be non-relativistic, the resulting photons will both have an energy equal to the mass of the WIMP and manifest themselves as a monochromatic spectral line in the energy spectrum. This type of signal would represent a 'smoking gun' for dark matter, since no other known astrophysical process should be able to produce it. In these proceedings we give an overview of the different approaches to a search for dark matter lines that the Fermi-LAT collaboration is pursuing and the various challenges involved.

Ylinen, Tomi; Edmonds, Yvonne; Bloom, Elliott D.; Conrad, Jan; /Royal Inst. Tech., Stockholm /Kalmar U. /KIPAC, Menlo Park /SLAC /Stockholm U.

2009-05-15

55

Human cancer cell line microRNAs associated with in vitro sensitivity to paclitaxel  

PubMed Central

Paclitaxel is a mainstay of treatment for many solid tumors, and frequently, clinical outcome is influenced by paclitaxel sensitivity. Despite this, our understanding of the molecular basis of paclitaxel response is incomplete. Recently, it has been shown that microRNAs (miRNAs) influence messenger RNA (mRNA) transcriptional control and can contribute to human carcinogenesis. In the present study, our objective was to identify miRNAs associated with cancer cell line response to paclitaxel and to evaluate these miRNAs as therapeutic targets to increase paclitaxel sensitivity. We measured the expression of 335 unique miRNAs in 40 human cancer cell lines selected from the NCI panel. We then integrated miRNA expression data with publicly available paclitaxel-sensitivity (GI50) data for each of the 40 cell lines to identify miRNAs associated with paclitaxel sensitivity. Ovarian cancer cell lines with differential miRNA expression and paclitaxel sensitivity were transiently transfected with miRNA precursors and inhibitors, and the effects on in vitro cell paclitaxel sensitivity were evaluated. Pearson’s correlation identified 2 miRNAs (miR-367 and miR-30a-5p) associated with the NCI40 cell line in vitro paclitaxel response (P<0.0003). Ovarian cancer cells were selected based on the association between paclitaxel sensitivity and miR-367/miR-30a-5p expression. Overexpression of miR-367 in the paclitaxel-sensitive cells [PA1; IC50, 1.69 nM, high miR-367 (2.997), low miR-30a-5p (?0.323)] further increased paclitaxel sensitivity, whereas miR-367 depletion decreased paclitaxel sensitivity. In contrast, overexpression and depletion of miR-30a-5p in the paclitaxel-resistant cells [OVCAR4; IC50, 17.8 nM, low miR-367 (?0.640), high miR-30a-5p (3.270)] decreased and increased paclitaxel sensitivity, respectively. We identified and successfully targeted miRNAs associated with human cancer cell line response to paclitaxel. Our strategy of integrating in vitro miRNA expression and drug sensitivity data may not only aid in the characterization of determinants of drug response but also in the identification of novel therapeutic targets to increase activity of existing therapeutics. PMID:24220856

CHEN, NING; CHON, HYE SOOK; XIONG, YIN; MARCHION, DOUGLAS C.; JUDSON, PATRICIA L.; HAKAM, ARDESHIR; GONZALEZ-BOSQUET, JESUS; PERMUTH-WEY, JENNIFER; WENHAM, ROBERT M.; APTE, SACHIN M.; CHENG, JIN Q.; SELLERS, THOMAS A.; LANCASTER, JOHNATHAN M.

2014-01-01

56

Increased sensitivity to triiodothyronine (T3) of broiler lines with a high susceptibility for ascites.  

PubMed

1. In the studies reported here, broiler lines divergently selected for susceptibility to ascites under low temperature conditions were tested for their sensitivity to 3,3',5-triiodothyronine (T3) with respect to growth rate, rate of mortality, plasma concentrations of T3, right ventricular hypertrophy (RVH) and incidence of ascites. 2. Mean body weight of the ascites-susceptible line (BC-line) was higher than that of the ascites-resistant line (A-line). Adding 0.5 mg T3/kg of the diet depressed growth rate to the same extent in both lines. The effect of T3 on growth was more pronounced for males than for females. 3. T3-supplementation increased the relative weight of the heart and the incidence of RVH to the same extent in both lines. More of the T3-treated BC-line chickens had fluid accumulation in the abdominal cavity than the T3-treated A-line chickens. 4. Dietary T3-treatment depressed the plasma concentration of growth hormone (GH) profoundly and insulin-like growth factor (IGF-I) slightly but to the same extent in both lines. The coefficient of variation of GH concentrations indicate that T3 treatment mainly decreased GH-pulsatility in young growing broilers. 5. Higher doses of dietary T3 (1 and 2 mg/kg) increased mortality in a dose-dependent manner. With 2 mg T3/kg, mortality in the BC-line was almost double that in the A-line. 6. These studies indicate that the development of ascites could be linked with thyroid function. Moreover, dietary T3 supplementation could be used to help identify ascites-inducing factors or genetic lines with differential sensitivity for ascites. PMID:8062112

Decuypere, E; Vega, C; Bartha, T; Buyse, J; Zoons, J; Albers, G A

1994-05-01

57

Annihilation Lines from Dark Matter with the Fermi-LAT  

SciTech Connect

Dark matter is today one of the most intriguing but so far unresolved issues in physics. Many extensions of the Standard Model of particle physics predict a stable Weakly Interacting Massive Particle (WIMP) that may annihilate directly into two gamma-rays. If the WIMPs are non-relativistic, the gamma-rays from this channel will have an energy equal to the mass of the WIMP. The signature caused by this annihilation is a spectral line, smeared out only by the energy resolution of the detector. The signal would be a ''smoking gun'' for dark matter, since no other astrophysical source should be able to produce it. We present here the preliminary results from the search for a dark matter line on a limited data set from the Fermi Large Area Telescope (LAT), the main instrument onboard the Fermi Gamma-ray Space Telescope, which was successfully launched on June 11, 2008. The Fermi-LAT is a pair-conversion detector for gamma-rays with an energy range from 20 MeV to 300 GeV and has an unprecedented resolution and sensitivity.

Ylinen, Tomi [Oskar Klein Centre for Cosmoparticle Physics and Department of Physics, Royal Institute of Technology (KTH), AlbaNova, SE-106 91 Stockholm (Sweden) and School of Pure and Applied Natural Sciences, University of Kalmar, SE-391 82 Kalmar (Sweden)

2010-06-23

58

Isolation and characterization of Chinese hamster ovary cell lines sensitive to mitomycin C and bleomycin  

SciTech Connect

Seven Chinese hamster ovary K1 cell lines exhibiting sensitivity to anticancer drugs have been isolated by a replica-plating technique. Five of the mutants are hypersensitive to the DNA cross-linking agent mitomycin C. Of these, one is also appreciably sensitive to UV light. Significant variations in their cross-sensitivity to cis-platinum(II) diammine dichloride, chlorambucil, and Adriamycin have also been observed. Two additional mutants have been isolated on the basis of sensitivity to the radiomimetic agent bleomycin. One of these shows greater than 6-fold sensitivity to bleomycin, while the other is approximately 14 times more sensitive than the parental strain to bleomycin and is also hypersensitive to a number of other DNA-damaging agents, including cis-platinum(II) diammine dichloride, chlorambucil, X-rays, and UV light. Both bleomycin-sensitive mutants also exhibit some degree of sensitivity to Adriamycin. In all cases, the cell lines have been grown in continuous culture for 3 months without evidence of reversion and should act as suitable recipients in DNA transfection experiments aimed at identifying human DNA repair genes.

Robson, C.N.; Harris, A.L.; Hickson, I.D.

1985-11-01

59

O6-alkylguanine-DNA-alkyltransferase activity and nitrosourea sensitivity in human cancer cell lines.  

PubMed Central

The DNA repair enzyme, O6-alkylguanine-DNA-alkyltransferase (ATase), is thought to be the principal mechanism controlling resistance to nitrosoureas and related alkylating agents. We compared the sensitivities of five human testis and five bladder tumour cell lines to two nitrosoureas (N-nitroso-N-methylurea (MNU) and mitozolomide) with cellular levels of ATase. Enzyme levels ranged from 3 to 206 fmol mg-1 protein (0.1 x 10(4) to 5.1 x 10(4) molecules/cell) in the testis lines and from 11 to 603 fmol mg-1 (0.4 x 10(4) to 9.1 x 10(4) molecules/cell) in the bladder lines. Based on IC50s in an MTT assay, the testis tumour cell lines were, on average, four times more sensitive to MNU and six times more sensitive to mitozolomide than the bladder cell lines. The cytotoxicities of MNU and mitozolomide were closely related (R = 0.9). In the testis cell lines ATase activity (molecules/cell) was related to IC50s for mitozolomide (R = 0.97) but not MNU (R = 0.78). In the bladder cell lines and overall, ATase activity correlated with cellular sensitivity to neither agent. Relatively high levels of resistance occurred in cells expressing low levels of ATase, and amongst cell lines expressing high levels of ATase, large differences in IC50s were observed. These results support the suggestion that resistance to nitrosoureas can be mediated by mechanisms other than ATase and that at relatively high levels of expression, ATase does not confer resistance in proportion to its activity. PMID:1419626

Walker, M. C.; Masters, J. R.; Margison, G. P.

1992-01-01

60

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

E-print Network

We present work on the detection of neutral particles via nuclear recoils in gas-filled 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 first 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 fissionable material.

Jared Yamaoka; Haolu Feng; Maurice Garcia-Sciveres; Igal Jaegle; John Kadyk; Young Nguyen; Marc Rosen; Steven Ross; Thomas Thorpe; Sven Vahsen

2012-06-11

61

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

62

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

E-print Network

was studied in osteosarcoma cell lines 143B-MM, 143-P and control murine osteoblast MC3T3-E1. Cell proliferation and sensitization effects were evaluated by MTS assay. Boyden chamber assay was used for migration/invasion studies. MMP activity was measured...

Bhamidi Lakshmi, Surya Kameshwari Priyanka

2012-08-31

63

Trust and Profit Sensitive Ranking for the Deep Web and On-line Advertisements  

E-print Network

is inapplicable (since deep web records do not have links). I formulated a method--namely SourceRank--to assessTrust and Profit Sensitive Ranking for the Deep Web and On-line Advertisements by Raju Balakrishnan of ranking the deep web data considering trustworthiness and relevance. I address the end-to-end deep web

Kambhampati, Subbarao

64

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

PubMed

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. PMID:20430010

Qin, J-Z; Xin, H; Nickoloff, B J

2010-05-28

65

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

Microsoft Academic Search

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.

Alvarado Tarun; Julius Jecong; Caesar Saloma

2005-01-01

66

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

PubMed Central

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

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

2012-01-01

67

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

PubMed

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

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

2012-03-29

68

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

69

Dark matter spin-dependent limits for WIMP interactions on 19F by PICASSO  

NASA Astrophysics Data System (ADS)

The PICASSO experiment at SNOLAB uses super-heated C4F10 droplets suspended in a gel as a target sensitive to WIMP-proton spin-dependent elastic scattering. The phase II setup has been improved substantially in sensitivity by using an array of 32 detectors with an active mass of ~65 g each and largely reduced background. First results are presented for a subset of two detectors with target masses of 19F of 65 g and 69 g respectively and a total exposure of 13.75 ± 0.48 kgd. No dark matter signal was found and for WIMP masses around 24 GeV/c2 new limits have been obtained on the spin-dependent cross section on 19F of ?F = 13.9 pb (90% C.L.) which can be converted into cross section limits on protons and neutrons of ?p = 0.15 pb and ?n = 2.45 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.

Beltran, Berta; Picasso Collaboration

2010-01-01

70

Differential sensitivities of human testicular and bladder tumor cell lines to chemotherapeutic drugs.  

PubMed

The in vitro drug sensitivities of 5 human testicular tumor cell lines (Tera II, SuSa, NEC-8, 833K, T3B1) and 5 human bladder carcinoma cell lines (RT4, RT112, T24, HT1197, HT1376) were compared. Cytotoxicities of cisplatin and doxorubicin were assessed by inhibition of colony-forming ability during continuous exposure to a range of drug concentrations. The ranges of the drug concentrations required to kill 70% of clonogenic cells obtained against the testicular cell lines were 1-7 ng/ml and 21-161 ng/ml for doxorubicin and cisplatin, respectively, compared with 4-19 ng/ml and 112-431 ng/ml for the bladder cell lines. This study shows that continuous cell lines retain the relative clinical chemosensitivities of their tumors of origin. The results also indicate that testicular tumor cells are inherently more sensitive to the cytotoxic effects of chemotherapeutic drugs than are bladder cancer cells. PMID:3474453

Walker, M C; Parris, C N; Masters, J R

1987-08-01

71

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

SciTech Connect

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

Denne, B.; Hinnov, E.

1984-04-01

72

A high-sensitivity OH 5-cm line survey in late-type stars  

E-print Network

We have undertaken a comprehensive search for 5-cm excited OH maser emission from evolved stars representative of various stages of late stellar evolution. Observed sources were selected from known 18-cm OH sources. This survey was conducted with the 100-m Effelsberg telescope to achieve high signal to noise ratio observations and a sensitivity limit of about 0.05 to 0.1 Jy. A total of 64 stellar sources were searched for both main line and satellite line emission. We confirm the previous detection of 5 cm OH in Vy 2-2, do not confirm emission from NML-Cyg and do not report any other new detection within the above sensitivity limit. Implications of these results on the pumping mechanism of the OH radical in circumstellar envelopes are briefly discussed.

J. -F. Desmurs; A. Baudry; P. Sivagnanam; C. Henkel

2002-10-07

73

Understanding Phonon Sensing for a WIMP Search Detector  

NASA Astrophysics Data System (ADS)

Astronomical observations on every scale from galaxies to the large scale structure of the universe indicate that most of the matter in the universe does not radiate in the electromagnetic spectrum. One hypothesis which is attractive for theoretical reasons-from both a cosmological point of view as well as an elementary particle point of view-is that the missing mass, or 'dark matter', is made of weakly interacting massive particles, or WIMPs. A search for these hypothetical particles which could make up the dark matter of the universe requires great efforts in detector development. Efforts in the Direct Detection group at UC Berkeley have concentrated on Neutron Transmutation Doped (NTD) germanium used as thermal sensors attached to larger (up to a current 165 g) crystal of pure germanium. A sensitivity of 500 eV has been achieved in the 165 g device. Theoretical calculations of various aspects of various aspects of phonon and thermal sensitivity are presented. The current understanding of the thermal and electrical physics of NTD Ge is outlined. The very sensitive temperature dependence of the resistivity is explained by the variable range hopping theory with a Coulomb gap density of states. The hot electron model is presented to explain the non-Ohmic behavior observed at high bias currents. This thesis also presents a new variation to the hot electron model which includes electron temperature and phonon temperature effects. The expected heat capacity of the NTD Ge devices is discussed, and a thermal model for the full composite detector plus absorber is calculated. The experimental results presented focus on a systematic characterization of the electrical and thermal parameters of many devices. Among the parameters discussed are the resistivity of NTD Ge at a constant temperature as a function of net dopant concentration, the thermal couplings between thermistors and heat sinks, and the volume dependence of electron-phonon coupling in a thermistor. The bulk thermal conductance of NTD Ge is also measured for the first time and shown to be geometry limited in the device used, implying a mean free path for phonons of more than 2 mm at 26 mK. Heat capacity measurements give inconsistent results, with some results showing temperature dependence and others showing none. Detector performance, measured by pulse heights normalized to the deposited energy and detector heat capacity, is also systematically compared among various detectors. Comparisons indicate that heat sink coupling strength, thermistor volume, and the thickness of the thermistor-absorber interface affect the detector performance.

Cummings, Alan Keith

74

RNA-seq reveals determinants for irinotecan sensitivity/resistance in colorectal cancer cell lines  

PubMed Central

Irinotecan is a topoisomerase I inhibitor approved worldwide as a first- and second-line chemotherapy for advanced or recurrent colorectal cancer (CRC). Although irinotecan showed significant survival advantage for patients, a relatively low response rate and severe adverse effects demonstrated the urgent need for biomarkers searching to select the suitable patients who can benefit from irinotecan-based therapy and avoid the adverse effects. In present work, the irinotecan response (IC50 doses) of 20 CRC cell lines were correlated with the basal expression profiles investigated by RNA-seq to figure out genes responsible for irinotecan sensitivity/resistance. Genes negatively or positively correlated to irinotecan sensitivity were given after biocomputation, and 7 (CDC20, CTNNAL1, FZD7, CITED2, ABR, ARHGEF7, and RNMT) of them were validated in two CRC cell lines by quantitative real-time PCR, several of these 7 genes has been proposed to promote cancer cells proliferation and hence may confer CRC cells resistance to irinotecan. Our work might provide potential biomarkers and therapeutic targets for irinotecan sensitivity in CRC cells. PMID:24966994

Li, Xin-Xiang; Zheng, Hong-Tu; Peng, Jun-Jie; Huang, Li-Yong; Shi, De-Bing; Liang, Lei; Cai, San-Jun

2014-01-01

75

RNA-seq reveals determinants for irinotecan sensitivity/resistance in colorectal cancer cell lines.  

PubMed

Irinotecan is a topoisomerase I inhibitor approved worldwide as a first- and second-line chemotherapy for advanced or recurrent colorectal cancer (CRC). Although irinotecan showed significant survival advantage for patients, a relatively low response rate and severe adverse effects demonstrated the urgent need for biomarkers searching to select the suitable patients who can benefit from irinotecan-based therapy and avoid the adverse effects. In present work, the irinotecan response (IC50 doses) of 20 CRC cell lines were correlated with the basal expression profiles investigated by RNA-seq to figure out genes responsible for irinotecan sensitivity/resistance. Genes negatively or positively correlated to irinotecan sensitivity were given after biocomputation, and 7 (CDC20, CTNNAL1, FZD7, CITED2, ABR, ARHGEF7, and RNMT) of them were validated in two CRC cell lines by quantitative real-time PCR, several of these 7 genes has been proposed to promote cancer cells proliferation and hence may confer CRC cells resistance to irinotecan. Our work might provide potential biomarkers and therapeutic targets for irinotecan sensitivity in CRC cells. PMID:24966994

Li, Xin-Xiang; Zheng, Hong-Tu; Peng, Jun-Jie; Huang, Li-Yong; Shi, De-Bing; Liang, Lei; Cai, San-Jun

2014-01-01

76

Sensitive Survey of Molecular lines in the Taurus Molecular Cloud in frequency 39 to 47 GHz  

NASA Astrophysics Data System (ADS)

We present a high velocity resolution (0.04 km/sec) molecular line survey of the Taurus Molecular Cloud in the frequency range 39 to 47 GHz. The observing method and data reduction process are described. We also describe the method of obtaining the calibrated, averaged spectral line data. The survey was made dividing the 39 to 47 GHz band into 43 different sub-bands, each covering 200 MHz of bandwidth. The goal of the survey was to observe each range for 1 hour. The RMS survey sensitivity (for 6kHz channels) was different for each frequency band, and ranged from 0.02 to 0.15 K for the different sub-bands. A large number of molecular lines are detected, most of which have previously been associated with previously discovered molecules. Other transitions remain unidentified. We present a summary of different processes methods to search for new molecular species.

Langston, Glen

2014-01-01

77

W. K. H. Panofsky Prize Talk: The Search for WIMP Dark Matter: CDMS Detectors  

NASA Astrophysics Data System (ADS)

As described in the accompanying talk by Bernard Sadoulet, the CDMS (cryogenic dark matter search) program has succeeded in pushing down by several orders of magnitude the sensitivity in the search for dark matter in the form of weakly interacting particles or WIMPs. In this talk we describe the technology that has enabled the CDMS detectors made of Ge and Si crystals to discriminate on an event by event basis electron recoils (most backgrounds from gammas) from nuclear recoils (the expected WIMP signal and neutrons). This rejection is accomplished by simultaneously measuring the ionization (electrons and holes in the semiconductor) and the phonons (lattice heat). To achieve the phonon measurement, the crystals are cooled to 0.05 K which allows the use of ultra low noise superconducting circuits. The phonon energy is collected at the surface of the crystals using Al films which absorb athermal phonons and produce quasiparticle excitations from the dissociated Cooper pairs. These excitations diffuse until the are trapped in superconducting tungsten transition edge sensors (TESs). The major advance of voltage biased TESs which are self biased in their transition region through negative feedback has been adopted very successfully for xray spectroscopy, gamma ray spectroscopy and CMB (cosmic microwave background) instruments. The most recent advance detectors called iZIPs (interleaved z-dependent ionization and phonon) provide a large improvement in surface electron rejection and remove that background for the next 200 kg Ge experiment and even for future ton scale experiments.

Cabrera, Blas

2013-04-01

78

Constraints on low-mass WIMP interactions on 19F from PICASSO  

NASA Astrophysics Data System (ADS)

Recent results from the PICASSO dark matter search experiment at SNOLAB are reported. These results were obtained using a subset of 10 detectors with a total target mass of 0.72 kg of 19F and an exposure of 114 kgd. The low backgrounds in PICASSO allow recoil energy thresholds as low as 1.7 keV to be obtained which results in an increased sensitivity to interactions from Weakly Interacting Massive Particles (WIMPs) with masses below 10 GeV/c2. No dark matter signal was found. Best exclusion limits in the spin dependent sector were obtained for WIMP masses of 20 GeV/c2 with a cross section on protons of ?pSD=0.032 pb (90% C.L.). In the spin independent sector close to the low mass region of 7 GeV/c2 favoured by CoGeNT and DAMA/LIBRA, cross sections larger than ?pSI=1.41×10-4 pb (90% C.L.) are excluded.

Archambault, S.; Behnke, E.; Bhattacharjee, P.; Bhattacharya, S.; Dai, X.; Das, M.; Davour, A.; Debris, F.; Dhungana, N.; Farine, J.; Gagnebin, S.; Giroux, G.; Grace, E.; Jackson, C. M.; Kamaha, A.; Krauss, C.; Kumaratunga, S.; Lafrenière, M.; Laurin, M.; Lawson, I.; Lessard, L.; Levine, I.; Levy, C.; MacDonald, R. P.; Marlisov, D.; Martin, J.-P.; Mitra, P.; Noble, A. J.; Piro, M.-C.; Podviyanuk, R.; Pospisil, S.; Saha, S.; Scallon, O.; Seth, S.; Starinski, N.; Stekl, I.; Wichoski, U.; Xie, T.; Zacek, V.

2012-05-01

79

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

80

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 ...

Keitel, David

2014-01-01

81

miRNAs associated with chemo-sensitivity in cell lines and in advanced bladder cancer  

PubMed Central

Background MicroRNA is a naturally occurring class of non-coding RNA molecules that mediate posttranscriptional gene regulation and are strongly implicated in cellular processes such as cell proliferation, carcinogenesis, cell survival and apoptosis. Consequently there is increasing focus on miRNA expression as prognostic factors for outcome and chemotherapy response. Only approximately 50% of patients with bladder cancer respond to chemotherapy. Therefore, predictive markers, such as miRNAs, that can identify subgroups of patients who will benefit from chemotherapy will have great value for treatment guidance. Methods We profiled the expression of 671 miRNAs in formalin fixed paraffin embedded tumors from patients with advanced bladder cancer treated with cisplatin based chemotherapy. We delineated differentially expressed miRNAs in tumors from patients with complete response vs. patients with progressive disease and in tumors form patients with short and long overall survival time. Furthermore, we studied the effect of up- and down regulation of key miRNAs on the cisplatin sensitivity in eight bladder cancer cell lines with different sensitivities to cisplatin. Results miRNA expression profiling identified 15 miRNAs that correlated with response to chemotherapy and 5 miRNAs that correlated with survival time. Three miRNAs were associated with both response and survival (886-3p, 923, 944). By changing the cellular level of the response-identified miRNAs in eight bladder cell lines with different cisplatin sensitivity we found that down-regulation of miR-27a, miR296-5p and miR-642 generally reduced the cell viability, whereas up-regulation of miR-138 and miR-886-3p reduced the viability of more than half of the cell lines. Decreasing miR-138 increased the cisplatin sensitivity in half of the cell lines and increasing miR-27a and miR-642 generally increased cisplatin sensitivity. Conclusions MiRNAs seem to be involved in cisplatin based chemo response and may form a new target for therapy and serve as biomarkers for treatment response. PMID:22954303

2012-01-01

82

The morphology and mechanical sensitivity of lateral line receptors in zebrafish larvae (Danio rerio).  

PubMed

The lateral line system of fish and amphibians detects water flow with receptors on the surface of the body. Although differences in the shape of these receptors, called neuromasts, are known to influence their mechanics, it is unclear how neuromast morphology affects the sensitivity of the lateral line system. We examined the functional consequences of morphological variation by measuring the dimensions of superficial neuromasts in zebrafish larvae (Danio rerio) and mathematically modeling their mechanics. These measurements used a novel morphometric technique that recorded landmarks in three dimensions at a microscopic scale. The mathematical model predicted mechanical sensitivity as the ratio of neuromast deflection to flow velocity for a range of stimulus frequencies. These predictions suggest that variation in morphology within this species generates a greater than 30-fold range in the amplitude of sensitivity and more than a 200-fold range of variation in cut-off frequency. Most of this variation was generated by differences in neuromast height that do not correlate with body position. Our results suggest that natural variation in cupular height within a species is capable of generating large differences in their mechanical filtering and dynamic range. PMID:18552300

Van Trump, William J; McHenry, Matthew J

2008-07-01

83

In-line microfluidic integration of photonic crystal fibres as a highly sensitive refractometer.  

PubMed

Photonic crystal fibres appear to be an ideal platform for the realisation of novel optofluidic devices and sensors due to their waveguide nature and microstructured architecture. In this paper, we present the fabrication and characterisation of an in-line photonic crystal fibre microfluidic refractometer enabled by a C-shaped fibre. The C-shaped fibre spliced in-between the photonic crystal fibre and the single-mode fibre allows simultaneous in-line optical signal delivery and analyte fluid feeding. Through an arc discharge pre-treatment technique, we successfully achieve selective exploitation of only the central two channels of the photonic crystal fibre for microfluidic sensing. After constructing a Sagnac interferometer, a highly sensitive refractometer with a sensitivity of 8699 nm per RIU was achieved experimentally; this agrees very well with the theoretical value of 8675 nm per RIU. As a demonstration for label-free optical sensing application, the refractometer was used to measure the concentration of NaCl solution with a sensitivity of 15.08 nm/(1 wt%) and a detection limit of 2.3 × 10(-3) wt% (23 ppm). PMID:25142213

Wu, Chuang; Tse, Ming-Leung Vincent; Liu, Zhengyong; Guan, Bai-Ou; Zhang, A Ping; Lu, Chao; Tam, Hwa-Yaw

2014-09-29

84

Radiation response of an intraspecific somatic cell hybrid (l5178y, x-ray resistant line x l5178y, x-ray sensitive line)  

Microsoft Academic Search

The radiosensitivities of an x-ray-sensitive L5178Y line, an x-ray-resistant L5178Y line, and of two hybrid lines produced by their fusion have been studied. The hybrid cells are similar in x-ray resistance to the more resistant parent. There was no significant difference in the extrapolation number of the survival curves nor in the ability of the parental and hybrid cells to

B Dale

1979-01-01

85

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

86

Design of a delay-line position-sensitive detector with improved performance  

SciTech Connect

A delay-line position-sensitive detector with improved performance is presented. In this device, timing is carried out by means of fast digitizer boards. The use of dedicated signal processing procedures leads to a timing accuracy of 70 ps and a dead-time below 1.5 ns. As a result, the spatial resolving power of this detector is close to 1 mm leading to a high multihit capability. A temporary detector has been designed in which the delay-line anode is combined with a phosphor screen allowing additional positioning to be made via a charge-coupled device camera. This additional positioning is used to unambiguously quantify performances in terms of spatial resolution and multihit capabilities. A three-dimensional atom probe analysis of a material containing low evaporation field phases is used to demonstrate the capabilities of this detector.

Costa, G. da; Vurpillot, F.; Bostel, A.; Bouet, M.; Deconihout, B. [GPM - UMR 6634 CNRS - Universite et INSA de Rouen, 76801 Saint-Etienne du Rouvray Cedex (France)

2005-01-01

87

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

88

Performance of a novel keratinocyte-based reporter cell line to screen skin sensitizers in vitro  

SciTech Connect

In vitro tests are needed to replace animal tests to screen for the skin sensitization potential of chemicals. Skin sensitizers are electrophilic molecules and the Nrf2-electrophile-sensing pathway comprising the repressor protein Keap1, the transcription factor Nrf2 and the antioxidant response element (ARE) is emerging as a toxicity pathway induced by skin sensitizers. Previously, we screened a large set of chemicals in the reporter cell line AREc32, which contains an eight-fold repeat of the rat GSTA2 ARE-sequence upstream of a luciferase reporter gene in the human breast cancer cell line MCF7. This approach was now further developed to bring it closer to the conditions in the human skin and to propose a fully standardized assay. To this end, a luciferase reporter gene under control of a single copy of the ARE-element of the human AKR1C2 gene was stably inserted into HaCaT keratinocytes. A standard operating procedure was developed whereby chemicals are routinely tested at 12 concentrations in triplicate for significant induction of gene activity. We report results from this novel assay on (i) a list of reference chemicals published by ECVAM, (ii) the ICCVAM list of chemicals for validation of alternative endpoints in the LLNA and (iii) on a more general list of 67 chemicals derived from the ICCVAM database. For comparison, peptide reactivity data are presented for the same chemicals. The results indicate a good predictive value of this approach for hazard identification. Its technical simplicity, the high-throughput format and the good predictivity may make this assay a candidate for rapid validation to meet the tight deadline to replace animal tests for skin sensitization by 2013 set by the European authorities.

Emter, Roger [Givaudan Schweiz AG, Ueberlandstrasse 138, CH-8600 Duebendorf (Switzerland); Ellis, Graham [Givaudan Schweiz AG, 5 Rue de la Parfumerie, CH-1214 Vernier (Switzerland); Natsch, Andreas, E-mail: andreas.natsch@givaudan.co [Givaudan Schweiz AG, Ueberlandstrasse 138, CH-8600 Duebendorf (Switzerland)

2010-06-15

89

Investigation of the magnetic and temperature sensitivity for the Stokes parameters of absorption lines in the solar photosphere  

NASA Astrophysics Data System (ADS)

The response functions to perturbations in the temperature, pressure, microturbulent velocity, and magnetic field strength have been obtained for the Stokes parameters profiles of Fe I ??525.06, 525.02, and Fe II 614.92 nm lines. We use the Grossmann-Doerth, Larsson, and Solanki (1988) technique for the numerical solution of the Unno-Rachkovskij transfer equations. An analysis of these functions confirms that they can be used for the quantitative estimation of the response of Stokes profiles and for the determination of the photospheric depth where the changes in physical conditions influence the radiative and absorption processes in the continuum and in the line. The sensitivity of the magnetoactive lines has been analyzed by the sensitivity indicators calculated as the integral of the response function all over photospheric layers. The anomalous temperature sensitivity of the V Stokes profiles has been found for lines with high excitation and ionization potentials, such as O I, C I, Fe II lines. The depression of these lines increases with the temperature. The magnetic sensitivity of the Stokes profiles is determined in the first place by the magnetic field regime. The greatest response takes place in the weak-field and intermediate-field regime for photospheric lines with large values of the Lande factor, wavelength, and equivalent width. The results of calculations of sensitivity indicators and indices of the magnetic and temperature strengthening for magnetoactive lines are presented.

Sheminova, V. A.

1995-03-01

90

WIMP Dark Matter Direct-Detection Searches in Noble Gases  

E-print Network

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

Baudis, Laura

2014-01-01

91

WIMP Dark Matter Direct-Detection Searches in Noble Gases  

E-print Network

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

Laura Baudis

2014-08-19

92

Equivalent neutrinos, light WIMPs, and the chimera of dark radiation  

NASA Astrophysics Data System (ADS)

According to conventional wisdom, in the standard model (SM) of particle physics and cosmology the “effective number of neutrinos” measured in the late Universe is Neff=3 (more precisely, 3.046). For extensions of the standard model allowing for the presence of ?N? “equivalent neutrinos” (or “dark radiation”), it is generally the case that Neff>3. These canonical results are reconsidered, demonstrating that a measurement of Neff>3 can be consistent with ?N?=0 (“dark radiation without dark radiation”). Conversely, a measurement consistent with Neff=3 is not inconsistent with the presence of dark radiation (?N?>0). In particular, if there is a light weakly interacting massive particle (WIMP) that annihilates to photons after the SM neutrinos have decoupled, the photons are heated beyond their usual heating from e± annihilation, reducing the late time ratio of neutrino and photon temperatures (and number densities), leading to Neff<3. This opens the window for one or more equivalent neutrinos, including “sterile neutrinos,” to be consistent with Neff=3. By reducing the neutrino number density in the present Universe, this also allows for more massive neutrinos, relaxing the current constraints on the sum of the neutrino masses. In contrast, if the light WIMP couples only to the SM neutrinos and not to the photons and e± pairs, its late time annihilation heats the neutrinos but not the photons, resulting in Neff>3 even in the absence of equivalent neutrinos or dark radiation. A measurement of Neff>3 is no guarantee of the presence of equivalent neutrinos or dark radiation. In the presence of a light WIMP and/or equivalent neutrinos, there are degeneracies among the light WIMP mass and its nature (fermion or boson, as well as its couplings to neutrinos and photons), the number and nature (fermion or boson) of the equivalent neutrinos, and their decoupling temperature (the strength of their interactions with the SM particles). As the analysis here reveals, there’s more to a measurement of Neff than meets the eye.

Steigman, Gary

2013-05-01

93

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

94

Equivalent Neutrinos, Light WIMPs, and the Chimera of Dark Radiation  

E-print Network

According to conventional wisdom, in the standard model (SM) of particle physics and cosmology the effective number of neutrinos is Neff=3 (more precisely, 3.046). In extensions of the standard model allowing for the presence of DeltaNnu equivalent neutrinos (or dark radiation), Neff is generally >3. The canonical results are reconsidered here, revealing that a measurement of Neff>3 can be consistent with DeltaNnu=0 (dark radiation without dark radiation). Conversely, a measurement consistent with Neff=3 is not inconsistent with the presence of dark radiation (DeltaNnu>0). In particular, if there is a light WIMP that annihilates to photons after the SM neutrinos have decoupled, the photons are heated beyond their usual heating from e+- annihilation, reducing the late time ratio of neutrino and photon temperatures (and number densities), leading to Neff3 even in the absence of equivalent neutrinos or dark radiation. A measurement of Neff>3 is thus no guarantee of the presence of equivalent neutrinos or dark radiation. In the presence of light WIMPs and/or equivalent neutrinos there are degeneracies among the light WIMP mass and its nature (fermion or boson, as well as its couplings to neutrinos or photons), the number and nature (fermion or boson) of the equivalent neutrinos, and their decoupling temperature (the strength of their interactions with the SM particles). There's more to a measurement of Neff than meets the eye.

Gary Steigman

2013-02-28

95

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

NASA Astrophysics Data System (ADS)

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

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

2013-10-01

96

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

NASA Astrophysics Data System (ADS)

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

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

2007-03-01

97

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.

98

Differentiation of Bulk and Surface Events in p-type Point-Contact Germanium Detectors for Light WIMP Searches  

E-print Network

The p-type point-contact germanium detectors are novel techniques offering kg-scale radiation sensors with sub-keV sensitivities. They have been used for light Dark Matter WIMPs searches and may have potential applications in neutrino physics. There are, however, anomalous surface behaviour which needs to be characterized and understood. We describe the methods and results of a research program whose goals are to identify the bulk and surface events via software pulse shape analysis techniques, and to devise calibration schemes to evaluate the selection efficiency factors. Efficiencies-corrected background spectra from the low-background facility at Kuo-Sheng Neutrino Laboratory are derived.

H. B. Li; the TEXONO Collaboration

2013-11-23

99

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

100

Investigation of the magnetic and temperature sensitivity of the Stokes parameters of absorption lines in the solar photosphere.  

NASA Astrophysics Data System (ADS)

Response functions to perturbations in the temperature, pressure, microturbulent velocity, and magnetic intensity were calculated for the Stokes parameter profiles of the lines Fe I ??525.06, 525.02 and Fe II ?614.92. The procedure proposed by Grossmann-Doerth, Larsson, and Solanki (1988) was used. The author shows that the depression response functions may be used not only to determine the depths at which changes in the physical conditions affect most effectively the absorption and emission in the continuum and in lines, but to estimate the response of Stokes profiles as well. The response was estimated using sensitivity indicators calculated as an integral of the response function over all photospheric layers. An anomalous temperature sensitivity was found for the Stokes V profiles in lines with high excitation and ionization potentials such as the lines of O I, C I, Fe II. The depression of such lines increases rather than decreases with growing temperature. The magnetic sensitivity of Stokes profiles depends primarily on the magnetic field conditions. The response of V profiles is the greatest under the weak-field and intermediate-field conditions for photospheric lines with large values of the Lande factor, wavelength, and equivalent width. The results of calculations of sensitivity indicators are presented for magnetic lines together with the indices of magnetic and temperature enhancement.

Sheminova, V. A.

101

Widespread Molecular Patterns Associated with Drug Sensitivity in Breast Cancer Cell Lines, with Implications for Human Tumors  

PubMed Central

Background Recent landmark studies have profiled cancer cell lines for molecular features, along with measuring the corresponding growth inhibitory effects for specific drug compounds. These data present a tool for determining which subsets of human cancer might be more responsive to particular drugs. To this end, the NCI-DREAM-sponsored DREAM7: Drug Sensitivity Prediction Challenge (sub-challenge 1) set out to predict the sensitivities of 18 breast cancer cell lines to 31 previously untested compounds, on the basis of molecular profiling data and a training subset of cell lines. Methods and Results With 47 teams submitting blinded predictions, team Creighton scored third in terms of overall accuracy. Team Creighton's method was simple and straightforward, incorporated multiple expression data types (RNA-seq, gene array, RPPA), and incorporated all profiled features (not only the “best” predictive ones). As an extension of the approach, cell line data, from public datasets of expression profiling coupled with drug sensitivities (Barretina, Garnett, Heiser) were used to “predict” the drug sensitivities in human breast tumors (using data from The Cancer Genome Atlas). Drug sensitivity correlations within human breast tumors showed differences by expression-based subtype, with many associations in line with the expected (e.g. Lapatinib sensitivity in HER2-enriched cancers) and others inviting further study (e.g. relative resistance to PI3K inhibitors in basal-like cancers). Conclusions Molecular patterns associated with drug sensitivity are widespread, with potentially hundreds of genes that could be incorporated into making predictions, as well as offering biological clues as to the mechanisms involved. Applying the cell line patterns to human tumor data may help generate hypotheses on what tumor subsets might be more responsive to therapies, where multiple cell line datasets representing various drugs may be used, in order to assess consistency of patterns. PMID:24386073

Creighton, Chad J.

2013-01-01

102

Relationship between p53 status and 5-fluorouracil sensitivity in 3 cell lines.  

PubMed

Mouse lymphoma L5178Ytk+/- (MOLY) cells and human lymphoblastoid TK6 and WTK-1 cells are widely used to detect mutagens in vitro. MOLY and WTK-1 cells have a p53 mutation, while TK6 cells, which were derived from the same parental line as WTK-1 cells, do not. In this study, we tested the clastogen 5-fluorouracil (5-FU) in the Tk assay and the in vitro micronucleus (MN) assay in MOLY, TK6, and WTK-1 cells to clarify whether differential responses were related to p53 gene status. We also determined the effect of 5-FU on the frequency of apoptotic cells and on cell cycle distribution in each cell line. Furthermore, we measured the activity of the 5-FU metabolizing enzymes (thymidylate synthetase (TS), dihydrouracil dehydrogenase (DPD), orotate phosphoribosyl transferase (OPRT), and thymidine phosphorylase (TP)) in each cell line. We treated MOLY cells with 1.0-8.0 microg/mL 5-FU for 3 h and TK6 and WTK-1 cells with 1.56-25 and 3.13-50 microg/mL, respectively, for 4 h. In MOLY cells, the mutation frequency (MF) and MN frequency increased. In WTK-1 cells, the MN frequency but not the MF increased. In TK6 cells, neither the MF nor the MN frequency increased. Furthermore, the IC50 of 5-FU was lower in MOLY cells than in the human cells. The response to 5-FU treatment differed in other ways as well. At the same level of cytotoxicity, the frequency of apoptotic cell was highest in TK6 cells. The cell cycle was delayed just after treatment in MOLY cells while the delay appeared 24 h later in TK6 and WTK-1 cells. Nothing in our analysis, however, revealed marked differences between the cell lines that could account for the severe cytotoxic and mutagenic responses that 5-FU elicited only in MOLY cells. 5-FU is phosphorylated by OPRT and TP and detoxified by DPD. MOLY cells have higher OPRT activity and markedly lower DPD and TP activity than TK6 and WTK-1 cells. The content of TS, however, the target enzyme of 5-FU, was similar in all cell lines, suggesting that 5-FU was more readily phosphorylated and less readily detoxified in MOLY cells than in TK6 and WTK-1 cells. MOLY cells were more sensitive to 5-FU than WTK-1 cells even though both have a mutated p53 gene, suggesting that the different responses to 5-FU were due to differences in 5-FU metabolism rather than the p53 status. PMID:16584912

Oka, Hiroaki; Ikeda, Kazumasa; Yoshimura, Hiromi; Ohuchida, Akinobu; Honma, Masamitsu

2006-07-14

103

Position sensitive VUV gaseous photomultiplier based on Thick-multipliers with resistive line readout  

NASA Astrophysics Data System (ADS)

In this work, a new position sensitive gas photomultiplier (GPM) based on a cascade configuration is proposed. The GPM is composed by two THGEMs, followed by a 2D-THCOBRA being operated in Ne/CH4(5%), at a pressure of 1 bar in VUV single photon mode. The 2D-THCOBRA is a hybrid microstructure which combines the benefits of a THGEM and a 2D-MHSP, presenting two independent charge multiplication stages. The position capability is performed by using two orthogonal resistive lines crossing each one the readout electrodes. The position is obtained by measuring the charge sharing in both ends of each resistive line, by using only 2 readout channels. This work focuses the study of the detector gain, Ion Back Flow (IBF) and spatial resolution. A charge gain of 106 and an Ion Back Flow (IBF) values of about 20% were measured. Position resolutions below 300 ?m (FWHM) were obtained for single VUV photon counting mode operation.

Lopes, T.; Silva, A. L. M.; Azevedo, C. D. R.; Carramate, L. F. N. D.; Covita, D. S.; Veloso, J. F. C. A.

2013-09-01

104

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

105

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

SciTech Connect

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

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

2009-03-01

106

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

NASA Technical Reports Server (NTRS)

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

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

2001-01-01

107

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

108

Direct WIMP detection in directional experiments  

SciTech Connect

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

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

2007-03-01

109

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

110

An Improved BAC Transgenic Fluorescent Reporter Line for Sensitive and Specific Identification of Striatonigral Medium Spiny Neurons  

PubMed Central

The development of BAC transgenic mice expressing promoter-specific fluorescent reporter proteins has been a great asset for neuroscience by enabling detection of neuronal subsets in live tissue. For the study of basal ganglia physiology, reporters driven by type 1 and 2 dopamine receptors have been particularly useful for distinguishing the two classes of striatal projection neurons – striatonigral and striatopallidal. However, emerging evidence suggests that some of the transgenic reporter lines may have suboptimal features. The ideal transgenic reporter line should (1) express a reporter with high sensitivity and specificity for detecting the cellular subset of interest and that does not otherwise alter the biology of the cells in which it is expressed, and (2) involve a genetic manipulation that does not cause any additional genetic effects other than expression of the reporter. Here we introduce a new BAC transgenic reporter line, Drd1a-tdTomato line 6, with features that approximate these ideals, offering substantial benefits over existing lines. In this study, we investigate the integrity of dopamine-sensitive behaviors and test the sensitivity and specificity of tdTomato fluorescence for identifying striatonigral projection neurons in mice. Behaviorally, hemizygous Drd1a-tdTomato line 6 mice are similar to littermate controls; while hemizygous Drd2-EGFP mice are not. In characterizing the sensitivity and specificity of line 6 mice, we find that both are high. The results of this characterization indicate that line 6 Drd1a-tdTomato+/? mice offer a useful alternative approach to identify both striatonigral and striatopallidal neurons in a single transgenic line with a high degree of accuracy. PMID:21713123

Ade, Kristen K.; Wan, Yehong; Chen, Meng; Gloss, Bernd; Calakos, Nicole

2011-01-01

111

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

2005-10-04

112

Antiviral effects of interferon on a somatic cell hybrid between two Burkitt's lymphoma cell lines of different interferon sensitivities.  

PubMed Central

A somatic cell hybrid between two human Burkitt's lymphoma cell lines, Raji and Daudi, was infected with either Epstein-Barr virus or vesicular stomatitis virus after interferon treatment. Raji cells are resistant to the antiviral effects of exogenously added interferon, whereas Daudi cells are interferon sensitive. The Raji-Daudi hybrid showed an interferon sensitivity that was intermediary to that of the parental cells against both viruses. PMID:6177642

Lidin, B; Lamon, E W

1982-01-01

113

Software modules of DAQ PCI board (DeLiDAQ) for positive-sensitive MWPC detectors with delay line readout  

Microsoft Academic Search

The data acquisition system for the position-sensitive delay line detectors on basis of the reprogrammable PCI DAQ board (DeLiDAQ) began to be used for scientific measurements with one- and two-dimensional position-sensitive MWPC detectors on the neutron reactors IBR-2 (JINR, Dubna) and BERII (HMI, Berlin). A stand-alone version of the system with the graphical user interface on the basis of packet

F. V. Levchanovsky; E. I. Litvinenko; A. S. Nikiforov; B. Gebauer; Ch. Schulz; Th. Wilpert

2006-01-01

114

Rituximab (chimeric anti-CD20) sensitizes B-NHL cell lines to Fas-induced apoptosis  

Microsoft Academic Search

Rituximab (chimeric anti-CD20 monoclonal antibodies) is currently being used in the treatment of B non-Hodgkin's lymphoma (NHL). We have recently reported that rituximab triggers and modifies various intracellular signaling pathways in NHL B-cell lines, resulting in reverting the chemoresistant phenotype to a sensitive phenotype. This study investigated whether rituximab also modifies intracellular signaling pathways resulting in the sensitization of NHL

Mario I Vega; Sara Huerta-Yepez; Ali R Jazirehi; Hermes Garban; Benjamin Bonavida

2005-01-01

115

INTENSITY RATIO OF DENSITY-SENSITIVE LINES IN Fe IONS OBSERVED WITH A WELL-DEFINED LABORATORY PLASMA  

SciTech Connect

We present spectra of highly charged Fe ions in the extreme ultraviolet range observed using an electron beam ion trap equipped with a flat-field grazing incidence spectrometer. The density dependence of line intensity ratios is investigated for several density-sensitive lines of Fe XIII, XIV, and XV. Unlike previous studies where the electron density was estimated from theoretical considerations, here it is derived from electron beam profile measurements. The experimental data are compared with model calculations.

Nakamura, Nobuyuki; Watanabe, Etsushi [Institute for Laser Science, The University of Electro-Communications, Chofu, Tokyo 182-8585 (Japan); Sakaue, Hiroyuki A.; Kato, Daiji; Murakami, Izumi [National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan); Yamamoto, Norimasa [Institute of Laser Engineering, Osaka University, Suita, Osaka 565-0871 (Japan); Hara, Hirohisa; Watanabe, Tetsuya, E-mail: n_nakamu@ils.uec.ac.jp [National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan)

2011-09-20

116

KRAS G13D Mutation and Sensitivity to Cetuximab or Panitumumab in a Colorectal Cancer Cell Line Model  

PubMed Central

ABSTRACT BACKGROUND: The treatment of metastatic colorectal cancer (mCRC) includes drugs targeting the epidermal growth factor receptor (EGFR). Mutation in codon 12 or 13 in the Kirsten rat sarcoma viral oncogene homolog (KRAS) gene, downstream of the EGFR, evokes constitutive activation of the RAS/RAF/MAPK signaling pathway and correlates with resistance to anti-EGFR monoclonal antibody (mAb) therapies. However, a retrospective study reported that a proportion of patients with the KRAS G13D mutation may respond to cetuximab. A similar analysis for panitumumab was not as conclusive. We sought to determine the sensitivity of CRC cell lines to cetuximab or panitumumab treatment and to investigate the correlation of the KRAS mutational status of the CRC cell lines to the responsiveness to cetuximab or panitumumab. METHODS: To determine the responsiveness of CRC cell lines to cetuximab or panitumumab, cell lines were treated with an optimized concentration of each mAb, and proliferation assays were conducted. RESULTS: After treatment with cetuximab or panitumumab, at the optimum concentration of 8 ?g/well, the KRAS G13D mutant cell lines HCT-116, LoVo, and T84 showed intermediate sensitivity to both treatments, between the resistant KRAS G12V mutant cell line SW480 and the sensitive KRAS wild-type cell line LIM1215. One of the G13D cell lines was significantly more sensitive to panitumumab than to cetuximab (P = .02). CONCLUSION: The specific KRAS mutation determines the responsiveness to anti-EGFR monoclonal antibody treatment, corresponding to reported clinical observations. PMID:24558511

Kumar, Shalini Sree; Price, Timothy J.; Mohyieldin, Omar; Borg, Matthew; Townsend, Amanda

2014-01-01

117

Cyclosporin-binding sites of murine sensitive and resistant lymphoid cell lines.  

PubMed

Cyclosporin (Cs)-binding sites on murine spleen lymphocytes and on Cs-sensitive (CsS) and Cs-resistant (CsR) cloned lymphoma lines were compared using a ditritiated derivative of cyclosporin C (d3H-CsC). All three types of lymphocytes displayed similar d3H-CsC-binding characteristics. There were no major differences in the d3H-CsC-binding sites in terms of their cell surface density (number per surface area), their affinity and their specificity (capacity to discriminate between different Cs forms). The presence of the presumably membranous Cs-binding site is therefore insufficient to confer susceptibility to Cs, and resistance can thus be obtained at a post-receptor level. With the CsS clone, there was a general correlation between the Cs-specific binding capacity and the Cs-specific biological activity inasmuch as Cs which were weakly or not at all cytostatic bound only very poorly to the d3H-CsC-binding site. Such a correlation could not be established in the case of a mixed spleen cell population; which implies that, in such a system, Cs processing might play a role in its activity. Binding to the receptor may be an early but only a permissive step in the mechanism of action of Cs. PMID:6607025

Koponen, M; Loor, F

1983-01-01

118

WIMP Dark Matter and the QCD Equation of State  

E-print Network

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

Mark Hindmarsh; Owe Philipsen

2005-01-25

119

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

120

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

SciTech Connect

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

Azam, Philippe [AFSSAPS, Unite BCM, 635 Rue de la Garenne, 34740 Vendargues (France); Peiffer, Jean-Luc [AFSSAPS, Unite BCM, 635 Rue de la Garenne, 34740 Vendargues (France); Chamousset, Delphine [AFSSAPS, Unite BCM, 635 Rue de la Garenne, 34740 Vendargues (France); Tissier, Marie-Helene [AFSSAPS, Unite BCM, 635 Rue de la Garenne, 34740 Vendargues (France); Bonnet, Pierre-Antoine [AFSSAPS, Unite BCM, 635 Rue de la Garenne, 34740 Vendargues (France); Vian, Laurence [Laboratoire de Toxicologie, Faculte de Pharmacie (UM1), 15 av Charles Flahault, BP 14491, 34093 Montpellier Cedex 5 (France); Fabre, Isabelle [AFSSAPS, Unite BCM, 635 Rue de la Garenne, 34740 Vendargues (France); Ourlin, Jean-Claude [AFSSAPS, Unite BCM, 635 Rue de la Garenne, 34740 Vendargues (France)]. E-mail: jean-claude.ourlin@afssaps.sante.fr

2006-04-01

121

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

E-print Network

disease whose phenotype mimics pre- mature aging. WRN patients develop a prematurely aged appearanceAbstract We have shown that Werner syndrome (WRN) fibroblast cell lines are unusually sensitive protein function. Introduction Werner syndrome (WRN; MIM 277700) is an uncommon autosomal recessive

Monnat, Ray

122

Drug Sensitivity Prediction by CpG Island Methylation Profile in the NCI60 Cancer Cell Line Panel  

Microsoft Academic Search

Aberrant promoter hypermethylation and associated gene silencing are epigenetic hallmarks of tumorigenesis. It has been suggested that aberrant DNA methylation can affect the sensitivity of cancers to antineoplastic agents by altering expression of genes critical to drug response. To study this issue, we used bisulfite PCR to assess DNA methylation of 32 promoter-associated CpG islands in human cancer cell lines

Lanlan Shen; Yutaka Kondo; Saira Ahmed; Yanis Boumber; Kazuo Konishi; Xinli Chen; Jill N. Vilaythong; Jean-Pierre J. Issa

123

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

124

Comparison of radiation sensitivity for three cell lines as measured by the cloning assay and the micro-nucleus test.  

PubMed

The correlation between cell killing and the induction of micro-nuclei was studied for three cell lines after treatment with gamma radiation to investigate whether the frequency of micro-nucleated cells can be used to determine the radiation sensitivity of a cell type. R1 rat rhabdomyosarcoma cells showed a higher sensitivity for the induction of proliferative death than RUC rat ureter carcinoma cells and V79 Chinese hamster cells which had a similar radiation sensitivity. The frequencies of micro-nucleated cells were measured at 48 hours after the treatment. It was determined by time-lapse cinematography that almost all the cells in the treated cultures had divided at that time. Our results indicate that for these cell lines the correlation between the effectiveness for cell killing and the induction of micro-nuclei was the same, within the experimental errors. PMID:2260014

Stap, J; Aten, J A

1990-11-01

125

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

SciTech Connect

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

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

2011-09-16

126

A new population of WIMPs in the solar system and indirect detection rates  

E-print Network

A new Solar System population of Weakly Interacting Massive Particle (WIMP) dark matter has been proposed to exist. We investigate the implications of this population on indirect signals in neutrino telescopes (due to WIMP annihilations in the Earth) for the case when the WIMP is the lightest neutralino of the MSSM, the minimal supersymmetric extension of the standard model. The velocity distribution and capture rate of this new population is evaluated and the flux of neutrino-induced muons from the center of the Earth in neutrino telescopes is calculated. We show that the effects of the new population can be crucial for masses around 60-120 GeV, where enhancements of the predicted muon flux from the center of the Earth by up to a factor of 100 compared to previously published estimates occur. As a result of the new WIMP population, neutrino telescopes should be able to probe a much larger region of parameter space in this mass range.

Lars Bergstrom; Thibault Damour; Joakim Edsjo; Lawrence M. Krauss; Piero Ullio

2000-12-11

127

Quantifying galactic propagation uncertainty in WIMP dark matter search with AMS01 Z=-1 spectrum  

E-print Network

A search for a WIMP dark matter annihilation signal is carried out in the AMS01 negatively charged (Z=-I) particle spectrum, following a set of supersymmetric benchmark scenarios in the mSUGRA framework. The result is ...

Xiao, Sa, Ph. D. Massachusetts Institute of Technology

2009-01-01

128

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

E-print Network

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

Gelmini, Graciela B

2014-01-01

129

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

E-print Network

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

Graciela B. Gelmini

2014-11-04

130

Search for dark matter WIMPs using upward through-going muons in Super-Kamiokande  

Microsoft Academic Search

We present the results of indirect searches for Weakly Interacting Massive Particles (WIMPs), with 1679.6 live days of data from the Super-Kamiokande detector using neutrino-induced upward through-going muons. The search is performed by looking for an excess of high energy muon neutrinos from WIMP annihilations in the Sun, the core of the Earth, and the Galactic Center, as compared to

Y. Ashie; S. Fukuda; Y. Fukuda; K. Ishihara; Y. Itow; Y. Koshio; A. Minamino; M. Miura; S. Moriyama; M. Nakahata; T. Namba; R. Nambu; Y. Obayashi; N. Sakurai; M. Shiozawa; Y. Suzuki; H. Takeuchi; Y. Takeuchi; S. Yamada; M. Ishitsuka; T. Kajita; K. Kaneyuki; S. Nakayama; A. Okada; T. Ooyabu; C. Saji; M. Earl; E. Kearns; J. L. Stone; L. R. Sulak; C. W. Walter; W. Wang; M. Goldhaber; T. Barszczak; D. Casper; J. P. Cravens; W. Gajewski; W. R. Kropp; S. Mine; D. W. Liu; M. B. Smy; H. W. Sobel; C. W. Sterner; M. R. Vagins; K. S. Ganezer; J. Hill; W. E. Keig; J. Y. Kim; I. T. Lim; R. W. Ellsworth; S. Tasaka; G. Guillian; A. Kibayashi; J. G. Learned; S. Matsuno; D. Takemori; M. D. Messier; Y. Hayato; A. K. Ichikawa; T. Ishida; T. Ishii; T. Iwashita; J. Kameda; T. Kobayashi; T. Maruyama; K. Nakamura; K. Nitta; Y. Oyama; M. Sakuda; Y. Totsuka; A. T. Suzuki; M. Hasegawa; K. Hayashi; T. Inagaki; I. Kato; H. Maesaka; T. Morita; T. Nakaya; K. Nishikawa; T. Sasaki; S. Ueda; S. Yamamoto; T. J. Haines; S. Dazeley; S. Hatakeyama; R. Svoboda; E. Blaufuss; J. A. Goodman; G. W. Sullivan; D. Turcan; K. Scholberg; A. Habig; C. K. Jung; T. Kato; K. Kobayashi; M. Malek; C. Mauger; C. McGrew; A. Sarrat; E. Sharkey; C. Yanagisawa; T. Toshito; C. Mitsuda; K. Miyano; T. Shibata; Y. Kajiyama; Y. Nagashima; M. Takita; M. Yoshida; H. I. Kim; S. B. Kim; J. Yoo; H. Okazawa; T. Ishizuka; Y. Choi; H. K. Seo; Y. Gando; T. Hasegawa; K. Inoue; J. Shirai; M. Koshiba; T. Hashimoto; Y. Nakajima; K. Nishijima; T. Harada; H. Ishino; M. Morii; R. Nishimura; Y. Watanabe; D. Kielczewska; J. Zalipska; R. Gran; K. K. Shiraishi; K. Washburn; R. J. Wilkes

2004-01-01

131

Final state sensitivity of particle dynamics in a magnetic neutral line field  

NASA Astrophysics Data System (ADS)

We examine chaotic scattering of charged particles in magnetic neutral line fields in the Earth's magnetotail. ThisHamiltonian system exhibits chaotic scattering over a wide range of parameter values. In the simpler current sheet field there is a well defined energy resonance that governs the dynamics, and we show that the neutral line model has no such resonance. Current sheet scattering has been shown to have a fractal exit basin boundary structure that closely follows the energy resonance. We show that the neutral line model has a more complex final state structure, which nonetheless indicates self-similarity, and a more complicated fractal behavior.

Martin, R. F.; Holland, D. L.; Svetich, J.; Brennan, C.

2013-12-01

132

A Novel Line Immunoassay Based on Recombinant Virulence Factors Enables Highly Specific and Sensitive Serologic Diagnosis of Helicobacter pylori Infection  

PubMed Central

Helicobacter pylori colonizes half of the world's population, and infection can lead to ulcers, gastric cancer, and mucosa-associated lymphoid tissue (MALT) lymphoma. Serology is the only test applicable for large-scale, population-based screening, but current tests are hampered by a lack of sensitivity and/or specificity. Also, no serologic test allows the differentiation of type I and type II strains, which is important for predicting the clinical outcome. H. pylori virulence factors have been associated with disease, but direct assessment of virulence factors requires invasive methods to obtain gastric biopsy specimens. Our work aimed at the development of a highly sensitive and specific, noninvasive serologic test to detect immune responses to important H. pylori virulence factors. This line immunoassay system (recomLine) is based on recombinant proteins. For this assay, six highly immunogenic virulence factors (CagA, VacA, GroEL, gGT, HcpC, and UreA) were expressed in Escherichia coli, purified, and immobilized to nitrocellulose membranes to detect serological immune responses in patient's sera. For the validation of the line assay, a cohort of 500 patients was screened, of which 290 (58.0%) were H. pylori negative and 210 (42.0%) were positive by histology. The assay showed sensitivity and specificity of 97.6% and 96.2%, respectively, compared to histology. In direct comparison to lysate blotting and enzyme-linked immunosorbent assay (ELISA), the recomLine assay had increased discriminatory power. For the assessment of individual risk for gastrointestinal disease, the test must be validated in a larger and defined patient cohort. Taking the data together, the recomLine assay provides a valuable tool for the diagnosis of H. pylori infection. PMID:24006137

Formichella, Luca; Romberg, Laura; Bolz, Christian; Vieth, Michael; Geppert, Michael; Gottner, Gereon; Nolting, Christina; Walter, Dirk; Schepp, Wolfgang; Schneider, Arne; Ulm, Kurt; Wolf, Petra; Busch, Dirk H.; Soutschek, Erwin

2013-01-01

133

Erythroid differentiation and the Na+,K+-pump in ouabain-sensitive and ouabain-resistant Friend erythroleukemia cell lines.  

PubMed

The selection and biochemical characterization of ouabain-resistant erythroleukemia cell lines are described. Treatment of ouabain-resistant Friend erythroleukemia cell (FLC) lines with 1 mM ouabain demonstrated a reduced ouabain-sensitive 86Rb+-uptake after Na+-preloading in comparison with ouabain-sensitive cells. The ouabain- and diuretic (piretanide)-insensitive component of the 86Rb+-uptake (residual influx) was significantly enhanced in the ouabain-resistant FLC clones. Measurements of the Na+,K+-ATPase activity (E.C. 3.6.1.3) in plasma membrane preparations of the ouabain-resistant FLC clone B6/2 indicated that a ouabain-resistant Na+,K+-ATPase activity of about 20% of the total enzyme activity existed in the presence of 1 mM ouabain. Further experiments showed that the Na+,K+-ion-gradient in ouabain-resistant B6/2 cells was unaffected by ouabain exposure whereas the gradient collapsed in wild type 12 N cells. Another property of the ouabain-resistant cell lines was a decrease of the 86Rb+-uptake due to the Na+,K+, 2Cl(-)-cotransport system measured as piretanide-sensitive 86Rb+-uptake. The data on ion transport mechanisms in QuaR and QuaS FLC are discussed with respect to mutagen-induced and spontaneous cellular ouabain resistance. In addition, the role of altered ion transport mechanisms is considered for induced erythroid differentiation. PMID:2422034

Munter, K H; Steinheider, G; Schaefer, A; Koch, G

1986-03-01

134

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

PubMed Central

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, F1 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

135

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

136

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

PubMed

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

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

2014-07-01

137

The effects of three bioreductive drugs (mitomycin C, RSU-1069 and SR4233) on cell lines selected for their sensitivity to mitomycin C or ionising radiation  

Microsoft Academic Search

We have investigated the cross-sensitivity of a number of cell lines to three different classes of bioreductive drugs under both aerobic and hypoxic conditions. The cell lines used were selected for their sensitivity to DNA-damaging agents and fall into two groups. One group, MMC cells derived from CHO-K1 cells (Robson et al., 1985), show a range of sensitivities to mitomycin

A Keohane; J Godden; IJ Stratford; GE Adams

1990-01-01

138

Pentacyclic triterpenes from Chrysobalanaceae species: cytotoxicity on multidrug resistant and sensitive leukemia cell lines.  

PubMed

Plants are known as important source in the search for new anti-cancer agents. Cytotoxicity-guided fractionation of leaves and fruits from Licania tomentosa Bench and leaves from Chrysobalanus icaco L. resulted in the isolation of betulinic, oleanolic and pomolic acids. These triterpenoids inhibited the growth and induced apoptosis of K562, an erythroleukemia cell line. Most importantly, they also inhibited the proliferation of Lucena 1, a vincristine-resistant derivative of K562 that displays several multidrug resistance (MDR) characteristics. Taken together, our findings emphasize the anti-tumor activity of these triterpenes on leukemia cell lines and call attention to their potential as anti MDR agents. PMID:12565171

Fernandes, Janaina; Castilho, Rachel Oliveira; da Costa, Mariana Rangel; Wagner-Souza, Karen; Coelho Kaplan, Maria Auxiliadora; Gattass, Cerli Rocha

2003-02-20

139

Sensitive Line Probe Assay That Simultaneously Detects Mutations Conveying Resistance to Lamivudine and Adefovir  

Microsoft Academic Search

Hepatitis B virus (HBV) mutations conveying resistance to antivirals are a major problem in the treatment of chronic hepatitis B. Direct sequencing is the most accurate method of characterizing drug resistance mutations, but it is tedious. The development of rapid, simple, and sensitive assays that can detect low levels of emerging antiviral-resistant HBV mutants is important for monitoring the response

Munira Hussain; Scott Fung; Evelien Libbrecht; Erwin Sablon; Carmela Cursaro; Pietro Andreone; Anna S. F. Lok; Innogenetics NV

2006-01-01

140

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...

141

Sensitivity of the Epstein-Barr Virus Transformed Human Lymphoid Cell Lines to Interferon  

Microsoft Academic Search

SUMMARY The effect of interferon on expression of Epstein-Barr virus (EBV) early gene functions was investigated. The' early antigen' synthesis which follows either EBV superinfection of established lymphoid cell lines or 5'-iododeoxyuridine activation of the intrinsic EBV genomes harboured by these cells could be suppressed with interferon. In contrast, the spontaneous early antigen expression that occurs in a few per

ALICE ADAMS; H. STRANDERI; K. Cantell

1975-01-01

142

Equivalent Neutrinos, Light WIMPs, and the Chimera of Dark Radiation  

E-print Network

According to conventional wisdom, in the standard model (SM) of particle physics and cosmology the effective number of neutrinos is Neff=3 (more precisely, 3.046). In extensions of the standard model allowing for the presence of DeltaNnu equivalent neutrinos (or dark radiation), Neff is generally >3. The canonical results are reconsidered here, revealing that a measurement of Neff>3 can be consistent with DeltaNnu=0 (dark radiation without dark radiation). Conversely, a measurement consistent with Neff=3 is not inconsistent with the presence of dark radiation (DeltaNnu>0). In particular, if there is a light WIMP that annihilates to photons after the SM neutrinos have decoupled, the photons are heated beyond their usual heating from e+- annihilation, reducing the late time ratio of neutrino and photon temperatures (and number densities), leading to Neff3 even in the absence of equivalent neutrinos or dark radiation. A measurement of Neff>3 is thus no guarantee of the presence of equivalent neutrinos or dark ra...

Steigman, Gary

2013-01-01

143

Lines  

ERIC Educational Resources Information Center

National Geography Standards for the middle school years generally stress the teaching of latitude and longitude. There are many creative ways to explain the great grid that encircles our planet, but the author has found that students in his college-level geography courses especially enjoy human-interest stories associated with lines of latitude…

Mires, Peter B.

2006-01-01

144

[Sensitivity of normal and Rous virus-transformed lines of Armenian hamster cells to infectious viruses].  

PubMed

The capacity of normal (NHET) and Rous virus-transformed cell line of armenian hamster both producing (SHET Sh-R) and not producing (SHET K-3) virus to support reproduction of vaccinia and Newcastle disease viruses was demonstrated. The former of these viruses replicated in the cell cultures with cytopathic effect, the latter did so without causing cell degeneration. The degree of Newcastle disease virus reproduction in all 3 cultures was the same whereas vaccinia virus synthesis in SHET Sh-R was inhibited as compared with NHET and SHET K-3 cultures. Interference between Rous virus and vaccinia virus in SHET Sh-R culture was not due to interferon. The infectious viruses under study caused no activation of Rous virus genome in the virogenic SHET K-3 cell line. PMID:176825

Nadzharian, N U; Kamalian, L A

1975-01-01

145

Pentacyclic triterpenes from Chrysobalanaceae species: cytotoxicity on multidrug resistant and sensitive leukemia cell lines  

Microsoft Academic Search

Plants are known as important source in the search for new anti-cancer agents. Cytotoxicity-guided fractionation of leaves and fruits from Licania tomentosa Bench and leaves from Chrysobalanus icaco L. resulted in the isolation of betulinic, oleanolic and pomolic acids. These triterpenoids inhibited the growth and induced apoptosis of K562, an erythroleukemia cell line. Most importantly, they also inhibited the proliferation

Janaina Fernandes; Rachel Oliveira Castilho; Mariana Rangel da Costa; Karen Wagner-Souza; Maria Auxiliadora Coelho Kaplan; Cerli Rocha Gattass

2003-01-01

146

Fission Product Gamma-Ray Line Pairs Sensitive to Fissile Material and Neutron Energy  

SciTech Connect

The beta-delayed gamma-ray spectra from the fission of {sup 235}U, {sup 238}U, and {sup 239}Pu by thermal and near-14-MeV neutrons have been measured for delay times ranging from 1 minute to 14 hours. Spectra at all delay times contain sets of prominent gamma-ray lines with intensity ratios that identify the fissile material and distinguish between fission induced by low-energy or high-energy neutrons.

Marrs, R E; Norman, E B; Burke, J T; Macri, R A; Shugart, H A; Browne, E; Smith, A R

2007-11-15

147

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

148

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

149

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

150

Software modules of DAQ PCI board (DeLiDAQ) for positive-sensitive MWPC detectors with delay line readout  

NASA Astrophysics Data System (ADS)

The data acquisition system for the position-sensitive delay line detectors on basis of the reprogrammable PCI DAQ board (DeLiDAQ) began to be used for scientific measurements with one- and two-dimensional position-sensitive MWPC detectors on the neutron reactors IBR-2 (JINR, Dubna) and BERII (HMI, Berlin). A stand-alone version of the system with the graphical user interface on the basis of packet ROOT can be used on any PC with the operating system Windows 2000 or Windows XP. Architecture of the created software ensures several ways of interfacing to experiment control systems. In the paper we provide a description of the DeLiDAQ software modules, their features and results of some performance tests.

Levchanovsky, F. V.; Litvinenko, E. I.; Nikiforov, A. S.; Gebauer, B.; Schulz, Ch.; Wilpert, Th.

2006-12-01

151

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

152

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

153

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

PubMed

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

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

2013-03-01

154

The presence of two Fc receptors on mouse macrophages: evidence from a variant cell line and differential trypsin sensitivity  

PubMed Central

A stable variant of a clone of the P388D1 macrophage line was isolated using four cycles of treatment with mouse IgG2a-rabbit anti-kappa complexes and rabbit complement. The variant had the same Ka and about the same number of sites per cell for IgG2a as the parent line. However, the variant had 10% as many binding sites for rabbit IgG in soluble antigen-antibody complexes, and the affinity of binding was threefold higher. This change in binding of complexes to cells of a cloned line without alternation of IgG2a binding provides evidence for the presence of two distinct Fc receptors. The two receptors could also be distiguished on the P388D1 line and on thioglycollate-induced mouse peritoneal macrophages by differential sensitivity to trypsinization. The receptors that bind monomeric IgG2a, sheep erythrocytes (SRBC) covalently bound with IgG2a or rabbit IgG using glutaraldehyde, and Sephadex beads coupled with IgG2a or rabbit IgG using cyanogen bromide activitation, is sensitive to trypsinization. The receptor that binds soluble rabbit antibody-antigen complexes, trinitrophenyl-SRBC and dinitrophenyl(DNP)-bovine serum albumin Sephadex beads coated with rabbit anti-DNP IgG is trypsin resitant, the observation that uncomplexed rabbit IgG oes not bind to the trypsin-resistant receptor, whereas the same IgG bound to its antigen does, suggests that conformational changes induced by the binding of ligand may be of consequence in macrophage function. PMID:323399

1977-01-01

155

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

NASA Astrophysics Data System (ADS)

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

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

2004-07-01

156

Electron density-sensitive line ratios for Fe XII in the solar corona  

NASA Technical Reports Server (NTRS)

The collision strengths for electron-impact excitation of fine-structure transitions from the ground 3s23p3 configuration to the excited 3s3p4 configuration in Fe XII are presented. These are calculated by transforming the K-matrices obtained in a nonrelativistic R-matrix method to K-matrices in intermediate coupling using term-coupling coefficients which take into account the effect of breakdown of target LS coupling. Extensive configuration-interaction wave functions are used to represent the target states. The effective collision strengths are determined assuming a Maxwellian distribution of electron energies. Rydberg series of resonances converging to the excited state thresholds are explicitly included in the calculation. The relative level populations and emission-line strengths for Fe XII are calculated using the new atomic data presented in this paper and that published by Tayal, Henry, and Pradhan (1987) and Tayal and Henry (1986) over a wide range of electron densities and temperatures (1-2 x 10 to the 6th K). Present results for collision strengths and emission-line strengths are compared with the previous calculation of Flower (1977). Some significant differences are noted.

Tayal, S. S.; Henry, Ronald J. W.

1988-01-01

157

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

158

Sensitivity Studies for Main Steam Line Break Exercises 2 and 3 with RELAP5/PANBOX  

SciTech Connect

This paper presents and discusses results obtained with the nuclear plant safety analysis code system RELAP5/PANBOX (R/P/C) for the return-to-power scenario of exercises 2 and 3 of the Organization for Economic Cooperation and Development/Nuclear Energy Agency Main Steam Line Break (MSLB) Benchmark. Both the external and internal coupling options of R/P/C have been considered for exercise 3; i.e., the COBRA module of PANBOX was used to calculate the core thermal hydraulics in the external coupling option, whereas the core thermal hydraulics of RELAP5 was used in the internal coupling option. For the representation of thermal-hydraulic channels, a fine channel geometry based on the 177 fuel assemblies was selected for the external coupling option, and a coarse channel geometry based on 19 coarse channels has been investigated for the internal coupling option. The comparison of the results shows very good agreement of important core parameters between the considered coupling variants. Both exercises 2 and 3 have been investigated with respect to local safety parameters like fuel centerline temperatures and minimum departure from nucleate boiling ratios using the on-line hot subchannel analysis capability of R/P/C in the external coupling option. The results show that both quantities are far from the safety-related limits.The benchmark demonstrates, that R/P/C - as part of the integrated CASCADE-3D core analysis system of Framatome ANP GmbH - has proven to be a powerful tool for detailed analyses of an MSLB accident.

Boeer, Rainer; Knoll, Alfred [Framatome ANP GmbH (France)

2003-05-15

159

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

160

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...

Hill, Richard J

2014-01-01

161

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

PubMed Central

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

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

2008-01-01

162

Protein profiles reveal diverse responsive signaling pathways in kernels of two maize inbred lines with contrasting drought sensitivity.  

PubMed

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

163

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

164

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

NSDL National Science Digital Library

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

Abusaidi, R.; Akerib, Daniel S.; Barnes, P. D.; Bauer, D. A.; Bolozdyna, A.; Brink, P. L.

2000-01-01

165

Cryogenic germanium detectors for a weakly interactive massive particle (WIMP) dark-matter search  

NASA Astrophysics Data System (ADS)

We are preparing an experimental search for weakly interacting massive particle (WIMP) dark matter using cryogenic germanium detectors. These detectors measure both the ionization and phonons produced by particle interactions in the substrate. The ionization measurement uses low drift fields, approximately equals 1 V/cm. The phonon measurement is made using neutron transmutation doped (NTD) germanium thermistors. Simultaneous detection of phonons and ionization allows us to discriminate between electron-recoil and nuclear-recoil events which gives a powerful method for isolating possible WIMP events (nuclear recoils) from background gamma ray events (electron recoils). Recent work on our understanding and optimization of these detectors will be presented.

Stockwell, Walter; Akerib, D.; Aubourg, E.; Barnes, P. D.; Cummings, A.; da Silva, A.; Emes, J.; Golwala, S.; Haller, Eugene E.; Margulies, S.; Pritychenko, B.; Ross, R. R.; Sadoulet, Bernard; Shutt, T.; Smith, Garth; Taylor, J.; White, S.; Young, B. A.

1994-09-01

166

High-pressure Xenon Gas Electroluminescent TPC Concept for Simultaneous Searches for Neutrino-less Double Beta Decay & WIMP Dark Matter  

NASA Astrophysics Data System (ADS)

Xenon is an especially attractive candidate for both direct WIMP and 0- decay searches. Although the current trend has exploited the liquid phase, gas phase xenon offers some remarkable performance advantages for energy resolution, topology visualization, and discrimination between electron and nuclear recoils. The NEXT-100 experiment, now beginning construction in the Canfranc Underground Laboratory, Spain, will operate at 12 bars with 100 kg of ^136Xe for the 0- decay search. I will describe recent results with small prototypes, indicating that NEXT-100 can provide about 0.5% FWHM energy resolution at the decay 2457.83 keV Q-value, as well as rejection of -rays by topology. However, sensitivity goals for WIMP dark matter and 0- decay searches indicate the need for ton-scale active masses; NEXT-100 provides the springboard to reach this scale with xenon gas. I describe a scenario for performing both searches in a single high-pressure ton-scale xenon gas detector, without significant compromise to either. In addition, -- even in a single, ton-scale, high-pressure xenon gas TPC, an intrinsic sensitivity to the nuclear recoil direction may exist -- plausibly offering an advance of more than two orders of magnitude relative to current low-pressure TPC concepts. I argue that, in an era of deepening fiscal austerity, such a dual-purpose detector may be possible, at acceptable cost, within the time frame of interest, and deserves our collective attention.

Nygren, David

2013-04-01

167

Radiation sensitivity depends on OGG1 activity status in human leukemia cell lines.  

PubMed

To assess the role of 8-oxoguanine glycosylase (OGG1) in the cell defense against radiation injury, the radiation-induced cytotoxicities were compared between the mutant type KG-1 featuring a loss of OGG1 activity due to a homozygous mutation of Arg 229 Gln, and the wild type U937. While the following three obvious toxicities were displayed in KG-1, they were observed only minimally in U937. These were: a dramatic arrest at the G2/M phase indicated by a marked increase in both the number of G2/M cells and the expression of cyclin B1, cdc2, and mitotic phosphoprotein monoclonal-2 (MPM-2)-reactive proteins; a severe apoptosis shown by a marked increase in the number of cells with hypo-diploid DNA and DNA fragmentation; and as a result, a severe inhibition of cell growth and proliferation measured by the MTT test and [(3)H]-thymidine uptake assay. As expected, KG-1 exhibited a significant increase in the 8-hydroxyguanine level in DNA whereas U937 did not. However, the level of irradiation-induced lipid peroxidation was almost the same in both cell lines. All of these symptoms shown by KG-1 were observed in Molt-4 and CEM-CM3, which were also found to feature low OGG1 activity. These findings suggest that OGG1 plays an important role in cell survival from radiation-induced damage and are also indicative of the capability of 8-hydroxyguanine in DNA to induce cellular toxicities. PMID:11827746

Hyun, Jin-Won; Cheon, Gi-Jeong; Kim, Hyun-Sook; Lee, Yun-Sil; Choi, Eun-Young; Yoon, Byung-Hak; Kim, Jeong-Soon; Chung, Myung-Hee

2002-02-01

168

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, Song KF, Campargue A. High sensitivity CW- cavity ring down spectroscopy of 12 CO2 near 1.35m (I): Line, the spectral region investigated by CW-Cavity Ring Down Spectroscopy has been extended up to 7917 cm-1

Boyer, Edmond

169

Topoisomerase II? content and topoisomerase II catalytic activity cannot explain drug sensitivities to topoisomerase II inhibitors in lung cancer cell lines  

Microsoft Academic Search

Purpose:?Topoisomerase II? content, topoisomerase II catalytic activity and drug sensitivities to the topoisomerase II inhibitors,\\u000a doxorubicin and etoposide, were examined in a panel of 14 unselected human lung cancer cell lines in order to determine the\\u000a relationship between topoisomerase II and drug sensitivities to the topoisomerase II inhibitors. Methods: Drug sensitivities were determined using a microculture tetrazolium assay. The topoisomerase

Kohichi Yamazaki; Hiroshi Isobe; Tarou Hanada; Tomoko Betsuyaku; Atsushi Hasegawa; Nobuyuki Hizawa; Shigeaki Ogura; Yoshikazu Kawakami

1996-01-01

170

Fundamental Studies on the Acid Generator to Improve the Resolution, Line Width Roughness, and Sensitivity Tradeoff under Ionizing Radiation  

NASA Astrophysics Data System (ADS)

The effects of acid generation efficiency and other properties on the resolution, line width roughness (LWR), and sensitivity (RLS) tradeoff for extreme ultraviolet (EUV) photoresists were evaluated under electron beam (EB) exposure. The acid generators (AGs) introducing a trifluoromethyl group as an electron-withdrawing group on the sulfur atom had a much higher reduction potential than current AGs. We determined acid generation efficiency by the 13C-NMR method and standard titration. The dissolution inhibitory effect on the alkaline developer and the thermal property of the resist film using each AG were also evaluated. The RLS performance of resists containing AGs with a higher acid generation efficiency than conventional AGs was characterized using the relative Z-factor under EB exposure.

Utsumi, Yoshiyuki; Irie, Makiko; Komuro, Yoshitaka; Matsuzawa, Kensuke; Hada, Hideo; Haga, Takashi; Ogawa, Satoshi

2010-06-01

171

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

PubMed

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

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

2014-07-15

172

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

173

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

174

Model-independent WIMP Scattering Responses and Event Rates: A Mathematica Package for Experimental Analysis  

E-print Network

The community's reliance on simplified descriptions of WIMP-nucleus interactions reflects the absence of analysis tools that integrate general theories of dark matter with standard treatments of nuclear response functions. To bridge this gap, we have constructed a public-domain Mathematica package for WIMP analyses based on our effective theory formulation. Script inputs are 1) the coefficients of the effective theory, through which one can characterize the low-energy consequences of arbitrary ultraviolet theories of WIMP interactions; and 2) one-body density matrices for commonly used targets, the most compact description of the relevant nuclear physics. The generality of the effective theory expansion guarantees that the script will remain relevant as new ultraviolet theories are explored; the use of density matrices to factor the nuclear physics from the particle physics will allow nuclear structure theorists to update the script as new calculations become available, independent of specific particle-physics contexts. The Mathematica package outputs the resulting response functions (and associated form factors) and also the differential event rate, once a galactic WIMP velocity profile is specified, and thus in its present form provides a complete framework for experimental analysis. The Mathematica script requires no a priori knowledge of the details of the non-relativistic effective field theory or nuclear physics, though the core concepts are reviewed here and in arXiv:1203.3542.

Nikhil Anand; A. Liam Fitzpatrick; W. C. Haxton

2013-08-28

175

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

E-print Network

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

Pat Scott; Malcolm Fairbairn; Joakim Edsjö

2008-10-30

176

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

177

Biophysical characterization of MDR breast cancer cell lines reveals the cytoplasm is critical in determining drug sensitivity.  

PubMed

Dielectrophoresis (DEP) was used to examine a panel of MCF-7 cell lines comprising parental MCF-7 cells and MDR derivatives: MCF-7TaxR (paclitaxel-resistant, P-glycoprotein (P-gp) positive), MCF-7DoxR (doxorubicin-resistant MRP2 positive) plus MCF-7MDR1 (MDR1 transfected, P-gp positive). MCF-7DoxR and MCF-7MDR1 were broadly cross-resistant to natural product anticancer agents, whereas MCF-7TaxR cells were not, contrary to P-gp expression. Whilst DEP revealed modest membrane changes in MDR sub-lines, we saw significant changes in their cytoplasmic conductivity: MCF-7TaxRsensitivity is associated with low ionic conductance (reduced cellular trafficking and ion transport) and substantial anthracycline accumulation. For classical MDR i.e. MCF-7MDR1, we saw the reverse picture. Thus, the drug resistance phenotypes of this panel of MCF-7 lines can be delineated by assessment of cytoplasmic biophysical properties using DEP. PMID:17270349

Coley, Helen M; Labeed, Fatima H; Thomas, Hilary; Hughes, Michael P

2007-04-01

178

Comparison of glucocorticoid receptors in two rat hepatoma cell lines with different sensitivities to glucocorticoids and antiglucocorticoids.  

PubMed

Two independently derived rat hepatoma cell lines, HTC and Fu5-5, differ in their sensitivities to both glucocorticoids and antiglucocorticoids, despite virtually identical number and affinity of glucocorticoid receptors. The present study further examined both receptors for differences that could account for the nonidentical responses of the two cell lines. HTC and Fu5-5 cell receptors that were covalently labeled with [3H] dexamethasone 21-mesylate ([3H]DM) had the same mol wt of about 97,000 on sodium dodecyl sulfate-polyacrylamide gel electrophoresis and the same isoelectric point of about 6.4 by nonequilibrium pH gradient electrophoresis. Limited proteolysis of receptor-[3H]DM complexes with three different proteases generated identical protease-specific digestion patterns regardless of the cellular origin of the receptors. Receptor-[3H]dexamethasone complexes prepared from either Fu5-5 or HTC cells bound calf thymus DNA with the same affinity in vitro. In intact cells, the intracellular distribution of receptor-dexamethasone or receptor-DM complexes at equilibrium was almost identical in the two cell lines. Thus, we detected no differences in the size, sequence, or net charge of Fu5-5 or HTC cell receptors; additionally, there were no significant differences in steroid uptake, receptor binding, or activation, translocation, and nuclear binding of receptor-steroid complexes. However, the DM labeling efficiency, calculated as the percentage of total receptors covalently labeled by DM, was higher in HTC cells (65.9 +/- 12.9%; n = 5) than in Fu5-5 cells (39.3 +/- 7.7%; n = 5). The labeling efficiency of DM correlated inversely with its ability to induce tyrosine aminotransferase activity, suggesting that DM forms noncovalent, as well as covalent, complexes in vivo which mediate the glucocorticoid and antiglucocorticoid activities of DM, respectively. Further research is required to identify the factor(s) that influences DM labeling efficiency, thereby affecting the amount of DM agonist activity and, possibly, the sensitivity of the cells to glucocorticoids. PMID:3163549

Miller, P A; Simons, S S

1988-06-01

179

The Phase of the Annual Modulation as a Tool for Determining the WIMP Mass  

E-print Network

The count rate of Weakly Interacting Massive Particle (WIMP) dark matter candidates in direct detection experiments experiences an annual modulation due to the Earth's motion around the Sun. In the standard isothermal halo model, the signal peaks near June 2nd at high recoil energies; however, the signal experiences a phase reversal and peaks in December at low energy recoils. We show that this phase reversal may be used to determine the WIMP mass. If an annual modulation were observed with the usual phase ({\\it i.e.}, peaking on June 2nd) in the lowest accessible energy recoil bins of the DAMA, CDMS-II, CRESST-II, EDELWEISS-II, GENIUS-TF, ZEPLIN-II, XENON, or ZEPLIN-IV detectors, one could immediately place upper bounds on the WIMP mass of [103, 48, 6, 97, 10, 52, 29, 29] GeV, respectively. In addition, detectors with adequate energy resolution and sufficiently low recoil energy thresholds may determine the crossover recoil energy at which the phase reverses, thereby obtaining an independent measurement of the WIMP mass. We study the capabilities of various detectors, and find that CRESST-II, ZEPLIN-II, and GENIUS-TF should be able to observe the phase reversal in a few years of runtime, and can thus determine the mass of the WIMP if it is $\\mathcal{O}(100$ GeV). Xenon based detectors with 1000 kg (XENON and ZEPLIN-IV) and with energy recoil thresholds of a few keV require 25 kg-yr exposure, which will be readily attained in upcoming experiments.

Matthew J. Lewis; Katherine Freese

2003-07-09

180

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

181

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

182

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

PubMed

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

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

2012-09-01

183

Predicting skin sensitization potential and inter-laboratory reproducibility of a human Cell Line Activation Test (h-CLAT) in the European Cosmetics Association (COLIPA) ring trials  

Microsoft Academic Search

Regulatory policies in Europe prohibited the testing of cosmetic ingredients in animals for a number of toxicological endpoints. Currently no validated non-animal test methods exist for skin sensitization. Evaluation of changes in cell surface marker expression in dendritic cell (DC)-surrogate cell lines represents one non-animal approach. The human Cell Line Activation Test (h-CLAT) examines the level of CD86 and CD54

Hitoshi Sakaguchi; Cindy Ryan; Jean-Marc Ovigne; Klaus R. Schroeder; Takao Ashikaga

2010-01-01

184

The REST Gene Signature Predicts Drug Sensitivity in Neuroblastoma Cell Lines and Is Significantly Associated with Neuroblastoma Tumor Stage  

PubMed Central

Neuroblastoma is the most common and deadly solid tumor in children, and there is currently no effective treatment available for neuroblastoma patients. The repressor element-1 silencing transcription (REST) factor has been found to play important roles in the regulation of neural differentiation and tumorigenesis. Recently, a REST signature consisting of downstream targets of REST has been reported to have clinical relevance in both breast cancer and glioblastoma. However it remains unclear how the REST signature works in neuroblastoma. Publicly available datasets were mined and bioinformatic approaches were used to investigate the utility of the REST signature in neuroblastoma with both preclinical and real patient data. The REST signature was found to be associated with drug sensitivity in neuroblastoma cell lines. Further, neuroblastoma patients with enhanced REST activity are significantly associated with higher clinical stages. Loss of heterozygosity on chromosome 11q23, which occurs in a large subset of high-risk neuroblastomas, tends to be correlated with high REST activity, with marginal significance. In conclusion, the REST signature has important implications for targeted therapy, and it is a prognostic factor in neuroblastoma patients. PMID:24968265

Liang, Jianfeng; Tong, Pan; Zhao, Wanni; Li, Yaqiao; Zhang, Li; Xia, Ying; Yu, Yanbing

2014-01-01

185

A cell line with unusual characteristics from an ovarian carcinoma patient: modulation of sensitivity to antitumour drugs.  

PubMed

A cell line (GZL-8) was established by cloning from ascitic fluid of an untreated ovarian carcinoma patient. The cells grew rapidly, accumulated lipids and showed chromosomal alterations. One of the marker chromosomes showed characteristics of a Y-like chromosome. This unusual finding was confirmed by DNA hybridisation using specific probes to the Y chromosome. The cells stained with fluorescent antibodies to desmoplakin and cytokeratins 8, 18, 19, and weakly with vimentin but not with desmin. The presence of epithelial membrane antigen, human milk fat globulin, alpha-lactalbumin, alpha-fetoprotein, placental alkaline phosphatase and oestrogen receptor-related antigen was demonstrated by indirect immunoperoxidase staining, but no CA-125 antigen could be detected. The cells showed positive reaction with antibodies to P-glycoprotein. The function of the P-glycoprotein transport system was demonstrated by the rhodamine-123 release test. The cells were initially responsive to doxorubicin, and to high concentrations of cisplatin. Growth inhibition by doxorubicin, especially at low doses was enhanced by the addition of verapamil or tamoxifen. This was shown by the soft agar clonogenic assay, by direct cell counting and by the MTT reducing test. Our results show that combination between drug and sensitivity modulators may be of potential clinical value in ovarian cancer. PMID:1348952

Wasserman, L; Aviram, R; Levavi, H; Ovadia, J; Shneyuor, Y; Frisch, A; Blau, O; Beery, E; Novogrodsky, A; Nordenberg, J

1992-01-01

186

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

SciTech Connect

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

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

2012-09-15

187

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

188

Resolution, Line-Edge Roughness, Sensitivity Tradeoff, and Quantum Yield of High Photo Acid Generator Resists for Extreme Ultraviolet Lithography  

NASA Astrophysics Data System (ADS)

Ultrahigh loadings of photoacid generators (PAGs) in phenolic extreme ultraviolet (EUV) resists have generated the highest known film quantum yields (FQYs). We evaluate the performance of these resists in terms of resolution, line-edge roughness (LER), and sensitivity and collectively evaluate these three parameters (known as RLS) in terms of KLUP and Z-Parameter figures of merit. An analytical model describing the kinetics of photodecomposition was developed to explain the relationship between film quantum yield and PAG concentration. Resists were prepared using a broad range of concentrations of iodonium (DTBPI-PFBS), sulfonium (TPS-PFBS), and non-ionic (NDI-PFBS) PAGs. The model fits the experimental data (correlation coefficient R2 = 0.998, 0.994, and 0.995) and compares the rate at which electrons react with PAGs or recombine with holes. Resists prepared with 15-20 wt % of iodonium nonaflate PAG exhibit both high quantum yields and the best RLS performance as determined using both KLUP and Z-Parameter methodologies. The improvement in RLS performance correlates with the increase in FQY at higher PAG concentrations.

Higgins, Craig D.; Szmanda, Charles R.; Antohe, Alin; Denbeaux, Greg; Georger, Jacque; Brainard, Robert L.

2011-03-01

189

Effects of residue background events in direct dark matter detection experiments on the determination of the WIMP mass  

SciTech Connect

In the earlier work on the development of a model-independent data analysis method for determining the mass of Weakly Interacting Massive Particles (WIMPs) by using measured recoil energies from direct Dark Matter detection experiments directly, it was assumed that the analyzed data sets are background-free, i.e., all events are WIMP signals. In this article, as a more realistic study, we take into account a fraction of possible residue background events, which pass all discrimination criteria and then mix with other real WIMP-induced events in our data sets. Our simulations show that, for the determination of the WIMP mass, the maximal acceptable fraction of residue background events in the analyzed data sets of O(50) total events is ? 20%, for background windows of the entire experimental possible energy ranges, or in low energy ranges; while, for background windows in relatively higher energy ranges, this maximal acceptable fraction of residue background events can not be larger than ? 10%. For a WIMP mass of 100 GeV with 20% background events in the windows of the entire experimental possible energy ranges, the reconstructed WIMP mass and the 1? statistical uncertainty are ? 97GeV{sup +61%}{sub ?35%} ( ? 94GeV{sup +55%}{sub ?33%} for background-free data sets)

Chou, Yu-Ting [Institute of Physics, National Chiao Tung University, No. 1001, University Road, Hsinchu City 30010, Taiwan, R.O.C. (China); Shan, Chung-Lin, E-mail: yuting.py97g@nctu.edu.tw, E-mail: clshan@mail.ncku.edu.tw [Department of Physics, National Cheng Kung University, No. 1, University Road, Tainan City 70101, Taiwan, R.O.C. (China)

2010-08-01

190

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

SciTech Connect

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

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

2007-01-01

191

Protein kinase C-dependent anti-apoptotic mechanism that is associated with high sensitivity to anti-Fas antibody in ovarian cancer cell lines.  

PubMed

We compared the sensitivities to apoptosis via anti-Fas antibody of two human ovarian cancer cell lines, NOS4 and SKOV-3, both of which strongly express the Fas antigen on their cell surface. Treatment with anti-Fas antibody induced extensive DNA fragmentation in NOS4 cells but none in SKOV-3 cells. However; both cell lines underwent apoptosis in response to calcium ionophore A23187 or sphingomyelinase, demonstrating that the latter cell line is capable of DNA fragmentation. DNA fragmentation was not induced in either cell line by treatment with PKC activator PMA, however treatment with protein kinase C (PKC) inhibitor H-7 induced extensive DNA fragmentation in NOS4 cells, but again none in SKOV-3 cells. Protein kinase A inhibitor HA1004 treatment did not induce DNA fragmentation in either cell line. Correspondingly, treatment of cells with PMA before anti-Fas antibody or A23187 treatment partially inhibited induction of DNA fragmentation in NOS4 cells but not in SKOV-3 cells. Both NOS4 and SKOV-3 cell lines expressed isozymes of PKC at comparable levels. These results suggest the presence of a PKC-dependent anti-apoptotic mechanism in association with high sensitivity to anti-Fas antibody in these ovarian cancer cell lines. PMID:10403549

Hayakawa, A; Yokoyama, I; Tajiri, H; Okamoto, T; Nakashima, I

1999-06-01

192

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

PubMed Central

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

Connett, Marie B.; Hanson, Maureen R.

1990-01-01

193

CPN\\/Tools: A Post-WIMP Interface for Editing and Simulating Coloured Petri Nets  

Microsoft Academic Search

CPN\\/Tools is a major redesign of the popular Design\\/CPN tool from the University of Aarhus CPN group. The new interface is\\u000a based on advanced, post-WIMP interaction techniques, including bi-manual interaction, toolglasses and marking menus and a\\u000a new metaphor for managing the workspace. It challenges traditional ideas about user interfaces, getting rid of pull-down menus,\\u000a scrollbars, and even selection, while providing

Michel Beaudouin-Lafon; Wendy E. Mackay; Peter Andersen; Paul Janecek; Mads Jensen; Michael Lassen; Kasper Lund; Kjeld Mortensen; Stephanie Munck; Anne Ratzer; Katrine Ravn; Søren Christensen; Kurt Jensen

194

Exclusion limits on the WIMP-nucleon cross section from the Cryogenic Dark Matter Search  

Microsoft Academic Search

The Cryogenic Dark Matter Search (CDMS) employs low-temperature Ge and Si detectors to search for weakly interacting massive particles (WIMPs) via their elastic-scattering interactions with nuclei while discriminating against interactions of background particles. For recoil energies above 10 keV, events due to background photons are rejected with >99.9% efficiency, and surface events are rejected with >95% efficiency. The estimate of

D. Abrams; D. S. Akerib; M. S. Armel-Funkhouser; L. Baudis; D. A. Bauer; A. Bolozdynya; P. L. Brink; R. Bunker; B. Cabrera; D. O. Caldwell; J. P. Castle; C. L. Chang; R. M. Clarke; M. B. Crisler; R. Dixon; D. Driscoll; S. Eichblatt; R. J. Gaitskell; S. R. Golwala; E. E. Haller; J. Hellmig; D. Holmgren; M. E. Huber; S. Kamat; A. Lu; V. Mandic; J. M. Martinis; P. Meunier; S. W. Nam; H. Nelson; T. A. Perera; M. C. Perillo Isaac; W. Rau; R. R. Ross; T. Saab; B. Sadoulet; J. Sander; R. W. Schnee; T. Shutt; A. Smith; A. H. Sonnenschein; A. L. Spadafora; G. Wang; S. Yellin; B. A. Young

2002-01-01

195

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

196

Indirect Detection of WIMP Dark Matter: a compact review  

E-print Network

Indirect detection of dark matter particles, i.e. the detection of annihilation or decay products of Weakly Interacting Massive Particles, has entered a pivotal phase as experiments reach sensitivities that probe the most interesting parameter space. This period is naturally accompanied by claims of detection. In this contribution I discuss and compare different probes (gamma-rays, neutrinos and charged cosmic rays) and review the status and prospects of constraints and recent detection claims.

Conrad, Jan

2014-01-01

197

Inhibition of PI3K/Akt/mTOR signaling pathway enhances the sensitivity of the SKOV3/DDP ovarian cancer cell line to cisplatin in vitro  

PubMed Central

The activation of the PI3K/AKT/mTOR pathway plays a key role in ovarian cancer tumorigenesis, progression and chemotherapy resistance. This study aimed to explore the possible mechanism that PI-103, a dual inhibitor of phosphatidylinositide 3-kinase and mTOR, enhances the sensitivity of SKOV3/DDP ovarian cancer cell line to cisplatin chemotherapy. The results showed that PI-103 could significantly increase the sensitivity of SKVO3/DDP cells to cisplatin through inhibiting the activation of PI3K/Akt/mTOR signaling pathway and inducing cell cycle arrest and apoptosis.

Cai, Yunlang; Tan, Xiaoqiang; Liu, Jun; Shen, Yang; Wu, Di; Ren, Mulan; Yu, Dandan

2014-01-01

198

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

199

Genome-wide transcriptomic analysis of response to low temperature reveals candidate genes determining divergent cold-sensitivity of maize inbred lines.  

PubMed

Maize, despite being thermophyllic due to its tropical origin, demonstrates high intraspecific diversity in cold-tolerance. To search for molecular mechanisms of this diversity, transcriptomic response to cold was studied in two inbred lines of contrasting cold-tolerance. Microarray analysis was followed by extensive statistical elaboration of data, literature data mining, and gene ontology-based classification. The lines used had been bred earlier specifically for determination of QTLs for cold-performance of photosynthesis. This allowed direct comparison of present transcriptomic data with the earlier QTL mapping results. Cold-treated (14 h at 8/6 °C) maize seedlings of cold-tolerant ETH-DH7 and cold-sensitive ETH-DL3 lines at V3 stage showed strong, consistent response of the third leaf transcriptome: several thousand probes showed similar, statistically significant change in both lines, while only tens responded differently in the two lines. The most striking difference between the responses of the two lines to cold was the induction of expression of ca. twenty genes encoding membrane/cell wall proteins exclusively in the cold-tolerant ETH-DH7 line. The common response comprised mainly repression of numerous genes related to photosynthesis and induction of genes related to basic biological activity: transcription, regulation of gene expression, protein phosphorylation, cell wall organization. Among the genes showing differential response, several were close to the QTL regions identified in earlier studies with the same inbred lines and associated with biometrical, physiological or biochemical parameters. These transcripts, including two apparently non-protein-coding ones, are particularly attractive candidates for future studies on mechanisms determining divergent cold-tolerance of inbred maize lines. PMID:24623520

Sobkowiak, Alicja; Jo?czyk, Maciej; Jarochowska, Emilia; Biecek, Przemys?aw; Trzcinska-Danielewicz, Joanna; Leipner, Jörg; Fronk, Jan; Sowi?ski, Pawe?

2014-06-01

200

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

PubMed Central

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

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

2010-01-01

201

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

PubMed Central

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; Rydstrom, Karin; Relander, Thomas; Drott, Kristina

2013-01-01

202

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

SciTech Connect

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

Wai, Larry; /SLAC

2007-02-05

203

Standard Model anatomy of WIMP dark matter direct detection I: weak-scale matching  

E-print Network

We present formalism necessary to determine weak-scale matching coefficients in the computation of scattering cross sections for putative dark matter candidates interacting with the Standard Model. Particular attention is paid to the heavy-particle limit. A consistent renormalization scheme in the presence of nontrivial residual masses is implemented. Two-loop diagrams appearing in the matching to gluon operators are evaluated. Details are given for the computation of matching coefficients in the universal limit of WIMP-nucleon scattering for pure states of arbitrary quantum numbers, and for singlet-doublet and doublet-triplet mixed states.

Hill, Richard J

2014-01-01

204

Standard Model anatomy of WIMP dark matter direct detection I: weak-scale matching  

E-print Network

We present formalism necessary to determine weak-scale matching coefficients in the computation of scattering cross sections for putative dark matter candidates interacting with the Standard Model. Particular attention is paid to the heavy-particle limit. A consistent renormalization scheme in the presence of nontrivial residual masses is implemented. Two-loop diagrams appearing in the matching to gluon operators are evaluated. Details are given for the computation of matching coefficients in the universal limit of WIMP-nucleon scattering for pure states of arbitrary quantum numbers, and for singlet-doublet and doublet-triplet mixed states.

Richard J. Hill; Mikhail P. Solon

2014-01-14

205

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

206

Improved Limits on Spin-Dependent WIMP-Proton Interactions from a Two Liter CF$_3$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 the strongest direct detection constraint to date on WIMP-proton spin-dependent scattering for WIMP masses > 20 GeV/c{sup 2}.

Behnke, E.; Behnke, J.; /Indiana U., South Bend; Brice, S.J.; Broemmelsiek, D.; /Fermilab; Collar, J.I.; /KICP, Chicago /Chicago U., EFI /Chicago U.; Cooper, P.S.; Crisler, M.; /Fermilab; Dahl, C.E.; Fustin, D.; /KICP, Chicago /Chicago U.; Hall, J.; /Fermilab; Hinnefeld, J.H.; /Indiana U., South Bend /Fermilab /Indiana U., South Bend /Fermilab /Indiana U., South Bend /Fermilab

2010-08-01

207

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

PubMed

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

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

2011-01-14

208

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

NASA Astrophysics Data System (ADS)

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

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

2011-01-01

209

Antitumor Effect of Adenovirus-mediated Bax Gene Transfer on p53-sensitive and p53-resistant Cancer Lines1  

Microsoft Academic Search

Antitumor effects of the proapoptotic Bax gene have been evaluated in vitro and in vivo by a binary adenovirus system expressing the human Bax gene. Overexpression of the Bax gene in cultured cell lines from human lung carcinoma results in caspase activation, apoptosis induction, and cell growth suppression. Intratumoral injection of adenovirus vector express- ing the Bax gene suppressed growth

Shunsuke Kagawa; Jian Gu; Stephen G. Swisher; Lin Ji; Jack A. Roth; Dejian Lai; L. Clifton Stephens; Bingliang Fang

2000-01-01

210

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

NASA Technical Reports Server (NTRS)

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

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

1999-01-01

211

Neutrinos from WIMP Annihilations Using a Full Three-Flavor Monte Carlo  

E-print Network

Weakly Interacting Massive Particles (WIMPs) are one of the main candidates for the dark matter in the Universe. If these particles make up the dark matter, then they can be captured by the Sun or the Earth, sink to the respective cores, annihilate, and produce neutrinos. Thus, these neutrinos can be a striking dark matter signature at neutrino telescopes looking towards the Sun and/or the Earth. Here, we improve previous analyses on computing the neutrino yields from WIMP annihilations in several respects. We include neutrino oscillations in a full three-flavor framework as well as all effects from neutrino interactions on the way through the Sun (absorption, energy loss, and regeneration from tau decays). In addition, we study the effects of non-zero values of the mixing angle $\\theta_{13}$ as well as the normal and inverted neutrino mass hierarchies. Our study is performed in an event-based setting which makes these results very useful both for theoretical analyses and for building a neutrino telescope Mon...

Blennow, Mattias; Ohlsson, Tommy

2007-01-01

212

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

213

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

2009-07-02

214

Dark matter spin-dependent limits for WIMP interactions on 19F by PICASSO  

NASA Astrophysics Data System (ADS)

The PICASSO experiment at SNOLAB reports new results for spin-dependent WIMP interactions on 19F 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 19F of 65 g and 69 g respectively and a total exposure of 13.75±0.48 kg d. No dark matter signal was found and for WIMP masses around 24 GeV /c new limits have been obtained on the spin-dependent cross section on 19F of ?=13.9 pb (90% C.L.) which can be converted into cross section limits on protons and neutrons of ?=0.16 pb and ?=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.

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

2009-11-01

215

Exclusion Limits on the WIMP-Nucleon Cross-Section from the Cryogenic Dark Matter Search  

E-print Network

The Cryogenic Dark Matter Search (CDMS) employs low-temperature Ge and Si detectors to search for Weakly Interacting Massive Particles (WIMPs) via their elastic-scattering interactions with nuclei while discriminating against interactions of background particles. For recoil energies above 10 keV, events due to background photons are rejected with >99.9% efficiency, and surface events are rejected with >95% efficiency. The estimate of the background due to neutrons is based primarily on the observation of multiple-scatter events that should all be neutrons. Data selection is determined primarily by examining calibration data and vetoed events. Resulting efficiencies should be accurate to about 10%. Results of CDMS data from 1998 and 1999 with a relaxed fiducial-volume cut (resulting in 15.8 kg-days exposure on Ge) are consistent with an earlier analysis with a more restrictive fiducial-volume cut. Twenty-three WIMP candidate events are observed, but these events are consistent with a background from neutrons i...

Abrams, D; Armel-Funkhouser, M S; Baudis, L; Bauer, D A; Bolozdynya, A; Brink, P L; Bunker, R; Cabrera, B; Caldwell, D O; Castle, J P; Chang, C L; Clarke, R M; Crisler, M B; Dixon, R; Driscoll, D; Eichblatt, S; Gaitskell, R J; Golwala, S R; Haller, E E; Hellmig, J; Holmgren, D; Huber, M E; Kamat, S; Lu, A; Mandic, V; Martinis, J M; Meunier, P; Nam, S W; Nelson, H; Perera, T A; Perillo-Isaac, M C; Rau, W; Ross, R R; Saab, T; Sadoulet, B; Sander, J; Schnee, R W; Shutt, T; Smith, A; Sonnenschein, A H; Spadafora, A L; Wang, G; Yellin, S; Young, B A

2002-01-01

216

Variation in cisplatinum sensitivity is not associated with Fanconi Anemia/BRCA pathway inactivation in head and neck squamous cell carcinoma cell lines.  

PubMed

Fanconi Anemia has recently been associated with a high risk of head and neck squamous cell carcinoma (HNSCC). Inactivation of the Fanconi Anemia (FANC-BRCA) pathway via promoter methylation of the FANCF gene has been proposed to be responsible for variation in cisplatinum (CDDP) sensitivity seen in ovarian and HNSCCs. Promoter methylation of the FANCF gene has been observed in 15% of HNSCC specimens, but the relationship to FANC pathway activation and CDDP sensitivity has not been reported. In the present study, 10 HNSCC cell lines were examined for expression of nine genes involved in the FANC-BRCA pathway by RT-PCR: FANCA, FANCC, FANCD2, FANCE, FANCF, FANCG, FANCL, BRCA1 and BRCA2. FANC pathway function was evaluated by western blotting for FANCD2 mono-ubiquitination. All of the cell lines were also analyzed for variation in CDDP cytotoxicity. While significant differences were found in CDDP cytotoxicity, Fanconi pathway defects are an infrequent cause, as no evidence of transcriptional down-regulation of FANCF or other FANC mRNAs, or functional FANC-BRCA pathway defects were observed. These findings suggest that the variation in CDDP sensitivity of many HNSCCs is most frequently due to factors other than FANC-BRCA pathway inactivation. PMID:16466850

Snyder, Eric R; Ricker, Justin L; Chen, Zhong; Waes, Carter Van

2007-01-01

217

Suppression of manganese superoxide dismutase augments sensitivity to radiation, hyperthermia and doxorubicin in colon cancer cell lines by inducing apoptosis  

Microsoft Academic Search

Increased expression of manganese superoxide dismutase (Mn-SOD), one of the mitochondrial enzymes involved in the redox system, has been shown to diminish the cytotoxic effects of several anti-cancer modalities, including tumour necrosis factor-?, ionizing radiation, certain chemotherapeutic agents and hyperthermia. We asked if Mn-SOD is a potential target to augment the sensitivity of cancer cells to various anti-cancer treatments and

S Kuninaka; Y Ichinose; K Koja; Y Toh

2000-01-01

218

Sensitivity of solar off-limb line profiles to electron density stratification and the velocity distribution anisotropy  

Microsoft Academic Search

The effect of the electron density stratification on the intensity profiles\\u000aof the H I Ly-$\\\\alpha$ line and the O VI and Mg X doublets formed in solar\\u000acoronal holes is investigated. We employ an analytical 2-D model of the large\\u000ascale coronal magnetic field that provides a good representation of the corona\\u000aat the minimum of solar activity. We

N.-E. Raouafi; S. K. Solanki

2007-01-01

219

Evidence for an Inducible Repair-Recombination System in the Female Germ Line of Drosophila Melanogaster. II. Differential Sensitivity to Gamma Rays  

PubMed Central

In a previous paper, we reported that the reactivity level, which regulates the frequency of transposition of I factor, a LINE element-like retrotransposon, is enhanced by the same agents that induce the SOS response in Escherichia coli. In this report, we describe experimental evidence that, for identical genotypes, the reactivity levels correlate with the sensitivity of oogenesis to gamma rays, measured by the number of eggs laid and by frequency of dominant lethals. This strongly supports the hypothesis that the reactivity level is one manifestation of an inducible DNA repair system taking place in the female germ line of Drosophila melanogaster. The implications of this finding for the understanding of the regulation of I factor are discussed and some other possible biological roles of this system are outlined. PMID:8647394

Laurencon, A.; Bregliano, J. C.

1995-01-01

220

Lymphoblastoid lines and skin fibroblasts from patients with tuberous sclerosis are abnormally sensitive to ionizing radiation and to a radiomimetic chemical  

SciTech Connect

Lymphoblastoid lines, derived by transforming peripheral blood lymphocytes with Epstein-Barr virus, and skin fibroblast lines were established from two patients with tuberous sclerosis. The number of viable lymphoblastoid cells was determined by their ability to exclude the vital dye trypan blue after their irradiation with x-rays or 254 nm ultraviolet light. The growth of fibroblasts was determined by their ability to form colonies after treatment with the radiomimetic, DNA-damaging chemical N-methyl-N'-nitro-N-nitrosoguanidine. The tuberous sclerosis lymphoblastoid lines were hypersensitive to x-rays but had normal sensitivity to the ultraviolet radiation. The tuberous sclerosis fibroblast lines were hypersensitive to the N-methyl-N'-nitro-N-nitrosoguanidine. The hypersensitivity of tuberous sclerosis cells to x-rays and to N-methyl-N'-nitro-N-nitrosoguanidine is believed to reflect defective repair of DNA damaged by these agents and may provide the basis for in vitro, including prenatal, diagnostic tests for tuberous sclerosis.

Scudiero, D.A.; Moshell, A.N.; Scarpinato, R.G.; Meyer, S.A.; Clatterbuck, B.E.; Tarone, R.E.; Robbins, J.H.

1982-03-01

221

Quantitative measurement of optical parameters of cell lines 5-8F and 6-10B using polarization sensitive optical coherence tomography.  

PubMed

The aim was to test whether the typical NPC cell lines of 5-8F (high tumorigenesis and metastasis) and 6-10B (low tumorigenesis and metastasis) could be differentiated by polarization sensitive optical coherence tomography (PS-OCT). We imaged the two types of low cellular differentiated NPC cell lines 5-8F and 6-10B pellets using PS-OCT; then extracted the optical parameters of attenuate coefficient and anisotropy from the A-scan lines based on the multiple scattering model; and compared their phase retardation. The fitting scattering coefficients were ?s=10.91±0.45 and ?s=11.33±0.27 cm(-1) for 5-8F and 6-10B pellets (p<0.05), respectively; and the anisotropy factors were g=0.900±0.013 and g=0.885±0.008 for 5-8F and 6-10B pellets (p<0.01), respectively. While the phase retardation of 6-10B was a little faster than 5-8F. These results indicated that PS-OCT could differentiate the two cell lines, and had the potential ability for typing the tissue of NPC. PMID:22525523

Li, Jianghua; Chen, Bingling; Du, Yong; Yang, Lifeng; Xia, Yunfei; He, Yonghong; Liu, Songhao; Chen, Changshui

2012-06-15

222

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 radioactivity suitable for WIMP dark matter searches.

C. Galbiati; R. Purtschert

2007-12-03

223

Search for very high energy gamma rays from WIMP annihilations near the Sun with the Milagro detector  

E-print Network

Search for very high energy gamma rays from WIMP annihilations near the Sun with the Milagro ``dark matter''. A profusion of such neutralinos can accumulate near the Sun when they lose energy upon of the Sun with an angular resolution of 0:75. Analysis of Milagro data with an exposure to the Sun of 1165

California at Santa Cruz, University of

224

Characterization of the androgen-sensitive MDA-kb2 cell line for assessing complex environmental mixtures.  

PubMed

Synthetic and natural steroidal androgens and estrogens and many other non-steroidal endocrine-active compounds commonly occur as complex mixtures in aquatic environments. It is important to understand the potential interactive effects of these mixtures to properly assess their risk. Estrogen receptor agonists exhibit additivity in mixtures when tested in vivo and in vitro. Little is known, however, concerning possible mixture interactions of androgen receptor agonists. In these studies we used the MDA-kb2 cell line, a human breast cancer cell line with endogenous androgen receptors and a stably transfected luciferase reporter gene construct to quantify the androgenic activity of seven natural and synthetic androgens: 17beta-trenbolone, dihydrotestosterone, methyltestosterone, testosterone, trendione, 17alpha-trenbolone, and androstenedione. We tested combinations of these androgens and compared the observed activity to expected androgenic activity based on a concentration addition model. Our analyses support the hypothesis that androgen receptor agonists cause additive responses in a mixture. Binary mixtures of 17beta-trenbolone with 17beta-estradiol or triclocarban (an anti-microbial found in the environment) were also tested. 17beta-Estradiol induced androgenic activity, but only at concentrations 600-fold greater than those found in the environment. Triclocarban enhanced the activity of 17beta-trenbolone. Additionally, three anti-androgens were each paired with three androgens of varying potencies. The relative potencies of the antagonists were a vinclozolin metabolite (M2) > procymidone > prochloraz regardless of the androgen used. The results of our studies demonstrate the potential utility of the androgen-responsive MDA-kb2 cell line for quantifying the activity of mixtures of endocrine-active chemicals in complex wastes such as municipal effluents and feedlot discharges. PMID:20821581

Blake, Lindsey S; Martinovi?, Dalma; Gray, L Earl; Wilson, Vickie S; Regal, Ron R; Villeneuve, Daniel L; Ankley, Gerald T

2010-06-01

225

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

226

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

PubMed

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

Olschläger, Veronika; Schrader, Andreas; Hockertz, Stefan

2009-01-01

227

Flies who cannot take the heat: genome-wide gene expression analysis of temperature-sensitive lethality in an inbred line of Drosophila melanogaster.  

PubMed

Fitness decreases associated with inbreeding depression often become more pronounced in a stressful environment. The functional genomic causes of these inbreeding-by-environment (I × E) interactions, and of inbreeding depression in general, are poorly known. To further our understanding of I × E interactions, we performed a genome-wide gene expression study of a single inbred line that suffers from temperature-sensitive lethality. We confirmed that increased differential expression between the thermosensitive line and the control line occurs at the restrictive temperature. This demonstrates that I × E interactions in survival are reflected in similar I × E interactions at the gene expression level. To make an impression of the cellular response associated with the lethal effect, we analysed all functional annotation terms that were overrepresented among the differentially expressed genes. Some sets of differentially expressed genes function in the general stress response, and these are more likely to also be differentially expressed in other studies of inbreeding, inbreeding depression, immunity and heat stress. Other sets of differentially expressed genes are shared with studies of gene expression in inbred lines, but not studies of the response to extrinsic stress, and represent a general transcriptomic signature of inbreeding. Finally, some sets of genes have an annotation that is not reported in other studies. These we consider to be candidates for the genes harbouring the mutations responsible for the thermosensitive phenotype, as these mutations are expected to be unique to this line. These genes may also serve as candidate QTL in studies of thermal tolerance and heat resistance. PMID:25233925

Vermeulen, C J; Sørensen, P; Gagalova, K K; Loeschcke, V

2014-10-01

228

Identification of death receptors DR4 and DR5 in HTB-12 astrocytoma cell lines and determination of TRAIL sensitivity  

PubMed Central

Astrocytomas are tumors which arise from astrocytes, cells that form the blood-brain barrier. There are very few drugs that successfully treat brain tumors. In this study, the cytotoxic effects on the HTB-12 astrocytoma cell line by tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) were studied. The presence of the TRAIL receptors, Death receptor 4 (DR4) and Death receptor 5 (DR5), were detected in HTB-12 cells by Enzyme-Linked Immunosorbent Assay (ELISA). Cytotoxicity assay by Trypan Blue Exclusion Method showed effective cell killing by TRAIL treatment. Thus, the presence of death receptors and TRAIL efficacy raises the therapeutic potential for this type of brain tumor.

Riddick, Elenia; Evans, Shavonda; Rousch, Jeffrey; Gwebu, Ephraim; Banerjee, Hirendra Nath

2014-01-01

229

Modulation of cisplatin sensitivity in human ovarian carcinoma A2780 and SKOV3 cell lines by sulforaphane.  

PubMed

Cisplatin resistance is one of the major obstacles in the treatment of ovarian cancer. In an effort to look for new possibilities of how to overcome this difficulty, we studied the mechanisms of the interactions between sulforaphane (SFN) and cisplatin (cisPt) in combined treatment of human ovarian carcinoma A2780 and SKOV3 cell lines. Synergy (A2780) and antagonism (SKOV3) found in MTT assay was confirmed by apoptosis. While SFN significantly potentiated cisPt-induced DNA damage in A2780 cells, it protected SKOV3 cells against cisPt-crosslinking. We revealed a less efficient Nrf-2 pathway inducibility by SFN in A2780 compared to SKOV3 cells, when activation of the Nrf-2 pathway incites its protectivity against cisPt. Thus, different activation of the Nrf-2 pathway may explain the dual effects of SFN. PMID:25159039

Hunakova, Luba; Gronesova, Paulina; Horvathova, Eva; Chalupa, Ivan; Cholujova, Dana; Duraj, Jozef; Sedlak, Jan

2014-11-01

230

siRNA targeting stathmin inhibits invasion and enhances chemotherapy sensitivity of stem cells derived from glioma cell lines.  

PubMed

Glioma is one of the most highly angiogenic tumors, and glioma stem cells (GSCs) are responsible for resistance to chemotherapy and radiotherapy, as well as recurrence after operation. Stathmin is substantial for mitosis and plays an important role in proliferation and migration of glioma-derived endothelial cells. However, the relationship between stathmin and GSCs is incompletely understood. Here we isolated GSCs from glioma cell lines U87MG and U251, and then used siRNA targeting stathmin for silencing. We showed that silencing of stathmin suppressed the proliferation, increased the apoptosis rate, and arrested the cell cycle at G2/M phase in GSCs. Silencing of stathmin in GSCs also resulted in inhibited the migration/invasion as well as the capability of vasculogenic mimicry. The susceptibility of GSCs to temozolomide was also enhanced by stathmin silencing. Our findings suggest stathmin as a potential target in GSCs for glioma treatment. PMID:25348735

Song, Yuwen; Mu, Luyan; Han, Xuezhe; Liu, Xiaoqian; Fu, Songbin

2014-12-01

231

Urokinase-type plasminogen activator receptor regulates apoptotic sensitivity of colon cancer HCT116 cell line to TRAIL via JNK-p53 pathway.  

PubMed

The urokinase-type plasminogen activator receptor (uPAR) serves not only as an anchor for urokinase-type plasminogen activator but also participates in intracellular signal transduction events. In this study, we investigated whether uPAR could modulate TRAIL-induced apoptosis in human colon cancer cells HCT116. Using an antisense strategy, we established a stable HCT116 cell line with down-regulated uPAR. The sensitivity to TRAIL-induced apoptosis was evaluated by FACS analysis. Our results show that the inhibition of uPAR could sensitize HCT116 to TRAIL-induced apoptosis. uPAR inhibition changed the expression of mitochondrial apoptotic pathway proteins, including Bcl-2, Bax, Bid and p53, in a pro-apoptotic manner. We also found that the inhibition of uPAR down-regulated the phosphorylation of FAK, ERK and JNK. The inhibition of p53 by RNA interference rescued cells from enhanced apoptosis, thus indicating that p53 is critical for enhancing TRAIL-induced apoptosis. Furthermore, JNK, but not ERK, inhibition involved in the up-regulation of p53. JNK negatively regulated p53 protein level. Overall, our results show that uPAR inhibition can sensitize colon cancer cells HCT116 to TRAIL-induced apoptosis via active p53 and mitochondrial apoptotic pathways that JNK inhibition is involved. PMID:25113506

Liu, Xiufeng; Qiu, Fan; Liu, Zhipeng; Lan, Yan; Wang, Kai; Zhou, Ping-Kun; Wang, Yao; Hua, Zi-Chun

2014-10-01

232

Sensitive analysis of amino acids with carrier-mediated single drop microextraction in-line coupled with capillary electrophoresis.  

PubMed

In order to analyze amino acids sensitively without derivatization, we have developed carrier-mediated single drop microextraction (SDME). Nonane-1-sulfonic acid was added to an acidic sample donor solution as a carrier to form neutral ion pair complexes with amino acids. The ion pair complexes were extracted to the organic phase, covering a drop of an aqueous basic acceptor phase hanging at the tip of a capillary, and then back-extracted to the basic acceptor phase, where both the amino acids and the carrier have negative charges and the ion pair complexes are broken. The resulting extract of enriched amino acids was injected into the capillary and analyzed by capillary electrophoresis. With 20-min SDME with agitation of the donor phase, enrichment factors of four aromatic amino acids were up to 120-fold, yielding the LOD of 70-500 nM. The linear dynamic ranges for corrected peak areas were 1-100 ?M with linear correlation coefficients larger than 0.9959. With internal standardization, the intraday RSDs of migration times and corrected peak areas were 0.01-0.04% and 2.0-3.7%, respectively. The capabilities of sample cleanup including desalting and preconcentration of carrier-mediated SDME were demonstrated with the analysis of human urine after minimal pretreatment of acidification and centrifugation. PMID:21906743

Choi, Jeongmi; Choi, Kihwan; Kim, Jihye; Ahmed, Ahmed Yacine Badjah Hadj; Al-Othman, Zeid A; Chung, Doo Soo

2011-10-14

233

Inhibition of Mus81 by siRNA enhances sensitivity to 5-FU in breast carcinoma cell lines  

PubMed Central

Purpose One of the most challenging aspects of breast carcinoma chemotherapy is the rapid acquirement of drug resistance. Improving the sensitivity to chemotherapeutic drugs is very important for successful treatment. Mus81 plays an important role in maintaining the stability of the genome and DNA repair. However, recent studies suggested that Mus81 expression levels correlate well with resistance to DNA-damaging drugs. The present study aimed to investigate the role of Mus81 on the chemosensitivity of breast carcinoma cells in response to 5-fluorouracil (5-FU), a chemotherapeutic drug that is widely used for treatment of breast malignancies. Methods The expression of Mus81 in MCF-7 and T47D cells was suppressed by small interfering RNA (siRNA). mRNA and protein levels of Mus81 were analyzed by quantitative real-time polymerase chain reaction and Western blot. Cell viability and colony survival were determined by Cell Counting Kit-8 and plate colony formation assay, respectively. Cell cycle and apoptosis were detected by flow cytometry. Results 5-FU inhibited the cell viability of MCF-7 and T47D cells in a concentration-dependent manner. We found that the Mus81-silenced MCF-7 and T47D cells exhibited decreased cell viability and clonogenic survival, but increased G2 accumulation, in response to 5-FU. In addition, Mus81 deficiency resulted in increased apoptosis and p53 expression in MCF-7 after 5-FU treatment. However, Mus81 deficiency did not affect the apoptosis of T47D cells with 5-FU. Conclusion Taken together, our data suggest that Mus81 inhibition significantly increased the chemosensitivity of MCF-7 and T47D cells in response to 5-FU. Thus, Mus81 siRNA is potentially a useful adjuvant strategy for breast cancer chemotherapy. PMID:25364260

Qian, Ying; Liu, Yanning; Yan, Qiuyue; Lv, Juan; Ni, Xiaoyan; Wu, Yunlu; Dong, Xuejun

2014-01-01

234

Embryonal subregion-derived stromal cell lines from novel temperature-sensitive SV40 T antigen transgenic mice support hematopoiesis.  

PubMed

Throughout life, the hematopoietic system requires a supportive microenvironment that allows for the maintenance and differentiation of hematopoietic stem cells (HSC). To understand the cellular interactions and molecules that provide these functions, investigators have previously established stromal cell lines from the late gestational stage and adult murine hematopoietic microenvironments. However, the stromal cell microenvironment that supports the emergence, expansion and maintenance of HSCs during mid-gestational stages has been largely unexplored. Since several tissues within the mouse embryo are known to harbor HSCs (i.e. aortagonads-mesonephros, yolk sac, liver), we generated numerous stromal cell clones from these mid-gestational sites. Owing to the limited cell numbers, isolations were performed with tissues from transgenic embryos containing the ts SV40 Tag gene (tsA58) under the transcriptional control of constitutive and ubiquitously expressing promoters. We report here that the growth and cloning efficiency of embryonic cells (with the exception of the aorta) is increased in the presence of the tsA58 transgene. Furthermore, our results show that the large panel of stromal clones isolated from the different embryonal subregions exhibit heterogeneity in their ability to promote murine and human hematopoietic differentiation. Despite our findings of heterogeneity in hematopoietic growth factor gene expression profiles, high-level expression of some factors may influence hematopoietic differentiation. Interestingly, a few of these stromal clones express a recently described chordin-like protein, which is an inhibitor of bone morphogenic proteins and is preferentially expressed in cells of the mesenchymal lineage. PMID:11973351

Oostendorp, Robert A J; Medvinsky, Alexander J; Kusadasi, Nuray; Nakayama, Naoki; Harvey, Kirsty; Orelio, Claudia; Ottersbach, Katrin; Covey, Todd; Ploemacher, Rob E; Saris, Chris; Dzierzak, Elaine

2002-05-15

235

Osmotic stress regulates mineralocorticoid receptor expression in a novel aldosterone-sensitive cortical collecting duct cell line.  

PubMed

Aldosterone effects are mediated by the mineralocorticoid receptor (MR), a transcription factor highly expressed in the distal nephron. Given that MR expression level constitutes a key element controlling hormone responsiveness, there is much interest in elucidating the molecular mechanisms governing MR expression. To investigate whether hyper- or hypotonicity could affect MR abundance, we established by targeted oncogenesis a novel immortalized cortical collecting duct (CCD) cell line and examined the impact of osmotic stress on MR expression. KC3AC1 cells form domes, exhibit a high transepithelial resistance, express 11beta-hydroxysteroid dehydrogenase 2 and functional endogenous MR, which mediates aldosterone-stimulated Na(+) reabsorption through the epithelial sodium channel activation. MR expression is tightly regulated by osmotic stress. Hypertonic conditions induce expression of tonicity-responsive enhancer binding protein, an osmoregulatory transcription factor capable of binding tonicity-responsive enhancer response elements located in MR regulatory sequences. Surprisingly, hypertonicity leads to a severe reduction in MR transcript and protein levels. This is accompanied by a concomitant tonicity-induced expression of Tis11b, a mRNA-destabilizing protein that, by binding to the AU-rich sequences of the 3'-untranslated region of MR mRNA, may favor hypertonicity-dependent degradation of labile MR transcripts. In sharp contrast, hypotonicity causes a strong increase in MR transcript and protein levels. Collectively, we demonstrate for the first time that optimal adaptation of CCD cells to changes in extracellular fluid composition is accompanied by drastic modification in MR abundance via transcriptional and posttranscriptional mechanisms. Osmotic stress-regulated MR expression may represent an important molecular determinant for cell-specific MR action, most notably in renal failure, hypertension, or mineralocorticoid resistance. PMID:19846540

Viengchareun, Say; Kamenicky, Peter; Teixeira, Marie; Butlen, Daniel; Meduri, Geri; Blanchard-Gutton, Nicolas; Kurschat, Christine; Lanel, Aurélie; Martinerie, Laetitia; Sztal-Mazer, Shoshana; Blot-Chabaud, Marcel; Ferrary, Evelyne; Cherradi, Nadia; Lombès, Marc

2009-12-01

236

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

PubMed Central

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

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

2012-01-01

237

Effects of n-3 fatty acids during neoplastic progression and comparison of in vitro and in vivo sensitivity of two human tumour cell lines.  

PubMed Central

Several studies have shown that dietary lipid exerts an effect on carcinogenesis. We report here that progression to malignancy in vitro is associated with changes in the response to fatty acids (FAs). Tumorigenic (THKE) cells were more sensitive to the n-3 FAs eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) than immortalised (IHKE) cells. The growth of THKE cells was inhibited 25% more than the growth of IHKE cells at 80 microM EPA (P < 0.01) and 35% more at 40 microM DHA (P < 0.001). Furthermore, the results indicate that there is a wide cell type variation in the response to FAs. We found that the in vitro inhibition by FAs correlated with the reduction in the growth rate of the tumour in nude mice fed K85 (55% EPA and 30% DHA). A significant difference in tumour latency was observed for the A427 cell tumour groups (10 days, P < 0.05). Tumours in the animals fed n-3 FA exhibited significantly higher levels of EPA and DHA; the level of arachidonic acid (ARA) was significantly lower in THKE tumours and the level of linoleic acid (LA) was significantly lower in A427 tumours than in controls fed corn oil. The higher sensitivity of the A427 cell line was not explained by higher uptake of EPA/DHA. PMID:7710930

Maehle, L.; Eilertsen, E.; Mollerup, S.; Sch?nberg, S.; Krokan, H. E.; Haugen, A.

1995-01-01

238

An in-line SPE strategy to enhance sensitivity in CE for the determination of pharmaceutical compounds in river water samples.  

PubMed

In this study, the suitability of solid-phase extraction (SPE) coupled in-line to CE with UV-Vis detection was evaluated for the preconcentration and separation of diluted solutions of five pharmaceuticals compounds: benzafibrate, piroxicam, diclofenac sodium, naproxen and clofibric acid. An SPE analyte concentrator containing Oasis(®) HLB sorbent was constructed without frits and placed near the inlet end of the separation capillary. Different parameters such as sample pH, composition and volume of the elution plug and sample loading time were studied in order to obtain the maximum preconcentration factors. The LODs reached for standard samples were in the range 0.06-0.5?ng/mL with good reproducibility, and the developed strategy provides sensitivity enhancement factors around 14,000-fold in peak area and 5900-fold in peak height compared with the normal hydrodynamic injection. Finally, river water samples fortified with the pharmaceutical compounds were analyzed by the developed in-line SPE-CE-UV method in order to show the potential of the methodology for the analysis of environmental aquatic samples. For these samples, high values of relative recoveries, between 73-107% and 79-103% for two concentration levels, 5 and 25?ng/mL, respectively, were obtained and LODs ranged between 0.19 and 1?ng/mL. PMID:21769895

Maijó, Irene; Borrull, Francesc; Calull, Marta; Aguilar, Carme

2011-08-01

239

Development of Oral Epithelial Cell Line ROE2 with Differentiation Potential from Transgenic Rats Harboring Temperature-Sensitive Simian Virus40 Large T-Antigen Gene  

PubMed Central

We have developed an immortalized oral epithelial cell line, ROE2, from fetal transgenic rats harboring temperature-sensitive simian virus 40 large T-antigen gene. The cells grew continuously at either a permissive temperature of 33°C or an intermediate temperature of 37°C. At the nonpermissive temperature of 39°C, on the other hand, growth decreased significantly, and the Sub-G1 phase of the cell cycle increased, indicating that the cells undergo apoptosis at a nonpermissive temperature. Histological and immunocytochemical analyses revealed that ROE2 cells at 37°C had a stratified epithelial-like morphology and expressed cytokeratins Krt4 and Krt13, marker proteins for oral nonkeratinized epithelial cells. Global-scale comprehensive microarray analysis, coupled with bioinformatics tools, demonstrated a significant gene network that was obtained from the upregulated genes. The gene network contained 16 genes, including Cdkn1a, Fos, Krt13, and Prdm1, and was associated mainly with the biological process of skin development in the category of biological functions, organ development. These four genes were validated by quantitative real-time polymerase chain reaction, and the results were nearly consistent with the microarray data. It is therefore anticipated that this cell line will be useful as an in vitro model for studies such as physiological functions, as well as for gene expression in oral epithelial cells. PMID:24521861

Tabuchi, Yoshiaki; Wada, Shigehito; Ikegame, Mika; Kariya, Ayako; Furusawa, Yukihiro; Hoshi, Nobuhiko; Yunoki, Tatsuya; Suzuki, Nobuo; Takasaki, Ichiro; Kondo, Takashi; Suzuki, Yoshihisa

2014-01-01

240

Accurate evaluation of hadronic uncertainties in spin-independent WIMP-nucleon scattering: Disentangling two- and three-flavor effects  

NASA Astrophysics Data System (ADS)

We show how to avoid unnecessary and uncontrolled assumptions usually made in the literature about soft SU(3) flavor symmetry breaking in determining the two-flavor nucleon matrix elements relevant for direct detection of weakly interacting massive particles (WIMPs). Based on SU(2) chiral perturbation theory, we provide expressions for the proton and neutron scalar couplings fup ,n and fdp ,n with the pion-nucleon ? term as the only free parameter, which should be used in the analysis of direct detection experiments. This approach for the first time allows for an accurate assessment of hadronic uncertainties in spin-independent WIMP-nucleon scattering and for a reliable calculation of isospin-violating effects. We find that the traditional determinations of fup-fun and fdp-fdn are off by a factor of 2.

Crivellin, Andreas; Hoferichter, Martin; Procura, Massimiliano

2014-03-01

241

Accurate evaluation of hadronic uncertainties in spin-independent WIMP-nucleon scattering: Disentangling two- and three-flavor effects  

E-print Network

We show how to avoid unnecessary and uncontrolled assumptions usually made in the literature about soft SU(3) flavor symmetry breaking in determining the two-flavor nucleon matrix elements relevant for direct detection of WIMPs. Based on SU(2) Chiral Perturbation Theory, we provide expressions for the proton and neutron scalar couplings $f_u^{p,n}$ and $f_d^{p,n}$ with the pion-nucleon sigma-term as the only free parameter, which should be used in the analysis of direct detection experiments. This approach for the first time allows for an accurate assessment of hadronic uncertainties in spin-independent WIMP-nucleon scattering and for a reliable calculation of isospin-violating effects. We find that the traditional determinations of $f_u^p-f_u^n$ and $f_d^p-f_d^n$ are off by a factor of 2.

Andreas Crivellin; Martin Hoferichter; Massimiliano Procura

2013-12-17

242

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

243

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

244

First measurement of the head–tail directional nuclear recoil signature at energies relevant to WIMP dark matter searches  

Microsoft Academic Search

We present first evidence for the so-called head–tail directional signature of neutron-induced nuclear recoil tracks at energies down to 1.5keV\\/amu using the DRIFT-IIc dark matter detector. This regime is appropriate for recoils induced by Weakly Interacting Massive Particle (WIMPs) but one where the differential ionization is poorly understood. We show that the distribution of recoil energies and directions induced here

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

2009-01-01

245

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

246

The role of cytidine deaminase and GATA1 mutations in the increased cytosine arabinoside sensitivity of Down syndrome myeloblasts and leukemia cell lines.  

PubMed

Myeloblasts from Down syndrome (DS) children with acute myeloid leukemia (AML) are significantly more sensitive in vitro to 1-beta-D-arabinofuranosylcytosine (ara-C) and generate higher 1-beta-D-arabinofuranosylcytosine 5'-triphosphate (ara-CTP) than non-DS AML myeloblasts. Semiquantitative reverse transcription-PCR analyses demonstrated that transcripts for cytidine deaminase (CDA) were 2.7-fold lower in DS than for non-DS myeloblasts. In contrast, transcripts of cystathionine-beta-synthase and deoxycytidine kinase were a median 12.5- and 2.6-fold higher in DS compared with non-DS myeloblasts. The ratio of deoxycytidine kinase/CDA transcripts significantly correlated with ara-C sensitivities and ara-CTP generation. In clinically relevant AML cell line models, high cystathionine-beta-synthase transcripts in DS CMK cells were accompanied by 10-fold greater ara-C sensitivity and 2.4-fold higher levels of ara-CTP compared with non-DS CMS cells. Overexpression of CDA in non-DS THP-1 cells was associated with a 100-fold decreased ara-C sensitivity and 40-fold decreased ara-CTP generation. THP-1 cells secreted CDA into the incubation media and converted extracellular ara-C completely to 1-beta-D-arabinofuranosyluracil within 30 min. Rapid amplification of 5'-cDNA ends (5'-RACE) and reverse transcription-PCR assays identified short- (sf) and long-form (lf) CDA transcripts in THP-1 cells with different 5' untranslated regions and translational start sites; however, only the latter resulted in the active CDA. Although 5' flanking sequences for both CDA transcripts exhibited promoter activity in reporter gene assays, activity for the CDAlf was low. The presence of several GATA1 binding sites in the CDAsf promoter and the uniform detection of GATA1 mutations in DS megakaryocytic leukemia suggested the potential role of GATA1 in regulating CDA transcription and the CDAsf promoter acting as an enhancer. Transfection of GATA1 into Drosophila Mel-2 cells stimulated the CDAlf promoter in a dose-dependent fashion. Additional identification of the mechanisms of differential expression of genes encoding enzymes involved in ara-C metabolism between DS and non-DS myeloblasts may lead to improvements in AML therapy. PMID:14744791

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

2004-01-15

247

Dark matter formation at Schwarz scales: primordial fog particles and WIMP superhalos  

E-print Network

Dark matter appears in two forms as a consequence of the fluid mechanics of self-gravitational condensation. Condensation occurs primarily on non-acoustic nuclei rather than on the acoustic nuclei of the Jeans (1902) criterion, leading to a very different scenario for structure formation. Viscous forces at 10^12 s (30,000 y) after the big bang permit decelerations of 10^47 kg protosupercluster plasma masses, and 10^42 kg protogalaxy masses at 10^13 s (300,000 y). Then gas formed, and all the baryonic universe became a "primordial fog" of 10^23 kg particles at the viscous Schwarz scale: 100% dark matter. Some of these H-He objects have collected to form stars, but most persist as dark dwarfs in galaxy halos. They manifest themselves in quasar microlensing observations as "rogue planets", Schild (1996), "dark galaxies", Hawkins (1996), and as comets "brought out of cold storage", O'Dell and Handron (1996). Non-baryonic WIMP fluids are superviscous, with large viscous Schwarz scales, and condense slowly to form most of the dark matter of galaxy superclusterhalos and clusterhalos.

Carl H. Gibson

1999-04-21

248

Silencing of MicroRNA-21 Confers Radio-Sensitivity through Inhibition of the PI3K/AKT Pathway and Enhancing Autophagy in Malignant Glioma Cell Lines  

PubMed Central

Radiation is a core part of therapy for malignant glioma and is often provided following debulking surgery. However, resistance to radiation occurs in most patients, and the underlying molecular mechanisms of radio-resistance are not fully understood. Here, we demonstrated that microRNA 21 (miR-21), a well-known onco-microRNA in malignant glioma, is one of the major players in radio-resistance. Radio-resistance in different malignant glioma cell lines measured by cytotoxic cell survival assay was closely associated with miR-21 expression level. Blocking miR-21 with anti-miR-21 resulted in radio-sensitization of U373 and U87 cells, whereas overexpression of miR-21 lead to a decrease in radio-sensitivity of LN18 and LN428 cells. Anti-miR-21 sustained ?-H2AX DNA foci formation, which is an indicator of double-strand DNA damage, up to 24 hours and suppressed phospho-Akt (ser473) expression after exposure to ?-irradiation. In a cell cycle analysis, a significant increase in the G2/M phase transition by anti-miR-21 was observed at 48 hours after irradiation. Interestingly, our results showed that anti-miR-21 increased factors associated with autophagosome formation and autophagy activity, which was measured by acid vesicular organelles, LC3 protein expression, and the percentage of GFP-LC3 positive cells. Furthermore, augmented autophagy by anti-miR-21 resulted in an increase in the apoptotic population after irradiation. Our results show that miR-21 is a pivotal molecule for circumventing radiation-induced cell death in malignant glioma cells through the regulation of autophagy and provide a novel phenomenon for the acquisition of radio-resistance. PMID:23077620

Jo, Guk Heui; Kim, Youn-Jae; Kwak, Hee-Jin; Kim, Jong Heon; Yin, Jinlong; Yoo, Heon; Lee, Seung Hoon; Park, Jong Bae

2012-01-01

249

Screening for (anti)androgenic properties using a standard operation protocol based on the human stably transfected androgen sensitive PALM cell line. First steps towards validation.  

PubMed

Despite more than a decade of research in the field of endocrine active compounds targeting the androgen receptor (AR), and although suitable cell lines can be obtained, no validated human stably transfected androgen sensitive transactivation assay is available. Bayer Schering Pharma (BSP) and the Flemish Institute for Technological Research (VITO), partners within the EU-sponsored 6th framework project ReProTect, made first steps towards such a validation. A standard operation protocol (SOP) developed at BSP based on the androgen sensitive PALM cell line was transferred to VITO and its performance and transferability were thoroughly studied. The investigation followed a generic protocol prepared for all reporter gene assays evaluated within ReProTect, and in both laboratories at least three independent experiments were performed. The highest concentration to be tested was limited to 10 microM, if needed. A few compounds, 17alpha-methyltestosterone (17alpha-MT), vinclozolin and linuron, were studied using a real world scenario, i.e., assuming that their interaction with the AR was not known: A prescreening for agonism and true, competitive antagonism was used to select conditions such as the appropriate mode of action, and the working range excluding cytotoxicity for the final screening. All other compounds were tested according to the generic protocol: Compounds screened for agonism were the reference androgen 17alpha-methyldihydrotestosterone (MDHT), levonorgestrel, norethynodrel, progesterone, o,p'-DDT, and dibutylphthalate (DBP), while compounds screened for antagonism were the reference anti-androgen flutamide, prochloraz, o,p'-DDT, progesterone, norethynodrel, and DBP. Cytotoxicity was assessed in parallel as lactate dehydrogenase release. The prescreen classified 17alpha-MT as androgenic, vinclozolin and linuron as anti-androgenic and compounds were tested accordingly. In the absence of cytotoxicity, appropriate androgenic properties of reference and test compounds were detected by both laboratories, o,p'-DDT and DBP had no androgenic activity. Across the two laboratories EC(50)-values for MDHT, 17alpha-MT, and levonorgestrel varied by not more than a factor of 3.4, for norethynodrel by a factor of 9.7. Progesterone effects could not fully be evaluated, as frequently concentration response curves were incomplete. In the absence of cytotoxicity anti-androgenic properties of reference and test compounds were also detected in both laboratories. DBP, the putative negative reference compound, was inactive, norethynodrel rather showed agonistic properties. Progesterone was an antagonist at low concentrations, but agonistic properties were observed in one laboratory at high concentrations. Since the highest test concentration was limited to 10 microM, for some compounds no complete concentration response curves were obtained and estimation of EC(50)-values was less robust. Our data demonstrated that the SOP was transferable, and that the assay was able to rank compounds with strong, weak, and without affinity for the AR and to discriminate agonists and antagonists. The sensitivity of the assay could be improved further, if the limit of solubility or beginning cytotoxicity was chosen as the highest test concentration. The assay avoids the use of tissues from laboratory animals, and thus contributes to the 3R concept. Furthermore, it could be adjusted to an intermediate/high throughput format. On the whole, this PALM assay is a promising candidate for further validation. PMID:19836445

Freyberger, A; Witters, H; Weimer, M; Lofink, W; Berckmans, P; Ahr, H-J

2010-08-01

250

Effects of Residue Background Events in Direct Dark Matter Detection Experiments on the Reconstruction of the Velocity Distribution Function of Halo WIMPs  

E-print Network

In our earlier work on the development of a model-independent data analysis method for reconstructing the (moments of the) time-averaged one-dimensional velocity distribution function of Weakly Interacting Massive Particles (WIMPs) by using measured recoil energies from direct Dark Matter detection experiments directly, it was assumed that the analyzed data sets are background-free, i.e., all events are WIMP signals. In this article, as a more realistic study, we take into account a fraction of possible residue background events, which pass all discrimination criteria and then mix with other real WIMP-induced events in our data sets. Our simulations show that, for the reconstruction of the one-dimensional WIMP velocity distribution, the maximal acceptable fraction of residue background events in the analyzed data set(s) of O(500) total events is ~10% - 20%. For a WIMP mass of 50 GeV with a negligible uncertainty and 20% residue background events, the deviation of the reconstructed velocity distribution would in principle be ~7.5% with a statistical uncertainty of ~18% (~19% for a background-free data set).

Chung-Lin Shan

2010-03-27

251

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

252

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

253

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) to indirectly detect weakly interacting massive particles (WIMPs) through the {gamma}-ray signal that their pair annihilation produces. WIMPs are among the favorite candidates to explain 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.; /SLAC /KIPAC, Menlo Park; Bertone, G.; /Paris, Inst. Astrophys.; Bergstrom, L.; /Stockholm U.; Bloom, E.; /SLAC /KIPAC, Menlo Park; Bringmann, T.; /Stockholm U.; Chiang, J.; Cohen-Tanugi, J.; /SLAC /KIPAC, Menlo Park; Conrad, J.; /Stockholm U.; Edmonds, Y.; /SLAC /KIPAC, Menlo Park; Edsjo, J.; /Stockholm U.; Godfrey, G.; /SLAC /KIPAC, Menlo Park; Hughes, R.E.; /Ohio State U.; Johnson, R.P.; /UC, Santa Cruz; Lionetto, A.; /Rome U.,Tor Vergata /INFN, Rome2; Moiseev, A.A.; /CRESST; Morselli, A.; /Rome U.,Tor Vergata /INFN, Rome2; Moskalenko, I.V.; /Stanford U., HEPL /KIPAC, Menlo Park; Nuss, E.; /Montpellier U.; Ormes, J.F.; /Denver U.; Rando, R.; /INFN, Padua /Ohio State U. /Stockholm U. /Ohio State U. /Garching, Max Planck Inst., MPE /SLAC /KIPAC, Menlo Park /Ohio State U.

2009-05-15

254

NADPH-oxidase and a Hydrogen Peroxide-Sensitive K+ Channel May Function as an Oxygen Sensor Complex in Airway Chemoreceptors and Small Cell Lung Carcinoma Cell Lines  

Microsoft Academic Search

Pulmonary neuroepithelial bodies (NEB) are widely distributed throughout the airway mucosa of human and animal lungs. Based on the observation that NEB cells have a candidate oxygen sensor enzyme complex (NADPH oxidase) and an oxygen-sensitive K+ current, it has been suggested that NEB may function as airway chemoreceptors. Here we report that mRNAs for both the hydrogen peroxide sensitive voltage

Dashou Wang; Charlotte Youngson; Veronica Wong; Herman Yeger; Mary C. Dinauer; Eleazar Vega-Saenz de Miera; Bernardo Rudy; Ernest Cutz

1996-01-01

255

Upper bounds on signals due to WIMP self--annihilation: comments on the case of the synchrotron radiation from the galactic center and the WMAP haze  

E-print Network

Two recent papers reconsider the possibility that the excess of microwave emission from a region within $\\sim 20^0$ of the galactic center (the {\\it WMAP haze}), measured by WMAP, can be due to the synchrotron emission originated by neutralino self-annihilation; on the basis of this possible occurrence, also upper bounds on the neutralino self-annihilation cross--section are suggested. In the present note, we show that in the common case of thermal WIMPs in a standard cosmological model, when the rescaling of the galactic WIMP density is duly taken into account for subdominant WIMPs, the upper bound applicable generically to {\\it any} signal due to self-conjugate WIMPs is more stringent than the ones obtained from analysis of the WMAP haze. We also argue that an experimental upper bound, which can compete with our generic upper limit, can rather be derived from measurements of cosmic antiproton fluxes, for some values of the parameters of the astrophysical propagation model. Finally, we comment on the possible impact of our generic upper bound on the interpretation of the WMAP haze in terms of thermal neutralinos in a standard cosmological scheme.

A. Bottino; F. Donato; N. Fornengo; S. Scopel

2008-02-05

256

Primary Cervical Carcinoma Cell Lines Overexpress Epithelial Cell Adhesion Molecule (EpCAM) and Are Highly Sensitive to Immunotherapy With MT201, a Fully Human Monoclonal Anti-EpCAM Antibody  

PubMed Central

Introduction Epithelial cell adhesion molecule (EpCAM) is a surface glycoprotein highly differentially expressed in many epithelial malignancies. The goal of this study was to evaluate the expression of EpCAM and the potential of MT201 (adecatumumab), a human monoclonal antibody targeting EpCAM, against multiple primary cervical carcinoma cell lines. Methods Epithelial cell adhesion molecule expression was evaluated by real-time polymerase chain reaction and flow cytometry in a total of 8 primary cervical cancer cell lines. Sensitivity to MT201-mediated cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity was tested in standard 4-hour 51Cr release assays. To investigate the effect of interleukin-2 (IL-2) on MT201-mediated ADCC, 4-hour 51Cr release assays were also conducted in the presence of low doses of IL-2. Results High messenger RNA expression by real-time polymerase chain reaction and high EpCAM surface expression by flow cytometry were detected in 4 (50%) of 8 primary cervical carcinoma cell lines. With no exception, the primary cell lines derived from clinically aggressive tumors showed EpCAM overexpression. Whereas these cell lines were highly resistant to complement-dependent cytotoxicity and natural killer (NK)-dependent cytotoxicity in vitro (range of killing, 4%–19%), EpCAM-positive cell lines showed high sensitivity to MT201-mediated ADCC (range of killing, 23%–59%). Incubation with IL-2 in addition to MT201 significantly increased the cytotoxic activity against EpCAM-positive cervical cancer cell lines (P = 0.007). Addition of human serum also further increased the MT201-mediated killing of EpCAM-positive cell lines (P = 0.03). Conclusions Epithelial cell adhesion molecule is highly expressed in primary cervical carcinoma cell lines, and these biologically aggressive tumors are highly sensitive to MT201-mediated cytotoxicity in vitro. MT201 may represent a novel, potentially highly effective treatment option for patients with cervical carcinoma, especially for those with advanced, recurrent, or metastatic disease refractory to standard salvage therapy. PMID:21370592

Richter, Christine E.; Cocco, Emiliano; Bellone, Stefania; Bellone, Marta; Casagrande, Francesca; Todeschini, Paola; Ruttinger, Dominik; Silasi, Dan-Arin; Azodi, Masoud; Schwartz, Peter E.; Rutherford, Thomas J.; Pecorelli, Sergio; Santin, Alessandro D.

2013-01-01

257

Downregulation of BRCA1 in A375 Melanoma Cell Line Increases RadioSensitivity and Modifies Metastatic and Angiogenic Gene Expression  

Microsoft Academic Search

The participation of BRCA1 (breast cancer 1) in DNA repair is well established, especially in mammary and ovarian cells. Our purpose was to develop a new in vivo radio-sensitizing therapy for melanoma. We therefore investigated the effect of downregulation of BRCA1 on irradiated melanoma cells using an anti-BRCA1 ribozyme. Our results show that BRCA1 downregulation increased radio-sensitivity of the A375

Cédric Hesling; Michel D'Incan; Chantal D'Incan; Pierre Souteyrand; Jean-Claude Monboisse; Sylvie Pasco; Jean-Claude Madelmont; Yves Jean Bignon

2004-01-01

258

Multidrug Resistance-associated Protein Gene Overexpression and Reduced Drug Sensitivity of Topoisomerase II in a Human Breast Carcinoma MCF7 Cell Line Selected for Etoposide Resistance  

Microsoft Academic Search

A human breast cancer cell line (MCF7\\/WT) was selected for resistance to etoposide (VP-16) by stepwise exposure to 2-fold increasing concentra- tions of this agent. The resulting cell line (MCF7\\/VP) was 28-, 21-, and 9-fold resistant to VP-16, VM-26, and doxorubicin, respectively. MCF7\\/VP cells also exhibited low-level cross-resistance to 4'-(9-acridinylamino)- methanesulfon-m-anisidide, mitoxantrone, and vincristine and no cross- resistance to genistein

Erasmus Schneider; Julie K. Horton; Chih-Hsin Yang; Masayuki Nakagawa; Kenneth H. Cowan

1994-01-01

259

High-Sensitivity Peptide Mapping by Micro-LC with On-Line Membrane Blotting and Subsequent Detection by Scanning-IR-MALDI Mass Spectrometry  

Microsoft Academic Search

A novel approach to the on-line mass determination of peptides from digested proteins by scanning infrared matrix-assisted laser desorption\\/ionization (scanning-IR-MALDI) is described. The peptides were continuously collected directly onto a PVDF (polyvinylidene fluoride) strip during a HPLC run. Individual peptides were detected by lining up the PVDF strip with the UV trace from the HPLC run, using visible dye markers

Christoph Eckerskorn; Kerstin Strupat; Josef Kellermann; Friedrich Lottspeich; Franz Hillenkamp

1997-01-01

260

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

261

Rapid, sensitive and on-line measurement of chemical oxygen demand by novel optical method based on UV photolysis and chemiluminescence  

Microsoft Academic Search

A novel on-line method based on the combination of UV photolysis and chemiluminescence detection was established and experimentally validated for the determination of chemical oxygen demand (COD). A quantitative amount of free radicals can be produced by analytes in the UV irradiation process. By utilizing the phenomenon that luminol can be oxidized by the free radicals to produce luminescence, COD

Yingying Su; Xiaohong Li; He Chen; Yi Lv; Xiandeng Hou

2007-01-01

262

Pharmacological inhibition of the MAPK\\/ERK pathway increases sensitivity to 2-chloro-2?-deoxyadenosine (CdA) in the B-cell leukemia cell line EHEB  

Microsoft Academic Search

EHEB leukemic cells, which are derived from a patient suffering B-cell chronic lymphocytic leukemia (B-CLL), display intermediate sensitivity to the purine analogue 2-chloro-2?-deoxyadenosine (CdA). Because the mitogen-activated protein kinase (MAPK)\\/extracellular signal-regulated kinase (ERK) pathway can rescue cancer cells from apoptotic signals, we investigated MAPK\\/ERK signaling in EHEB cells in response to CdA. We observed that CdA, at concentrations around its

Caroline Smal; Stéphanie Lisart; Marie Maerevoet; Augustin Ferrant; Françoise Bontemps; Eric Van Den Neste

2007-01-01

263

Reduced sensitivity to linguistic context in schizophrenic thought disorder: Evidence from on-line monitoring for words in linguistically anomalous sentences  

Microsoft Academic Search

The use of linguistic context in positively thought-disordered (TD) schizophrenics was investigated through examination of their performance on an on-line word-monitoring task. Controls and non- TD schizophrenics took longer to recognize words preceded by linguistic anomalies compared with words in normal sentences. Compared with both other groups, TD schizophrenics showed signifi- cantly smaller differences in reaction time, suggesting that they

Gina R. Kuperberg; Philip K. McGuire; Anthony S. David

1998-01-01

264

Validation of real-time RT-PCR for analysis of human breast cancer cell lines resistant or sensitive to treatment with antiestrogens.  

PubMed

Using a quantitative real-time RT-PCR technique we have compared the expression of a number of genes in two different human breast cancer model systems for development of acquired resistance to antiestrogens. The model system developed at the Danish Cancer Society comprises the cell lines MCF-7, MCF-7/TAMR-1, MCF-7/182R-6 and MCF-7/182R-7, and the model system developed at the Lombardi Cancer Research Center consists of the cell lines MCF-7/LCC1, MCF-7/LCC2 and MCF-7/LCC9. The findings on the well-known parameters estrogen receptor (ER)alpha, progesterone receptor (PR) and epidermal growth factor receptor (EGFR) are in good agreement with previous reports, thus documenting the usefulness of the real-time RT-PCR technique for multiparametric RNA analysis. The gene expression levels in the two model systems were found to be quite similar in relation to ERalpha, AIB1 (amplified in breast cancer-1), breast cancer antiestrogen resistance gene 1 (BCAR1) and ErbB-2 mRNA expression, whereas significant differences were observed on the expression of ERbeta, multidrug resistance gene 1 (MDR1), PR and EGFR. Furthermore, the presented data suggest that ERbeta, AIB1, BCAR1, CYP19 and MDR1 are unlikely to be causally involved in development of antiestrogen resistance in these breast cancer cell lines. PMID:14503918

de Cremoux, P; Tran-Perennou, C; Brockdorff, B L; Boudou, E; Brünner, N; Magdelénat, H; Lykkesfeldt, A E

2003-09-01

265

Dark matter sensitivities of the Majorana Demonstrator  

NASA Astrophysics Data System (ADS)

The Majorana Demonstrator is an array of natural and enriched high purity germanium detectors that will search for the neutrinoless double-beta decay of Germanium-76 and perform a search for weakly interacting massive particles with masses below 10 GeV. To reach the background rate goal in the neutrinoless double-beta decay region of interest of 4 counts/keV/t/y, the DEMONSTRATOR will utilize a number of background reduction strategies, including a time-correlated event cut for 68Ge that requires a sub-keV energy threshold. This low energy threshold allows the DEMONSTRATOR to extend its physics reach to include a search for light WIMPs. We will discuss the detector systems and data analysis techniques required to achieve sub-keV thresholds as well as present the projected dark matter sensitivities of the Majorana Demonstrator.

Giovanetti, G. K.; Aguayo, E.; Avignone, F. T., Iii; Back, H. O.; Barabash, A. S.; Beene, J. R.; Bergevin, M.; Bertrand, F. E.; Boswell, M.; Brudanin, V.; Busch, M.; Chan, Y.-D.; Christofferson, C. D.; Collar, J. I.; Combs, D. C.; Cooper, R. J.; Detwiler, J. A.; Doe, P. J.; Efremenko, Yu; Egorov, V.; Ejiri, H.; Elliott, S. R.; Esterline, J.; Fast, J. E.; Fields, N.; Finnerty, P.; Fraenkle, F. M.; Gehman, V. M.; Green, M. P.; Guiseppe, V. E.; Gusey, K.; Hallin, A. L.; Hazama, R.; Henning, R.; Hoppe, E. W.; Horton, M.; Howard, S.; Howe, M. A.; Johnson, R. A.; Keeter, K. J.; Keller, C.; Kidd, M. F.; Knecht, A.; Kochetov, O.; Konovalov, S. I.; Kouzes, R. T.; LaFerriere, B. D.; LaRoque, B. H.; Leon, J.; Leviner, L. E.; Loach, J. C.; MacMullin, S.; Marino, M. G.; Martin, R. D.; Mei, D.-M.; Merriman, J. H.; Miller, M. L.; Mizouni, L.; Nomachi, M.; Orrell, J. L.; Overman, N. R.; Phillips, D. G., Ii; Poon, A. W. P.; Perumpilly, G.; Prior, G.; Radford, D. C.; Rielage, K.; Robertson, R. G. H.; Ronquest, M. C.; Schubert, A. G.; Shima, T.; Shirchenko, M.; Snavely, K. J.; Steele, D.; Strain, J.; Thomas, K.; Timkin, V.; Tornow, W.; Vanyushin, I.; Varner, R. L.; Vetter, K.; Vorren, K.; Wilkerson, J. F.; Yakushev, E.; Young, A. R.; Yu, C.-H.; Yumatov, V.; Zhang, C.

2012-07-01

266

Genetic Variants in Cytosolic 5?-Nucleotidase II Are Associated with Its Expression and Cytarabine Sensitivity in HapMap Cell Lines and in Patients with Acute Myeloid LeukemiaS?  

PubMed Central

Cytosolic 5?-nucleotidase II (NT5C2) is involved in the development of 1-?-d-arabinofuranosylcytosine (ara-C) resistance and has been associated with clinical outcome in patients receiving ara-C-based chemotherapy. NT5C2 inactivates ara-C by dephosphorylating ara-C monophosphate to ara-C. In this study, we sequenced NT5C2 in genomic DNA samples from International HapMap project panels with European [Centre d'Etude du Polymorphisme Humain (CEU); n = 90] or African [Yoruba people in Ibadan, Nigeria (YRI); n = 90] ancestry. We identified 41 genetic variants [one insertion-deletion and 40 single nucleotide polymorphisms (SNPs)], including three nonsynonymous SNPs (Y3A, K47R, and Q136R). Twenty-five SNPs were novel and 16 overlapped with the HapMap data. Subjects with African ancestry had NT5C2 mRNA expression levels that was significantly higher than those with European ancestry (p = 0.005). Furthermore, there was a correlation between NT5C2 mRNA expression and ara-C sensitivity in CEU but not in YRI cell lines. None of the nonsynonymous SNPs demonstrated any effect on NT5C2 activity. The genotypes of several SNPs were significantly associated with NT5C2 mRNA expression and/or ara-C sensitivity in CEU cell lines, but very few were significant in YRI cell lines. Of most interest, SNPs (linkage disequilibrium group CEU.12) in the 5?-untranslated region were associated with NT5C2 expression and ara-C sensitivity in HapMap cell lines and with NT5C2 mRNA expression and ara-C sensitivity in diagnostic leukemic blasts from pediatric patients with acute myeloid leukemia. Functional genomics analysis demonstrated that the promoter SNP rs11191612 was associated with altered luciferase activation in reporter assays and altered DNA-protein binding in gel shift assays. These results suggest that genetic variations in NT5C2 influence its expression and, potentially, cellular responses to nucleoside analogs. PMID:21712425

Mitra, Amit K.; Crews, Kristine R.; Pounds, Stanley; Cao, Xueyuan; Feldberg, Tanya; Ghodke, Yogita; Gandhi, Varsha; Plunkett, William; Dolan, M. Eileen; Hartford, Christine; Raimondi, Susana; Campana, Dario; Downing, James; Rubnitz, Jeffrey E.; Ribeiro, Raul C.

2011-01-01

267

High-grade, chemotherapy-resistant primary ovarian carcinoma cell lines overexpress human trophoblast cell-surface marker (Trop-2) and are highly sensitive to immunotherapy with hRS7, a humanized monoclonal anti-Trop-2 antibody  

PubMed Central

Objective We evaluated the expression of human trophoblast cell-surface marker (Trop-2) and the potential of hRS7, a humanized monoclonal anti-Trop-2 antibody, as a therapeutic agent against chemotherapy-resistant ovarian disease. Methods Trop-2 expression was evaluated by immunohistochemistry (IHC) in 50 ovarian serous papillary carcinoma specimens. Trop-2 expression was also evaluated by real-time PCR (qRT-PCR) and flow cytometry in a total of 6 primary ovarian cancer cell lines derived from patients with chemotherapy-resistant disease. Sensitivity to hRS7 antibody-dependent cellular cytotoxicity (ADCC) was tested in standard 5-hours 51Cr-release assays. The effect of serum and interleukin-2 (IL-2) on hRS7-mediated ADCC was also studied. Results Trop-2 expression was found in 41 of 50 (82%) tumor tissues tested by IHC. 83% (5 of 6) of the ovarian cancer cell lines tested by qRT-PCR and flow cytometry demonstrated high Trop-2 expression. All primary ovarian cancer cell lines expressing Trop-2 were highly sensitive to hRS7-mediated ADCC in vitro (range of killing: 19.3% to 40.8%) (p<0.001). Negligible cytotoxicity against chemotherapy-resistant ovarian cancers was seen in the absence of hRS7 or in the presence of rituximab control antibody (range of killing: 1.1% to 8.9%). Human serum did not significantly inhibit hRS7-mediated-cytotoxicity while incubation with IL-2 in addition to hRS7 further increased the cytotoxic activity (p=0.04). Conclusions Trop-2 is highly expressed in chemotherapy-resistant ovarian cancer cell lines at mRNA and protein levels. Primary ovarian carcinoma cell lines are highly sensitive to hRS7-mediated cytotoxicity in vitro. hRS7 may represent a novel therapeutic agent for the treatment of high-grade, chemotherapy-resistant ovarian cancer. PMID:21453957

Varughese, Joyce; Cocco, Emiliano; Bellone, Stefania; Bellone, Marta; Todeschini, Paola; Carrara, Luisa; Schwartz, Peter E.; Rutherford, Thomas J.; Pecorelli, Sergio; Santin, Alessandro D.

2011-01-01

268

$B_s \\to ?^+ ?^-$ 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

269

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

270

The Stream algorithm: computationally efficient ridge-regression via Bayesian model averaging, and applications to pharmacogenomic prediction of cancer cell line sensitivity.  

PubMed

Computational efficiency is important for learning algorithms operating in the "large p, small n" setting. In computational biology, the analysis of data sets containing tens of thousands of features ("large p"), but only a few hundred samples ("small n"), is nowadays routine, and regularized regression approaches such as ridge-regression, lasso, and elastic-net are popular choices. In this paper we propose a novel and highly efficient Bayesian inference method for fitting ridge-regression. Our method is fully analytical, and bypasses the need for expensive tuning parameter optimization, via cross-validation, by employing Bayesian model averaging over the grid of tuning parameters. Additional computational efficiency is achieved by adopting the singular value decomposition reparametrization of the ridge-regression model, replacing computationally expensive inversions of large p × p matrices by efficient inversions of small and diagonal n × n matrices. We show in simulation studies and in the analysis of two large cancer cell line data panels that our algorithm achieves slightly better predictive performance than cross-validated ridge-regression while requiring only a fraction of the computation time. Furthermore, in comparisons based on the cell line data sets, our algorithm systematically out-performs the lasso in both predictive performance and computation time, and shows equivalent predictive performance, but considerably smaller computation time, than the elastic-net. PMID:24297531

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

2014-01-01

271

Different target range and cytotoxic specificity of adaphostin and 17-allylamino-17-demethoxygeldanamycin in imatinib-resistant and sensitive cell lines.  

PubMed

Imatinib mesylate is a selective inhibitor of the oncogenic tyrosine kinase, Bcr-Abl, and is widely used as a first-line treatment for chronic myeloid leukaemia (CML). Prolonged monotherapy is frequently associated with patients becoming refractory to imatinib. Therefore, there is considerable interest in small molecule inhibitors which may be used either as replacements or as adjuncts to existing imatinib therapy. For this purpose, it is most likely that drugs which do not share imatinib's mechanism of action will be most valuable. We compared two such compounds with different modes of action, adaphostin and 17-allylamino-17-demethoxygeldanamycin (17-AAG), for their cytotoxic effect and ability to induce the downregulation of cellular proteins in a murine haemopoietic cell line transformed with human p210(Bcr-Abl), and two subclones resistant to imatinib owing to an Abl-kinase domain mutation (E255K) or amplification of the BCR-ABL gene, respectively. We found that, whereas 17-AAG selectively killed Bcr-Abl-positive cells and inhibited proteins dependent on heat-shock protein 90 for their stability (p210(Bcr-Abl) and Akt), adaphostin induced the downregulation of multiple cell-signalling proteins (p210(Bcr-Abl), Akt, Bcr, Abl and STAT5a) and was cytotoxic to both Bcr-Abl-positive and -negative cells. We suggest that both compounds may prove useful in the treatment of CML but caution that undesirable side-effects may result from the inhibition of multiple cell signalling proteins. PMID:17252018

Barnes, D J; De, S; van Hensbergen, P; Moravcsik, E; Melo, J V

2007-03-01

272

Improvement of the sensitivity of 2D LC-MEKC separation of phenolic acids and flavonoids natural antioxidants using the on-line preconcentration step.  

PubMed

A 2D method was developed for separation of phenolic acids and flavonoids natural antioxidants combining LC with MEKC. The in-capillary preconcentration step was applied for the improvement of the sensitivity of 2D method before the second dimension MEKC analysis. The influence of first dimension LC mobile phase composition on migration times in the second MEKC dimension was evaluated. When gradient elution is applied in the first dimension of 2D LC-MEKC system, increasing concentration of organic solvent in the mobile phase and in fractions transferred from LC influences the electroosmotic flow, partitioning equilibria of samples in micelles and properties of the micelles, which results in shifts of migration times during the consecutive runs in the second MEKC separation dimension. The shifts of migration times caused by the influence of increasing concentration of ACN on MEKC separation in second dimension of 2D LC-MEKC system were compensated by aligning the time axis using electroosmotic flow and micellar marker migration times. The optimized LC-MEKC method was applied on the separation of natural antioxidants in the plant extracts samples. PMID:22887169

Cesla, Petr; Fischer, Jan; Jandera, Pavel

2012-08-01

273

IRE1 inhibition perturbs the unfolded protein response in a pancreatic ?-cell line expressing mutant proinsulin, but does not sensitize the cells to apoptosis  

PubMed Central

Background The Akita mutation (C96Y) in the insulin gene results in early onset diabetes in both humans and mice. Expression of mutant proinsulin (C96Y) causes endoplasmic reticulum (ER) stress in pancreatic ?-cells and consequently the cell activates the unfolded protein response (UPR). Since the proinsulin is terminally misfolded ER stress is irremediable and chronic activation of the UPR eventually activates apoptosis in some cells. Here we analyzed the IRE1-dependent activation of genes in response to misfolded proinsulin production in an inducible mutant proinsulin (C96Y) insulinoma cell line. Results The IRE1 endoribonuclease inhibitors 4?8c and MKC-3946 prevented the splicing of the XBP1 mRNA in response to ER stress caused by mutant proinsulin production. Microarray expression analysis and qPCR validation of select genes revealed that maximal upregulation of many UPR genes in response to mutant proinsulin production required IRE1, although most were still increased above control. Interestingly, neither degradation of misfolded proinsulin via ER-associated degradation (ERAD), nor apoptosis induced by prolonged misfolded proinsulin expression were affected by inhibiting IRE1. Conclusions Although maximal induction of most UPR genes requires IRE1, inhibition of IRE1 does not affect ERAD of misfolded proinsulin or predispose pancreatic ?-cells expressing misfolded proinsulin to chronic ER stress-induced apoptosis. PMID:25011481

2014-01-01

274

Novel type of Gq/11 protein-coupled neurosteroid receptor sensitive to endocrine disrupting chemicals in mast cell line (RBL-2H3)  

PubMed Central

Agonistic neurosteroids, including pregnenolone, dehydroepiandrosterone and its sulfate (DHEAS), caused rapid degranulation in measurements of ?-hexosaminidase (?-HEX) release from a mast cell line, RBL-2H3. This degranulation was blocked by BSA-conjugated progesterone (PROG-BSA) or 17?-estradiol, both of which are antagonistic neurosteroids. DHEAS-induced ?-HEX release was blocked by U-73122 or xestospongin C, but not by PTX or EGTA. DHEAS-induced ?-HEX release was also abolished by Gq/11-AS, but not by Gq/11-MS. Pharmacological analyses revealed that the neurosteroids stimulated a putative membrane receptor through activation of the novel Gq/11 and phospholipase C. While representative endocrine-disrupting chemicals (EDCs) did not show any degranulation or nocifensive actions by themselves, they blocked the DHEAS-induced degranulation. The binding of a PROG-BSA-fluorescein isothiocyanate conjugate (PROG-BSA-FITC) to cells was inhibited by neurosteroids and EDCs. In the algogenic-induced biting and licking responses test, DHEAS caused agonistic nocifensive actions in a dose-dependent manner between 1 and 10?fmol (i.pl.). DHEAS-induced nocifensive actions were abolished by PROG-BSA or nonylphenol. Taken together, these results suggest that a Gq/11-coupled neurosteroid receptor may regulate the neuroimmunological activity related to sensory stimulation and that some EDCs have antagonistic actions for this receptor. PMID:15821754

Mizota, Kaori; Yoshida, Akira; Uchida, Hitoshi; Fujita, Ryousuke; Ueda, Hiroshi

2005-01-01

275

A sensitive emulsification liquid phase microextraction coupled with on-line phase separation followed by HPLC for trace determination of sulfonamides in water samples.  

PubMed

For the first time, ion-pair based emulsification liquid phase microextraction coupled with a novel approach for phase separation followed by high performace liquid chromatgraphy (HPLC) was utilized for trace determination of sulfonamides in water samples. After the formation of ion-pair complex with a cationic surfactant, sulfonamides were extracted into the drops of dispersed organic extracting solvent. Then, the cloudy solution was passed through an in-line filter located in a suitable holder and was separated based on emulsion filtration. By changing the HPLC valve position, the filter was laid in the mobile phase path, and the extraction phase was eluted by the mobile phase and introduced into the separation column for analysis. The effects of important parameters, such as type of extraction solvent, type of ion-pair agent and its concentration, pH of sample solution, ionic strength, and volume of extraction phase, on the extraction efficiency, were investigated and optimized. Under optimal conditions, the linear range, limits of detection, and precision (relative standard deviations) were 0.3-100, 0.1-0.3 ?g L(-1), and 4.7-5.8 %, respectively. Preconcentration factors (PFs) for the compounds studied were obtained in the range of 268-664. These PFs correspond to extraction recoveries in the range of 41-97 %. The sample throughput of the method was 3 samples per hour, regarding 20 min analysis time for a single procedure. Finally, the method was successfully applied to determine the selected sulfonamides in some water samples. PMID:25427828

Ebrahimpour, Behnam; Yamini, Yadollah; Rezazadeh, Maryam

2015-01-01

276

Impact of polyglutamation on sensitivity to raltitrexed and methotrexate in relation to drug-induced inhibition of de novo thymidylate and purine biosynthesis in CCRF-CEM cell lines.  

PubMed

The aim of this study was to investigate the influence of folylpolyglutamyl synthetase (FPGS) activity on the cellular pharmacology of the classical antifolates raltitrexed and methotrexate (MTX) using two human leukemia cell lines, CCRF-CEM and CCRF-CEM:RC2Tomudex. Cell growth inhibition and drug-induced inhibition of de novo thymidylate and purine biosynthesis were used as measures of the cellular effects of the drugs. CCRF-CEM:RC2Tomudex cells had <11% of the FPGS activity of CCRF-CEM cells, whereas MTX uptake and TS activity were equivalent. In CCRF-CEM:RC2Tomudex cells, MTX polyglutamate formation was undetectable after exposure to 1 microM [3H]MTX for 24 h. After exposure to 0.1 microM raltitrexed, levels of total intracellular raltitrexed-derived material in CCRF-CEM:RC2Tomudex cells were 30- to 50-fold lower than in the CCRF-CEM cell line. CCRF-CEM: RC2Tomudex cells were >1000-fold resistant to raltitrexed and 6-fold resistant to lometrexol but sensitive to MTX and nolatrexed when exposed to these antifolates for 96 h. After 6 h of exposure, CCRF-CEM cells retained sensitivity to MTX and raltitrexed but were less sensitive to lometrexol-mediated growth inhibition. In contrast, CCRF-CEM: RC2Tomudex cells were markedly insensitive to raltitrexed, lometrexol, and to a lesser degree, MTX. Simultaneous measurement of de novo thymidylate and purine biosynthesis revealed 90% inhibition of TS activity by 100 nM MTX in both cell lines, whereas inhibition of de novo purine synthesis was only observed in CCRF-CEM cells, and only after exposure to 1000 nM MTX. Ten nM raltitrexed induced >90% inhibition of TS activity in CCRF-CEM cells, whereas in CCRF-CEM:RC2Tomudex cells, there was no evidence of inhibition after exposure to 1000 nM raltitrexed. These studies demonstrate that polyglutamation is a critical determinant of the cellular pharmacology of both raltitrexed and MTX, markedly influencing potency in the case of raltitrexed and locus of action in the case of MTX. PMID:10499632

Barnes, M J; Estlin, E J; Taylor, G A; Aherne, G W; Hardcastle, A; McGuire, J J; Calvete, J A; Lunec, J; Pearson, A D; Newell, D R

1999-09-01

277

Targeting MAGE-C1/CT7 Expression Increases Cell Sensitivity to the Proteasome Inhibitor Bortezomib in Multiple Myeloma Cell Lines  

PubMed Central

The MAGE-C1/CT7 encodes a cancer/testis antigen (CTA), is located on the chromosomal region Xq26–27 and is highly polymorphic in humans. MAGE-C1/CT7 is frequently expressed in multiple myeloma (MM) that may be a potential target for immunotherapy in this still incurable disease. MAGEC1/CT7 expression is restricted to malignant plasma cells and it has been suggested that MAGE-C1/CT7 might play a pathogenic role in MM; however, the exact function this protein in the pathophysiology of MM is not yet understood. Our objectives were (1) to clarify the role of MAGE-C1/CT7 in the control of cellular proliferation and cell cycle in myeloma and (2) to evaluate the impact of silencing MAGE-C1/CT7 on myeloma cells treated with bortezomib. Myeloma cell line SKO-007 was transduced for stable expression of shRNA-MAGE-C1/CT7. Downregulation of MAGE-C1/CT7 was confirmed by real time quantitative PCR and western blot. Functional assays included cell proliferation, cell invasion, cell cycle analysis and apoptosis. Western blot showed a 70–80% decrease in MAGE-C1/CT7 protein expression in inhibited cells (shRNA-MAGE-C1/CT7) when compared with controls. Functional assays did not indicate a difference in cell proliferation and DNA synthesis when inhibited cells were compared with controls. However, we found a decreased percentage of cells in the G2/M phase of the cell cycle among inhibited cells, but not in the controls (p<0.05). When myeloma cells were treated with bortezomib, we observed a 48% reduction of cells in the G2/M phase among inhibited cells while controls showed 13% (empty vector) and 9% (ineffective shRNA) reduction, respectively (p<0.01). Furthermore, inhibited cells treated with bortezomib showed an increased percentage of apoptotic cells (Annexin V+/PI-) in comparison with bortezomib-treated controls (p<0.001). We found that MAGE-C1/CT7 protects SKO-007 cells against bortezomib-induced apoptosis. Therefore, we could speculate that MAGE-C1/CT7 gene therapy could be a strategy for future therapies in MM, in particular in combination with proteasome inhibitors. PMID:22110734

de Carvalho, Fabricio; Costa, Erico T.; Camargo, Anamaria A.; Gregorio, Juliana C.; Masotti, Cibele; Andrade, Valeria C.C.; Strauss, Bryan E.; Caballero, Otavia L.; Atanackovic, Djordje; Colleoni, Gisele W.B.

2011-01-01

278

Sensitive Agent: Sensitive Agent  

E-print Network

social interaction must be simulated. Conventional agents already have rich communication skills including nonverbal communication; however, lack the sensitivity that is necessary for social interaction-78. [13] MIT, Affective Computing, http://affect.media.mit.edu/AC_affect.html [14] Helmut Prendinger

Nakanishi, Hideyuki

279

Development of bubble chambers with enhanced stability and sensitivity to low-energy nuclear recoils  

NASA Astrophysics Data System (ADS)

The viability of using Bubble Chambers as dark matter particle detectors is considered. Techniques leading to the enhanced chamber stability needed for this new application are described in detail. Prototype trials show that sensitivity to the low-energy nuclear recoils induced by Weakly Interacting Massive Particles (WIMP) is possible in conditions of extreme insensitivity to minimum ionizing backgrounds. An understanding of detector response is demonstrated using existing theoretical models. We briefly comment on the prospects for detection of supersymmetric dark matter with large CF3I chambers.

Bolte, W. J.; Collar, J. I.; Crisler, M.; Hall, J.; Holmgren, D.; Nakazawa, D.; Odom, B.; O'Sullivan, K.; Plunkett, R.; Ramberg, E.; Raskin, A.; Sonnenschein, A.; Vieira, J. D.

2007-07-01

280

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

SciTech Connect

Multiple lines of evidence indicate an anomalous injection of high-energy e{sup +}e{sup -} in the galactic halo. The recent e{sup +} 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{sup +}e{sup -} 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{sup +}e{sup -} (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; Goodenough, Lisa; Weiner, Neal [Center for Cosmology and Particle Physics, Department of Physics, New York University, New York, New York 10003 (United States); Dobler, Gregory; Finkbeiner, Douglas P. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138 (United States)

2009-12-15

281

The chemotherapy of rodent malaria. XLIX. The activities of some synthetic 1,2,4-trioxanes against chloroquine-sensitive and chloroquine-resistant parasites. Part 2: Structure-activity studies on cis-fused cyclopenteno-1,2,4-trioxanes (fenozans) against drug-sensitive and drug-resistant lines of Plasmodium berghei and P. yoelii ssp. NS in vivo.  

PubMed

The activity of 51 synthetic cis-fused cyclopenteno-1,2,4-trioxanes has been examined against drug-sensitive and chloroquine-resistant malaria parasites in vivo. Some of them display high levels of blood schizontocidal activity when administered orally or subcutaneously. They retain their activity against lines of parasites that are resistant to widely differing antimalarials such as 4-aminoquinolines, aminoalcohols, dihydrofolate reductase inhibitors and artemisinin. The most potent compound of the present series is cis-(+/-)-4a,7a-dihydro-6,7a-di(p-fluorophenyl)spiro [cyclopentane-3,3'-7H-cyclopenta-1,2,4-trioxin], otherwise known as Fenozan-50F. PMID:8346994

Peters, W; Robinson, B L; Rossier, J C; Misra, D; Jefford, C W; Rossiter, J C

1993-02-01

282

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

283

Signaling and drug sensitivity  

Microsoft Academic Search

Even though alterations in receptor and nonreceptor kinases are involved in the development of human cancer, many cancer cell lines still retain their responsiveness to growth factors. We have investigated the hypothesis that cellular signaling events regulate the sensitivity of cancer cells to chemotherapeutic agents. In 2008 human ovarian carcinoma cells, activation of a number of different transduction pathways resulted

Randolph D. Christen; Seiji Isonishi; Jeffrey A. Jones; Antti P. Jekunen; Doreen K. Hom; Relef Kröning; Dennis P. Gately; Franz B. Thiebaut; Gerrit Los; Stephen B. Howell

1994-01-01

284

The physics of background discrimination in liquid xenon, and first results from Xenon10 in the hunt for WIMP dark matter  

NASA Astrophysics Data System (ADS)

The WIMP limit set by the Xenon10 experiment in 2007 signals a new era in direct detection of dark matter, with several large-scale liquid target detectors now under construction. A major challenge in these detectors will be to understand backgrounds at the level necessary to claim a positive WIMP signal. In liquid xenon, these backgrounds are dominated by electron recoils, which may be distinguished from the WIMP signal (nuclear recoils) by their higher charge-to-light ratio. During the construction and operation of Xenon10, the prototype detector Xed probed the physics of this discrimination. Particle interactions in liquid xenon both ionize and excite xenon atoms, giving charge and scintillation signals, respectively. Some fraction of ions recombine, reducing the charge signal and creating additional scintillation. The charge-to-light ratio, determined by the initial exciton-ion ratio and the ion recombination fraction, provides the basis for discrimination between electron and nuclear recoils. Intrinsic fluctuations in the recombination fraction limit discrimination. Changes in recombination induce an exact anti-correlation between charge and light, and when calibrated this anti-correlation distinguishes recombination fluctuations from uncorrelated fluctuations in the measured signals. We determine the mean recombination and recombination fluctuations as a function of energy and applied field for electron and nuclear recoils, finding that recombination fluctuations are already the limiting factor for discrimination above ~12 keVr (nuclear recoil energy). Below 12 keVr statistical fluctuations in the number of scintillation photons counted dominate, and we project a x6 improvement in background rejection with a x2 increase in light collection efficiency. We also build a simple recombination model that successfully reproduces the mean recombination in electron and nuclear recoils, including the surprising reversal of the expected trend for recombination with ionization density in low energy electron recoils. The model also reproduces the measured recombination fluctuations to within a factor of two at high energies. Surprisingly, the model suggests that recombination at low energies is independent of ionization density, and our observed discrimination is due not to the different stopping powers of electrons and nuclei as was thought, but rather to a different initial exciton-ion ratio. We suggest two possible physical models for this new result.

Dahl, Carl Eric

2009-06-01

285

Lining up your service lines.  

PubMed

Steps in implementing a service line approach include: Defining the service line. Allocating service line revenue and expense. Analyzing service line contribution margin and profitability. Determining the value of other factors. Creating standards for investment decisions, benchmarking, and ranking. PMID:17687972

Bilsky, Steven D; Aber, Jeffrey M

2007-07-01

286

Altered expression of estrogen-regulated genes in a tamoxifen-resistant and ICI 164,384 and ICI 182,780 sensitive human breast cancer cell line, MCF-7/TAMR-1.  

PubMed

A stable, tamoxifen-resistant subline, MCF-7/TAMR-1, of the human breast cancer cell line MCF-7 has been established in tissue culture after long-term treatment with 10(-6) M tamoxifen. The MCF-7/TAMR-1 cell line grows equally well in the presence and absence of tamoxifen, whereas the steroidal antiestrogens ICI 164,384 and ICI 182,780 exert profound inhibitory activity on cell proliferation, although higher concentrations are required to inhibit these cells compared to the parent cells. The MCF-7/TAMR-1 cells grown in tissue culture deviate from parent characteristics by the complete lack of expression of progesterone receptors even when grown with estradiol, by an altered tamoxifen regulation of M(r) 52,000 cathepsin D synthesis and secretion, and by lack of tamoxifen stimulation of an estradiol down-regulated M(r) 42,000 protein with presumed growth inhibitory function. MCF-7/TAMR-1 cells are estrogen receptor positive. The estrogen receptors have wild-type characteristics with respect to (a) binding of estradiol, tamoxifen, and ICI 164,384; (b) estrogen and antiestrogen regulation of the estradiol-regulated proteins pS2, M(r) 61,000 alpha 1-antitrypsin-like protein, M(r) 66,000 alpha 1-antichymotrypsin-like protein, and corresponding mRNAs; and (c) estrogen and antiestrogen regulation of a transiently transfected estrogen responsive reporter gene. We suggest that the lack of tamoxifen up-regulation of the M(r) 42,000 protein synthesis in MCF-7/TAMR-1 cells may at least partly explain the resistance to tamoxifen treatment. The sensitivity to the growth inhibitory activity of ICI 164,384 and ICI 182,780 may be ascribed to the maintenance of the pure antagonistic effect of these steroidal antiestrogens on MCF-7/TAMR-1 cells. Our results indicate that treatment with pure antiestrogens may be effective when patients become refractory to tamoxifen therapy. PMID:8137264

Lykkesfeldt, A E; Madsen, M W; Briand, P

1994-03-15

287

Evidence for efficient phosphorylation of EGFR and rapid endocytosis of phosphorylated EGFR via the early/late endocytic pathway in a gefitinib-sensitive non-small cell lung cancer cell line  

PubMed Central

Gefitinib (Iressa)–a specific inhibitor of epidermal growth factor receptor (EGFR) tyrosine kinase–has been shown to suppress the activation of EGFR signaling required for cell survival and proliferation in non-small cell lung cancer (NSCLC) cell lines. We recently provided novel evidence that gefitinib-sensitive PC9 cells show normal endocytosis of EGFR: internalized EGF-EGFR complexes were transported to late endosomes/lysosomes 15 min after EGF stimulation, and then degraded within the lysosomes. However, gefitinib-resistant QG56 cells showed internalized EGFR accumulation in early endosomes after 60 min of internalization, instead of its trafficking to lysosomes, indicating an aberration in some steps of EGF-EGFR trafficking from the early endosomes to late endosomes/lysosomes. Therefore, we postulate that impairment in some steps of EGF-EGFR trafficking from early endosomes to late endosomes/lysosomes might confer gefitinib-resistance in NSCLC cell lines. To further substantiate the detailed internalization mechanism of gefitinib-sensitive and gefitinib-resistant cells, using confocal immunofluorescence microscopy, we examined the endocytic trafficking of phosphorylated EGFR (pEGFR) in the absence or presence of gefitinib. In PC9 and QG56 cells without EGF stimulation, a large number of pEGFR-positive small vesicular structures not colocalized with late endosomes/lysosomes were spread throughout the cytoplasm, and some pEGFR staining was distributed in the nucleus. This implies a novel intracellular trafficking pathway for pEGFR from cytoplasmic vesicles to the nucleus. Furthermore, an aggregated vesicular structure of early endosomes was observed in the perinuclear region of QG56 cells; it was revealed to be associated with SNX1, originally identified as a protein that interacts with EGFR. Therefore, we confirmed our previous data that an aberration in some steps of EGF-EGFR trafficking from the early endosomes to late endosomes/lysosomes occurs in QG56 cells. Furthermore, in PC9 cells, efficient phosphorylation of EGFR and rapid internalization of pEGFR was observed at 3 min after EGF stimulation; these internalized pEGFR-positive vesicles were trafficked to late endosomes at 15 min, indicating rapid trafficking of EGF-pEGFR complexes from early to late endosomes in PC9 cells. Gefitinib treatment strongly reduced the phosphorylation level of EGFR, and subsequent endocytosis of EGFR was significantly suppressed in PC9 cells. In contrast, in QG56 cells, EGFR trafficking via the early endocytic pathway was basically impaired; therefore, gefitinib appeared to slightly suppress the internalization of pEGFR. Collectively, our data provide novel evidence that extensive impairment in pEGFR endocytosis via the early endocytic pathway might confer gefitinib-resistance in QG56 cells. PMID:18492291

Nishimura, Yukio; Yoshioka, Kiyoko; Bereczky, Biborka; Itoh, Kazuyuki

2008-01-01

288

Measure Lines  

NSDL National Science Digital Library

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 measu

Crissman, Sally

2011-01-01

289

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

290

Climate Sensitivity  

NASA Astrophysics Data System (ADS)

Discussion of climate sensitivity requires careful definition of forcings, feedbacks and response times, indeed, foggy definitions have produced flawed assessments of climate sensitivity. The best information available on climate sensitivity comes from insightful interpretation of the Earth's history aided by quantitative information from climate models and understanding of climate processes. Climate sensitivity is a strong function of time scale, in part because of the nature of climate feedbacks. Unfortunately for humanity, the preponderance of feedbacks on the century time scale appears to be positive. The chief implication is the need for a sharp reversal in the trend of human-made climate forcing, if we are to avoid creating a planet that is dramatically different than the one on which civilization developed.

Hansen, J.

2007-12-01

291

Spectral gamma-ray signatures of cosmological dark matter annihilations.  

PubMed

We propose a new signature for weakly interacting massive particle (WIMP) dark matter, a spectral feature in the diffuse extragalactic gamma-ray radiation. This feature, a sudden drop of the gamma-ray intensity at an energy corresponding to the WIMP mass, comes from the asymmetric distortion of the line due to WIMP annihilation into two gamma rays caused by the cosmological redshift. Unlike other proposed searches for a line signal, this method is not very sensitive to the exact dark matter density distribution in halos and subhalos. PMID:11736555

Bergström, L; Edsjö, J; Ullio, P

2001-12-17

292

World lines.  

PubMed

In this paper we present World Lines as a novel interactive visualization that provides complete control over multiple heterogeneous simulation runs. In many application areas, decisions can only be made by exploring alternative scenarios. The goal of the suggested approach is to support users in this decision making process. In this setting, the data domain is extended to a set of alternative worlds where only one outcome will actually happen. World Lines integrate simulation, visualization and computational steering into a single unified system that is capable of dealing with the extended solution space. World Lines represent simulation runs as causally connected tracks that share a common time axis. This setup enables users to interfere and add new information quickly. A World Line is introduced as a visual combination of user events and their effects in order to present a possible future. To quickly find the most attractive outcome, we suggest World Lines as the governing component in a system of multiple linked views and a simulation component. World Lines employ linking and brushing to enable comparative visual analysis of multiple simulations in linked views. Analysis results can be mapped to various visual variables that World Lines provide in order to highlight the most compelling solutions. To demonstrate this technique we present a flooding scenario and show the usefulness of the integrated approach to support informed decision making. PMID:20975187

Waser, Jürgen; Fuchs, Raphael; Ribici?, Hrvoje; Schindler, Benjamin; Blöschl, Günther; Gröller, Eduard

2010-01-01

293

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

294

UV Completions of Magnetic Inelastic Dark Matter and RayDM for the Fermi Line(s)  

E-print Network

Models that seek to produce a line at ~130 GeV as possibly present in the Fermi data face a number of phenomenological hurdles, not the least of which is achieving the high cross section into gamma gamma required. A simple explanation is a fermionic dark matter particle that couples to photons through loops of charged messengers. We study the size of the dimension 5 dipole (for a pseudo-Dirac state) and dimension 7 Rayleigh operators in such a model, including all higher order corrections in 1/M_{mess}. Such corrections tend to enhance the annihilation rates beyond the naive effective operators. We find that while freezeout is generally dominated by the dipole, the present day gamma-ray signatures are dominated by the Rayleigh operator, except at the most strongly coupled points, motivating a hybrid approach. With this, the Magnetic inelastic Dark Matter scenario provides a successful explanation of the lines at only moderately strong coupling. We also consider the pure Majorana WIMP, where both freezeout and the Fermi lines can be explained, but only at very strong coupling with light (~200 - 300 GeV) messengers. In both cases there is no conflict with non-observation of continuum photons.

Neal Weiner; Itay Yavin

2012-09-05

295

The nuclear export of DNA topoisomerase iialpha in hematological myeloma cell lines as a function of drug sensitivity: Clinical implications and a theoretical approach for overcoming the observed drug resistance  

Microsoft Academic Search

The focus of this investigation is about DNA topoisomerases, the molecular targets of clinically important chemotherapy, and mechanisms of drug resistance in human myeloma and leukemia cell lines. The ultimate goal of this investigation was to identify mechanism(s) of drug resistance to anticancer agents so that a strategy to overcome drug resistance could be conceived. We established an in vitro

Roxane Engel

2005-01-01

296

Polarization Sensitivity  

NASA Astrophysics Data System (ADS)

Optical coherence tomography (OCT) (Huang et al. Science 254(5035): 1178-1181, 1991; Fercher et al. Rep Prog Phys 66:239-303, 2003; Drexler and Fujimoto Prog Retin Eye Res 27(1):45-88, 2008) is a well-established tool for high-resolution cross-sectional imaging of human ocular structures. Despite its great success in improving ocular diagnostic imaging, conventional OCT cannot directly differentiate between different tissues. However, polarization-sensitive (PS) OCT is able to generate tissue-specific contrast that can be further used to segment ocular structures and to obtain quantitative information.

Schmidt-Erfurth, U.; Schlanitz, F.; Bolz, M.; Vass, C.; Lammer, J.; Schütze, C.; Pircher, M.; Götzinger, E.; Baumann, B.; Hitzenberger, C. K.

297

Transmission Lines  

NSDL National Science Digital Library

All About Circuits is a website that âÂÂprovides a series of online textbooks covering electricity and electronics.â Written by Tony R. Kuphaldt, the textbooks available here are wonderful resources for students, teachers, and anyone who is interested in learning more about electronics. This specific section, Transmission Lines, is the fourteenth chapter in Volume II â Alternating Current. A few of the topics covered in this chapter include: Circuits and the speed of light; Finite-length transmission lines; and Waveguides. Diagrams and detailed descriptions of concepts are included throughout the chapter to provide users with a comprehensive lesson. Visitors to the site are also encouraged to discuss concepts and topics using the All About Circuits discussion forums (registration with the site is required to post materials).

Kuphaldt, Tony R.

2008-07-03

298

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

299

Diatomic predissociation line widths  

NASA Technical Reports Server (NTRS)

Predissociation by rotation and curve crossing in diatomic molecules is discussed. The pattern of predissociation line widths is seen as providing a highly sensitive yardstick for the determination of unknown potential curves. In addition, the computation of such a pattern for given potential curves is considered a matter of routine, unless the predissociation happens to occur from an adiabatic potential curve. Analytic formulas are used to provide physical insight into the details of the predissociation pattern, to the extent that a direct inversion procedure is developed for determination of the repulsive potential curves for Type 1 predissociations.

Child, M. S.

1973-01-01

300

Line Defaults Modify Line/Shipping/Accounting  

E-print Network

Line Defaults and Modify Line/Shipping/Accounting NUFinancials Supply Chain FMS815 03/31/2010 --rkw, vlr Line Defaults & Modify Line/Shipping/Accounting © 2010 Northwestern University FMS815­ Job Aid Page 1 of 5 This job aid describes how and when to use Line Defaults and Modify Line/Shipping/Accounting

Shull, Kenneth R.

301

A plan for directional dark matter sensitivity in high-pressure xenon detectors through the addition of wavelength shifting gaseous molecules  

NASA Astrophysics Data System (ADS)

Xenon is an especially attractive candidate for both direct WIMP and 0??? decay searches. Although the current trend has exploited the liquid phase, the gas phase xenon offers remarkable performance advantages for: energy resolution, topology visualization, and discrimination between electron and nuclear recoils. The NEXT-100 experiment, now under construction in the Canfranc Underground Laboratory, Spain, will operate at ~ 15 bars with 100 kg of 136Xe for the 0??? decay search. We will describe recent results with small prototypes, indicating that NEXT-100 can provide about 0.5% FWHM energy resolution at the decay's Q value (2457.83 keV), as well as rejection of ?-rays with topological cuts. However, sensitivity goals for WIMP dark matter and 0??? decay searches indicate the probable need for ton-scale active masses. NEXT-100 provides the springboard to reach this scale with xenon gas. We describe a scenario for performing both searches in a single, high-pressure, ton-scale xenon gas detector, without significant compromise to either. In addition, even in a single ton-scale, high-pressure xenon gas TPC, an intrinsic sensitivity to the nuclear recoil direction may exist. This plausibly offers an advance of more than two orders of magnitude relative to current low-pressure TPC concepts. We argue that, in an era of deepening fiscal austerity, such a dual-purpose detector may be possible at acceptable cost, within the time frame of interest, and deserves our collective attention.

Gehman, V. M.; Goldschmidt, A.; Nygren, D.; Oliveira, C. A. B.; Renner, J.

2013-10-01

302

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

303

Accumulation of anthracenyl-amino acid topoisomerase I and II inhibitors in drug-sensitive and drug-resistant human ovarian cancer cell lines determined by high-performance liquid chromatography.  

PubMed

Anthracenyl amino acid/dipeptide conjugates (AADC) represent novel structures rationally designed for their DNA-binding properties. A high-performance liquid chromatography method is described for simultaneous determination of five compounds that exhibit novel mechanisms of action as topoisomerase I and II inhibitors. The method uses an Apex ODS-2 column and a mobile phase of 0.25 M ammonium acetate/trifluoroacetic acid (pH 3) in methanol with gradient elution. Selective detection is achieved by monitoring at 545 nm, with limits of detection ranging between 2 and 4 ng on the column. AADC are recovered from cell sonicates by solid-phase extraction using C2 cartridges, with extraction efficiencies ranging from 84% to 95%. Drug uptake studies were performed with three active compounds in the human ovarian cancer cell line A2780 and its multi-drug-resistant counterpart 2780AD. Marked differences were observed in the pattern of cellular accumulation produced by each compound. NU/ICRF 505 (tyrosine derivative) was taken up most avidly, reaching plateau levels of 4000 pmol/10(6) cells after 2 h, with no difference being apparent between A2780 and 2780AD. NU/ICRF 510 (arginine derivative) accumulated slowly in A2780, failing to achieve an equilibrium after 4 h, and appeared to be completely excluded from 2780AD. NU/ICRF 500 (serine derivative) was most rapidly taken up by A2780, producing a plateau of 800 pmol/10(6) cells after only 30 min with approximately 3-fold less accumulation in 2780AD. These results are correlated to the chemosensitivity of the two cell lines to the three compounds. PMID:7497578

Cummings, J; Meikle, I; Macpherson, J S; Smyth, J F

1995-01-01

304

Multivariate Ensemble Sensitivity with Localization  

NASA Astrophysics Data System (ADS)

So far in the literature, covariance localization (tapering) has not been applied when performing ensemble sensitivity analysis. Sampling error in computing the sensitivities via lagged covariances leads to an over-estimation of the impact of a perturbation. Most commonly when computing sensitivities, the analysis covariance is approximated with the corresponding diagonal matrix. Two consequences follow: (1) the multi-variate sensitivity is approximated by a univariate sensitivity, and (2) sampling error in off-diagonal elements are obviated. It is unknown, however, how much information is lost by ignoring the off-diagonal elements in the full covariance. When forecasts depend on many details of the previous analysis, it is reasonable to expect that the diagonal approximation is too severe. The purpose of this presentation is to clarify the effects of the diagonal approximation, and investigate the need for localization when off-diagonal elements are considered. Motivated by examples arising from sensitivities estimated within a cycling mesoscale ensemble data assimilation system, for easier interpretation we turn to the two-scale model first presented by Lorenz in 2005. We show that for most problems, an efficient matrix inversion is possible by finding a minimum-norm solution, and employing appropriate matrix factorization. Comparing the full inversion with off-diagonal elements, the fine-scale sensitivity estimates can be substantially different from those arising when the diagonal approximation is used. Localization on the sensitivity can be handled by an off-line empirical or Bayesian estimation technique. Because the sensitivity estimated from the full inversion is subject to sampling error, it is sensitive to the localization. The results show that compared to typical practices, more complete ensemble sensitivity formulations may be needed to draw robust inferences in general.

Hacker, Joshua; Lei, Lili

2014-05-01

305

WIMP Detection Using Liquid Xenon  

NASA Astrophysics Data System (ADS)

The missing mass 'Dark Matter' problem of the Universe is one of the most important questions facing the moden physics and astronomy. This thesis work developed the Liquid Xenon technology to detect the SUSY ark matter. The background rejection principle was tested and many technical problem are studied, including the purification of the liquid xenon to yield both long electron lifetime and long xenon scintillation light attenuation length, and xenon recoil scintillation efficiency measurement. The detector design and construction are studied. Finally a two phase xenon detector was realized for the future dark matter experiment. The key working principle is the use of proportional scintillation and electro-luminescence to detector the ionization components, which is different between background and recoil signals. The two phase test results shown that a detector energy threshold as low as 10keV can be achieved.

Wang, Hanguo

306

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

307

Familial melanoma associated with dominant ultraviolet radiation sensitivity  

SciTech Connect

Sensitivity to ultraviolet radiation was studied in lymphoblastoid cell lines derived from 32 members of two families with histories of multiple primary melanomas in several generations. As assayed by colony formation in agar or by trypan blue exclusion following irradiation, cellular sensitivity showed a bimodal distribution. All persons with melanoma or multiple moles were in the sensitive group, while some family members exhibited responses similar to those of controls. Cells from four cases of sporadic melanoma showed normal levels of sensitivity. The data are consistent with a dominantly inherited ultraviolet light sensitivity associated with these examples of familial melanoma. Spontaneous and ultraviolet light-induced sister chromatid exchange frequencies were similar to those in control cell lines. No defect in excision repair was detected in any of the above cell lines, but the sensitive group showed postirradiation inhibition of DNA replication intermediate between controls and an excision-deficient xeroderma pigmentosum cell line.

Ramsay, R.G.; Chen, P.; Imray, F.P.; Kidson, C.; Lavin, M.F.; Hockey, A.

1982-07-01

308

Gamma-ray line transients  

SciTech Connect

Early interpretations of the variability of the narrow 0.511 MeV annihilation line from the Galactic center (GC) were confused by the unrecognized presence of a very extended component (mid 70s-mid 80s). Transient behavior was suggested by comparisons of measurements made by instruments with comparable fields of view, and by detection of other lines which could be interpreted as broadened and Doppler-shifted versions of the line. A new generation of instruments (late 80s-early 90s) provided more compelling evidence, by improved imaging capability (identifying a known transient high-energy candidate source, 1E 1740.7-2942), and by improved sensitivity. Additional broadened, shifted, and Compton-scattered derivatives of the annihilation line were detected from this and other sources. At the same time, theoretical developments suggested exciting new physics which might arise in the accretion regimes around black holes, of which these features would be important diagnostics. In the GRO era the existence of such transient lines has been brought into question by the failure of long-term monitoring to detect them. A seemingly critical observation of the GC by three different instruments simultaneously, in which transient emission was detected only by one, provides the strongest evidence that the earlier results were in error. Recent developments in accretion disk theory have weakened the theoretical case for the lines. I draw conclusions concerning the nature of scientific inquiry and public outreach efforts in science.

Harris, Michael J. [USRA/GVSP, Code 661, NASA/Goddard Spaceflight Center, Greenbelt, Maryland 20771 (United States)

1997-05-10

309

C IV line ratios in the sun  

NASA Astrophysics Data System (ADS)

Theoretical electron temperature-sensitive emission-line ratios are calculated with R-matrix analysis of electron-impact excitation rates for transitions in C IV. Two of the emission-line ratios are found to agree with observational data on the sun taken with a slitless spectrograph aboard Skylab, and the two remaining lines have inaccuracies that can be attributed to blending of the 312.43 A line. The agreement between the observational and analytical data lends credence to the accuracy of the atomic data used in the analysis.

Keenan, F. P.; Conlon, E. S.; Harra, L. K.; Burke, V. M.; Widing, K. G.

1992-01-01

310

Familial melanoma associated with dominant ultraviolet radiation sensitivity  

Microsoft Academic Search

Sensitivity to ultraviolet radiation was studied in lymphoblastoid cell lines derived from 32 members of two families with histories of multiple primary melanomas in several generations. As assayed by colony formation in agar or by trypan blue exclusion following irradiation, cellular sensitivity showed a bimodal distribution. All persons with melanoma or multiple moles were in the sensitive group, while some

R. G. Ramsay; P. Chen; F. P. Imray; C. Kidson; M. F. Lavin; A. Hockey

1982-01-01

311

Familial Melanoma Associated with Dominant Ultraviolet Radiation Sensitivity1  

Microsoft Academic Search

Sensitivity to ultraviolet radiation was studied in lymphoblas- toid cell lines derived from 32 members of two families with histories of multiple primary melanomas in several generations. As assayed by colony formation in agar or by trypan blue exclusion following irradiation, cellular sensitivity showed a bimodal distribution. All persons with melanoma or multiple moles were in the sensitive group, while

Robert G. Ramsay; Philip Chen; F. Paula Imray; Chev Kidson; Martin F. Lavin; Athel Hockey

312

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

313

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

314

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

315

A Pencil of Lines  

ERIC Educational Resources Information Center

Given two interesecting lines, the "pencil" of this interesection is the family of all lines passing through the point of intersection. Presented is a characterization of all lines both in the plane and lying in opposite sectors of the plane as determined by one of the original intersecting lines. (JP)

Bender, Edward D.

1974-01-01

316

Architecture of product lines  

Microsoft Academic Search

A product line is a family of products designed to take advantage of their common aspects (commonalities) and predicted variabilities. A product line may be software only, e.g., a family of GUIs; software + hardware, e.g., a family of televisions; or hardware only. Where software is a part of the product line, the variability accommodated by the product line is

David M. Weiss

2009-01-01

317

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 ($\\sim \\rm TeV$) 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. 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. Thermal models freeze-out as in the normal XDM setup, via annihilations to the light boson $\\phi$. For suitable...

Finkbeiner, Douglas P

2014-01-01

318

First on-line results from the CRIS (Collinear Resonant Ionisation Spectroscopy) beam line at ISOLDE  

NASA Astrophysics Data System (ADS)

The CRIS (Collinear Resonant Ionisation Spectroscopy) experiment at the on-line isotope separator facility, ISOLDE, CERN, has been constructed for high-sensitivity laser spectroscopy measurements on radioactive isotopes. The technique determines the magnetic dipole and electric quadrupole moments, nuclear spin and changes in mean-square charge radii of exotic nuclei via measurement of their hyperfine structures and isotope shifts. In November 2011 the first on-line run was performed using the CRIS beam line, when the hyperfine structure of 207Fr was successfully measured. This paper will describe the technique and experimental setup of CRIS and present the results from the first on-line experiment.

Procter, T. J.; Flanagan, K. T.

2013-04-01

319

Development of the PEFP's beam line BPM  

NASA Astrophysics Data System (ADS)

The Proton Engineering Frontier Project (PEFP) has 20-MeV and 100-MeV beam lines to supply proton beams to users. A stripline-type Beam Position Monitor (BPM) was designed and fabricated in order to measure the beam's position in the beam line. The RF properties of the BPM were measured and compared with the simulation. After the sensitivity of the BPM at a test stand had been obtained, we performed a beam test in a test beam line of the PEFP 20-MeV proton linac.

Ryu, Jin-Yeong; Kwon, Hyeok-Jung; Jang, Ji-Ho; Kim, Han-Sung; Seol, Kyung-Tae; Cho, Yong-Sub

2013-01-01

320

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

321

Solar flare gamma-ray line shapes  

NASA Technical Reports Server (NTRS)

A computer code has been developed which is used to calculate ab initio the laboratory shapes and energy shifts of gamma-ray lines from (C-12)(p, gamma/4.438/)p-prime(C-12) and (O-16)(p, gamma/6.129/)p-prime(O-16) reactions and to calculate the expected shapes of these lines from solar flares. The sensitivity of observable solar flare gamma-ray line shapes to the directionality of the incident particles is investigated for several projectile angular distributions. Shapes of the carbon and oxygen lines are calculated assuming realistic proton energy spectra for particles in circular orbits at the mirror points of magnetic loops, for particle beams directed downward into the photosphere, and for isotropic particle distributions. Line shapes for flare sites near the center of the sun and on the limb are shown for both thin-target and thick-target interaction models.

Werntz, C.; Kim, Y. E.; Lang, Frederick L.

1990-01-01

322

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

323

Central line infections - hospitals  

MedlinePLUS

... and increase how long you are in the hospital. Your central line needs special care to prevent ... The hospital staff will use aseptic technique when a central line is put in your chest or arm. Aseptic ...

324

Superconducting Delay Lines  

Microsoft Academic Search

Many superconducting delay line structures have been implemented, using various technologies. In this paper, a comprehensive\\u000a overview of these delay-lines is given. The advantages and disadvantages of using different planar technologies for the construction\\u000a of superconducting delay lines are discussed in greater detail. It was revealed that most of the superconducting delay line\\u000a structures reported can be categorized into a

Hieng Tiong Su; Yi Wang; Frederick Huang; Michael J. Lancaster

2008-01-01

325

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.

Roberts, Donna

326

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!

Consortium, The C.

2012-05-21

327

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

328

RF Transmission Lines  

NSDL National Science Digital Library

This is a description for a learning module from Maricopa Advanced Technology Education Center. This PDF describes the module; access may be purchased by visiting the MATEC website. After completing this module, learners will be able to describe the type of transmission lines needed in RF systems and how transmission lines work together with other RF system components to deliver maximum power while maintaining reflected power. They also learn how to interpret transmission line specifications, select a transmission line for a given application, calculate transmission line power losses, and measure standing wave ratio. Finally, this module will use visual examples and present industry best practices for identifying type of connectors used with transmission lines and procedures for transmission line testing and troubleshooting.

2012-12-07

329

Health Perceptions and Anxiety Sensitivity in Patients with Panic Disorder  

Microsoft Academic Search

Separate lines of research indicate that patients with panic disorder display negative perceptions of physical health and elevated fear of autonomic arousal. Because health perceptions and anxiety sensitivity may be related, the present study evaluated the degree to which these constructs can be distinguished in patients meeting DSM-IV criteria for panic disorder (N = 44). Perceived health, anxiety sensitivity, and

Norman B. Schmidt; Thomas E. Joiner Jr; Jeffrey P. Staab; Foluso M. Williams

2003-01-01

330

Intrinsically Polarized Blend Lines  

NASA Astrophysics Data System (ADS)

The Second Solar Spectrum formed by coherent scattering processes in the Sun, is highly structured. It is characterized by numerous blend lines, both intrinsically polarizing and depolarizing, superposed on the background continuum. These blend lines play an important role in the interpretation of the Second Solar Spectrum. Since blend lines affect the shapes of the neighboring spectral lines they have to be treated in a sophisticated manner in order to efficiently model a given spectral line of interest. The depolarizing blend lines - mostly considered to be formed under LTE conditions - depolarize the background continuum and thereby affect the absolute scale of the polarization measurement. An understanding of the influence of the blend lines leads to a proper determination of the zero-point of the polarization scale. With this motivation we extend a previously developed framework to include many blend lines formed under NLTE conditions, in the radiative transfer equation. The results are shown for the particular case of two blend lines situated on either side of the main spectral line.

Sowmya, K.; Nagendra, K. N.; Sampoorna, M.

2014-10-01

331

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

332

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

E-print Network

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 ($k\\approx0.1$ 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. ...

Evoli, Carmelo; Ferrara, Andrea

2014-01-01

333

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

334

Are Psychopaths Morally Sensitive?  

ERIC Educational Resources Information Center

Philosophical and psychological opinion is divided over whether moral sensitivity, understood as the ability to pick out a situation's morally salient features, necessarily involves emotional engagement. This paper seeks to offer insight into this question. It reasons that if moral sensitivity does draw significantly on affective capacities of…

Maxwell, Bruce; Le Sage, Leonie

2009-01-01

335

LEVEL 1 BIOASSAY SENSITIVITY  

EPA Science Inventory

The report, based on a survey of published literature, establishes a set of sensitivity estimates for the Level 1 environmental assessment (EA) bioassays recommended by EPA's IERL-RTP. The estimates permit comparison of bioassay sensitivity for detecting toxicity or mutagenicity ...

336

Tuned cavity magnetometer sensitivity.  

SciTech Connect

We have developed a high sensitivity (sensitivity levels.

Okandan, Murat; Schwindt, Peter

2009-09-01

337

High energy beam lines  

NASA Astrophysics Data System (ADS)

The ISAC post accelerator comprises an RFQ, DTL and SC-linac. The high energy beam lines connect the linear accelerators as well as deliver the accelerated beams to two different experimental areas. The medium energy beam transport (MEBT) line connects the RFQ to the DTL. The high energy beam transport (HEBT) line connects the DTL to the ISAC-I experimental stations (DRAGON, TUDA-I, GPS). The DTL to superconducting beam (DSB) transport line connects the ISAC-I and ISAC-II linacs. The superconducting energy beam transport (SEBT) line connects the SC linac to the ISAC-II experimental station (TUDA-II, HERACLES, TIGRESS, EMMA and GPS). All these lines have the function of transporting and matching the beams to the downstream sections by manipulating the transverse and longitudinal phase space. They also contain diagnostic devices to measure the beam properties.

Marchetto, M.; Laxdal, R. E.

2014-01-01

338

Lunar magnetic permeability studies and magnetometer sensitivity  

NASA Technical Reports Server (NTRS)

A regression of quiet magnetic field components simultaneously measured by the two Explorer 35 magnetometers reveals uncertainties in effective sensitivity factors of up to a few percent in one or both of these instruments. Given this, the validity of previous lunar permeability studies based on Explorer 35/ALSEP regressions, wherein inferences are drawn from regression line slopes differing from unity by the order of one percent, is called into question. We emphasize the need to critically address the question of small deviations in magnetometer sensitivity factors from nominal values as a part of any two-magnetometer lunar permeability study.

King, J. H.; Ness, N. F.

1977-01-01

339

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

340

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

341

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

342

Series Transmission Line Transformer  

SciTech Connect

A series transmission line transformer is set forth which includes two or more of impedance matched sets of at least two transmissions lines such as shielded cables, connected in parallel at one end ans series at the other in a cascading fashion. The cables are wound about a magnetic core. The series transmission line transformer (STLT) which can provide for higher impedance ratios and bandwidths, which is scalable, and which is of simpler design and construction.

Buckles, Robert A. (Livermore, CA); Booth, Rex (Livermore, CA); Yen, Boris T. (El Cerrito, CA)

2004-06-29

343

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

344

The Iron Line Background  

E-print Network

We investigate the presence of iron line emission among faint X-ray sources identified in the 1Ms Chandra Deep Field South and in the 2Ms Chandra Deep Field North. Individual source spectra are stacked in seven redshift bins over the range z=0.5-4. We find that iron line emission is an ubiquitous property of X-ray sources up to z~3. The measured line strengths are in good agreement with those expected by simple pre-Chandra estimates based on X-ray background synthesis models. The average rest frame equivalent width of the iron line does not show significant changes with redshift.

Marcella Brusa; Roberto Gilli; Andrea Comastri

2005-01-25

345

Line orientation adaptation: local or global?  

PubMed

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 1(st)-and 2(nd)-order lines, with the 2(nd)-order lines being encoded by a subset of the mechanisms sensitive to 1(st)-order lines. PMID:24023677

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

2013-01-01

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

Sensitive webpage content detection  

US Patent & Trademark Office Database

Computer-readable media, systems, and methods for sensitive webpage content detection are described. In embodiments, a multi-class classifier is developed and one or more webpages with webpage content are received. In various embodiments, the one or more webpages are analyzed with the multi-class classifier and, in various embodiments, a sensitivity level is predicted that is associated with the webpage content of the one or more webpages. In various other embodiments, the multi-class classifier includes one or more sensitivity categories.

2011-07-05

348

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

349

On-line surfactant monitoring  

SciTech Connect

This group has developed a process to extract metal ions from dilute aqueous solutions. The process uses water soluble polymers to complex metal ions. The metal/polymer complex is concentrated by ultrafiltration and the metals are recovered by a pH adjustment that frees the metal ions. The metal ions pass through the ultrafiltration membrane and are recovered in a concentrated form suitable for reuse. Surfactants are present in one of the target waste streams. Surfactants foul the costly ultrafiltration membranes. It was necessary to remove the surfactants before processing the waste stream. This paper discusses an on-line device the authors fabricated to monitor the process stream to assure that all the surfactant had been removed. The device is inexpensive and sensitive to very low levels of surfactants.

Mullen, K.I.; Neal, E.E.; Soran, P.D.; Smith, B. [Los Alamos National Lab., NM (United States). Chemical Science and Technology Div.

1995-04-01

350

Segmenting cruise passengers with price sensitivity  

Microsoft Academic Search

It has been suggested that discounted cruises have degraded the industry's standards (Berlitz Guide to Cruising and Cruise Ships, Berlitz, Princeton, NJ, 1994), and that value-oriented cruise lines are gaining a competitive advantage over “high-end” cruises (http:\\/\\/www.cruisinformationservice.co.uk\\/press\\/factsheetdetail.aspx?id=45). This use of price discounting has created new challenges for the cruise industry, as they have attracted a more price-sensitive market than they

James F. Petrick

2005-01-01

351

CRIRES spectroscopy and empirical line-by-line identification of FeH molecular absorption in an M dwarf  

NASA Astrophysics Data System (ADS)

Molecular FeH provides a large number of sharp and isolated absorption lines that can be used to measure radial velocity, rotation, or magnetic field strength with high accuracy. Our aim is to provide an FeH atlas for M-type stars in the spectral region from 986 nm to 1077 nm (Wing-Ford band). To identify these lines in CRIRES spectra of the magnetically inactive, slowly rotating, M5.5 dwarf GJ1002, we calculated model spectra for the selected spectral region with theoretical FeH line data. In general this line list agrees with the observed data, but several individual lines differ significantly in position or in line strength. After identification of as many as possible FeH lines, we corrected the line data for position and line strength to provide an accurate atlas of FeH absorption lines for use in high precision spectroscopy of low mass stars. For all lines, we used a Voigt function to obtain their positions and equivalent widths. Identification with theoretical lines was done by hand. For confirmation of the identified lines, we used statistical methods, cross-correlation techniques, and line intensities. Eventually, we were able to identify FeH lines from the (0,0), (1,0), (1,1), (2,1), (2,2), (3,2), and (4,3) vibrational bands in the observed spectra and correct the positions of the lines if necessary. The deviations between theoretical and observed positions follow a normal distribution approximately around zero. In order to empirically correct the line strength, we determined Teff, instrumental broadening (rotational broadening) and a van der Waals enhancement factor for the FeH lines in GJ1002. We also give the scaling factors for the Einstein A values to correct the line strengths. With the identified lines, we derived rotational temperatures from the line intensities for GJ1002. We conclude that FeH lines can be used for a wide variety of applications in astrophysics. With the identified lines it will be possible for example to characterize magnetically sensitive or very temperature sensitive lines, which can be used to investigate M-type stars. Data were taken at ESO Telescopes under the program 79.D-0357(A).Full Table 4 and FeH atlas are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/viz-bin/qcat?J/A+A/523/A58

Wende, S.; Reiners, A.; Seifahrt, A.; Bernath, P. F.

2010-11-01

352

Adaptive line transect sampling.  

PubMed

Adaptive line transect sampling offers the potential of improved population density estimation efficiency over conventional line transect sampling when populations are spatially clustered. In adaptive sampling, survey effort is increased when areas of high animal density are located, thereby increasing the number of observations. Its disadvantage is that the survey effort required is not known in advance. We develop an adaptive line transect methodology that, by varying the degree of adaptation, allows total effort to be fixed at the design stage. Relative to conventional line transect surveys, it also provides better survey coverage in the event of disruption in survey effort, e.g., due to poor weather. In analysis, sightings from the adaptive sections are downweighted in proportion to the increase in effort. We evaluate the methodology by simulation and report on surveys of harbor porpoise in the Gulf of Maine, in which the approach was compared with conventional line transect sampling. PMID:12495140

Pollard, J H; Palka, D; Buckland, S T

2002-12-01

353

Performance-Sensitive Debt  

E-print Network

This article studies performance-sensitive debt (PSD), the class of debt obligations whose interest payments depend on some measure of the borrower’s performance. We demonstrate that the existence of PSD obligations cannot ...

Manso, Gustavo

354

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.

Yao, Junjie; Wang, Lihong V.

2014-01-01

355

Linear Polarization Measurements of Chromospheric Emission Lines  

NASA Technical Reports Server (NTRS)

We have used the Zurich Imaging Stokes Polarimeter (ZIMPOL I) with the McMath-Pierce 1.5 m main telescope on Kitt Peak to obtain linear polarization measurements of the off-limb chromosphere with a sensitivity better than 1 x 10(exp -5). We found that the off-disk observations require a combination of good seeing (to show the emission lines) and a clean heliostat (to avoid contamination by scattered light from the Sun's disk). When these conditions were met, we obtained the following principal results: 1. Sometimes self-reversed emission lines of neutral and singly ionized metals showed linear polarization caused by the transverse Zeeman effect or by instrumental cross talk from the longitudinal Zeeman effect in chromospheric magnetic fields. Otherwise, these lines tended to depolarize the scattered continuum radiation by amounts that ranged up to 0.2%. 2. Lines previously known to show scattering polarization just inside the limb (such as the Na I lambda5889 D2 and the He I lambda5876 D3 lines) showed even more polarization above the Sun's limb, with values approaching 0.7%. 3. The O I triplet at lambda7772, lambda7774, and lambda7775 showed a range of polarizations. The lambda7775 line, whose maximum intrinsic polarizability, P(sub max), is less than 1%, revealed mainly Zeeman contributions from chromospheric magnetic fields. However, the more sensitive lambda7772 (P(sub max) = 19%) and lambda7774 (P(sub max) = 29%) lines had relatively strong scattering polarizations of approximately 0.3% in addition to their Zeeman polarizations. At times of good seeing, the polarization spectra resolve into fine structures that seem to be chromospheric spicules.

Sheeley, N. R., Jr.; Keller, C. U.

2003-01-01

356

Sensitivity to wild vegetation.  

PubMed

74 patients suspected of having allergic contact dermatitis to wild vegetation were patch tested with either extracts of 13 plants of the family Compositae and 7 other weeds or trees. Anthemis cotula (dog fennel) and Xanthium strumarium (cocklebur) gave the most frequent positive results, demonstrating a change of frequency in sensitivity compared to the 1950s, when Ambrosia artemisiifolia (ragweed) was recognized as the most frequently sensitizing weed. The reasons for these changes of incidence and clinical patterns are examined. PMID:3581826

Menz, J; Winkelmann, R K

1987-03-01

357

Neutral line chaos and phase space structure  

NASA Technical Reports Server (NTRS)

Phase space structure and chaos near a neutral line are studied with numerical surface-of-section (SOS) techniques and analytic methods. Results are presented for a linear neutral line model with zero crosstail electric field. It was found that particle motion can be divided into three regimes dependening on the value of the conserved canonical momentum, Py, and the conserved Hamiltonian, h. The phase space structure, using Poincare SOS plots, is highly sensitive to bn = Bn/B0 variations, but not to h variations. It is verified that the slow motion preserves the action, Jz, as evaluated by Sonnerup (1971), when the period of the fast motion is smaller than the time scale of the slow motion. Results show that the phase space structure and particle chaos depend sensitively upon Py and bn, but are independent of h.

Burkhart, Grant R.; Speiser, Theodore W.; Martin, Richard F., Jr.; Dusenbery, Paul B.

1991-01-01

358

Robust Design of Dual Band\\/Polarization Patch Antenna Using Sensitivity Analysis and Taguchi's Method  

Microsoft Academic Search

In this paper, sensitivity analysis and Taguchi's method are applied to the design of dual band patch antenna using gap coupling. The proposed structure uses T-slotted aperture coupling between patch and feed line of ground plane. Using sensitivity analysis, optimum dimensions of patch and coplanar waveguide (CPW) feed line are first sought. Then the optimized values are modified by Taguchi's

Jae-Hyeong Ko; Jin-Kyu Byun; Jun-Seok Park; Hyeong-Seok Kim

2011-01-01

359

Real-time polarization-sensitive optical coherence tomography data processing with  

E-print Network

Real-time polarization-sensitive optical coherence tomography data processing with parallel With the increase of the A-line speed of optical coherence tomography (OCT) systems, real-time proces- sing than 80 K A-lines per second. A real-time, fiber-based, swept source polarization-sensitive OCT system

Chen, Zhongping

360

The EVE Doppler Sensitivity and Flare Observations  

NASA Technical Reports Server (NTRS)

The Extreme-ultraviolet Variability Experiment (EVE) obtains continuous EUV spectra of the Sun viewed as a star. Its primary objective is the characterization of solar spectral irradiance, but its sensitivity and stability make it extremely interesting for observations of variability on time scales down to the limit imposed by its basic 10 s sample interval. In this paper we characterize the Doppler sensitivity of the EVE data. We find that the 30.4 nm line of He II has a random Doppler error below 0.001 nm (1 pm, better than 10 km/s as a redshift), with ample stability to detect the orbital motion of its satellite, the Solar Dynamics Observatory (SDO). Solar flares also displace the spectrum, both because of Doppler shifts and because of EVE's optical layout, which (as with a slitless spectrograph) confuses position and wavelength. As a flare develops, the centroid of the line displays variations that reflect Doppler shifts and therefore flare dynamics. For the impulsive phase of the flare SOL2010-06-12, we find the line centroid to have a redshift of 16.8 +/- 5.9 km/s relative to that of the flare gradual phase (statistical errors only). We find also that high-temperature lines, such as Fe XXIV 19.2 nm, have well-determined Doppler components for major flares, with decreasing apparent blueshifts as expected from chromospheric evaporation flows.

Hudson, H. S.; Woods, T. N.; Chamberlin, P. C.; Didkovsky, L.; Del Zanna, G.

2011-01-01

361

Cryogenic Transfer Line Chilldown  

NASA Technical Reports Server (NTRS)

The transient behavior of a small scale cryogenic transfer line was investigated during chilldown to cryogenic temperatures. The vacuum-jacketed apparatus consisted of a vertical tube followed by a near horizontal tube. The apparatus was equipped with view ports in the near horizontal section to allow visual observation of the flow patterns. Wall temperatures were measured at various locations along the length of the transfer line. Each test was conducted at a constant liquid volumetric flowrate at the transfer line inlet until saturation temperatures were obtained throughout the system.

VanDresar, Neil T.; Siegwarth, James D.

2003-01-01

362

Vertical Line Test  

NSDL National Science Digital Library

In this activity, students try to connect given points on a graph in a way that they will pass the vertical line test. If the points can't be made to pass the vertical line test, the student must adjust the points so they will pass the test. This activity allows students to explore the vertical line test for functions. This activity includes supplemental materials, including background information about the topics covered, a description of how to use the application, and exploration questions for use with the java applet.

2010-01-01

363

Behavior of metal linings  

Microsoft Academic Search

Conclusions  \\u000a \\u000a \\u000a \\u000a 1. \\u000a \\u000a The characteristic damage to steel linings is fracture due to metal fatigue in flexing, which is possible when the lining\\u000a is not flush against the concrete.\\u000a \\u000a \\u000a \\u000a \\u000a 2. \\u000a \\u000a Steel linings should not be used in pressure and free-flow conduits operating at part flow, in particular in the draft tubes\\u000a of hydroelectric stations where the flow velocities and the energy

V. A. Varaksin; A. M. Palvanov

1969-01-01

364

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

365

Number Line Arithmetic  

NSDL National Science Digital Library

This applet demonstrates operations with whole numbers on a number line. The student selects an operation and the applet represents an example. It helps students understand the commutativity of multiplication, remainders in division, inverse operations, and the relationships between operations.

1999-01-01

366

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

2010-06-21

367

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

368

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

369

IRIS Spectrum Line Plot  

NASA Video Gallery

This video shows a line plot of the spectrum. The spectra here are shown for various locations on the Sun. The changes in the movie are caused by differing physical conditions in the locations. Cre...

370

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

371

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

372

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

373

PORTION OF A LINE (AT LEFT) AND B LINE (AT ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

PORTION OF A LINE (AT LEFT) AND B LINE (AT RIGHT) ON GENTLE TERRACE SLOPE. A LINE POLE 75A (LEFT FOREGROUND) HAS ORIGINAL GLASS PIN-TYPE INSULATORS AND INTACT COMMUNICATION LINE CROSS ARM. VIEW TO WEST-SOUTHWEST. - Mystic Lake Hydroelectric Facility, Electric Transmission A Line, Along West Rosebud Creek, Fishtail, Stillwater County, MT

374

Line formation in the solar chromosphere. I - The C II resonance lines observed with OSO 8  

NASA Technical Reports Server (NTRS)

The temperature structure of the upper chromosphere is investigated using center-to-limb measurements of the C II resonance lines at 1335 A from the University of Colorado spectrometer aboard OSO 8. Spectrum synthesis of these lines shows them to be extremely sensitive to the temperature and the physical extent of the 20,000 K plateau proposed by Vernazza et al (1973). Hydrostatic equilibrium models of the quiet chromosphere are computed to obtain theoretical spectra of the Lyman lines and continuum as well as the center-to-limb behavior of the C II lines. Good agreement is found with observations for a plateau at 16,500 K with about 25% more material than that of Vernazza et al.

Lites, B. W.; Shine, R. A.; Chipman, E. G.

1978-01-01

375

RESRAD parameter sensitivity analysis  

SciTech Connect

Three methods were used to perform a sensitivity analysis of RESRAD code input parameters -- enhancement of RESRAD by the Gradient Enhanced Software System (GRESS) package, direct parameter perturbation, and graphic comparison. Evaluation of these methods indicated that (1) the enhancement of RESRAD by GRESS has limitations and should be used cautiously, (2) direct parameter perturbation is tedious to implement, and (3) the graphics capability of RESRAD 4.0 is the most direct and convenient method for performing sensitivity analyses. This report describes procedures for implementing these methods and presents a comparison of results. 3 refs., 9 figs., 8 tabs.

Cheng, J.J.; Yu, C.; Zielen, A.J.

1991-08-01

376

Transmission line capital costs  

SciTech Connect

The displacement or deferral of conventional AC transmission line installation is a key benefit associated with several technologies being developed with the support of the U.S. Department of Energy`s Office of Energy Management (OEM). Previous benefits assessments conducted within OEM have been based on significantly different assumptions for the average cost per mile of AC transmission line. In response to this uncertainty, an investigation of transmission line capital cost data was initiated. The objective of this study was to develop a database for preparing preliminary estimates of transmission line costs. An extensive search of potential data sources identified databases maintained by the Bonneville Power Administration (BPA) and the Western Area Power Administration (WAPA) as superior sources of transmission line cost data. The BPA and WAPA data were adjusted to a common basis and combined together. The composite database covers voltage levels from 13.8 to 765 W, with cost estimates for a given voltage level varying depending on conductor size, tower material type, tower frame type, and number of circuits. Reported transmission line costs vary significantly, even for a given voltage level. This can usually be explained by variation in the design factors noted above and variation in environmental and land (right-of-way) costs, which are extremely site-specific. Cost estimates prepared from the composite database were compared to cost data collected by the Federal Energy Regulatory Commission (FERC) for investor-owned utilities from across the United States. The comparison was hampered because the only design specifications included with the FERC data were voltage level and line length. Working within this limitation, the FERC data were not found to differ significantly from the composite database. Therefore, the composite database was judged to be a reasonable proxy for estimating national average costs.

Hughes, K.R.; Brown, D.R.

1995-05-01

377

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

378

Naegleria fowleri: Trimethoprim Sensitivity  

Microsoft Academic Search

Trimethoprim in a concentration of 4 micrograms per milliliter of Bacto-Casitone (Difco) medium inhibits the growth of nonvirulent Naegleria fowleri isolates. The growth of virulent strains is unaffected even with 400 micrograms of the drug per milliliter of medium. Differences in sensitivity constitute the possibility of a simple selection of environmental isolates. The pathogenicity and virulence of Naegleria species may

Lubor Cerva

1980-01-01

379

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

380

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

381

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

382

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

383

Sensitive Questions in Surveys  

Microsoft Academic Search

Psychologists have worried about the distortions introduced into standardized personality measures by social desirability bias. Survey researchers have had similar concerns about the accuracy of survey reports about such topics as illicit drug use, abortion, and sexual behavior. The article reviews the research done by survey methodologists on reporting errors in surveys on sensitive topics, noting parallels and differences from

Roger Tourangeau; Ting Yan

2007-01-01

384

What Is Sensitivity Training?  

ERIC Educational Resources Information Center

Sensitivity training is one type of experience-based learning in which participants work together in a small group over an extended period of time learning through analysis of their own experiences. The primary setting is the T Group (T for training) in which a staff member sets up an ambiguous situation which allows participants to choose the…

Seashore, Charles

1968-01-01

385

Fundamental Physics Microgravity Sensitivity  

NASA Technical Reports Server (NTRS)

An introduction followed by a brief discussion about the sensitivity to microgravity environment disturbances for some recent and planned experiments in microgravity fundamental physics will be presented. In particular, correlation between gravity disturbances and the quality of science data sets measured by the Confined Helium Experiment (CHEX) during ground testing and during the November 1997 USMP-4 flight will be described.

Israelsson, Ulf

1998-01-01

386

Attention-Sensitive Alerting  

Microsoft Academic Search

Abstract We introduce utility - directed procedures for mediating the ow of potentially distract - ing alerts and communications to computer users We present models and inference pro - cedures that balance the context - sensitive costs of deferring alerts with the cost of in - terruption We describe the challenge of rea - soning about such costs under uncertainty

Eric Horvitz; Andy Jacobs; David Hovel

1999-01-01

387

PROTECTING SENSITIVE INFORMATION TRANSMITTED  

E-print Network

on implementing security services based on Internet Protocol Security (IPsec). The protection of sensitive on Internet Protocol Security (IPsec). IPsec is a framework of open standards for ensuring private communications over public networks. IPsec is frequently used to achieve security controls in the layered

388

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

389

Interpreting broad emission-line variations - I. Factors influencing the emission-line response  

NASA Astrophysics Data System (ADS)

We investigate the sensitivity of the measured broad emission-line responsivity dlog fline/dlog fcont to continuum variations in the context of straw-man broad emission-line region (BLR) geometries of varying size with fixed BLR boundaries, and for which the intrinsic emission-line responsivity is known a priori. We find for a generic emission line that the measured responsivity ?eff, delay and maximum of the cross-correlation function are correlated for characteristic continuum variability time-scales Tchar less than the maximum delay for that line ?max(line) for a particular choice of BLR geometry and observer orientation. The above correlations are manifestations of geometric dilution arising from reverberation effects within the spatially extended BLR. When present, geometric dilution reduces the measured responsivity, delay and maximum of the cross-correlation function. Conversely, geometric dilution is minimized if Tchar ? ?max(line). We also find that the measured responsivity and delay show a strong dependence on light-curve duration, with shorter campaigns resulting in smaller than expected values, and only a weak dependence on sampling rate (for irregularly sampled data). The observed strong negative correlation between continuum level and line responsivity found in previous studies cannot be explained by differences in the sampling pattern, light-curve duration or in terms of purely geometrical effects. To explain this and to satisfy the observed positive correlation between continuum luminosity and BLR size in an individual source, the responsivity-weighted radius must increase with increasing continuum luminosity. For a BLR with fixed inner and outer boundaries this requires radial surface emissivity distributions which deviate significantly from a simple power law, and in such a way that the intrinsic emission-line responsivity increases towards larger BLR radii, in line with photoionization calculations.

Goad, M. R.; Korista, K. T.

2014-10-01

390

Pipe Line Control  

NASA Technical Reports Server (NTRS)

The array of tanks, pipes and valves in the photo below is a petroleum tank farm in Georgia, part of a petrochemical pipe line system that moves refined petroleum products from Texas and Louisiana to the mid-Eastern seaboard. The same pipes handle a number of different products, such as gasoline, kerosene, jet fuel or fuel oil. The fluids are temporarily stored in tanks, pumped into the pipes in turn and routed to other way stations along the pipe line. The complex job of controlling, measuring and monitoring fuel flow is accomplished automatically by a computerized control and communications system which incorporates multiple space technologies.

1978-01-01

391

Dark matter detection in two easy steps  

NASA Astrophysics Data System (ADS)

Multicomponent dark matter particles may have a more intricate direct detection signal than simple elastic scattering on nuclei. In a broad class of well-motivated models, the inelastic excitation of dark matter particles is followed by de-excitation via ? decay. In experiments with fine energy resolution, such as many 0?2? decay experiments, this motivates a highly model-independent search for the sidereal daily modulation of an unexpected ? line. Such a signal arises from a two-step weakly interacting massive particle (WIMP) interaction: the WIMP is first excited in the lead shielding and subsequently decays back to the ground state via the emission of a monochromatic ? within the detector volume. We explore this idea in detail by considering the model of magnetic inelastic WIMPs and take a sequence of CUORE-type detectors as an example. We find that under reasonable assumptions about detector performance it is possible to efficiently explore mass splittings of up to a few hundred keV for a WIMP of weak-scale mass and transitional magnetic moments. The modulation can be cheaply and easily enhanced by the presence of additional asymmetric lead shielding. We devise a toy simulation to show that a specially designed asymmetric shielding may result in up to 30% diurnal modulations of the two-step WIMP signal, leading to additional strong gains in sensitivity.

Pospelov, Maxim; Weiner, Neal; Yavin, Itay

2014-03-01

392

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

393

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

394

Endothelium and “silver lines  

Microsoft Academic Search

The significance of endothelial “silver lines” was studied by TEM in rat aortas after perfusion with glutaraldehyde followed by silver nitrate. Standard TEM technique proved unsatisfactory (coarse silver granules, imprecise localization, artefacts). Exposure of the silver-treated aortas to photographic fixer markedly improved the image of the deposits leaving fine, stable, uniform “residual granules” about 100 Å in diameter. Most of

Thomas Zand; Jean M. Underwood; John J. Nunnari; Guido Majno; Isabelle Joris

1982-01-01

395

Dashed lines relationships  

E-print Network

interactions Bold lines imply more-certain interactions Species 1 (e.g., mouse) Species 2 (e.g., human) N N N N applications of systems biology to biomedical research are to identify genetic risk factors for disease, allow for model-based personalized diagnostics and treatment regimens and suggest new avenues for drug discovery

396

Explosives with Lined Cavities  

Microsoft Academic Search

Explosives detonated in contact with thick steel plates produce much deeper holes in the steel when there is a cavity in the explosive in contact with the plate. While this phenomenon has been known for more than 150 years, the enormous increase in penetrating power that can be produced by lining the explosive cavity with thin metal has been discovered

Garrett Birkhoff; Duncan P. MacDougall; Emerson M. Pugh; Geoffrey Taylor

1948-01-01

397

The Front Line.  

ERIC Educational Resources Information Center

The author draws an analogy between today's school system and an assembly line, deploring the notion that all children are taught the same thing at the same time, ending in humiliation, disgrace, and failure for some, and nonchallenging academic activities for others. (KC)

Unks, Gerald

1979-01-01

398

Building with a Line  

ERIC Educational Resources Information Center

Architecture is a versatile, multifaceted area to study in the artroom with multiple age levels. It can easily stimulate a study of basic line, shape, and various other art elements and principles. It can then be extended into a more extensive study of architectural elements, styles, specific architects, architecture of different cultures, and…

Hubbert, Beth

2011-01-01

399

On contrail climate sensitivity  

Microsoft Academic Search

In equilibrium climate change simulations with a global climate model we estimate the climate sensitivity parameter to contrail cirrus to be 0.43 K\\/(Wm?2), only about 60% of the corresponding value for a CO2 forcing. The spatial pattern of the surface temperature response is much smoother than the forcing pattern of contrails with little correlation between both. As the thermal inertia

M. Ponater; S. Marquart; R. Sausen; U. Schumann

2005-01-01

400

On contrail climate sensitivity  

Microsoft Academic Search

In equilibrium climate change simulations with a global climate model we estimate the climate sensitivity parameter to contrail cirrus to be 0.43 K\\/(Wm-2), only about 60% of the corresponding value for a CO2 forcing. The spatial pattern of the surface temperature response is much smoother than the forcing pattern of contrails with little correlation between both. As the thermal inertia

M. Ponater; S. Marquart; R. Sausen; U. Schumann

2005-01-01

401

CDF's Higgs sensitivity status  

SciTech Connect

The combined sensitivity of CDF's current Standard Model Higgs boson searches is presented. The expected 95% CL limits on the production cross section times the relevant Higgs boson branching ratios are computed for the W{sup {+-}}H {yields} {ell}{sup {+-}}{nu}b{bar b}, ZH {yields} {nu}{bar {nu}}b{bar b}, gg {yields} H {yields} W{sup +}W{sup -} W{sup {+-}}H {yields} W{sup {+-}}W{sup +}W{sup -} channels as they stand as of the October 2005, using results which were prepared for Summer 2005 conferences and a newer result form the gg {yields} H {yields} W{sup +}W{sup -} channel. Correlated and uncorrelated systematic uncertainties are taken into account, and the luminosity requirements for 95% CL exclusion, 3{sigma} evidence, and 5{sigma} discovery are computed for median experimental outcomes. A list of improvements required to achieve the sensitivity to a SM Higgs boson as quantified in the Higgs Sensitivity Working Group's report is provided.

Junk, Tom; /Illinois U., Urbana

2005-10-01

402

Sensitivity testing and analysis  

SciTech Connect

New methods of sensitivity testing and analysis are proposed. The new test method utilizes Maximum Likelihood Estimates to pick the next test level in order to maximize knowledge of both the mean, {mu}, and the standard deviation, {sigma} of the population. Simulation results demonstrate that this new test provides better estimators (less bias and smaller variance) of both {mu} and {sigma} than the other commonly used tests (Probit, Bruceton, Robbins-Monro, Langlie). A new method of analyzing sensitivity tests is also proposed. It uses the Likelihood Ratio Test to compute regions of arbitrary confidence. It can calculate confidence regions, for {mu}, {sigma}, and arbitrary percentiles. Unlike presently used methods, such as the program ASENT which is based on the Cramer-Rao theorem, it can analyze the results of all sensitivity tests, and it does not significantly underestimate the size of the confidence regions. The new test and analysis methods will be explained and compared to the presently used methods. 19 refs., 12 figs.

Neyer, B.T.

1991-01-01

403

PORTION OF A LINE (LEFT) AND B LINE (RIGHT) ON ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

PORTION OF A LINE (LEFT) AND B LINE (RIGHT) ON STEEP, ROCKY SLOPE. A LINE POLE 20 (LEFT BACKGROUND) HAS ORIGINAL GLASS PIN-TYPE INSULATORS. VIEW TO SOUTHEAST. - Mystic Lake Hydroelectric Facility, Electric Transmission A Line, Along West Rosebud Creek, Fishtail, Stillwater County, MT

404

Ultraviolet interstellar absorption lines from low-z galaxies  

NASA Astrophysics Data System (ADS)

The importance of studying absorption lines from z<<0.1 galaxies are discussed. The Mg II ??2796 and 2803 Å doublet absorption is sensitive to low column density gas and has been used to search for absorption lines from low-z galaxies. Recent studies of abundances and depletion patterns toward the Small Magellanic Cloud (Welty et al. 1997) and the NGC 1705 sightline (Sahu & Blades, 1997) are reviewed.

Sahu, M. S.

1997-05-01

405

Spetroscopic Line-Depth Ratios and Solar Variability  

Microsoft Academic Search

The ratios of the central depths of selected spectral lines has proved to be a sensitive index of a star's temperature. Line-depth ratios have been successfully applied to main sequence stars (Gray 1994 P.A.S.P. 106, 1248) as well as giants (Gray &Brown 2001 P.A.S.P., 113, 723). A stellar calibration and subsequent application to solar data over a magnetic cycle gave

D. Gray

2002-01-01

406

WIMP Dark Matter through the Dilaton Portal  

E-print Network

We study a model in which dark matter couples to the Standard Model through a dilaton of a sector with spontaneously broken approximate scale invariance. Scale invariance fixes the dilaton couplings to the Standard Model and dark matter fields, leaving three main free parameters: the symmetry breaking scale $f$, the dilaton mass $m_{\\sigma}$, and the dark matter mass $m_{\\chi}$. We analyze the experimental constraints on the parameter space from collider, direct and indirect detection experiments including the effect of Sommerfeld enhancement, and show that dilaton exchange provides a consistent, calculable framework for cold dark matter with $f,\\,m_\\sigma,\\,m_\\chi$ of roughly similar magnitude and in the range $\\sim 1-10$ TeV. Direct and indirect detection experiments, notably future ground-based gamma ray and space-based cosmic ray measurements, can probe the model all the way to dark matter mass in the multi-TeV regime.

Blum, Kfir; Csaki, Csaba; Lee, Seung J

2014-01-01

407

Sensitizers, protectors and oncogenic transformation in vitro  

SciTech Connect

Systems developed to assay oncogenic transformation in vitro represent a rapid and powerful tool to screen and compare new radiosensitizers in their carcinogenic potential, and to search for compounds that reduce or inhibit carcinogenesis produced by both radiation and sensitizers. An established line of mouse embryo fibroblasts (C3H/10T1/2 cells) has been used to determine the incidence of transformation produced by a variety of 2 and 5 substituted nitroimidazoles; these include metronidazole, desmethylmisonidazle, misonidazole, SR 2508, SR 2555, R0-07-0741, RSU-1047 and RSU-1021. Most of these sensitizers produce a similar level of transformation; for example a three day exposure of aerated cells to a concentration of 1 mM of the drug results in a transformation incidence comparable to 1 Gy of X rays. The notable exception is SR 2508 which produces a five-fold higher incidence of transformation. The potential carcinogenicity of sensitizers must be considered in choosing which of the currently available new drugs is to be used in clinical trials as an alternative to misonidazle. Superoxide dismutase (SOD), a known free radical scavenger, has been shown to reduce the level of transformation produced by radiation and sensitizers. To be effective, SOD must be present for prolonged periods during the fixation and expression period of the transformation process.

Miller, R.C.; Osmak, R.; Zimmerman, M.; Hall, E.J.

1982-03-01

408

A survey of human breast cancer sensitivity to growth inhibition by calmodulin antagonists in tissue culture.  

PubMed

We compared the ability of N-(4-aminobutyl)-5-chloro-2-naphthalenesulfonamide (W-13), a calmodulin antagonist, to inhibit the growth of seven human breast cancer cell lines in tissue culture, to determine whether drug sensitivity was related to estrogen receptor (ER) status, tamoxifen resistance (tamr), or levels of calmodulin activity. We examined three ER+ (estrogen receptor-positive) cell lines (MCF-7, ZR-75-1B, and T47D), two ER+/tamr lines (LY2 and RR), and two ER- (estrogen receptor-negative) cell lines (MDA-MB-231 and MDA-MB-435). There was no difference in the inhibition of cell growth by W-13 in MCF-7 cells and the two tamr MCF-7 cell derivatives, LY2 and RR. In addition, the sensitivity to W-13 did not appear to be related to ER status. Although the mean Ki of the five ER+ cell lines (31 microM) was somewhat higher than the mean Ki of the two ER- cell lines (23 microM), the two cell lines most sensitive to W-13 were the ER+ T47D cells (Ki 15 microM) and the ER- MDA-MB-435 cells (Ki 10 microM). Calmodulin activity was measured in three representative cell lines, MCF-7, LY2, and MDA-MB-435. Calmodulin levels were higher in the most sensitive cell line (MDA-MB-435, 2.7 ng calmodulin/micrograms protein) than in the two less sensitive cell lines, MCF-7 and LY2 (1.3 and 1.6 ng calmodulin/micrograms protein, respectively). However, the MCF-7, LY2, and MDA-MB-435 cells were equally sensitive to another specific calmodulin antagonist, calmidazolium. We conclude that neither ER status, tamoxifen resistance, nor levels of calmodulin activity predict the sensitivity of human breast cancer cell lines to growth inhibition in tissue culture by calmodulin antagonists. PMID:8031308

Strobl, J S; Peterson, V A; Woodfork, K A

1994-06-15

409

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.

Ikezi, Hiroyuki (Rancho Santa Fe, CA); Lin-Liu, Yuh-Ren (San Diego, CA); DeGrassie, John S. (Encinitas, CA)

1991-01-01

410

Earthquakes and Fault Lines  

NSDL National Science Digital Library

The purpose of this activity is for students to find the locations of the fault lines in Utah and understand that fault lines are often earthquake zones. They will learn how often earthquakes are expected to occur, when Utah is due for another one, and where the next one is expected to occur. This meets the Utah Core Standard for fifth grade science: Standard 2: Students will understand that volcanoes, earthquakes, uplift, weathering, and erosion reshape Earth's surface. Objective 1,c: Explain the relationship between time and specific geological changes. Objective 2: Explain how volcanoes, earthquakes, and uplift affect Earth's surface. Situation You are from Montana, and your dad just got a new job in Northern Utah. Your family will have to move there. Your parents have heard that Utah has the potential for major earthquakes, and don?t know where to build your new house. They ...

Bennington, Miss

2010-04-26

411

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

412

Cryogenic Transfer Line Chilldown  

Microsoft Academic Search

The transient behavior of a small-scale cryogenic transfer line was investigated during chilldown to cryogenic temperatures. The vacuum-jacketed apparatus consisted of a vertical tube followed by a near-horizontal tube. The tube diameter was 1 cm and the overall length was 4.4 m. The apparatus was equipped with view-ports in the near-horizontal section to allow visual observation of the flow patterns.

N. T. van Dresar; J. D. Siegwarth

2004-01-01

413

On-Line Expeditions  

NSDL National Science Digital Library

On-line expeditions explores the ocean depths by introducing deep-sea research with interactive features, photos, audio and video clips and middle/high school classroom participation. The topics covered include deep sea geology and hydrothermal vents; history of deep-sea exploration and technology; hydrography and chemical oceanography; marine life and more. Teachers can access a resource guide and activities. The period of time covered is from 2000 to 2004.

414

Line Up! Classroom Activity  

NSDL National Science Digital Library

In this lesson from Math Machines, students will complete the programming for a calculator program which will automate a pulley to move a stick. The goal will be to line the stick up between two points on a pegboard. Students will gain experience with linear algebra via this exercise. A participant handout (including worksheets) and facilitator notes are made available for download in DOC file format. Links to the required calculator programs are also provided.

Chaney, Robert

2011-11-10

415

Psychiatry On-Line  

NSDL National Science Digital Library

The field of psychiatry is one that is vast and rather complex, and fortunately for academics and practitioners in the field, the Psychiatry On-Line Web site provides a well-conceived international forum for the discipline. Edited and maintained since 1994 by Dr. Ben Green (a licensed psychiatrist in the United Kingdom), the site features peer-reviewed articles, papers, and case reports from around the world. Part of the Priory group, Psychiatry On-Line contains links to other germane online journals, including the Italian and Brazilian counterparts to the English-language version of Psychiatry On-Line. Visitors will want to browse the archives of previously featured papers, which are thematically organized under topics ranging from affective disorders to substance abuse. The general public will find the section Psychiatry in the Cinema of note, as Dr. Green offers commentary on the depiction of persons with psychiatric conditions (such as schizophrenia) in films like "A Beautiful Mind" and "As Good as it Gets."

1994-01-01

416

Cryogenic Transfer Line Chilldown  

NASA Astrophysics Data System (ADS)

The transient behavior of a small-scale cryogenic transfer line was investigated during chilldown to cryogenic temperatures. The vacuum-jacketed apparatus consisted of a vertical tube followed by a near-horizontal tube. The tube diameter was 1 cm and the overall length was 4.4 m. The apparatus was equipped with view-ports in the near-horizontal section to allow visual observation of the flow patterns. Wall temperatures were measured at various locations along the length of the transfer line. Each test was conducted at a constant liquid volumetric flowrate at the transfer line inlet until saturation temperatures were obtained throughout the system. Liquid flowrate was varied by more than two orders of magnitude and resulted in chilldown times ranging from a few minutes to several hours. An optimum flowrate exists that minimizes liquid consumption during the chilldown process. At higher flowrates, there is insufficient time for heat transfer from the liquid to the wall and inefficiencies result from the greater amount of incompletely vaporized liquid passing through the system. At lower flowrates, chilldown time and total ambient heat leak into the system increase, which raises liquid consumption. The experimental values of liquid consumption are compared to analytical estimates. At low flowrates, the data compares favorably to a minimum consumption model while at high flowrates the maximum consumption model overpredicts hydrogen consumption and underpredicts nitrogen consumption.

Van Dresar, N. T.; Siegwarth, J. D.

2004-06-01

417

A genetic animal model of differential sensitivity to methamphetamine reinforcement  

PubMed Central

Sensitivity to reinforcement from methamphetamine (MA) likely influences risk for MA addiction, and genetic differences are one source of individual variation. Generation of two sets of selectively bred mouse lines for high and low MA drinking has shown that genetic factors influence MA intake, and pronounced differences in sensitivity to rewarding and aversive effects of MA play a significant role. Further validation of these lines as a unique genetic model relevant to MA addiction was obtained using operant methods to study MA reinforcement. High and low MA drinking line mice were used to test the hypotheses that: 1) oral and intracerebroventricular (ICV) MA serve as behavioral reinforcers, and 2) MA exhibits greater reinforcing efficacy in high than low MA drinking mice. Operant responses resulted in access to an MA or non-MA drinking tube or intracranial delivery of MA. Behavioral activation consequent to orally consumed MA was determined. MA available for consumption maintained higher levels of reinforced instrumental responding in high than low MA drinking line mice, and MA intake in the oral operant procedure was greater in high than low MA drinking line mice. Behavioral activation was associated with amount of MA consumed during operant sessions. High line mice delivered more MA via ICV infusion than did low line mice across a range of doses. Thus, genetic risk factors play a critical role in the reinforcing efficacy of MA and the oral self-administration procedure is suitable for delineating genetic contributions to MA reinforcement. PMID:22280875

Shabani, Shkelzen; Dobbs, Lauren K; Ford, Matthew M; Mark, Gregory P; Finn, Deborah A; Phillips, Tamara J

2012-01-01

418

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 reve