Search Results - (Author, Cooperation:C. Christensen)

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  1. 1
    Staff View
    Publication Date:
    2018-02-02
    Publisher:
    BMJ Publishing
    Electronic ISSN:
    2044-6055
    Topics:
    Medicine
    Keywords:
    Geriatric medicine, Open access, Geriatric medicine
    Published by:
    Latest Papers from Table of Contents or Articles in Press
  2. 2
    Jeffrey A. Thompson; Brock C. Christensen; Carmen J. Marsit
    Nature Publishing Group (NPG)
    Published 2018
    Staff View
    Publication Date:
    2018-03-27
    Publisher:
    Nature Publishing Group (NPG)
    Electronic ISSN:
    2045-2322
    Topics:
    Natural Sciences in General
    Published by:
    Latest Papers from Table of Contents or Articles in Press
  3. 3
    Staff View
    Publication Date:
    2015-09-19
    Publisher:
    American Association for the Advancement of Science (AAAS)
    Print ISSN:
    0036-8075
    Electronic ISSN:
    1095-9203
    Topics:
    Biology
    Chemistry and Pharmacology
    Computer Science
    Medicine
    Natural Sciences in General
    Physics
    Keywords:
    Acclimatization/*genetics ; Alleles ; Arctic Regions ; Body Height/genetics ; Body Weight/genetics ; Chromosomes, Human, Pair 11/genetics ; Climate ; *Diet, High-Fat ; Fatty Acids, Omega-3/*administration & dosage/analysis ; Female ; Genetic Loci ; Genome, Human/genetics ; Genome-Wide Association Study ; Greenland ; Humans ; Inuits/*genetics ; Linkage Disequilibrium ; Male ; Membrane Lipids/analysis/genetics ; Polymorphism, Single Nucleotide ; Selection, Genetic
    Published by:
    Latest Papers from Table of Contents or Articles in Press
  4. 4
    Staff View
    Publication Date:
    2012-03-01
    Publisher:
    Nature Publishing Group (NPG)
    Print ISSN:
    0028-0836
    Electronic ISSN:
    1476-4687
    Topics:
    Biology
    Chemistry and Pharmacology
    Medicine
    Natural Sciences in General
    Physics
    Keywords:
    Adaptor Proteins, Signal Transducing/metabolism ; Animals ; Benzoxazoles/pharmacology ; Cell Line, Tumor ; Cell Movement/drug effects/genetics ; Eukaryotic Initiation Factor-4E/metabolism ; Eukaryotic Initiation Factors/metabolism ; Gene Expression Regulation, Neoplastic/drug effects/genetics ; Genome/genetics ; Humans ; Male ; Mice ; Mice, Inbred C57BL ; Neoplasm Invasiveness/genetics ; *Neoplasm Metastasis/drug therapy/genetics ; Phosphoproteins/metabolism ; Prostatic Neoplasms/drug therapy/genetics/*pathology ; *Protein Biosynthesis ; Pyrimidines/pharmacology ; RNA, Messenger/genetics/metabolism ; Repressor Proteins/metabolism ; *Signal Transduction ; TOR Serine-Threonine Kinases/antagonists & inhibitors/*metabolism
    Published by:
    Latest Papers from Table of Contents or Articles in Press
  5. 5
    Staff View
    Publication Date:
    2018-09-21
    Publisher:
    American Association for the Advancement of Science (AAAS)
    Print ISSN:
    0036-8075
    Electronic ISSN:
    1095-9203
    Topics:
    Biology
    Chemistry and Pharmacology
    Geosciences
    Computer Science
    Medicine
    Natural Sciences in General
    Physics
    Keywords:
    Physics
    Published by:
    Latest Papers from Table of Contents or Articles in Press
  6. 6
    Staff View
    ISSN:
    1089-7674
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    Detailed measurements and transport analysis of divertor conditions in Alcator C-Mod [Phys. Plasmas 1, 1511 (1994)] are presented for a range of line-averaged densities, 0.7〈n¯e〈2.2×1020 m−3. Three parallel heat transport regimes are evident in the scrape-off layer: sheath-limited conduction, high-recycling divertor, and detached divertor, which can coexist in the same discharge. Local cross-field pressure gradients are found to scale simply with a local electron temperature. This scaling is consistent with classical electron parallel conduction being balanced by anomalous cross-field transport (χ⊥∼0.2 m2 s−1) proportional to the local pressure gradient. A 60%–80% of divertor power is radiated in attached discharges, approaching 100% in detached discharges. Detachment occurs when the heat flux to the plate is low and the plasma pressure is high (Te∼5 eV). High neutral pressures in the divertor are nearly always present (1–20 mTorr), sufficient to remove parallel momentum via ion–neutral collisions. © 1995 American Institute of Physics.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  7. 7
    Staff View
    ISSN:
    1089-7674
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    The regime of high particle and energy confinement known as the H mode [Phys. Rev. Lett. 49, 1408 (1982)] has been extended to a unique range of operation for divertor tokamaks up to toroidal fields of nearly 8 T, line-averaged electron densities of 3×1020 m−3, and surface power densities of nearly 0.6 MW/m2 in the compact high-field tokamak Alcator C Mod [Phys. Plasmas 1, 1511 (1994)]. H modes are achieved in Alcator C Mod with Ion Cyclotron Resonant Frequency (ICRF) heating and with Ohmic heating alone without boronization of the all molybdenum tiled first wall. Large increases in charge exchange flux are observed during the H mode over the entire range of energies from 2 to 10 keV. There appears to be an upper limit to the midplane neutral pressure, of about 0.08 Pa above which no H modes have been observed. The plasmas with the best energy confinement have the lowest midplane neutral pressures, below 0.01 Pa. There is an edge electron temperature threshold such that Te≥280 eV ±40 eV for sustaining the H mode, which is equal at L–H and H–L transitions. The hysteresis in the threshold power between L–H and H–L transitions is less than 25% on average. Both core and edge particle confinement improve by a factor of 2–4 from L mode to H mode. Energy confinement also improves by up to a factor of 2 over L mode. © 1996 American Institute of Physics.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  8. 8
    Staff View
    ISSN:
    1089-7674
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    Highly localized direct electron heating [full width at half-maximum (FWHM)≅0.2a] via mode converted ion Bernstein waves has been observed in the Alcator C-Mod Tokamak [I. H. Hutchinson et al., Phys. Plasmas 1, 1511 (1994)]. Electron heating at or near the plasma center (r/a≥0.3) has been observed in H(3He) discharges at B0=(6.0–6.5) T and ne(0)≅1.8×1020 m−3. [Here, the minority ion species is indicated parenthetically.] Off-axis heating (r/a≥0.5) has also been observed in D(3He) plasmas at B0=7.9 T. The concentration of 3He in these experiments was in the range of n3He/ne≅(0.2–0.3) and the locations of the mode conversion layer and electron heating peak could be controlled by changing the 3He concentration or toroidal magnetic field (B0). The electron heating profiles were deduced using a rf modulation technique. Detailed comparisons with one-dimensional and toroidal full-wave models in the ion cyclotron range of frequencies have been carried out. One-dimensional full-wave code predictions were found to be in qualitative agreement with the experimental results. Toroidal full-wave calculations indicated the importance of volumetric and wave focusing effects in the interpretation of the experimental results. © 1997 American Institute of Physics.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  9. 9
    Staff View
    ISSN:
    1089-7674
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    Early operation of the Alcator-C-MOD tokamak [I.H. Hutchinson, Proceedings of IEEE 13th Symposium on Fusion Engineering, Knoxville, TN, edited by M. Lubell, M. Nestor, and S. Vaughan (Institute of Electrical and Electronic Engineers, New York, 1990), Vol. 1, p. 13] is surveyed. Reliable operation, with plasma current up to 1 MA, has been obtained, despite the massive conducting superstructure and the associated error fields. However, vertical disruptions are not slowed by the long vessel time constant. With pellet fueling, peak densities up to 9×1020 m−3 have been attained and "snakes'' are often seen. Initial characterization of divertor and scrape-off layer is presented and indicates approximately Bohm diffusion. The edge plasma shows a wealth of marfe-like phenomena, including a transition to detachment from the divertor plates with accompanying radiative divertor regions. Energy confinement generally appears to exceed the expectations of neo-Alcator scaling. A transition to Ohmic H mode has been observed. Ion cyclotron heating experiments have demonstrated good power coupling, in agreement with theory.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  10. 10
    Staff View
    ISSN:
    1089-7674
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    Enhanced confinement modes up to a toroidal field of BT=8 T have been studied with up to 3.5 MW of radiofrequency (rf) heating power in the ion cyclotron range of frequencies (ICRF) at 80 MHz. H-mode is observed when the edge temperature exceeds a threshold value. The high confinement mode (H-mode) with higher confinement enhancement factors (H) and longer duration became possible after boronization by reducing the radiated power from the main plasma. A quasi-steady state with high confinement (H=2.0), high normalized beta (βN=1.5), low radiated power fraction (Pradmain/Ploss=0.3), and low effective charge (Zeff=1.5) has been obtained in Enhanced Dα H-mode. This type of H-mode has enhanced levels of continuous Dα emission and very little or no edge localized mode (ELM) activity, and reduced core particle confinement time relative to ELM-free H-mode. The pellet enhanced performance (PEP) mode is obtained by combining core fueling with pellet injection and core heating. A highly peaked pressure profile with a central value of 8 atmospheres was observed. The steep pressure gradient drives off-axis bootstrap current, resulting in a shear reversed safety factor (q) profile. Suppression of sawteeth appears to be important in maintaining the highly peaked pressure profile. Lithium pellets were found to be more effective than deuterium pellets in raising q0. © 1997 American Institute of Physics.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  11. 11
    Staff View
    ISSN:
    1089-7674
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    A series of transport experiments has been carried out in Alcator-C-Mod. [Phys Plasmas 1, 1511 (1994)]. Data from both Ohmic and ICRF (ion cyclotron range of frequencies) heated plasmas can be fitted with an L-mode (low mode) scaling law. The Ohmic τE's show no scaling with density in any regime and can reach values of 2–3 times neo-Alcator. Impurity confinement has been studied with the laser blow-off technique with τI showing nearly linear scaling with plasma current. Ohmic and ICRF H modes are obtained over a wide range of discharge parameters, extending the range in the international database for nB, by almost a factor of 10. The power threshold for ELM-free (edge localized mode) discharges is in rough agreement with the scaling P/S=0.044nB. Energy diffusivities of Ohmic and ICRF heated plasmas have been measured from local analysis of plasma profiles and power fluxes. The same analysis produces a value for plasma resistivity which lies between the Spitzer and neoclassical calculations. Analysis of plasma transients have yielded values for particle diffusivity and convection velocity. © 1995 American Institute of Physics.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  12. 12
    Hunn, John D. ; Withrow, S. P. ; White, C. W. ; Clausing, R. E. ; Heatherly, L. ; Christensen, C. Paul

    Woodbury, NY : American Institute of Physics (AIP)
    Published 1994
    Staff View
    ISSN:
    1077-3118
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    We have combined a technique for the lift-off of thin diamond films from a bulk diamond with a technique for engraving diamond with a focused excimer laser to produce free-standing single-crystal diamond microstructures. One microcomponent that has been produced is a 12 tooth gear ∼400 μm in diameter and ∼13 μm thick. Other microstructures have also been demonstrated, showing the versatility of this method. This process should be applicable to producing diamond microcomponents down to spatial dimensions (width and thickness) of a few micrometers. © 1994 American Institute of Physics.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  13. 13
    Grønningsaeter, H. ; Christensen, C. C. ; Larsen, S. ; Ursin, H.

    Oxford, UK : Blackwell Publishing Ltd
    Published 1991
    Staff View
    ISSN:
    1600-0838
    Source:
    Blackwell Publishing Journal Backfiles 1879-2005
    Topics:
    Medicine
    Sports Science
    Notes:
    The relationships between levels of physical activity and self-reports of health complaints, job stress and psychological defense were investigated in a broad screening on clerical workers in an insurance company (n= 171). The workers were divided into 4 groups, based on self-reports of self-administered leisure physical activity or sports. The highly physically active group (n= 43) had 3 or more sessions of at least 45 min regular physical exercise per week. The moderately active group (n= 31) had 1–2 sessions, the seldom active group (n= 31) less than 1 session per week and the totally inactive group (n= 66). The moderately active subjects reported significantly lower levels of subjective health complaints, including anxiety and depression, and higher job satisfaction than the seldom active and inactive subjects. There did not seem to be any additional benefits related to subjectively reported health or job stress in the group having 3 or more exercise sessions per week. The activity groups also differed with regard to psychological defense mechanisms. The highly active group showed more compensation than less active groups, and the inactive had more projection than the other groups. Projection was related to subjective health complaints.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  14. 14
    KRANTZ, T. ; CHRISTENSEN, C. B.

    Oxford, UK : Blackwell Publishing Ltd
    Published 1987
    Staff View
    ISSN:
    1365-2044
    Source:
    Blackwell Publishing Journal Backfiles 1879-2005
    Topics:
    Medicine
    Notes:
    Morphine 20 mg and pethidine 50 mg were accidentally injected intrathecally in a patient who had received large doses of opioids epidurally for cancer pain and who had shown tolerance to their effects. The well established tolerance to spinal opioids did not protect the patient against a moderate degree of respiratory depression. Morphine concentrations 6.5 hours after the morphine injection were 103 500 ng/ml and 52 ng/ml in cerebrospinal fluid and serum, respectively.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  15. 15
    CHRISTENSEN, C. M. ; CASPER, L. M.

    Oxford, UK : Blackwell Publishing Ltd
    Published 1987
    Staff View
    ISSN:
    1750-3841
    Source:
    Blackwell Publishing Journal Backfiles 1879-2005
    Topics:
    Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Process Engineering, Biotechnology, Nutrition Technology
    Notes:
    Solution viscosity, like many other textural properties of foods, can be perceived by more than one sensory modality or method of sensory exploration. The present study compared judgments of solution viscosity obtained by oral (tactile/kinesthetic) and nonoral (visual and tactile/kinesthetic) modes of sensing. The slopes of the functions describing physical and perceptual viscosity were similar for the different methods but solutions were perceived as more viscous when judged in the mouth.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  16. 16
    Saunders, D.E. ; Christensen, C. ; Brooks, S.C.

    Amsterdam : Elsevier
    Staff View
    ISSN:
    0039-128X
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Medicine
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  17. 17
    Staff View
    ISSN:
    0375-9474
    Keywords:
    Nuclear reactions
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Physics
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  18. 18
    Staff View
    ISSN:
    0006-291X
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Biology
    Chemistry and Pharmacology
    Physics
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  19. 19
    Staff View
    ISSN:
    0362-3319
    Source:
    Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics:
    Sociology
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses
  20. 20
    Christensen, C. M.
    Springer
    Published 1971
    Staff View
    ISSN:
    1573-0832
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Biology
    Medicine
    Notes:
    Abstract In sorghum seed stored at 22–25° C for 535 days, invasion by storage fungi and loss of germinability increased greatly with small increases in moisture content between 13.5 and 15.5 %. Seeds dried for 18 hours at 70° C, then exposed to a relative humidity of 75 %, had a lower equilibrium moisture content, but were more heavily invaded by storage fungi and lost germinability fsater, than those that had been conditioned to 20 % moisture before storage at 75 % relative humidity. The 10 samples of Grade No. 2 sorghum examined averaged about 13.0 % moisture, germinated an average of 59 %, yieldedAlternaria from 75 % of the surface-disinfected kernels andAspergillus glaucus from 4 %; judged by these criteria, the lots from which the samples came were in good condition for continued storage.
    Type of Medium:
    Electronic Resource
    URL:
    Articles: DFG German National Licenses