Search

Your search keyword '"Karttunen, S"' showing total 109 results
Start Over Author "Karttunen, S"
109 results on '"Karttunen, S"'

2. Oxygen-dependent hydroxylation by FIH regulates the TRPV3 ion channel

Author

Karttunen, S, Duffield, M, Scrimgeour, NR, Squires, L, Lim, WL, Dallas, ML, Scragg, JL, Chicher, J, Dave, KA, Whitelaw, ML, Peers, C, Gorman, JJ, Gleadle, JM, Rychkov, GY, and Peet, DJ

Abstract

Factor inhibiting HIF (FIH, also known as HIF1AN) is an oxygendependent asparaginyl hydroxylase that regulates the hypoxiainducible factors (HIFs). Several proteins containing ankyrin repeat domains (ARDs) have been characterised as substrates of FIH, although there is little evidence for a functional consequence of hydroxylation on these substrates. This study demonstrates that the transient receptor potential vanilloid 3 (TRPV3) channel is hydroxylated by FIH on asparagine 242 within the cytoplasmic ARD. Hypoxia, FIH inhibitors and mutation of asparagine 242 all potentiated TRPV3-mediated current, without altering TRPV3 protein levels, indicating that oxygen-dependent hydroxylation inhibits TRPV3 activity. This novel mechanism of channel regulation by oxygen-dependent asparaginyl hydroxylation is likely to extend to other ion channels.

Published
2015

4. Progress in LHCD: a tool for advanced regimes on ITER

Author

Tuccillo, A A, primary, Barbato, E, additional, Bae, Y S, additional, Becoulet, A, additional, Bernabei, S, additional, Bibet, P, additional, Calabrò, G, additional, Cardinali, A, additional, Castaldo, C, additional, Cesario, R, additional, Cho, M H, additional, Cirant, S, additional, Crisanti, F, additional, Ekedahl, A, additional, Eriksson, L-G, additional, Farina, D, additional, Giruzzi, G, additional, Goniche, M, additional, Granucci, G, additional, Ide, S, additional, Imbeaux, F, additional, Karttunen, S, additional, Litaudon, X, additional, Mailloux, J, additional, Mazon, D, additional, Mirizzi, F, additional, Moreau, D, additional, Nowak, S, additional, Namkung, W, additional, Panaccione, L, additional, Pericoli-Ridolfini, V, additional, Peysson, Y, additional, Petrzilka, V, additional, Podda, S, additional, Rantamaki, K, additional, Santini, F, additional, Saveliev, A, additional, Schneider, M, additional, Sozzi, C, additional, and Suzuki, T, additional

Published
2005
Full Text
View/download PDF

5. Bright spots generated by lower hybrid waves on JET

Author

Rantamäki, K M, primary, Petržílka, V, additional, Andrew, P, additional, Coffey, I, additional, Ekedahl, A, additional, Erents, K, additional, Fuchs, V, additional, Goniche, M, additional, Granucci, G, additional, Joffrin, E, additional, Karttunen, S J, additional, Lomas, P, additional, Mailloux, J, additional, Mantsinen, M, additional, Mayoral, M-L, additional, McDonald, D C, additional, Noterdaeme, J-M, additional, Parail, V, additional, Tuccillo, A A, additional, Žáček, F, additional, and Workprogramme, Contributors to the EFDA—JET, additional

Published
2005
Full Text
View/download PDF

16. Observations of relativistic plasma waves excited by a and laser beat

Author

Dyson, A, primary, Dangor, A E, additional, Dymoke-Bradshaw, A K L, additional, Ashfar-Rad, T, additional, Gibbon, P, additional, Bell, A R, additional, Danson, C N, additional, Edwards, C B, additional, Amiranoff, F, additional, Matthieusent, G, additional, Karttunen, S J, additional, and Salomaa, R R E, additional

Published
1996
Full Text
View/download PDF

26. Particle-in-cell simulation of ion Bernstein wave excitation.

Author

Lo¨nnroth, J. S., Heikkinen, J. A., Rantama¨ki, K. M., and Karttunen, S. J.

Subjects
ION acoustic waves, PLASMA dynamics
Abstract

Ion Bernstein wave excitation is investigated with the self-consistent two-dimensional particle-in-cell method. The real ion to electron mass ratio is used in simulations in high harmonic frequency bands. The simulation results are compared with linear theory and ray tracing. Successful excitation of the ion Bernstein wave has been demonstrated with the particle-in-cell method. In some cases, the excited wave temporarily propagates in the opposite direction and slows down permanently due to complicated dispersive behavior, which makes it very difficult to use the particle-in-cell method. The excitation is studied as a function of temperature and frequency, i.e., it is determined how the dispersive behavior varies in the parameter space. The simulations indicate that there is a temperature-and-frequency-dependent critical level of coupled energy flux above which excitation fails. Possible effects causing the failure of excitation at high power intensity are identified. [ABSTRACT FROM AUTHOR]

Published
2002
Full Text
View/download PDF

27. Parametric scattering in electron-cyclotron resonance heating.

Author

Heikkinen, J. A. and Karttunen, S. J.

Subjects
*CYCLOTRON waves, *SCATTERING (Physics), *PLASMA gases, *DISPERSION relations
Abstract

The problem of parametric scattering of the extraordinary and ordinary waves near electron-cyclotron frequency off ion-cyclotron waves is investigated. Convective thresholds for an inhomogeneous plasma are obtained analytically in the case when the scattered ordinary or extraordinary waves and the ion-cyclotron wave are weakly damped. There are no restrictions on the angles the waves make with the ambient magnetic field. The dependence of the thresholds on the plasma density, electron and ion temperatures, and propagation angles is described. It is found that in present-day electron-cyclotron resonance heating experiments (I<=1 kW/cm2) the thresholds are evidently too high for parametric scattering, but in high-intensity (I>=10 kW/cm2) experiments the possibility for scattering exists. [ABSTRACT FROM AUTHOR]

Published
1986
Full Text
View/download PDF

28. Intensity saturation of stimulated Raman scattering by ion-wave coupling.

Author

Heikkinen, J. A. and Karttunen, S. J.

Subjects
*RAMAN effect, *ION acoustic waves, *PLASMONS (Physics)
Abstract

Nonlinear saturation of stimulated Raman scattering caused by ion-wave coupling is investigated analytically and numerically. Various linear damping conditions for plasmons and ion-acoustic waves are included in the analysis. The main results can be summarized in terms of the normalized damping coefficient β (β=Raman gain length/plasmon absorption length), which decreases with the laser intensity I as β∼I-1/2. At low intensities (β>4) the Raman reflectivity increases according to the well-known three-wave process. At high intensities (0.2<β<2) a steady state still exists and the reflectivity is saturated as a function of the laser intensity. At very high intensities (β<0.1) temporally spiky and chaotic reflectivity is obtained. The reflectivities remain at very low levels, except for large interaction lengths. [ABSTRACT FROM AUTHOR]

Published
1986
Full Text
View/download PDF

32. 3ω0/2 harmonic emission from thin foils.

Author

Aboites, V., Hughes, T. P., McGoldrick, E., Sim, S. M. L., Karttunen, S. J., and Evans, R. G.

Subjects
ULTRASHORT laser pulses, LIGHT
Abstract

Temporally and spectrally resolved 3ω[sub 0]/2 harmonic emission has been recorded from 1.05 µm laser-irradiated thin foil targets which become underdense during the laser pulse of 600-900 psec. Changes in the spectra of both the backscattered and forward scattered harmonic light are observed coincident with the disappearance of the n[sub c] surface. The results are analyzed by considering the matching conditions for the generation of the 3ω[sub 0]/2 light, including the effects of plasma wave refraction in the inhomogeneous plasma. [ABSTRACT FROM AUTHOR]

Published
1985
Full Text
View/download PDF

34. Electromagnetic particle-in-cell simulations of a lower hybrid grill

Author

Rantamäki, K M, Pättikangas, T J H, Karttunen, S J, Alm-Lytz, K M, Verboncoeur, J P, and Mardahl, P

Abstract

The coupling of lower hybrid waves to the plasma is a crucial issue for efficient current drive in tokamaks. In this work, the coupling problem is attacked with a new tool in this context: an electromagnetic particle-in-cell (PIC) code, (Verboncoeur J P et al 1995 Comp. Phys. Comm. 87 199). A model for a grill with 32 waveguides is constructed using perfectly conducting walls. The wave propagation in the waveguides and the coupling to plasma is followed. The wave–plasma interaction is studied and the evolution of the launched spectrum is resolved in the near-field of the grill. The reflection coefficients in the individual waveguides are determined.

Published
2002
Full Text
View/download PDF

38. Systems Planning and Development in Finnish Newspapers

Author

Karttunen, S.

Abstract

Newspapers are becoming a significant user of systems. This has changed the strategy, investment and personnel structure of Finnish newspaper production plants already during the 1970's National joint efforts and firm policies are reviewed. The reasons for this development are analyzed. At the same time as systems are implemented improvements have been obtained in work flow, productivity and economy. There are also problems as many newspapers cannot follow the accelerating technology transfer. In the most successful cases the firms change from passive buyers to active systems development and planning units which both create and transfer new technology. Newspaper systems are highly individual and require an essential software tailoring. On the other hand graphic mass communication -- such as newspaper -- gets new alternative and competing forms. Newspapers as many other institutions are interested in developing advertising and electronic media such as cable-TV, pay-TV, videotex and video recordings.

Published
1982

42. Forced Raman scattering in air by a two-frequency laser beam

Author

Dangor, A E, primary, Dymoke-Bradshaw, A K L, additional, Dyson, A, additional, Garvey, T, additional, Karttunen, S J, additional, Partanen, J P, additional, Salomaa, R R E, additional, Cole, A J, additional, Danson, C, additional, Edwards, C B, additional, and Evans, R G, additional

Published
1989
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results