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21 results on '"Sierchio, J."'

1. Measuring Competency of Machine Learning Systems and Enforcing Reliability

Author

Planer, M., Sierchio, J. M., and Systems, for BAE

Subjects
Computer Science - Machine Learning, C.4
Abstract

We explore the impact of environmental conditions on the competency of machine learning agents and how real-time competency assessments improve the reliability of ML agents. We learn a representation of conditions which impact the strategies and performance of the ML agent enabling determination of actions the agent can make to maintain operator expectations in the case of a convolutional neural network that leverages visual imagery to aid in the obstacle avoidance task of a simulated self-driving vehicle., Comment: 2 pages with 1 figure, Appears in Proceedings of AAAI FSS-22 Symposium Lessons Learned for Autonomous Assessment of Machine Abilities (LLAAMA)

Published
2022

2. ARC: A compact, high-field, fusion nuclear science facility and demonstration power plant with demountable magnets

Author

Sorbom, B. N., Ball, J., Palmer, T. R., Mangiarotti, F. J., Sierchio, J. M., Bonoli, P., Kasten, C., Sutherland, D. A., Barnard, H. S., Haakonsen, C. B., Goh, J., Sung, C., and Whyte, D. G.

Subjects
Physics - Plasma Physics, Physics - Instrumentation and Detectors
Abstract

The affordable, robust, compact (ARC) reactor conceptual design study aims to reduce the size, cost, and complexity of a combined fusion nuclear science facility (FNSF) and demonstration fusion Pilot power plant. ARC is a 200-250 MWe tokamak reactor with a major radius of 3.3 m, a minor radius of 1.1 m, and an on-axis magnetic field of 9.2 T. ARC has rare earth barium copper oxide (REBCO) superconducting toroidal field coils, which have joints to enable disassembly. This allows the vacuum vessel to be replaced quickly, mitigating first wall survivability concerns, and permits a single device to test many vacuum vessel designs and divertor materials. The design point has a plasma fusion gain of Q_p~13.6, yet is fully non-inductive, with a modest bootstrap fraction of only ~63%. Thus ARC offers a high power gain with relatively large external control of the current profile. This highly attractive combination is enabled by the ~23 T peak field on coil with newly available REBCO superconductor technology. External current drive is provided by two innovative inboard RF launchers using 25 MW of lower hybrid and 13.6 MW of ion cyclotron fast wave power. The resulting efficient current drive provides a robust, steady state core plasma far from disruptive limits. ARC uses an all-liquid blanket, consisting of low pressure, slowly flowing fluorine lithium beryllium (FLiBe) molten salt. The liquid blanket is low-risk technology and provides effective neutron moderation and shielding, excellent heat removal, and a tritium breeding ratio >= 1.1. The large temperature range over which FLiBe is liquid permits blanket operation at 900 K with single phase fluid cooling and a high-efficiency Brayton cycle, allowing for net electricity generation when operating ARC as a Pilot power plant., Comment: 35 pages, 32 figures

Published
2014
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3. The Decay of Debris Disks around Solar-Type Stars

Author

Sierchio, J. M., Rieke, G. H., Su, K. Y. L., and Gaspar, Andras

Subjects
Astrophysics - Earth and Planetary Astrophysics, Astrophysics - Solar and Stellar Astrophysics
Abstract

We present a Spitzer MIPS study of the decay of debris disk excesses at 24 and 70 $\mu$m for 255 stars of types F4 - K2. We have used multiple tests, including consistency between chromospheric and X-ray activity and placement on the HR diagram, to assign accurate stellar ages. Within this spectral type range, at 24 $\mu$m, $13.6 \pm 2.8 \%$ of the stars younger than 5 Gyr have excesses at the 3$\sigma$ level or more, while none of the older stars do, confirming previous work. At 70 $\mu$m, $22.5 \pm 3.6\%$ of the younger stars have excesses at $ \ge$ 3 $\sigma$ significance, while only $4.7^{+3.7}_{-2.2}$% of the older stars do. To characterize the far infrared behavior of debris disks more robustly, we double the sample by including stars from the DEBRIS and DUNES surveys. For the F4 - K4 stars in this combined sample, there is only a weak (statistically not significant) trend in the incidence of far infrared excess with spectral type (detected fractions of 21.9$^{+4.8}_{-4.3}\%$, late F; 16.5$^{+3.9}_{-3.3}\%$, G; and 16.9$^{+6.3}_{-5.0}\%$, early K). Taking this spectral type range together, there is a significant decline between 3 and 4.5 Gyr in the incidence of excesses with fractional luminosities just under $10^{-5}$. There is an indication that the timescale for decay of infrared excesses varies roughly inversely with the fractional luminosity. This behavior is consistent with theoretical expectations for passive evolution. However, more excesses are detected around the oldest stars than is expected from passive evolution, suggesting that there is late-phase dynamical activity around these stars., Comment: 46 pages. 7 figures. Accepted to ApJ

Published
2014
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4. Debris Disks around Solar-Type Stars: Observations of the Pleiades with Spitzer Space Telescope

Author

Sierchio, J. M., Rieke, G. H., Su, K. Y. L., Plavchan, P., Stauffer, J. R., and Gorlova, N. I.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

We present Spitzer MIPS observations at 24 um of 37 solar-type stars in the Pleiades and combine them with previous observations to obtain a sample of 71 stars. We report that 23 stars, or 32 +/- 6.8%, have excesses at 24 um at least 10% above their photospheric emission. We compare our results with studies of debris disks in other open clusters and with a study of A stars to show that debris disks around solar-type stars at 115 Myr occur at nearly the same rate as around A-type stars. We analyze the effects of binarity and X-ray activity on the excess flux. Stars with warm excesses tend not to be in equal-mass binary systems, possibly due to clearing of planetesimals by binary companions in similar orbits. We find that the apparent anti-correlations in the incidence of excess and both the rate of stellar rotation and also the level of activity as judged by X-ray emission are statistically weak., Comment: 34 pages; accepted for publication in ApJ; new version included corrections of typos, etc to match published version

Published
2010
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5. Modeling the System Parameters of 2M1533+3759: A New Longer-Period Low-Mass Eclipsing sdB+dM Binary

Author

For, B. -Q., Green, E. M., Fontaine, G., Drechsel, H., Shaw, J. S., Dittmann, J. A., Fay, A. G., Francoeur, M., Laird, J., Moriyama, E., Morris, M., Rodríguez-López, C., Sierchio, J. M., Story, S. M., Strom, A., Wang, C., Adams, S. M., Bolin, D. E., Eskew, M., and Chayer, P.

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

We present new photometric and spectroscopic observations for 2M 1533+3759 (= NSVS 07826147). It has an orbital period of 0.16177042 day, significantly longer than the 2.3--3.0 hour periods of the other known eclipsing sdB+dM systems. Spectroscopic analysis of the hot primary yields Teff = 29230 +/- 125 K, log g = 5.58 +/- 0.03 and log N(He)/N(H) = -2.37 +/- 0.05. The sdB velocity amplitude is K1 = 71.1 +/- 1.0 km/s. The only detectable light contribution from the secondary is due to the surprisingly strong reflection effect. Light curve modeling produced several solutions corresponding to different values of the system mass ratio, q(M2/M1), but only one is consistent with a core helium burning star, q=0.301. The orbital inclination is 86.6 degree. The sdB primary mass is M1 = 0.376 +/- 0.055 Msun and its radius is R1 = 0.166 +/- 0.007 Rsun. 2M1533+3759 joins PG0911+456 (and possibly also HS2333+3927) in having an unusually low mass for an sdB star. SdB stars with masses significantly lower than the canonical value of 0.48 Msun, down to as low as 0.30 Msun, were theoretically predicted by Han et al. (2002, 2003), but observational evidence has only recently begun to confirm the existence of such stars. The existence of core helium burning stars with masses lower than 0.40--0.43 Msun implies that at least some sdB progenitors have initial main sequence masses of 1.8--2.0 Msun or more, i.e. they are at least main sequence A stars. The secondary is a main sequence M5 star., Comment: 47 pages, 7 figures

Published
2009
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7. 20 years of research on the Alcator C-Mod tokamak

Author

Greenwald, M., Bader, A., Baek, S., Bakhtiari, M., Barnard, H., Beck, W., Bergerson, W., Bespamyatnov, I., Bonoli, P., Brower, D., Brunner, D., Burke, W., Candy, J., Churchill, M., Cziegler, I., Diallo, A., Dominguez, A., Duval, B., Edlund, E., Ennever, P., Ernst, D., Faust, I., Fiore, C., Fredian, T., Garcia, O., Gao, C., Goetz, J., Golfinopoulos, T., Granetz, R., Grulke, O., Hartwig, Z., Horne, S., Howard, N., Hubbard, A., Hughes, J., Hutchinson, I., Irby, J., Izzo, V., Kessel, C., Labombard, B., Lau, C., Li, C., Lin, Y., Lipschultz, B., Loarte, A., Marmar, E., Mazurenko, A., Mccracken, G., Mcdermott, R., Meneghini, O., Mikkelsen, D., Mossessian, D., Mumgaard, R., Myra, J., Nelson-Melby, E., Ochoukov, R., Olynyk, G., Parker, R., Pitcher, S., Podpaly, Y., Porkolab, M., Reinke, M., Rice, J., Rowan, W., Schmidt, A., Scott, S., Shiraiwa, S., Sierchio, J., Smick, N., Snipes, J. A., Snyder, P., Sorbom, B., Stillerman, J., Sung, C., Takase, Y., Tang, V., Terry, J., Terry, D., Theiler, C., Tronchin-James, A., Tsujii, N., Vieira, R., Walk, J., Wallace, G., White, A., Whyte, D., Wilson, J., Wolfe, S., Wright, G., Wright, J., Wukitch, S., Zweben, S., Greenwald, M., Bader, A., Baek, S., Bakhtiari, M., Barnard, H., Beck, W., Bergerson, W., Bespamyatnov, I., Bonoli, P., Brower, D., Brunner, D., Burke, W., Candy, J., Churchill, M., Cziegler, I., Diallo, A., Dominguez, A., Duval, B., Edlund, E., Ennever, P., Ernst, D., Faust, I., Fiore, C., Fredian, T., Garcia, O., Gao, C., Goetz, J., Golfinopoulos, T., Granetz, R., Grulke, O., Hartwig, Z., Horne, S., Howard, N., Hubbard, A., Hughes, J., Hutchinson, I., Irby, J., Izzo, V., Kessel, C., Labombard, B., Lau, C., Li, C., Lin, Y., Lipschultz, B., Loarte, A., Marmar, E., Mazurenko, A., Mccracken, G., Mcdermott, R., Meneghini, O., Mikkelsen, D., Mossessian, D., Mumgaard, R., Myra, J., Nelson-Melby, E., Ochoukov, R., Olynyk, G., Parker, R., Pitcher, S., Podpaly, Y., Porkolab, M., Reinke, M., Rice, J., Rowan, W., Schmidt, A., Scott, S., Shiraiwa, S., Sierchio, J., Smick, N., Snipes, J. A., Snyder, P., Sorbom, B., Stillerman, J., Sung, C., Takase, Y., Tang, V., Terry, J., Terry, D., Theiler, C., Tronchin-James, A., Tsujii, N., Vieira, R., Walk, J., Wallace, G., White, A., Whyte, D., Wilson, J., Wolfe, S., Wright, G., Wright, J., Wukitch, S., and Zweben, S.

Abstract

The object of this review is to summarize the achievements of research on the Alcator C-Mod tokamak [Hutchinson et al., Phys. Plasmas 1, 1511 (1994) and Marmar, Fusion Sci. Technol. 51, 261 (2007)] and to place that research in the context of the quest for practical fusion energy. C-Mod is a compact, high-field tokamak, whose unique design and operating parameters have produced a wealth of new and important results since it began operation in 1993, contributing data that extends tests of critical physical models into new parameter ranges and into new regimes. Using only high-power radio frequency (RF) waves for heating and current drive with innovative launching structures, C-Mod operates routinely at reactor level power densities and achieves plasma pressures higher than any other toroidal confinement device. C-Mod spearheaded the development of the vertical-target divertor and has always operated with high-Z metal plasma facing components-approaches subsequently adopted for ITER. C-Mod has made ground-breaking discoveries in divertor physics and plasma-material interactions at reactor-like power and particle fluxes and elucidated the critical role of cross-field transport in divertor operation, edge flows and the tokamak density limit. C-Mod developed the I-mode and the Enhanced D alpha H-mode regimes, which have high performance without large edge localized modes and with pedestal transport self-regulated by short-wavelength electromagnetic waves. C-Mod has carried out pioneering studies of intrinsic rotation and demonstrated that self-generated flow shear can be strong enough in some cases to significantly modify transport. C-Mod made the first quantitative link between the pedestal temperature and the H-mode's performance, showing that the observed self-similar temperature profiles were consistent with critical-gradient-length theories and followed up with quantitative tests of nonlinear gyrokinetic models. RF research highlights include direct experimental obs

Published
2015
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8. Nonlinear gyrokinetic simulations of the I-mode high confinement regime and comparisons with experimenta)

Author

White, A. E., primary, Howard, N. T., additional, Creely, A. J., additional, Chilenski, M. A., additional, Greenwald, M., additional, Hubbard, A. E., additional, Hughes, J. W., additional, Marmar, E., additional, Rice, J. E., additional, Sierchio, J. M., additional, Sung, C., additional, Walk, J. R., additional, Whyte, D. G., additional, Mikkelsen, D. R., additional, Edlund, E. M., additional, Kung, C., additional, Holland, C., additional, Candy, J., additional, Petty, C. C., additional, Reinke, M. L., additional, and Theiler, C., additional

Published
2015
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9. Debris Disks around Solar-type Stars: Observations of the Pleiades with the Spitzer Space Telescope

Author

Sierchio, J. M., Rieke, G. H., Su, K. Y. L., Plavchan, P., Stauffer, J. R., and Gorlova, N. I.

Subjects
Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

We present Spitzer MIPS observations at 24 μm of 37 solar-type stars in the Pleiades and combine them with previous observations to obtain a sample of 71 stars. We report that 23 stars, or 32% ± 6.8%, have excesses at 24 μm at least 10% above their photospheric emission. We compare our results with studies of debris disks in other open clusters and with a study of A stars to show that debris disks around solar-type stars at 115 Myr occur at nearly the same rate as around A-type stars. We analyze the effects of binarity and X-ray activity on the excess flux. Stars with warm excesses tend not to be in equal-mass binary systems, possibly due to clearing of planetesimals by binary companions in similar orbits. We find that the apparent anti-correlations in the incidence of excess and both the rate of stellar rotation and also the level of activity as judged by X-ray emission are statistically weak.

Published
2010

10. 20 years of research on the Alcator C-Mod tokamak

Author

Greenwald, M., primary, Bader, A., additional, Baek, S., additional, Bakhtiari, M., additional, Barnard, H., additional, Beck, W., additional, Bergerson, W., additional, Bespamyatnov, I., additional, Bonoli, P., additional, Brower, D., additional, Brunner, D., additional, Burke, W., additional, Candy, J., additional, Churchill, M., additional, Cziegler, I., additional, Diallo, A., additional, Dominguez, A., additional, Duval, B., additional, Edlund, E., additional, Ennever, P., additional, Ernst, D., additional, Faust, I., additional, Fiore, C., additional, Fredian, T., additional, Garcia, O., additional, Gao, C., additional, Goetz, J., additional, Golfinopoulos, T., additional, Granetz, R., additional, Grulke, O., additional, Hartwig, Z., additional, Horne, S., additional, Howard, N., additional, Hubbard, A., additional, Hughes, J., additional, Hutchinson, I., additional, Irby, J., additional, Izzo, V., additional, Kessel, C., additional, LaBombard, B., additional, Lau, C., additional, Li, C., additional, Lin, Y., additional, Lipschultz, B., additional, Loarte, A., additional, Marmar, E., additional, Mazurenko, A., additional, McCracken, G., additional, McDermott, R., additional, Meneghini, O., additional, Mikkelsen, D., additional, Mossessian, D., additional, Mumgaard, R., additional, Myra, J., additional, Nelson-Melby, E., additional, Ochoukov, R., additional, Olynyk, G., additional, Parker, R., additional, Pitcher, S., additional, Podpaly, Y., additional, Porkolab, M., additional, Reinke, M., additional, Rice, J., additional, Rowan, W., additional, Schmidt, A., additional, Scott, S., additional, Shiraiwa, S., additional, Sierchio, J., additional, Smick, N., additional, Snipes, J. A., additional, Snyder, P., additional, Sorbom, B., additional, Stillerman, J., additional, Sung, C., additional, Takase, Y., additional, Tang, V., additional, Terry, J., additional, Terry, D., additional, Theiler, C., additional, Tronchin-James, A., additional, Tsujii, N., additional, Vieira, R., additional, Walk, J., additional, Wallace, G., additional, White, A., additional, Whyte, D., additional, Wilson, J., additional, Wolfe, S., additional, Wright, G., additional, Wright, J., additional, Wukitch, S., additional, and Zweben, S., additional

Published
2014
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12. Overview of experimental results and code validation activities at Alcator C-Mod

Author

Greenwald, M., primary, Bader, A., additional, Baek, S., additional, Barnard, H., additional, Beck, W., additional, Bergerson, W., additional, Bespamyatnov, I., additional, Bitter, M., additional, Bonoli, P., additional, Brookman, M., additional, Brower, D., additional, Brunner, D., additional, Burke, W., additional, Candy, J., additional, Chilenski, M., additional, Chung, M., additional, Churchill, M., additional, Cziegler, I., additional, Davis, E., additional, Dekow, G., additional, Delgado-Aparicio, L., additional, Diallo, A., additional, Ding, W., additional, Dominguez, A., additional, Ellis, R., additional, Ennever, P., additional, Ernst, D., additional, Faust, I., additional, Fiore, C., additional, Fitzgerald, E., additional, Fredian, T., additional, Garcia, O.E., additional, Gao, C., additional, Garrett, M., additional, Golfinopoulos, T., additional, Granetz, R., additional, Groebner, R., additional, Harrison, S., additional, Harvey, R., additional, Hartwig, Z., additional, Hill, K., additional, Hillairet, J., additional, Howard, N., additional, Hubbard, A.E., additional, Hughes, J.W., additional, Hutchinson, I., additional, Irby, J., additional, James, A.N., additional, Kanojia, A., additional, Kasten, C., additional, Kesner, J., additional, Kessel, C., additional, Kube, R., additional, LaBombard, B., additional, Lau, C., additional, Lee, J., additional, Liao, K., additional, Lin, Y., additional, Lipschultz, B., additional, Ma, Y., additional, Marmar, E., additional, McGibbon, P., additional, Meneghini, O., additional, Mikkelsen, D., additional, Miller, D., additional, Mumgaard, R., additional, Murray, R., additional, Ochoukov, R., additional, Olynyk, G., additional, Pace, D., additional, Park, S., additional, Parker, R., additional, Podpaly, Y., additional, Porkolab, M., additional, Preynas, M., additional, Pusztai, I., additional, Reinke, M., additional, Rice, J., additional, Rowan, W., additional, Scott, S., additional, Shiraiwa, S., additional, Sierchio, J., additional, Snyder, P., additional, Sorbom, B., additional, Soukhanovskii, V., additional, Stillerman, J., additional, Sugiyama, L., additional, Sung, C., additional, Terry, D., additional, Terry, J., additional, Theiler, C., additional, Tsujii, N., additional, Vieira, R., additional, Walk, J., additional, Wallace, G., additional, White, A., additional, Whyte, D., additional, Wilson, J., additional, Wolfe, S., additional, Woller, K., additional, Wright, G., additional, Wright, J., additional, Wukitch, S., additional, Wurden, G., additional, Xu, P., additional, Yang, C., additional, and Zweben, S., additional

Published
2013
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13. Fluctuating zonal flows in the I-mode regime in Alcator C-Mod

Author

Cziegler, I., primary, Diamond, P. H., additional, Fedorczak, N., additional, Manz, P., additional, Tynan, G. R., additional, Xu, M., additional, Churchill, R. M., additional, Hubbard, A. E., additional, Lipschultz, B., additional, Sierchio, J. M., additional, Terry, J. L., additional, and Theiler, C., additional

Published
2013
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15. MODELING THE SYSTEM PARAMETERS OF 2M 1533+3759: A NEW LONGER PERIOD LOW-MASS ECLIPSING sdB+dM BINARY

Author

For, B.-Q., primary, Green, E. M., additional, Fontaine, G., additional, Drechsel, H., additional, Shaw, J. S., additional, Dittmann, J. A., additional, Fay, A. G., additional, Francoeur, M., additional, Laird, J., additional, Moriyama, E., additional, Morris, M., additional, Rodríguez-López, C., additional, Sierchio, J. M., additional, Story, S. M., additional, Strom, A., additional, Wang, C., additional, Adams, S. M., additional, Bolin, D. E., additional, Eskew, M., additional, and Chayer, P., additional

Published
2009
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16. Tactical/Environmental Decision Aids for Naval Strike Warfare.

Author

NAVAL RESEARCH LAB STENNIS SPACE CENTER MS, Sierchio, J. M., Brand, Sam, NAVAL RESEARCH LAB STENNIS SPACE CENTER MS, Sierchio, J. M., and Brand, Sam

Abstract

The strike warfare community requires accurate meteorological analyses and forecasts to properly plan and effectively execute tactical operations. This point was vividly illustrated during the Persian Gulf War and documented by the Center for Naval Analyses in its quarterly progress report of April-June 1991: Analysis of Desert Storm TACAIR operations indicated that unfavorable environmental conditions were responsible for 29 Navy strike mission aborts or cancellations and for 63 strike diversions from the primary target. Moreover, at least one-third of all missions executed by Navy TACAIR were impaired by restricted meteorologic visibility. Atmospheric effects, Environmental support, Strike warfare.

Published
1993

17. Evaluation of calcium entry blockers in several models of immediate hypersensitivity.

Author

Ritchie, D M, Sierchio, J N, Bishop, C M, Hedli, C C, Levinson, S L, and Capetola, R J

Abstract

Several calcium-entry blockers, i.e., verapamil, nifedipine, flunarizine and diltiazem, were evaluated for their effects in models of immediate hypersensitivity disease. Verapamil, flunarizine and diltiazem were all effective in inhibiting antigen-induced bronchospasm in the guinea pig; however, the effects seen were at relatively high doses compared to the doses known to cause cardiovascular effects. Nifedipine caused no significant inhibition of resistance or compliance changes induced by antigen. Flunarizine, verapamil and diltiazem were ineffective in inhibiting antigen-induced histamine release from rat peritoneal mast cells in vitro. Although these compounds were active inhibitors of 5-D-[5,6,8,9,H,12,14,15-3H(N)]-hydroxy-6,8,11,14-eicosatetraenoic acid production in rat basophilic leukemia-1 cells, only flunarizine and verapamil showed effects on the 5-lipoxygenase enzyme when assayed directly. Also, these compounds were ineffective on SRS-A mediated bronchospasm in vivo. These data suggest that the currently available calcium entry blockers have little potential use in immediate hypersensitivity reactions.

Published
1984

19. Blind Source Separation - Based Motion Detector for Sub-Micrometer, Periodic Displacement in Ultrasonic Imaging.

Author

Hossain MM, Thapa D, Sierchio J, Oldenburg A, and Gallippil C

Abstract

Sub-micrometer, periodic motion detection using blind source separation (BSS) via principal component analysis (PCA) is presented in the context of magnetomotive ultrasound (MMUS) imaging and Shearwave Dispersion Ultrasound Vibrometry (SDUV). In MMUS, an oscillating external magnetic field displaces tissue loaded with superparamagnetic iron oxide (SPIO) particles, whereas in SDUV, periodic tissue motion is induced using acoustic radiation force (ARF) to measure visco-elastic properties. BSS motion detection performance in MMUS imaging and SDUV was compared against frequency-phase locked (FPL) and normalized cross-correlation (NCC) motion detectors, respectively, in silico and in experimental phantoms. Parametric MMUS phantom images constructed using the BSS method had nearly twice the SNR of the corresponding images constructed using FPL method when a 0.043 mm or smaller kernel size was used. In FEM models of SDUV, the error in the BSS-estimated viscoelastic properties of simulated materials was < 10%, whereas the error was > 20% using NCC when the simulated SNR was 15 dB. In a calibrated elasticity phantom, the amplitude of the motion was ≤ 0.5 μm for a scanner power level ≤ 20%. The median percent error in BSS-derived shear modulus of the phantom was -6.8%, -1.55%, -17.11% for power level of 20%, 15%, and 10%, respectively. The corresponding NCC-derived errors were 29.90%, 127.1%, and 244.70%. These results suggest the relevance of using BSS for the detection of sub-micrometer, periodic motion in MMUS and SDUV imaging, particularly when SNR is less than 15 dB and/or induced displacements are less than 0.5 μm.

Published
2016
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20. SRS-A mediated bronchospasm by pharmacologic modification of lung anaphylaxis in vivo.

Author

Ritchie DM, Sierchio JN, Capetola RJ, and Rosenthale ME

Subjects
Animals, Chromones pharmacology, Ethers pharmacology, Guinea Pigs, Male, Anaphylaxis physiopathology, Bronchial Spasm physiopathology, Lung physiopathology, SRS-A pharmacology
Abstract

Antigen challenge of actively sensitized guinea pigs results in the release of histamine eicosanoids (products of the cyclooxygenase pathway of arachidonic acid metabolism) and slow reducing substance of anaphylaxis (SRS-A). By antagonizing the effects of histamine, serotonin, and acetylcholine, inhibiting the cyclooxygenase pathway and supplying arachidonic acid as substrate, the contribution of SRS-A to anaphylactic bronchospasm can be enhanced, thus allowing suitable quantitation of antagonists. This SRS-A mediated bronchospasm can be inhibited in a dose dependent fashion by FPL55712, a selective antagonist of SRS-A. This system represents an in vivo method capable of detecting compounds which inhibit SRS-A synthesis/release of SRS-A action at the effector organ.

Published
1981
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21. Flunarizine and verapamil: effects on central nervous system and peripheral consequences of cytotoxic hypoxia in rats.

Author

Dubinsky B, Sierchio JN, Temple DE, and Ritchie DM

Subjects
Animals, Cinnarizine analogs & derivatives, Flunarizine, Hyperventilation prevention & control, Hypoxia prevention & control, Male, Potassium Cyanide toxicity, Rats, Rats, Inbred Strains, Calcium Channel Blockers therapeutic use, Cinnarizine therapeutic use, Hypoxia physiopathology, Piperazines therapeutic use, Verapamil therapeutic use
Abstract

Flunarizine is a calcium entry blocking drug possessing antihypoxic activity in animal models of cerebral and peripheral ischemia-anoxia and has clinical usefulness in circulatory disorders of both central and peripheral origin. This report compares the activity of flunarizine and verapamil, another calcium entry blocking drug, on the central nervous system (CNS) and peripheral consequences of cytotoxic hypoxia induced by high and low doses of KCN. The lethal effect of KCN (6 mg/kg, i.p.) in rats was prevented by orally administered flunarizine (ED50 = 12 mg/kg with four-hr pretreatment) but not by verapamil (at oral doses up to 80 mg/kg with one-hr pretreatment). Since the lethal effect of KCN involves failure of respiration at the CNS level, these results suggest that flunarizine protects against the hypoxic effect of the cyanide ion by an action in brain tissue. We found also that the stimulant effect of low intravenous doses (0.5 mg/kg/min) of KCN upon respiration rate was not altered in pentobarbital- and chloralose-anesthetized rats treated with oral doses of flunarizine up to 80 mg/kg (with four hr pretreatment). In contrast, KCN-stimulated respiration rate in pentobarbital anesthetized rats was significantly attenuated by verapamil (20 and 40 mg/kg, p.o. with one hr pretreatment). Since low doses of the cyanide ion render respiration quicker and deeper by an action on chemoreceptive cells in peripheral arteries, the effect of verapamil against the hypoxic effect of KCN is mediated by an action in the periphery. In summary, we have shown that the physiological consequences of cytotoxic hypoxia can be affected by calcium entry blocking drugs having site-specific activities. Based on our results, flunarizine is more effective than verapamil against cellular anoxia involving the CNS.

Published
1984
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