Modification of the Development of Acute Opiate Tolerance by Increased Dopamine Receptor Sensitivity1

ABSTRACT Earlier studies have suggested that the acute administration of an opiate can result in the development of supersensitive dopemine receptors

Oral Ethanol-Reinforced Responding in Rhesus Monkeys: Effects of Opioid Antagonists Selective for the Μ-,Κ-, or Δ-Receptor

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65904/1/j.1530-0277.1998.tb03960.x.pd

Solar 8B and hep Neutrino Measurements from 1258 Days of Super-Kamiokande Data

Solar neutrino measurements from 1258 days of data from the Super-Kamiokande detector are presented. The measurements are based on recoil electrons in the energy range 5.0-20.0MeV. The measured solar neutrino flux is 2.32 +- 0.03(stat.) +0.08-0.07(sys.)*10^6cm^{-2}s^{-1}, which is 45.1+-0.5(stat.)+1.6-1.4(sys.)% of that predicted by the BP2000 SSM. The day vs night flux asymmetry is 0.033+-0.022(stat.)+0.013-0.012(sys.). The recoil electron energy spectrum is consistent with no spectral distortion (\chi^2/d.o.f. = 19.0/18). The seasonal variation of the flux is consistent with that expected from the eccentricity of the Earth's orbit (\chi^2/d.o.f. = 3.7/7). For the hep neutrino flux, we set a 90% C.L. upper limit of 40 *10^3cm^{-2}s^{-1}, which is 4.3 times the BP2000 SSM prediction.Comment: 7 pages, 5 figures, submitted to PRL (part of this paper

Search for nucleon decay via modes favored by supersymmetric grand unification models in Super-Kamiokande-I

We report the results for nucleon decay searches via modes favored by supersymmetric grand unified models in Super-Kamiokande. Using 1489 days of full Super-Kamiokande-I data, we searched for $p \to \bar{\nu} K^+$, $n \to \bar{\nu} K^0$, $p \to \mu^+ K^0$ and $p \to e^+ K^0$ modes. We found no evidence for nucleon decay in any of these modes. We set lower limits of partial nucleon lifetime 2.3$\times10^{33}$, 1.3$\times10^{32}$, 1.3$\times10^{33}$ and 1.0$\times10^{33}$ years at 90% confidence level for $p \to \bar{\nu} K^+$, $n \to \bar{\nu} K^0$, $p \to \mu^+ K^0$ and $p \to e^+ K^0$ modes, respectively. These results give a strong constraint on supersymmetric grand unification models.Comment: 14 pages, 13 figure

Measurement of a small atmospheric νμ/νe\nu_\mu/\nu_e ratio

From an exposure of 25.5~kiloton-years of the Super-Kamiokande detector, 900 muon-like and 983 electron-like single-ring atmospheric neutrino interactions were detected with momentum $p_e > 100$ MeV/$c$, $p_\mu > 200$ MeV/$c$, and with visible energy less than 1.33 GeV. Using a detailed Monte Carlo simulation, the ratio $(\mu/e)_{DATA}/(\mu/e)_{MC}$ was measured to be $0.61 \pm 0.03(stat.) \pm 0.05(sys.)$, consistent with previous results from the Kamiokande, IMB and Soudan-2 experiments, and smaller than expected from theoretical models of atmospheric neutrino production.Comment: 14 pages with 5 figure

Constraints on neutrino oscillation parameters from the measurement of day-night solar neutrino fluxes at Super-Kamiokande

A search for day-night variations in the solar neutrino flux resulting from neutrino oscillations has been carried out using the 504 day sample of solar neutrino data obtained at Super-Kamiokande. The absence of a significant day-night variation has set an absolute flux independent exclusion region in the two neutrino oscillation parameter space.Comment: 11 pages, 3 figures, submitted to PRL, single-spacin

Evidence for an oscillatory signature in atmospheric neutrino oscillation

Muon neutrino disappearance probability as a function of neutrino flight length L over neutrino energy E was studied. A dip in the L/E distribution was observed in the data, as predicted from the sinusoidal flavor transition probability of neutrino oscillation. The observed L/E distribution constrained nu_mu nu_tau neutrino oscillation parameters; 1.9x10^-3 < Delta m^2 < 3.0x10^-3 eV^2 and \sin^2(2theta) > 0.90 at 90% confidence level.Comment: 5 pages, 5 figures, submitted to PR

Constraints on Neutrino Oscillations Using 1258 Days of Super-Kamiokande Solar Neutrino Data

We report the result of a search for neutrino oscillations using precise measurements of the recoil electron energy spectrum and zenith angle variations of the solar neutrino flux from 1258 days of neutrino-electron scattering data in Super-Kamiokande. The absence of significant zenith angle variation and spectrum distortion places strong constraints on neutrino mixing and mass difference in a flux-independent way. Using the Super-Kamiokande flux measurement in addition, two allowed regions at large mixing are found.Comment: 6 pages, 4 figures, submitted to PR