Search

The Sudbury Neutrino Observatory is a 1000 T D 2 O Cerenkov detector that is sensitive to 8 B solar neutrinos. The energy, radius, and direction with respect to the sun is measured for each neutrino event; these distributions are used to separately determine the rates of the charged current, neutral current and electron scattering reactions of neutrinos on deuterium. Assuming an undistorted 8 B spectrum, the ν e component of the 8 B solar flux is φ e = 1.76 +0.05 −0.05 (stat.) +0.09 −0.09 (syst.) × 10 6 cm −2 s −1 based on events with a measured kinetic enegy above 5 MeV. The non- ν e component is φ μτ = 3.41 +0.45 −0.45 (stat.) +0.48 −0.45 (syst.) × 10 6 cm −2 s −1 , 5.3 σ greater than zero, providing strong evidence for solar ν e flavor transformation. The total flux measured with the NC reaction is φ NC = 5.09 +0.044 −0.43 (stat.) +0.46 −0.43 (syst.) × 10 6 cm −2 s −1 , consistent with solar models. The night minus day rate is 14.0% ± 6.3% +1.5 −1.4 % of the average rate. If the total flux of active neutrinos is additionally constrained to have no asymmetry, the ν e asymmetry is found to be 7.0% ± 4.9% +1.3 −1.2 %. A global solar neutrino analysis is terms of matter-enhanced oscillations of two active flavors strongly favors the Large Mixing Angle (LMA) solution.

Data from the Sudbury Neutrino Observatory have been used to constrain the lifetime for nucleon decay to ``invisible'' modes, such as n -> 3 nu. The analysis was based on a search for gamma-rays from the de-excitation of the residual nucleus that would result from the disappearance of either a proton or neutron from O16. A limit of tau_inv > 2 x 10^{29} years is obtained at 90% confidence for either neutron or proton decay modes. This is about an order of magnitude more stringent than previous constraints on invisible proton decay modes and 400 times more stringent than similar neutron modes., Update includes missing efficiency factor (limits change by factor of 2) Submitted to Physical Review Letters

We present a detailed description of the geological setting of the burial site of the WLH 50 human remains along with attempts to constrain the age of this important human fossil. Freshwater shells collected at the surface of Unit 3, which is most closely associated with the human remains, and a carbonate sample that encrusted the human bone were analysed. Gamma spectrometry was carried out on the WLH 50 calvaria and TIMS U-series analysis on a small post-cranial bone fragment. OSL dating was applied to a sample from Unit 3 at a level from which the WLH 50 remains may have eroded, as well as from the underlying sediments. Considering the geochemistry of the samples analysed, as well as the possibility of reworking or burial from younger layers, the age of the WLH 50 remains lies between 12.2 ± 1.8 and 32.8 ± 4.6 ka (2-σ errors).

The technique used at the Sudbury Neutrino Observatory (SNO) to measure the concentration of 222 Rn in water is described. Water from the SNO detector is passed through a vacuum degasser (in the light water system) or a membrane contact degasser (in the heavy water system) where dissolved gases, including radon, are liberated. The degasser is connected to a vacuum system which collects the radon on a cold trap and removes most other gases, such as water vapor and N2. After roughly 0.5 tonnes of H2O or 6 tonnes of D2O have been sampled, the accumulated radon is transferred to a Lucas cell. The cell is mounted on a photomultiplier tube which detects the α-particles from the decay of 222 Rn and its progeny. The overall degassing and concentration efficiency is about 38% and the single-α counting efficiency is approximately 75%. The sensitivity of the radon assay system for D2O is equivalent to ∼3×10 −15 g U/g water. The radon concentration in both the H2O and D2O is sufficiently low that the rate of background events from U-chain elements is a small fraction of the interaction rate of solar neutrinos by the neutral current reaction.

Tinnitus is a debilitating condition from which some 0.5-1% of the population of the Western world suffer sufficiently badly as to interfere with their normal working and leisure life. There is no satisfactory treatment at the present time and the uncertainty surrounding the mechanism of its generation makes it difficult to devise an effective cure. After much debate, the consensus of opinion amongst researchers regarding its site of origin is that it is primarily a central nervous system pathology although there certainly exists a class of patients whose tinnitus is peripherally based. In this paper, we provide some speculative ideas on how an initial auditory insult can be translated into central neurological substrates that represent tinnitus. Plastic changes arising from sensory deprivation trigger a change in synaptology and neurotransmission with a consequent change in receptor configuration. From neuroanatomical considerations and analogies with other clinical conditions, we postulate the involvement of serotonin (5-HT) in these plastic changes and consider the evidence available from the use of serotonergic drugs in different conditions. A possible relationship between 5-HT and lidocaine is also discussed.

We have carried out a comprehensive ESR and U-series dating study on the Lake Mungo 3 (LM3) human skeleton. The isotopic Th/U and Pa/U ratios indicate that some minor uranium mobilization may have occurred in the past. Taking such effects into account, the best age estimate for the human skeleton is obtained through the combination of U-series and ESR analyses yielding 62,000±6000 years. This age is in close agreement with OSL age estimates on the sediment into which the skeleton was buried of 61,000±2000 years. Furthermore, we obtained a U-series age of 81,000±21,000 years for the calcitic matrix that was precipitated on the bones after burial. All age results are considerably older than the previously assumed age of LM3 and demonstrate the necessity for directly dating hominid remains. We conclude that the Lake Mungo 3 burial documents the earliest known human presence on the Australian continent. The age implies that people who were skeletally within the range of the present Australian indigenous population colonized the continent during or before oxygen isotope stage 4 (57,000–71,000 years).

The Neanderthal hominid Tabun C1, found in Israel by Garrod & Bate, was attributed to either layer B or C of their stratigraphic sequence. We have used gamma-ray spectrometry to determine the230Th/234U and231Pa/235U ratios of two bones from this skeleton, the mandible and a femur. The ages calculated from these ratios depend on the uranium uptake history of the bones. Assuming a model of early U (EU) uptake the age of the Tabun C1 mandible is 34±5 ka. The EU age of the femur is 19±2 ka. The femur may have experienced continuous (linear) U uptake which would give an age of 33±4 ka, in agreement with the mandible's EU age, but implies marked inhomogeneity in U uptake history at the site. These new age estimates for the skeleton suggest that it was younger than deposits of layer C. This apparent age is less than those of other Neanderthals found in Israel, and distinctly younger than the ages of the Skhul and Qafzeh burials. This suggests that Neanderthals did not necessarily coexist with the earliest modern humans in the region. All of the more complete Neanderthal fossils from Israel are now dated to the cool period of the last glacial cycle, suggesting that Neanderthals may have arrived in this region as a result of the southward expansion of their habitable range. The young age determined for the Tabun skeleton would suggest that Neanderthals survived as late in the Levant as they did in Europe.

Prehistoric hominid fossils are too valuable to be dated by destructive or even partially destructive methods. Non-destructive U-series dating by γ-ray counting can therefore be a valuable method if relatively large hominid fragments, such as skulls, containing measurable amounts of uranium are available. We present a description of the method as well as some results including those obtained from a previously dated coral as well as two Australian hominid skulls (WLH 50 and Mungo 3). The dating procedure is designed to minimise systematic errors which may easily overwhelm statistical errors if care is not taken. The gamma spectrometric results are in good agreement with alpha and mass spectrometric measurements as well as independent age determinations. The results show no evidence for any uranium uptake over longer time periods.

We report results from a combined analysis of solar neutrino data from all phases of the Sudbury Neutrino Observatory. By exploiting particle identification information obtained from the proportional counters installed during the third phase, this analysis improved background rejection in that phase of the experiment. The combined analysis resulted in a total flux of active neutrino flavors from 8B decays in the Sun of (5.25 \pm 0.16(stat.)+0.11-0.13(syst.))\times10^6 cm^{-2}s^{-1}. A two-flavor neutrino oscillation analysis yielded \Deltam^2_{21} = (5.6^{+1.9}_{-1.4})\times10^{-5} eV^2 and tan^2{\theta}_{12}= 0.427^{+0.033}_{-0.029}. A three-flavor neutrino oscillation analysis combining this result with results of all other solar neutrino experiments and the KamLAND experiment yielded \Deltam^2_{21} = (7.41^{+0.21}_{-0.19})\times10^{-5} eV^2, tan^2{\theta}_{12} = 0.446^{+0.030}_{-0.029}, and sin^2{\theta}_{13} = (2.5^{+1.8}_{-1.5})\times10^{-2}. This implied an upper bound of sin^2{\theta}_{13} < 0.053 at the 95% confidence level (C.L.).

This paper details the solar neutrino analysis of the 385.17-day phase-III data set acquired by the Sudbury Neutrino Observatory (SNO). An array of He-3 proportional counters was installed in the heavy-water target to measure precisely the rate of neutrino-deuteron neutral-current interactions. This technique to determine the total active B-8 solar neutrino flux was largely independent of the methods employed in previous phases. The total flux of active neutrinos was measured to be 5.54(-0.31)(+0.33)(stat.)(-0.34)(+0.36)(syst.) x 10(6) cm(-2) s(-1), consistent with previous measurements and standard solar models. A global analysis of solar and reactor neutrino mixing parameters yielded the best-fit values of Delta m(2) = 7.59(-0.21)(+0.19) x 10(-5) eV(2) and theta = 34.4(-1.2)(+1.3) degrees. DOI: 10.1103/PhysRevC.87.015502

The Sudbury Neutrino Observatory (SNO) has confirmed the standard solar model and neutrino oscillations through the observation of neutrinos from the solar core. In this paper we present a search for neutrinos associated with sources other than the solar core, such as gamma-ray bursts and solar flares. We present a new method for looking for temporal coincidences between neutrino events and astrophysical bursts of widely varying intensity. No correlations were found between neutrinos detected in SNO and such astrophysical sources., United States. Dept. of Energy, National Energy Research Scientific Computing Center (U.S.), Alfred P. Sloan Foundation

A recent comment from Gordon and Evans took issue with two aspects of the analysis of Coastal Zone Color Scanner (CZCS) pigment extraction algorithms. This reply refuted the arguments of Gordon and Evans. The multiple Rayleigh scattering algorithm does not always make physical sense, nor has the physical validity of Angstrom's coefficient been established as a means of parameterizing the aerosol scale factor. We also disagreed with the position put forward by Gordon and Evans that the artifacts in the CZCS data will disappear in the next generation sensor (SeaWiFS) because the problem of quantifying the aerosol contribution from these satellite measurements has not yet been solved to sufficient accuracy. Finally, these factors, coupled with electronic overshoot and the decay of the CZCS sensor's sensitivity over time, make it unlikely that the quality of derived pigment values will be significantly improved by reprocessing the CZCS archive yet one more time as suggested by Gordon and Evans.

Superdeformed bands observed in {sup 131}Ce, {sup 132}Ce, and {sup 133}Ce have sequences of {gamma}-ray transition energies that exhibit a {Delta}{ital I}=2 staggering. This staggering has different characteristics to that seen in previously known cases in other mass regions. The energy staggering starts at low rotational frequency ({sq_bullet}{omega}=3 MeV for {sup 131}Ce) at a magnitude of {approximately}{plus_minus}0.3 keV, dies away to zero at intermediate frequency ({sq_bullet}{omega}=0.6{minus}0.7 MeV), and reappears at higher frequencies ({sq_bullet}{omega}{approximately}0.7 MeV). {copyright} {ital 1996 The American Physical Society.}

This article establishes a context for secure information systems development as well as a set of models used to develop and apply a secure software production pedagogy. A generic system model is presented to support the system context development, and to provide a framework for discussing security relationships that exist between and among information systems and their applications. An asset protection model is tailored to provide a conceptual ontology for secure information system topics, and a stable logical framework that is independent of specific organizations, technologies, and their associated changes. This asset protection model provides a unique focus for each of the three primary professional communities associated with the development and operation of secure information systems. In this paper, a secure adaptive response model is discussed to provide an analytical tool to assess risk associated with the development and deployment of secure information systems, and to use as a security metric. A pedagogical model for information assurance curriculum development is then established in the context and terms of the developed secure information system models. The relevance of secure coding techniques to the production of secure systems, architectures, and organizational operations is also discussed.

The complete spectrum of [gamma] rays following the decay of superdeformed (SD) states in [sup 192]Hg has been extracted. The spectrum, which comprises a quasicontinuous component and sharp lines, reveals the decay mechanism and defines the excitation energies of the SD band. The decay of SD states results from the coupling between a cold, ordered SD system with a hot, chaotic one with normal deformation.

An excited superdeformed (SD) band in 150 Gd is associated with a two-particle-two-hole proton excitation and provides the first evidence for collective proton pair excitations in a SD nucleus. This band is seen to exhibit a discontinuity in the γ-ray transition energies (backbending), which is interpreted as a band crossing associated with the alignment of a pair of N=6 protons. There is further evidence that this excited SD band decays into the yrast SD band.

The effect of optical water characteristics upon the diurnal variability of upper ocean temperatures and heat content has been studied. A second moment turbulent closure scheme was employed for the simulations. Realistic thermal forcing as well as uniform and time varying wind stresses were used for boundary conditions. The diurnal amplitude in sea surface temperature and long term changes in heat content are strongly influenced by water type for constant wind speeds up to 6 m s -1 . The phasing of time-dependent wind stresses can lead to enhanced diurnal sea surface temperature amplitudes (e.g. solar insolation 12 hours out of phase with maximum wind stress). Long term trends in heat content, however, are nearly independent of phase. The results of the simulations are consistent with the range of reported observations. The present work suggests that variability in biological productivity and consequent variations in the optical properties of seawater may be important for realistic modelling of upper ocean structure and climate. DOI: 10.1111/j.1600-0889.1983.tb00018.x

Results are reported from a search for low-multiplicity neutrino bursts in the Sudbury Neutrino Observatory (SNO). Such bursts could indicate detection of a nearby core-collapse supernova explosion. The data were taken from Phase I (November 1999 - May 2001), when the detector was filled with heavy water, and Phase II (July 2001 - August 2003), when NaCl was added to the target. The search was a blind analysis in which the potential backgrounds were estimated and analysis cuts were developed to eliminate such backgrounds with 90% confidence before the data were examined. The search maintained a greater than 50% detection probability for standard supernovae occurring at a distance of up to 60 kpc for Phase I and up to 70 kpc for Phase II. No low-multiplicity bursts were observed during the data-taking period., 11 pages, 4 figures, submitted to ApJ

Improvements in the detection limits of thorium and uranium in acrylics by neutron activation analysis are described. The average of results from 10 g samples was found to be higher than the results from 450 g samples taken from the same acrylic sheet. Using eighteen large (450 g) samples from a single sheet of acrylic gave an average value of 3.2±0.3 pg/g thorium and 1.1±0.7 pg/g uranium. Interpretation of the results is discussed. Epithermal neutron activation with Cd shielded irradiations did not improve the detection sensitivity for thorium.

Measurements have been made of the thorium, uranium and potassium concentrations in a variety of materials. The methods of direct γ-ray counting and neutron activation analysis have been employed, and cases of secular disequilibrium most notably in aluminum have been identified. Several comprehensive tables of results are provided.

The intensity of the 1001 keV γ-ray occurring in the decay of234mPa in equilibrium with natural uranium sources is found to be (0.818±0.030)%. This value is in agreement with a recent measurement employing depleted uranium sources, but does not agree with earlier reports employing radiochemically pure sources.

The experimental evidence of a distortion in the β-spectra of 3H, 35S, 63Ni, 14C and IBEC-spectrum of 71Ge is reviewed. The distortions seen in the five nuclei are consistent with their interpretation as the signal of the emission of a neutrino of 17-keV mass and mixing angle of 0.1. Some of the implications of this discovery are reviewed.

Results are reported on the measurement of the atmospheric neutrino-induced muon flux at a depth of 2 kilometers below the Earth's surface from 1229 days of operation of the Sudbury Neutrino Observatory (SNO). By measuring the flux of through-going muons as a function of zenith angle, the SNO experiment can distinguish between the oscillated and un-oscillated portion of the neutrino flux. A total of 514 muon-like events are measured between $-1 \le \cos{\theta}_{\rm zenith} \le 0.4$ in a total exposure of 2.30\times 10^{14}$ cm$^{2}$ s. The measured flux normalization is $1.22 \pm 0.09$ times the Bartol three-dimensional flux prediction. This is the first measurement of the neutrino-induced flux where neutrino oscillations are minimized. The zenith distribution is consistent with previously measured atmospheric neutrino oscillation parameters. The cosmic ray muon flux at SNO with zenith angle $\cos{\theta}_{\rm zenith} > 0.4$ is measured to be $(3.31 \pm 0.01 {\rm (stat.)} \pm 0.09 {\rm (sys.)}) \times 10^{-10}~\mu$/s/cm$^{2}$., Comment: 17 pages, 11 figures

Clouds are removed from Coastal Zone Color Scanner (CZCS) data using channel 5. Instrumentation problems require pre-processing of channel 5 before an intelligent cloud-screening algorithm can be used. For example, at intervals of about 16 lines, the sensor records anomalously low radiances. Moreover, the calibration equation yields negative radiances when the sensor records zero counts, and pixels corrupted by electronic overshoot must also be excluded. The remaining pixels may then be used in conjunction with the procedure of Simpson and Humphrey to determine the CZCS cloud mask. These results plus in situ observations of phytoplankton pigment concentration show that pre-processing and proper cloud-screening of CZCS data are necessary for accurate satellite-derived pigment concentrations. This is especially true in the coastal margins, where pigment content is high and image distortion associated with electronic overshoot is also present. The pre-processing algorithm is critical to obtaining accurate global estimates of pigment from spacecraft data.

It is suggested that the late neutrino events from supernova SN 1987 A detected by the Kamiokande and IMB detectors can be understood as arising from massive neutrinos decaying in flight. If the neutrino mass is 17 keV, the estimated mean life is (0.6–1.6) x 10 4 s. The shorter prompt pulse then implies an upper limit to the mass of the lightest neutrino of 13 eV.

Computation of phytoplankton pigment concentrations from the radiances received by the coastal zone color scanner (CZCS) is a complicated process. Water-leaving radiance, a small portion of the total signal, controls the pigment content, but fully 80–90 per cent of the total radiance is due to Rayleigh and aerosol scattering. These effects must be accurately modelled if reasonable pigment concentrations are to be computed. Rayleigh radiance is relatively easy to determine from either single or multiple scattering algorithms. Several examples of the effects of single versus multiple Rayleigh scattering on pigment content are given. The aerosol component varies both spatially and temporally and is poorly determined. Historically, the ratios of aerosol radiance in channels 1–3 to that in channel 4 have been assumed to be constant for an entire image. The proportionality constants are found by assuming values of water-leaving radiance for low pigment waters and theoretically should be independent of ...

The Sudbury Neutrino Observatory (SNO) used an array of 3He proportional counters to measure the rate of neutral-current interactions in heavy water and precisely determined the total active (nu_x) 8B solar neutrino flux. This technique is independent of previous methods employed by SNO. The total flux is found to be 5.54_-0.31;+0.33(stat)-0.34+0.36(syst)x10(6) cm(-2) s(-1), in agreement with previous measurements and standard solar models. A global analysis of solar and reactor neutrino results yields Deltam2=7.59_-0.21;+0.19x10(-5) eV2 and theta=34.4_-1.2;+1.3 degrees. The uncertainty on the mixing angle has been reduced from SNO's previous results.

This article provides the complete description of resultsfrom the Phase I data set of the Sudbury Neutrino Observatory (SNO). ThePhase I data set is based on a 0.65 kt-year exposure of heavy water tothe solar 8B neutrino flux. Included here are details of the SNO physicsand detector model, evaluations of systematic uncertainties, andestimates of backgrounds. Also discussed are SNO's approach tostatistical extraction of the signals from the three neutrino reactions(charged current, neutral current, and elastic scattering) and theresults of a search for a day-night asymmetry in the ?e flux. Under theassumption that the 8B spectrum is undistorted, the measurements fromthis phase yield a solar ?e flux of ?(?e) =1.76+0.05?0.05(stat.)+0.09?0.09 (syst.) x 106 cm?2 s?1, and a non-?ecomponent ?(? mu) = 3.41+0.45?0.45(stat.)+0.48?0.45 (syst.) x 106 cm?2s?1. The sum of these components provides a total flux in excellentagreement with the predictions of Standard Solar Models. The day-nightasymmetry in the ?e flux is found to be Ae = 7.0 +- 4.9 (stat.)+1.3?1.2percent (sys.), when the asymmetry in the total flux is constrained to bezero.

Results are reported from the complete salt phase of the Sudbury Neutrino Observatory experiment in which NaCl was dissolved in the {sup 2}H{sub 2}O (''D{sub 2}O'') target. The addition of salt enhanced the signal from neutron capture as compared to the pure D{sub 2}O detector. By making a statistical separation of charged-current events from other types based on event-isotropy criteria, the effective electron recoil energy spectrum has been extracted. In units of 10{sup 6}cm{sup -2}s{sup -1}, the total flux of active-flavor neutrinos from {sup 8}B decay in the Sun is found to be 4.94{sub -0.21}{sup +0.21}(stat){sub -0.34}{sup +0.38}(syst) and the integral flux of electron neutrinos for an undistorted {sup 8}B spectrum is 1.68{sub -0.06}{sup +0.06}(stat){sub -0.09}{sup +0.08}(syst); the signal from ({nu}{sub x},e) elastic scattering is equivalent to an electron-neutrino flux of 2.35{sub -0.22}{sup +0.22}(stat){sub -0.15}{sup +0.15}(syst). These results are consistent with those expected for neutrino oscillations with the so-called large mixing angle parameters and also with an undistorted spectrum. A search for matter-enhancement effects in the Earth through a possible day-night asymmetry in the charged-current integral rate is consistent with no asymmetry. Including results from other experiments, the best-fit values for two-neutrino mixing parameters are {delta}m{sup 2}=(8.0{sub -0.4}{sup +0.6})x10{sup -5}more » eV{sup 2} and {theta}=33.9{sub -2.2}{sup +2.4} degrees.« less

A search has been made for sinusoidal periodic variations in the 8B solar neutrino flux using data collected by the Sudbury Neutrino Observatory over a 4-year time interval. The variation at a period of 1 yr is consistent with modulation of the 8B neutrino flux by the Earth's orbital eccentricity. No significant sinusoidal periodicities are found with periods between 1 d and 10 years with either an unbinned maximum likelihood analysis or a Lomb-Scargle periodogram analysis. The data are inconsistent with the hypothesis that the results of the recent analysis by Sturrock et al., based on elastic scattering events in Super-Kamiokande, can be attributed to a 7% sinusoidal modulation of the total 8B neutrino flux.

Upper limits on the \nuebar flux at the Sudbury Neutrino Observatory have been set based on the \nuebar charged-current reaction on deuterium. The reaction produces a positron and two neutrons in coincidence. This distinctive signature allows a search with very low background for \nuebar's from the Sun and other potential sources. Both differential and integral limits on the \nuebar flux have been placed in the energy range from 4 -- 14.8 MeV. For an energy-independent ��_e --> \nuebar conversion mechanism, the integral limit on the flux of solar \nuebar's in the energy range from 4 -- 14.8 MeV is found to be ��_\nuebar, submitted to Phys. Rev. D

The Sudbury Neutrino Observatory has precisely determined the total active (nu(x)) B-8 solar neutrino flux without assumptions about the energy dependence of the nu(e) survival probability. The measurements were made with dissolved NaCl in heavy water to enhance the sensitivity and signature for neutral-current interactions. The flux is found to be 5.21+/-0.27(stat)+/-0.38(syst)x10(6) cm(-2) s(-1), in agreement with previous measurements and standard solar models. A global analysis of these and other solar and reactor neutrino results yields Deltam(2)=7.1(-0.6)(+1.2)x10(-5) eV(2) and theta= 32.5(-2.3)(+2.4) degrees. Maximal mixing is rejected at the equivalent of 5.4 standard deviations.

The Sudbury Neutrino Observatory has precisely determined the total active (nu(x)) 8B solar neutrino flux without assumptions about the energy dependence of the nu(e) survival probability. The measurements were made with dissolved NaCl in heavy water to enhance the sensitivity and signature for neutral-current interactions. The flux is found to be 5.21 +/- 0.27(stat)+/-0.38(syst) x 10(6) cm(-2) s(-1), in agreement with previous measurements and standard solar models. A global analysis of these and other solar and reactor neutrino results yields Deltam(2)=7.1(+1.2)(-0.6) x 10(-5) eV(2) and theta=32.5(+2.4)(-2.3) degrees. Maximal mixing is rejected at the equivalent of 5.4 standard deviations.

The latest generation gamma-ray detection system, GAMMASPHERE, coupled with the Microball charged-particle detector, has made possible a new class of nuclear lifetime measurement. For the first time differential lifetime measurements free from common systematic errors for over 15 different nuclei ( >30 rotational bands in various isotopes of Ce, Pr, Nd, Pm, and Sm) have been extracted at high spin within a single experiment. This comprehensive study establishes the effective single-particle transition quadrupole moments in the A approximately 135 light rare-earth region. Detailed comparisons are made with theoretical calculations using the self-consistent cranked mean-field theory which convincingly demonstrates the validity of the additivity of single-particle quadrupole moments in this mass region.

A calibration source employing 8Li (t_1/2 = 0.838s) has been developed for use with the Sudbury Neutrino Observatory (SNO). This source creates a spectrum of beta particles with an energy range similar to that of the SNO 8B solar neutrino signal. The source is used to test the SNO detector's energy response, position reconstruction and data reduction algorithms. The 8Li isotope is created using a deuterium-tritium neutron generator in conjunction with a 11B target, and is carried to a decay chamber using a gas/aerosol transport system. The decay chamber detects prompt alpha particles by gas scintillation in coincidence with the beta particles which exit through a thin stainless steel wall. A description is given of the production, transport, and tagging techniques along with a discussion of the performance and application of the source., 11 pages plus 9 figures, Sumbitted to Nuclear Instruments and Methods A

Observations of neutral current neutrino interactions on deuterium in the Sudbury Neutrino Observatory are reported. Using the neutral current, elastic scattering, and charged current reactions and assuming the standard 8B shape, the electron-neutrino component of the 8B solar flux is 1.76 +/-0.05(stat.)+/-0.09(syst.) x10^6/(cm^2 s), for a kinetic energy threshold of 5 MeV. The non-electron neutrino component is 3.41+/-0.45(stat.)+0.48,-0.45(syst.) x10^6/(cm^2 s), 5.3 standard deviations greater than zero, providing strong evidence for solar electron neutrino flavor transformation. The total flux measured with the NC reaction is 5.09 +0.44,-0.43(stat.)+0.46,-0.43(syst.)x10^6/(cm^2 s), consistent with solar models., Comment: 6 pages, 3 figures, correction to author list and minor typographical corrections to references

The Sudbury Neutrino Observatory (SNO) is a 1,000 tonne heavy water Cerenkov‐based neutrino detector situated 2,000 meters underground in INCO’s Creighton Mine near Sudbury, Ontario, Canada. For the neutrinos from 8B decay in the Sun SNO observes the Charged Current neutrino reaction sensitive only to electron neutrinos and others (Neutral Current and Elastic Scattering) sensitive to all active neutrino types and thereby can search for direct evidence of neutrino flavor change. Using these reactions and assuming the standard 8B shape, the ve component of the 8B solar flux is φe = 1.76−0.05+0.05(stat.)−0.09+0.09 (syst.) × 106 cm−2s−1 for a kinetic energy threshold of 5 MeV. The non‐ve component is φμτ = 3.41−0.45+0.45(stat.)−0.45+0.48 (syst.) × 106 cm−2s−1, 5.3σ greater than zero, providing strong evidence for solar ve flavor transformation. The total flux measured with the NC reaction is φNC = 5.09−0.43+0.44(stat.)−0.43+0.46 (syst.) × 106 cm−2s−1, consistent with solar models. For charged current events, ...

The Sudbury Neutrino Observatory (SNO) has measured day and night solar neutrino energy spectra and rates. For charged current events, assuming an undistorted $^8$B spectrum, the night minus day rate is $14.0% \pm 6.3% ^{+1.5}_{-1.4}%$ of the average rate. If the total flux of active neutrinos is additionally constrained to have no asymmetry, the $\nu_e$ asymmetry is found to be $7.0% \pm 4.9% ^{+1.3}_{-1.2}%$. A global solar neutrino analysis in terms of matter-enhanced oscillations of two active flavors strongly favors the Large Mixing Angle (LMA) solution., Comment: 5 pages, 4 figures; very minor revisions, accepted by Physical Review Letters

Solar neutrinos from the decay of 8B have been detected at the Sudbury Neutrino Observatory (SNO) via the charged current (CC) reaction on deuterium and by the elastic scattering (ES) of electrons. The CC reaction is sensitive exclusively to νe, while the ES reaction also has a small sensitivity to νμ and ντ. The flux of νe from 8B decay measured by the CC reaction rate is φCC(ν e )=[1.75±0.07(stat.) −0.11 +0.12 (syst.)×0.05(theor.)]×106cm−2s−1. Assuming no flavor transformation, the flux inferred from the ES reaction rate is φES(ν x )=[2.39±0.34(stat.) −0.14 +0.16 (syst.)]×106cm−2s−1. Comparison of φCC(νe) to the Super-Kamiokande collaboration’s precision value of φES(νx) yields a 3.3σ difference, assuming the systematic uncertainties are normally distributed, providing evidence that there is a nonelectron flavor active neutrino component in the solar flux. The total flux of active 8B neutrinos is thus determined to be (5.44±0.99)×106 cm−2 s−1, in close agreement with the predictions of solar models.

Tinnitus is an extremely prevalent condition that currently has no satisfactory clinical treatment. Development of therapy has been hampered by the diversity of underlying conditions that give rise to the symptom of tinnitus. A drug that has multiple actions may have an improved chance of being effective. One such drug is lamotrigine, a recently developed antiepileptic agent that has both glutamate release inhibition and sodium channel antagonist activity.Lamotrigine was evaluated in a double-blind, placebo-controlled, crossover clinical trial. Patients initially were tested with an intravenous infusion of lidocaine (10 mg/mL) to a maximum of 100 mg or until a reduction in tinnitus. Lamotrigine or placebo tablets were taken once daily (25 mg) for 2 weeks, 50 mg for 2 weeks, and 100 mg for 4 weeks.Patients were chosen from among volunteers from the tinnitus clinic in the local hospital without reference to underlying pathology.Those patients whose tinnitus had been present for less than 6 months or whose tinnitus was likely to vary spontaneously were excluded.Perceived intensity and intrusiveness of tinnitus was assessed before entry onto the trial and at 4-week intervals throughout the trial.Assessment comprised questionnaires, visual analog scales, and a battery of audiologic measurements.There was no correlation between the response to lidocaine and the response to lamotrigine. There was good agreement between the questionnaires and visual analog scales in the reporting of perceived changes; however, this was not reflected as changes in the audiologic tests.Of the 31 participants who completed the trial, questionnaires indicated that lamotrigine was effective in a very few of these persons.

Tinnitus is a prevalent condition which has no practical and effective pharmacological treatment. In the absence of relief by conventional routes, sufferers are increasingly turning to 'alternative' or 'complementary' medicine. This paper reports the evaluation of a homeopathic preparation 'Tinnitus' by a double-blind, placebo-controlled clinical trial. The remedy was taken in tablet form at a homeopathic D60 potency. Perceived intensity and intrusiveness of the tinnitus was assessed at four points during the trial by subjective procedures (visual analogue scales and questionnaires) and by a battery of audiological measurements. Although questionnaire responses indicated that the homeopathic preparation was preferred to placebo by 14 of the 28 subjects, an analysis of variance indicated that neither the VAS scores nor the audiological measures showed significant improvement in tinnitus symptoms in response to 'Tinnitus' versus the placebo. It was concluded that 'Tinnitus' could not be shown to be more effective than the matched placebo.

Computation of phytoplankton pigment concentrations from radiances received by the Coastal Zone Color Scanner (CZCS) is a complex process. Water-leaving radiances, a small portion of the total signal, control the value of pigment computed, but fully 80 to 90% of the total radiance is due to Rayleigh and aerosol scattering. These latter effects must be accurately modeled if reliable pigment concentrations are to be retrieved from CZCS data. In addition, prior to pigment retrieval a series of pre-processing steps must be performed to: (1) correct for instrumentation problems (e.g. drop-outs, zero counts, electronic overshoot); and (2) eliminate clouds from the scene. This paper critically reviews all of the aforementioned factors involved in the valid extraction of phytoplankton pigment concentrations from CZCS data. Also, several possible new approaches for improving the basic closure of the radiative transfer model used in CZCS pigment extraction algorithms (i.e., more robust approaches to the aerosol radiance terms) are introduced. Finally, based upon the community-wide CZCS experience, a few guidelines are suggested for the calibration and timely distribution of ocean color data from future generation sensors.

Scripps Satellite Archive Browsing for Localized Environments (SSable) is a new interactive tool for browsing the Scripps Satellite Oceanography Center's (SSOC) archive of satellite data in your laboratory or office. The archive contains data from the National Atmospheric and Oceanic Administration/Advanced Very High Resolution Radiometer(AVHRR) series of satellites dating from 1979 to present. SSOC maintains a capture station, and data are continually being added to the SSable system within 10 minutes of capture completion. SSable provides an easy-to-use, pointand-click, mouse driven user interface developed around the OSF/Motif widget set and the X Window protocol. All options are selected by either directly clicking the mouse on the desired push button, or pulling down a sub-menu from a push-button. A “fill-inthe-blanks” window appears to guide the user in defining the operation. All SSable option menus have a cancel button to abort the operation. Users can search for data by time, day, geographic coordinate or, if the user knows the structure of the Scripps archive, by explicit archive number.

Ericson fluctuations of the triton and helium-3 decays of the compound nucleus /sup 26/Al formed in the /sup 14/N + /sup 12/C reaction have been studied for excitation energies between 33 and 38 MeV. These mirror channels are only weakly correlated; this result is partly attributed to an isospin-nonconserving width of about 20 keV.

The reaction $^{32}\mathrm{S}(^{14}\mathrm{N}, \mathrm{pn}\ensuremath{\gamma})^{44}\mathrm{Ti}$ has been studied with a view to populating high spin states in $^{44}\mathrm{Ti}$. In singles and $\ensuremath{\gamma}\ensuremath{-}\ensuremath{\gamma}$ coincidence experiments $\ensuremath{\gamma}$-ray transitions in the ground state band and a negative parity band are seen and three levels connected to the ground state band, at 6508, 7671, and 8040 keV, are inferred. Angular distributions are consistent with stretched cascades. The lifetime of the 7671-keV level, presumed ${10}^{+}$, has been determined by the attenuated Doppler-shift method to be 2.7 \ifmmode\pm\else\textpm\fi{} 0.5 ps. A comparison of the present reaction with the recently reported $^{28}\mathrm{Si}(^{19}\mathrm{F}, p2n\ensuremath{\gamma})^{44}\mathrm{Ti}$ reaction is made and a method for predicting the propensity of these types of reaction to feed high spin states is proposed. $\mathrm{An}{(\mathrm{fp})}^{4}$ shell model calculation of yrast levels up to $J=12$ has been made.

From January 9 to 17, 1981, detailed observations of the horizontal and vertical structure beneath one of the quasi-permanent semi-stationary mesoscale offshore eddy signatures in the California Current System (CCS) discussed by Bernstein, Breaker and Whritner (1977), Burkov and Pavlova (1980), and Simpson (1982) were made. The vertical sections of temperature and density show the presence of three-layer system. A subsurface warm-core eddy, whose diameter is about 150 km at the 7°C isotherm, is the dominant feature. A warm surface layer, which extends to a depth of 75 m, lies over the eddy. Between the warm surface layer and the subsurface warm-core eddy, there is a cold-core region which extends to a depth of about 200 m. There is a high degree of symmetry about the vertical axis of rotation. Vertical sections of salinity and dissolved oxygen are entirely different from sections of temperature and density. Diagrams of water mass characteristics confirm that the core of the eddy, found between 250–600 m, consists of inshore water from the California Undercurrent (CU). Below about 700 m, local waters from the Deep Poleward Flow (DPF) have been incorporated into the eddy. The observed distributions of properties (T, S, δ θ , O 2 ) are inconsistent with a single, local generation process for the eddy system. Radial distributions of angular velocity, normalized gradient velocity and relative vorticity support the use of a Gaussian radial height field as an initial condition in eddy models. Possible reasons why CCS eddies may differ dynamically from Gulf Stream rings are given in the text. At the time the observations were made, the system as a whole was in near geostrophic balance. Local geostrophic balance, however, cannot explain the observed distribution of properties and structure. The observed symmetry in the structure of the eddy system, chemical evidence (Simpson, 1984), biological distributions (Haury, 1984) and satellite images of the CC (Koblinsky, Simpson and Dickey, 1984) suggest that lateral entrainment of warm (oceanic) and cold (coastal) water into the upper two layers of the three-layer system by the subsurface eddy is a likely generation mechanism for the cold-core region. The coastal origin of the frontal structure along the northeastern quadrant and the oceanic origin of the frontal structure along the southwestern quadrant of the eddy system further support lateral entrainment as a generation mechanism for the cold core. This entrainment makes the CCS eddy system different from cold-core rings in the Gulf Stream and rather similar to some warm-core eddies found in the East Australian Current. The presence of CU water in the core of this eddy raises the question of how CU water was transported from the continental slope. Eddy generation mechanisms, other than baroclinic instability of the CC, may be required to explain the distribution, persistence, and core composition of offshore mesoscale eddies in the CCS. There is evidence that barotropic, in addition to baroclinic, processes may be important.