Science.gov

Sample records for neutron rem meters

  1. Proton recoil scintillator neutron rem meter

    DOEpatents

    Olsher, Richard H.; Seagraves, David T.

    2003-01-01

    A neutron rem meter utilizing proton recoil and thermal neutron scintillators to provide neutron detection and dose measurement. In using both fast scintillators and a thermal neutron scintillator the meter provides a wide range of sensitivity, uniform directional response, and uniform dose response. The scintillators output light to a photomultiplier tube that produces an electrical signal to an external neutron counter.

  2. Neutron dose equivalent meter

    DOEpatents

    Olsher, Richard H.; Hsu, Hsiao-Hua; Casson, William H.; Vasilik, Dennis G.; Kleck, Jeffrey H.; Beverding, Anthony

    1996-01-01

    A neutron dose equivalent detector for measuring neutron dose capable of accurately responding to neutron energies according to published fluence to dose curves. The neutron dose equivalent meter has an inner sphere of polyethylene, with a middle shell overlying the inner sphere, the middle shell comprising RTV.RTM. silicone (organosiloxane) loaded with boron. An outer shell overlies the middle shell and comprises polyethylene loaded with tungsten. The neutron dose equivalent meter defines a channel through the outer shell, the middle shell, and the inner sphere for accepting a neutron counter tube. The outer shell is loaded with tungsten to provide neutron generation, increasing the neutron dose equivalent meter's response sensitivity above 8 MeV.

  3. Comparing Geant4 hadronic models for the WENDI-II rem meter response function.

    PubMed

    Vanaudenhove, T; Dubus, A; Pauly, N

    2013-01-01

    The WENDI-II rem meter is one of the most popular neutron dosemeters used to assess a useful quantity of radiation protection, namely the ambient dose equivalent. This is due to its high sensitivity and its energy response that approximately follows the conversion function between neutron fluence and ambient dose equivalent in the range of thermal to 5 GeV. The simulation of the WENDI-II response function with the Geant4 toolkit is then perfectly suited to compare low- and high-energy hadronic models provided by this Monte Carlo code. The results showed that the thermal treatment of hydrogen in polyethylene for neutron <4 eV has a great influence over the whole detector range. Above 19 MeV, both Bertini Cascade and Binary Cascade models show a good correlation with the results found in the literature, while low-energy parameterised models are not suitable for this application.

  4. Response of six neutron survey meters in mixed fields of fast and thermal neutrons.

    PubMed

    Kim, S I; Kim, B H; Chang, I; Lee, J I; Kim, J L; Pradhan, A S

    2013-10-01

    Calibration neutron fields have been developed at KAERI (Korea Atomic Energy Research Institute) to study the responses of commonly used neutron survey meters in the presence of fast neutrons of energy around 10 MeV. The neutron fields were produced by using neutrons from the (241)Am-Be sources held in a graphite pile and a DT neutron generator. The spectral details and the ambient dose equivalent rates of the calibration fields were established, and the responses of six neutron survey meters were evaluated. Four single-moderator-based survey meters exhibited an under-responses ranging from ∼9 to 55 %. DINEUTRUN, commonly used in fields around nuclear reactors, exhibited an over-response by a factor of three in the thermal neutron field and an under-response of ∼85 % in the mixed fields. REM-500 (tissue-equivalent proportional counter) exhibited a response close to 1.0 in the fast neutron fields and an under-response of ∼50 % in the thermal neutron field.

  5. DOSIMETRIC response of a REM-500 in low energy neutron fields typical of nuclear power plants.

    PubMed

    Aslam; Matysiak, W; Atanackovic, J; Waker, A J

    2012-06-01

    This study investigates the response of a REM-500 to assess neutron quality factor and dose equivalent in low energy neutron fields, which are commonly encountered in the workplace environment of nuclear power stations. The McMaster University 3 MV Van de Graaff accelerator facility was used to measure the response of the instrument in monoenergetic neutron fields in the energy range 51 to 727 keV by bombarding a thin LiF target with 1.93-2.50 MeV protons. The energy distribution of the neutron fields produced in the facility was measured by a (3)He filled gas ionization chamber. The MCA mode of the REM-500 instrument was used to collect lineal energy distributions at varying neutron energies and to calculate the frequency and dose-mean lineal energies. The effective quality factor, Q-, was also calculated using the values of Q(y)listed in the REM-500 operation manual and compared with those of ICRP 60. The authors observed a continuously increasing trend in y - F, y-D, and Q-with an increase in neutron energy. It is interesting to note that standard tissue equivalent proportional counters (TEPCs) filled with tissue equivalent(TE) gas give rise to a similar trend for these microdosimetric quantities of interest in the same energy range; however, the averages calculated in this study are larger by about 15%compared to a TEPC filled with propane-based TE gas probably because of the larger stopping power of protons in propane compared to TE gas. These somewhat larger event sizes did not result in any significant increase in the Q-compared to those obtained from a TEPC filled with TE gas and were found to be in good agreement with other measurements reported earlier at corresponding neutron energies. The instrument quality factor response, R(Q), defined as the ratio of measured quality factor to the calculated quality factor in an ICRU tissue sphere,was found to vary with neutron energy. The instrument response,R(Q), was ~0.6 at 727 keV, which deteriorates further to

  6. Study of the response of a lithium yttrium borate scintillator based neutron rem counter by Monte Carlo radiation transport simulations

    NASA Astrophysics Data System (ADS)

    Sunil, C.; Tyagi, Mohit; Biju, K.; Shanbhag, A. A.; Bandyopadhyay, T.

    2015-12-01

    The scarcity and the high cost of 3He has spurred the use of various detectors for neutron monitoring. A new lithium yttrium borate scintillator developed in BARC has been studied for its use in a neutron rem counter. The scintillator is made of natural lithium and boron, and the yield of reaction products that will generate a signal in a real time detector has been studied by FLUKA Monte Carlo radiation transport code. A 2 cm lead introduced to enhance the gamma rejection shows no appreciable change in the shape of the fluence response or in the yield of reaction products. The fluence response when normalized at the average energy of an Am-Be neutron source shows promise of being used as rem counter.

  7. Fission meter and neutron detection using poisson distribution comparison

    SciTech Connect

    Rowland, Mark S; Snyderman, Neal J

    2014-11-18

    A neutron detector system and method for discriminating fissile material from non-fissile material wherein a digital data acquisition unit collects data at high rate, and in real-time processes large volumes of data directly into information that a first responder can use to discriminate materials. The system comprises counting neutrons from the unknown source and detecting excess grouped neutrons to identify fission in the unknown source. Comparison of the observed neutron count distribution with a Poisson distribution is performed to distinguish fissile material from non-fissile material.

  8. Design and use of a 6 meter neutron small-angle scattering spectrometer at KUR

    NASA Astrophysics Data System (ADS)

    Komura, S.; Takeda, T.; Fujii, H.; Osamura, K.; Mochiki, K.; Hasegawa, K.

    1983-05-01

    A 6 meter neutron small-angle scattering spectrometer has been constructed at the Kyoto University Reactor (KUR) and has been used successfully in various fields of application. The design principles and the characteristics of the spectrometer are described briefly. Some examples of the scattering measurements are presented.

  9. A 6-Meter Neutron Small-Angle Scattering Spectrometer at KUR

    NASA Astrophysics Data System (ADS)

    Komura, Shigehiro; Takeda, Takayoshi; Fujii, Hironobu; Toyoshima, Yoshinori; Osamura, Kozo; Mochiki, Koichi; Hasegawa, Ken'ichi

    1983-02-01

    A 6-meter neutron small-angle scattering spectrometer has been constructed at Kyoto University Reactor (KUR) and has been used successfully for various fields of application in these three years. This paper describes overall design principles and the characteristics of the various parts of the spectrometers which can be assembled and disassembled easily at KUR. Some examples of scattering measurements are presented to show the performance of the spectrometer.

  10. Sensitivity and uncertainty in the measurement of H*(10) in neutron fields using an REM500 and a multi-element TEPC.

    PubMed

    Waker, Anthony; Taylor, Graeme

    2014-10-01

    The REM500 is a commercial instrument based on a tissue-equivalent proportional counter (TEPC) that has been successfully deployed as a hand-held neutron monitor, although its sensitivity is regarded by some workers as low for nuclear power plant radiation protection work. Improvements in sensitivity can be obtained using a multi-element proportional counter design in which a large number of small detecting cavities replace the single large volume cavity of conventional TEPCs. In this work, the authors quantify the improvement in uncertainty that can be obtained by comparing the ambient dose equivalent measured with a REM500, which utilises a 5.72 cm (2(1/4) inch) diameter Rossi counter, with that of a multi-element TEPC designed to have the sensitivity of a 12.7 cm (5 inch) spherical TEPC. The results obtained also provide some insight into the influence of other design features of TEPCs, such as geometry and gas filling, on the measurement of ambient dose equivalent.

  11. Status Report on the Passive Neutron Enrichment Meter (PNEM) for UF6 Cylinder Assay

    SciTech Connect

    Miller, Karen A.; Swinhoe, Martyn T.; Menlove, Howard O.; Marlow, Johnna B.

    2012-05-02

    The Passive Neutron Enrichment Meter (PNEM) is a nondestructive assay (NDA) system being developed at Los Alamos National Laboratory (LANL). It was designed to determine {sup 235}U mass and enrichment of uranium hexafluoride (UF{sub 6}) in product, feed, and tails cylinders (i.e., 30B and 48Y cylinders). These cylinders are found in the nuclear fuel cycle at uranium conversion, enrichment, and fuel fabrication facilities. The PNEM is a {sup 3}He-based neutron detection system that consists of two briefcase-sized detector pods. A photograph of the system during characterization at LANL is shown in Fig. 1. Several signatures are currently being studied to determine the most effective measurement and data reduction technique for unfolding {sup 235}U mass and enrichment. The system collects total neutron and coincidence data for both bare and cadmium-covered detector pods. The measurement concept grew out of the success of the Uranium Cylinder Assay System (UCAS), which is an operator system at Rokkasho Enrichment Plant (REP) that uses total neutron counting to determine {sup 235}U mass in UF{sub 6} cylinders. The PNEM system was designed with higher efficiency than the UCAS in order to add coincidence counting functionality for the enrichment determination. A photograph of the UCAS with a 48Y cylinder at REP is shown in Fig. 2, and the calibration measurement data for 30B product and 48Y feed and tails cylinders is shown in Fig. 3. The data was collected in a low-background environment, meaning there is very little scatter in the data. The PNEM measurement concept was first presented at the 2010 Institute of Nuclear Materials Management (INMM) Annual Meeting. The physics design and uncertainty analysis were presented at the 2010 International Atomic Energy Agency (IAEA) Safeguards Symposium, and the mechanical and electrical designs and characterization measurements were published in the ESARDA Bulletin in 2011.

  12. PING Gamma Ray and Neutron Measurements of a Meter-Sized Carbonaceous Asteroid Analog

    NASA Technical Reports Server (NTRS)

    Bodnarik, J.; Burger, D.; Evans, L.; Floyd, S.; Lim, L.; McClanahan, T.; Namkung, M.; Nowicki, S.; Parsons, A.; Schweitzer, J.; Starr, R.; Trombka, J.

    2011-01-01

    Determining the elemental composition of carbonaceous (spectral type C) asteroids is still one of the basic problems when studying these objects. The only main source of elemental composition information for asteroids is from their optical, NIR and IR properties, which include their spectral reflectance characteristics, albedo, polarization, and the comparison of optical spectroscopy with meteorite groups corresponding to asteroids of every spectral type. Unfortunately, these sources reflect observations from widely contrasting spatial scales that presently yield a void in the continuum of microscopic and macroscopic evidence, a lack of in situ measurement confirmation, and require deeper sensing techniques to discern the nature of these asteroids. The Probing In situ with Neutrons and Gamma rays (PING) instrument is ideally suited to address this problem because it can be used to determine the bulk elemental composition, H and C content, the average atomic weight and density of the surface and subsurface layers of C-type asteroids, and can provide measurements used to determine the difference between and distinguish between different types of asteroids. We are currently developing the PING instrument that combines gamma ray and neutron detectors with a 14 Me V pulsed neutron generator to determine the in-situ bulk elemental abundances and geochemistry of C-type asteroids with a spatial resolution of 1 m down to depths of tens of cm to 1 m. One aspect of the current work includes experimentally testing and optimizing PING on a known meter-sized Columbia River basalt C-type asteroid analog sample that has a similar composition and the same neutron response as that of a C-type asteroid. An important part of this effort focuses on utilizing timing measurements to isolate gamma rays produced by neutron inelastic scattering, neutron capture and delayed activation processes. Separating the gamma ray spectra by nuclear processes results in higher precision and sensitivity

  13. Neutron spectra as a function of angle at two meters from the Little Boy assembly

    SciTech Connect

    Griffith, R.V.; Huntzinger, C.J.; Thorngate, J.H.

    1984-07-02

    Measurements of neutron spectra produced by the Los Alamos National Laboratory (LANL) Little Boy replica assembly (Comet) were made with a combined multisphere and liquid scintillator system, that has been widely used at the Lawrence Livermore National Laboratory. The combined system was used for measurements at the side (90/sup 0/) and nose (0/sup 0/) of the assembly; additional measurements were made at 45/sup 0/ using only the liquid scintillator. Data were obtained at two meters from the center of the reactive region of the assembly, with good agreement between the multisphere and scintillator results. Comparison with liquid scintillator measurements performed by experimenters from the Canadian Defence Research Establishment, Ottawa (DREO) and calculations from LANL depended on the specific angle, obtaining the best agreement at 90/sup 0/. 32 references, 11 figures, 4 tables.

  14. REM sleep - by default?

    PubMed

    Horne, J A

    2000-12-01

    Elements of three old, overlapping theories of REM sleep (REM) function, the Ontogenetic, Homeostatic and Phylogenetic hypotheses, together still provide a plausible framework - that REM (i) is directed towards early cortical development, (ii) "tones up" the sleeping cortex, (iii) can substitute for wakefulness, (iv) has a calming effect. This framework is developed in the light of recent findings. It is argued that the "primitiveness" of REM and its similarity to wakefulness liken it to a default state of "non-wakefulness" or a waking antagonist, anteceding "true" (non-REM) sleep. The "toning up" is reflected by inhibition of motor, sensory and (importantly) emotional systems, together pointing to integrated "flight or fight" activity, that preoccupies/distracts the organism when non-REM is absent and wakefulness unnecessary. Dreaming facilitates this distraction. In rodents, REM can provide stress coping and calming, but REM deprivation procedures incorporating immobility may further enhance stress and confound outcomes. REM "pressure" (e.g. REM rebounds) may be a default from a loss of inhibition of REM by non-REM. REM can be reduced and/or replaced by wakefulness, without adverse effects. REM has little advantage over wakefulness in providing positive cerebral recovery or memory consolidation. PMID:11118606

  15. Recent Development of a 36 meter Small-Angle Neutron Scattering BATAN Spectrometer (SMARTer) in Serpong Indonesia

    NASA Astrophysics Data System (ADS)

    Giri Rachman Putra, Edy; Bharoto; Seong, Baek Seok

    2010-10-01

    The 36 meter small-angle neutron scattering (SANS) spectrometer BATAN (SMARTer) in Serpong, Indonesia has been revitalised for several years. The work on replacing, upgrading and improving the control system and the experimental method were conducted in order to setup the spectrometer back in operation. Two main personal computers, one for handling and controlling the mechanical system and another one for acquiring neutron data were employed at the spectrometer. The standard and established SANS data reduction and analysis programs, such as GRASP and NIST Igor have been implemented to subtract the raw scattered neutron data with the backgrounds and then analyse the corrected data. The scattering data of ferrofluids samples, Fe3O4 and MnZnFe2O4 have been obtained using SANS spectrometers in BATAN Serpong, Indonesia and HANARO-KAERI, Republic of Korea for inter-laboratory comparison and investigation of proposed research interest. The results were comparable from both scattering data analysis.

  16. Dreaming without REM sleep.

    PubMed

    Oudiette, Delphine; Dealberto, Marie-José; Uguccioni, Ginevra; Golmard, Jean-Louis; Merino-Andreu, Milagros; Tafti, Mehdi; Garma, Lucile; Schwartz, Sophie; Arnulf, Isabelle

    2012-09-01

    To test whether mental activities collected from non-REM sleep are influenced by REM sleep, we suppressed REM sleep using clomipramine 50mg (an antidepressant) or placebo in the evening, in a double blind cross-over design, in 11 healthy young men. Subjects were awakened every hour and asked about their mental activity. The marked (81%, range 39-98%) REM-sleep suppression induced by clomipramine did not substantially affect any aspects of dream recall (report length, complexity, bizarreness, pleasantness and self-perception of dream or thought-like mentation). Since long, complex and bizarre dreams persist even after suppressing REM sleep either partially or totally, it suggests that the generation of mental activity during sleep is independent of sleep stage.

  17. [A new correction method for radionuclide formation in neutron activation analysis using a reactor power meter coupled with a microcomputer].

    PubMed

    Hirai, S; Yoshino, Y; Suzuki, S; Horiuchi, N

    1982-05-01

    Neutron flux and irradiation time should be accurately known in neutron activation analysis using very short lived nuclides in which conventional monitoring methods i.e., a comparator method, flux monitor method and so on cannot be used satisfactorily. Especially, fluctuation of neutron flux has not been corrected. We noted a change of reactor power at a pneumatic operation, and found out a new correction method for its correction in activation analysis. In our small nuclear reactor, TRIGA-II, the reactor power increased rapidly a few % when a pneumatic-operated capsule arrived at a core of the reactor, and decreased when the capsule left from the core. If the duration between these two changes of the reactor power is equal to the irradiation time, and that the reactor power is proportional to the neutron flux, we can regard an activity formation as a time integration of the reactor power. Then, the correction system was made of a reactor power meter, a V-F converter (voltage to frequency converter), a clock time, a counter, a microcomputer, electric circuits and so on. The signal of the reactor power during the irradiation was counted through the V-F converter, and was accumulated in a memory of the microcomputer. The neutron fluence was calculated in this microcomputer. This method was examined by means of activation of copper and selenium standard samples by 9-11 sec irradiations. The observed activity involved +/- 10% error. However, the error in the corrected activity was decreased to a few % using this correction method. As a result, we found that this method can be used to obtain accurate value for radionuclide formation.

  18. Shielding Calculations for the BDMS UF6 Mass Flow Meter

    SciTech Connect

    Radev, R; Hall, J

    2001-09-13

    We performed Monte Carlo calculations of the neutron and gamma ray spectra and neutron and gamma dose rates outside the shielding of the UF{sub 6} mass flowmeter. The UF{sub 6} mass flowmeter and the UF{sub 6} mass flowmeter are the two main components of the Blend Down Monitoring System (BDMS) equipment. The BDMS equipment is designed to continuously monitor the UF{sub 6} enrichment and mass flow rates in processing pipes at uranium facilities. The UF{sub 6} mass flowmeter incorporates four {sup 252}Cf neutron sources, surrounded by a polyethylene shielding block. The uranium fission products generated by the {sup 252}Cf neutrons are detected down the pipe, thus confirming the UF{sub 6} mass flow rate. The dose calculations used both U.S. and Russian gamma and neutron fluence-to-dose conversion coefficients. The purpose of these calculations was to facilitate proper interpretation of the neutron dose rate measurements from rem meters (e.g., rem balls) outside of BDMS shielding. An accurate determination of the dose rate is particular interest in that it enables dose rates to be compared with the applicable regulatory limit. The calculations show that neutrons outside of BDMS shielding are significantly reduced in energy, i.e., the spectrum is shifted (i.e., moderated) towards lower energies and contains significantly larger amount of neutrons in the energy range below 100 keV. Results of the calculations indicate that neutron dose rate measurements taken outside of BDMS shielding are overestimated by 25% to 55%, depending on the location around BDMS, when using either Russian or U.S. dose conversion coefficients. For an accurate neutron dose rate evaluation, application of an appropriate correction factor to the neutron dose rate measurements is necessary.

  19. The 27.3 meter neutron time-of-flight system for the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Grim, G. P.; Morgan, G. L.; Aragonez, R.; Archuleta, T. N.; Bower, D. E.; Danly, C. R.; Drury, O. B.; Dzenitis, J. M.; Fatherley, V. E.; Felker, B.; Fittinghoff, D. N.; Guler, N.; Merrill, F. E.; Oertel, J. A.; Wilde, C. H.; Wilke, M. D.

    2013-09-01

    One of the scientific goals of the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory, Livermore CA, is to obtain thermonuclear ignition by compressing 2.2 mm diameter capsules filed with deuterium and tritium to densities approaching 1000 g/cm3 and temperatures in excess of 4 keV. Thefusion reaction d + t --> n + a results in a 14.03 MeV neutron providing a source of diagnostic particles to characterize the implosion. The spectrum of neutrons emanating from the assembly may be used to infer the fusion yield, plasma ion temperature, and fuel areal density, all key diagnostic quantities of implosion quality. The neutron time-of-flight (nToF) system co-located along the Neutron Imaging System line-of-site, (NIToF), is a set of 4 scintillation detectors located approximately 27.3 m from the implosion source. Neutron spectral information is inferred using arrival time at the detector. The NIToF system is described below, including the hardware elements, calibration data, analysis methods, and an example of its basic performance characteristics.

  20. Is the nonREM-REM sleep cycle reset by forced awakenings from REM sleep?

    PubMed

    Grözinger, Michael; Beersma, Domien G M; Fell, Jürgen; Röschke, Joachim

    2002-11-01

    In selective REM sleep deprivation (SRSD), the occurrence of stage REM is repeatedly interrupted by short awakenings. Typically, the interventions aggregate in clusters resembling the REM episodes in undisturbed sleep. This salient phenomenon can easily be explained if the nonREM-REM sleep process is continued during the periods of forced wakefulness. However, earlier studies have alternatively suggested that awakenings from sleep might rather discontinue and reset the ultradian process. Theoretically, the two explanations predict a different distribution of REM episode duration. We evaluated 117 SRSD treatment nights recorded from 14 depressive inpatients receiving low dosages of Trimipramine. The alarms were triggered by an automatic mechanism for the detection of REM sleep and had to be canceled by the subjects themselves. The REM episodes were determined as in undisturbed sleep-they had to include the remaining REM activity and were separated by 30 min without REM epochs. The frequency histogram of REM episodes declined exponentially with episode duration for each of the first four sleep cycles. The duration of nonREM intervals revealed bimodal distributions. These results were found consistent with the model assuming a reset of the ultradian cycle upon awakening. Whether REM or nonREM activity is resumed on return to sleep can be modeled by a random decision whereby the probability for REM sleep might depend on the momentary REM pressure.

  1. Recent re-measurement of neutron and gamma-ray spectra 1080 meters from the APRD (Army Pulse Radiation Division) critical facility

    NASA Astrophysics Data System (ADS)

    Robitaille, H. A.; Hoffarth, B. E.

    1984-01-01

    Previously reported measurements of long-range air-transported neutron and gamma-ray spectra from the fast-critical facility at the US Army Aberdeen Proving Ground have been supplemented recently at the 1080-meter position. The results of these determinations are presented herein and compared to several recent calculations from other research establishments. In addition, a summary of all dosimetric measurements obtained in the period 1979-1982 are appended, as are new determinations of APRD soil composition. Integral quantities such as neutron and gamma-ray kermas are very well predicted by the latest calculations, however there still exist significant spectral differences. At short ranges calculated neutron spectra are somewhat softer than experimental measurements, but at the farthest range of 1080 meters agreement is surprisingly good. Gamma-ray spectra remain well-calculated at all ranges.

  2. Long-term Passive Mode Data Measured by the Dynamic Albedo of Neutrons (DAN) Instrument onboard Mars Science Laboratory (MSL) and Comparison to REMS Surface Pressure and Temperature Measurements

    NASA Astrophysics Data System (ADS)

    Jun, I.; Mitrofanov, I. G.; Litvak, M. L.; Sanin, A. B.; Martín-Torres, J.; Zorzano, M. P.; Boynton, W. V.; Fedosov, F.; Golovin, D.; Hardgrove, C. J.; Harshman, K.; Kozyrev, A.; Kuzmin, R.; Malakhov, A. V.; Mischna, M. A.; Moersch, J.; Mokrousov, M.; Nikiforov, S.; Tate, C. G.

    2014-12-01

    Since the landing in August 2012, DAN has provided a wealth of scientific data from the successful surface operation in both Active mode and Passive mode. While the main DAN science investigation so far has focused in estimating the contents of water-equivalent-hydrogen (WEH) and chlorine-equivalent-neutron-absorption in the surface, here we will provide/discuss low energy (less than about 1 keV) background neutron environment at the Martian surface as measured by DAN Passive mode operation. Passive mode measurements have been done on almost every sols with durations ranging from 1 hour to ~9 hour, covering different times of a day. Neutrons from the onboard power source Multi Mission Radioisotope Thermonuclear Generator (MMRTG) and induced by Galactic Cosmic Ray (GCR)/Solar Energetic Particles (SEP) interactions with the Martian atmosphere and the surface material contribute to the DAN passive data. An approach to separate out the respective contributions from the DAN total count rates was developed previously (Jun et al., 2013) using the data collected at Rocknest (where the rover stayed from sol 60 to sol 100). The main goal of this paper is to extend the same analysis to other locations encountered during the rover traverse especially to understand the long-term (through Sol 800, covering more than 1 Martian year) behavior of the neutron environment at the Martian surface as measured by DAN in response to variation of the free space GCR/SEP environment. Extensive Monte Carlo transport simulations using Monte Carlo N-Particle eXtended (MCNPX) have been performed to support the analysis and to aid interpretation of the DAN passive data. In addition, the DAN passive data are compared to the long-term surface temperature and pressure data (both measured and modeled) from Rover Environmental Monitoring Station (REMS) to investigate possible correlation of the DAN data with ambient environmental conditions.

  3. Responses of selected neutron monitors to cosmic radiation at aviation altitudes.

    PubMed

    Yasuda, Hiroshi; Yajima, Kazuaki; Sato, Tatsuhiko; Takada, Masashi; Nakamura, Takashi

    2009-06-01

    Cosmic radiation exposure of aircraft crew, which is generally evaluated by numerical simulations, should be verified by measurements. From the perspective of radiological protection, the most contributing radiation component at aviation altitude is neutrons. Measurements of cosmic neutrons, however, are difficult in a civilian aircraft because of the limitations of space and electricity; a small, battery-operated dosimeter is required whereas larger-size instruments are generally used to detect neutrons with a broad range of energy. We thus examined the applicability of relatively new transportable neutron monitors for use in an aircraft. They are (1) a conventional rem meter with a polyethylene moderator (NCN1), (2) an extended energy-range rem meter with a tungsten-powder mixed moderator (WENDI-II), and (3) a recoil-proton scintillation rem meter (PRESCILA). These monitors were installed onto the racks of a business jet aircraft that flew two times near Japan. Observed data were compared to model calculations using a PHITS-based Analytical Radiation Model in the Atmosphere (PARMA). Excellent agreement between measured and calculated values was found for the WENDI-II. The NCN1 showed approximately half of predicted values, which were lower than those expected from its response function. The observations made with PRESCILA showed much higher than expected values; which is attributable to the presence of cosmic-ray protons and muons. These results indicate that careful attention must be paid to the dosimetric properties of a detector employed for verification of cosmic neutron dose.

  4. Responses of selected neutron monitors to cosmic radiation at aviation altitudes.

    PubMed

    Yasuda, Hiroshi; Yajima, Kazuaki; Sato, Tatsuhiko; Takada, Masashi; Nakamura, Takashi

    2009-06-01

    Cosmic radiation exposure of aircraft crew, which is generally evaluated by numerical simulations, should be verified by measurements. From the perspective of radiological protection, the most contributing radiation component at aviation altitude is neutrons. Measurements of cosmic neutrons, however, are difficult in a civilian aircraft because of the limitations of space and electricity; a small, battery-operated dosimeter is required whereas larger-size instruments are generally used to detect neutrons with a broad range of energy. We thus examined the applicability of relatively new transportable neutron monitors for use in an aircraft. They are (1) a conventional rem meter with a polyethylene moderator (NCN1), (2) an extended energy-range rem meter with a tungsten-powder mixed moderator (WENDI-II), and (3) a recoil-proton scintillation rem meter (PRESCILA). These monitors were installed onto the racks of a business jet aircraft that flew two times near Japan. Observed data were compared to model calculations using a PHITS-based Analytical Radiation Model in the Atmosphere (PARMA). Excellent agreement between measured and calculated values was found for the WENDI-II. The NCN1 showed approximately half of predicted values, which were lower than those expected from its response function. The observations made with PRESCILA showed much higher than expected values; which is attributable to the presence of cosmic-ray protons and muons. These results indicate that careful attention must be paid to the dosimetric properties of a detector employed for verification of cosmic neutron dose. PMID:19430218

  5. REM sleep Behaviour Disorder.

    PubMed

    Ferini-Strambi, Luigi; Rinaldi, Fabrizio; Giora, Enrico; Marelli, Sara; Galbiati, Andrea

    2016-01-01

    Rapid Eye Movement (REM) sleep Behaviour Disorder (RBD) is a REM sleep parasomnia characterized by loss of the muscle atonia that typically occurs during REM sleep, therefore allowing patients to act out their dreams. RBD manifests itself clinically as a violent behaviour occurring during the night, and is detected at the polysomnography by phasic and/or tonic muscle activity on the electromyography channel. In absence of neurological signs or central nervous system lesions, RBD is defined as idiopathic. Nevertheless, in a large number of cases the development of neurodegenerative diseases in RBD patients has been described, with the duration of the follow-up representing a fundamental aspect. A growing number of clinical, neurophysiologic and neuropsychological studies aimed to detect early markers of neurodegenerative dysfunction in RBD patients. Anyway, the evidence of impaired cortical activity, subtle neurocognitive dysfunction, olfactory and autonomic impairment and neuroimaging brain changes in RBD patients is challenging the concept of an idiopathic form of RBD, supporting the idea of RBD as an early manifestation of a more complex neurodegenerative process. PMID:26427638

  6. REM sleep Behaviour Disorder.

    PubMed

    Ferini-Strambi, Luigi; Rinaldi, Fabrizio; Giora, Enrico; Marelli, Sara; Galbiati, Andrea

    2016-01-01

    Rapid Eye Movement (REM) sleep Behaviour Disorder (RBD) is a REM sleep parasomnia characterized by loss of the muscle atonia that typically occurs during REM sleep, therefore allowing patients to act out their dreams. RBD manifests itself clinically as a violent behaviour occurring during the night, and is detected at the polysomnography by phasic and/or tonic muscle activity on the electromyography channel. In absence of neurological signs or central nervous system lesions, RBD is defined as idiopathic. Nevertheless, in a large number of cases the development of neurodegenerative diseases in RBD patients has been described, with the duration of the follow-up representing a fundamental aspect. A growing number of clinical, neurophysiologic and neuropsychological studies aimed to detect early markers of neurodegenerative dysfunction in RBD patients. Anyway, the evidence of impaired cortical activity, subtle neurocognitive dysfunction, olfactory and autonomic impairment and neuroimaging brain changes in RBD patients is challenging the concept of an idiopathic form of RBD, supporting the idea of RBD as an early manifestation of a more complex neurodegenerative process.

  7. [REM sleep behavior disorder (RBD) and dissociated REM sleep].

    PubMed

    Watanabe, T; Sugita, Y

    1998-02-01

    REM sleep behavior disorder (RBD) is characterized by the appearance of somnambulism-like behavior associated with dream mentation, and the intermittent loss of muscle atonia during REM sleep (stage 1-REM with tonic EMG; stage 1-REM). RBD is caused symptomatically or idiopathically, and its manifestation of symptoms sometimes associated with psychosocial stress. Muscle tone is often augmented during impared REM sleep observed in RBD patients. Animal experimental studies suggest that dysfunction or lesions of muscle inhibitory system in brain stem is rerated with pathogenesis of RBD. Clonazepam is effective for organic behavior and nightmare, but not remarkable for dissociated REM sleep. Other benzodiazepines and tricyclic antidepressants can be one of the choices of medications. Directions for safe-bedroom and psychotherapy is sometimes necessary. PMID:9503847

  8. Dissociative symptoms and REM sleep.

    PubMed

    van Heugten-van der Kloet, Dalena; Merckelbach, Harald; Lynn, Steven Jay

    2013-12-01

    Llewellyn has written a fascinating article about rapid eye movement (REM) dreams and how they promote the elaborative encoding of recent memories. The main message of her article is that hyperassociative and fluid cognitive processes during REM dreaming facilitate consolidation. We consider one potential implication of this analysis: the possibility that excessive or out-of-phase REM sleep fuels dissociative symptomatology. Further research is warranted to explore the psychopathological ramifications of Llewellyn's theory. PMID:24304772

  9. Measurement of the neutron spectrum and ambient neutron dose rate equivalent from the small 252Cf source at 1 meter

    SciTech Connect

    Radev, R.

    2015-07-07

    NASA Langley Research Center requested a measurement of the neutron spectral distribution and fluence from the 252Cf source (model NS-120, LLNL serial # 7001677, referred as the SMALL Cf source) and determination of the ambient neutron dose rate equivalent and kerma at 100 cm for the Radiation Budget Instrument Experiment (Rad-X). The dosimetric quantities should be based on the neutron spectrum and the current neutron-to-dose conversion coefficients.

  10. REM sleep and neural nets.

    PubMed

    Crick, F; Mitchison, G

    1995-01-01

    The broad features of rapid eye movement (REM) sleep are reviewed. Memory storage in the brain is probably quite unlike that in a digital computer, being distributed, superimposed and robust. Such memory systems are easily overloaded. If the stored memories share common features, random stimulation often produces mixed outputs. Simulations show that such overloading can be reduced by a process we call 'reverse learning'. We propose that this process is what is happening in REM sleep and that it explains in an unforced manner the condensation commonly found in dreams. Evidence for and against the proposed theory is discussed and several alternative theories are briefly described. The absence of REM sleep in the Enchidna and in two species of dolphins (that have relatively large brains) suggests that REM may allow the brain to be smaller than if REM were lacking.

  11. REM-containing silicate concentrates

    NASA Astrophysics Data System (ADS)

    Pavlov, V. F.; Shabanova, O. V.; Pavlov, I. V.; Pavlov, M. V.; Shabanov, A. V.

    2016-01-01

    A new method of advanced complex processing of ores containing rare-earth elements (REE) is proposed to obtain porous X-ray amorphous aluminosilicate material with a stable chemical composition which concentrates oxides of rare-earth metals (REM). The ferromanganese oxide ores of Chuktukon deposit (Krasnoyarsk Region, RF) were used for the experiment. The obtained aluminosilicate material is appropriate for treatment with 5 - 15% solutions of mineral acids to leach REM.

  12. REM sleep homeostasis in the absence of REM sleep: Effects of antidepressants.

    PubMed

    McCarthy, Andrew; Wafford, Keith; Shanks, Elaine; Ligocki, Marcin; Edgar, Dale M; Dijk, Derk-Jan

    2016-09-01

    Most antidepressants suppress rapid eye movement (REM) sleep, which is thought to be important to brain function, yet the resulting REM sleep restriction is well tolerated. This study investigated the impact of antidepressants with different mechanisms of action, such as selective serotonin reuptake inhibitors (SSRIs) and tricyclic antidepressants (TCA), on the regulation of REM sleep in rats. REM sleep was first demonstrated to be homeostatically regulated using 5, 8 and 10 h of REM-sleep specific restriction through EEG-triggered arousals, with an average of 91 ± 10% of lost REM sleep recovered following a 26-29 -hour recovery period. Acute treatment with the antidepressants paroxetine, citalopram and imipramine inhibited REM sleep by 84 ± 8, 84 ± 8 and 69 ± 9% respectively relative to vehicle control. The pharmacologically-induced REM sleep deficits by paroxetine and citalopram were not fully recovered, whereas, after imipramine the REM sleep deficit was fully compensated. Given the marked difference between REM sleep recovery following the administration of paroxetine, citalopram, imipramine and REM sleep restriction, the homeostatic response was further examined by pairing REM sleep specific restriction with the three antidepressants. Surprisingly, the physiologically-induced REM sleep deficits incurred prior to suppression of REM sleep by all antidepressants was consistently recovered. The data indicate that REM sleep homeostasis remains operative following subsequent treatment with antidepressants and is unaffected by additional pharmacological inhibition of REM sleep. PMID:27150557

  13. Retention over a Period of REM or non-REM Sleep.

    ERIC Educational Resources Information Center

    Tilley, Andrew J.

    1981-01-01

    Subjects, awaked, presented with a word list, and tested with arousal measures, were reawaked during REM or non-REM sleep and retested. Recall was facilitated by REM sleep. It was hypothesized that the high arousal level associated with REM sleep incidentally maintained the memory trace in a more retrievable form. (Author/SJL)

  14. REM sleep homeostasis in the absence of REM sleep: Effects of antidepressants.

    PubMed

    McCarthy, Andrew; Wafford, Keith; Shanks, Elaine; Ligocki, Marcin; Edgar, Dale M; Dijk, Derk-Jan

    2016-09-01

    Most antidepressants suppress rapid eye movement (REM) sleep, which is thought to be important to brain function, yet the resulting REM sleep restriction is well tolerated. This study investigated the impact of antidepressants with different mechanisms of action, such as selective serotonin reuptake inhibitors (SSRIs) and tricyclic antidepressants (TCA), on the regulation of REM sleep in rats. REM sleep was first demonstrated to be homeostatically regulated using 5, 8 and 10 h of REM-sleep specific restriction through EEG-triggered arousals, with an average of 91 ± 10% of lost REM sleep recovered following a 26-29 -hour recovery period. Acute treatment with the antidepressants paroxetine, citalopram and imipramine inhibited REM sleep by 84 ± 8, 84 ± 8 and 69 ± 9% respectively relative to vehicle control. The pharmacologically-induced REM sleep deficits by paroxetine and citalopram were not fully recovered, whereas, after imipramine the REM sleep deficit was fully compensated. Given the marked difference between REM sleep recovery following the administration of paroxetine, citalopram, imipramine and REM sleep restriction, the homeostatic response was further examined by pairing REM sleep specific restriction with the three antidepressants. Surprisingly, the physiologically-induced REM sleep deficits incurred prior to suppression of REM sleep by all antidepressants was consistently recovered. The data indicate that REM sleep homeostasis remains operative following subsequent treatment with antidepressants and is unaffected by additional pharmacological inhibition of REM sleep.

  15. The pontine REM switch: past and present.

    PubMed

    Fuller, Patrick M; Saper, Clifford B; Lu, Jun

    2007-11-01

    Rapid eye movement (REM) sleep is a behavioural state characterized by activation of the cortical and hippocampal EEG, rapid eye movements and muscle atonia. For the past 30 years, the most widely accepted neural circuitry model for the regulation of REM sleep has emphasized reciprocal inhibitory interactions between pontine brainstem monoaminergic and cholinergic neurons. In general support of the reciprocal interaction model, neuropharmacological studies have shown that cholinergic agonists promote REM sleep and muscarinic antagonists and monoamines inhibit REM sleep. It has nevertheless proven difficult to reconcile both the theoretical framework of this model and the pharmacological data with the fact that selective lesions of either cholinergic or monoaminergic (noradrenergic, serotoninergic or dopaminergic) nuclei in the brainstem have relatively limited effects on REM sleep. Recent work by our laboratory has revealed the presence of non-cholinergic and non-monoaminergic mutually inhibitory REM-off and REM-on areas in the mesopontine tegmentum that may form the neuroanatomical basis of the switching circuitry for REM sleep. These findings posit a REM switching circuitry model that is analogous to an electronic 'flip-flop' switch. In this flip-flop switch arrangement, GABAergic REM-on neurons (located in the sublaterodorsal tegmental nucleus (SLD)) inhibit GABAergic REM-off neurons (located in the ventrolateral periaqueductal grey matter (vlPAG) and lateral pontine tegmentum (LPT)) and vice versa. In the REM-on area are two populations of glutamatergic neurons, the first of which projects to the basal forebrain and regulates EEG components of REM sleep and the second of which projects to the ventromedial medulla and spinal cord and regulates atonia during REM sleep. Our findings demonstrating independent pathways mediating atonia and the EEG components of REM provide a basis for their occasional dissociation in pathological states, e.g. REM sleep behaviour

  16. Increases in number of REMS and REM density in humans following an intensive learning period.

    PubMed

    Smith, C; Lapp, L

    1991-08-01

    Animal studies have recently demonstrated that increases in rapid eye movement (REM) sleep and actual number of rapid eye movements (REMs) over normal levels followed successful learning of an avoidance task. These increases persisted for many days following the end of the training sessions. It was hypothesized that similar extended increases in REM sleep parameters would follow an intensive learning task in humans. Senior college students were sleep monitored following the end of their Christmas examinations. Results showed that there was a significant increase in the number of REMs observed following the exams as compared to baseline and control subject values. The number of extra REMs was mot prominent during the fifth REM period of the night. A significantly increased REM density was observed at the fourth REM sleep period of the night. Results support the idea of REM sleep and/or the REMs themselves being involved in long-term memory processing several days after the end of training.

  17. Manipulating REM sleep in older adults by selective REM sleep deprivation and physiological as well as pharmacological REM sleep augmentation methods.

    PubMed

    Hornung, Orla P; Regen, Francesca; Schredl, Michael; Heuser, Isabella; Danker-Hopfe, Heidi

    2006-02-01

    Experimental approaches to manipulate REM sleep within the cognitive neuroscience of sleep are usually based on sleep deprivation paradigms and focus on younger adults. In the present study, a traditional selective REM sleep deprivation paradigm as well as two alternative manipulation paradigms targeting REM sleep augmentation were investigated in healthy older adults. The study sample consisted of 107 participants, male and female, between the ages of 60 and 82 years, who had been randomly assigned to five experimental groups. During the study night, a first group was deprived of REM sleep by selective REM sleep awakenings, while a second group was woken during stage 2 NREM sleep in matched frequency. Physiological REM sleep augmentation was realized by REM sleep rebound after selective REM sleep deprivation, pharmacological REM sleep augmentation by administering an acetylcholinesterase inhibitor in a double-blind, placebo-controlled design. Deprivation and augmentation paradigms manipulated REM sleep significantly, the former affecting more global measures such as REM sleep minutes and percentage, the latter more organizational aspects such as stage shifts to REM sleep, REM latency, REM density (only pharmacological augmentation) and phasic REM sleep duration. According to our findings, selective REM sleep deprivation seems to be an efficient method of REM sleep manipulation in healthy older adults. While physiological rebound-based and pharmacological cholinergic REM sleep augmentation methods both failed to affect global measures of REM sleep, their efficiency in manipulating organizational aspects of REM sleep extends the traditional scope of REM sleep manipulation methods within the cognitive neuroscience of sleep.

  18. Flow Meter

    NASA Astrophysics Data System (ADS)

    1990-01-01

    Hedland Flow Meters manufactures a complete line of flow meters used in industrial operations to monitor the flow of oil, water or other liquids, air and other compressed gases, including caustics or corrosive liquids/gases. The company produces more than 1,000 types of flow meters featuring rugged construction, simplicity of installation and the ability to operate in any position.

  19. REM sleep, energy balance and 'optimal foraging'.

    PubMed

    Horne, Jim

    2009-03-01

    Mechanisms underlying mammalian REM sleep (REM) indicate commonality with feeding and energy balance. REM 'epiphenomena' may facilitate this, in providing heat conservation and appetite modulation, with the atonia reflecting search (foraging?) behaviour, and the lost neck muscle tonus a suppressed ingestion. In rodents, REM deprivation severely undermines energy balance. It is argued that REM may also facilitate 'optimal foraging' in wakefulness by updating 'decisions' about: appropriate food, where to find it, allocation of time in obtaining it, the locomotion/energy expenditure required to do so, vs. risk of predation. Whereas REM in the early sleep period is oriented to this updating, later REM can put feeding 'on hold'. PGO intensity changes over successive REM periods may reflect this shift. Humans, pets, zoo and laboratory mammals, and neonates have easy food accessibility, without need to forage, leading to a potential excess of REM in the later sleep period; loss of which has different outcomes to total REM deprivation. A more ecological approach in understanding REM function is desirable.

  20. Plugging meter

    DOEpatents

    Nagai, Akinori

    1979-01-01

    A plugging meter for automatically measuring the impurity concentration in a liquid metal is designed to have parallel passages including a cooling passage provided with a plugging orifice and with a flow meter, and a by-pass passage connected in series to a main passage having another flow meter, so that the plugging points may be obtained from the outputs of both flow meters. The plugging meter has a program signal generator, a flow-rate ratio setter and a comparator, and is adapted to change the temperature of the plugging orifice in accordance with a predetermined pattern or gradient, by means of a signal representative of the temperature of plugging orifice and a flow-rate ratio signal obtained from the outputs of both flow meters. This plugging meter affords an automatic and accurate measurement of a multi-plugging phenomenon taking place at the plugging orifice.

  1. Selective REM sleep deprivation in narcolepsy.

    PubMed

    Vu, Manh Hoang; Hurni, Christoph; Mathis, Johannes; Roth, Corinne; Bassetti, Claudio L

    2011-03-01

    Narcolepsy is characterized by excessive daytime sleepiness and rapid eye movement (REM) sleep abnormalities, including cataplexy. The aim of this study was to assess REM sleep pressure and homeostasis in narcolepsy. Six patients with narcolepsy and six healthy controls underwent a REM sleep deprivation protocol, including one habituation, one baseline, two deprivation nights (D1, D2) and one recovery night. Multiple sleep latency tests (MSLTs) were performed during the day after baseline and after D2. During D1 and D2 REM sleep was prevented by awakening the subjects at the first polysomnographic signs of REM sleep for 2 min. Mean sleep latency and number of sleep-onset REM periods (SOREMs) were determined on all MSLT. More interventions were required to prevent REM sleep in narcoleptics compared with control subjects during D1 (57 ± 16 versus 24 ± 10) and D2 (87 ± 22 versus 35 ± 8, P = 0.004). Interventions increased from D1 to D2 by 46% in controls and by 53% in narcoleptics (P < 0.03). Selective REM sleep deprivation was successful in both controls (mean reduction of REM to 6% of baseline) and narcoleptics (11%). Both groups had a reduction of total sleep time during the deprivation nights (P = 0.03). Neither group had REM sleep rebound in the recovery night. Narcoleptics had, however, an increase in the number of SOREMs on MSLT (P = 0.005). There was no increase in the number of cataplexies after selective REM sleep deprivation. We conclude that: (i) REM sleep pressure is higher in narcoleptics; (ii) REM sleep homeostasis is similar in narcoleptics and controls; (iii) in narcoleptics selective REM sleep deprivation may have an effect on sleep propensity but not on cataplexy.

  2. Biperiden administration during REM sleep deprivation diminished the frequency of REM sleep attempts.

    PubMed

    Salin-Pascual, R J; Grandos-Fuentes, D; Galicia-Polo, L; Nieves, E; Roehrs, T A; Roth, T

    1992-06-01

    Sixteen subjects were assigned to a group using either placebo or biperiden, with eight subjects in each group. Both groups were studied for one acclimatization night, one baseline night, four nights of rapid eye movement (REM) sleep deprivation and two recovery nights. All the subjects received either placebo or 4 mg biperiden 1 hour before sleep during the four nights of REM sleep deprivation. During the baseline and the recovery nights both groups received placebo capsules. The results showed that REM sleep time during the REM sleep deprivation was reduced by 70-75% below the baseline night in both groups. The number of attempts to enter REM sleep was significantly reduced by biperiden as compared to placebo for each of the four REM sleep deprivation nights. Because the total sleep time in the biperiden group was reduced, the number of REM sleep attempts was corrected by the total sleep time. The adjusted number of REM sleep attempts was also significantly reduced in the biperiden group. REM sleep latency showed a reduction in the placebo group, whereas in the biperiden group REM sleep latency was unchanged throughout the deprivation nights. In the recovery night REM sleep time was increased in both groups, with no differences between the groups. The REM sleep latency showed a reduction in the first recovery night in both groups that persisted through the second recovery night. The above findings support the role of biperiden as a REM sleep suppressive drug.

  3. REM sleep deprivation and food intake.

    PubMed

    Bhanot, J L; Chhina, G S; Singh, B; Sachdeva, U; Kumar, V M

    1989-01-01

    The effect of REM-sleep deprivation (REM-SD) on diet preference was studied in rats. REM-SD for a period of 72 hrs produced an increase in day, night and 24 hrs (day plus night) intakes of Carbohydrate Rich diet (CRD) and Total diet (TD). Body weight (BWt) was also increased. The maximum increase in the above parameters were recorded on the 2nd day of REM-SD. During recovery period the intakes of TD fully recovered, but the BWt and consumption of CRD remained high. Intakes of Balanced diet (BD) remained significantly on the lower side when compared to the pre REM-SD mean values. During REM-SD, the rats preferred CRD than BD. The body temperature did not show any change. The increase in TD intake and BWt could be the result of an increase in insulin level and the change appears to be mediated by the activation of hypothalamic feeding centre.

  4. REM sleep predicts subsequent food intake.

    PubMed

    Siegel, J M

    1975-10-01

    REM sleep time in a 12 hr period was found to predict accurately food intake in the subsequent 12 hr period in undisturbed cats fed ad lib. In all but one of the cats, the correlation between REM sleep and subsequent food intake was negative. REM sleep was a better predictor of food intake than either waking, slow wave sleep or previous food intake. Cats were then fed only during the 12 hr day period. It was found that REM sleep at night, during which no food was available, no longer predicted food intake.

  5. Fission meter

    DOEpatents

    Rowland, Mark S.; Snyderman, Neal J.

    2012-04-10

    A neutron detector system for discriminating fissile material from non-fissile material wherein a digital data acquisition unit collects data at high rate, and in real-time processes large volumes of data directly into information that a first responder can use to discriminate materials. The system comprises counting neutrons from the unknown source and detecting excess grouped neutrons to identify fission in the unknown source.

  6. A study of the interrupted REM episode.

    PubMed

    Merica, H; Gaillard, J M

    1991-12-01

    Brief interruptions of REM sleep are considered to be part of the REM episode. The maximum allowable duration of such an interruption, which is used to define the end of the REM episode, is currently a matter of debate. Making measurements on individual REM cycles, inter-REM interval analysis was carried out to determine whether the generally adopted 15 minute empirical rule for this maximum needs to be extended to 25 minutes as suggested by several including Kobayashi et al. Our results show that there is no reason to alter the 15 minute rule and that measurements which do not take into account the time-of-night effect may be misleading. The proportion of interrupted REM episodes observed in our population of healthy adults is high. We have therefore also examined in some detail the phenomenology of the temporal evolution of the structure and content of the interrupted REM episodes. Both showed a definite change over the night: the interruptions in the earlier episodes tend to return the system to slow wave sleep while those in the later episodes tend to return it to wake. It is hypothesized that these interruptions reflect a measure of REM sleep pressure and its interaction with both slow wave sleep and wake pressures. PMID:1798770

  7. Cells of a common developmental origin regulate REM/non-REM sleep and wakefulness in mice.

    PubMed

    Hayashi, Yu; Kashiwagi, Mitsuaki; Yasuda, Kosuke; Ando, Reiko; Kanuka, Mika; Sakai, Kazuya; Itohara, Shigeyoshi

    2015-11-20

    Mammalian sleep comprises rapid eye movement (REM) sleep and non-REM (NREM) sleep. To functionally isolate from the complex mixture of neurons populating the brainstem pons those involved in switching between REM and NREM sleep, we chemogenetically manipulated neurons of a specific embryonic cell lineage in mice. We identified excitatory glutamatergic neurons that inhibit REM sleep and promote NREM sleep. These neurons shared a common developmental origin with neurons promoting wakefulness; both derived from a pool of proneural hindbrain cells expressing Atoh1 at embryonic day 10.5. We also identified inhibitory γ-aminobutyric acid-releasing neurons that act downstream to inhibit REM sleep. Artificial reduction or prolongation of REM sleep in turn affected slow-wave activity during subsequent NREM sleep, implicating REM sleep in the regulation of NREM sleep.

  8. Short-term homeostasis of REM sleep assessed in an intermittent REM sleep deprivation protocol in the rat.

    PubMed

    Ocampo-Garcés, Adrián; Vivaldi, Ennio A

    2002-03-01

    An intermittent rapid eye movement (REM) sleep deprivation protocol was applied to determine whether an increase in REM sleep propensity occurs throughout an interval without REM sleep comparable with the spontaneous sleep cycle of the rat. Seven chronically implanted rats under a 12 : 12 light-dark schedule were subjected to an intermittent REM sleep deprivation protocol that started at hour 6 after lights-on and lasted for 3 h. It consisted of six instances of a 10-min REM sleep permission window alternating with a 20-min REM sleep deprivation window. REM sleep increased throughout the protocol, so that total REM sleep in the two REM sleep permission windows of the third hour became comparable with that expected in the corresponding baseline hour. Attempted REM sleep transitions were already increased in the second deprivation window. Attempted transitions to REM sleep were more frequent in the second than in the first half of any 20-min deprivation window. From one deprivation window to the next, transitions to REM sleep changed in correspondence to the amount of REM sleep in the permission window in-between. Our results suggest that: (i) REM sleep pressure increases throughout a time segment similar in duration to a spontaneous interval without REM sleep; (ii) it diminishes during REM sleep occurrence; and (iii) that drop is proportional to the intervening amount of REM sleep. These results are consistent with a homeostatic REM sleep regulatory mechanism that operates in the time scale of spontaneous sleep cycle.

  9. Arousal responses to added inspiratory resistance during REM and non-REM sleep in normal subjects.

    PubMed Central

    Gugger, M; Bögershausen, S; Schäffler, L

    1993-01-01

    BACKGROUND: Arousal in response to increased airflow resistance during sleep, especially rapid eye movement sleep (REM), could be an important protective mechanism against asphyxia. METHODS: The arousal response to the application of an external inspiratory resistance of 25 cm H2O/l/s was determined during REM and non-REM sleep in ten healthy men. RESULTS: The number of arousals occurring within two minutes of the load application was significantly higher during REM sleep than during either of the non-REM sleep stages 2 and 3/4, and was similar to that during stage 1. The proportion of arousals to non-arousals decreased significantly from stage 1 to stage 4. The mean time to arousal in REM was significantly shorter than in non-REM stages 1, 2 or 3/4 and increased significantly from stage 1 to stage 3/4. The duration of sleep (comparing the results of the first with the second half of the sleep period time) did not modify the arousal response in stages 2 and 3/4. CONCLUSIONS: The results show a significantly increased arousal response to an added inspiratory resistive load in REM sleep compared with non-REM sleep stages 2, 3 or 4 in normal men. In the context of previous studies these data could add support to the hypothesis that the decreased arousal response during REM sleep in patients with sleep apnoea might be due to an impairment of the normal "central processing" of this stimulus. PMID:8493624

  10. SU-E-T-591: Measurement and Monte Carlo Simulation of Stray Neutrons in Passive Scattering Proton Therapy: Needs and Challenges

    SciTech Connect

    Farah, J; Bonfrate, A; Donadille, L; Dubourg, N; Lacoste, V; Martinetti, F; Sayah, R; Trompier, F; Clairand, I; Caresana, M; Delacroix, S; Nauraye, C; Herault, J; Piau, S; Vabre, I

    2014-06-01

    Purpose: Measure stray radiation inside a passive scattering proton therapy facility, compare values to Monte Carlo (MC) simulations and identify the actual needs and challenges. Methods: Measurements and MC simulations were considered to acknowledge neutron exposure associated with 75 MeV ocular or 180 MeV intracranial passively scattered proton treatments. First, using a specifically-designed high sensitivity Bonner Sphere system, neutron spectra were measured at different positions inside the treatment rooms. Next, measurement-based mapping of neutron ambient dose equivalent was fulfilled using several TEPCs and rem-meters. Finally, photon and neutron organ doses were measured using TLDs, RPLs and PADCs set inside anthropomorphic phantoms (Rando, 1 and 5-years-old CIRS). All measurements were also simulated with MCNPX to investigate the efficiency of MC models in predicting stray neutrons considering different nuclear cross sections and models. Results: Knowledge of the neutron fluence and energy distribution inside a proton therapy room is critical for stray radiation dosimetry. However, as spectrometry unfolding is initiated using a MC guess spectrum and suffers from algorithmic limits a 20% spectrometry uncertainty is expected. H*(10) mapping with TEPCs and rem-meters showed a good agreement between the detectors. Differences within measurement uncertainty (10–15%) were observed and are inherent to the energy, fluence and directional response of each detector. For a typical ocular and intracranial treatment respectively, neutron doses outside the clinical target volume of 0.4 and 11 mGy were measured inside the Rando phantom. Photon doses were 2–10 times lower depending on organs position. High uncertainties (40%) are inherent to TLDs and PADCs measurements due to the need for neutron spectra at detector position. Finally, stray neutrons prediction with MC simulations proved to be extremely dependent on proton beam energy and the used nuclear models and

  11. Saturation meter

    DOEpatents

    Gregurech, S.

    1984-08-01

    A saturation meter for use in a pressurized water reactor plant comprising a differential pressure transducer having a first and second pressure sensing means and an alarm. The alarm is connected to the transducer and is preset to activate at a level of saturation prior to the formation of a steam void in the reactor vessel.

  12. Response of the Hanford Combination Neutron Dosimeter in plutonium environments

    SciTech Connect

    Endres, A.W.; Brackenbush, L.W.; Baumgartner, W.V.

    1996-02-01

    This report documents response characteristics and the development of dose algorithms for the Hanford Combination Neutron Dosimeter (HCNO) implemented on January 1, 1995. The HCND was accredited under the U.S. Department of Energy (DOE) Laboratory Accreditation Program (DOELAP) during 1994. The HCND employs two neutron dose components consisting of (1) an albedo thermoluminescent dosimeter (TLD), and (2) a track-etch dosimeter (TED). Response characteristics of these two dosimeter components were measured under the low-scatter conditions of the Hanford 318 Building Calibration Laboratory, and under the high-scatter conditions in the workplace at the Plutonium Finishing Plant (PFP). The majority of personnel neutron dose at Hanford (currently and historically) occurs at the PFP. National Institute of Standards and Technology (NIST) traceable sources were used to characterize dosimeter response in the laboratory. At the PFP, neutron spectra and dose-measuring instruments, including a multisphere spectrometer, tissue equivalent proportional counters, and specially calibrated rem meters, were used to determine the neutron dose under several configurations from three different plutonium sources: (1) plutonium tetrafluoride, (2) plutonium metal, and (3) plutonium oxide. In addition, measurements were performed at many selected work locations. The HCNDs were included in all measurements. Comparison of dosimeter- and instrument-measured dose equivalents provided the data necessary to develop HCND dose algorithms and to assess the accuracy of estimated neutron dose under actual work conditions.

  13. Intercomparison of radiation protection instrumentation in a pulsed neutron field

    NASA Astrophysics Data System (ADS)

    Caresana, M.; Denker, A.; Esposito, A.; Ferrarini, M.; Golnik, N.; Hohmann, E.; Leuschner, A.; Luszik-Bhadra, M.; Manessi, G.; Mayer, S.; Ott, K.; Röhrich, J.; Silari, M.; Trompier, F.; Volnhals, M.; Wielunski, M.

    2014-02-01

    In the framework of the EURADOS working group 11, an intercomparison of active neutron survey meters was performed in a pulsed neutron field (PNF). The aim of the exercise was to evaluate the performances of various neutron instruments, including commercially available rem-counters, personal dosemeters and instrument prototypes. The measurements took place at the cyclotron of the Helmholtz-Zentrum Berlin für Materialien und Energie GmbH. The cyclotron is routinely used for proton therapy of ocular tumours, but an experimental area is also available. For the therapy the machine accelerates protons to 68 MeV. The interaction of the proton beam with a thick tungsten target produces a neutron field with energy up to about 60 MeV. One interesting feature of the cyclotron is that the beam can be delivered in bursts, with the possibility to modify in a simple and flexible way the burst length and the ion current. Through this possibility one can obtain radiation bursts of variable duration and intensity. All instruments were placed in a reference position and irradiated with neutrons delivered in bursts of different intensity. The analysis of the instrument response as a function of the burst charge (the total electric charge of the protons in the burst shot onto the tungsten target) permitted to assess for each device the dose underestimation due to the time structure of the radiation field. The personal neutron dosemeters were exposed on a standard PMMA slab phantom and the response linearity was evaluated.

  14. Why does arterial blood pressure rise actively during REM sleep?

    PubMed

    Sei, H; Morita, Y

    1999-02-01

    A large fluctuation in autonomic function is one of the most important characteristics of REM sleep. Arterial blood pressure (AP) increases during the transition from non-REM to REM sleep, showing phasic surges during REM sleep. REM-associated AP changes involve 1) a long-term recovery process after surgery, 2) circadian rhythm, 3) relationships with ambient temperature. REM-associated AP changes are mediated by sympathetic nerves, buffered by baroreflex, abolished in decerebrated cats, and related to hippocampal theta activity in rats. Furthermore, the midbrain dopaminergic system has been recently found to be involved in increases in REM-associated AP. PMID:10408152

  15. Mechanisms and models of REM sleep control.

    PubMed

    McCarley, R W

    2004-07-01

    The first sections of this paper survey the history and recent developments relevant to the major neurotransmitters and neuromodulators involved in REM sleep control. The last portion of this paper proposes a structural model of cellular interaction that produces the REM sleep cycle, and constitutes a further revision of the reciprocal interaction model This paper proposes seven criteria to define a causal role in REM sleep control for putative neuro-transmitters/modulators. The principal criteria are measurements during behavioral state changes of the extracellular concentrations of the putative substances, and electrophysiological recording of their neuronal source. A cautionary note is that, while pharmacological manipulations are suggestive, they alone do not provide definitive causal evidence. The extensive body of in vivo and in vitro evidence supporting cholinergic promotion of REM sleep via LDT/PPT neuronal activity is surveyed. An interesting question raised by some studies is whether cholinergic influences in rat are less puissant than in cat. At least some of the apparent lesser REM-inducing effect of carbachol in the rat may be due to incomplete control of circadian influences; almost all experiments have been run only in the daytime, inactive period, when REM sleep is more prominent, rather than in the REM-sparse nighttime inactive period. Monoaminergic inhibition of cholinergic neurons, once thought to be the most shaky proposal of the reciprocal interaction model, now enjoys considerable support from both in vivo and in vitro data. However, the observed time course of monoaminergic neurons, their "turning off" discharge activity as REM sleep is approached and entered would seem to be difficult to produce from feedback inhibition, as originally postulated by the reciprocal interaction model. New data suggest the possibility that GABAergic inhibition of Locus Coeruleus and Dorsal Raphe monoaminergic neurons may account for the "REM-off" neurons turning

  16. An experimental antidepressant increases REM sleep.

    PubMed

    Soldatos, C R; Stefanis, C N; Bergiannaki, J D; Christodoulou, C; Botsis, A; Sakkas, P N

    1988-01-01

    1. An experimental antidepressant was studied through sleep laboratory recordings, psychoendocrinological tests and clinical measurements in terms of its efficacy, side effects and effects on sleep. 2. The design included a four-week drug administration period, preceeded and followed by a one week placebo period. 3. In the presence of antidepressant efficacy, the drug did not disturb sleep induction and maintainance. 4. The only effect on sleep stages was an increase of REM sleep during the short-term drug administration period which is contrary to the REM supressant effect of most antidepressants. 5. This finding suggests that REM supression and antidepressant efficacy are not necessarily related. 6. Further, given that the only known action of the drug is its inhibitory effect on GABAergic transmission, one can speculate that GABA mechanisms may be involved in REM sleep modulation. PMID:3241873

  17. REMS Wind Sensor Preliminary Results

    NASA Astrophysics Data System (ADS)

    De La Torre Juarez, M.; Gomez-Elvira, J.; Navarro, S.; Marin, M.; Torres, J.; Rafkin, S. C.; Newman, C. E.; Pla-García, J.

    2015-12-01

    The REMS instrument is part of the Mars Science Laboratory payload. It is a sensor suite distributed over several parts of the rover. The wind sensor, which is composed of two booms equipped with a set of hot plate anemometers, is installed on the Rover Sensing Mast (RSM). During landing most of the hot plates of one boom were damaged, most likely by the pebbles lifted by the Sky Crane thruster. The loss of one wind boom necessitated a full review of the data processing strategy. Different algorithms have been tested on the readings of the first Mars year, and these results are now archived in the Planetary Data System (PDS), The presentation will include a description of the data processing methods and of the resulting products, including the typical evolution of wind speed and direction session-by-session, hour-by-hour and other kinds of statistics . A review of the wind readings over the first Mars year will also be presented.

  18. Intrahippocampal administration of anandamide increases REM sleep.

    PubMed

    Rueda-Orozco, Pavel Ernesto; Soria-Gómez, Edgar; Montes-Rodríguez, Corinne Jennifer; Pérez-Morales, Marcel; Prospéro-García, Oscar

    2010-04-01

    A nascent literature has postulated endocannabinoids (eCBs) as strong sleep-inducing lipids, particularly rapid-eye-movement sleep (REMs), nevertheless the exact mechanisms behind this effect remain to be determined. Anandamide and 2-arachidonyl glycerol, two of the most important eCBS, are synthesized in the hippocampus. This structure also expresses a high concentration of cannabinoid receptor 1 (CB1). Recent extensive literature supports eCBs as important regulators of hippocampal activity. It has also been shown that these molecules vary their expression on the hippocampus depending on the light-dark cycle. In this context we decided to analyze the effect of intrahippocampal administration of the eCB anandamide (ANA) on the sleep-waking cycle at two points of the light-dark cycle. Our data indicate that the administration of ANA directly into the hippocampus increases REMs in a dose dependent manner during the dark but not during the light phase of the cycle. The increase of REMs was blocked by the CB1 antagonist AM251. This effect was specific for the hippocampus since ANA administrations in the surrounding cortex did not elicit any change in REMs. These results support the idea of a direct relationship between hippocampal activity and sleep mechanisms by means of eCBs. The data presented here show, for the first time that eCBs administered into the hippocampus trigger REMs and support previous studies where chemical stimulation of limbic areas triggered sleep.

  19. REM Sleep Behavioral Events and Dreaming

    PubMed Central

    Muntean, Maria-Lucia; Trenkwalder, Claudia; Walters, Arthur S.; Mollenhauer, Brit; Sixel-Döring, Friederike

    2015-01-01

    Study Objectives: To clarify whether motor behaviors and/ or vocalizations during REM sleep, which do not yet fulfill diagnostic criteria for REM sleep behavior disorder (RBD) and were defined as REM sleep behavioral events (RBEs), correspond to dream enactments. Methods: 13 subjects (10 patients with Parkinson disease [PD] and 3 healthy controls) originally identified with RBE in a prospective study (DeNoPa cohort) were reinvestigated 2 years later with 2 nights of video-supported polysomnography (vPSG). The first night was used for sleep parameter analysis. During the 2nd night, subjects were awakened and questioned for dream recall and dream content when purposeful motor behaviors and/or vocalizations became evident during REM sleep. REM sleep without atonia (RWA) was analyzed on chin EMG and the cutoff set at 18.2% as specific for RBD. Results: At the time of this investigation 9 of 13 subjects with previous RBE were identified with RBD based upon clinical and EMG criteria. All recalled vivid dreams, and 7 subjects were able to describe dream content in detail. Four of 13 subjects with RBE showed RWA values below cutoff values for RBD. Three of these 4 subjects recalled having non-threatening dreams, and 2 (of these 3) were able to describe these dreams in detail. Conclusion: RBE with RWA below the RBD defining criteria correlate to dreaming in this selected cohort. There is evidence that RBEs are a precursor to RBD. Citation: Muntean ML, Trenkwalder C, Walters AS, Mollenhauer B, Sixel-Döring F. REM sleep behavioral events and dreaming. J Clin Sleep Med 2015;11(5):537–541. PMID:25665694

  20. [Nightmares and behavior during REM sleep].

    PubMed

    Barraquer I Bordas, L

    2001-05-01

    This study reports the current neurobiologic data on REM sleep including psychoanalysis, distinguishing between the "instincts of pleasure" and the "instincts of death" (Beyond the principles of pleasure, S. Freud, 1920). The award and punishment systems are also reported and current data related to nightmares and mainly dream behavior during REM sleep without atonia are presented underlining the frequency of parasomnia in ponto-cerebellous atrophy and Parkinson's disease. The author emphasizes the need for establishing discussions among the different neuroscientific fields related to these questions.

  1. REM, not incubation, improves creativity by priming associative networks

    PubMed Central

    Cai, Denise J.; Mednick, Sarnoff A.; Harrison, Elizabeth M.; Kanady, Jennifer C.; Mednick, Sara C.

    2009-01-01

    The hypothesized role of rapid eye movement (REM) sleep, which is rich in dreams, in the formation of new associations, has remained anecdotal. We examined the role of REM on creative problem solving, with the Remote Associates Test (RAT). Using a nap paradigm, we manipulated various conditions of prior exposure to elements of a creative problem. Compared with quiet rest and non-REM sleep, REM enhanced the formation of associative networks and the integration of unassociated information. Furthermore, these REM sleep benefits were not the result of an improved memory for the primed items. This study shows that compared with quiet rest and non-REM sleep, REM enhances the integration of unassociated information for creative problem solving, a process, we hypothesize, that is facilitated by cholinergic and noradrenergic neuromodulation during REM sleep. PMID:19506253

  2. Data processing unit and power system for the LANL REM instrument package. Final report

    SciTech Connect

    Lockhart, W.

    1994-03-01

    The NEPSTP spacecraft needs highly reliable instrumentation to measure the nuclear reactor health and performance. These reactor measurements are essential for initial on-orbit phase operations and documentation of performance over time. Los Alamos National Laboratory (LANL), under the guidance of W. C. Feldman, principal investigator, has designed the Radiation Environment Monitoring (REM) package to meet these needs. The instrumentation package contains two neutron detectors, one gamma-ray detector, a data processing unit, and an instrument power system. The REM package is an integration of quick turn-around, state of the practice technology for detectors, data processors, and power systems. A significant portion of REM consists of subsystems with flight history. Southwest Research Institute (SwRI) has been tasked by LANL to design support electronics, including the Data Processing Unit (DPU) and Power System for REM. The goal for this project is to use technologies from current programs to speed up and simplify the design process. To meet these design goals, the authors use an open architecture VME bus for the DPU and derivatives of CASSINI power supplies for the instrument power system. To simplify integration and test activities, they incorporate a proven software development strategy and tool kits from outside vendors. The objective of this report is to illustrate easily incorporated system level designs for the DPU, power system and ground support electronics (GSE) in support of the important NEPSTP program.

  3. REM sleep rescues learning from interference.

    PubMed

    McDevitt, Elizabeth A; Duggan, Katherine A; Mednick, Sara C

    2015-07-01

    Classical human memory studies investigating the acquisition of temporally-linked events have found that the memories for two events will interfere with each other and cause forgetting (i.e., interference; Wixted, 2004). Importantly, sleep helps consolidate memories and protect them from subsequent interference (Ellenbogen, Hulbert, Stickgold, Dinges, & Thompson-Schill, 2006). We asked whether sleep can also repair memories that have already been damaged by interference. Using a perceptual learning paradigm, we induced interference either before or after a consolidation period. We varied brain states during consolidation by comparing active wake, quiet wake, and naps with either non-rapid eye movement sleep (NREM), or both NREM and REM sleep. When interference occurred after consolidation, sleep and wake both produced learning. However, interference prior to consolidation impaired memory, with retroactive interference showing more disruption than proactive interference. Sleep rescued learning damaged by interference. Critically, only naps that contained REM sleep were able to rescue learning that was highly disrupted by retroactive interference. Furthermore, the magnitude of rescued learning was correlated with the amount of REM sleep. We demonstrate the first evidence of a process by which the brain can rescue and consolidate memories damaged by interference, and that this process requires REM sleep. We explain these results within a theoretical model that considers how interference during encoding interacts with consolidation processes to predict which memories are retained or lost. PMID:25498222

  4. REM sleep rescues learning from interference.

    PubMed

    McDevitt, Elizabeth A; Duggan, Katherine A; Mednick, Sara C

    2015-07-01

    Classical human memory studies investigating the acquisition of temporally-linked events have found that the memories for two events will interfere with each other and cause forgetting (i.e., interference; Wixted, 2004). Importantly, sleep helps consolidate memories and protect them from subsequent interference (Ellenbogen, Hulbert, Stickgold, Dinges, & Thompson-Schill, 2006). We asked whether sleep can also repair memories that have already been damaged by interference. Using a perceptual learning paradigm, we induced interference either before or after a consolidation period. We varied brain states during consolidation by comparing active wake, quiet wake, and naps with either non-rapid eye movement sleep (NREM), or both NREM and REM sleep. When interference occurred after consolidation, sleep and wake both produced learning. However, interference prior to consolidation impaired memory, with retroactive interference showing more disruption than proactive interference. Sleep rescued learning damaged by interference. Critically, only naps that contained REM sleep were able to rescue learning that was highly disrupted by retroactive interference. Furthermore, the magnitude of rescued learning was correlated with the amount of REM sleep. We demonstrate the first evidence of a process by which the brain can rescue and consolidate memories damaged by interference, and that this process requires REM sleep. We explain these results within a theoretical model that considers how interference during encoding interacts with consolidation processes to predict which memories are retained or lost.

  5. Posttraining Increases in REM Sleep Intensity Implicate REM Sleep in Memory Processing and Provide a Biological Marker of Learning Potential

    ERIC Educational Resources Information Center

    Nader, Rebecca S.; Smith, Carlyle T.; Nixon, Margaret R.

    2004-01-01

    Posttraining rapid eye movement (REM) sleep has been reported to be important for efficient memory consolidation. The present results demonstrate increases in the intensity of REM sleep during the night of sleep following cognitive procedural/implicit task acquisition. These REM increases manifest as increases in total number of rapid eye…

  6. Changes in REM-Sleep Percentage Over the Adult Lifespan

    PubMed Central

    Floyd, Judith A.; Janisse, James J.; Jenuwine, Elizabeth S.; Ager, Joel W.

    2007-01-01

    Study Objectives: To resolve inconsistencies in previously reported changes in percentage of rapid eye movement sleep (REM%) over the adult lifespan and to identify gaps in available information about adults' REM sleep. Design: A research synthesis approach specifically designed to detect nonlinear change. Cubic B smoothing splines were fitted to scatterplots generated from reported means and variance for REM%, REM minutes, and total sleep time. Participants: 382 English-language research reports provided REM% values for 4171 subjects; REM minutes values for 2722 subjects; and values of total sleep time for 5037 subjects. Samples were composed of subjects described by authors as normal or healthy. Mean ages of samples ranged from 18.0 to 91.7 years. Setting: University research center. Interventions: N/A. Measurements and Results: Two coders extracted information. Intercoder reliability was above cutoffs for excellent. Authors often failed to describe screening procedures used to determine subjects' health status. Few results were reported separately for women. The functional relationship between age and REM% was essentially linear over much of the adult lifespan, decreasing about 0.6% per decade. The best estimate of when REM% ceased its small linear decline was the mid-70s, after which time a small increase in REM% was observed due to REM minutes increasing while total sleep time declined. Conclusions: Ability to detect both linear and nonlinear change in REM%, REM minutes, and total sleep time over the lifespan was useful for resolving inconsistent findings about the existence of changes in REM% with aging. This approach to research synthesis also facilitated identification of ages for which little normative information about REM sleep was available. Citation: Floyd JA; Janisse JJ; Jenuwine ES et al. Changes in REM-sleep percentage over the adult lifespan. SLEEP 2007;30(7):829-836. PMID:17682652

  7. Characterization of neutron reference fields at US Department of Energy calibration fields.

    PubMed

    Olsher, R H; McLean, T D; Mallett, M W; Seagraves, D T; Gadd, M S; Markham, Robin L; Murphy, R O; Devine, R T

    2007-01-01

    The Health Physics Measurements Group at the Los Alamos National Laboratory (LANL) has initiated a study of neutron reference fields at selected US Department of Energy (DOE) calibration facilities. To date, field characterisation has been completed at five facilities. These fields are traceable to the National Institute for Standards and Technology (NIST) through either a primary calibration of the source emission rate or through the use of a secondary standard. However, neutron spectral variation is caused by factors such as room return, scatter from positioning tables and fixtures, source anisotropy and spectral degradation due to source rabbits and guide tubes. Perturbations from the ideal isotropic point source field may impact the accuracy of instrument calibrations. In particular, the thermal neutron component of the spectrum, while contributing only a small fraction of the conventionally true dose, can contribute a significant fraction of a dosemeter's response with the result that the calibration becomes facility-specific. A protocol has been developed to characterise neutron fields that relies primarily on spectral measurements with the Bubble Technology Industries (BTI) rotating neutron spectrometer (ROSPEC) and the LANL Bonner sphere spectrometer. The ROSPEC measurements were supplemented at several sites by the BTI Simple Scintillation Spectrometer probe, which is designed to extend the ROSPEC upper energy range from 5 to 15 MeV. In addition, measurements were performed with several rem meters and neutron dosemeters. Detailed simulations were performed using the LANL MCNPX Monte Carlo code to calculate the magnitude of source anisotropy and scatter factors.

  8. Study of the ratio of non-neutron to neutron dose components of cosmic radiation at typical commercial flight altitudes.

    PubMed

    Romero, A M; Saez-Vergara, J C; Rodriguez, R; Domínguez-Mompell, R

    2004-01-01

    CIEMAT, in close co-operation with Iberia Airlines, carried out an extensive programme of in-flight measurements, covering both hemispheres, during the years 2001 and 2002. Although the instrumentation onboard included different active devices, the results presented here were obtained from a polyethylene/tungsten-moderated rem meter (SWENDI2; Eberline) and an ionisation chamber (RSS-131; Reuter-Stokes) used for measuring the ambient dose equivalent due to the neutron and the non-neutron components of cosmic radiation, respectively. This paper presents a study of each of the dose components mentioned as a function of the vertical cut-off rigidity and the flight altitude. The ratio between the two components is also presented to determine the variations in cosmic radiation composition as a function of the aforementioned parameters. The experimental results have also been compared with those predicted by the code EPCARD3.2 for the non-neutron and the neutron components of the ambient dose equivalent.

  9. Control of REM sleep by ventral medulla GABAergic neurons.

    PubMed

    Weber, Franz; Chung, Shinjae; Beier, Kevin T; Xu, Min; Luo, Liqun; Dan, Yang

    2015-10-15

    Rapid eye movement (REM) sleep is a distinct brain state characterized by activated electroencephalogram and complete skeletal muscle paralysis, and is associated with vivid dreams. Transection studies by Jouvet first demonstrated that the brainstem is both necessary and sufficient for REM sleep generation, and the neural circuits in the pons have since been studied extensively. The medulla also contains neurons that are active during REM sleep, but whether they play a causal role in REM sleep generation remains unclear. Here we show that a GABAergic (γ-aminobutyric-acid-releasing) pathway originating from the ventral medulla powerfully promotes REM sleep in mice. Optogenetic activation of ventral medulla GABAergic neurons rapidly and reliably initiated REM sleep episodes and prolonged their durations, whereas inactivating these neurons had the opposite effects. Optrode recordings from channelrhodopsin-2-tagged ventral medulla GABAergic neurons showed that they were most active during REM sleep (REMmax), and during wakefulness they were preferentially active during eating and grooming. Furthermore, dual retrograde tracing showed that the rostral projections to the pons and midbrain and caudal projections to the spinal cord originate from separate ventral medulla neuron populations. Activating the rostral GABAergic projections was sufficient for both the induction and maintenance of REM sleep, which are probably mediated in part by inhibition of REM-suppressing GABAergic neurons in the ventrolateral periaqueductal grey. These results identify a key component of the pontomedullary network controlling REM sleep. The capability to induce REM sleep on command may offer a powerful tool for investigating its functions. PMID:26444238

  10. Control of REM sleep by ventral medulla GABAergic neurons.

    PubMed

    Weber, Franz; Chung, Shinjae; Beier, Kevin T; Xu, Min; Luo, Liqun; Dan, Yang

    2015-10-15

    Rapid eye movement (REM) sleep is a distinct brain state characterized by activated electroencephalogram and complete skeletal muscle paralysis, and is associated with vivid dreams. Transection studies by Jouvet first demonstrated that the brainstem is both necessary and sufficient for REM sleep generation, and the neural circuits in the pons have since been studied extensively. The medulla also contains neurons that are active during REM sleep, but whether they play a causal role in REM sleep generation remains unclear. Here we show that a GABAergic (γ-aminobutyric-acid-releasing) pathway originating from the ventral medulla powerfully promotes REM sleep in mice. Optogenetic activation of ventral medulla GABAergic neurons rapidly and reliably initiated REM sleep episodes and prolonged their durations, whereas inactivating these neurons had the opposite effects. Optrode recordings from channelrhodopsin-2-tagged ventral medulla GABAergic neurons showed that they were most active during REM sleep (REMmax), and during wakefulness they were preferentially active during eating and grooming. Furthermore, dual retrograde tracing showed that the rostral projections to the pons and midbrain and caudal projections to the spinal cord originate from separate ventral medulla neuron populations. Activating the rostral GABAergic projections was sufficient for both the induction and maintenance of REM sleep, which are probably mediated in part by inhibition of REM-suppressing GABAergic neurons in the ventrolateral periaqueductal grey. These results identify a key component of the pontomedullary network controlling REM sleep. The capability to induce REM sleep on command may offer a powerful tool for investigating its functions.

  11. Impact of the Revised 10 CFR 835 on the Neutron Dose Rates at LLNL

    SciTech Connect

    Radev, R

    2009-01-13

    In June 2007, 10 CFR 835 [1] was revised to include new radiation weighting factors for neutrons, updated dosimetric models, and dose terms consistent with the newer ICRP recommendations. A significant aspect of the revised 10 CFR 835 is the adoption of the recommendations outlined in ICRP-60 [2]. The recommended new quantities demand a review of much of the basic data used in protection against exposure to sources of ionizing radiation. The International Commission on Radiation Units and Measurements has defined a number of quantities for use in personnel and area monitoring [3,4,5] including the ambient dose equivalent H*(d) to be used for area monitoring and instrument calibrations. These quantities are used in ICRP-60 and ICRP-74. This report deals only with the changes in the ambient dose equivalent and ambient dose rate equivalent for neutrons as a result of the implementation of the revised 10 CFR 835. In the report, the terms neutron dose and neutron dose rate will be used for convenience for ambient neutron dose and ambient neutron dose rate unless otherwise stated. This report provides a qualitative and quantitative estimate of how much the neutron dose rates at LLNL will change with the implementation of the revised 10 CFR 835. Neutron spectra and dose rates from selected locations at the LLNL were measured with a high resolution spectroscopic neutron dose rate system (ROSPEC) as well as with a standard neutron rem meter (a.k.a., a remball). The spectra obtained at these locations compare well with the spectra from the Radiation Calibration Laboratory's (RCL) bare californium source that is currently used to calibrate neutron dose rate instruments. The measurements obtained from the high resolution neutron spectrometer and dose meter ROSPEC and the NRD dose meter compare within the range of {+-}25%. When the new radiation weighting factors are adopted with the implementation of the revised 10 CFR 835, the measured dose rates will increase by up to 22

  12. Clinical Considerations of Obstructive Sleep Apnea with Little REM Sleep

    PubMed Central

    Koo, Dae Lim

    2016-01-01

    Background and Purpose Obstructive sleep apnea (OSA) is more severe during rapid eye movement (REM) sleep than during non-REM sleep. We aimed to determine the features of patients with OSA who experience little REM sleep. Methods Patients with a chief complaint of sleep-disordered breathing were enrolled. All subjects underwent overnight polysomnography (PSG) and completed questionnaires on sleep quality. Patients were divided into the following three groups according to the proportion of REM sleep detected in overnight PSG: little REM sleep [REM sleep <20% of total sleep time (TST)], normal REM sleep (20–25% of TST), and excessive REM sleep (>25% of TST). Multiple logistic regression analyses were applied to the data. The success rate of continuous positive airway pressure (CPAP) titration was estimated in these groups. Results The age and body mass index of the patients were 47.9±15.9 years (mean±SD) and 25.2±4.1 kg/m2, respectively. The 902 patients comprised 684 (76%) men and 218 (24%) women. The apnea-hypopnea index (AHI) in the little-REM-sleep group was 22.1±24.4 events/hour, which was significantly higher than those in the other two groups (p<0.05). Multiple logistic regression showed that a higher AHI (p<0.001; odds ratio, 1.512; 95% confidence interval, 1.020–1.812) was independently predictive of little REM sleep. The titration success rate was lower in the little-REM-sleep group than in the normal-REM-sleep group (p=0.038). Conclusions The AHI is higher and the success rate of CPAP titration is lower in OSA patients with little REM sleep than those with normal REM sleep.

  13. Spot scanning proton therapy minimizes neutron dose in the setting of radiation therapy administered during pregnancy.

    PubMed

    Wang, Xin; Poenisch, Falk; Sahoo, Narayan; Zhu, Ronald X; Lii, MingFwu; Gillin, Michael T; Li, Jing; Grosshans, David

    2016-01-01

    This is a real case study to minimize the neutron dose equivalent (H) to a fetus using spot scanning proton beams with favorable beam energies and angles. Minimum neutron dose exposure to the fetus was achieved with iterative planning under the guidance of neutron H measurement. Two highly conformal treatment plans, each with three spot scanning beams, were planned to treat a 25-year-old pregnant female with aggressive recurrent chordoma of the base of skull who elected not to proceed with termination. Each plan was scheduled for delivery every other day for robust target coverage. Neutron H to the fetus was measured using a REM500 neutron survey meter placed at the fetus position of a patient simulating phantom. 4.1 and 44.1 μSv/fraction were measured for the two initial plans. A vertex beam with higher energy and the fetal position closer to its central axis was the cause for the plan that produced an order higher neutron H. Replacing the vertex beam with a lateral beam reduced neutron H to be comparable with the other plan. For a prescription of 70 Gy in 35 fractions, the total neutron H to the fetus was estimated to be 0.35 mSv based on final measurement in single fraction. In comparison, the passive scattering proton plan and photon plan had an estimation of 26 and 70 mSv, respectively, for this case. While radiation therapy in pregnant patients should be avoided if at all possible, our work demonstrated spot scanning beam limited the total neutron H to the fetus an order lower than the suggested 5 mSv regulation threshold. It is far superior than passive scattering beam and careful beam selection with lower energy and keeping fetus further away from beam axis are essential in minimizing the fetus neutron exposure. PMID:27685136

  14. Your Glucose Meter

    MedlinePlus

    ... by Audience For Women Women's Health Topics Your Glucose Meter Share Tweet Linkedin Pin it More sharing ... Español Basic Facts 7 Tips for Testing Your Blood Sugar and Caring for Your Meter Glucose meters test ...

  15. REM sleep dysregulation in depression: state of the art.

    PubMed

    Palagini, Laura; Baglioni, Chiara; Ciapparelli, Antonio; Gemignani, Angelo; Riemann, Dieter

    2013-10-01

    Disturbances of sleep are typical for most depressed patients and belong to the core symptoms of the disorder. Since the 1960s polysomnographic sleep research has demonstrated that besides disturbances of sleep continuity, depression is associated with altered sleep architecture, i.e., a decrease in slow wave sleep (SWS) production and disturbed rapid eye movement (REM) sleep regulation. Shortened REM latency (i.e., the interval between sleep onset and the occurrence of the first REM period), increased REM sleep duration and increased REM density (i.e., the frequency of rapid eye movements per REM period) have been considered as biological markers of depression which might predict relapse and recurrence. High risk studies including healthy relatives of patients with depression demonstrate that REM sleep alterations may precede the clinical expression of depression and may thus be useful in identifying subjects at high risk for the illness. Several models have been developed to explain REM sleep abnormalities in depression, like the cholinergic-aminergic imbalance model or chronobiologically inspired theories, which are reviewed in this overview. Moreover, REM sleep alterations have been recently considered not only as biological "scars" but as true endophenotypes of depression. This review discusses the genetic, neurochemical and neurobiological factors that have been implicated to play a role in the complex relationships between REM sleep and depression. We hypothesize on the one hand that REM sleep dysregulation in depression may be linked to a genetic predisposition/vulnerability to develop the illness; on the other hand it is conceivable that REM sleep disinhibition in itself is a part of a maladaptive stress reaction with increased allostatic load. We also discuss whether the REM sleep changes in depression may contribute themselves to the development of central symptoms of depression such as cognitive distortions including negative self-esteem and the

  16. Human REM sleep: influence on feeding behaviour, with clinical implications.

    PubMed

    Horne, James A

    2015-08-01

    Rapid eye movement (REM) sleep shares many underlying mechanisms with wakefulness, to a much greater extent than does non-REM, especially those relating to feeding behaviours, appetite, curiosity, exploratory (locomotor) activities, as well as aspects of emotions, particularly 'fear extinction'. REM is most evident in infancy, thereafter declining in what seems to be a dispensable manner that largely reciprocates increasing wakefulness. However, human adults retain more REM than do other mammals, where for us it is most abundant during our usual final REM period (fREMP) of the night, nearing wakefulness. The case is made that our REM is unusual, and that (i) fREMP retains this 'dispensability', acting as a proxy for wakefulness, able to be forfeited (without REM rebound) and substituted by physical activity (locomotion) when pressures of wakefulness increase; (ii) REM's atonia (inhibited motor output) may be a proxy for this locomotion; (iii) our nocturnal sleep typically develops into a physiological fast, especially during fREMP, which is also an appetite suppressant; (iv) REM may have 'anti-obesity' properties, and that the loss of fREMP may well enhance appetite and contribute to weight gain ('overeating') in habitually short sleepers; (v) as we also select foods for their hedonic (emotional) values, REM may be integral to developing food preferences and dislikes; and (vii) REM seems to have wider influences in regulating energy balance in terms of exercise 'substitution' and energy (body heat) retention. Avenues for further research are proposed, linking REM with feeding behaviours, including eating disorders, and effects of REM-suppressant medications.

  17. Breathing during REM and non-REM sleep: correlated versus uncorrelated behaviour

    NASA Astrophysics Data System (ADS)

    Kantelhardt, Jan W.; Penzel, Thomas; Rostig, Sven; Becker, Heinrich F.; Havlin, Shlomo; Bunde, Armin

    2003-03-01

    Healthy sleep can be characterized by several stages: deep sleep, light sleep, and REM sleep. Here we show that these sleep stages lead to different autonomic regulation of breathing. Using the detrended fluctuation analysis up to the fourth order we find that breath-to-breath intervals and breath volumes separated by several breaths are long-range correlated during the REM stages and during wake states. In contrast, in the non-REM stages (deep sleep and light sleep), long-range correlations are absent. This behaviour is very similar to the correlation behaviour of the heart rate during the night and may be related to the phase synchronization between heartbeat and breathing found recently. We speculate that the differences are caused by different cortically influenced control of the autonomic nervous system.

  18. Intrinsic dreams are not produced without REM sleep mechanisms: evidence through elicitation of sleep onset REM periods.

    PubMed

    Takeuchi, T; Miyasita, A; Inugami, M; Yamamoto, Y

    2001-03-01

    The hypothesis that there is a strict relationship between dreams and a specific rapid eye movement (REM) sleep mechanism is controversial. Many researchers have recently denied this relationship, yet none of their studies have simultaneously controlled both sleep length and depth prior to non-REM (NREM) and REM sleep awakenings, due to the natural rigid order of the NREM--REM sleep cycle. The failure to control sleep length and depth prior to arousal has confounded interpretations of the REM-dreams relationship. We have hypothesised that different physiological mechanisms underlie dreaming during REM and NREM sleep, based on recent findings concerning the specificity of REM sleep for cognitive function. Using the Sleep Interruption Technique, we elicited sleep onset REM periods (SOREMP) from 13 normal subjects to collect SOREMP and sleep onset NREM (NREMP) dreams without the confounds described above. Regression analyses showed that SOREMP dream occurrences were significantly related to the amount of REM sleep, while NREMP dream occurrences were related to arousals from NREM sleep. Dream properties evaluated using the Dream Property Scale showed qualitative differences between SOREMP and NREMP dream reports. These results support our hypothesis and we have concluded that although 'dreaming' may occur during both REM and NREM periods as previous researchers have suggested, the dreams obtained from these distinct periods differ significantly in their quantitative and qualitative aspects and are likely to be produced by different mechanisms.

  19. Association between the activation of MCH and orexin immunorective neurons and REM sleep architecture during REM rebound after a three day long REM deprivation.

    PubMed

    Kitka, Tamas; Adori, Csaba; Katai, Zita; Vas, Szilvia; Molnar, Eszter; Papp, Rege S; Toth, Zsuzsanna E; Bagdy, Gyorgy

    2011-10-01

    Rapid eye movement (REM) sleep rebound following REM deprivation using the platform-on-water method is characterized by increased time spent in REM sleep and activation of melanin-concentrating hormone (MCH) expressing neurons. Orexinergic neurons discharge reciprocally to MCH-ergic neurons across the sleep-wake cycle. However, the relation between REM architecture and the aforementioned neuropeptides remained unclear. MCH-ergic neurons can be divided into two subpopulations regarding their cocaine- and amphetamine-regulated transcript (CART) immunoreactivity, and among them the activation of CART-immunoreactive subpopulation is higher during the REM rebound. However, the possible role of stress in this association has not been elucidated. Our aims were to analyze the relationship between the architecture of REM rebound and the activation of hypothalamic MCH-ergic and orexinergic neurons. We also intended to separate the effect of stress and REM deprivation on the subsequent activation of subpopulations of MCH-ergic neurons. In order to detect neuronal activity, we performed MCH/cFos and orexin/cFos double immunohistochemistry on home cage, sleep deprived and sleep-rebound rats using the platform-on-water method with small and large (stress control) platforms. Furthermore, REM architecture was analyzed and a triple MCH/CART/cFos immunohistochemistry was also performed on the rebound groups in the same animals. We found that the activity of MCH- and orexin-immunoreactive neurons during REM rebound was positively and negatively correlated with the number of REM bouts, respectively. A negative reciprocal correlation was also found between the activation of MCH- and orexin-immunoreactive neurons during REM rebound. Furthermore, difference between the activation of CART-immunoreactive (CART-IR) and non-CART-immunoreactive MCH-ergic neuron subpopulations was found only after selective REM deprivation, it was absent in the large platform (stress control) rebound group

  20. Portable peak flow meters.

    PubMed

    McNaughton, J P

    1997-02-01

    There are several portable peak flow meters available. These instruments vary in construction and performance. Guidelines are recommended for minimum performance and testing of portable peak flow meters, with the aim of establishing a procedure for standardizing all peak flow meters. Future studies to clarify the usefulness of mechanical test apparatus and clinical trials of peak flow meters are also recommended. PMID:9098706

  1. Quad RF power meter

    SciTech Connect

    Stone, D.W.

    1987-09-01

    This report shows how to construct a four-channel RF power meter from circuit boards and components found in a Hewlett Packard Model 432A Power Meter. Included are descriptions of necessary modifications, electrical circuit diagrams, and a parts list. Each of the four power meters is compatible with a Hewlett Packard 432A Power Meter.

  2. Portable neutron spectrometer and dosimeter

    DOEpatents

    Waechter, David A.; Erkkila, Bruce H.; Vasilik, Dennis G.

    1985-01-01

    The disclosure relates to a battery operated neutron spectrometer/dosimeter utilizing a microprocessor, a built-in tissue equivalent LET neutron detector, and a 128-channel pulse height analyzer with integral liquid crystal display. The apparatus calculates doses and dose rates from neutrons incident on the detector and displays a spectrum of rad or rem as a function of keV per micron of equivalent tissue and also calculates and displays accumulated dose in millirads and millirem as well as neutron dose rates in millirads per hour and millirem per hour.

  3. Portable neutron spectrometer and dosimeter

    DOEpatents

    Waechter, D.A.; Erkkila, B.H.; Vasilik, D.G.

    The disclosure relates to a battery operated neutron spectrometer/dosimeter utilizing a microprocessor, a built-in tissue equivalent LET neutron detector, and a 128-channel pulse height analyzer with integral liquid crystal display. The apparatus calculates doses and dose rates from neutrons incident on the detector and displays a spectrum of rad or rem as a function of keV per micron of equivalent tissue and also calculates and displays accumulated dose in millirads and millirem as well as neutron dose rates in millirads per hour and millirem per hour.

  4. Sleep- and circadian-dependent modulation of REM density.

    PubMed

    Khalsa, Sat Bir S; Conroy, Deirdre A; Duffy, Jeanne F; Czeisler, Charles A; Dijk, Derk-Jan

    2002-03-01

    Rapid eye movement (REM) density, a measure of the frequency of rapid eye movements during REM sleep, is known to increase over the course of the sleep episode. However, the circadian modulation of REM density has not been thoroughly evaluated. Data from a forced desynchrony protocol, in which 20 consecutive sleep opportunities were systematically scheduled over the entire circadian cycle, were analysed. The REM density was evaluated from polysomnographically recorded REM sleep episodes, and analyzed as a function of time in the sleep opportunity and as a function of phase in the circadian cycle. The REM density showed a robust increase over the course of the sleep episode. This sleep-dependent increase was observed regardless of circadian phase, because data analyzed from different thirds of the circadian cycle exhibited a similar pattern. The REM density did not show a significant circadian-dependent modulation for data from the entire sleep opportunity. However, analysis of circadian modulation from separate thirds of the sleep opportunity revealed a significant circadian modulation in the last third of the sleep episode. Maximum REM densities were observed when the last third of the sleep episode coincided with the wake-maintenance zone, i.e.;8-10 h before the crest of the circadian rhythm of REM sleep propensity. These results confirm the dominant sleep-dependent modulation of REM density, and indicate that the density of REMs is greatest when sleep pressure is low, such as in the latter part of the sleep episode, at which time the circadian modulation of REM density is also appreciable.

  5. Control of REM Sleep by Ventral Medulla GABAergic Neurons

    PubMed Central

    Weber, Franz; Chung, Shinjae; Beier, Kevin T.; Luo, Liqun; Dan, Yang

    2015-01-01

    Rapid eye movement (REM) sleep is a distinct brain state characterized by activated electroencephalogram (EEG) and complete skeletal muscle paralysis, and it is associated with vivid dreams1-3. Transection studies by Jouvet first demonstrated that the brainstem is both necessary and sufficient for REM sleep generation2, and the neural circuits in the pons have since been studied extensively4-8. The medulla also contains neurons that are active during REM sleep9-13, but whether they play a causal role in REM sleep generation remains unclear. Here we show that a GABAergic pathway originating from the ventral medulla (vM) powerfully promotes REM sleep. Optogenetic activation of vM GABAergic neurons rapidly and reliably initiated REM sleep episodes and prolonged their durations, whereas inactivating these neurons had the opposite effects. Optrode recordings from channelrhodopsin 2 (ChR2)-tagged vM GABAergic neurons showed that they were most active during REM sleep (REM-max), and during wakefulness they were preferentially active during eating and grooming. Furthermore, dual retrograde tracing showed that the rostral projections to the pons and midbrain and caudal projections to the spinal cord originate from separate vM neuron populations. Activating the rostral GABAergic projections was sufficient for both the induction and maintenance of REM sleep, which are likely mediated in part by inhibition of REM-suppressing GABAergic neurons in the ventrolateral periaqueductal gray (vlPAG). These results identify a key component of the pontomedullary network controlling REM sleep. The capability to induce REM sleep on command may offer a powerful tool for investigating its functions. PMID:26444238

  6. Selective REM Sleep Deprivation Improves Expectation-Related Placebo Analgesia

    PubMed Central

    Chouchou, Florian; Chauny, Jean-Marc; Rainville, Pierre; Lavigne, Gilles J.

    2015-01-01

    The placebo effect is a neurobiological and psychophysiological process known to influence perceived pain relief. Optimization of placebo analgesia may contribute to the clinical efficacy and effectiveness of medication for acute and chronic pain management. We know that the placebo effect operates through two main mechanisms, expectations and learning, which is also influenced by sleep. Moreover, a recent study suggested that rapid eye movement (REM) sleep is associated with modulation of expectation-mediated placebo analgesia. We examined placebo analgesia following pharmacological REM sleep deprivation and we tested the hypothesis that relief expectations and placebo analgesia would be improved by experimental REM sleep deprivation in healthy volunteers. Following an adaptive night in a sleep laboratory, 26 healthy volunteers underwent classical experimental placebo analgesic conditioning in the evening combined with pharmacological REM sleep deprivation (clonidine: 13 volunteers or inert control pill: 13 volunteers). Medication was administered in a double-blind manner at bedtime, and placebo analgesia was tested in the morning. Results revealed that 1) placebo analgesia improved with REM sleep deprivation; 2) pain relief expectations did not differ between REM sleep deprivation and control groups; and 3) REM sleep moderated the relationship between pain relief expectations and placebo analgesia. These results support the putative role of REM sleep in modulating placebo analgesia. The mechanisms involved in these improvements in placebo analgesia and pain relief following selective REM sleep deprivation should be further investigated. PMID:26678391

  7. Selective REM Sleep Deprivation Improves Expectation-Related Placebo Analgesia.

    PubMed

    Chouchou, Florian; Chauny, Jean-Marc; Rainville, Pierre; Lavigne, Gilles J

    2015-01-01

    The placebo effect is a neurobiological and psychophysiological process known to influence perceived pain relief. Optimization of placebo analgesia may contribute to the clinical efficacy and effectiveness of medication for acute and chronic pain management. We know that the placebo effect operates through two main mechanisms, expectations and learning, which is also influenced by sleep. Moreover, a recent study suggested that rapid eye movement (REM) sleep is associated with modulation of expectation-mediated placebo analgesia. We examined placebo analgesia following pharmacological REM sleep deprivation and we tested the hypothesis that relief expectations and placebo analgesia would be improved by experimental REM sleep deprivation in healthy volunteers. Following an adaptive night in a sleep laboratory, 26 healthy volunteers underwent classical experimental placebo analgesic conditioning in the evening combined with pharmacological REM sleep deprivation (clonidine: 13 volunteers or inert control pill: 13 volunteers). Medication was administered in a double-blind manner at bedtime, and placebo analgesia was tested in the morning. Results revealed that 1) placebo analgesia improved with REM sleep deprivation; 2) pain relief expectations did not differ between REM sleep deprivation and control groups; and 3) REM sleep moderated the relationship between pain relief expectations and placebo analgesia. These results support the putative role of REM sleep in modulating placebo analgesia. The mechanisms involved in these improvements in placebo analgesia and pain relief following selective REM sleep deprivation should be further investigated.

  8. Narcolepsy presenting as REM sleep behaviour disorder.

    PubMed

    Bonakis, Anastasios; Howard, Robin S; Williams, Adrian

    2008-05-01

    REM sleep behaviour disorder (RBD) is a neurological condition well known to be associated with the synucleinopathies in middle-aged patients. However, there is much less data concerning its development, evolution, and association with other disorders in younger patients. We report two patients aged less than 33 years who presented with clinical and polysomnographical features of RBD, both of whom proved to have previously undiagnosed narcolepsy. Whilst the association of narcolepsy with RBD has been previously recognised, this is the first report of narcoleptic patients presenting with RBD. Narcolepsy should be included in the differential diagnosis of young patients presenting with abnormal behaviour during sleep compatible with RBD. PMID:18343568

  9. Correlations using the NREM-REM sleep cycle frequency support distinct regulation mechanisms for REM and NREM sleep.

    PubMed

    Le Bon, O; Staner, L; Rivelli, S K; Hoffmann, G; Pelc, I; Linkowski, P

    2002-07-01

    Polysomnograms of most homeothermic species distinguish two states, rapid eye movement (REM) and non-REM (NREM) sleep. These alternate several times during the night for reasons and following rules that remain poorly understood. It is unknown whether each state has its own function and regulation or whether they represent two facets of the same process. The present study compared the mean REM/NREM sleep ratio and the mean number of NREM-REM sleep cycles across 3 consecutive nights. The rationale was that, if REM and NREM sleep are tightly associated, their ratio should be comparable whatever the cycle frequency in the night. Twenty-six healthy subjects of both sexes were recorded at their home for 4 consecutive nights. The correlation between the REM/NREM sleep ratio and the number of cycles was highly significant. Of the two sleep components, REM sleep was associated to the number of cycles, whereas NREM sleep was not. This suggests that the relationship between REM sleep and NREM sleep is rather weak within cycles, does not support the concept of NREM-REM sleep cycles as miniature units of the sleep process, and favors the concept of distinct mechanisms of regulation for the two components.

  10. Brainstem mechanisms of paradoxical (REM) sleep generation.

    PubMed

    Luppi, Pierre-Hervé; Clement, Olivier; Sapin, Emilie; Peyron, Christelle; Gervasoni, Damien; Léger, Lucienne; Fort, Patrice

    2012-01-01

    Paradoxical sleep (PS) is characterized by EEG activation with a disappearance of muscle tone and the occurrence of rapid eye movements (REM) in contrast to slow-wave sleep (SWS, also known as non-REM sleep) identified by the presence of delta waves. Soon after the discovery of PS, it was demonstrated that the structures necessary and sufficient for its genesis are restricted to the brainstem. We review here recent results indicating that brainstem glutamatergic and GABAergic, rather than cholinergic and monoaminergic, neurons play a key role in the genesis of PS. We hypothesize that the entrance to PS from SWS is due to the activation of PS-on glutamatergic neurons localized in the pontine sublaterodorsal tegmental nucleus. The activation of these neurons would be due to a permanent glutamatergic input arising from the lateral and ventrolateral periaqueductal gray (vlPAG) and the removal at the onset of PS of a GABAergic inhibition present during W and SWS. Such inhibition would be coming from PS-off GABAergic neurons localized in the vlPAG and the adjacent deep mesencephalic reticular nucleus. The cessation of activity of these PS-off GABAergic neurons at the onset and during PS would be due to direct projections from intermingled GABAergic PS-on neurons. Activation of PS would depend on the reciprocal interactions between the GABAergic PS-on and PS-off neurons, intrinsic cellular and molecular events, and integration of multiple physiological parameters.

  11. Endogenous cholinergic input to the pontine REM sleep generator is not required for REM sleep to occur.

    PubMed

    Grace, Kevin P; Vanstone, Lindsay E; Horner, Richard L

    2014-10-22

    Initial theories of rapid eye movement (REM) sleep generation posited that induction of the state required activation of the pontine subceruleus (SubC) by cholinergic inputs. Although the capacity of cholinergic neurotransmission to contribute to REM sleep generation has been established, the role of cholinergic inputs in the generation of REM sleep is ultimately undetermined as the critical test of this hypothesis (local blockade of SubC acetylcholine receptors) has not been rigorously performed. We used bilateral microdialysis in freely behaving rats (n = 32), instrumented for electroencephalographic and electromyographic recording, to locally manipulate neurotransmission in the SubC with select drugs. As predicted, combined microperfusion of D-AP5 (glutamate receptor antagonist) and muscimol (GABAA receptor agonist) in the SubC virtually eliminated REM sleep. However, REM sleep was not reduced by scopolamine microperfusion in this same region, at a concentration capable of blocking the effects of cholinergic receptor stimulation. This result suggests that transmission of REM sleep drive to the SubC is acetylcholine-independent. Although SubC cholinergic inputs are not majorly involved in REM sleep generation, they may perform a minor function in the reinforcement of transitions into REM sleep, as evidenced by increases in non-REM-to-REM sleep transition duration and failure rate during cholinergic receptor blockade. Cholinergic receptor antagonism also attenuated the normal increase in hippocampal θ oscillations that characterize REM sleep. Using computational modeling, we show that our in vivo results are consistent with a mutually excitatory interaction between the SubC and cholinergic neurons where, importantly, cholinergic neuron activation is gated by SubC activity.

  12. Does obstructive sleep apnea worsen during REM sleep?

    PubMed

    Peregrim, I; Grešová, S; Pallayová, M; Fulton, B L; Štimmelová, J; Bačová, I; Mikuľaková, A; Tomori, Z; Donič, V

    2013-01-01

    Although it is thought that obstructive sleep apnea (OSA) is worse during rapid eye movement (REM) sleep than in non-REM (NREM) sleep there are some uncertainties, especially about apnoe-hypopnoe-index (AHI). Several studies found no significant difference in AHI between both sleep stages. However, REM sleep is associated more with side sleeping compared to NREM sleep, which suggests that body position is a possible confounding factor. The main purpose of this study was to compare the AHI in REM and NREM sleep in both supine and lateral body position. A retrospective study was performed on 422 consecutive patients who underwent an overnight polysomnography. Women had higher AHI in REM sleep than NREM sleep in both supine (46.05+/-26.26 vs. 23.91+/-30.96, P<0.01) and lateral (18.16+/-27.68 vs. 11.30+/-21.09, P<0.01) body position. Men had higher AHI in REM sleep than NREM sleep in lateral body position (28.94+/-28.44 vs. 23.58+/-27.31, P<0.01), however, they did not reach statistical significance in supine position (49.12+/-32.03 in REM sleep vs. 45.78+/-34.02 in NREM sleep, P=0.50). In conclusion, our data suggest that REM sleep is a contributing factor for OSA in women as well as in men, at least in lateral position. PMID:24020811

  13. REM Sleep at its Core - Circuits, Neurotransmitters, and Pathophysiology.

    PubMed

    Fraigne, Jimmy J; Torontali, Zoltan A; Snow, Matthew B; Peever, John H

    2015-01-01

    Rapid eye movement (REM) sleep is generated and maintained by the interaction of a variety of neurotransmitter systems in the brainstem, forebrain, and hypothalamus. Within these circuits lies a core region that is active during REM sleep, known as the subcoeruleus nucleus (SubC) or sublaterodorsal nucleus. It is hypothesized that glutamatergic SubC neurons regulate REM sleep and its defining features such as muscle paralysis and cortical activation. REM sleep paralysis is initiated when glutamatergic SubC cells activate neurons in the ventral medial medulla, which causes release of GABA and glycine onto skeletal motoneurons. REM sleep timing is controlled by activity of GABAergic neurons in the ventrolateral periaqueductal gray and dorsal paragigantocellular reticular nucleus as well as melanin-concentrating hormone neurons in the hypothalamus and cholinergic cells in the laterodorsal and pedunculo-pontine tegmentum in the brainstem. Determining how these circuits interact with the SubC is important because breakdown in their communication is hypothesized to underlie narcolepsy/cataplexy and REM sleep behavior disorder (RBD). This review synthesizes our current understanding of mechanisms generating healthy REM sleep and how dysfunction of these circuits contributes to common REM sleep disorders such as cataplexy/narcolepsy and RBD.

  14. REM Sleep at its Core – Circuits, Neurotransmitters, and Pathophysiology

    PubMed Central

    Fraigne, Jimmy J.; Torontali, Zoltan A.; Snow, Matthew B.; Peever, John H.

    2015-01-01

    Rapid eye movement (REM) sleep is generated and maintained by the interaction of a variety of neurotransmitter systems in the brainstem, forebrain, and hypothalamus. Within these circuits lies a core region that is active during REM sleep, known as the subcoeruleus nucleus (SubC) or sublaterodorsal nucleus. It is hypothesized that glutamatergic SubC neurons regulate REM sleep and its defining features such as muscle paralysis and cortical activation. REM sleep paralysis is initiated when glutamatergic SubC cells activate neurons in the ventral medial medulla, which causes release of GABA and glycine onto skeletal motoneurons. REM sleep timing is controlled by activity of GABAergic neurons in the ventrolateral periaqueductal gray and dorsal paragigantocellular reticular nucleus as well as melanin-concentrating hormone neurons in the hypothalamus and cholinergic cells in the laterodorsal and pedunculo-pontine tegmentum in the brainstem. Determining how these circuits interact with the SubC is important because breakdown in their communication is hypothesized to underlie narcolepsy/cataplexy and REM sleep behavior disorder (RBD). This review synthesizes our current understanding of mechanisms generating healthy REM sleep and how dysfunction of these circuits contributes to common REM sleep disorders such as cataplexy/narcolepsy and RBD. PMID:26074874

  15. REM Sleep at its Core - Circuits, Neurotransmitters, and Pathophysiology.

    PubMed

    Fraigne, Jimmy J; Torontali, Zoltan A; Snow, Matthew B; Peever, John H

    2015-01-01

    Rapid eye movement (REM) sleep is generated and maintained by the interaction of a variety of neurotransmitter systems in the brainstem, forebrain, and hypothalamus. Within these circuits lies a core region that is active during REM sleep, known as the subcoeruleus nucleus (SubC) or sublaterodorsal nucleus. It is hypothesized that glutamatergic SubC neurons regulate REM sleep and its defining features such as muscle paralysis and cortical activation. REM sleep paralysis is initiated when glutamatergic SubC cells activate neurons in the ventral medial medulla, which causes release of GABA and glycine onto skeletal motoneurons. REM sleep timing is controlled by activity of GABAergic neurons in the ventrolateral periaqueductal gray and dorsal paragigantocellular reticular nucleus as well as melanin-concentrating hormone neurons in the hypothalamus and cholinergic cells in the laterodorsal and pedunculo-pontine tegmentum in the brainstem. Determining how these circuits interact with the SubC is important because breakdown in their communication is hypothesized to underlie narcolepsy/cataplexy and REM sleep behavior disorder (RBD). This review synthesizes our current understanding of mechanisms generating healthy REM sleep and how dysfunction of these circuits contributes to common REM sleep disorders such as cataplexy/narcolepsy and RBD. PMID:26074874

  16. REM and delta sleep in anorexia nervosa and bulimia.

    PubMed

    Levy, A B; Dixon, K N; Schmidt, H

    1987-03-01

    Several recent investigations have suggested that neurobiological similarities may exist between patients with eating disorders and those with depression. We performed polysomnograms for two consecutive nights on nine bulimic and six anorectic patients who had no concomitant diagnosis of endogenous depression. The rapid eye movement (REM) latency, REM density, and delta sleep of these subjects on night 2 were compared to those of 10 healthy controls of similar ages. Contrary to reports of shortened REM latency and increased REM density in depressed patients, we did not find significant REM differences between eating disorder patients without endogenous depression and healthy control subjects. Low weight anorectics did appear to have less delta sleep than did controls. These findings do not support the contention that eating disorders are variants of affective disorders.

  17. A Matter of Meter

    ERIC Educational Resources Information Center

    Harrison, David L.

    2006-01-01

    Writing verse is a learning experience. Arranging words, sounds and syllables can turn everyday language into metered language (language that can be measured), and metered language is the definition of verse. This article discusses the use of meter in helping students establish sets of syllables and lines that can be counted, enabling them to…

  18. INVESTIGATION OF THE EXTENDED RANGE REM-COUNTER SMARTREM-LINUS IN REFERENCE AND WORKPLACE FIELDS EXPECTED AROUND HIGH-ENERGY ACCELERATORS.

    PubMed

    Hohmann, Eike; Trovati, S; Strauch, U; Mayer, S

    2016-09-01

    Radiation survey instrumentation is adequate for the use around high-energy accelerators if capable to measure the dose arising from neutrons with energies ranging from thermal up to a few gigaelectronvolts. The SmartREM-LINUS is a commercial extended range rem-counter, consisting of a central (3)He-proportional counter surrounded by a spherical moderator made of borated polyethylene with an internal shield made of lead. The dose rate indicated by the SmartREM-LINUS was investigated for two different irradiation conditions. The linearity and the angular dependence of the indicated dose rate were investigated using reference neutron fields produced by (241)AmBe and (252)Cf. Additional measurements were performed in two different workplace fields with a component of neutrons with energies >20 MeV, namely the CERN-EU high-energy reference field and near the beam dump of the SwissFEL injector test facility. The measured dose rates were compared to a commercial rem-counter (WENDI2) and the results of Monte Carlo simulations. PMID:27315828

  19. Physiology of REM sleep, cataplexy, and sleep paralysis.

    PubMed

    Hishikawa, Y; Shimizu, T

    1995-01-01

    The main neural structures generating muscle atonia and other phenomena characteristic of REM sleep are present in dorsolateral portions of the pons in the brainstem. Occurrence of REM sleep and the NREM-REM sleep cycle are probably determined by a balance or interaction between the cholinergic and cholinoceptive REM sleep-on neuronal populations and the monoaminergic REM sleep-off neuronal population. Neural activities producing generalized muscle atonia in REM sleep originate mainly in dorsolateral portions of the pontine reticular formation, descend through the medulla and spinal cord, and inhibit the motoneurons in the brainstem and spinal cord, bringing about postural atonia. Cataplexy and sleep paralysis are pathological, dissociated manifestations of the generalized muscle atonia characteristic REM sleep. Cataplexy is triggered by emotional stimuli, probably through activation of the neural structure generating the muscle atonia of REM sleep. During long-lasting cataplectic attacks, narcoleptic humans often experience sleep paralysis and vivid hypnagogic hallucinations in the latter sleep state. Sleep paralysis is caused by the marked dissociation between level of alertness and muscle atonia that often occurs in SOREM sleep episodes. Frequent SOREM sleep episodes in narcoleptic humans and dogs may occur when some of the neural mechanisms producing wakefulness and/or NREM sleep that normally inhibit the occurrence of REM sleep are abnormally weak, or when neural mechanisms facilitating the occurrence of REM sleep are hypersensitive or hyperactive, or both. Both abnormalities may contribute to the occurrence of SOREM sleep episodes and sleep paralysis, and also to the emotional triggering of cataplexy. Frequent occurrence of SOREM sleep episodes seems to be prerequisite but not sufficient for the occurrence of cataplexy. Some additional neural activities induced by emotion also contribute by inhibiting and/or activating the disturbed neural mechanisms related

  20. The role of REM sleep theta activity in emotional memory

    PubMed Central

    Hutchison, Isabel C.; Rathore, Shailendra

    2015-01-01

    While non-REM (NREM) sleep has been strongly implicated in the reactivation and consolidation of memory traces, the role of rapid-eye movement (REM) sleep remains unclear. A growing body of research on humans and animals provide behavioral evidence for a role of REM sleep in the strengthening and modulation of emotional memories. Theta activity—which describes low frequency oscillations in the local field potential within the hippocampus, amygdala and neocortex—is a prominent feature of both wake and REM sleep in humans and rodents. Theta coherence between the hippocampus and amygdala drives large-scale pontine-geniculo-occipital (PGO) waves, the density of which predicts increases in plasticity-related gene expression. This could potentially facilitate the processing of emotional memory traces within the hippocampus during REM sleep. Further, the timing of hippocampal activity in relation to theta phase is vital in determining subsequent potentiation of neuronal activity. This could allow the emotionally modulated strengthening of novel and gradual weakening of consolidated hippocampal memory traces during REM sleep. Hippocampal theta activity is also correlated with REM sleep levels of achetylcholine - which is thought to reduce hippocampal inputs in the neocortex. The additional low levels of noradrenaline during REM sleep, which facilitate feedback within the neocortex, could allow the integration of novel memory traces previously consolidated during NREM sleep. We therefore propose that REM sleep mediates the prioritized processing of emotional memories within the hippocampus, the integration of previously consolidated memory traces within the neocortex, as well as the disengagement of consolidated neocortical memory traces from the hippocampus. PMID:26483709

  1. The role of REM sleep theta activity in emotional memory.

    PubMed

    Hutchison, Isabel C; Rathore, Shailendra

    2015-01-01

    While non-REM (NREM) sleep has been strongly implicated in the reactivation and consolidation of memory traces, the role of rapid-eye movement (REM) sleep remains unclear. A growing body of research on humans and animals provide behavioral evidence for a role of REM sleep in the strengthening and modulation of emotional memories. Theta activity-which describes low frequency oscillations in the local field potential within the hippocampus, amygdala and neocortex-is a prominent feature of both wake and REM sleep in humans and rodents. Theta coherence between the hippocampus and amygdala drives large-scale pontine-geniculo-occipital (PGO) waves, the density of which predicts increases in plasticity-related gene expression. This could potentially facilitate the processing of emotional memory traces within the hippocampus during REM sleep. Further, the timing of hippocampal activity in relation to theta phase is vital in determining subsequent potentiation of neuronal activity. This could allow the emotionally modulated strengthening of novel and gradual weakening of consolidated hippocampal memory traces during REM sleep. Hippocampal theta activity is also correlated with REM sleep levels of achetylcholine - which is thought to reduce hippocampal inputs in the neocortex. The additional low levels of noradrenaline during REM sleep, which facilitate feedback within the neocortex, could allow the integration of novel memory traces previously consolidated during NREM sleep. We therefore propose that REM sleep mediates the prioritized processing of emotional memories within the hippocampus, the integration of previously consolidated memory traces within the neocortex, as well as the disengagement of consolidated neocortical memory traces from the hippocampus. PMID:26483709

  2. The role of REM sleep theta activity in emotional memory.

    PubMed

    Hutchison, Isabel C; Rathore, Shailendra

    2015-01-01

    While non-REM (NREM) sleep has been strongly implicated in the reactivation and consolidation of memory traces, the role of rapid-eye movement (REM) sleep remains unclear. A growing body of research on humans and animals provide behavioral evidence for a role of REM sleep in the strengthening and modulation of emotional memories. Theta activity-which describes low frequency oscillations in the local field potential within the hippocampus, amygdala and neocortex-is a prominent feature of both wake and REM sleep in humans and rodents. Theta coherence between the hippocampus and amygdala drives large-scale pontine-geniculo-occipital (PGO) waves, the density of which predicts increases in plasticity-related gene expression. This could potentially facilitate the processing of emotional memory traces within the hippocampus during REM sleep. Further, the timing of hippocampal activity in relation to theta phase is vital in determining subsequent potentiation of neuronal activity. This could allow the emotionally modulated strengthening of novel and gradual weakening of consolidated hippocampal memory traces during REM sleep. Hippocampal theta activity is also correlated with REM sleep levels of achetylcholine - which is thought to reduce hippocampal inputs in the neocortex. The additional low levels of noradrenaline during REM sleep, which facilitate feedback within the neocortex, could allow the integration of novel memory traces previously consolidated during NREM sleep. We therefore propose that REM sleep mediates the prioritized processing of emotional memories within the hippocampus, the integration of previously consolidated memory traces within the neocortex, as well as the disengagement of consolidated neocortical memory traces from the hippocampus.

  3. Pontine regulation of REM sleep components in cats: integrity of the pedunculopontine tegmentum (PPT) is important for phasic events but unnecessary for atonia during REM sleep.

    PubMed

    Shouse, M N; Siegel, J M

    1992-01-31

    Transection, lesion and unit recording studies have localized rapid eye movement (REM) sleep mechanisms to the pons. Recent work has emphasized the role of pontine cholinergic cells, especially those of the pedunculopontine tegmentum (PPT). The present study differentiated REM sleep deficits associated with lesions of the PPT from other pontine regions implicated in REM sleep generation, including those with predominantly cholinergic vs non-cholinergic cells. Twelve hour polygraphic recordings were obtained in 18 cats before and 1-2 weeks after bilateral electrolytic or radio frequency lesions of either: (1) PPT, which contains the dorsolateral pontine cholinergic cell column; (2) laterodorsal tegmental nucleus (LDT), which contains the dorsomedial pontine cholinergic cell column; (3) locus ceruleus (LC), which contains mostly noradrenergic cells; or (4) subceruleus (LC alpha, peri-LC alpha and the lateral tegmental field), which also contains predominantly noncholinergic cells. There were three main findings: (i) Only lesions of PPT and subceruleus significantly affected REM sleep time. These lesions produced comparable reductions in REM sleep time but influenced REM sleep components quite differently: (ii) PPT lesions, estimated to damage 90 +/- 4% of cholinergic cells, reduced the number of REM sleep entrances and phasic events, including ponto-geniculooccipital (PGO) spikes and rapid eye movements (REMs), but did not prevent complete atonia during REM sleep: (iii) Subceruleus lesions eliminated atonia during REM sleep. Mobility appeared to arouse the cat prematurely from REM sleep and may explain the brief duration of REM sleep epochs seen exclusively in this group. Despite the reduced amount of REM sleep, the total number of PGO spikes and REM sleep entrances increased over baseline values. Collectively, the results distinguish pontine loci regulating phasic events vs atonia. PPT lesions reduced phasic events, whereas subceruleus lesions created REM sleep

  4. Carbachol models of REM sleep: recent developments and new directions.

    PubMed

    Kubin, L

    2001-02-01

    Since the early '60s, injections of a broad-spectrum muscarinic cholinergic agonist, carbachol, into the medial pontine reticular formation (mPRF) of cats have been extensively used as a tool with which to study the neural mechanisms of rapid eye movement (REM) sleep. During the last decade, new carbachol models of REM sleep were introduced, including chronically instrumented/behaving rats and "reduced" preparations such as decerebrate or anesthetized cats and rats. The combined results from these distinct models show interspecies similarities and differences. The dual nature, both REM sleep-promoting and wakefulness (or arousal)-promoting, of the cholinergic effects exerted within the mPRF is more strongly expressed in rats than in cats. This strengthens the possibility suggested by earlier central neuronal recordings that active wakefulness and REM sleep have extensive common neuronal substrates, and may have evolved from a common behavioral state. Carbachol studies using different intact and reduced models also suggest that powerful REM sleep episode-terminating effects originate in suprapontine structures. In contrast, the timing of REM sleep-like episodes in decerebrate models is determined by a pontomedullary neuronal network responsible for the generation of an ultradian cycle similar to the basic rest-activity cycle of N. Kleitman. Other presumed species differences, such as the more widespread distribution of carbachol-sensitive sites or the relative failure of carbachol to increase the duration of REM sleep episodes in rats when compared to cats, may be of a quantitative or technical nature. While carbachol and many other neurotransmitters and peptides microinjected into the mPRF evoke, enhance or suppress REM sleep, the most sensitive site(s) of their actions have not been fully mapped, and the nature of the cellular and neurochemical interactions taking place at the sites where carbachol triggers the REM sleep-like state remain largely unknown

  5. Field dependence and the effect of REM deprivation on thirst.

    PubMed

    Koulack, D; De Koninck, J; Oczkowski, G

    1978-04-01

    Recently a number of studies have concerned the possible function of rapid eye movement (REM) sleep and the mastery of stress. The present study was designed to explore the possibility that REM sleep might play a function in reducing the potency of a stressful physiological stimulus, thirst, as well as the possibility that such a function might be specific to individuals falling at different points along the field-dependence dimension. While there was no difference between REM deprivation and non-REM awakening nights in subsequent morning thirst, there was a significant interaction between field dependence and night on morning thirst measures for 10 college students. These results are discussed in light of previous work on stylistic differences in dreaming and their possible role in adaptation to stress. PMID:208050

  6. Slow waves, sharp waves, ripples, and REM in sleeping dragons.

    PubMed

    Shein-Idelson, Mark; Ondracek, Janie M; Liaw, Hua-Peng; Reiter, Sam; Laurent, Gilles

    2016-04-29

    Sleep has been described in animals ranging from worms to humans. Yet the electrophysiological characteristics of brain sleep, such as slow-wave (SW) and rapid eye movement (REM) activities, are thought to be restricted to mammals and birds. Recording from the brain of a lizard, the Australian dragon Pogona vitticeps, we identified SW and REM sleep patterns, thus pushing back the probable evolution of these dynamics at least to the emergence of amniotes. The SW and REM sleep patterns that we observed in lizards oscillated continuously for 6 to 10 hours with a period of ~80 seconds. The networks controlling SW-REM antagonism in amniotes may thus originate from a common, ancient oscillator circuit. Lizard SW dynamics closely resemble those observed in rodent hippocampal CA1, yet they originate from a brain area, the dorsal ventricular ridge, that has no obvious hodological similarity with the mammalian hippocampus. PMID:27126045

  7. Slow waves, sharp waves, ripples, and REM in sleeping dragons.

    PubMed

    Shein-Idelson, Mark; Ondracek, Janie M; Liaw, Hua-Peng; Reiter, Sam; Laurent, Gilles

    2016-04-29

    Sleep has been described in animals ranging from worms to humans. Yet the electrophysiological characteristics of brain sleep, such as slow-wave (SW) and rapid eye movement (REM) activities, are thought to be restricted to mammals and birds. Recording from the brain of a lizard, the Australian dragon Pogona vitticeps, we identified SW and REM sleep patterns, thus pushing back the probable evolution of these dynamics at least to the emergence of amniotes. The SW and REM sleep patterns that we observed in lizards oscillated continuously for 6 to 10 hours with a period of ~80 seconds. The networks controlling SW-REM antagonism in amniotes may thus originate from a common, ancient oscillator circuit. Lizard SW dynamics closely resemble those observed in rodent hippocampal CA1, yet they originate from a brain area, the dorsal ventricular ridge, that has no obvious hodological similarity with the mammalian hippocampus.

  8. Computer models and output, Spartan REM: Appendix B

    NASA Technical Reports Server (NTRS)

    Marlowe, D. S.; West, E. J.

    1984-01-01

    A computer model of the Spartan Release Engagement Mechanism (REM) is presented in a series of numerical charts and engineering drawings. A crack growth analysis code is used to predict the fracture mechanics of critical components.

  9. Neuroscience: A Distributed Neural Network Controls REM Sleep.

    PubMed

    Peever, John; Fuller, Patrick M

    2016-01-11

    How does the brain control dreams? New science shows that a small node of cells in the medulla - the most primitive part of the brain - may function to control REM sleep, the brain state that underlies dreaming. PMID:26766231

  10. Materials properties, loads, and stress analysis, Spartan REM: Appendix A

    NASA Technical Reports Server (NTRS)

    Marlowe, D. S.; West, E. J.

    1984-01-01

    The mechanical properties, load tests, and stress analysis of the Spartan Release Engagement Mechanism (REM) is presented. The fracture properties of the components of the unit are also discussed. Detailed engineering drawings are included.

  11. Performance tests of the IAE dose equivalent meter in radiation field of high energy calibration facility at SPS-CERN

    NASA Astrophysics Data System (ADS)

    Rusinowski, Z.; Golnik, N.

    1998-02-01

    The performance of the IEA dose equivalent meter based on the REM-2 recombination chamber was tested in pulsed high energy radiation field at CERN-EC calibration facility. The device was working with its own monitoring circuit, and provided accurate and stable results, within 2% of statistical uncertainty.

  12. The Swift Mission and the REM Telescope

    NASA Technical Reports Server (NTRS)

    Gehrels, N.; Chincarini, G.; Giommi, P.; Mason, K. O.; Nousek, J. A.; Wells, A. A.; White, N. E.; Barthelemy, S. D.; Burrow, D. N.; Hurley, K. C.

    2003-01-01

    Following a description of the science drive which originated the Swift Mission, this is US NASA MIDEX Mission with the collaboration of Italy and the UK, we will describe the status of the hardware and the observing strategy. The telemetry is carried out via the TDRSS satellite for those communications that need immediate response. The data transfer and the scheduled uploading of routine commands will be done through the ASI Malindi station in Kenia. Both in the US and in Europe a large effort will be done to follow the bursts with the maximum of efficiency and as soon as possible after the alert. We will describe how the ESO VLT telescopes are able to respond to the alert. To address the problematic of the dark bursts and to immediately follow up all of the bursts also in the Near Infrared we designed and built a 60 cm NIR Robotic telescope, REM, to be located on the ESO ground at Cerro La Silla. The instrumentation includes also a low dispersion spectrograph with the capability of multi wavelength optical photometry.

  13. Neutron and Proton Dosages in the Upper Atmosphere from Solar Flare Radiation.

    PubMed

    Flamm, E J; Lingenfelter, R E

    1964-06-26

    The radiation dosage from secondary neutrons as well as from primary and secondary protons in the earth's atmosphere during solar particle events is calculated as a function of the solar proton flux, atmospheric depth, and geomagnetic-cutoff rigidity. The dosage in rems from secondary neutrons exceeds the dosage from protons below 30 g/cm(2) of residual atmosphere. Neutron dosages in rads are less than the dosage from primary protons at all depths above 100 g/cm(2). The maximum neutron dose to travelers in supersonic aircraft during solar particle events of the magnitude observed during the last solar cycle would be of the order of I rem.

  14. LET spectrometry of 14 MeV (D-T) neutrons using CR-39 track detectors

    NASA Astrophysics Data System (ADS)

    Sahoo, G. S.; Tripathy, S. P.; Sunil, C.; Sarkar, P. K.

    2013-04-01

    Linear energy transfer (LET) spectrum in water in the range of 12 keV/μm to 382 keV/μm due to 14 MeV (D-T) neutrons is estimated using the track size parameters in two different types of CR-39 track detectors, viz. Intercast (1.5 mm) and Pershore (0.5 mm). Another set of CR-39s (Intercast) combined with 1 mm polyethylene (PE) radiators is exposed to study the effect of enhanced recoils on the LET spectrum. The detection efficiencies for all these cases and the enhancement ratio due to PE radiator are determined. Using this LET spectrum, the microdosimetric spectra of absorbed doses and dose equivalents are estimated based on the Q-L conversion factors as given in ICRP 60. The shape of the LET spectra are found to be similar in all the cases, however, the dose equivalents obtained with the CR-39+PE radiator is about 20% more than the other detectors without PE. The ratios of dose equivalents obtained from LET spectra (HLET) and the ambient dose equivalent (H*(10)) obtained from fluence-to-dose equivalent conversion factors (ICRP 74) for 14 MeV neutrons are used to estimate the dose response of the detectors. H*(10) is also measured using a neutron rem meter, the response of which is found to be about 23% less than the actual dose.

  15. Functional Anatomy of Non-REM Sleep

    PubMed Central

    de Andrés, Isabel; Garzón, Miguel; Reinoso-Suárez, Fernando

    2011-01-01

    The state of non-REM sleep (NREM), or slow wave sleep, is associated with a synchronized EEG pattern in which sleep spindles and/or K complexes and high-voltage slow wave activity (SWA) can be recorded over the entire cortical surface. In humans, NREM is subdivided into stages 2 and 3–4 (presently named N3) depending on the proportions of each of these polygraphic events. NREM is necessary for normal physical and intellectual performance and behavior. An overview of the brain structures involved in NREM generation shows that the thalamus and the cerebral cortex are absolutely necessary for the most significant bioelectric and behavioral events of NREM to be expressed; other structures like the basal forebrain, anterior hypothalamus, cerebellum, caudal brain stem, spinal cord and peripheral nerves contribute to NREM regulation and modulation. In NREM stage 2, sustained hyperpolarized membrane potential levels resulting from interaction between thalamic reticular and projection neurons gives rise to spindle oscillations in the membrane potential; the initiation and termination of individual spindle sequences depends on corticothalamic activities. Cortical and thalamic mechanisms are also involved in the generation of EEG delta SWA that appears in deep stage 3–4 (N3) NREM; the cortex has classically been considered to be the structure that generates this activity, but delta oscillations can also be generated in thalamocortical neurons. NREM is probably necessary to normalize synapses to a sustainable basal condition that can ensure cellular homeostasis. Sleep homeostasis depends not only on the duration of prior wakefulness but also on its intensity, and sleep need increases when wakefulness is associated with learning. NREM seems to ensure cell homeostasis by reducing the number of synaptic connections to a basic level; based on simple energy demands, cerebral energy economizing during NREM sleep is one of the prevalent hypotheses to explain NREM homeostasis

  16. Causal evidence for the role of REM sleep theta rhythm in contextual memory consolidation.

    PubMed

    Boyce, Richard; Glasgow, Stephen D; Williams, Sylvain; Adamantidis, Antoine

    2016-05-13

    Rapid eye movement sleep (REMS) has been linked with spatial and emotional memory consolidation. However, establishing direct causality between neural activity during REMS and memory consolidation has proven difficult because of the transient nature of REMS and significant caveats associated with REMS deprivation techniques. In mice, we optogenetically silenced medial septum γ-aminobutyric acid-releasing (MS(GABA)) neurons, allowing for temporally precise attenuation of the memory-associated theta rhythm during REMS without disturbing sleeping behavior. REMS-specific optogenetic silencing of MS(GABA) neurons selectively during a REMS critical window after learning erased subsequent novel object place recognition and impaired fear-conditioned contextual memory. Silencing MS(GABA) neurons for similar durations outside REMS episodes had no effect on memory. These results demonstrate that MS(GABA) neuronal activity specifically during REMS is required for normal memory consolidation. PMID:27174984

  17. Optogenetic activation of cholinergic neurons in the PPT or LDT induces REM sleep.

    PubMed

    Van Dort, Christa J; Zachs, Daniel P; Kenny, Jonathan D; Zheng, Shu; Goldblum, Rebecca R; Gelwan, Noah A; Ramos, Daniel M; Nolan, Michael A; Wang, Karen; Weng, Feng-Ju; Lin, Yingxi; Wilson, Matthew A; Brown, Emery N

    2015-01-13

    Rapid eye movement (REM) sleep is an important component of the natural sleep/wake cycle, yet the mechanisms that regulate REM sleep remain incompletely understood. Cholinergic neurons in the mesopontine tegmentum have been implicated in REM sleep regulation, but lesions of this area have had varying effects on REM sleep. Therefore, this study aimed to clarify the role of cholinergic neurons in the pedunculopontine tegmentum (PPT) and laterodorsal tegmentum (LDT) in REM sleep generation. Selective optogenetic activation of cholinergic neurons in the PPT or LDT during non-REM (NREM) sleep increased the number of REM sleep episodes and did not change REM sleep episode duration. Activation of cholinergic neurons in the PPT or LDT during NREM sleep was sufficient to induce REM sleep.

  18. Groundwater-Seepage Meter

    NASA Technical Reports Server (NTRS)

    Walthall, Harry G.; Reay, William G.

    1993-01-01

    Instrument measures seepage of groundwater into inland or coastal body of water. Positioned at depth as great as 40 meters, and measures flow at low rate and low pressure differential. Auxiliary pressure meter provides data for correlation of flow of groundwater with tides and sea states. Seepage meter operates independently for several weeks. Its sampling rate adjusted to suit hydrologic conditions; to measure more frequently when conditions changing rapidly. Used in water-quality management and for biological and geological research. Potential industrial uses include measurement of seepage of caustic and corrosive liquids.

  19. DC attenuation meter

    DOEpatents

    Hargrove, Douglas L.

    2004-09-14

    A portable, hand-held meter used to measure direct current (DC) attenuation in low impedance electrical signal cables and signal attenuators. A DC voltage is applied to the signal input of the cable and feedback to the control circuit through the signal cable and attenuators. The control circuit adjusts the applied voltage to the cable until the feedback voltage equals the reference voltage. The "units" of applied voltage required at the cable input is the system attenuation value of the cable and attenuators, which makes this meter unique. The meter may be used to calibrate data signal cables, attenuators, and cable-attenuator assemblies.

  20. Space Age Meter.

    ERIC Educational Resources Information Center

    Phillips, Julie

    1983-01-01

    Discusses the history and evolution of measurement standards from 3000 BC to the modern metric system. Traces measurement techniques from comparisons with the human body to use of atomic clocks and lasers to establish the length of a meter. (JM)

  1. Water cycle at Gale crater through MSL/REMS observations

    NASA Astrophysics Data System (ADS)

    Harri, Ari-Matti; Genzer, Maria; Kemppinen, Osku; Gomez-Elvira, Javier; Savijärvi, Hannu; McConnochie, Tim; De la Torre, Manuel; Haberle, Robert; Polkko, Jouni; Paton, Mark; Richardson, Mark I.; Newman, Claire E.; Siili, Tero; Makinen, Terhi

    2016-10-01

    The Mars Science laboratory (MSL) has been successfully operating at the Gale crater since early August 2012 and has provided a wealth of extremely valuable data. That includes atmospheric observations by the REMS instrument performing atmospheric pressure, temperature of the air, ground temperature, wind speed and direction, relative humidity (REMS-H), and UV measurements.The REMS-H relative humidity device is based on polymeric capacitive humidity sensors developed by Vaisala Inc. and it makes use of three (3) humidity sensor heads. The humidity device is mounted on the REMS boom providing ventilation with the ambient atmosphere through a filter protecting the device from airborne dust.The REMS-H humidity instrument has created an unprecedented data record of more than two full Martian. REMS-H measured the relative humidity and temperature at 1.6 m height for a period of 5 minutes every hour as part of the MSL/REMS instrument package. We focus on describing the annual in situ water cycle with the new REMS-H instrument calibration for the period of two Martian years. The results will be constrained through comparison with independent indirect observations and through modeling efforts.We inferred the hourly atmospheric VMR from the REMS-H observations and compared these VMR measurements with predictions of VMR from our 1D column Martian atmospheric model and regolith to investigate the local water cycle, exchange processes and the local climate in Gale Crater. The strong diurnal variation suggests there are surface-atmosphere exchange processes at Gale Crater during all seasons, which depletes moisture to the ground in the evening and nighttime and release the moisture back to the atmosphere during the daytime. On the other hand, these processes do not result in significant water deposition on the ground, because frost has not been detected in Gale Crater by any of the MSL observations. Hence, our modelling results presumably indicate that adsorption processes take

  2. Rapid increase to double breathing rate appears during REM sleep in synchrony with REM - a higher CNS control of breathing? -.

    PubMed

    Sato, Shinichi; Kanbayashi, Takashi; Kondo, Hideaki; Matsubuchi, Namiko; Ono, Kyoichi; Shimizu, Tetsuo

    2010-01-01

    Breathing rate (BR) during rapid eye movement (REM) sleep is known to fluctuate largely, while increases in BR during REM sleep reported were small. In our mice experiments, we found that mice exhibit a rapid increase in instantaneous BR (RIBR) of >2 fold during natural sleep with accompanying atonia, laying their sides down. The RIBR was further found in a sleeping mouse attached with EEG electrodes when the EEG amplitude and delta wave power were lower. Therefore, it is likely that mice show RIBRs during REM sleep. Interestingly, similar RIBRs accompanied by atonia and REM burst during REM sleep were also found in humans by standard polysomnographic studies in 11 healthy volunteers (age: 22.3 +/- 2.8) with BR measurement by nasal/oral airflow sensors and chest/abdomen belt sensors. All subjects underwent RIBR of doubled BR at least once a night. As SpO(2) before RIBRs was a level not effective to be a respiratory stimulant (96.7 +/- 1.6 %, n = 63), the RIBR seems to be controlled by higher central nervous system rather than autonomic nervous system control on response to central and peripheral chemical sensors. In fact, tachypnea with suppressed amplitude during RIBR resulted in a slight fall in SpO(2) (96.4 +/- 1.7 %, p = 0.0007). In the present study, RIBRs accompanied by atonia and REM were not necessarily consistent in change in rate and/or amplitude, therefore, these various pattern of RIBRs may be potential indices of dreams with various emotional contents. Analysis of instantaneous BR, thus, may be a helpful tool for understanding the neural control of breathing during REM sleep. PMID:20217359

  3. DIGITAL Q METER

    DOEpatents

    Briscoe, W.L.

    1962-02-13

    A digital Q meter is described for measuring the Q of mechanical or electrical devices. The meter comprises in combination a transducer coupled to an input amplifier, and an upper and lower level discriminator coupled to the amplifier and having their outputs coupled to an anticoincidence gate. The output of the gate is connected to a scaler. The lower level discriminator is adjusted to a threshold level of 36.8 percent of the operating threshold level of the upper level discriminator. (AEC)

  4. Water Cycle at Gale Crater Through MSL REMS Observations

    NASA Astrophysics Data System (ADS)

    Harri, Ari-Matti; Genzer, Maria; Kemppinen, Osku; Gomez-Elvira, Javier; McConnochie, Timothy; Savijarvi, Hannu; Polkko, Jouni; de la Torre-Juarez, Manuel; Newman, Claire; Martinez, German; Paton, Mark; Martin-Torres, Javier; Haberle, Robert; Vazquez, Luis; Renno, Nilton; Makinen, Terhi; Schmidt, Walter; Siili, Tero

    2016-04-01

    The Mars Science laboratory (MSL) has been successfully operating at the Gale crater since early August 2012 and provided a wealth of extremely valuable data. That includes atmospheric observations by the REMS (Rover Environmental Monitoring Station) comprising instrumentation for the observation of atmospheric pressure, temperature of the air, ground temperature, wind speed and direction, relative humidity (REMS-H), and UV measurements. The REMS-H device is based on polymeric capacitive humidity sensors developed by Vaisala Inc. and it makes use of transducer electronics section placed in the vicinity of the three (3) humidity sensor heads. The humidity device is mounted on the REMS boom providing ventilation with the ambient atmosphere through a filter protecting the device from airborne dust. We focus on describing the first annual water cycle at the Martian surface using the improved REMS-H calibration for the period of almost two Martian years. The characteristics of the Martian water cycle with the relative humidity, mixing ratio and partial water pressure will be discussed. The results will be constrained through comparison with independent indirect observations and through modeling efforts.

  5. Arrival Metering Precision Study

    NASA Technical Reports Server (NTRS)

    Prevot, Thomas; Mercer, Joey; Homola, Jeffrey; Hunt, Sarah; Gomez, Ashley; Bienert, Nancy; Omar, Faisal; Kraut, Joshua; Brasil, Connie; Wu, Minghong, G.

    2015-01-01

    This paper describes the background, method and results of the Arrival Metering Precision Study (AMPS) conducted in the Airspace Operations Laboratory at NASA Ames Research Center in May 2014. The simulation study measured delivery accuracy, flight efficiency, controller workload, and acceptability of time-based metering operations to a meter fix at the terminal area boundary for different resolution levels of metering delay times displayed to the air traffic controllers and different levels of airspeed information made available to the Time-Based Flow Management (TBFM) system computing the delay. The results show that the resolution of the delay countdown timer (DCT) on the controllers display has a significant impact on the delivery accuracy at the meter fix. Using the 10 seconds rounded and 1 minute rounded DCT resolutions resulted in more accurate delivery than 1 minute truncated and were preferred by the controllers. Using the speeds the controllers entered into the fourth line of the data tag to update the delay computation in TBFM in high and low altitude sectors increased air traffic control efficiency and reduced fuel burn for arriving aircraft during time based metering.

  6. Cold exposure impairs dark-pulse capacity to induce REM sleep in the albino rat.

    PubMed

    Baracchi, Francesca; Zamboni, Giovanni; Cerri, Matteo; Del Sindaco, Elide; Dentico, Daniela; Jones, Christine Ann; Luppi, Marco; Perez, Emanuele; Amici, Roberto

    2008-06-01

    In the albino rat, a REM sleep (REMS) onset can be induced with a high probability and a short latency when the light is suddenly turned off (dark pulse, DP) during non-REM sleep (NREMS). The aim of this study was to investigate to what extent DP delivery could overcome the integrative thermoregulatory mechanisms that depress REMS occurrence during exposure to low ambient temperature (Ta). To this aim, the efficiency of a non-rhythmical repetitive DP (3 min each) delivery during the first 6-h light period of a 12 h:12 h light-dark cycle in inducing REMS was studied in the rat, through the analysis of electroencephalogram, electrocardiogram, hypothalamic temperature and motor activity at different Tas. The results showed that DP delivery triggers a transition from NREMS to REMS comparable to that which occurs spontaneously. However, the efficiency of DP delivery in inducing REMS was reduced during cold exposure to an extent comparable with that observed in spontaneous REMS occurrence. Such impairment was associated with low Delta activity and high sympathetic tone when DPs were delivered. Repetitive DP administration increased REMS amount during the delivery period and a subsequent negative REMS rebound was observed. In conclusion, DP delivery did not overcome the integrative thermoregulatory mechanisms that depress REMS in the cold. These results underline the crucial physiological meaning of the mutual exclusion of thermoregulatory activation and REMS occurrence, and support the hypothesis that the suspension of the central control of body temperature is a prerequisite for REMS occurrence.

  7. A Temporally Controlled Inhibitory Drive Coordinates Twitch Movements during REM Sleep.

    PubMed

    Brooks, Patricia L; Peever, John

    2016-05-01

    During REM sleep, skeletal muscles are paralyzed in one moment but twitch and jerk in the next. REM sleep twitches are traditionally considered random motor events that result from momentary lapses in REM sleep paralysis [1-3]. However, recent evidence indicates that twitches are not byproducts of REM sleep, but are in fact self-generated events that could function to promote motor learning and development [4-6]. If REM twitches are indeed purposefully generated, then they should be controlled by a coordinated and definable mechanism. Here, we used behavioral, electrophysiological, pharmacological, and neuroanatomical methods to demonstrate that an inhibitory drive onto skeletal motoneurons produces a temporally coordinated pattern of muscle twitches during REM sleep. First, we show that muscle twitches in adult rats are not uniformly distributed during REM sleep, but instead follow a well-defined temporal trajectory. They are largely absent during REM initiation but increase steadily thereafter, peaking toward REM termination. Next, we identify the transmitter mechanism that controls the temporal nature of twitch activity. Specifically, we show that a GABA and glycine drive onto motoneurons prevents twitch activity during REM initiation, but progressive weakening of this drive functions to promote twitch activity during REM termination. These results demonstrate that REM twitches are not random byproducts of REM sleep, but are instead rather coherently generated events controlled by a temporally variable inhibitory drive. PMID:27040781

  8. Role of corticosterone on sleep homeostasis induced by REM sleep deprivation in rats.

    PubMed

    Machado, Ricardo Borges; Tufik, Sergio; Suchecki, Deborah

    2013-01-01

    Sleep is regulated by humoral and homeostatic processes. If on one hand chronic elevation of stress hormones impair sleep, on the other hand, rapid eye movement (REM) sleep deprivation induces elevation of glucocorticoids and time of REM sleep during the recovery period. In the present study we sought to examine whether manipulations of corticosterone levels during REM sleep deprivation would alter the subsequent sleep rebound. Adult male Wistar rats were fit with electrodes for sleep monitoring and submitted to four days of REM sleep deprivation under repeated corticosterone or metyrapone (an inhibitor of corticosterone synthesis) administration. Sleep parameters were continuously recorded throughout the sleep deprivation period and during 3 days of sleep recovery. Plasma levels of adrenocorticotropic hormone and corticosterone were also evaluated. Metyrapone treatment prevented the elevation of corticosterone plasma levels induced by REM sleep deprivation, whereas corticosterone administration to REM sleep-deprived rats resulted in lower corticosterone levels than in non-sleep deprived rats. Nonetheless, both corticosterone and metyrapone administration led to several alterations on sleep homeostasis, including reductions in the amount of non-REM and REM sleep during the recovery period, although corticosterone increased delta activity (1.0-4.0 Hz) during REM sleep deprivation. Metyrapone treatment of REM sleep-deprived rats reduced the number of REM sleep episodes. In conclusion, reduction of corticosterone levels during REM sleep deprivation resulted in impairment of sleep rebound, suggesting that physiological elevation of corticosterone levels resulting from REM sleep deprivation is necessary for plentiful recovery of sleep after this stressful event.

  9. A Temporally Controlled Inhibitory Drive Coordinates Twitch Movements during REM Sleep.

    PubMed

    Brooks, Patricia L; Peever, John

    2016-05-01

    During REM sleep, skeletal muscles are paralyzed in one moment but twitch and jerk in the next. REM sleep twitches are traditionally considered random motor events that result from momentary lapses in REM sleep paralysis [1-3]. However, recent evidence indicates that twitches are not byproducts of REM sleep, but are in fact self-generated events that could function to promote motor learning and development [4-6]. If REM twitches are indeed purposefully generated, then they should be controlled by a coordinated and definable mechanism. Here, we used behavioral, electrophysiological, pharmacological, and neuroanatomical methods to demonstrate that an inhibitory drive onto skeletal motoneurons produces a temporally coordinated pattern of muscle twitches during REM sleep. First, we show that muscle twitches in adult rats are not uniformly distributed during REM sleep, but instead follow a well-defined temporal trajectory. They are largely absent during REM initiation but increase steadily thereafter, peaking toward REM termination. Next, we identify the transmitter mechanism that controls the temporal nature of twitch activity. Specifically, we show that a GABA and glycine drive onto motoneurons prevents twitch activity during REM initiation, but progressive weakening of this drive functions to promote twitch activity during REM termination. These results demonstrate that REM twitches are not random byproducts of REM sleep, but are instead rather coherently generated events controlled by a temporally variable inhibitory drive.

  10. Coupled Flip-Flop Model for REM Sleep Regulation in the Rat

    PubMed Central

    Dunmyre, Justin R.; Mashour, George A.; Booth, Victoria

    2014-01-01

    Recent experimental studies investigating the neuronal regulation of rapid eye movement (REM) sleep have identified mutually inhibitory synaptic projections among REM sleep-promoting (REM-on) and REM sleep-inhibiting (REM-off) neuronal populations that act to maintain the REM sleep state and control its onset and offset. The control mechanism of mutually inhibitory synaptic interactions mirrors the proposed flip-flop switch for sleep-wake regulation consisting of mutually inhibitory synaptic projections between wake- and sleep-promoting neuronal populations. While a number of synaptic projections have been identified between these REM-on/REM-off populations and wake/sleep-promoting populations, the specific interactions that govern behavioral state transitions have not been completely determined. Using a minimal mathematical model, we investigated behavioral state transition dynamics dictated by a system of coupled flip-flops, one to control transitions between wake and sleep states, and another to control transitions into and out of REM sleep. The model describes the neurotransmitter-mediated inhibitory interactions between a wake- and sleep-promoting population, and between a REM-on and REM-off population. We proposed interactions between the wake/sleep and REM-on/REM-off flip-flops to replicate the behavioral state statistics and probabilities of behavioral state transitions measured from experimental recordings of rat sleep under ad libitum conditions and after 24 h of REM sleep deprivation. Reliable transitions from REM sleep to wake, as dictated by the data, indicated the necessity of an excitatory projection from the REM-on population to the wake-promoting population. To replicate the increase in REM-wake-REM transitions observed after 24 h REM sleep deprivation required that this excitatory projection promote transient activation of the wake-promoting population. Obtaining the reliable wake-nonREM sleep transitions observed in the data required that

  11. Coupled flip-flop model for REM sleep regulation in the rat.

    PubMed

    Dunmyre, Justin R; Mashour, George A; Booth, Victoria

    2014-01-01

    Recent experimental studies investigating the neuronal regulation of rapid eye movement (REM) sleep have identified mutually inhibitory synaptic projections among REM sleep-promoting (REM-on) and REM sleep-inhibiting (REM-off) neuronal populations that act to maintain the REM sleep state and control its onset and offset. The control mechanism of mutually inhibitory synaptic interactions mirrors the proposed flip-flop switch for sleep-wake regulation consisting of mutually inhibitory synaptic projections between wake- and sleep-promoting neuronal populations. While a number of synaptic projections have been identified between these REM-on/REM-off populations and wake/sleep-promoting populations, the specific interactions that govern behavioral state transitions have not been completely determined. Using a minimal mathematical model, we investigated behavioral state transition dynamics dictated by a system of coupled flip-flops, one to control transitions between wake and sleep states, and another to control transitions into and out of REM sleep. The model describes the neurotransmitter-mediated inhibitory interactions between a wake- and sleep-promoting population, and between a REM-on and REM-off population. We proposed interactions between the wake/sleep and REM-on/REM-off flip-flops to replicate the behavioral state statistics and probabilities of behavioral state transitions measured from experimental recordings of rat sleep under ad libitum conditions and after 24 h of REM sleep deprivation. Reliable transitions from REM sleep to wake, as dictated by the data, indicated the necessity of an excitatory projection from the REM-on population to the wake-promoting population. To replicate the increase in REM-wake-REM transitions observed after 24 h REM sleep deprivation required that this excitatory projection promote transient activation of the wake-promoting population. Obtaining the reliable wake-nonREM sleep transitions observed in the data required that

  12. Risk evaluation and mitigation strategies (REMS): educating the prescriber.

    PubMed

    Nicholson, Susan C; Peterson, Janet; Yektashenas, Behin

    2012-02-01

    The US FDA Amendments Act of 2007 was signed into law on 27 September 2007. A provision of this law granted the FDA new powers to enhance drug safety by requiring the pharmaceutical industry to develop Risk Evaluation and Mitigation Strategies (REMS). REMS are deemed necessary when a question exists as to whether the benefits of a drug outweigh its risks. REMS constitute a safety plan with several potential components, including a medication guide, a communication plan, elements to ensure safe use and an implementation system to help guide the prescribers, pharmacists and patients. This applies to existing drugs on the market, new drug applications (NDAs), abbreviated NDAs (generics) and biologics licence applications. REMS represent an 'upgrade' from previously required risk minimization action plans, based on the strengthening of FDA powers of authority and enforceability to incur monetary penalties against individuals representing the pharmaceutical industry who fail to comply. For illustrative purposes, we chose the drug romiplostim (Nplate®) to present an REMS, as all components were utilized to help assuage risks associated with the drug. Romiplostim is an FDA-approved drug used to treat thrombocytopenia in patients with chronic immune (idiopathic) thrombocytopenic purpura that has a significant adverse safety profile based on the risk of changes in bone marrow reticulin formation and bone marrow fibroses, and other associated risks. This review of current REMS policy is intended to provide the prescriber with a better understanding of current modalities in FDA-mandated drug safety programmes, which will impact day-to-day healthcare provider practices. PMID:22171604

  13. The Neurobiological Mechanisms and Treatments of REM Sleep Disturbances in Depression

    PubMed Central

    Wang, Yi-Qun; Li, Rui; Zhang, Meng-Qi; Zhang, Ze; Qu, Wei-Min; Huang, Zhi-Li

    2015-01-01

    Most depressed patients suffer from sleep abnormalities, which are one of the critical symptoms of depression. They are robust risk factors for the initiation and development of depression. Studies about sleep electroencephalograms have shown characteristic changes in depression such as reductions in non-rapid eye movement sleep production, disruptions of sleep continuity and disinhibition of rapid eye movement (REM) sleep. REM sleep alterations include a decrease in REM sleep latency, an increase in REM sleep duration and REM sleep density with respect to depressive episodes. Emotional brain processing dependent on the normal sleep-wake regulation seems to be failed in depression, which also promotes the development of clinical depression. Also, REM sleep alterations have been considered as biomarkers of depression. The disturbances of norepinephrine and serotonin systems may contribute to REM sleep abnormalities in depression. Lastly, this review also discusses the effects of different antidepressants on REM sleep disturbances in depression. PMID:26412074

  14. The Neurobiological Mechanisms and Treatments of REM Sleep Disturbances in Depression.

    PubMed

    Wang, Yi-Qun; Li, Rui; Zhang, Meng-Qi; Zhang, Ze; Qu, Wei-Min; Huang, Zhi-Li

    2015-01-01

    Most depressed patients suffer from sleep abnormalities, which are one of the critical symptoms of depression. They are robust risk factors for the initiation and development of depression. Studies about sleep electroencephalograms have shown characteristic changes in depression such as reductions in non-rapid eye movement sleep production, disruptions of sleep continuity and disinhibition of rapid eye movement (REM) sleep. REM sleep alterations include a decrease in REM sleep latency, an increase in REM sleep duration and REM sleep density with respect to depressive episodes. Emotional brain processing dependent on the normal sleep-wake regulation seems to be failed in depression, which also promotes the development of clinical depression. Also, REM sleep alterations have been considered as biomarkers of depression. The disturbances of norepinephrine and serotonin systems may contribute to REM sleep abnormalities in depression. Lastly, this review also discusses the effects of different antidepressants on REM sleep disturbances in depression.

  15. Endogenous GABA levels in the pontine reticular formation are greater during wakefulness than during REM sleep

    PubMed Central

    Vanini, Giancarlo; Wathen, Bradley L.; Lydic, Ralph; Baghdoyan, Helen A.

    2011-01-01

    Studies using drugs that increase or decrease GABAergic transmission suggest that GABA in the pontine reticular formation (PRF) promotes wakefulness and inhibits rapid eye movement (REM) sleep. Cholinergic transmission in the PRF promotes REM sleep, and levels of endogenous acetylcholine (ACh) in the PRF are significantly greater during REM sleep than during wakefulness or non-REM (NREM) sleep. No previous studies have determined whether levels of endogenous GABA in the PRF vary as a function of sleep and wakefulness. This study tested the hypothesis that GABA levels in cat PRF are greatest during wakefulness and lowest during REM sleep. Extracellular GABA levels were measured during wakefulness, NREM sleep, REM sleep, and the REM sleep-like state (REMNeo) caused by microinjecting neostigmine into the PRF. GABA levels varied significantly as a function of sleep and wakefulness, and decreased significantly below waking levels during REM sleep (−42%) and REMNeo (−63%). The decrease in GABA levels during NREM sleep (22% below waking levels) was not statistically significant. Compared to NREM sleep, GABA levels decreased significantly during REM sleep (−27%) and REMNeo (−52%). Comparisons of REM sleep and REMNeo revealed no differences in GABA levels or cortical EEG power. GABA levels did not vary significantly as a function of dialysis site within the PRF. The inverse relationship between changes in PRF levels of GABA and ACh during REM sleep indicates that low GABAergic tone combined with high cholinergic tone in the PRF contributes to the generation of REM sleep. PMID:21325533

  16. The utility of respiratory inductance plethysmography in REM sleep scoring during multiple sleep latency testing.

    PubMed

    Drakatos, Panagis; Higgins, Sean; Duncan, Iain; Bridle, Kate; Briscoe, Sam; Leschziner, Guy D; Kent, Brian D; Williams, Adrian J

    2016-08-01

    Rapid eye movement sleep (REM) presents with a characteristic erratic breathing pattern. We investigated the feasibility of using respiration, derived from respiratory inductance plethysmography (RIP), in conjunction with chin electromyography, electrocardiography and pulse oximetry to facilitate the identification of REM sleep (RespREM) during nocturnal polysomnography (NPSG) and Multiple Sleep Latency Testing (MSLT). The Cohen's weighted kappa for the presence of REM and its duration in 20 consecutive NPSGs, using RespREM and compared to the current guidelines, ranged between 0.74-0.93 and 0.68-0.73 respectively for 5 scorers. The respective intraclass correlation coefficients were above 0.89. In 97.7% of the Sleep-Onset-REM-Periods (SOREMPs) during 41 consecutive MSLTs with preserved RIP, the RespREM was present and in 46.6% it coincided with the REM onset, while in the majority of the remainder RespREM preceded conventional REM onset. The erratic breathing pattern during REM, derived from RIP, is present and easily recognisable during SOREMPs in the MSLTs and may serve as a useful adjunctive measurement in identifying REM sleep.

  17. REM Restriction Persistently Alters Strategy Used to Solve a Spatial Task

    ERIC Educational Resources Information Center

    Bjorness, Theresa E.; Tysor, Michael K.; Poe, Gina R.; Riley, Brett T.

    2005-01-01

    We tested the hypothesis that rapid eye movement (REM) sleep is important for complex associative learning by restricting rats from entering REM sleep for 4 h either immediately after training on an eight-box spatial task (0-4 REMr) or 4 h following training (4-8 REMr). Both groups of REM-restricted rats eventually reached the same overall…

  18. REM sleep behavior disorder: from dreams to neurodegeneration.

    PubMed

    Postuma, Ronald B; Gagnon, Jean-Francois; Montplaisir, Jacques Y

    2012-06-01

    REM sleep behavior disorder is a unique parasomnia characterized by dream enactment behavior during REM sleep. Unless triggered by pharmacologic agents such as antidepressants, it is generally related to damage of pontomedullary brainstem structures. Idiopathic REM sleep behavior disorder (RBD) is a well-established risk factor for neurodegenerative disease. Prospective studies have estimated that at least 40-65% of patients with idiopathic RBD will eventually develop a defined neurodegenerative phenotype, almost always a 'synucleinopathy' (Parkinson's disease, Lewy Body dementia or multiple system atrophy). In most cases, patients appear to develop a syndrome with overlapping features of both Parkinson's disease and Lewy body dementia. The interval between RBD onset and disease onset averages 10-15 years, suggesting a promisingly large window for intervention into preclinical disease stages. The ability of RBD to predict disease has major implications for design and development of neuroprotective therapy, and testing of other predictive markers of synuclein-mediated neurodegeneration. Recent studies in idiopathic RBD patients have demonstrated that olfaction, color vision, severity of REM atonia loss, transcranial ultrasound of the substantia nigra, and dopaminergic neuroimaging can predict development of neurodegenerative disease.

  19. Management of REM sleep behavior disorder: An evidence based review

    PubMed Central

    Devnani, Preeti; Fernandes, Racheal

    2015-01-01

    Rapid eye movement (REM) sleep behavior disorder (RBD) is characterized by dream enactment behavior resulting from a loss of REM skeletal muscle atonia. The neurobiology of REM sleep and the characteristic features of REM atonia have an important basis for understanding the aggravating etiologies the proposed pharmacological interventions in its management. This review outlines the evidence for behavioral and therapeutic measures along with evidence-based guidelines for their implementation, impact on falls, and effect on polysomnography (PSG) while highlighting the non-motor, autonomic, and cognitive impact of this entity. PubMed databases were reviewed upto May 2013 in peer-reviewed scientific literature regarding the pathophysiology and management of RBD in adults. The literature was graded according to the Oxford centre of evidence-based Medicine Levels. An early intervention that helps prevent consequences such as falls and provides a base for intervention with neuroprotective mechanisms and allocates a unique platform that RBD portrays with its high risk of disease conversion with a sufficiently long latency. RBD provides a unique platform with its high risk of disease conversion with a sufficiently long latency, providing an opportunity for early intervention both to prevent consequences such as falls and provide a base for intervention with neuroprotective mechanisms. PMID:25745301

  20. Elbow mass flow meter

    DOEpatents

    McFarland, Andrew R.; Rodgers, John C.; Ortiz, Carlos A.; Nelson, David C.

    1994-01-01

    Elbow mass flow meter. The present invention includes a combination of an elbow pressure drop generator and a shunt-type mass flow sensor for providing an output which gives the mass flow rate of a gas that is nearly independent of the density of the gas. For air, the output is also approximately independent of humidity.

  1. Metering Characteristics of Carburetors

    NASA Technical Reports Server (NTRS)

    Tice, Percival S; Dickinson, H C

    1919-01-01

    Report presents the results of an extensive experimental investigation of the performance of different types of carburetors as effecting the maintenance under all conditions of correct ratio between the weights of fuel and air. It also gives a description of the Bureau of Standards carburetor test plant, test equipment and measuring instruments used to determine the metering characteristics of carburetors.

  2. Charge depletion meter

    NASA Astrophysics Data System (ADS)

    Schneider, J. F.

    1984-11-01

    This invention relates to a charge depletion meter apparatus having a current to frequency converter to sense and convert the current drain of a battery source to a digital signal which is divided and then accumulated in a counter. An LCD display unit displays the accumulated charge which is received from the counter.

  3. Rhythmic Meter Munchies

    ERIC Educational Resources Information Center

    Quinn, Ashley

    2005-01-01

    In this article, the author presents an activity which allows students to construct various rhythm patterns in 2/4, 3/4, and 4/4 meter by using M&Ms and pretzels as an extrinsic motivation. Rhythmic notation is a foundation for learning music concepts. Engaging students in representative modules helps them to learn and recognize note values and…

  4. Characteristics of REM Sleep Behavior Disorder in Childhood

    PubMed Central

    Lloyd, Robin; Tippmann-Peikert, Maja; Slocumb, Nancy; Kotagal, Suresh

    2012-01-01

    Study Objective: To describe our experience regarding the clinical and polysomnographic features of REM sleep behavior disorder (RBD) in childhood. Methods: This was a retrospective chart review of children and adolescents with RBD and REM sleep without atonia. Demographics, and clinical and polysomnographic information were tabulated. Our findings were compared with those in the existing literature. Results: The 15 subjects identified (13 RBD and 2 having REM sleep without atonia) had a mean age at diagnosis of 9.5 years (range 3-17 years); 11/15 (73%) were male. Nightmares were reported in 13/15 and excessive daytime sleepiness in 6/15. Two children had caused bodily harm to bedmate siblings. Comorbidities, which were multiple in some subjects, included anxiety (8/15), attention deficit disorder (10/15), nonspecific developmental delay (6/15), Smith-Magenis syndrome (1/15), pervasive developmental disorder (1/15), narcolepsy (1/15), idiopathic hypersomnia (1/15), and Moebius Syndrome (1/15). Abnormal MRI scans were seen in 5/8 evaluated subjects. Treatments consisted of clonazepam (10/15), melatonin (2/15), and discontinuation of a tricyclic agent (1/15), with a favorable response in 11 of 13. Two of 15 patients with REM sleep without atonia did not require pharmacotherapy. Conclusions: RBD in children may be associated with neurodevelopmental disabilities, narcolepsy, or medication use. It seems to be modestly responsive to benzodiazepines or melatonin. The etiology is distinct from that of common childhood arousal parasomnias and RBD in adults; congenital and neurodevelopmental disorders, medication effect, and narcolepsy coexisted in some, but none had an extrapyramidal neurodegenerative disorder. Citation: Lloyd R; Tippmann-Peikert M; Slocumb N; Kotagal S. Characteristics of REM sleep behavior disorder in childhood. J Clin Sleep Med 2012;8(2):127-131. PMID:22505856

  5. Cerebrovascular Response to Arousal from NREM and REM Sleep

    PubMed Central

    Bangash, Muhammad Fuad; Xie, Ailiang; Skatrud, James B.; Reichmuth, Kevin J.; Barczi, Steven R.; Morgan, Barbara J.

    2008-01-01

    Study Objective: To determine the effect of arousal from sleep on cerebral blood flow velocity (CBFV) in relation to associated ventilatory and systemic hemodynamic changes. Participants: Eleven healthy individuals (6 men, 5 women). Measurements: Pulsed Doppler ultrasonography was used to measure CBFV in the middle cerebral artery with simultaneous measurements of sleep state (EEG, EOG, and EMG), ventilation (inductance plethysmography), heart rate (ECG), and arterial pressure (finger plethysmography). Arousals were induced by auditory tones (range: 40–80 dB; duration: 0.5 sec). Cardiovascular responses were examined beat-by-beat for 30 sec before and 30 sec after auditory tones. Results: During NREM sleep, CBFV declined following arousals (-15% ± 2%; group mean ± SEM) with a nadir at 9 sec after the auditory tone, followed by a gradual return to baseline. Mean arterial pressure (MAP; +20% ± 1%) and heart rate (HR; +17% ± 2%) increased with peaks at 5 and 3 sec after the auditory tone, respectively. Minute ventilation (VE) was increased (+35% ± 10%) for 2 breaths after the auditory tone. In contrast, during REM sleep, CBFV increased following arousals (+15% ± 3%) with a peak at 3 sec. MAP (+17% ± 2%) and HR (+15% ± 2%) increased during arousals from REM sleep with peaks at 5 and 3 sec post tone. VE increased (+16% ± 7%) in a smaller, more sustained manner during arousals from REM sleep. Conclusions: Arousals from NREM sleep transiently reduce CBFV, whereas arousals from REM sleep transiently increase CBFV, despite qualitatively and quantitatively similar increases in MAP, HR, and VE in the two sleep states. Citation: Bangash MF; Xie A; Skatrud JB; Reichmuth KJ; Barczi SR; Morgan BJ. Cerebrovascular response to arousal from NREM and REM sleep. SLEEP 2008;31(3):321-327. PMID:18363307

  6. Morning REM Sleep Naps Facilitate Broad Access to Emotional Semantic Networks

    PubMed Central

    Carr, Michelle; Nielsen, Tore

    2015-01-01

    Study Objectives: The goals of the study were to assess semantic priming to emotion and nonemotion cue words using a novel measure of associational breadth for participants who either took rapid eye movement (REM) or nonrapid eye movement (NREM) naps or who remained awake, and to assess the relation of priming to REM sleep consolidation and REM sleep inertia effects. Design: The associational breadth task was applied in both a priming condition, where cue words were signaled to be memorized prior to sleep (primed), and a nonpriming condition, where cue words were not memorized (nonprimed). Cue words were either emotional (positive, negative) or nonemotional. Participants were randomly assigned to either an awake (WAKE) or a sleep condition, which was subsequently split into NREM or REM groups depending on stage at awakening. Setting: Hospital-based sleep laboratory. Participants: Fifty-eight healthy participants (22 male) ages 18 to 35 y (mean age = 23.3 ± 4.08 y). Measurements and Results: The REM group scored higher than the NREM or WAKE groups on primed, but not nonprimed emotional cue words; the effect was stronger for positive than for negative cue words. However, REM time and percent correlated negatively with degree of emotional priming. Priming occurred for REM awakenings but not for NREM awakenings, even when the latter sleep episodes contained some REM sleep. Conclusions: Associational breadth may be selectively consolidated during REM sleep for stimuli that have been tagged as important for future memory retrieval. That priming decreased with REM time and was higher only for REM sleep awakenings is consistent with two explanatory REM sleep processes: REM sleep consolidation serving emotional downregulation and REM sleep inertia. Citation: Carr M, Nielsen T. Morning REM sleep naps facilitate broad access to emotional semantic networks. SLEEP 2015;38(3):433–443. PMID:25409100

  7. Increases in cAMP, MAPK activity, and CREB phosphorylation during REM sleep: implications for REM sleep and memory consolidation.

    PubMed

    Luo, Jie; Phan, Trongha X; Yang, Yimei; Garelick, Michael G; Storm, Daniel R

    2013-04-10

    The cyclic adenosine monophosphate (cAMP), mitogen-activated protein kinase (MAPK), and cAMP response element-binding protein (CREB) transcriptional pathway is required for consolidation of hippocampus-dependent memory. In mice, this pathway undergoes a circadian oscillation required for memory persistence that reaches a peak during the daytime. Because mice exhibit polyphasic sleep patterns during the day, this suggested the interesting possibility that cAMP, MAPK activity, and CREB phosphorylation may be elevated during sleep. Here, we report that cAMP, phospho-p44/42 MAPK, and phospho-CREB are higher in rapid eye movement (REM) sleep compared with awake mice but are not elevated in non-REM sleep. This peak of activity during REM sleep does not occur in mice lacking calmodulin-stimulated adenylyl cyclases, a mouse strain that learns but cannot consolidate hippocampus-dependent memory. We conclude that a preferential increase in cAMP, MAPK activity, and CREB phosphorylation during REM sleep may contribute to hippocampus-dependent memory consolidation. PMID:23575844

  8. Digital Receiver Phase Meter

    NASA Technical Reports Server (NTRS)

    Marcin, Martin; Abramovici, Alexander

    2008-01-01

    The software of a commercially available digital radio receiver has been modified to make the receiver function as a two-channel low-noise phase meter. This phase meter is a prototype in the continuing development of a phase meter for a system in which radiofrequency (RF) signals in the two channels would be outputs of a spaceborne heterodyne laser interferometer for detecting gravitational waves. The frequencies of the signals could include a common Doppler-shift component of as much as 15 MHz. The phase meter is required to measure the relative phases of the signals in the two channels at a sampling rate of 10 Hz at a root power spectral density <5 microcycle/(Hz)1/2 and to be capable of determining the power spectral density of the phase difference over the frequency range from 1 mHz to 1 Hz. Such a phase meter could also be used on Earth to perform similar measurements in laser metrology of moving bodies. To illustrate part of the principle of operation of the phase meter, the figure includes a simplified block diagram of a basic singlechannel digital receiver. The input RF signal is first fed to the input terminal of an analog-to-digital converter (ADC). To prevent aliasing errors in the ADC, the sampling rate must be at least twice the input signal frequency. The sampling rate of the ADC is governed by a sampling clock, which also drives a digital local oscillator (DLO), which is a direct digital frequency synthesizer. The DLO produces samples of sine and cosine signals at a programmed tuning frequency. The sine and cosine samples are mixed with (that is, multiplied by) the samples from the ADC, then low-pass filtered to obtain in-phase (I) and quadrature (Q) signal components. A digital signal processor (DSP) computes the ratio between the Q and I components, computes the phase of the RF signal (relative to that of the DLO signal) as the arctangent of this ratio, and then averages successive such phase values over a time interval specified by the user.

  9. Evaluating the Evidence Surrounding Pontine Cholinergic Involvement in REM Sleep Generation

    PubMed Central

    Grace, Kevin P.; Horner, Richard L.

    2015-01-01

    Rapid eye movement (REM) sleep – characterized by vivid dreaming, motor paralysis, and heightened neural activity – is one of the fundamental states of the mammalian central nervous system. Initial theories of REM sleep generation posited that induction of the state required activation of the “pontine REM sleep generator” by cholinergic inputs. Here, we review and evaluate the evidence surrounding cholinergic involvement in REM sleep generation. We submit that: (i) the capacity of pontine cholinergic neurotransmission to generate REM sleep has been firmly established by gain-of-function experiments, (ii) the function of endogenous cholinergic input to REM sleep generating sites cannot be determined by gain-of-function experiments; rather, loss-of-function studies are required, (iii) loss-of-function studies show that endogenous cholinergic input to the PTF is not required for REM sleep generation, and (iv) cholinergic input to the pontine REM sleep generating sites serve an accessory role in REM sleep generation: reinforcing non-REM-to-REM sleep transitions making them quicker and less likely to fail. PMID:26388832

  10. Evaluating the Evidence Surrounding Pontine Cholinergic Involvement in REM Sleep Generation.

    PubMed

    Grace, Kevin P; Horner, Richard L

    2015-01-01

    Rapid eye movement (REM) sleep - characterized by vivid dreaming, motor paralysis, and heightened neural activity - is one of the fundamental states of the mammalian central nervous system. Initial theories of REM sleep generation posited that induction of the state required activation of the "pontine REM sleep generator" by cholinergic inputs. Here, we review and evaluate the evidence surrounding cholinergic involvement in REM sleep generation. We submit that: (i) the capacity of pontine cholinergic neurotransmission to generate REM sleep has been firmly established by gain-of-function experiments, (ii) the function of endogenous cholinergic input to REM sleep generating sites cannot be determined by gain-of-function experiments; rather, loss-of-function studies are required, (iii) loss-of-function studies show that endogenous cholinergic input to the PTF is not required for REM sleep generation, and (iv) cholinergic input to the pontine REM sleep generating sites serve an accessory role in REM sleep generation: reinforcing non-REM-to-REM sleep transitions making them quicker and less likely to fail. PMID:26388832

  11. Evaluating the Evidence Surrounding Pontine Cholinergic Involvement in REM Sleep Generation.

    PubMed

    Grace, Kevin P; Horner, Richard L

    2015-01-01

    Rapid eye movement (REM) sleep - characterized by vivid dreaming, motor paralysis, and heightened neural activity - is one of the fundamental states of the mammalian central nervous system. Initial theories of REM sleep generation posited that induction of the state required activation of the "pontine REM sleep generator" by cholinergic inputs. Here, we review and evaluate the evidence surrounding cholinergic involvement in REM sleep generation. We submit that: (i) the capacity of pontine cholinergic neurotransmission to generate REM sleep has been firmly established by gain-of-function experiments, (ii) the function of endogenous cholinergic input to REM sleep generating sites cannot be determined by gain-of-function experiments; rather, loss-of-function studies are required, (iii) loss-of-function studies show that endogenous cholinergic input to the PTF is not required for REM sleep generation, and (iv) cholinergic input to the pontine REM sleep generating sites serve an accessory role in REM sleep generation: reinforcing non-REM-to-REM sleep transitions making them quicker and less likely to fail.

  12. Turbine meters for liquid measurement

    SciTech Connect

    Yon, M.C.

    1984-04-01

    Turbine meters presently used for liquid measurement are presented here. Through the evolution of technology, the turbine meter has maintained its reliability and ruggedness while attaining a high degree of accuracy. The paper attempts to explain the basic principles involved with the utilization of turbine meters, as well as the application of the meter by the aerospace industry, petroleum industry, and petrochemical industry. The use of turbine meters for custody transfer of refined products and pipeline systems, tankers and barge loading or unloading of crude oil has brought the turbine meter to worldwide recognition as a primary register for the exchange of energy.

  13. Flow metering valve

    DOEpatents

    Blaedel, Kenneth L.

    1985-01-01

    An apparatus for metering fluids at high pressures of about 20,000 to 60,000 psi is disclosed. The apparatus includes first and second plates which are positioned adjacent each other to form a valve chamber. The plates are made of materials which have substantially equal elastic properties. One plate has a planar surface area, and the other a recessed surface area defined by periphery and central lips. When the two plates are positioned in adjacent contacting relationship, a valve chamber is formed between the planar surface area and the recessed surface area. Fluid is introduced into the chamber and exits therefrom when a deformation occurs at positions where they no longer form a valve seat. This permits the metering of fluids at high pressures and at slow variable rates. Fluid then exits from the chamber until an applied external force becomes large enough to bring the valve seats back into contact.

  14. Flow metering valve

    DOEpatents

    Blaedel, K.L.

    1983-11-03

    An apparatus for metering fluids at high pressures of about 20,000 to 60,000 psi is disclosed. The apparatus includes first and second plates which are positioned adjacent each other to form a valve chamber. The plates are made of materials which have substantially equal elastic properties. One plate has a planar surface area, and the other a recessed surface area defined by periphery and central lips. When the two plates are positioned in adjacent contacting relationship, a valve chamber is formed between the planar surface area and the recessed surface area. Fluid is introduced into the chamber and exits therefrom when a deformation occurs at positions where they no longer form a valve seat. This permits the metering of fluids at high pressures and at slow variable rates. Fluid then exits from the chamber until an applied external force becomes large enough to bring the valve seats back into contact.

  15. Period meter for reactors

    DOEpatents

    Rusch, Gordon K.

    1976-01-06

    An improved log N amplifier type nuclear reactor period meter with reduced probability for noise-induced scrams is provided. With the reactor at low power levels a sampling circuit is provided to determine the reactor period by measuring the finite change in the amplitude of the log N amplifier output signal for a predetermined time period, while at high power levels, differentiation of the log N amplifier output signal provides an additional measure of the reactor period.

  16. REM sleep diversity following the pedunculopontine tegmental nucleus lesion in rat.

    PubMed

    Petrovic, Jelena; Lazic, Katarina; Kalauzi, Aleksandar; Saponjic, Jasna

    2014-09-01

    The aim of this study was to demonstrate that two REM clusters, which emerge following bilateral pedunculopontine tegmental nucleus (PPT) lesions in rats, are two functionally distinct REM states. We performed the experiments in Wistar rats, chronically instrumented for sleep recording. Bilateral PPT lesions were produced by the microinfusion of 100 nl of 0.1M ibotenic acid (IBO). Following a recovery period of 2 weeks, we recorded their sleep for 6h. Bilateral PPT lesions were identified by NADPH - diaphorase histochemistry. We applied Fourier analysis to the signals acquired throughout the 6h recordings, and each 10s epoch was differentiated as a Wake, NREM or REM state. We analyzed the topography of the sleep/wake states architecture and their transition structure, their all state-related EEG microstructures, and the sensorimotor (SMCx) and motor (MCx) cortex REM related cortico-muscular coherences (CMCs). Bilateral PPT lesion in rats increased the likelihood of the emergence of two distinct REM sleep states, specifically expressed within the MCx: REM1 and REM2. Bilateral PPT lesion did not change the sleep/wake states architecture of the SMCx, but pathologically increased the duration of REM1 within the MCx, alongside increasing Wake/REM1/Wake and NREM/REM2/NREM transitions within both cortices. In addition, the augmented total REM SMCx EEG beta amplitude and REM1 MCx EEG theta amplitude was the underlying EEG microstructure pathology. PPT lesion induced REM1 and REM2 are differential states with regard to total EMG power, topographically distinct EEG microstructures, and locomotor drives to nuchal musculature.

  17. Relabeling exchange method (REM) for learning in neural networks

    NASA Astrophysics Data System (ADS)

    Wu, Wen; Mammone, Richard J.

    1994-02-01

    The supervised training of neural networks require the use of output labels which are usually arbitrarily assigned. In this paper it is shown that there is a significant difference in the rms error of learning when `optimal' label assignment schemes are used. We have investigated two efficient random search algorithms to solve the relabeling problem: the simulated annealing and the genetic algorithm. However, we found them to be computationally expensive. Therefore we shall introduce a new heuristic algorithm called the Relabeling Exchange Method (REM) which is computationally more attractive and produces optimal performance. REM has been used to organize the optimal structure for multi-layered perceptrons and neural tree networks. The method is a general one and can be implemented as a modification to standard training algorithms. The motivation of the new relabeling strategy is based on the present interpretation of dyslexia as an encoding problem.

  18. Spartan Release Engagement Mechanism (REM) stress and fracture analysis

    NASA Technical Reports Server (NTRS)

    Marlowe, D. S.; West, E. J.

    1984-01-01

    The revised stress and fracture analysis of the Spartan REM hardware for current load conditions and mass properties is presented. The stress analysis was performed using a NASTRAN math model of the Spartan REM adapter, base, and payload. Appendix A contains the material properties, loads, and stress analysis of the hardware. The computer output and model description are in Appendix B. Factors of safety used in the stress analysis were 1.4 on tested items and 2.0 on all other items. Fracture analysis of the items considered fracture critical was accomplished using the MSFC Crack Growth Analysis code. Loads and stresses were obtaind from the stress analysis. The fracture analysis notes are located in Appendix A and the computer output in Appendix B. All items analyzed met design and fracture criteria.

  19. Why does serotonergic activity drastically decrease during REM sleep?

    PubMed

    Sato, Kohji

    2013-10-01

    Here, I postulate two hypotheses that can explain the missing link between sleep and the serotonergic system in terms of spine homeostasis and memory consolidation. As dendritic spines contain many kinds of serotonin receptors, and the activation of serotonin receptors generally increases the number of spines in the cortex and hippocampus, I postulate that serotonin neurons are down-regulated during sleep to decrease spine number, which consequently maintains the total spine number at a constant level. Furthermore, since synaptic consolidation during REM sleep needs long-term potentiation (LTP), and serotonin is reported to inhibit LTP in the cortex, I postulate that serotonergic activity must drastically decrease during REM sleep to induce LTP and do memory consolidation. Until now, why serotonergic neurons show these dramatic changes in the sleep-wake cycle remains unexplained; however, making these hypotheses, I can confer physiological meanings on these dramatic changes of serotonergic neurons in terms of spine homeostasis and memory consolidation.

  20. REM sleep abnormalities in severe athetoid cerebral palsy.

    PubMed

    Hayashi, M; Inoue, Y; Iwakawa, Y; Sasaki, H

    1990-01-01

    Various abnormalities of sleep have been reported in extrapyramidal diseases in adults. We have investigated the disturbances of REM sleep (SREM) in severe athetoid cerebral palsy (ACP) originating perinatally. Ten ACP patients, 5 males and 5 females ranging from 15 to 30 years old, were studied by means of all-night polygraphic examination. Three cases showed a marked decrease in rapid eye movements in SREM. Moreover, the tone of submental muscle in SREM was also disturbed in three. Regarding body movements during sleep, gross movements and twitch movements of the submental muscle were analyzed. In most of the patients, an abnormal distribution of body movements according to sleep stages was observed, the rate being significantly reduced in SREM. REMs, atonia and body movements are considered to be related to the brainstem function in animals. The results of the present study suggest that perinatal extrapyramidal diseases could also coincide with brainstem dysfunctions.

  1. On the 90th Birthday of Rem Viktorovich Khokhlov

    NASA Astrophysics Data System (ADS)

    Makarov, V. A.

    2016-08-01

    July 15th 2016 marked the 90th birthday of Rem Viktorovich Khokhlov, a prominent Russian physicist, talented organiser of national and world science and higher education, rector of Lomonosov Moscow State University, vice-president of the USSR Academy of Sciences, founder and head of the Department of Wave Processes. He tragically died on 8 August 1977 trying to conquer the highest peak of the Pamir Mountains.

  2. Schema-conformant memories are preferentially consolidated during REM sleep.

    PubMed

    Durrant, Simon J; Cairney, Scott A; McDermott, Cathal; Lewis, Penelope A

    2015-07-01

    Memory consolidation is most commonly described by the standard model, which proposes an initial binding role for the hippocampus which diminishes over time as intracortical connections are strengthened. Recent evidence suggests that slow wave sleep (SWS) plays an essential role in this process. Existing animal and human studies have suggested that memories which fit tightly into an existing knowledge framework or schema might use an alternative consolidation route in which the medial prefrontal cortex takes on the binding role. In this study we sought to investigate the role of sleep in this process using a novel melodic memory task. Participants were asked to remember 32 melodies, half of which conformed to a tonal schema present in all enculturated listeners, and half of which did not fit with this schema. After a 24-h consolidation interval, participants were asked to remember a further 32 melodies, before being given a recognition test in which melodies from both sessions were presented alongside some previously unheard foils. Participants remembered schema-conformant melodies better than non-conformant ones. This was much more strongly the case for consolidated melodies, suggesting that consolidation over a 24-h period preferentially consolidated schema-conformant items. Overnight sleep was monitored between the sessions, and the extent of the consolidation benefit for schema-conformant items was associated with both the amount of REM sleep obtained and EEG theta power in frontal and central regions during REM sleep. Overall our data suggest that REM sleep plays a crucial role in the rapid consolidation of schema-conformant items. This finding is consistent with previous results from animal studies and the SLIMM model of Van Kesteren, Ruiter, Fernández, and Henson (2012), and suggest that REM sleep, rather than SWS, may be involved in an alternative pathway of consolidation for schema-conformant memories. PMID:25754499

  3. Schema-conformant memories are preferentially consolidated during REM sleep.

    PubMed

    Durrant, Simon J; Cairney, Scott A; McDermott, Cathal; Lewis, Penelope A

    2015-07-01

    Memory consolidation is most commonly described by the standard model, which proposes an initial binding role for the hippocampus which diminishes over time as intracortical connections are strengthened. Recent evidence suggests that slow wave sleep (SWS) plays an essential role in this process. Existing animal and human studies have suggested that memories which fit tightly into an existing knowledge framework or schema might use an alternative consolidation route in which the medial prefrontal cortex takes on the binding role. In this study we sought to investigate the role of sleep in this process using a novel melodic memory task. Participants were asked to remember 32 melodies, half of which conformed to a tonal schema present in all enculturated listeners, and half of which did not fit with this schema. After a 24-h consolidation interval, participants were asked to remember a further 32 melodies, before being given a recognition test in which melodies from both sessions were presented alongside some previously unheard foils. Participants remembered schema-conformant melodies better than non-conformant ones. This was much more strongly the case for consolidated melodies, suggesting that consolidation over a 24-h period preferentially consolidated schema-conformant items. Overnight sleep was monitored between the sessions, and the extent of the consolidation benefit for schema-conformant items was associated with both the amount of REM sleep obtained and EEG theta power in frontal and central regions during REM sleep. Overall our data suggest that REM sleep plays a crucial role in the rapid consolidation of schema-conformant items. This finding is consistent with previous results from animal studies and the SLIMM model of Van Kesteren, Ruiter, Fernández, and Henson (2012), and suggest that REM sleep, rather than SWS, may be involved in an alternative pathway of consolidation for schema-conformant memories.

  4. REM sleep modulation by perifornical orexinergic inputs to the pedunculo-pontine tegmental neurons in rats.

    PubMed

    Khanday, M A; Mallick, B N

    2015-11-12

    Rapid eye movement sleep (REMS) is regulated by the interaction of the REM-ON and REM-OFF neurons located in the pedunculo-pontine-tegmentum (PPT) and the locus coeruleus (LC), respectively. Many other brain areas, particularly those controlling non-REMS (NREMS) and waking, modulate REMS by modulating these REMS-related neurons. Perifornical (PeF) orexin (Ox)-ergic neurons are reported to increase waking and reduce NREMS as well as REMS; dysfunction of the PeF neurons are related to REMS loss-associated disorders. Hence, we were interested in understanding the neural mechanism of PeF-induced REMS modulation. As a first step we have recently reported that PeF Ox-ergic neurons modulate REMS by influencing the LC neurons (site for REM-OFF neurons). Thereafter, in this in vivo study we have explored the role of PeF inputs on the PPT neurons (site for REM-ON neurons) for the regulation of REMS. Chronic male rats were surgically prepared with implanted bilateral cannulae in PeF and PPT and electrodes for recording sleep-waking patterns. After post-surgical recovery sleep-waking-REMS were recorded when bilateral PeF neurons were stimulated by glutamate and simultaneously bilateral PPT neurons were infused with either saline or orexin receptor1 (OX1R) antagonist. It was observed that PeF stimulation increased waking and decreased NREMS as well as REMS, which were prevented by OX1R antagonist into the PPT. We conclude that the PeF stimulation-induced reduction in REMS was likely to be due to inhibition of REM-ON neurons in the PPT. As waking and NREMS are inversely related, subject to confirmation, the reduction in NREMS could be due to increased waking or vice versa. Based on our findings from this and earlier studies we have proposed a model showing connections between PeF- and PPT-neurons for REMS regulation.

  5. Acoustic velocity meter systems

    USGS Publications Warehouse

    Laenen, Antonius

    1985-01-01

    Acoustic velocity meter (AVM) systems operate on the principles that the point-to-point upstream traveltime of an acoustic pulse is longer than the downstream traveltime and that this difference in traveltime can be accurately measured by electronic devices. An AVM system is capable of recording water velocity (and discharge) under a wide range of conditions, but some constraints apply: 1. Accuracy is reduced and performance is degraded if the acoustic path is not a continuous straight line. The path can be bent by reflection if it is too close to a stream boundary or by refraction if it passes through density gradients resulting from variations in either water temperature or salinity. For paths of less than 100 m, a temperature gradient of 0.1' per meter causes signal bending less than 0.6 meter at midchannel, and satisfactory velocity results can be obtained. Reflection from stream boundaries can cause signal cancellation if boundaries are too close to signal path. 2. Signal strength is attenuated by particles or bubbles that absorb, spread, or scatter sound. The concentration of particles or bubbles that can be tolerated is a function of the path length and frequency of the acoustic signal. 3. Changes in streamline orientation can affect system accuracy if the variability is random. 4. Errors relating to signal resolution are much larger for a single threshold detection scheme than for multiple threshold schemes. This report provides methods for computing the effect of various conditions on the accuracy of a record obtained from an AVM. The equipment must be adapted to the site. Field reconnaissance and preinstallation analysis to detect possible problems are critical for proper installation and operation of an AVM system.

  6. Cognitive flexibility across the sleep-wake cycle: REM-sleep enhancement of anagram problem solving.

    PubMed

    Walker, Matthew P; Liston, Conor; Hobson, J Allan; Stickgold, Robert

    2002-11-01

    Flexible or 'fluid' cognitive processes are regarded as fundamental to problem solving and creative ability, requiring a specific neurophysiological milieu. REM-sleep dreaming is associated with creative processes and abstract reasoning with increased strength of weak associations in cognitive networks. REM sleep is also mediated by a distinctive neurophysiological profile, different to that of wake and NREM sleep. This study compared the performance of 16 subjects on a test of cognitive flexibility using anagram word puzzles following REM and NREM awakenings across the night, and waking performances during the day. REM awakenings provided a significant 32% advantage in the number of anagrams solved compared with NREM awakenings and was equal to that of wake time trials. Correlations of individual performance profiles suggest that REM sleep may offer a different mode of problem solving compared with wake and NREM. When early and late REM and NREM awakening data were separated, a dissociation was evident, with NREM task performance becoming more REM-like later in the night, while REM performance remained constant. These data suggest that the neurophysiology of REM sleep represents a brain state more amenable to flexible cognitive processing than NREM and different from that in wake, and may offer insights into the neurocognitive properties of REM-sleep dreaming.

  7. Identification of the transmitter and receptor mechanisms responsible for REM sleep paralysis.

    PubMed

    Brooks, Patricia L; Peever, John H

    2012-07-18

    During REM sleep the CNS is intensely active, but the skeletal motor system is paradoxically forced into a state of muscle paralysis. The mechanisms that trigger REM sleep paralysis are a matter of intense debate. Two competing theories argue that it is caused by either active inhibition or reduced excitation of somatic motoneuron activity. Here, we identify the transmitter and receptor mechanisms that function to silence skeletal muscles during REM sleep. We used behavioral, electrophysiological, receptor pharmacology and neuroanatomical approaches to determine how trigeminal motoneurons and masseter muscles are switched off during REM sleep in rats. We show that a powerful GABA and glycine drive triggers REM paralysis by switching off motoneuron activity. This drive inhibits motoneurons by targeting both metabotropic GABA(B) and ionotropic GABA(A)/glycine receptors. REM paralysis is only reversed when motoneurons are cut off from GABA(B), GABA(A) and glycine receptor-mediated inhibition. Neither metabotropic nor ionotropic receptor mechanisms alone are sufficient for generating REM paralysis. These results demonstrate that multiple receptor mechanisms trigger REM sleep paralysis. Breakdown in normal REM inhibition may underlie common sleep motor pathologies such as REM sleep behavior disorder.

  8. Identification of the transmitter and receptor mechanisms responsible for REM sleep paralysis.

    PubMed

    Brooks, Patricia L; Peever, John H

    2012-07-18

    During REM sleep the CNS is intensely active, but the skeletal motor system is paradoxically forced into a state of muscle paralysis. The mechanisms that trigger REM sleep paralysis are a matter of intense debate. Two competing theories argue that it is caused by either active inhibition or reduced excitation of somatic motoneuron activity. Here, we identify the transmitter and receptor mechanisms that function to silence skeletal muscles during REM sleep. We used behavioral, electrophysiological, receptor pharmacology and neuroanatomical approaches to determine how trigeminal motoneurons and masseter muscles are switched off during REM sleep in rats. We show that a powerful GABA and glycine drive triggers REM paralysis by switching off motoneuron activity. This drive inhibits motoneurons by targeting both metabotropic GABA(B) and ionotropic GABA(A)/glycine receptors. REM paralysis is only reversed when motoneurons are cut off from GABA(B), GABA(A) and glycine receptor-mediated inhibition. Neither metabotropic nor ionotropic receptor mechanisms alone are sufficient for generating REM paralysis. These results demonstrate that multiple receptor mechanisms trigger REM sleep paralysis. Breakdown in normal REM inhibition may underlie common sleep motor pathologies such as REM sleep behavior disorder. PMID:22815493

  9. Post-learning REM sleep deprivation impairs long-term memory: reversal by acute nicotine treatment.

    PubMed

    Aleisa, A M; Alzoubi, K H; Alkadhi, K A

    2011-07-15

    Rapid eye movement sleep deprivation (REM-SD) is associated with spatial learning and memory impairment. During REM-SD, an increase in nicotine consumption among habitual smokers and initiation of tobacco use by non-smokers have been reported. We have shown recently that nicotine treatment prevented learning and memory impairments associated with REM-SD. We now report the interactive effects of post-learning REM-SD and/or nicotine. The animals were first trained on the radial arm water maze (RAWM) task, then they were REM-sleep deprived using the modified multiple platform paradigm for 24h. During REM-SD period, the rats were injected with saline or nicotine (1mg/kg s.c. every 12h: a total of 3 injections). The animals were tested for long-term memory in the RAWM at the end of the REM-SD period. The 24h post-learning REM-SD significantly impaired long-term memory. However, nicotine treatment reversed the post-learning REM-SD-induced impairment of long-term memory. On the other hand, post-learning treatment of normal rats with nicotine for 24h enhanced long-term memory. These results indicate that post-learning acute nicotine treatment prevented the deleterious effect of REM-SD on cognitive abilities.

  10. Direct reading inductance meter

    NASA Technical Reports Server (NTRS)

    Kolby, R. B. (Inventor)

    1977-01-01

    A direct reading inductance meter comprised of a crystal oscillator and an LC tuned oscillator is presented. The oscillators function respectively to generate a reference frequency, f(r), and to generate an initial frequency, f(0), which when mixed produce a difference equal to zero. Upon connecting an inductor of small unknown value in the LC circuit to change its resonant frequency to f(x), a difference frequency (f(r)-f(x)) is produced that is very nearly a linear function of the inductance of the inductor. The difference frequency is measured and displayed on a linear scale in units of inductance.

  11. Portable wastewater flow meter

    DOEpatents

    Hunter, Robert M.

    1999-02-02

    A portable wastewater flow meter particularly adapted for temporary use at a single location in measuring the rate of liquid flow in a circular entrance conduit of a sewer manhole both under free flow and submerged, open channel conditions and under fill pipe, surcharged conditions, comprising an apparatus having a cylindrical external surface and an inner surface that constricts the flow through the apparatus in such a manner that a relationship exists between (1) the difference between the static pressure head of liquid flowing through the entrance of the apparatus and the static pressure head of liquid flowing through the constriction, and (2) the rate of liquid flow through the apparatus.

  12. Portable wastewater flow meter

    DOEpatents

    Hunter, Robert M.

    1990-01-01

    A portable wastewater flow meter particularly adapted for temporary use at a single location in measuring the rate of liquid flow in a circular entrance conduit of a sewer manhole both under free flow and submerged, open channel conditions and under full pipe, surcharged conditions, comprising an apparatus having a cylindrical external surface and an inner surface that constricts the flow through the apparatus in such a manner that a relationship exists between (1) the difference between the static pressure head of liquid flowing through the entrance of the apparatus and the static pressure head of liquid flowing through the constriction, and (2) the rate of liquid flow through the apparatus.

  13. The 'scanning hypothesis' of rapid eye movements during REM sleep: a review of the evidence.

    PubMed

    Arnulf, I

    2011-12-01

    Rapid eye movements (REMs) and visual dreams are salient features of REM sleep. However, it is unclear whether the eyes scan dream images. Several lines of evidence oppose the scanning hypothesis: REMs persist in animals and humans without sight (pontine cats, foetus, neonates, born-blinds), some binocular REMs are not conjugated (no focus point), REMs occur in parallel (not in series) with the stimulation of the visual cortex by ponto-geniculo-occipital spikes, and visual dreams can be obtained in non REM sleep. Studies that retrospectively compared the direction of REMs to dream recall recorded after having awakened the sleeper yielded inconsistent results, with a concordance varying from 9 to 80%. However, this method was subject to methodological flaws, including the bias of retrospection and neck atonia that does not allow the determination of the exact direction of gaze. Using the model of RBD (in which patients are able to enact their dreams due to the absence of muscle atonia) in 56 patients, we directly determined if the eyes moved in the same directions as the head and limbs. When REMs accompanied goal-oriented motor behaviour during RBD (e.g., framing something, greeting with the hand, climbing a ladder), 90% were directed towards the action of the patient (same plane and direction). REMs were however absent in 38% of goal-oriented behaviours. This directional coherence between limbs, head and eye movements during RBD suggests that, when present, REMs imitate the scanning of the dream scene. Because REMs index and complexity were similar in patients with RBD and controls, this concordance can be extended to normal REM sleep. These results are consistent with the model of a brainstem generator activating simultaneously images, sounds, limbs movements and REMs in a coordinated parallel manner, as in a virtual reality.

  14. The 'scanning hypothesis' of rapid eye movements during REM sleep: a review of the evidence.

    PubMed

    Arnulf, I

    2011-12-01

    Rapid eye movements (REMs) and visual dreams are salient features of REM sleep. However, it is unclear whether the eyes scan dream images. Several lines of evidence oppose the scanning hypothesis: REMs persist in animals and humans without sight (pontine cats, foetus, neonates, born-blinds), some binocular REMs are not conjugated (no focus point), REMs occur in parallel (not in series) with the stimulation of the visual cortex by ponto-geniculo-occipital spikes, and visual dreams can be obtained in non REM sleep. Studies that retrospectively compared the direction of REMs to dream recall recorded after having awakened the sleeper yielded inconsistent results, with a concordance varying from 9 to 80%. However, this method was subject to methodological flaws, including the bias of retrospection and neck atonia that does not allow the determination of the exact direction of gaze. Using the model of RBD (in which patients are able to enact their dreams due to the absence of muscle atonia) in 56 patients, we directly determined if the eyes moved in the same directions as the head and limbs. When REMs accompanied goal-oriented motor behaviour during RBD (e.g., framing something, greeting with the hand, climbing a ladder), 90% were directed towards the action of the patient (same plane and direction). REMs were however absent in 38% of goal-oriented behaviours. This directional coherence between limbs, head and eye movements during RBD suggests that, when present, REMs imitate the scanning of the dream scene. Because REMs index and complexity were similar in patients with RBD and controls, this concordance can be extended to normal REM sleep. These results are consistent with the model of a brainstem generator activating simultaneously images, sounds, limbs movements and REMs in a coordinated parallel manner, as in a virtual reality. PMID:22205589

  15. Turbine meters for liquid measurement

    SciTech Connect

    Wass, D.J.; Allen, C.R.

    1995-12-01

    Liquid turbine meters operate in response to fundamental engineering principles, Operation with a single moving part produces excellent longevity and reliability. Liquid turbine meters display wide rangeability, high accuracy, excellent repeatability, low pressure drop and moderate cost. Liquid turbine meters may be applied to many different fluids with different physical properties and corrosive tendencies. The marriage of liquid turbine meters to electronic instruments allows instantaneous flow calculations and produces the flexibility to display data, store data, transmit data in the most convenient form. Liquid turbine meters should be the first flow measurement instrument considered for liquid measurement applications.

  16. Neutron multiplicity ,easurements With 3He alternative: Straw neutron detectors

    DOE PAGESBeta

    Mukhopadhyay, Sanjoy; Wolff, Ronald S.; Meade, John A.; Detweiler, Ryan; Maurer, Richard J.; Mitchell, Stephen E.; Guss, Paul P.; Lacy, Jeffrey L.; Sun, Liang; Athanasiades, Athanasios

    2015-01-27

    Counting neutrons emitted by special nuclear material (SNM) and differentiating them from the background neutrons of various origins is the most effective passive means of detecting SNM. Unfortunately, neutron detection, counting, and partitioning in a maritime environment are complex due to the presence of high-multiplicity spallation neutrons (commonly known as “ship effect”) and to the complicated nature of the neutron scattering in that environment. In this study, a prototype neutron detector was built using 10B as the converter in a special form factor called “straws” that would address the above problems by looking into the details of multiplicity distributions ofmore » neutrons originating from a fissioning source. This paper describes the straw neutron multiplicity counter (NMC) and assesses the performance with those of a commercially available fission meter. The prototype straw neutron detector provides a large-area, efficient, lightweight, more granular (than fission meter) neutron-responsive detection surface (to facilitate imaging) to enhance the ease of application of fission meters. Presented here are the results of preliminary investigations, modeling, and engineering considerations leading to the construction of this prototype. This design is capable of multiplicity and Feynman variance measurements. This prototype may lead to a near-term solution to the crisis that has arisen from the global scarcity of 3He by offering a viable alternative to fission meters. This paper describes the work performed during a 2-year site-directed research and development (SDRD) project that incorporated straw detectors for neutron multiplicity counting. The NMC is a two-panel detector system. We used 10B (in the form of enriched boron carbide: 10B4C) for neutron detection instead of 3He. In the first year, the project worked with a panel of straw neutron detectors, investigated its characteristics, and developed a data acquisition (DAQ) system to collect

  17. Plant chlorophyll content meter

    NASA Technical Reports Server (NTRS)

    Spiering, Bruce A. (Inventor); Carter, Gregory A. (Inventor)

    2000-01-01

    A plant chlorophyll content meter is described which collects light reflected from a target plant and separates the collected light into two different wavelength bands. These wavelength bands, or channels, are described as having center wavelengths of 700 nm and 840 nm. The light collected in these two channels are processed using photo detectors and amplifiers. An analog to digital converter is described which provides a digital representation of the level of light collected by the lens and falling within the two channels. A controller provided in the meter device compares the level of light reflected from a target plant with a level of light detected from a light source, such as light reflected by a target having 100% reflectance, or transmitted through a diffusion receptor. The percent of reflection in the two separate wavelength bands from a target plant are compared to provide a ratio which indicates a relative level of plant physiological stress. A method of compensating for electronic drift is described where a sample is taken when a collection lens is covered to prevent light from entering the device. This compensation method allows for a more accurate reading by reducing error contributions due to electronic drift from environmental conditions at the location where a hand-held unit is used.

  18. Advanced metering techniques

    SciTech Connect

    Szydlowski, R.F.

    1993-01-01

    The goal of the US Department of Energy Federal Energy Management Program (FEMP) is to facilitate energy-efficiency improvements at federal facilities. This is accomplished by a balanced program of technology development, facility assessment, and use of cost-sharing procurement mechanisms. Technology development focuses upon the tools and procedures used to identify and evaluate efficiency improvements. For facility assessment, FEMP provides metering equipment and trained analysts to federal agencies exhibiting a commitment to improve energy-use efficiency. To assist in implementing energy-efficiency measures, FEMP helps federal agencies with identifying efficiency opportunities and in implementing energy-efficiency and demand-side management programs at federal sites. As the lead laboratory for FEMP, Pacific Northwest Laboratory (PNL) provides technical assistance to federal agencies to better understand and characterize energy systems. The US Army Forces Command (FORSCOM) has tasked PNL to provide technical assistance to characterize and modernize energy systems at FORSCOM installations. As part of that technical assistance, PNL performed an in-depth examination of automatic meter-reading system technologies currently available. The operating characteristics and relative merits of all the major systems were reviewed in the context of applicability to federal installations. That review is documented in this report.

  19. 10 meter airborne observatory

    NASA Astrophysics Data System (ADS)

    Ditto, Thomas D.; Ritter, Joseph M.

    2008-07-01

    Inside an aircraft fuselage there is little room for the mass of all the instrumentation of a ground-based observatory much less a primary objective aperture at the scale of 10 meters. We have proposed a solution that uses a primary objective grating (POG) which matches the considerable length of the aircraft, approximately 10 meters, and conforms to aircraft aerodynamics. Light collected by the POG is diffracted at an angle of grazing exodus inside the aircraft where it is disambiguated by an optical train that fits within to the interior tunnel. Inside the aircraft, light is focused by a parabolic mirror onto a spectrograph slit. The design has a special benefit in that all objects in the field-of-view of the free spectral range of the POG can have their spectra taken as the aircraft changes orientation. We suggest flight planes that will improve integration times, angular resolution and spectral resolution to acquire targets of high stellar magnitudes or alternatively increase the number of sources acquired per flight at the cost of sensitivity.

  20. Increases in cAMP, MAPK Activity and CREB Phosphorylation during REM Sleep: Implications for REM Sleep and Memory Consolidation

    PubMed Central

    Luo, Jie; Phan, Trongha X.; Yang, Yimei; Garelick, Michael G.; Storm, Daniel R.

    2013-01-01

    The cyclic adenosine monophosphate (cAMP), mitogen-activated protein kinase (MAPK) and cAMP response element-binding protein (CREB) transcriptional pathway is required for consolidation of hippocampus-dependent memory. In mice, this pathway undergoes a circadian oscillation required for memory persistence that reaches a peak during the daytime. Since mice exhibit polyphasic sleep patterns during the day, this suggested the interesting possibility that cAMP, MAPK activity and CREB phosphorylation may be elevated during sleep. Here, we report that cAMP, phospho-p44/42 MAPK and phospho-CREB are higher in rapid eye movement (REM) sleep compared to awake mice but are not elevated in non-rapid eye movement (NREM) sleep. This peak of activity during REM sleep does not occur in mice lacking calmodulin-stimulated adenylyl cyclases, a mouse strain that learns but cannot consolidate hippocampus-dependent memory. We conclude that a preferential increase in cAMP, MAPK activity and CREB phosphorylation during REM sleep may contribute to hippocampus-dependent memory consolidation. PMID:23575844

  1. REM Sleep Behavior Disorder and REM Sleep Without Atonia as an Early Manifestation of Degenerative Neurological Disease

    PubMed Central

    McCarter, Stuart J.; St Louis, Erik K.

    2013-01-01

    Rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia characterized by repeated episodes of dream enactment behavior and REM sleep without atonia (RSWA) during polysomnography recording. RSWA is characterized by increased phasic or tonic muscle activity seen on polysomnographic electromyogram channels. RSWA is a requisite diagnostic feature of RBD, but may also be seen in patients without clinical symptoms or signs of dream enactment as an incidental finding in neurologically normal individuals, especially in patients receiving antidepressant therapy. RBD may be idiopathic or symptomatic. Patients with idiopathic RBD often later develop other neurological features including parkinsonism, orthostatic hypotension, anosmia, or cognitive impairment. RSWA without clinical symptoms as well as clinically overt RBD also often occurs concomitantly with the α-synucleinopathy family of neurodegenerative disorders, which includes idiopathic Parkinson disease, Lewy body dementia, and multiple system atrophy. This review article considers the epidemiology of RBD, clinical and polysomnographic diagnostic standards for both RBD and RSWA, previously reported associations of RSWA and RBD with neurodegenerative disorders and other potential causes, the pathophysiology of which brain structures and networks mediate dysregulation of REM sleep muscle atonia, and considerations for the effective and safe management of RBD. PMID:22328094

  2. Semi-Empirical Study of the Indirect Exchange Interaction in the Rem - Al System

    NASA Astrophysics Data System (ADS)

    Shakarov, Kh. O.

    2016-05-01

    The Ruderman-Kittel-Kasuya-Yosida exchange interaction (RKKY) is semi-empirically studied for the first time in compounds of binary REM - Al systems (REM - rare-earth metals: Gd, Dy, Ho, Er) using experimental values of paramagnetic Curie point (θp) of these compounds. Prediction of the RKKY theory was confirmed, i.e. there is a direct proportional dependence of θp value on de Gennes factor for equiatomic compounds of heavy REM with aluminum, just as in the case of pure REM. Values of the indirect exchange interaction parameter were semi-empirically estimated for the studied compounds. In general, it was established that RKKY-type exchange interaction is typical for REM compounds with aluminum, just as for pure REM.

  3. Impaired extinction of fear conditioning after REM deprivation is magnified by rearing in an enriched environment.

    PubMed

    Hunter, Amy Silvestri

    2015-07-01

    Evidence from both human and animal studies indicates that rapid eye movement sleep (REM) is essential for the acquisition and retention of information, particularly of an emotional nature. Learning and memory can also be impacted by manipulation of housing condition such as exposure to an enriched environment (EE). This study investigated the effects of REM deprivation and EE, both separately and combined, on the extinction of conditioned fear in rats. Consistent with prior studies, conditioning was enhanced in EE-reared rats and extinction was impaired in REM deprived rats. In addition, rats exposed to both REM deprivation and EE showed the greatest impairment in extinction, with effects persisting through the first two days of extinction training. This study is the first to explore the combination of REM deprivation and EE and suggests that manipulations that alter sleep, particularly REM, can have persisting deleterious effects on emotional memory processing.

  4. Cold Exposure and Sleep in the Rat: REM Sleep Homeostasis and Body Size

    PubMed Central

    Amici, Roberto; Cerri, Matteo; Ocampo-Garcés, Adrian; Baracchi, Francesca; Dentico, Daniela; Jones, Christine Ann; Luppi, Marco; Perez, Emanuele; Parmeggiani, Pier Luigi; Zamboni, Giovanni

    2008-01-01

    Study Objectives: Exposure to low ambient temperature (Ta) depresses REM sleep (REMS) occurrence. In this study, both short and long-term homeostatic aspects of REMS regulation were analyzed during cold exposure and during subsequent recovery at Ta 24°C. Design: EEG activity, hypothalamic temperature, and motor activity were studied during a 24-h exposure to Tas ranging from 10°C to −10°C and for 4 days during recovery. Setting: Laboratory of Physiological Regulation during the Wake-Sleep Cycle, Department of Human and General Physiology, Alma Mater Studiorum-University of Bologna. Subjects: 24 male albino rats. Interventions: Animals were implanted with electrodes for EEG recording and a thermistor to measure hypothalamic temperature. Measurements and Results: REMS occurrence decreased proportionally with cold exposure, but a fast compensatory REMS rebound occurred during the first day of recovery when the previous loss went beyond a “fast rebound” threshold corresponding to 22% of the daily REMS need. A slow REMS rebound apparently allowed the animals to fully restore the previous REMS loss during the following 3 days of recovery. Conclusion: Comparing the present data on rats with data from earlier studies on cats and humans, it appears that small mammals have less tolerance for REMS loss than large ones. In small mammals, this low tolerance may be responsible on a short-term basis for the shorter wake-sleep cycle, and on long-term basis, for the higher percentage of REMS that is quickly recovered following REMS deprivation. Citation: Amici R; Cerri M; Ocampo-Garcés A; Baracchi F; Dentico D; Jones CA; Luppi M; Perez E; Parmeggiani PL; Zamboni G. Cold exposure and sleep in the rat: REM sleep homeostasis and body size. SLEEP 2008;31(5):708–715. PMID:18517040

  5. GAS METERING PUMP

    DOEpatents

    George, C.M.

    1957-12-31

    A liquid piston gas pump is described, capable of pumping minute amounts of gas in accurately measurable quantities. The pump consists of a flanged cylindrical regulating chamber and a mercury filled bellows. Sealed to the ABSTRACTS regulating chamber is a value and having a gas inlet and outlet, the inlet being connected by a helical channel to the bellows. A gravity check valve is in the gas outlet, so the gas passes through the inlet and the helical channel to the bellows where the pumping action as well as the metering is accomplished by the actuation of the mercury filled bellows. The gas then flows through the check valve and outlet to any associated apparatus.

  6. Microwave fluid flow meter

    DOEpatents

    Billeter, Thomas R.; Philipp, Lee D.; Schemmel, Richard R.

    1976-01-01

    A microwave fluid flow meter is described utilizing two spaced microwave sensors positioned along a fluid flow path. Each sensor includes a microwave cavity having a frequency of resonance dependent upon the static pressure of the fluid at the sensor locations. The resonant response of each cavity with respect to a variation in pressure of the monitored fluid is represented by a corresponding electrical output which can be calibrated into a direct pressure reading. The pressure drop between sensor locations is then correlated as a measure of fluid velocity. In the preferred embodiment the individual sensor cavities are strategically positioned outside the path of fluid flow and are designed to resonate in two distinct frequency modes yielding a measure of temperature as well as pressure. The temperature response can then be used in correcting for pressure responses of the microwave cavity encountered due to temperature fluctuations.

  7. How to use your peak flow meter

    MedlinePlus

    Peak flow meter - how to use; Asthma - peak flow meter; Reactive airway disease - peak flow meter; Bronchial asthma - peak flow meter ... your airways are narrowed and blocked due to asthma, your peak flow values drop. You can check ...

  8. Phasic Motor Activity of Respiratory and Non-Respiratory Muscles in REM Sleep

    PubMed Central

    Fraigne, Jimmy J.; Orem, John M.

    2011-01-01

    Objectives: In this study, we quantified the profiles of phasic activity in respiratory muscles (diaphragm, genioglossus and external intercostal) and non-respiratory muscles (neck and extensor digitorum) across REM sleep. We hypothesized that if there is a unique pontine structure that controls all REM sleep phasic events, the profiles of the phasic twitches of different muscle groups should be identical. Furthermore, we described how respiratory parameters (e.g., frequency, amplitude, and effort) vary across REM sleep to determine if phasic processes affect breathing. Methods: Electrodes were implanted in Wistar rats to record brain activity and muscle activity of neck, extensor digitorum, diaphragm, external intercostal, and genioglossal muscles. Ten rats were studied to obtain 313 REM periods over 73 recording days. Data were analyzed offline and REM sleep activity profiles were built for each muscle. In 6 animals, respiratory frequency, effort, amplitude, and inspiratory peak were also analyzed during 192 REM sleep periods. Results: Respiratory muscle phasic activity increased in the second part of the REM period. For example, genioglossal activity increased in the second part of the REM period by 63.8% compared to the average level during NREM sleep. This profile was consistent between animals and REM periods (η2 = 0.58). This increased activity seen in respiratory muscles appeared as irregular bursts and trains of activity that could affect rythmo-genesis. Indeed, the increased integrated activity seen in the second part of the REM period in the diaphragm was associated with an increase in the number (28.3%) and amplitude (30%) of breaths. Non-respiratory muscle phasic activity in REM sleep did not have a profile like the phasic activity of respiratory muscles. Time in REM sleep did not have an effect on nuchal activity (P = 0.59). Conclusion: We conclude that the concept of a common pontine center controlling all REM phasic events is not supported by our

  9. Effects of selective REM sleep deprivation on prefrontal gamma activity and executive functions.

    PubMed

    Corsi-Cabrera, M; Rosales-Lagarde, A; del Río-Portilla, Y; Sifuentes-Ortega, R; Alcántara-Quintero, B

    2015-05-01

    Given that the dorsolateral prefrontal cortex is involved in executive functions and is deactivated and decoupled from posterior associative regions during REM sleep, that Gamma temporal coupling involved in information processing is enhanced during REM sleep, and that adult humans spend about 90 min of every 24h in REM sleep, it might be expected that REM sleep deprivation would modify Gamma temporal coupling and have a deteriorating effect on executive functions. We analyzed EEG Gamma activity and temporal coupling during implementation of a rule-guided task before and after REM sleep deprivation and its effect on verbal fluency, flexible thinking and selective attention. After two nights in the laboratory for adaptation, on the third night subjects (n=18) were randomly assigned to either selective REM sleep deprivation effectuated by awakening them at each REM sleep onset or, the same number of NREM sleep awakenings as a control for unspecific effects of sleep interruptions. Implementation of abstract rules to guide behavior required greater activation and synchronization of Gamma activity in the frontopolar regions after REM sleep reduction from 20.6% at baseline to just 3.93% of total sleep time. However, contrary to our hypothesis, both groups showed an overall improvement in executive task performance and no effect on their capacity to sustain selective attention. These results suggest that after one night of selective REM sleep deprivation executive functions can be compensated by increasing frontal activation and they still require the participation of supervisory control by frontopolar regions.

  10. Fundamental principles of diaphragm meters

    SciTech Connect

    Thomson, J.

    1995-12-01

    A diaphragm meter is a positive displacement instrument which is used to measure the volume of gas that passes through it. This is accomplished through the known volume that is displaced for each stroke of the diaphragm. The diaphragm also provides the seal between the measuring chambers of the device. As such the diaphragm meter has proven to be an accurate and reliable means of measurement of gas for many years. This is especially true at low flow rates because of its positive displacement characteristics. This paper includes a brief history of diaphragm meters, an explanation of the operation of the diaphragm meter, a basic review of the function and design of the positive displacement meter, discusses meter ratings and capacity, and introduces temperature compensation.

  11. 77 FR 40586 - Draft NIST Interagency Report (NISTIR) 7823, Advanced Metering Infrastructure Smart Meter...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-10

    ... 7823 includes numerous stakeholders in the Smart Grid space, particularly customers, Smart Meter... Metering Infrastructure Smart Meter Upgradeability Test Framework; Request for Comments AGENCY: National... Metering Infrastructure Smart Meter Upgradeability Test Framework (Draft NISTIR 7823). This draft...

  12. Overnight improvements in two REM sleep-sensitive tasks are associated with both REM and NREM sleep changes, sleep spindle features, and awakenings for dream recall.

    PubMed

    Nielsen, T; O'Reilly, C; Carr, M; Dumel, G; Godin, I; Solomonova, E; Lara-Carrasco, J; Blanchette-Carrière, C; Paquette, T

    2015-07-01

    Memory consolidation is associated with sleep physiology but the contribution of specific sleep stages remains controversial. To clarify the contribution of REM sleep, participants were administered two REM sleep-sensitive tasks to determine if associated changes occurred only in REM sleep. Twenty-two participants (7 men) were administered the Corsi Block Tapping and Tower of Hanoi tasks prior to and again after a night of sleep. Task improvers and non-improvers were compared for sleep structure, sleep spindles, and dream recall. Control participants (N = 15) completed the tasks twice during the day without intervening sleep. Overnight Corsi Block improvement was associated with more REM sleep whereas Tower of Hanoi improvement was associated with more N2 sleep. Corsi Block improvement correlated positively with %REM sleep and Tower of Hanoi improvement with %N2 sleep. Post-hoc analyses suggest Tower of Hanoi effects-but not Corsi Block effects-are due to trait differences. Sleep spindle density was associated with Tower of Hanoi improvement whereas spindle amplitude correlated with Corsi Block improvement. Number of REM awakenings for dream reporting (but not dream recall per se) was associated with Corsi Block, but not Tower of Hanoi, improvement but was confounded with REM sleep time. This non-replication of one of 2 REM-sensitive task effects challenges both 'dual-process' and 'sequential' or 'sleep organization' models of sleep-dependent learning and points rather to capacity limitations on REM sleep. Experimental awakenings for sampling dream mentation may not perturb sleep-dependent learning effects; they may even enhance them. PMID:25291630

  13. Blockage of dopaminergic D(2) receptors produces decrease of REM but not of slow wave sleep in rats after REM sleep deprivation.

    PubMed

    Lima, Marcelo M S; Andersen, Monica L; Reksidler, Angela B; Silva, Andressa; Zager, Adriano; Zanata, Sílvio M; Vital, Maria A B F; Tufik, Sergio

    2008-04-01

    Dopamine (DA) has, as of late, become singled out from the profusion of other neurotransmitters as what could be called a key substance, in the regulation of the sleep-wake states. We have hypothesized that dopaminergic D(2) receptor blockage induced by haloperidol could generate a reduction or even an ablation of rapid eye movement (REM) sleep. Otherwise, the use of the selective D(2) agonist, piribedil, could potentiate REM sleep. Electrophysiological findings demonstrate that D(2) blockage produced a dramatic reduction of REM sleep during the rebound (REB) period after 96 h of REM sleep deprivation (RSD). This reduction of REM sleep was accompanied by an increment in SWS, which is possibly accounted for the observed increase in the sleep efficiency. Conversely, our findings also demonstrate that the administration of piribedil did not generate additional increase of REM sleep. Additionally, D(2) receptors were found down-regulated, in the haloperidol group, after RSD, and subsequently up-regulated after REB group, contrasting to the D(1) down-regulation at the same period. In this sense, the current data indicate a participation of the D(2) receptor for REM sleep regulation and consequently in the REM sleep/SWS balance. Herein, we propose that the mechanism underlying the striatal D(2) up-regulation is due to an effect as consequence of RSD which originally produces selective D(2) supersensitivity, and after its period probably generates a surge in D(2) expression. In conclusion we report a particular action of the dopaminergic neurotransmission in REM sleep relying on D(2) activation.

  14. Antidepressant suppression of non-REM sleep spindles and REM sleep impairs hippocampus-dependent learning while augmenting striatum-dependent learning.

    PubMed

    Watts, Alain; Gritton, Howard J; Sweigart, Jamie; Poe, Gina R

    2012-09-26

    Rapid eye movement (REM) sleep enhances hippocampus-dependent associative memory, but REM deprivation has little impact on striatum-dependent procedural learning. Antidepressant medications are known to inhibit REM sleep, but it is not well understood if antidepressant treatments impact learning and memory. We explored antidepressant REM suppression effects on learning by training animals daily on a spatial task under familiar and novel conditions, followed by training on a procedural memory task. Daily treatment with the antidepressant and norepinephrine reuptake inhibitor desipramine (DMI) strongly suppressed REM sleep in rats for several hours, as has been described in humans. We also found that DMI treatment reduced the spindle-rich transition-to-REM sleep state (TR), which has not been previously reported. DMI REM suppression gradually weakened performance on a once familiar hippocampus-dependent maze (reconsolidation error). DMI also impaired learning of the novel maze (consolidation error). Unexpectedly, learning of novel reward positions and memory of familiar positions were equally and oppositely correlated with amounts of TR sleep. Conversely, DMI treatment enhanced performance on a separate striatum-dependent, procedural T-maze task that was positively correlated with the amounts of slow-wave sleep (SWS). Our results suggest that learning strategy switches in patients taking REM sleep-suppressing antidepressants might serve to offset sleep-dependent hippocampal impairments to partially preserve performance. State-performance correlations support a model wherein reconsolidation of hippocampus-dependent familiar memories occurs during REM sleep, novel information is incorporated and consolidated during TR, and dorsal striatum-dependent procedural learning is augmented during SWS.

  15. Overnight improvements in two REM sleep-sensitive tasks are associated with both REM and NREM sleep changes, sleep spindle features, and awakenings for dream recall.

    PubMed

    Nielsen, T; O'Reilly, C; Carr, M; Dumel, G; Godin, I; Solomonova, E; Lara-Carrasco, J; Blanchette-Carrière, C; Paquette, T

    2015-07-01

    Memory consolidation is associated with sleep physiology but the contribution of specific sleep stages remains controversial. To clarify the contribution of REM sleep, participants were administered two REM sleep-sensitive tasks to determine if associated changes occurred only in REM sleep. Twenty-two participants (7 men) were administered the Corsi Block Tapping and Tower of Hanoi tasks prior to and again after a night of sleep. Task improvers and non-improvers were compared for sleep structure, sleep spindles, and dream recall. Control participants (N = 15) completed the tasks twice during the day without intervening sleep. Overnight Corsi Block improvement was associated with more REM sleep whereas Tower of Hanoi improvement was associated with more N2 sleep. Corsi Block improvement correlated positively with %REM sleep and Tower of Hanoi improvement with %N2 sleep. Post-hoc analyses suggest Tower of Hanoi effects-but not Corsi Block effects-are due to trait differences. Sleep spindle density was associated with Tower of Hanoi improvement whereas spindle amplitude correlated with Corsi Block improvement. Number of REM awakenings for dream reporting (but not dream recall per se) was associated with Corsi Block, but not Tower of Hanoi, improvement but was confounded with REM sleep time. This non-replication of one of 2 REM-sensitive task effects challenges both 'dual-process' and 'sequential' or 'sleep organization' models of sleep-dependent learning and points rather to capacity limitations on REM sleep. Experimental awakenings for sampling dream mentation may not perturb sleep-dependent learning effects; they may even enhance them.

  16. Characterization of neutron calibration fields at the TINT's 50 Ci americium-241/beryllium neutron irradiator

    NASA Astrophysics Data System (ADS)

    Liamsuwan, T.; Channuie, J.; Ratanatongchai, W.

    2015-05-01

    Reliable measurement of neutron radiation is important for monitoring and protection in workplace where neutrons are present. Although Thailand has been familiar with applications of neutron sources and neutron beams for many decades, there is no calibration facility dedicated to neutron measuring devices available in the country. Recently, Thailand Institute of Nuclear Technology (TINT) has set up a multi-purpose irradiation facility equipped with a 50 Ci americium-241/beryllium neutron irradiator. The facility is planned to be used for research, nuclear analytical techniques and, among other applications, calibration of neutron measuring devices. In this work, the neutron calibration fields were investigated in terms of neutron energy spectra and dose equivalent rates using Monte Carlo simulations, an in-house developed neutron spectrometer and commercial survey meters. The characterized neutron fields can generate neutron dose equivalent rates ranging from 156 μSv/h to 3.5 mSv/h with nearly 100% of dose contributed by neutrons of energies larger than 0.01 MeV. The gamma contamination was less than 4.2-7.5% depending on the irradiation configuration. It is possible to use the described neutron fields for calibration test and routine quality assurance of neutron dose rate meters and passive dosemeters commonly used in radiation protection dosimetry.

  17. Determining gas-meter accuracy

    SciTech Connect

    Valenti, M.

    1997-03-01

    This article describes how engineers at the Metering Research Facility are helping natural-gas companies improve pipeline efficiency by evaluating and refining the instruments used for measuring and setting prices. Accurate metering of natural gas is more important than ever as deregulation subjects pipeline companies to competition. To help improve that accuracy, the Gas Research Institute (GRI) in Chicago has sponsored the Metering Research Facility (MRF) at the Southwest Research Institute (SWRI) in San Antonio, Tex. The MRF evaluates and improves the performance of orifice, turbine, diaphragm, and ultrasonic meters as well as the gas-sampling methods that pipeline companies use to measure the flow of gas and determine its price.

  18. Roadmap to risk evaluation and mitigation strategies (REMS) success

    PubMed Central

    Balian, John D.; Malhotra, Rachpal; Perentesis, Valerie

    2010-01-01

    Medical safety-related risk management is a rapidly evolving and increasingly important aspect of drug approval and market longevity. To effectively meet the challenges of this new era, we describe a risk management roadmap that proactively yet practically anticipates risk-management requirements, provides the foundation for enduring yet appropriately flexible risk-management practices, and leverages these techniques to efficiently and effectively utilize risk evaluation and mitigation strategies (REMS)/risk minimization programs as market access enablers. This fully integrated risk-management paradigm creates exciting opportunities for newer tools, techniques, and approaches to more successfully optimize product development, approval, and commercialization, with patients as the ultimate beneficiaries. PMID:25083193

  19. Analytical Expressions for the REM Model of Recognition Memory

    PubMed Central

    Montenegro, Maximiliano; Myung, Jay I.; Pitt, Mark A.

    2014-01-01

    An inordinate amount of computation is required to evaluate predictions of simulation-based models. Following Myung et al (2007), we derived an analytic form expression of the REM model of recognition memory using a Fourier transform technique, which greatly reduces the time required to perform model simulations. The accuracy of the derivation is verified by showing a close correspondence between its predictions and those reported in Shiffrin and Steyvers (1997). The derivation also shows that REM’s predictions depend upon the vector length parameter, and that model parameters are not identifiable unless one of the parameters is fixed. PMID:25089060

  20. Relation of pontine choline acetyltransferase immunoreactive neurons with cells which increase discharge during REM sleep.

    PubMed

    Shiromani, P J; Armstrong, D M; Bruce, G; Hersh, L B; Groves, P M; Gillin, J C

    1987-03-01

    The purpose of this study was to determine whether neurons in the medial pontine reticular formation with high discharge rates during REM sleep could be localized in regions of the brainstem having neurons displaying choline acetyltransferase immunoreactivity. Six cats were implanted with sleep recording electrodes and microwires to record extracellular potentials of neurons in the pontine reticular formation. Single-units with a S:N ratio greater than 2:1 were recorded for at least two REM sleep cycles. A total of 49 units was recorded from the pontine reticular formation at medial-lateral planes ranging from 0.8 to 3.7 mm. The greatest proportion of the units (28.6%) showed highest discharge during active waking and phasic REM sleep compared to quiet waking, non-REM sleep, transition into REM sleep or quiet REM sleep periods. A percentage (20.4%) of the cells had high discharge associated with phasic REM sleep periods while 8.2% of the cells showed a progressive increase in discharge from waking to REM sleep. Subsequent examination of the distribution of choline acetyltransferase immunoreactive cells in the PRF revealed that cells showing high discharge during REM sleep were not localized near presumed cholinergic neurons. Indeed, we did not find any ChAT immunoreactive somata in the medial PRF, an area which has traditionally been implicated in the generation of REM sleep. These results suggest that while increased discharge of PRF cells may be instrumental to REM sleep generation, these cells are not cholinergic.

  1. Neutron scattering and absorption properties

    SciTech Connect

    Holden, N.E.

    1993-12-01

    The Table in this report presents an evaluated set of values for the experimental quantities, which characterize the properties for scattering and absorption of neutrons. The neutron cross section is given for room temperature neutrons, 20.43{degree}C, corresponds to a thermal neutron energy of 0.0253 electron volts (eV) or a neutron velocity of 2200 meters/second. The neutron resonance integral is defined over the energy range from 0.5 eV to 0.1 {times} 10{sup 6} eV, or 0.1 MeV. A list of the major references used is given below. The literature cutoff data is October 1993. Uncertainties are given in parentheses. Parentheses with two or more numbers indicate values to the excited states(s) and to the ground state of the product nucleus.

  2. The Metering Guide for Managers.

    ERIC Educational Resources Information Center

    Qayoumi, Mohammed H.

    This volume provides a guide to management of utilities metering in educational facilities, especially colleges and universities. Chapter 1 gives an overview of why utility measurement, specifically the metering of energy consumption, is important in facilities management. Chapter 2 defines the basic units of measurement for both electric and…

  3. Impact of orifice metering uncertainties

    SciTech Connect

    Stuart, J.W. )

    1990-12-01

    In a recent utility study, attributed 38% of its unaccounted-for UAF gas to orifice metering uncertainty biasing caused by straightening vanes. How this was determined and how this applied to the company's orifice meters is described. Almost all (97%) of the company's UAF gas was found to be attributed to identifiable accounting procedures, measurement problems, theft and leakage.

  4. Wavelength meter having elliptical wedge

    DOEpatents

    Hackel, R.P.; Feldman, M.

    1992-12-01

    A wavelength meter is disclosed which can determine the wavelength of a laser beam from a laser source within an accuracy range of two parts in 10[sup 8]. The wavelength meter has wedge having an elliptically shaped face to the optical path of the laser source and includes interferometer plates which form a vacuum housing. 7 figs.

  5. Wavelength meter having elliptical wedge

    DOEpatents

    Hackel, Richard P.; Feldman, Mark

    1992-01-01

    A wavelength meter is disclosed which can determine the wavelength of a laser beam from a laser source within an accuracy range of two parts in 10.sup.8. The wavelength meter has wedge having an elliptically shaped face to the optical path of the laser source and includes interferometer plates which form a vacuum housing.

  6. Maternal stress induces adult reduced REM sleep and melatonin level.

    PubMed

    Feng, Pingfu; Hu, Yufen; Vurbic, Drina; Guo, Yang

    2012-05-01

    We have previously reported that neonatal maternal deprivation (MD) resulted in a decrease of total sleep and an increase of orexin A in adult rats. Now, we characterized features of sleep, activity, and melatonin levels in rats neonatally treated with MD and control (MC) procedures. Adult male Sprague-Dawley rats were treated with either MD or MC procedures for 10 days starting at postnatal day 4. At 3 months of age, sleep was recorded for 48 h in one set of MD and MC rats, while another set of MD and MC rats was measured for locomotor activity (under LD = 12:12). Melatonin levels in the blood, pineal gland, and hypothalamus were measured as well as clock protein level in the hypothalamus. Compared to the MC rats, REM sleep in the MD rats was significantly reduced in the light periods but not in the dark periods. Both quiet wake and total wake in the MD rats were significantly increased during the light period compared to the MC rats. The weight of the pineal gland of the MD rats was significantly smaller than in MC rats. Melatonin levels of the MD group were significantly reduced in the pineal gland and hypothalamus compared to the MC group. No significant difference was identified between groups in the expression of the clock protein in the hypothalamus. Neonatal MD resulted in reduced REM sleep and melatonin levels, without changes of circadian cycle of locomotor activity and levels of clock protein.

  7. H-reflex suppression and autonomic activation during lucid REM sleep: a case study.

    PubMed

    Brylowski, A; Levitan, L; LaBerge, S

    1989-08-01

    A single subject, a proficient lucid dreamer experienced with signaling the onset of lucidity (reflective consciousness of dreaming) by means of voluntary eye movements, spent 4 nonconsecutive nights in the sleep laboratory. The subject reported becoming lucid and signaling in 8 of the 18 rapid-eye movement (REM) periods recorded. Ten lucid dream reports were verified by polygraphic examination of signals, providing a total of 12.5 min of signal-verified lucid REM. H-Reflex amplitude was recorded every 5 s, along with continuous recording of electroencephalogram, electrooculogram, electromyogram, electrocardiogram, finger pulse, and respiration. Significant findings included greater mean H-reflex suppression during lucid REM sleep than during nonlucid REM and correlations of H-reflex suppression with increased eye movement density, heart rate, and respiration rate. These results support previous studies reporting that lucid REM is not, as might be supposed, a state closer to awakening than ordinary, or nonlucid, REM; rather, lucid dreaming occurs during unequivocal REM sleep and is characteristically associated with phasic REM activation. PMID:2762692

  8. H-reflex suppression and autonomic activation during lucid REM sleep: a case study.

    PubMed

    Brylowski, A; Levitan, L; LaBerge, S

    1989-08-01

    A single subject, a proficient lucid dreamer experienced with signaling the onset of lucidity (reflective consciousness of dreaming) by means of voluntary eye movements, spent 4 nonconsecutive nights in the sleep laboratory. The subject reported becoming lucid and signaling in 8 of the 18 rapid-eye movement (REM) periods recorded. Ten lucid dream reports were verified by polygraphic examination of signals, providing a total of 12.5 min of signal-verified lucid REM. H-Reflex amplitude was recorded every 5 s, along with continuous recording of electroencephalogram, electrooculogram, electromyogram, electrocardiogram, finger pulse, and respiration. Significant findings included greater mean H-reflex suppression during lucid REM sleep than during nonlucid REM and correlations of H-reflex suppression with increased eye movement density, heart rate, and respiration rate. These results support previous studies reporting that lucid REM is not, as might be supposed, a state closer to awakening than ordinary, or nonlucid, REM; rather, lucid dreaming occurs during unequivocal REM sleep and is characteristically associated with phasic REM activation.

  9. The supramammillary nucleus and the claustrum activate the cortex during REM sleep

    PubMed Central

    Renouard, Leslie; Billwiller, Francesca; Ogawa, Keiko; Clément, Olivier; Camargo, Nutabi; Abdelkarim, Mouaadh; Gay, Nadine; Scoté-Blachon, Céline; Touré, Rouguy; Libourel, Paul-Antoine; Ravassard, Pascal; Salvert, Denise; Peyron, Christelle; Claustrat, Bruno; Léger, Lucienne; Salin, Paul; Malleret, Gael; Fort, Patrice; Luppi, Pierre-Hervé

    2015-01-01

    Evidence in humans suggests that limbic cortices are more active during rapid eye movement (REM or paradoxical) sleep than during waking, a phenomenon fitting with the presence of vivid dreaming during this state. In that context, it seemed essential to determine which populations of cortical neurons are activated during REM sleep. Our aim in the present study is to fill this gap by combining gene expression analysis, functional neuroanatomy, and neurochemical lesions in rats. We find in rats that, during REM sleep hypersomnia compared to control and REM sleep deprivation, the dentate gyrus, claustrum, cortical amygdaloid nucleus, and medial entorhinal and retrosplenial cortices are the only cortical structures containing neurons with an increased expression of Bdnf, FOS, and ARC, known markers of activation and/or synaptic plasticity. Further, the dentate gyrus is the only cortical structure containing more FOS-labeled neurons during REM sleep hypersomnia than during waking. Combining FOS staining, retrograde labeling, and neurochemical lesion, we then provide evidence that FOS overexpression occurring in the cortex during REM sleep hypersomnia is due to projections from the supramammillary nucleus and the claustrum. Our results strongly suggest that only a subset of cortical and hippocampal neurons are activated and display plasticity during REM sleep by means of ascending projections from the claustrum and the supramammillary nucleus. Our results pave the way for future studies to identify the function of REM sleep with regard to dreaming and emotional memory processing. PMID:26601158

  10. REM sleep behavior disorder in Parkinson's disease: A case from India confirmed with polysomnographic data

    PubMed Central

    Gupta, Ravi; Goel, Deepak; Walker, Jim; Farney, Robert J

    2013-01-01

    Rapid eye movement (REM) sleep behavior disorder is a condition characterized by dream enactment. This condition may accompany neurodegenerative disorders. However, only a few reports from India are available, that too, without any polysomnographic evidence. We are reporting a case of REM sleep behavior disorder with polysomnographic evidence. PMID:24174810

  11. The supramammillary nucleus and the claustrum activate the cortex during REM sleep.

    PubMed

    Renouard, Leslie; Billwiller, Francesca; Ogawa, Keiko; Clément, Olivier; Camargo, Nutabi; Abdelkarim, Mouaadh; Gay, Nadine; Scoté-Blachon, Céline; Touré, Rouguy; Libourel, Paul-Antoine; Ravassard, Pascal; Salvert, Denise; Peyron, Christelle; Claustrat, Bruno; Léger, Lucienne; Salin, Paul; Malleret, Gael; Fort, Patrice; Luppi, Pierre-Hervé

    2015-04-01

    Evidence in humans suggests that limbic cortices are more active during rapid eye movement (REM or paradoxical) sleep than during waking, a phenomenon fitting with the presence of vivid dreaming during this state. In that context, it seemed essential to determine which populations of cortical neurons are activated during REM sleep. Our aim in the present study is to fill this gap by combining gene expression analysis, functional neuroanatomy, and neurochemical lesions in rats. We find in rats that, during REM sleep hypersomnia compared to control and REM sleep deprivation, the dentate gyrus, claustrum, cortical amygdaloid nucleus, and medial entorhinal and retrosplenial cortices are the only cortical structures containing neurons with an increased expression of Bdnf, FOS, and ARC, known markers of activation and/or synaptic plasticity. Further, the dentate gyrus is the only cortical structure containing more FOS-labeled neurons during REM sleep hypersomnia than during waking. Combining FOS staining, retrograde labeling, and neurochemical lesion, we then provide evidence that FOS overexpression occurring in the cortex during REM sleep hypersomnia is due to projections from the supramammillary nucleus and the claustrum. Our results strongly suggest that only a subset of cortical and hippocampal neurons are activated and display plasticity during REM sleep by means of ascending projections from the claustrum and the supramammillary nucleus. Our results pave the way for future studies to identify the function of REM sleep with regard to dreaming and emotional memory processing. PMID:26601158

  12. The supramammillary nucleus and the claustrum activate the cortex during REM sleep.

    PubMed

    Renouard, Leslie; Billwiller, Francesca; Ogawa, Keiko; Clément, Olivier; Camargo, Nutabi; Abdelkarim, Mouaadh; Gay, Nadine; Scoté-Blachon, Céline; Touré, Rouguy; Libourel, Paul-Antoine; Ravassard, Pascal; Salvert, Denise; Peyron, Christelle; Claustrat, Bruno; Léger, Lucienne; Salin, Paul; Malleret, Gael; Fort, Patrice; Luppi, Pierre-Hervé

    2015-04-01

    Evidence in humans suggests that limbic cortices are more active during rapid eye movement (REM or paradoxical) sleep than during waking, a phenomenon fitting with the presence of vivid dreaming during this state. In that context, it seemed essential to determine which populations of cortical neurons are activated during REM sleep. Our aim in the present study is to fill this gap by combining gene expression analysis, functional neuroanatomy, and neurochemical lesions in rats. We find in rats that, during REM sleep hypersomnia compared to control and REM sleep deprivation, the dentate gyrus, claustrum, cortical amygdaloid nucleus, and medial entorhinal and retrosplenial cortices are the only cortical structures containing neurons with an increased expression of Bdnf, FOS, and ARC, known markers of activation and/or synaptic plasticity. Further, the dentate gyrus is the only cortical structure containing more FOS-labeled neurons during REM sleep hypersomnia than during waking. Combining FOS staining, retrograde labeling, and neurochemical lesion, we then provide evidence that FOS overexpression occurring in the cortex during REM sleep hypersomnia is due to projections from the supramammillary nucleus and the claustrum. Our results strongly suggest that only a subset of cortical and hippocampal neurons are activated and display plasticity during REM sleep by means of ascending projections from the claustrum and the supramammillary nucleus. Our results pave the way for future studies to identify the function of REM sleep with regard to dreaming and emotional memory processing.

  13. REM sleep deprivation inhibits LTP in vivo in area CA1 of rat hippocampus.

    PubMed

    Kim, Eun Young; Mahmoud, Ghada S; Grover, Lawrence M

    2005-11-18

    Rapid eye movement (REM) sleep deprivation has previously been shown to interfere with normal learning and memory and to inhibit long-term potentiation (LTP) in vitro. Previous studies on REM sleep deprivation and LTP have relied on in vitro analysis in isolated brain slices taken from animals following several days of sleep deprivation. LTP in the hippocampus in situ may differ from LTP in vitro due to modulatory inputs from other brain regions, which are altered after REM sleep deprivation. Here, we examined LTP in unanesthetized, behaving animals on the first and second recovery days following REM sleep deprivation to determine if similar effects are seen in vivo as previously reported in vitro. We found that LTP was significantly impaired in REM sleep-deprived animals on the second recovery day but not the first recovery day. Our results extend previous findings by showing that REM sleep deprivation continues to affect hippocampal function for more than 24h following the end of deprivation. Our results also suggest the presence of a modulatory process not present in vitro. Our findings are not explained by stress during REM sleep deprivation because equivalent circulating corticosterone levels (an index of stress) were found during both REM sleep deprivation and control treatment.

  14. Measurement of neutron dose equivalent outside and inside of the treatment vault of GRID therapy

    SciTech Connect

    Wang, Xudong; Charlton, Michael A.; Esquivel, Carlos; Eng, Tony Y.; Li, Ying; Papanikolaou, Nikos

    2013-09-15

    Purpose: To evaluate the neutron and photon dose equivalent rates at the treatment vault entrance (H{sub n,D} and H{sub G}), and to study the secondary radiation to the patient in GRID therapy. The radiation activation on the grid was studied.Methods: A Varian Clinac 23EX accelerator was working at 18 MV mode with a grid manufactured by .decimal, Inc. The H{sub n,D} and H{sub G} were measured using an Andersson–Braun neutron REM meter, and a Geiger Müller counter. The radiation activation on the grid was measured after the irradiation with an ion chamber γ-ray survey meter. The secondary radiation dose equivalent to patient was evaluated by etched track detectors and OSL detectors on a RANDO{sup ®} phantom.Results: Within the measurement uncertainty, there is no significant difference between the H{sub n,D} and H{sub G} with and without a grid. However, the neutron dose equivalent to the patient with the grid is, on average, 35.3% lower than that without the grid when using the same field size and the same amount of monitor unit. The photon dose equivalent to the patient with the grid is, on average, 44.9% lower. The measured average half-life of the radiation activation in the grid is 12.0 (±0.9) min. The activation can be categorized into a fast decay component and a slow decay component with half-lives of 3.4 (±1.6) min and 15.3 (±4.0) min, respectively. There was no detectable radioactive contamination found on the surface of the grid through a wipe test.Conclusions: This work indicates that there is no significant change of the H{sub n,D} and H{sub G} in GRID therapy, compared with a conventional external beam therapy. However, the neutron and scattered photon dose equivalent to the patient decrease dramatically with the grid and can be clinical irrelevant. Meanwhile, the users of a grid should be aware of the possible high dose to the radiation worker from the radiation activation on the surface of the grid. A delay in handling the grid after the beam

  15. Semiempirical Investigation of the Indirect Exchange Interaction in a rem-IN System

    NASA Astrophysics Data System (ADS)

    Shakarov, Kh. O.

    2014-05-01

    The Ruderman-Kittel-Kasuya-Yosida (RKKY) exchange interaction is investigated for the first time in compounds of binary REM (rare-earth metal) - In systems (REМ = Gd, Tb, Dy, Ho, Er, or Тm) using experimental values of the paramagnetic Curie temperature (θp ) of these compounds. The prediction of the RKKY theory on the direct proportionality between θp and the de Gennes factor for equiatomic compounds of heavy REM with indium, similarly to pure REM, is confirmed. Values of the indirect exchange interaction parameter are estimated semiempirically for the examined compounds. As a whole, it is established that for the compounds of REM with indium, as for pure REM, the exchange interaction of RKKY type is characteristic.

  16. Visual hallucinations and pontine demyelination in a child: possible REM dissociation?

    PubMed

    Vita, Maria Gabriella; Batocchi, Anna Paola; Dittoni, Serena; Losurdo, Anna; Cianfoni, Alessandro; Stefanini, Maria Chiara; Vollono, Catello; Della Marca, Giacomo; Mariotti, Paolo

    2008-12-15

    An 11 year-old-boy acutely developed complex visual and acoustic hallucinations. Hallucinations, consisting of visions of a threatening, evil character of the Harry Potter saga, persisted for 3 days. Neurological and psychiatric examinations were normal. Ictal EEG was negative. MRI documented 3 small areas of hyperintense signal in the brainstem, along the paramedian and lateral portions of pontine tegmentum, one of which showed post-contrast enhancement. These lesions were likely of inflammatory origin, and treatment with immunoglobulins was started. Polysomnography was normal, multiple sleep latency test showed a mean sleep latency of 8 minutes, with one sleep-onset REM period. The pontine tegmentum is responsible for REM sleep regulation, and contains definite "REM-on" and "REM-off" regions. The anatomical distribution of the lesions permits us to hypothesize that hallucinations in this boy were consequent to a transient impairment of REM sleep inhibitory mechanisms, with the appearance of dream-like hallucinations during wake.

  17. Visual hallucinations and pontine demyelination in a child: possible REM dissociation?

    PubMed

    Vita, Maria Gabriella; Batocchi, Anna Paola; Dittoni, Serena; Losurdo, Anna; Cianfoni, Alessandro; Stefanini, Maria Chiara; Vollono, Catello; Della Marca, Giacomo; Mariotti, Paolo

    2008-12-15

    An 11 year-old-boy acutely developed complex visual and acoustic hallucinations. Hallucinations, consisting of visions of a threatening, evil character of the Harry Potter saga, persisted for 3 days. Neurological and psychiatric examinations were normal. Ictal EEG was negative. MRI documented 3 small areas of hyperintense signal in the brainstem, along the paramedian and lateral portions of pontine tegmentum, one of which showed post-contrast enhancement. These lesions were likely of inflammatory origin, and treatment with immunoglobulins was started. Polysomnography was normal, multiple sleep latency test showed a mean sleep latency of 8 minutes, with one sleep-onset REM period. The pontine tegmentum is responsible for REM sleep regulation, and contains definite "REM-on" and "REM-off" regions. The anatomical distribution of the lesions permits us to hypothesize that hallucinations in this boy were consequent to a transient impairment of REM sleep inhibitory mechanisms, with the appearance of dream-like hallucinations during wake. PMID:19110890

  18. Selective REM-sleep deprivation does not diminish emotional memory consolidation in young healthy subjects.

    PubMed

    Morgenthaler, Jarste; Wiesner, Christian D; Hinze, Karoline; Abels, Lena C; Prehn-Kristensen, Alexander; Göder, Robert

    2014-01-01

    Sleep enhances memory consolidation and it has been hypothesized that rapid eye movement (REM) sleep in particular facilitates the consolidation of emotional memory. The aim of this study was to investigate this hypothesis using selective REM-sleep deprivation. We used a recognition memory task in which participants were shown negative and neutral pictures. Participants (N=29 healthy medical students) were separated into two groups (undisturbed sleep and selective REM-sleep deprived). Both groups also worked on the memory task in a wake condition. Recognition accuracy was significantly better for negative than for neutral stimuli and better after the sleep than the wake condition. There was, however, no difference in the recognition accuracy (neutral and emotional) between the groups. In summary, our data suggest that REM-sleep deprivation was successful and that the resulting reduction of REM-sleep had no influence on memory consolidation whatsoever. PMID:24587073

  19. Selective REM-sleep deprivation does not diminish emotional memory consolidation in young healthy subjects.

    PubMed

    Morgenthaler, Jarste; Wiesner, Christian D; Hinze, Karoline; Abels, Lena C; Prehn-Kristensen, Alexander; Göder, Robert

    2014-01-01

    Sleep enhances memory consolidation and it has been hypothesized that rapid eye movement (REM) sleep in particular facilitates the consolidation of emotional memory. The aim of this study was to investigate this hypothesis using selective REM-sleep deprivation. We used a recognition memory task in which participants were shown negative and neutral pictures. Participants (N=29 healthy medical students) were separated into two groups (undisturbed sleep and selective REM-sleep deprived). Both groups also worked on the memory task in a wake condition. Recognition accuracy was significantly better for negative than for neutral stimuli and better after the sleep than the wake condition. There was, however, no difference in the recognition accuracy (neutral and emotional) between the groups. In summary, our data suggest that REM-sleep deprivation was successful and that the resulting reduction of REM-sleep had no influence on memory consolidation whatsoever.

  20. The effect of a REM sleep deprivation procedure on different aspects of memory function in humans.

    PubMed

    Saxvig, Ingvild West; Lundervold, Astri Johansen; Grønli, Janne; Ursin, Reidun; Bjorvatn, Bjørn; Portas, Chiara Maria

    2008-03-01

    Previous studies have suggested that memory is dependent on the occurrence of REM sleep. Research has mainly focused on two distinct types of memory function, declarative and procedural, and it seems that the latter may more directly depend on REM sleep. Memory consolidation has been more investigated than acquisition, maintenance, and recall, despite the fact that sleep may affect flow of information into/from storage. Moreover, tests have often been limited to stimuli within only one modality (usually visual or verbal). This study aimed to clarify the role of REM sleep in memory by investigating aspects of memory function, processing, and modality in the same experimental setting. Tests of acquisition and consolidation of multiple aspects of memory function within the visual and verbal modalities were administrated to subjects before and after REM sleep deprivation. Results show that test performance was not affected by REM sleep deprivation.

  1. Cardiac Autonomic Regulation During Sleep in Idiopathic REM Sleep Behavior Disorder

    PubMed Central

    Lanfranchi, Paola A.; Fradette, Lorraine; Gagnon, Jean-François; Colombo, Roberto; Montplaisir, Jacques

    2007-01-01

    Objective: To assess cardiac autonomic and respiratory changes from stage 2 non-rapid eye movement sleep (NREM) to rapid eye movement (REM) sleep in subjects with idiopathic REM sleep behavior disorder (RBD) and controls. We tested the hypothesis that REM-related cardiorespiratory activation is altered in subjects with RBD. Design: Retrospective case-control study. Setting: University hospital-based sleep research laboratory. Patients: Ten subjects with idiopathic RBD (2 women, mean age 63.4 ± 6.2 years) and 10 sex- and age-matched controls (mean age 63.9 ± 6.3 years). Intervention: One-night polysomnography was used to assess R-R variability during NREM and REM sleep. Measurements and Results: Spectral analysis of R-R interval and respiration were performed. Mean R-R interval, low-frequency (LF) and high-frequency (HF) components in both absolute and normalized units (LFnu and HFnu), and the LF/HF ratio were obtained from 5-minute electrocardiogram segments selected during NREM and REM sleep under stable conditions (stable breathing pattern, no microarousals or leg movements). Respiratory frequency was also assessed. Values obtained were then averaged for each stage and analyzed by 2 × 2 analysis of variance with group (RBD subjects and controls) as factor and state (NREM and REM) as repeated measures. RR interval, HF, and HFnu components decreased from NREM to REM in controls but did not change in RBD subjects (Interaction P < 0.05). LFnu (interaction P < 0. 001), LF/HF (interaction P < 0. 001), and respiratory frequency (interaction P < 0. 05) increased from NREM to REM sleep in controls but remained stable in RBD subjects. Conclusion: REM-related cardiac and respiratory responses are absent in subjects with idiopathic RBD. Citation: Lanfranchi PA; Fradette L; Gagnon JF; Colombo R; Montplaisir J. Cardiac autonomic regulation during sleep in idiopathic REM sleep behavior disorder. SLEEP 2007;30(8):1019–1025. PMID:17702272

  2. Diagnostic Thresholds for Quantitative REM Sleep Phasic Burst Duration, Phasic and Tonic Muscle Activity, and REM Atonia Index in REM Sleep Behavior Disorder with and without Comorbid Obstructive Sleep Apnea

    PubMed Central

    McCarter, Stuart J.; St. Louis, Erik K.; Duwell, Ethan J.; Timm, Paul C.; Sandness, David J.; Boeve, Bradley F.; Silber, Michael H.

    2014-01-01

    Objectives: We aimed to determine whether phasic burst duration and conventional REM sleep without atonia (RSWA) methods could accurately diagnose REM sleep behavior disorder (RBD) patients with comorbid OSA. Design: We visually analyzed RSWA phasic burst durations, phasic, “any,” and tonic muscle activity by 3-s mini-epochs, phasic activity by 30-s (AASM rules) epochs, and conducted automated REM atonia index (RAI) analysis. Group RSWA metrics were analyzed and regression models fit, with receiver operating characteristic (ROC) curves determining the best diagnostic cutoff thresholds for RBD. Both split-night and full-night polysomnographic studies were analyzed. Setting: N/A. Participants: Parkinson disease (PD)-RBD (n = 20) and matched controls with (n = 20) and without (n = 20) OSA. Interventions: N/A. Measurements and Results: All mean RSWA phasic burst durations and muscle activities were higher in PD-RBD patients than controls (P < 0.0001), and RSWA associations with PD-RBD remained significant when adjusting for age, gender, and REM AHI (P < 0.0001). RSWA muscle activity (phasic, “any”) cutoffs for 3-s mini-epoch scorings were submentalis (SM) (15.5%, 21.6%), anterior tibialis (AT) (30.2%, 30.2%), and combined SM/AT (37.9%, 43.4%). Diagnostic cutoffs for 30-s epochs (AASM criteria) were SM 2.8%, AT 11.3%, and combined SM/AT 34.7%. Tonic muscle activity cutoff of 1.2% was 100% sensitive and specific, while RAI (SM) cutoff was 0.88. Phasic muscle burst duration cutoffs were: SM (0.65) and AT (0.79) seconds. Combining phasic burst durations with RSWA muscle activity improved sensitivity and specificity of RBD diagnosis. Conclusions: This study provides evidence for REM sleep without atonia diagnostic thresholds applicable in Parkinson disease-REM sleep behavior disorder (PD-RBD) patient populations with comorbid OSA that may be useful toward distinguishing PD-RBD in typical outpatient populations. Citation: McCarter SJ, St. Louis EK, Duwell EJ, Timm PC

  3. Orexin-1 receptor blockade dysregulates REM sleep in the presence of orexin-2 receptor antagonism

    PubMed Central

    Dugovic, Christine; Shelton, Jonathan E.; Yun, Sujin; Bonaventure, Pascal; Shireman, Brock T.; Lovenberg, Timothy W.

    2014-01-01

    In accordance with the prominent role of orexins in the maintenance of wakefulness via activation of orexin-1 (OX1R) and orexin-2 (OX2R) receptors, various dual OX1/2R antagonists have been shown to promote sleep in animals and humans. While selective blockade of OX2R seems to be sufficient to initiate and prolong sleep, the beneficial effect of additional inhibition of OX1R remains controversial. The relative contribution of OX1R and OX2R to the sleep effects induced by a dual OX1/2R antagonist was further investigated in the rat, and specifically on rapid eye movement (REM) sleep since a deficiency of the orexin system is associated with narcolepsy/cataplexy based on clinical and pre-clinical data. As expected, the dual OX1/2R antagonist SB-649868 was effective in promoting non-REM (NREM) and REM sleep following oral dosing (10 and 30 mg/kg) at the onset of the dark phase. However, a disruption of REM sleep was evidenced by a more pronounced reduction in the onset of REM as compared to NREM sleep, a marked enhancement of the REM/total sleep ratio, and the occurrence of a few episodes of direct wake to REM sleep transitions (REM intrusion). When administered subcutaneously, the OX2R antagonist JNJ-10397049 (10 mg/kg) increased NREM duration whereas the OX1R antagonist GSK-1059865 (10 mg/kg) did not alter sleep. REM sleep was not affected either by OX2R or OX1R blockade alone, but administration of the OX1R antagonist in combination with the OX2R antagonist induced a significant reduction in REM sleep latency and an increase in REM sleep duration at the expense of the time spent in NREM sleep. These results indicate that additional blockade of OX1R to OX2R antagonism elicits a dysregulation of REM sleep by shifting the balance in favor of REM sleep at the expense of NREM sleep that may increase the risk of adverse events. Translation of this hypothesis remains to be tested in the clinic. PMID:24592208

  4. Plutonium Detection with Straw Neutron Detectors

    SciTech Connect

    Mukhopadhyay, Sanjoy; Maurer, Richard; Guss, Paul

    2014-03-27

    A kilogram of weapons grade plutonium gives off about 56,000 neutrons per second of which 55,000 neutrons come from spontaneous fission of 240Pu (~6% by weight of the total plutonium). Actually, all even numbered isotopes (238Pu, 240Pu, and 242Pu) produce copious spontaneous fission neutrons. These neutrons induce fission in the surrounding fissile 239Pu with an approximate multiplication of a factor of ~1.9. This multiplication depends on the shape of the fissile materials and the surrounding material. These neutrons (typically of energy 2 MeV and air scattering mean free path >100 meters) can be detected 100 meters away from the source by vehicle-portable neutron detectors. [1] In our current studies on neutron detection techniques, without using 3He gas proportional counters, we designed and developed a portable high-efficiency neutron multiplicity counter using 10B-coated thin tubes called straws. The detector was designed to perform like commercially available fission meters (manufactured by Ortec Corp.) except instead of using 3He gas as a neutron conversion material, we used a thin coating of 10B.

  5. The Significance of REM Sleep on Routine EEG.

    PubMed

    Gangadhara, Shreyas; Pizarro-Otero, Jose; Bozorg, Ali; Benbadis, Selim

    2016-03-01

    The objective of this study was to report on sleep-onset REM period (SOREMP) during routine EEG and conditions associated with it at a comprehensive epilepsy program. We retrospectively reviewed all outpatient and inpatient EEGs performed at Tampa General Hospital, a comprehensive epilepsy center over a four-month period. All EEGs were reviewed by experienced board-certified epileptologists. When SOREMP was identified, the chart was reviewed to identify the most likely etiology and the associated conditions that might be contributing. A total of 449 EEGs were reviewed between August 10, 2009, and December 9, 2009. Of those, 106 were outpatient EEGs and 343 were inpatient EEGs. There were 7 EEGs with SOREMP identified, 6 from inpatient EEGs, and 1 from an outpatient EEG. Thus, SOREMP was more common in the inpatinent setting than outpatient. There is an association of SOREMP with sleep deprivation and drug withdrawal. PMID:27180506

  6. Hyperkalemic periodic paralysis associated with multiple sleep onset REM periods.

    PubMed

    Iranzo, A; Santamaria, J

    1999-12-15

    A 24-year-old man with sporadic hyperkalemic periodic paralysis (HPP) presented with moderate excessive daytime sleepiness and transitory episodes of weakness which occurred during and after sleep. Multiple sleep latency test (MSLT) demonstrated the presence of five sleep onset REM periods (SOREMPs) and a sleep latency of five minutes. Treatment with a diuretic which decreases serum potassium resolved all the clinical symtomps and a new MSLT showed the absence of SOREMPs and a sleep latency of 13.5 minutes. To our knowledge, the patient herein reported is the first case that associates sleep abnormalities and multiple SOREMPs with HPP. Furthermore, the present case suggests that SOREMPs may be explained by an increased extracellular potassium conductance related to HPP.

  7. What's a Peak Flow Meter?

    MedlinePlus

    ... KidsHealth in the Classroom What Other Parents Are Reading Upsetting News Reports? What to Say Vaccines: Which ... the meter reads (this is known as a reading). Repeat three times and note the highest recorded ...

  8. Dream to Predict? REM Dreaming as Prospective Coding

    PubMed Central

    Llewellyn, Sue

    2016-01-01

    The dream as prediction seems inherently improbable. The bizarre occurrences in dreams never characterize everyday life. Dreams do not come true! But assuming that bizarreness negates expectations may rest on a misunderstanding of how the predictive brain works. In evolutionary terms, the ability to rapidly predict what sensory input implies—through expectations derived from discerning patterns in associated past experiences—would have enhanced fitness and survival. For example, food and water are essential for survival, associating past experiences (to identify location patterns) predicts where they can be found. Similarly, prediction may enable predator identification from what would have been only a fleeting and ambiguous stimulus—without prior expectations. To confront the many challenges associated with natural settings, visual perception is vital for humans (and most mammals) and often responses must be rapid. Predictive coding during wake may, therefore, be based on unconscious imagery so that visual perception is maintained and appropriate motor actions triggered quickly. Speed may also dictate the form of the imagery. Bizarreness, during REM dreaming, may result from a prospective code fusing phenomena with the same meaning—within a particular context. For example, if the context is possible predation, from the perspective of the prey two different predators can both mean the same (i.e., immediate danger) and require the same response (e.g., flight). Prospective coding may also prune redundancy from memories, to focus the image on the contextually-relevant elements only, thus, rendering the non-relevant phenomena indeterminate—another aspect of bizarreness. In sum, this paper offers an evolutionary take on REM dreaming as a form of prospective coding which identifies a probabilistic pattern in past events. This pattern is portrayed in an unconscious, associative, sensorimotor image which may support cognition in wake through being mobilized as a

  9. Sleepiness in Idiopathic REM Sleep Behavior Disorder and Parkinson Disease

    PubMed Central

    Arnulf, Isabelle; Neutel, Dulce; Herlin, Bastien; Golmard, Jean-Louis; Leu-Semenescu, Smaranda; Cochen de Cock, Valérie; Vidailhet, Marie

    2015-01-01

    Objective: To determine whether patients with idiopathic and symptomatic RBD were sleepier than controls, and if sleepiness in idiopathic RBD predicted earlier conversion to Parkinson disease. Methods: The Epworth Sleepiness Scale (ESS) and its determinants were compared at the time of a video-polysomnography for an RBD diagnosis in patients with idiopathic RBD, in patients with Parkinson disease, and in controls. Whether sleepiness at time of RBD diagnosis predicted an earlier conversion to neurodegenerative diseases was retrospectively analyzed in the followed-up patients. Results: The 75 patients with idiopathic RBD were sleepier (ESS: 7.8 ± 4.6) at the time of RBD diagnosis than 74 age- and sex-matched controls (ESS: 5.0 ± 3.6, P < 0.0001). They reached the levels of 114 patients with Parkinson disease (ESS: 8.7 ± 4.8), whether they had (n = 78) or did not have (n = 36) concomitant RBD. The severity of sleepiness in idiopathic RBD correlated with younger age, but not with sleep measures. Among the 69 patients with idiopathic RBD who were followed up for a median 3 years (1–15 years), 16 (23.2%) developed parkinsonism (n = 6), dementia (n = 6), dementia plus parkinsonism (n = 2), and multiple system atrophy (n = 2). An ESS greater than 8 at time of RBD diagnosis predicted a shorter time to phenoconversion to parkinsonism and dementia, from RBD onset, and from RBD diagnosis (when adjusted for age and time between RBD onset and diagnosis). Conclusions: Sleepiness is associated with idiopathic REM sleep behavior disorder and predicts more rapid conversion to parkinsonism and dementia, suggesting it is an early marker of neuronal loss in brainstem arousal systems. Citation: Arnulf I, Neutel D, Herlin B, Golmard JL, Leu-Semenescu S, Cochen de Cock V, Vidailhet M. Sleepiness in idiopathic REM sleep behavior disorder and Parkinson disease. SLEEP 2015;38(10):1529–1535. PMID:26085299

  10. Dream to Predict? REM Dreaming as Prospective Coding.

    PubMed

    Llewellyn, Sue

    2015-01-01

    The dream as prediction seems inherently improbable. The bizarre occurrences in dreams never characterize everyday life. Dreams do not come true! But assuming that bizarreness negates expectations may rest on a misunderstanding of how the predictive brain works. In evolutionary terms, the ability to rapidly predict what sensory input implies-through expectations derived from discerning patterns in associated past experiences-would have enhanced fitness and survival. For example, food and water are essential for survival, associating past experiences (to identify location patterns) predicts where they can be found. Similarly, prediction may enable predator identification from what would have been only a fleeting and ambiguous stimulus-without prior expectations. To confront the many challenges associated with natural settings, visual perception is vital for humans (and most mammals) and often responses must be rapid. Predictive coding during wake may, therefore, be based on unconscious imagery so that visual perception is maintained and appropriate motor actions triggered quickly. Speed may also dictate the form of the imagery. Bizarreness, during REM dreaming, may result from a prospective code fusing phenomena with the same meaning-within a particular context. For example, if the context is possible predation, from the perspective of the prey two different predators can both mean the same (i.e., immediate danger) and require the same response (e.g., flight). Prospective coding may also prune redundancy from memories, to focus the image on the contextually-relevant elements only, thus, rendering the non-relevant phenomena indeterminate-another aspect of bizarreness. In sum, this paper offers an evolutionary take on REM dreaming as a form of prospective coding which identifies a probabilistic pattern in past events. This pattern is portrayed in an unconscious, associative, sensorimotor image which may support cognition in wake through being mobilized as a predictive

  11. 5-HT1A receptor-responsive pedunculopontine tegmental neurons suppress REM sleep and respiratory motor activity.

    PubMed

    Grace, Kevin P; Liu, Hattie; Horner, Richard L

    2012-02-01

    Serotonin type 1A (5-HT(1A)) receptor-responsive neurons in the pedunculopontine tegmental nucleus (PPTn) become maximally active immediately before and during rapid eye movement (REM) sleep. A prevailing model of REM sleep generation indicates that activation of such neurons contributes significantly to the generation of REM sleep, and if correct then inactivation of such neurons ought to suppress REM sleep. We test this hypothesis using bilateral microperfusion of the 5-HT(1A) receptor agonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT, 10 μm) into the PPTn; this tool has been shown to selectively silence REM sleep-active PPTn neurons while the activity of wake/REM sleep-active PPTn neurons is unaffected. Contrary to the prevailing model, bilateral microperfusion of 8-OH-DPAT into the PPTn (n = 23 rats) significantly increased REM sleep both as a percentage of the total recording time and sleep time, compared with both within-animal vehicle controls and between-animal time-controls. This increased REM sleep resulted from an increased frequency of REM sleep bouts but not their duration, indicating an effect on mechanisms of REM sleep initiation but not maintenance. Furthermore, an increased proportion of the REM sleep bouts stemmed from periods of low REM sleep drive quantified electrographically. Targeted suppression of 5-HT(1A) receptor-responsive PPTn neurons also increased respiratory rate and respiratory-related genioglossus activity, and increased the frequency and amplitude of the sporadic genioglossus activations occurring during REM sleep. These data indicate that 5-HT(1A) receptor-responsive PPTn neurons normally function to restrain REM sleep by elevating the drive threshold for REM sleep induction, and restrain the expression of respiratory rate and motor activities.

  12. Gamma radiation field intensity meter

    DOEpatents

    Thacker, L.H.

    1994-08-16

    A gamma radiation intensity meter measures dose rate of a radiation field. The gamma radiation intensity meter includes a tritium battery emitting beta rays generating a current which is essentially constant. Dose rate is correlated to an amount of movement of an electroscope element charged by the tritium battery. Ionizing radiation decreases the voltage at the element and causes movement. A bleed resistor is coupled between the electroscope support element or electrode and the ionization chamber wall electrode. 4 figs.

  13. Gamma radiation field intensity meter

    DOEpatents

    Thacker, Louis H.

    1994-01-01

    A gamma radiation intensity meter measures dose rate of a radiation field. The gamma radiation intensity meter includes a tritium battery emitting beta rays generating a current which is essentially constant. Dose rate is correlated to an amount of movement of an electroscope element charged by the tritium battery. Ionizing radiation decreases the voltage at the element and causes movement. A bleed resistor is coupled between the electroscope support element or electrode and the ionization chamber wall electrode.

  14. Gamma radiation field intensity meter

    DOEpatents

    Thacker, Louis H.

    1995-01-01

    A gamma radiation intensity meter measures dose rate of a radiation field. The gamma radiation intensity meter includes a tritium battery emitting beta rays generating a current which is essentially constant. Dose rate is correlated to an amount of movement of an electroscope element charged by the tritium battery. Ionizing radiation decreases the voltage at the element and causes movement. A bleed resistor is coupled between the electroscope support element or electrode and the ionization chamber wall electrode.

  15. Healthcare Energy Metering Guidance (Brochure)

    SciTech Connect

    Not Available

    2011-07-01

    This brochure is intended to help facility and energy managers plan and prioritize investments in energy metering. It offers healthcare-specific examples of metering applications, benefits, and steps that other health systems can reproduce. It reflects collaborative input from the U.S. Department of Energy national laboratories and the health system members of the DOE Hospital Energy Alliance's Benchmarking and Measurement Project Team.

  16. Gamma radiation field intensity meter

    DOEpatents

    Thacker, L.H.

    1995-10-17

    A gamma radiation intensity meter measures dose rate of a radiation field. The gamma radiation intensity meter includes a tritium battery emitting beta rays generating a current which is essentially constant. Dose rate is correlated to an amount of movement of an electroscope element charged by the tritium battery. Ionizing radiation decreases the voltage at the element and causes movement. A bleed resistor is coupled between the electroscope support element or electrode and the ionization chamber wall electrode. 4 figs.

  17. Mass meters for liquid measurement

    SciTech Connect

    Apple, C.

    1995-12-01

    Flowmeters that are capable of providing a direct mass flow measurement include: Coriolis, thermal, gyroscopic and angular momentum. However, Coriolis meters are the only commercially viable device that can cover the breadth of measurements required by the petroleum industry. In addition to providing a direct mass flow measurement, Coriolis meters are extremely accurate, typically {+-}0.1 % to {+-}0.2 %. The advantage of measuring mass is that the mass of a fluid is unaffected by changes in process temperature and pressure. Whereas, volume measurements must be corrected to standard conditions of temperature and pressure for accounting purposes. Although measuring a product on a mass basis would be the simplest approach, most petroleum products are accounted for on a volume basis. This is primarily because only volumetric flowmeters were available prior to the introduction of industrial quality Coriolis meter in the early 1980`s. Due to the lack of means to perform a mass measurement, the petroleum industry has standardized on volume measurement. Systems and procedures are currently in place for performing and verifying volume measurements. Therefore, the petroleum industry will be slow in moving to mass measurement. Coriolis meters are currently gaining acceptance in the petroleum industry for the metering of light hydrocarbons, which are difficult to properly account for on a volume basis. However, due to the many advantages that Coriolis meters provide, they will become a preferred flow measurement device for all areas of petroleum measurement.

  18. Orifice meters for liquid measurement

    SciTech Connect

    Vickrey, R.E.

    1995-12-01

    Orifice meters have been used for centuries in measuring and regulating the flow of water. Historians have recorded the use of orifices by the Romans to regulate the flow of water to houses. Equations used to calculate gas flow rate were originally based on data using water. Although orifice meters are used extensively today by the gas Transmission industry for measuring large quantities of gas in custody transfer, they are also used for the measurement of natural gas liquids such as ethylene, carbon dioxide raw mix, demethanized ethane-propane mix, oil, water, air and steam. An ORIFICE METER consists of a thin flat round plate in which a circular concentric bore with a sharp square edge has been machined and mounted two flanges, each attached to a tube, or an orifice-plate holder with a pressure tap upstream and a pressure tap downstream to provide a means of measuring the pressure drop across the orifice plate. These parts, when assembled as a unit, are the METER and it is called the Primary Element. Occasionally a chart recorder is called a meter but that is not correct. Other instruments used in conjunction with the meter to record or transmit line pressure, differential pressure, temperature, relative density, etc. are the Secondary Elements.

  19. Heart rate variability during carbachol-induced REM sleep and cataplexy.

    PubMed

    Torterolo, Pablo; Castro-Zaballa, Santiago; Cavelli, Matías; Velasquez, Noelia; Brando, Victoria; Falconi, Atilio; Chase, Michael H; Migliaro, Eduardo R

    2015-09-15

    The nucleus pontis oralis (NPO) exerts an executive control over REM sleep. Cholinergic input to the NPO is critical for REM sleep generation. In the cat, a single microinjection of carbachol (a cholinergic agonist) into the NPO produces either REM sleep (REMc) or wakefulness with muscle atonia (cataplexy, CA). In order to study the central control of the heart rate variability (HRV) during sleep, we conducted polysomnographic and electrocardiogram recordings from chronically prepared cats during REMc, CA as well as during sleep and wakefulness. Subsequently, we performed statistical and spectral analyses of the HRV. The heart rate was greater during CA compared to REMc, NREM or REM sleep. Spectral analysis revealed that the low frequency band (LF) power was significantly higher during REM sleep in comparison to REMc and CA. Furthermore, we found that during CA there was a decrease in coupling between the RR intervals plot (tachogram) and respiratory activity. In contrast, compared to natural behavioral states, during REMc and CA there were no significant differences in the HRV based upon the standard deviation of normal RR intervals (SDNN) and the mean squared difference of successive intervals (rMSSD). In conclusion, there were differences in the HRV during naturally-occurring REM sleep compared to REMc. In addition, in spite of the same muscle atonia, the HRV was different during REMc and CA. Therefore, the neuronal network that controls the HRV during REM sleep can be dissociated from the one that generates the muscle atonia during this state. PMID:25997581

  20. Analysis of automated quantification of motor activity in REM sleep behaviour disorder.

    PubMed

    Frandsen, Rune; Nikolic, Miki; Zoetmulder, Marielle; Kempfner, Lykke; Jennum, Poul

    2015-10-01

    Rapid eye movement (REM) sleep behaviour disorder (RBD) is characterized by dream enactment and REM sleep without atonia. Atonia is evaluated on the basis of visual criteria, but there is a need for more objective, quantitative measurements. We aimed to define and optimize a method for establishing baseline and all other parameters in automatic quantifying submental motor activity during REM sleep. We analysed the electromyographic activity of the submental muscle in polysomnographs of 29 patients with idiopathic RBD (iRBD), 29 controls and 43 Parkinson's (PD) patients. Six adjustable parameters for motor activity were defined. Motor activity was detected and quantified automatically. The optimal parameters for separating RBD patients from controls were investigated by identifying the greatest area under the receiver operating curve from a total of 648 possible combinations. The optimal parameters were validated on PD patients. Automatic baseline estimation improved characterization of atonia during REM sleep, as it eliminates inter/intra-observer variability and can be standardized across diagnostic centres. We found an optimized method for quantifying motor activity during REM sleep. The method was stable and can be used to differentiate RBD from controls and to quantify motor activity during REM sleep in patients with neurodegeneration. No control had more than 30% of REM sleep with increased motor activity; patients with known RBD had as low activity as 4.5%. We developed and applied a sensitive, quantitative, automatic algorithm to evaluate loss of atonia in RBD patients. PMID:25923472

  1. The effect of REM sleep deprivation on motivation for food reward.

    PubMed

    Hanlon, Erin C; Andrzejewski, Matthew E; Harder, Bridgette K; Kelley, Ann E; Benca, Ruth M

    2005-08-30

    Prolonged sleep deprivation in rats produces a characteristic syndrome consisting of an increase in food intake yet a decrease in weight. Moreover, the increase in food intake generally precedes the weight loss, suggesting that sleep deprivation may affect appetitive behaviors. Using the multiple platform method to produce rapid eye movement (REM) sleep deprivation, we investigated the effect of REM sleep deprivation (REMSD) on motivation for food reward utilizing food-reinforced operant tasks. In acquisition or maintenance of an operant task, REM sleep-deprived rats, with or without simultaneous food restriction, decreased responding for sucrose pellet reward in comparison to controls, despite the fact that all REM sleep-deprived rats lost weight. Furthermore, the overall response deficit of the REM sleep-deprived rats was due to a within-session decline in responding. REM sleep-deprived rats showed evidence of understanding the contingency of the task comparable to controls throughout deprivation period, suggesting that the decrements in responding were not primarily related to deficits in learning or memory. Rather, REM sleep deprivation appears to alter systems involved in motivational processes, reward, and/or attention.

  2. Analysis of automated quantification of motor activity in REM sleep behaviour disorder.

    PubMed

    Frandsen, Rune; Nikolic, Miki; Zoetmulder, Marielle; Kempfner, Lykke; Jennum, Poul

    2015-10-01

    Rapid eye movement (REM) sleep behaviour disorder (RBD) is characterized by dream enactment and REM sleep without atonia. Atonia is evaluated on the basis of visual criteria, but there is a need for more objective, quantitative measurements. We aimed to define and optimize a method for establishing baseline and all other parameters in automatic quantifying submental motor activity during REM sleep. We analysed the electromyographic activity of the submental muscle in polysomnographs of 29 patients with idiopathic RBD (iRBD), 29 controls and 43 Parkinson's (PD) patients. Six adjustable parameters for motor activity were defined. Motor activity was detected and quantified automatically. The optimal parameters for separating RBD patients from controls were investigated by identifying the greatest area under the receiver operating curve from a total of 648 possible combinations. The optimal parameters were validated on PD patients. Automatic baseline estimation improved characterization of atonia during REM sleep, as it eliminates inter/intra-observer variability and can be standardized across diagnostic centres. We found an optimized method for quantifying motor activity during REM sleep. The method was stable and can be used to differentiate RBD from controls and to quantify motor activity during REM sleep in patients with neurodegeneration. No control had more than 30% of REM sleep with increased motor activity; patients with known RBD had as low activity as 4.5%. We developed and applied a sensitive, quantitative, automatic algorithm to evaluate loss of atonia in RBD patients.

  3. Heart rate variability during carbachol-induced REM sleep and cataplexy.

    PubMed

    Torterolo, Pablo; Castro-Zaballa, Santiago; Cavelli, Matías; Velasquez, Noelia; Brando, Victoria; Falconi, Atilio; Chase, Michael H; Migliaro, Eduardo R

    2015-09-15

    The nucleus pontis oralis (NPO) exerts an executive control over REM sleep. Cholinergic input to the NPO is critical for REM sleep generation. In the cat, a single microinjection of carbachol (a cholinergic agonist) into the NPO produces either REM sleep (REMc) or wakefulness with muscle atonia (cataplexy, CA). In order to study the central control of the heart rate variability (HRV) during sleep, we conducted polysomnographic and electrocardiogram recordings from chronically prepared cats during REMc, CA as well as during sleep and wakefulness. Subsequently, we performed statistical and spectral analyses of the HRV. The heart rate was greater during CA compared to REMc, NREM or REM sleep. Spectral analysis revealed that the low frequency band (LF) power was significantly higher during REM sleep in comparison to REMc and CA. Furthermore, we found that during CA there was a decrease in coupling between the RR intervals plot (tachogram) and respiratory activity. In contrast, compared to natural behavioral states, during REMc and CA there were no significant differences in the HRV based upon the standard deviation of normal RR intervals (SDNN) and the mean squared difference of successive intervals (rMSSD). In conclusion, there were differences in the HRV during naturally-occurring REM sleep compared to REMc. In addition, in spite of the same muscle atonia, the HRV was different during REMc and CA. Therefore, the neuronal network that controls the HRV during REM sleep can be dissociated from the one that generates the muscle atonia during this state.

  4. REM Sleep-Dependent Bidirectional Regulation of Hippocampal-Based Emotional Memory and LTP.

    PubMed

    Ravassard, Pascal; Hamieh, Al Mahdy; Joseph, Mickaël Antoine; Fraize, Nicolas; Libourel, Paul-Antoine; Lebarillier, Léa; Arthaud, Sébastien; Meissirel, Claire; Touret, Monique; Malleret, Gaël; Salin, Paul-Antoine

    2016-04-01

    Prolonged rapid-eye-movement (REM) sleep deprivation has long been used to study the role of REM sleep in learning and memory processes. However, this method potentially induces stress and fatigue that may directly affect cognitive functions. Here, by using a short-term and nonstressful REM sleep deprivation (RSD) method we assessed in rats the bidirectional influence of reduced and increased REM sleep amount on hippocampal-dependent emotional memory and plasticity. Our results indicate that 4 h RSD impaired consolidation of contextual fear conditioning (CFC) and induction of long-term potentiation (LTP), while decreasing density of Egr1/Zif268-expressing neurons in the CA1 region of the dorsal hippocampus. LTP and Egr1 expression were not affected in ventral CA1. Conversely, an increase in REM sleep restores and further facilitates CFC consolidation and LTP induction, and also increases Egr1 expression in dorsal CA1. Moreover, CFC consolidation, Egr1 neuron density, and LTP amplitude in dorsal CA1 show a positive correlation with REM sleep amount. Altogether, these results indicate that mild changes in REM sleep amount bidirectionally affect memory and synaptic plasticity mechanisms occurring in the CA1 area of the dorsal hippocampus.

  5. Repeated REM sleep deprivation after chronic haloperidol administration in the rat.

    PubMed

    Salín-Pascual, R J; García-Ferreiro, R; Moro-López, M L; Blanco-Centurión, C; Drucker-Colín, R

    1997-06-01

    Repeated haloperidol administration produces up-regulation of dopamine (DA) receptors. REM sleep deprivation (REMSD) does also, but in addition, has been shown to produce REM sleep rebound. Should DA receptor up-regulation play a role in REM sleep rebound, haloperidol could conceivably have effects similar to those observed following REMSD. This is the central question investigated in this study. Male Wistar rats were prepared for sleep recordings. They were randomly assigned to the following groups: group 1, REMSD by small platforms (40 h REMSD + 8 h recording); group 2, was the large platform control group (40 h in large platforms + 8 h of recording); group 3, received 2-week daily administration of haloperidol (3 mg/kg, i.p.) plus REMSD (40 h REMSD + 8 h of recording); group 4, 2-week administration of haloperidol (3 mg/kg) without sleep manipulation and at the end 40 h were allowed to elapse, following which 8 h of sleep recordings was carried out. In each group the sleep manipulation and/or sleep recordings were repeated five consecutive times. Repeated REMSD produced increases of REM sleep time after each recovery in group 1. Large platforms did not produce increases of REM sleep during the recovery trials. The 2-week administration of haloperidol plus REMSD prevented REM sleep rebound (group 3). The 2-week administration of haloperidol without sleep manipulation (group 4) produced a REM sleep reduction. Dopamine modulation seems not to be important for REM sleep rebound. Hypersensitivity of DA receptors developed after REMSD may be an epiphenomenon associated with this sleep manipulation, but seems not to participate in REM sleep enhancement after REMSD.

  6. Enhanced emotional reactivity after selective REM sleep deprivation in humans: an fMRI study

    PubMed Central

    Rosales-Lagarde, Alejandra; Armony, Jorge L.; del Río-Portilla, Yolanda; Trejo-Martínez, David; Conde, Ruben; Corsi-Cabrera, Maria

    2012-01-01

    Converging evidence from animal and human studies suggest that rapid eye movement (REM) sleep modulates emotional processing. The aim of the present study was to explore the effects of selective REM sleep deprivation (REM-D) on emotional responses to threatening visual stimuli and their brain correlates using functional magnetic resonance imaging (fMRI). Twenty healthy subjects were randomly assigned to two groups: selective REM-D, by awakening them at each REM sleep onset, or non-rapid eye movement sleep interruptions (NREM-I) as control for potential non-specific effects of awakenings and lack of sleep. In a within-subject design, a visual emotional reactivity task was performed in the scanner before and 24 h after sleep manipulation. Behaviorally, emotional reactivity was enhanced relative to baseline (BL) in the REM deprived group only. In terms of fMRI signal, there was, as expected, an overall decrease in activity in the NREM-I group when subjects performed the task the second time, particularly in regions involved in emotional processing, such as occipital and temporal areas, as well as in the ventrolateral prefrontal cortex, involved in top-down emotion regulation. In contrast, activity in these areas remained the same level or even increased in the REM-D group, compared to their BL level. Taken together, these results suggest that lack of REM sleep in humans is associated with enhanced emotional reactivity, both at behavioral and neural levels, and thus highlight the specific role of REM sleep in regulating the neural substrates for emotional responsiveness. PMID:22719723

  7. REM Sleep and Its Loss-associated Epigenetic Regulation with Reference to Noradrenaline in Particular

    PubMed Central

    Mehta, Rachna; Singh, Abhishek; Bókkon, István; Nath Mallick, Birendra

    2016-01-01

    Sleep is an essential physiological process, which has been divided into rapid eye movement sleep (REMS) and non-REMS (NREMS) in higher animals. REMS is a unique phenomenon that unlike other sleep-waking states is not under voluntary control. Directly or indirectly it influences or gets influenced by most of the physiological processes controlled by the brain. It has been proposed that REMS serves housekeeping function of the brain. Extensive research has shown that during REMS at least noradrenaline (NA) -ergic neurons must cease activity and upon REMS loss, there are increased levels of NA in the brain, which then induces many of the REMS loss associated acute and chronic effects. The NA level is controlled by many bio-molecules that are regulated at the molecular and transcriptional levels. Similarly, NA can also directly or indirectly modulate the synthesis and levels of many molecules, which in turn may affect physiological processes. The burgeoning field of behavioral neuroepigenetics has gained importance in recent years and explains the regulatory mechanisms underlying several behavioral phenomena. As REMS and its loss associated changes in NA modulate several pathophysiological processes, in this review we have attempted to explain on one hand how the epigenetic mechanisms regulating the gene expression of factors like tyrosine hydroxylase (TH), monoamine oxidase (MAO), noradrenaline transporter (NAT) control NA levels and on the other hand, how NA per se can affect other molecules in neural circuitry at the epigenetic level resulting in behavioral changes in health and diseases. An understanding of these events will expose the molecular basis of REMS and its loss-associated pathophysiological changes; which are presented as a testable hypothesis for confirmation. PMID:26813120

  8. Enhanced emotional reactivity after selective REM sleep deprivation in humans: an fMRI study.

    PubMed

    Rosales-Lagarde, Alejandra; Armony, Jorge L; Del Río-Portilla, Yolanda; Trejo-Martínez, David; Conde, Ruben; Corsi-Cabrera, Maria

    2012-01-01

    Converging evidence from animal and human studies suggest that rapid eye movement (REM) sleep modulates emotional processing. The aim of the present study was to explore the effects of selective REM sleep deprivation (REM-D) on emotional responses to threatening visual stimuli and their brain correlates using functional magnetic resonance imaging (fMRI). Twenty healthy subjects were randomly assigned to two groups: selective REM-D, by awakening them at each REM sleep onset, or non-rapid eye movement sleep interruptions (NREM-I) as control for potential non-specific effects of awakenings and lack of sleep. In a within-subject design, a visual emotional reactivity task was performed in the scanner before and 24 h after sleep manipulation. Behaviorally, emotional reactivity was enhanced relative to baseline (BL) in the REM deprived group only. In terms of fMRI signal, there was, as expected, an overall decrease in activity in the NREM-I group when subjects performed the task the second time, particularly in regions involved in emotional processing, such as occipital and temporal areas, as well as in the ventrolateral prefrontal cortex, involved in top-down emotion regulation. In contrast, activity in these areas remained the same level or even increased in the REM-D group, compared to their BL level. Taken together, these results suggest that lack of REM sleep in humans is associated with enhanced emotional reactivity, both at behavioral and neural levels, and thus highlight the specific role of REM sleep in regulating the neural substrates for emotional responsiveness.

  9. Insert metering plates for gas turbine nozzles

    DOEpatents

    Burdgick, Steven S.; Itzel, Gary; Chopra, Sanjay; Abuaf, Nesim; Correia, Victor H.

    2004-05-11

    The invention comprises a metering plate which is assembled to an impingement insert for use in the nozzle of a gas turbine. The metering plate can have one or more metering holes and is used to balance the cooling flow within the nozzle. A metering plate with multiple holes reduces static pressure variations which result from the cooling airflow through the metering plate. The metering plate can be assembled to the insert before or after the insert is inserted into the nozzle.

  10. REM sleep deprivation reduces auditory evoked inhibition of dorsolateral pontine neurons.

    PubMed

    Mallick, B N; Fahringer, H M; Wu, M F; Siegel, J M

    1991-06-28

    In many dorsolateral pontine neurons, auditory stimulation produces an initial excitation followed by a sustained inhibition. We now report that rapid eye movement (REM) sleep deprivation, for periods of from 22-48 h, reduced this auditory evoked inhibition of unit discharge. Inhibition returned to baseline levels after recovery REM sleep. Prior work indicates that the auditory evoked inhibition seen in noradrenergic cells in this region is partially mediated by norepinephrine. We hypothesize that the reduction in inhibition that we see is a consequence of either downregulation/desensitization of norepinephrine receptors or reduced norepinephrine release resulting from REM sleep deprivation. PMID:1913194

  11. Rem2, a member of the RGK family of small GTPases, is enriched in nuclei of the basal ganglia

    PubMed Central

    Liput, Daniel J.; Lu, Van B.; Davis, Margaret I.; Puhl, Henry L.; Ikeda, Stephen R.

    2016-01-01

    Rem2 is a member of the RGK subfamily of RAS small GTPases. Rem2 inhibits high voltage activated calcium channels, is involved in synaptogenesis, and regulates dendritic morphology. Rem2 is the primary RGK protein expressed in the nervous system, but to date, the precise expression patterns of this protein are unknown. In this study, we characterized Rem2 expression in the mouse nervous system. In the CNS, Rem2 mRNA was detected in all regions examined, but was enriched in the striatum. An antibody specific for Rem2 was validated using a Rem2 knockout mouse model and used to show abundant expression in striatonigral and striatopallidal medium spiny neurons but not in several interneuron populations. In the PNS, Rem2 was abundant in a subpopulation of neurons in the trigeminal and dorsal root ganglia, but was absent in sympathetic neurons of superior cervical ganglia. Under basal conditions, Rem2 was subject to post-translational phosphorylation, likely at multiple residues. Further, Rem2 mRNA and protein expression peaked at postnatal week two, which corresponds to the period of robust neuronal maturation in rodents. This study will be useful for elucidating the functions of Rem2 in basal ganglia physiology. PMID:27118437

  12. Neutron radiation dosimetry in high altitude flight personnel.

    PubMed

    Baily, P E

    1982-08-01

    In an attempt to determine cosmic radiation exposure in high altitude NASA flight personnel, eight WB-57F flight crewmen were monitored for a period of six months using a combination radiation dosimeter. Each dosimeter consisted of two thermoluminescent chips capable of measuring gamma dose and one Albedo and two Track Etch neutron dosimeters. A total of 78 flights were monitored consisting of 251 flight hours at altitudes above 14 km (45,000 ft). The maximum yearly dose equivalent measured was 104 mrem, a value well below the Maximum Permissible Dose (MPD) of 5.0 rem/y for occupational exposures and 0.5 rem/y for members of the general public. A discussion of the theory and use of several types of neutron dosimeters is included. PMID:7181814

  13. Managing resident to resident elder mistreatment (R-REM) in nursing homes: the SEARCH approach

    PubMed Central

    Ellis, Julie; Teresi, Jeanne A.; Ramirez, Mildred; Silver, Stephanie; Boratgis, Gabriel; Kong, Jian; Eimicke, Joseph P.; Sukha, Gail; Lachs, Mark S.; Pillemer, Karl A.

    2014-01-01

    This article describes an educational program to inform nursing and care staff in the management of resident-to-resident elder mistreatment (R-REM) in nursing homes, using the SEARCH approach. Although relatively little research has been conducted on this form of abuse, there is mounting interest in R-REM, as such aggression has been found to be extensive and can have both physical and psychological consequences for residents and staff. The aim of the SEARCH approach is to support staff in the identification and recognition of R-REM, and suggesting recommendations for management. The education program and the SEARCH approach are described. Three case studies from the research project are presented, illustrating how the SEARCH approach can be used by nurses and care staff to manage R-REM in nursing homes. Resident- and staff safety and well-being can be enhanced by the use of the evidence-based SEARCH approach. PMID:24548656

  14. Augmented In Situ Subsurface Bioremediation Process™BIO-REM, Inc. - Demonstration Bulletin

    EPA Science Inventory

    The Augmented In Situ Subsurface Bioremediation Process™ developed by BIO-REM, Inc., uses microaerophilic bacteria and micronutrients (H-10) and surface tension depressants/penetrants for the treatment of hydrocarbon contaminated soils and groundwater. The bacteria utilize hydroc...

  15. The hypocretins (orexins) mediate the “phasic” components of REM sleep: A new hypothesis

    PubMed Central

    Torterolo, Pablo; Chase, Michael H.

    2014-01-01

    In 1998, a group of phenotypically distinct neurons were discovered in the postero-lateral hypothalamus which contained the neuropeptides hypocretin 1 and hypocretin 2 (also called orexin A and orexin B), which are excitatory neuromodulators. Hypocretinergic neurons project throughout the central nervous system and have been involved in the generation and maintenance of wakefulness. The sleep disorder narcolepsy, characterized by hypersomnia and cataplexy, is produced by degeneration of these neurons. The hypocretinergic neurons are active during wakefulness in conjunction with the presence of motor activity that occurs during survival-related behaviors. These neurons decrease their firing rate during non-REM sleep; however there is still controversy upon the activity and role of these neurons during REM sleep. Hence, in the present report we conducted a critical review of the literature of the hypocretinergic system during REM sleep, and hypothesize a possible role of this system in the generation of REM sleep. PMID:26483897

  16. Motivation and affect in REM sleep and the mentation reporting process.

    PubMed

    Smith, Mark R; Antrobus, John S; Gordon, Evelyn; Tucker, Matthew A; Hirota, Yasutaka; Wamsley, Erin J; Ross, Lars; Doan, Tieu; Chaklader, Annie; Emery, Rebecca N

    2004-09-01

    Although the emotional and motivational characteristics of dreaming have figured prominently in folk and psychoanalytic conceptions of dream production, emotions have rarely been systematically studied, and motivation, never. Because emotions during sleep lack the somatic components of waking emotions, and they change as the sleeper awakens, their properties are difficult to assess. Recent evidence of limbic system activation during REM sleep suggests a basis in brain architecture for the interaction of motivational and cognitive properties in dreaming. Motivational and emotional content in REM and NREM laboratory mentation reports from 25 participants were compared. Motivational and emotional content was significantly greater in REM than NREM sleep, even after controlling for the greater word count of REM reports.

  17. REM sleep and emotional face memory in typically-developing children and children with autism.

    PubMed

    Tessier, Sophie; Lambert, Andréane; Scherzer, Peter; Jemel, Boutheina; Godbout, Roger

    2015-09-01

    Relationship between REM sleep and memory was assessed in 13 neurotypical and 13 children with Autistic Spectrum Disorder (ASD). A neutral/positive/negative face recognition task was administered the evening before (learning and immediate recognition) and the morning after (delayed recognition) sleep. The number of rapid eye movements (REMs), beta and theta EEG activity over the visual areas were measured during REM sleep. Compared to neurotypical children, children with ASD showed more theta activity and longer reaction time (RT) for correct responses in delayed recognition of neutral faces. Both groups showed a positive correlation between sleep and performance but different patterns emerged: in neurotypical children, accuracy for recalling neutral faces and overall RT improvement overnight was correlated with EEG activity and REMs; in children with ASD, overnight RT improvement for positive and negative faces correlated with theta and beta activity, respectively. These results suggest that neurotypical and children with ASD use different sleep-related brain networks to process faces. PMID:26219603

  18. Immunocytochemical distribution of VIP and PACAP in the rat brain stem: implications for REM sleep physiology.

    PubMed

    Ahnaou, Abdel; Yon, Laurent; Arluison, Michel; Vaudry, Hubert; Hannibal, Jens; Hamon, Michel; Adrien, Joelle; Bourgin, Patrice

    2006-07-01

    Recent evidence indicates that pituitary adenylate cyclase-activating polypeptide (PACAP) and vasoactive intestinal polypeptide (VIP) might play an important role in rapid eye movement sleep (REMS) generation at the pontine level in rats. We have thus examined the immunohistochemical distribution of VIP and PACAP in the pontine and mesencephalic areas known to be involved in REMS control in rats. A dense network of VIP-immunoreactive cell bodies and fibers was found in the dorsal raphe nucleus. A large number of PACAP-positive perikarya and nerve fibers was observed in the area known as the REMS induction zone within the pontine reticular formation (PRF). The present results provide an anatomical basis to our previous functional data, and suggest that PACAPergic mechanisms within the PRF play a critical role in long-term regulation of REMS.

  19. LINEAR COUNT-RATE METER

    DOEpatents

    Henry, J.J.

    1961-09-01

    A linear count-rate meter is designed to provide a highly linear output while receiving counting rates from one cycle per second to 100,000 cycles per second. Input pulses enter a linear discriminator and then are fed to a trigger circuit which produces positive pulses of uniform width and amplitude. The trigger circuit is connected to a one-shot multivibrator. The multivibrator output pulses have a selected width. Feedback means are provided for preventing transistor saturation in the multivibrator which improves the rise and decay times of the output pulses. The multivibrator is connected to a diode-switched, constant current metering circuit. A selected constant current is switched to an averaging circuit for each pulse received, and for a time determined by the received pulse width. The average output meter current is proportional to the product of the counting rate, the constant current, and the multivibrator output pulse width.

  20. Low Cost Digital Vibration Meter

    PubMed Central

    Payne, W. Vance; Geist, Jon

    2007-01-01

    This report describes the development of a low cost, digital Micro Electro Mechanical System (MEMS) vibration meter that reports an approximation to the RMS acceleration of the vibration to which the vibration meter is subjected. The major mechanical element of this vibration meter is a cantilever beam, which is on the order of 500 µm in length, with a piezoresistor deposited at its base. Vibration of the device in the plane perpendicular to the cantilever beam causes it to bend, which produces a measurable change in the resistance of a piezoresistor. These changes in resistance along with a unique signal-processing scheme are used to determine an approximation to the RMS acceleration sensed by the device. PMID:27110459

  1. Arduino based radiation survey meter

    NASA Astrophysics Data System (ADS)

    Rahman, Nur Aira Abd; Lombigit, Lojius; Abdullah, Nor Arymaswati; Azman, Azraf; Dolah, Taufik; Muzakkir, Amir; Jaafar, Zainudin; Mohamad, Glam Hadzir Patai; Ramli, Abd Aziz Mhd; Zain, Rasif Mohd; Said, Fazila; Khalid, Mohd Ashhar; Taat, Muhamad Zahidee

    2016-01-01

    This paper presents the design of new digital radiation survey meter with LND7121 Geiger Muller tube detector and Atmega328P microcontroller. Development of the survey meter prototype is carried out on Arduino Uno platform. 16-bit Timer1 on the microcontroller is utilized as external pulse counter to produce count per second or CPS measurement. Conversion from CPS to dose rate technique is also performed by Arduino to display results in micro Sievert per hour (μSvhr-1). Conversion factor (CF) value for conversion of CPM to μSvhr-1 determined from manufacturer data sheet is compared with CF obtained from calibration procedure. The survey meter measurement results are found to be linear for dose rates below 3500 µSv/hr.

  2. Seepage meters and Bernoulli's revenge

    USGS Publications Warehouse

    Shinn, E.A.; Reich, C.D.; Hickey, T.D.

    2002-01-01

    Evaluation of seepage data from a network of 50 permanently deployed submarine seepage meters, specially constructed from fiberglass, indicates that the devices artificially advect (Bernoulli effect) shallow ground water. Reverse flow into the rock was not observed even when adjacent piezometers installed 2-m to 20-m below the rock-water interface indicated negative groundwater heads. Quantitative testing of five different designs, including conventional end-of-oil-drum designs, indicates that meters presenting positive relief on the sea floor are subject to the Bernoulli effect when placed in areas where there are waves and/or currents. Advection does not appear to be caused by flexing of the collection bags.

  3. Melanin-Concentrating Hormone (MCH): Role in REM Sleep and Depression.

    PubMed

    Torterolo, Pablo; Scorza, Cecilia; Lagos, Patricia; Urbanavicius, Jessika; Benedetto, Luciana; Pascovich, Claudia; López-Hill, Ximena; Chase, Michael H; Monti, Jaime M

    2015-01-01

    The melanin-concentrating hormone (MCH) is a peptidergic neuromodulator synthesized by neurons of the lateral sector of the posterior hypothalamus and zona incerta. MCHergic neurons project throughout the central nervous system, including areas such as the dorsal (DR) and median (MR) raphe nuclei, which are involved in the control of sleep and mood. Major Depression (MD) is a prevalent psychiatric disease diagnosed on the basis of symptomatic criteria such as sadness or melancholia, guilt, irritability, and anhedonia. A short REM sleep latency (i.e., the interval between sleep onset and the first REM sleep period), as well as an increase in the duration of REM sleep and the density of rapid-eye movements during this state, are considered important biological markers of depression. The fact that the greatest firing rate of MCHergic neurons occurs during REM sleep and that optogenetic stimulation of these neurons induces sleep, tends to indicate that MCH plays a critical role in the generation and maintenance of sleep, especially REM sleep. In addition, the acute microinjection of MCH into the DR promotes REM sleep, while immunoneutralization of this peptide within the DR decreases the time spent in this state. Moreover, microinjections of MCH into either the DR or MR promote a depressive-like behavior. In the DR, this effect is prevented by the systemic administration of antidepressant drugs (either fluoxetine or nortriptyline) and blocked by the intra-DR microinjection of a specific MCH receptor antagonist. Using electrophysiological and microdialysis techniques we demonstrated also that MCH decreases the activity of serotonergic DR neurons. Therefore, there are substantive experimental data suggesting that the MCHergic system plays a role in the control of REM sleep and, in addition, in the pathophysiology of depression. Consequently, in the present report, we summarize and evaluate the current data and hypotheses related to the role of MCH in REM sleep and MD

  4. Assessing the dream-lag effect for REM and NREM stage 2 dreams.

    PubMed

    Blagrove, Mark; Fouquet, Nathalie C; Henley-Einion, Josephine A; Pace-Schott, Edward F; Davies, Anna C; Neuschaffer, Jennifer L; Turnbull, Oliver H

    2011-01-01

    This study investigates evidence, from dream reports, for memory consolidation during sleep. It is well-known that events and memories from waking life can be incorporated into dreams. These incorporations can be a literal replication of what occurred in waking life, or, more often, they can be partial or indirect. Two types of temporal relationship have been found to characterize the time of occurrence of a daytime event and the reappearance or incorporation of its features in a dream. These temporal relationships are referred to as the day-residue or immediate incorporation effect, where there is the reappearance of features from events occurring on the immediately preceding day, and the dream-lag effect, where there is the reappearance of features from events occurring 5-7 days prior to the dream. Previous work on the dream-lag effect has used spontaneous home recalled dream reports, which can be from Rapid Eye Movement Sleep (REM) and from non-Rapid Eye Movement Sleep (NREM). This study addresses whether the dream-lag effect occurs only for REM sleep dreams, or for both REM and NREM stage 2 (N2) dreams. 20 participants kept a daily diary for over a week before sleeping in the sleep laboratory for 2 nights. REM and N2 dreams collected in the laboratory were transcribed and each participant rated the level of correspondence between every dream report and every diary record. The dream-lag effect was found for REM but not N2 dreams. Further analysis indicated that this result was not due to N2 dream reports being shorter, in terms of number of words, than the REM dream reports. These results provide evidence for a 7-day sleep-dependent non-linear memory consolidation process that is specific to REM sleep, and accord with proposals for the importance of REM sleep to emotional memory consolidation.

  5. Brain structures and mechanisms involved in the generation of REM sleep.

    PubMed

    Reinoso-Suárez, Fernando; de Andrés, Isabel; Rodrigo-Angulo, Margarita L.; Garzón, Miguel

    2001-02-01

    This article reviews the central nervous mechanisms involved in the broad network that generates and maintains REM sleep. Experimental investigations have identified the pontine tegmentum as the critical substrate for REM sleep mechanisms. Several pontine structures are involved in the generation of each particular polygraphic event that characterizes REM sleep: desynchronization in the electroencephalogram, theta rhythm in the hippocampus, muscle atonia, pontogeniculooccipital waves and rapid eye movements. The pontine tegmentum also holds the region where cholinergic stimulation can trigger all the behavioural and bioelectric signs of REM sleep. The exact location has been investigated and amply discussed over the last few years. Studies in the authors> laboratory, mapping the pontine tegmentum with small volume carbachol (a cholinergic agonist) microinjections, have demonstrated that the executive neurons for REM sleep generation are neither located in the dorsal part of the pontine tegmentum, nor diffusely spread through the medial pontine reticular formation: they are concentrated in a discrete area in the ventral part of the oral pontine reticular nucleus (vRPO). In turn, the vRPO has connections with structures involved in the generation of the other states of the sleep-wake cycle as well as with structures responsible for the generation of each of the different events characterizing REM sleep. This allows us to propose the vRPO as the crucial region for REM sleep generation. Related research, with invivo and invitro experiments, into the actions of different neurotransmitters on vRPO neurones indicates that not only acetylcholine but other neurotransmitters have an active key role in vRPO REM sleep generation mechanisms.

  6. Melatonin in patients with reduced REM sleep duration: two randomized controlled trials.

    PubMed

    Kunz, Dieter; Mahlberg, Richard; Müller, Cordula; Tilmann, Amely; Bes, Frederik

    2004-01-01

    Recent data suggest that melatonin may influence human physiology, including the sleep-wake cycle, in a time-dependent manner via the body's internal clock. Rapid-eye-movement (REM) sleep expression is strongly circadian modulated, and the impact of REM sleep on primary brain functions, metabolic processes, and immune system function has become increasingly clear over the past decade. In our study, we evaluated the effects of exogenous melatonin on disturbed REM sleep in humans. Fourteen consecutive outpatients (five women, nine men; mean age, 50 yr) with unselected neuropsychiatric sleep disorders and reduced REM sleep duration (25% or more below age norm according to diagnostic polysomnography) were included in two consecutive, randomized, double-blind, placebo-controlled, parallel design clinical trials. Patients received 3 mg melatonin daily, administered between 2200 and 2300 h for 4 wk. The results of the study show that melatonin was significantly more effective than placebo: patients on melatonin experienced significant increases in REM sleep percentage (baseline/melatonin, 14.7/17.8 vs. baseline/placebo, 14.3/12.0) and improvements in subjective measures of daytime dysfunction as well as clinical global impression score. Melatonin did not shift circadian phase or suppress temperature but did increase REM sleep continuity and promote decline in rectal temperature during sleep. These results were confirmed in patients who received melatonin in the second study (REM sleep percentage baseline/placebo/melatonin, 14.3/12.0/17.9). In patients who received melatonin in the first study and placebo in the second, the above mentioned effects outlasted the period of melatonin administration and diminished only slowly over time (REM sleep percentage baseline/melatonin/placebo, 14.7/17.8/16.2). Our findings show that exogenous melatonin, when administered at the appropriate time, seems to normalize circadian variation in human physiology. It may, therefore, have a

  7. Arousal state feedback as a potential physiological generator of the ultradian REM/NREM sleep cycle.

    PubMed

    Phillips, A J K; Robinson, P A; Klerman, E B

    2013-02-21

    Human sleep episodes are characterized by an approximately 90-min ultradian oscillation between rapid eye movement (REM) and non-REM (NREM) sleep stages. The source of this oscillation is not known. Pacemaker mechanisms for this rhythm have been proposed, such as a reciprocal interaction network, but these fail to account for documented homeostatic regulation of both sleep stages. Here, two candidate mechanisms are investigated using a simple model that has stable states corresponding to Wake, REM sleep, and NREM sleep. Unlike other models of the ultradian rhythm, this model of sleep dynamics does not include an ultradian pacemaker, nor does it invoke a hypothetical homeostatic process that exists purely to drive ultradian rhythms. Instead, only two inputs are included: the homeostatic drive for Sleep and the circadian drive for Wake. These two inputs have been the basis for the most influential Sleep/Wake models, but have not previously been identified as possible ultradian rhythm generators. Using the model, realistic ultradian rhythms are generated by arousal state feedback to either the homeostatic or circadian drive. For the proposed 'homeostatic mechanism', homeostatic pressure increases in Wake and REM sleep, and decreases in NREM sleep. For the proposed 'circadian mechanism', the circadian drive is up-regulated in Wake and REM sleep, and is down-regulated in NREM sleep. The two mechanisms are complementary in the features they capture. The homeostatic mechanism reproduces experimentally observed rebounds in NREM sleep duration and intensity following total sleep deprivation, and rebounds in both NREM sleep intensity and REM sleep duration following selective REM sleep deprivation. The circadian mechanism does not reproduce sleep state rebounds, but more accurately reproduces the temporal patterns observed in a normal night of sleep. These findings have important implications in terms of sleep physiology and they provide a parsimonious explanation for the

  8. REM sleep loss and recovery regulates blood-brain barrier function.

    PubMed

    Gómez-González, Beatriz; Hurtado-Alvarado, Gabriela; Esqueda-León, Enrique; Santana-Miranda, Rafael; Rojas-Zamorano, José Ángel; Velázquez-Moctezuma, Javier

    2013-08-01

    The functions of rapid eye movement (REM) sleep have remained elusive since more than 50 years. Previous reports have identified several independent processes affected by the loss and subsequent recovery of REM sleep (hippocampal neurogenesis, brain stem neuronal cell death, and neurotransmitter content in several brain regions); however, a common underlying mechanism has not been found. We propose that altered brain homeostasis secondary to blood-brain barrier breakdown may explain all those changes induced by REM sleep loss. Therefore, the present report aimed to study the consequences of REM sleep restriction upon blood-brain barrier permeability to Evans blue. REM sleep restriction was induced by the multiple platform technique; male rats were REM sleep restricted 20h daily (with 4h sleep opportunity) during 10 days; control groups included large platform and intact rats. To study blood-brain barrier permeability Evans blue was intracardially administered; stained brains were sliced and photographed for optical density quantification. An independent experiment was carried out to elucidate the mechanism of blood-brain breakdown by transmission electron microscopy. REM sleep restriction increased blood-brain barrier permeability to Evans blue in the whole brain as compared to both control groups. Brief periods of sleep recovery rapidly and effectively restored the severe alteration of blood-brain barrier function by reducing blood-to-brain transfer of Evans blue. The mechanism of blood-brain barrier breakdown involved increased caveolae formation at brain endothelial cells. In conclusion, our data suggest that REM sleep regulates the physical barrier properties of the blood-brain barrier.

  9. GABA(A) receptors implicated in REM sleep control express a benzodiazepine binding site.

    PubMed

    Nguyen, Tin Quang; Liang, Chang-Lin; Marks, Gerald A

    2013-08-21

    It has been reported that non-subtype-selective GABAA receptor antagonists injected into the nucleus pontis oralis (PnO) of rats induced long-lasting increases in REM sleep. Characteristics of these REM sleep increases were identical to those resulting from injection of muscarinic cholinergic agonists. Both actions were blocked by the muscarinic antagonist, atropine. Microdialysis of GABAA receptor antagonists into the PnO resulted in increased acetylcholine levels. These findings were consistent with GABAA receptor antagonists disinhibiting acetylcholine release in the PnO to result in an acetylcholine-mediated REM sleep induction. Direct evidence has been lacking for localization in the PnO of the specific GABAA receptor-subtypes mediating the REM sleep effects. Here, we demonstrated a dose-related, long-lasting increase in REM sleep following injection (60 nl) in the PnO of the inverse benzodiazepine agonist, methyl-6,7-dimethoxy-4-ethyl-β-carboline (DMCM, 10(-2)M). REM sleep increases were greater and more consistently produced than with the non-selective antagonist gabazine, and both were blocked by atropine. Fluorescence immunohistochemistry and laser scanning confocal microscopy, colocalized in PnO vesicular acetylcholine transporter, a presynaptic marker of cholinergic boutons, with the γ2 subunit of the GABAA receptor. These data provide support for the direct action of GABA on mechanisms of acetylcholine release in the PnO. The presence of the γ2 subunit at this locus and the REM sleep induction by DMCM are consistent with binding of benzodiazepines by a GABAA receptor-subtype in control of REM sleep.

  10. The predictive value of Muller maneuver in REM-dependent obstructive sleep apnea.

    PubMed

    Ozcan, Kursat Murat; Ozcan, Muge; Ozdogan, Fatih; Hizli, Omer; Dere, Huseyin; Unal, Adnan

    2013-09-01

    To our knowledge, no studies up to date have investigated the correlation of rapid eye movement (REM) dependent obstructive sleep apnea syndrome (OSAS) and Muller maneuver. The aim of this study is to investigate whether REM-dependent OSAS is predicted by the findings of the Muller maneuver. The study was conducted on 149 patients with witnessed apnea and daytime sleepiness. Muller maneuver was performed to all patients and the obstruction site was determined using a five-point scale. Then, polysomnography of the patient was obtained and the apnea-hypopnea indexes were determined in total sleep time, REM-dependent sleep and non-REM-dependent sleep. The correlations between the Muller maneuver findings and polysomnographic data were analyzed. The ages of the patients included in the study ranged between 25 and 73 years with a mean age of 49.3 ± 10.1 years. Their mean body mass index was 30.8 ± 5.1 kg/m(2) (range 21.9-55.4 kg/m(2)). The patients' mean apnea-hypopnea indexes in total sleep time was 28.1 and ranged between 5.4 and 124.3. REM-dependent OSAS was determined in 49 patients. When the data were analyzed, it was determined that there were no statistically significant correlations between tongue base or lateral pharyngeal band obstruction at the level of hypopharynx and the REM-dependent OSAS. At the level of the soft palate, the obstruction caused by the lateral pharyngeal bands or soft palate and REM dependency did not show any statistically significant correlation (p > 0.05). In conclusion, Muller maneuver does not provide useful data to predict REM dependency of OSAS.

  11. Melanin-Concentrating Hormone (MCH): Role in REM Sleep and Depression

    PubMed Central

    Torterolo, Pablo; Scorza, Cecilia; Lagos, Patricia; Urbanavicius, Jessika; Benedetto, Luciana; Pascovich, Claudia; López-Hill, Ximena; Chase, Michael H.; Monti, Jaime M.

    2015-01-01

    The melanin-concentrating hormone (MCH) is a peptidergic neuromodulator synthesized by neurons of the lateral sector of the posterior hypothalamus and zona incerta. MCHergic neurons project throughout the central nervous system, including areas such as the dorsal (DR) and median (MR) raphe nuclei, which are involved in the control of sleep and mood. Major Depression (MD) is a prevalent psychiatric disease diagnosed on the basis of symptomatic criteria such as sadness or melancholia, guilt, irritability, and anhedonia. A short REM sleep latency (i.e., the interval between sleep onset and the first REM sleep period), as well as an increase in the duration of REM sleep and the density of rapid-eye movements during this state, are considered important biological markers of depression. The fact that the greatest firing rate of MCHergic neurons occurs during REM sleep and that optogenetic stimulation of these neurons induces sleep, tends to indicate that MCH plays a critical role in the generation and maintenance of sleep, especially REM sleep. In addition, the acute microinjection of MCH into the DR promotes REM sleep, while immunoneutralization of this peptide within the DR decreases the time spent in this state. Moreover, microinjections of MCH into either the DR or MR promote a depressive-like behavior. In the DR, this effect is prevented by the systemic administration of antidepressant drugs (either fluoxetine or nortriptyline) and blocked by the intra-DR microinjection of a specific MCH receptor antagonist. Using electrophysiological and microdialysis techniques we demonstrated also that MCH decreases the activity of serotonergic DR neurons. Therefore, there are substantive experimental data suggesting that the MCHergic system plays a role in the control of REM sleep and, in addition, in the pathophysiology of depression. Consequently, in the present report, we summarize and evaluate the current data and hypotheses related to the role of MCH in REM sleep and MD

  12. A Mathematical Model towards Understanding the Mechanism of Neuronal Regulation of Wake-NREMS-REMS States

    PubMed Central

    Kumar, Rupesh; Bose, Amitabha; Mallick, Birendra Nath

    2012-01-01

    In this study we have constructed a mathematical model of a recently proposed functional model known to be responsible for inducing waking, NREMS and REMS. Simulation studies using this model reproduced sleep-wake patterns as reported in normal animals. The model helps to explain neural mechanism(s) that underlie the transitions between wake, NREMS and REMS as well as how both the homeostatic sleep-drive and the circadian rhythm shape the duration of each of these episodes. In particular, this mathematical model demonstrates and confirms that an underlying mechanism for REMS generation is pre-synaptic inhibition from substantia nigra onto the REM-off terminals that project on REM-on neurons, as has been recently proposed. The importance of orexinergic neurons in stabilizing the wake-sleep cycle is demonstrated by showing how even small changes in inputs to or from those neurons can have a large impact on the ensuing dynamics. The results from this model allow us to make predictions of the neural mechanisms of regulation and patho-physiology of REMS. PMID:22905114

  13. Single-neuron activity and eye movements during human REM sleep and awake vision

    PubMed Central

    Andrillon, Thomas; Nir, Yuval; Cirelli, Chiara; Tononi, Giulio; Fried, Itzhak

    2015-01-01

    Are rapid eye movements (REMs) in sleep associated with visual-like activity, as during wakefulness? Here we examine single-unit activities (n=2,057) and intracranial electroencephalography across the human medial temporal lobe (MTL) and neocortex during sleep and wakefulness, and during visual stimulation with fixation. During sleep and wakefulness, REM onsets are associated with distinct intracranial potentials, reminiscent of ponto-geniculate-occipital waves. Individual neurons, especially in the MTL, exhibit reduced firing rates before REMs as well as transient increases in firing rate immediately after, similar to activity patterns observed upon image presentation during fixation without eye movements. Moreover, the selectivity of individual units is correlated with their response latency, such that units activated after a small number of images or REMs exhibit delayed increases in firing rates. Finally, the phase of theta oscillations is similarly reset following REMs in sleep and wakefulness, and after controlled visual stimulation. Our results suggest that REMs during sleep rearrange discrete epochs of visual-like processing as during wakefulness. PMID:26262924

  14. Oximetry Signal Processing Identifies REM Sleep-Related Vulnerability Trait in Asthmatic Children

    PubMed Central

    Perez, Geovanny F.; Gutierrez, Maria J.; Huseni, Shehlanoor; Pancham, Khrisna; Rodriguez-Martinez, Carlos E.; Nino, Cesar L.; Nino, Gustavo

    2013-01-01

    Rationale. The sleep-related factors that modulate the nocturnal worsening of asthma in children are poorly understood. This study addressed the hypothesis that asthmatic children have a REM sleep-related vulnerability trait that is independent of OSA. Methods. We conducted a retrospective cross-sectional analysis of pulse-oximetry signals obtained during REM and NREM sleep in control and asthmatic children (n = 134). Asthma classification was based on preestablished clinical criteria. Multivariate linear regression model was built to control for potential confounders (significance level P ≤ 0.05). Results. Our data demonstrated that (1) baseline nocturnal respiratory parameters were not significantly different in asthmatic versus control children, (2) the maximal % of SaO2 desaturation during REM, but not during NREM, was significantly higher in asthmatic children, and (3) multivariate analysis revealed that the association between asthma and REM-related maximal % SaO2 desaturation was independent of demographic variables. Conclusion. These results demonstrate that children with asthma have a REM-related vulnerability trait that impacts oxygenation independently of OSA. Further research is needed to delineate the REM sleep neurobiological mechanisms that modulate the phenotypical expression of nocturnal asthma in children. PMID:24288619

  15. Individual differences in compensatory rebound of REM sleep, with particular reference to their relationship to personality and behavioral characteristics.

    PubMed

    Nakazawa, Y; Kotorii, M; Kotorii, T; Tachibana, H; Nakano, T

    1975-07-01

    In subjecting 14 healthy university students to partial differential rapid eye movement (REM) sleep deprivation (PDRD), the compensatory rebound of REM sleep during the next night was determined, and showed fairly substantial individual differences in the increased percentage of REM sleep time. This rate was approximately the same for the same individual for two sleep recordings. These individual differences had no positive correlation with the decreased rate of REM time in the PDRD nights or with the percentage of REM time in the baseline night. Therefore, the individual differences in the increased percentage of REM time can be presumed to reflect individual differences in need for deprived REM sleep. Next, we looked into the relationship between the individual subject's personality and behavior characteristics, and his increased percentage of REM time. This revealed that the individuals who were extrovertive, active, optimistic, showy, and who had many friends had significantly higher increases in the percentage of REM time than the individuals who were introvertive, neurotic, inactive, nervous, modest, and who had few friends. Also discussed was the neurophysiological and biochemical basis of the central nervous system as the background for the relationship between the personality and behavioral characteristics and the increased percentage of REM sleep time. PMID:168312

  16. Bioanalysis young investigator: Alexander Medina-Remón.

    PubMed

    Medina-Remón, Alexander; Raventós, Rosa Maria Lamuela

    2011-07-01

    Supervisor's supporting comments Alex Medina joined my research group, Natural Antioxidants, in January 2006 to start his PhD program. He has been working intensively and efficiently on several projects; initially for his thesis he developed a new bioanalytical methodology to quantify phenols in urine (Medina-Remón A et al. 2009) to correlate with the hypertension prevention in the PREDIMED study ( www.predimed.org ). Thanks to this new bioanalytical method, we are currently starting collaboration projects with different research centers. In addition, he has been working on other research projects on tomatoes, grapes, citric fruits and wine. Medina is helpful whenever needed and efficient. He has shown himself to be responsible, well-prepared, intelligent, organized and to have very good teaching skills. Moreover, he is patient and able to solve problems calmly, but at the same time, he is enthusiastic about what he does and can transmit this enthusiasm to his colleagues. He is really a thoughtful scientist. I have now contracted him as a Postdoctoral researcher. His responsibilities include leading several master's students and he is writing several papers on the health effects of polyphenols using his method.

  17. UV Opacity at Gale Crater from MSL/REMS Measurements

    NASA Astrophysics Data System (ADS)

    Vicente-Retortillo, Á.; Martinez, G.; Renno, N. O.; Lemmon, M. T.; Mason, E. L.; de la Torre-Juárez, M.

    2015-12-01

    We use the UV photodiode output currents (TELRDR products) measured by the REMS Ultraviolet Sensor to calculate UV opacities at Gale crater during the first 804 sols of the MSL mission. We propose a novel technique to calculate the atmospheric opacity that is not sensitive to the degradation of the sensor due to the deposition of dust on it. We estimate the diffuse and total radiation signals by analyzing the events in which the direct solar beam was temporarily blocked by the masthead or by the mast of the rover. Then we use a radiative transfer model based on the Monte-Carlo method to obtain the UV opacity from those measurements. We compare the UV opacities with the opacities derived from Mastcam observations at 880 nm. Both opacities follow a similar seasonal trend, with the UV opacity showing values generally lower than those at 880 nm. The difference between both opacities varies over the year, with the minimum difference occurring when both opacities show their annual lowest values (Ls ~ 130º). The temporal variation of this difference may be attributed to changes in the dust size distribution.

  18. Direct-reading inductance meter

    NASA Technical Reports Server (NTRS)

    Kolbly, R. B.

    1977-01-01

    Meter indicates from 30 nH to 3 micro H. Reference inductor of 15 micro H is made by winding 50 turns of Number 26 Formvar wire on Micrometal type 50-2 (or equivalent) core. Circuit eliminates requirement for complex instrument compensation prior to taking coil inductance measurement and thus is as easy to operate as common ohmmeter.

  19. A Redesigned DFA Moisture Meter

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The DFA moisture meter has been internationally recognized as the standard for determining moisture content of dried fruit in general and is AOAC Official Method 972.2 for measuring moisture in prunes and raisins since 1972. The device has remained virtually unchanged since its inception, with its o...

  20. A Classification method for eye movements direction during REM sleep trained on wake electro-oculographic recordings

    PubMed Central

    Betta, M.; Laurino, M.; Gemignani, A.; Landi, A.; Menicucci, D.

    2016-01-01

    Rapid eye movements (REMs) are a peculiar and intriguing aspect of REM sleep, even if their physiological function still remains unclear. During this work, a new automatic tool was developed, aimed at a complete description of REMs activity during the night, both in terms of their timing of occurrence that in term of their directional properties. A classification stage of each singular movement detected during the night according to its main direction, was in fact added to our procedure of REMs detection and ocular artifact removal. A supervised classifier was constructed, using as training and validation set EOG data recorded during voluntary saccades of five healthy volunteers. Different classification methods were tested and compared. The further information about REMs directional characteristic provided by the procedure would represent a valuable tool for a deeper investigation into REMs physiological origin and functional meaning. PMID:26736276

  1. Prediction analysis of dose equivalent responses of neutron dosemeters used at a MOX fuel facility.

    PubMed

    Tsujimura, N; Yoshida, T; Takada, C

    2011-07-01

    To predict how accurately neutron dosemeters can measure the neutron dose equivalent (rate) in MOX fuel fabrication facility work environments, the dose equivalent responses of neutron dosemeters were calculated by the spectral folding method. The dosemeters selected included two types of personal dosemeter, namely a thermoluminescent albedo neutron dosemeter and an electronic neutron dosemeter, three moderator-based neutron survey meters, and one special instrument called an H(p)(10) monitor. The calculations revealed the energy dependences of the responses expected within the entire range of neutron spectral variations observed in neutron fields at workplaces. PMID:21498409

  2. Fast Neutron Sensitivity with HPGe

    SciTech Connect

    Seifert, Allen; Hensley, Walter K.; Siciliano, Edward R.; Pitts, W. K.

    2008-01-22

    In addition to being excellent gamma-ray detectors, germanium detectors are also sensitive to fast neutrons. Incident neutrons undergo inelastic scattering {Ge(n,n')Ge*} off germanium nuclei and the resulting excited states emit gamma rays or conversion electrons. The response of a standard 140% high-purity germanium (HPGe) detector with a bismuth germanate (BGO) anti-coincidence shield was measured for several neutron sources to characterize the ability of the HPGe detector to detect fast neutrons. For a sensitivity calculation performed using the characteristic fast neutron response peak that occurs at 692 keV, the 140% germanium detector system exhibited a sensitivity of ~175 counts / kg of WGPumetal in 1000 seconds at a source-detector distance of 1 meter with 4 in. of lead shielding between source and detector. Theoretical work also indicates that it might be possible to use the shape of the fast-neutron inelastic scattering signatures (specifically, the end-point energy of the long high energy tail of the resulting asymmetric peak) to gain additional information about the energy distribution of the incident neutron spectrum. However, the experimentally observed end-point energies appear to be almost identical for each of the fast neutron sources counted. Detailed MCNP calculations show that the neutron energy distributions impingent on the detector for these sources are very similar in this experimental configuration, due to neutron scattering in a lead shield (placed between the neutron source and HPGe detector to reduce the gamma ray flux), the BGO anti-coincidence detector, and the concrete floor.

  3. Radiation obscuration by dust devils at Gale as observed by the REMS UV Sensor

    NASA Astrophysics Data System (ADS)

    Zorzano, María-Paz; Martín-Torres, Francisco Javier; Kahanpää, Henrik; Moore, John; Navarro, Sara; Lepinette, Alain; Sebastian, Eduardo; Gómez-Elvira, Javier; REMS Team; MSL Science Team

    2013-04-01

    The Rover Environmental Monitoring Station (REMS) on board the Curiosity rover has been exploring the surface environment of Mars since its arrival to Gale on August 2012. REMS provides a mimimum of 5 minutes of acquisitions every hour and extended 1-hour acquisitions of all its sensors, namely wind, air temperature, ground temperature, pressure, humidity and ultraviolet sensors. The UV sensor (UVS) of REMS is dedicated to monitoring the downwelling UV irradiance as well as to monitor the atmospheric dust cycle of Mars. This includes observation of plausible dust loading processes such as dust devils. A dust devil is a convective vortex that rises dust in a whirlwind structure. The base of the dust devil moves with a certain speed and its column of dust may traverse the path of observation of the Sun. Usually when this happens a sudden drop of the UV signature is observed. In other cases a plume rises dust and changes the UV diffuse irradiance profile. Since the beginning of REMS operations in Mars, a number of processes have left signatures on the UV direct or diffuse irradiance as observed by the REMS UV sensor. The signatures of some specific examples are analyzed and compared with the observations provided by other REMS sensors. These are the first measurements of its kind of a dust devil in Mars and provide estimates of the UV opacity of these structures and of their scale. When an obscuration is observed the decay of each specific channel can used to evaluate the spectral variation of the irradiance. This kind of studies may be extremelly interesting to compare with visible opacities of dust devils as observed by the MSL cameras. The regular acquisition pattern of REMS will allow to estimate sistematically the opacity of these structures during the two years of nominal operation from the Martian surface.

  4. REM sleep loss associated changes in orexin-A levels in discrete brain areas in rats.

    PubMed

    Mehta, Rachna; Khanday, Mudasir Ahmad; Mallick, Birendra Nath

    2015-03-17

    Rapid eye movement sleep (REMS) serves house-keeping function of the brain and its loss affects several pathophysiological processes. Relative levels of neurotransmitters including orexin A (Orx-A) in various parts of the brain in health and diseases are among the key factors for modulation of behaviors, including REMS. The level of neurotransmitter in an area in the brain directly depends on number of projecting neurons and their firing rates. The locus coeruleus (LC), the site of REM-OFF neurons, receives densest, while the pedunculo-pontine area (PPT), the site of REM-ON neurons receives lesser projections from the Orx-ergic neurons. Further, the Orx-ergic neurons are active during waking and silent during REMS and NREMS. Therefore, the level of Orx-A in discrete regions of the brain is likely to be different during normal and altered states, which in turn is likely to be responsible for altered behaviors in health and diseases, including in relation to REMS. Therefore, in the present study, we estimated Orx-A level in LC, cortex, posterior hypothalamus (PH), hippocampus, and PPT after 96 h REMSD, in post-deprivation recovered rats and in control rats. This is the first report of estimation of Orx-A in different brain regions after prolonged REMSD. It was observed that after REMSD the Orx-A level increased significantly in LC, cortex and PH which returned to normal level after recovery; however, the level did not change in the hippocampus and PPT. The Orx-A induced modulation of REMS could be secondary to increased waking.

  5. REM sleep changes in rats induced by siRNA-mediated orexin knockdown.

    PubMed

    Chen, Lichao; Thakkar, Mahesh M; Winston, Stuart; Bolortuya, Yunren; Basheer, Radhika; McCarley, Robert W

    2006-10-01

    Short interfering RNAs (siRNA) targeting prepro-orexin mRNA were microinjected into the rat perifornical hypothalamus. Prepro-orexin siRNA-treated rats had a significant (59%) reduction in prepro-orexin mRNA compared to scrambled siRNA-treated rats 2 days postinjection, whereas prodynorphin mRNA was unaffected. The number of orexin-A-positive neurons on the siRNA-treated side decreased significantly (23%) as compared to the contralateral control (scrambled siRNA-treated) side. Neither the colocalized dynorphin nor the neighbouring melanin-concentrating hormone neurons were affected. The number of orexin-A-positive neurons on the siRNA-treated side did not differ from the number on the control side 4 or 6 days postinjection. Behaviourally, there was a persistent (approximately 60%) increase in the amount of time spent in rapid eye movement (REM) sleep during the dark (active) period for 4 nights postinjection, in rats treated with prepro-orexin siRNA bilaterally. This increase occurred mainly because of an increased number of REM episodes and decrease in REM-to-REM interval. Cataplexy-like episodes were also observed in some of these animals. Wakefulness and NREM sleep were unaffected. The siRNA-induced increase in REM sleep during the dark cycle reverted to control values on the 5th day postinjection. In contrast, the scrambled siRNA-treated animals only had a transient increase in REM sleep for the first postinjection night. Our results indicate that siRNA can be usefully employed in behavioural studies to complement other loss-of-function approaches. Moreover, these data suggest that the orexin system plays a role in the diurnal gating of REM sleep.

  6. Effects of age on recovery of body weight following REM sleep deprivation of rats.

    PubMed

    Koban, Michael; Stewart, Craig V

    2006-01-30

    Chronically enforced rapid eye (paradoxical) movement sleep deprivation (REM-SD) of rats leads to a host of pathologies, of which hyperphagia and loss of body weight are among the most readily observed. In recent years, the etiology of many REM-SD-associated pathologies have been elucidated, but one unexplored area is whether age affects outcomes. In this study, male Sprague-Dawley rats at 2, 6, and 12 months of age were REM sleep-deprived with the platform (flowerpot) method for 10-12 days. Two-month-old rats resided on 7-cm platforms, while 10-cm platforms were used for 6- and 12-month-old rats; rats on 15-cm platforms served as tank controls (TCs). Daily changes in food consumption (g/kg(0.67)) and body weight (g) during baseline, REM-SD or TCs, and post-experiment recovery in home cages were determined. Compared to TCs, REM-SD resulted in higher food intake and decreases in body weight. When returned to home cages, food intake rapidly declined to baseline levels. Of primary interest was that rates of body weight gain during recovery differed between the age groups. Two-month-old rats rapidly restored body weight to pre-REM-SD mass within 5 days; 6-month-old rats were extrapolated by linear regression to have taken about 10 days, and for 12-month-old rats, the estimate was about 35 days. The observation that restoration of body weight following its loss during REM-SD may be age-dependent is in general agreement with the literature on aging effects on how mammals respond to stress. PMID:16243367

  7. Federal Building Metering Guidance (per 42 U.S.C. 8253(e), Metering of Energy Use)

    SciTech Connect

    2014-11-01

    Guidance defines which federal buildings are appropriate to meter, provides metering prioritization recommendations for agencies with limited resources, and discusses the requirement for agencies to submit metering implementation plans to the U.S. Department of Energy.

  8. Microinjection of the melanin-concentrating hormone into the sublaterodorsal tegmental nucleus inhibits REM sleep in the rat.

    PubMed

    Monti, Jaime M; Torterolo, Pablo; Jantos, Héctor; Lagos, Patricia

    2016-09-01

    A study was performed on the effects of local microinjection of melanin-concentrating hormone (MCH) into the right sublaterodorsal tegmental nucleus (SLD) on sleep and wakefulness in rats prepared for chronic sleep recordings. MCH 200ng significantly decreased rapid-eye-movement sleep (REMS) time during the first and second 2-h of the recording period which was related to the reduction of the number of REMS periods and the increase of REMS latency. It is proposed that REMS inhibition was related to the direct deactivation of SLD glutamatergic neurons by the peptide. PMID:27461793

  9. Effects of REM sleep awakenings and related wakening paradigms on the ultradian sleep cycle and the symptoms in depression.

    PubMed

    Grözinger, Michael; Kögel, Pia; Röschke, Joachim

    2002-01-01

    In 1975 Vogel and coworkers published their classical study where they compared selective rapid eye movement (REM) sleep deprivation by brief awakenings to a control intervention paradigm in depressed patients. The superior antidepressive impact of the first procedure was attributed to the REM pressure accumulating during the treatment period. The laborious procedure and the considerable effort necessary to evaluate the sleep profiles in real time have prevented similar experiments so far. Based on artificial neural networks we developed a software for the real time detection of REM sleep. In combination with an alarm system the algorithm allowed us to wake up subjects automatically and to reduce REM sleep by about 50%. The procedure was then compared to a modified nonREM intervention paradigm for a treatment period of ten consecutive nights in depressed patients (n(1)=14, n(2)=13). These simultaneously received moderate dosages of Trimipramine. We found a strong and robust but not significantly different reduction of the average Hamilton rating scores (33 and 41% of baseline levels). While the REM sleep awakenings shortened the sleep cycle duration considerably, our nonREM intervention paradigm lengthened the ultradian alternations. Both effects might be interpreted as a challenge imposed on the nonREM-REM alternating mechanism possibly responsible for the antidepressive impact. A different timing of the control interventions might have caused the discrepancy between our findings and those of Vogel and coworkers.

  10. Increased REM sleep after intra-locus coeruleus nucleus microinjection of melanin-concentrating hormone (MCH) in the rat.

    PubMed

    Monti, Jaime M; Lagos, Patricia; Jantos, Héctor; Torterolo, Pablo

    2015-01-01

    A study was carried out on the effects of unilateral microinjection of melanin-concentrating hormone (MCH) into the right locus coeruleus (LC) on the sleep-wake cycle in rats prepared for chronic sleep recordings. MCH 200 ng significantly augmented rapid-eye-movement sleep (REMS) time during the first, second and third 2-h of recording. Furthermore, MCH 100 ng induced a significant increase of REMS during the first 2-h period after treatment. The increment of the behavioral state was related to a greater number of REMS episodes. It is suggested that MCH deactivation of noradrenergic neurons located in the LC facilitates the occurrence of REMS.

  11. Activation of serotonin 5-HT(1B) receptor in the dorsal raphe nucleus affects REM sleep in the rat.

    PubMed

    Monti, Jaime M; Jantos, Héctor; Lagos, Patricia

    2010-01-01

    The effects of CP-94253, a selective 5-HT(1B) receptor agonist, and of SB 224-289, a selective 5-HT(1B) receptor antagonist, on spontaneous sleep were studied in adult rats implanted for chronic sleep recordings. The 5-HT(1B) receptor ligands were microinjected directly into the dorsal raphe nucleus (DRN) during the light period of the 12-h light/12-h dark cycle. Infusion of CP-94253 (1-4 mM) into the DRN induced a significant reduction of rapid-eye-movement sleep (REMS) and of the mean duration of REM episodes. On the other hand, SB 224-289 (0.25-0.5 mM) decreased REMS and the number of REM periods. Pretreatment with SB 224-289 (0.125-0.25 mM) antagonized the CP-94253 (4 mM)-induced reduction of REMS and of the mean duration of REM periods. Administration of the GABA(A) receptor agonist muscimol (1.5mM), which by itself did not significantly affect sleep variables, prevented the effect of CP-94253 (4 mM) on REMS suppression. It is proposed that the suppression of REMS after microinjection of CP-94253 into the DRN is related to the inhibition of GABAergic interneurons that make synaptic contacts with serotonergic cells. The resultant increase of serotonin release at postsynaptic sites involved in the induction and maintenance of REMS would induce the suppression of the behavioral state.

  12. Effects of biperiden on sleep at baseline and after 72 h of REM sleep deprivation in the cat.

    PubMed

    Salin-Pascual, R J; Jimenez-Anguiano, A; Granados-Fuentes, D; Drucker-Colin, R

    1992-01-01

    We examined the effects of the muscarinic M1 antagonist biperiden in cats. In the first experiment a dose-response analysis was performed with intraventricular injection (IV ventricle) of biperiden. In the second experiment after REM sleep deprivation cats were injected with either biperiden (0.1 mg/kg) or saline. Biperiden produced a reduction in REM sleep percentage and an increase in REM sleep latency with these high doses. The 0.1 mg/kg biperiden dose, which did not suppress REM sleep at baseline, did reduce the REM sleep rebound. The present study suggests a modulatory role of biperiden on REM sleep regulatory processes. The fact that an effect of biperiden is noted only at the high doses suggests that at these doses the drug is influencing non-M1 receptors. Changes in the sensitivity of these receptors as a result of REM sleep deprivation might explain why a dose of biperiden will reduce REM sleep rebound, while being ineffective in suppressing REM sleep at baseline.

  13. Senior Vipassana Meditation practitioners exhibit distinct REM sleep organization from that of novice meditators and healthy controls.

    PubMed

    Maruthai, Nirmala; Nagendra, Ravindra P; Sasidharan, Arun; Srikumar, Sulekha; Datta, Karuna; Uchida, Sunao; Kutty, Bindu M

    2016-06-01

    Abstract/Summary The present study is aimed to ascertain whether differences in meditation proficiency alter rapid eye movement sleep (REM sleep) as well as the overall sleep-organization. Whole-night polysomnography was carried out using 32-channel digital EEG system. 20 senior Vipassana meditators, 16 novice Vipassana meditators and 19 non-meditating control subjects participated in the study. The REM sleep characteristics were analyzed from the sleep-architecture of participants with a sleep efficiency index >85%. Senior meditators showed distinct changes in sleep-organization due to enhanced slow wave sleep and REM sleep, reduced number of intermittent awakenings and reduced duration of non-REM stage 2 sleep. The REM sleep-organization was significantly different in senior meditators with more number of REM episodes and increased duration of each episode, distinct changes in rapid eye movement activity (REMA) dynamics due to increased phasic and tonic activity and enhanced burst events (sharp and slow bursts) during the second and fourth REM episodes. No significant differences in REM sleep organization was observed between novice and control groups. Changes in REM sleep-organization among the senior practitioners of meditation could be attributed to the intense brain plasticity events associated with intense meditative practices on brain functions.

  14. Government Program Briefing: Smart Metering

    SciTech Connect

    Doris, E.; Peterson, K.

    2011-09-01

    This document is adapted and updated from a memo delivered to the City Council of New Orleans, the office of the Mayor of New Orleans, the Chairperson of the Citizen Stakeholders Group (New Orleans Energy Task Force) and the U.S. Department of Energy (DOE) Project Officer in March 2008. This briefing piece provides an overview of the benefits, costs, and challenges of smart metering.

  15. A color sensor wavelength meter

    NASA Astrophysics Data System (ADS)

    Durfee, Dallin; Jackson, Jarom; Otterstrom, Nils; Jones, Tyler; Archibald, James

    2016-05-01

    We will discuss a laser wavelength meter based on a commercial color sensor chip consisting of an array of photodiodes with different absorptive color filters. By comparing the relative amplitudes of light on the photodiodes, the wavelength of light can be determined with picometer-level precision and with picometer-scale calibration drift over a period longer than a month. This work was supported by NSF Grant Number PHY-1205736.

  16. Quantification of tonic and phasic muscle activity in REM sleep behavior disorder.

    PubMed

    Mayer, Geert; Kesper, Karl; Ploch, Thomas; Canisius, Sebastian; Penzel, Thomas; Oertel, Wolfgang; Stiasny-Kolster, Karin

    2008-02-01

    REM sleep behavior disorder (RBD) is characterized by excessive tone of the chin muscle and limb movement during sleep. In the past, quantification of increased muscle tone in REM sleep has been performed visually, using no stringent criteria. The aim of this study was to develop an automatic analysis, allowing the quantification of muscle activity and its amplitude for all sleep stages, with a focus on REM sleep in patients with RBD. Forty-eight patients (27 male, 21 female) with RBD were included in the analysis. Twenty-one had idiopathic RBD; 28 had narcolepsy plus RBD. Twenty-five patients without confirmed sleep disorder served as control subjects. The amplitude of the EMG was generated from the difference of the upper and lower envelope of the mentalis muscle recordings. By smoothing the amplitude curve, a threshold curve was defined. Any muscle activity beyond the threshold curve was defined as motor activity. The means of the motor activity per second were summarized statistically and calculated for each sleep stage. Due to variable distribution of REM sleep, the latter was assigned to respective quartiles of the recorded night. Muscle activity was defined according to a histogram as short-lasting (<0.5 second) and long-lasting (>0.5 second) activity. No difference in the distribution of REM sleep/quartile and mean muscle tone throughout the sleep cycle could be found within the RBD groups and control subjects. Muscle activity was in the range of 200 ms. No clusters or regular distribution of muscle activity were found. Long muscle activity in the group with manifest clinical RBD was significantly higher than in control subjects, whereas it was nonsignificantly higher in subclinical RBD. The correlation between the frequency of long muscle activity in REM sleep and age was highly significant only for patients with idiopathic RBD. Automatic analysis of muscle activity in sleep is a reliable, easy method that may easily be used in the evaluation for REM sleep

  17. Coherent neocortical gamma oscillations decrease during REM sleep in the rat.

    PubMed

    Cavelli, Matías; Castro, Santiago; Schwarzkopf, Natalia; Chase, Michael H; Falconi, Atilio; Torterolo, Pablo

    2015-03-15

    Higher cognitive functions require the integration and coordination of large populations of neurons in cortical and subcortical regions. Oscillations in the high frequency band (30-100 Hz) of the electroencephalogram (EEG), that have been postulated to be a product of this interaction, are involved in the binding of spatially separated but temporally correlated neural events, which results in a unified perceptual experience. The extent of this functional connectivity can be examined by means of the mathematical algorithm called "coherence", which is correlated with the "strength" of functional interactions between cortical areas. As a continuation of previous studies in the cat [6,7], the present study was conducted to analyze EEG coherence in the gamma band of the rat during wakefulness (W), non-REM (NREM) sleep and REM sleep. Rats were implanted with electrodes in different cortical areas to record EEG activity, and the magnitude squared coherence values within the gamma frequency band of EEG (30-48 and 52-100 Hz) were determined. Coherence between all cortical regions in the low and high gamma frequency bands was greater during W compared with sleep. Remarkably, EEG coherence in the low and high gamma bands was smallest during REM sleep. We conclude that high frequency interactions between cortical areas are radically different during sleep and wakefulness in the rat. Since this feature is conserved in other mammals, including humans, we suggest that the uncoupling of gamma frequency activity during REM sleep is a defining trait of REM sleep in mammals. PMID:25557796

  18. Tonic inhibition and ponto-geniculo-occipital-related activities shape abducens motoneuron discharge during REM sleep.

    PubMed

    Escudero, Miguel; Márquez-Ruiz, Javier

    2008-07-15

    Eye movements, ponto-geniculo-occipital (PGO) waves, muscular atonia and desynchronized cortical activity are the main characteristics of rapid eye movement (REM) sleep. Although eye movements designate this phase, little is known about the activity of the oculomotor system during REM sleep. In this work, we recorded binocular eye movements by the scleral search-coil technique and the activity of identified abducens (ABD) motoneurons along the sleep-wake cycle in behaving cats. The activity of ABD motoneurons during REM sleep was characterized by a tonic decrease of their mean firing rate throughout this period, and short bursts and pauses coinciding with the occurrence of PGO waves. We demonstrate that the decrease in the mean firing discharge was due to an active inhibition of ABD motoneurons, and that the occurrence of primary and secondary PGO waves induced a pattern of simultaneous but opposed phasic activation and inhibition on each ABD nucleus. With regard to eye movements, during REM sleep ABD motoneurons failed to codify eye position as during alertness, but continued to codify eye velocity. The pattern of tonic inhibition and the phasic activations and inhibitions shown by ABD motoneurons coincide with those reported in other non-oculomotor motoneurons, indicating that the oculomotor system - contrary to what has been accepted until now - is not different from other motor systems during REM sleep, and that all motor systems are receiving similar command signals during this period.

  19. Shorter REM latency associated with more sleep cycles of a shorter duration in healthy humans.

    PubMed

    Le Bon, O; Staner, L; Hoffmann, G; Kentos, M; Pelc, I; Linkowski, P

    2001-10-10

    A significant association between rapid eye movement (REM) sleep latency and the number of non-REM/REM sleep cycles was found 15 years ago in a large retrospective study. The present prospective study further explored this intra-sleep relationship and analyzed the links between these two variables and the mean cycle duration. It was based on a carefully selected group of healthy control subjects whose sleep was polysomnographically recorded at home for 4 sequential nights. The latency of REM sleep was inversely correlated with the number of cycles and positively correlated with the mean cycle duration, both in individual nights and on means of 4 nights. The present study demonstrated that variations in the number of cycles or the mean cycle duration between the nights are far less important than the substantial differences observed between subjects. Present outcomes support the study of sleep cycle periods and frequencies in those psychiatric disorders where REM sleep latencies have been found to be shorter, and they suggest that these variables be included in sleep studies in which cycles are compared with each other.

  20. Story-like organization of REM-dreams in patients with narcolepsy-cataplexy.

    PubMed

    Cipolli, Carlo; Bellucci, Claudia; Mattarozzi, Katia; Mazzetti, Michela; Tuozzi, Giovanni; Plazzi, Giuseppe

    2008-10-22

    Narcolepsy with cataplexy (NC) is a neurological disorder characterized by excessive daytime sleepiness and an altered architecture of sleep. Previous laboratory studies have shown that frightening, bizarre and visually vivid contents are more frequent in dream experiences developed during the first period of REM sleep by NC patients than healthy subjects. As the structural organization of dream experiences of NC patients has not been yet examined, we compared its indicators in dream reports collected from a sample of NC patients and their matched controls. During an experimental night two awakenings were provoked after 8min of REM sleep in the first and third sleep cycle. Dream reports were analyzed using the rules of story grammars, capable of identifying units larger than single contents and describing their story-like organization. While dream recall (about 85%) was comparable in NC patients and controls, 1st-REM dream reports were longer in NC patients. Statistical analyses on the 12 NC patients and their matched controls who reported dreams after both REM periods showed that dream experiences occurring in 1st-REM reports of NC patients were longer and had a more complex organization than those of controls. These findings suggest that the cognitive processes underlying dream generation reach their optimal functioning earlier in the night in NC patients than in normal subjects.

  1. Orexin 2 Receptor Antagonism is Sufficient to Promote NREM and REM Sleep from Mouse to Man.

    PubMed

    Gotter, Anthony L; Forman, Mark S; Harrell, Charles M; Stevens, Joanne; Svetnik, Vladimir; Yee, Ka Lai; Li, Xiaodong; Roecker, Anthony J; Fox, Steven V; Tannenbaum, Pamela L; Garson, Susan L; Lepeleire, Inge De; Calder, Nicole; Rosen, Laura; Struyk, Arie; Coleman, Paul J; Herring, W Joseph; Renger, John J; Winrow, Christopher J

    2016-01-01

    Orexin neuropeptides regulate sleep/wake through orexin receptors (OX1R, OX2R); OX2R is the predominant mediator of arousal promotion. The potential for single OX2R antagonism to effectively promote sleep has yet to be demonstrated in humans. MK-1064 is an OX2R-single antagonist. Preclinically, MK-1064 promotes sleep and increases both rapid eye movement (REM) and non-REM (NREM) sleep in rats at OX2R occupancies higher than the range observed for dual orexin receptor antagonists. Similar to dual antagonists, MK-1064 increases NREM and REM sleep in dogs without inducing cataplexy. Two Phase I studies in healthy human subjects evaluated safety, tolerability, pharmacokinetics and sleep-promoting effects of MK-1064, and demonstrated dose-dependent increases in subjective somnolence (via Karolinska Sleepiness Scale and Visual Analogue Scale measures) and sleep (via polysomnography), including increased REM and NREM sleep. Thus, selective OX2R antagonism is sufficient to promote REM and NREM sleep across species, similarly to that seen with dual orexin receptor antagonism. PMID:27256922

  2. Orexin 2 Receptor Antagonism is Sufficient to Promote NREM and REM Sleep from Mouse to Man.

    PubMed

    Gotter, Anthony L; Forman, Mark S; Harrell, Charles M; Stevens, Joanne; Svetnik, Vladimir; Yee, Ka Lai; Li, Xiaodong; Roecker, Anthony J; Fox, Steven V; Tannenbaum, Pamela L; Garson, Susan L; Lepeleire, Inge De; Calder, Nicole; Rosen, Laura; Struyk, Arie; Coleman, Paul J; Herring, W Joseph; Renger, John J; Winrow, Christopher J

    2016-01-01

    Orexin neuropeptides regulate sleep/wake through orexin receptors (OX1R, OX2R); OX2R is the predominant mediator of arousal promotion. The potential for single OX2R antagonism to effectively promote sleep has yet to be demonstrated in humans. MK-1064 is an OX2R-single antagonist. Preclinically, MK-1064 promotes sleep and increases both rapid eye movement (REM) and non-REM (NREM) sleep in rats at OX2R occupancies higher than the range observed for dual orexin receptor antagonists. Similar to dual antagonists, MK-1064 increases NREM and REM sleep in dogs without inducing cataplexy. Two Phase I studies in healthy human subjects evaluated safety, tolerability, pharmacokinetics and sleep-promoting effects of MK-1064, and demonstrated dose-dependent increases in subjective somnolence (via Karolinska Sleepiness Scale and Visual Analogue Scale measures) and sleep (via polysomnography), including increased REM and NREM sleep. Thus, selective OX2R antagonism is sufficient to promote REM and NREM sleep across species, similarly to that seen with dual orexin receptor antagonism.

  3. Story-like organization of REM-dreams in patients with narcolepsy-cataplexy.

    PubMed

    Cipolli, Carlo; Bellucci, Claudia; Mattarozzi, Katia; Mazzetti, Michela; Tuozzi, Giovanni; Plazzi, Giuseppe

    2008-10-22

    Narcolepsy with cataplexy (NC) is a neurological disorder characterized by excessive daytime sleepiness and an altered architecture of sleep. Previous laboratory studies have shown that frightening, bizarre and visually vivid contents are more frequent in dream experiences developed during the first period of REM sleep by NC patients than healthy subjects. As the structural organization of dream experiences of NC patients has not been yet examined, we compared its indicators in dream reports collected from a sample of NC patients and their matched controls. During an experimental night two awakenings were provoked after 8min of REM sleep in the first and third sleep cycle. Dream reports were analyzed using the rules of story grammars, capable of identifying units larger than single contents and describing their story-like organization. While dream recall (about 85%) was comparable in NC patients and controls, 1st-REM dream reports were longer in NC patients. Statistical analyses on the 12 NC patients and their matched controls who reported dreams after both REM periods showed that dream experiences occurring in 1st-REM reports of NC patients were longer and had a more complex organization than those of controls. These findings suggest that the cognitive processes underlying dream generation reach their optimal functioning earlier in the night in NC patients than in normal subjects. PMID:18755253

  4. A study on fear memory retrieval and REM sleep in maternal separation and isolation stressed rats.

    PubMed

    Sampath, Dayalan; Sabitha, K R; Hegde, Preethi; Jayakrishnan, H R; Kutty, Bindu M; Chattarji, Sumantra; Rangarajan, Govindan; Laxmi, T R

    2014-10-15

    As rapid brain development occurs during the neonatal period, environmental manipulation during this period may have a significant impact on sleep and memory functions. Moreover, rapid eye movement (REM) sleep plays an important role in integrating new information with the previously stored emotional experience. Hence, the impact of early maternal separation and isolation stress (MS) during the stress hyporesponsive period (SHRP) on fear memory retention and sleep in rats were studied. The neonatal rats were subjected to maternal separation and isolation stress during postnatal days 5-7 (6h daily/3d). Polysomnographic recordings and differential fear conditioning was carried out in two different sets of rats aged 2 months. The neuronal replay during REM sleep was analyzed using different parameters. MS rats showed increased time in REM stage and total sleep period also increased. MS rats showed fear generalization with increased fear memory retention than normal control (NC). The detailed analysis of the local field potentials across different time periods of REM sleep showed increased theta oscillations in the hippocampus, amygdala and cortical circuits. Our findings suggest that stress during SHRP has sensitized the hippocampus-amygdala-cortical loops which could be due to increased release of corticosterone that generally occurs during REM sleep. These rats when subjected to fear conditioning exhibit increased fear memory and increased fear generalization. The development of helplessness, anxiety and sleep changes in human patients, thus, could be related to the reduced thermal, tactile and social stimulation during SHRP on brain plasticity and fear memory functions.

  5. Orexin 2 Receptor Antagonism is Sufficient to Promote NREM and REM Sleep from Mouse to Man

    PubMed Central

    Gotter, Anthony L.; Forman, Mark S.; Harrell, Charles M.; Stevens, Joanne; Svetnik, Vladimir; Yee, Ka Lai; Li, Xiaodong; Roecker, Anthony J.; Fox, Steven V.; Tannenbaum, Pamela L.; Garson, Susan L.; Lepeleire, Inge De; Calder, Nicole; Rosen, Laura; Struyk, Arie; Coleman, Paul J.; Herring, W. Joseph; Renger, John J.; Winrow, Christopher J.

    2016-01-01

    Orexin neuropeptides regulate sleep/wake through orexin receptors (OX1R, OX2R); OX2R is the predominant mediator of arousal promotion. The potential for single OX2R antagonism to effectively promote sleep has yet to be demonstrated in humans. MK-1064 is an OX2R-single antagonist. Preclinically, MK-1064 promotes sleep and increases both rapid eye movement (REM) and non-REM (NREM) sleep in rats at OX2R occupancies higher than the range observed for dual orexin receptor antagonists. Similar to dual antagonists, MK-1064 increases NREM and REM sleep in dogs without inducing cataplexy. Two Phase I studies in healthy human subjects evaluated safety, tolerability, pharmacokinetics and sleep-promoting effects of MK-1064, and demonstrated dose-dependent increases in subjective somnolence (via Karolinska Sleepiness Scale and Visual Analogue Scale measures) and sleep (via polysomnography), including increased REM and NREM sleep. Thus, selective OX2R antagonism is sufficient to promote REM and NREM sleep across species, similarly to that seen with dual orexin receptor antagonism. PMID:27256922

  6. Visual short-term memory deficits in REM sleep behaviour disorder mirror those in Parkinson's disease.

    PubMed

    Rolinski, Michal; Zokaei, Nahid; Baig, Fahd; Giehl, Kathrin; Quinnell, Timothy; Zaiwalla, Zenobia; Mackay, Clare E; Husain, Masud; Hu, Michele T M

    2016-01-01

    Individuals with REM sleep behaviour disorder are at significantly higher risk of developing Parkinson's disease. Here we examined visual short-term memory deficits--long associated with Parkinson's disease--in patients with REM sleep behaviour disorder without Parkinson's disease using a novel task that measures recall precision. Visual short-term memory for sequentially presented coloured bars of different orientation was assessed in 21 patients with polysomnography-proven idiopathic REM sleep behaviour disorder, 26 cases with early Parkinson's disease and 26 healthy controls. Three tasks using the same stimuli controlled for attentional filtering ability, sensorimotor and temporal decay factors. Both patients with REM sleep behaviour disorder and Parkinson's disease demonstrated a deficit in visual short-term memory, with recall precision significantly worse than in healthy controls with no deficit observed in any of the control tasks. Importantly, the pattern of memory deficit in both patient groups was specifically explained by an increase in random responses. These results demonstrate that it is possible to detect the signature of memory impairment associated with Parkinson's disease in individuals with REM sleep behaviour disorder, a condition associated with a high risk of developing Parkinson's disease. The pattern of visual short-term memory deficit potentially provides a cognitive marker of 'prodromal' Parkinson's disease that might be useful in tracking disease progression and for disease-modifying intervention trials.

  7. Sleep disturbances in Parkinson's disease: the contribution of dopamine in REM sleep regulation.

    PubMed

    Lima, Marcelo M S

    2013-10-01

    Nearly all patients with Parkinson's disease (PD) have sleep disturbances. While it has been suggested that these disturbances involve a dopaminergic component, the specific mechanisms that contribute to this behavior are far from being fully understood. In this article, we have reviewed the current understanding of the linkage between sleep and PD, focusing on the participation of the dopaminergic system in the regulation of rapid eye movement (REM) sleep. The presence of an REM sleep behavior disorder in patients with PD might reflect the early involvement of dopaminergic neurotransmission in REM sleep-related structures. Therefore, it has been suggested that these structures are affected by an imbalance of dopamine levels. Several studies have demonstrated that neurons in the substantia nigra pars compacta (SNpc) and in the ventral tegmental area (VTA) are active during REM sleep and that sleep-related disturbances may result when these neurons are targeted by neurotoxins. We discuss current evidence suggesting the presence of a putative reciprocal connectivity between the SNpc, VTA, the pedunculopontine tegmental nucleus and reticular formation, which may exert an important influence on the REM sleep mechanism. This review provides a comprehensive overview of the literature that addresses this challenging and unrecognized component of PD.

  8. Neutron multiplicity measurements with 3He alternative: Straw neutron detectors

    SciTech Connect

    Mukhopadhyay, Sanjoy; Wolff, Ronald; Detwiler, Ryan; Maurer, Richard; Mitchell, Stephen; Guss, Paul; Lacy, Jeffrey L.; Sun, Liang; Athanasiades, Athanasios

    2015-01-27

    Counting neutrons emitted by special nuclear material (SNM) and differentiating them from the background neutrons of various origins is the most effective passive means of detecting SNM. Unfortunately, neutron detection, counting, and partitioning in a maritime environment are complex due to the presence of high-multiplicity spallation neutrons (commonly known as ‘‘ship effect ’’) and to the complicated nature of the neutron scattering in that environment. A prototype neutron detector was built using 10B as the converter in a special form factor called ‘‘straws’’ that would address the above problems by looking into the details of multiplicity distributions of neutrons originating from a fissioning source. This paper describes the straw neutron multiplicity counter (NMC) and assesses the performance with those of a commercially available fission meter. The prototype straw neutron detector provides a large-area, efficient, lightweight, more granular (than fission meter) neutron-responsive detection surface (to facilitate imaging) to enhance the ease of application of fission meters. Presented here are the results of preliminary investigations, modeling, and engineering considerations leading to the construction of this prototype. This design is capable of multiplicity and Feynman variance measurements. This prototype may lead to a near-term solution to the crisis that has arisen from the global scarcity of 3He by offering a viable alternative to fission meters. This paper describes the work performed during a 2-year site-directed research and development (SDRD) project that incorporated straw detectors for neutron multiplicity counting. The NMC is a two-panel detector system. We used 10B (in the form of enriched boron carbide: 10B4C) for neutron detection instead of 3He. In the first year, the project worked with a panel of straw neutron detectors, investigated its characteristics, and

  9. Neutron multiplicity ,easurements With 3He alternative: Straw neutron detectors

    SciTech Connect

    Mukhopadhyay, Sanjoy; Wolff, Ronald S.; Meade, John A.; Detweiler, Ryan; Maurer, Richard J.; Mitchell, Stephen E.; Guss, Paul P.; Lacy, Jeffrey L.; Sun, Liang; Athanasiades, Athanasios

    2015-01-27

    Counting neutrons emitted by special nuclear material (SNM) and differentiating them from the background neutrons of various origins is the most effective passive means of detecting SNM. Unfortunately, neutron detection, counting, and partitioning in a maritime environment are complex due to the presence of high-multiplicity spallation neutrons (commonly known as “ship effect”) and to the complicated nature of the neutron scattering in that environment. In this study, a prototype neutron detector was built using 10B as the converter in a special form factor called “straws” that would address the above problems by looking into the details of multiplicity distributions of neutrons originating from a fissioning source. This paper describes the straw neutron multiplicity counter (NMC) and assesses the performance with those of a commercially available fission meter. The prototype straw neutron detector provides a large-area, efficient, lightweight, more granular (than fission meter) neutron-responsive detection surface (to facilitate imaging) to enhance the ease of application of fission meters. Presented here are the results of preliminary investigations, modeling, and engineering considerations leading to the construction of this prototype. This design is capable of multiplicity and Feynman variance measurements. This prototype may lead to a near-term solution to the crisis that has arisen from the global scarcity of 3He by offering a viable alternative to fission meters. This paper describes the work performed during a 2-year site-directed research and development (SDRD) project that incorporated straw detectors for neutron multiplicity counting. The NMC is a two-panel detector system. We used 10B (in the form of enriched boron carbide: 10B4C) for neutron detection instead of 3He. In the first year, the project worked with a panel of straw neutron detectors, investigated its characteristics

  10. 1-Meter Digital Elevation Model specification

    USGS Publications Warehouse

    Arundel, Samantha T.; Archuleta, Christy-Ann M.; Phillips, Lori A.; Roche, Brittany L.; Constance, Eric W.

    2015-10-21

    In January 2015, the U.S. Geological Survey National Geospatial Technical Operations Center began producing the 1-Meter Digital Elevation Model data product. This new product was developed to provide high resolution bare-earth digital elevation models from light detection and ranging (lidar) elevation data and other elevation data collected over the conterminous United States (lower 48 States), Hawaii, and potentially Alaska and the U.S. territories. The 1-Meter Digital Elevation Model consists of hydroflattened, topographic bare-earth raster digital elevation models, with a 1-meter x 1-meter cell size, and is available in 10,000-meter x 10,000-meter square blocks with a 6-meter overlap. This report details the specifications required for the production of the 1-Meter Digital Elevation Model.

  11. 1-Meter Digital Elevation Model specification

    USGS Publications Warehouse

    Arundel, Samantha T.; Archuleta, Christy-Ann M.; Phillips, Lori A.; Roche, Brittany L.; Constance, Eric W.

    2015-01-01

    In January 2015, the U.S. Geological Survey National Geospatial Technical Operations Center began producing the 1-Meter Digital Elevation Model data product. This new product was developed to provide high resolution bare-earth digital elevation models from light detection and ranging (lidar) elevation data and other elevation data collected over the conterminous United States (lower 48 States), Hawaii, and potentially Alaska and the U.S. territories. The 1-Meter Digital Elevation Model consists of hydroflattened, topographic bare-earth raster digital elevation models, with a 1-meter x 1-meter cell size, and is available in 10,000-meter x 10,000-meter square blocks with a 6-meter overlap. This report details the specifications required for the production of the 1-Meter Digital Elevation Model.

  12. Atmospheric neutrons

    NASA Technical Reports Server (NTRS)

    Korff, S. A.; Mendell, R. B.; Merker, M.; Light, E. S.; Verschell, H. J.; Sandie, W. S.

    1979-01-01

    Contributions to fast neutron measurements in the atmosphere are outlined. The results of a calculation to determine the production, distribution and final disappearance of atmospheric neutrons over the entire spectrum are presented. An attempt is made to answer questions that relate to processes such as neutron escape from the atmosphere and C-14 production. In addition, since variations of secondary neutrons can be related to variations in the primary radiation, comment on the modulation of both radiation components is made.

  13. Prompt neutron multiplicity measurements with portable detectors

    NASA Astrophysics Data System (ADS)

    Mukhopadhyay, Sanjoy; Wolff, Ronald; Maurer, Richard; Mitchell, Stephen; Smith, Ethan X.; Guss, Paul; Lacy, Jeffrey L.; Sun, L.; Athanasiades, A.

    2011-09-01

    Mobile detection of kilogram quantities of special nuclear materials (SNM) during maritime transportation is a challenging problem for the U.S. Department of Homeland Security. Counting neutrons emitted by the SNM and partitioning them from background neutrons of multiple origins is the most effective passive means of detecting the SNM. Unfortunately, neutron detection, counting, and partitioning in a maritime environment is complex due to the presence of spallation neutrons (commonly known as "ship effect") and to the complicated nature of the neutron scattering in that environment. This work studied the possibilities of building a prototype neutron detector using boron- 10 (10B) as the converter in a novel form factor called "straws" that would address the above problem by examining multiplicity distributions of neutrons originating from a fissioning source. Currently, commercially manufactured fission meters (FM) are available that separate cosmic neutrons from non-cosmic neutrons and quantitatively determine the strength of a fissioning source; however, these FMs use 3He, which is becoming increasingly difficult to procure; also the size and weight of a commercial FM is not conducive to manual neutron detection operations in a maritime environment. The current project may provide a near-term solution to the crisis that has arisen from the global scarcity of 3He by offering a viable alternative to the FM. The prototype detector provides a large-area, efficient, lightweight, more granular neutron responsive detection surface (to facilitate imaging) to ease the application of the new FMs.

  14. Neutron guide

    DOEpatents

    Greene, Geoffrey L.

    1999-01-01

    A neutron guide in which lengths of cylindrical glass tubing have rectangular glass plates properly dimensioned to allow insertion into the cylindrical glass tubing so that a sealed geometrically precise polygonal cross-section is formed in the cylindrical glass tubing. The neutron guide provides easier alignment between adjacent sections than do the neutron guides of the prior art.

  15. Neutron dosimetry

    DOEpatents

    Quinby, Thomas C.

    1976-07-27

    A method of measuring neutron radiation within a nuclear reactor is provided. A sintered oxide wire is disposed within the reactor and exposed to neutron radiation. The induced radioactivity is measured to provide an indication of the neutron energy and flux within the reactor.

  16. The homeostatic regulation of REM sleep: A role for localized expression of brain-derived neurotrophic factor in the brainstem.

    PubMed

    Datta, Subimal; Knapp, Clifford M; Koul-Tiwari, Richa; Barnes, Abigail

    2015-10-01

    Homeostatic regulation of REM sleep plays a key role in neural plasticity and deficits in this process are implicated in the development of many neuropsychiatric disorders. Little is known, however, about the molecular mechanisms that underlie this homeostatic regulation process. This study examined the hypothesis that, during selective REM sleep deprivation (RSD), increased brain-derived neurotrophic factor (BDNF) expression in REM sleep regulating areas is critical for the development of homeostatic drive for REM sleep, as measured by an increase in the number of REM sleep transitions. Rats were assigned to RSD, non-sleep deprived (BSL), or total sleep deprivation (TSD) groups. Physiological recordings were obtained from cortical, hippocampal, and pontine EEG electrodes over a 6h period, in which sleep deprivation occurred during the first 3h. In the RSD, but not the other conditions, homeostatic drive for REM sleep increased progressively. BDNF protein expression was significantly greater in the pedunculopontine tegmentum (PPT) and subcoeruleus nucleus (SubCD) in the RSD as compared to the TSD and BSL groups, areas that regulate REM sleep, but not in the medial preoptic area, which regulates non-REM sleep. There was a significant positive correlation between RSD-induced increases in number of REM sleep episodes and increased BDNF expression in the PPT and SubCD. These increases positively correlated with levels of homeostatic drive for REM sleep. These results, for the first time, suggest that selective RSD-induced increased expression of BDNF in the PPT and SubCD are determinant factors in the development of the homeostatic drive for REM sleep.

  17. 10 CFR 451.7 - Metering requirements.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 3 2013-01-01 2013-01-01 false Metering requirements. 451.7 Section 451.7 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION RENEWABLE ENERGY PRODUCTION INCENTIVES § 451.7 Metering requirements... renewable energy facility must be measured by a standard metering device that— (a) Meets generally...

  18. 10 CFR 451.7 - Metering requirements.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 3 2012-01-01 2012-01-01 false Metering requirements. 451.7 Section 451.7 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION RENEWABLE ENERGY PRODUCTION INCENTIVES § 451.7 Metering requirements... renewable energy facility must be measured by a standard metering device that— (a) Meets generally...

  19. 10 CFR 451.7 - Metering requirements.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 3 2014-01-01 2014-01-01 false Metering requirements. 451.7 Section 451.7 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION RENEWABLE ENERGY PRODUCTION INCENTIVES § 451.7 Metering requirements... renewable energy facility must be measured by a standard metering device that— (a) Meets generally...

  20. MTI compact electronic meter testing program

    SciTech Connect

    O`Rourke, E.L.

    1995-12-31

    MTI has completed an extensive test program to ensure a new compact electronic gas meter meets all specifications and standards customarily employed by the U.S. gas industry. Thirty (30) test plans were developed to cover all American National Standards Institute (ANSI) performance requirements. (1) The prototype meters have met or exceeded the ANSI B109.1 standards. (2) The prototype meters have demonstrated the feasibility of GRI`s decision to seek a compact meter for early market entry. (3) Several leading U.S. utilities have participated in sponsoring the project and have expressed keen interest in field testing the compact meter. (4) American Meter Company (AMC), the predominant U.S. meter manufacturer, has participated in the sponsorship and testing of the compact meter and has formed a joint venture with Select Corporation to bring the meter to the U.S. and world-wide marketplace. (5) The meter generates the necessary electronic output for either telephonic or radio based automatic meter reading (AMR). The pre-production meters for the North American market are being fabricated currently by AMC. Following their completion, an extensive field test program will take place. Three hundred units will be installed at ten to fifteen utilities and tested for a period of up to one year.

  1. Embedded solution for a microwave moisture meter

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this paper, the conversion of a PC or laptop-controlled microwave moisture meter to a stand-alone meter hosting its own embedded system is discussed. The moisture meter is based on the free-space transmission measurement technique and uses low-intensity microwaves to measure the attenuation and p...

  2. A new method to calculate the response of the WENDI-II rem counter using the FLUKA Monte Carlo Code

    NASA Astrophysics Data System (ADS)

    Jägerhofer, Lukas; Feldbaumer, Eduard; Theis, Christian; Roesler, Stefan; Vincke, Helmut

    2012-11-01

    The FHT-762 WENDI-II is a commercially available wide range neutron rem counter which uses a 3He counter tube inside a polyethylene moderator. To increase the response above 10 MeV of kinetic neutron energy, a layer of tungsten powder is implemented into the moderator shell. For the purpose of the characterization of the response, a detailed model of the detector was developed and implemented for FLUKA Monte Carlo simulations. In common practice Monte Carlo simulations are used to calculate the neutron fluence inside the active volume of the detector. The resulting fluence is then folded offline with the reaction rate of the 3He(n,p)3H reaction to yield the proton-triton production rate. Consequently this approach does not consider geometrical effects like wall effects, where one or both reaction products leave the active volume of the detector without triggering a count. This work introduces a two-step simulation method which can be used to determine the detector's response, including geometrical effects, directly, using Monte Carlo simulations. A "first step" simulation identifies the 3He(n,p)3H reaction inside the active volume of the 3He counter tube and records its position. In the "second step" simulation the tritons and protons are started in accordance with the kinematics of the 3He(n,p)3H reaction from the previously recorded positions and a correction factor for geometrical effects is determined. The three dimensional Monte Carlo model of the detector as well as the two-step simulation method were evaluated and tested in the well-defined fields of an 241Am-Be(α,n) source as well as in the field of a 252Cf source. Results were compared with measurements performed by Gutermuth et al. [1] at GSI with an 241Am-Be(α,n) source as well as with measurements performed by the manufacturer in the field of a 252Cf source. Both simulation results show very good agreement with the respective measurements. After validating the method, the response values in terms of

  3. Melatonin Therapy for REM Sleep Behavior Disorder: A Critical Review of Evidence

    PubMed Central

    Leung, Jonathan G.; St Louis, Erik K.; Boeve, Bradley F.

    2014-01-01

    REM sleep behavior disorder (RBD) is a parasomnia associated with dream enactment often involving violent or potentially injurious behaviors during REM sleep that is strongly associated with synucleinopathy neurodegeneration. Clonazepam has long been suggested as the first-line treatment option for RBD. However, evidence supporting melatonin therapy is expanding. Melatonin appears to be beneficial for the management of RBD with reductions in clinical behavioral outcomes and decrease in muscle tonicity during REM sleep. Melatonin also has a favorable safety and tolerability profile over clonazepam with limited potential for drug-drug interactions, an important consideration especially in elderly individuals with RBD receiving polypharmacy. Prospective clinical trials are necessary to establish evidence-basis for melatonin and clonazepam as RBD therapies. PMID:25454845

  4. Melatonin therapy for REM sleep behavior disorder: a critical review of evidence.

    PubMed

    McGrane, Ian R; Leung, Jonathan G; St Louis, Erik K; Boeve, Bradley F

    2015-01-01

    Rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia associated with dream enactment often involving violent or potentially injurious behaviors during REM sleep that is strongly associated with synucleinopathy neurodegeneration. Clonazepam has long been suggested as the first-line treatment option for RBD. However, evidence supporting melatonin therapy is expanding. Melatonin appears to be beneficial for the management of RBD with reductions in clinical behavioral outcomes and decrease in muscle tonicity during REM sleep. Melatonin also has a favorable safety and tolerability profile over clonazepam with limited potential for drug-drug interactions, an important consideration especially in elderly individuals with RBD receiving polypharmacy. Prospective clinical trials are necessary to establish the evidence basis for melatonin and clonazepam as RBD therapies. PMID:25454845

  5. REM sleep deprivation of rats induces acute phase response in liver.

    PubMed

    Pandey, Atul Kumar; Kar, Santosh Kumar

    2011-07-01

    REM sleep is essential for maintenance of body physiology and its deprivation is fatal. We observed that the levels of ALT and AST enzymes and pro-inflammatory cytokines like IL-1 β, IL-6 and IL-12 circulating in the blood of REM sleep deprived rats increased in proportion to the extent of sleep loss. But in contrast the levels of IFN-γ and a ∼200 kDa protein, identified by N-terminal sequencing to be alpha-1-inhibitor-3(A1I3), decreased significantly. Quantitative PCR analysis confirmed that REM sleep deprivation down regulates AII3 gene and up regulates IL1 β, IL6 and their respective receptors gene expression in the liver initiating its inflammation.

  6. Reassessment of NRC`s dollar per person-rem conversion factor policy

    SciTech Connect

    1995-12-01

    The US Nuclear Regulatory Commission (NRC) has completed a review and analysis of its dollar per person-rem conversion factor policy. As a result of this review, the NRC has decided to adopt a $2000 per person-rem conversion factor, subject it to present worth considerations, and limit its scope solely to health effects. This is in contrast to the previous policy and staff practice of using an undiscounted $1000 per person-rem conversion factor that served as a surrogate for all offsite consequences (health and offsite property). The policy shift has been incorporated in ``Regulatory Analysis Guidelines of the US Nuclear Regulatory Commission,`` NUREG/BR-0058, Revision 2, November 1995.

  7. A Dosimetry Study of Deuterium-Deuterium Neutron Generator-based In Vivo Neutron Activation Analysis.

    PubMed

    Sowers, Daniel; Liu, Yingzi; Mostafaei, Farshad; Blake, Scott; Nie, Linda H

    2015-12-01

    A neutron irradiation cavity for in vivo neutron activation analysis (IVNAA) to detect manganese, aluminum, and other potentially toxic elements in human hand bone has been designed and its dosimetric specifications measured. The neutron source is a customized deuterium-deuterium neutron generator that produces neutrons at 2.45 MeV by the fusion reaction 2H(d, n)3He at a calculated flux of 7 × 10(8) ± 30% s(-1). A moderator/reflector/shielding [5 cm high density polyethylene (HDPE), 5.3 cm graphite and 5.7 cm borated (HDPE)] assembly has been designed and built to maximize the thermal neutron flux inside the hand irradiation cavity and to reduce the extremity dose and effective dose to the human subject. Lead sheets are used to attenuate bremsstrahlung x rays and activation gammas. A Monte Carlo simulation (MCNP6) was used to model the system and calculate extremity dose. The extremity dose was measured with neutron and photon sensitive film badges and Fuji electronic pocket dosimeters (EPD). The neutron ambient dose outside the shielding was measured by Fuji NSN3, and the photon dose was measured by a Bicron MicroREM scintillator. Neutron extremity dose was calculated to be 32.3 mSv using MCNP6 simulations given a 10-min IVNAA measurement of manganese. Measurements by EPD and film badge indicate hand dose to be 31.7 ± 0.8 mSv for neutrons and 4.2 ± 0.2 mSv for photons for 10 min; whole body effective dose was calculated conservatively to be 0.052 mSv. Experimental values closely match values obtained from MCNP6 simulations. These are acceptable doses to apply the technology for a manganese toxicity study in a human population. PMID:26509624

  8. A dosimetry study of deuterium-deuterium neutron generator-based in vivo neutron activation analysis

    NASA Astrophysics Data System (ADS)

    Sowers, Daniel A.

    A neutron irradiation cavity for in vivo Neutron Activation Analysis (IVNAA) to detect manganese, aluminum, and other potentially toxic elements in human hand bone has been designed and its dosimetric specifications measured. The neutron source is a customized deuterium-deuterium neutron generator which produces neutrons at 2.45 MeV by the fusion reaction 2H(d, n)3He at a calculated flux of 7 x 108 +/-30% s-1. A moderator/reflector/shielding (5 cm high density polyethylene (HDPE), 5.3 cm graphite & 5.7 cm borated HDPE) assembly has been designed and built to maximize the thermal neutron flux inside the hand irradiation cavity and to reduce the extremity dose and effective dose to the human subject. Lead sheets are used to attenuate bremsstrahlung x rays and activation gammas. A Monte Carlo simulation (MCNP6) was used to model the system and calculate extremity dose. The extremity dose was measured with neutron and photon sensitive film badges and Fuji electronic pocket dosimeter (EPD). The neutron ambient dose outside the shielding was measured by Fuji NSN3, and photon dose by a Bicron MicroREM scintillator. Neutron extremity dose was calculated to be 32.3 mSv using MCNP6 simulations given a 10 min IVNAA measurement of manganese. Measurements by EPD and film badge indicate hand dose to be 31.7 +/- 0.8 mSv for neutron and 4.2 +/- 0.2 mSv for photon for 10 mins; whole body effective dose was calculated conservatively to be 0.052 mSv. Experimental values closely match values obtained from MCNP6 simulations. These are acceptable doses to apply the technology for a manganese toxicity study in a human population.

  9. A Dosimetry Study of Deuterium-Deuterium Neutron Generator-based In Vivo Neutron Activation Analysis.

    PubMed

    Sowers, Daniel; Liu, Yingzi; Mostafaei, Farshad; Blake, Scott; Nie, Linda H

    2015-12-01

    A neutron irradiation cavity for in vivo neutron activation analysis (IVNAA) to detect manganese, aluminum, and other potentially toxic elements in human hand bone has been designed and its dosimetric specifications measured. The neutron source is a customized deuterium-deuterium neutron generator that produces neutrons at 2.45 MeV by the fusion reaction 2H(d, n)3He at a calculated flux of 7 × 10(8) ± 30% s(-1). A moderator/reflector/shielding [5 cm high density polyethylene (HDPE), 5.3 cm graphite and 5.7 cm borated (HDPE)] assembly has been designed and built to maximize the thermal neutron flux inside the hand irradiation cavity and to reduce the extremity dose and effective dose to the human subject. Lead sheets are used to attenuate bremsstrahlung x rays and activation gammas. A Monte Carlo simulation (MCNP6) was used to model the system and calculate extremity dose. The extremity dose was measured with neutron and photon sensitive film badges and Fuji electronic pocket dosimeters (EPD). The neutron ambient dose outside the shielding was measured by Fuji NSN3, and the photon dose was measured by a Bicron MicroREM scintillator. Neutron extremity dose was calculated to be 32.3 mSv using MCNP6 simulations given a 10-min IVNAA measurement of manganese. Measurements by EPD and film badge indicate hand dose to be 31.7 ± 0.8 mSv for neutrons and 4.2 ± 0.2 mSv for photons for 10 min; whole body effective dose was calculated conservatively to be 0.052 mSv. Experimental values closely match values obtained from MCNP6 simulations. These are acceptable doses to apply the technology for a manganese toxicity study in a human population.

  10. RF-source resistance meters

    NASA Technical Reports Server (NTRS)

    Oakley, E. C. (Inventor)

    1973-01-01

    Several embodiments of RF source resistance measuring devices are disclosed. Common to all embodiments in the feature of the inclusion of at least one variable resistor, and a peak readout meter. In one embodiment, two ganged unloaded potentiometers are employed while another embodiment comprises an automaticnulling RF power bridge circuit with a variable rather than a fixed bridge reference resistance. A third embodiment comprises a calorimeter with a varible rather than a fixed resistor, while in another embodiment attenuator pads with variable resistors are employed.

  11. Why Does Rem Sleep Occur? A Wake-Up Hypothesis1

    PubMed Central

    Klemm, W. R.

    2011-01-01

    Brain activity differs in the various sleep stages and in conscious wakefulness. Awakening from sleep requires restoration of the complex nerve impulse patterns in neuronal network assemblies necessary to re-create and sustain conscious wakefulness. Herein I propose that the brain uses rapid eye movement (REM) to help wake itself up after it has had a sufficient amount of sleep. Evidence suggesting this hypothesis includes the facts that, (1) when first going to sleep, the brain plunges into Stage N3 (formerly called Stage IV), a deep abyss of sleep, and, as the night progresses, the sleep is punctuated by episodes of REM that become longer and more frequent toward morning, (2) conscious-like dreams are a reliable component of the REM state in which the dreamer is an active mental observer or agent in the dream, (3) the last awakening during a night's sleep usually occurs in a REM episode during or at the end of a dream, (4) both REM and awake consciousness seem to arise out of a similar brainstem ascending arousal system (5) N3 is a functionally perturbed state that eventually must be corrected so that embodied brain can direct adaptive behavior, and (6) cortico-fugal projections to brainstem arousal areas provide a way to trigger increased cortical activity in REM to progressively raise the sleeping brain to the threshold required for wakefulness. This paper shows how the hypothesis conforms to common experience and has substantial predictive and explanatory power regarding the phenomenology of sleep in terms of ontogeny, aging, phylogeny, abnormal/disease states, cognition, and behavioral physiology. That broad range of consistency is not matched by competing theories, which are summarized herein. Specific ways to test this wake-up hypothesis are suggested. Such research could lead to a better understanding of awake consciousness. PMID:21922003

  12. REM and NREM sleep as natural accompaniments of the evolution of warm-bloodedness.

    PubMed

    Lee Kavanau, J

    2002-12-01

    Divergence of primitive sleep into REM and NREM states is thought to have occurred in the nocturnal Triassic ancestors of mammals as a natural accompaniment of the evolution of warm-bloodedness. As ambient temperatures during twilight portions of primitive sleep traversed these evolving ancestors' core temperature, mechanisms of thermoregulatory control that employ muscle contractions became superfluous. The resulting loss of need for such contractions during twilight sleep led to muscle atonia. With muscle tone absent, selection favored the persistence of the fast waves of nocturnal activity during twilight sleep. Stimulations by these waves reinforce motor circuits at the increasing temperatures of evolving warm-bloodedness without leading to sleep-disturbing muscle contractions. By these and related interlinked adaptations, twilight sleep evolved into REM sleep. The daytime period of sleep became NREM sleep. The evolution of NREM and REM sleep following this scenario has implications for sleep's maintenance processes for long-term memories. During NREM sleep, there is an unsynchronized, uncoordinated stimulation and reinforcement of individual distributed component circuits of consolidated memories by slow wave potentials, a process termed 'uncoordinated reinforcement'. The corresponding process during REM sleep is the coordinated stimulation and reinforcement of these circuits by fast wave potentials. This action temporally binds the individual component circuit outputs into fully formed memories, a process termed 'coordinated reinforcement'. Sequential uncoordinated and coordinated reinforcement, that is, NREM followed by REM sleep, emerges as the most effective mechanism of long-term memory maintenance in vertebrates. With the evolution of this two-stage mechanism of long-term memory maintenance, it became adaptive to partition sleep into several NREM-REM cycles, thereby achieving a more lengthy application of the cooperative sequential actions. PMID:12667495

  13. REM and NREM sleep as natural accompaniments of the evolution of warm-bloodedness.

    PubMed

    Lee Kavanau, J

    2002-12-01

    Divergence of primitive sleep into REM and NREM states is thought to have occurred in the nocturnal Triassic ancestors of mammals as a natural accompaniment of the evolution of warm-bloodedness. As ambient temperatures during twilight portions of primitive sleep traversed these evolving ancestors' core temperature, mechanisms of thermoregulatory control that employ muscle contractions became superfluous. The resulting loss of need for such contractions during twilight sleep led to muscle atonia. With muscle tone absent, selection favored the persistence of the fast waves of nocturnal activity during twilight sleep. Stimulations by these waves reinforce motor circuits at the increasing temperatures of evolving warm-bloodedness without leading to sleep-disturbing muscle contractions. By these and related interlinked adaptations, twilight sleep evolved into REM sleep. The daytime period of sleep became NREM sleep. The evolution of NREM and REM sleep following this scenario has implications for sleep's maintenance processes for long-term memories. During NREM sleep, there is an unsynchronized, uncoordinated stimulation and reinforcement of individual distributed component circuits of consolidated memories by slow wave potentials, a process termed 'uncoordinated reinforcement'. The corresponding process during REM sleep is the coordinated stimulation and reinforcement of these circuits by fast wave potentials. This action temporally binds the individual component circuit outputs into fully formed memories, a process termed 'coordinated reinforcement'. Sequential uncoordinated and coordinated reinforcement, that is, NREM followed by REM sleep, emerges as the most effective mechanism of long-term memory maintenance in vertebrates. With the evolution of this two-stage mechanism of long-term memory maintenance, it became adaptive to partition sleep into several NREM-REM cycles, thereby achieving a more lengthy application of the cooperative sequential actions.

  14. No effect of odor-induced memory reactivation during REM sleep on declarative memory stability

    PubMed Central

    Cordi, Maren J.; Diekelmann, Susanne; Born, Jan; Rasch, Björn

    2014-01-01

    Memory reactivations in hippocampal brain areas are critically involved in memory consolidation processes during sleep. In particular, specific firing patterns of hippocampal place cells observed during learning are replayed during subsequent sleep and rest in rodents. In humans, experimentally inducing hippocampal memory reactivations during slow-wave sleep (but not during wakefulness) benefits consolidation and immediately stabilizes declarative memories against future interference. Importantly, spontaneous hippocampal replay activity can also be observed during rapid eye movement (REM) sleep and some authors have suggested that replay during REM sleep is related to processes of memory consolidation. However, the functional role of reactivations during REM sleep for memory stability is still unclear. Here, we reactivated memories during REM sleep and examined its consequences for the stability of declarative memories. After 3 h of early, slow-wave sleep (SWS) rich sleep, 16 healthy young adults learned a 2-D object location task in the presence of a contextual odor. During subsequent REM sleep, participants were either re-exposed to the odor or to an odorless vehicle, in a counterbalanced within subject design. Reactivation was followed by an interference learning task to probe memory stability after awakening. We show that odor-induced memory reactivation during REM sleep does not stabilize memories against future interference. We propose that the beneficial effect of reactivation during sleep on memory stability might be critically linked to processes characterizing SWS including, e.g., slow oscillatory activity, sleep spindles, or low cholinergic tone, which are required for a successful redistribution of memories from medial temporal lobe regions to neocortical long-term stores. PMID:25225474

  15. Characterization of neutron field in a NPP workplace.

    PubMed

    Breznik, B; Pochat, J L; Muller, H; Asselineau, B; Pavlin, M

    2007-01-01

    At the Krsko Nuclear Power Plant (NPP), albedo dosimeters are used for personal neutron dosimetry. Spectrometric measurements allow determination of reference dosimetric values of realistic neutron fields to be used for calibration of albedo dosimeters. The Laboratory for Neutron Metrology and Dosimetry from the Institute for Radiological Protection and Nuclear Safety (IRSN) was in charge of characterising neutron fields in the plant at two representative points with high neutron and gamma dose rate. Calibration of the dosimeters in the workplace used to be performed only by a spherical survey meter. Based on the reference dosimetric values, the Plant Dosimetry Laboratory has verified the response of albedo dosimeters.

  16. Characterization of neutron field in a NPP workplace.

    PubMed

    Breznik, B; Pochat, J L; Muller, H; Asselineau, B; Pavlin, M

    2007-01-01

    At the Krsko Nuclear Power Plant (NPP), albedo dosimeters are used for personal neutron dosimetry. Spectrometric measurements allow determination of reference dosimetric values of realistic neutron fields to be used for calibration of albedo dosimeters. The Laboratory for Neutron Metrology and Dosimetry from the Institute for Radiological Protection and Nuclear Safety (IRSN) was in charge of characterising neutron fields in the plant at two representative points with high neutron and gamma dose rate. Calibration of the dosimeters in the workplace used to be performed only by a spherical survey meter. Based on the reference dosimetric values, the Plant Dosimetry Laboratory has verified the response of albedo dosimeters. PMID:17416593

  17. How Coriolis meter design affects field performance

    SciTech Connect

    Levien, A.; Dudiak, A.

    1995-12-31

    Although many possibilities exist for the design of Coriolis flowmeters, a common set of fundamental physical principles affect practical meter design. Design criteria such as tube geometry, alloy section, operating frequencies, stress levels, and tubing wall thickness have varying impacts on meter performance. Additionally, field conditions such as changing temperature, pressure, pipeline stress and vibration affect measurement performance. The challenge created in Coriolis flow meter design is to maximize the sensitivity of the meter Coriolis forces, while minimizing the impact of outside environmental influences. Data are presented on the physical principles that affect Coriolis flowmeters, and how the various aspects of meter design influence field performance.

  18. Semantic priming effect during REM-sleep inertia in patients with narcolepsy.

    PubMed

    Mazzetti, Michela; Campi, Claudio; Mattarozzi, Katia; Plazzi, Giuseppe; Tuozzi, Giovanni; Vandi, Stefano; Vignatelli, Luca; Cipolli, Carlo

    2006-12-11

    Patients with narcolepsy-cataplexy (NC) present excessive daytime sleepiness (EDS), cataplexy and an altered architecture of nocturnal sleep, with frequent episodes of REM-sleep at sleep onset (SOREM-sleep). This altered organization of nocturnal sleep may be accompanied by some differences in the functioning of the cognitive processes involved in the access, organization and consolidation of information during sleep. This study attempts to ascertain whether the activation of semantic memory during REM-sleep, as measured using a technique of semantic priming (namely, the facilitation of the activation of strongly-related rather than weakly-related and, overall, unrelated pairs of prime-target words) is different in NC patients compared to normal subjects. A lexical decision task (LDT) was carried out twice in wakefulness (at 10a.m. and after a 24h interval) and twice in the period of sleep inertia following awakening from SOREM and 4th-cycle REM-sleep on 12 NC patients and from 1st- and 4th-cycle REM-sleep on 12 matched controls. Reaction time (RT) to target words, taken as a measure of the semantic priming effect, proved to be longer (a) in NC patients than in control subjects; (b) in the period of REM-sleep inertia than in wakefulness; (c) in the first rather than the second session; and (d) for unrelated compared to weakly-related and, overall, strongly-related prime-target pairs. RT in post-REM-sleep sessions was less impaired, compared to waking sessions, and less dependent on the associative strength of prime-target pairs in NC patients than in normal subjects. Finally, RT of NC patients, although longer than that of normal subjects in waking sessions, significantly improved in the second session, as a consequence of either the amount of exercise or the consolidation advantage provided by REM-sleep for the procedural components of the task. The whole picture suggests a greater effectiveness of the activation of semantic memory during (SO)REM-sleep in NC

  19. Is a purpose of REM sleep atonia to help regenerate intervertebral disc volumetric loss?

    PubMed Central

    Fryer, Jerome CJ

    2009-01-01

    The nature of atonia in sleep continues to be enigmatic. This article discusses a new hypothesis for complete core muscle relaxation in REM sleep, suggesting a bottom-up recuperative perspective. That is, does the atonia in REM sleep provide a utility to help restore the mechanobiology and respective diurnal intervertebral disc hydraulic loss? By combining the effects of gravity with current compressive concepts in spinal stability, this article looks at vertebral approximation as a deleterious experience with an intrinsic biological need to keep vertebrae separated. Methods using polysomnography and recumbent MRI are discussed. PMID:19123938

  20. Central Apneas and REM Sleep Behavior Disorder as an Initial Presentation of Multiple System Atrophy

    PubMed Central

    Garcia-Sanchez, Aldara; Fernandez-Navarro, Isabel; Garcia-Rio, Francisco

    2016-01-01

    We present the case of a patient with multiple system atrophy who presented with central apnea as the only sleep disordered breathing, associated with REM behavior disorder and restless legs syndrome. This presentation of the disease is unusual and probably reflects more widespread involvement at the onset. With this case, we show the importance of considering this kind of disease in the differential diagnosis of central sleep apnea syndromes. Citation: Garcia-Sanchez A, Fernandez-Navarro I, Garcia-Rio F. Central apneas and REM sleep behavior disorder as an initial presentation of multiple system atrophy. J Clin Sleep Med 2016;12(2):267–270. PMID:26518702

  1. Replay of conditioned stimuli during late REM and stage N2 sleep influences affective tone rather than emotional memory strength.

    PubMed

    Rihm, Julia S; Rasch, Björn

    2015-07-01

    Emotional memories are reprocessed during sleep, and it is widely assumed that this reprocessing occurs mainly during rapid eye movement (REM) sleep. In support for this notion, vivid emotional dreams occur mainly during REM sleep, and several studies have reported emotional memory enhancement to be associated with REM sleep or REM sleep-related parameters. However, it is still unknown whether reactivation of emotional memories during REM sleep strengthens emotional memories. Here, we tested whether re-presentation of emotionally learned stimuli during REM sleep enhances emotional memory. In a split-night design, participants underwent Pavlovian conditioning after the first half of the night. Neutral sounds served as conditioned stimuli (CS) and were either paired with a negative odor (CS+) or an odorless vehicle (CS-). During sound replay in subsequent late REM or N2 sleep, half of the CS+ and half of the CS- were presented again. In contrast to our hypothesis, replay during sleep did not affect emotional memory as measured by the differentiation between CS+ and CS- in expectancy, arousal and valence ratings. However, replay unspecifically decreased subjective arousal ratings of both emotional and neutral sounds and increased positive valence ratings also for both CS+ and CS- sounds, respectively. These effects were slightly more pronounced for replay during REM sleep. Our results suggest that re-exposure to previously conditioned stimuli during late sleep does not affect emotional memory strength, but rather influences the affective tone of both emotional and neutral memories. PMID:25933506

  2. The H1 histamine receptor blocker, chlorpheniramine, completely prevents the increase in REM sleep induced by immobilization stress in rats.

    PubMed

    Rojas-Zamorano, J A; Esqueda-Leon, E; Jimenez-Anguiano, A; Cintra-McGlone, L; Mendoza Melendez, M A; Velazquez Moctezuma, J

    2009-01-01

    Chlorpheniramine is a selective antagonist of the H1 histaminergic receptor subtype and its effects in humans include somnolence. Chlorpheniramine affects sleep in rats, mainly by decreasing REM sleep. On the other hand, stress by immobilization induces an important increase in the percentage of REM sleep. In this study we analyzed the effects of blocking histaminergic receptors on REM sleep induced by immobilization stress. Adult male Wistar rats were chronically implanted for sleep recording. Immobilization stress was induced by placing the rat in a small cylinder for 2 h. Experimental conditions were: A. Control; B. Stress; C. Stress plus vehicle and D. Stress plus chlorpheniramine. Independent experiments were done both in the dark, as well as the light period. Results showed that the increase in REM sleep observed after immobilization stress was completely abolished by chlorpheniramine, both in the dark and in the light phase. Furthermore, the decrease in REM sleep was significant even when compared to the non-stressed control rats. REM sleep latency was also significantly longer during both light phases. The present results suggest that REM sleep is quite sensitive to histaminergic blockage. It is possible that chlorpheniramine is also blocking the cholinergic mechanisms generating REM sleep.

  3. The effect of selective REM-sleep deprivation on the consolidation and affective evaluation of emotional memories.

    PubMed

    Wiesner, Christian D; Pulst, Julika; Krause, Fanny; Elsner, Marike; Baving, Lioba; Pedersen, Anya; Prehn-Kristensen, Alexander; Göder, Robert

    2015-07-01

    Emotion boosts the consolidation of events in the declarative memory system. Rapid eye movement (REM) sleep is believed to foster the memory consolidation of emotional events. On the other hand, REM sleep is assumed to reduce the emotional tone of the memory. Here, we investigated the effect of selective REM-sleep deprivation, SWS deprivation, or wake on the affective evaluation and consolidation of emotional and neutral pictures. Prior to an 9-h retention interval, sixty-two healthy participants (23.5 ± 2.5 years, 32 female, 30 male) learned and rated their affect to 80 neutral and 80 emotionally negative pictures. Despite rigorous deprivation of REM sleep or SWS, the residual sleep fostered the consolidation of neutral and negative pictures. Furthermore, emotional arousal helped to memorize the pictures. The better consolidation of negative pictures compared to neutral ones was most pronounced in the SWS-deprived group where a normal amount of REM sleep was present. This emotional memory bias correlated with REM sleep only in the SWS-deprived group. Furthermore, emotional arousal to the pictures decreased over time, but neither sleep nor wake had any differential effect. Neither the comparison of the affective ratings (arousal, valence) during encoding and recognition, nor the affective ratings of the recognized targets and rejected distractors supported the hypothesis that REM sleep dampens the emotional reaction to remembered stimuli. The data suggest that REM sleep fosters the consolidation of emotional memories but has no effect on the affective evaluation of the remembered contents. PMID:25708092

  4. Replay of conditioned stimuli during late REM and stage N2 sleep influences affective tone rather than emotional memory strength.

    PubMed

    Rihm, Julia S; Rasch, Björn

    2015-07-01

    Emotional memories are reprocessed during sleep, and it is widely assumed that this reprocessing occurs mainly during rapid eye movement (REM) sleep. In support for this notion, vivid emotional dreams occur mainly during REM sleep, and several studies have reported emotional memory enhancement to be associated with REM sleep or REM sleep-related parameters. However, it is still unknown whether reactivation of emotional memories during REM sleep strengthens emotional memories. Here, we tested whether re-presentation of emotionally learned stimuli during REM sleep enhances emotional memory. In a split-night design, participants underwent Pavlovian conditioning after the first half of the night. Neutral sounds served as conditioned stimuli (CS) and were either paired with a negative odor (CS+) or an odorless vehicle (CS-). During sound replay in subsequent late REM or N2 sleep, half of the CS+ and half of the CS- were presented again. In contrast to our hypothesis, replay during sleep did not affect emotional memory as measured by the differentiation between CS+ and CS- in expectancy, arousal and valence ratings. However, replay unspecifically decreased subjective arousal ratings of both emotional and neutral sounds and increased positive valence ratings also for both CS+ and CS- sounds, respectively. These effects were slightly more pronounced for replay during REM sleep. Our results suggest that re-exposure to previously conditioned stimuli during late sleep does not affect emotional memory strength, but rather influences the affective tone of both emotional and neutral memories.

  5. A Change of Possible Neurological and Psychological Significance Within the First Week of Neonate Life: Sleeping REM Rate.

    ERIC Educational Resources Information Center

    Minard, James; And Others

    The percentage of rapid eye movement (REM) during sleep is substantially greater in neonates (infants in first month after birth) than in other children or adults. It was hypothesized that REM rate may decline as rates of many response sequences do when repeatedly elicited. Electrical recordings of eye movements were obtained from a 3-day-old male…

  6. The role of REM sleep in the processing of emotional memories: evidence from behavior and event-related potentials.

    PubMed

    Groch, S; Wilhelm, I; Diekelmann, S; Born, J

    2013-01-01

    Emotional memories are vividly remembered for the long-term. Rapid eye movement (REM) sleep has been repeatedly proposed to support the superior retention of emotional memories. However, its exact contribution and, specifically, whether its effect is mainly on the consolidation of the contents or the processing of the affective component of emotional memories is not clear. Here, we investigated the effects of sleep rich in slow wave sleep (SWS) or REM sleep on the consolidation of emotional pictures and the accompanying changes in affective tone, using event-related potentials (ERPs) together with subjective ratings of valence and arousal. Sixteen healthy, young men learned 50 negative and 50 neutral pictures before 3-h retention sleep intervals that were filled with either SWS-rich early or REM sleep-rich late nocturnal sleep. In accordance with our hypothesis, recognition was better for emotional pictures than neutral pictures after REM compared to SWS-rich sleep. This emotional enhancement after REM-rich sleep expressed itself in an increased late positive potential of the ERP over the frontal cortex 300-500 ms after stimulus onset for correctly classified old emotional pictures compared with new emotional and neutral pictures. Valence and arousal ratings of emotional pictures were not differentially affected by REM or SWS-rich sleep after learning. Our results corroborate that REM sleep contributes to the consolidation of emotional contents in memory, but suggest that the affective tone is preserved rather than reduced by the processing of emotional memories during REM sleep.

  7. Affect Intensity and Phasic REM Sleep in Depressed Men before and after Treatment with Cognitive-Behavioral Therapy.

    ERIC Educational Resources Information Center

    Nofzinger, Eric A.; And Others

    1994-01-01

    Explored relationship between daytime affect and REM (rapid eye movement) sleep in 45 depressed men before and after treatment with cognitive-behavioral therapy and in control group of 43 healthy subjects. For depressed subjects only, intensity of daytime affect correlated significantly and positively with phasic REM sleep measures at pre- and…

  8. The effect of selective REM-sleep deprivation on the consolidation and affective evaluation of emotional memories.

    PubMed

    Wiesner, Christian D; Pulst, Julika; Krause, Fanny; Elsner, Marike; Baving, Lioba; Pedersen, Anya; Prehn-Kristensen, Alexander; Göder, Robert

    2015-07-01

    Emotion boosts the consolidation of events in the declarative memory system. Rapid eye movement (REM) sleep is believed to foster the memory consolidation of emotional events. On the other hand, REM sleep is assumed to reduce the emotional tone of the memory. Here, we investigated the effect of selective REM-sleep deprivation, SWS deprivation, or wake on the affective evaluation and consolidation of emotional and neutral pictures. Prior to an 9-h retention interval, sixty-two healthy participants (23.5 ± 2.5 years, 32 female, 30 male) learned and rated their affect to 80 neutral and 80 emotionally negative pictures. Despite rigorous deprivation of REM sleep or SWS, the residual sleep fostered the consolidation of neutral and negative pictures. Furthermore, emotional arousal helped to memorize the pictures. The better consolidation of negative pictures compared to neutral ones was most pronounced in the SWS-deprived group where a normal amount of REM sleep was present. This emotional memory bias correlated with REM sleep only in the SWS-deprived group. Furthermore, emotional arousal to the pictures decreased over time, but neither sleep nor wake had any differential effect. Neither the comparison of the affective ratings (arousal, valence) during encoding and recognition, nor the affective ratings of the recognized targets and rejected distractors supported the hypothesis that REM sleep dampens the emotional reaction to remembered stimuli. The data suggest that REM sleep fosters the consolidation of emotional memories but has no effect on the affective evaluation of the remembered contents.

  9. Quantitative differences among EMG activities of muscles innervated by subpopulations of hypoglossal and upper spinal motoneurons during non-REM sleep - REM sleep transitions: a window on neural processes in the sleeping brain.

    PubMed

    Rukhadze, I; Kamani, H; Kubin, L

    2011-12-01

    In the rat, a species widely used to study the neural mechanisms of sleep and motor control, lingual electromyographic activity (EMG) is minimal during non-rapid eye movement (non-REM) sleep and then phasic twitches gradually increase after the onset of REM sleep. To better characterize the central neural processes underlying this pattern, we quantified EMG of muscles innervated by distinct subpopulations of hypoglossal motoneurons and nuchal (N) EMG during transitions from non-REM sleep to REM sleep. In 8 chronically instrumented rats, we recorded cortical EEG, EMG at sites near the base of the tongue where genioglossal and intrinsic muscle fibers predominate (GG-I), EMG of the geniohyoid (GH) muscle, and N EMG. Sleep-wake states were identified and EMGs quantified relative to their mean levels in wakefulness in successive 10 s epochs. During non-REM sleep, the average EMG levels differed among the three muscles, with the order being N>GH>GG-I. During REM sleep, due to different magnitudes of phasic twitches, the order was reversed to GG-I>GH>N. GG-I and GH exhibited a gradual increase of twitching that peaked at 70-120 s after the onset of REM sleep and then declined if the REM sleep episode lasted longer. We propose that a common phasic excitatory generator impinges on motoneuron pools that innervate different muscles, but twitching magnitudes are different due to different levels of tonic motoneuronal hyperpolarization. We also propose that REM sleep episodes of average durations are terminated by intense activity of the central generator of phasic events, whereas long REM sleep episodes end as a result of a gradual waning of the tonic disfacilitatory and inhibitory processes.

  10. Choose the right flow meter

    SciTech Connect

    Dolenc, J.W.

    1996-01-01

    Flow measurement is distinguished from other measurements by the large number of viable technologies available. Many flow meter selection guides have been published, all of which come to the same basic conclusions: choice depends upon the purpose of the measurement, the value of the fluid being measured, its physical characteristics, and installation constrains associated with the location of the meter. When selecting a flow measurement technology for any application, seven key questions must be answered: (1) What is being measured? (2) Why is the particular measurement being made? (3) What is the value of the fluid? (4) What are the physical properties of the fluid at the point of measurement? (5) What materials of construction are acceptable? (6) What are the installation constraints? and (7) What are the track records of the various technologies in this application? Finally, after these questions are answered, performance vs. cost can be judged. This judgment can be made via a formal procedure with written documentation or, for an experienced engineer, based on an information analysis utilizing accumulated knowledge or preferences.

  11. Discussion series on PURPA related topics: metering

    SciTech Connect

    Sturgeon, J I

    1980-08-01

    Time-differentiated metering of electricity consumption and demand is required in both rate-structure experimentation and the implementation of most time-of-use rate designs. Time-differentiated metering takes three major forms: multi-register watthour meters, magnetic-tape recording meters, and remote automatic meter-reading systems. The majority of projects selected magnetic-tape meters for their flexibility with respect to rate structure, load-survey capabilities, and ready availability. The small-scale, experimental nature of the projects reduced the significance of the large difference in per-unit cost and operational/maintenance complexity between this form of metering and the multi-register form. Magnetic-tape meters are not likely candidates for system-wide implementation of time-differentiated metering. Automatic remote-meter-reading systems were not adequately available during the project years; those projects attempting to use these were unable to bring them to full operational status before project termination, due to the many problems of design, quality control, and equipment acquisition encountered. Delays in acquisition and problems of quality control also followed the selection of magnetic-tape meters and multi-register meters by a number of the projects. Though less complex than automatic remote-reading systems, these technologies are still new and more complex than standard watthour metering. Thus, both equipment vendors and utilities encountered numerous problems in getting properly functioning meters to the service entrances on time. A variety of factors contributed to installation delays, including unforeseen space limitations, incompatible wiring, problems of task organization, and customer reluctance.

  12. Radio Detection of Neutron Star Binary Mergers

    NASA Astrophysics Data System (ADS)

    Bear, Brandon; Cardena, Brett; Dispoto, Dana; Papadopoulos, Joanna; Kavic, Michael; Simonetti, John

    2011-10-01

    Neutron star binary systems lose energy through gravitational radiation, and eventually merge. The gravitational radiation from the merger can be detected by the Laser Interferometer Gravitational-Wave Observatory (LIGO). It is expected that a transient radio pulse will also be produced during the merger event. Detection of such radio transients would allow for LIGO to search for signals within constrained time periods. We calculate the LWA-1 detection rate of transient events from neutron star binary mergers. We calculate the detection rate of transient events from neutron star binary mergers for the Long Wavelength Array and the Eight-meter-wavelength Transient Array.

  13. Spatial and Reversal Learning in the Morris Water Maze Are Largely Resistant to Six Hours of REM Sleep Deprivation Following Training

    ERIC Educational Resources Information Center

    Walsh, Christine M.; Booth, Victoria; Poe, Gina R.

    2011-01-01

    This first test of the role of REM (rapid eye movement) sleep in reversal spatial learning is also the first attempt to replicate a much cited pair of papers reporting that REM sleep deprivation impairs the consolidation of initial spatial learning in the Morris water maze. We hypothesized that REM sleep deprivation following training would impair…

  14. Compact gas meter development shows promise

    SciTech Connect

    Norman, R.S.

    1995-07-01

    In the mid-1980s, the Gas Research Institute (GRI) surveyed the needs of the natural gas industry to determine where improved operations technology would assist the industry in the residential gas market. A compact gas meter was identified as an advance in the metering area which would be beneficial for future growth of natural gas usage, especially in the multi-family construction area. GRI currently is pursuing development of a compact diaphragm meter and evaluating several advanced electronic meters for future use in the US. Overall benefits to the natural gas distribution industry will be: greater installation flexibility for a smaller meter; easier integration with automatic meter reading equipment; lower total installation costs including meter, meter supports, and regulator; better appearance in confined, exterior installations. Smaller gas meters will become a viable option for gas companies, builders, and contractors i the near future and will enhance gas energy use for many residential and commercial buildings within the next five years. GRI`s overall goal is to have 50,000 compact gas meters installed in the US by the end of 1997.

  15. EXPERIENCE MONITORING FOR LOW LEVEL NEUTRON RADIATION AT THE H-CANYON AT THE SAVANNAH RIVER SITE

    SciTech Connect

    HOGUE, MARK

    2005-10-07

    Department of Energy contractors are required to monitor external occupational radiation exposure of an individual likely to receive an effective dose equivalent to the whole body of 0.1 rem (0.001sievert) or more in a year. For a working year of 2000 hours, this translates to a dose rate of 0.05 mrem/hr (0.5 {micro}Sv/hr). This can be a challenging requirement for neutron exposure because traditional surveys with shielded BF{sub 3} proportional counters are difficult to conduct, particularly at low dose rates. A modified survey method was used at the Savannah River Site to find low dose rates in excess of 0.05 mrem/hr. An unshielded He{sup 3} detector was used to find elevated gross slow neutron counts. Areas with high count rates on the unshielded He{sup 3} detector were further investigated with shielded BF{sub 3} proportional counters and thermoluminescent neutron dosimeters were placed in the area of interest. An office area was investigated with this method. The data initially suggested that whole body neutron dose rates to office workers could be occurring at levels significantly higher than 0.1 rem (0.001sievert). The final evaluation, however, showed that the office workers were exposed to less than 0.1 rem/yr (0.001sievert/yr) of neutron radiation.

  16. Coherent neocortical 40-Hz oscillations are not present during REM sleep.

    PubMed

    Castro, Santiago; Falconi, Atilio; Chase, Michael H; Torterolo, Pablo

    2013-04-01

    During cognitive processes there are extensive interactions between various regions of the cerebral cortex. Oscillations in the gamma frequency band (≈40 Hz) of the electroencephalogram (EEG) are involved in the binding of spatially separated but temporally correlated neural events, which results in a unified perceptual experience. The extent of these interactions can be examined by means of a mathematical algorithm called 'coherence', which reflects the 'strength' of functional interactions between cortical areas. The present study was conducted to analyse EEG coherence in the gamma frequency band of the cat during alert wakefulness (AW), quiet wakefulness (QW), non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep. Cats were implanted with electrodes in the frontal, parietal and occipital cortices to monitor EEG activity. Coherence values within the gamma frequency (30-100 Hz) from pairs of EEG recordings were analysed. A large increase in coherence occurred between all cortical regions in the 30-45 Hz frequency band during AW compared with the other behavioral states. As the animal transitioned from AW to QW and from QW to NREM sleep, coherence decreased to a moderate level. Remarkably, there was practically no EEG coherence in the entire gamma band spectrum (30-100 Hz) during REM sleep. We conclude that functional interactions between cortical areas are radically different during sleep compared with wakefulness. The virtual absence of gamma frequency coherence during REM sleep may underlie the unique cognitive processing that occurs during dreams, which is principally a REM sleep-related phenomenon. PMID:23406153

  17. REM Sleep Enhancement of Probabilistic Classification Learning is Sensitive to Subsequent Interference

    PubMed Central

    Barsky, Murray M.; Tucker, Matthew A.; Stickgold, Robert

    2015-01-01

    During wakefulness the brain creates meaningful relationships between disparate stimuli in ways that escape conscious awareness. Processes active during sleep can strengthen these relationships, leading to more adaptive use of those stimuli when encountered during subsequent wake. Performance on the weather prediction task (WPT), a well-studied measure of implicit probabilistic learning, has been shown to improve significantly following a night of sleep, with stronger initial learning predicting more nocturnal REM sleep. We investigated this relationship further, studying the effect on WPT performance of a daytime nap containing REM sleep. We also added an interference condition after the nap/wake period as an additional probe of memory strength. Our results show that a nap significantly boosts WPT performance, and that this improvement is correlated with the amount of REM sleep obtained during the nap. When interference training is introduced following the nap, however, this REM-sleep benefit vanishes. In contrast, following an equal period of wake, performance is both unchanged from training and unaffected by interference training. Thus, while the true probabilistic relationships between WPT stimuli are strengthened by sleep, these changes are selectively susceptible to the destructive effects of retroactive interference, at least in the short term. PMID:25769506

  18. [Modulation by the GABA of the ventro-oral-pontine reticular REM sleep-inducing neurons].

    PubMed

    Reinoso Suárez, Fernando

    2007-01-01

    From a multidisciplinary study in our laboratory we have compiled numerous findings on the role played by the inhibitory neurotransmitter GABA in the ventral part of the oral pontine reticular nucleus (vRPO), REM sleep induction and maintenance brainstem structure. Functional GABA in the vRPO is located in a few small and scattered neuronal bodies, and in an abundant number of synaptic terminals: 30% of all synaptic terminals in vRPO are GABAergic. These terminals form inhibitory, symmetric synapses on the soma and different segments of the dendritic tree of the vRPO neurons, mainly in those of large diameter. In unitary intracellular studies, in vitro, we have demonstrated that GABA produces hyperpolarization of the vRPO neurons. In vivo experiments in freely moving cats, local microinjections of the GABA(A) receptor agonist muscimol decreased REM sleep. The different densities of GABA-immunoreactions and the diverse and complex morphological ultrastructure of the vRPO GABAergic terminals suggest that they have different origins and physiologic functions. There are GABAergic projections to the vRPO from diencephalic structures related with the other phases of the sleep-wakefulness cycle: wakefulness and non-REM sleep, which may be anatomical substrata for the GABAergic inhibition of the vRPO REM sleep-inducing neurons during these other phases.

  19. Periodic leg movements and REM sleep without atonia in Parkinson's disease with camptocormia.

    PubMed

    Lavault, Sophie; Bloch, Frederic; Houeto, Jean-Luc; Konofal, Eric; Welter, Marie-Laure; Agid, Yves; Arnulf, Isabelle

    2009-12-15

    Camptocormia (a flexion of the trunk that only appears when standing or walking) affects a minority of patients with Parkinson's disease (PD). As it responds poorly to levodopa and is associated with reduced midbrain and pons volume, it may result from non-dopaminergic, brainstem lesions. As several sleep abnormalities in PD also result from non-dopaminergic brainstem lesions, we monitored sleep in 24 non-demented PD patients with (n = 12) and without (n = 12) camptocormia and in 12 controls. Nearly half (42%) patients with camptocormia had abnormal periodic leg movement indices (>15/h), versus 17% patients without camptocormia and 8% of controls (p = 0.02). In addition, the percentage of enhanced muscle activity during REM sleep (measured on the chin and on the limb muscles) tended to be higher in patients with than without camptocormia (51 +/- 39% vs. 20 +/- 25%, p = 0.06). The other sleep and REM sleep characteristics (sleep and REM sleep onset latencies, sleep time and sleep stage percentages, REMs density, arousal, and apnea-hypopnea indices) were not different between these two PD groups. Lesions causing this axial dystonia may spare the sleep systems but affect the control of movements during sleep. PMID:19891002

  20. Ultradian cycles in mice: definitions and links with REMS and NREMS.

    PubMed

    Le Bon, O; Popa, D; Streel, E; Alexandre, C; Lena, C; Linkowski, P; Adrien, J

    2007-10-01

    Sleep can be organized in two quite different ways across homeothermic species: either in one block (monophasic), or in several bouts across the 24 h (polyphasic). Yet, the main relationships between variables, as well as regulating mechanisms, are likely to be similar. Correlations and theories on sleep regulation should thus be examined on both types of sleepers. In previous studies on monophasic humans, we have shown preferential links between the number of ultradian cycles and the rapid eye movement sleep (REMS) time, rather than with its counterpart non-rapid eye movement sleep (NREMS). Here, the sleep of 26 polyphasic mice was examined, both to better describe the NREMS distribution, which is far more complex than in humans, and to replicate the analyses performed on humans. As in humans, the strongest links with the number of cycles were with REMS. Links were not significant with NREMS taken as a whole, although positive correlations were found with the NREMS immediately preceding REMS episodes and inversely significant with the residue. This convergence between monophasic and polyphasic patterns supports the central role played by REMS in sleep alternation. PMID:17724599

  1. Purpose of REM sleep: endogenous anti-epileptogenesis in man -- a hypothesis.

    PubMed

    Jaseja, Harinder

    2004-01-01

    Neuro-scientists, worldwide, are endeavoring to elucidate the purpose of sleep which still remains largely elusive. There is, however, consensus on many aspects of sleep functions; one such aspect is its relationship with seizures/epilepsy. There is unequivocal agreement on increased susceptibility to epilepsy during nonrapid eye movement (NREM, slow-wave) sleep. Large number of studies have shown increased frequency of seizures and interictal epileptiform discharges in epileptic patients during NREM sleep (esp., stages I and II) which is associated with EEG synchronization. Similarly, there is widespread acceptance of de-synchronized brain-activity states being associated with rarity/total absence of epileptic potentials, one such state being rapid eye movement (REM) sleep. Certain drugs and substances which inhibit NREM sleep have been found to possess anti-convulsant properties. Not surprisingly, drugs/chemicals which enhance/promote NREM sleep or suppress/inhibit REM sleep are associated with increased susceptibility to seizures and are contraindicated in epilepsy. The manner and pattern in which REM phase occurs in sleep are also naturally programmed to exert anti-epileptogenic influence. This hypothesis-article highlights and conceptualizes the primary function of REM-sleep as endogenous anti-epileptogenic system in the body akin to the endogenous analgesia and immune systems man is born with. PMID:15050104

  2. Loss of Gnas Imprinting Differentially Affects REM/NREM Sleep and Cognition in Mice

    PubMed Central

    Lassi, Glenda; Ball, Simon T.; Maggi, Silvia; Colonna, Giovanni; Nieus, Thierry; Cero, Cheryl; Bartolomucci, Alessandro; Peters, Jo; Tucci, Valter

    2012-01-01

    It has been suggested that imprinted genes are important in the regulation of sleep. However, the fundamental question of whether genomic imprinting has a role in sleep has remained elusive up to now. In this work we show that REM and NREM sleep states are differentially modulated by the maternally expressed imprinted gene Gnas. In particular, in mice with loss of imprinting of Gnas, NREM and complex cognitive processes are enhanced while REM and REM–linked behaviors are inhibited. This is the first demonstration that a specific overexpression of an imprinted gene affects sleep states and related complex behavioral traits. Furthermore, in parallel to the Gnas overexpression, we have observed an overexpression of Ucp1 in interscapular brown adipose tissue (BAT) and a significant increase in thermoregulation that may account for the REM/NREM sleep phenotypes. We conclude that there must be significant evolutionary advantages in the monoallelic expression of Gnas for REM sleep and for the consolidation of REM–dependent memories. Conversely, biallelic expression of Gnas reinforces slow wave activity in NREM sleep, and this results in a reduction of uncertainty in temporal decision-making processes. PMID:22589743

  3. REM sleep enhancement of probabilistic classification learning is sensitive to subsequent interference.

    PubMed

    Barsky, Murray M; Tucker, Matthew A; Stickgold, Robert

    2015-07-01

    During wakefulness the brain creates meaningful relationships between disparate stimuli in ways that escape conscious awareness. Processes active during sleep can strengthen these relationships, leading to more adaptive use of those stimuli when encountered during subsequent wake. Performance on the Weather Prediction Task (WPT), a well-studied measure of implicit probabilistic learning, has been shown to improve significantly following a night of sleep, with stronger initial learning predicting more nocturnal REM sleep. We investigated this relationship further, studying the effect on WPT performance of a daytime nap containing REM sleep. We also added an interference condition after the nap/wake period as an additional probe of memory strength. Our results show that a nap significantly boosts WPT performance, and that this improvement is correlated with the amount of REM sleep obtained during the nap. When interference training is introduced following the nap, however, this REM-sleep benefit vanishes. In contrast, following an equal period of wake, performance is both unchanged from training and unaffected by interference training. Thus, while the true probabilistic relationships between WPT stimuli are strengthened by sleep, these changes are selectively susceptible to the destructive effects of retroactive interference, at least in the short term. PMID:25769506

  4. REMIR: The REM infrared camera to follow up the early phases of GRBs afterglows

    NASA Astrophysics Data System (ADS)

    Calzoletti, L.; Melandri, A.; Testa, V.; Antonelli, L. A.; Vitali, F.; D'Alessio, F.; di Paola, A.; Zerbi, F. M.; Chincarini, G.; Cunniffe, R.; Jordan, B.; Rodonò, M.; Conconi, P.; Covino, S.; Cutispoto, G.; Molinari, E.; Tosti, G.; Ross/Rem Team

    2005-07-01

    REMIR is a near-infrared camera, covering the 0.95-2.3 μm range with 5 filters (z,J,H,Ks and H2), mounted at one of the Nasmyth foci of the REM (Rapid Eye Mount) telescope. REM is a fully robotic fast-slewing 60 cm telescope, primarily designed to follow-up the early phases of the afterglow of GRBs detected by dedicated instruments onboard satellites (like SWIFT, a satellite entirely dedicated to GRBs science launched the 12 November 2004). Moreover REM hosts a slitless spectrograph covering the range 0.45-0.95 μm, with 30 sample points and with the possibility to perform broad-band V,R,I photometry (ROSS, REM Optical Slitless Spectrograph). The main task of REMIR is to perform realtime NIR observations of GRBs detected by gamma-ray monitors onboard satellites, looking for any possible infrared transient source. As soon as a transient source is detected in the IR images, larger telescopes are promptly alerted to perform early spectroscopy of the afterglow. All the above operations are performed in a fully automatic way and without any human supervision. We present the results of on-site tests that have been done to characterize the REMIR camera and the performances of the dedicated reduction pipeline AQuA (Automatic Quick Analysis), suited for fast transients detection.

  5. Estradiol modulates recovery of REM sleep in a time-of-day-dependent manner.

    PubMed

    Schwartz, Michael D; Mong, Jessica A

    2013-08-01

    Ovarian hormones are thought to modulate sleep and fluctuations in the hormonal milieu are coincident with sleep complaints in women. In female rats, estradiol increases waking and suppresses sleep. In this study, we asked whether this effect is mediated via circadian or homeostatic regulatory mechanisms. Ovariectomized female rats received daily injections of estradiol benzoate (EB) or sesame oil that mimicked the rapid increase and subsequent decline of circulating estradiol at proestrus. In one experiment, animals were sleep deprived for 6 h starting at lights-on, so that recovery began in the mid-light phase; in the second experiment, animals were sleep deprived starting in the mid-light phase, so that recovery began at lights-off. EB suppressed baseline rapid eye movement (REM) and non-REM (NREM) sleep and increased waking in the dark phase. In both experiments, EB enhanced REM recovery in the light phase while suppressing it in the dark compared with oil; this effect was most pronounced in the first 6 h of recovery. By contrast, NREM recovery was largely unaffected by EB. In summary, EB enhanced waking and suppressed sleep, particularly REM sleep, in the dark under baseline and recovery conditions. These strong temporally dependent effects suggest that EB consolidates circadian sleep-wake rhythms in female rats.

  6. REM sleep deprivation in rats results in inflammation and interleukin-17 elevation.

    PubMed

    Yehuda, Shlomo; Sredni, Benjamin; Carasso, Rafi L; Kenigsbuch-Sredni, Dvora

    2009-07-01

    Sleep deprivation is a major health problem in modern society. Deprivation of rapid eye movement (REM) sleep is particularly damaging to cognition and to spatial memory; however, the mechanisms that mediate these deteriorations in function are not known. We explored the possibility that REM sleep deprivation may provoke major changes in the immune system by inducing inflammation. Rats were subjected to 72 h of REM sleep deprivation, and the plasma levels of proinflammatory cytokines (IL-1, IL-1beta, IL-6, IL-17A, and TNF-alpha), an anti-inflammatory cytokine (IL-10), the inflammatory markers homocysteine, corticosterone, and hyperthermia were measured immediately after the deprivation period, and 7 days later. The results indicate that REM sleep deprivation induced an inflammatory response. The levels of the proinflammatory cytokines and markers were significantly elevated in sleep-deprived rats as compared to control rats. After 7 days of recovery, the levels of some markers, including hyperthermia, remained higher in sleep-deprived rats versus the control animals. IL-17A appears to play a pivotal role in coordinating the inflammation. These data shed new light on the mechanism of sleep deprivation-induced inflammation.

  7. REM sleep enhancement of probabilistic classification learning is sensitive to subsequent interference.

    PubMed

    Barsky, Murray M; Tucker, Matthew A; Stickgold, Robert

    2015-07-01

    During wakefulness the brain creates meaningful relationships between disparate stimuli in ways that escape conscious awareness. Processes active during sleep can strengthen these relationships, leading to more adaptive use of those stimuli when encountered during subsequent wake. Performance on the Weather Prediction Task (WPT), a well-studied measure of implicit probabilistic learning, has been shown to improve significantly following a night of sleep, with stronger initial learning predicting more nocturnal REM sleep. We investigated this relationship further, studying the effect on WPT performance of a daytime nap containing REM sleep. We also added an interference condition after the nap/wake period as an additional probe of memory strength. Our results show that a nap significantly boosts WPT performance, and that this improvement is correlated with the amount of REM sleep obtained during the nap. When interference training is introduced following the nap, however, this REM-sleep benefit vanishes. In contrast, following an equal period of wake, performance is both unchanged from training and unaffected by interference training. Thus, while the true probabilistic relationships between WPT stimuli are strengthened by sleep, these changes are selectively susceptible to the destructive effects of retroactive interference, at least in the short term.

  8. REM Dreaming and Cognitive Skills at Ages 5-8: A Cross-Sectional Study.

    ERIC Educational Resources Information Center

    Foulkes, David; And Others

    1990-01-01

    Describes laboratory research on REM (rapid eye movement) sleep in children ages five to eight. Image quality, self-representation, and narrative complexity of dreams all develop as age progresses. Children's representational intelligence predicts their rate of dream production, but language skills do not. (GH)

  9. The Memory Function of Noradrenergic Activity in Non-REM Sleep

    ERIC Educational Resources Information Center

    Gais, Steffen; Rasch, Bjorn; Dahmen, Johannes C.; Sara, Susan; Born, Jan

    2011-01-01

    There is a long-standing assumption that low noradrenergic activity during sleep reflects mainly the low arousal during this brain state. Nevertheless, recent research has demonstrated that the locus coeruleus, which is the main source of cortical noradrenaline, displays discrete periods of intense firing during non-REM sleep, without any signs of…

  10. Neutron detector

    DOEpatents

    Stephan, Andrew C.; Jardret; Vincent D.

    2011-04-05

    A neutron detector has a volume of neutron moderating material and a plurality of individual neutron sensing elements dispersed at selected locations throughout the moderator, and particularly arranged so that some of the detecting elements are closer to the surface of the moderator assembly and others are more deeply embedded. The arrangement captures some thermalized neutrons that might otherwise be scattered away from a single, centrally located detector element. Different geometrical arrangements may be used while preserving its fundamental characteristics. Different types of neutron sensing elements may be used, which may operate on any of a number of physical principles to perform the function of sensing a neutron, either by a capture or a scattering reaction, and converting that reaction to a detectable signal. High detection efficiency, an ability to acquire spectral information, and directional sensitivity may be obtained.

  11. Neutron detector

    SciTech Connect

    Stephan, Andrew C; Jardret, Vincent D

    2009-04-07

    A neutron detector has a volume of neutron moderating material and a plurality of individual neutron sensing elements dispersed at selected locations throughout the moderator, and particularly arranged so that some of the detecting elements are closer to the surface of the moderator assembly and others are more deeply embedded. The arrangement captures some thermalized neutrons that might otherwise be scattered away from a single, centrally located detector element. Different geometrical arrangements may be used while preserving its fundamental characteristics. Different types of neutron sensing elements may be used, which may operate on any of a number of physical principles to perform the function of sensing a neutron, either by a capture or a scattering reaction, and converting that reaction to a detectable signal. High detection efficiency, an ability to acquire spectral information, and directional sensitivity may be obtained.

  12. Inherent limitations of nondestructive chlorophyll meters: a comparison of two types of meters

    NASA Technical Reports Server (NTRS)

    Monje, O. A.; Bugbee, B.

    1992-01-01

    Two types of nondestructive chlorophyll meters were compared with a standard, destructive chlorophyll measurement technique. The nondestructive chlorophyll meters were 1) a custom built, single-wavelength meter, and 2) the recently introduced, dual-wavelengh, chlorophyll meter from Minolta (model SPAD-502). Data from both meters were closely correlated with destructive measurements of chlorophyll (r2 = 0.90 and 0.93; respectively) for leaves with chlorophyll concentrations ranging from 100 to 600 mg m-2, but both meters consistently overestimated chlorophyll outside this range. Although the dual-wavelength meter was slightly more accurate than the single-wavelength meter (higher r2), the light-scattering properties of leaf cells and the nonhomogeneous distribution of chlorophyll in leaves appear to limit the ability of all meters to estimate in vivo chlorophyll concentration.

  13. Electroencephalographic and autonomic alterations in subjects with frequent nightmares during pre-and post-REM periods.

    PubMed

    Simor, Péter; Körmendi, János; Horváth, Klára; Gombos, Ferenc; Ujma, Péter P; Bódizs, Róbert

    2014-11-01

    Abnormal arousal processes, sympathetic influences, as well as wake-like alpha activity during sleep were reported as pathophysiological features of Nightmare Disorder. We hypothesized that in Nightmare Disorder, wake-like cortical activity and peripheral measures linked to arousals would be triggered by physiological processes related to the initiation of REM periods. Therefore, we examined electroencephalographic (EEG), motor and autonomous (cardiac) activity in a group of nightmare (NM) and healthy control (CTL) subjects during sleep-state-transitions while controlling for the confounding effects of trait anxiety. Based on the second-nights' polysomnographic recordings of 19 Nightmare Disordered (NM) and 21 control (CTL) subjects, we examined the absolute power spectra focusing on the alpha range, measures of heart rate variability (HRV) and motor (muscle tone) activity during pre-REM and post-REM periods, separately. According to our results, the NM group exhibited increased alpha power during pre-REM, but not in post-REM, or stable, non-transitory periods. While CTL subjects showed increased HRV during pre-REM periods in contrast to post-REM ones, NM subjects did not exhibit such sleep state-specific differences in HRV, but showed more stable values across the examined sleep stages and less overall variability reflecting generally attenuated parasympathetic activity during sleep-state-transitions and during stable, non-transitory NREM states. These differences were not mediated by waking levels of trait anxiety. Moreover, in both groups, significant differences emerged regarding cortical and motor (muscle tone) activity between pre-REM and post-REM conditions, reflecting the heterogeneity of NREM sleep. Our findings indicate that NM subjects' sleep is compromised during NREM-REM transitions, but relatively stabilized after REM periods. The coexistence of sleep-like and wake-like cortical activity in NM subjects seems to be triggered by REM/WAKE promoting

  14. A restricted parabrachial pontine region is active during non-REM sleep

    PubMed Central

    Torterolo, Pablo; Sampogna, Sharon; Chase, Michael H.

    2011-01-01

    The principal site that generates both REM sleep and wakefulness is located in the mesopontine reticular formation, whereas non-REM sleep (NREM) is primarily dependent upon the functioning of neurons that are located in the preoptic region of the hypothalamus. In the present study, we were interested in determining whether the occurrence of NREM might also depend on the activity of mesopontine structures, as has been shown for wakefulness and REM sleep. Adult cats were maintained in one of the following states: quiet wakefulness (QW), alert wakefulness (AW), NREM, or REM sleep induced by microinjections of carbachol into the nucleus pontis oralis (REM-carbachol). Subsequently, they were euthanized and single labeling immunohistochemical studies were undertaken to determine state-dependent patterns of neuronal activity in the brainstem based upon the expression of the protein Fos. In addition, double labeling immunohistochemical studies were carried out to detect neurons that expressed Fos as well as choline acetyltransferase, tyrosine hydroxylase or GABA. During NREM, only a few Fos immunoreactive cells were present in different regions of the brainstem; however, a discrete cluster of Fos+ neurons was observed in the caudolateral peribrachial region (CLPB). The number of the Fos+ neurons in the CLPB during NREM was significantly greater (67.9 ± 10.9, P < 0.0001) compared to QW (8.0 ± 6.7), AW (5.2 ± 4.2) or REM-carbachol (8.0 ± 4.7). In addition, there was a positive correlation (R = 0.93) between the time the animals spent in NREM and the number of Fos+ neurons in the CLPB. Fos-immunoreactive neurons in the CLPB were neither cholinergic nor catecholaminergic; however about 50% of these neurons were GABAergic. We conclude that a group of GABAergic and unidentified neurons in the CLPB are active during NREM and likely involved in the control of this behavioral state. These data open new avenues for the study of NREM, as well as for the explorations of

  15. The Antarctic permafrost as a testbed for REMS (Rover Environmental Monitoring Station-Mars Science Laboratory)

    NASA Astrophysics Data System (ADS)

    Esteban, B.; Ramos, M.; Sebastián, E.; Armiens, C.; Gómez-Elvira, J.; Cabos, W.; de Pablo, M. A.

    2009-04-01

    The present climatic characteristics of Mars favor the presence of extense permafrost areas in this lonely planet. Therefore environmental parameters that are included in Martian Rover missions are also used for monitoring thermal soil surface evolution in order to study the permafrost active layer thickness and the energy balance in the soil-atmosphere boundary limit layer. The REMS (Rover Environmental Monitoring Station) is an environmental station designed by the Centro de Astrobiología (CAB- Spain) with the collaboration of national and international partners (CRISA/EADS, UPC and FMI), which is part of the payload of the MSL (Mars Science Laboratory) NASA mission to Mars (http://mars.jpl.nasa.gov/msl/overview/). This mission is expected to be launched in the final months of 2009, and mainly consists of a Rover, with a complete set of scientific instruments; the Rover will carry the biggest, most advanced suite of instruments for scientific studies ever sent to the Martian surface. Five sensors compose the REMS instrument: ground (GT-REMS) and air temperatures, wind speed and direction, pressure, humidity and ultraviolet radiation (UV-REMS). A simplified setup of the REMS was deployed on Antarctica in the surroundings of the Spanish Antarctic Stations on Livingston and Deception Islands (Maritime Antarctica), where the permafrost distribution is well-known. The aim of the experiment was to check REMS's sensors response against hard environmental conditions and calibrates their measures with standard Antarctic devices. The experimental apparatuses included some standard meteorological and thermopiles sensors corresponding to the REMS. All the sensors are mounted in a 1.8 m mast and include a Pt100 air temperature sensor with shield solar protection on the mast top, a Kipp and Zonnen CNR1 net radiometer for measuring infrared (5-50 μm) and short wave solar (305-2800 nm) radiation at 1.5 m high, GT-REMS sensor and its amplification box at 0.7 m high and finally

  16. Atmospheric neutrons

    NASA Technical Reports Server (NTRS)

    Preszler, A. M.; Moon, S.; White, R. S.

    1976-01-01

    Additional calibrations of the University of California double-scatter neutron detector and additional analysis corrections lead to slightly changed neutron fluxes. The theoretical angular distributions of Merker (1975) are in general agreement with the reported experimental fluxes but do not give the peaks for vertical upward and downward moving neutrons. The theoretical neutron escape current is in agreement with the experimental values from 10 to 100 MeV. The experimental fluxes obtained agree with those of Kanbach et al. (1974) in the overlap region from 70 to 100 MeV.

  17. Characterization of extended range Bonner Sphere Spectrometers in the CERF high-energy broad neutron field at CERN

    NASA Astrophysics Data System (ADS)

    Agosteo, S.; Bedogni, R.; Caresana, M.; Charitonidis, N.; Chiti, M.; Esposito, A.; Ferrarini, M.; Severino, C.; Silari, M.

    2012-12-01

    The accurate determination of the ambient dose equivalent in the mixed neutron-photon fields encountered around high-energy particle accelerators still represents a challenging task. The main complexity arises from the extreme variability of the neutron energy, which spans over 10 orders of magnitude or more. Operational survey instruments, which response function attempts to mimic the fluence-to-ambient dose equivalent conversion coefficient up to GeV neutrons, are available on the market, but their response is not fully reliable over the entire energy range. Extended range rem counters (ERRC) do not require the exact knowledge of the energy distribution of the neutron field and the calibration can be done with a source spectrum. If the actual neutron field has an energy distribution different from the calibration spectrum, the measurement is affected by an added uncertainty related to the partial overlap of the fluence-to-ambient dose equivalent conversion curve and the response function. For this reason their operational use should always be preceded by an "in-field" calibration, i.e. a calibration made against a reference instrument exposed in the same field where the survey-meter will be employed. In practice the extended-range Bonner Sphere Spectrometer (ERBSS) is the only device which can serve as reference instrument in these fields, because of its wide energy range and the possibility to assess the neutron fluence and the ambient dose equivalent (H*(10)) values with the appropriate accuracy. Nevertheless, the experience gained by a number of experimental groups suggests that mandatory conditions for obtaining accurate results in workplaces are: (1) the use of a well-established response matrix, thus implying validation campaigns in reference monochromatic neutrons fields, (2) the expert and critical use of suitable unfolding codes, and (3) the performance test of the whole system (experimental set-up, elaboration and unfolding procedures) in a well

  18. Using the relational event model (REM) to investigate the temporal dynamics of animal social networks

    PubMed Central

    Tranmer, Mark; Marcum, Christopher Steven; Morton, F. Blake; Croft, Darren P.; de Kort, Selvino R.

    2015-01-01

    Social dynamics are of fundamental importance in animal societies. Studies on nonhuman animal social systems often aggregate social interaction event data into a single network within a particular time frame. Analysis of the resulting network can provide a useful insight into the overall extent of interaction. However, through aggregation, information is lost about the order in which interactions occurred, and hence the sequences of actions over time. Many research hypotheses relate directly to the sequence of actions, such as the recency or rate of action, rather than to their overall volume or presence. Here, we demonstrate how the temporal structure of social interaction sequences can be quantified from disaggregated event data using the relational event model (REM). We first outline the REM, explaining why it is different from other models for longitudinal data, and how it can be used to model sequences of events unfolding in a network. We then discuss a case study on the European jackdaw, Corvus monedula, in which temporal patterns of persistence and reciprocity of action are of interest, and present and discuss the results of a REM analysis of these data. One of the strengths of a REM analysis is its ability to take into account different ways in which data are collected. Having explained how to take into account the way in which the data were collected for the jackdaw study, we briefly discuss the application of the model to other studies. We provide details of how the models may be fitted in the R statistical software environment and outline some recent extensions to the REM framework. PMID:26190856

  19. Locus Coeruleus and Tuberomammillary Nuclei Ablations Attenuate Hypocretin/Orexin Antagonist-Mediated REM Sleep.

    PubMed

    Schwartz, Michael D; Nguyen, Alexander T; Warrier, Deepti R; Palmerston, Jeremiah B; Thomas, Alexia M; Morairty, Stephen R; Neylan, Thomas C; Kilduff, Thomas S

    2016-01-01

    Hypocretin 1 and 2 (Hcrts; also known as orexin A and B), excitatory neuropeptides synthesized in cells located in the tuberal hypothalamus, play a central role in the control of arousal. Hcrt inputs to the locus coeruleus norepinephrine (LC NE) system and the posterior hypothalamic histaminergic tuberomammillary nuclei (TMN HA) are important efferent pathways for Hcrt-induced wakefulness. The LC expresses Hcrt receptor 1 (HcrtR1), whereas HcrtR2 is found in the TMN. Although the dual Hcrt/orexin receptor antagonist almorexant (ALM) decreases wakefulness and increases NREM and REM sleep time, the neural circuitry that mediates these effects is currently unknown. To test the hypothesis that ALM induces sleep by selectively disfacilitating subcortical wake-promoting populations, we ablated LC NE neurons (LCx) or TMN HA neurons (TMNx) in rats using cell-type-specific saporin conjugates and evaluated sleep/wake following treatment with ALM and the GABAA receptor modulator zolpidem (ZOL). Both LCx and TMNx attenuated the promotion of REM sleep by ALM without affecting ALM-mediated increases in NREM sleep. Thus, eliminating either HcrtR1 signaling in the LC or HcrtR2 signaling in the TMN yields similar effects on ALM-induced REM sleep without affecting NREM sleep time. In contrast, neither lesion altered ZOL efficacy on any measure of sleep-wake regulation. These results contrast with those of a previous study in which ablation of basal forebrain cholinergic neurons attenuated ALM-induced increases in NREM sleep time without affecting REM sleep, indicating that Hcrt neurotransmission influences distinct aspects of NREM and REM sleep at different locations in the sleep-wake regulatory network.

  20. Adherence to risk evaluation and mitigation strategies (REMS) requirements for monthly testing of liver function

    PubMed Central

    Blanchette, Christopher M; Nunes, Anthony P; Lin, Nancy D; Mortimer, Kathleen M; Noone, Joshua; Tangirala, Krishna; Johnston, Stephen; Gutierrez, Benjamin

    2015-01-01

    Background: Risk evaluation and mitigation strategies (REMS), as mandated by the US Food and Drug Administration (FDA) for medications with the potential for harm, are increasingly incorporating rigid protocols for patient evaluation, but little is known about compliance with these programs. Despite the inherent limitations, data on administrative claims may provide an opportunity to investigate adherence to these programs. Methods: We assessed adherence to liver function test (LFT) requirements included in the REMS program for bosentan through use of administrative claims. Patients observed in the Optum Research Database who were initiators of bosentan from November 20, 2001 to March 31, 2013 were included. Adherence to LFTs was calculated using pharmacy claims for bosentan dispensation and medical claims for laboratory services, and was assessed at the time of drug initiation and within specified time intervals throughout follow-up. Results: Of 742 patients, 523 (70.5%) had ≥1 qualifying LFT. Among patients with ≥12 dispensations, claims for LFTs at individual dispensations were 53.2–64.0%. Median proportion of dispensations with ≥1 LFT was 0.8 among patients with ≥6 (interquartile range, 0.7–1.0) or ≥12 (0.7–0.9) dispensations. Adherence was 90–100% for 33.3% of all initiators, whereas 29.3% of initiators were non-adherent (defined as <50% of on-therapy LFTs). Conclusions: Analyses of administrative claims suggest that the REMS program for bosentan may not have adequately guaranteed adherence to the program’s monthly monitoring of LFTs. Such investigations of existing REMS programs may provide insight on how to accomplish more successful evaluation of REMS. PMID:25709706

  1. Locus Coeruleus and Tuberomammillary Nuclei Ablations Attenuate Hypocretin/Orexin Antagonist-Mediated REM Sleep123

    PubMed Central

    Nguyen, Alexander T.; Warrier, Deepti R.; Palmerston, Jeremiah B.; Thomas, Alexia M.; Morairty, Stephen R.; Neylan, Thomas C.

    2016-01-01

    Abstract Hypocretin 1 and 2 (Hcrts; also known as orexin A and B), excitatory neuropeptides synthesized in cells located in the tuberal hypothalamus, play a central role in the control of arousal. Hcrt inputs to the locus coeruleus norepinephrine (LC NE) system and the posterior hypothalamic histaminergic tuberomammillary nuclei (TMN HA) are important efferent pathways for Hcrt-induced wakefulness. The LC expresses Hcrt receptor 1 (HcrtR1), whereas HcrtR2 is found in the TMN. Although the dual Hcrt/orexin receptor antagonist almorexant (ALM) decreases wakefulness and increases NREM and REM sleep time, the neural circuitry that mediates these effects is currently unknown. To test the hypothesis that ALM induces sleep by selectively disfacilitating subcortical wake-promoting populations, we ablated LC NE neurons (LCx) or TMN HA neurons (TMNx) in rats using cell-type-specific saporin conjugates and evaluated sleep/wake following treatment with ALM and the GABAA receptor modulator zolpidem (ZOL). Both LCx and TMNx attenuated the promotion of REM sleep by ALM without affecting ALM-mediated increases in NREM sleep. Thus, eliminating either HcrtR1 signaling in the LC or HcrtR2 signaling in the TMN yields similar effects on ALM-induced REM sleep without affecting NREM sleep time. In contrast, neither lesion altered ZOL efficacy on any measure of sleep–wake regulation. These results contrast with those of a previous study in which ablation of basal forebrain cholinergic neurons attenuated ALM-induced increases in NREM sleep time without affecting REM sleep, indicating that Hcrt neurotransmission influences distinct aspects of NREM and REM sleep at different locations in the sleep–wake regulatory network. PMID:27022631

  2. Balanced Flow Meters without Moving Parts

    NASA Technical Reports Server (NTRS)

    Kelley, Anthony R.; VanBuskirk, Paul

    2008-01-01

    Balanced flow meters are recent additions to an established class of simple, rugged flow meters that contain no moving parts in contact with flow and are based on measurement of pressure drops across objects placed in flow paths. These flow meters are highly accurate, minimally intrusive, easily manufacturable, and reliable. A balanced flow meter can be easily mounted in a flow path by bolting it between conventional pipe flanges. A balanced flow meter can be used to measure the flow of any of a variety of liquids or gases, provided that it has been properly calibrated. Relative to the standard orifice-plate flow meter, the balanced flow meter introduces less turbulence and two times less permanent pressure loss and is therefore capable of offering 10 times greater accuracy and repeatability with less dissipation of energy. A secondary benefit of the reduction of turbulence is the reduction of vibration and up to 15 times less acoustic noise generation. Both the balanced flow meter and the standard orifice-plate flow meter are basically disks that contain holes and are instrumented with pressure transducers on their upstream and downstream faces. The most obvious difference between them is that the standard orifice plate contains a single, central hole while the balanced flow meter contains multiple holes. The term 'balanced' signifies that in designing the meter, the sizes and locations of the holes are determined in an optimization procedure that involves balancing of numerous factors, including volumetric flow, mass flow, dynamic pressure, kinetic energy, all in an effort to minimize such undesired effects as turbulence, pressure loss, dissipation of kinetic energy, and non-repeatability and nonlinearity of response over the anticipated range of flow conditions. Due to proper balancing of these factors, recent testing demonstrated that the balanced flow-meter performance was similar to a Venturi tube in both accuracy and pressure recovery, but featured reduced

  3. Model Performance of Water-Current Meters

    USGS Publications Warehouse

    Fulford, J.M.; ,

    2002-01-01

    The measurement of discharge in natural streams requires hydrographers to use accurate water-current meters that have consistent performance among meters of the same model. This paper presents the results of an investigation into the performance of four models of current meters - Price type-AA, Price pygmy, Marsh McBirney 2000 and Swoffer 2100. Tests for consistency and accuracy for six meters of each model are summarized. Variation of meter performance within a model is used as an indicator of consistency, and percent velocity error that is computed from a measured reference velocity is used as an indicator of meter accuracy. Velocities measured by each meter are also compared to the manufacturer's published or advertised accuracy limits. For the meters tested, the Price models werer found to be more accurate and consistent over the range of test velocities compared to the other models. The Marsh McBirney model usually measured within its accuracy specification. The Swoffer meters did not meet the stringent Swoffer accuracy limits for all the velocities tested.

  4. Off-level corrections for gravity meters

    NASA Astrophysics Data System (ADS)

    Niebauer, T. M.; Blitz, Thomas; Constantino, Andy

    2016-04-01

    Gravity meters must be aligned with the local gravity at any location on the surface of the earth in order to measure the full amplitude of the gravity vector. The gravitational force on the sensitive component of the gravity meter decreases by the cosine of the angle between the measurement axis and the local gravity vector. Most gravity meters incorporate two horizontal orthogonal levels to orient the gravity meter for a maximum gravity reading. In order to calculate a gravity correction it is often necessary to estimate the overall angular deviation between the gravity meter and the local gravity vector using two measured horizontal tilt meters. Typically this is done assuming that the two horizontal angles are independent and that the product of the cosines of the horizontal tilts is equivalent to the cosine of the overall deviation. These approximations, however, break down at large angles. This paper derives analytic formulae to transform angles measured by two orthogonal tilt meters into the vertical deviation of the third orthogonal axis. The equations can be used to calibrate the tilt sensors attached to the gravity meter or provide a correction for a gravity meter used in an off-of-level condition.

  5. Endothelial function and sleep: associations of flow-mediated dilation with perceived sleep quality and rapid eye movement (REM) sleep.

    PubMed

    Cooper, Denise C; Ziegler, Michael G; Milic, Milos S; Ancoli-Israel, Sonia; Mills, Paul J; Loredo, José S; Von Känel, Roland; Dimsdale, Joel E

    2014-02-01

    Endothelial function typically precedes clinical manifestations of cardiovascular disease and provides a potential mechanism for the associations observed between cardiovascular disease and sleep quality. This study examined how subjective and objective indicators of sleep quality relate to endothelial function, as measured by brachial artery flow-mediated dilation (FMD). In a clinical research centre, 100 non-shift working adults (mean age: 36 years) completed FMD testing and the Pittsburgh Sleep Quality Index, along with a polysomnography assessment to obtain the following measures: slow wave sleep, percentage rapid eye movement (REM) sleep, REM sleep latency, total arousal index, total sleep time, wake after sleep onset, sleep efficiency and apnea-hypopnea index. Bivariate correlations and follow-up multiple regressions examined how FMD related to subjective (i.e., Pittsburgh Sleep Quality Index scores) and objective (i.e., polysomnography-derived) indicators of sleep quality. After FMD showed bivariate correlations with Pittsburgh Sleep Quality Index scores, percentage REM sleep and REM latency, further examination with separate regression models indicated that these associations remained significant after adjustments for sex, age, race, hypertension, body mass index, apnea-hypopnea index, smoking and income (Ps < 0.05). Specifically, as FMD decreased, scores on the Pittsburgh Sleep Quality Index increased (indicating decreased subjective sleep quality) and percentage REM sleep decreased, while REM sleep latency increased (Ps < 0.05). Poorer subjective sleep quality and adverse changes in REM sleep were associated with diminished vasodilation, which could link sleep disturbances to cardiovascular disease.

  6. Neutronic reactor

    DOEpatents

    Wende, Charles W. J.

    1976-08-17

    A safety rod for a nuclear reactor has an inner end portion having a gamma absorption coefficient and neutron capture cross section approximately equal to those of the adjacent shield, a central portion containing materials of high neutron capture cross section and an outer end portion having a gamma absorption coefficient at least equal to that of the adjacent shield.

  7. NEUTRONIC REACTOR

    DOEpatents

    Fermi, E.; Zinn, W.H.; Anderson, H.L.

    1958-09-16

    Means are presenied for increasing the reproduction ratio of a gaphite- moderated neutronic reactor by diminishing the neutron loss due to absorption or capture by gaseous impurities within the reactor. This means comprised of a fluid-tight casing or envelope completely enclosing the reactor and provided with a valve through which the casing, and thereby the reactor, may be evacuated of atmospheric air.

  8. New gravity meter improves measurements

    NASA Astrophysics Data System (ADS)

    Carter, W. E.; Peter, G.; Sasagawa, G. S.; Klopping, F. J.; Berstis, K. A.; Hilt, R. L.; Christy, G. L.; Nelson, P.; Hollander, W.; Niebauer, T. M.; Seeger, H.; Richter, B.; Wilmes, H.; Lothammer, A.

    One of the best-known anecdotes in the history of science recounts how the observation of an apple falling from a tree led Isaac Newton to discover the law of gravitation. For good reason, Newton's discovery did not trigger the development of “free-fall” gravity meters and grand expeditions to the far corners of the Earth to measure gravity. Directly measuring the acceleration of a body in free fall near the surface of the Earth may be conceptually simple, but it is technologically difficult. It wasn't until more than 2 centuries later that time and length measurement techniques reached levels that motivated researchers to build free-fall absolute gravimeters. These efforts were limited to the construction of one-of-a-kind “laboratory” instruments, minus one notable exception: the construction of six identical absolute gravimeters by the Joint Institute for Laboratory Astrophysics (JILA) [Niebauer, 1987a]. Geodetic organizations worldwide used the JILA instruments to measure gravity at more than one hundred stations achieving repeatability or precision of a few microgals (1 μGal equals l×10-8ms-2).

  9. Neutron tubes

    DOEpatents

    Leung, Ka-Ngo; Lou, Tak Pui; Reijonen, Jani

    2008-03-11

    A neutron tube or generator is based on a RF driven plasma ion source having a quartz or other chamber surrounded by an external RF antenna. A deuterium or mixed deuterium/tritium (or even just a tritium) plasma is generated in the chamber and D or D/T (or T) ions are extracted from the plasma. A neutron generating target is positioned so that the ion beam is incident thereon and loads the target. Incident ions cause D-D or D-T (or T-T) reactions which generate neutrons. Various embodiments differ primarily in size of the chamber and position and shape of the neutron generating target. Some neutron generators are small enough for implantation in the body. The target may be at the end of a catheter-like drift tube. The target may have a tapered or conical surface to increase target surface area.

  10. Neutron source

    DOEpatents

    Cason, J.L. Jr.; Shaw, C.B.

    1975-10-21

    A neutron source which is particularly useful for neutron radiography consists of a vessel containing a moderating media of relatively low moderating ratio, a flux trap including a moderating media of relatively high moderating ratio at the center of the vessel, a shell of depleted uranium dioxide surrounding the moderating media of relatively high moderating ratio, a plurality of guide tubes each containing a movable source of neutrons surrounding the flux trap, a neutron shield surrounding one part of each guide tube, and at least one collimator extending from the flux trap to the exterior of the neutron source. The shell of depleted uranium dioxide has a window provided with depleted uranium dioxide shutters for each collimator. Reflectors are provided above and below the flux trap and on the guide tubes away from the flux trap.

  11. Development of active environmental and personal neutron dosemeters.

    PubMed

    Nakamura, T; Nunomiya, T; Sasaki, M

    2004-01-01

    For neutron dosimetry in the radiation environment surrounding nuclear facilities, two types of environmental neutron dosemeters, the high-sensitivity rem counter and the high-sensitivity multi-moderator, the so-called Bonner ball, have been developed and the former is commercially available from Fuji Electric Co. By using these detectors, the cosmic ray neutrons at sea level have been sequentially measured for about 3 y to investigate the time variation of neutron spectrum and ambient dose equivalent influenced by cosmic and terrestrial effects. Our Bonner ball has also been selected as the neutron detector in the International Space Station and has already been used to measure neutrons in the US experimental module. The real time wide-range personal neutron dosemeter which uses two silicon semiconductor detectors has been developed for personal dosimetry and is commercially available from Fuji Electric Co. This dosemeter has good characteristics, fitted to the fluence-to-dose conversion factor in the energy range from thermal energies to several tens of mega-electron-volts and is now widely used in various nuclear facilities.

  12. 10 CFR 451.7 - Metering requirements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 3 2011-01-01 2011-01-01 false Metering requirements. 451.7 Section 451.7 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION RENEWABLE ENERGY PRODUCTION INCENTIVES § 451.7 Metering requirements. The net electric energy generated and sold (kilowatt-hours) by the owner or operator of a...

  13. 10 CFR 451.7 - Metering requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 3 2010-01-01 2010-01-01 false Metering requirements. 451.7 Section 451.7 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION RENEWABLE ENERGY PRODUCTION INCENTIVES § 451.7 Metering requirements. The net electric energy generated and sold (kilowatt-hours) by the owner or operator of a...

  14. Simplified Processing Method for Meter Data Analysis

    SciTech Connect

    Fowler, Kimberly M.; Colotelo, Alison H. A.; Downs, Janelle L.; Ham, Kenneth D.; Henderson, Jordan W.; Montgomery, Sadie A.; Vernon, Christopher R.; Parker, Steven A.

    2015-11-01

    Simple/Quick metered data processing method that can be used for Army Metered Data Management System (MDMS) and Logistics Innovation Agency data, but may also be useful for other large data sets. Intended for large data sets when analyst has little information about the buildings.

  15. Physiological correlates to 800 meter running performance.

    PubMed

    Deason, J; Powers, S K; Lawler, J; Ayers, D; Stuart, M K

    1991-12-01

    Much of the previous research efforts aimed at determining those physiological characteristics that contribute to distance running success have centered around distances greater than 1500 meters with little attention to events such as the 800 meter run. Therefore, this investigation examined the relationship between selected physiological and body composition, characteristics and performance in an 800 meter run. Measurements of body composition, VO2max, running economy, and performance times for 100 and 300 meter dashes were obtained on 11 male track athletes. Stepwise multiple regression analysis was performed using 800 meter race time as the dependent variable. Although the combination of 300 and 100 meter run times, percent body fat, running economy and VO2 max as independent variables accounted for the greatest amount of total variance (r2 = .89), the additional variance explained by the model did not increase significantly (p greater than 0.05), when VO2max, percent body fat, and running economy were added to a model which contained 300 and 100 meter run time (r2 = .85) as the explanatory variables. These data offer additional support for the notion that much of the intramuscular ATP produce and utilized during an 800 meter run comes from anaerobic metabolic pathway.

  16. Evaluating Metal Probe Meters for Soil Testing.

    ERIC Educational Resources Information Center

    Hershey, David R.

    1992-01-01

    Inexpensive metal probe meters that are sold by garden stores can be evaluated by students for their accuracy in measuring soil pH, moisture, fertility, and salinity. The author concludes that the meters are inaccurate and cannot be calibrated in standard units. However, the student evaluations are useful in learning the methods of soil analysis…

  17. Proper installation ensures turbine meter accuracy

    SciTech Connect

    Peace, D.W.

    1995-07-01

    Turbine meters are widely used for natural gas measurement and provide high accuracy over large ranges of operation. However, as with many other types of flowmeters, consideration must be given to the design of the turbine meter and the installation piping practice to ensure high-accuracy measurement. National and international standards include guidelines for proper turbine meter installation piping and methods for evaluating the effects of flow disturbances on the design of those meters. Swirl or non-uniform velocity profiles, such as jetting, at the turbine meter inlet can cause undesirable accuracy performance changes. Sources of these types of flow disturbances can be from the installation piping configuration, an upstream regulator, a throttled valve, or a partial blockage upstream of the meter. Test results on the effects of swirl and jetting on different types of meter designs and sizes emphasize the need to consider good engineering design for turbine meters, including integral flow conditioning vanes and adequate installation piping practices for high accuracy measurement.

  18. Martian Surface Temperature and Spectral Response from the MSL REMS Ground Temperature Sensor

    NASA Astrophysics Data System (ADS)

    Martin-Torres, Javier; Martínez-Frías, Jesús; Zorzano, María-Paz; Serrano, María; Mendaza, Teresa; Hamilton, Vicky; Sebastián, Eduardo; Armiens, Carlos; Gómez-Elvira, Javier; REMS Team

    2013-04-01

    The Rover Environmental Monitoring Station (REMS) on the Mars Science Laboratory (MSL) offers the opportunity to explore the near surface atmospheric conditions and, in particular will shed new light into the heat budget of the Martian surface. This is important for studies of the atmospheric boundary layer (ABL), as the ground and air temperatures measured directly by REMS control the coupling of the atmosphere with the surface [Zurek et al., 1992]. This coupling is driven by solar insolation. The ABL plays an important role in the general circulation and the local atmospheric dynamics of Mars. One of the REMS sensors, the ground temperature sensor (GTS), provides the data needed to study the thermal inertia properties of the regolith and rocks beneath the MSL rover. The GTS includes thermopile detectors, with infrared bands of 8-14 µm and 16-20 µm [Gómez-Elvira et al., 2012]. These sensors are clustered in a single location on the MSL mast and the 8-14 µm thermopile sounds the surface temperature. The infrared radiation reaching the thermopile is proportional to the emissivity of the surface minerals across these thermal wavelengths. We have developed a radiative transfer retrieval method for the REMS GTS using a database of thermal infrared laboratory spectra of analogue minerals and their mixtures. [Martín Redondo et al. 2009, Martínez-Frías et al. 2012 - FRISER-IRMIX database]. This method will be used to assess the perfomance of the REMS GTS as well as determine, through the error analysis, the surface temperature and emissivity values where MSL is operating. Comparisons with orbiter data will be performed. References Gómez-Elvira et al. [2012], REMS: The Environmental Sensor Suite for the Mars Science Laboratory Rover, Space Science Reviews, Volume 170, Issue 1-4, pp. 583-640. Martín-Redondo et al. [2009] Journal of Environmental Monitoring 11:, pp. 1428-1432. Martínez-Frías et al. [2012] FRISER-IRMIX database http

  19. Vivid dreams, hallucinations, psychosis and REM sleep in Guillain-Barré syndrome.

    PubMed

    Cochen, V; Arnulf, I; Demeret, S; Neulat, M L; Gourlet, V; Drouot, X; Moutereau, S; Derenne, J P; Similowski, T; Willer, J C; Pierrot-Deseiligny, C; Bolgert, F

    2005-11-01

    We conducted a prospective controlled study of the clinical and biological determinants of the mental status abnormalities in 139 patients with Guillain-Barré syndrome (GBS) and 55 patients without GBS placed in the intensive care unit (ICU controls). There were mental status changes in 31% of GBS patients and in 16% of controls (odds ratio = 2.3; P = 0.04). In GBS patients, they included vivid dreams (19%), illusions (30%, including an illusory body tilt), hallucinations (60%, mainly visual) and delusions (70%, mostly paranoid). They appeared a median 9 days after disease onset (range 1-40 days, during the progression or the plateau of the disease), and lasted a median 8 days. Seven (16%) patients experienced the symptoms before their admission to the ICU. Hallucinations were frequently hypnagogic, occurring as soon as the patients closed their eyes. Autonomic dysfunction, assisted ventilation and high CSF protein levels were significant risk factors for abnormal mental status in GBS patients. CSF hypocretin-1 (a hypothalamic neuropeptide deficient in narcolepsy) levels, measured in 20 patients, were lower in GBS patients with hallucinations (555 +/- 132 pg/ml) than in those without (664 +/- 71 pg/ml, P = 0.03). Since the mental status abnormalities had dream-like aspects, we examined their association with rapid eye movement sleep (REM sleep) using continuous sleep monitoring in 13 GBS patients with (n = 7) and without (n = 6) hallucinations and 6 tetraplegic ICU controls without hallucinations. Although sleep was short and fragmented in all groups, REM sleep latency was shorter in GBS patients with hallucinations (56 +/- 115 min) than in GBS patients without hallucinations (153 +/- 130 min) and in controls (207 +/- 179 min, P < 0.05). In addition, sleep structure was highly abnormal in hallucinators, with sleep onset in REM sleep periods (83%), abnormal eye movements during non-REM sleep (57%), high percentages of REM sleep without atonia (92 +/- 22%), REM

  20. Metering research facility program: Installation effects on orifice meter performance. Topical report, January 1991-December 1992

    SciTech Connect

    Morrow, T.B.; Park, J.T.

    1993-09-01

    The objective of the report is to acquire orifice discharge coefficient (Cd) data in the Gas Research Institute (GRI) Metering Research Facility (MRF) for various metering configurations typical of field metering installations in the natural gas industry, and to evaluate the effects of using flow conditioning devices to assure proper upstream flow conditions for accurate flow rate measurements.

  1. Design Analyses and Shielding of HFIR Cold Neutron Scattering Instruments

    SciTech Connect

    Gallmeier, F.X.; Selby, D.L.; Winn, B.; Stoica, D.; Jones, A.B.; Crow, L.

    2011-07-01

    Research reactor geometries and special characteristics present unique dosimetry analysis and measurement issues. The introduction of a cold neutron moderator and the production of cold neutron beams at the Oak Ridge National Laboratory High Flux Isotope Reactor have created the need for modified methods and devices for analyzing and measuring low energy neutron fields (0.01 to 100 meV). These methods include modifications to an MCNPX version to provide modeling of neutron mirror reflection capability. This code has been used to analyze the HFIR cold neutron beams and to design new instrument equipment that will use the beams. Calculations have been compared with time-of-flight measurements performed at the start of the neutron guides and at the end of one of the guides. The results indicate that we have a good tool for analyzing the transport of these low energy beams through neutron mirror and guide systems for distance up to 60 meters from the reactor. (authors)

  2. The effects of meter orientation downstream of a short radius elbow on electromagnetic flow meters

    NASA Astrophysics Data System (ADS)

    Justensen, Jared C.

    Electromagnetic flowmeters (known as magnetic flow meters) are a widely used type of flowmeter. The accuracy of magnetic flow meters are a function of several factors, not the least of which is the flow condition inside the pipe. It has been shown that disturbances in the velocity profile affects the accuracy of a magnetic flow meter (Luntta, 1998). Accordingly, manufacturers of magnetic flow meters give installation guidelines. These guidelines help prevent the user from installing the meter in a pipe configuration that is likely to cause the meter to produce inaccurate results. Although most manufacturers provide recommendations about the amount of straight pipe that is necessary upstream of the meter, little is said about the orientation of the meter in relation to upstream disturbances. This study examines the performance of magnetic flow meters when positioned at two different orientations: EIP (electrodes in plane with an upstream 90-degree short radius elbow) and EOP (electrodes out of plane). Four different meters were included in the study in which a baseline straight pipe test was first performed using over fifty diameters of straight pipe upstream of each meter. The straight pipe test was used to determine the baseline accuracy of each of the meters over a velocity range that is typical for the size and function of the meters. Meters were then installed at five different locations downstream from a 90-degree short-radius elbow. At each location the meters were tested in two orientations at five different flow rates. The intent of the research is to show that the orientation of a magnetic flow meter affects the meter's ability to produce accurate flow readings when it is installed downstream of a flow disturbance. The results from this research showed a significant shift in measurement accuracy when the meter was in EIP and EOP orientations. All of the meters in the study produced accuracy readings at one point of another that were outside the specified

  3. NEUTRON SOURCE

    DOEpatents

    Bernander, N.K. et al.

    1960-10-18

    An apparatus is described for producing neutrons through target bombardment with deuterons. Deuterium gas is ionized by electron bombardment and the deuteron ions are accelerated through a magnetic field to collimate them into a continuous high intensity beam. The ion beam is directed against a deuteron pervious metal target of substantially the same nnaterial throughout to embed the deuterous therein and react them to produce neutrons. A large quantity of neutrons is produced in this manner due to the increased energy and quantity of ions bombarding the target.

  4. Metering research facility program: Review of field meter provers. Topical report, October 1993-September 1994

    SciTech Connect

    Park, J.T.; Behring, K.A.; Krueger, P.J.

    1995-12-01

    Field meter provers are flowmeters for verification of the performance of field meter stations in the natural gas industry. This report is a review of the current technology for field meter provers at large volume flow rates and high pressure. The review includes a literature review of over 100 documents, an analysis of the prover performance, and a quantitative uncertainty analysis. Field meter provers may either be a permanent installation or a portable device mounted on a truck or trailer. The most viable devices for field proving are the gas piston prover, sonic nozzle, and turbine meter.

  5. Thermal neutron detection system

    DOEpatents

    Peurrung, Anthony J.; Stromswold, David C.

    2000-01-01

    According to the present invention, a system for measuring a thermal neutron emission from a neutron source, has a reflector/moderator proximate the neutron source that reflects and moderates neutrons from the neutron source. The reflector/moderator further directs thermal neutrons toward an unmoderated thermal neutron detector.

  6. Regulation of flagellar, motility and chemotaxis genes in Rhizobium leguminosarum by the VisN/R-Rem cascade.

    PubMed

    Tambalo, Dinah D; Del Bel, Kate L; Bustard, Denise E; Greenwood, Paige R; Steedman, Audrey E; Hynes, Michael F

    2010-06-01

    In this paper, we describe the regulatory roles of VisN, VisR and Rem in the expression of flagellar, motility and chemotaxis genes in Rhizobium leguminosarum biovar viciae strains VF39SM and 3841. Individual mutations in the genes encoding these proteins resulted in a loss of motility and an absence of flagella, indicating that these regulatory genes are essential for flagellar synthesis and function. Transcriptional experiments involving gusA-gene fusions in wild-type and mutant backgrounds were performed to identify the genes under VisN/R and Rem regulation. Results showed that the chemotaxis and motility genes of R. leguminosarum could be separated into two groups: one group under VisN/R-Rem regulation and another group that is independent of this regulation. VisN and VisR regulate the expression of rem, while Rem positively regulates the expression of flaA, flaB, flaC, flaD, motA, motB, che1 and mcpD. All of these genes except mcpD are located within the main motility and chemotaxis gene cluster of R. leguminosarum. Other chemotaxis and motility genes, which are found outside of the main motility gene cluster (che2 operon, flaH for VF39SM, and flaG) or are plasmid-borne (flaE and mcpC), are not part of the VisN/R-Rem regulatory cascade. In addition, all genes exhibited the same regulation pattern in 3841 and in VF39SM, except flaE and flaH. flaE is not regulated by VisN/R-Rem in 3841 but it is repressed by Rem in VF39SM. flaH is under VisN/R-Rem regulation in 3841, but not in VF39SM. A kinetics experiment demonstrated that a subset of the flagellar genes is continuously expressed in all growth phases, indicating the importance of continuous motility for R. leguminosarum under free-living conditions. On the other hand, motility is repressed under symbiotic conditions. Nodulation experiments showed that the transcriptional activators VisN and Rem are dramatically downregulated in the nodules, suggesting that the symbiotic downregulation of motility-related genes

  7. Regulation of flagellar, motility and chemotaxis genes in Rhizobium leguminosarum by the VisN/R-Rem cascade.

    PubMed

    Tambalo, Dinah D; Del Bel, Kate L; Bustard, Denise E; Greenwood, Paige R; Steedman, Audrey E; Hynes, Michael F

    2010-06-01

    In this paper, we describe the regulatory roles of VisN, VisR and Rem in the expression of flagellar, motility and chemotaxis genes in Rhizobium leguminosarum biovar viciae strains VF39SM and 3841. Individual mutations in the genes encoding these proteins resulted in a loss of motility and an absence of flagella, indicating that these regulatory genes are essential for flagellar synthesis and function. Transcriptional experiments involving gusA-gene fusions in wild-type and mutant backgrounds were performed to identify the genes under VisN/R and Rem regulation. Results showed that the chemotaxis and motility genes of R. leguminosarum could be separated into two groups: one group under VisN/R-Rem regulation and another group that is independent of this regulation. VisN and VisR regulate the expression of rem, while Rem positively regulates the expression of flaA, flaB, flaC, flaD, motA, motB, che1 and mcpD. All of these genes except mcpD are located within the main motility and chemotaxis gene cluster of R. leguminosarum. Other chemotaxis and motility genes, which are found outside of the main motility gene cluster (che2 operon, flaH for VF39SM, and flaG) or are plasmid-borne (flaE and mcpC), are not part of the VisN/R-Rem regulatory cascade. In addition, all genes exhibited the same regulation pattern in 3841 and in VF39SM, except flaE and flaH. flaE is not regulated by VisN/R-Rem in 3841 but it is repressed by Rem in VF39SM. flaH is under VisN/R-Rem regulation in 3841, but not in VF39SM. A kinetics experiment demonstrated that a subset of the flagellar genes is continuously expressed in all growth phases, indicating the importance of continuous motility for R. leguminosarum under free-living conditions. On the other hand, motility is repressed under symbiotic conditions. Nodulation experiments showed that the transcriptional activators VisN and Rem are dramatically downregulated in the nodules, suggesting that the symbiotic downregulation of motility-related genes

  8. A Preliminary Interpretation of the First Results from the REMS Surface Pressure Measurements of the MSL Mission

    NASA Technical Reports Server (NTRS)

    Haberle, Robert M.; Gomez-Elvira, J.; dalaTorreJuarez, M.; Harri, A-M.; Hollingsworth, J. L.; Kahanapaa, H.; Kahre, M. A.; Martin-Torres, F. J.; Mischna, M.; Newman, C.; Ratfkin, S. C. R.; Renno, N.; Richardson, M. I.; Rodriquez-Manfredi, J. A.; Vasavada, A. R.; Zorzano-Mier, M-P

    2013-01-01

    The Rover Environmental Monitoring Station (REMS) on the Mars Science Laboratory (MSL) Curiosity rover consists of a suite of meteorological instruments that measure pressure, temperature (air and ground), wind (speed and direction), relative humidity, and the UV flux. A description of the instruments is described elsewhere.. Here we focus on interpreting the first 90 sols of REMS operations with a particular emphasis on the pressure data.

  9. Testosterone not associated with violent dreams or REM sleep behavior disorder in men with Parkinson's.

    PubMed

    Chou, Kelvin L; Moro-De-Casillas, Maria L; Amick, Melissa M; Borek, Leora L; Friedman, Joseph H

    2007-02-15

    We examined the relationship between testosterone levels, violent dreams, and REM sleep behavior disorder (RBD) in 31 men with Parkinson's disease (PD): 12 with clinical RBD and 19 without. All PD patients with clinical RBD experienced violent dreams, but none of the 19 non-RBD patients reported violent dreams. While dream content appears to be more aggressive in PD patients with clinical RBD, the presence of violent dreams or clinical RBD is not associated with testosterone levels in men with PD.

  10. From REM sleep behaviour disorder to status dissociatus: insights into the maze of states of being.

    PubMed

    Vetrugno, Roberto; Montagna, Pasquale

    2011-12-01

    Sleep is a coordinated process involving more or less simultaneous changes in sensory, motor, autonomic, hormonal, and cerebral processes. On the other hand, none of the changes occurring with sleep are invariably coupled to sleep. EEG synchrony, heat loss, sleep-related hormone secretion, and even REM-related motoneuron paralysis may occur independent of the parent state. In REM sleep behaviour disorder (RBD) the muscle tone of wakefulness intrudes into REM sleep, allowing the release of dream-enacting behaviours. Status dissociatus (SD) is a condition in which brain and mind are in disarray along the boundaries of sleep and wakefulness. The existence of such dissociated behaviours shows that they have separate neuronal control systems and indicates that the whole organization of sleep is an emergent property of the collective neuronal systems to synchronize. Insults to the brain can drastically alter the circuitries responsible for maintaining the integrity of wakefulness, NREM sleep, and REM sleep. As a consequence, the basic states of existence can become admixed and interchanged with striking disturbances of consciousness, brain electrophysiology, and the behavioural and polygraphic expression of sleep and wakefulness. The evolution of RBD into SD may result from a disarray of (brainstem) structures that orchestrate the whole brain wake-sleep conditions, but with preserved discrete systems and dissociable strategies to still place navigation in wake and sleep. Advances in the fields of genetics, neuroimaging, and behavioural neurology will expand the understanding of the mechanisms underlying the organization of the states of being along with their somatic/behavioural manifestations.

  11. Detection of Northern Hemisphere Transient Baroclinic Eddies in REMS Pressure Data at Gale Crater Mars

    NASA Astrophysics Data System (ADS)

    Haberle, Robert; Kahre, Melinda A.; De la Torre, Manuel; Kass, David M.; Mars Science Laboratory Science Team

    2016-10-01

    Wintertime transient baroclinic eddies in the northern midlatitudes of Mars were identified in Viking Lander 2 (VL2, 48.3N, 134.0E) surface pressure data back in the early 1980s. Here we report the results of an analysis of REMS surface pressure data acquired by the Curiosity Rover in Gale Crater (4.5S, 137.4E) that suggests the meridional scale of these eddies is so large that the disturbances in the surface pressure fields they create extend across the equator and into the southern hemisphere. A power spectrum analysis of the seasonally detrended REMS pressure data from Ls=240-280 shows dominant periods of ~ 6 sols and ~2.2 sols (though with greatly reduced power) which are close the dominant periods of the transient eddies observed by VL2 at this season. Analysis of the surface pressure fields from the Ames Mars GCM for the same season also shows dominant periods at the grid points closest to VL2 and Gale Crater similar to those observed. In the model, the disturbances responsible for these oscillations are eastward traveling baroclinic eddies whose amplitudes are greatest at northern mid latitudes at this season, but whose meridional extent does indeed extend into the low latitudes of the southern hemisphere. REMS appears to be seeing the signature of these eddies, not only for this season but for the early fall and late winter seasons as well. While orbital images of the so called "flushing storms", which more closely correspond to the shorter period waves, show dust-lifting frontal systems that cross the equator, REMS data - even though acquired at a longitude of comparatively weak storm activity - provide the first in-situ evidence that northern hemisphere transient eddies can be detected at the surface in low latitudes of the southern hemisphere.

  12. Idiopathic REM Sleep Behavior Disorder: A Report on Two Cases with Contrasting Features.

    PubMed

    Gupta, Sriniwas; Raju, M S V K; Pawar, Alka

    2015-01-01

    REM sleep behavior disorder (RBD) is a rare parasomnia in which persons exhibit uncharacteristic violent behavior, while dreaming. Secondary RBD occurs due to some neurological conditions, psychoactive substance or psychotropic drug use. There are no case reports on idiopathic RBD in India. We report here two cases to underscore the importance of identifying the disease as behavior associated with RBD may be quite serious in nature and might lead to catastrophic consequences. PMID:26664088

  13. REM sleep deprivation attenuates actin-binding protein cortactin: a link between sleep and hippocampal plasticity.

    PubMed

    Davis, Christopher J; Meighan, Peter C; Taishi, Ping; Krueger, James M; Harding, Joseph W; Wright, John W

    2006-06-12

    Rapid eye-movement sleep (REMS) is thought to affect synaptic plasticity. Cortactin is a cytoskeletal protein critically involved in the regulation of actin branching and stabilization including the actin backbone of dendritic spines. Hippocampal cortactin levels, phosphorylation, and processing appear to be altered during learning and long-term potentiation (LTP); consistent with a role for cortactin in the dendritic restructuring that accompanies synaptic plasticity. In this study juvenile male Sprague-Dawley rats were selectively REMS-deprived (RD) for 48 h by the flowerpot method. Cage control (CC) and large pedestal control (PC) animals were used for comparison. Animals were euthanized immediately, or 12 h, after removal from the pedestal. The hippocampus was dissected, flash-frozen, and stored for subsequent Western blot or quantitative RT-PCR analysis of cortactin. Cortactin mRNA/cDNA levels initially rose in PC and RD rats but returned to CC levels by 12 h after removal from the pedestal. Predictably cortactin protein levels were initially unchanged but were up-regulated after 12 h. The PC group had more total and tyrosine-phosphorylated cortactin protein expression than the RD and CC groups. This increase in cortactin was likely due to the exposure of the rats to the novel environment of the deprivation chambers thus triggering plasticity events. The lack of REMS, however, severely hampered cortactin protein up-regulation and phosphorylation observed in the PC group suggesting an attenuation of plasticity-related events. Thus, these data support a functional link between REMS and cytoskeletal reorganization in the hippocampus, a process that is essential for synaptic plasticity.

  14. Rapid-Eye-Movement-Sleep (REM) Associated Enhancement of Working Memory Performance after a Daytime Nap.

    PubMed

    Lau, Esther Yuet Ying; Wong, Mark Lawrence; Lau, Kristy Nga Ting; Hui, Florence Wai Ying; Tseng, Chia-huei

    2015-01-01

    The main objective was to study the impact of a daytime sleep opportunity on working memory and the mechanism behind such impact. This study adopted an experimental design in a sleep research laboratory. Eighty healthy college students (Age:17-23, 36 males) were randomized to either have a polysomnography-monitored daytime sleep opportunity (Nap-group, n=40) or stay awake (Wake-group, n=40) between the two assessment sessions. All participants completed a sleep diary and wore an actigraph-watch for 5 days before and one day after the assessment sessions. They completed the state-measurement of sleepiness and affect, in addition to a psychomotor vigilance test and a working memory task before and after the nap/wake sessions. The two groups did not differ in their sleep characteristics prior to and after the lab visit. The Nap-group had higher accuracy on the working memory task, fewer lapses on the psychomotor vigilance test and lower state-sleepiness than the Wake-group. Within the Nap-group, working memory accuracy was positively correlated with duration of rapid eye movement sleep (REM) and total sleep time during the nap. Our findings suggested that "sleep gain" during a daytime sleep opportunity had significant positive impact on working memory performance, without affecting subsequent nighttime sleep in young adult, and such impact was associated with the duration of REM. While REM abnormality has long been noted in pathological conditions (e.g. depression), which are also presented with cognitive dysfunctions (e.g. working memory deficits), this was the first evidence showing working memory enhancement associated with REM in daytime napping in college students, who likely had habitual short sleep duration but were otherwise generally healthy. PMID:25970511

  15. Rapid-Eye-Movement-Sleep (REM) Associated Enhancement of Working Memory Performance after a Daytime Nap

    PubMed Central

    Lau, Kristy Nga Ting; Hui, Florence Wai Ying; Tseng, Chia-huei

    2015-01-01

    The main objective was to study the impact of a daytime sleep opportunity on working memory and the mechanism behind such impact. This study adopted an experimental design in a sleep research laboratory. Eighty healthy college students (Age:17-23, 36 males) were randomized to either have a polysomnography-monitored daytime sleep opportunity (Nap-group, n=40) or stay awake (Wake-group, n=40) between the two assessment sessions. All participants completed a sleep diary and wore an actigraph-watch for 5 days before and one day after the assessment sessions. They completed the state-measurement of sleepiness and affect, in addition to a psychomotor vigilance test and a working memory task before and after the nap/wake sessions. The two groups did not differ in their sleep characteristics prior to and after the lab visit. The Nap-group had higher accuracy on the working memory task, fewer lapses on the psychomotor vigilance test and lower state-sleepiness than the Wake-group. Within the Nap-group, working memory accuracy was positively correlated with duration of rapid eye movement sleep (REM) and total sleep time during the nap. Our findings suggested that “sleep gain” during a daytime sleep opportunity had significant positive impact on working memory performance, without affecting subsequent nighttime sleep in young adult, and such impact was associated with the duration of REM. While REM abnormality has long been noted in pathological conditions (e.g. depression), which are also presented with cognitive dysfunctions (e.g. working memory deficits), this was the first evidence showing working memory enhancement associated with REM in daytime napping in college students, who likely had habitual short sleep duration but were otherwise generally healthy. PMID:25970511

  16. Estradiol suppresses recovery of REM sleep following sleep deprivation in ovariectomized female rats.

    PubMed

    Schwartz, Michael D; Mong, Jessica A

    2011-10-24

    Sleep complaints such as insufficient sleep and insomnia are twice as prevalent in women. Symptoms of sleep disruption are often coincident with changes in the gonadal hormone profile across a women's lifespan. Data from a number of different species, including humans, non-human primates and rodents strongly implicate a role for gonadal hormones in the modulation of sleep. In female rats, increased levels of circulating estradiol increase wakefulness and reduce sleep in the dark phase. In this study, we asked whether this reduction in sleep is driven by estradiol-dependent reduction in sleep need during the dark phase by assessing sleep before and after sleep deprivation (SD). Ovariectomized rats implanted with EEG telemetry transmitters were given Silastic capsules containing either 17-β estradiol in sesame oil (E2) or sesame oil alone. After a 24-hour baseline, animals were sleep-deprived via gentle handling for the entire 12-hour light phase, and then allowed to recover. E2 treatment suppressed baseline REM sleep duration in the dark phase, but not NREM or Wake duration, within three days. While SD induced a compensatory increase in REM duration in both groups, this increase was smaller in E2-treated rats compared to oils, as measured in absolute duration as well as by relative increase over baseline. Thus, E2 suppressed REM sleep in the dark phase both before and after SD. E2 also suppressed NREM and increased waking in the early- to mid-dark phase on the day after SD. NREM delta power tracked NREM sleep before and after SD, with small hormone-dependent reductions in delta power in recovery, but not spontaneous sleep. These results demonstrate that E2 powerfully and specifically suppresses spontaneous and recovery REM sleep in the dark phase, and suggest that ovarian steroids may consolidate circadian sleep-wake rhythms.

  17. Idiopathic REM Sleep Behavior Disorder: A Report on Two Cases with Contrasting Features

    PubMed Central

    Gupta, Sriniwas; Raju, M. S. V. K.; Pawar, Alka

    2015-01-01

    REM sleep behavior disorder (RBD) is a rare parasomnia in which persons exhibit uncharacteristic violent behavior, while dreaming. Secondary RBD occurs due to some neurological conditions, psychoactive substance or psychotropic drug use. There are no case reports on idiopathic RBD in India. We report here two cases to underscore the importance of identifying the disease as behavior associated with RBD may be quite serious in nature and might lead to catastrophic consequences. PMID:26664088

  18. Rapid-Eye-Movement-Sleep (REM) Associated Enhancement of Working Memory Performance after a Daytime Nap.

    PubMed

    Lau, Esther Yuet Ying; Wong, Mark Lawrence; Lau, Kristy Nga Ting; Hui, Florence Wai Ying; Tseng, Chia-huei

    2015-01-01

    The main objective was to study the impact of a daytime sleep opportunity on working memory and the mechanism behind such impact. This study adopted an experimental design in a sleep research laboratory. Eighty healthy college students (Age:17-23, 36 males) were randomized to either have a polysomnography-monitored daytime sleep opportunity (Nap-group, n=40) or stay awake (Wake-group, n=40) between the two assessment sessions. All participants completed a sleep diary and wore an actigraph-watch for 5 days before and one day after the assessment sessions. They completed the state-measurement of sleepiness and affect, in addition to a psychomotor vigilance test and a working memory task before and after the nap/wake sessions. The two groups did not differ in their sleep characteristics prior to and after the lab visit. The Nap-group had higher accuracy on the working memory task, fewer lapses on the psychomotor vigilance test and lower state-sleepiness than the Wake-group. Within the Nap-group, working memory accuracy was positively correlated with duration of rapid eye movement sleep (REM) and total sleep time during the nap. Our findings suggested that "sleep gain" during a daytime sleep opportunity had significant positive impact on working memory performance, without affecting subsequent nighttime sleep in young adult, and such impact was associated with the duration of REM. While REM abnormality has long been noted in pathological conditions (e.g. depression), which are also presented with cognitive dysfunctions (e.g. working memory deficits), this was the first evidence showing working memory enhancement associated with REM in daytime napping in college students, who likely had habitual short sleep duration but were otherwise generally healthy.

  19. NEUTRONIC REACTOR

    DOEpatents

    Wade, E.J.

    1958-09-16

    This patent relates to a reflector means for a neutronic reactor. A reflector comprised of a plurality of vertically movable beryllium control members is provided surrounding the sides of the reactor core. An absorber of fast neutrons comprised of natural uramum surrounds the reflector. An absorber of slow neutrons surrounds the absorber of fast neutrons and is formed of a plurality of beryllium blocks having natural uranium members distributcd therethrough. in addition, a movable body is positioned directly below the core and is comprised of a beryllium reflector and an absorbing member attached to the botiom thereof, the absorbing member containing a substance selected from the goup consisting of natural urantum and Th/sup 232/.

  20. Thermoregulatory adjustments to thermal transients during slow wave sleep and REM sleep in man.

    PubMed

    Libert, J P; Candas, V; Muzet, A; Ehrhart, J

    1982-01-01

    The present study was performed on five nude male subjects by increasing the ambient temperature during well-established slow wave sleep (SWS) and rapid eye movement (REM) sleep episodes. 1. Air temperature was raised from 25 to 41 degrees C at rates of + 0.8 degrees C.min-1 or + 1.6 degrees C min-1 and, afterwards, was maintained at 41 degrees C during 10 min before returning to the initial pre-heating condition. During these thermal transients, wall temperatures (Tw), dew-point temperature (Tdp) and air velocity (Va) were kept constant (Tw = 37.5 degrees C; Tdp = 10 degrees C; Va = 0.3 m.s.-1). Physiological data included 3 EEGs, 2 EOGs, 4 EMGs, heart rate, finger pulse amplitude, esophageal temperature and 10 local skin temperatures. Upper chest sweating rate was recorded by a 12 cm2-capsule using a dew-point hygrometer technique. 2. The results showed that during REM sleep sweat gland activity persists at a lower level than during SWS. The lower sensitivity of the thermoregulatory system described during the REM sleep episodes could be interpreted by an increase of the hypothalamic set-point temperature, or by an action of extra-hypothalamic thermosensitive neurons. However, a change at the sweat gland level cannot be ruled out.

  1. REM sleep EEG spectral analysis in patients with first-episode schizophrenia.

    PubMed

    Poulin, Julie; Stip, Emmanuel; Godbout, Roger

    2008-10-01

    The pathophysiology of schizophrenia includes abnormalities in subcortical-cortical transfer of information that can be studied using REM sleep EEG spectral analysis, a measure that reflects spontaneous and endogenous thalamocortical activity. We recorded 10 patients with first-episode schizophrenia and 30 healthy controls for two consecutive nights in a sleep laboratory, using a 10-electrode EEG montage. Sixty seconds of REM sleep EEG without artifact were analyzed using FFT spectral analysis. Absolute and relative spectral amplitudes of five frequency bands (delta, theta, alpha, beta1 and beta2) were extracted and compared between the two groups. Frequency bands with significant differences were correlated with BPRS positive and negative symptoms scores. Patients with schizophrenia showed lower relative alpha and higher relative beta2 spectral amplitudes compared to healthy controls over the averaged total scalp. Analysis using cortical regions showed lower relative alpha over frontal, central and temporal regions and higher relative beta2 over the occipital region. Absolute spectral amplitude was not different between groups for any given EEG band. However, absolute alpha activity correlated negatively with BPRS positive symptoms scores and correlated positively with negative symptoms scores. Since similar results have been reported following EEG spectral analysis during the waking state, we conclude that abnormalities of subcortical-cortical transfer of information in schizophrenia could be generated by mechanisms common to REM sleep and waking. PMID:18280502

  2. Acute and subchronic administration of anandamide or oleamide increases REM sleep in rats.

    PubMed

    Herrera-Solís, Andrea; Vásquez, Khalil Guzmán; Prospéro-García, Oscar

    2010-03-01

    Anandamide and oleamide, induce sleep when administered acutely, via the CB1 receptor. Their subchronic administration must be tested to demonstrate the absence of tolerance to this effect, and that the sudden withdrawal of these endocannabinoids (eCBs) does not affect sleep negatively. The sleep-waking cycle of rats was evaluated for 24h, under the effect of an acute or subchronic administration of eCBs, and during sudden eCBs withdrawal. AM251, a CB1 receptor antagonist (CB1Ra) was utilized to block eCBs effects. Our results indicated that both acute and subchronic administration of eCBs increase REMS. During eCBs withdrawal, rats lack the expression of an abstinence-like syndrome. AM251 was efficacious to prevent REMS increase caused by both acute and subchronic administration of these eCBs, suggesting that this effect is mediated by the CB1 receptor. Our data further support a role of the eCBs in REMS regulation.

  3. Modafinil treatment prevents REM sleep deprivation-induced brain function impairment by increasing MMP-9 expression.

    PubMed

    He, Bin; Peng, Hua; Zhao, Ying; Zhou, Hui; Zhao, Zhongxin

    2011-12-01

    Previous work showed that sleep deprivation (SD) impairs hippocampal-dependent cognitive function and synaptic plasticity, and a novel wake-promoting agent modafinil prevents SD-induced memory impairment in rat. However, the mechanisms by which modafinil prevented REM-SD-induced impairment of brain function remain poorly understood. In the present study, rats were sleep-deprived by using the modified multiple platform method and brain function was detected. The results showed that modafinil treatment prevented REM-SD-induced impairment of cognitive function. Modafinil significantly reduced the number of errors compared to placebo and upregulated synapsin I expression in the dorsal hippocampal CA3 region. A synaptic plasticity-related gene, MMP-9 expression was also upregulated in modafinil-treated rats. Importantly, downregulation of MMP-9 expression by special siRNA decreased synapsin I protein levels and synapse numbers. Therefore, we demonstrated that modafinil increased cognition function and synaptic plasticity, at least in part by increasing MMP-9 expression in REM-SD rats.

  4. Differential impact of REM sleep deprivation on cytoskeletal proteins of brain regions involved in sleep regulation.

    PubMed

    Rodríguez-Vázquez, Jennifer; Camacho-Arroyo, Ignacio; Velázquez-Moctezuma, Javier

    2012-01-01

    Rapid eye movement (REM) sleep is involved in memory consolidation, which implies synaptic plasticity. This process requires protein synthesis and the reorganization of the neural cytoskeleton. REM sleep deprivation (REMSD) has an impact on some neuronal proteins involved in synaptic plasticity, such as glutamate receptors and postsynaptic density protein 95, but its effects on cytoskeletal proteins is unknown. In this study, the effects of REMSD on the content of the cytoskeletal proteins MAP2 and TAU were analyzed. Adult female rats were submitted to selective REMSD by using the multiple platform technique. After 24, 48 or 72 h of REMSD, rats were decapitated and the following brain areas were dissected: pons, preoptic area, hippocampus and frontal cortex. Protein extraction and Western blot were performed. Results showed an increase in TAU content in the pons, preoptic area and hippocampus after 24 h of REMSD, while in the frontal cortex a significant increase in TAU content was observed after 72 h of REMSD. A TAU content decrease was observed in the hippocampus after 48 h of REMSD. Interestingly, a marked increase in TAU content was observed after 72 h of REMSD. MAP2 content only increased in the preoptic area at 24 h, and in the frontal cortex after 24 and 72 h of REMSD, without significant changes in the pons and hippocampus. These results support the idea that REM sleep plays an important role in the organization of neural cytoskeleton, and that this effect is tissue-specific.

  5. Pattern of REM sleep occurrence in continuous darkness following the exposure to low ambient temperature in the rat.

    PubMed

    Zamboni, G; Amici, R; Perez, E; Jones, C A; Parmeggiani, P L

    2001-07-01

    The occurrence of REM sleep episodes, separated by intervals >3 min (single episodes) and < or =3 min (sequential episodes), was determined in the rat during the recovery (ambient temperature (Ta) 23 degrees C, L period of the LD [12 h:12 h]-cycle), which followed the exposure to low Ta (0 and -10 degrees C) during the D period of the previous LD-cycle, either in normal light (DL) or in continuous darkness (DD). Both exposures were characterized by an almost complete disappearance of REM sleep, whilst the recoveries showed an increase in the amount of REM sleep in the form of sequential episodes, which in DD was particularly prominent and concomitant with a decrease in the amount of REM sleep in the form of single episodes. The initial 2 h-rate of REM sleep occurrence was lower following the exposure to Ta -10 degrees C, than to Ta 0 degrees C. In DD, such an effect was due to the large reduction in the occurrence of sequential REM sleep episodes. A functional correlate of this finding is that the accumulation capacity of a second messenger (cAMP) was found to be lower at the end of the exposure to Ta -10 degrees C, with respect to both the control (Ta 23 degrees C) and the end of exposure to Ta 0 degrees C, in the preoptic-anterior hypothalamus, but not in the cerebral cortex.

  6. GABAA receptors are located in cholinergic terminals in the nucleus pontis oralis of the rat: implications for REM sleep control.

    PubMed

    Liang, Chang-Lin; Marks, Gerald A

    2014-01-16

    The oral pontine reticular formation (PnO) of rat is one region identified in the brainstem as a rapid eye movement (REM) sleep induction zone. Microinjection of GABA(A) receptor antagonists into PnO induces a long lasting increase in REM sleep, which is similar to that produced by cholinergic agonists. We previously showed that this REM sleep-induction can be completely blocked by a muscarinic antagonist, indicating that the REM sleep-inducing effect of GABA(A) receptor antagonism is dependent upon the local cholinergic system. Consistent with these findings, it has been reported that GABA(A) receptor antagonists microdialyzed into PnO resulted in increased levels of acetylcholine. We hypothesize that GABA(A) receptors located on cholinergic boutons in the PnO are responsible for the REM sleep induction by GABA(A) receptor antagonists through blocking GABA inhibition of acetylcholine release. Cholinergic, varicose axon fibers were studied in the PnO by immunofluorescence and confocal, laser scanning microscopy. Immunoreactive cholinergic boutons were found to be colocalized with GABA(A) receptor subunit protein γ2. This finding implicates a specific subtype and location of GABA(A) receptors in PnO of rat in the control of REM sleep. PMID:24141149

  7. Age-related effects of bilateral frontal eye fields lesions on rapid eye movements during REM sleep in rhesus monkeys.

    PubMed

    Yu, Shan; Liu, Ning; Zeng, Tao; Tian, Shaohua; Chen, Nanhui; Zhou, Yifeng; Ma, Yuanye

    2004-08-01

    Rapid eye movement (REM) is one of the most characteristic features of REM sleep, but the mechanisms underlying its regulation remain unclear. The present study aims to investigate whether the frontal eye field (FEF) is involved in the regulation of the rapid eye movements during REM sleep. To address this question, we ablated the FEF in four rhesus monkeys and observed the effects of the lesions on sleep architecture. After lesions, two adult monkeys did not show any lesion effect. However, in the other two adolescent monkeys, both the total duration and percentage of the rapid eye movements during REM sleep were decreased moderately. The result suggests that the relation between the FEF and the regulation of the rapid eye movements during REM sleep may be affected by age factor, also indicating that both the functions of the FEF and the mechanisms underlying the control of rapid eye movements during REM sleep might not be the same throughout the whole life span of an animal. PMID:15265590

  8. Noradrenaline acting on alpha1-adrenoceptor mediates REM sleep deprivation-induced increased membrane potential in rat brain synaptosomes.

    PubMed

    Das, Gitanjali; Mallick, Birendra Nath

    2008-01-01

    We hypothesized that one of the functions of REM sleep is to maintain brain excitability and therefore, REM sleep deprivation is likely to modulate neuronal transmembrane potential; however, so far there was no direct evidence to support the claim. In this study a cationic dye, 3,3'-diethylthiacarbocyanine iodide was used to estimate the potential in synaptosomal samples prepared from control and REM sleep deprived rat brains. The activity of Na-K-ATPase that maintains the transmembrane potential was also estimated in the same sample. Further, the roles of noradrenaline and alpha1-adrenoceptor in mediating the responses were studied both in vivo as well as in vitro. Rats were REM sleep deprived for 4 days by the classical flower-pot method; large platform and recovery controls were carried out in addition to free-moving control. The fluorescence intensity increased in samples prepared from REM sleep deprived rat brain as compared to control, which reflected synaptosomal depolarization after deprivation. The Na-K-ATPase activity also increased in the same deprived sample. Furthermore, both the effects were mediated by noradrenaline acting on alpha1-adrenoceptors in the brain. This is the first direct evidence showing that REM sleep deprivation indeed increased neuronal depolarization, which is the likely cause for increased brain excitability, thus supporting our hypothesis and the effect was mediated by noradrenaline acting through the alpha1-adrenoceptor.

  9. Brain distribution of c-fos expression as a result of prolonged rapid eye movement (REM) sleep period duration.

    PubMed

    Merchant-Nancy, H; Vázquez, J; García, F; Drucker-Colín, R

    1995-05-29

    Auditory stimulation (AS) or recovery from sleep deprivation (SD) has been shown to increase REM sleep periods in rats, cats and humans. This increment in REM has been credited to an amplified level of excitability in a widely distributed neuronal network throughout the brain. Fos-like immunostaining (FLI) has been useful in constructing maps of post-synaptic neuronal activity with single cell resolution, and has been proposed to be tightly related with progressing neuronal activation. This study utilized FLI as a marker to determine the number of neurons and structures which express c-fos in broadly distributed areas of the brain in animals with REM periods prolonged by either AS or SD. The results indicated that the brain stem and diencephalon present FLI increases in a variety of structures that possibly share various functional aspects of the REM sleep mechanism. These results are discussed in terms of the possibility that REM maintenance is related to an increase in the recruitment of REM-on neurons.

  10. NEUTRONIC REACTOR

    DOEpatents

    Fraas, A.P.; Mills, C.B.

    1961-11-21

    A neutronic reactor in which neutron moderation is achieved primarily in its reflector is described. The reactor structure consists of a cylindrical central "island" of moderator and a spherical moderating reflector spaced therefrom, thereby providing an annular space. An essentially unmoderated liquid fuel is continuously passed through the annular space and undergoes fission while contained therein. The reactor, because of its small size, is particularly adapted for propulsion uses, including the propulsion of aircraft. (AEC)

  11. NEUTRON SOURCES

    DOEpatents

    Richmond, J.L.; Wells, C.E.

    1963-01-15

    A neutron source is obtained without employing any separate beryllia receptacle, as was formerly required. The new method is safer and faster, and affords a source with both improved yield and symmetry of neutron emission. A Be container is used to hold and react with Pu. This container has a thin isolating layer that does not obstruct the desired Pu--Be reaction and obviates procedures previously employed to disassemble and remove a beryllia receptacle. (AEC)

  12. REM sleep deprivation induces changes of down regulatory antagonist modulator (DREAM) expression in the ventrobasal thalamic nuclei of sprague-dawley rats.

    PubMed

    Siran, Rosfaiizah; Ahmad, Asma Hayati; Abdul Aziz, Che Badariah; Ismail, Zalina

    2014-12-01

    REM sleep is a crucial component of sleep. Animal studies indicate that rapid eye movement (REM) sleep deprivation elicits changes in gene expression. Down regulatory antagonist modulator (DREAM) is a protein which downregulates other gene transcriptions by binding to the downstream response element site. The aim of this study is to examine the effect of REM sleep deprivation on DREAM expression in ventrobasal thalamic nuclei (VB) of rats. Seventy-two male Sprague-Dawley rats were divided into four major groups consisting of free-moving control rats (FMC) (n = 18), 72-h REM sleep-deprived rats (REMsd) (n = 18), 72-h REM sleep-deprived rats with 72-h sleep recovery (RG) (n = 18), and tank control rats (TC) (n = 18). REM sleep deprivation was elicited using the inverted flower pot technique. DREAM expression was examined in VB by immunohistochemical, Western blot, and quantitative real-time polymerase chain reaction (qRT-PCR) studies. The DREAM-positive neuronal cells (DPN) were decreased bilaterally in the VB of rats deprived of REM sleep as well as after sleep recovery. The nuclear DREAM extractions were increased bilaterally in animals deprived of REM sleep. The DREAM messenger RNA (mRNA) levels were decreased after sleep recovery. The results demonstrated a link between DREAM expression and REM sleep deprivation as well as sleep recovery which may indicate potential involvement of DREAM in REM sleep-induced changes in gene expression, specifically in nociceptive processing.

  13. Calibration of water-velocity meters

    USGS Publications Warehouse

    Kaehrle, William R.; Bowie, James E.

    1988-01-01

    The U.S. Geological Survey, Department of the Interior, as part of its responsibility to appraise the quantity of water resources in the United States, maintains facilities for the calibration of water-velocity meters at the Gulf Coast Hydroscience Center's Hydraulic Laboratory Facility, NSTL, Mississippi. These meters are used in hydrologic studies by the Geological Survey, U.S. Army Corps of Engineers, U.S. Department of Energy, state agencies, universities, and others in the public and private sector. This paper describes calibration facilities, types of water-velocity meters calibrated, and calibration standards, methods and results.

  14. NEUTRONIC REACTOR

    DOEpatents

    Wigner, E.P.

    1958-04-22

    A nuclear reactor for isotope production is described. This reactor is designed to provide a maximum thermal neutron flux in a region adjacent to the periphery of the reactor rather than in the center of the reactor. The core of the reactor is generally centrally located with respect tn a surrounding first reflector, constructed of beryllium. The beryllium reflector is surrounded by a second reflector, constructed of graphite, which, in tune, is surrounded by a conventional thermal shield. Water is circulated through the core and the reflector and functions both as a moderator and a coolant. In order to produce a greatsr maximum thermal neutron flux adjacent to the periphery of the reactor rather than in the core, the reactor is designed so tbat the ratio of neutron scattering cross section to neutron absorption cross section averaged over all of the materials in the reflector is approximately twice the ratio of neutron scattering cross section to neutron absorption cross section averaged over all of the material of the core of the reactor.

  15. High Intensity Neutron Beams for Small Samples

    NASA Astrophysics Data System (ADS)

    Böni, Peter

    2014-04-01

    As novel materials of excellent homogeneity can often only be grown in small quantities it is important to optimize the transport of neutrons from the moderator to the sample while keeping the background low. Using elliptically or parabolically tapered guides the losses can be strongly reduced such that 50% - 90% of the useful neutrons arrive at the sample. If not properly designed, however, the divergence at the sample becomes inhomogeneous. In contrast, pairs of nested Kirkpatrick-Baez mirrors in Montel geometry yield well focused beams with a compact phase space. The mirrors extract only the useful neutrons from the moderator and effectively interrupt the line of sight leading to a very low background. As the focal distances are typically several meters, the extraction of the neutrons and the installation of bulky sample environment is facilitated.

  16. FOREWORD: Neutron metrology Neutron metrology

    NASA Astrophysics Data System (ADS)

    Thomas, David J.; Nolte, Ralf; Gressier, Vincent

    2011-12-01

    The International Committee for Weights and Measures (CIPM) has consultative committees covering various areas of metrology. The Consultative Committee for Ionizing Radiation (CCRI) differs from the others in having three sections: Section (I) deals with radiation dosimetry, Section (II) with radionuclide metrology and Section (III) with neutron metrology. In 2003 a proposal was made to publish special issues of Metrologia covering the work of the three Sections. Section (II) was the first to complete their task, and their special issue was published in 2007, volume 44(4). This was followed in 2009 by the special issue on radiation dosimetry, volume 46(2). The present issue, volume 48(6), completes the trilogy and attempts to explain neutron metrology, the youngest of the three disciplines, the neutron only having been discovered in 1932, to a wider audience and to highlight the relevance and importance of this field. When originally approached with the idea of this special issue, Section (III) immediately saw the value of a publication specifically on neutron metrology. It is a topic area where papers tend to be scattered throughout the literature in journals covering, for example, nuclear instrumentation, radiation protection or radiation measurements in general. Review articles tend to be few. People new to the field often ask for an introduction to the various topics. There are some excellent older textbooks, but these are now becoming obsolete. More experienced workers in specific areas of neutron metrology can find it difficult to know the latest position in related areas. The papers in this issue attempt, without presenting a purely historical outline, to describe the field in a sufficiently logical way to provide the novice with a clear introduction, while being sufficiently up-to-date to provide the more experienced reader with the latest scientific developments in the different topic areas. Neutron radiation fields obviously occur throughout the nuclear

  17. FOREWORD: Neutron metrology Neutron metrology

    NASA Astrophysics Data System (ADS)

    Thomas, David J.; Nolte, Ralf; Gressier, Vincent

    2011-12-01

    The International Committee for Weights and Measures (CIPM) has consultative committees covering various areas of metrology. The Consultative Committee for Ionizing Radiation (CCRI) differs from the others in having three sections: Section (I) deals with radiation dosimetry, Section (II) with radionuclide metrology and Section (III) with neutron metrology. In 2003 a proposal was made to publish special issues of Metrologia covering the work of the three Sections. Section (II) was the first to complete their task, and their special issue was published in 2007, volume 44(4). This was followed in 2009 by the special issue on radiation dosimetry, volume 46(2). The present issue, volume 48(6), completes the trilogy and attempts to explain neutron metrology, the youngest of the three disciplines, the neutron only having been discovered in 1932, to a wider audience and to highlight the relevance and importance of this field. When originally approached with the idea of this special issue, Section (III) immediately saw the value of a publication specifically on neutron metrology. It is a topic area where papers tend to be scattered throughout the literature in journals covering, for example, nuclear instrumentation, radiation protection or radiation measurements in general. Review articles tend to be few. People new to the field often ask for an introduction to the various topics. There are some excellent older textbooks, but these are now becoming obsolete. More experienced workers in specific areas of neutron metrology can find it difficult to know the latest position in related areas. The papers in this issue attempt, without presenting a purely historical outline, to describe the field in a sufficiently logical way to provide the novice with a clear introduction, while being sufficiently up-to-date to provide the more experienced reader with the latest scientific developments in the different topic areas. Neutron radiation fields obviously occur throughout the nuclear

  18. Advanced smoke meter development survey and analysis

    NASA Technical Reports Server (NTRS)

    Pitz, R. W.; Penney, C. M.; Stanforth, C. M.; Shaffernocker, W. M.

    1984-01-01

    Ideal smoke meter characteristics are determined to provide a basis for evaluation of candidate systems. Five promising techniques are analyzed in detail to evaluate compilance with the practical smoke meter requirements. Four of the smoke measurement concepts are optical methods: Modulated Transmission (MODTRAN), Cross Beam Absorption Counter (CBAC), Laser Induced Incandescence (LIN), and Photoacoustic Spectroscopy (PAS). A rapid response filter instrument called a Taper Element Oscillating Microbalance (TEOM) is also evaluated. For each technique, the theoretical principles are described, the expected performance is determined, and the advantages and disadvantages are discussed The expected performance is evaluated against each of the smoke meter specifications, and the key questions for further study are given. The most promising smoke meter technique analyzed was MODTRAN, which is a variation on a direct transmission measurement. The soot-laden gas is passed through a transmission cell, and the gas pressure is modulated by a speaker.

  19. EMMNet: Sensor Networking for Electricity Meter Monitoring

    PubMed Central

    Lin, Zhi-Ting; Zheng, Jie; Ji, Yu-Sheng; Zhao, Bao-Hua; Qu, Yu-Gui; Huang, Xu-Dong; Jiang, Xiu-Fang

    2010-01-01

    Smart sensors are emerging as a promising technology for a large number of application domains. This paper presents a collection of requirements and guidelines that serve as a basis for a general smart sensor architecture to monitor electricity meters. It also presents an electricity meter monitoring network, named EMMNet, comprised of data collectors, data concentrators, hand-held devices, a centralized server, and clients. EMMNet provides long-distance communication capabilities, which make it suitable suitable for complex urban environments. In addition, the operational cost of EMMNet is low, compared with other existing remote meter monitoring systems based on GPRS. A new dynamic tree protocol based on the application requirements which can significantly improve the reliability of the network is also proposed. We are currently conducting tests on five networks and investigating network problems for further improvements. Evaluation results indicate that EMMNet enhances the efficiency and accuracy in the reading, recording, and calibration of electricity meters. PMID:22163551

  20. Continuous flow measurements using fixed ultrasonic meters

    USGS Publications Warehouse

    Oltmann, Rick

    1993-01-01

    USGS has or soon will be installing four continuous flow-monitoring stations in the delta that will use ultrasonic velocity meters (DVM). Funding for the stations has been provided by USGS, DWR, USBR, and Contra Costa Water District.

  1. EMMNet: sensor networking for electricity meter monitoring.

    PubMed

    Lin, Zhi-Ting; Zheng, Jie; Ji, Yu-Sheng; Zhao, Bao-Hua; Qu, Yu-Gui; Huang, Xu-Dong; Jiang, Xiu-Fang

    2010-01-01

    Smart sensors are emerging as a promising technology for a large number of application domains. This paper presents a collection of requirements and guidelines that serve as a basis for a general smart sensor architecture to monitor electricity meters. It also presents an electricity meter monitoring network, named EMMNet, comprised of data collectors, data concentrators, hand-held devices, a centralized server, and clients. EMMNet provides long-distance communication capabilities, which make it suitable suitable for complex urban environments. In addition, the operational cost of EMMNet is low, compared with other existing remote meter monitoring systems based on GPRS. A new dynamic tree protocol based on the application requirements which can significantly improve the reliability of the network is also proposed. We are currently conducting tests on five networks and investigating network problems for further improvements. Evaluation results indicate that EMMNet enhances the efficiency and accuracy in the reading, recording, and calibration of electricity meters.

  2. Solid state recording current meter conversion

    USGS Publications Warehouse

    Cheng, Ralph T.; Wang, Lichen

    1985-01-01

    The authors describe the conversion of an Endeco-174 current meter to a solid-state recording current meter. A removable solid-state module was designed to fit in the space originally occupied by an 8-track tape cartridge. The module contains a CPU and 128 kilobytes of nonvolatile CMOS memory. The solid-state module communicates with any terminal or computer using an RS-232C interface at 4800 baud rate. A primary consideration for conversion was to keep modifications of the current meter to a minimum. The communication protocol was designed to emulate the Endeco tape translation unit, thus the need for a translation unit was eliminated and the original data reduction programs can be used without any modification. After conversion, the data recording section of the current meter contains no moving parts; the storage capacity of the module is equivalent to that of the original tape cartridge.

  3. Development and construction of a neutron beam line for accelerator-based boron neutron capture synovectomy.

    PubMed

    Gierga, D P; Yanch, J C; Shefer, R E

    2000-01-01

    A potential application of the 10B(n, alpha)7Li nuclear reaction for the treatment of rheumatoid arthritis, termed Boron Neutron Capture Synovectomy (BNCS), is under investigation. In an arthritic joint, the synovial lining becomes inflamed and is a source of great pain and discomfort for the afflicted patient. The goal of BNCS is to ablate the synovium, thereby eliminating the symptoms of the arthritis. A BNCS treatment would consist of an intra-articular injection of boron followed by neutron irradiation of the joint. Monte Carlo radiation transport calculations have been used to develop an accelerator-based epithermal neutron beam line for BNCS treatments. The model includes a moderator/reflector assembly, neutron producing target, target cooling system, and arthritic joint phantom. Single and parallel opposed beam irradiations have been modeled for the human knee, human finger, and rabbit knee joints. Additional reflectors, placed to the side and back of the joint, have been added to the model and have been shown to improve treatment times and skin doses by about a factor of 2. Several neutron-producing charged particle reactions have been examined for BNCS, including the 9Be(p,n) reaction at proton energies of 4 and 3.7 MeV, the 9Be(d,n) reaction at deuteron energies of 1.5 and 2.6 MeV, and the 7Li(p,n) reaction at a proton energy of 2.5 MeV. For an accelerator beam current of 1 mA and synovial boron uptake of 1000 ppm, the time to deliver a therapy dose of 10,000 RBEcGy ranges from 3 to 48 min, depending on the treated joint and the neutron producing charged particle reaction. The whole-body effective dose that a human would incur during a knee treatment has been estimated to be 3.6 rem or 0.75 rem, for 1000 ppm or 19,000 ppm synovial boron uptake, respectively, although the shielding configuration has not yet been optimized. The Monte Carlo design process culminated in the construction, installation, and testing of a dedicated BNCS beam line on the high

  4. Laser wavelength meter: analysis of measurement uncertainties

    NASA Astrophysics Data System (ADS)

    Skrzeczanowski, Wojciech; Zyczkowski, Marek; Dlugaszek, Andrzej

    1999-08-01

    Principle of operation of laser radiation wavelength meter based on Fabry-Perot interferometer and linear CCD camera is presented in the paper. A dependence, on the base of which laser wavelength can be calculated, is found and a way of defining of all component uncertainties of a measurement is shown. An analysis of an influence and examples of definition of uncertainties of a measurement for four wavelength meter structural sets of different objective focal lengths are presented.

  5. Comparison of five portable peak flow meters

    PubMed Central

    Takara, Glaucia Nency; Ruas, Gualberto; Pessoa, Bruna Varanda; Jamami, Luciana Kawakami; Di Lorenzo, Valéria Amorim Pires; Jamami, Mauricio

    2010-01-01

    OBJECTIVE To compare the measurements of spirometric peak expiratory flow (PEF) from five different PEF meters and to determine if their values are in agreement. Inaccurate equipment may result in incorrect diagnoses of asthma and inappropriate treatments. METHODS Sixty-eight healthy, sedentary and insufficiently active subjects, aged from 19 to 40 years, performed PEF measurements using Air Zone®, Assess®, Galemed®, Personal Best® and Vitalograph® peak flow meters. The highest value recorded for each subject for each device was compared to the corresponding spirometric values using Friedman’s test with Dunn’s post-hoc (p<0.05), Spearman’s correlation test and Bland-Altman’s agreement test. RESULTS The median and interquartile ranges for the spirometric values and the Air Zone®, Assess®, Galemed®, Personal Best® and Vitalograph® meters were 428 (263–688 L/min), 450 (350–800 L/min), 420 (310–720 L/min), 380 (300–735 L/min), 400 (310–685 L/min) and 415 (335–610 L/min), respectively. Significant differences were found when the spirometric values were compared to those recorded by the Air Zone® (p<0.001) and Galemed ® (p<0.01) meters. There was no agreement between the spirometric values and the five PEF meters. CONCLUSIONS The results suggest that the values recorded from Galemed® meters may underestimate the actual value, which could lead to unnecessary interventions, and that Air Zone® meters overestimate spirometric values, which could obfuscate the need for intervention. These findings must be taken into account when interpreting both devices’ results in younger people. These differences should also be considered when directly comparing values from different types of PEF meters. PMID:20535364

  6. Similar molecular determinants on Rem mediate two distinct modes of inhibition of CaV1.2 channels

    PubMed Central

    Puckerin, Akil A.; Chang, Donald D.; Subramanyam, Prakash; Colecraft, Henry M.

    2016-01-01

    ABSTRACT Rad/Rem/Rem2/Gem (RGK) proteins are Ras-like GTPases that potently inhibit all high-voltage-gated calcium (CaV1/CaV2) channels and are, thus, well-positioned to tune diverse physiological processes. Understanding how RGK proteins inhibit CaV channels is important for perspectives on their (patho)physiological roles and could advance their development and use as genetically-encoded CaV channel blockers. We previously reported that Rem can block surface CaV1.2 channels in 2 independent ways that engage distinct components of the channel complex: (1) by binding auxiliary β subunits (β-binding-dependent inhibition, or BBD); and (2) by binding the pore-forming α1C subunit N-terminus (α1C-binding-dependent inhibition, or ABD). By contrast, Gem uses only the BBD mechanism to block CaV1.2. Rem molecular determinants required for BBD CaV1.2 inhibition are the distal C-terminus and the guanine nucleotide binding G-domain which interact with the plasma membrane and CaVβ, respectively. However, Rem determinants for ABD CaV1.2 inhibition are unknown. Here, combining fluorescence resonance energy transfer, electrophysiology, systematic truncations, and Rem/Gem chimeras we found that the same Rem distal C-terminus and G-domain also mediate ABD CaV1.2 inhibition, but with different interaction partners. Rem distal C-terminus interacts with α1C N-terminus to anchor the G-domain which likely interacts with an as-yet-unidentified site. In contrast to some previous studies, neither the C-terminus of Rem nor Gem was sufficient to inhibit CaV1/CaV2 channels. The results reveal that similar molecular determinants on Rem are repurposed to initiate 2 independent mechanisms of CaV1.2 inhibition. PMID:27115600

  7. Perception of strong-meter and weak-meter rhythms in children with spina bifida meningomyelocele

    PubMed Central

    HOPYAN, TALAR; SCHELLENBERG, E. GLENN; DENNIS, MAUREEN

    2011-01-01

    Neurodevelopmental disorders such as spina bifida meningomyelocele (SBM) are often associated with dysrhythmic movement. We studied rhythm discrimination in 21 children with SBM and in 21 age-matched controls, with the research question being whether both groups showed a strong-meter advantage whereby rhythm discrimination is better for rhythms with a strong-meter, in which onsets of longer intervals occurred on the beat, than those with a weak-meter, in which onsets of longer intervals occurred off the beat. Compared to controls, the SBM group was less able to discriminate strong-meter rhythms, although they performed comparably in discriminating weak-meter rhythms. The attenuated strong-meter advantage in children with SBM shows that their rhythm deficits occur at the level of both perception and action, and may represent a central processing disruption of the brain mechanisms for rhythm. PMID:19573270

  8. Don't count your chickens before they're hatched: elaborative encoding in REM dreaming in face of the physiology of sleep stages.

    PubMed

    Deliens, Gaétane; Schwartz, Sophie; Peigneux, Philippe

    2013-12-01

    Llewellyn suggests that episodic memories undergo "elaborative encoding" during rapid eye movement (REM) dreams, generating novel associations between recent and remote memories that are then instantiated during non-REM (NREM) sleep. This hypothesis conflicts with our knowledge of the physiology of NREM and then REM sleep stages and their ordered succession. Moreover, associations during sleep might also involve the extraction of hidden patterns rather than de novo associations.

  9. A variety of neutron sensors based on scintillating glass waveguides

    SciTech Connect

    Bliss, M.; Craig, R.A.

    1995-05-01

    Pacific Northwest Laboratory (PNL) has fabricated cerium-activated, lithium-silicate glass scintillating fiber neutron sensors via a hot-downdraw process. These fibers typically have a transmission length (e{sup {minus}1} length) of greater than 2 meters. The underlying physics of, the properties of, and selected devices incorporating these fibers are described. These fibers constitute an enabling technology for a wide variety of neutron sensors.

  10. Variety of neutron sensors based on scintillating glass waveguides

    NASA Astrophysics Data System (ADS)

    Bliss, Mary; Craig, Richard A.

    1995-04-01

    Pacific Northwest Laboratory (PNL) has fabricated cerium-activated lithium silicate glass scintillating fiber waveguide neutron sensors via a hot-downdraw process. These fibers typically have a transmission length (e-1 length) of greater than 2 meters. The underlying physics of, the properties of, and selected devices incorporating these fibers are described. These fibers constitute an enabling technology for a wide variety of neutron sensors.

  11. Neutron therapy of cancer

    NASA Technical Reports Server (NTRS)

    Frigerio, N. A.; Nellans, H. N.; Shaw, M. J.

    1969-01-01

    Reports relate applications of neutrons to the problem of cancer therapy. The biochemical and biophysical aspects of fast-neutron therapy, neutron-capture and neutron-conversion therapy with intermediate-range neutrons are presented. Also included is a computer program for neutron-gamma radiobiology.

  12. NEUTRONIC REACTOR

    DOEpatents

    Hurwitz, H. Jr.; Brooks, H.; Mannal, C.; Payne, J.H.; Luebke, E.A.

    1959-03-24

    A reactor of the heterogeneous, liquid cooled type is described. This reactor is comprised of a central region of a plurality of vertically disposed elongated tubes surrounded by a region of moderator material. The central region is comprised of a central core surrounded by a reflector region which is surrounded by a fast neutron absorber region, which in turn is surrounded by a slow neutron absorber region. Liquid sodium is used as the primary coolant and circulates through the core which contains the fuel elements. Control of the reactor is accomplished by varying the ability of the reflector region to reflect neutrons back into the core of the reactor. For this purpose the reflector is comprised of moderator and control elements having varying effects on reactivity, the control elements being arranged and actuated by groups to give regulation, shim, and safety control.

  13. NEUTRONIC REACTOR

    DOEpatents

    Fermi, E.; Szilard, L.

    1957-09-24

    Reactors of the type employing plates of natural uranium in a moderator are discussed wherein the plates are um-formly disposed in parallel relationship to each other thereby separating the moderator material into distinct and individual layers. Each plate has an uninterrupted sunface area substantially equal to the cross-sectional area of the active portion of the reactor, the particular size of the plates and the volume ratio of moderator to uranium required to sustain a chain reaction being determinable from the known purity of these materials and other characteristics such as the predictable neutron losses due to the formation of radioactive elements of extremely high neutron capture cross section.

  14. NEUTRONIC REACTOR

    DOEpatents

    Wigner, E.P.; Weinberg, A.W.; Young, G.J.

    1958-04-15

    A nuclear reactor which uses uranium in the form of elongated tubes as fuel elements and liquid as a coolant is described. Elongated tubular uranium bodies are vertically disposed in an efficient neutron slowing agent, such as graphite, for example, to form a lattice structure which is disposed between upper and lower coolant tanks. Fluid coolant tubes extend through the uranium bodies and communicate with the upper and lower tanks and serve to convey the coolant through the uranium body. The reactor is also provided with means for circulating the cooling fluid through the coolant tanks and coolant tubes, suitable neutron and gnmma ray shields, and control means.

  15. DNA Radiation Environments Program: Fall 1989 2-meter box experiments and analysis

    SciTech Connect

    Santoro, R.T.

    1991-05-01

    This effort, sponsored by the Defense Nuclear Agency under the Radiation Environments Program, was carried out to obtain measured data for benchmarking MASH, the Monte Carlo Adjoint Code System. MASH was developed to replace the Vehicle Code System, VCS, that has been used by the Department of Defense and NATO for calculating neutron and gamma-ray radiation fields and shielding protection factors inside armored vehicles and structures from nuclear weapon radiation. Free-field data were obtained at distances of 170- and 400-meters from the APR while in-box measurements were made at 400 meters only. The box, included to obtain neutron and gamma-ray reduction factors, was a 2-meter cube configuration having 0.1016-m-thick steel walls. Calculated data were obtained using MASH by analysts from the Oak Ridge National Laboratory and Science Applications International Corporation. Calculated (C) results were compared with experimental (E) data in terms of C/E ratios. Free-field and in-box neutron kerma generally agreed within {+-}20%, although some C/E comparisons fell outside this range depending upon the detector against which the calculated data were compared. For those cases where the C/E ratio is marginal or unacceptable, problems in the detector systems were acknowledged to be principal cause of the discrepancy. Generally poor agreement ({approx}25-35%) was achieved among the C/E ratios for the free-field gamma-ray kerma at the 170- and 400-m locations while excellent (10%, or better) C/E values were obtained for the in-box conditions. The discrepancy for the free-field comparison was attributed to the failure by the analysts to include a tree line adjacent to the measurement site in the calculational geometry. C/E values for the neutron and gamma-ray reduction factors ranged from 1% to 23% depending on the detector. 4 refs., 2 figs., 14 tabs.

  16. Operational experiences proving mass flow meters with small volume provers

    SciTech Connect

    Whitman, S.K.

    1996-09-01

    Small Volume Provers were introduced several decades ago, and numerous papers have been presented covering the technical and empirical operation of these provers. During this time, mass flow meters based upon the coriolis effect have evolved. The measurement accuracy of these meters has continually improved to the degree that the Hydrocarbon Industry is closely evaluating them for custody transfer measurement. Flow meters used in custody transfer measurement normally require some means of verification, which is generally referred to as meter proving. Meter proving methods for traditional volumetric meters are well established, while those for mass flow meters are still evolving. Coriolis mass flow meters are fundamentally different from traditional custody transfer meters. Therefore, a basic understanding of the principles of operation is necessary to properly prove mass flow meters. This paper will focus on the basic knowledge needed to prove mass meters, with actual case histories to demonstrate operational experiences with small volume provers.

  17. Aminergic and cholinergic afferents to REM sleep induction regions of the pontine reticular formation in the rat.

    PubMed

    Semba, K

    1993-04-22

    Microinjection of cholinergic agonists in a dorsolateral part of the mesopontine tegmentum has been shown to induce a rapid eye movement (REM) sleep-like state. Physiological evidence indicates that not only acetylcholine but also various amine transmitters, including those implicated in behavioral state regulation, affect neuronal activity in this region of the pontine reticular formation. In the present study, sources of select aminergic and cholinergic inputs to this REM sleep induction zone were identified and quantitatively analyzed by using fluorescence retrograde tracing combined with immunofluorescence in the rat. In addition to previously demonstrated cholinergic projections from the pedunculopontine and laterodorsal tegmental nuclei, the REM sleep induction zone received various aminergic inputs that originated in widely distributed regions of the brainstem and hypothalamus. Serotoninergic afferents represented a mean of 44% of all aminergic/cholinergic source neurons projecting to the REM sleep induction zone, which was comparable to the mean percentage of 39% represented by cholinergic afferent neurons. The serotoninergic afferents originated from the raphe nuclei at all brainstem levels, with heavier projections from the pontine than from the medullary raphe nuclei. Unexpectedly, an additional major serotoninergic input was provided by serotoninergic neurons in the nucleus prosupralemniscus (B9). Noradrenergic afferent neurons represented a mean of 14% of all aminergic/cholinergic source neurons, which was only about one-third of the mean percentage of either cholinergic or serotoninergic source neurons. These noradrenergic projection neurons were located not only in the locus ceruleus (8%) but also in the lateral tegmentum, including the A5 (4%) and A7 (2%) cell groups. Histaminergic neurons in the tuberomammillary hypothalamic nucleus represented a minor group of afferent neurons (3%), and a still smaller input came from adrenergic C1 neurons. The

  18. Prevalence and Clinical Correlates of a Short Onset REM Period (SOREMP) during Routine PSG

    PubMed Central

    Cairns, Alyssa; Bogan, Richard

    2015-01-01

    Study Objectives: The objectives of this study were to quantify the (1) sensitivity and specificity of nocturnal PSG SOREMP (REM latency ≤ 15 min) for narcolepsy in those being evaluated for hypersomnolence and (2) prevalence and predictors of SOREMP during baseline PSG for patients being evaluated for various sleep disorders. Design: This was a retrospective analysis of a large repository of de-identified PSG and MSLT test results from 2007 to 2013. Setting and Patients: Patient records were retrieved from a repository of studies completed at a variety of sleep laboratories across the USA. Included in the analyses were 79,651 general sleep clinic patients (without an MSLT; 48% male; 72% Caucasian) and an additional 3,059 patients (31.3% male; 72% Caucasian) being evaluated for hypersomnolence (with a consecutive MSLT). Interventions: NA. Measurements and Results: For patients being evaluated for hypersomnolence, the prevalence of PSG SOREMP increased in a dose-response fashion with the number of REM onsets that occurred on a consecutive MSLT (0.5% for no MSLT SOREMPs to > 33.0% for those with 5 MSLT SOREMPs). Overall, having a PSG SOREMP was highly specific (99.5%; 95% CI: 99.1–99.7%) but not sensitive (6.7%; 95% CI: 4.7–9.2%) for narcolepsy. The prevalence of PSG SOREMP for patients in the general sleep clinic sample (i.e., not being evaluated by a consecutive MSLT) was 0.8% and was much higher in those that work night/swing shift. In adjusted models, African American race contributed to the most variance in PSG SOREMP. Conclusions: A short onset rapid eye movement (REM) latency occurs rarely in general sleep clinic samples (< 1.0%), but is highly specific for the diagnosis of narcolepsy. Although rare, the prevalence of the phenomenon is much higher than the estimated prevalence of narcolepsy and may provide a critical opportunity for practitioners to identify narcolepsy in sleep clinic patients. These data also suggest that the utility of polysomnography

  19. First Measurements of the Rover Environmental Monitoring Station (REMS) on the Mars Science Laboratory

    NASA Astrophysics Data System (ADS)

    Martín-Torres, F. J.; Zorzano-Mier, M.; Gomez-Elvira, J.

    2012-12-01

    The Rover Environmental Monitoring Station (REMS) on the Mars Science Laboratory (MSL) mission has sensors recording air and ground temperature, pressure, relative humidity, wind speed in the horizontal and vertical directions, as well as ultraviolet radiation in different bands. Typical daily REMS observations will collect 180 minutes of data from all sensors simultaneously (arranged in 5 minute hourly samples plus 60 additional minutes taken at times to be decided, daily, during the course of the mission). REMS will add significantly to the environmental record collected by prior missions through the range of simultaneous observations including water vapor; the ability to take measurements routinely through the night; the intended minimum of one Martian year of observations; and the first measurement of surface UV irradiation. The capability of multiple, consistent, and simultaneous data is essential for meaningful interpretation of near-surface processes including the characterization of soil thermal properties. The Martian atmosphere is generally transparent to solar radiation, but atmospheric dust absorbs solar radiation and heats the atmosphere, while UV radiation ionizes atmospheric gases and is harmful to any potential Martian organisms (past or present). For this reason, knowledge of the UV radiation flux at the surface of Mars is important for the understanding habitability conditions, one of the main goals of the MSL mission. Moreover UV radiation is a significant driver in the photochemistry of the atmosphere and surface. In this paper we present a first analysis of REMS measurements, the status of the different sensors and the potential of REMS for Mars environmental studies. REMS Team: C. Armiens, I. Carrasco, F. Gómez, A. Lepinette, J. Martín, J. Martínez-Frías, L. Mora, S. Navarro, V. Peinado, J. Rodríguez-Manfredi, J. Romeral, E. Sebastián, J. Torres, J. Verdasca (Centro de Astrobiología (CSIC-INTA), Carretera de Ajalvir, km. 4, 28850 Torrej

  20. The 4-meter lunar engineering telescope

    NASA Technical Reports Server (NTRS)

    Peacock, Keith; Giannini, Judith A.; Kilgus, Charles C.; Bely, Pierre Y.; May, B. Scott; Cooper, Shannon A.; Schlimm, Gerard H.; Sounder, Charles; Ormond, Karen; Cheek, Eric

    1991-01-01

    The 16-meter diffraction limited lunar telescope incorporates a primary mirror with 312 one-meter segments; 3 nanometer active optics surface control with laser metrology and hexapod positioners; a space frame structure with one-millimeter stability; and a hexapod mount for pointing. The design data needed to limit risk in this development can be obtained by building a smaller engineering telescope on the moon with all of the features of the 16-meter design. This paper presents a 4.33-meter engineering telescope concept developed by the Summer 1990 Student Program of the NASA/JHU Space Grant Consortium Lunar Telescope Project. The primary mirror, made up of 18 one-meter hexagonal segments, is sized to provide interesting science as well as engineering data. The optics are configured as a Ritchey-Chretien with a coude relay to the focal plane beneath the surface. The optical path is continuously monitored with 3-nanometer precision interferometrically. An active optics processor and piezoelectric actuators operate to maintain the end-to-end optical configuration established by wave front sensing using a guide star. The mirror segments, consisting of a one-centimeter thick faceplate on 30-cm deep ribs, maintain the surface figure to a few nanometers under lunar gravity and thermal environment.

  1. 20 Meter Solar Sail Analysis and Correlation

    NASA Technical Reports Server (NTRS)

    Taleghani, B. K.; Lively, P. S.; Banik, J.; Murphy, D. M.; Trautt, T. A.

    2005-01-01

    This paper describes finite element analyses and correlation studies to predict deformations and vibration modes/frequencies of a 20-meter solar sail system developed by ATK Space Systems. Under the programmatic leadership of NASA Marshall Space Flight Center's In-Space Propulsion activity, the 20-meter solar sail program objectives were to verify the design, to assess structural responses of the sail system, to implement lessons learned from a previous 10-meter quadrant system analysis and test program, and to mature solar sail technology to a technology readiness level (TRL) of 5. For this 20 meter sail system, static and ground vibration tests were conducted in NASA Glenn Research Center's 100 meter diameter vacuum chamber at Plum Brook station. Prior to testing, a preliminary analysis was performed to evaluate test conditions and to determine sensor and actuator locations. After testing was completed, an analysis of each test configuration was performed. Post-test model refinements included updated properties to account for the mass of sensors, wiring, and other components used for testing. This paper describes the development of finite element models (FEM) for sail membranes and masts in each of four quadrants at both the component and system levels, as well as an optimization procedure for the static test/analyses correlation.

  2. Use of Coriolis meters in gas applications

    SciTech Connect

    Patten, T.; Pawlas, G.

    1995-12-31

    Coriolis mass flowmeters provide a solution for measuring the mass flow rate of gases directly. Recent calibration data on compressed air shows that the factory water calibration is also valid on air. In addition, a Coriolis meter is fundamentally linear resulting in an accurate measurement over a wide flow range. Data are presented based on testing performed on Micro Motion 25 mm, 50 mm, and 75 mm Coriolis mass flowmeters on compressed air. Test pressures ranging between 1.7 bar (25 psia) and 100 bar (1450 psia) and mass flow rates ranging between 100:1 to 10:1, depending on the meter size. All calibration points fell with {plus_minus}2%, with a significant portion of the data within {plus_minus}5%. Data are also presented for a 6 mm meter on natural gas at 100 bar; all data are within {plus_minus}0.5%. Repeatability data are presented for a 9 mm meter calibrated on 100 bar air for calibration run times between 10 and 60 seconds. Meter repeatability improved approximately 10 times to {plus_minus}0.15% when the calibration time was 60 seconds.

  3. Diagnostic Flow Metering using Ultrasound Tomography

    NASA Astrophysics Data System (ADS)

    Chun, Sejong; Yoon, Byung-Ro; Lee, Kwang-Bock; Paik, Jong-Seung

    2010-06-01

    Flow meters, which are used for transferring water or crude oil through pipelines, require well-defined flow conditions for accurate flow rate monitoring. Even though all the installation conditions for the flow meters are satisfied, there could be unexpected flow disturbances, such as abrupt increase of upstream pressure, affecting on the performance of flow meters. To investigate any differences between measured and actual flow rates, flow velocity profiles inside the pipeline must be known. Ultrasound tomography is a means of reconstructing flow profiles from line-averaged velocities by Radon transformation. Diagnostic parameters are then extracted from the reconstructed flow profiles to give information whether the flow conditions are appropriate for accurate flow metering. In the present study, flow profiles downstream of a mass flow meter and a butterfly valve are reconstructed. Flow diagnostic parameters are defined using statistical moments such as mean value, standard deviation, skewness and kurtosis. The measured diagnostic parameters in the above-mentioned flow conditions are compared with those of fully-developed laminar and turbulent flow profiles to validate their usefulness.

  4. Witnessing orifice meter calibration and field testing

    SciTech Connect

    Woods, D.

    1995-12-01

    It would seem with the advent of electronic measurement and electronic custody transfer of natural gas and other petroleum products that witnessing orifice meter calibration and field testing would become an obsolete practice in the petroleum industry. This however, is not the case. Due to low volume measurement, remote locations, dollar cost of electronic measurement, and arrangements between companies regarding electronic custody, transfer, witnessing orifice meter calibration and field testing will continue to be an integral part of the petroleum industry`s future. Even as technology moves forward and electronic measurement becomes common within the petroleum industry, electronic hardware used in measurement will, like the orifice recorder, only be a secondary measuring device. The meter tube and orifice plate will continue to be the primary measuring device. Due to these circumstances witnessing orifice meter calibration and field testing will also continue to be important even though some emphasis will be shifted to witnessing field testing of electronic equipment. The information in this paper is not meant to be an absolute, but, to be used as a guide in witnessing and field testing orifice meters. There are many variables in testing that. due to the length of this paper, will not be discussed.

  5. Evolution of opioid risk management and review of the classwide REMS for extended-release/long-acting opioids.

    PubMed

    Stanos, Steven

    2012-11-01

    In 2007, the Food and Drug Administration Amendments Act (FDAAA) afforded the US Food and Drug Administration (FDA) the ability to enforce postmarketing risk management strategies for prescription medicines. Under this policy, certain medications with known or potential risks could be required to have a Risk Evaluation and Mitigation Strategy (REMS), a risk management program designed to ensure that a product's therapeutic benefit outweighs its risks. Prescription opioid analgesics, particularly extended-release (ER)/long-acting (LA) formulations, have undergone scrutiny in recent years due to the serious risks associated with their use, especially when they are prescribed improperly, misused, or abused. In July 2012, the FDA approved a classwide REMS for ER and LA opioids. This ER/LA opioid REMS program is designed to improve prescriber education and patient awareness about safe opioid use to minimize the risks of addiction, unintentional overdose, and death. Because clinicians often encounter patients with moderate-to-severe chronic, noncancer pain who are in need of around-the-clock opioid analgesia, knowledge of the conditions of this classwide REMS may become essential to continue prescribing ER/LA opioids. This article briefly describes the changes in US risk management policies that have shaped today's regulatory environment and provides an overview of the requirements for the classwide ER/LA opioid REMS.

  6. Visual short-term memory deficits in REM sleep behaviour disorder mirror those in Parkinson’s disease

    PubMed Central

    Rolinski, Michal; Baig, Fahd; Giehl, Kathrin; Quinnell, Timothy; Zaiwalla, Zenobia; Mackay, Clare E.; Husain, Masud; Hu, Michele T. M.

    2016-01-01

    Individuals with REM sleep behaviour disorder are at significantly higher risk of developing Parkinson’s disease. Here we examined visual short-term memory deficits—long associated with Parkinson’s disease—in patients with REM sleep behaviour disorder without Parkinson’s disease using a novel task that measures recall precision. Visual short-term memory for sequentially presented coloured bars of different orientation was assessed in 21 patients with polysomnography-proven idiopathic REM sleep behaviour disorder, 26 cases with early Parkinson’s disease and 26 healthy controls. Three tasks using the same stimuli controlled for attentional filtering ability, sensorimotor and temporal decay factors. Both patients with REM sleep behaviour disorder and Parkinson’s disease demonstrated a deficit in visual short-term memory, with recall precision significantly worse than in healthy controls with no deficit observed in any of the control tasks. Importantly, the pattern of memory deficit in both patient groups was specifically explained by an increase in random responses. These results demonstrate that it is possible to detect the signature of memory impairment associated with Parkinson’s disease in individuals with REM sleep behaviour disorder, a condition associated with a high risk of developing Parkinson’s disease. The pattern of visual short-term memory deficit potentially provides a cognitive marker of ‘prodromal’ Parkinson’s disease that might be useful in tracking disease progression and for disease-modifying intervention trials. PMID:26582557

  7. Pedunculopontine Nucleus Gamma Band Activity-Preconscious Awareness, Waking, and REM Sleep.

    PubMed

    Urbano, Francisco J; D'Onofrio, Stasia M; Luster, Brennon R; Beck, Paige B; Hyde, James Robert; Bisagno, Veronica; Garcia-Rill, Edgar

    2014-01-01

    The pedunculopontine nucleus (PPN) is a major component of the reticular activating system (RAS) that regulates waking and REM sleep, states of high-frequency EEG activity. Recently, we described the presence of high threshold, voltage-dependent N- and P/Q-type calcium channels in RAS nuclei that subserve gamma band oscillations in the mesopontine PPN, intralaminar parafascicular nucleus (Pf), and pontine subcoeruleus nucleus dorsalis (SubCD). Cortical gamma band activity participates in sensory perception, problem solving, and memory. Rather than participating in the temporal binding of sensory events as in the cortex, gamma band activity in the RAS may participate in the processes of preconscious awareness, and provide the essential stream of information for the formulation of many of our actions. That is, the RAS may play an early permissive role in volition. Our latest results suggest that (1) the manifestation of gamma band activity during waking may employ a separate intracellular pathway compared to that during REM sleep, (2) neuronal calcium sensor (NCS-1) protein, which is over expressed in schizophrenia and bipolar disorder, modulates gamma band oscillations in the PPN in a concentration-dependent manner, (3) leptin, which undergoes resistance in obesity resulting in sleep dysregulation, decreases sodium currents in PPN neurons, accounting for its normal attenuation of waking, and (4) following our discovery of electrical coupling in the RAS, we hypothesize that there are cell clusters within the PPN that may act in concert. These results provide novel information on the mechanisms controlling high-frequency activity related to waking and REM sleep by elements of the RAS.

  8. The Prevalence and Characteristics of REM Sleep without Atonia (RSWA) in Patients Taking Antidepressants

    PubMed Central

    Lee, Kenneth; Baron, Kelly; Soca, Rodolfo; Attarian, Hrayr

    2016-01-01

    Study Objectives: The association of REM sleep without atonia (RSWA) as well as REM sleep behavior disorder (RBD) with the intake of selective serotonin reuptake inhibitors (SSRI) and selective norepinephrine reuptake inhibitors (SNRI) is well established. Our study objective was to determine the prevalence of RSWA and RBD among a group of sleep center patients taking SSRI and SNRI. Methods: A retrospective chart review was done at our tertiary sleep center, and 10,746 consecutive records from October 1, 2007, through October 31, 2013, were searched for SSRI and SNRI names using the Sleep Cataloguer Software. Results: The search resulted in 1,444 records, which were then reviewed for keywords of RSWA and RBD. The AASM scoring criteria were used to determine RSWA. Reports of 41 patients with known narcolepsy or α-synucleinopathies were excluded. The remaining records were mined for age, sex, presence of obstructive sleep apnea (OSA), type of antidepressant (SSRI or SNRI), and diagnosis for which antidepressant was prescribed. We used logistic regression analysis to adjust for age, OSA, and sex. Of the 1,444 participants on antidepressants, 176 (12.2%) had RSWA (all confirmed by the investigators) compared to 226 of the entire sleep lab population of 10,746 (2.1%), risk ratio (95% CI) 9.978 (8.149, 12.22). Seven of the 176 patients on antidepressants had RBD (0.48%) compared to 108 of 10,746 (1%), p = 0.005. Conclusions: SSRI and SNRI are associated with a higher prevalence of RSWA but not of RBD. This is independent of medication type. Citation: Lee K, Baron K, Soca R, Attarian H. The prevalence and characteristics of rem sleep without atonia (RSWA) in patients taking antidepressants. J Clin Sleep Med 2016;12(3):351–355. PMID:26446247

  9. Fear Extinction Memory Consolidation Requires Potentiation of Pontine-Wave Activity during REM Sleep

    PubMed Central

    Datta, Subimal; O'Malley, Matthew W .

    2013-01-01

    Sleep plays an important role in memory consolidation within multiple memory systems including contextual fear extinction memory, but little is known about the mechanisms that underlie this process. Here, we show that fear extinction training in rats, which extinguished conditioned fear, increased both slow-wave sleep and rapid-eye movement (REM) sleep. Surprisingly, 24 h later, during memory testing, only 57% of the fear-extinguished animals retained fear extinction memory. We found that these animals exhibited an increase in phasic pontine-wave (P-wave) activity during post-training REM sleep, which was absent in the 43% of animals that failed to retain fear extinction memory. The results of this study provide evidence that brainstem activation, specifically potentiation of phasic P-wave activity, during post-training REM sleep is critical for consolidation of fear extinction memory. The results of this study also suggest that, contrary to the popular hypothesis of sleep and memory, increased sleep after training alone does not guarantee consolidation and/or retention of fear extinction memory. Rather, the potentiation of specific sleep-dependent physiological events may be a more accurate predictor for successful consolidation of fear extinction memory. Identification of this unique mechanism will significantly improve our present understanding of the cellular and molecular mechanisms that underlie the sleep-dependent regulation of emotional memory. Additionally, this discovery may also initiate development of a new, more targeted treatment method for clinical disorders of fear and anxiety in humans that is more efficacious than existing methods such as exposure therapy that incorporate only fear extinction. PMID:23467372

  10. Pedunculopontine Nucleus Gamma Band Activity-Preconscious Awareness, Waking, and REM Sleep

    PubMed Central

    Urbano, Francisco J.; D’Onofrio, Stasia M.; Luster, Brennon R.; Beck, Paige B.; Hyde, James Robert; Bisagno, Veronica; Garcia-Rill, Edgar

    2014-01-01

    The pedunculopontine nucleus (PPN) is a major component of the reticular activating system (RAS) that regulates waking and REM sleep, states of high-frequency EEG activity. Recently, we described the presence of high threshold, voltage-dependent N- and P/Q-type calcium channels in RAS nuclei that subserve gamma band oscillations in the mesopontine PPN, intralaminar parafascicular nucleus (Pf), and pontine subcoeruleus nucleus dorsalis (SubCD). Cortical gamma band activity participates in sensory perception, problem solving, and memory. Rather than participating in the temporal binding of sensory events as in the cortex, gamma band activity in the RAS may participate in the processes of preconscious awareness, and provide the essential stream of information for the formulation of many of our actions. That is, the RAS may play an early permissive role in volition. Our latest results suggest that (1) the manifestation of gamma band activity during waking may employ a separate intracellular pathway compared to that during REM sleep, (2) neuronal calcium sensor (NCS-1) protein, which is over expressed in schizophrenia and bipolar disorder, modulates gamma band oscillations in the PPN in a concentration-dependent manner, (3) leptin, which undergoes resistance in obesity resulting in sleep dysregulation, decreases sodium currents in PPN neurons, accounting for its normal attenuation of waking, and (4) following our discovery of electrical coupling in the RAS, we hypothesize that there are cell clusters within the PPN that may act in concert. These results provide novel information on the mechanisms controlling high-frequency activity related to waking and REM sleep by elements of the RAS. PMID:25368599

  11. REM Sleep Behavior and Motor Findings in Parkinson's Disease: A Cross-sectional Analysis

    PubMed Central

    Mahajan, Abhimanyu; Rosenthal, Liana S.; Gamaldo, Charlene; Salas, Rachel E.; Pontone, Gregory M.; McCoy, Arita; Umeh, Chizoba; Mari, Zoltan

    2014-01-01

    Background Parkinson's disease (PD) represents a major public health challenge that will only grow in our aging population. Understanding the connection between PD and associated prodromal conditions, such as rapid eye movement sleep behavioral disorder (RBD), is critical to identifying prevention strategies. However, the relationship between RBD and severity of motor findings in early PD is unknown. This study aims to examine this relationship. Methods The study population consisted of 418 PD patients who completed the Movement Disorders Society-United Parkinson's Disease Rating Scale (MDS-UPDRS) and rapid eye movement sleep (REM) disorder questionnaires at the baseline visit of the Michael J. Fox's Parkinson's Progression Markers Initiative (PPMI). Cross-sectional analysis was carried out to assess the association between REM Sleep Behavior Screening Questionnaire score and MDS UPDRS-3 (motor) score categories. Correlation with a higher score category was described as “worse motor findings”. A score of 5 on the REM disorder questionnaire was defined as predictive of RBD. Results Out of the 418 PD patients, 113 (27.0%) had RBD. With univariate logistic regression analysis, individuals with scores predictive of RBD were 1.66 times more likely to have worse motor findings (p = 0.028). Even with age, gender, and Geriatric Depression Scale scores taken into account, individuals with scores predictive of RBD were 1.69 times more likely to have worse motor findings (p = 0.025). Discussion PD patients with RBD symptoms had worse motor findings than those unlikely to have RBD. This association provides further evidence for the relationship between RBD and PD. PMID:25009765

  12. Role of spinal 5-HT receptors in cutaneous hypersensitivity induced by REM sleep deprivation.

    PubMed

    Wei, Hong; Ma, Ainiu; Wang, Yong-Xiang; Pertovaara, Antti

    2008-06-01

    Previous studies indicate that rapid eye movement (REM) sleep deprivation facilitates pain sensitivity. Since serotoninergic raphe neurons are involved both in regulation of sleep and descending pain modulation, we studied whether spinal 5-HT receptors have a role in sleep deprivation-induced facilitation of pain-related behavior. REM sleep deprivation of 48h was induced by the flower pot method in the rat. The pain modulatory influence of various serotoninergic compounds administered intrathecally was assessed by determining limb withdrawal response to monofilaments. REM sleep deprivation produced a marked hypersensitivity. Sleep deprivation-induced hypersensitivity and normal sensitivity in controls were reduced both by a 5-HT(1A) receptor antagonist (WAY-100635) and a 5-HT(2C) receptor antagonist (RS-102221). An antagonist of the 5-HT(3) receptor (LY-278584) failed to modulate hypersensitivity in sleep-deprived or control animals. Paradoxically, sensitivity in sleep-deprived and control animals was reduced not only by a 5-HT(1A) receptor antagonist but also by a 5-HT(1A) receptor agonist (8-OHDPAT). The results indicate that serotoninergic receptors in the spinal cord have a complex role in the control of sleep-deprivation induced cutaneous hypersensitivity as well as baseline sensitivity in control conditions. While endogenous serotonin acting on 5-HT(1A) and 5-HT(2C) receptors may facilitate mechanical sensitivity in animals with a sleep deprivation-induced hypersensitivity as well as in controls, increased activation of spinal 5-HT(1A) receptors by an exogenous agonist leads to suppression of mechanical sensitivity in both conditions. Spinal 5-HT(3) receptors do not contribute to cutaneous hypersensitivity induced by sleep deprivation.

  13. A Highly Efficient Neutron Veto Using Boron-Loaded Liquid Scintillator

    SciTech Connect

    Wright, A.; Mosteiro, P.; Loer, B.; Calaprice, F.

    2011-04-27

    By surrounding a dark matter detector with a layer of boron-loaded liquid scintillator, a highly efficient neutron veto can be produced. In Monte Carlo studies, a one meter thick layer of scintillator has a veto efficiency greater than 99.5% for nuclear recoil events induced by radiogenic neutrons, and a veto efficiency of more than 95% for nuclear recoil events produced by cosmogenic neutrons. The use of boron-loaded scintillator both reduces the veto-induced dead time by decreasing the neutron capture time and allows high neutron detection efficiency to be achieved in a relatively compact geometry.

  14. Neutronic reactor

    DOEpatents

    Carleton, John T.

    1977-01-25

    A graphite-moderated nuclear reactor includes channels between blocks of graphite and also includes spacer blocks between adjacent channeled blocks with an axis of extension normal to that of the axis of elongation of the channeled blocks to minimize changes in the physical properties of the graphite as a result of prolonged neutron bombardment.

  15. NEUTRONIC REACTORS

    DOEpatents

    Anderson, H.L.

    1958-10-01

    The design of control rods for nuclear reactors are described. In this design the control rod consists essentially of an elongated member constructed in part of a neutron absorbing material and having tube means extending therethrough for conducting a liquid to cool the rod when in use.

  16. NEUTRONIC REACTOR

    DOEpatents

    Wigner, E.P.

    1960-09-27

    A unit assembly is described for a neutronic reactor comprising a tube and plurality of spaced parallel sandwiches in the tube extending lengthwise thereof, each sandwich including a middle plate having a central opening for plutonium and other openings for fertile material at opposite ends of the plate.

  17. Classification of awake, REM, and NREM from EEG via singular spectrum analysis.

    PubMed

    Mohammadi, Sara Mahvash; Enshaeifar, Shirin; Ghavami, Mohammad; Sanei, Saeid

    2015-01-01

    In this study, a single-channel electroencephalography (EEG) analysis method has been proposed for automated 3-state-sleep classification to discriminate Awake, NREM (non-rapid eye movement) and REM (rapid eye movement). For this purpose, singular spectrum analysis (SSA) is applied to automatically extract four brain rhythms: delta, theta, alpha, and beta. These subbands are then used to generate the appropriate features for sleep classification using a multi class support vector machine (M-SVM). The proposed method provided 0.79 agreement between the manual and automatic scores.

  18. Instantaneous bit-error-rate meter

    NASA Astrophysics Data System (ADS)

    Slack, Robert A.

    1995-06-01

    An instantaneous bit error rate meter provides an instantaneous, real time reading of bit error rate for digital communications data. Bit error pulses are input into the meter and are first filtered in a buffer stage to provide input impedance matching and desensitization to pulse variations in amplitude, rise time and pulse width. The bit error pulses are transformed into trigger signals for a timing pulse generator. The timing pulse generator generates timing pulses for each transformed bit error pulse, and is calibrated to generate timing pulses having a preselected pulse width corresponding to the baud rate of the communications data. An integrator generates a voltage from the timing pulses that is representative of the bit error rate as a function of the data transmission rate. The integrated voltage is then displayed on a meter to indicate the bit error rate.

  19. Fuel metering and transfer control system

    SciTech Connect

    Mathieson, R.W.

    1980-10-14

    An auxiliary fuel metering and transfer control system for an internal combustion engine is described. The system consists essentially of a pressure vessel for storage of propane, methane, natural gas or a similar gaseous fuel, a pressure regulator for maintaining constant gaseous fuel pressure during operation of the system, a solenoid valve and a magnetic reset safety switch, a metering valve, a transfer valve and an auxiliary fuel nozzle positioned in the venturi of the carburetor on the engine using the system. The metering valve operates in response to changes in the intake manifold vacuum of the engine and changes in the air velocity in the carburetor of the engine. The transfer valve operates in response to movement of the throttle linkage on the carburetor of the engine. During operation of the engine, the system is substituted for both the idle circuit or system and the acceleration circuit or system of the carburetor.

  20. Methods for absorbing neutrons

    DOEpatents

    Guillen, Donna P.; Longhurst, Glen R.; Porter, Douglas L.; Parry, James R.

    2012-07-24

    A conduction cooled neutron absorber may include a metal matrix composite that comprises a metal having a thermal neutron cross-section of at least about 50 barns and a metal having a thermal conductivity of at least about 1 W/cmK. Apparatus for providing a neutron flux having a high fast-to-thermal neutron ratio may include a source of neutrons that produces fast neutrons and thermal neutrons. A neutron absorber positioned adjacent the neutron source absorbs at least some of the thermal neutrons so that a region adjacent the neutron absorber has a fast-to-thermal neutron ratio of at least about 15. A coolant in thermal contact with the neutron absorber removes heat from the neutron absorber.

  1. Recent Advances in Neutron Physics

    ERIC Educational Resources Information Center

    Feshbach, Herman; Sheldon, Eric

    1977-01-01

    Discusses new studies in neutron physics within the last decade, such as ultracold neutrons, neutron bottles, resonance behavior, subthreshold fission, doubly radiative capture, and neutron stars. (MLH)

  2. Fission foil measurements of neutron and proton fluences in the A0015 experiment

    NASA Technical Reports Server (NTRS)

    Frank, A. L.; Benton, E. V.; Armstrong, T. W.; Colborn, B. L.

    1995-01-01

    Results are given from sets of fission foil detectors (FFD's) (Ta-181, Bi-209, Th-232, U-238) which were included in the A0015 experiment to measure combined proton/neutron fluences. Use has been made of recent FFD high energy proton calibrations for improved accuracy of response. Comparisons of track density measurements have been made with the predictions of environmental modeling based on simple 1-D (slab) geometry. At 1 g/cm(exp 2) (trailing edge) the calculations were approximately 25 percent lower than measurements; at 13 g/cm(exp 2) (Earthside) calculations were more than a factor of 2 lower. A future 3-D modeling of the experiment is needed for a more meaningful comparison. Approximate mission proton doses and neutron dose equivalents were found. At Earthside (13 g/cm(exp 2) the dose was 171 rad and dose equivalent was 82 rem. At the trailing edge (1 g/cm(exp 2) dose was 315 rad and dose equivalent was 33 rem. The proton doses are less than expected from TLD doses by 16 percent and 37 percent, respectively. These differences can be explained by uncertainties in the proton and neutron spectra and in the method used to separate proton and neutron contributions to the measurements.

  3. Spatial and reversal learning in the Morris water maze are largely resistant to six hours of REM sleep deprivation following training.

    PubMed

    Walsh, Christine M; Booth, Victoria; Poe, Gina R

    2011-07-01

    This first test of the role of REM (rapid eye movement) sleep in reversal spatial learning is also the first attempt to replicate a much cited pair of papers reporting that REM sleep deprivation impairs the consolidation of initial spatial learning in the Morris water maze. We hypothesized that REM sleep deprivation following training would impair both hippocampus-dependent spatial learning and learning a new target location within a familiar environment: reversal learning. A 6-d protocol was divided into the initial spatial learning phase (3.5 d) immediately followed by the reversal phase (2.5 d). During the 6 h following four or 12 training trials/day of initial or reversal learning phases, REM sleep was eliminated and non-REM sleep left intact using the multiple inverted flowerpot method. Contrary to our hypotheses, REM sleep deprivation during four or 12 trials/day of initial spatial or reversal learning did not affect training performance. However, some probe trial measures indicated REM sleep-deprivation-associated impairment in initial spatial learning with four trials/day and enhancement of subsequent reversal learning. In naive animals, REM sleep deprivation during normal initial spatial learning was followed by a lack of preference for the subsequent reversal platform location during the probe. Our findings contradict reports that REM sleep is essential for spatial learning in the Morris water maze and newly reveal that short periods of REM sleep deprivation do not impair concurrent reversal learning. Effects on subsequent reversal learning are consistent with the idea that REM sleep serves the consolidation of incompletely learned items.

  4. The effects of 1 week of REM sleep deprivation on parvalbumin and calbindin immunoreactive neurons in central visual pathways of kittens.

    PubMed

    Hogan, D; Roffwarg, H P; Shaffery, J P

    2001-12-01

    Many maturational processes in the brain are at high levels prenatally as well as neonatally before eye-opening, when extrinsic sensory stimulation is limited. During these periods of rapid brain development, a large percentage of time is spent in rapid eye movement (REM) sleep, a state characterized by high levels of endogenously produced brain activity. The abundance of REM sleep in early life and its ensuing decline to lower levels in adulthood strongly suggest that REM sleep constitutes an integral part of the activity-dependent processes that enable normal physiological and structural brain development. We examined the effect of REM sleep deprivation during the critical period for visual development on the development of two calcium-binding proteins that are associated with developmental synaptic plasticity and are found in the lateral geniculate nucleus (LGN) and visual cortex. In this study, REM sleep deprivation was carried out utilizing a computer-controlled, cage-shaking apparatus that successfully suppressed REM sleep. Body weight data suggested that this method of REM sleep deprivation produced less stress than the classical multiple-platform-over-water method. In REM sleep-deprived animals with normal binocular vision, the number of parvalbumin-immunoreactive (PV) neurons in LGN was found to be lower compared with control animals but was not affected in visual cortex. The pattern of calbindin-immunoreactivity (CaB) was unchanged at either site after REM sleep deprivation. Parvalbumin-immunoreactivity develops later than calbindin-immunoreactivity in the LGN, and the REM sleep deprivation that we applied from postnatal day 42-49 delayed this essential step in the development of the kitten's visual system. These data suggest that in early postnatal brain development, REM sleep facilitates the usual time course of the expression of PV-immunoreactivity in LGN neurons.

  5. Activity-Dependent Subcellular Cotrafficking of the Small GTPase Rem2 and Ca2+/CaM-Dependent Protein Kinase IIα

    PubMed Central

    Flynn, Robyn; Labrie-Dion, Etienne; Bernier, Nikolas; Colicos, Michael A.; De Koninck, Paul; Zamponi, Gerald W.

    2012-01-01

    Background Rem2 is a small monomeric GTP-binding protein of the RGK family, whose known functions are modulation of calcium channel currents and alterations of cytoskeletal architecture. Rem2 is the only RGK protein found predominantly in the brain, where it has been linked to synaptic development. We wished to determine the effect of neuronal activity on the subcellular distribution of Rem2 and its interacting partners. Results We show that Rem2 undergoes activity-and N-Methyl-D-Aspartate Receptor (NMDAR)-dependent translocation in rat hippocampal neurons. This redistribution of Rem2, from a diffuse pattern to one that is highly punctate, is dependent on Ca2+ influx, on binding to calmodulin (CaM), and also involves an auto-inhibitory domain within the Rem2 distal C-terminus region. We found that Rem2 can bind to Ca2+/CaM-dependent protein kinase IIα (CaMKII) a in Ca2+/CaM-dependent manner. Furthermore, our data reveal a spatial and temporal correlation between NMDAR-dependent clustering of Rem2 and CaMKII in neurons, indicating co-assembly and co-trafficking in neurons. Finally, we show that inhibiting CaMKII aggregation in neurons and HEK cells reduces Rem2 clustering, and that Rem2 affects the baseline distribution of CaMKII in HEK cells. Conclusions Our data suggest a novel function for Rem2 in co-trafficking with CaMKII, and thus potentially expose a role in neuronal plasticity. PMID:22815963

  6. Neutron reflecting supermirror structure

    DOEpatents

    Wood, J.L.

    1992-12-01

    An improved neutron reflecting supermirror structure comprising a plurality of stacked sets of bilayers of neutron reflecting materials. The improved neutron reflecting supermirror structure is adapted to provide extremely good performance at high incidence angles, i.e. up to four time the critical angle of standard neutron mirror structures. The reflection of neutrons striking the supermirror structure at a high critical angle provides enhanced neutron throughput, and hence more efficient and economical use of neutron sources. 2 figs.

  7. Neutron reflecting supermirror structure

    DOEpatents

    Wood, James L.

    1992-01-01

    An improved neutron reflecting supermirror structure comprising a plurality of stacked sets of bilayers of neutron reflecting materials. The improved neutron reflecting supermirror structure is adapted to provide extremely good performance at high incidence angles, i.e. up to four time the critical angle of standard neutron mirror structures. The reflection of neutrons striking the supermirror structure at a high critical angle provides enhanced neutron throughput, and hence more efficient and economical use of neutron sources.

  8. 8-Meter UV/Optical Space Telescope

    NASA Technical Reports Server (NTRS)

    Stahl, H. Philip

    2008-01-01

    This slide presentation proposes using the unprecedented capability of the planned Ares V launch vehicle, to place a 8 meter monolithic space telescope at the Earth-Sun L2 point. This new capability enables a new design pardigm -- simplicity. The six to eight meter class telescope with a massive high Technical Readiness Level ground observatory class monolithic primary mirror has been determined feasible. The proposed design, structural analysis, spacecraft design and shroud integration, thermal analysis, propulsion system, guidance navigation and pointing control assumptions about the avionics, and power systems, operational lifetime, and the idea of in-space servicing are reviewed.

  9. Liquid metal Flow Meter - Final Report

    SciTech Connect

    Andersen, C.; Hoogendoom, S.; Hudson, B.; Prince, J.; Teichert, K.; Wood, J.; Chase, K.

    2007-01-30

    Measuring the flow of liquid metal presents serious challenges. Current commercially-available flow meters use ultrasonic, electromagnetic, and other technologies to measure flow, but are inadequate for liquid metal flow measurement because of the high temperatures required by most liquid metals. As a result of the reactivity and high temperatures of most liquid metals, corrosion and leakage become very serious safety concerns. The purpose of this project is to develop a flow meter for Lockheed Martin that measures the flow rate of molten metal in a conduit.

  10. The Thirty Meter Telescope (TMT) Project

    NASA Astrophysics Data System (ADS)

    Sanders, G.; TMT Project

    2004-12-01

    The Thirty Meter Telescope (TMT) Project is engaged in a design and development phase. TMT is proposed as a private-public partnership of the California Institute of Technology and the University of California (partners in the earlier CELT design study), AURA (designers of the earlier GSMT concept), and the Canadian ACURA consortium (designers of the VLOT concept). The partners are developing a 30 meter diameter, finely segmented filled aperture telescope with seeing-limited and diffraction-limited capabilities to address the broad range of GSMT science goals. The paper will present the status of the project development and telescope and instrument design.

  11. 49 CFR 192.359 - Customer meter installations: Operating pressure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Customer meter installations: Operating pressure... Meters, Service Regulators, and Service Lines § 192.359 Customer meter installations: Operating pressure. (a) A meter may not be used at a pressure that is more than 67 percent of the manufacturer's...

  12. 40 CFR 1065.225 - Intake-air flow meter.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... flow meter. (a) Application. You may use an intake-air flow meter in combination with a chemical..., you may use an intake-air flow meter signal that does not give the actual value of raw exhaust, as... requirements. We recommend that you use an intake-air flow meter that meets the specifications in Table 1...

  13. 49 CFR 192.357 - Customer meters and regulators: Installation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Customer meters and regulators: Installation. 192... Meters, Service Regulators, and Service Lines § 192.357 Customer meters and regulators: Installation. (a) Each meter and each regulator must be installed so as to minimize anticipated stresses upon...

  14. 49 CFR 192.357 - Customer meters and regulators: Installation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Customer meters and regulators: Installation. 192... Meters, Service Regulators, and Service Lines § 192.357 Customer meters and regulators: Installation. (a) Each meter and each regulator must be installed so as to minimize anticipated stresses upon...

  15. 49 CFR 192.359 - Customer meter installations: Operating pressure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Customer meter installations: Operating pressure... Meters, Service Regulators, and Service Lines § 192.359 Customer meter installations: Operating pressure. (a) A meter may not be used at a pressure that is more than 67 percent of the manufacturer's...

  16. 49 CFR 192.353 - Customer meters and regulators: Location.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Customer meters and regulators: Location. 192.353... TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Customer Meters, Service Regulators, and Service Lines § 192.353 Customer meters and regulators: Location. (a) Each meter and...

  17. 49 CFR 192.353 - Customer meters and regulators: Location.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Customer meters and regulators: Location. 192.353... TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Customer Meters, Service Regulators, and Service Lines § 192.353 Customer meters and regulators: Location. (a) Each meter and...

  18. 49 CFR 192.357 - Customer meters and regulators: Installation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Customer meters and regulators: Installation. 192... Meters, Service Regulators, and Service Lines § 192.357 Customer meters and regulators: Installation. (a) Each meter and each regulator must be installed so as to minimize anticipated stresses upon...

  19. 49 CFR 192.359 - Customer meter installations: Operating pressure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Customer meter installations: Operating pressure... Meters, Service Regulators, and Service Lines § 192.359 Customer meter installations: Operating pressure. (a) A meter may not be used at a pressure that is more than 67 percent of the manufacturer's...

  20. 49 CFR 192.353 - Customer meters and regulators: Location.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Customer meters and regulators: Location. 192.353... TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Customer Meters, Service Regulators, and Service Lines § 192.353 Customer meters and regulators: Location. (a) Each meter and...