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Sample records for observation period suggesting

  1. Some Suggestions for Writing up Asteroid Lightcurve Observations for Publication

    NASA Astrophysics Data System (ADS)

    Harris, A. W.

    2005-05-01

    Over the years I have spent many hours re-constructing photometric observa- tions from published works that would have been much easier if the authors had provided full and accurate details of the observations being reported. In this paper I will present the essential elements of reporting that render the photometric observations reported most useful and convenient for future analysis. The underlying principle to keep in mind is that the composite lightcurve you construct may not be right, or may not serve the purposes of some future research project, such that someone may need to recover your original observations as a time series rather than just the composite lightcurve presented. Other ancillary information should be provided to assist in using the data in combination with observations at other times, e.g. the aspect data (sky position, phase angle, light time correction if applied, etc.), and the color band and magnitude scale information. In a composite lightcurve figure, vertical (magnitude) offsets applied night to night should be indicated (in the figure or in a data table), days of obser- vation should be plotted with different symbols and identified, and if cov- erage on a single night exceeds the rotation period such that the time series is "wrapped", it should be possible to determine the actual time of obser- vation of each datum. In constructing a composite, it is essential that the period used to fold the data be the exact value stated so that the exact observation times can be reconstructed from the composite. Ideally, all data presented should also be made available in electronic form in a public archive (this will be a topic of considerable discussion at the meeting). Another essential feature is to reference and critically evaluate any pre- vious lightcurves of an object that can be found in the literature. In addi- tion to checking for consistency of results and possibly incorporating other observations in the analysis, the task of reconstructing observations from ancient publications will serve by example (good or bad) the importance of unambiguous presentation of results, and what is required to achieve that. At the risk of committing a blunder myself, I will illustrate my presentation with an example of an "ideal publication" of a lightcurve result, done in the style of the Minor Planet Bulletin.

  2. Spitzer Observations Suggest a Low Kepler False Postive Rate.

    NASA Astrophysics Data System (ADS)

    Desert, Jean-Michel; Charbonneau, D.; Fressin, F.; Ballard, S.; Kepler Team

    2011-09-01

    I present the results from a large project that uses 800 hours of the Spitzer Space Telescope to gather near-infrared photometric measurements of Kepler Object of Interest (KOI). The project's main purposes are to validate the planetary status of the Kepler candidates and to estimate observationally the Kepler false positive rate. A small amount of this telescope time is also dedicated to study the atmospheres of confirmed planets. I revue the project and introduce our target sample which is composed of 34 candidates selected amongst the first 400 KOIs. This list contains mainly sub-Neptune sizes candidates orbiting a wide range of spectral type stars. I present the analysis of the complete sample. By comparing the transit light curves of candidates observed with Kepler and Spitzer, we can exclude significant sources of astrophysical false positives resulting from blends (eclipsing binaries, hierarchical triples, etc...) that can mimic an exoplanetary signature in the Kepler bandpass. I show that our measured Spitzer transit depths are almost entirely in agreement with the Kepler depths. Our results suggest that the Kepler false positive rate is extremely low.

  3. OBSERVED POLARIZATION OF BROWN DWARFS SUGGESTS LOW SURFACE GRAVITY

    SciTech Connect

    Sengupta, Sujan; Marley, Mark S. E-mail: Mark.S.Marley@NASA.go

    2010-10-20

    Light scattering by atmospheric dust particles is responsible for the polarization observed in some L dwarfs. Whether this polarization arises from an inhomogeneous distribution of dust across the disk or an oblate shape induced by rotation remains unclear. Here, we argue that the latter case is plausible and, for many L dwarfs, the more likely one. Furthermore, evolutionary models of mature field L dwarfs predict surface gravities ranging from about 200 to 2500 m s{sup -2} (corresponding to masses of {approx}15-70 M {sub Jupiter}). Yet comparison of observed spectra to available synthetic spectra often does not permit more precise determination of the surface gravity of individual field L dwarfs, leading to important uncertainties in their properties. Since rotationally induced non-sphericity, which gives rise to non-zero disk-integrated polarization, is more pronounced at lower gravities, polarization is a promising low gravity indicator. Here, we combine a rigorous multiple scattering analysis with a self-consistent cloudy atmospheric model and observationally inferred rotational velocities and find that the observed optical polarization can be explained if the surface gravity of the polarized objects is about 300 m s{sup -2} or less, potentially providing a new method for constraining L dwarf masses.

  4. Periodic Properties and Inquiry: Student Mental Models Observed during a Periodic Table Puzzle Activity

    ERIC Educational Resources Information Center

    Larson, Kathleen G.; Long, George R.; Briggs, Michael W.

    2012-01-01

    The mental models of both novice and advanced chemistry students were observed while the students performed a periodic table activity. The mental model framework seems to be an effective way of analyzing student behavior during learning activities. The analysis suggests that students do not recognize periodic trends through the examination of…

  5. Periodic Properties and Inquiry: Student Mental Models Observed during a Periodic Table Puzzle Activity

    ERIC Educational Resources Information Center

    Larson, Kathleen G.; Long, George R.; Briggs, Michael W.

    2012-01-01

    The mental models of both novice and advanced chemistry students were observed while the students performed a periodic table activity. The mental model framework seems to be an effective way of analyzing student behavior during learning activities. The analysis suggests that students do not recognize periodic trends through the examination of

  6. Multispacecraft observations of quasi-periodic emissions

    NASA Astrophysics Data System (ADS)

    Nemec, Frantisek; Picket, Jolene S.; Santolik, Ondrej

    2014-05-01

    Quasi-periodic (QP) emissions are VLF electromagnetic waves in the frequency range of about 0.5-5 kHz which exhibit a periodic time modulation of the wave intensity. The modulation period is usually on the order of a few tens of seconds. The generation mechanism of these emissions is still not understood, but at least in some cases it appears to be related to ULF magnetic field pulsations which result in periodic modifications of the resonant conditions in the source region. We use multipoint measurements of QP emissions by the 4 Cluster spacecraft. The observations are obtained close to the equatorial region at radial distances of about 4 Earth radii, i.e. close to a possible generation region. A combined analysis of the high resolution data obtained by the WBD instruments and the ULF magnetic field data obtained by the FGM instruments allows for a detailed case-study analysis of these unique emissions. The presented analysis benefits from the recent close-separation configuration of three of the Cluster spacecraft (?20-100 km) and a related timing analysis, which would be impossible otherwise.

  7. Earth and Mars observation using periodic orbits

    NASA Astrophysics Data System (ADS)

    Ortore, E.; Circi, C.; Bunkheila, F.; Ulivieri, C.

    2012-01-01

    This paper reports the results of a general study carried out on the Periodic Multi-SunSynchronous Orbits (PMSSOs), which the classical Periodic SunSynchronous Orbits (PSSOs) represent a specific solution of. Such orbits allow to obtain cycles of observation of the same region in which the solar illumination regularly varies according to the value of the orbit elements and comes back to the initial condition after a time interval which is multiple of the revisit time. Therefore this kind of orbits meets all the remote sensing applications that need observations of the same area at different local times (for example the reconstruction of the day-nighttime trend of the surface temperature of the planet) and it is particularly suitable to the study of several terrestrial and martian phenomena (diurnal cycle of the hazes and clouds, dynamics of the thermal tides, density variations, meteorology phenomena, etc.). The design of PMSSO is based on the variation of the Right Ascension of the Ascending Node due to the Earth oblateness (referred as basic solution). However, with respect to the basic solution, the analysis of the perturbative effects has demonstrated the need, especially in the case of Mars, to take into account all the superior harmonics of the gravitational field. To this end a corrective factor, to add to the basic equations, has been proposed, allowing a significant saving of propellant (of the order of 2 km/s per year). Besides, single and multi-plane satellite constellations have been taken into account in order to improve the repetition of observation and the ground spatial resolution.

  8. Lengthened Cutaneous Silent Period in Fibromyalgia Suggesting Central Sensitization as a Pathogenesis.

    PubMed

    Baek, Seol-Hee; Seok, Hung Youl; Koo, Yong Seo; Kim, Byung-Jo

    2016-01-01

    The pathogenesis of fibromyalgia (FM) has not been clearly elucidated, but central sensitization, which plays an important role in the development of neuropathic pain, is considered to be the main mechanism. The cutaneous silent period (CSP), which is a spinal reflex mediated by A-delta cutaneous afferents, is useful for the evaluation of sensorimotor integration at the spinal and supraspinal levels. To understand the pathophysiology of FM, we compared CSP patterns between patients with FM and normal healthy subjects. Twenty-four patients with FM diagnosed in accordance with the 1990 American College of Rheumatology classification system and 24 age- and sex-matched healthy volunteers were recruited. The CSP was measured from the abductor pollicis brevis muscle. Demographic data, number of tender points, and visual analog scale and FM impact questionnaire scores were collected. The measured CSP and clinical parameters of the patient and control groups were compared. In addition, possible correlations between the CSP parameters and the other clinical characteristics were analyzed. Mean CSP latencies did not differ between patients (55.50 ± 10.97 ms) and healthy controls (60.23 ± 11.87 ms; p = 0.158), although the mean CSP duration was significantly longer in patients (73.75 ± 15.67 ms) than in controls (63.50 ± 14.05 ms; p = 0.021). CSP variables did not correlate with any clinical variables. The significantly longer CSP duration in FM patients suggests central dysregulation at the spinal and supraspinal levels, rather than peripheral small fiber dysfunction. PMID:26871583

  9. Lengthened Cutaneous Silent Period in Fibromyalgia Suggesting Central Sensitization as a Pathogenesis

    PubMed Central

    Koo, Yong Seo; Kim, Byung-Jo

    2016-01-01

    The pathogenesis of fibromyalgia (FM) has not been clearly elucidated, but central sensitization, which plays an important role in the development of neuropathic pain, is considered to be the main mechanism. The cutaneous silent period (CSP), which is a spinal reflex mediated by A-delta cutaneous afferents, is useful for the evaluation of sensorimotor integration at the spinal and supraspinal levels. To understand the pathophysiology of FM, we compared CSP patterns between patients with FM and normal healthy subjects. Twenty-four patients with FM diagnosed in accordance with the 1990 American College of Rheumatology classification system and 24 age- and sex-matched healthy volunteers were recruited. The CSP was measured from the abductor pollicis brevis muscle. Demographic data, number of tender points, and visual analog scale and FM impact questionnaire scores were collected. The measured CSP and clinical parameters of the patient and control groups were compared. In addition, possible correlations between the CSP parameters and the other clinical characteristics were analyzed. Mean CSP latencies did not differ between patients (55.50 ± 10.97 ms) and healthy controls (60.23 ± 11.87 ms; p = 0.158), although the mean CSP duration was significantly longer in patients (73.75 ± 15.67 ms) than in controls (63.50 ± 14.05 ms; p = 0.021). CSP variables did not correlate with any clinical variables. The significantly longer CSP duration in FM patients suggests central dysregulation at the spinal and supraspinal levels, rather than peripheral small fiber dysfunction. PMID:26871583

  10. Urbana Meteor Radar observations during GRMWSP/CTOP periods

    NASA Technical Reports Server (NTRS)

    Hess, G. C.; Geller, M. A.

    1978-01-01

    Observations with the Urbana Meteor Radar during three GRMWSP/CTOP observational periods are presented. These data were collected at Urbana during the periods 12-13 August 1974, 13-17 October 1975 and 14-23 January 1976. The height-averaged wind is presented for the August period. Determinations of prevailing wind and tidal variability are made during the October period. Tidal determinations and an observed temporary dominance by short period dynamics are presented for the January period. More data supporting our earlier result of a significant correlation between equatorward flow and d-region ionization during winter are shown.

  11. Cumulative dose on fractional delivery of tomotherapy to periodically moving organ: A phantom QA suggestion

    SciTech Connect

    Shin, Eunhyuk; Han, Youngyih; Park, Hee-Chul; Sung Kim, Jin; Hwan Ahn, Sung; Suk Shin, Jung; Gyu Ju, Sang; Ho Choi, Doo; Lee, Jaiki

    2013-01-01

    This study was conducted to evaluate the cumulative dosimetric error that occurs in both target and surrounding normal tissues when treating a moving target in multifractional treatment with tomotherapy. An experiment was devised to measure cumulative error in multifractional treatments delivered to a horseshoe-shaped clinical target volume (CTV) surrounding a cylinder shape of organ at risk (OAR). Treatments differed in jaw size (1.05 vs 2.5 cm), pitch (0.287 vs 0.660), and modulation factor (1.5 vs 2.5), and tumor motion characteristics differing in amplitude (1 to 3 cm), period (3 to 5 second), and regularity (sinusoidal vs irregular) were tested. Treatment plans were delivered to a moving phantom up to 5-times exposure. Dose distribution on central coronal plane from 1 to 5 times exposure was measured with GAFCHROMIC EBT film. Dose differences occurring across 1 to 5 times exposure of treatment and between treatment plans were evaluated by analyzing measurements of gamma index, gamma index histogram, histogram changes, and dose at the center of the OAR. The experiment showed dose distortion due to organ motion increased between multiexposure 1 to 3 times but plateaued and remained constant after 3-times exposure. In addition, although larger motion amplitude and a longer period of motion both increased dosimetric error, the dose at the OAR was more significantly affected by motion amplitude rather than motion period. Irregularity of motion did not contribute significantly to dosimetric error when compared with other motion parameters. Restriction of organ motion to have small amplitude and short motion period together with larger jaw size and small modulation factor (with small pitch) is effective in reducing dosimetric error. Pretreatment measurements for 3-times exposure of treatment to a moving phantom with patient-specific tumor motion would provide a good estimation of the delivered dose distribution.

  12. CCD observations and period determination of fifteen minor planets

    NASA Astrophysics Data System (ADS)

    Ivarsen, Kevin; Willis, Sarah; Ingleby, Laura; Matthews, Dan; Simet, Melanie

    2004-06-01

    We have determined the periods of fifteen minor planets using differential photometry. Eleven of these minor planets had unknown periods, one had an uncertain period, and three had well-known periods. We observed a minimum of two epochs for each object in order to construct composite lightcurves. The periods ranged from 3.7 to 15.2 hours. The objects we report results for are: 174 Phaedra, 228 Agathe, 342 Endymion, 354 Eleonora, 365 Corduba, 373 Melusina, 575 Renate, 1084 Tamariwa, 1171 Rusthawelia, 1388 Aphrodite, 1501 Baade, 1544 Vinterhanseni, 1645 Waterfield, 1799 Koussevitzky, and 2097 Galle.

  13. SDO/AIA observations of periodic and quasi-periodic phenomenon associated with an EUV jet

    NASA Astrophysics Data System (ADS)

    Morton, Richard; Verth, Gary; Erdelyi, Robertus; Srivastava, Abhi

    2013-04-01

    It has long been advocated that explosive magnetic activity is responsible for the mass-balance in the solar atmosphere, supplying the corona and the solar wind with heated plasma. The explosive events are thought to be the result of emerging bi-polar (EB) regions reconnecting with pre-existing, open fields, with the size of the EB's (i.e., granular, super-granular) being related to size of the resulting feature (i.e., spicules, EUV/X-ray jets). Recent evidence has suggested a deeper relationship between spicules and EUV jets (Sterling et al., 2010). We present here observations of a EUV jet observed with SDO/AIA close to a southern coronal hole. The jet can be considered as a 'Blowout jet' (using the terminology of Moore et al., 2010), launching vast amounts of chromospheric plasma into the atmosphere along with hotter material. The hotter part of the jet appears to be composed of multiple, (quasi-)periodic ejections that individually resemble fast moving (>100 km/s) spicules. The multiple ejections appear crucial for distributing the hotter material high into the corona, possibly suggesting that larger EUV/X-ray are composed of many smaller spicule-like events. Although the event is close to the limb, evidence for reconnection at the chromospheric level is provided. Further, evidence for helicity (or torsional motion) and the presence of slow and fast Magnetohydrodynamic waves is given, with the wave mode excitation likely due to the reconnection process. Exploiting the observed wave motion, we also use magneto-seismological techniques to determine local plasma parameters with sub-resolution accuracy along one of the jets unique features.

  14. Optimizing observing sequence design for periodic and non-periodic phenomena : a Bayesian approach

    NASA Technical Reports Server (NTRS)

    Johnston, Mark D.; Knight, Russell

    2005-01-01

    In this paper we report on our progress on addressing these issues. We have developed an approximate expression for the uniformity of phase coverage that can be used when scheduling to assess candidate sample times. We describe the results obtained using this estimator, and compare them with detailed simulations. We describe our progress and plans for integrating optimizing criteria for both periodic and non-periodic observations into a single observation sequence.

  15. Long-term polarization observations of Mira variable stars suggest asymmetric structures

    NASA Astrophysics Data System (ADS)

    Neilson, Hilding R.; Ignace, Richard; Henson, Gary D.

    2014-02-01

    Mira and semi-regular variable stars have been studied for centuries but continue to be enigmatic. One unsolved mystery is the presence of polarization from these stars. In particular, we present 40 years of polarization measurements for the prototype o Ceti and V CVn and find very different phenomena for each star. The polarization fraction and position angle for Mira is found to be small and highly variable. On the other hand, the polarization fraction for V CVn is large and variable, from 2-7%, and its position angle is approximately constant, suggesting a long-term asymmetric structure. We suggest a number of potential scenarios to explain these observations.

  16. Phylogeny and oscillating expression of period and cryptochrome in short and long photoperiods suggest a conserved function in Nasonia vitripennis

    PubMed Central

    van de Zande, Louis; Beukeboom, Leo W.; Beersma, Domien G. M.

    2014-01-01

    Photoperiodism, the ability to respond to seasonal varying day length with suitable life history changes, is a common trait in organisms that live in temperate regions. In most studied organisms, the circadian system appears to be the basis for photoperiodic time measurement. In insects this is still controversial: while some data indicate that the circadian system is causally involved in photoperiodism, others suggest that it may have a marginal or indirect role. Resonance experiments in the parasitic wasp Nasonia vitripennis have revealed a circadian component in photoperiodic time measurement compatible with a mechanism of internal coincidence where a two components oscillator system obtains information from dawn and dusk, respectively. The identity of this oscillator (or oscillators) is still unclear but possible candidates are the oscillating molecules of the auto-regulatory feedback loops in the heart of the circadian system. Here, we show for the first time the circadian oscillation of period and cryptochrome mRNAs in the heads of Nasonia females kept under short and long photoperiods. Period and cryptochrome mRNA levels display a synchronous oscillation in all conditions tested and persist, albeit with reduced amplitude, during the first day in constant light as well as constant darkness. More importantly, the signal for the period and cryptochrome oscillations is set by the light-on signal. These results, together with phylogenetic analyses, indicate that Nasonia’s period and cryptochrome display characteristics of homologous genes in other hymenopteran species. PMID:24758403

  17. The Search for Periodic Components in Observational Data

    NASA Astrophysics Data System (ADS)

    Baluev, R. V.

    2014-09-01

    This review is devoted to the problem of searching for periodicities in observational data using periodograms based on the general statistical likelihood ratio test and special variants of it, including the classical Lomb-Scargle periodogram. Primary emphasis is on the problem of estimating the statistical significance of the periodicities detected in this manner. We assume that a universal solution of this problem exists involving an effective method in which the periodogram is regarded as a random process (or random field), while an approximation for the required "false alarm probability" is constructed by a generalized Rice method. Besides a unified method for determining the expected noise levels (or significance levels) of these periodograms, we also examine some important special cases with different models of periodic signals (linear and nonlinear). The false alarm probability associated with an observed signal is approximated in most cases by a formula of the type , where z is the observed maximum readout in the periodogram and P is an algebraic polynomial with coefficients that depend on the conditions of the problem. We also examine the problem of separating composite signals with several frequencies from noise. In this case correct analysis of the data requires the use of so-called multifrequency periodograms based on models of signals containing several periodic components. We show that a complete solution to this problem requires construction of 2n-1 such periodograms, where n is the total number of possible frequencies. Finally, we describe some program packages that we have developed which make it easier to perform practical frequency analysis of series using this theory.

  18. 313 new asteroid rotation periods from Palomar Transient Factory observations

    SciTech Connect

    Chang, Chan-Kao; Ip, Wing-Huen; Lin, Hsing-Wen; Cheng, Yu-Chi; Ngeow, Chow-Choong; Yang, Ting-Chang; Waszczak, Adam; Kulkarni, Shrinivas R.; Levitan, David; Sesar, Branimir; Prince, Thomas A.; Laher, Russ; Surace, Jason

    2014-06-10

    A new asteroid rotation period survey has been carried out by using the Palomar Transient Factory (PTF). Twelve consecutive PTF fields, which covered an area of 87 deg{sup 2} in the ecliptic plane, were observed in the R band with a cadence of ∼20 minutes during 2013 February 15-18. We detected 2500 known asteroids with a diameter range of 0.5 km ≤D ≤ 200 km. Of these, 313 objects had highly reliable rotation periods and exhibited the 'spin barrier' at ∼2 hr. In contrast to the flat spin-rate distribution of the asteroids with 3 km ≤D ≤ 15 km shown by Pravec et al., our results deviated somewhat from a Maxwellian distribution and showed a decrease at the spin rate greater than 5 rev day{sup –1}. One superfast rotator candidate and two possible binary asteroids were also found in this work.

  19. The Changing Surface of Saturn's Titan: Cassini Observations Suggest Active Cryovolcanism

    NASA Astrophysics Data System (ADS)

    Nelson, R. M.

    2008-12-01

    R. M. Nelson(1), L. Kamp(1), R. M. C. Lopes(1), D. L. Matson(1), S. D. Wall(1), R. L. Kirk(2), K. L Mitchell(1), G. Mitri(1), B. W. Hapke(3), M. D. Boryta(4), F. E. Leader(1) , W. D. Smythe(1), K. H. Baines(1), R. Jauman(5), C. Sotin(1), R. N. Clark(6), D. P. Cruikshank(7) , P. Drossart(9), B. J. Buratti(1) , J.Lunine(8), M. Combes(9), G. Bellucci(10), J.-P. Bibring(11), F. Capaccioni(10), P. Cerroni(10), A. Coradini(10), V. Formisano(10), G Filacchione(10), R. Y. Langevin(11), T. B. McCord(12), V. Mennella(13), P. D. Nicholson(14) , B. Sicardy(8) 1-JPL, 4800 Oak Grove Drive, Pasadena CA 91109, 2-USGS, Flagstaff, 3-U Pittsburgh, 4-Mt. Sac Col, 5- DLR, Berlin, 6-USGS Denver, 7-NASA AMES, 8-U Paris-Meudon, 9-Obs de Paris, 10-ISFI-CNR Rome, 11-U Paris -Sud. Orsay, 12-Bear Flt Cntr Winthrop WA, 13-Obs Capodimonte Naples, 14-Cornell U. Several Instruments on the Cassini Saturn Orbiter have been observing the surface of Saturn's moon Titan since mid 2004. The Visual and Infrared Mapping Spectrometer (VIMS) reports that regions near 26oS, 78oW (region 1) and 7oS, 138oW (region 2) exhibit photometric changes consistent with on-going surface activity. These regions are photometrically variable with time(1). Cassini Synthetic Aperture Rader (SAR) has investigated these regions and reports that both of these regions exhibit morphologies consistent with cryovolcanism (2). VIMS observed region 1 eight times and reported that on two occasions the region brightened two-fold and then decreased again on timescales of several weeks. Region 2 was observed on four occasions (Tb-Dec13/2004 ,T8-Oct27/2005, T10-Jan15/2006, T12-Mar18/2006) and exhibited a pronounced change in I/F betweenT8 and T10. Our photometric analysis finds that both regions do not exhibit photometric properties consistent with atmospheric phenomena such as tropospheric clouds. These changes must be at or very near the surface. Radar images of these regions reveal morphology that is consistent with cryovolcanoes. We conclude that the VIMS instrument has found two instances in which selected regions on Titan's surface became unusually reflective and remained reflective on time scales of days to months. In both cases the area of reflectance variability is large (~100000 sq km), larger than either Loki or the Big Island of Hawaii. This is a strong evidence for currently active surface processes on Titan. Pre-Cassini, Titan was thought of as a pre-biotic earth that was frozen in time. Cassini VIMS and SAR observations combined suggest that Titan is the present day is not frozen solid, and is instead an episodically changing or evolving world. References: [1] Nelson R. M. et al, LPSC 2007 , Europlanets 2007, AGU 2007, EGU 2008, Accepted in Icarus 2008. [2] Lopes et al (this meeting), Stofan et al. Icarus 185, 443-456, 2007. Lopes et al. Icarus 186, 395- 412, 2007. Kirk et al., DPS 2007. Acknowledgement: This work done at JPL under contract with NASA

  20. Countergradient heat flux observations during the evening transition period

    NASA Astrophysics Data System (ADS)

    Blay-Carreras, E.; Pardyjak, E. R.; Pino, D.; Alexander, D. C.; Lohou, F.; Lothon, M.

    2014-09-01

    Gradient-based turbulence models generally assume that the buoyancy flux ceases to introduce heat into the surface layer of the atmospheric boundary layer in temporal consonance with the gradient of the local virtual potential temperature. Here, we hypothesize that during the evening transition a delay exists between the instant when the buoyancy flux goes to zero and the time when the local gradient of the virtual potential temperature indicates a sign change. This phenomenon is studied using a range of data collected over several intensive observational periods (IOPs) during the Boundary Layer Late Afternoon and Sunset Turbulence field campaign conducted in Lannemezan, France. The focus is mainly on the lower part of the surface layer using a tower instrumented with high-speed temperature and velocity sensors. The results from this work confirm and quantify a flux-gradient delay. Specifically, the observed values of the delay are ~ 30-80 min. The existence of the delay and its duration can be explained by considering the convective timescale and the competition of forces associated with the classical Rayleigh-Bnard problem. This combined theory predicts that the last eddy formed while the sensible heat flux changes sign during the evening transition should produce a delay. It appears that this last eddy is decelerated through the action of turbulent momentum and thermal diffusivities, and that the delay is related to the convective turnover timescale. Observations indicate that as horizontal shear becomes more important, the delay time apparently increases to values greater than the convective turnover timescale.

  1. Countergradient heat flux observations during the evening transition period

    NASA Astrophysics Data System (ADS)

    Blay-Carreras, E.; Pardyjak, E. R.; Pino, D.; Alexander, D. C.; Lohou, F.; Lothon, M.

    2014-03-01

    Gradient-based turbulence models generally assume that the buoyancy flux ceases to introduce heat into the surface layer of the atmospheric boundary layer in temporal consonance with the gradient of the local virtual potential temperature. Here, we hypothesize that during the evening transition a delay exists between the instant when the buoyancy flux goes to zero and the time when the local gradient of the virtual potential temperature indicates a sign change. This phenomenon is studied using a range of data collected over several Intensive Observational Periods (IOPs) during the Boundary Layer Late Afternoon and Sunset Turbulence field campaign conducted in Lannemezan, France. The focus is mainly on the lower part of the surface layer using a tower instrumented with high-speed temperature and velocity sensors. The results from this work confirm and quantify a flux-gradient delay. Specifically, the observed values of the delay are ~30-80 min. The existence of the delay and its duration can be explained by considering the convective time scale and the competition of forces associated with the classical Rayleigh-Bnard problem. This combined theory predicts that the last eddy formed while the sensible heat flux changes sign during the evening transition should produce a delay. It appears that this last eddy is decelerated through the action of turbulent momentum and thermal diffusivities, and that the delay is related to the convective turn - over time - scale. Observations indicate that as horizontal shear becomes more important, the delay time apparently increases to values greater than the convective turnover time-scale.

  2. HF radar observations of ionospheric backscatter during geomagnetically quiet periods

    NASA Astrophysics Data System (ADS)

    Kane, T. A.; Makarevich, R. A.; Devlin, J. C.

    2012-01-01

    The quiet-time coherent backscatter from the F-region observed by the Tasman International Geospace Environment Radar (TIGER) Bruny Island HF radar is analysed statistically in order to determine typical trends and controlling factors in the ionospheric echo occurrence. A comparison of the F-region peak density values from the IRI-2007 model and ionosonde measurements in the vicinity of the radar's footprint shows a very good agreement, particularly at subauroral and auroral latitudes, and model densities within the radar's footprint are used in the following analyses. The occurrence of F-region backscatter is shown to exhibit distinct diurnal, seasonal and solar cycle variations and these are compared with model trends in the F-region peak electron density and Pedersen conductance of the underlying ionosphere. The solar cycle effects in occurrence are demonstrated to be strong and more complex than a simple proportionality on a year-to-year basis. The diurnal and seasonal effects are strongly coupled to each other, with diurnal trends exhibiting a systematic gradual variation from month to month that can be explained when both electron density and conductance trends are considered. During the night, the echo occurrence is suggested to be controlled directly by the density conditions, with a direct proportionality observed between the occurrence and peak electron density. During the day, the echo occurrence appears to be controlled by both conductance and propagation conditions. It is shown that the range of echo occurrence values is smaller for larger conductances and that the electron density determines what value the echo occurrence takes in that range. These results suggest that the irregularity production rates are significantly reduced by the highly conducting E layer during the day while F-region density effects dominate during the night.

  3. Are Dietary Restraint Scales Valid Measures of Acute Dietary Restriction? Unobtrusive Observational Data Suggest Not

    ERIC Educational Resources Information Center

    Stice, Eric; Fisher, Melissa; Lowe, Michael R.

    2004-01-01

    The finding that dietary restraint scales predict onset of bulimic pathology has been interpreted as suggesting that dieting causes this eating disturbance, despite the dearth of evidence that these scales are valid measures of dietary restriction. The authors conducted 4 studies that tested whether dietary restraint scales were inversely…

  4. The Prosaics of Figurative Language in Preschool: Some Observations and Suggestions for Research

    ERIC Educational Resources Information Center

    Pramling, Niklas; Samuelsson, Ingrid Pramling

    2007-01-01

    In a significant work, "Metaphor in educational discourse", Cameron has suggested that we study metaphor as "prosaics" (i.e. as a feature of mundane talk). In this paper, by means of some brief examples, we point to instances of such talk in the setting of preschool. We also discuss opportunities for learning that such talk could offer children,

  5. The Prosaics of Figurative Language in Preschool: Some Observations and Suggestions for Research

    ERIC Educational Resources Information Center

    Pramling, Niklas; Samuelsson, Ingrid Pramling

    2009-01-01

    In a significant book, Cameron suggested that we study metaphor as "prosaics" (i.e. as a feature of mundane talk). In this article, by means of a few brief examples, we point to instances of such talk in the setting of preschool. We also discuss some opportunities for learning that such talk could offer children, and what the implications for the

  6. Are Dietary Restraint Scales Valid Measures of Acute Dietary Restriction? Unobtrusive Observational Data Suggest Not

    ERIC Educational Resources Information Center

    Stice, Eric; Fisher, Melissa; Lowe, Michael R.

    2004-01-01

    The finding that dietary restraint scales predict onset of bulimic pathology has been interpreted as suggesting that dieting causes this eating disturbance, despite the dearth of evidence that these scales are valid measures of dietary restriction. The authors conducted 4 studies that tested whether dietary restraint scales were inversely

  7. Periodic variations of oxygen EUV dayglow in the upper atmosphere of Venus: Hisaki/EXCEED observations

    NASA Astrophysics Data System (ADS)

    Masunaga, K.; Seki, K.; Terada, N.; Tsuchiya, F.; Kimura, T.; Yoshioka, K.; Murakami, G.; Yamazaki, A.; Kagitani, M.; Tao, C.; Fedorov, A.; Futaana, Y.; Zhang, T. L.; Shiota, D.; Leblanc, F.; Chaufray, J.-Y.; Yoshikawa, I.

    2015-12-01

    Using the Extreme Ultraviolet Spectroscope for Exospheric Dynamics (EXCEED) aboard Hisaki and the Solar Extreme Ultraviolet Monitor on the Solar and Heliospheric Observatory, we investigate variations of the extreme ultraviolet (EUV) dayglow brightness for OII 83.4 nm, OI 130.4 nm, and OI 135.6 nm in the Venusian upper atmosphere observed in March-April (period 1), April-May (period 2), and June-July (period 3) in 2014. The result shows that characteristic periodicities exist in the dayglow variations other than the ~27 day solar rotational effect of the solar EUV flux: 1.8, 2.8, 3.1, 4.5, and 9.9 day in period 1; 1.1 day in period 2; and 1.0 and 11 day in period 3. Many of these periodicities are consistent with previous observations and theory. We suggest these periodicities are related to density oscillations of oxygen atoms or photoelectrons in the thermosphere. The cause of these periodicities is still uncertain, but planetary-scale waves and/or gravity waves propagating from the middle atmosphere, and/or minor periodic variations of the solar EUV radiation flux may play a role. Effects of the solar wind parameters (velocity, dynamic pressure, and interplanetary magnetic field's intensity) on the dayglow variations are also investigated using the Analyser of Space Plasma and Energetic Atoms (ASPERA-4) and magnetometer aboard Venus Express. Although clear correlation with the dayglow variations is not found, their minor periodicities are similar to the dayglow periodicities. Contribution of the solar wind to the dayglow remains still unknown, but the solar wind parameters might affect the dayglow variations.

  8. Observations by a University Anatomy Teacher and a Suggestion for Curricular Change: Integrative Anatomy for Undergraduates

    ERIC Educational Resources Information Center

    Darda, David M.

    2010-01-01

    The observation that anatomical course offerings have decreased in undergraduate biology curricula is supported by a survey of undergraduate institutions in the state of Washington. This reduction, due partially to increased emphasis in other areas of the biology curriculum, along with the lack of anatomy prerequisites for admission to most…

  9. CCD observations and period determination of six minor planets

    NASA Astrophysics Data System (ADS)

    Willis, Sarah

    2004-12-01

    I report new period determinations for five minor planets and a revised period for a sixth. The new results are: 1528 Conrada, 6.321 0.001h; 1816 Liberia, 3.0861 0.0001h; 2653 Principia, 5.5228 0.0007h; 3455 Kristensen, 8.111 0.002; and (5599) 1991 SG1, 3.620 0.005. 206 Hersilia had a previously published period of 7.33 hours which was inconsistent with my data, showing a revised period of 11.11 0.05 hours.

  10. NOMADSS Aircraft Observations Suggest Rapid Oxidation of Elemental Mercury in the Subtropical Free Troposphere

    NASA Astrophysics Data System (ADS)

    Shah, V.; Jaegle, L.; Gratz, L.; Ambrose, J. L., II; Jaffe, D. A.

    2014-12-01

    Oxidized mercury species constitute a small fraction of the total atmospheric burden of mercury, but play an important role in the cycling of mercury in the environment. They dominate the deposition flux of mercury from the atmosphere to the Earth's surfaces, because of their high solubility and low vapor pressure. Their primary source is in-situ oxidation of elemental mercury, but our understanding of these oxidation mechanisms is limited. The Nitrogen, Oxidants, Mercury, and Aerosol Distribution, Sources, and Sinks (NOMADSS) experiment was designed with the aim of addressing these limitations, using aircraft-based speicated measurements of mercury in the troposphere over the eastern US in the summer of 2013. We observed high concentrations of oxidized mercury in clean, dry pockets of air originating in the upper troposphere. We analyze these observations with the GEOS-Chem model, which simulates oxidation of mercury by bromine radicals. The modeled concentrations of oxidized mercury are found to be low, by up to a factor of ten, compared to the observations. This indicates that the oxidation rate of mercury is much faster than that calculated in the model. We perform two simulations to test the sensitivity of the modeled oxidation: (i) by increasing bromine radical concentrations by a factor of three in the 45°S-45°N latitude band, and (ii) by using an oxidation rate constant that is higher by a factor of five. We find that the model performance improves considerably in both these simulations. Here, we present a comparison of the standard and the sensitivity simulations to the NOMADSS and the surface-based Mercury Deposition Network (MDN) observations. We further discuss the potential implications of the faster oxidation on the global transport, distribution, and burden of oxidized mercury.

  11. A nutrition and conditioning intervention for natural bodybuilding contest preparation: observations and suggestions.

    PubMed

    Gentil, Paulo

    2015-01-01

    Bodybuilding is full of myths and practices that are contrary to the scientific literature, which can lead to health problems. Adopting a scientifically designed approach is very important, as it may help bodybuilders to achieve better results while preserving their health. However, I have some criticism regarding some practices adopted in the referred article as ad libitum ingestion of sugar-free cordial and flavored tea and the performance of the exercise in fasted state, as it seems to bring no benefit and have some potential problems. Some suggestion are made in order to preserve FFM, like changing training split and exercise selection; increasing carbohydrate ingestion and decreasing protein intake; changing the resistance training stimuli and reducing the volume of aerobic exercises and increase its intensity. PMID:26696792

  12. Observational diagnostics for two-fluid turbulence in molecular clouds as suggested by simulations

    NASA Astrophysics Data System (ADS)

    Meyer, Chad D.; Balsara, Dinshaw S.; Burkhart, Blakesley; Lazarian, Alex

    2014-04-01

    We present high-resolution simulations of two-fluid (ion-neutral) magnetohydrodynamic (MHD) turbulence with resolutions as large as 5123. All of the simulations are supersonic. We explore simulations that range from mildly sub-Alfvnic to super-Alfvnic. Such turbulence is thought to influence star formation processes in molecular clouds because typical cores form on length scales that are comparable to the dissipation scales of this turbulence in the ions. The simulations are motivated by the fact that recent studies of isophotologue lines in molecular clouds have found significant differences in the linewidth-size relationship for neutral and ion species. Our first goal in this paper is to explain those observations using simulations and analytic theory. Our second goal in this paper is to present a new set of density-based diagnostics by drawing on similar diagnostics that have been obtained by studying single-fluid turbulence. We further show that our two-fluid simulations play a vital role in reconciling alternative models of star formation. The velocity-dependent diagnostics display a very interesting complementarity with the density-dependent diagnostics. We find that the linewidth-size relationship should show a prominent difference between ions and neutrals when the line of sight is orthogonal to the mean field. We also find that the density probability distribution functions and their derived diagnostics should show prominent differences between the ions and neutrals when the line of sight is parallel to the mean field.

  13. Spectroscopic observations of evolving flare ribbon substructure suggesting origin in current sheet waves

    NASA Astrophysics Data System (ADS)

    Brannon, Sean R.; Longcope, Dana; Qiu, Jiong

    2015-04-01

    A flare ribbon is the chromospheric image of reconnection at a coronal current sheet. The dynamics and structure of the ribbon can thus reveal properties of the current sheet, including motion of the reconnecting flare loops. We present imaging and spectroscopic observations from the Interface Region Imaging Spectrograph (IRIS) of the evolution of a flare ribbon at high spatial resolution and time cadence. These reveal small-scale substructure in the ribbon, which manifest as oscillations in both position and Doppler velocities. We consider various alternative explanations for these oscillations, including modulation of chromospheric evaporation flows. Among these we find the best support for some form of elliptical wave localized to the coronal current sheet, such as a tearing mode or Kelvin-Helmholtz instability.IRIS is a NASA Small Explorer mission developed and operated by Lockheed Martin Solar and Astrophysics Laboratory. This work is supported by contract 8100002702 from Lockheed Martin to Montana State University, a Montana Space Grant Consortium fellowship, and by NASA through HSR.

  14. Quasi-periodic pulsations with varying period in multi-wavelength observations of an X-class flare

    SciTech Connect

    Huang, Jing; Tan, Baolin; Zhang, Yin; Karlický, Marian; Mészárosová, Hana

    2014-08-10

    This work presents an interesting phenomenon of the period variation in quasi-periodic pulsations (QPPs) observed during the impulsive phase of a coronal mass ejection-related X1.1 class flare on 2012 July 6. The period of QPPs was changed from 21 s at soft X-rays (SXR) to 22-23 s at microwaves, to ∼24 s at extreme ultraviolet emissions (EUV), and to 27-32 s at metric-decimetric waves. The microwave, EUV, and SXR QPPs, emitted from flare loops of different heights, were oscillating in phase. Fast kink mode oscillations were proposed to be the modulation mechanism, which may exist in a wide region in the solar atmosphere from the chromosphere to the upper corona or even to the interplanetary space. Changed parameters of flare loops through the solar atmosphere could result in the varying period of QPPs at different wavelengths. The first appearing microwave QPPs and quasi-periodic metric-decimetric type III bursts were generated by energetic electrons. This may imply that particle acceleration or magnetic reconnection were located between these two non-thermal emission sources. Thermal QPPs (in SXR and EUV emissions) occurred later than the nonthermal ones, which would suggest a some time for plasma heating or energy dissipation in flare loops during burst processes. At the beginning of flare, a sudden collapse and expansion of two separated flare loop structures occurred simultaneously with the multi-wavelength QPPs. An implosion in the corona, including both collapse and expansion of flare loops, could be a trigger of loop oscillations in a very large region in the solar atmosphere.

  15. Cybersemiotics: A suggestion for a transdisciplinary framework for description of observing, anticipatory and meaning producing systems

    NASA Astrophysics Data System (ADS)

    Brier, Soren

    1998-07-01

    The ability of systems to be anticipatory seems to be intricate connected with the ability to observe and to cognate by reducing complexity through signification. The semantic capacity of living systems, the cognitive ability to assign meaning to differences perturbating the system's self-organization, seems to be the prerequisite for the phenomenon of communication, language and consciousness. In cybernetics Bateson developed the idea that information is a difference that makes a difference and second order cybernetics developed the concept of organisms as self-organized and self-produced systems (autopoietic) as the prerequisite of life and cognition. The cognitive ability seems to be qualitative different from what so far is computable on any known machine although parts of different aspects of the process can be partly simulated in AI, neutral network and AL. In semiotics the fundamental process of cognition and communication is called semiosis or signification and C. S. Peirce created a special triadic, objective idealistic, pragmatic and evolutionary philosophy to be able to give a fruitful description of the process and its relation to logic and the concept of natural law. Both second order cybernetics and semiotics sees information and meaning as something produced by individual organisms through structural couplings to the environments or other individuals through historical drift and further developed in social communication. Luhmann points out that social communication also only functions through structural couplings which he calls generalized media such as science, art, power, love and money. Peirce talks of the semiotic net as a triadic view of meanings developing through history and in animals through evolution. In accordance with this Wittgenstein points out that signification is created in language games developed in specific life forms. Life forms are the things we do in society such as seducing, commanding and explaining. As animals do not have language in the true sense I have extended his concept into ethology and bio-semiotics by talking of sign games related to specific motivations and innate response mechanisms. Life as such seems to be an anticipatory function generating expectations through evolution through open genetic programs as Konrad Lorenz pointed out. The phenomenon of imprinting in ducks for instance is a standard example of programmed anticipation. Expectations are expectations of meaning and order (information) related to the semiosphere the organism constructs as its individual world view and live in. (The Umwelt of von Uexküll). On this basis events that perpetuates the semiosphere are reduced to meaning, i.e. something related to the survival and procreation of the individual living system, it conatus, to use one of Spinoza's terms. The framework of cybersemiotics, uniting second order cybernetics, semiotics and language game theory, is created to make transdisciplinary concepts and models that can handle the process of cognition, information and communication across the domains of the sciences, the arts and social sciences in a non-reductionistic way. It is seen as an alternative based on biological and semiotic thinking (biosemiotics) to the functionalistic information processing paradigm of cognitive science that is build on the computer as paradigm and based on classical logic and mechanistic physics—and therefore has severe problems of dealing with semantics and signification.

  16. Comparative energetics of the observed and simulated global circulation during the special observing periods of FGGE

    NASA Technical Reports Server (NTRS)

    Kung, E. C.; Baker, W. E.

    1986-01-01

    Energetics of the observed and simulated global circulation are evaluated in the zonal spectral domain for the special observing periods of FGGE. The study utilizes GLA analyses of FGGE observational data and parallel simulation experiments. There are noticeable differences in energy transformations between the observation and simulation during SOP-1. These include the baroclinic conversion C(n) by the zonal mean motion and short-wave disturbances, and the nonlinear wave-wave interaction L(n) at the long and short waves. The energy transformations of the short-wave disturbances are much more intense in the simulated circulation than in the observation. However, good agreement is noted in the conversion and dissipation of kinetic energy in the large- and cyclone-wave range n = 1-10. Spectral distributions of global energy transformations at the long- and cyclone-wave range indicate that the SOP-2 simulation agrees more closely with the observed fields than the SOP-1 simulation. Other pertinent points of energetics diagnosis are also included in the discussion.

  17. Examining Periodic Solar-Wind Density Structures Observed in the SECCHI Heliospheric Imagers

    NASA Technical Reports Server (NTRS)

    Viall, Nicholeen M.; Spence, Harlan E.; Vourlidas, Angelos; Howard, Russell

    2010-01-01

    We present an analysis of small-scale, periodic, solar-wind density enhancements (length scales as small as approximately equals 1000 Mm) observed in images from the Heliospheric Imager (HI) aboard STEREO-A. We discuss their possible relationship to periodic fluctuations of the proton density that have been identified at 1 AU using in-situ plasma measurements. Specifically, Viall, Kepko, and Spence examined 11 years of in-situ solar-wind density measurements at 1 AU and demonstrated that not only turbulent structures, but also nonturbulent, periodic density structures exist in the solar wind with scale sizes of hundreds to one thousand Mm. In a subsequent paper, Viall, Spence, and Kasper analyzed the alpha-to-proton solar-wind abundance ratio measured during one such event of periodic density structures, demonstrating that the plasma behavior was highly suggestive that either temporally or spatially varying coronal source plasma created those density structures. Large periodic density structures observed at 1 AU, which were generated in the corona, can be observable in coronal and heliospheric white-light images if they possess sufficiently high density contrast. Indeed, we identify such periodic density structures as they enter the HI field of view and follow them as they advect with the solar wind through the images. The smaller, periodic density structures that we identify in the images are comparable in size to the larger structures analyzed in-situ at 1 AU, yielding further evidence that periodic density enhancements are a consequence of coronal activity as the solar wind is formed.

  18. Spurious One-Month and One-Year Periods in Visual Observations of Variable Stars

    NASA Astrophysics Data System (ADS)

    Percy, J. R.

    2015-12-01

    Visual observations of variable stars, when time-series analyzed with some algorithms such as DC-DFT in vstar, show spurious periods at or close to one synodic month (29.5306 days), and also at about a year, with an amplitude of typically a few hundredths of a magnitude. The one-year periods have been attributed to the Ceraski effect, which was believed to be a physiological effect of the visual observing process. This paper reports on time-series analysis, using DC-DFT in vstar, of visual observations (and in some cases, V observations) of a large number of stars in the AAVSO International Database, initially to investigate the one-month periods. The results suggest that both the one-month and one-year periods are actually due to aliasing of the stars' very low-frequency variations, though they do not rule out very low-amplitude signals (typically 0.01 to 0.02 magnitude) which may be due to a different process, such as a physiological one. Most or all of these aliasing effects may be avoided by using a different algorithm, which takes explicit account of the window function of the data, and/or by being fully aware of the possible presence of and aliasing by very low-frequency variations.

  19. Viking magnetic and electric field observations of periodic Pc 1 waves: Pearl pulsations

    SciTech Connect

    Erlandson, R.E.; Anderson, B.J.; Zanetti, L.J.

    1992-10-01

    Pearl pulsations, with an average repetition period of 60 s, were recorded using the magnetic and electric field experiments on the polar-orbiting Viking satellite. The wave event occurred on September 30, 1986, during Viking orbit 1212 at 1030 MLT, from L=3.6 to L=4.1, and at an altitude of 13,500 km. Electron density observations obtained from Viking show that the waves were generated at the plasmapause and at lower amplitudes in the plasmasphere. The wave Poynting flux, calculated using the magnetic and electric field, indicated that the waves generally were propagating downward toward the ionosphere, although upward Poynting fluxes were observed. Clear evidence of upward propagating waves, associated with downward propagating waves reflected at the ionosphere, was not observed. Linear convective growth rates suggest that the anisotropic ions which provide the free energy have a perpendicular temperature around 15 keV. The repetition period, calculated using the measured electron density and magnetic field strength at Viking, is consistent with the double-hop transit time for ion cyclotron waves which propagate along field lines from one hemisphere to the other. However, the absence of upward propagating waves packets implies that the upper limit of the wave ionospheric reflection coefficient is on the order of 10 to 20%. Alternative mechanism for producing the observed repetition are also investigated and include a periodic generation model of pearl pulsations at the ion bounce period. 42 refs., 5 figs., 4 tabs.

  20. Large-Scale periodic solar velocities: An observational study

    NASA Technical Reports Server (NTRS)

    Dittmer, P. H.

    1977-01-01

    Observations of large-scale solar velocities were made using the mean field telescope and Babcock magnetograph of the Stanford Solar Observatory. Observations were made in the magnetically insensitive ion line at 5124 A, with light from the center (limb) of the disk right (left) circularly polarized, so that the magnetograph measures the difference in wavelength between center and limb. Computer calculations are made of the wavelength difference produced by global pulsations for spherical harmonics up to second order and of the signal produced by displacing the solar image relative to polarizing optics or diffraction grating.

  1. Exclusion of linkage between hypokalemic periodic paralysis and a candidate region in 1q31-32 suggests genetic heterogeneity

    SciTech Connect

    Sillen, A.; Wadelius, C.; Gustabson, K.H.

    1994-09-01

    Familial hypokalemic periodic paralysis (HOKPP) is an autosomal dominant disease with attacks of paralysis of varying severity. The attacks occur at intervals of days to years in otherwise healthy people combined with hypokalemia during attacks. The paralysis attacks are precipitated by a number of different factors, like carbohydrate-rich meals, cold, exercise and mental stress. Recently linkage for HOKPP was shown for chromosome 1q31-32 and the disease was mapped between D1S413 and D1S249. The gene for the calcium channel alfa1-subunit (CACNL 1A3) maps to this interval and in two families no recombination was found between a polymorphism in the CACNL 1A3 gene and the disease. This gene is therefore considered to be a candidate for HOKPP. The analysis of a large Danish family excludes linkage to this region and to the CACNL 1A3 gene. In each direction from D1S413, 18.8 cM could be excluded and for D1S249, 14.9 cM. The present study clearly excludes the possibility that the gene causing HOKPP in a large Danish family is located in the region 1q31-32. This result shows that HOKPP is a heterogenous disease, with only one mapped gene so far.

  2. Recurrence times and periodicities in 4U 1608-52 as observed by Vela 5B

    NASA Technical Reports Server (NTRS)

    Lochner, James C.; Roussel-Dupre, Diane

    1994-01-01

    We report on the Vela 5B 10 year history of the soft X-ray transient 4U 1608-52, and on the characteristics of its soft X-ray outbursts. The Vela 5B satellite observed the four known outbursts in 1975, 1977, and 1979, and four new outbursts in 1970 and 1971, altering the recurrence pattern of outbursts from this source. One of the 1970 outbursts is symmetric in its intensity profile, while the two outbursts in 1971 have short exponential profiles separated by 80 days. Despite suggestive recurrence periods of approximately 85 and approximately 150 days evident in the time intervals between the outbursts, there is no single statistically significant recurrence time on which the outbursts recur consistently. In the 1970 symmetric event, there is evidence for a period of either 4.10 or 5.19 days. Drawing upon the analogy with SU Ursa Majoris dwarf novae, we suggest that the short period is orbital and any longer period would be associated with a precession period of the accretion disk.

  3. Periodic waves in the lower thermosphere observed by OI630 nm airglow images

    NASA Astrophysics Data System (ADS)

    Paulino, I.; Medeiros, A. F.; Vadas, S. L.; Wrasse, C. M.; Takahashi, H.; Buriti, R. A.; Leite, D.; Filgueira, S.; Bageston, J. V.; Sobral, J. H. A.; Gobbi, D.

    2016-02-01

    Periodic wave structures in the thermosphere have been observed at São João do Cariri (geographic coordinates: 36.5° W, 7.4° S; geomagnetic coordinates based on IGRF model to 2015: 35.8° E, 0.48° N) from September 2000 to November 2010 using OI630.0 nm airglow images. During this period, which corresponds to almost one solar cycle, characteristics of 98 waves were studied. Similarities between the characteristics of these events and observations at other places around the world were noted, primarily the spectral parameters. The observed periods were mostly found between 10 and 35 min; horizontal wavelengths ranged from 100 to 200 km, and phase speed from 30 to 180 m s-1. These parameters indicated that some of the waves, presented here, are slightly faster than those observed previously at low and middle latitudes (Indonesia, Carib and Japan), indicating that the characteristics of these waves may change at different places. Most of observed waves have appeared during magnetically quiet nights, and the occurrence of those waves followed the solar activity. Another important characteristic is the quasi-monochromatic periodicity that distinguish them from the single-front medium-scale traveling ionospheric disturbances (MSTIDs) that have been observed previously over the Brazilian region. Moreover, most of the observed waves did not present a phase front parallel to the northeast-southwest direction, which is predicted by the Perkins instability process. It strongly suggests that most of these waves must have had different generation mechanisms from the Perkins instability, which have been pointed out as being a very important mechanism for the generation of MSTIDs in the lower thermosphere.

  4. Enhancement of ARM surface meteorological observations during the fall 1996 water vapor intensive observation period.

    SciTech Connect

    Richardson, S. J.; Splitt, M. E.; Lesht, B. M.; Environmental Research; Univ.of Oklahoma; Univ. of Utah

    2000-03-01

    This work describes in situ moisture sensor comparisons that were performed in conjunction with the first Water Vapor Intensive Observation Period (IOP) conducted at the Atmospheric Radiation Measurement (ARM) Program Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) site during September of 1996. Two Raman lidars, two Atmospheric Emitted Radiance Interferometers, (AERIs), and a suite of 13 microwave radiometers were assembled at the CART site during the IOP, and in situ measurements were used for calibration and verification. In addition, this work was meant to help assess the current observing strategy in an effort to make improvements to the routine continuous measurements. To accomplish these goals, verification of the in situ measurements was required. Therefore, a laboratory intercomparison of the in situ moisture sensors (nine capacitive chip relative humidity sensors and four chilled mirror sensors) was performed at the Oklahoma Mesonet temperature and relative humidity testing and calibration facility. Tests were conducted both before and after the instruments were used in the IOP, making it possible to detect instrument problems prior to the IOP and to determine if instrument failure or drift occurred during the IOP.

  5. Imaging Observations of Quasi-periodic Pulsations in Solar Flare Loops with SDO/AIA

    NASA Astrophysics Data System (ADS)

    Su, J. T.; Shen, Y. D.; Liu, Y.; Liu, Y.; Mao, X. J.

    2012-08-01

    Quasi-periodic pulsations (QPPs) of flaring emission with periods from a few seconds to tens of minutes have been widely detected from radio bands to ?-ray emissions. However, in the past the spatial information of pulsations could not be utilized well due to the instrument limits. We report here imaging observations of the QPPs in three loop sections during a C1.7 flare with periods of P = 24 s-3 minutes by means of the extreme-ultraviolet 171 channel of the Atmospheric Imaging Assembly (AIA) instrument on board the Solar Dynamics Observatory. We confirm that the QPPs with the shortest period of 24 s were not of an artifact produced by the Nyquist frequency of the AIA 12 s cadence. The QPPs in the three loop sections were interconnected and closely associated with the flare. The detected perturbations propagated along the loops at speeds of 65-200 km s-1, close to those of acoustic waves in them. The loops were made up of many bright blobs arranged in alternating bright and dark changes in intensity (spatial periodical distribution) with the wavelengths 2.4-5 Mm (as if they were magnetohydrodynamic waves). Furthermore, in the time-distance diagrams, the detected perturbation wavelengths of the QPPs are estimated to be ~10 Mm, which evidently do not fit the above ones of the spatial periodic distributions and produce a difference of a factor of 2-4 with them. It is suggested that the short QPPs with periods P < 60 s were possibly sausage-mode oscillations and the long QPPs with periods P > 60 s were the higher (e.g., >2nd) harmonics of slow magnetoacoustic waves.

  6. IMAGING OBSERVATIONS OF QUASI-PERIODIC PULSATIONS IN SOLAR FLARE LOOPS WITH SDO/AIA

    SciTech Connect

    Su, J. T.; Mao, X. J.; Shen, Y. D.; Liu, Y.

    2012-08-20

    Quasi-periodic pulsations (QPPs) of flaring emission with periods from a few seconds to tens of minutes have been widely detected from radio bands to {gamma}-ray emissions. However, in the past the spatial information of pulsations could not be utilized well due to the instrument limits. We report here imaging observations of the QPPs in three loop sections during a C1.7 flare with periods of P = 24 s-3 minutes by means of the extreme-ultraviolet 171 A channel of the Atmospheric Imaging Assembly (AIA) instrument on board the Solar Dynamics Observatory. We confirm that the QPPs with the shortest period of 24 s were not of an artifact produced by the Nyquist frequency of the AIA 12 s cadence. The QPPs in the three loop sections were interconnected and closely associated with the flare. The detected perturbations propagated along the loops at speeds of 65-200 km s{sup -1}, close to those of acoustic waves in them. The loops were made up of many bright blobs arranged in alternating bright and dark changes in intensity (spatial periodical distribution) with the wavelengths 2.4-5 Mm (as if they were magnetohydrodynamic waves). Furthermore, in the time-distance diagrams, the detected perturbation wavelengths of the QPPs are estimated to be {approx}10 Mm, which evidently do not fit the above ones of the spatial periodic distributions and produce a difference of a factor of 2-4 with them. It is suggested that the short QPPs with periods P < 60 s were possibly sausage-mode oscillations and the long QPPs with periods P > 60 s were the higher (e.g., >2nd) harmonics of slow magnetoacoustic waves.

  7. SPITZER OBSERVATIONS OF GX17+2: CONFIRMATION OF A PERIODIC SYNCHROTRON SOURCE

    SciTech Connect

    Harrison, Thomas E.; McNamara, Bernard J.; Bornak, Jillian; Gelino, Dawn M.; Wachter, Stefanie; Gelino, Christopher R. E-mail: bmcnamar@nmsu.edu E-mail: dawn@ipac.caltech.edu E-mail: mrupen@aoc.nrao.edu

    2011-07-20

    GX17+2 is a low-mass X-ray binary (LMXB) that is also a member of a small family of LMXBs known as 'Z-sources' that are believed to have persistent X-ray luminosities that are very close to the Eddington limit. GX17+2 is highly variable at both radio and X-ray frequencies, a feature common to Z-sources. What sets GX17+2 apart is its dramatic variability in the near-infrared, where it changes by {Delta}K {approx} 3 mag. Previous investigations have shown that these brightenings are periodic, recurring every 3.01 days. Given its high extinction (A{sub V} {>=} 9 mag), it has not been possible to ascertain the nature of these events with ground-based observations. We report mid-infrared Spitzer observations of GX17+2 which indicate a synchrotron spectrum for the infrared brightenings. In addition, GX17+2 is highly variable in the mid-infrared during these events. The combination of the large-scale outbursts, the presence of a synchrotron spectrum, and the dramatic variability in the mid-infrared suggest that the infrared brightening events are due to the periodic transit of a synchrotron jet across our line of sight. An analysis of both new, and archival, infrared observations has led us to revise the period for these events to 3.0367 days. We also present new Rossi X-Ray Timing Explorer (RXTE) data for GX17+2 obtained during two predicted infrared brightening events. Analysis of these new data, and data from the RXTE archive, indicates that there is no correlation between the X-ray behavior of this source and the observed infrared brightenings. We examine various scenarios that might produce periodic jet emission.

  8. Observations of Very-Long-Period Tremor at the Tatun Volcano Group, Northern Taiwan

    NASA Astrophysics Data System (ADS)

    Yeh, Y.; Lin, C.; Konstantino, K.

    2006-12-01

    The Tatun Volcano Group lies at the northern tip of Taiwan and is only 15 km north of the capital Taipei, which has more than seven million inhabitants. To examine the possibility of both volcanic and seismic activity in the future, a dense seismic array consisting of 8 stations equipped with both broad-band and short-period sensors has been installed in Tatun area since 2003. In addition to common volcano-tectonic earthquakes, we have observed a variety of volcanoseismic signals such as tornillos, short duration monochromatic events and long duration spasmodic bursts from the short-period seismic data. Further examination of broadband seismic data shows that there also were some very-long-period (VLP) volcanic signals, which are often reported at some active volcanoes in the world. Based on the polarization and travel-time of the VLP signals recorded at 4 broadband stations, the source of VLP seismic signals was located at a depth around 2.0 km. These observations put into doubt the long-standing suggestion that the Tatun volcanoes are extinct and prompt for a thorough assessment of the volcanic hazard for this area.

  9. OBSERVABLE QUASI-PERIODIC OSCILLATIONS PRODUCED BY STEEP PULSE PROFILES IN MAGNETAR FLARES

    SciTech Connect

    D'Angelo, C. R.; Watts, A. L.

    2012-06-01

    Strong quasi-periodic oscillations (QPOs) in the tails of the giant gamma-ray flares seen in SGR 1806-20 and SGR 1900+14 are thought to be produced by starquakes in the flaring magnetar. However, the large fractional amplitudes (up to {approx}20%) observed are difficult to reconcile with predicted amplitudes of starquakes. Here, we demonstrate that the steeply pulsed emission profile in the tail of the giant flare can enhance the observed amplitude of the underlying oscillation, analogous to a beam of light oscillating in and out of the line of sight. This mechanism will also broaden the feature in the power spectrum and introduce power at harmonics of the oscillation. The observed strength of the oscillation depends on the amplitude of the underlying starquake, the orientation and location of the emission on the surface of the star, and the gradient of the light curve profile. While the amplification of the signal can be significant, we demonstrate that, even with uncertainties in the emission geometry, this effect is not sufficient to produce the observed QPOs. This result excludes the direct observation of a starquake and suggests that the observed variations come from modulations in the intensity of the emission.

  10. Evaluation of and Suggested Improvements to the WSM6 Microphysics in WRF- ARW Using Synthetic and Observed GOES-13 Imagery

    SciTech Connect

    Grasso, Lewis; Lindsey, Daniel T.; Lim, Kyo-Sun; Clark, Adam; Bikos, Dan; Dembek, Scott R.

    2014-10-01

    Synthetic satellite imagery can be employed to evaluate simulated cloud fields. Past studies have revealed that the Weather Research and Forecasting (WRF) WRF Single-Moment 6-class (WSM6) microphysics in WRF-ARW produces less upper level ice clouds within synthetic images compared to observations. Synthetic Geostationary Operational Environmental Satellite (GOES)-13 imagery at 10.7 μm of simulated cloud fields from the 4 km National Severe Storms Laboratory (NSSL) WRF-ARW is compared to observed GOES-13 imagery. Histograms suggest that too few points contain upper level simulated ice clouds. In particular, side-by-side examples are shown of synthetic and observed convective anvils. Such images illustrate the lack of anvil cloud associated with convection produced by the NSSL WRF-ARW. A vertical profile of simulated hydrometeors suggests that too much cloud water mass may be converted into graupel mass, effectively reducing the main source of ice mass in a simulated anvil. Further, excessive accretion of ice by snow removes ice from an anvil by precipitation settling. Idealized sensitivity tests reveal that a 50% reduction of the conversion of cloud water mass to graupel and a 50% reduction of the accretion rate of ice by snow results in a significant increase in anvil ice of a simulated storm. Such results provide guidance as to which conversions could be reformulated, in a more physical manner, to increase simulated ice mass in the upper troposphere.

  11. Outflow of low-energy O+ ion beams observed during periods without substorms

    NASA Astrophysics Data System (ADS)

    Parks, G. K.; Lee, E.; Fu, S. Y.; Fillingim, M.; Dandouras, I.; Cui, Y. B.; Hong, J.; Rme, H.

    2015-03-01

    Numerous observations have shown that ions flow out of the ionosphere during substorms with more fluxes leaving as the substorm intensity increases (Wilson et al., 2004). In this article we show observations of low-energy (few tens of electron volts) ionospheric ions flowing out periods without substorms, determined using the Wideband Imaging Camera (WIC) and Auroral Electrojet (AE) indices. We use Cluster ion composition data and show the outflowing ions are field-aligned H+, He+ and O+ beams accelerated to energies of ~40-80 eV, after correcting for spacecraft potential. The estimated fluxes of the low-energy O+ ions measured at ~20 000 km altitude are >103-105 cm-2 s. Assuming the auroral oval is the source of the escaping ions, the measured fluxes correspond to a flow rate of ~1019-1021 ions s-1 leaving the ionosphere. However, periods without substorms can persist for hours suggesting the low-energy ions flowing out during these times could be a major source of the heavy ion population in the plasma sheet and lobe.

  12. Periodization

    PubMed Central

    Lorenz, Daniel S.; Reiman, Michael P.; Walker, John C.

    2010-01-01

    Background: Clinicians are constantly faced with the challenge of designing training programs for injured and noninjured athletes that maximize healing and optimize performance. Periodization is a concept of systematic progressionthat is, resistance training programs that follow predictable patterns of change in training variables. The strength training literature is abundant with studies comparing periodization schemes on uninjured, trained, and untrained athletes. The rehabilitation literature, however, is scarce with information about how to optimally design resistance training programs based on periodization principles for injured athletes. The purpose of this review is to discuss relevant training variables and methods of periodization, as well as periodization program outcomes. A secondary purpose is to provide an anecdotal framework regarding implementation of periodization principles into rehabilitation programs. Evidence Acquisition: A Medline search from 1979 to 2009 was implemented with the keywords periodization, strength training, rehabilitation, endurance, power, hypertrophy, and resistance training with the Boolean term AND in all possible combinations in the English language. Each author also undertook independent hand searching of article references used in this review. Results: Based on the studies researched, periodized strength training regimens demonstrate improved outcomes as compared to nonperiodized programs. Conclusions: Despite the evidence in the strength training literature supporting periodization programs, there is a considerable lack of data in the rehabilitation literature about program design and successful implementation of periodization into rehabilitation programs. PMID:23015982

  13. Quasi-periodic Fluctuations and Chromospheric Evaporation in a Solar Flare Ribbon Observed by IRIS

    NASA Astrophysics Data System (ADS)

    Brosius, Jeffrey W.; Daw, Adrian N.

    2015-09-01

    The Interface Region Imaging Spectrograph (IRIS) satellite obtained rapid cadence (9.4 s) stare spectra of an M7 flare ribbon in AR 12036 on 2014 April 18. Chromospheric and transition region line emission exhibited quasi-periodic intensity and velocity fluctuations in the ribbon prior to the appearance of Fe xxi emission. Seven intensity peaks were observed in light curves from small (0\\buildrel{\\prime\\prime}\\over{.} 333 0\\buildrel{\\prime\\prime}\\over{.} 333) tracked spatial locations in the ribbon, the first four of which show variable time separations around 3 minutes, and the last four of which show variable time separations about half that value, i.e., the frequency appears to have doubled. The Fe xxi intensity increased rapidly and impulsively after the quasi-periodic fluctuations in chromospheric and transition region lines. The entire Fe xxi line profile was blueshifted when the line first appeared, corresponding to an upward velocity around -100 km s-1. This upward velocity increased to a maximum of about -150 km s-1 before diminishing to zero around the time of maximum intensity. Simultaneous, cospatial velocities observed with Si iv line emission were directed downward, consistent with explosive chromospheric evaporation. During this flare the Fe xxi lines profile is well fit with only one Gaussian component that is either wholly blueshifted or wholly at rest; no significant secondary blueshifted or redshifted components are observed. This suggests that IRIS may have sufficient spatial resolution to resolve loop strands in these flare observations. Under the assumption that the Fe xxi line is at rest when its width is thermal, we derive a rest wavelength of 1354.0714 0.0108 for this forbidden line.

  14. On the Merits of Direct Observation of Periodical Usage: An Empirical Study.

    ERIC Educational Resources Information Center

    Bustion, Marifran; And Others

    1992-01-01

    An auxiliary study of the direct observation method for counting periodical usage in Evans Library at Texas A&M University found that student observations contain substantial error and that aggregation problems and cost issues are fundamental constraints to this method. Concludes direct observation may be useful in calibrating the results of other

  15. New Observations and Period Change Study for the Anomalous Cepheid in M 92

    NASA Astrophysics Data System (ADS)

    Osborn, W.; Kopacki, G.; Haberstroh, J.

    2012-12-01

    New observations of the variable star V7 in the globular cluster M 92 have been used to determine the parameters of its B, V and IC light curves. The star's classification as an anomalous Cepheid type is confirmed. The asymmetric shape of the light curve and position in the observed period-luminosity relation for anomalous Cepheids indicate the star is pulsating in the fundamental mode. Data from photographic plates, extending back to 1900, have been combined with published material and recent CCD observations to carry out a period change study. No evidence of a period change is found. Expected period change rates have been calculated using theoretical relations for the pulsational periods of anomalous Cepheids and evolutionary tracks for metal-poor horizontal branch stars with masses 1.0?M/Msun?1.6. Only models for stars close to central helium exhaustion show measurable rates, which indicates V7 is in the core helium burning phase of evolution.

  16. Archive of observations of periodic comet Crommelin made during its 1983-84 apparition

    NASA Technical Reports Server (NTRS)

    Sekanina, Z. (Editor); Aronsson, M.

    1985-01-01

    This is an archive of 680 reduced observations of Periodic Comet Crommelin made during its 1984 apparition. The archive integrates reports by members of the eight networks of the International Halley Watch (IHW) and presents the results of a trial run designed to test the preparedness of the IHW organization for the current apparition of Periodic Comet Halley.

  17. Observation of monolayer and bilayer period RHEED oscillations during epitaxial growth of Ge on Ge(1 0 0)

    NASA Astrophysics Data System (ADS)

    Berrie, Cindy L.; Leone, Stephen R.

    2000-06-01

    Both monolayer and bilayer periods are observed during the growth of germanium on Ge(1 0 0) using reflection high-energy electron diffraction (RHEED). Oscillations in the specular beam intensity of the RHEED pattern are recorded for substrate temperatures of 400-850 K over a wide range of incident germanium fluxes. With careful sample preparation, the period of the RHEED oscillations consistently goes through a transition from a bilayer period to an alternating intensity monolayer period as the surface temperature is raised above ˜700 K. Without this preparation, only bilayer periods characterized by symmetric-shaped oscillations are observed. This indicates that the sample preparation plays a key role in determining the resulting growth. The period of the RHEED oscillations is not strongly dependent on the incident angle of the electron beam, suggesting that the observed periods are not a result of a diffraction condition, such as Kikuchi lines. The data are consistent with a mobility-controlled dynamic bilayer versus monolayer growth mechanism.

  18. Observations of deep long-period (DLP) seismic events beneath Aleutian arc volcanoes; 1989-2002

    USGS Publications Warehouse

    Power, J.A.; Stihler, S.D.; White, R.A.; Moran, S.C.

    2004-01-01

    Between October 12, 1989 and December 31, 2002, the Alaska Volcano Observatory (AVO) located 162 deep long-period (DLP) events beneath 11 volcanic centers in the Aleutian arc. These events generally occur at mid- to lower-crustal depths (10-45 km) and are characterized by emergent phases, extended codas, and a strong spectral peak between 1.0 and 3.0 Hz. Observed wave velocities and particle motions indicate that the dominant phases are P- and S-waves. DLP epicenters often extend over broad areas (5-20 km) surrounding the active volcanoes. The average reduced displacement of Aleutian DLPs is 26.5 cm2 and the largest event has a reduced displacement of 589 cm2 (or ML 2.5). Aleutian DLP events occur both as solitary events and as sequences of events with several occurring over a period of 1-30 min. Within the sequences, individual DLPs are often separated by lower-amplitude volcanic tremor with a similar spectral character. Occasionally, volcano-tectonic earthquakes that locate at similar depths are contained within the DLP sequences. At most, Aleutian volcanoes DLPs appear to loosely surround the main volcanic vent and occur as part of background seismicity. A likely explanation is that they reflect a relatively steady-state process of magma ascent over broad areas in the lower and middle portions of the crust. At Mount Spurr, DLP seismicity was initiated by the 1992 eruptions and then slowly declined until 1997. At Shishaldin Volcano, a short-lived increase in DLP seismicity occurred about 10 months prior to the April 19, 1999 eruption. These observations suggest a link between eruptive activity and magma flux in the mid- to lower-crust and uppermost mantle.

  19. Globally enumerating unstable periodic orbits for observed data using symbolic dynamics.

    PubMed

    Buhl, Michael; Kennel, Matthew B

    2007-09-01

    The unstable periodic orbits of a chaotic system provide an important skeleton of the dynamics in a chaotic system, but they can be difficult to find from an observed time series. We present a global method for finding periodic orbits based on their symbolic dynamics, which is made possible by several recent methods to find good partitions for symbolic dynamics from observed time series. The symbolic dynamics are approximated by a Markov chain estimated from the sequence using information-theoretical concepts. The chain has a probabilistic graph representation, and the cycles of the graph may be exhaustively enumerated with a classical deterministic algorithm, providing a global, comprehensive list of symbolic names for its periodic orbits. Once the symbolic codes of the periodic orbits are found, the partition is used to localize the orbits back in the original state space. Using the periodic orbits found, we can estimate several quantities of the attractor such as the Lyapunov exponent and topological entropy. PMID:17902984

  20. Globally enumerating unstable periodic orbits for observed data using symbolic dynamics

    NASA Astrophysics Data System (ADS)

    Buhl, Michael; Kennel, Matthew B.

    2007-09-01

    The unstable periodic orbits of a chaotic system provide an important skeleton of the dynamics in a chaotic system, but they can be difficult to find from an observed time series. We present a global method for finding periodic orbits based on their symbolic dynamics, which is made possible by several recent methods to find good partitions for symbolic dynamics from observed time series. The symbolic dynamics are approximated by a Markov chain estimated from the sequence using information-theoretical concepts. The chain has a probabilistic graph representation, and the cycles of the graph may be exhaustively enumerated with a classical deterministic algorithm, providing a global, comprehensive list of symbolic names for its periodic orbits. Once the symbolic codes of the periodic orbits are found, the partition is used to localize the orbits back in the original state space. Using the periodic orbits found, we can estimate several quantities of the attractor such as the Lyapunov exponent and topological entropy.

  1. Observations and Light Curve Solutions of Four Ultrashort-Period Binaries

    NASA Astrophysics Data System (ADS)

    Kjurkchieva, D.; Popov, V.; Vasileva, D.; Petrov, N.

    2016-03-01

    The paper presents light curve solutions of our observations of four new ultrashort-period eclipsing binaries with MS components. Two of them have periods almost at the upper limit (0.22 days) of the ultrashort-period binaries, while the periods of around 0.18 days of CSS J171508.5+350658 and CSS J214633.8+120016 are amongst the shortest known orbital periods. CSS J171410.0+445850, CSS J214633.8+120016 and CSS J224326.0+154532 are overcontact binaries with fillout factors around 0.25 while CSS J171508.5+350658 is a semidetached system. The two targets with shortest periods consist of M dwarfs.

  2. Solar wind plasma periodicities observed at 1 AU by IMP 8

    NASA Technical Reports Server (NTRS)

    Paularena, K. I.; Szabo, A.; Lazarus, A. J.

    1995-01-01

    The IMP 8 spacecraft has been in Earth orbit since 1973, gathering plasma data over one complete 22-year solar cycle. These data are being examined to look for periodicities at time scales ranging from several hours to the entire span of the data set. A 1.3-year periodicity in the radial speed observed by IMP 8 and Voyager 2 has already been reported for the years from 1987 to 1993. The periodogram method, useful for unevenly sampled data such as the IMP 8 plasma data, has been used to search for other periods. It is interesting to note that the 13-year period is not present in the out-of-the-ecliptic component of the velocity (Vz), although a 1-year period is very obvious both visually and on the periodogram. Both components show a very strong peak associated with the 11-year solar cycle variation. This work will be extended to the thermal speed (a measure of the wind's temperature) and density, although the frequent correlations between these parameters and the velocity are expected to cause similar results. Additionally, the fine resolution data will be examined for shorter time periods than are visible using the hourly average data which are appropriate for longer periods. A comparison with periods observed at other spacecraft may also be made.

  3. Observed periodicities and the spectrum of field variations in Holocene magnetic records

    NASA Astrophysics Data System (ADS)

    Panovska, S.; Finlay, C. C.; Hirt, A. M.

    2013-10-01

    In order to understand mechanisms that maintain and drive the evolution of the Earth's magnetic field, a characterization of its behavior on time scales of centuries to millennia is required. We have conducted a search for periodicities in Holocene sediment magnetic records, by applying three techniques: multitaper spectral estimation, wavelet analysis and empirical mode decomposition. When records are grouped according to their geographical locations, we find encouraging consistency amongst the observed periods, especially in nearby inclination records. No evidence was obtained for discrete, globally observed, periods. Rather we find a continuous broadband spectrum, with a slope corresponding to a power law with exponent of -2.30.6 for the period range between 300 and 4000 yr. This is consistent with the hypothesis that chaotic convection in the outer core drives the majority of secular variation.

  4. Spectroscopic observations and Doppler tomography of the short-period cataclysmic variable star V455 And

    NASA Astrophysics Data System (ADS)

    Kononov, D. A.; Bisikalo, D. V.; Puzin, V. B.; Zhilkin, A. G.; Sytov, A. Yu.

    2013-09-01

    We present the results of spectroscopic observations and Doppler tomography of the short-period cataclysmic variable star V455 And. The investigated spectra indicate that the disk in the system periodically changes its size. Besides, we suppose that there is a dense region in the disk, moving in the retrograde precession. This region can periodically amplify shock waves, which may be seen in the light curves of the system. The Doppler tomograms, computed, using the spectra, obtained at different orbital phases, demonstrate different bright regions. This may be an additional argument, supporting the idea of the moving dense region.

  5. Lidar observations of the stratospheric aerosol layer over southern Italy in the period 1991-1995

    NASA Astrophysics Data System (ADS)

    di Girolamo, P.; Pappalardo, G.; Spinelli, N.; Berardi, V.; Velotta, R.

    1996-08-01

    Lidar measurements of the stratospheric aerosol layer have been carried out in Napoli (4050' N-1410' E) and Potenza (4036' N-1544' E) during the period 1991-1995, covering the history of the aerosol cloud produced by the eruption of Mount Pinatubo (June 1991, Philippines). Measurements are expressed in terms of aerosol backscattering coefficient ?A(z), aerosol integrated backscattering IB and aerosol optical thickness ?A at ? = 351 nm and 355 nm; ?A(z) and ?A are determined from a single-wavelength elastic return. IB, ?A, and ?max, the peak aerosol backscattering, reached their maximum value in December 1991, displaying a subsequent decay with e-folding times of 237 25, 250 111, and 257 33 days, respectively, Rmax, the peak scattering ratio, is characterized by a decay time of 235 13 days. Measurements of the extinction-to-backscattering ratio, ?A(z)/?A(z), and of the column parameter, ?A/IB, allowed us to retrieve aerosol dimensional characteristics. The time evolution of the height, zc, of the aerosol cloud center of mass was also determined. Downward gravitational settling of stratospheric aerosols with time suggests aerosol particles fall within the size range 0.1-0.3 ?m. An abrupt change in IB and ?max is observed approximately 1000 days after the eruption as a result of the winter-summer transition and the tropospheric removal of the lower portion of the stratospheric aerosol layer. Changes in the values of IB, ?A/IB, and zc suggest that this transition is characterized by a change in the aerosol mean radius from 0.3 to 0.1 ?m.

  6. On Quasi-Periodic Variations of Cosmic Rays Observed at Earth: Direct Measurements

    NASA Astrophysics Data System (ADS)

    Kudela, K.; Perez-Peraza, J. A.

    2013-05-01

    Important role in space weather related studies play cosmic rays (CR). Their temporal variability, both of quasi-periodic character as well as of irregular one, is studied on the ground from direct measurements as well as from cosmogenic nuclides, over long time. We attempt to describe the current knowledge on selected quasi-periodicities in CR flux, especially in energy range above the atmospheric threshold, from direct measurement. Quasi-periodicities in relativistic electron flux near Earth is discussed shortly too. The power spectrum density (PSD) of the CR time series at a single station has rather complicated character. Along with the shape (slope) of PSD the knowledge of contribution of quasi-periodic variations to the CR signal is of importance for the modulation as well as for the checking the links of CR to space weather and/or space climate effects. Rotation of the Earth and solar rotation cause two types of mechanisms behind the certain quasi-periodicities observed in secondary CR on the Earth's surface. Solar activity and solar magnetic field cyclicities contribute to the quasi-periodic signals in CR if studied over longer time periods. The complexity of spatial structure of IMF and its evolution within the heliosphere as well as the changes in the geomagnetic field cause variability in contributions of the quasi-periodicities in CR. Wavelet spectra are useful tool for checking the fine strucure of quasi-periodicities and their temporal behaviour. Over long time the neutron monitors and muon telescopes provide the informations about quasi-periodicities in CR. In addition to that, in recent years there are new installations on the ground from which the unique information about CR variability can be deduced (higher statistical accuracy, different response function to primaries). The unsolved questions and few tasks for the future studies are listed.

  7. On Determination of Angular Sizes of Some Relatively Hot Stars by Lunar Occultation Observations and on Suggested Interferometric Investigation of these Stars

    NASA Astrophysics Data System (ADS)

    Trunkovsky, E. M.

    2010-02-01

    Interferometric and lunar occultation observations of stars are both the effective techniques which allow us to reach high angular resolution at a level of 1 milliarcsecond and better both in the visual and in the near-IR spectral ranges. Several tens of photoelectric diffraction curves of the lunar occultations of various stars have been recorded with a high time resolution of 1 millisecond at the observatories of the Sternberg Astronomical Institute during about two ten-year periods. Among the stars studied by this method there is a number of relatively hot stars. For some of them the angular sizes determined from analysis of the recorded occultation diffraction curves prove to be different from the expected ones. Possible explanations of such a discrepancy are suggested. A table with information on the stars which could be suspected to have complex structure on the basis of analysis of the lunar occultation observations and other available data is presented. The stellar objects described here could become a subject of interferometric investigation by modern powerful interferometric systems.

  8. Observed temporal evolution of global mean age of stratospheric air for the 2002 to 2010 period

    NASA Astrophysics Data System (ADS)

    Stiller, G. P.; von Clarmann, T.; Haenel, F.; Funke, B.; Glatthor, N.; Grabowski, U.; Kellmann, S.; Kiefer, M.; Linden, A.; Lossow, S.; Lpez-Puertas, M.

    2012-04-01

    An extensive observational data set from MIPAS measurements, consisting of more than one million SF6 vertical profiles distributed globally has been condensed into monthly zonal means of mean age of air for the period September 2002 to January 2010, binned at 10 latitude and 1-2 km altitude. The data were analysed with respect to their temporal variation by fitting a regression model consisting of: a constant and a linear increase term, 2 proxies for the QBO variation, sinusoidal terms for the seasonal and semi-annual variation and overtones for the correction of the shapes to the observed data set. The impact of subsidence of mesospheric SF6-depleted air and in-mixing into non-polar latitudes on mid-latitudinal age of air and its linear increase was assessed and found to be small. The linear increase of mean age of stratospheric air was found to be positive and partly larger than the trend derived by Engel et al. (2009) for most of the Northern mid-latitudes, the middle stratosphere in the tropics, and parts of the Southern mid-latitudes, as well as for the Southern polar upper stratosphere. Multi-year decrease of age of air was found for the lowermost and the upper stratospheric tropics, for parts of Southern mid-latitudes, and for the Northern polar regions. Analyses of the amplitudes and phases of the seasonal variation shed light on the coupling between different stratospheric regions. In particular, the Northern mid-latitude stratosphere is well coupled to the tropics, while the Northern lowermost mid-latitudinal stratosphere is decoupled, confirming the separation of the shallow branch of the Brewer-Dobson circulation from the deep branch. We suggest an overall increased tropical upwelling, together with a weakening of mixing barriers, especially in the Northern hemisphere, as possible explanations for the observed patterns. Reference: Engel, A., Mbius, T., Bnisch, H., Schmidt, U., Heinz, R., Levin, I., Atlas, E., Aoki, S., Nakazawa, T., Sugawara, S., Moore, F., Hurst, D., Elkins, J., Schauffler, S., Andrews, A., and Boering, K.: Age of stratospheric air unchanged within uncertainties over the past 30 years, Nature Geosci., 2, 28-31, doi:10.1038/ngeo388, 2009.

  9. Observed temporal evolution of global mean age of stratospheric air for the 2002 to 2010 period

    NASA Astrophysics Data System (ADS)

    Stiller, G. P.; von Clarmann, T.; Haenel, F.; Funke, B.; Glatthor, N.; Grabowski, U.; Kellmann, S.; Kiefer, M.; Linden, A.; Lossow, S.; Lpez-Puertas, M.

    2012-04-01

    An extensive observational data set, consisting of more than 106 SF6 vertical profiles from MIPAS measurements distributed over the whole globe has been condensed into monthly zonal means of mean age of air for the period September 2002 to January 2010, binned at 10 latitude and 1-2 km altitude. The data were analysed with respect to their temporal variation by fitting a regression model consisting of a constant and a linear increase term, 2 proxies for the QBO variation, sinusoidal terms for the seasonal and semi-annual variation and overtones for the correction of the shapes to the observed data set. The impact of subsidence of mesospheric SF6-depleted air and in-mixing into non-polar latitudes on mid-latitudinal absolute age of air and its linear increase was assessed and found to be small. The linear increase of mean age of stratospheric air was found to be positive and partly larger than the trend derived by Engel et al. (2009) for most of the Northern mid-latitudes, the middle stratosphere in the tropics, and parts of the Southern mid-latitudes, as well as for the Southern polar upper stratosphere. Multi-year decrease of age of air was found for the lowermost and the upper stratospheric tropics, for parts of Southern mid-latitudes, and for the Northern polar regions. Analysis of the amplitudes and phases of the seasonal variation shed light on the coupling of stratospheric regions to each other. In particular, the Northern mid-latitude stratosphere is well coupled to the tropics, while the Northern lowermost mid-latitudinal stratosphere is decoupled, confirming the separation of the shallow branch of the Brewer-Dobson circulation from the deep branch. We suggest an overall increased tropical upwelling, together with weakening of mixing barriers, especially in the Northern Hemisphere, as a hypothetical model to explain the observed pattern of linear multi-year increase/decrease, and amplitudes and phase shifts of the seasonal variation.

  10. Overview of the first HyMeX Special Observation Period over Italy: observations and model results

    NASA Astrophysics Data System (ADS)

    Ferretti, R.; Pichelli, E.; Gentile, S.; Maiello, I.; Cimini, D.; Davolio, S.; Miglietta, M. M.; Panegrossi, G.; Baldini, L.; Pasi, F.; Marzano, F. S.; Zinzi, A.; Mariani, S.; Casaioli, M.; Bartolini, G.; Loglisci, N.; Montani, A.; Marsigli, C.; Manzato, A.; Pucillo, A.; Ferrario, M. E.; Colaiuda, V.; Rotunno, R.

    2013-09-01

    During the first Hymex campaign (5 September-6 November 2012) referred to as Special Observation Period (SOP-1), dedicated to heavy precipitation events and flash floods in Western Mediterranean, three Italian hydro-meteorological monitoring sites were activated: Liguria-Tuscany, North-Eastern Italy and Central Italy. The extraordinary deployment of advanced instrumentation, including instrumented aircrafts, and the use of several different operational weather forecast models has allowed an unprecedented monitoring and analysis of high impact weather events around the Italian hydro-meteorological sites. This activity has seen the strict collaboration between the Italian scientific and operational communities. In this paper, an overview of the Italian organization during the SOP-1 is provided, and selected Intensive Observation Periods (IOPs) are described. A significant event for each Italian target area is chosen for this analysis: IOP2 (12-13 September 2012) in North-Eastern Italy, IOP13 (15-16 October 2012) in Central Italy and IOP19 (3-5 November 2012) in Liguria and Tuscany. For each IOP the meteorological characteristics, together with special observations and weather forecasts, are analyzed with the aim of highlighting strengths and weaknesses of the forecast modeling systems. Moreover, using one of the three events, the usefulness of different operational chains is highlighted.

  11. Equatorial late-afternoon periodic TEC fluctuations observed by multiple GPS receivers

    NASA Astrophysics Data System (ADS)

    Tsugawa, T.; Maruyama, T.; Saito, S.; Ishii, M.

    2009-12-01

    We report, for the first time, equatorial periodic total electron content (TEC) fluctuations observed in the late afternoon by multiple GPS receivers. As a part of Southeast Asia low-latitude ionospheric network (SEALION), GPS receivers at Chiang Mai and Chumphon, Thailand, have been operated since 2005. We found that periodic TEC fluctuations (PTF) with the periods of 15-30 minutes are often observed at these two sites in the spring (Apr-May) late afternoon. Further investigations using multiple GPS receivers in Southeast Asia revealed that the PTFs propagate at 150-200 m/s away from the equator and their amplitudes depend on the satellite azimuth angle. Statistical study of the PTF activity at different latitudes and longitudes clarified that the PTFs are not observed at mid-latitudes, and their seasonal variations are different at different longitudes and at geomagnetically conjugate regions. These observational results indicate that the PTFs are caused by the atmospheric gravity waves (AGW) which are generated in the equatorial lower atmosphere and propagate away from the equator. Simultaneous GPS-TEC and ionosonde observations at Chumphon revealed that the day-to-day variations of PTF activities are well correlated with those of the rate of TEC change index (ROTI) and the occurrence of equatorial spread F (ESF) after the sunset, indicating the PTFs may be related with the onset of the ESF and plasma bubbles.

  12. Real-Space Observation of Short-Period Cubic Lattice of Skyrmions in MnGe.

    PubMed

    Tanigaki, Toshiaki; Shibata, Kiyou; Kanazawa, Naoya; Yu, Xiuzhen; Onose, Yoshinori; Park, Hyun Soon; Shindo, Daisuke; Tokura, Yoshinori

    2015-08-12

    Three-dimensional forms of skyrmion aggregate, such as a cubic lattice of skyrmions, are anticipated to exist, yet their direct observations remain elusive. Here, we report real-space observations of spin configurations of the skyrmion-antiskyrmion cubic-lattice in MnGe with a very short period (?3 nm) and hence endowed with the largest skyrmion number density. The skyrmion lattices parallel to the {100} atomic lattices are directly observed using high-resolution Lorentz transmission electron microscopes, simultaneously with underlying atomic-lattice fringes. PMID:26237493

  13. IS COMPTON COOLING SUFFICIENT TO EXPLAIN EVOLUTION OF OBSERVED QUASI-PERIODIC OSCILLATIONS IN OUTBURST SOURCES?

    SciTech Connect

    Mondal, Santanu; Chakrabarti, Sandip K.; Debnath, Dipak E-mail: chakraba@bose.res.in

    2015-01-01

    In outburst sources, quasi-periodic oscillation (QPO) frequency is known to evolve in a certain way: in the rising phase, it monotonically goes up until a soft intermediate state is achieved. In the propagating oscillatory shock model, oscillation of the Compton cloud is thought to cause QPOs. Thus, in order to increase QPO frequency, the Compton cloud must collapse steadily in the rising phase. In decline phases, the exact opposite should be true. We investigate cause of this evolution of the Compton cloud. The same viscosity parameter that increases the Keplerian disk rate also moves the inner edge of the Keplerian component, thereby reducing the size of the Compton cloud and reducing the cooling timescale. We show that cooling of the Compton cloud by inverse Comptonization is enough for it to collapse sufficiently so as to explain the QPO evolution. In the two-component advective flow configuration of Chakrabarti-Titarchuk, centrifugal force-induced shock represents the boundary of the Compton cloud. We take the rising phase of 2010 outburst of Galactic black hole candidate H 1743-322 and find an estimation of variation of the α parameter of the sub-Keplerian flow to be monotonically rising from 0.0001 to 0.02, well within the range suggested by magnetorotational instability. We also estimate the inward velocity of the Compton cloud to be a few meters per second, which is comparable to what is found in several earlier studies of our group by empirically fitting the shock locations with the time of observations.

  14. Is Compton Cooling Sufficient to Explain Evolution of Observed Quasi-periodic Oscillations in Outburst Sources?

    NASA Astrophysics Data System (ADS)

    Mondal, Santanu; Chakrabarti, Sandip K.; Debnath, Dipak

    2015-01-01

    In outburst sources, quasi-periodic oscillation (QPO) frequency is known to evolve in a certain way: in the rising phase, it monotonically goes up until a soft intermediate state is achieved. In the propagating oscillatory shock model, oscillation of the Compton cloud is thought to cause QPOs. Thus, in order to increase QPO frequency, the Compton cloud must collapse steadily in the rising phase. In decline phases, the exact opposite should be true. We investigate cause of this evolution of the Compton cloud. The same viscosity parameter that increases the Keplerian disk rate also moves the inner edge of the Keplerian component, thereby reducing the size of the Compton cloud and reducing the cooling timescale. We show that cooling of the Compton cloud by inverse Comptonization is enough for it to collapse sufficiently so as to explain the QPO evolution. In the two-component advective flow configuration of Chakrabarti-Titarchuk, centrifugal force-induced shock represents the boundary of the Compton cloud. We take the rising phase of 2010 outburst of Galactic black hole candidate H 1743-322 and find an estimation of variation of the α parameter of the sub-Keplerian flow to be monotonically rising from 0.0001 to 0.02, well within the range suggested by magnetorotational instability. We also estimate the inward velocity of the Compton cloud to be a few meters per second, which is comparable to what is found in several earlier studies of our group by empirically fitting the shock locations with the time of observations.

  15. EVOLUTIONARY TRACKS OF TRAPPED, ACCRETING PROTOPLANETS: THE ORIGIN OF THE OBSERVED MASS-PERIOD RELATION

    SciTech Connect

    Hasegawa, Yasuhiro; Pudritz, Ralph E. E-mail: pudritz@physics.mcmaster.ca

    2012-12-01

    The large number of observed exoplanets ({approx}>700) provides important constraints on their origin as deduced from the mass-period diagram of planets. The most surprising features in the diagram are (1) the (apparent) pileup of gas giants at a period of {approx}500 days ({approx}1 AU) and (2) the so-called mass-period relation, which indicates that planetary mass is an increasing function of orbital period. We construct the evolutionary tracks of growing planets at planet traps in evolving protoplanetary disks and show that they provide a good physical understanding of how these observational properties arise. The fundamental feature of our model is that inhomogeneities in protoplanetary disks give rise to multiple (up to 3) trapping sites for rapid (type I) planetary migration of planetary cores. The viscous evolution of disks results in the slow radial movement of the traps and their cores from large to small orbital periods. In our model, the slow inward motion of planet traps is coupled with the standard core accretion scenario for planetary growth. As planets grow, type II migration takes over. Planet growth and radial movement are ultimately stalled by the dispersal of gas disks via photoevaporation. Our model makes a number of important predictions: that distinct sub-populations of planets that reflect the properties of planet traps where they have grown result in the mass-period relation, that the presence of these sub-populations naturally explains a pileup of planets at {approx}1 AU, and that evolutionary tracks from the ice line do put planets at short periods and fill an earlier claimed {sup p}lanet desert{sup -}a sparse population of planets in the mass-semimajor axis diagram.

  16. Period of the Slichter mode of Mercury and its possible observation

    NASA Astrophysics Data System (ADS)

    Coyette, A.; Van Hoolst, T.; Dehant, V.

    2012-07-01

    Aims: We study the period of the Slichter mode (vibrational mode of the inner core of a planet) of Mercury in relation to its interior structure and assess the possibility to observe this mode with the probes MESSENGER and BepiColombo. Methods: The methodology of Grinfeld & Wisdom (2005, Phys. Earth Planet. Int., 151, 77) for the determination of the period of the polar Slichter modes of a planetary interior consisting of three homogeneous layers is generalized to models with an arbitrary but finite number of layers. Slichter modes periods are calculated for a large set of interior structure models of Mercury. We study the possible excitation of Slichter modes by a colllision with a meteoroid and estimate the minimal size of the meteoroid that could lead to a detection of these modes by BepiColombo. Results: The Slichter mode period obtained is on the order of several hours. Observation of the Slichter mode of Mercury allows constraining the inner core. An impact by a meteoroid with a radius of at least 100 m could excite the Slichter mode to a level observable by BepiColombo (assuming that the Slichter mode is the only excited mode), but since the estimated damping time of the Slichter mode is well below the average time between impacts of at least that size such an impact must have occured recently (less than 0.5 My ago).

  17. Local Scale Radiobrightness Modelling during Intensive Observing Period-4 of the Cold Land Processes Experiment-1

    NASA Technical Reports Server (NTRS)

    Kim, Edward J.; Tedesco, Marco; deRoo, Roger; England, Anthony W.; Gu, Haoyu; Pham, Hanh; Boprie, David; Graf, Tobias; Koike, Toshio; Armstrong, Richard

    2004-01-01

    The NASA Cold Land Processes Field Experiment (CLPX-1) was designed to provide microwave remote sensing observations and ground truth for studies of snow and frozen ground remote sensing, particularly issues related to scaling. CLPX-1 was conducted in the spring of 2003 in Colorado, USA. Initial forward model validation work is concentrating on the Local-Scale Observation Site (LSOS), a 0.8 ha study site consisting of open meadows separated by trees where the most detailed measurements were made of snow depth and temperature, density, and grain size profiles. This paper will focus on the ability of forward Dense Medium Radiative Transfer (DMRT) modelling, combined with snowpack measurements to reproduce the radiobrightness signatures observed by the University of Michigan s Truck-Mounted Radiometer System at 19 and 37 GHz during the 4th Intensive Observing Period (IOP4) in March, 2003. Unlike the earlier IOP3, conditions during IOP4 include both wet and dry periods, providing a valuable test of DMRT model performance. Observations of upwelling and downwelling tree radiobrightness will be used to formulate a simple model for the effect of trees within the field of view. In addition, a comparison will be made for the one day of coincident observations by the University of Tokyo s Ground- Based Microwave Radiometer-7 (GBMR-7). These analyses will help guide the choice of future snow retrieval algorithms and the design of future Cold Lands observing systems.

  18. VizieR Online Data Catalog: Observed Periods of Ap and Bp stars (Catalano+ 1998)

    NASA Astrophysics Data System (ADS)

    Catalano, F. A.; Renson, P.

    1997-11-01

    A catalogue of all the periods published up to 31 October 1996 on 364 CP stars is presented; it supersedes the previous version (catalog ). The paper version (catalog.tex) is arranged in three tables: the bulk of the data, i.e. those referring to CP2, CP3, and CP4 stars, are given in Table 1, while the data concerning He-strong stars are given in Table 2 and those for eclipsing or ellipsoidal variables are collected in Table 3. Notes are also provided at the end of each table, mainly about duplicities. The machine-readable version was arranged in two main parts: the main parameters of the 364 stars (identifiers and names, positions, spectral types, magnitudes and peculiarities) are tabulated in the file 'stars'; periods and the of the observed variations (light, spectrum, magnetic field, etc.) are listed in the 'periods' file. Two other files contains the notes and the references. (5 data files).

  19. Elemental GCR Observations during the 2009-2010 Solar Minimum Period

    NASA Technical Reports Server (NTRS)

    Lave, K. A.; Israel, M. H.; Binns, W. R.; Christian, E. R.; Cummings, A. C.; Davis, A. J.; deNolfo, G. A.; Leske, R. A.; Mewaldt, R. A.; Stone, E. C.; vonRosenvinge, T. T.; Wiedenbeck, M. E.

    2013-01-01

    Using observations from the Cosmic Ray Isotope Spectrometer (CRIS) onboard the Advanced Composition Explorer (ACE), we present new measurements of the galactic cosmic ray (GCR) elemental composition and energy spectra for the species B through Ni in the energy range approx. 50-550 MeV/nucleon during the record setting 2009-2010 solar minimum period. These data are compared with our observations from the 1997-1998 solar minimum period, when solar modulation in the heliosphere was somewhat higher. For these species, we find that the intensities during the 2009-2010 solar minimum were approx. 20% higher than those in the previous solar minimum, and in fact were the highest GCR intensities recorded during the space age. Relative abundances for these species during the two solar minimum periods differed by small but statistically significant amounts, which are attributed to the combination of spectral shape differences between primary and secondary GCRs in the interstellar medium and differences between the levels of solar modulation in the two solar minima. We also present the secondary-to-primary ratios B/C and (Sc+Ti+V)/Fe for both solar minimum periods, and demonstrate that these ratios are reasonably well fit by a simple "leaky-box" galactic transport model that is combined with a spherically symmetric solar modulation model.

  20. First continuous ground-based observations of long period oscillations in strato-/mesospheric wind profiles

    NASA Astrophysics Data System (ADS)

    Rfenacht, R.; Hocke, K.; Kmpfer, N.

    2015-12-01

    Direct measurements of middle-atmospheric wind oscillations with periods between 5 and 50 days in the altitude range between mid-stratosphere (5 hPa) and upper mesosphere (0.02 hPa) have been made using a novel ground-based Doppler wind radiometer. The oscillations were not inferred from measurements of tracers, as the radiometer offers the unique capability of near-continuous horizontal wind profile measurements. Observations from four campaigns at high, mid and low latitudes with an average duration of 10 months have been analyzed. The dominant oscillation has mostly been found to lie in the extra-long period range (20-40 days), while the well-known atmospheric normal modes around 5, 10 and 16 days have also been observed. Comparisons of our results with ECMWF operational analysis model data revealed remarkably good agreement below 0.3 hPa but discrepancies above.

  1. Period doubling observed in the circadian photosynthetic rhythm of the prokaryotic cyanobacterium Cyanothece RF-1

    NASA Astrophysics Data System (ADS)

    Yen, Tsu-Chiang; Cheng, Da-Long

    2005-03-01

    The circadian rhythm is an endogenous biological clock that governs biochemical phenomena or behavior in organisms. The Cyanothece RF-1 is the first prokaryote shown to exhibit circadian nitrogen-fixing rhythm. The observation of the circadian photosynthetic rhythm of this strain was recently reported by the authors. In this work, the dissolved-oxygen variation in the culture of Cyanothece RF-1 was recorded, which would reveal the photosynthetic activity of the strain. For a culture of about 1x10^8 cells/ml in concentration, a period-doubling pattern was clearly displayed in the circadian photosynthetic rhythm signals. The mechanism corresponding to this nonlinear effect will be discussed. These results represent the first observation of the period doubling in the circadian rhythm of a prokaryotic cyanobacterium.

  2. Recurring Swarms of Deep Long Period Earthquakes in the Denali Volcanic Gap Suggest a Continuation of Volcanic Processes in the Absence of Active Volcanism

    NASA Astrophysics Data System (ADS)

    Holtkamp, S. G.; Ruppert, N. A.; Silwal, V.; Christensen, D. H.; Nye, C. J.

    2014-12-01

    Seismicity in the northern segment of the Denali Volcanic Gap clusters bimodally with depth, with dense clusters of earthquakes occurring in the subducting slab at >100 km depth beneath Denali, and within the crust north of the Denali fault at <20 km depth. On January 22, 2014, the Alaska Earthquake Center recorded a Deep Long Period earthquake (DLP), magnitude 1.7, at 40 km depth north of the Denali Fault. The epicenter for this event was <5 km of broadband station TRF, so the depth is well constrained. The DLP event is almost devoid of energy above 5 Hz. Receiver functions for stations TRF and SBL, both <10 km of the epicenter, show Moho depths of 36-40 km.We used waveforms of this DLP as a template event for network matched filtering, which identifies similar signals in continuous time series. We processed this template event from June 1999 to July 2014. We use several matches produced by this template as additional templates, iterating the process. Using this methodology, we identify over 300 DLP's. Events typically come in swarms lasting hours to days with no events exceeding magnitude 2. Swarms are separated by months to years of little detectable activity. A swarm of events on June 30, 2001 coincides with the Broadband Experiment Across the Alaska Range (BEAAR) seismic deployment, and was recorded by 15 broadband seismometers within 100 km of the epicenter. A preliminary waveform inversion for the focal mechanism of this event results in isotropic (implosive) and double couple components.We argue that these DLP's are evidence of magmatic or volatile movement through the sub-arc mantle wedge, even though there is no active volcanism at the surface. Relative relocations, utilizing cross correlated p- and s- waveforms, highlight a nest of seismicity with no structures such as planes or conduits. Lack of planar features, as well as the isotopic component and lack of strike slip to the focal mechanism, may argue against a deep extension of the Hines Creek or Denali faults (both strike-slip) as a source for the DLP's (as is the case for low frequency earthquakes along the deep extension of the San Andreas). High Poisson's ratios have been inferred for the sub-arc mantle wedge by McNamera and Pasyanos (2002), and in the crust north of Denali (Rossi et al., 2006), suggesting the presence of volatiles or magma migrating through to the crust.

  3. Reconstruction of mean sea level and polar ice periodical variations by Earth rotation observations

    NASA Astrophysics Data System (ADS)

    Chapanov, Yavor; Gambis, Daniel

    2010-05-01

    The global water redistribution between continental ice sheets and oceans, due to climatic and weather conditions, leads to significant changes of the main axial inertial moment of the Earth. These changes are compensated by corresponding variations of the angular velocity of the Earth, according to the law of angular momentum conservation. The Earth rotation variations are determined by monitoring of the rotational angle and angular velocity changes, so-called Universal Time (UT1) and Length of Day (LOD) observations. The modern astronomical and space-based observational techniques provide high-accurate UT1 and LOD solutions since 1962. Long time series of UT1 and LOD variations since 1623 are determined on the base of historical astronomical observations of star occultaions. These time series are useful to determine Earth rotation response to the solar activity cycles with periods of 11, 22, 45 and more years. The solar activity cycles, represented by Wolf's numbers and Total Solar Irradiance (TSI) variations, are synchronized with the corresponding oscillations of the Earth rotation, drought indices and Mean Sea Level (MSL), determined from maregraph data. The empirical model of global water redistribution between the oceans and continental ice, due to variations of the TSI and additional water evaporation during the sunspot cycles, is the only explanation of the observed common oscillations of TSI, MSL, drought indices, UT1 and LOD. The amplitude of 1mm of the mean sea level oscillation with periods 11, 22 and 45 years corresponds to UT1 oscillations with the same periods and amplitudes 12.5ms, 25ms and 50ms, according to the model. This model allows backward reconstruction of the MSL, continental and sea ice periodical variations for the last 4 centuries, synchronized with the solar cycles, by means of the existing Earth rotation data.

  4. A Multiband Generalization of the Multiharmonic Analysis of Variance Period Estimation Algorithm and the Effect of Inter-band Observing Cadence on Period Recovery Rate

    NASA Astrophysics Data System (ADS)

    Mondrik, N.; Long, J. P.; Marshall, J. L.

    2015-10-01

    We present a new method of extending the single-band multiharmonic analysis of variance period estimation algorithm to multiple bands. We use Sloan Digital Sky Survey Stripe 82 RR Lyrae to show that in the case of a low number of observations per band and non-simultaneous observations, improvements in period recovery rates of up to ?50% are observed. We also investigate the effect of inter-band observing cadence on period recovery rates. We find that using non-simultaneous observation times between bands is ideal for the multiband method, and using simultaneous multiband data is only marginally better than using single-band data. These results will be particularly useful in planning observing cadences for wide-field astronomical imaging surveys such as Large Synoptic Survey Telescope. They also have the potential to improve the extraction of transient data from surveys with few (?30) observations per band across several bands, such as the Dark Energy Survey.

  5. Comparison of Sunphotometric Measurements During the Fall 1997 ARM Intensive Observation Period

    NASA Technical Reports Server (NTRS)

    Michalsky, J. J.; Schmid, B.; Halthore, R. N.; Pavloski, C. F.; Ackerman, T. P.; Beauharnois, M. C.; Harrison, L. C.; Livingston, J. M.; Russell, P. B.

    2000-01-01

    In the Fall of 1997 the Atmospheric Radiation Measurement (ARM) program held an intensive observation period (IOP) to study atmospheric aerosols using in situ and remote sensing techniques at its Southern Great Plains (SGP) site near Lamont, Oklahoma. As part of this experiment five automated, tracking sunphotometers were present to measure total column aerosol optical depth over the three-week period. which included many clear days or parts of days that were clear. The World Meteorological Organization (WMO 1993) has recommended a comparison of tracking sunphotometers to assess the ability of different instruments to arrive at similar aerosol optical depths. It was further recommended that the comparison be staged at a clean mountain site. In fact, this comparison has not occurred, but the comparison that we describe in this paper is representative of what contemporary instruments may accomplish in an environment more typical of sites where aerosols measurements will be required. The measurements were made over the period 15 September to 5 October 1997. The aerosol loading varied from extremely clean to moderately turbid conditions. In the next section the instruments will be described along with a brief explanation of the calibration techniques. The third section contains the results compared graphically on moderately turbid and fairly clean days and in a table representing the whole period. The paper ends with a section of discussion and a summary of the results.

  6. Local Scale Radiobrightness Modeling During the Intensive Observing Period-4 of the Cold Land Processes Experiment-1

    NASA Technical Reports Server (NTRS)

    Kim, Edward J.; Tedesco, Marco; deRoo, Roger; England, Anthony W.; Gu, Hao-Yu; Pham, Hanh; Boprie, David; Graf, Tobias; Koike, Toshio; Armstrong, Richard

    2005-01-01

    The NASA Cold Land Processes Field Experiment (CLPX-1) was designed to provide microwave remote sensing observations and ground truth for studies of snow and frozen ground remote sensing, particularly issues related to scaling. CLPX-1 was conducted in 2002 and 2003 in Colorado, USA. One of the goals of the experiment was to test the capabilities of microwave emission models at different scales. Initial forward model validation work has concentrated on the Local-Scale Observation Site (LSOS), a 0.8 ha study site consisting of open meadows separated by trees where the most detailed measurements were made of snow depth and temperature, density, and grain size profiles. Results obtained in the case of the 3& Intensive Observing Period (IOP3) period (Feb., 2003, dry snow) suggest that a model based on Dense Medium Radiative Transfer (DMRT) theory is able to model the recorded brightness temperatures using snow parameters derived from field measurements. This paper focuses on the ability of forward DMRT modelling, combined with snowpack measurements, to reproduce the radiobrightness signatures observed by the University of Michigan s Truck-Mounted Radiometer System (TMRS) at 19 and 37 GHz during the 4th IOP (IOP4) in March, 2003. Unlike IOP3, conditions during IOP4 include both wet and dry periods, providing a valuable test of DMRT model performance. In addition, a comparison will be made for the one day of coincident observations by the University of Tokyo's Ground-Based Microwave Radiometer-7 (GBMR-7) and the TMRS. The plot-scale study in this paper establishes a baseline of DMRT performance for later studies at successively larger scales. And these scaling studies will help guide the choice of future snow retrieval algorithms and the design of future Cold Lands observing systems.

  7. Confrontation Between a Quantized Periods of Some Exo-planetary Systems and Observations

    NASA Astrophysics Data System (ADS)

    El Fady Morcos, Abd

    2012-07-01

    Confrontation Between a Quantized Periods of Some Exo-planetary Systems and Observations A.B. Morcos Corot and Kepler were designed to detect Earth-like extra solar planets. The orbital elements and periods of these planets will contain some uncertainties. Many theoretical treatments depend on the idea of quantization were done aiming to find orbital elements of these exoplenets. In the present work, as an extension of previous works, the periods of some extoplanetary systems are calculated by using a simple derived formula. The orbital velocities of some of them are predicted . A comparison between the calculated and observed data is done References 1-J.M. Barnothy , the stability of the Solar System and of small Stellar Systems . (Y.Kazai edn,IAU,1974). 2-L.Nottale,Fractal Space-Time and Microphysics,Towards a Theory of Scale Relativity,( World Scientific, London,1994). 3-L. Nottale, A&A Lett. 315, L9 (1996). 4-L. Nottale, G. Schumacher and J. Gay, A&A , 322, 1018 , (1997). 5-L. Nottale, A&A , 361, 379 (2000). 6-A.G. Agnese and R.Festa, arXiv:astro-ph/9807186v1, (1998). 7-A.G. Agnese and R.Festa, arXiv:astro-ph/9910534v2. (1999). 8- A.B.Morcos, MG 12 , France (2009). 9- A.B.Morcs, Cospar 38 , Bremen , Germany (2010)

  8. Some observations regarding the thermal flux from Earth's erupting volcanoes for the period 2000 to 2014

    NASA Astrophysics Data System (ADS)

    Wright, R.; Blackett, M.; Hill-Butler, C.

    2014-12-01

    This presentation will describe 15 years of MODIS observations of the thermal flux from Earth's sub-aerially erupting volcanoes. The MODVOLC algorithm has been providing data regarding volcanic eruptions on Earth to the volcanological community since the launch of Terra MODIS, via the internet, in near-real-time (http:modis.higp.hawaii.edu). During this time, eruptions at 102 volcanoes have been observed, including activity associated with mafic lava flows, lava lakes, vent-based explosive activity and felsic lava domes. This presentation will present an overview of how MODIS has documented every eruption to occur on Earth since 2000, and will describe some of the more interesting result that have been obtained from the analysis of this archive. The total amount of energy radiated into the atmosphere can be divided into two parts: a baseline level of emission which has increased gradually over this 15 period, superimposed on which are large "spikes" attributable to large, lava-flow-forming eruptions. The most intense eruption during this period of time was the 2004 eruption of Nyamuragira, in the Democratic Republic of Congo, whilst the largest magnitude event was the 2012-2013 eruption of Tolbachik, Russia. Spatio-temporal patterns in thermal output will be addressed. Time-series analysis of heat flux from these 102 volcanoes has revealed while some volcanoes exhibit statistically significant periodicity in the magnitude of their heat output, many do not.

  9. Observing and Modeling Long-Period Tidal Variations in Polar Motion

    NASA Technical Reports Server (NTRS)

    Gross, Richard S.; Dickman, S. R.

    2011-01-01

    By exchanging angular momentum with the solid Earth, ocean tides cause the Earth's rotation to change. While hydrodynamic tide models have been used to study the effect of ocean tides on polar motion, it is shown here that none of the published models can fully account for the observed variations. An empirical ocean tide model is therefore determined by fitting periodic terms at the tidal frequencies to polar motion excitation observations, from which atmospheric and non-tidal oceanic effects were removed. While the empirical ocean tide model does fully account for allof the observed tidal power, tests indicate that the model may not have completely converged. So better models of the effects of ocean tides on polar motion are still needed, both dynamical and empirical.

  10. Observations of 20-day period meridional current oscillations in the upper ocean along the Pacific Equator

    NASA Technical Reports Server (NTRS)

    Halpern, David; Knox, Robert A.; Luther, Douglas S.

    1988-01-01

    Prominent oscillations of the meridional current, with a mean period of approximately 20 days, is observed in the upper ocean from May 1979 to October 1985 using moored current measurements along the Pacific equator at 95, 110, 124, 140, and 152 deg W, as well as off (but near) the equator at 110 and 140 deg W. The fluctuations are relatively narrowband in frequency. A 95 percent statistically significant peak in the power spectra of the meridional current occurs at 110, 124, and 140 deg W, but not at 95 and 152 deg W where the spectral peaks are smaller. The dominant wave period decreases by about 4 percent from 110 to 140 deg W. The wave amplitude decreases with depth, and the wave is essentially confined to the upper 80 m. The penetration depth of the oscillation is greatest at 110 deg W and least at 140 deg W.

  11. On quasi-periodic variations of low-energy cosmic rays observed near earth.

    PubMed

    Kudela, Karel; Langer, Ronald

    2015-06-01

    Cosmic ray (CR) may partially, especially at high altitudes, contribute to the dosimetric characteristics. Along with irregular CR variations as Forbush decreases and solar particle events are, the quasi-periodic variations may be of some relevance too. A very short review (with references to original papers) of the present knowledge of various types of such variations is presented, namely (i) diurnal wave, (ii) ~27 d variability due to the solar rotation, (iii) Rieger-type periodicity, and (iv) quasi-biennial oscillations as well as waves on longer time scales related to solar activity and to polarity of magnetic field of the Sun. Variability is illustrated in measurements of secondary CR on the ground including the high-altitude observations at Lomnický štít. PMID:25979741

  12. SOHO/SWAN OBSERVATIONS OF SHORT-PERIOD SPACECRAFT TARGET COMETS

    SciTech Connect

    Combi, M. R.; Lee, Y.; Patel, T. S.; Maekinen, J. T. T.; Bertaux, J.-L.; Quemerais, E.

    2011-04-15

    SWAN, the Solar Wind ANisotropies all-sky hydrogen Ly{alpha} camera on the Solar and Heliospheric Observatory spacecraft that makes all-sky images of interplanetary neutral hydrogen, has an ongoing campaign to make special observations of comets, both short- and long-period ones, in addition to the serendipitous observations of comets as part of the all-sky monitoring program. We report here on a study of several short-period comets that were detected by SWAN: 21P/Giacobini-Zinner (1998 and 2005 apparitions), 19P/Borrelly (2001 apparition), 81P/Wild 2 (1997 apparition), and 103P/Hartley 2 (1997 apparition). SWAN observes comets over long continuous stretches of their visible apparitions and therefore provides excellent temporal coverage of the water production. For some of the observations we are also able to analyze an entire sequence of images over many days to several weeks/months using our time-resolved model and extract daily average water production rates over continuous periods of several days to months. The short-term (outburst) and long-term behavior can be correlated with other observations. The overall long-term variation is examined in light of seasonal effects seen in the pre- to post-perihelion differences. For 21P/Giacobini-Zinner and 81P/Wild 2 the activity variations over each apparition were more continuously monitored but nonetheless consistent with previous observations. For 19P/Borrelly we found a very steep variation of water production rates, again consistent with some previous observations, and a variation over six months around perihelion that was reasonably consistent with the spin-axis model of Schleicher et al. and the illumination of the main active areas. During the 1997-1998 apparition of 103P/Hartley 2, the target comet of the EPOXI mission (the Deep Impact extended mission), we found a variation with heliocentric distance ({approx}r{sup -3.6}) that was almost as steep as 19P/Borrelly and, given the small measured radius near aphelion, this places a number of possible constraints on the size, shape, and/or distribution active of areas on the surface.

  13. Dynamics of long-period ULF waves in the plasma sheet: Coordinated space and ground observations

    NASA Astrophysics Data System (ADS)

    Tian, A. M.; Zong, Q. G.; Zhang, T. L.; Nakamura, R.; Du, A. M.; Baumjohann, W.; Glassmeier, K. H.; Volwerk, M.; Hartinger, M.; Wang, Y. F.; Du, J.; Yang, B.; Zhang, X. Y.; Panov, E.

    2012-03-01

    Spacecraft and ground-based observations are used to study characteristics of ultralow frequency waves in the plasma sheet from the postmidnight to morning local time sectors in the terrestrial magnetosphere. Field line resonance (FLR) type oscillations with discrete and latitude-dependent frequencies in the ranges of 1.7-2.0 and 3.0-3.2 mHz are observed in situ by the Time History of Events and Macroscale Interactions during Substorms C (THEMIS C), THEMIS D, THEMIS E, and GOES 12 spacecraft. The ground resonant oscillations in the two mentioned frequency bands are also observed at corresponding spacecraft footprints. Spectral peaks at these frequencies are observed by nearly all ground stations from premidnight to noon, with the larger-amplitude oscillations occurring in a narrow range of latitudes (3-6). The largest wave activity occurred in the magnetic local time of 05:00. The ground observations indicate westward propagation for the 1.8 mHz wave activity with an azimuthal wave number of about -2.6. The Poynting vectors from the THEMIS spacecraft show weak net energy flow (antifield aligned) toward the ionosphere of the southern hemisphere. They also show notable net energy flow toward the west. A possible interpretation is that the observed FLRs are driven by cavity and waveguide modes in the nightside outer magnetosphere after a period of long-lasting northward interplanetary magnetic field.

  14. Results of IPS Observations in the Period Near Solar Activity Minimum

    NASA Astrophysics Data System (ADS)

    Chashei, I. V.; Shishov, V. I.; Tyul'bashev, S. A.; Subaev, I. A.; Oreshko, V. V.

    2013-07-01

    IPS observations with the Big Scanning Array of Lebedev Physical Institute (BSA LPI) radio telescope at the frequency 111 MHz have been monitored since 2006. All the sources, about several hundred daily, with a scintillating flux greater than 0.2 Jy are recorded for 24 hours in the 16 beams of the radio telescope covering a sky strip of 8∘ declination width. We present some results of IPS observations for the recent period of low solar activity considering a statistical ensemble of scintillating radio sources. The dependences of the averaged over ensemble scintillation index on heliocentric distance are considerably weaker than the dependence expected for a spherically symmetric geometry. The difference is especially pronounced in the year 2008 during the very deep solar activity minimum period. These features are explained by the influence of the heliospheric current sheet that is seen as a strong concentration of turbulent solar wind plasma aligned with the solar equatorial plane. A local maximum of the scintillation index is found in the anti-solar direction. Future prospects of IPS observations using BSA LPI are briefly discussed.

  15. Direct experimental observation of periodic intensity modulation along a straight hollow-core optical waveguide

    SciTech Connect

    Pfeifer, T.; Downer, M. C.

    2007-05-15

    We report the direct observation of periodic intensity modulation of a laser pulse propagating in a hollow-core waveguide. A series of equally spaced plasma sparks along the gas-filled capillary is produced. This effect can be explained by the beating of different fiber modes, which are excited by controlling the size of the focal spot at the capillary entrance. As compared with an artificial modulated waveguide structure, our presented approach represents an easier and more flexible quasi-phase-matching scheme for nonlinear-optical frequency conversion.

  16. The continuous spectrum of Markarian 421 during periods of X-ray satellite observations

    NASA Technical Reports Server (NTRS)

    Mufson, S. L.; Wood, K.; Mcnutt, D. P.; Yentis, D. J.; Meekins, J. F.; Byram, E. T.; Chubb, T. A.; Friedman, H.; Wisniewski, W. Z.

    1980-01-01

    New UBVRI photometry of Mrk 421 obtained during periods of X-ray satellite observations are presented. An X-ray light curve for 1977 November from the HEAO A-1 experiment is also given. The decomposition of the UBVR fluxes into a compact nonthermal component and an extended galactic component shows that there are coordinated variations in the optical nonthermal and X-ray emission. The data are consistent with the hypothesis that the mini-BL Lac object is emitting by the synchrontron-self-Compton process. The host galaxy of this composite source has properties like those of a giant elliptical.

  17. Real-Space Observation of Short-Period Cubic Lattice of Skyrmions in MnGe

    NASA Astrophysics Data System (ADS)

    Tanigaki, Toshiaki; Shibata, Kiyou; Kanazawa, Naoya; Yu, Xiuzhen; Onose, Yoshinori; Park, Hyun Soon; Shindo, Daisuke; Tokura, Yoshinori

    2015-08-01

    Emergent phenomena and functions arising from topological electron-spin textures in real space or momentum space are attracting growing interest for new concept of states of matter as well as for possible applications to spintronics. One such example is a magnetic skyrmion, a topologically stable nanoscale spin vortex structure characterized by a topological index. Real-space regular arrays of skyrmions are described by combination of multi-directional spin helixes. Nanoscale configurations and characteristics of the two-dimensional skyrmion hexagonal-lattice have been revealed extensively by real-space observations. Other three-dimensional forms of skyrmion lattices, such as a cubic-lattice of skyrmions, are also anticipated to exist, yet their direct observations remain elusive. Here we report real-space observations of spin configurations of the skyrmion cubic-lattice in MnGe with a very short period (~3 nm) and hence endowed with the largest skyrmion number density. The skyrmion lattices parallel to the {100} atomic lattices are directly observed using Lorentz transmission electron microscopes (Lorentz TEMs). It enables the first simultaneous observation of magnetic skyrmions and underlying atomic-lattice fringes. These results indicate the emergence of skyrmion-antiskyrmion lattice in MnGe, which is a source of emergent electromagnetic responses and will open a possibility of controlling few-nanometer scale skyrmion lattices through atomic lattice modulations.

  18. Photometric and spectrophotometric observations of CH Cygni in the period 1978-1982

    NASA Astrophysics Data System (ADS)

    Ipatov, A. P.; Taranova, O. G.; Iudin, B. F.

    1984-06-01

    The authors present results obtained from photometric (in the UBVRJHKLMNQ system) and spectrophotometric (in the range of 0.33 to 1.1 ?m) observations of CH Cygni, carried out in the period 1978 - 1982. The maximum UV emission of the star was observed in the spring of 1982. However, the bolometric luminosity of the UV source never exceeded 10% of that of the cool star, classified as M6III. The relatively small bolometric luminosity of the hot source does not enable to reject the single-star model with a hot spot in the atmosphere of the red giant for explaining the phenomenon of CH Cyg. In the middle of 1977, the luminosity of the hot radiation source increased, at the same time, the flux from the circumstellar dust envelope started growing. A possible explanation is that the emission of the hot source appearing against the background of the red giant, inevitably has a pronounced effect upon the envelope luminosity.

  19. Observation of quasi-periodic route to chaos in driven dusty plasma

    NASA Astrophysics Data System (ADS)

    Theisen, W. L.; Sheridan, T. E.

    2008-10-01

    Chaotic dynamics have previously been observed in a driven dusty plasma with three particles [T. E. Sheridan, Phys. Plasma 12, 080701 (2005)] due to a resonance overlap between the center-of-mass and breathing modes. In the present work, the transition to chaos in this system is characterized as a function of driving amplitude for two different driving frequencies. In the first case, the driving frequency is matched to the frequency minimum of the Arnold tongue, while in the second case, the driving frequency is slightly above this value. Dynamics are characterized by the power spectrum, Lyapunov exponent, and correlation dimension, as a function of driving amplitude. For the higher driving frequency we observe asymmetric spectral sidebands at intermediate driving amplitudes, a clear indication of quasi-periodic dynamics. For large driving amplitudes the dynamics become chaotic.

  20. Observation of gamma rays with a 4.8 hour periodicity from CYG X-3

    NASA Technical Reports Server (NTRS)

    Lamb, R. C.; Fichtel, C. E.; Hartman, R. C.; Kniffen, D. A.; Thompson, D. J.

    1976-01-01

    Energetic (E35 MeV) Gamma rays were observed from Cyg X-3 with the SAS-2 Gamma ray telescope. They are modulated at the 4.8 sup h period observed in the X-ray and infrared regions, and within the statistical error are in phase with this emission. The flux above 100 MeV has an average value of (4.4 + or - 1.1)x 10 to the -6 power/sq cm/sec. If the distance to Cyg X-3 is 10 kpcs, this flux implies a luminosity of more than 10 to the 37th power ergs/s if the radiation is isotropic and about 10 to the 36th power ergs/s if the radiation is restricted to a cone of one steradian, as it might be in a pulsar.

  1. Cluster observations of quasi-periodic impulsive signatures in the dayside northern lobe: High-latitude flux transfer events?

    NASA Technical Reports Server (NTRS)

    Thompson, S. M.; Kivelson, M. G.; Khurana, K. K.; Balogh, A.; Reme, H.; Fazakerley, A. N.; Kistler, L. M.

    2004-01-01

    We report on a series of quasi-periodic reversals in GSM B(sub Z) observed by the four Cluster spacecraft in the northern dayside lobe poleward of the cusp on 23 February 2001. During an interval of about 35 min, multiple reversals (negative to positive) in B(sub Z) of approximately 1-min duration with an approximate 8-min recurrence time were observed. The individual structures do not resemble low-latitude flux transfer events (FTE) [Russell and Elphic, 1979] but the 8-min recurrence frequency suggests that intermittent reconnection may be occurring .Measurements (appropriately lagged) of the solar wind at ACE show that the IMF was southward-oriented with a strong B(sub X) and that a modest dynamic pressure increased as the events started. The multi-point observations afforded by the Cluster spacecraft were used to infer the motion (direction and speed) of the observed magnetic field reversals. The associated currents were also calculated and they are consistent with the spatial confinement of the observed magnetic field reversals. We propose that the observed reversals are due to flux tubes reconnecting with closed field lines on the dayside. Ancillary data from the Cluster Ion Spectrometry (CIS) and Plasma Electron And Current Experiment (PEACE) instruments were used to develop a physical picture of the reversals.

  2. The French component of the FENNEC Saharan Climate project 2011 Special Observing Period

    NASA Astrophysics Data System (ADS)

    Flamant, C.; Chaboureau, J.-P.; Kocha, C.; Lavaysse, C.; Schepanski, K.; Chazette, P.; Bock, O.; Marticorena, B.; Tulet, P.; Pelon, J.; Marnas, F.; Mokhtari, M.; Lafore, J.-P.; Roehrig, R.; Koulali Idrissi, A.; Tsamalis, C.; Chedin, A.

    2012-04-01

    The central Sahara has one of the most extreme climates on Earth. During the northern summer months, a large low pressure system caused by intense solar heating develops over a huge, largely uninhabited expanse of northern Mali, southern Algeria and eastern Mauritania. This Saharan heat low plays a pivotal role in the West African Monsoon. Based on this, the interested French, British and German communities have decided to propose the FENNEC project which aims at (i) characterizing the Saharan atmospheric boundary layer, (ii) evaluating its representation in regional and global models, and (iii) improving "aerosol" products issued from space-borne observations. A key element of this programme was the organization of an international field campaign in June 2011 over the Saharan heat low region, which will include both ground-based and airborne detachments. The Special Observing Period component of FENNEC-France included the implementation of the SAFIRE Falcon 20 to conduct research on the atmospheric boundary layer and the dust cycle of the Sahara, the installation of a remote sensing station in southern Spain, equipped with a backscatter lidar and a sunphotometer, to study the transport of desert dust to Europe, as well as a couple of GPS stations installed in southern Morocco to investigate the moisture inflow from the Atlantic Ocean into the Sahara. For the first time, the ALADIN and AROME models (5 and 24 km grid spacing, respectively) have been implemented operationally to provide forecasts of dust events over the Sahara and parts of the Sahel in June 2011 to assist in planning for airborne operations. This effort was complemented by the forecasts made with the Meso-NH model (5 and 20 km resolution). During the SOP period, the ground-based, airborne and space-borne observations have documented the evolution of dynamic properties of thermodynamic and the atmospheric boundary layer Saharan Africa (Mauritania and Mali) during the installation phase of the Saharan heat low west of the continent as well as the increase in aerosol loading associated with the phase shift of the heat low from east to west. During this period, episodes of intense uplift of desert aerosols associated with various dynamic phenomena (fronts, "Mediterannean surges", "Atlantic inflow" of low-level jets, etc ...) have also been documented as well as the export of dust over the Atlantic Ocean. An overview of implementation plan and of the first observational and modelling results acquired during the time of the SOP will be presented.

  3. Climatic Changes over the Republic of Belarus during the Period of Instrumental Observations

    NASA Astrophysics Data System (ADS)

    Taberka, A. N.

    2009-12-01

    Contemporary meteorological observations over the territory of Belarus commenced in the second quarter of the 19th century (e.g., Grodno and Svisloch in 1839, Gorki in 1841, Brest in 1951). The meteorological station in the national capital, Minsk, was established only in 1887 as a part of large program initiated in early 1880s to cover with a standard meteorological network the entire territory of the Russian Empire, which encompassed Belarus at that time. Thus, it is a common practice to begin climatological analyses of surface air temperature changes over the nation from 1881 and of precipitation from 1891 respectively, when standard thermometer and rain gauge installations and observational procedures were developed. For the Republic of Belarus, we present analyses of nationwide changes in mean monthly temperature and precipitation during these more than century-long periods that span up to year 2008. However, all our time series have a gap during the period of the World War II (1941-44). For the past seventy years (since 1936; when most of daily and synoptic information became available in digital form), daily and sub-daily data from 54 stations across the country are used to show spatial variability and pattern of changes in the surface air temperature, near surface wind, relative humidity, and precipitation totals adjusted for observational practice changes (cf., Groisman and Rankova 2001, Int. J. Climatol.). We shall focus on the past two decades when unprecedented global climatic changes have occurred and assess their regional impact on the nation climate. The presentation will also provide short information about climate of the Republic of Belarus and description of its meteorological network. Existing data issues (homogeneity, quality control, archiving procedures) will be briefly discussed.

  4. Strong aerosol-cloud interaction in altocumulus during updraft periods: lidar observations over central Europe

    NASA Astrophysics Data System (ADS)

    Schmidt, J.; Ansmann, A.; Bhl, J.; Wandinger, U.

    2015-09-01

    For the first time, a liquid-water cloud study of the aerosol-cloud-dynamics relationship, solely based on lidar, was conducted. Twenty-nine cases of pure liquid-water altocumulus layers were observed with a novel dual-field-of-view Raman lidar over the polluted central European site of Leipzig, Germany, between September 2010 and September 2012. By means of the novel Raman lidar technique, cloud properties such as the droplet effective radius and cloud droplet number concentration (CDNC) in the lower part of altocumulus layers are obtained. The conventional aerosol Raman lidar technique provides the aerosol extinction coefficient (used as aerosol proxy) below cloud base. A collocated Doppler lidar measures the vertical velocity at cloud base and thus updraft and downdraft occurrence. Here, we present the key results of our statistical analysis of the 2010-2012 observations. Besides a clear aerosol effect on cloud droplet number concentration in the lower part of the altocumulus layers during updraft periods, turbulent mixing and entrainment of dry air is assumed to be the main reason for the found weak correlation between aerosol proxy and CDNC higher up in the cloud. The corresponding aerosol-cloud interaction parameter based on changes in cloud droplet number concentration with aerosol loading was found to be close to 0.8 at 30-70 m above cloud base during updraft periods and below 0.4 when ignoring vertical-wind information in the analysis. Our findings are extensively compared with literature values and agree well with airborne observations.

  5. A Bayesian Estimation for Spica's Apsidal Period from 111 years of Spectroscopic Observations

    NASA Astrophysics Data System (ADS)

    Aufdenberg, Jason P.; Robinette, Timothy M.

    2015-01-01

    Toward the goal of constraining the short period (P = 4.01 d) massive binary star Spica's apsidal constant, which in turn constrains the internal structure of the primary star (B1.5 IV), we have modified the Bayesian Markov Chain Monte Carlo code EXOFAST (Eastman et al. 2013) to fit six radial velocity (RV) data sets obtained between 1889 to 2000. The code was modified to take radial velocity input from two stars rather than a single exoplanet host star. In addition the apsidal period (U) and the RV amplitude of the secondary star (K2) have been added as fit parameters, and the longitude of periastron is now a function of time. Measurements from Vogel (1889), Baker (1910), Struve & Ebigghausen (1934), Struve et al. (1958), Shobbrook et al. (1972) and Riddle (2000) provide 338 and 239 RV measurements for the primary and secondary stars respectively.Preliminary results yield: (1) a median apsidal period (U) of 118.91.3 years with 68% confidence consistent with the value of Herbison-Evans et al. (1971), 12411 years. The ratio of the orbital period to the apsidal period (P/U), one of three parameters needed for observationally determined apsidal-motion constant k2obs (Claret & Willems 2002), is now tentatively constrained to 1%, P/U = 9.240.01x10-5. (2) The eccentricity is constrained in our solution with an uncertainty of 9%, down from an uncertainly of 20% found by Riddle (2000). (3) The uncertainty in k2obs is dominated by the uncertainty of the ratio of the primary star radius, R1,to the semi-major axis, a, since k2obs is proportional to (R1/a)5. The semi-major axis can be found from a?sini which is constrained with an uncertainty of 3%, similar to previous work. The influence of the prior values on the posterior distributions will be described. The next step is to constrain the inclination from the light curve and long-baseline near-IR interferometry.

  6. Estimating interevent time distributions from finite observation periods in communication networks

    NASA Astrophysics Data System (ADS)

    Kivelä, Mikko; Porter, Mason A.

    2015-11-01

    A diverse variety of processes—including recurrent disease episodes, neuron firing, and communication patterns among humans—can be described using interevent time (IET) distributions. Many such processes are ongoing, although event sequences are only available during a finite observation window. Because the observation time window is more likely to begin or end during long IETs than during short ones, the analysis of such data is susceptible to a bias induced by the finite observation period. In this paper, we illustrate how this length bias is born and how it can be corrected without assuming any particular shape for the IET distribution. To do this, we model event sequences using stationary renewal processes, and we formulate simple heuristics for determining the severity of the bias. To illustrate our results, we focus on the example of empirical communication networks, which are temporal networks that are constructed from communication events. The IET distributions of such systems guide efforts to build models of human behavior, and the variance of IETs is very important for estimating the spreading rate of information in networks of temporal interactions. We analyze several well-known data sets from the literature, and we find that the resulting bias can lead to systematic underestimates of the variance in the IET distributions and that correcting for the bias can lead to qualitatively different results for the tails of the IET distributions.

  7. mtDNA from the early Bronze Age to the Roman period suggests a genetic link between the Indian subcontinent and Mesopotamian cradle of civilization.

    PubMed

    Witas, Henryk W; Tomczyk, Jacek; J?drychowska-Da?ska, Krystyna; Chaubey, Gyaneshwer; P?oszaj, Tomasz

    2013-01-01

    Ancient DNA methodology was applied to analyse sequences extracted from freshly unearthed remains (teeth) of 4 individuals deeply deposited in slightly alkaline soil of the Tell Ashara (ancient Terqa) and Tell Masaikh (ancient Kar-Assurnasirpal) Syrian archaeological sites, both in the middle Euphrates valley. Dated to the period between 2.5 Kyrs BC and 0.5 Kyrs AD the studied individuals carried mtDNA haplotypes corresponding to the M4b1, M49 and/or M61 haplogroups, which are believed to have arisen in the area of the Indian subcontinent during the Upper Paleolithic and are absent in people living today in Syria. However, they are present in people inhabiting today's Tibet, Himalayas, India and Pakistan. We anticipate that the analysed remains from Mesopotamia belonged to people with genetic affinity to the Indian subcontinent since the distribution of identified ancient haplotypes indicates solid link with populations from the region of South Asia-Tibet (Trans-Himalaya). They may have been descendants of migrants from much earlier times, spreading the clades of the macrohaplogroup M throughout Eurasia and founding regional Mesopotamian groups like that of Terqa or just merchants moving along trade routes passing near or through the region. None of the successfully identified nuclear alleles turned out to be ?F508 CFTR, LCT-13910T or ?32 CCR5. PMID:24040024

  8. mtDNA from the Early Bronze Age to the Roman Period Suggests a Genetic Link between the Indian Subcontinent and Mesopotamian Cradle of Civilization

    PubMed Central

    Witas, Henryk W.; Tomczyk, Jacek; J?drychowska-Da?ska, Krystyna; Chaubey, Gyaneshwer; P?oszaj, Tomasz

    2013-01-01

    Ancient DNA methodology was applied to analyse sequences extracted from freshly unearthed remains (teeth) of 4 individuals deeply deposited in slightly alkaline soil of the Tell Ashara (ancient Terqa) and Tell Masaikh (ancient Kar-Assurnasirpal) Syrian archaeological sites, both in the middle Euphrates valley. Dated to the period between 2.5 Kyrs BC and 0.5 Kyrs AD the studied individuals carried mtDNA haplotypes corresponding to the M4b1, M49 and/or M61 haplogroups, which are believed to have arisen in the area of the Indian subcontinent during the Upper Paleolithic and are absent in people living today in Syria. However, they are present in people inhabiting todays Tibet, Himalayas, India and Pakistan. We anticipate that the analysed remains from Mesopotamia belonged to people with genetic affinity to the Indian subcontinent since the distribution of identified ancient haplotypes indicates solid link with populations from the region of South Asia-Tibet (Trans-Himalaya). They may have been descendants of migrants from much earlier times, spreading the clades of the macrohaplogroup M throughout Eurasia and founding regional Mesopotamian groups like that of Terqa or just merchants moving along trade routes passing near or through the region. None of the successfully identified nuclear alleles turned out to be ?F508 CFTR, LCT-13910T or ?32 CCR5. PMID:24040024

  9. Periodic behaviors in the observed vertical column abundances of atmospheric hydroxyl

    NASA Technical Reports Server (NTRS)

    Burnett, Elizabeth Beaver; Burnett, Clyde R.; Minschwaner, Kenneth R.

    1989-01-01

    The data base for the vertical column abundance of atmospheric hydroxyl (OH) for Fritz Peak Observatory, Colorado (40 N, 105 W), now extends from 1976 through 1988 and is composed of 8849 independent data sets, averaging about 15 percent uncertainty and 20-minute time resolution each. The dominant solar zenith angle (chi) dependence of the OH abundance is characterized by an empirical curve, N(88), which has been updated from N(82) to include all valid data from 1980 through 1988. The chi-dependence of the OH abundance has been, to a first order, removed from the data base by a normalization procedure in which each data point is divided by the N(88,AM) value for the corresponding solar zenith angle. The resulting normalized OH values may then be examined for other systematic effects, particularly for periodic variations. Observations have also been made at Boca Raton, Florida (26 N, 80 W) and at Truk, Federated States of Micronesia (7 N, 152 E). These data bases are much less extensive and, as such, are less amenable to analysis for periodic behaviors. Some comparisons with the Colorado data may be made, however.

  10. Multipoint observations of quasi-periodic substorms associated with ULF pulsations

    NASA Astrophysics Data System (ADS)

    Lee, D.; Lyons, L.; Zou, S.; Kim, K.; Ruohoniemi, J. M.; Weygand, J. M.

    2007-12-01

    Using auroral images from the IMAGE WIC instrument, geomagnetic data from various ground stations, and geosynchronous particle data, we have identified six consecutive substorms separated by about 45 min to 1.6 hr on November 8, 2000. Most of these substorms are of small to medium size and occurred under a weakly northward IMF condition: IMF Bz was near zero to about +5 nT prior to each substorm. IMF By was also weak, being within about 3 nT. Most interestingly, we have found that for most of the substorms, about 10-15 min period ULF pulsation begins to amplify prior to each onset and tends to decline near the time of onset. The pulsation features are clearly seen at auroral zone and some higher latitude stations of the CANOPUS magnetic network when they cover morning side MLT regions. Similar features are also seen in the GOES magnetic field observations in similar MLT regions. For the first two substorms, the IMAGE magnetic network stations were at postnoon MLT regions and indicated similar ULF pulsation features. The SuperDARN data show that for most of the substorms, the ionospheric convection within the polar cap shows high-amplitude oscillations with a period of about 15 min that tend to amplify prior to onset and to decline after the onset. Based on the results, we will discuss the possible association between substorm triggering and convection associated with large-amplitude ULF pulsations.

  11. "Radiative Closure Studies for Clear Skies During the ARM 2003 Aerosol Intensive Observation Period"

    SciTech Connect

    J. J. Michalsky, G. P. Anderson, J. Barnard, J. Delamere, C. Gueymard, S. Kato, P. Kiedron, A. McComiskey, and P. Ricchiazzi

    2006-04-01

    The Department of Energy's Atmospheric Radiation Measurement (ARM) program sponsored a large intensive observation period (IOP) to study aerosol during the month of May 2003 around the Southern Great Plains (SGP) Climate Research Facility (CRF) in north central Oklahoma. Redundant measurements of aerosol optical properties were made using different techniques at the surface as well as in vertical profile with sensors aboard two aircraft. One of the principal motivations for this experiment was to resolve the disagreement between models and measurements of diffuse horizontal broadband shortwave irradiance at the surface, especially for modest aerosol loading. This paper focuses on using the redundant aerosol and radiation measurements during this IOP to compare direct beam and diffuse horizontal broadband shortwave irradiance measurements and models at the surface for a wide range of aerosol cases that occurred during 30 clear-sky periods on 13 days of May 2003. Models and measurements are compared over a large range of solar-zenith angles. Six different models are used to assess the relative agreement among them and the measurements. Better agreement than previously achieved appears to be the result of better specification of input parameters and better measurements of irradiances than in prior studies. Biases between modeled and measured direct irradiances are less than 1%, and biases between modeled and measured diffuse irradiances are less than 2%.

  12. An overview of an intensive observation period on variability of coastal atmospheric refractivity

    NASA Astrophysics Data System (ADS)

    Paulus, Richard A.

    1995-02-01

    This paper is an overview of an experiment called Variability of Coastal Atmospheric Refractivity (VOCAR). VOCAR was designed to be conducted under a larger program called Coastal Variability Analysis, Measurements, and Prediction and is a multi-year experimental effort to investigate the variability of atmospheric refractivity with emphasis on the coastal zone. The experiment is being conducted jointly with the Naval Air Warfare Center Weapons Division, Point Mugu, CA, the Naval Research Laboratory, and the Naval Postgraduate School. In addition, the National Oceanic and Atmospheric Administration Environmental Technology Laboratory and Penn State University/Applied Research Laboratory are participating in the measurement phase of VOCAR. The propagation measurements being made during VOCAR consist of monitoring signal strength variations of VHF/UHF transmitters in the southern California coastal region. Corresponding meteorological measurements are made during routine, special, and intensive observation periods. During an intensive measurement period from 23 August to 3 September 1993, radio data were collected at two receiver sites and meteorological data were collected from three profiler sites, eight radiosonde sites, three aircraft, and numerous surface weather sites. Samples of the data will be shown.

  13. Observation of Exchange Anisotropy in Single-Phase Layer-Structured Oxides with Long Periods.

    PubMed

    Huang, Yan; Wang, Guopeng; Sun, Shujie; Wang, Jianlin; Peng, Ranran; Lin, Yue; Zhai, Xiaofang; Fu, Zhengping; Lu, Yalin

    2015-01-01

    A remarkable exchange bias effect arising from the temperature-dependent interaction among the ferromagnetic-like cluster glasses and antiferromagnetic regions was observed in a newly developed single-phase multiferroic compound of Bi10Fe6Ti3O30 which has a nine-layer Aurivillius structure. Inhomogeneous distribution of magnetic Fe ions inside this long-period layered structure was experimentally identified via the atomic level imaging. The results confirmed the presence of the short-range magnetic ordering (the cluster glassy state) and the canted antiferromagnetism, and then the direct interaction among them was further confirmed. Finding of this new single-phase material accompanying this remarkable exchange bias effect would be beneficial to both basic physics understanding and the potential device development. PMID:26487509

  14. First observations of quasi-periodic radar echoes from Stanford, California

    NASA Astrophysics Data System (ADS)

    Tsunoda, Roland T.; Buonocore, John J.; Saito, Akinori; Kishimoto, Takeshi; Fukao, Shoichiro; Yamamoto, Mamoru

    We present first results from a search for quasi-periodic (QP) radar echoes in the American sector. These echoes, which are produced by underdense backscatter from field-aligned irregularities in nighttime midlatitude sporadic E (Es), have been observed in the Asian sector but never before at other longitudes. Using radar data collected during the summer in 1998 from Stanford, California, we show that QP echoes can indeed be detected in the American sector and that they resemble those found in central and southern Japan. We then show that the invariance of a feature in the pattern of QP echoes, which persisted for five hours on 3 August 1998, raises questions regarding the existing models for QP echoes.

  15. Evaporation over land surfaces - First results from HAPEX-MOBILHY Special Observing Period

    NASA Technical Reports Server (NTRS)

    Andre, Jean-Claude; Goutorbe, Jean-Paul; Bessemoulin, Pierre; Perrier, Alain; Becker, Francois

    1988-01-01

    Preliminary results are presented from the May 7-July 15, 1986 Special Observing Period (SOP) of the HAPEX-MOBILHY program, which examines the hydrological budget and evaporation flux at the scale of a 10,000 sq km GCM grid square to determine soil moisture, surface-energy budgets, and surface hydrology. The SOP used two highly instrumented remote sensing aircraft to obtain detailed measurements of atmospheric fluxes and surface properties. It is noted that the measurements are reliable at spatially local and short time scales, as well as on the monthly time scale. The data base obtained may be used in parametrization schemes against which land-surface water budgets can be tested.

  16. Observation of Exchange Anisotropy in Single-Phase Layer-Structured Oxides with Long Periods

    PubMed Central

    Huang, Yan; Wang, Guopeng; Sun, Shujie; Wang, Jianlin; Peng, Ranran; Lin, Yue; Zhai, Xiaofang; Fu, Zhengping; Lu, Yalin

    2015-01-01

    A remarkable exchange bias effect arising from the temperature-dependent interaction among the ferromagnetic-like cluster glasses and antiferromagnetic regions was observed in a newly developed single-phase multiferroic compound of Bi10Fe6Ti3O30 which has a nine-layer Aurivillius structure. Inhomogeneous distribution of magnetic Fe ions inside this long-period layered structure was experimentally identified via the atomic level imaging. The results confirmed the presence of the short-range magnetic ordering (the cluster glassy state) and the canted antiferromagnetism, and then the direct interaction among them was further confirmed. Finding of this new single-phase material accompanying this remarkable exchange bias effect would be beneficial to both basic physics understanding and the potential device development. PMID:26487509

  17. Cancer incidence among asbestos-exposed chemical industry workers: An extended observation period

    SciTech Connect

    Hilt, B.; Andersen, A.; Rosenberg, J.; Langard, S. )

    1991-01-01

    A previous study on the incidence of cancer in a cohort of 286 asbestos-exposed electrochemical industry workers observed from 1953 through 1980 has been extended with another 8 years of follow-up. The incidence of cancer was derived from the Cancer Registry of Norway, and the expected figures were calculated by a life table method. During the extended follow-up period from 1981 through 1988, among the cohort members there were 12 new cancer cases versus 14.2 expected (SIR 85, 95% CI 44-158). In a lightly exposed sub-cohort, the extended follow-up revealed 4 cases of lung cancer or pleural mesothelioma (ICD, 7th revision 162-163) versus 1.6 cases expected (SIR 256, 95% CI71-654). In a heavily exposed sub-cohort, the corresponding figures were 3 and 0.5 (SIR 588, 95% CI 118-1,725).

  18. Observation of Exchange Anisotropy in Single-Phase Layer-Structured Oxides with Long Periods

    NASA Astrophysics Data System (ADS)

    Huang, Yan; Wang, Guopeng; Sun, Shujie; Wang, Jianlin; Peng, Ranran; Lin, Yue; Zhai, Xiaofang; Fu, Zhengping; Lu, Yalin

    2015-10-01

    A remarkable exchange bias effect arising from the temperature-dependent interaction among the ferromagnetic-like cluster glasses and antiferromagnetic regions was observed in a newly developed single-phase multiferroic compound of Bi10Fe6Ti3O30 which has a nine-layer Aurivillius structure. Inhomogeneous distribution of magnetic Fe ions inside this long-period layered structure was experimentally identified via the atomic level imaging. The results confirmed the presence of the short-range magnetic ordering (the cluster glassy state) and the canted antiferromagnetism, and then the direct interaction among them was further confirmed. Finding of this new single-phase material accompanying this remarkable exchange bias effect would be beneficial to both basic physics understanding and the potential device development.

  19. Dorsal Raphe Serotonin Neurons in Mice: Immature Hyperexcitability Transitions to Adult State during First Three Postnatal Weeks Suggesting Sensitive Period for Environmental Perturbation

    PubMed Central

    Rood, Benjamin D.; Calizo, Lyngine H.; Piel, David; Spangler, Zachary P.; Campbell, Kaitlin

    2014-01-01

    Trauma during early life is a major risk factor for the development of anxiety disorders and suggests that the developing brain may be particularly sensitive to perturbation. Increased vulnerability most likely involves altering neural circuits involved in emotional regulation. The role of serotonin in emotional regulation is well established, but little is known about the postnatal development of the raphe where serotonin is made. Using whole-cell patch-clamp recording and immunohistochemistry, we tested whether serotonin circuitry in the dorsal and median raphe was functionally mature during the first 3 postnatal weeks in mice. Serotonin neurons at postnatal day 4 (P4) were hyperexcitable. The increased excitability was due to depolarized resting membrane potential, increased resistance, increased firing rate, lack of 5-HT1A autoreceptor response, and lack of GABA synaptic activity. Over the next 2 weeks, membrane resistance decreased and resting membrane potential hyperpolarized due in part to potassium current activation. The 5-HT1A autoreceptor-mediated inhibition did not develop until P21. The frequency of spontaneous inhibitory and excitatory events increased as neurons extended and refined their dendritic arbor. Serotonin colocalized with vGlut3 at P4 as in adulthood, suggesting enhanced release of glutamate alongside enhanced serotonin release. Because serotonin affects circuit development in other brain regions, altering the developmental trajectory of serotonin neuron excitability and release could have many downstream consequences. We conclude that serotonin neuron structure and function change substantially during the first 3 weeks of life during which external stressors could potentially alter circuit formation. PMID:24695701

  20. Dorsal raphe serotonin neurons in mice: immature hyperexcitability transitions to adult state during first three postnatal weeks suggesting sensitive period for environmental perturbation.

    PubMed

    Rood, Benjamin D; Calizo, Lyngine H; Piel, David; Spangler, Zachary P; Campbell, Kaitlin; Beck, Sheryl G

    2014-04-01

    Trauma during early life is a major risk factor for the development of anxiety disorders and suggests that the developing brain may be particularly sensitive to perturbation. Increased vulnerability most likely involves altering neural circuits involved in emotional regulation. The role of serotonin in emotional regulation is well established, but little is known about the postnatal development of the raphe where serotonin is made. Using whole-cell patch-clamp recording and immunohistochemistry, we tested whether serotonin circuitry in the dorsal and median raphe was functionally mature during the first 3 postnatal weeks in mice. Serotonin neurons at postnatal day 4 (P4) were hyperexcitable. The increased excitability was due to depolarized resting membrane potential, increased resistance, increased firing rate, lack of 5-HT1A autoreceptor response, and lack of GABA synaptic activity. Over the next 2 weeks, membrane resistance decreased and resting membrane potential hyperpolarized due in part to potassium current activation. The 5-HT1A autoreceptor-mediated inhibition did not develop until P21. The frequency of spontaneous inhibitory and excitatory events increased as neurons extended and refined their dendritic arbor. Serotonin colocalized with vGlut3 at P4 as in adulthood, suggesting enhanced release of glutamate alongside enhanced serotonin release. Because serotonin affects circuit development in other brain regions, altering the developmental trajectory of serotonin neuron excitability and release could have many downstream consequences. We conclude that serotonin neuron structure and function change substantially during the first 3 weeks of life during which external stressors could potentially alter circuit formation. PMID:24695701

  1. Observing and Modeling the Optical Counterparts of Short-Period Binary Millisecond Pulsars

    NASA Astrophysics Data System (ADS)

    Schroeder, Joshua

    In this dissertation, I explore the subject of short-period binary millisecond pulsars discovered by the Fermi Gamma-ray Space Telescope and radio follow-up teams, and present observations of fields containing eight recently discovered short-period (Porb < 1 d) binary millisecond pulsars using the telescopes at MDM Observatory. The goal of these observations was to detect the optical counterparts of the binaries and, for the best-suited counterparts detected, to observe the photometric variation of the companion that happens over the course of the orbit in various filters. The hope was to then use the light curves to model the systems and obtain constraints on the mass of the neutron stars which are likely to be some of the most massive neutron stars in the galaxy. Optical counterparts to four of these systems are detected, one of which, PSR J2214+3000, is a novel detection. Additionally, I present the fully orbital phase-resolved B, V , and R light curves of the optical counterparts to two objects, PSR J1810+1744 and PSR J2215+5135, for which I employ the ELC model of Orosz & Hauschildt (2000) to measure the unknown system parameters. For PSR J1810+1744 I find that the system parameters cannot be fit even assuming that 100% of the spin-down luminosity of the pulsar is irradiating the secondary, and so radial velocity measurements of this object will be required for the complete solution. However, PSR J2215+5135 exhibits light curves that are extremely well constrained using the ELC model and we find that the mass of the neutron star is constrained by these and the radio observations to be MNS > 1.75 solar masses; at the 3-sigma level. I also find a discrepancy between the model temperature and the measured colors of this object which I interpret as possible evidence for an additional high-temperature source such as a quiescent disk. Given this and the fact that PSR J2215+5135 contains a relatively high mass companion (Mc > 0.1 solar masses), I propose that similar to the binary pulsar systems PSR J1023+0038 and IGR J18245-2452, the pulsar may transition between accretion- and rotation-powered modes.

  2. Multi-sensor precipitation measurements during HyMeX Special Observation Period in Northeast Italy

    NASA Astrophysics Data System (ADS)

    Borga, Marco; Kalogiros, John; Nikolopoulos, Efthymios; Anagnostou, Marios; Anagnostou, Emmanouil; Petersen, Walter; Tollardo, Mauro; Marra, Francesco; Bertoldi, Giacomo

    2013-04-01

    The Northeast Italy Hydrometeorological Observatory represents one of the three HyMeX sites that participated in the first Special Observation Period (Sept-Nov 2012). Located in the center of the Alps, the site represents a strategic location for collecting hydrometeorological observations on heavy rainfall events triggering flash floods and debris flows in complex terrain. The intensively monitored area (1600 km2) is located in the Upper Adige river basin (Italy), at the boundary between Italy, Austria and Switzerland. The area covers a partially glaciated surface ranging in altitude from 600 m to 4000 m asl. Within this area, a set of experimental watersheds (ranging in size from 8 to 64 km2) with dedicated instrumentation for the high frequency sampling of runoff, soil moisture, piezometric response and sediment transport are included. The instrumentation dedicated to the observation of rainfall parameters involves: a dense network of raingauges located at different elevations, an X-band polarimetric mobile radar, two C-band Doppler radar covering the area at a 60-70 km range, one 2DVD and two Parsivel disdrometers. The hydrometeorological data collected in this experiment range in scale from in situ to regional radar observations that can facilitate studies of hydrological processes and remote sensing of precipitation in complex terrain basins. In this study we will compare rainfall data derived from three observational scales: in situ stations (1 meter, 1 min), locally deployed X-POL radar (200 meters, 1 min) and two regional radars (1km, 5-10 min). We will present a methodology to transfer radar algorithm calibration across scales considering the in situ observations as ground truth, then transferring calibration to the local XPOL radar observations, which will be finally used to transfer calibration to the regional C-band radar-rainfall algorithms. Regional radar-rainfall estimates will then be used to investigate hydrological processes at a range of basin scales and evaluate high-resolution satellite rainfall retrievals during two major flood events that took place during the SOP.

  3. [Clinical and pathological evaluation of periodic synchronous discharge observed in advanced dementia of Alzheimer type].

    PubMed

    Imazu, O

    1990-02-01

    Among 78 carefully diagnosed dementia of Alzheimer type (DAT) patients, periodic synchronous discharges (PSD) on electroencephalograms (EEGs) were observed in 12 advanced cases. Although several case studies have been made since 1970, it is not widely recognized that PSD can be observed in advanced DAT patients. In this study the clinical picture, the nature of PSD, background activity of EEGs and 2 autopsied cases have been clinicopathologically investigated. The mean duration of the disease in the 12 cases was 6.7 years. The mean age of onset of the disease was 67 years of age. Among the 12 cases, 9 patients presented akinetic mutism or symptoms closely resembling akinetic mutism, who were completely bed-ridden with their extremities fixed in flexion. The other 3 patients were severely demented. They presented various degrees of Parkinsonian syndromes or paratonic rigidity accompanied by some infection and general fatigue. In one of these 3 patients, PSD were observed during the transient apallic state and the PSD themselves were also transient. The basic rhythm in EEGs were 4-6 c/s: middle amplitude theta waves dominant with delta waves on frontal leads. Triphasic delta, theta and sharp waves of PSD were dominant on centro-parieto-occipital leads. Background activity was not suppressed differing from that of Creutzfeld Jacob disease (CJD). According to the interval histograms of PSD, the majority presented an interval of 1-2 s (1.5 s mean) with some lability which was relatively slower than that of CJD. Fronto-parieto-occipital delay was not observed. By 1 c/s photic stimulation, PSD was not driven.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2329177

  4. Changes in ENACW observed in the Bay of Biscay over the period 1975-2010

    NASA Astrophysics Data System (ADS)

    Gómez-Gesteira, M.; deCastro, M.; Santos, F.; Álvarez, I.; Costoya, X.

    2013-08-01

    Trends in Eastern North Atlantic Central Water (ENACW) were calculated in the Bay of Biscay over the period 1975-2010 using the Simple Ocean Data Assimilation (SODA) package. This approach, which reanalyzes data from different sources, allows obtaining information beneath the sea surface on a fine 0.5°×0.5° grid with 40 vertical layers, providing a complete view of the different hydrographic processes in the area. ENACW, which was associated to salinity and temperature values corresponding to the density interval 27.0-27.2 kg m-3, was observed to warm and salinificate in most of the area at a maximum rate of 0.11 °C per decade and 0.03 psu per decade, respectively. Trends are more intense in the middle part of the Bay and near the northeastern boundary. The origin of the changes in ENACW observed inside the Bay of Biscay is not due to local effects. Actually, trends seem to be related to changes in the subpolar mode of ENACW (ENACWsp), affecting a wider North Atlantic area. The highest trends (0.3 °C per decade in temperature and 0.05 psu per decade in salinity) were observed north of the bay, especially at the shallow area that stretches from Brest to Ireland, which is characterized by deep winter mixing. The dependence of changes in ENACW on the two main modes of variability over the North Atlantic (NAO and EA) was also analyzed. Trends in salinity and temperature showed to be consistent with changes observed in EA. In addition, air temperature and precipitation minus evaporation (P-E) balance showed to contribute to warming and salinification of ENACW.

  5. (abstract) Role of Long Equatorial Wave Reflection in the Low-Frequency Variability Observed During the TOPEX/POSEIDON Period: Data Analysis and Coupled Model Study

    NASA Technical Reports Server (NTRS)

    Boulanger, J. P.; Perigaud, C.; Fu, L. L.

    1996-01-01

    The analysis of TOPEX/POSEIDON sea level and ERS-1 zonal wind stress data gives evidence that first mode meridonal long Rossby waves fully reflected into Kelvin waves at the equatorial western Pacific boundary at different periods including the January-June 1994 period. The evolution of the conditions (zonal wind stress, sea surface temperature and sea level anomalies) in the central Pacific suggests that this reflection may have played a role in the reversal of cold to warm anomalies observed in the central Pacific in June-July 1994. To investigate the actual role of reflected Kelvin waves observed by TOPEX/POSEIDON, a simple ocean-atmosphere coupled model is designed. Starting from these initial conditions, several simulations are run for testing the role western bundary reflection evidenced in TOPEX/POSEIDON data. Coupled mechanisms are suggested to explain the low-frequency variability observed during this period.

  6. Turbulence Kinetic Energy budget during the afternoon transition - Part 1: Observed surface TKE budget and boundary layer description for 10 intensive observation period days

    NASA Astrophysics Data System (ADS)

    Nilsson, E.; Lohou, F.; Lothon, M.; Pardyjak, E.; Mahrt, L.; Darbieu, C.

    2015-11-01

    The decay of turbulence kinetic energy (TKE) and its budget in the afternoon period from mid-day until zero buoyancy flux at the surface is studied in a two-part paper by means of measurements from the Boundary Layer Late Afternoon and Sunset Turbulence (BLLAST) field campaign for 10 Intensive Observation Period days. Here, in Part 1, near-surface measurements from a small tower are used to estimate a TKE budget. The overall boundary layer characteristics and meso-scale situation at the site are also described based upon taller tower measurements, radiosoundings and remote sensing instrumentation. Analysis of the TKE budget during the afternoon transition reveals a variety of different surface layer dynamics in terms of TKE and TKE decay. This is largely attributed to variations in the 8 m wind speed, which is responsible for different amounts of near-surface shear production on different afternoons and variations within some of the afternoon periods. The partitioning of near surface production into local dissipation and transport in neutral and unstably stratified conditions was investigated. Although variations exist both between and within afternoons, as a rule of thumb, our results suggest that about 50 % of the near surface production of TKE is compensated by local dissipation near the surface, leaving about 50 % available for transport. This result indicates that it is important to also consider TKE transport as a factor influencing the near-surface TKE decay rate, which in many earlier studies has mainly been linked with the production terms of TKE by buoyancy and wind shear. We also conclude that the TKE tendency is smaller than the other budget terms, indicating a quasi-stationary evolution of TKE in the afternoon transition. Even though the TKE tendency was observed to be small, a strong correlation to mean buoyancy production of -0.69 was found for the afternoon period. For comparison with previous results, the TKE budget terms are normalized with friction velocity and measurement height and discussed in the framework of Monin-Obukhov similarity theory. Empirically fitted expressions are presented. Alternatively, we also suggest a non-local parametrization of dissipation using a TKE-length scale model which takes into account the boundary layer depth in addition to distance above the ground. The non-local formulation is shown to give a better description of dissipation compared to a local parametrization.

  7. Possible identifications of newly observed magnetar quasi-periodic oscillations as crustal shear modes

    NASA Astrophysics Data System (ADS)

    Sotani, Hajime; Iida, Kei; Oyamatsu, Kazuhiro

    2016-02-01

    Quasi-periodic oscillations (QPOs) discovered in soft-gamma repeaters (SGRs) are expected to help us to study the properties of matter in neutron stars. In earlier investigations, we identified the QPOs of frequencies below ˜100 Hz observed in giant flares of SGR 1806 -20 and SGR 1900+14 as the crustal torsional oscillations. For this purpose, we calculated the frequencies of the fundamental torsional oscillations with various angular indices ℓ, by changing the stellar mass and radius. In this work, we try to explain the additional QPO frequencies recently reported by Huppenkothen et al. (2014a, 2014b) within the same framework as before except that we newly take into account the effect of electron screening, which acts to decrease the frequencies by a small amount. Those QPOs were discovered in two different SGRs, i.e., SGR 1806 -20 and SGR J1550 -5418. Then, we find that the newly observed QPO frequency in SGR 1806 -20 can be still identified as one of the frequencies of the fundamental torsional oscillations, while those in SGR J1550 -5418 can also be explained in terms of the torsional oscillations although the relevant angular indices are difficult to identify.

  8. Observations of evapotranspiration in a break of slope plantation susceptible to periodic drought stress.

    PubMed

    McJannet, D. L.; Vertessy, R. A.; Clifton, C. A.

    2000-02-01

    Break of slope (BOS) plantations are advocated as a means of water table control in areas where groundwater flows through colluvial deposits overlying low permeability bedrock. It is also believed that BOS plantations can supplement their water use requirements by exploiting shallow groundwater at the breaks in topographic slope. We compared measurements of BOS plantation and pasture evapotranspiration during spring, when the weather was warm and soils moist, and late summer when drought conditions prevailed. Microlysimeters and ventilated chambers were used to determine pasture and plantation floor evaporation, and heat pulse sensors were used to determine transpiration of the plantation. In spring, pasture evapotranspiration was 65% of that of the plantation, whereas, in summer, pasture evapotranspiration was equivalent to only 35% of that of the plantation. Rainfall interception by the canopy of the plantation was twice that of the pasture, reinforcing the notion that trees can help reduce groundwater recharge and alleviate dryland salinity and waterlogging. During the summer drought period, daily plantation transpiration was only 20% of that measured during spring, suggesting that the plantation was not utilizing groundwater supplies but was instead drawing from soil water supplies. This hypothesis was supported by the comparison of relative abundances of the isotopes of water ((2)H and (18)O) in soil and wood samples. We conclude that the BOS plantation is not behaving in the manner predicted, and our findings raise doubts about the predicted advantages of establishing plantations in break of slope positions. PMID:12651469

  9. Concentric waves and short-period oscillations observed in the ionosphere after the 2013 Moore EF5 tornado

    NASA Astrophysics Data System (ADS)

    Nishioka, Michi; Tsugawa, Takuya; Kubota, Minoru; Ishii, Mamoru

    2013-11-01

    We detected clear concentric waves and short-period oscillations in the ionosphere after an Enhanced Fujita scale (EF)5 tornado hit Moore, Oklahoma, U.S., on 20 May 2013 using dense wide-coverage ionospheric total electron content (TEC) observations in North America. These concentric waves were nondispersive, with a horizontal wavelength of ~120 km and a period of ~13 min. They were observed for more than 7 h throughout North America. TEC oscillations with a period of ~4 min were also observed to the south of Moore for more than 8 h. A comparison between the TEC observations and infrared cloud image from the GOES satellite indicates that the concentric waves and short-period oscillations are caused by supercell-induced atmospheric gravity waves and acoustic resonances, respectively. This observational result provides the first clear evidence of a severe meteorological event causing atmospheric waves propagating upward in the upper atmosphere and reaching the ionosphere.

  10. Comparison of Columnar Water Vapor Measurements During The Fall 1997 ARM Intensive Observation Period: Optical Methods

    NASA Technical Reports Server (NTRS)

    Schmid, Beat; Michalsky, J.; Slater, D.; Barnard, J.; Halthore, R.; Liljegren, J.; Holben, B.; Eck, T.; Livingston, J.; Russell, P.; Hipskind, R. Stephen (Technical Monitor)

    2000-01-01

    In the fall of 1997 the Atmospheric Radiation Measurement (ARM program conducted an intensive Observation Period (IOP) to study water vapor at its Southern Great Plains (SGP) site. Among the large number of instruments, four sun-tracking radiometers were present to measure the columnar water vapor (CWV). All four solar radiometers retrieve CWV by measuring solar transmittance in the 0.94-micrometer water vapor absorption band. As one of the steps in the CWV retrievals the aerosol component is subtracted from the total transmittance, in the 0.94-micrometer band. The aerosol optical depth comparisons among the same four radiometers are presented elsewhere. We have used three different methods to retrieve CWV. Without attempting to standardize on the same radiative transfer model and its underlying water vapor spectroscopy we found the CWV to agree within 0.13 cm (rms) for CWV values ranging from 1 to 5 cm. Preliminary results obtained when using the same updated radiative transfer model with updated spectroscopy for all instruments will also be shown. Comparisons to the microwave radiometer results will be included in the comparisons.

  11. Weekly periodicities of aerosol properties observed at an urban location in India

    SciTech Connect

    Satheesh, S. K.; Vinoj, V.; Moorthy, K. Krishna

    2011-07-01

    Multi-year (~7 years) observations of aerosol optical and microphysical properties were conducted at a tropical urban location in Bangalore, India. As a consequence of rapid urbanization, Bangalore presents high local atmospheric emissions, which makes it an interesting site to study the effect of anthropogenic activities on aerosol properties. It has been found that both column (aerosol optical depth, AOD) and ground-level measurements (black carbon (BC) and composite aerosol mass) exhibit a weekly cycle with low aerosol concentrations on weekends. In comparison to the weekdays, the weekend reductions of aerosol optical depth, black carbon and composite aerosol mass concentrations were ~15%, 25% and 24%, respectively. The magnitude of weekend reduction of black carbon is as much as ~1 μg m−3. The similarity in the weekly cycle between the column and surface measurements suggests that the aerosol column loading at this location is governed by local anthropogenic emissions. The strongest weekly cycle in composite aerosol mass concentration was observed in the super micron mass range (N1 μm). The weekly cycle of composite aerosol mass in the sub micron mass range (b1 μm) was weak in comparison to the super micron aerosol mass.

  12. Observation of atomic ordering of triple-period-A and -B type in GaAsBi

    SciTech Connect

    Wu, Mingjian Luna, Esperanza; Trampert, Achim; Puustinen, Janne; Guina, Mircea

    2014-07-28

    We report the observation of atomic ordering of triple-period (TP)-A and -B type in low temperature (LT) grown GaAsBi alloy using transmission electron microscopy (TEM). In addition to previous reports, where only TP-A ordering was identified in III-V alloys, here, we confirm by electron diffraction, high-resolution (HR) TEM, and HR Z-contrast scanning TEM that two ordering variants coexists for LT-GaAsBi. We find that the TP-A ordering variant dominates over the TP-B variant. TP-A domains extend over 50–100 nm (projected lateral width) and are of higher perfection compared to TP-B domains. HR Z-contrast scanning TEM on different domains reveals a variation in the Bi occupancy in the (111) planes with triple period sequence. Since the formation of ordered phases has been directly linked to the occurrence of specific surface reconstructions, our results suggest a correlation between the TP-A and B type domains and the multiple stability of n × 3 and 3 × n reconstructions on the (001) surface of GaAsBi under low temperature growth.

  13. Tracing non-conservative mass transfer eras in close binaries from observed period variations

    NASA Astrophysics Data System (ADS)

    Nanouris, N.; Kalimeris, A.; Antonopoulou, E.; Rovithis-Livaniou, H.

    2013-09-01

    The pure information directly taken from the observed orbital evolution of eclipsing binary stars (centuries at most) is valuable for the study of many important physical mechanisms related to the stellar structure. Especially in the case of eclipsing binary systems, this may happen by monitoring their eclipse timing variations, i.e. by means of an O-C diagram analysis. As long as a binary system attains a semi-detached configuration, material begins to flow from the component that fills its Roche lobe toward its mate through the first Lagrangian (L1) point. Here, we examine two non conservative mass transfer (MT) paths. The MT process is then accompanied by mass and angular momentum loss from the system. In the first path, angular momentum is removed through a hot spot which re-emits part of the incoming material, and in the second, angular momentum is carried away via an outer Lagrangian point (L2/L3) due to the small accumulating efficiency of the accretion disk surrounding the gainer. Dealing with the less massive component as the donor in the latter path, it is shown that there is always a critical mass ratio over which the period is expected to decrease, contrary to what the fully conservative MT predicts. Consistent with our expectations, the critical values become progressively smaller as the degree of liberalism is gradually widened. The O-C diagram of several semi-detached systems, expecting to experience a liberal era, is individually examined aiming to estimate both the mass transfer and the mass loss rate.

  14. Period Analysis of AAVSO Visual Observations of 55 Semiregular (SR/SRa/SRb) Variable Stars

    NASA Astrophysics Data System (ADS)

    Percy, J. R.; Tan, P. J.

    2013-06-01

    We have used AAVSO visual data, and Fourier analysis and self-correlation analysis, to study the periodicity of 55 semiregular (SR) variables - 21 SRa and 34 SRb. According to the standard system of variable star classification, these are pulsating red giants, with visual amplitudes less than 2.5 magnitudes, which show noticeable periodicity (SRa) or less-obvious periodicity (SRb). We find that their behavior ranges from highly periodic to irregular; some are not significantly variable. We have used a simple index, based on self-correlation analysis, to show that, on average, the SRa variables have a larger component of periodicity than the SRb variables, as expected. The distributions of this index for the two groups, however, overlap considerably. Of our 55 stars, 11 definitely or possibly show two radial periods, and at least 16 definitely or possibly show a long secondary period. We also analyzed three non-SR stars: T Cet is a double-mode SRc star; T Cen is an RVa star which should be reclassified as RVb; V930 Cyg is an irregular (Lb) star with a strong 250-day period.

  15. Diurnal-period currents trapped above Fieberling Guyot: observed characteristics and model comparisons

    USGS Publications Warehouse

    Noble, M.A.; Brink, K.H.; Eriksen, C.C.

    1994-01-01

    Current measurements at depths of 19, 115, 264 and 464 m above the summit of Fieberling Guyot (32??28???N, 127??47???W) for 13 months in 1989 show that the diurnal tides are strongly amplified. The measured variances for K1, P1 and O1 at the 115 m depth were 810, 140 and 80 times larger than the variances of the respective estimated barotropic tides. The diurnal currents closer to the summit were also strongly amplified, through the variance ratios were 40-50% of the ratios observed at 115 m. The diurnal band currents were only amplified at the precise tidal frequencies; the bandwidth of the response was less than 0.0002 cph. The discrete character of the response suggests that only currents with large spatial scales will be amplified. The characteristics of the amplified diurnal currents are compared to those predicted by a model for Fieberling Guyot of seamount-trapped waves driven by the barotropic tide. The amplitudes of the responses at this one site on the seamount compare favourably to the predicted. ?? 1994.

  16. Simultaneous observations of quasi-periodic (QP) VLF wave emissions and related ULF fluctuations of the geomagnetic field

    NASA Astrophysics Data System (ADS)

    Hayosh, Mykhaylo; Santolik, Ondrej; Parrot, Michel; Nemec, Frantisek

    We present case studies of quasi-periodic (QP) VLF emissions detected onboard the DEMETER satellite. The analyzed events with modulation periods from 40 s to 80 s were observed at geomagnetic latitudes larger than 40 degrees. The magnetometers of the CARISMA network along the same geomagnetic longitude (within 5 degrees) were used for monitoring simultaneous fluctuations of the geomagnetic field. Correlated ULF magnetic field pulsations with periods corresponding to the modulation periods of QP emissions are detected. These ULF pulsations in the Pc3 - Pc5 range are likely related to the generation mechanism of the QP emissions. We attempt to define the spatial extent of the disturbed area.

  17. What can HST-GHRS Fe II observations of ? Orionis (M2 Iab) tell us about short-period heating?

    NASA Astrophysics Data System (ADS)

    Cuntz, M.; Harper, G. M.; Bennett, P. D.

    2001-09-01

    Cuntz (\\cite{Cuntz97}) suggested that apparent velocity shifts in Fe II emission lines observed in Betelgeuse (alpha Orionis: M2 Iab) indicate that non-magnetic wave modes are relevant for the heating and dynamics of alpha Ori's chromosphere. This claim was based on the similarity of computed stochastic velocities in 1-D short-period acoustic wave models and velocity shifts in profile fits to Fe II emission lines (Carpenter & Robinson \\cite{Carpenter97}), which is now identified as coincidental. While acoustic waves may indeed be important for the heating and dynamics of alpha Ori's chromosphere, the interpretation of the Fe II emission line profiles does not provide evidence for this possibility. The line formation of optically thick scattering lines in an extended outflow makes Fe II emission lines poorly suited as a diagnostic for small-scale structure in hydrodynamical models. Better diagnostics include electron density sensitive, low opacity lines such as C II]. In the view of these findings, we discuss directions of future research. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

  18. Polar cap ionosphere and thermosphere during the solar minimum period: EISCAT Svalbard radar observations and GCM simulations

    NASA Astrophysics Data System (ADS)

    Fujiwara, Hitoshi; Nozawa, Satonori; Maeda, Sawako; Ogawa, Yasunobu; Miyoshi, Yasunobu; Jin, Hidekatsu; Shinagawa, Hiroyuki; Terada, Kaori

    2012-06-01

    The IPY long-run data were obtained from the European Incoherent Scatter Svalbard radar (ESR) observations during March 2007 and February 2008. Since the solar and geomagnetic activities were quite low during the period, this data set is extremely helpful for describing the basic states (ground states) of the thermosphere and ionosphere in the polar cap region. The monthly-averaged ion temperatures for 12 months show similar local time (or UT) variations to each other. The ion temperatures also show significant seasonal variations. The amplitudes of the local time and seasonal variations observed are much larger than the ones predicted by the IRI-2007 model. In addition, we performed numerical simulations with a general circulation model (GCM), which covers all the atmospheric regions, to investigate variations of the neutrals in the polar thermosphere. The GCM simulations show significant variations of the neutral temperature in the polar region in comparison with the NRLMSISE-00 empirical model. These results indicate that both the ions and neutrals would show larger variations than those described by the empirical models, suggesting significant heat sources in the polar cap region even under solar minimum and geomagnetically quiet conditions.

  19. An assessment of the FGGE satellite observing system during SOP-1. [Special Observing Period in First GARP Global Experiment

    NASA Technical Reports Server (NTRS)

    Halem, M.; Kalnay, E.; Baker, W. E.; Atlas, R.

    1982-01-01

    The sensitivity of a Goddard Laboratory for Atmospheric Sciences global objective analysis cycle to the addition of FGGE level II-b data is assessed. The GOAS system comprises a predictive continuity provided by a model first-guess forecast integrated from a previous forecast and updated by data gathered in the interim. FGGE data originated in the Jan.-Mar. 1979 period and were acquired by rawinsondes, pilot balloons, surface stations, satellites, ships, and drifting buoys deployed during SOP-1. Focussing on 2-5 and 8-day forecasts, comparisons were made of the 6 hr forecast error at the 300 mb height in three experiments using all, no-satellite (NOSAT), and without rawinsondes or pilot balloons modes. Larger errors occurred in the case of NOSAT, while significant corrections to the GOAS predictions were noted using all the FGGE data. It was concluded that all forecasts were improved by inclusion of full FGGE data sets, including forecasting beyond one week.

  20. Rotation periods and seismic ages of KOIs - comparison with stars without detected planets from Kepler observations

    NASA Astrophysics Data System (ADS)

    Ceillier, T.; van Saders, J.; García, R. A.; Metcalfe, T. S.; Creevey, O.; Mathis, S.; Mathur, S.; Pinsonneault, M. H.; Salabert, D.; Tayar, J.

    2016-02-01

    One of the most difficult properties to derive for stars is their age. For cool main-sequence stars, gyrochronology relations can be used to infer stellar ages from measured rotation periods and Hertzsprung Russell diagram positions. These relations have few calibrators with known ages for old, long rotation period stars. There is a significant sample of old Kepler objects of interest, or KOIs, which have both measurable surface rotation periods and precise asteroseismic measurements from which ages can be accurately derived. In this work, we determine the age and the rotation period of solar-like pulsating KOIs to both compare the rotation properties of stars with and without known planets and enlarge the gyrochronology calibration sample for old stars. We use Kepler photometric light curves to derive the stellar surface rotation periods while ages are obtained with asteroseismology using the Asteroseismic Modelling Portal in which individual mode frequencies are combined with high-resolution spectroscopic parameters. We thus determine surface rotation periods and ages for 11 planet-hosting stars, all over 2 Gyr old. We find that the planet-hosting stars exhibit a rotational behaviour that is consistent with the latest age-rotation models and similar to the rotational behaviour of stars without detected planets. We conclude that these old KOIs can be used to test and calibrate gyrochronology along with stars not known to host planets.

  1. Simultaneous observations of periodic non-Io decametric radio emission by ground radio telescope URAN-2 and STEREO/WAVES

    NASA Astrophysics Data System (ADS)

    Panchenko, M.; Brazhenko, A. I.; Rucker, H. O.; Frantzusenko, A.; Shaposhnikov, V. E.; Konovalenko, A. A.

    2013-09-01

    Periodic bursts of the non-Io component of Jovian decametric radio emission (non-Io DAM) is observed as (1) series of arc-like radio bursts with negative frequency drift which reoccur with 1.5% longer period than the Jovian magnetosphere rotation rate, (2) series of bursts with positive frequency drift which reoccur with Jupiter's rotation period and (3) periodic non-arc like radio features [1, 2]. These bursts are typically detected during several Jupiter rotations in decametric frequency range from 4 MHz to 12 - 16 MHz between 300° and 60° of CML. We present simultaneous observations of the periodic non-Io controlled DAM performed by the WAVES radio experiment onboard the two STEREO spacecraft and the groundbased radio telescope URAN-2 (Poltava, Ukraine) operated in the decametric frequency range. URAN-2 with an effective area of about 30000 m2 consists of 512 broadband crossed dipoles and equipped with the high performance digital radio spectrometer with polarization measurement capability. During the observation campaign Sep., 2012 - Apr., 2013 URAN-2 recorded a large amount of Jovian DAM events with the high time-frequency resolution (4 kHz - 100 ms) in a frequency range 8-32 MHz. In the same time the two spatially separated STEREO spacecraft was able to observe DAM in the frequency range up to 16 MHz. The first analysis of the acquired stereoscopic observations is presented. In particular, we show one episode when the periodic non-arc DAM was recorded together with long lasting Jovian narrow band (NB) emissions. These NB emission was observed at the high frequency cutoff of DAM and can be interpreted as propagation of the decametric radiation in the Jovian ionosphere [3]. We discuss the possible relations between the observed NB events and the periodic non-Io controlled Jovian decametric radio emission.

  2. Quantization and symmetry in periodic coverage patterns with applications to earth observation

    NASA Technical Reports Server (NTRS)

    King, J. C.

    1975-01-01

    Analytical approaches based on an idealized physical model and concepts from number theory show that in periodic coverage patterns, uniquely defined by their revolution numbers R (orbital) and N (rotational), the subnodal points are earth-fixed, and they divide the equator into R equal segments of length s. The ascending subsatellite trace crosses each point once (only) each period. The descending subnodal points coincide with the ascending points if the integers N and R have like parity, and bisect the intervals between them if opposite. The interval between consecutive unidirectional crossings is Ns. Symmetries extend the equatorial results to all parallels of latitude. Complete periodic patterns of traces exhibit an overall symmetry, with trace intersections confined to discrete coordinate values which are quantized in longitude (basic s-unit) and symmetric in latitude.

  3. How the Initial Thinking Period Affects Student Argumentation during Peer Instruction: Students' Experiences versus Observations

    ERIC Educational Resources Information Center

    Nielsen, Kjetil L.; Hansen, Gabrielle; Stav, John B.

    2016-01-01

    The authors have compared students discussing multiple-choice quizzes during peer instruction with and without the initial thinking period before discussion. Video clips of students engaged in peer discussion in groups of three of varying group combinations, a total of 140 different students in all, were compared to students' own experiences…

  4. How the Initial Thinking Period Affects Student Argumentation during Peer Instruction: Students' Experiences versus Observations

    ERIC Educational Resources Information Center

    Nielsen, Kjetil L.; Hansen, Gabrielle; Stav, John B.

    2016-01-01

    The authors have compared students discussing multiple-choice quizzes during peer instruction with and without the initial thinking period before discussion. Video clips of students engaged in peer discussion in groups of three of varying group combinations, a total of 140 different students in all, were compared to students' own experiences

  5. Meridional Circulation Cells Observed In The Upper Troposphere Over Suriname During The Monsoon Period

    NASA Astrophysics Data System (ADS)

    Fortuin, P.; Kelder, H.

    Since September 1999, weekly balloon sondes are released at tropical Paramaribo sta- tion (5.8N 55.2W), located at the northern coast of South America. The station lies approximately in the middle of the annual migration range of the ITCZ, and therefore experiences either a northeast or a southeast trade wind regime (ITCZ respectively to the south, north). The wet season corresponds with the period of northeasterly trade winds (December-July) and is normally interrupted by a short dry period (February- March) when the ITCZ lies farthest to the south. During this monsoon period a sys- tematic return flow to higher latitudes can be detected, centered around 12 km (200 hPa), which seems to constitute the upper branch of the Hadley cell. However, this upper branch of the Hadley cell seems to be flanked above and below by southward flow. On closer inspection, these meridional sub-cells persist in a domain of negative potential vorticity, brought about by the horizontal gradient in zonal wind near the Equator as the northern subtropical jet reaches its southern-most point. As predicted by Stevens (1982), this inertially unstable domain responds with vertically sctacked meridional flow cells, in order to restore a minimum horizontal shear in zonal wind near the Equator. These meridional cells continuously exhibit alternating periods of growth and decay, on a time-scale consistent with inertial instability. Their meridional extent is from the Equator to approcimately 10-12 degrees North, such that Paramaribo (at 5.8N) witnesses approximately the maximal merinional wind velocity near the cen- ter of these cells. Due to their persistent recurring nature in the monsoon period, they leave a signature on the water vapor distribution in the upper troposphere, which shows a dry layer sandwithced between wetter layers - with a spatial distribution similar to the sub-cellular flow.

  6. IUE observations of periodic comets Tempel-2, Kopff, and Tempel-1

    NASA Technical Reports Server (NTRS)

    Feldman, Paul D.; Festou, Michel C.

    1992-01-01

    We summarize the results of observations made between 10 Jun. - 18 Dec. 1988 with the International Ultraviolet Explorer (IUS) of comet P/Tempel-2 during its 1988 appearance. The derived water production rate and relative gas/dust ratio are compared with those of P/Halley, observed with IUE in 1985-86, and other potential Comet Rendezvous/Asteroid Flyby (CRAF) target comets, P/Kopff and P/Tempel-1, both observed with IUE in 1983.

  7. Estimating the period and Q of the Chandler Wobble from observations and models of its excitation (Abstract)

    NASA Astrophysics Data System (ADS)

    Gross, R.; Nastula, J.

    2015-08-01

    Any irregularly shaped solid body rotating about some axis that is not aligned with its figure axis will freely wobble as it rotates. For the Earth, this free wobble is known as the Chandler wobble in honor of S.C. Chandler, Jr. who first observed it in 1891. Unlike the forced wobbles of the Earth, such as the annual wobble, whose periods are the same as the periods of the forcing mechanisms, the period of the free Chandler wobble is a function of the internal structure and rheology of the Earth, and its decay time constant, or quality factor Q, is a function of the dissipation mechanism(s), like mantle anelasticity, that are acting to dampen it. Improved estimates of the period and Q of the Chandler wobble can therefore be used to improve our understanding of these properties of the Earth. Here, estimates of the period and Q of the Chandler wobble are obtained by finding those values that minimize the power within the Chandler band of the difference between observed and modeled polar motion excitation spanning 1962- 2010. Atmosphere, ocean, and hydrology models are used to model the excitation caused by both mass and motion variations within these global geophysical fluids. Direct observations of the excitation caused by mass variations as determined from GRACE time varying gravitational field measurements are also used. The resulting estimates of the period and Q of the Chandler wobble will be presented along with a discussion of the robustness of the estimates.

  8. Observation of self-assembled periodic nano-structures induced by femtosecond laser in both ablation and deposition regimes

    NASA Astrophysics Data System (ADS)

    Tang, Mingzhen; Zhang, Haitao; Her, Tsing-Hua

    2008-02-01

    We observed the spontaneous formation of periodic nano-structures in both femtosecond laser ablation and deposition. The former involved 400-nm femtosecond pulses from a 250-KHz regenerated amplified mode-locked Ti:sapphire laser and periodic nanocracks and the nano-structure are in the form of periodic nanocracks in the substrate, the latter applied an 80-MHz mode-locked Ti:sapphire oscillator with pulse energy less than half nanojoule in a laser-induced chemical vapor deposition configuration and tungsten nanogratings grow heterogeneously on top of the substrates. These two observed periodic nanostructures have opposite orientations respecting to laser polarization: the periodic nanocracks are perpendicular to, whereas the deposited tungsten nanogratings are parallel to laser polarization direction. By translating the substrate respecting to the laser focus, both the periodic nanocrack and tungsten nanograting extend to the whole scanning range. The deposited tungsten nanogratings possess excellent uniformity on both the grating period and tooth length. Both the attributes can be tuned precisely by controlling the laser power and scanning speed. Furthermore, we discovered that the teeth of transverse tungsten nanogratings are self aligned along their axial direction during multiple scanning with appropriate offset between scans. We demonstrate the feasibility of fabricating large-area one-dimensional grating by exploiting such unique property. These distinct phenomena of nanocracks and tungsten nanogratings indicate different responsible mechanisms.

  9. Simultaneous ground-satellite observations of quasi-periodic /QP/ ELF-VLF emissions near L = 6

    NASA Astrophysics Data System (ADS)

    Sata, N.; Fukunishi, H.; Ozaki, T.; Yoshino, T.

    1981-11-01

    The quasi-periodic intensity modulation of ELF-VLF emissions at the level of the ISIS 1 and 2 satellites was found to be in one-to-one correspondence with the intensity modulation of quasi-periodic (QP) emissions at Syowa station in Antarctica, during simultaneous observations over the latitude range of -54 to -78 deg MLAT. The spectral form of QP emissions observed on the ISIS satellites showed a dependence on latitude, with the higher frequency range emissions observed at lower latitudes and vice versa. Although quasi-periodic intensity modulation of the polar chorus was in general one-to-one correspondence between ground and satellite data, burst-like discrete emissions did not always show such high correspondence between both sets of data. The results confirm the phenomenological model proposed by Sato and Fukunishi (1981) for the generation of QP emissions.

  10. Entrainment in solution of an oscillating NADH oxidase activity from the bovine milk fat globule membrane with a temperature-compensated period length suggestive of an ultradian time-keeping (clock) function

    NASA Technical Reports Server (NTRS)

    Morre, D. James; Lawler, Juliana; Wang, Sui; Keenan, Thomas W.; Morre, Dorothy M.

    2002-01-01

    Entrainment in solution of an oscillating activity with a temperature compensated period of 24 min is described for a NADH oxidase (NOX) activity of the bovine milk fat globule membrane, a derivative of the mammary epithelial cell plasma membrane. The period of 24 min remained unchanged at 17 degrees C, 27 degrees C and 37 degrees C whereas the amplitude approximately doubled with each 10 degree C rise in temperature (Q(10)congruent with 2). The periodicity was observed with both intact milk fat globule membranes and with detergent-solubilized membranes, demonstrating that the oscillations did not require an association with membranes. The periodicity was not the result of instrument variation or of chemical interactions among reactants in solution. Preparations with different periodicities entrained (autosynchronized) when mixed. Upon mixing, the preparations exhibited two oscillatory patterns but eventually a single pattern representing the mean of the farthest separated maxima of the two preparations analyzed separately emerged. The cell surface NOX protein is the first reported example of an entrainable biochemical entity with a temperature-compensated periodicity potentially capable of functioning as an ultradian or circadian clock driver.

  11. Frequency Dependence of Short Period Seismic Noise from Two Decades of Observations at Warramunga Seismic Array (WRA), Australia

    NASA Astrophysics Data System (ADS)

    Gal, M.; Reading, A. M.; Ellingsen, S. P.; Koper, K. D.; Tkalcic, H.; Hemer, M. A.

    2014-12-01

    The analysis of the seismic ambient noise field has recently received increased attention owing to its success in mapping the Earth's shallow and deep structures. The origin of the passive seismic wavefield is associated with deep ocean and coastal regions where ocean waves, under certain conditions, can excite seismic waves (microseisms) that propagate as surface and body waves. Previous seismological studies mainly focused on the observation of the strongest microseisms that are associated with the frequency range 0.1-0.3Hz. In our study, we focus on short period microseisms (0.325-0.725Hz) and examine the frequency dependant wave field and temporal variations over two decades. We use data recorded over two decades (1991-2012) from the Warramunga array (WRA) in central Australia. The analysis is carried out using IAS Capon beamforming that shows robust estimates of slowness and backazimuth, and is able to resolve multiple wave arrivals. Continuous data records are divided into one hour long recordings and evaluated for multiple arrivals in 8 separate frequency bands. We find multiple surface and body wave sources, which display seasonality and frequency dependence and remain stationary for two decades. We observe, for surface waves, that Rayleigh waves dominate for low frequencies while higher frequencies show a transition to leaky Rayleigh waves. The strong stationarity of the signal over multiple years, supports the suggestion that bathymetry and other site effects, such as coast line geometry, create favourable conditions for the generation of ocean induced surface waves. For body waves, source locations are identified in deep ocean regions for low frequencies and in shallow waters for higher frequencies. We further discuss correlation between arrivals and a WAVEWATCH III ocean wave hindcast for strong events. Fig 1: a) Shows the slowness of strongest incoming arrivals for 1 hour of WRA data over two decades. b) Displays the surface waves paths of incoming Rayleigh (red) and leaky Rayleigh (blue) waves. c) Shows source locations from back projected body wave arrivals.

  12. Observations and modeling of northern mid-latitude recurring slope lineae (RSL) suggest recharge by a present-day martian briny aquifer

    NASA Astrophysics Data System (ADS)

    Stillman, David E.; Michaels, Timothy I.; Grimm, Robert E.; Hanley, Jennifer

    2016-02-01

    Recurring slope lineae (RSL) are narrow (0.5-5 m) dark features on Mars that incrementally lengthen down steep slopes, fade in colder seasons, and recur annually. These features have been identified from the northern to southern mid-latitudes. Here, we describe how observations of northern mid-latitude RSL in northern Chryse Planitia and southwestern Acidalia Planitia (CAP) suggest that brines start flowing before northern spring equinox and continue for more than half a Mars-year (490 ± 40 sols, spanning solar longitude 337° ± 11°-224° ± 20°). All CAP RSL are found on the steep slopes of craters and their source zones are at or below the elevation of the surrounding plains. Spacecraft-derived surface temperature observations cannot resolve individual RSL, so thermal modeling was used to determine that CAP RSL have a freezing temperature of 238-252 K, freeze and melt diurnally, and flow only occurs within the top ∼8 cm of the regolith. Furthermore, we calculate that a typical CAP RSL has a water budget of 1.5-5.6 m3/m of headwall. Therefore, such a large water budget makes annual recharge via atmospheric or subsurface diffusion sources unlikely. Alternatively, we hypothesize that the most plausible RSL source is a briny aquifer with a freezing temperature less than or equal to the mean annual CAP surface temperature (220-225 K). The annual cycle is as follows: in late autumn, the shallowest part of the brine feeding the source zone freezes, forming an ice dam. As spring approaches, temperatures rise and the dam is breached. Brine is discharged and the RSL initially lengthens rapidly (>1.86 m/sol), the lengthening rate then slows considerably, to ∼0.25 m/sol. Eventually, the losses equal the discharge rate and the RSL reaches its equilibrium phase. As brine flows in the RSL some of the water is lost to the atmosphere, therefore the freezing temperature of the brine within the RSL is higher (238-252 K) as the brine transitions to a super-eutectic salt concentration. In the late autumn, falling temperatures restore the ice dam and the H2O in the RSL slowly sublimates away. Overall, CAP RSL possess a significantly different seasonality and much longer duration than typical southern mid-latitude RSL, suggesting that RSL at different latitude bands have different source types. Lastly, CAP RSL are the best evidence that shallow groundwater may still exist on Mars.

  13. Spatial log-periodic oscillations of first-passage observables in fractals.

    PubMed

    Akkermans, Eric; Benichou, Olivier; Dunne, Gerald V; Teplyaev, Alexander; Voituriez, Raphael

    2012-12-01

    For transport processes in geometrically restricted domains, the mean first-passage time (MFPT) admits a general scaling dependence on space parameters for diffusion, anomalous diffusion, and diffusion in disordered or fractal media. For transport in self-similar fractal structures, we obtain an expression for the source-target distance dependence of the MFPT that exhibits both the leading power-law behavior, depending on the Hausdorff and spectral dimension of the fractal, as well as small log-periodic oscillations that are a clear and definitive signal of the underlying fractal structure. We also present refined numerical results for the Sierpinski gasket that confirm this oscillatory behavior. PMID:23367911

  14. [The academic trend of Oriental medicine during the Japanese colonial period as observed through the publication of medical books].

    PubMed

    Kim, Nam-Il

    2006-06-01

    This thesis examines the academical trend of Oriental Medicine in the Japanese colonial period observed through medical books published during the Japanese colonial period. This is a period in which Western Medicine was introduced, and due to the lean-to-one-side policy by the Japanese, Western Medicine became the mainstream medical science while Oriental Medicine was pushed to the outskirts. Even after all this, the academic activity was flourishing during this period compared to any other periods. This article is divided into various chapters each with its own theme in order to understand the academic trend of Oriental Medicine during the Japanese colonial period. Focusing on the publication of medical books, this article is divided and observed according to various themes such as the study of Dong-Eui-Bo-Gam (see text), the study of Bang-Yak-Hap-Pyeun (see text), the study of Sang-Han-Ron (see text), the study of Sa-sang (see text) constitutional medicine, the study of Eui-Hak-Ip-Mun (see text), the study about Bu-Yang-Ron (see text), On-Bo-Ron (see text), and pediatrics, compromise between Western and Oriental Medicine, the study of experience medicine, the study of acupuncture and moxibustion, and etc. PMID:17214426

  15. High-Order Quantum Resonances Observed in a Periodically Kicked Bose-Einstein Condensate

    NASA Astrophysics Data System (ADS)

    Ryu, C.; Andersen, M. F.; Vaziri, A.; D'Arcy, M. B.; Grossman, J. M.; Helmerson, K.; Phillips, W. D.

    2006-04-01

    We have observed high-order quantum resonances in a realization of the quantum ?-kicked rotor, using Bose-condensed Na atoms subjected to a pulsed standing wave of laser light. These resonances occur for pulse intervals that are rational fractions of the Talbot time, and are characterized by ballistic momentum transfer to the atoms. The condensates narrow momentum distribution not only permits the observation of the quantum resonances at 3/4 and 1/3 of the Talbot time, but also allows us to study scaling laws for the resonance width in quasimomentum and pulse interval.

  16. High-Order Quantum Resonances Observed in a Periodically-Kicked Bose Condensate

    NASA Astrophysics Data System (ADS)

    Ryu, Changhyun; Andersen, Mikkel; Vaziri, Alipasha; D'Arcy, Michael; Grossman, Joshua; Helmerson, Kristian; Phillips, William

    2006-05-01

    We have observed high-order quantum resonances in a realization of the quantum ?-kicked rotor, using Bose-condensed Na atoms subjected to a pulsed standing wave of laser light. These resonances occur for pulse intervals that are rational fractions of the Talbot time, and are characterized by ballistic momentum transfer to the atoms. The condensate's narrow momentum distribution not only permits the observation of the quantum resonances at 3/4 and 1/3 of the Talbot time, but also allows us to study scaling laws for the resonance width in quasimomentum and pulse interval.

  17. Particle and field observations from Explorer 45 during the December 1971 magnetic storm period

    NASA Technical Reports Server (NTRS)

    Hoffman, R. A.

    1972-01-01

    Simultaneous observations are presented from the S3-A (Explorer 45) satellite of the magnetic signature of the ring current and complete measurements of the proton ring current to distances of 5.24 R sub E during the double magnetic storm of 16 to 19 December 1971.

  18. On the periodicity of symbolic observations of piecewise smooth discrete-time systems

    NASA Technical Reports Server (NTRS)

    Ramadge, Peter J.

    1990-01-01

    A study is made of the behavior of discrete-time systems composed of a set of smooth transition maps coupled by a quantized feedback function. The feedback function partitions the state space into disjoint regions and assigns a smooth transition function to each region. The main result is that under a constraint on the norm of the derivative of the transition maps, a bounded state trajectory with limit points in the interior of the switching regions leads to a region index sequence that is eventually periodic. Under these assumptions, it is shown that eventually the feedback function is determined by a finite state automaton. A similar result is proved in the case of finite state dynamic feedback.

  19. Observations of Diurnal Period Wind-Driven and Wave-Driven Flows in Northern Monterey Bay

    NASA Astrophysics Data System (ADS)

    Suanda, S. A.; Barth, J. A.

    2008-12-01

    In July 2007, the Partnership for Interdisciplinary Studies of Coastal Oceans (PISCO) conducted a biophysical experiment with the goal of examining the physical processes that determine the delivery of invertebrate larvae and juvenile rockfish to communities in northern Monterey Bay. Simultaneous measurement of currents and waves are analyzed to isolate forcing mechanisms that drive cross-shelf flow and provide insight to the on/offshore transport of mass and momentum to the inner shelf. These mechanisms include wind- driven motions from large-scale and local diurnal winds as well as wave-driven motions. The work here focuses on the variability of wind-driven and wave-driven transports associated with a diurnal sea breeze in this part of Monterey Bay. An amplitude modulation technique is used to examine the relationship between the diurnal period winds, along- and cross-shelf transports, as well as wave-driven transports.

  20. Daytime Raman lidar measurements of water vapor during the ARM 1997 water vapor intensive observation period

    SciTech Connect

    Turner, D.D.; Goldsmith, J.E.M.

    1998-04-01

    Because of the importance of water vapor, the ARM program initiated a series of three intensive operating periods (IOPs) at its CART (Cloud And Radiation Testbed) site. The goal of these IOPs is to improve and validate the state-of-the-art capabilities in measuring water vapor. To date, two of the planned three IOPs have occurred: the first was in September of 1996, with an emphasis on the lowest kilometer, while the second was conducted from September--October 1997 with a focus on both the upper troposphere and lowest kilometer. These IOPs provided an excellent opportunity to compare measurements from other systems with those made by the CART Raman lidar. This paper addresses primarily the daytime water vapor measurements made by the lidar system during the second of these IOPs.

  1. Space Technology 5 Observations of Short-Period ULF Waves: Temporal and Spatial Patterns

    NASA Astrophysics Data System (ADS)

    Westerman, A.; Otto, N.; Engebretson, M.; Slavin, J.; Le, G.; Strangeway, R.

    2007-05-01

    The three microsatellites that comprise the Space Technology 5 (ST5) mission were launched into a dawn-dusk, 300 x 4500 km sun-synchronous orbit in a "pearls-on-a-string" configuration, with spacings ranging from >5000 km down to under 50 km. Fluxgate magnetometers on board each spacecraft collected vector magnetic field data from March 26 through June 30, 2006. In this study we present the first results of a survey of ULF waves in the Pc 1-2 frequency range, with a total of 105 events, recorded by these spacecraft. Waves in the middle magnetosphere (L from 4 to 7) were observed to have a nearly uniform diurnal occurrence rate. At higher latitudes (L > 7) occurrence was maximum in the dawn-noon sector, consistent with stimulation by magnetospheric compressions. Only five wave events were observed at L < 4. The temporal occurrence distribution roughly followed the occurrence of Pc 1-2 activity recorded at Halley, Antarctica (L = 4.5), in that the number and intensity of events was increased during magnetospheric compressions, during the recovery phase of magnetic storms, and during one extended interval of disturbed but only modestly negative Dst. Somewhat surprisingly, only eight events were observed by all three spacecraft as they passed over similar L shells, and only 14 events, including two each on three days, were observed by two spacecraft. Nearly all of these events occurred during storm recovery. We interpret the lack of more multi-spacecraft observations as indicating the highly localized nature of regions in the magnetosphere that become unstable to electromagnetic ion cyclotron instabilities.

  2. A single administration of methamphetamine to mice early in the light period decreases running wheel activity observed during the dark period

    PubMed Central

    Kitanaka, Nobue; Kitanaka, Junichi; Hall, F. Scott; Uhl, George R.; Watabe, Kaname; Kubo, Hitoshi; Takahashi, Hitoshi; Tatsuta, Tomohiro; Morita, Yoshio; Takemura, Motohiko

    2014-01-01

    Repeated intermittent administration of amphetamines acutely increases appetitive and consummatory aspects of motivated behaviors as well as general activity and exploratory behavior, including voluntary running wheel activity. Subsequently, if the drug is withdrawn, the frequency of these behaviors decrease, which is thought to be indicative of dysphoric symptoms associated with amphetamine withdrawal. Such decreases may be observed after chronic treatment or even after single drug administrations. In the present study, the effect of acute methamphetamine (METH) on running wheel activity, horizontal locomotion, appetitive behavior (food access), and consummatory behavior (food and water intake) was investigated in mice. A multi-configuration behavior apparatus designed to monitor the five behaviors was developed, where combined measures were recorded simultaneously. In the first experiment, naïve male ICR mice showed gradually increasing running wheel activity over three consecutive days after exposure to a running wheel, while mice without a running wheel showed gradually decreasing horizontal locomotion, consistent with running wheel activity being a positively motivated form of natural motor activity. In experiment 2, increased horizontal locomotion and food access, and decreased food intake, were observed for the initial 3 h after acute METH challenge. Subsequently, during the dark phase period decreased running wheel activity and horizontal locomotion were observed. The reductions in running wheel activity and horizontal locomotion may be indicative of reduced dopaminergic function, although it remains to be seen if these changes may be more pronounced after more prolonged METH treatments. PMID:22079320

  3. Long-Term Satellite Observations of Microcystin Concentrations in Lake Taihu during Cyanobacterial Bloom Periods.

    PubMed

    Shi, Kun; Zhang, Yunlin; Xu, Hai; Zhu, Guangwei; Qin, Boqiang; Huang, Changchun; Liu, Xiaohan; Zhou, Yongqiang; Lv, Heng

    2015-06-01

    Microcystins (MCs) produced by cyanobacteria pose a serious threat to public health. Intelligence on MCs distributions in freshwater is therefore critical for environmental agencies, water authorities, and public health organizations. We developed and validated an empirical model to quantify MCs in Lake Taihu during cyanobacterial bloom periods using the atmospherically Rayleigh-corrected moderate resolution imaging spectroradiometer (MODIS-Aqua) (Rrc) products and in situ data by means of chlorophyll a concentrations (Chla). First, robust relationships were constructed between MCs and Chla (r = 0.91; p < 0.001; t-test) and between Chla and a spectral index derived from Rrc (r = -0.86; p < 0.05; t-test). Then, a regional algorithm to analyze MCs in Lake Taihu was constructed by combining the two relationships. The model was validated and then applied to an 11-year series of MODIS-Aqua data to investigate the spatial and temporal distributions of MCs. MCs in the lake were markedly variable both spatially and temporally. Cyanobacterial bloom scums, temperature, wind, and light conditions probably affected the temporal and spatial distribution of MCs in Lake Taihu. The findings demonstrate that remote sensing reconnaissance in conjunction with in situ monitoring can greatly aid MCs assessment in freshwater. PMID:25936388

  4. Periodicities of the inner plasma disk of Saturn - Cassini RPWS observations

    NASA Astrophysics Data System (ADS)

    Holmberg, M.; Wahlund, J. E.; Morooka, M. W.

    2014-12-01

    We use Radio and Plasma Wave Science (RPWS) Langmuir probe (LP) data from 200 Cassini orbits, recorded between the years 2005 and 2014, to study the connection between periodicities of various subsystems of the Saturnian system and the recently detected dayside/nightside asymmetry of ion densities and velocities in Saturn's inner plasma disk. First we study the effect of the variability of the Enceladus plume activity, that is varying with the distance of the moon from Saturn. The brightness of the plume is largest at apocentre and smallest at pericentre. This implies that more material is escaping the plume when Enceladus is further away from Saturn and the fissures of Enceladus south polar region is under tension due to tidal stresses, than when Enceladus is closer to Saturn. We show that the variability of the Enceladus plume cannot explain the large dayside/nightside asymmetry detected by the LP. Instead, the ion density and velocity asymmetry seems to be related to the recently detected noon to midnight electric field of the E ring, which could be created by negatively charged nanometer-sized grains in the E ring. We investigate what nanograin properties that are needed in order to cause such large scale effects as the density and velocity dayside/nightside asymmetry. We also study the relation between the previously reported electron density variation with SLS4 and the ion density variation detected by the LP.

  5. OBSERVING EVOLUTION IN THE SUPERGRANULAR NETWORK LENGTH SCALE DURING PERIODS OF LOW SOLAR ACTIVITY

    SciTech Connect

    McIntosh, Scott W.; Rast, Mark P.; Leamon, Robert J.; Hock, Rachel A.; Ulrich, Roger K.

    2011-03-20

    We present the initial results of an observational study into the variation of the dominant length scale of quiet solar emission: supergranulation. The distribution of magnetic elements in the lanes that from the network affects, and reflects, the radiative energy in the plasma of the upper solar chromosphere and transition region at the magnetic network boundaries forming as a result of the relentless interaction of magnetic fields and convective motions of the Suns' interior. We demonstrate that a net difference of {approx}0.5 Mm in the supergranular emission length scale occurs when comparing observation cycle 22/23 and cycle 23/24 minima. This variation in scale is reproduced in the data sets of multiple space- and ground-based instruments and using different diagnostic measures. By means of extension, we consider the variation of the supergranular length scale over multiple solar minima by analyzing a subset of the Mount Wilson Solar Observatory Ca II K image record. The observations and analysis presented provide a tantalizing look at solar activity in the absence of large-scale flux emergence, offering insight into times of 'extreme' solar minimum and general behavior such as the phasing and cross-dependence of different components of the spectral irradiance. Given that the modulation of the supergranular scale imprints itself in variations of the Suns' spectral irradiance, as well as in the mass and energy transport into the entire outer atmosphere, this preliminary investigation is an important step in understanding the impact of the quiet Sun on the heliospheric system.

  6. Suzaku And Multi-Wavelength Observations of OJ 287 During the Periodic Optical Outburst in 2007

    SciTech Connect

    Seta, Hiromi; Isobe, N.; Tashiro, Makoto S.; Yaji, Yuichi; Arai, Akira; Fukuhara, Masayuki; Kohno, Kotaro; Nakanishi, Koichiro; Sasada, Mahito; Shimajiri, Yoshito; Tosaki, Tomoka; Uemura, Makoto; Anderhub, Hans; Antonelli, L.A.; Antoranz, Pedro; Backes, Michael; Baixeras, Carmen; Balestra, Silvia; Barrio, Juan Abel; Bastieri, Denis; Becerra Gonzalez, Josefa; /IAC, La Laguna /Dortmund U. /Lodz U. /Lodz U. /DESY /Zurich, ETH /Munich, Max Planck Inst. /Padua U. /INFN, Padua /Siena U. /INFN, Siena /Barcelona, IEEC /Munich, Max Planck Inst. /Barcelona, IEEC /Madrid U. /Zurich, ETH /Wurzburg U. /Zurich, ETH /Madrid U. /Munich, Max Planck Inst. /Zurich, ETH /Madrid U. /Barcelona, IFAE /IAC, La Laguna /Laguna U., Tenerife /INFN, Rome /Dortmund U. /Udine U. /INFN, Udine /INFN, Padua /Udine U. /INFN, Udine /Barcelona, IEEC /Madrid U. /Udine U. /INFN, Udine /Udine U. /INFN, Udine /Udine U. /INFN, Udine /IAC, La Laguna /Madrid, CIEMAT /Sierra Nevada Observ. /Zurich, ETH /Padua U. /INFN, Padua /Wurzburg U. /Barcelona, IFAE /UC, Davis /Barcelona, IFAE /Barcelona, IFAE /Madrid U. /Barcelona, Autonoma U. /Munich, Max Planck Inst. /IAC, La Laguna /Laguna U., Tenerife /Barcelona, IFAE /IAC, La Laguna /Munich, Max Planck Inst. /Barcelona, Autonoma U. /Munich, Max Planck Inst. /SLAC /IAC, La Laguna /Laguna U., Tenerife /Zurich, ETH /Wurzburg U. /Munich, Max Planck Inst. /Munich, Max Planck Inst. /Munich, Max Planck Inst. /Zurich, ETH /INFN, Rome /UC, Davis /Siena U. /INFN, Siena /Turku U. /Padua U. /INFN, Padua /Udine U. /INFN, Udine /Padua U. /INFN, Padua /Zurich, ETH /Munich, Max Planck Inst. /DESY /Sofiya, Inst. Nucl. Res. /Udine U. /INFN, Udine /Wurzburg U. /INFN, Rome /Padua U. /INFN, Padua /Barcelona, IFAE /Barcelona, IFAE /Siena U. /INFN, Siena /Wurzburg U. /Madrid U. /Munich, Max Planck Inst. /Munich, Max Planck Inst. /Barcelona, IEEC /Sierra Nevada Observ. /Barcelona, IFAE /Madrid U. /Turku U. /Munich, Max Planck Inst. /Munich, Max Planck Inst. /UC, Santa Cruz /Madrid U. /Siena U. /INFN, Siena /Barcelona, IEEC /Turku U. /Padua U. /INFN, Padua /Zurich, ETH /Siena U. /INFN, Siena /Sierra Nevada Observ. /Udine U. /INFN, Udine /INFN, Trieste /Padua U. /INFN, Padua /Sierra Nevada Observ. /Padua U. /INFN, Padua /Barcelona, IFAE /Barcelona, IFAE /Dortmund U. /Barcelona, IEEC /ICREA, Barcelona /Barcelona, IFAE /Zurich, ETH /Barcelona, Autonoma U. /Wurzburg U. /Padua U. /INFN, Padua /Munich, Max Planck Inst. /INFN, Rome /Sierra Nevada Observ. /DESY /Padua U. /INFN, Padua /Udine U. /INFN, Udine /Munich, Max Planck Inst. /Munich, Max Planck Inst. /Pisa U. /INFN, Pisa /Barcelona, IFAE /Barcelona, IEEC /Turku U. /Munich, Max Planck Inst. /Lodz U. /Lodz U. /Wurzburg U. /Siena U. /INFN, Siena /Zurich, ETH /Turku U. /INFN, Rome /Sofiya, Inst. Nucl. Res. /Barcelona, IFAE /Munich, Max Planck Inst. /DESY /ICREA, Barcelona /Barcelona, IEEC /Siena U. /INFN, Siena /Sofiya, Inst. Nucl. Res. /Munich, Max Planck Inst. /Munich, Max Planck Inst. /Barcelona, IEEC /Sierra Nevada Observ. /Barcelona, IFAE /Barcelona, Autonoma U.

    2011-12-01

    Suzaku observations of the blazar OJ 287 were performed in 2007 April 10-13 and November 7-9. They correspond to a quiescent and a flaring state, respectively. The X-ray spectra of the source can be well described with single power-law models in both exposures. The derived X-ray photon index and the flux density at 1 keV were found to be {Lambda} = 1.65 {+-} 0.02 and S{sub 1keV} = 215 {+-} 5 nJy, in the quiescent state. In the flaring state, the source exhibited a harder X-ray spectrum ({Lambda} = 1.50 {+-} 0.01) with a nearly doubled X-ray flux density S{sub 1keV} = 404{sub -5}{sup +6} nJy. Moreover, significant hard X-ray signals were detected up to {approx} 27 keV. In cooperation with the Suzaku, simultaneous radio, optical, and very-high-energy {gamma}-ray observations of OJ 287 were performed with the Nobeyama Millimeter Array, the KANATA telescope, and the MAGIC telescope, respectively. The radio and optical fluxes in the flaring state (3.04 {+-} 0.46 Jy and 8.93 {+-} 0.05 mJy at 86.75 Hz and in the V-band, respectively) were found to be higher by a factor of 2-3 than those in the quiescent state (1.73 {+-} 0.26 Jy and 3.03 {+-} 0.01 mJy at 86.75 Hz and in the V-band, respectively). No notable {gamma}-ray events were detected in either observation. The spectral energy distribution of OJ 287 indicated that the X-ray spectrum was dominated by inverse Compton radiation in both observations, while synchrotron radiation exhibited a spectral cutoff around the optical frequency. Furthermore, no significant difference in the synchrotron cutoff frequency was found between the quiescent and flaring states. According to a simple synchrotron self-Compton model, the change of the spectral energy distribution is due to an increase in the energy density of electrons with small changes of both the magnetic field strength and the maximum Lorentz factor of electrons.

  7. Quasi-periodic Slipping Magnetic Reconnection During an X-class Solar Flare Observed by the Solar Dynamics Observatory and Interface Region Imaging Spectrograph

    NASA Astrophysics Data System (ADS)

    Li, Ting; Zhang, Jun

    2015-05-01

    We first report the quasi-periodic slipping motion of flare loops during an eruptive X-class flare on 2014 September 10. The slipping motion was investigated at a specific location along one of the two ribbons and can be observed throughout the impulsive phase of the flare. The apparent slipping velocity was 20-110 km s-1, and the associated period was 3-6 minutes. The footpoints of flare loops appeared as small-scale bright knots observed in 1400 , corresponding to fine structures of the flare ribbon. These bright knots were observed to move along the southern part of the longer ribbon and also exhibited a quasi-periodic pattern. The Si iv 1402.77 line was redshifted by 30-50 km s-1 at the locations of moving knots with a 40-60 km s-1 line width, larger than other sites of the flare ribbon. We suggest that the quasi-periodic slipping reconnection is involved in this process and the redshift at the bright knots is probably indicative of reconnection downflow. The emission line of Si iv at the northern part of the longer ribbon also exhibited obvious redshifts of about 10-70 km s-1 in the impulsive phase of the flare, with the redshifts at the outer edges of the ribbon larger than those in the middle. The redshift velocities at post-flare loops reached about 80-100 km s-1 in the transition region.

  8. OBSERVATIONAL STUDY OF THE QUASI-PERIODIC FAST-PROPAGATING MAGNETOSONIC WAVES AND THE ASSOCIATED FLARE ON 2011 MAY 30

    SciTech Connect

    Shen Yuandeng; Liu Yu

    2012-07-01

    On 2011 May 30, quasi-periodic fast-propagating (QFP) magnetosonic waves accompanied by a C2.8 flare were directly imaged by the Atmospheric Imaging Assembly instrument on board the Solar Dynamics Observatory. The QFP waves successively emanated from the flare kernel, they propagated along a cluster of open coronal loops with a phase speed of {approx}834 km s{sup -1} during the flare's rising phase, and the multiple arc-shaped wave trains can be fitted with a series of concentric circles. We generate the k - {omega} diagram of the Fourier power and find a straight ridge that represents the dispersion relation of the waves. Along the ridge, we find a lot of prominent nodes which represent the available frequencies of the QFP waves. On the other hand, the frequencies of the flare are also obtained by analyzing the flare light curves using the wavelet technique. The results indicate that almost all the main frequencies of the flare are consistent with those of the QFP waves. This suggests that the flare and the QFP waves were possibly excited by a common physical origin. On the other hand, a few low frequencies (e.g., 2.5 mHz (400 s) and 0.7 mHz (1428 s)) revealed by the k - {omega} diagram cannot be found in the accompanying flare. We propose that these low frequencies were possibly due to the leakage of the pressure-driven p-mode oscillations from the photosphere into the low corona, which should be a noticeable mechanism for driving the QFP waves observed in the corona.

  9. Observational Study of the Quasi-periodic Fast-propagating Magnetosonic Waves and the Associated Flare on 2011 May 30

    NASA Astrophysics Data System (ADS)

    Shen, Yuandeng; Liu, Yu

    2012-07-01

    On 2011 May 30, quasi-periodic fast-propagating (QFP) magnetosonic waves accompanied by a C2.8 flare were directly imaged by the Atmospheric Imaging Assembly instrument on board the Solar Dynamics Observatory. The QFP waves successively emanated from the flare kernel, they propagated along a cluster of open coronal loops with a phase speed of ~834 km s-1 during the flare's rising phase, and the multiple arc-shaped wave trains can be fitted with a series of concentric circles. We generate the k - ? diagram of the Fourier power and find a straight ridge that represents the dispersion relation of the waves. Along the ridge, we find a lot of prominent nodes which represent the available frequencies of the QFP waves. On the other hand, the frequencies of the flare are also obtained by analyzing the flare light curves using the wavelet technique. The results indicate that almost all the main frequencies of the flare are consistent with those of the QFP waves. This suggests that the flare and the QFP waves were possibly excited by a common physical origin. On the other hand, a few low frequencies (e.g., 2.5 mHz (400 s) and 0.7 mHz (1428 s)) revealed by the k - ? diagram cannot be found in the accompanying flare. We propose that these low frequencies were possibly due to the leakage of the pressure-driven p-mode oscillations from the photosphere into the low corona, which should be a noticeable mechanism for driving the QFP waves observed in the corona.

  10. Ground deformation of Nisyros Volcano (Greece) for the period 1995 2002: Results from DInSAR and DGPS observations

    NASA Astrophysics Data System (ADS)

    Lagios, E.; Sakkas, V.; Parcharidis, Is.; Dietrich, V.

    2005-12-01

    Differential GPS (DGPS) and Differential Interferometric Synthetic Aperture Radar (DInSAR) analyses were applied to the Kos-Yali-Nisyros Volcanic Field (SE Hellenic Volcanic Arc) to quantify the ground deformation of Nisyros Volcano. After intense seismic activity in 1996, a GPS network was installed in June 1997 and re-occupied annually up to 2002. A general uplift ranging from 14 to 140 mm was determined at all stations of the network. The corresponding horizontal displacements ranged from 13 to 53 mm. The displacement vectors indicate that the island is undergoing extension towards the East, West and South. A two-source Mogi model combined with assumed motion along the Mandraki Fault was constructed to fit the observed deformation. The best-fit model assumes sources at a depth of 5500 m NW of the centre of the island and at 6500 m offshore ESE of Yali Island. DInSAR analysis using four pairs of images taken between May 1995 and September 2000 suggests that deformation was occurring during 1995 before the start of the seismic crisis. An amplitude of at least 56 mm along the slant range appeared for the period 1996 through 1999. This deformation is consistent with the two-source model invoked in DGPS modelling. Surface evidence of ground deformation is expressed in the contemporaneous reactivation of the Mandraki Fault. In addition, a 600 m long N-S trending irregular rupture in the caldera floor was formed between 2001 and 2002. This rupture is interpreted as the release of surface stress in the consolidated epiclastic and hydrothermal sediments of the caldera floor.

  11. Period variations in pulsating X-ray sources. I - Accretion flow parameters and neutron star structure from timing observations

    NASA Technical Reports Server (NTRS)

    Lamb, F. K.; Shaham, J.; Pines, D.

    1978-01-01

    Torque fluctuations which can lead to variations in the periods of pulsating X-ray sources are examined. A description of torque variations in terms of noise processes is developed, and the resulting noise models are applied to observations of several pulsating X-ray sources. It is shown that fluctuations in accretion torque could account for the observed period variations and spindown episodes in Her X-1 and Cen X-3. The values of the torque noise strengths inferred from either a nonresonant response or, in the case of Her X-1, a Tkachenko-mode interpretation of the data are found to be consistent with those expected from processes at the magnetospheric boundary of an accreting neutron star. Ways to distinguish among the various interpretations of the period variations are considered. It is noted that fluctuating mass-flow rates may be responsible for other phenomena observed in compact X-ray sources, such as wobble with zero initial amplitude and binary period variations in close binary systems experiencing mass transfer.

  12. Incidence of cancer among ferrochromium and ferrosilicon workers: an extended observation period.

    PubMed Central

    Langård, S; Andersen, A; Ravnestad, J

    1990-01-01

    Results are presented of a cohort study on the incidence of cancers and crude death rates in ferrochromium and ferrosilicon workers. The whole cohort was observed from 1 January 1953 to 31 December 1985. Two sets of results are presented; one restricted to workers first employed before 1960 and one to workers first employed before 1965. The latter cohort consists of 1235 workers. The total mortality in the whole cohort was low (SMR = 81) as was the overall incidence of cancers (SIR = 84). There was an overall deficit of deaths and cases of cancer in the ferrosilicon group. An excess of lung cancer (SIR = 154) and cancer of the prostate (SIR = 151) was observed in the ferrochromium workers employed before 1965. Cancer of the kidney was also in excess (SIR = 273) in the ferrochromium group, with a mean "latency time" of 39 years. Two cases of malignant melanomas had occurred versus 0.19 expected in a small subgroup of workers in electrical shops and an electric power station. PMID:2310703

  13. Theory and observations: Model simulations of the period 1955-1985

    NASA Technical Reports Server (NTRS)

    Isaksen, Ivar S. A.; Eckman, R.; Lacis, A.; Ko, Malcolm K. W.; Prather, M.; Pyle, J.; Rodhe, H.; Stordal, Frode; Stolarski, R. S.; Turco, R. P.

    1989-01-01

    The main objective of the theoretical studies presented here is to apply models of stratospheric chemistry and transport in order to understand the processes that control stratospheric ozone and that are responsible for the observed variations. The model calculations are intended to simulate the observed behavior of atmospheric ozone over the past three decades (1955-1985), for which there exists a substantial record of both ground-based and, more recently, satellite measurements. Ozone concentrations in the atmosphere vary on different time scales and for several different causes. The models described here were designed to simulate the effect on ozone of changes in the concentration of such trace gases as CFC, CH4, N2O, and CO2. Changes from year to year in ultraviolet radiation associated with the solar cycle are also included in the models. A third source of variability explicitly considered is the sporadic introduction of large amounts of NO sub x into the stratosphere during atmospheric nuclear tests.

  14. Plasma-wave observations at Uranus from Voyager 2. Progress report for period ending February 1986

    SciTech Connect

    Gurnett, D.A.; Kurth, W.S.; Scarf, F.L.; Poynter, R.L.

    1986-03-26

    Radio emissions from Uranus were detected by the Voyager 2 plasma-wave instrument about 5 days before closest approach at frequencies of 31.1 and 56.2 khz. The bow shock was identified by an abrupt broadband burst of electrostatic turbulence about 10 hours before closest approach at a radial distance of 23.5 ru. Once inside of the magnetosphere, strong whistler mode hiss and chorus emissions were observed at radial distances less than about 8 R/sub u/, in the same region where the energetic-particle instruments detected intense fluxes of energetic electrons. A variety of other plasma waves, such as (f sub c) electron-cyclotron waves, were also observed in this same region. At the ring plane crossing, the plasma wave instrument detected a large number of impulsive events that are interpreted as impacts of micron-sized dust particles on the spacecraft. The maximum impact rate was about 20 to 30 impacts/sec, and the north-south thickness of the impact region was about 4000 km. This paper presents an overview of the principal results from the plasma-wave instrument, starting with the first detection of radio emissions from Uranus, and ending a few days after closest approach.

  15. Tidally distorted exoplanets: Density corrections for short-period hot-Jupiters based solely on observable parameters

    SciTech Connect

    Burton, J. R.; Watson, C. A.; Fitzsimmons, A.; Moulds, V.; Pollacco, D.; Wheatley, P. J.; Littlefair, S. P.

    2014-07-10

    The close proximity of short-period hot-Jupiters to their parent star means they are subject to extreme tidal forces. This has a profound effect on their structure and, as a result, density measurements that assume that the planet is spherical can be incorrect. We have simulated the tidally distorted surface for 34 known short-period hot-Jupiters, assuming surfaces of constant gravitational equipotential for the planet, and the resulting densities have been calculated based only on observed parameters of the exoplanet systems. Comparing these results to the density values, assuming the planets are spherical, shows that there is an appreciable change in the measured density for planets with very short periods (typically less than two days). For one of the shortest-period systems, WASP-19b, we determine a decrease in bulk density of 12% from the spherical case and, for the majority of systems in this study, this value is in the range of 1%-5%. On the other hand, we also find cases where the distortion is negligible (relative to the measurement errors on the planetary parameters) even in the cases of some very short period systems, depending on the mass ratio and planetary radius. For high-density gas planets requiring apparently anomalously large core masses, density corrections due to tidal deformation could become important for the shortest-period systems.

  16. Water vapor measurements by Raman lidar during the ARM 1997 water vapor intensive observation period

    SciTech Connect

    Turner, D.D.; Whiteman, D.N.; Schwemmer, G.K.; Evans, K.D. |; Melfi, S.H.; Goldsmith, J.E.

    1998-04-01

    Water vapor is the most important greenhouse gas in the atmosphere, as it is the most active infrared absorber and emitter of radiation, and it also plays an important role in energy transport and cloud formation. Accurate, high resolution measurements of this variable are critical in order to improve the understanding of these processes and thus their ability to model them. Because of the importance of water vapor, the Department of Energy`s Atmospheric Radiation Measurement (ARM) program initiated a series of three intensive operating periods (IOPs) at its Cloud and Radiation Testbed (CART) site in northern Oklahoma. The goal of these IOPs is to improve and validate the state-of-the-art capabilities in measuring water vapor. To date, two of the planned three IOPs have occurred: the first was in September of 1996, with an emphasis on the lowest kilometer, while the second was conducted from September--October 1997 with a focus on both the upper troposphere and lowest kilometer. The ARM CART site is the home of several different water vapor measurement systems. These systems include a Raman lidar, a microwave radiometer, a radiosonde launch site, and an instrumented tower. During these IOPs, additional instrumentation was brought to the site to augment the normal measurements in the attempt to characterize the CART instruments and to address the need to improve water vapor measurement capabilities. Some of the instruments brought to the CART site include a scanning Raman lidar system from NASA/GSFC, additional microwave radiometers from NOAA/ETL, a chilled mirror that was flown on a tethersonde and kite system, and dewpoint hygrometer instruments flow on the North Dakota Citation. This paper will focus on the Raman lidar intercomparisons from the second IOP.

  17. Millimeter and some near infra-red observations of short-period Miras and other AGB stars

    NASA Astrophysics Data System (ADS)

    Groenewegen, M. A. T.; Baas, F.; Blommaert, J. A. D. L.; Stehle, R.; Josselin, E.; Tilanus, R. P. J.

    1999-12-01

    Millimeter observations of 48 oxygen- and 20 carbon-rich AGB Miras with periods shorter than 400 days are presented. In addition, observations of 14 O-rich and 15 C-stars with longer, or no known, periods have also been obtained. The detection statistics is as follows: in 12CO J=1-0 and 2-1 we observed 97 stars, and detected 66 in at least one line. We find 24 new detections in the 1-0 line, 38 new detections in the 2-1 line, and 29 stars have been detected for the first time in one or both lines. In 12CO J=3-2 we observed 14 stars and detected 11, with 4 new detections. In 13CO J=2-1, 3-2 we observed 2 stars and had one new detection. In HCN(1-0) we observed 5 carbon stars and detected 3, one new. In SO(6_5-5_4) we observed the same 5 stars and detected none. In CS(3-2) we observed 8 carbon stars and detected 3, all new. In SiO(3-2, v=0) we observed 34 O-rich stars and detected 25, all new except one. Near-infrared JHK photometry is presented for seven stars. For four stars it is the first NIR data published. The luminosity and dust mass loss rate are obtained for seven very red stars with unknown pulsation period from modelling the spectral energy distribution (SED) and IRAS LRS spectra. Thereby, a new IR supergiant is confirmed (AFGL 2968). For the rest of the sample, luminosity and distance are obtained in a variety of ways: using hipparcos parallaxes, period-luminosity and period-M_K-relations combined with apparent K magnitudes, and kinematic distances. The dust mass loss rate is obtained from model fitting of the SED (either from the literature, or presented in the present paper), or from the observed IRAS 60 mu m flux, corrected for the photospheric contribution. The gas mass loss rate is derived from the observed CO line intensities, as presented here, combined with existing literature data, if any. This allows the derivation of the dust-to-gas ratio. Our and literature CO J = 3-2 data has been used to calibrate the relation between mass loss rate and peak intensity of the CO(3-2) line. Diagrams showing mass loss rate, dust-to-gas ratio and expansion velocity versus pulsation period are presented. Our observations confirm the existence of an upper limit for the expansion velocity of C- and O-rich stars, and that this maximum is larger for C-stars, as predicted by the theory of radiation pressure on dust particles. The James Clerk Maxwell Telescope is operated by the Observatories on behalf of the Science and Engineering Council of the UK, the Netherlands Organization for Scientific Research, and the National Research Council of Canada. Based on observations made with the Carlos Sanchez telescope operated on the island of Tenerife in the Spanish Observatorio del Teide of the Instituto de Astrof\\'\\i sica de Canarias. Based on observations collected at the European Southern Observatory, La Silla, Chile within programs ESO 57.E-0105, 59.E-0198 and 61.E-0254. Based on data from the ESA Hipparcos astrometry satellite.

  18. The origin of long-period lattice spacings observed in iron-carbide nanowires encapsulated by multiwall carbon nanotubes.

    PubMed

    Boi, Filippo S; Mountjoy, Gavin; Luklinska, Zofia; Spillane, Liam; Karlsson, Lisa S; Wilson, Rory M; Corrias, Anna; Baxendale, Mark

    2013-10-01

    Structures comprising single-crystal, iron-carbon-based nanowires encapsulated by multiwall carbon nanotubes self-organize on inert substrates exposed to the products of ferrocene pyrolysis at high temperature. The most commonly observed encapsulated phases are Fe?C, ?-Fe, and ?-Fe. The observation of anomalously long-period lattice spacings in these nanowires has caused confusion since reflections from lattice spacings of ? 0.4 nm are kinematically forbidden for Fe?C, most of the rarely observed, less stable carbides, ?-Fe, and g-Fe. Through high-resolution electron microscopy, selective area electron diffraction, and electron energy loss spectroscopy we demonstrate that the observed long-period lattice spacings of 0.49, 0.66, and 0.44 nm correspond to reflections from the (100), (010), and (001) planes of orthorhombic Fe?C (space group Pnma). Observation of these forbidden reflections results from dynamic scattering of the incident beam as first observed in bulk Fe?C crystals.With small amounts of beam tilt these reflections can have significant intensities for crystals containing glide planes such as Fe?C with space groups Pnma or Pbmn. PMID:23816334

  19. Observation of a periodic runaway in the reactive Ar/O2 high power impulse magnetron sputtering discharge

    NASA Astrophysics Data System (ADS)

    Shayestehaminzadeh, Seyedmohammad; Arnalds, Unnar B.; Magnusson, Rögnvaldur L.; Olafsson, Sveinn

    2015-11-01

    This paper reports the observation of a periodic runaway of plasma to a higher density for the reactive discharge of the target material (Ti) with moderate sputter yield. Variable emission of secondary electrons, for the alternating transition of the target from metal mode to oxide mode, is understood to be the main reason for the runaway occurring periodically. Increasing the pulsing frequency can bring the target back to a metal (or suboxide) mode, and eliminate the periodic transition of the target. Therefore, a pulsing frequency interval is defined for the reactive Ar/O2 discharge in order to sustain the plasma in a runaway-free mode without exceeding the maximum power that the magnetron can tolerate.

  20. Features of sporadic hyperbolic meteors observed in the period 2007-2009

    NASA Astrophysics Data System (ADS)

    Guliyev, A.

    2014-07-01

    We have analyzed 238 hyperbolic meteors observed within the framework of the Japanese SonotaCo program in 2007--2009. A variety of eccentricities was noticed as well as irregular distribution of angular orbital elements. Also no cases were found with domination of perihelia near the ecliptic. The derived eccentricities are distibuted exponentially ranging from 1 to 1.31. A possible errors in determination of meteor orbits could partly explain these results. It was found that perihelion of these orbits are concentrated close to the anti-apex of the Sun. Additionaly we consider a distribution of orbital elements in the galactic coordinate system, however no regularity was found. Distribution of distant nodes and MOID of hyperbolic meteors relatively to the orbits of planets-giants were investigated as well. However, in majority of cases the hyperbolic excess of speed was not possible to explain with the gravitational influence of the giant planets. Thus the question of interaction with 14 known transneptunian planetary bodies (TNOs) brighter than 3_.^m5 was also considered. This investigation of distant nodes and MOID values specified 3 TNOs (2003 MW12, 2007 OR10 and Qaoaor) most influencing the system of hyperbolic meteors. In the next stage we evaluated 78 TNOs with absolute brightness up to 5_.^m5. From these objects we identified 9 additiobnal TNOs influencing the system of hyperbolic meteors. Based on our results we conclude that distant planetary bodies may have more significant effects on the system than giant planets.

  1. Long-period humidity variability in the Arctic atmosphere from upper-air observations

    NASA Astrophysics Data System (ADS)

    Agurenko, A.; Khokhlova, A.

    2014-12-01

    Under climate change, atmospheric water content also tends to change. This gives rise to changes in the amount of moisture transferred, clouds and precipitation, as well as in hydrological regime. This work analyzes seasonal climatic characteristics of precipitated water in the Arctic atmosphere, by using 1972-2011 data from 55 upper-air stations located north of 60°N. Regions of maximum and minimum mean values and variability trends are determined. In the summer, water amount is shown to increase in nearly the whole of the latitudinal zone. The comparison with the similar characteristics of reanalysis obtained by the other authors shows a good agreement. Time variation in the atmosphere moisture transport crossing 70°N, which is calculated from observation data, is presented and compared with model results. The work is supported by the joint EC ERA.Net RUS and Russian Fundamental Research Fund Project "Arctic Climate Processes Linked Through the Circulation of the Atmosphere" (ACPCA) (project 12-05-91656-ЭРА_а).

  2. X-Ray and EUV Observations of Simultaneous Short and Long Period Oscillations in Hot Coronal Arcade Loops

    NASA Astrophysics Data System (ADS)

    Kumar, Pankaj; Nakariakov, Valery M.; Cho, Kyung-Suk

    2015-05-01

    We report decaying quasi-periodic intensity oscillations in the X-ray (6-12 keV) and extreme-ultraviolet (EUV) channels (131, 94, 1600, 304 ) observed by the Fermi Gamma-ray Burst Monitor and Solar Dynamics Observatory/Atmospheric Imaging Assembly (AIA), respectively, during a C-class flare. The estimated periods of oscillation and decay time in the X-ray channel (6-12 keV) were about 202 and 154 s, respectively. A similar oscillation period was detected at the footpoint of the arcade loops in the AIA 1600 and 304 channels. Simultaneously, AIA hot channels (94 and 131 ) reveal propagating EUV disturbances bouncing back and forth between the footpoints of the arcade loops. The period of the oscillation and decay time were about 409 and 1121 s, respectively. The characteristic phase speed of the wave is about 560 km s-1 for about 115 Mm of loop length, which is roughly consistent with the sound speed at the temperature about 10-16 MK (480-608 km s-1). These EUV oscillations are consistent with the Solar and Heliospheric Observatory/Solar Ultraviolet Measurement of Emitted Radiation Doppler-shift oscillations interpreted as the global standing slow magnetoacoustic wave excited by a flare. The flare occurred at one of the footpoints of the arcade loops, where the magnetic topology was a 3D fan-spine with a null-point. Repetitive reconnection at this footpoint could have caused the periodic acceleration of non-thermal electrons that propagated to the opposite footpoint along the arcade and that are precipitating there, causing the observed 202 s periodicity. Other possible interpretations, e.g., the second harmonics of the slow mode, are also discussed.

  3. Imaging observation of quasi-periodic disturbances' amplitudes increasing with height in the polar region of the solar corona

    SciTech Connect

    Su, J. T.; Priya, T. G.; Liu, Y.; Shen, Y. D.

    2014-08-01

    At present, there have been few extreme ultraviolet (EUV) imaging observations of spatial variations of the density perturbations due to the slow magnetoacoustic waves (SMWs) propagating along the solar coronal magnetic fields. In this paper, we present such observations taken from the polar region of the corona with the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory and investigate the amplitude of quasi-periodic propagating disturbances that increase with height in the lower corona (0-9 Mm over the solar limb). We statistically determined the following parameters associated with the disturbances: pressure scale height, period, and wavelength in AIA 171 Å, 193 Å, and 211 Å channels. The scale height and wavelength are dependent of temperature, while the period is independent of temperature. The acoustic velocities inferred from the scale height highly correlate with the ratios of wavelength to period, i.e., phase speeds. They provide evidence that the propagating disturbances in the lower corona are likely SMWs and the spatial variations in EUV intensity in the polar region likely reflects the density compressional effect by the propagating SMWs.

  4. Observations and Modeling of the Near Surface Vertical Structure of the Atmosphere in the Southern Appalachians during the Integrated Precipitation and Hydrology Experiment (IPHEx) Extended Observing Period

    NASA Astrophysics Data System (ADS)

    Wilson, A. M.; Barros, A. P.

    2014-12-01

    Accurate, high resolution observations of precipitation accumulations and intensity in regions of complex terrain are largely unavailable, due to a lack of existing in situ observations and obstacles to remote sensing (radar and satellite observations) such as beam blockage and ground clutter. For the past six years, a high-elevation, high-density rain gauge network has been recording precipitation observations along ridgelines in the Pigeon River Basin in the Southern Appalachians. These longer term observations complement the 4-D database of observations, which are being collected in support of the Global Precipitation Mission (GPM) during the first field campaign after the launch of the GPM satellite, the Integrated Precipitation and Hydrology Experiment (IPHEx). The observations focused on here are those at the near surface, within 2 kilometers of the ground level. The IPHEx extended observation period lasts until the end of 2014. This presentation will focus on ground-based measurements made by MicroRain Radars, disdrometers, radiometers, rain gauges, fog collectors and aerosol spectrometers among others during the spring, summer and fall of 2014. These measurements will be analyzed to provide information on the diurnal cycle of microphysical and dynamical processes and properties in the region, with an emphasis on describing the characteristics of local cloud and fog. These observations will be discussed in the context of previous findings based on observations and model results (stochastic column model and the Advanced Research Weather and Forecasting Model (WRF)). Specifically, this presentation will address whether the IPHEx observations support the hypothesis, validated for specific case studies in previous work, that Bergeron processes govern the enhancement of light rainfall in the Southern Appalachians through increased coalescence efficiency in stratiform rainfall due to the interactions with low level clouds and topography modulated fog. WRF simulations for IPHEx cases will also be discussed.

  5. VI-Band Follow-Up Observations of Ultra-Long-Period Cepheid Candidates in M31

    NASA Astrophysics Data System (ADS)

    Ngeow, Chow-Choong; Lee, Chien-Hsiu; Ting-Chang Yang, Michael; Lin, Chi-Sheng; Hsiao, Hsiang-Yao; Cheng, Yu-Chi; Lin, Zhong-Yi; Lin, I.-Ling; Kanbur, Shashi M.; Ip, Wing-Huen

    2015-02-01

    The ultra-long-period Cepheids (ULPCs) are classical Cepheids with pulsation periods exceeding ? 80 days. The intrinsic brightness of ULPCs are 1 to 3 mag brighter than their shorter period counterparts. This makes them attractive in future distance scale work to derive distances beyond the limit set by the shorter period Cepheids. We have initiated a program to search for ULPCs in M31, using the single-band data taken from the Palomar Transient Factory, and identified eight possible candidates. In this work, we presented the VI-band follow-up observations of these eight candidates. Based on our VI-band light curves of these candidates and their locations in the color-magnitude diagram and the Period-Wesenheit diagram, we verify two candidates as being truly ULPCs. The six other candidates are most likely other kinds of long-period variables. With the two confirmed M31 ULPCs, we tested the applicability of ULPCs in distance scale work by deriving the distance modulus of M31. It was found to be {{? }M31,ULPC}=24.30+/- 0.76 mag. The large error in the derived distance modulus, together with the large intrinsic dispersion of the Period-Wesenheit (PW) relation and the small number of ULPCs in a given host galaxy, means that the question of the suitability of ULPCs as standard candles is still open. Further work is needed to enlarge the sample of calibrating ULPCs and reduce the intrinsic dispersion of the PW relation before re-considering ULPCs as suitable distance indicators.

  6. Summary of single-column model intensive observation period workshop at annual atmospheric radiation measurement science team meeting

    SciTech Connect

    Randall, D.A.; Cederwall, R.T.

    1995-04-01

    The objectives of this working group are to: Review recently completed winter single-column model (SCM) intensive observation period (IOP), including data collected and delivery schedule to Atmospheric Radiation Measurement (ARM) Science Team; Evaluate adequacy of measurements (value-added data) available from recent and future SCM IOPs; Recommend changes and additions to ARM observation strategies, external data acquisition, and data algorithms to enhance SCM efforts in ARM; Increase the interaction among SCM investigators and facilitate interaction with and guidance of the ARM infrastructure support of SCM activities within ARM.

  7. Quasi-periodic variations in x-ray emission and long-term radio observations: Evidence for a two-component jet in Sw J1644+57

    SciTech Connect

    Wang, Jiu-Zhou; Lei, Wei-Hua; Wang, Ding-Xiong; Zou, Yuan-Chuan; Huang, Chang-Yin; Zhang, Bing; Gao, He E-mail: dxwang@hust.edu.cn E-mail: zhang@physics.unlv.edu

    2014-06-10

    The continued observations of Sw J1644+57 in X-ray and radio bands accumulated a rich data set to study the relativistic jet launched in this tidal disruption event. The X-ray light curve of Sw J1644+57 from 5-30 days presents two kinds of quasi-periodic variations: a 200 s quasi-periodic oscillation (QPO) and a 2.7 day quasi-periodic variation. The latter has been interpreted by a precessing jet launched near the Bardeen-Petterson radius of a warped disk. Here we suggest that the ?200 s QPO could be associated with a second, narrower jet sweeping the observer line-of-sight periodically, which is launched from a spinning black hole in the misaligned direction with respect to the black hole's angular momentum. In addition, we show that this two-component jet model can interpret the radio light curve of the event, especially the re-brightening feature starting ?100 days after the trigger. From the data we infer that inner jet may have a Lorentz factor of ?{sub j} ? 5.5 and a kinetic energy of E {sub k,} {sub iso} ? 3.0 10{sup 52} erg, while the outer jet may have a Lorentz factor of ?{sub j} ? 2.5 and a kinetic energy of E{sub k,} {sub iso} ? 3.0 10{sup 53} erg.

  8. Quasi-periodic Variations in X-Ray Emission and Long-term Radio Observations: Evidence for a Two-component Jet in Sw J1644+57

    NASA Astrophysics Data System (ADS)

    Wang, Jiu-Zhou; Lei, Wei-Hua; Wang, Ding-Xiong; Zou, Yuan-Chuan; Zhang, Bing; Gao, He; Huang, Chang-Yin

    2014-06-01

    The continued observations of Sw J1644+57 in X-ray and radio bands accumulated a rich data set to study the relativistic jet launched in this tidal disruption event. The X-ray light curve of Sw J1644+57 from 5-30 days presents two kinds of quasi-periodic variations: a 200 s quasi-periodic oscillation (QPO) and a 2.7 day quasi-periodic variation. The latter has been interpreted by a precessing jet launched near the Bardeen-Petterson radius of a warped disk. Here we suggest that the ~200 s QPO could be associated with a second, narrower jet sweeping the observer line-of-sight periodically, which is launched from a spinning black hole in the misaligned direction with respect to the black hole's angular momentum. In addition, we show that this two-component jet model can interpret the radio light curve of the event, especially the re-brightening feature starting ~100 days after the trigger. From the data we infer that inner jet may have a Lorentz factor of Γj ~ 5.5 and a kinetic energy of E k, iso ~ 3.0 × 1052 erg, while the outer jet may have a Lorentz factor of Γj ~ 2.5 and a kinetic energy of E k, iso ~ 3.0 × 1053 erg.

  9. Superorbital periodic modulation in wind-accretion high-mass X-ray binaries from swift burst alert telescope observations

    SciTech Connect

    Corbet, Robin H. D.; Krimm, Hans A.

    2013-11-20

    We report the discovery using data from the Swift-Burst Alert Telescope (BAT) of superorbital modulation in the wind-accretion supergiant high-mass X-ray binaries 4U 1909+07 (= X 1908+075), IGR J164184532, and IGR J164794514. Together with already known superorbital periodicities in 2S 0114+650 and IGR J164934348, the systems exhibit a monotonic relationship between superorbital and orbital periods. These systems include both supergiant fast X-ray transients and classical supergiant systems, and have a range of inclination angles. This suggests an underlying physical mechanism which is connected to the orbital period. In addition to these sources with clear detections of superorbital periods, IGR J163934643 (= AX J16390.44642) is identified as a system that may have superorbital modulation due to the coincidence of low-amplitude peaks in power spectra derived from BAT, Rossi X-Ray Timing Explorer Proportional Counter Array, and International Gamma-Ray Astrophysics Laboratory light curves. 1E 1145.16141 may also be worthy of further attention due to the amount of low-frequency modulation of its light curve. However, we find that the presence of superorbital modulation is not a universal feature of wind-accretion supergiant X-ray binaries.

  10. Superorbital Periodic Modulation in Wind-Accretion High-Mass X-Ray Binaries from Swift Burst Alert Telescope Observations

    NASA Technical Reports Server (NTRS)

    Corbet, Robin H. D.; Krimm, Hans A.

    2013-01-01

    We report the discovery using data from the Swift-Burst Alert Telescope (BAT) of superorbital modulation in the wind-accretion supergiant high-mass X-ray binaries 4U 1909+07 (= X 1908+075), IGR J16418-4532, and IGR J16479-4514. Together with already known superorbital periodicities in 2S 0114+650 and IGR J16493-4348, the systems exhibit a monotonic relationship between superorbital and orbital periods. These systems include both supergiant fast X-ray transients and classical supergiant systems, and have a range of inclination angles. This suggests an underlying physical mechanism which is connected to the orbital period. In addition to these sources with clear detections of superorbital periods, IGR J16393-4643 (= AX J16390.4-4642) is identified as a system that may have superorbital modulation due to the coincidence of low-amplitude peaks in power spectra derived from BAT, Rossi X-Ray Timing Explorer Proportional Counter Array, and International Gamma-Ray Astrophysics Laboratory light curves. 1E 1145.1-6141 may also be worthy of further attention due to the amount of low-frequency modulation of its light curve. However, we find that the presence of superorbital modulation is not a universal feature of wind-accretion supergiant X-ray binaries.

  11. Influence of regional biomass burning on the highly elevated organic carbon concentrations observed at Gosan, South Korea during a strong Asian dust period.

    PubMed

    Nguyen, Duc Luong; Kim, Jin Young; Ghim, Young Sung; Shim, Shang-Gyoo

    2015-03-01

    PM2.5 carbonaceous particles were measured at Gosan, South Korea during 29 March-11 April 2002 which includes a pollution period (30 March-01 April) when the highest concentrations of major anthropogenic species (nss-SO4 (2-), NO3 (-), and NH4 (+)) were observed and a strong Asian dust (AD) period (08-10 April) when the highest concentrations of mainly dust-originated trace elements (Al, Ca, Mg, and Fe) were seen. The concentrations of elemental carbon (EC) measured in the pollution period were higher than those measured in the strong AD period, whereas an inverse variation in the concentrations of organic carbon (OC) was observed. Based on the OC/EC ratios, the possible source that mainly contributed to the highly elevated OC concentrations measured in the strong AD period was biomass burning. The influence of the long-range transport of smoke plumes emitted from regional biomass burning sources was evaluated by using MODIS (Moderate Resolution Imaging Spectroradiometer) satellite data for fire locations and the potential source contribution function analysis. The most potential source regions of biomass burning were the Primorsky and Amur regions in Far Eastern Russia and southeastern and southwestern Siberia, Russia. Further discussion on the source characteristics suggested that the high OC concentrations measured in the strong AD period were significantly affected by the smoldering phase of biomass burning. In addition to biomass burning, secondary OC (SOC) formed during atmospheric long-range transport should be also considered as an important source of OC concentration measured at Gosan. Although this study dealt with the episodic case of the concurrent increase of dust and biomass burning particles, understanding the characteristics of heterogeneous mixing aerosol is essential in assessing the radiative forcing of aerosol. PMID:25253054

  12. ICESat Observations of Ocean Swells and Possible Long-Period Ocean Waves Propagating Through Antarctic Sea Ice

    NASA Astrophysics Data System (ADS)

    Heinrichs, J. F.; Holt, B.

    2009-12-01

    Several ICESat profiles taken across sea ice in the Weddell Sea exhibit wavelike patterns that suggest the passage and attenuation of ocean swells and long-period (200 s) waves through sea ice over distances of hundreds of kilometers. Detailed examination of the profiles, associated sensor telemetry, and MODIS imagery excludes sensor artifacts and other phenomena in the atmosphere and ice as explanations for the patterns. Wavelet analysis of the patterns shows that, as expected, shorter waves decay most rapidly after crossing the ice edge. Calculation of attenuation coefficients for the ocean swells provides values that are reasonable when compared to previous work using airborne laser altimetry and other measurements. Multiple possible explanations exist for the cause of the long-period waves, including lee waves, internal waves, infragravity waves, and rissaga (meteotsunamis).

  13. Evidence of low-latitude daytime large-scale traveling ionospheric disturbances observed by high-frequency multistatic backscatter sounding system during a geomagnetically quiet period

    NASA Astrophysics Data System (ADS)

    Zhou, Chen; Zhao, Zhengyu; Yang, Guobin; Chen, Gang; Hu, Yaogai; Zhang, Yuannong

    2012-06-01

    Observations from the high-frequency multistatic backscatter sounding radars on a geomagnetically quiet day (minimum Dst = -14 nT) captured the anti-equatorward propagation of daytime large-scale traveling ionospheric disturbance (LSTID) at the low-latitude regions. The observed LSTID was characterized approximately by a meridional propagation speed of 347 78 m/s and azimuthal angle of -4.7 27.6 (counterclockwise from north), with a period of 76 min and a wavelength of 1583 354 km by means of maximum entropy cross-spectral analysis. Vertical phase velocity was also evaluated to be <42 m/s through the Doppler measurements. These results provide evidence that the low-latitude ionosphere can undergo large-scale perturbations even under geomagnetically quiet conditions. We suggest that this observed LSTID could be due to the secondary gravity waves from thermospheric body forces created from the dissipation of primary gravity waves from deep tropospheric convection.

  14. Testing the asymptotic relation for period spacings from mixed modes of red giants observed with the Kepler mission

    NASA Astrophysics Data System (ADS)

    Buysschaert, B.; Beck, P. G.; Corsaro, E.; Christensen-Dalsgaard, J.; Aerts, C.; Arentoft, T.; Kjeldsen, H.; García, R. A.; Silva Aguirre, V.; Degroote, P.

    2016-04-01

    Context. Dipole mixed pulsation modes of consecutive radial order have been detected for thousands of low-mass red-giant stars with the NASA space telescope Kepler. These modes have the potential to reveal information on the physics of the deep stellar interior. Aims: Different methods have been proposed to derive an observed value for the gravity-mode period spacing, the most prominent one relying on a relation derived from asymptotic pulsation theory applied to the gravity-mode character of the mixed modes. Our aim is to compare results based on this asymptotic relation with those derived from an empirical approach for three pulsating red-giant stars. Methods: We developed a data-driven method to perform frequency extraction and mode identification. Next, we used the identified dipole mixed modes to determine the gravity-mode period spacing by means of an empirical method and by means of the asymptotic relation. In our methodology we consider the phase offset, ɛg, of the asymptotic relation as a free parameter. Results: Using the frequencies of the identified dipole mixed modes for each star in the sample, we derived a value for the gravity-mode period spacing using the two different methods. These values differ by less than 5%. The average precision we achieved for the period spacing derived from the asymptotic relation is better than 1%, while that of our data-driven approach is 3%. Conclusions: Good agreement is found between values for the period spacing derived from the asymptotic relation and from the empirical method. The achieved uncertainties are small, but do not support the ultra-high precision claimed in the literature. The precision from our data-driven method is mostly affected by the differing number of observed dipole mixed modes. For the asymptotic relation, the phase offset, ɛg, remains ill defined, but enables a more robust analysis of both the asymptotic period spacing and the dimensionless coupling factor. However, its estimation might still offer a valuable observational diagnostic for future theoretical modeling.

  15. The reconstruction of air pressure in Gda?sk in the period of instrumental observations, 1739-2012

    NASA Astrophysics Data System (ADS)

    Filipiak, Janusz

    2015-04-01

    The purpose of the paper is to characterise the details of reconstruction of air pressure in Gda?sk in the whole period of regular instrumental records spanning the period 1739-2012. Gda?sk pressure series has been reconstructed by joining air pressure observations of 15 local shorter series. The entire instrumental series can be divided into three sub-periods: the Early Observers period, lasting to 1806, the First Meteorological Networks, covering the years from 1807 to 1875 and Modern Measurements begun in 1876. During the first period, observations were made from two to four times per day, sometimes even at midnight. In the 19th century and up to 1945 thrice-daily barometer readings were a standard, in the last few decades the density of data is much denser. A serious gap in the original daily data exists for the period 1849-1875, where it appears that no original source of data have survived. Selected data are presented in the form of five-day or monthly averages. Numerous errors made probably during the re-writing of original observers' data by their assistants were discovered during digitalization. Despite this the quality of observations can be regarded as good. Data have been corrected to provide a monthly-mean measure of atmospheric pressure in the unit of hPa at standard conditions, i.e. standard gravity, 0 C and at sea level. Some inconsistencies may still arise as the procedure of the homogenization of air temperature is not completed and in case of a few oldest series air temperature was estimated. Numerous breakpoints were identified in the homogenisation of the series and they cannot be always linked to known causes. A reasonably detailed station history has been compiled by incorporating metadata contained in various written sources. These metadata have facilitated the homogenisation of the data series. Mean annual atmospheric pressure in Gda?sk in period 1739-2012 calculated on the basis of homogenized series was 1014.9 hPa. Mean seasonal means are equalled as follows: winter - 1015.2 hPa, spring - 1014.9 hPa, summer - 1014.2 hPa and autumn - 1015.4 hPa. The average annual course of air pressure in Gda?sk in the period 1739-2010 reveals some characteristic features. Winter is characterized by the highest variability, what is connected to most intense cyclonic activity in this season. Thus in winter occur the highest daily maxima and lowest minima. Several cases of extremely deep cyclones with the pressure of less than 960 hPa were identified as well a few barometer readings exceeding 1045 hPa. It is also evident that annual minima occurs in summer and this season is also described as of the lowest value of standard deviation.

  16. TESTING THE NO-HAIR THEOREM WITH OBSERVATIONS IN THE ELECTROMAGNETIC SPECTRUM. III. QUASI-PERIODIC VARIABILITY

    SciTech Connect

    Johannsen, Tim; Psaltis, Dimitrios E-mail: dpsaltis@email.arizona.edu

    2011-01-01

    According to the no-hair theorem, astrophysical black holes are uniquely described by their masses and spins. An observational test of the no-hair theorem can be performed by measuring at least three different multipole moments of the spacetime of a black hole and verifying whether their values are consistent with the unique combinations of the Kerr solution. In this paper, we study quasi-periodic variability observed in the emission from black holes across the electromagnetic spectrum as a test of the no-hair theorem. We derive expressions for the Keplerian and epicyclic frequencies in a quasi-Kerr spacetime, in which the quadrupole moment is a free parameter in addition to mass and spin. We show that, for moderate spins, the Keplerian frequency is practically independent of small deviations of the quadrupole moment from the Kerr value, while the epicyclic frequencies exhibit significant variations. We apply this framework to quasi-periodic oscillations (QPOs) in black hole X-ray binaries in two different scenarios. In the case that a pair of QPOs can be identified as the fundamental g- and c-modes in the accretion disk, we show that the no-hair theorem can be tested in conjunction with an independent mass measurement. If pairs of oscillations are identified with non-parametric resonance of dynamical frequencies in the accretion disk, then testing the no-hair theorem also requires an independent measurement of the black hole spin. In addition, we argue that VLBI observations of Sgr A* may test the no-hair theorem through a combination of imaging observations and the detection of quasi-periodic variability.

  17. Ferroelectrics. Observation of a periodic array of flux-closure quadrants in strained ferroelectric PbTiO? films.

    PubMed

    Tang, Y L; Zhu, Y L; Ma, X L; Borisevich, A Y; Morozovska, A N; Eliseev, E A; Wang, W Y; Wang, Y J; Xu, Y B; Zhang, Z D; Pennycook, S J

    2015-05-01

    Nanoscale ferroelectrics are expected to exhibit various exotic domain configurations, such as the full flux-closure pattern that is well known in ferromagnetic materials. Here we observe not only the atomic morphology of the flux-closure quadrant but also a periodic array of flux closures in ferroelectric PbTiO3 films, mediated by tensile strain on a GdScO3 substrate. Using aberration-corrected scanning transmission electron microscopy, we directly visualize an alternating array of clockwise and counterclockwise flux closures, whose periodicity depends on the PbTiO3 film thickness. In the vicinity of the core, the strain is sufficient to rupture the lattice, with strain gradients up to 10(9) per meter. Engineering strain at the nanoscale may facilitate the development of nanoscale ferroelectric devices. PMID:25883317

  18. VI-band follow-up observations of ultra-long-period Cepheid candidates in M31

    SciTech Connect

    Ngeow, Chow-Choong; Yang, Michael Ting-Chang; Lin, Chi-Sheng; Hsiao, Hsiang-Yao; Cheng, Yu-Chi; Lin, Zhong-Yi; Lin, I-Ling; Ip, Wing-Huen; Lee, Chien-Hsiu; Kanbur, Shashi M.

    2015-02-01

    The ultra-long-period Cepheids (ULPCs) are classical Cepheids with pulsation periods exceeding ≈80 days. The intrinsic brightness of ULPCs are ∼1 to ∼3 mag brighter than their shorter period counterparts. This makes them attractive in future distance scale work to derive distances beyond the limit set by the shorter period Cepheids. We have initiated a program to search for ULPCs in M31, using the single-band data taken from the Palomar Transient Factory, and identified eight possible candidates. In this work, we presented the VI-band follow-up observations of these eight candidates. Based on our VI-band light curves of these candidates and their locations in the color–magnitude diagram and the Period–Wesenheit diagram, we verify two candidates as being truly ULPCs. The six other candidates are most likely other kinds of long-period variables. With the two confirmed M31 ULPCs, we tested the applicability of ULPCs in distance scale work by deriving the distance modulus of M31. It was found to be μ{sub M31,ULPC}=24.30±0.76 mag. The large error in the derived distance modulus, together with the large intrinsic dispersion of the Period–Wesenheit (PW) relation and the small number of ULPCs in a given host galaxy, means that the question of the suitability of ULPCs as standard candles is still open. Further work is needed to enlarge the sample of calibrating ULPCs and reduce the intrinsic dispersion of the PW relation before re-considering ULPCs as suitable distance indicators.

  19. The growth of the oceanic boundary layer during the COARE intensive observational period: Large Eddy simulation results

    SciTech Connect

    Skyllingstad, E.D.; Wijesekera, H.W.; Gregg, M.C.

    1995-03-01

    A principal goal of the Tropical Ocean Global Atmosphere (TOGA) Coupled Ocean-Atmosphere Response Experiment (COARE) is to gain an understanding of the processes that control mixing in the upper 100 m of the western tropical Pacific warm pool. The warm pool is an important heat reservoir for the global ocean and is responsible for many of the observed climatic changes associated with El Nino/Southern Oscillation (ENSO) events. This water mass is highly sensitive to mixed-layer processes that are controlled by surface heat, salinity, and momentum fluxes. During most of the year, these fluxes are dominated by solar heating and occasional squalls that freshen the top of the mixed layer and force shallow mixing of about 10-20 m. From November to April, the usual weather pattern is frequently altered by westerly wind bursts that are forced by tropical cyclones and intraseasonal oscillations. These wind bursts generate a strong eastward surface current and can force mixing as deep as 100 m over a period of days. Observations from the intensive observation period (IOP) in COARE indicate that mixed-layer deepening is accompanied by strong turbulence dissipation at the mixed layer base. A short westerly wind burst occurred during the first leg of TOGA-COARE, and lasted about 4-5 days. During this period, the maximum winds were about 10 m s{sup -1}, and the resulting eastward surface flow was about 0.5 m s{sup -1}. The strength of this event was somewhat weaker than a typical westerly wind burst, but the mixed-layer structure and growth are similar to the more vigorous wind bursts discussed.

  20. Comparison of Aerosol Optical Depth from Four Solar Radiometers During the Fall 1997 ARM Intensive Observation Period

    NASA Technical Reports Server (NTRS)

    Schmid, B.; Michalsky, J.; Halthore, R.; Beauharnois, M.; Harrison, L.; Livingston, J.; Russell, P.; Holben, B.; Eck, T.; Smirnov, A.

    2000-01-01

    In the Fall of 1997 the Atmospheric Radiation Measurement (ARM) program conducted an Intensive Observation Period (IOP) to study aerosols. Five sun-tracking radiometers were present to measure the total column aerosol optical depth. This comparison performed on the Southern Great Plains (SGP) demonstrates the capabilities and limitations of modern tracking sunphotometers at a location typical of where aerosol measurements are required. The key result was agreement in aerosol optical depth measured by 4 of the 5 instruments within 0.015 (rms). The key to this level of agreement was meticulous care in the calibrations of the instruments.

  1. Variability of aerosol properties over Eastern Europe observed from ground and satellites in the period from 2003 to 2011

    NASA Astrophysics Data System (ADS)

    Bovchaliuk, A.; Milinevsky, G.; Danylevsky, V.; Goloub, P.; Dubovik, O.; Holdak, A.; Ducos, F.; Sosonkin, M.

    2013-01-01

    The paper presents the study of aerosol variability in the period from 2003 to 2011 over Eastern Europe region with latitude ranging from 40 N to 60 N and longitude from 20 E to 50 E. The analysis was based on the POLDER/PARASOL and POLDER-2/ADEOS satellites and AERONET ground-based sunphotometer observations. The aerosol optical thickness (AOT) of the studied area is characterized by the values (referenced to 870 nm wavelength) ranging from 0.05 to 0.2 except the period of July-August 2010 with strong forest and peat wildfires when the AOT typical values range from 0.3 to 0.5. The analysis of seasonal dynamics of aerosol loading has revealed two AOT high value peaks. The first peak observed in April-May is the result of solitary transportation of Sahara dust in the atmosphere over Eastern Europe, infrequent agricultural fires, transportation of sea salt aerosols by southern winds to Ukraine and Moldova from the Black and Azov Seas. The second peak in August-September is associated with forest and peat wildfires, considerable transportation of Sahara dust and presence of soil dust aerosols due to harvesting activity. The maximum values of AOT are observed in May 2006 (0.1-0.15), April 2009 (0.07-0.15) and August 2010 (0.2-0.5). Furthermore, the study has identified a distinct pattern of anthropogenic aerosols over the industrial areas, especially in the central Ukraine, eastern Belarus, as well as Moscow, Nizhny Novgorod and Stavropol regions in Russia. The comparison of the fine mode AOT (particle radius < 0.3 ?m) derived by standard algorithm POLDER/PARASOL from reflected polarized radiances with those recomputed from AERONET inversions was performed over a number of AERONET sites: over Kyiv and Sevastopol sites for the period of 2008-2009 and over Moscow, Minsk, Belsk, and Moldova sites for the period of 2005-2009. The correlation coefficients are 0.78 for Moscow, 0.76 - Minsk, 0.86 - Belsk, 0.93 - Kyiv, 0.81 - Moldova and 0.63 for Sevastopol sites. The deviations are explained by the spatial inhomogeneity of the surface polarization that has stronger effect on aerosol retrieval for clear atmospheric conditions with low aerosol loading when surface impact on satellite observations is more pronounced. In addition, the preliminary analysis of the detailed aerosol properties derived by new generation PARASOL algorithm was accomplished. The AOT and single scattering albedo retrieved by the algorithm over Kyiv were compared with the closest AERONET retrievals within two hour of satellite overpass time and the stable atmospheric conditions.

  2. Vitamin D during pregnancy: why observational studies suggest deficiency and interventional studies show no improvement in clinical outcomes? A narrative review.

    PubMed

    Karras, S N; Anagnostis, P; Naughton, D; Annweiler, C; Petroczi, A; Goulis, D G

    2015-12-01

    A considerable number of studies have examined vitamin D status during pregnancy. Although data from observational studies denote vitamin D hypovitaminosis (deficiency or insufficiency) during pregnancy is associated with a plethora of adverse maternal and neonatal outcomes, data from interventional (supplementation) trials fail to reveal a significant impact on maternal and offspring health. The aim of this narrative review was to critically appraise the methodology of the most representative published randomized controlled trials in an attempt to explain the difference between observational and supplementation results. We found that this difference could be attributed to a variety of factors, namely: (i) study design (lack of a specific outcome in conjunction with timing of supplementation, enrolment of participants with heterogeneous vitamin D status); (ii) pitfalls in the interpretation of vitamin D equilibrium (lack of determination of plasma half-life); (iii) supplementation regimen (administration of a wide range of regimens, in terms of dose, bolus and form); (iv) geographical characteristics (vitamin D needs could vary significantly within a country, particularly in areas with a wide range of latitude gradient); (v) adaptations of vitamin D metabolism during pregnancy (vitamin D and calcium equilibrium are changed during pregnancy compared with the non-pregnant state) and (vi) supplementation of populations with low baseline 25(OH)D values would likely manifest beneficial effects. All these parameters should be taken into consideration in the design of future vitamin D supplementation trials. PMID:26219612

  3. Whole Earth Telescope observations of the subdwarf B star KPD 1930+2752: a rich, short-period pulsator in a close binary

    NASA Astrophysics Data System (ADS)

    Reed, M. D.; Harms, S. L.; Poindexter, S.; Zhou, A.-Y.; Eggen, J. R.; Morris, M. A.; Quint, A. C.; McDaniel, S.; Baran, A.; Dolez, N.; Kawaler, S. D.; Kurtz, D. W.; Moskalik, P.; Riddle, R.; Zola, S.; stensen, R. H.; Solheim, J.-E.; Kepler, S. O.; Costa, A. F. M.; Provencal, J. L.; Mullally, F.; Winget, D. W.; Vuckovic, M.; Crowe, R.; Terry, D.; Avila, R.; Berkey, B.; Stewart, S.; Bodnarik, J.; Bolton, D.; Binder, P.-M.; Sekiguchi, K.; Sullivan, D. J.; Kim, S.-L.; Chen, W.-P.; Chen, C.-W.; Lin, H.-C.; Jian, X.-J.; Wu, H.; Gou, J.-P.; Liu, Z.; Leibowitz, E.; Lipkin, Y.; Akan, C.; Cakirli, O.; Janulis, R.; Pretorius, R.; Ogloza, W.; Stachowski, G.; Paparo, M.; Szabo, R.; Csubry, Z.; Zsuffa, D.; Silvotti, R.; Marinoni, S.; Bruni, I.; Vauclair, G.; Chevreton, M.; Matthews, J. M.; Cameron, C.; Pablo, H.

    2011-03-01

    KPD 1930+2752 is a short-period pulsating subdwarf B (sdB) star. It is also an ellipsoidal variable with a known binary period of 2.3 h. The companion is most likely a white dwarf and the total mass of the system is close to the Chandresekhar limit. In this paper, we report the results of Whole Earth Telescope (WET) photometric observations during 2003 and a smaller multisite campaign of 2002. From 355 h of WET data, we detect 68 pulsation frequencies and suggest an additional 13 frequencies within a crowded and complex temporal spectrum between 3065 and 6343 ?Hz (periods between 326 and 157 s). We examine pulsation properties including phase and amplitude stability in an attempt to understand the nature of the pulsation mechanism. We examine a stochastic mechanism by comparing amplitude variations with simulated stochastic data. We also use the binary nature of KPD 1930+2752 for identifying pulsation modes via multiplet structure and a tidally induced pulsation geometry. Our results indicate a complicated pulsation structure that includes short-period (?16 h) amplitude variability, rotationally split modes, tidally induced modes and some pulsations which are geometrically limited on the sdB star.

  4. Long-term trends and extremes in observed daily precipitation and near surface air temperature in the Philippines for the period 1951-2010

    NASA Astrophysics Data System (ADS)

    Cinco, Thelma A.; de Guzman, Rosalina G.; Hilario, Flaviana D.; Wilson, David M.

    2014-08-01

    Observed daily precipitation and near surface air temperature data from 34 synoptic weather stations in the Philippines for the period 1951-2010 were subjected to trend analysis which revealed an overall warming tendency compared to the normal mean values for the period 1961-1990. This warming trend can be observed in the annual mean temperatures, daily minimum mean temperatures and to a lesser extent, daily maximum mean temperatures. Precipitation and temperature extremes for the period 1951-2010 were also analysed relative to the mean 1961-1990 baseline values. Some stations (Cotabato, Iloilo, Laoag and Tacloban,) show increases in both frequency and intensity of extreme daily rainfall events which are significant at the 95% level with none of the stations showing decreasing trends. The frequency of daily temperature maximum above the 99th percentile (hot days) and nights at the 1st percentile (cold nights) suggests that both days and nights in particular are becoming warmer. Such indicators of a warming trend and increase in extreme events in the Philippines are discussed in the context of similar national, regional (Asia Pacific) and global studies. The relevance of such empirically based climatology studies, particularly for nations such as the Philippines which are increasingly vulnerable to the multiple impacts of global climate change, is also considered.

  5. SWIFT OBSERVATIONS OF THE HIGH-MASS X-RAY BINARY IGR J16283-4838 UNVEIL A 288 DAY ORBITAL PERIOD

    SciTech Connect

    Cusumano, G.; Segreto, A.; La Parola, V.; D'Aì, A.; Masetti, N.; Tagliaferri, G.

    2013-09-20

    We report on the temporal and spectral properties of the high-mass X-ray binary IGR J16283-4838 in the hard X-ray band. We searched the first 88 months of Swift Burst Alert Telescope (BAT) survey data for long-term periodic modulations. We also investigated the broad band (0.2-150 keV) spectral properties of IGR J16283-4838 complementing the BAT dataset with soft X-ray data from the available Swift-XRT pointed observations. The BAT light curve of IGR J16283-4838 revealed a periodic modulation at P{sub o} = 287.6 ± 1.7 days (with a significance higher than 4 standard deviations). The profile of the light curve folded at P{sub o} shows a sharp peak lasting ∼12 days over a flat plateau. The long-term light curve also shows a ∼300 day interval of prolonged enhanced emission. The observed phenomenology suggests that IGR J16283-4838 has a Be nature, where the narrow periodic peaks and the ∼300 day outburst can be interpreted as Type I and Type II outbursts, respectively. The broad band 0.2-150 keV spectrum can be described with an absorbed power-law and a steepening in the BAT energy range.

  6. Multi-Resonance Orbital Model Applied to High-Frequency Quasi-Periodic Oscillations Observed in Sgr A*

    NASA Astrophysics Data System (ADS)

    Kotrlov, A.; Stuchlk, Z.; Trk, G.

    2013-06-01

    The multi-resonance orbital model of high-frequency quasi-periodic oscillations (HF QPOs) enables precise determination of the black hole dimensionless spin a if observed set of oscillations demonstrates three (or more) commensurable frequencies. The black hole spin a is related to the frequency ratio only, while its mass M is related to the frequency magnitude. The model is applied to the triple frequency set of HF QPOs observed in Sgr A* source with frequency ratio 3:2:1. Acceptable versions of the multi-resonance model are determined by the restrictions on the Sgr A* supermassive black hole mass. The version of strong resonances related to the black hole "magic" spin a=0.983 is acceptable but the version demonstrating the best agreement with the mass restrictions predicts spin a=0.980.

  7. Observations of quasi-periodic scintillations and their possible relation to the dynamics of Es plasma blobs

    SciTech Connect

    Maruyama, Takashi )

    1991-06-01

    Quasi-periodic scintillations at a mid-latitude station, Wakkanai, Japan, are examined using 136-MHz geostationary satellite transmissions. Observations are compared with the ionospheric parameter obtained at the same station and random scintillation records. The results indicate that the quasi-periodic scintillations are most likely produced by plasma blobs within the sporadic E layers. Discussion focuses on characteristics of the ringing pattern which precedes and follows the primary deep fade-out, in field strength. In the majority of events the ringing pattern tends to develop after the distinct deep fade-out, i.e., the pattern is asymmetric. Quasi-periodic scintillation patterns are produced by the movement of plasma blobs in the case of geostationary satellite experiments. Thus the shape of the blob must be deformed so that a steep density gradient is attained on the backside. When the blob is highly deformed by the plasma instability which grows at the steep density gradient, burstlike random scintillations may be produced by the blob. 16 refs.

  8. A Comprehensive Evaluation of Global Chemistry Transport Models Versus Observations For The 4-year Simulation Period 1995-1998

    NASA Astrophysics Data System (ADS)

    Brunner, D.; Tradeoff Team

    As part of the EU funded project TRADEOFF (Aircraft Emissions: Contributions of various climate compounds to changes in composition and radiative forcing - trade- off to reduce atmospheric impact) several European chemistry transport (CTM) and general circulation models (GCM) have been evaluated against observed tracer con- centrations. The study focuses on the upper troposphere/lower stratosphere (UT/LS) region aiming to better assess the models' capability of estimating the impact of air- craft emissions upon the atmosphere. For this purpose an extensive database of insitu observations of major compounds related to O3 photochemistry was established for the 4-year period 1995 to 1998, covering observations from the most relevant com- mercial and scientific aircraft measurement campaigns as well as O3 soundings. Ta- bles of the positions and times of each observation were supplied to the modellers and used to interpolate at every model time step the simulated tracer fields to the observa- tion points. In this way a direct comparison with observations taking into account the specific meteorological conditions during the measurements was achieved. A com- mon database of surface and aircraft emissions (except for hydrocarbons) was used for the runs such that any remaining differences between the models can be ascribed to their different formulations of chemistry and transport processes only. The results were evaluated with respect to the capability of the models to accurately simulate the observed concentration levels and variability, and the seasonal, latitudinal, and verti- cal distributions. Consistencies and inconsistences with observations will be discussed and possible paths for model improvements will be outlined.

  9. Analysis of long decay periods observed from the HEO satellites in the vicinity of the slot region

    NASA Astrophysics Data System (ADS)

    Ripoll, J.; Chen, Y.; Fennell, J. F.; Friedel, R. H.

    2013-12-01

    Long decay periods of electron counts, that follow abrupt rises and last from weeks to months, have been measured by HEO3 in the vicinity of the slot region between the years 1998 and 2007. After selecting the most stable decay periods, i.e. lasting the longest, spread over L values ranging between 2.2 to 3.5, and stable for each one of the six HEO energy channels (between >100 keV to >3 MeV), e-folding timescales are extracted for every location and energy. These values will be compared to the timescales previously observed from SAMPEX during the same period [Meredith et al., 2007; Baker et al., 2007], to the first HEO ones extracted at L=3 [Fennell et al., 2012] and to the ones measured by CRRES [Meredith et al., 2006]. Another challenge is to be able to reproduce the observed timescales from simulations of pitch angle diffusion by the different acting waves of the plasmasphere, mostly plasmaspheric hiss, lightning-generated, and VLF transmitter waves. To do that, the recently developed analytical model of [Mourenas and Ripoll, 2012] is used to narrow the ranges of all wave amplitudes, as well as to locate the resonance domains associated with each of the different waves. Full numerical simulations are then performed, with the use of either the wave parameters from CRRES or the ones from [Abel & Thorne, 1998], to compute accurately the electron lifetimes. Similarities and differences between measurements and simulations will be discussed. We will also show how such understanding leads eventually to relate particular wave properties to the diffused electron energy and the implication it has on future analysis.

  10. Quasi-periodic Oscillations Associated with Spectral Branches in Rossi X-Ray Timing Explorer Observations of Circinus X-1

    NASA Astrophysics Data System (ADS)

    Shirey, Robert E.; Bradt, Hale V.; Levine, Alan M.; Morgan, Edward H.

    1998-10-01

    We present Rossi X-Ray Timing Explorer (RXTE) All-Sky Monitor observations of the X-ray binary Circinus X-1 that illustrate the variety of intensity profiles associated with the 16.55 day flaring cycle of the source. We also present eight observations of Cir X-1 made with the RXTE Proportional Counter Array over the course of a cycle wherein the average intensity of the flaring state decreased gradually over ~12 days. Fourier power density spectra for these observations show a narrow quasi-periodic oscillation (QPO) peak that shifts in frequency between 6.8 and 32 Hz, as well as a broad QPO peak that remains roughly stationary at ~4 Hz. We identify these as Z-source horizontal and normal branch oscillations (HBOs/NBOs), respectively. Color-color and hardness-intensity diagrams (CDs/HIDs) show curvilinear tracks for each of the observations. The properties of the QPOs and very low frequency noise allow us to identify segments of these tracks with Z-source horizontal, normal, and flaring branches that shift location in the CDs and HIDs over the course of the 16.55 day cycle. These results contradict a previous prediction, based on the hypothesis that Cir X-1 is a high-? atoll source, that HBOs should never occur in this source.

  11. Quasi-periodic oscillations in accreting magnetic white dwarfs. I. Observational constraints in X-ray and optical

    NASA Astrophysics Data System (ADS)

    Bonnet-Bidaud, J. M.; Mouchet, M.; Busschaert, C.; Falize, E.; Michaut, C.

    2015-07-01

    Quasi-periodic oscillations (QPOs) are observed in the optical flux of some polars with typical periods of 1 to 3 s but none have been observed yet in X-rays where a significant part of the accreting energy is released. QPOs are expected and predicted from shock oscillations. Most of the polars have been observed by the XMM-Newton satellite. We made use of the homogeneous set of observations of the polars by XMM-Newton to search for the presence of QPOs in the (0.5-10 keV) energy range and to set significant upper limits for the brightest X-ray polars. We extracted high time-resolution X-ray light curves by taking advantage of the 0.07 s resolution of the EPIC-PN camera. Among the 65 polars observed with XMM-Newton from 1998 to 2012, a sample of 24 sources was selected on the basis of their counting rate in the PN instrument to secure significant limits. We searched for QPOs using Fast Fourier Transform (FFT) methods and defined limits of detection using statistical tools. Among the sample surveyed, none shows QPOs at a significant level. Upper limits to the fractional flux in QPOs range from 7% to 71%. These negative results are compared to the detailed theoretical predictions of numerical simulations based on a 2D hydrodynamical code presented in Paper II. Cooling instabilities in the accretion column are expected to produce shock quasi-oscillations with a maximum amplitude reaching ~40% in the bremsstrahlung (0.5-10 keV) X-ray emission and ~20% in the optical cyclotron emission. The absence of X-ray QPOs imposes an upper limit of ~(5-10) g cm-2 s-1 on the specific accretion rate but this condition is found inconsistent with the value required to account for the amplitudes and frequencies of the observed optical QPOs. This contradiction outlines probable shortcomings with the shock instability model. Figures 1-3 are available in electronic form at http://www.aanda.org

  12. FASTSAT-HSV01 Synergistic Observations of the Magnetospheric Response During Active Periods: MINI-ME, PISA and TTI

    NASA Technical Reports Server (NTRS)

    Casas, Joseph C.; Collier, Michael R.; Rowland, Douglas E.; Sigwarth, John B.; Boudreaux, Mark E.

    2010-01-01

    Understanding the complex processes within the inner magnetosphere of Earth particularly during storm periods requires coordinated observations of the particle and field environment using both in-situ and remote sensing techniques. In fact in order to gain a better understanding of our Heliophysics and potentially improve our space weather forecasting capabilities, new observation mission approaches and new instrument technologies which can provide both cost effective and robust regular observations of magnetospheric activity and other space weather related phenomenon are necessary. As part of the effort to demonstrate new instrument techniques and achieve necessary coordinated observation missions, NASA's Fast Affordable Science and Technology Satellite Huntsville 01 mission (FASTSAT-HSVOI) scheduled for launch in 2010 will afford a highly synergistic solution which satisfies payload mission opportunities and launch requirements as well as contributing iri the near term to our improved understanding of Heliophysics. NASA's FASTSAT-HSV01 spacecraft on the DoD Space Test Program-S26 (STP-S26) Mission is a multi-payload mission executed by the DoD Space Test Program (STP) at the Space Development and Test Wing (SDTW), Kirtland AFB, NM. and is an example of a responsive and economical breakthrough in providing new possibilities for small space technology-driven and research missions. FASTSAT-HSV is a unique spacecraft platform that can carry multiple small instruments or experiments to low-Earth orbit on a wide range of expendable launch vehicles for a fraction of the cost traditionally required for such missions. The FASTSAT-HSV01 mission allows NASA to mature and transition a technical capability to industry while increasing low-cost access to space for small science and technology (ST) payloads. The FASTSAT-HSV01 payload includes three NASA Goddard Space Flight Center (GSFC) new technology built instruments that will study the terrestrial space environment and potentially contribute to space weather research in a synergistic manner. MINI-ME, a neutral atom imager, will observe the neutral atom inputs to ionospheric heating which can be important during high levels of magnetospheric activity. PISA, a plasma impedance spectrometer, will measure simultaneously the local electron densities and temperatures as well as measure small scale density structure (500 m spatial scale) during these active periods. TTI, a thermospheric imager, will remotely determine the thermospheric temperature response to this magnetospheric activity. Together, these observations will contribute significantly to a comprehensive understanding of the flow of energy through and the response of the storm-time terrestrial magnetosphere.

  13. High Angular Resolution Observations of Episodic Dust Emission from Long Period Variable Stars Twenty Years of Observations with the Berkeley Infrared Spatial Interferometer

    NASA Technical Reports Server (NTRS)

    Danchi, William

    2010-01-01

    Over the past twenty years the U. C. Berkeley Infrared Spatial Interferometer has observed a number of Long Period Variable stars in the mid-infrared, obtaining information on the spatial distribution of dust around these stars with resolutions of the order of a few tens of milliarcseconds. The ISI is a heterodyne interferometer operating mostly at 11.15 microns, initially with two telescopes. In the last decade, it has been taking data regularly with three telescopes, thus obtaining visibility data on three baselines and also a closure phase. Over the course of the years, the ISI has been able to measure the physical properties of the dust shells surrounding these stars, in particular the inner radii of the dust shells, as well as the temperature and density distribution. For some stars, the ISI has also made precision measurements of their diameters in the mid-infrared. Closure phase measurements have revealed asymmetries in the dust distributions around many stars. Most surprisingly the ISI data has shown evidence for substantial changes in the amount of dust on time scales of 5-10 years, rather than being directly correlated with the stellar pulsation periods, which are of the order of one year. We discuss past results and new results from the ISI that highlight the dynamic environment around these stars.

  14. Van Allen Probes observations and test particle simulations of radiation belt wave-particle interactions during periods of intense wave activity

    NASA Astrophysics Data System (ADS)

    Kersten, K.; Wygant, J. R.; Cattell, C. A.; Breneman, A. W.; Dai, L.; Zhang, S.; Bonnell, J. W.; Tao, J.; Roth, I.; Kletzing, C.; Kurth, W. S.; Hospodarsky, G. B.; Fennell, J. F.; Blake, J. B.; Claudepierre, S. G.; Spence, H.

    2013-12-01

    Recent observations of trapped radiation belt electrons suggest that increased fluxes of high energy electrons during geomagnetically active periods can be attributed to local acceleration and scattering through wave-particle interactions. We present case studies of Van Allen Probes EFW high time resolution electric and magnetic field waveforms and filterbank (wave packet counting) data during geomagnetically active periods to assess the nature of the wave-particle interactions responsible for the rapid heating of trapped particle populations. We present these observations with large scale test particle simulations of oblique whistler-mode wave-particle interactions. These simulations resolve the gyro- and bounce-motion of large distributions of test particles through multiple resonant interactions with large amplitude oblique waves, and are used to predict the evolution of trapped particle distributions through interaction with large amplitude wave fields. We will discuss the results and limitations of these simulations in the context of the waves and particle distributions observed by the twin Van Allen Probes.

  15. Eclipses in the Middle East from the Late Medieval Islamic Period to the Early Modern Period. Part 1: The observation of six lunar eclipses from the Late Medieval Islamic Period

    NASA Astrophysics Data System (ADS)

    Mozaffari, S. Mohammad

    2013-11-01

    This paper deals with the analysis of data obtained from observations of two sets of three lunar eclipses in the Late Medieval Islamic Period. The first trio consists of the lunar eclipses of 7 March 1262, 7 April 1270 and 24 January 1274, observed by Muḥyī al-Dīn al-Maghribī; from the Maragha Observatory (in north-western Iran), and the second includes those of 2 June and 26 November 1406, and 22 May 1407, observed by Jamshīd Ghiyāth al-Dīn al-Kāshī from Kāshān (in central Iran). The results are that al-Maghribī's values for the magnitudes of these eclipses agree excellently with modern data, and his values for the times when the maximum phases occurred agree to within five minutes with modern values. Al-Kāshī's values for the times of the maximum phases show a rather larger divergence from modern data, varying from about ten minutes to about one hour. The errors in all six values both astronomers computed from their own solar parameters for the longitude of the Sun at the instant of the opposition of the Moon to the Sun in these eclipses remain below ten minutes of arc. The motivation for doing these observations was to measure the lunar epicycle radius r in the Ptolemaic model. Al-Maghribī achieved r = 5;12 and al-Kāshī r ∼ 5;17,1 in terms of the radius of an orbit of R = 60 arbitrary units. It is argued that comparing with modern theory, neither of these two medieval values can be considered an improvement on Ptolemy's value of r = 5;15.

  16. An overview of the lightning and atmospheric electricity observations collected in Southern France during the HYdrological cycle in Mediterranean EXperiment (HyMeX), Special Observation Period 1

    NASA Astrophysics Data System (ADS)

    Defer, E.; Pinty, J.-P.; Coquillat, S.; Martin, J.-M.; Prieur, S.; Soula, S.; Richard, E.; Rison, W.; Krehbiel, P.; Thomas, R.; Rodeheffer, D.; Vergeiner, C.; Malaterre, F.; Pedeboy, S.; Schulz, W.; Farges, T.; Gallin, L.-J.; Ortéga, P.; Ribaud, J.-F.; Anderson, G.; Betz, H.-D.; Meneux, B.; Kotroni, V.; Lagouvardos, K.; Roos, S.; Ducrocq, V.; Roussot, O.; Labatut, L.; Molinié, G.

    2014-08-01

    The PEACH (Projet en Electricité Atmosphérique pour la Campagne HyMeX - the Atmospheric Electricity Project of HyMeX Program) project is the Atmospheric Electricity component of the HyMeX (Hydrology cycle in the Mediterranean Experiment) experiment and is dedicated to the observation of both lightning activity and electrical state of continental and maritime thunderstorms in the area of the Mediterranean Sea. During the HyMeX SOP1 (Special Observation Period; 5 September-6 November 2012), four European Operational Lightning Locating Systems (OLLSs) (ATDNET, EUCLID, LINET, ZEUS) and the HyMeX Lightning Mapping Array network (HyLMA) were used to locate and characterize the lightning activity over the Southeastern Mediterranean at flash, storm and regional scales. Additional research instruments like slow antennas, video cameras, micro-barometer and microphone arrays were also operated. All these observations in conjunction with operational/research ground-based and airborne radars, rain gauges and in situ microphysical records aimed at characterizing and understanding electrically active and highly precipitating events over Southeastern France that often lead to severe flash floods. Simulations performed with Cloud Resolving Models like Meso-NH and WRF are used to interpret the results and to investigate further the links between dynamics, microphysics, electrification and lightning occurrence. A description of the different instruments deployed during the field campaign as well as the available datasets is given first. Examples of concurrent observations from radio frequency to acoustic for regular and atypical lightning flashes are then presented showing a rather comprehensive description of lightning flashes available from the SOP1 records. Then examples of storms recorded during HyMeX SOP1 over Southeastern France are briefly described to highlight the unique and rich dataset collected. Finally the next steps of the work required for the delivery of reliable lightning-derived products to the HyMeX community are discussed.

  17. Preliminary analysis of the Intensive Observation Period events occurred in Italy during the HyMeX campaign

    NASA Astrophysics Data System (ADS)

    Ferretti, Rossella

    2013-04-01

    HyMeX (Hydrological cycle in the Mediterranean eXperiment) is a project aimed at a better understanding and quantification of the hydrological cycle and related processes in the Mediterranean. As a part of HyMeX, Special Observation Periods (SOPs) are dedicated to provide detailed and specific observations to study key processes leading to orographic precipitation (ORP), heavy precipitation events (HPEs), and flash flood events (FFEs) in certain Target Areas (TAs). Informed by numerical weather forecasts and standard observations, Intensive Operation Periods (IOPs) are declared during the SOPs. Specific observations in the TAs are provided by operational measurements (ground meteorological networks, soundings, and remote-sensing instruments), coupled with specific measurements during IOPs from several instruments, such as disdrometers, sodars, lidars, research radars, extra soundings, etc. In this paper an overview is presented of the HyMeX IOPs in Italy during SOP1 (5 September - 6 November, 2012). The Hydro-Meteorological sites of interest were: Liguria-Tuscany (LT), northeastern Italy (NEI) and central Italy (CI). Typical situations encountered for HPEs in LT involved upper-level southwesterly flow with low-level moist southerly or southeasterly flow over the Tyrrhenian and the Ligurian Sea. Highlights include a measurement of 300 mm/24h of rain at the border between Liguria and Emilia on Sept. 26, 2012 during IOP7b. For NEI region, HPEs mainly occurred with upper level southwesterly flow ahead of advancing troughs with low-level moist southerly or southeasterly flow over the Adriatic Sea. Highlights include 120 mm/24h of rain in Friuli Venezia Giulia on Sept. 12, 2012 during IOP2. For CI region, HPEs and FFEs, a slowly propagating cut-off low centered over southern Italy was observed; the associated easterly flow on the north side of the cut-off low would frequently bring moisture into east central Italy from the Adriatic Sea. Highlights include an event with very intense convective cells producing more than 150 mm of rain in several hours in Abruzzo on Sept. 14, 2012 in IOP4; extensive flood occurred in this case. The ongoing analyses of these cases will shed light on the complex chain of events that determines the timing, location and intensity of HPEs over complex orography in the vicinity of maritime air masses and on the forecasting ability of the different meteorological models implemented for the campaign.

  18. AROME-WMED, a real-time mesoscale model designed for the HyMeX Special Observation Periods

    NASA Astrophysics Data System (ADS)

    Fourrié, N.; Bresson, É.; Nuret, M.; Jany, C.; Brousseau, P.; Doerenbecher, A.; Kreitz, M.; Nuissier, O.; Sevault, E.; Bénichou, H.; Amodei, M.; Pouponneau, F.

    2015-02-01

    During autumn 2012 and winter 2013, two Special Observation Periods (SOPs) of the Hydrological cycle in the Mediterranean Experiment (HyMeX) took place. For the preparatory studies and to support the instrument deployment during the field campaign, a dedicated version of the operational convective-scale AROME-France model was developed: the AROME-WMED model. It covers the western Mediterranean basin with a 48 h forecast range. It provided real time analyses and forecasts which were sent daily to the HyMeX operational centre to forecast high precipitation events and to help decision makers on the deployment of observation instruments. This paper presents the main features of this numerical weather prediction system in terms of data assimilation and forecast. Some specific data of the HyMeX SOP were assimilated in real time. The forecast skill of the AROME-WMED is then assessed with objective scores and compared to the operational AROME-France model, for both autumn 2012 (5 September to 6 November 2012) and winter 2013 (1 February to 15 March 2013) SOPs. The overall performance of AROME-WMED is good and similar to those of AROME-France for the 0 to 30 h common forecast range. The 24 to 48 h forecast range is of course less accurate but remains useful for scheduling observation deployment. The characteristics of parameters such as precipitation, temperature or humidity, are illustrated by one heavy precipitation case study that occurred over the south of Spain.

  19. Observations of the Nocturnal Boundary Layer and Morning Transitional Periods in Houston, Texas during the TexAQS II Campaign

    NASA Astrophysics Data System (ADS)

    Day, B. M.; Clements, C. B.; Rappenglueck, B.

    2007-12-01

    High-temporal resolution tethersonde profiles taken during the TexAQS II field campaign in Houston were used to study the overnight development and progression of the nocturnal boundary layer (NBL) and the evolution of the convective boundary layer after sunrise. The measurements were made at the University of Houston campus, located approximately 4 km southeast of the downtown Houston central business district, and consisted of vertical profiles of potential temperature, water vapor mixing ratio, wind speed, wind direction, and ozone concentration. Profile heights averaged 250 m AGL with a few reaching 400 m AGL. Profiles were taken at approximately 30 min intervals throughout 4 nights during Intensive Observational Periods (IOPs), including both the evening and morning transitional periods. Tethersonde experiments also were performed during several additional morning break-up periods during the campaign. Preliminary results from the overnight experiments of Sept 7-8 and Sept 14-15, 2006 showed different NBL evolutions. Sept 7-8 exhibited a stronger and deeper inversion compared with Sept 14-15 when the inversion was weak with a fairly constant height throughout the night. The Sept 7-8 profiles showed elevated bluff-like structures in the virtual potential temperature profiles between 0300-0400 CDT, indicating neutral stability within the 40-90 m AGL level. And, just before sunrise a neutral layer with constant potential temperature developed between the surface and 75 m AGL reflecting horizontal cold air advection. Further analyses will be presented for other vertical profiles taken during the campaign, including the additional overnight profiles as well as the profiles taken during the morning transition to the convective boundary layer.

  20. Variability of aerosol properties over Eastern Europe observed from ground and satellites in the period from 2003 to 2011

    NASA Astrophysics Data System (ADS)

    Bovchaliuk, A.; Milinevsky, G.; Danylevsky, V.; Goloub, P.; Dubovik, O.; Holdak, A.; Ducos, F.; Sosonkin, M.

    2013-07-01

    The paper presents some results of the study on aerosol variability in the period from 2003 to 2011 over the Eastern Europe region, with latitude ranging from 40 N to 60 N and longitude from 20 E to 50 E. The analysis was based on the POLDER/PARASOL and POLDER-2/ADEOS satellites and AERONET (AErosol RObotic NETwork) ground-based sun photometer observations. The aerosol optical thickness (AOT) of the studied area is characterized by values (referenced to 870 nm wavelength) ranging from 0.05 to 0.2, except for in the period of July-August 2010 with strong forest and peat wildfires when the AOT typical values range from 0.3 to 0.5 according to both retrievals. The analysis of seasonal dynamics of aerosol loading has revealed two AOT high value peaks. The spring peak observed in April-May is the result of solitary transportation of Saharan dust in the atmosphere over Eastern Europe, infrequent agricultural fires, transportation of sea salt aerosols by southern winds to Ukraine and Moldova from the Black and Azov seas. The autumn peak in August-September is associated with forest and peat wildfires, considerable transportation of Saharan dust and the presence of soil dust aerosols due to harvesting activity. The maximum values of AOT are observed in May 2006 (0.1-0.15), April 2009 (0.07-0.15) and August 2010 (0.2-0.5). Furthermore, the study has identified a distinct pattern of anthropogenic aerosols over the industrial areas, especially in central Ukraine and eastern Belarus as well as Moscow region in Russia. The comparison of the AOT derived by standard algorithm POLDER/PARASOL with those recomputed from AERONET inversions for fine mode particles with radius < 0.3 ?m was performed over several AERONET sites. The correlation coefficients for the POLDER/AERONET AOT retrieval comparisons are equal: 0.78 for Moscow site, 0.76 - Minsk, 0.86 - Belsk, 0.81 - Moldova (period 2005-2009), 0.93 - Kyiv and 0.63 for Sevastopol sites (2008-2009). The deviations are explained by the spatial inhomogeneity of the surface polarization that has a stronger effect on aerosol retrieval for clear atmospheric conditions with low aerosol loading when surface impact on satellite observations is more pronounced. In addition, the preliminary analysis of the detailed aerosol properties derived by a new generation PARASOL algorithm was evaluated. The comparison of AOT and single scattering albedo retrieved from the POLDER/PARASOL observations over Kyiv with the closest AERONET retrievals within 30 min of satellite overpass time and with a cloudless day shows acceptable agreement of the aerosol dynamics. The correspondence of those data is observed even for extreme AOT440 value 1.14, which was caused by the forest and peat fires in August 2010.

  1. Assessing spatial patterns of extreme droughts associated to return periods from observed dataset: Case study of Segura River Basin (Spain)

    NASA Astrophysics Data System (ADS)

    García Galiano, Sandra G.; Diego Giraldo Osorio, Juan

    2013-04-01

    In basins of South-eastern Spain, such as the Segura River Basin (SRB), a strong decrease in runoff from the end of the 1970s has been observed. In the SRB, due to intensive reforestation aimed at halting desertification and erosion, added to climate variability and change, the default assumption of stationarity in water resources systems cannot be guaranteed. Therefore there is an important need for improvement in the ability of monitoring and predicting the impacts associated with the change of hydrologic regime. It is thus necessary to apply non-stationary probabilistic models, which are able to reproduce probability density functions whose parameters vary with time. From a high-resolution daily gridded rainfall dataset of more than 50 years (1950-2007 time period), the spatial distribution of lengths of maximum dry spells for several thresholds are assessed, applying GAMLSS (Generalized Additive Models for Location Scale and Shape) models at grid site. Results reveal an intensification of extreme drought events in some headbasins of the SRB important for water supply. The identification of spatial patterns of drought hazards at basin scale, associated to return periods, contribute to designing strategies of drought contingency preparedness and recovery operations, which are the leading edge of adaptation strategies.

  2. Vertical structure of the wind field during the Special Observing Period I of the Global Weather Experiment

    NASA Technical Reports Server (NTRS)

    Paegle, J. N.; Paegle, J.; Zhen, Z.; Sampson, G.

    1986-01-01

    The vertical structure of the global atmosphere is analyzed for selected periods of the Special Observing Period I (SOP-I) for the Global Weather Experiment (GWE). The analysis consists of projection of the stream-function and velocity potential at 200 and 850 mb on spherical harmonics and of the wind and height fields on the normal modes of a linearized form of the primitive equations for a basic state at rest. The kinematic vertical structure is discussed in terms of correlation coefficients of the 200 mb and 850 mb winds and analysis of the internal and external normal modes of the primitive equations. The reliability of the results is checked by applying the same analysis methods to data sets obtained from three different institutions: Geophysical Fluid Dynamics Laboratory (GFDL), European Center for Medium Range Weather Forecasting (ECMWF), and Goddard Laboratory for the Atmospheres (GLA). It is found that, on a global basis, vertically reversing circulations are as important as the equivalent barotropic structures. For the verticaly reversing components, the gravity and mixed Rossby-gravity modes have contributions of the same order of magnitude as those of the Rossby modes in tropical latitudes.

  3. Regional modeling of tropospheric NO2 vertical column density over East Asia during the period 2000-2010: comparison with multisatellite observations

    NASA Astrophysics Data System (ADS)

    Itahashi, S.; Uno, I.; Irie, H.; Kurokawa, J.-I.; Ohara, T.

    2014-04-01

    Satellite observations of the tropospheric NO2 vertical column density (VCD) are closely correlated to, and thus can be used to estimate, surface NOx emissions. In this study, the NO2 VCD simulated by a regional chemical transport model with emissions data from the updated Regional Emission inventory in ASia (REAS) version 2.1 were validated through comparison with multisatellite observations during the period 2000-2010. Rapid growth in NO2 VCD (~11% year-1) driven by the expansion of anthropogenic NOx emissions was identified above the central eastern China (CEC) region, except for the period during the economic downturn. In contrast, slightly decreasing trends (~2% year-1) were identified above Japan accompanied by a decline in anthropogenic emissions. To systematically compare the modeled NO2 VCD, we estimated sampling bias and the effect of applying the averaging kernel information, with particular focus on the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) data. Using the updated REAS, the modeled NO2 VCD reasonably reproduced annual trends observed by multisatellites, suggesting that the rate of increase of NOx emissions estimated by the updated REAS inventory would be robust. Province-scale revision of emissions above CEC is needed to further refine emission inventories. Based on the close linear relationship between modeled and observed NO2 VCD and anthropogenic NOx emissions, NOx emissions in 2009 and 2010, which were not covered by the updated REAS inventory, were estimated. NOx emissions from anthropogenic sources in China in 2009 and 2010 were determined to be 26.4 and 28.5 Tg year-1, respectively, indicating that NOx emissions increased more than twofold between 2000 and 2010. This increase reflected the strong growth of anthropogenic emissions in China following the rapid recovery from the economic downturn from late 2008 until mid-2009. Our method consists of simple estimations from satellite observations and provides results that are consistent with the most recent inventory of emissions data for China.

  4. Quasi-periodic oscillations in accreting magnetic white dwarfs. II. The asset of numerical modelling for interpreting observations

    NASA Astrophysics Data System (ADS)

    Busschaert, C.; Falize, .; Michaut, C.; Bonnet-Bidaud, J.-M.; Mouchet, M.

    2015-07-01

    Context. Magnetic cataclysmic variables are close binary systems containing a strongly magnetized white dwarf that accretes matter coming from an M-dwarf companion. The high magnetic field strength leads to the formation of an accretion column instead of an accretion disk. High-energy radiation coming from those objects is emitted from the column close to the white dwarf photosphere at the impact region. Its properties depend on the characteristics of the white dwarf and an accurate accretion column model allows the properties of the binary system to be inferred, such as the white dwarf mass, its magnetic field, and the accretion rate. Aims: We study the temporal and spectral behaviour of the accretion region and use the tools we developed to accurately connect the simulation results to the X-ray and optical astronomical observations. Methods: The radiation hydrodynamics code Hades was adapted to simulate this specific accretion phenomena. Classical approaches were used to model the radiative losses of the two main radiative processes: bremsstrahlung and cyclotron. Synthetic light curves and X-ray spectra were extracted from numerical simulations. A fast Fourier analysis was performed on the simulated light curves. The oscillation frequencies and amplitudes in the X-ray and optical domains are studied to compare those numerical results to observational ones. Different dimensional formulae were developed to complete the numerical evaluations. Results: The complete characterization of the emitting region is described for the two main radiative regimes: when only the bremsstrahlung losses and when both cyclotron and bremsstrahlung losses are considered. The effect of the non-linear cooling instability regime on the accretion column behaviour is analysed. Variation in luminosity on short timescales (~1 s quasi-periodic oscillations) is an expected consequence of this specific dynamic. The importance of secondary shock instability on the quasi-periodic oscillation phenomenon is discussed. The stabilization effect of the cyclotron process is confirmed by our numerical simulations, as well as the power distribution in the various modes of oscillation.

  5. Observations of Sub-3 nm Particles and Sulfuric acid Concentrations during Aerosol Life Cycle Intensive Observation Period 2011 in Long Island, New York

    NASA Astrophysics Data System (ADS)

    Yu, H.; Kanawade, V. P.; You, Y.; Hallar, A. G.; Mccubbin, I. B.; Chirokova, G.; Sedlacek, A. J.; Springston, S. R.; Wang, J.; Kuang, C.; Lee, Y.; McGraw, R. L.; Mikkila, J.; Lee, S.

    2012-12-01

    Atmospheric new particle formation (NPF) is an important source of aerosol particles. But the NPF processes are not well understood, in part because of our limited understanding of the formation of atmospheric sub-3 nm size aerosols and the limited number of simultaneous observations of particle size distributions and the aerosol nucleation precursors. During Aerosol Life Cycle Intensive Observation Period (July-August 2011) in Long Island, New York, we deployed a particle size magnifier (Airmodus A09) running at different working fluid saturation ratios and a TSI CPC3776 to extract the information of sub-3 nm particles formation. A scanning mobility particle spectrometer (SMPS), a chemical ionization mass spectrometer (CIMS), and a number of atmospheric trace gas analyzers were used to simultaneously measure aerosol size distributions, sulfuric acid, and other possible aerosol precursors, respectively. Our observation results show that sub-3 nm particles existed during both NPF and non-NPF events, indicating the formation of sub-3nm particle didn't always lead to NPF characterized by typical banana shaped aerosol size distributions measured by SMPS. However, sub-3 nm particles were much higher during NPF events. Sub-3 nm particles were well-correlated with sulfuric acid showing the same diurnal variations and noontime peaks, especially for NPF days. These results are consistent with laboratory studies showing that formation of sub-3 nm particles is very sensitive to sulfuric acid (than amines and ammonia) [Yu et al. GRL 2012]. HYSPLIT back trajectory analysis indicates that air masses from Great Lakes, containing more SO2, VOCs and secondary organics, may contribute to growth of sub-3 nm particles and NPF.

  6. Meteorological and dust aerosol conditions over the western Saharan region observed at Fennec Supersite-2 during the intensive observation period in June 2011

    NASA Astrophysics Data System (ADS)

    Todd, M. C.; Allen, C. J. T.; Bart, M.; Bechir, M.; Bentefouet, J.; Brooks, B. J.; Cavazos-Guerra, C.; Clovis, T.; Deyane, S.; Dieh, M.; Engelstaedter, S.; Flamant, C.; Garcia-Carreras, L.; Gandega, A.; Gascoyne, M.; Hobby, M.; Kocha, C.; Lavaysse, C.; Marsham, J. H.; Martins, J. V.; McQuaid, J. B.; Ngamini, J. B.; Parker, D. J.; Podvin, T.; Rocha-Lima, A.; Traore, S.; Wang, Y.; Washington, R.

    2013-08-01

    The climate of the Sahara is relatively poorly observed and understood, leading to errors in forecast model simulations. We describe observations from the Fennec Supersite-2 (SS2) at Zouerate, Mauritania during the June 2011 Fennec Intensive Observation Period. These provide an improved basis for understanding and evaluating processes, models, and remote sensing. Conditions during June 2011 show a marked distinction between: (i) a "Maritime phase" during the early part of the month when the western sector of the Sahara experienced cool northwesterly maritime flow throughout the lower troposphere with shallow daytime boundary layers, very little dust uplift/transport or cloud cover. (ii) A subsequent "heat low" phase which coincided with a marked and rapid westward shift in the Saharan heat low towards its mid-summer climatological position and advection of a deep hot, dusty air layer from the central Sahara (the "Saharan residual layer"). This transition affected the entire western-central Sahara. Dust advected over SS2 was primarily from episodic low-level jet (LLJ)-generated emission in the northeasterly flow around surface troughs. Unlike Fennec SS1, SS2 does not often experience cold pools from moist convection and associated dust emissions. The diurnal evolution at SS2 is strongly influenced by the Atlantic inflow (AI), a northwesterly flow of shallow, cool and moist air propagating overnight from coastal West Africa to reach SS2 in the early hours. The AI cools and moistens the western Saharan and weakens the nocturnal LLJ, limiting its dust-raising potential. We quantify the ventilation and moistening of the western flank of the Sahara by (i) the large-scale flow and (ii) the regular nocturnal AI and LLJ mesoscale processes.

  7. An overview of the lightning and atmospheric electricity observations collected in southern France during the HYdrological cycle in Mediterranean EXperiment (HyMeX), Special Observation Period 1

    NASA Astrophysics Data System (ADS)

    Defer, E.; Pinty, J.-P.; Coquillat, S.; Martin, J.-M.; Prieur, S.; Soula, S.; Richard, E.; Rison, W.; Krehbiel, P.; Thomas, R.; Rodeheffer, D.; Vergeiner, C.; Malaterre, F.; Pedeboy, S.; Schulz, W.; Farges, T.; Gallin, L.-J.; Ortéga, P.; Ribaud, J.-F.; Anderson, G.; Betz, H.-D.; Meneux, B.; Kotroni, V.; Lagouvardos, K.; Roos, S.; Ducrocq, V.; Roussot, O.; Labatut, L.; Molinié, G.

    2015-02-01

    The PEACH project (Projet en Electricité Atmosphérique pour la Campagne HyMeX - the Atmospheric Electricity Project of the HyMeX Program) is the atmospheric electricity component of the Hydrology cycle in the Mediterranean Experiment (HyMeX) experiment and is dedicated to the observation of both lightning activity and electrical state of continental and maritime thunderstorms in the area of the Mediterranean Sea. During the HyMeX SOP1 (Special Observation Period) from 5 September to 6 November 2012, four European operational lightning locating systems (ATDnet, EUCLID, LINET, ZEUS) and the HyMeX lightning mapping array network (HyLMA) were used to locate and characterize the lightning activity over the northwestern Mediterranean at flash, storm and regional scales. Additional research instruments like slow antennas, video cameras, microbarometer and microphone arrays were also operated. All these observations in conjunction with operational/research ground-based and airborne radars, rain gauges and in situ microphysical records are aimed at characterizing and understanding electrically active and highly precipitating events over southeastern France that often lead to severe flash floods. Simulations performed with cloud resolving models like Meso-NH and Weather Research and Forecasting are used to interpret the results and to investigate further the links between dynamics, microphysics, electrification and lightning occurrence. Herein we present an overview of the PEACH project and its different instruments. Examples are discussed to illustrate the comprehensive and unique lightning data set, from radio frequency to acoustics, collected during the SOP1 for lightning phenomenology understanding, instrumentation validation, storm characterization and modeling.

  8. Observations of Non-Methane Hydrocarbons Over India During the Asian Summer Monsoon Period: Results from CARIBIC

    NASA Astrophysics Data System (ADS)

    Baker, A. K.; Schuck, T. J.; Slemr, F.; Brenninkmeijer, C. A.

    2008-12-01

    The CARIBIC project (Civil Aircraft for the Regular Investigation of the Atmosphere Based on an Instrument Container, www.caribic-atmospheric.com) involves the monthly deployment of an instrument container equipped to make atmospheric measurements from onboard a long-range commercial airliner. Since December 2004, flights for the second phase of CARIBIC have been aboard a Lufthansa Airbus A340-600 traveling between Frankfurt, Germany and destinations in Asia, North America and South America. The instrument package housed in the container (1.5 ton) is fully automated and during each monthly set of flights carries out a variety of real-time trace gas and aerosol measurements, and also collects 28 air samples, which are analyzed upon return to the laboratory. Routine measurements made from the sampling flasks include non-methane hydrocarbon (NMHC) analysis, and these measurements provide the basis for the data presented here. Between April and September of 2008, the container was deployed monthly on two sequential roundtrip flights between Frankfurt and Chennai, India. To achieve greater resolution, air samples were collected only on the first of the roundtrip flights, with 14 samples collected on the flight to Chennai and 14 collected on the return. These flights provided the opportunity to study the composition of the upper troposphere in this region during the Asian summer monsoon period (typically June-September), which is characterized by anticyclonic circulation in the upper troposphere coupled with deep convection. Samples collected during the monsoon period exhibit elevated levels of NMHCs relative to samples collected outside of the monsoon period, with enhancements in ethyne and benzene being more substantial than enhancements in the alkanes. Enhanced mixing ratios are observed between 15N and 40N, and correspond to enhancements in other trace gases, namely methane and CO. Ethyne in particular is strongly correlated with both methane and CO in this region; while CO and ethyne share a common, combustion, source, methane and ethyne do not, and this relationship indicates convection of a well-mixed air mass that is strongly and recently influenced by both agricultural and anthropogenic/urban sources. Trends in and relationships between NMHCs during the monsoon period will be discussed here, as well as their relationships to other trace gases.

  9. Short-Period Gravity Variations Induced by the Local Hydrology: Observations with Three Superconducting Gravity Sensors at Metshovi, Finland

    NASA Astrophysics Data System (ADS)

    Raja-Halli, A.; Virtanen, H.; Makinen, J.; Hokkanen, T. M.; Mkinen, R. P.

    2014-12-01

    The main hydrological signal in gravity recordings by superconducting gravimeters (SGs) is typically seasonal. At the Metshovi Geodetic Observatory of the Finnish Geodetic Institute the seasonal signal is up to 8 microgal peak-to-peak. Here we concentrate on the much smaller short-period hydrological signals in the minutes-to-hours range, due to the direct attraction of very close water masses within some hundred meters from the gravity laboratory. This period range is interesting e.g. for SG observations of the gravity signature of deep earth processes, where the signal is very small, and a possible decrease in noise level obtained from hydrological modeling would be useful. Around the gravity laboratory at Metshovi we have installed 12 arrays of soil moisture sensors at depths of 0.1 to 1 m below surface, three borehole wells to groundwater in the fractures of the crystalline bedrock, and 11 observation tubes into groundwater level in sediments, typically at 1 to 4 m depth below surface. Since January 2014 we record the snow water equivalent with a passive gamma ray device. However, a major component in local water mass remains inaccessible to these sensors. From earlier research we know that during summer months, even a major rainfall pulse is quickly removed from the surface layers of the soil by evapotranspiration, and frequently never reaches the depth of the soil moisture sensors; let alone the groundwater. Obviously, this also depends on the prior moisture state of the soil layers. But in any case the water mass is present for a while, and the input pulse is detectable not only by a rain gauge but also by an upward slope in the SG record. At the laboratory we now have three superconducting gravity sensors: the SG T020 has been operating since 1994, and in February 2014 the new SG OSG-073 with two individual sensors was installed at two meters' distance from the T020. The characteristics of the three sensors are different, and also the different locations influence slightly the gravity signal from variation in local masses. We present first results of the modeling of short-period gravity variation using all hydrological sensors, and compare them with the three SG gravity time series.

  10. Luminosity and spin-period evolution of GX 304-1 during outbursts from 2009 to 2013 observed with the MAXI/GSC, RXTE/PCA, and Fermi/GBM

    NASA Astrophysics Data System (ADS)

    Sugizaki, Mutsumi; Yamamoto, Takayuki; Mihara, Tatehiro; Nakajima, Motoki; Makishima, Kazuo

    2015-08-01

    A report is made on the luminosity and pulse period evolution of the Be binary X-ray pulsar GX 304-1 during a series of outbursts from 2009 to 2013 observed by MAXI/GSC, RXTE/PCA, and Fermi/GBM. In total, 12 outbursts repeated by ˜ 132.2 d were observed, which is consistent with the X-ray periodicity of this object observed in the 1970s. These 12 outbursts, together with those in the 1970s, were all found to recur with a well-defined period of 132.189 ± 0.02 d, which can be identified with the orbital period. The pulse period of ˜ 275 s, obtained from the RXTE/PCA and Fermi/GBM data, apparently exhibited a periodic modulation synchronized with the outburst period, suggesting the pulsar orbital motion, which is superposed on a secular spin-up trend throughout the entire active phase. The observed pulse period changes were successfully represented by a model composed of the binary orbital modulation and pulsar spin up caused by mass accretion through an accretion disk. The orbital elements obtained from the best-fit model, including the projected orbital semi-major axis ax sin i ≃ 500-600 light-s and an eccentricity e ≃ 0.5, are typical of Be binary X-ray pulsars.

  11. Water quality observations of ice-covered, stagnant, eutrophic water bodies and analysis of influence of ice-covered period on water quality

    NASA Astrophysics Data System (ADS)

    sugihara, K.; Nakatsugawa, M.

    2013-12-01

    The water quality characteristics of ice-covered, stagnant, eutrophic water bodies have not been clarified because of insufficient observations. It has been pointed out that climate change has been shortening the duration of ice-cover; however, the influence of climate change on water quality has not been clarified. This study clarifies the water quality characteristics of stagnant, eutrophic water bodies that freeze in winter, based on our surveys and simulations, and examines how climate change may influence those characteristics. We made fixed-point observation using self-registering equipment and vertical water sampling. Self-registering equipment measured water temperature and dissolved oxygen(DO).vertical water sampling analyzed biological oxygen demand(BOD), total nitrogen(T-N), nitrate nitrogen(NO3-N), nitrite nitrogen(NO2-N), ammonium nitrogen(NH4-N), total phosphorus(TP), orthophosphoric phosphorus(PO4-P) and chlorophyll-a(Chl-a). The survey found that climate-change-related increases in water temperature were suppressed by ice covering the water area, which also blocked oxygen supply. It was also clarified that the bottom sediment consumed oxygen and turned the water layers anaerobic beginning from the bottom layer, and that nutrient salts eluted from the bottom sediment. The eluted nutrient salts were stored in the water body until the ice melted. The ice-covered period of water bodies has been shortening, a finding based on the analysis of weather and water quality data from 1998 to 2008. Climate change was surveyed as having caused decreases in nutrient salts concentration because of the shortened ice-covered period. However, BOD in spring showed a tendency to increase because of the proliferation of phytoplankton that was promoted by the climate-change-related increase in water temperature. To forecast the water quality by using these findings, particularly the influence of climate change, we constructed a water quality simulation model that incorporates the freezing-over of water bodies. The constructed model shows good temporal and spatial reproducibility and enables water quality to be forecast throughout the year, including during the ice-covered period. The forecasts using the model agree well with the survey results of shortened ice period and climate-change-related increase in the BOD in spring. From the result of calculations and observations, it is suggested that water quality of spring has been deteriorate because of freezing period to be shortened due to temperature rising.

  12. ITG-CHAMP01: a CHAMP gravity field model from short kinematic arcs over a one-year observation period

    NASA Astrophysics Data System (ADS)

    Mayer-Gürr, T.; Ilk, K. H.; Eicker, A.; Feuchtinger, M.

    2005-03-01

    Global gravity field models have been determined based on kinematic orbits covering an observation period of one year beginning from March 2002. Three different models have been derived up to a maximum degree of n=90 of a spherical harmonic expansion of the gravitational potential. One version, ITG-CHAMP01E, has been regularized beginning from degree n=40 upwards, based on the potential coefficients of the gravity field model EGM96. A second model, ITG-CHAMP01K, has been determined based on Kaula's rule of thumb, also beginning from degree n=40. A third version, ITG-CHAMP01S, has been determined without any regularization. The physical model of the gravity field recovery technique is based on Newton's equation of motion, formulated as a boundary value problem in the form of a Fredholm-type integral equation. The observation equations are formulated in the space domain by dividing the one-year orbit into short sections of approximately 30-minute arcs. For every short arc, a variance factor has been determined by an iterative computation procedure. The three gravity field models have been validated based on various criteria, and demonstrate the quality of not only the gravity field recovery technique but also the kinematically determined orbits.

  13. Some observations regarding the thermal flux from Earth's erupting volcanoes for the period of 2000 to 2014

    NASA Astrophysics Data System (ADS)

    Wright, Robert; Blackett, Matthew; Hill-Butler, Charley

    2015-01-01

    present satellite measurements of the thermal flux observed from 95 active volcanoes, based on observations made daily over the past 15 years by NASA's Terra and Aqua Moderate Resolution Imaging Spectroradiometer sensors. Excursions from an apparent baseline level of thermal emission are attributable to episodic lava-flow-forming eruptions. Highest average intensity was associated with the July 2001 eruption of Etna, Italy, which radiated an average of 2.5 109 W over 23 days. However, recent fissure eruptions in the Afar Rift have attained higher average intensities of 2.4-4.4 109 W, albeit for days, not weeks. The largest magnitude eruption was the ongoing eruption of Bardarbunga, Iceland, which radiated 2.6 1016 J. K?lauea, Hawai'i, has radiated the most energy since 2000, although the lava lake at Nyiragongo, Democratic Republic of Congo, comes a close second. Time series analysis reveals evidence for periodicity in radiant flux at some volcanoes but not at others.

  14. Us Contributions to the Coordinated Enhanced Observing Period (ceop) and Their Benefits to us Water Cycle Research

    NASA Astrophysics Data System (ADS)

    Lawford, R. G.

    2003-12-01

    The USA is a major contributor to the World Climate Research Programme's Coordinated Enhanced Observing Period (CEOP). Many US scientists are engaged in the project because they are convinced of the project's value for longer-term climate studies. The facilities of DOE, NASA and NOAA feature in US contributions to CEOP data set development. Through support from NOAA and NASA, UCAR is playing a major role in data processing and data set development. In return for these contributions, US scientists now have access to large international data sets that did not previously exist or were difficult to access. The use of these data sets for Water and Energy Simulations and Predictions and Monsoon system studies are already underway. These efforts will contribute to the Climate Change Science Program's (CCSP) Water Cycle theme, GEWEX Americas Prediction Project and NOAA's emerging Intraseasonal to Interannual Prediction (ISIP) program. The systems being developed through this process will advance some of the goals of the Water Cycle theme within the Integrated Global Observing Strategy (IGOS) Partnership. However, there will be many more opportunities for creative use of these data sets. The purpose of this presentation is to increase awareness of the US contributions to CEOP; to provide interested scientists with information on how to access these data sets and to obtain feedback on additional uses of these unique global data sets.

  15. Direct observation of single stationary-phase bacteria reveals a surprisingly long period of constant protein production activity

    PubMed Central

    Gefen, Orit; Fridman, Ofer; Ronin, Irine; Balaban, Nathalie Q.

    2014-01-01

    Exponentially growing bacteria are rarely found in the wild, as microorganisms tend to spend most of their lifetime at stationary phase. Despite this general prevalence of stationary-phase bacteria, they are as yet poorly characterized. Our goal was to quantitatively study this phase by direct observation of single bacteria as they enter into stationary phase and by monitoring their activity over several days during growth arrest. For this purpose, we devised an experimental procedure for starving single Escherichia coli bacteria in microfluidic devices and measured their activity by monitoring the production rate of fluorescent proteins. When amino acids were the sole carbon source, the production rate decreased by an order of magnitude upon entry into stationary phase. We found that, even while growth-arrested, bacteria continued to produce proteins at a surprisingly constant rate over several days. Our identification of this newly observed period of constant activity in nongrowing cells, designated as constant activity stationary phase, makes possible the conduction of assays that require constant protein expression over time, and are therefore difficult to perform under exponential growth conditions. Moreover, we show that exogenous protein expression bears no fitness cost on the regrowth of the population when starvation ends. Further characterization of constant activity stationary phasea phase where nongrowing bacteria can be quantitatively studied over several days in a reproducible mannershould contribute to a better understanding of this ubiquitous but overlooked physiological state of bacteria in nature. PMID:24344288

  16. AROME-WMED, a real-time mesoscale model designed for the HyMeX special observation periods

    NASA Astrophysics Data System (ADS)

    Fourrié, N.; Bresson, É.; Nuret, M.; Jany, C.; Brousseau, P.; Doerenbecher, A.; Kreitz, M.; Nuissier, O.; Sevault, E.; Bénichou, H.; Amodei, M.; Pouponneau, F.

    2015-07-01

    During autumn 2012 and winter 2013, two special observation periods (SOPs) of the HYdrological cycle in the Mediterranean EXperiment (HyMeX) took place. For the preparatory studies and to support the instrument deployment during the field campaign, a dedicated version of the operational convective-scale Application of Research to Operations at Mesoscale (AROME)-France model was developed: the AROME-WMED (West Mediterranean Sea) model. It covers the western Mediterranean basin with a 48 h forecast range. It provided real-time analyses and forecasts which were sent daily to the HyMeX operational centre to forecast high-precipitation events and to help decision makers on the deployment of meteorological instruments. This paper presents the main features of this numerical weather prediction system in terms of data assimilation and forecast. Some specific data of the HyMeX SOP were assimilated in real time. The forecast skill of AROME-WMED is then assessed with objective scores and compared to the operational AROME-France model, for both autumn 2012 (05 September to 06 November 2012) and winter 2013 (01 February to 15 March 2013) SOPs. The overall performance of AROME-WMED is good for the first HyMeX special observation period (SOP1) (i.e. mean 2 m temperature root mean square error (RMSE) of 1.7 °C and mean 2 m relative humidity RMSE of 10 % for the 0-30 h forecast ranges) and similar to those of AROME-France for the 0-30 h common forecast range (maximal absolute difference of 2 m temperature RMSE of 0.2 °C and 0.21 % for the 2 m relative humidity); conversely, for the 24-48 h forecast range it is less accurate (relative loss between 10 and 12 % in 2 m temperature and relative humidity RMSE, and equitable threat score (ETS) for 24 h accumulated rainfall), but it remains useful for scheduling observation deployment. The characteristics of parameters, such as precipitation, temperature or humidity, are illustrated by one heavy precipitation case study that occurred over the south of Spain.

  17. TIME DELAYS IN QUASI-PERIODIC PULSATIONS OBSERVED DURING THE X2.2 SOLAR FLARE ON 2011 FEBRUARY 15

    SciTech Connect

    Dolla, L.; Marque, C.; Seaton, D. B.; Dominique, M.; Berghmans, D.; Cabanas, C.; De Groof, A.; Verdini, A.; West, M. J.; Zhukov, A. N.; Van Doorsselaere, T.; Schmutz, W.; Zender, J.

    2012-04-10

    We report observations of quasi-periodic pulsations (QPPs) during the X2.2 flare of 2011 February 15, observed simultaneously in several wavebands. We focus on fluctuations on timescale 1-30 s and find different time lags between different wavebands. During the impulsive phase, the Reuven Ramaty High Energy Solar Spectroscopic Imager channels in the range 25-100 keV lead all the other channels. They are followed by the Nobeyama RadioPolarimeters at 9 and 17 GHz and the extreme-ultraviolet (EUV) channels of the Euv SpectroPhotometer (ESP) on board the Solar Dynamic Observatory. The zirconium and aluminum filter channels of the Large Yield Radiometer on board the Project for On-Board Autonomy satellite and the soft X-ray (SXR) channel of ESP follow. The largest lags occur in observations from the Geostationary Operational Environmental Satellite, where the channel at 1-8 A leads the 0.5-4 A channel by several seconds. The time lags between the first and last channels is up to Almost-Equal-To 9 s. We identified at least two distinct time intervals during the flare impulsive phase, during which the QPPs were associated with two different sources in the Nobeyama RadioHeliograph at 17 GHz. The radio as well as the hard X-ray channels showed different lags during these two intervals. To our knowledge, this is the first time that time lags are reported between EUV and SXR fluctuations on these timescales. We discuss possible emission mechanisms and interpretations, including flare electron trapping.

  18. A few minor suggestions.

    PubMed

    Michael, J; Clark, J W

    2001-05-01

    We agree with almost all of the analysis in this excellent presentation of the molecular view of avoidance behavior. A few suggestions are made as follows: Referring to response-generated stimuli as ''readily observable" seems not quite right for the kinesthetic components of such stimuli, although their scientific legitimacy is not questioned. Interpreting response-generated stimuli as a form of positive reinforcement is contested, and an alternative interpretation is offered. A possibly simpler interpretation of the Sidman (1962) two-lever experiment is suggested. We question Dinsmoor's (2001) explanation for warning stimuli not being avoided, except for the reference to the weakness of third-order conditioning effects. A final question is raised regarding the nature of the variables that are responsible for the momentary evocation of the avoidance response. PMID:11453627

  19. The quasi-biennial periodicity (QBP) in velocity and intensity helioseismic observations. The seismic QBP over solar cycle 23

    NASA Astrophysics Data System (ADS)

    Simoniello, R.; Finsterle, W.; Salabert, D.; Garca, R. A.; Turck-Chize, S.; Jimnez, A.; Roth, M.

    2012-03-01

    Aims: We looked for signatures of quasi-biennial periodicity (QBP) over different phases of solar cycle by means of acoustic modes of oscillation. Low-degree p-mode frequencies are shown to be sensitive to changes in magnetic activity due to the global dynamo. Recently there has been reported evidence of two-year variations in p-mode frequencies. Methods: Long high-quality helioseismic data are provided by BiSON (Birmingham Solar Oscillation Network), GONG (Global Oscillation Network Group), GOLF (Global Oscillation at Low Frequency) and VIRGO (Variability of Solar IRradiance and Gravity Oscillation) instruments. We determined the solar cycle changes in p-mode frequencies for spherical degree ? = 0, 1, 2 with their azimuthal components in the frequency range 2.5 mHz ? ? ? 3.5 mHz. Results: We found signatures of QBP at all levels of solar activity in the modes more sensitive to higher latitudes. The signal strength increases with latitude and the equatorial component also seems to be modulated by the 11-year envelope. Conclusions: The persistent nature of the seismic QBP is not observed in the surface activity indices, where mid-term variations are found only from time to time and mainly in periods of high activity. This feature, together with the latitudinal dependence, provides more evidence of a mechanism that is almost independent and different from the one that brings the active regions up to the surface. Therefore, these findings can be used to provide more constraints on dynamo models that consider a further cyclic component on top of the 11-year cycle.

  20. Observations of Atmospheric Nitrogen and Phosphorus Deposition During the Period of Algal Bloom Formation in Northern Lake Taihu, China

    NASA Astrophysics Data System (ADS)

    Zhai, Shuijing; Yang, Longyuan; Hu, Weiping

    2009-09-01

    Cyanobacterial blooms in Lake Taihu occurred at the end of April 2007 and had crucial impacts on the livelihood of millions of people living there. Excessive nutrients may promote bloom formation. Atmospheric nitrogen (N) and phosphorus (P) deposition appears to play an important role in algal bloom formation. Bulk deposition and rain water samples were collected respectively from May 1 to November 30, 2007, the period of optimal algal growth, to measure the bulk atmospheric deposition rate, wet deposition rate, and dry deposition rate for total nitrogen (TN; i.e., all species of nitrogen), and total phosphorus (TP; i.e., all species of phosphorus), in northern Lake Taihu, China. The trends of the bulk atmospheric deposition rate for TN and the wet deposition rate for TN showed double peaks during the observation period and distinct influence with plum rains and typhoons. Meanwhile, monthly bulk atmospheric deposition rates for TP showed little influence of annual precipitation. However, excessive rain may lead to high atmospheric N and P deposition rates. In bulk deposition samples, the average percentage of total dissolved nitrogen accounting for TN was 91.2% and changed little with time. However, the average percentage of total dissolved phosphorus accounting for TP was 65.6% and changed substantially with time. Annual bulk atmospheric deposition rates of TN and TP during 2007 in Lake Taihu were estimated to be 2,976 and 84 kg km-2 a-1, respectively. The results showed decreases of 34.4% and 78.7%, respectively, compared to 2002-2003. Annual bulk deposition load of TN for Lake Taihu was estimated at 6,958 t a-1 in 2007 including 4,642 t a-1 of wet deposition, lower than the values obtained in 2002-2003. This may be due to measures taken to save energy and emission control regulations in the Yangtze River Delta. Nevertheless, high atmospheric N and P deposition loads helped support cyanobacterial blooms in northern Lake Taihu during summer and autumn, the period of favorable algal growth.

  1. chelle diagrams and period spacings of g modes in ? Doradus stars from four years of Kepler observations

    NASA Astrophysics Data System (ADS)

    Bedding, Timothy R.; Murphy, Simon J.; Colman, Isabel L.; Kurtz, Donald W.

    2015-09-01

    We use photometry from the Kepler Mission to study oscillations in ? Do radus stars. Some stars show remarkably clear sequences of g modes and we use period chelle diagrams to measure period spacings and identify rotationally split multiplets with ? = 1 and ? = 2. We find small deviations from regular period spacings that arise from the gradient in the chemical composition just outside the convective core. We also find stars for which the period spacing shows a strong linear trend as a function of period, consistent with relatively rapid rotation. Overall, the results indicate it will be possible to apply asteroseismology to a range of ? Dor stars.

  2. Comparisons of observed and modeled OH and HO2 concentrations during the ambient measurement period of the HOxComp field campaign

    NASA Astrophysics Data System (ADS)

    Kanaya, Y.; Hofzumahaus, A.; Dorn, H.-P.; Brauers, T.; Fuchs, H.; Holland, F.; Rohrer, F.; Bohn, B.; Tillmann, R.; Wegener, R.; Wahner, A.; Kajii, Y.; Miyamoto, K.; Nishida, S.; Watanabe, K.; Yoshino, A.; Kubistin, D.; Martinez, M.; Rudolf, M.; Harder, H.

    2012-04-01

    A photochemical box model constrained by ancillary observations was used to simulate OH and HO2 concentrations for three days of ambient observations during the HOxComp field campaign held in Jülich, Germany in July 2005. Daytime OH levels observed by four instruments were fairly well reproduced to within 33% by a base model run (Regional Atmospheric Chemistry Mechanism with updated isoprene chemistry adapted from Master Chemical Mechanism ver. 3.1) with high R2 values (0.72-0.97) over a range of isoprene (0.3-2 ppb) and NO (0.1-10 ppb) mixing ratios. Daytime HO2(*) levels, reconstructed from the base model results taking into account the sensitivity toward speciated RO2 (organic peroxy) radicals, as recently reported from one of the participating instruments in the HO2 measurement mode, were 93% higher than the observations made by the single instrument. Adding isomerization of isoprene peroxy radicals to the model increased OH and HO2(*) by 28% and 13% on average. Although these are still only 4% higher than the OH observations made by one of the instruments, larger overestimations (42-70%) occurred with respect to the OH observations made by the other three instruments. These model runs tend to underestimate observed OH reactivity which may be explained by unmeasured hydrocarbon species. In the base run, the good agreement for the OH levels was retained when four different types of hydrocarbons were added as mixture to explain the missing OH reactivity. In the model run with isomerization of isoprene peroxy radicals, on the other hand, OH levels agreed to the ensemble of observations only when unmeasured anthropogenic hydrocarbons was added at implausibly high concentrations, implying that the rates of the isomerization were not readily supported by the ensemble of radical observations. The overprediction of the HO2(*) levels by the model occurred independently of the inclusion of the isoprene isomerization scheme, indicating that more loss processes for peroxy radicals were necessary to explain the observations. One of the measurement days was characterized by low isoprene concentrations (~0.5 ppb) and OH reactivity that was well explained by the observed species, especially before noon. For this selected period, as opposed to the general behavior, the model tended to underestimate HO2(*). We found that this tendency is associated with high NOx concentrations, suggesting that some HO2 production or regeneration processes under high NOx conditions were being overlooked; this might require revision of ozone production regimes.

  3. Hypnosis, suggestion, and suggestibility: an integrative model.

    PubMed

    Lynn, Steven Jay; Laurence, Jean-Roch; Kirsch, Irving

    2015-01-01

    This article elucidates an integrative model of hypnosis that integrates social, cultural, cognitive, and neurophysiological variables at play both in and out of hypnosis and considers their dynamic interaction as determinants of the multifaceted experience of hypnosis. The roles of these variables are examined in the induction and suggestion stages of hypnosis, including how they are related to the experience of involuntariness, one of the hallmarks of hypnosis. It is suggested that studies of the modification of hypnotic suggestibility; cognitive flexibility; response sets and expectancies; the default-mode network; and the search for the neurophysiological correlates of hypnosis, more broadly, in conjunction with research on social psychological variables, hold much promise to further understanding of hypnosis. PMID:25928681

  4. Combined ligand-observe 19F and protein-observe 15N,1H-HSQC NMR suggests phenylalanine as the key ?-somatostatin residue recognized by human protein disulfide isomerase

    PubMed Central

    Richards, Kirsty L.; Rowe, Michelle L.; Hudson, Paul B.; Williamson, Richard A.; Howard, Mark J.

    2016-01-01

    Human protein disulphide isomerase (hPDI) is an endoplasmic reticulum (ER) based isomerase and folding chaperone. Molecular detail of ligand recognition and specificity of hPDI are poorly understood despite the importance of the hPDI for folding secreted proteins and its implication in diseases including cancer and lateral sclerosis. We report a detailed study of specificity, interaction and dissociation constants (Kd) of the peptide-ligand ?-somatostatin (AGSKNFFWKTFTSS) binding to hPDI using 19F ligand-observe and 15N,1H-HSQC protein-observe NMR methods. Phe residues in ?-somatostatin are hypothesised as important for recognition by hPDI therefore, step-wise peptide Phe-to-Ala changes were progressively introduced and shown to raise the Kd from 103?+?47??M until the point where binding was abolished when all Phe residues were modified to Ala. The largest step-changes in Kd involved the F11A peptide modification which implies the C-terminus of ?-somatostatin is a prime recognition region. Furthermore, this study also validated the combined use of 19F ligand-observe and complimentary 15N,1H-HSQC titrations to monitor interactions from the proteins perspective. 19F ligand-observe NMR was ratified as mirroring 15N protein-observe but highlighted the advantage that 19F offers improved Kd precision due to higher spectrum resolution and greater chemical environment sensitivity. PMID:26786784

  5. Combined ligand-observe (19)F and protein-observe (15)N,(1)H-HSQC NMR suggests phenylalanine as the key ?-somatostatin residue recognized by human protein disulfide isomerase.

    PubMed

    Richards, Kirsty L; Rowe, Michelle L; Hudson, Paul B; Williamson, Richard A; Howard, Mark J

    2016-01-01

    Human protein disulphide isomerase (hPDI) is an endoplasmic reticulum (ER) based isomerase and folding chaperone. Molecular detail of ligand recognition and specificity of hPDI are poorly understood despite the importance of the hPDI for folding secreted proteins and its implication in diseases including cancer and lateral sclerosis. We report a detailed study of specificity, interaction and dissociation constants (Kd) of the peptide-ligand ?-somatostatin (AGSKNFFWKTFTSS) binding to hPDI using (19)F ligand-observe and (15)N,(1)H-HSQC protein-observe NMR methods. Phe residues in ?-somatostatin are hypothesised as important for recognition by hPDI therefore, step-wise peptide Phe-to-Ala changes were progressively introduced and shown to raise the Kd from 103?+?47??M until the point where binding was abolished when all Phe residues were modified to Ala. The largest step-changes in Kd involved the F11A peptide modification which implies the C-terminus of ?-somatostatin is a prime recognition region. Furthermore, this study also validated the combined use of (19)F ligand-observe and complimentary (15)N,(1)H-HSQC titrations to monitor interactions from the protein's perspective. (19)F ligand-observe NMR was ratified as mirroring (15)N protein-observe but highlighted the advantage that (19)F offers improved Kd precision due to higher spectrum resolution and greater chemical environment sensitivity. PMID:26786784

  6. Comparison of Columnar Water Vapor Measurements During The Fall 1997 ARM Intensive Observation Period: Solar Transmittance Methods

    NASA Technical Reports Server (NTRS)

    Schmid, B.; Michalsky, J. J.; Slater, D. W.; Barnard, J. C.; Halthore, R. N.; Liljegren, J. C.; Holben, B. N.; Eck, T. F.; Livingston, J. M.; Russell, P. B.

    2000-01-01

    In the fall of 1997, during an Intensive Observation Period (IOP), the Atmospheric Radiation Measurement (ARM) program conducted a study of water vapor abundance measurement at its Southern Great Plains (SGP) site. Among a large number of instruments, four sun-tracking radiometers were present to measure the columnar water vapor (CWV). All four solar radiometers retrieve CWV by measuring total solar transmittance in the 0.94-gm water vapor absorption band and subtracting contributions due to Rayleigh, ozone and aerosol transmittances. The aerosol optical depth comparisons among the same four radiometers has been presented elsewhere (Geophys. Res. Lett., 26, 17, 2725-2728, 1999). We have used three different methods to retrieve CWV. In a first round of comparison no attempt was made to standardize on the same radiative transfer model and its underlying water vapor spectroscopy. In the second round of comparison we used the same line-by-line code (which includes recently corrected H2O spectroscopy) to retrieve CAN from all four suntracking radiometers. This decreased the mean CWV by 8% or 13%. The spread of 8% in the solar radiometer results found when using the same model is an indication of the other-than-model uncertainties involved in determining CWV from solar transmittance measurements with current instrumentation.

  7. Changes of duplex parameters and splenic size in liver transplant recipients during a long period of observation

    PubMed Central

    Boozari, Bita; Gebel, Michael; Bahr, Mathias J; Manns, Michael P; Strassburg, Christian P; Bleck, Joerg S; Klempnauer, J; Nashan, Bjoern

    2005-01-01

    AIM: To assess the changes of portal and arterial velocities, resistance index, spleen and liver size during a long observation period (13.7 years) after orthotopic liver transplantation (OLT). METHODS: Two hundred and sixty patients were recruited retrospectively for this study and divided into groups with defined time intervals after OLT. The cross-sectional changes of portal and arterial velocities, resistance index, spleen and liver size between the defined time intervals were studied. The complications detected by ultrasound were compared to gold standard methods. RESULTS: The mean values for liver size were all within the normal range. The splenic size decreased between the time intervals 100 and 1 000 d after OLT (t; P<0.01). While portal and arterial flow velocities decreased up to 5.5 years (t; portal velocity P<0.01, maximal systolic velocity P = 0.05, maximal end diastolic velocity P<0.01), RI increased during this interval (t: P<0.01). Higher RI values were found in older patients (r = 0.24, P<0.001). CONCLUSION: The arterial and portal velocities show adaptation processes continuing over the course of many years after OLT and are reported for the first time. The vascular complications detected by ultrasound occur mostly up to 100 d after OLT. PMID:16425385

  8. The features of sporadic hyperbolic meteors observed by television techniques in the period of 2007-2009

    NASA Astrophysics Data System (ADS)

    Guliyev, Ayyub; Nabiyev, Shaig

    2015-12-01

    The features of 238 hyperbolic meteors observed within the framework of the Japanese program SonotaCo in the period of 2007-2009 are investigated in this paper. Irregularity of the eccentricities, explicitly dominance of retrograde orbits over direct ones, absence of domination of perihelia closes the ecliptic, irregular distribution of angular elements for these bodies' orbits were noticed. The values of eccentricities are distributed in the interval from 1 up to 1.31. The significant concentration of these particles perihelia closes the anti-apex of the Sun's peculiarity movements in the Galaxy was noticed. Distribution of elements of orbits in the galactic system of coordinates was considered also, however it was not possible to find the appreciable regularities. The distributions of the distant nodes and MOID-Minimum Orbit Intersection Distance of the hyperbolic meteors relatively to the orbits of the planets-giants were investigated as well. However it was not possible to prove, that the majority of the particles could receive the hyperbolic excess of speed due to the gravitational influence of the planets-giants. The statistics of relation of the hyperbolic meteors with 14 known trans-Neptunian planetary bodies brighter 3m.5 is considered. Testing of the distant nodes and MOID values only for 2003 MW12, 2007 OR10 and Qaoaor have the positive results. In the next stage we have made analogical calculations for the 78 TNO having absolute brightness 5m.5 also and obtained the reasonable results for 9 of them.

  9. The HyMeX Special Observation Period in Central Italy: Precipitation Measurements, Retrieval Techniques and Preliminary Results

    NASA Technical Reports Server (NTRS)

    Gatlin, Patrick; Wingo, Matt; Petersen, Walt; Marzano, Frank Silvio; Baldini, Luca; Picciotti, Errico; Colantonio, Matteo; Barbieri, Stefano; Di Fabio, Saverio; Montopoli, Mario; Roberto, Nicoletta; Adirosi, Elisa; Gorgucci, Eugenio; Anagnostou, Emmanoil N..; Ferretti, Rossella

    2013-01-01

    The Mediterranean area concentrates the major natural risks related to the water cycle, including heavy precipitation and flash-flooding during the fall season. The capability to predict such high-impact events remains weak because of the contribution of very fine-scale processes and their non-linear interactions with the larger scale processes. These societal and science issues motivate the HyMeX (Hydrological cycle in the Mediterranean Experiment, http://www.hymex.orgl) experimental programme. HyMeX aims at a better quantification and understanding of the water cycle in the Mediterranean with emphasis on intense events. The observation strategy of HyMEX is organized in a long-term (4 years) Enhanced Observation Periods (EOP) and short-term (2 months) Special Observation Periods (SOP). HyMEX has identified 3 main Mediterranean target areas: North-West (NW), Adriatic (A) and South-East (SE). Within each target area several hydrometeorological sites for heavy rainfall and flash flooding have been set up. The hydrometeorological sire in Central Italy (CI) is interested by both western and eastern fronts coming from the Atlantic Ocean and Siberia, respectively. Orographic precipitations play an important role due to the central Apennine range, which reaches nearly 3000 m (Gran Sasso peak). Moreover, convective systems commonly develop in CI during late summer and beginning of autumn, often causing localized hailstorms with cluster organized cells. Western fronts may heavily hit the Tiber basin crossing large urban areas (Rome), whereas eastern fronts can cause flash floods along the Adriatic coastline. Two major basins are involved within Cl region: Tiber basin (1000 km long) and its tributary Aniene and the Aterno-Pescara basin (300 km long). The first HyMeX SOP1.1 was carried out from Sept. till Nov. 2012 in the NW target area The Italian SOP1.1 was coordinated by the Centre of Excellence CETEMPS, University of L'Aquila, a city located in the CI heart. The CI area was covered by a uniquely dense meteorological instrumentation thanks to a synergy between Italian institutions and NASA-GSFC. The following RADARs were operated: a Doppler single-polarization C-band radar located at Mt Midia; the Polar 55C Doppler dual-polarization C-band radar located in Rome; a Doppler C-hand polarimetric radar located at Il Monte (Abnazo); a polarimetric X-band mini-radar in L' Aquila; a polarimetric X-hand portable mini-radar in Rome; a single-polarization X-band mini-radar in Rome. DISDROMETERs were also deployed: 4 Parsivel optical disdrometers in Rome (at Sapienza, CNR-ISAC and CNR-INSEAN); 1 2D-video disdrometer in Rome; 3 Parsivels optical disdrometer respectively in L'Aquila (Abnazo), Avezzano (Abruzzo) and Pescara (Abnazo). Other INSTRUMENTS were available: 1 K-band vertically-pointing micro rain-radar (MRR), 2 Pludix X-band disdrometers, 1 VLF lightning sensor, 1 microwave radiometer at 23-31 GHz in Rome (at Sapienza); the raingauge network with more than 200 stations in Central Italy. Three overpasses in CI were also performed by the Falcon 20 aircraft equipped with the 950Hz cloud radar RASTA Analysis of the SOP1.1 main events in CI will be described by focusing on the raindrop size distribution statistics and its geographical variability. Intercomparison of rainfall estimates from disdrometers, raingauges and radars will be illustrated with the aim to provide a quality-controlled and physically consistent rainfall dataset for meteorological modeling validation and assimilation purposes.

  10. Trends and projections of temperature, precipitation, and snow cover during snow cover-observed period over southwestern Iran

    NASA Astrophysics Data System (ADS)

    Zarenistanak, Mohammad; Dhorde, Amit G.; Kripalani, R. H.; Dhorde, Anargha A.

    2015-11-01

    In the present study, tendencies in temperature, precipitation, and snow cover area over the southwestern part of Iran have been assessed. The research mainly focused on snow cover-observed period which included the months of December, January, February, March, and April in the area. This research has been divided into two parts. First part consists of an analysis of the trends in temperature, precipitation, and snow cover area during the above months. Trends in these parameters were tested by linear regression, and significance was determined by t test. Mann-Kendall rank test (MK test) was also employed to confirm the results of linear regression. Sequential Mann-Kendall test (SQ-MK test) was applied for change point detection in the series. For snow cover analysis, remote sensing images from National Oceanic and Atmospheric Administration (NOAA) satellite with advanced very high resolution radiometer (AVHRR) sensor for the period 1987-2007 were used. The second part of the research involved future projections based on four models under B1 and A1B emission scenarios. The models used were centre national de recherches meteorologiques (CNRM), European Center Hamburg model (ECHAM), Model for Interdisciplinary Research on Climate (MIROCH) and United Kingdom Meteorological Office (UKMOC) under the Intergovernmental Panel on Climate Change (IPCC) AR4. The analysis of temperature trends revealed a significant increase during February and April. Temperature projections showed that temperature may increase between 1.12 to 7.87 °C by 2100 in the study area. The results of precipitation series indicated that majority of the stations registered insignificant trends during the twentieth century. However, precipitation may decrease according to most of the models under both scenarios, but the decrease may not be large, except according to MIROCH model. The results of trend analysis of snow cover area indicated that no significant trends were detected by any statistical tests at 95 % confidence level during the twentieth century. Snow cover projection showed that snow cover area may decrease as indicated by all the models under both scenarios at the end of twenty-first century consistent with the projected increase in temperature.

  11. Observation of Fano resonance using a coupled resonator metamaterial composed of meta-atoms arranged by double periodicity

    NASA Astrophysics Data System (ADS)

    Nishida, Tsubasa; Nakata, Yosuke; Miyamaru, Fumiaki; Nakanishi, Toshihiro; Takeda, Mitsuo W.

    2016-01-01

    We studied the transmission characteristics of a planar metamaterial consisting of an array of electric split-ring resonators (eSRRs) with double periodicity. Because of coupling between different resonant modes induced by different lattice periods in metamaterials with double periodicity, the appearance of Fano resonance can be expected in the same manner as that in the case of coupled classical oscillators. We fabricated complementary eSRRs and verified that a Fano-like spectral shape appeared in the transmission spectra of eSRRs with double periodicity in the terahertz region.

  12. Pulsations and period changes of the non-Blazhko RR lyrae variable Y oct observed from Dome A, Antarctica

    SciTech Connect

    Zhihua, Huang; Jianning, Fu; Weikai, Zong; Lingzhi, Wang; Zonghong, Zhu; M, Macri Lucas; Lifan, Wang; Ashley, Michael C. B.; S, Lawrence Jon; Daniel, Luong-Van; Xiangqun, Cui; Long-Long, Feng; Xuefei, Gong; Qiang, Liu; Huigen, Yang; Xiangyan, Yuan; Xu, Zhou; Zhenxi, Zhu; R, Pennypacker Carl; G, York Donald

    2015-01-01

    During the operation of the Chinese Small Telescope Array (CSTAR) in Dome A of Antarctica in the years 2008, 2009, and 2010, large amounts of photometric data have been obtained for variable stars in the CSTAR field. We present here the study of one of six RR Lyrae variables, Y Oct, observed with CSTAR in Dome A, Antarctica. Photometric data in the i band were obtained in 2008 and 2010, with a duty cycle (defined as the fraction of time representing scientifically available data to CSTAR observation time) of about 44% and 52%, respectively. In 2009, photometric data in the g and r bands were gathered for this star, with a duty cycle of 65% and 60%, respectively. Fourier analysis of the data in the three bands only shows the fundamental frequency and its harmonics, which is characteristic of the non-Blazhko RR Lyrae variables. Values of the fundamental frequency and the amplitudes, as well as the total pulsation amplitude, are obtained from the data in the three bands separately. The amplitude of the fundamental frequency and the total pulsation amplitude in the g band are the largest, and those in the i band the smallest. Two-hundred fifty-one times of maximum are obtained from the three seasons of data, which are analyzed together with 38 maximum times provided in the GEOS RR Lyrae database. A period change rate of −0.96 ± 0.07 days Myr{sup −1} is then obtained, which is a surprisingly large negative value. Based on relations available in the literature, the following physical parameters are derived: [Fe/H] = −1.41 ± 0.14, M{sub V} = 0.696 ± 0.014 mag, V−K = 1.182 ± 0.028 mag, logT{sub eff} = 3.802 ± 0.003 K, logg = 2.705 ± 0.004, logL/L{sub ⊙} = 1.625 ± 0.013, and logM/M{sub ⊙} = −0.240 ± 0.019.

  13. Estimating Asian terrestrial carbon fluxes from CONTRAIL aircraft and surface CO2 observations for the period 2006-2010

    NASA Astrophysics Data System (ADS)

    Zhang, H. F.; Chen, B. Z.; Machida, T.; Matsueda, H.; Sawa, Y.; Fukuyama, Y.; Langenfelds, R.; van der Schoot, M.; Xu, G.; Yan, J. W.; Cheng, M. L.; Zhou, L. X.; Tans, P. P.; Peters, W.

    2014-06-01

    Current estimates of the terrestrial carbon fluxes in Asia show large uncertainties particularly in the boreal and mid-latitudes and in China. In this paper, we present an updated carbon flux estimate for Asia ("Asia" refers to lands as far west as the Urals and is divided into boreal Eurasia, temperate Eurasia and tropical Asia based on TransCom regions) by introducing aircraft CO2 measurements from the CONTRAIL (Comprehensive Observation Network for Trace gases by Airline) program into an inversion modeling system based on the CarbonTracker framework. We estimated the averaged annual total Asian terrestrial land CO2 sink was about -1.56 Pg C yr-1 over the period 2006-2010, which offsets about one-third of the fossil fuel emission from Asia (+4.15 Pg C yr-1). The uncertainty of the terrestrial uptake estimate was derived from a set of sensitivity tests and ranged from -1.07 to -1.80 Pg C yr-1, comparable to the formal Gaussian error of 1.18 Pg C yr-1 (1-sigma). The largest sink was found in forests, predominantly in coniferous forests (-0.64 0.70 Pg C yr-1) and mixed forests (-0.14 0.27 Pg C yr-1); and the second and third large carbon sinks were found in grass/shrub lands and croplands, accounting for -0.44 0.48 Pg C yr-1 and -0.20 0.48 Pg C yr-1, respectively. The carbon fluxes per ecosystem type have large a priori Gaussian uncertainties, and the reduction of uncertainty based on assimilation of sparse observations over Asia is modest (8.7-25.5%) for most individual ecosystems. The ecosystem flux adjustments follow the detailed a priori spatial patterns by design, which further increases the reliance on the a priori biosphere exchange model. The peak-to-peak amplitude of inter-annual variability (IAV) was 0.57 Pg C yr-1 ranging from -1.71 Pg C yr-1 to -2.28 Pg C yr-1. The IAV analysis reveals that the Asian CO2 sink was sensitive to climate variations, with the lowest uptake in 2010 concurrent with a summer flood and autumn drought and the largest CO2 sink in 2009 owing to favorable temperature and plentiful precipitation conditions. We also found the inclusion of the CONTRAIL data in the inversion modeling system reduced the uncertainty by 11% over the whole Asian region, with a large reduction in the southeast of boreal Eurasia, southeast of temperate Eurasia and most tropical Asian areas.

  14. Results from two studies in seismology: I. Seismic observations and modeling in the Santa Clara Valley, California. II. Observations and removal of the long-period noise at the Monterey ocean bottom broadband station (MOBB)

    NASA Astrophysics Data System (ADS)

    Dolenc, David

    2006-12-01

    Results from two projects are presented in this work. Following brief introductory Chapter 1 that provides general background, Chapter 2 describes the influence of the Santa Clara Valley (SCV) basin structure on the propagation of teleseismic waves. Teleseismic P-waves recorded during the 1998 deployment of the 41-station seismic array are used in the analysis. Observations are compared to synthetics computed by 3D finite-difference simulations using the University of California, Berkeley (UCB) and the U.S. Geological Survey (USGS) 3D velocity models. Chapter 3 includes further study of the ground-motion amplification in the SCV using microseisms recorded by the SCV seismic array in 1998. The obtained results are compared to the local earthquake amplification. Chapter 4 presents results of the 3D simulations using the most recent version of the USGS velocity model for the greater San Francisco Bay Area. Results are compared to 1998 SCV seismic array observations and to simulations presented in Chapter 2. Results presented in Chapters 2 to 4 all show strong correlations between basin depth reported in the USGS 3D seismic velocity model and different relative measures of ground motion parameters. The teleseismic, local earthquake and microseism observations are also found to be strongly correlated with one another. Since the results suggest that all three datasets are sensitive to the basin structure, they can be used to improve the 3D velocity model. I started to develop a simultaneous inversion of the teleseismic, local, and microseism observations to refine the seismic velocity model. Chapter 5 presents preliminary results and future plans. Results from the second project are included in Chapters 6 to 9. Chapter 6 provides information about the Monterey ocean bottom broadband seismic station (MOBB). It explains why seismology is moving into the oceans, describes the MOBB location, provides details about the instruments that comprise the MOBB, and describes the deployment. Examples of data and preliminary analysis are also included. Chapter 7 presents observations of infragravity waves at MOBB. Combined with the information from the ocean buoys, the MOBB data show that the infragravity waves in the longer than 20 s period band are mainly locally generated from shorter-period ocean waves. Two types of the observed infragravity band signal modulation are presented and possible mechanisms for the modulation are discussed. Also included is the analysis of the ocean bottom seismic data from the temporary Oregon ULF/VLF deployment that also indicates that the infragravity waves are primarily locally generated. Chapter 8 describes analysis of data from another ocean bottom station. KEBB is located offshore Washington, in deeper water and further offshore than MOBB. Results suggests that in this case the infragravity waves are generated from shorter period ocean waves in the coastal region and not locally at KEBB. Chapter 9 focuses on the removal of the long-period background as well as signal-generated noise from the MOBB data. Methods used to improve signal-to-noise ratio for the ocean bottom seismic data are presented.

  15. What Are the Trends in Tonsillectomy Techniques in Wales? A Prospective Observational Study of 19,195 Tonsillectomies over a 10-Year Period

    PubMed Central

    Walijee, Hussein; Al-Hussaini, Ali; Harris, Andrew; Owens, David

    2015-01-01

    There are a multitude of techniques to undertake tonsillectomy, with hot techniques such as diathermy and coblation being associated with a higher risk of secondary haemorrhage. The UK National Prospective Tonsillectomy Audit (2004) advocated cold steel dissection and ties to be the gold standard. This prospective observational study investigates the trends in tonsillectomy techniques across Wales in the last decade to establish if surgeons have adhered to this national guidance. Data relating to tonsillectomy were extracted over a 10-year period from 1 January 2003 to 31 December 2012 from the Wales Surgical Instrument Surveillance Programme database. A total of 19,195 patients were included. Time-series analysis using linear regression showed there was an increase in the number of bipolar diathermy tonsillectomies by 84% (Pearson's r = 0.762, p = 0.010) and coblation tonsillectomies by 120% (r = 0.825, p = 0.003). In contrast, there was a fall in the number of cold steel dissection tonsillectomies with ties by 60% (r = −0.939, p < 0.001). This observational study suggests that the use of bipolar and coblation techniques for tonsillectomy has increased. This deviation from national guidance may be due to these techniques being faster with less intraoperative bleeding. Further study for the underlying reasons for the increase in these techniques is warranted. PMID:26693228

  16. Stable time patterns of railway suicides in Germany: comparative analysis of 7,187 cases across two observation periods (1995–1998; 2005–2008)

    PubMed Central

    2014-01-01

    Background The majority of fatalities on the European Union (EU) railways are suicides, representing about 60% of all railway fatalities. The aim of this study was to compare time patterns of suicidal behaviour on railway tracks in Germany between two observation periods (1995–1998 and 2005–2008) in order to investigate their stability and value in railway suicide prevention. Methods Cases were derived from the National Central Registry of person accidents on the German railway network (STABAG). The association of daytime, weekday and month with the mean number of suicides was analysed applying linear regression. Potential differences by observation period were assessed by adding observation period and the respective interaction terms into the linear regression. A 95% confidence interval for the mean number of suicides was computed using the t distribution. Results A total of 7,187 railway suicides were recorded within both periods: 4,102 (57%) in the first period (1995–1998) and 3,085 (43%) in the second (2005–2008). The number of railway suicides was highest on Mondays and Tuesdays in the first period with an average of 3.2 and 3.5 events and of 2.6 events on both days in the second period. In both periods, railway suicides were more common between 6:00 am and noon, and between 6:00 pm and midnight. Seasonality was only prominent in the period 1995–1998. Conclusions Over the course of two observation periods, the weekday and circadian patterns of railway suicides remained stable. Therefore, these patterns should be an integral part of railway suicide preventive measures, e.g. gatekeeper training courses. PMID:24498876

  17. Estimating Asian terrestrial carbon fluxes from CONTRAIL aircraft and surface CO2 observations for the period 2006 to 2010

    NASA Astrophysics Data System (ADS)

    Zhang, H. F.; Chen, B. Z.; van der Laan-Luijkx, I. T.; Machida, T.; Matsueda, H.; Sawa, Y.; Fukuyama, Y.; Labuschagne, C.; Langenfelds, R.; van der Schoot, M.; Xu, G.; Yan, J. W.; Zhou, L. X.; Tans, P. P.; Peters, W.

    2013-10-01

    Current estimates of the terrestrial carbon fluxes in Asia ("Asia" refers to lands as far west as the Urals and is divided into Boreal Eurasia, Temperate Eurasia and tropical Asia based on TransCom regions) show large uncertainties particularly in the boreal and mid-latitudes and in China. In this paper, we present an updated carbon flux estimate for Asia by introducing aircraft CO2 measurements from the CONTRAIL (Comprehensive Observation Network for Trace gases by Airline) program into an inversion modeling system based on the CarbonTracker framework. We estimated the averaged annual total Asian terrestrial land CO2 sink was about -1.56 Pg C yr-1 over the period 2006-2010, which offsets about one-third of the fossil fuel emission from Asia (+4.15 Pg C yr-1). The uncertainty of the terrestrial uptake estimate was derived from a set of sensitivity tests and ranged from -1.07 to -1.80 Pg C yr-1, comparable to the formal Gaussian error of 1.18 Pg C yr-1 (1-sigma). The largest sink was found in forests, predominantly in coniferous forests (-0.64 Pg C yr-1) and mixed forests (-0.14 Pg C yr-1); and the second and third large carbon sinks were found in grass/shrub lands and crop lands, accounting for -0.44 Pg C yr-1 and -0.20 Pg C yr-1, respectively. The peak-to-peak amplitude of inter-annual variability (IAV) was 0.57 Pg C yr-1 ranging from -1.71 Pg C yr-1 to -2.28 Pg C yr-1. The IAV analysis reveals that the Asian CO2 sink was sensitive to climate variations, with the lowest uptake in 2010 concurrent with summer flood/autumn drought and the largest CO2 sink in 2009 owing to favorable temperature and plentiful precipitation conditions. We also found the inclusion of the CONTRAIL data in the inversion modeling system reduced the uncertainty by 11% over the whole Asian region, with a large reduction in the southeast of Boreal Eurasia, southeast of Temperate Eurasia and most Tropical Asian areas.

  18. Dynamics of CO2-exchange and C-budgets due to soil erosion: Insights from a 4 years observation period

    NASA Astrophysics Data System (ADS)

    Hoffmann, Mathias; Albiac Borraz, Elisa; Garcia Alba, Juana; Augustin, Jürgen; Sommer, Michael

    2015-04-01

    Agriculture in the hummocky ground moraine landscape of NE-Germany is characterized by an increase in energy crop cultivation, like maize or sorghum. Both enhance lateral C fluxes by erosion and induce feedbacks on C dynamics of agroecosystems as a result of reduced wintertime plant cover and vigorous crop growth during summer. However, the actual impact of these phenomena on the CO2-sink/-source function of agricultural landscapes, is still not clear. Therefore, the interdisciplinary project "CarboZALF" was established in Dedelow/Prenzlau (NE-Germany) in 2009. Within the field experiment CarboZALF-D, CO2 fluxes for the soil-plant systems were monitored, covering typical landscape relevant soil states in respect to erosion and deposition, like Calcic Cutanic Luvisol and Endogleyic Colluvic Regosol. Automated chamber systems, each consisting of four transparent chambers (2.5 m height, basal area 2.25 m2), were placed along gradients at both measurement sites. Monitored CO2 fluxes were gap-filled on a high-temporal resolution by modelling ecosystem respiration (Reco), gross primary productivity (GPP) and net ecosystem exchange (NEE) based on parallel and continuous measurements of the CO2 exchange, soil and air temperatures as well as photosynthetic active radiation (PAR). Gap-filling was e.g. needed in case of chamber malfunctions and abrupt disturbances by farming practice. The monitored crop rotation was corn-winter wheat (2 a), sorghum-winter triticale and alfalfa (1.5 a). In our presentation we would like to show insights from a 4 years observation period, with prounounced differences between the eroded and the colluvial soil: The Endogleyic Colluvic Regosol showed higher flux rates for Reco, GPP and NEE compared to the Calcic Cutanic Luvisol. Site-specific NEE and C-balances were positively related to soil C-stocks as well as biomass production, and generated a minor C-sink in case of the Calcic Cutanic Luvisol and a highly variable C-source in case of the Endogleyic Colluvic Regosol. Moreover, obtained high local variability in CO2 fluxes and C-balances at both sites, can be interpreted in terms of relevant drivers.

  19. Open to Suggestion.

    ERIC Educational Resources Information Center

    Journal of Reading, 1987

    1987-01-01

    Offers (1) suggestions for improving college students' study skills; (2) a system for keeping track of parent, teacher, and community contacts; (3) suggestions for motivating students using tic tac toe; (4) suggestions for using etymology to improve word retention; (5) a word search grid; and (6) suggestions for using postcards in remedial reading

  20. The Two Complexes of Activity Observed in the Northern Hemisphere during 1982 and the 24-Day Periodicity of Flare Occurrence

    NASA Astrophysics Data System (ADS)

    Ruždjak, V.; Ruždjak, D.; Brajša, R.; Temmer, M.; Hanslmeier, A.

    Daily numbers of solar Hα flares of importance classes ≥ 1 for the northern solar hemisphere in 1982 are studied applying wavelet power spectra (WPS). Special attention is paid to the occurrence of a 24-day period in the WPS. The wavelet power spectra method is combined with synoptic maps of the magnetic fields. Separately, flare indices of two activity complexes mainly contributing to flare occrrence in this period are examined. It is found that the detected 24-day signal in the WPS is mainly a consequence of the presence of the two flare activity complexes separated by about 45° in longitude during several succesive Carrington rotations.

  1. Observations of Periodic Comet 2P/Encke: Physical Properties of the Nucleus and First Visual-Wavelength Detection of Its Dust Trail

    NASA Technical Reports Server (NTRS)

    Lowry, Stephen C.; Weissman, Paul R.; Sykes, Mark V.; Reach, William T.

    2003-01-01

    We are conducting an observational program designed to determine the overall distributions of size, shape, rotation period, and surface characteristics of cometary nuclei. Here, we present results from a study of the Jupiter- family comet 2P/Encke based on observations from Steward Observatory's 2.3m Bok Telescope at Kitt Peak. This comet has been observed extensively in the past and was one of the primary flyby targets of the recently failed CONTOUR mission.

  2. The Life of Suggestions

    ERIC Educational Resources Information Center

    Pearce, Cathie

    2010-01-01

    Using the notion of a suggestion, or rather charting the life of suggestions, this article considers the happenings of chance and embodiment as the "problems that got away." The life of suggestions helps us to ask how connectivities are made, how desire functions, and how "immanence" rather than "transcendence" can open up the politics and ethics

  3. A new high-resolution BOLAM-MOLOCH suite for the SIMM forecasting system: assessment over two HyMeX intense observation periods

    NASA Astrophysics Data System (ADS)

    Mariani, S.; Casaioli, M.; Coraci, E.; Malguzzi, P.

    2015-01-01

    High-resolution numerical models can be effective in monitoring and predicting natural hazards, especially when dealing with Mediterranean atmospheric and marine intense/severe events characterised by a wide range of interacting scales. The understanding of the key factors associated to these Mediterranean phenomena, and the usefulness of adopting high-resolution numerical models in their simulation, are among the aims of the international initiative HyMeX - HYdrological cycle in Mediterranean EXperiment. At the turn of 2013, two monitoring campaigns (SOPs - Special Observation Periods) were devoted to these issues. For this purpose, a new high-resolution BOlogna Limited Area Model-MOdello LOCale (BOLAM-MOLOCH) suite was implemented in the Institute for Environmental Protection and Research (ISPRA) hydro-meteo-marine forecasting system (SIMM - Sistema Idro-Meteo-Mare) as a possible alternative to the operational meteorological component based on the BOLAM model self-nested over two lower-resolution domains. The present paper provides an assessment of this new configuration of SIMM with respect to the operational one that was also used during the two SOPs. More in details, it investigates the forecast performance of these SIMM configurations during two of the Intense Observation Periods (IOPs) declared in the first SOP campaign. These IOPs were characterised by high precipitations and very intense and exceptional high waters over the northern Adriatic Sea (acqua alta). Concerning the meteorological component, the high-resolution BOLAM-MOLOCH forecasts are compared against the lower-resolution BOLAM forecasts over three areas - mostly corresponding to the Italian HyMeX hydrometeorological sites - using the rainfall observations collected in the HyMeX database. Three-month categorical scores are also calculated for the MOLOCH model. Despite the presence of a slight positive bias of the MOLOCH model, the results show that the precipitation forecast turns out to improve with increasing resolution. In both SIMM configurations, the sea storm surge component is based on the same version of the Shallow water HYdrodynamic Finite Element Model (SHYFEM). Hence, it is evaluated the impact of the meteorological forcing provided by the two adopted BOLAM configurations on the SHYFEM forecasts for six tide-gauge stations. A benchmark for this part of the study is given by the performance of the SHYFEM model forced by the ECMWF IFS forecast fields. For this component, both BOLAM-SHYFEM configurations clearly outperform the benchmark. The results are, however, strongly affected by the predictability of the weather systems associated to the IOPs, thus suggesting the opportunity to develop and test a time-lagged multi-model ensemble for the prediction of high storm surge events.

  4. Oscillations of the sun with a period of 159.966 minutes in the Crimean 25-year observations

    NASA Astrophysics Data System (ADS)

    Kotov, V. A.; Khaneychuk, V. I.; Tsap, T. T.

    2000-01-01

    Measurements of low-degree oscillations of the Sun were carried out at the Crimean Astrophysical Observatory during 25 years (1974-1998; in all 1530 days, about 9733 hours). These data showed that within the frequency range near the 9th daily harmonic the most significant oscillation corresponds to the period P1 = 159.9660± 0.0010 min. It agrees well with the main periodicity PSt = 159.9663±0.0014 min found earlier in the similar Doppler measurements of the solar photosphere performed at the Stanford University in 1977-1994. The initial phase of the P1 oscillation is found to be remarkably stable over the entire 25-year interval. This phenomenon cannot be ascribed to some terrestrial cause or to an artifact of the data reduction procedure. It presents a challenging problem for the physics of the Sun and models of its interior structure.

  5. Observations and Modeling of Low Level Moisture Convergence Patterns in the Southern Appalachians during the Integrated Precipitation and Hydrology Experiment (IPHEx) Extended Observing Period

    NASA Astrophysics Data System (ADS)

    Wilson, Anna M.; Barros, Ana P.

    2015-04-01

    Accurate fields of precipitation accumulations and intensity at high spatial resolution in regions of complex terrain are largely unavailable. This is due to first, a lack of existing in situ observations, both because of the challenge in having high enough density in the instrument placement to represent the large spatial heterogeneity in rainfall patterns in these regions and because of the remote, harsh nature of the terrain that makes it difficult to install and maintain instrumentation and second, obstacles to remote sensing such as beam blockage and ground clutter that are caused by the complex orography. In this study we leverage observations from two sources: 1) a high-elevation, high-density tipping bucket rain gauge network that has been recording precipitation observations for over six years along ridgelines in the Pigeon River Basin, a small watershed in the Southern Appalachians, and 2) the 4-D database of observations collected in 2014 in support of the Global Precipitation Mission (GPM) during the first field campaign after the launch of the GPM satellite, the Integrated Precipitation and Hydrology Experiment (IPHEx), to learn about formation and maintenance mechanisms for fog and low cloud in this region and the resulting impact on the precipitation regime. The observations focused on here are those at the near surface, within 2 kilometers of the ground level. This presentation will focus on process-based modeling studies using the Advanced Research Weather and Forecasting Model conducted based upon observations made during this campaign. Case studies will be presented for real events simulated during the IPHEx campaign. These case studies occurred with different synoptic conditions, but include observational evidence of orographic enhancement. The case studies are simulated and analyzed in order to investigate how the topography modulates the regional, diurnal patterns of moisture convergence and fog and low cloud formation, as well as the mid latitude cyclones crossing the region. Enhancement due to pre existing low level moisture is shown to be significant regardless of the strength of the synoptic scale system for the case studies looked at here. Future work will explore in more detail using modeling the formation mechanisms of the near surface moisture.

  6. Observations of the surge-type Black Rapids Glacier, Alaska, during a quiescent period, 1970-92

    USGS Publications Warehouse

    Heinrichs, Thomas A.; Mayo, L.R.; Trabant, D.C.; March, R.S.

    1995-01-01

    This report presents 23 years (1970 to 1992) of observations of Black Rapids Glacier, Alaska. Black Rapids Glacier is a surge-type glacier which most recently surged in 1936-37, and is currently in its quiescent phase. This glacier is of special interest because it is a potential hazard to the trans-Alaska oil pipeline. Ten sites on the glacier were monitored from 1972 to 1987, and three sites were monitored from 1988 to 1992. The measurement program presented here includes observations of surface mass balance, ice velocity, and surface altitude made twice each year. Additional one-time data include observations of ice thickness, previously unreported observations of the 1936-37 surge, establishment of the geodetic control monuments, and a new map of Black Rapids Glacier.

  7. Chemistry Curricula. Course Suggestions.

    ERIC Educational Resources Information Center

    American Chemical Society, Washington, DC.

    Listings of suggested topics aimed at helping university and college faculties plan courses in the main areas of the chemistry curricula are provided. The suggestions were originally offered as appendices to the American Chemical Society's (ACS) Committee on Professional Training's 1983 guidelines for ACS-approved schools. The course data included…

  8. Chemistry Curricula. Course Suggestions.

    ERIC Educational Resources Information Center

    American Chemical Society, Washington, DC.

    Listings of suggested topics aimed at helping university and college faculties plan courses in the main areas of the chemistry curricula are provided. The suggestions were originally offered as appendices to the American Chemical Society's (ACS) Committee on Professional Training's 1983 guidelines for ACS-approved schools. The course data included

  9. Detecting non-sinusoidal periodicities in observational data: the von Mises periodogram for variable stars and exoplanetary transits

    NASA Astrophysics Data System (ADS)

    Baluev, Roman V.

    2013-05-01

    This paper introduces an extension of the linear least-squares (or Lomb-Scargle) periodogram for the case when the model of the signal to be detected is non-sinusoidal and depends on unknown parameters in a non-linear manner. The problem of estimating the statistical significance of candidate periodicities found using such non-linear periodograms is examined. This problem is related to the task of quantifying the distributions of the maximum values of these periodograms. Based on recent results in the mathematical theory of extreme values of a random field (the generalized Rice method), a general approach is provided to find a useful analytic approximation for these distributions. This approximation has the general form e^{-z} P(?{z}), where P is an algebraic polynomial and z is the periodogram maximum. The general tools developed in this paper can be used in a wide variety of astronomical applications, for instance in the study of variable stars and extra-solar planets. With this in mind, we develop and consider in detail the so-called von Mises periodogram - a specialized non-linear periodogram in which the signal is modelled by the von Mises periodic function exp (? cos ?t). This simple function with an additional non-linear parameter ? can model the light curves of many astronomical objects that show various types of periodic photometric variability. We prove that our approach can be perfectly applied to this non-linear periodogram. We provide a package of auxiliary C++ programs, attached as online-only material. These programs should facilitate the use of the von Mises periodogram in practice.

  10. How well does WWLLN reproduce the satellite-observed distribution of flashes during the 2007-2012 time period?

    NASA Astrophysics Data System (ADS)

    Allen, D. J.; Pickering, K. E.; Ring, A.; Holzworth, R. H.

    2013-12-01

    Lightning is the dominant source of nitrogen oxides (NOx) involved in the production of ozone in the middle and upper troposphere in the tropics and in summer in the midlatitudes. Therefore it is imperative that the lightning NOx (LNOx) source strength per flash be better constrained. This process requires accurate information on the location and timing of lightning flashes. In the past fifteen years satellite-based lightning monitoring by the Optical Transient Detector (OTD) and Lightning Imaging Sensor (LIS) has greatly increased our understanding of the global distribution of lightning as a function of season and time-of-day. However, detailed information at higher temporal resolutions is only available for limited regions where ground-based networks such as the United States National Lightning Detection Network (NLDN) exist. In 2004, the ground-based World Wide Lightning Location Network (WWLLN) was formed with the goal of providing continuous flash rate information over the entire globe. It detects very low frequency (VLF) radio waves emitted by lightning with a detection efficiency (DE) that varies with stroke energy, time-of-day, surface type, and network coverage. This study evaluated the DE of WWLLN strokes relative to climatological OTD/LIS flashes using data from the 2007 to 2012 time period, a period during which the mean number of working sensors increased from 28 to 53. The analysis revealed that the mean global DE increased from 5% in 2007 to 13% in 2012. Regional variations were substantial with mean 2012 DEs of 5-10% over much of Argentina, Africa, and Asia and 15-30% over much of the Atlantic, Pacific, and Indian Oceans, the United States and the Maritime Continent. Detection-efficiency adjusted WWLLN flash rates were then compared to NLDN-based flash rates. Spatial correlations for individual summer months ranged from 0.66 to 0.93. Temporal correlations are currently being examined for regions of the U.S. and will also be shown.

  11. First observational evidence for opposite zonal electric fields in equatorial E and F region altitudes during a geomagnetic storm period

    NASA Astrophysics Data System (ADS)

    Tulasi Ram, S.; Balan, N.; Veenadhari, B.; Gurubaran, S.; Ravindran, S.; Tsugawa, T.; Liu, H.; Niranjan, K.; Nagatsuma, T.

    2012-09-01

    The strong westward electrojet and simultaneous upward drift of the equatorial ionospheric peak observed over South-East Asia and Indian equatorial regions during the prolonged Dst minimum phase of an intense geomagnetic storm during 14-15 December 2006 are investigated for the altitudinal variation of zonal electric field polarity using ground based and space-borne observations. The results show first observational evidence for simultaneous existence of daytime westward and eastward zonal electric fields at equatorial E and F region altitudes, respectively, in a wide longitude sector. While the westward electric fields at E region altitudes cause westward electrojet, at the same time, the eastward zonal electric fields at F region altitudes cause the upward drift of the equatorial ionospheric peak and reinforcement of the equatorial ionization anomaly (EIA) even in the topside ionosphere (660 km). The reversal of the electric fields is found to occur at 280 km height. A clear bifurcation of F region plasma at 280 km is evident in the iso-electron density contours due to these oppositely polarized zonal electric fields, which manifests as an unusually deep cusp between F1 and F2 layers on equatorial ionograms.

  12. Super-spinning compact objects and models of high-frequency quasi-periodic oscillations observed in Galactic microquasars

    NASA Astrophysics Data System (ADS)

    Kotrlov, Andrea; Trk, Gabriel; rmkov, Eva; Stuchlk, Zden?k

    2014-12-01

    We have previously applied several models of high-frequency quasi-periodic oscillations (HF QPOs) to estimate the spin of the central Kerr black hole in the three Galactic microquasars, GRS 1915+105, GRO J1655-40, and XTE J1550-564. Here we explore the alternative possibility that the central compact body is a super-spinning object (or a naked singularity) with the external space-time described by Kerr geometry with a dimensionless spin parameter a ? cJ/GM2> 1. We calculate the relevant spin intervals for a subset of HF QPO models considered in the previous study. Our analysis indicates that for all but one of the considered models there exists at least one interval of a> 1 that is compatible with constraints given by the ranges of the central compact object mass independently estimated for the three sources. For most of the models, the inferred values of a are several times higher than the extreme Kerr black hole value a = 1. These values may be too high since the spin of superspinars is often assumed to rapidly decrease due to accretion when a ? 1. In this context, we conclude that only the epicyclic and the Keplerian resonance model provides estimates that are compatible with the expectation of just a small deviation from a = 1.

  13. Implementation of an Aerosol-Cloud Microphysics-Radiation Coupling into the NASA Unified WRF: Simulation Results for the 6-7 August 2006 AMMA Special Observing Period

    NASA Technical Reports Server (NTRS)

    Shi, J. J.; Matsui, T.; Tao, W.-K.; Tan, Q.; Peters-Lidard, C.; Chin, M.; Pickering, K.; Guy, N.; Lang, S.; Kemp, E. M.

    2014-01-01

    Aerosols affect the Earth's radiation balance directly and cloud microphysical processes indirectly via the activation of cloud condensation and ice nuclei. These two effects have often been considered separately and independently, hence the need to assess their combined impact given the differing nature of their effects on convective clouds. To study both effects, an aerosol-microphysics-radiation coupling, including Goddard microphysics and radiation schemes, was implemented into the NASA Unified Weather Research and Forecasting model (NU-WRF). Fully coupled NU-WRF simulations were conducted for a mesoscale convective system (MCS) that passed through the Niamey, Niger area on 6-7 August 2006 during an African Monsoon Multidisciplinary Analysis (AMMA) special observing period. The results suggest that rainfall is reduced when aerosol indirect effects are included, regardless of the aerosol direct effect. Daily mean radiation heating profiles in the area traversed by the MCS showed the aerosol (mainly mineral dust) direct effect had the largest impact near cloud tops just above 200 hectopascals where short-wave heating increased by about 0.8 Kelvin per day; the weakest long-wave cooling was at around 250 hectopascals. It was also found that more condensation and ice nuclei as a result of higher aerosol/dust concentrations led to increased amounts of all cloud hydrometeors because of the microphysical indirect effect, and the radiation direct effect acts to reduce precipitating cloud particles (rain, snow and graupel) in the middle and lower cloud layers while increasing the non-precipitating particles (ice) in the cirrus anvil. However, when the aerosol direct effect was activated, regardless of the indirect effect, the onset of MCS precipitation was delayed about 2 hours, in conjunction with the delay in the activation of cloud condensation and ice nuclei. Overall, for this particular environment, model set-up and physics configuration, the effect of aerosol radiative heating due to mineral dust overwhelmed the effect of the aerosols on microphysics.

  14. The low-level jet dust emission mechanism in the central Sahara: Observations from Bordj-Badji Mokhtar during the June 2011 Fennec Intensive Observation Period

    NASA Astrophysics Data System (ADS)

    Allen, Christopher J. T.; Washington, Richard

    2014-03-01

    This paper presents the first detailed analysis of low-level jets (LLJs) in the central Sahara from ground-based observations at Bordj-Badji Mokhtar, Algeria, and addresses their operation as a dust emission mechanism. On LLJ mornings, composite wind speeds in the core (300 m aboveground level) reach 13.5 m s-1 at 0400. Surface temperatures increase from 0545 (30 min after sunrise), and jet decay begins around 0600. Ten meter winds lag those in the core by 5 h; peak 10 m wind speed, 7.5 m s-1, occurs at 0900. Only the deepest and strongest LLJs lead to dust emission. At 0600, these five LLJs have core wind speeds ?16 m s-1, below-core wind shear ? 0.6 m s-1/30 m, and wind shear between the core and 500 m above the core ?-1.8 m s-1. On these occasions, momentum mixes down from the LLJ after surface heating, leading to emission. On nondusty LLJ mornings, the convective boundary layer is 100 m shallower, and the LLJ is too weak to provide enough momentum to be mixed down for emission. LLJs are most frequently embedded in the monsoon flow or in the Harmattan; there is a clear association with the Saharan Heat Low. ERA-Interim reanalysis underestimates both Harmattan and monsoon LLJ core winds (by 4 m s-1 and 6 m s-1, respectively). The Met Office Africa Limited Area Model underestimates Harmattan LLJ core winds by only 0.2 m s-1. Monsoon LLJ core winds, however, are underestimated by 8.5 m s-1. Surface winds at 0900 are underestimated in both cases by up to 6 m s-1.

  15. Multi-point ground-based ULF magnetic field observations in Europe during seismic active periods in 2004 and 2005

    NASA Astrophysics Data System (ADS)

    Prattes, G.; Schwingenschuh, K.; Eichelberger, H. U.; Magnes, W.; Boudjada, M.; Stachel, M.; Vellante, M.; Wesztergom, V.; Nenovski, P.

    2008-05-01

    We present the results of ground-based Ultra Low Frequency (ULF) magnetic field measurements observed from June to August 2004 during the Bovec earthquake on 12 July 2004. Further we give information about the seismic activity in the local observatory region for an extended time span 2004 and 2005. ULF magnetic field data are provided by the South European Geomagnetic Array (SEGMA) where the experience and heritage from the CHInese MAGnetometer (CHIMAG) fluxgate magnetometer comes to application. The intensities of the horizontal H and vertical Z magnetic field and the polarization ratio R of the vertical and horizontal magnetic field intensity are analyzed taking into consideration three SEGMA observatories located at different close distances and directions from the earthquake epicenter. We observed a significant increase of high polarization ratios during strong seismic activity at the observatory nearest to the Bovec earthquake epicenter. Apart from indirect ionospheric effects electromagnetic noise could be emitted in the lithosphere due to tectonic effects in the earthquake focus region causing anomalies of the vertical magnetic field intensity. Assuming that the measured vertical magnetic field intensities are of lithospheric origin, we roughly estimate the amplitude of electromagnetic noise in the Earths crust considering an average electrical conductivity of =10-3 S/m and a certain distance of the observatory to the earthquake epicenter.

  16. Earth Observing-1 Advanced Imager Flight Performance Assessment: Investigating Dark Current Stability Over One-Half Orbit Period during the First 60 Days

    NASA Technical Reports Server (NTRS)

    Mendenhall, J. A.

    2001-01-01

    The stability of the EO-1 Advanced Land Imager dark current levels over the period of one-half orbit is investigated. A series of two-second dark current collections, over the course of 40 minutes, was performed during the first sixty days the instrument was in orbit. Analysis of this data indicates only two dark current reference periods, obtained entering and exiting eclipse, are required to remove ALI dark current offsets for 99.9% of the focal plane to within 1.5 digital numbers for any observation on the solar illuminated portion of the orbit.

  17. Observations and Modeling of the Companions of Short Period Binary Millisecond Pulsars: Evidence for High-mass Neutron Stars

    NASA Astrophysics Data System (ADS)

    Schroeder, Joshua; Halpern, Jules

    2014-10-01

    We present observations of fields containing eight recently discovered binary millisecond pulsars using the telescopes at MDM Observatory. Optical counterparts to four of these systems are detected, one of which, PSR J2214+3000, is a novel detection. Additionally, we present the fully phase-resolved B, V, and R light curves of the optical counterparts to two objects, PSR J1810+1744 and PSR J2215+5135 for which we employ model fitting using the eclipsing light curve (ELC) model of Orosz & Hauschildt to measure the unknown system parameters. For PSR J1810+1744, we find that the system parameters cannot be fit even assuming that 100% of the spin-down luminosity of the pulsar is irradiating the secondary, and so radial velocity measurements of this object will be required for the complete solution. However, PSR J2215+5135 exhibits light curves that are extremely well constrained using the ELC model and we find that the mass of the neutron star is constrained by these and the radio observations to be M NS > 1.75 M ? at the 3? level. We also find a discrepancy between the model temperature and the measured colors of this object, which we interpret as possible evidence for an additional high-temperature source such as a quiescent disk. Given this and the fact that PSR J2215+5135 contains a relatively high mass companion (M c > 0.1 M ?), we propose that similar to the binary pulsar systems PSR J1023+0038 and IGR J18245-2452, the pulsar may transition between accretion- and rotation-powered modes.

  18. Observations and modeling of the companions of short period binary millisecond pulsars: evidence for high-mass neutron stars

    SciTech Connect

    Schroeder, Joshua; Halpern, Jules

    2014-10-01

    We present observations of fields containing eight recently discovered binary millisecond pulsars using the telescopes at MDM Observatory. Optical counterparts to four of these systems are detected, one of which, PSR J2214+3000, is a novel detection. Additionally, we present the fully phase-resolved B, V, and R light curves of the optical counterparts to two objects, PSR J1810+1744 and PSR J2215+5135 for which we employ model fitting using the eclipsing light curve (ELC) model of Orosz and Hauschildt to measure the unknown system parameters. For PSR J1810+1744, we find that the system parameters cannot be fit even assuming that 100% of the spin-down luminosity of the pulsar is irradiating the secondary, and so radial velocity measurements of this object will be required for the complete solution. However, PSR J2215+5135 exhibits light curves that are extremely well constrained using the ELC model and we find that the mass of the neutron star is constrained by these and the radio observations to be M {sub NS} > 1.75 M {sub ☉} at the 3σ level. We also find a discrepancy between the model temperature and the measured colors of this object, which we interpret as possible evidence for an additional high-temperature source such as a quiescent disk. Given this and the fact that PSR J2215+5135 contains a relatively high mass companion (M {sub c} > 0.1 M {sub ☉}), we propose that similar to the binary pulsar systems PSR J1023+0038 and IGR J18245–2452, the pulsar may transition between accretion- and rotation-powered modes.

  19. Peculiar lapse of periodic eclipsing event at low-mass X-ray binary GRS 1747-312 during Suzaku observation in 2009

    NASA Astrophysics Data System (ADS)

    Saji, Shigetaka; Mori, Hideyuki; Matsumoto, Hironori; Dotani, Tadayasu; Iwai, Masachika; Maeda, Yoshitomo; Mitsuishi, Ikuyuki; Ozaki, Masanobu; Tawara, Yuzuru

    2016-03-01

    GRS 1747-312 is a neutron star low-mass X-ray binary in the globular cluster Terzan 6, located at a distance of 9.5 kpc from the Earth. During its outbursts, periodic eclipses were known to occur. Observations for the outbursts were performed with Chandra in 2004 and Swift in 2013. XMM-Newton observed its quiescent state in 2004. In addition, when Suzaku observed it in 2009 as a part of Galactic center mapping observations, GRS 1747-312 was found to be in a low-luminosity state with Lx ˜ 1.2 × 1035 erg s-1. All of the observations except for XMM-Newton included the time of the eclipses predicted. We analyzed archival data of these observations. During the Chandra and Swift observations, we found clear flux decreases at the expected time of the eclipses. During the Suzaku observation, however, there were no clear signs for the predicted eclipses. The lapse of the predicted eclipses during the Suzaku observation can be explained by a contaminant source quite close to GRS 1747-312. When GRS 1747-312 is in the quiescent state, we observe X-rays from the contaminant source rather than from GRS 1747-312. However, we have no clear evidence for the contaminant source in our data. The lapse might also be explained by thick material (NH > 1024 cm-2) between the neutron star and the companion star, though the origin of the thick material is not clear.

  20. Observations of Cygnus X-3 with the Einstein /HEAO 2/ X-ray Observatory The period derivative and the asymmetric X-ray light curve

    NASA Technical Reports Server (NTRS)

    Elsner, R. F.; Ghosh, P.; Darbro, W.; Weisskopf, M. C.; Sutherland, P. G.; Grindlay, J. E.

    1980-01-01

    Cygnus X-3 was observed by the Monitor Proportional Counter on the Einstein (HEAO 2) X-ray Observatory for 2.4 days in 1978 December. The analysis of the data from these observations is used in conjunction with a self-consistent re-examination of previous results from the Uhuru, ANS, COS B, and SAS 3 satellites to investigate earlier reports that the 4.8 hour period of Cygnus X-3 is increasing. It is found that there is indeed a period derivative, P = (1.78 plus or minus 0.40) x 10 to the -9th s/s, which confirms the principal conclusion of previous authors. The possibility that the X-ray source is in an elliptical orbit and that some, or all, of the observed period derivative may be due to apsidal motion is discussed. The elliptic orbit hypothesis explains the observed asymmetry in the average X-ray light curve and leads to the conclusion that the most likely companion to the X-ray source is a helium star, possibly with a light hydrogen envelope

  1. Observation of Periodic and Transient Cosmic Ray Flux Variations by the Daejeon Neutron Monitor and the Seoul muon Detector

    NASA Astrophysics Data System (ADS)

    Oh, Suyeon; Kang, Jeongsoo

    2013-09-01

    Recently, two instruments of cosmic ray are operating in South Korea. One is Seoul muon detector after October 1999 and the other is Daejeon neutron monitor (Kang et al. 2012) after October 2011. The former consists of four small plastic scintillators and the latter is the standard 18 NM 64 type. In this report, we introduce the characteristics of both instruments. We also analyze the flux variations of cosmic ray such as diurnal variation and Forbush decrease. As the result, the muon flux shows the typical seasonal and diurnal variations. The neutron flux also shows the diurnal variation. The phase which shows the maximum flux in the diurnal variation is around 13-14 local time. We found a Forbush decrease on 7 March 2012 by both instruments. It is also identified by Nagoya multi-direction muon telescope and Oulu neutron monitor. The observation of cosmic ray at Jangbogo station as well as in Korean peninsula can support the important information on space weather in local area. It can also enhance the status of Korea in the international community of cosmic ray experiments.

  2. Freshening of the South Indian Ocean during the Argo period: observations, causes, and impact on regional sea level change

    NASA Astrophysics Data System (ADS)

    Llovel, William; Lee, Tong

    2015-04-01

    Steric sea level change has been identified as one of the major contributors to the regional sea level changes. This contribution varies in space and time. Temperature (thermosteric) contribution to sea level has been found to be generally more important than salinity (halosteric) effect. Based on temperature and salinity data from Argo floats during 2005-2013 and coincident sea level measurements from satellite altimetry, we found that the central-eastern part of the South Indian Ocean stood out in the entire world ocean as a region that had a more dominant halosteric contribution to sea level change. The conspicuously large halosteric contribution was associated with a freshening in the upper few hundred meters. Neither local atmospheric forcing nor halosteric signal transmitted from the Pacific can explain this freshening. An observed strengthening of the Indonesian throughflow since early 2007 and the enhanced precipitation in the Indonesian Seas inferred from various precipitation estimates compounded by strong tidal mixing are the likely causes of the freshening of the South Indian Ocean. The findings also have implications to the potential influence of regional water cycle and ocean currents in the maritime Continent region to sea level changes in the South Indian Ocean prior to the Argo era and sea level projection in the future in response to climate change. Sustained measurements of sea surface salinity from satellites will significantly enhance our capability to study the impact of regional water cycle in the Maritime Continent region to related changes in the marginal seas and the Indian Ocean.

  3. Long-period effects of the Denali earthquake on water bodies in the Puget Lowland: Observations and modeling

    USGS Publications Warehouse

    Barberopoulou, A.; Qamar, A.; Pratt, T.L.; Steele, W.P.

    2006-01-01

    Analysis of strong-motion instrument recordings in Seattle, Washington, resulting from the 2002 Mw 7.9 Denali, Alaska, earthquake reveals that amplification in the 0.2-to 1.0-Hz frequency band is largely governed by the shallow sediments both inside and outside the sedimentary basins beneath the Puget Lowland. Sites above the deep sedimentary strata show additional seismic-wave amplification in the 0.04- to 0.2-Hz frequency range. Surface waves generated by the Mw 7.9 Denali, Alaska, earthquake of 3 November 2002 produced pronounced water waves across Washington state. The largest water waves coincided with the area of largest seismic-wave amplification underlain by the Seattle basin. In the current work, we present reports that show Lakes Union and Washington, both located on the Seattle basin, are susceptible to large water waves generated by large local earthquakes and teleseisms. A simple model of a water body is adopted to explain the generation of waves in water basins. This model provides reasonable estimates for the water-wave amplitudes in swimming pools during the Denali earthquake but appears to underestimate the waves observed in Lake Union.

  4. Ocean drilling suggestions

    NASA Astrophysics Data System (ADS)

    Marszalek, Donald S.

    1984-04-01

    The Ocean Drilling Program replaces the recently completed drilling phase of the Deep Sea Drilling Project (DSDP). A new and larger deep sea drilling vessel with expanded capabilities including a longer drill string, bare rock spudin, enhanced logging, and the potential for riser drilling will replace the D/V Glomar Challenger. Drilling is scheduled to commence in January 1985, and planning is now underway. The drill ship will then proceed to the Pacific Ocean and circumnavigate the earth at least twice during the 10-year program. Suggestions for drilling objectives, downhole experiments, etc., for all areas worldwide are now being solicited by JOIDES (Joint Oceanographic Institutions for Deep Earth Sampling).

  5. Difference in production routes of water-soluble organic carbon in PM2.5 observed during non-biomass and biomass burning periods in Gwangju, Korea.

    PubMed

    Yu, Geun-Hye; Cho, Sung-Yong; Bae, Min-Suk; Park, Seung-Shik

    2014-07-01

    4 h integrated PM2.5 samples were collected from an urban site of Gwangju, Korea, for five days and analyzed for organic carbon and elemental carbon (OC and EC), total water-soluble OC (WSOC), hydrophilic and hydrophobic WSOC fractions (WSOCHPI and WSOCHPO), oxalate, and inorganic ionic species (sodium (Na(+)), ammonium (NH4(+)), potassium (K(+)), calcium (Ca(2+)), magnesium (Mg(2+)), chloride (Cl(-)), nitrate (NO3(-)), and sulfate (SO4(2-))) to investigate the possible sources of water-soluble organic aerosols. Two types of sampling periods were classified according to the regression relationship between black carbon (BC) concentrations measured at wavelengths of 370 nm (BC370nm) and 880 nm (BC880nm) using an aethalometer; the first period was traffic emission influence ("non-biomass burning (BB) period") and the second was biomass burning influence ("BB period"). The slope of the regression equation (BC370nm/BC880nm) was 0.95 for the non-BB period and 1.29 for the BB period. However, no noticeable difference in the WSOC/OC ratio, which can be used to infer the extent of secondary organic aerosol (SOA) formation, was found between the non-BB (0.61, range = 0.43-0.75) and BB (0.61, range = 0.52-0.68) periods, due to significant contribution of primary BB emissions to the WSOC. The concentrations of OC, WSOC and K(+), which were used as the BB emission markers, were 15.7 μg C m(-3) (11.5-24.3), 9.4 μg C m(-3) (7.0-12.7), and 1.2 μg m(-3) (0.6-2.7), respectively, during the BB period, and these results were approximately 1.7, 1.7, and 3.9 times higher than those during the non-BB period. During the non-BB period, good correlations among WSOC, SO4(2-) and oxalate, and poor correlations among WSOC, EC, and K(+) suggest that SOA is probably an important source of WSOC (and WSOCHPI) concentration. For the WSOC fractions, better correlations among WSOCHPI, oxalate (R(2) = 0.52), and SO4(2-) (R(2) = 0.57) were found than among WSOCHPO, oxalate (R(2) = 0.23), and SO4(2-) (R(2) = 0.20), suggesting that a significant proportion of the WSOCHPI fraction of OC could be produced through processes (gas-phase and heterogeneous oxidations) such as SOA formation. However, during the BB period, the BB emission source accounted for the high correlations between total WSOC (and WSOC fractions) and other relevant atmospheric parameters (EC, Na(+), Cl(-), K(+), and oxalate), with higher correlations in WSOCHPI than in WSOCHPO. These results suggest a significant contribution of BB emissions to WSOC. PMID:24824766

  6. Learning Semantic Query Suggestions

    NASA Astrophysics Data System (ADS)

    Meij, Edgar; Bron, Marc; Hollink, Laura; Huurnink, Bouke; de Rijke, Maarten

    An important application of semantic web technology is recognizing human-defined concepts in text. Query transformation is a strategy often used in search engines to derive queries that are able to return more useful search results than the original query and most popular search engines provide facilities that let users complete, specify, or reformulate their queries. We study the problem of semantic query suggestion, a special type of query transformation based on identifying semantic concepts contained in user queries. We use a feature-based approach in conjunction with supervised machine learning, augmenting term-based features with search history-based and concept-specific features. We apply our method to the task of linking queries from real-world query logs (the transaction logs of the Netherlands Institute for Sound and Vision) to the DBpedia knowledge base. We evaluate the utility of different machine learning algorithms, features, and feature types in identifying semantic concepts using a manually developed test bed and show significant improvements over an already high baseline. The resources developed for this paper, i.e., queries, human assessments, and extracted features, are available for download.

  7. Two-day period fluctuation of PMC occurrence over Syowa Station, Antarctica observed by a ground-based lidar and AIM satellite.

    NASA Astrophysics Data System (ADS)

    Nakamura, T.; Suzuki, H.; Tsutsumi, M.; Ejiri, M. K.; Tomikawa, Y.; Abo, M.; Kawahara, T.; Tsuda, T. T.; Nishiyama, T.

    2014-12-01

    A Rayleigh/Raman lidar system has been operated by the Japanese Antarctic Research Expedition (JARE) since February, 2011 (JARE 52nd) in Syowa Station Antarctica (69.0S, 39.5E). The lidar system consists of a pulsed Nd:YAG laser (355nm) as a transmitter and two telescopes with four photo multiplier tubes which are to detect Rayleigh scattered light from low and high atmosphere at 355 nm and N2 Raman emission at 387nm. Polar Mesospheric Cloud (PMC) was detected by the lidar at 22:30UT (+3hr for LT) on Feb 4th, 2011, the first day of a routine operation. This event was the first time to detect PMC over Syowa Station by a lidar [Suzuki et al., Ann. Geophys., 2013]. However, signal to noise ratio (SNR) of the PMC event was not so good due to large shot noises from daytime background signals. Moreover, a receiver system was designed mainly for nighttime observations. In this way, observation of PMC during the midnight sun, which also corresponds to most frequent PMC season, was difficult. Thus, to improve SNR of the PMC observation with the lidar during daytime, a narrow band-pass Fabry-Perot etalon unit has been developed and installed in the receiver system on Dec 2013 by JARE 55th. By using this new system, clear PMC signals were successfully detected under daylight condition during the period of summer operation of JARE55th. During this period of 53 days (from 17 Dec. 2013 to 7 Feb. 2014), only 11 days were with a clear sky and suitable for PMC observation. Thus, it was difficult to study temporal variations on a PMC activity only by using the lidar data. Fortunately, NASA's AIM satellite had passed near Syowa Station and provided with complimentary PMC data during observation gap of the lidar. By combining our lidar data with the AIM/CIPS data, nearly continuous monitoring of PMC variability over Syowa Station was achieved for period between 13th and 18th in January 2014. PMC occurrence with an interval of two days over Syowa Station during the period was clearly confirmed. Co-located MF radar also showed clear two days fluctuation in horizontal wind velocities around PMC altitude during the same period. In this presentation, we will discuss the cause of the two-day oscillation found in PMC occurrence and horizontal wind velocity. In particular, two-day planetary wave will be quantitatively investigated as a potential cause of the fluctuation.

  8. An observational study suggesting clinical benefit for adjuvant postoperative chemoradiation in a population of over 500 cases after gastric resection with D2 nodal dissection for adenocarcinoma of the stomach

    SciTech Connect

    Kim, Sung; Lim, Do Hoon; Lee, Jeeyun; Kang, Won Ki . E-mail: wkkang@smc.samsung.co.kr; MacDonald, John S.; Park, Chan Hyung; Park, Se Hoon; Lee, Se-Hoon; Kim, Kihyun; Park, Joon Oh; Kim, Won Seog; Jung, Chul Won; Park, Young Suk; Im, Young-Hyuck; Sohn, Tae Sung; Noh, Jae Hyung; Heo, Jin Seok; Kim, Yong Il; Park, Chul Keun; Park, Keunchil

    2005-12-01

    Purpose: The role of adjuvant chemoradiotherapy (CRT) in D2-resected gastric-cancer patients has not been defined yet. We investigated the effect of postoperative chemoradiotherapy on the relapse rate and survival rate of patients with D2-resected gastric cancer. Methods and Materials: From August 1995 to April 2001, 544 patients received postoperative CRT after curative D2 resection. During the same period of time, 446 patients received surgery without further adjuvant treatment. The adjuvant CRT consisted of 400 mg/m{sup 2} of fluorouracil plus 20 mg/m{sup 2} of leucovorin for 5 days, followed by 4,500 cGy of radiotherapy for 5 weeks, with fluorouracil and leucovorin on the first 4 and the last 3 days of radiotherapy. Two 5-day cycles of fluorouracil and leucovorin were given 4 weeks after the completion of radiotherapy. Results: The median duration of overall survival was significantly longer in the CRT group than in the comparison group (95.3 months vs. 62.6 months), which corresponds to a hazard ratio for death of 0.80 (p = 0.0200) or a reduction of 20% in the risk of death in the CRT group. The 5-year survival rates were consistently longer in the CRT group at Stages II, IIIA, IIIB, and IV than those in the comparison group. The CRT was associated with increases in the median duration of relapse-free survival (75.6 months vs. 52.7 months; hazard ratio for relapse, 0.80, p = 0.0160). Conclusion: Our results highly suggest that the postoperative chemoradiotherapy in D2-resected gastric-cancer patients can prolong survival and decrease recurrence.

  9. A collection of sub-daily pressure and temperature observations for the early instrumental period with a focus on the "year without a summer" 1816

    NASA Astrophysics Data System (ADS)

    Brugnara, Y.; Auchmann, R.; Brönnimann, S.; Allan, R. J.; Auer, I.; Barriendos, M.; Bergström, H.; Bhend, J.; Brázdil, R.; Compo, G. P.; Cornes, R. C.; Dominguez-Castro, F.; van Engelen, A. F. V.; Filipiak, J.; Holopainen, J.; Jourdain, S.; Kunz, M.; Luterbacher, J.; Maugeri, M.; Mercalli, L.; Moberg, A.; Mock, C. J.; Pichard, G.; Řezníčková, L.; van der Schrier, G.; Slonosky, V.; Ustrnul, Z.; Valente, M. A.; Wypych, A.; Yin, X.

    2015-08-01

    The eruption of Mount Tambora (Indonesia) in April 1815 is the largest documented volcanic eruption in history. It is associated with a large global cooling during the following year, felt particularly in parts of Europe and North America, where the year 1816 became known as the "year without a summer". This paper describes an effort made to collect surface meteorological observations from the early instrumental period, with a focus on the years of and immediately following the eruption (1815-1817). Although the collection aimed in particular at pressure observations, correspondent temperature observations were also recovered. Some of the series had already been described in the literature, but a large part of the data, recently digitised from original weather diaries and contemporary magazines and newspapers, is presented here for the first time. The collection puts together more than 50 sub-daily series from land observatories in Europe and North America and from ships in the tropics. The pressure observations have been corrected for temperature and gravity and reduced to mean sea level. Moreover, an additional statistical correction was applied to take into account common error sources in mercury barometers. To assess the reliability of the corrected data set, the variance in the pressure observations is compared with modern climatologies, and single observations are used for synoptic analyses of three case studies in Europe. All raw observations will be made available to the scientific community in the International Surface Pressure Databank.

  10. Spectral Index and Quasi-Periodic Oscillation Frequency Correlation in Black Hole Sources: Observational Evidence of Two Phases and Phase Transition in Black Holes

    NASA Technical Reports Server (NTRS)

    Titarchuk, Lev; Fiorito, Ralph

    2004-01-01

    Recent studies have shown that strong correlations are observed between the low frequencies (1-10 Hz) of quasi-periodic oscillations (QPOs) and the spectral power law index of several black hole (BH) candidate sources, in low (hard) states, steep power law (soft) states, and transitions between these states. The observations indicate that the X-ray spectra of such state (phases) show the presence of a power-law component and are sometimes related to simultaneous radio emission, indicating the probable presence of a jet. Strong QPOs (>20% rms) are present in the power density spectrum in the spectral range where the power-law component is dominant (i.e., 60%90%). This evidence contradicts the dominant, long-standing interpretation of QPOs as a signature of the thermal accretion disk. We present the data from the literature and our own data to illustrate the dominance of power-law index-QPO frequency correlations. We provide a model that identifies and explains the origin of the QPOs and how they are imprinted on the properties of the power-law flux component. We argue for the existence of a bounded compact coronal region that is a natural consequence of the adjustment of the Keplerian disk flow to the innermost sub-Keplerian boundary conditions near the central object and that ultimately leads to the formation of a transition layer (TL) between the adjustment radius and the innermost boundary. The model predicts two phases or states dictated by the photon upscattering produced in the TL: (1) a hard state, in which the TL is optically thin and very hot (kT approximately greater than 50 keV), producing photon upscattering via thermal Comptonization (the photon spectrum index Gamma approximates 1.7 for this state is dictated by gravitational energy release and Compton cooling in an optically thin shock near the adjustment radius), and (2) a soft state that is optically thick and relatively cold (kT approximately less than 5 keV the index for this state, Gamma approximates 2.8, is determined by soft-photon upscattering and photon trapping in a converging flow into the BH). In the TL model for the corona, the QPO frequency V(sub high) is related to the gravitational (close to Keplerian) frequency V(sub K) at the outer (adjustment) radius and v(sub low) is related to the TL's normal mode (magnetoacoustic) oscillation frequency v(sub MA) . The observed correlations between index and low and high QPO frequencies are readily explained in terms of this model. We also suggest a new method for evaluation of the BH mass using the index-frequency correlation.

  11. Evolutionary outcomes for pairs of planets undergoing orbital migration and circularization: second-order resonances and observed period ratios in Kepler's planetary systems

    NASA Astrophysics Data System (ADS)

    Xiang-Gruess, M.; Papaloizou, J. C. B.

    2015-05-01

    In order to study the origin of the architectures of low-mass planetary systems, we perform numerical surveys of the evolution of pairs of coplanar planets in the mass range (1-4) M?. These evolve for up to 2 107 yr under a range of orbital migration torques and circularization rates assumed to arise through interaction with a protoplanetary disc. Near the inner disc boundary, significant variations of viscosity, interaction with density waves or with the stellar magnetic field could occur and halt migration, but allow circularization to continue. This was modelled by modifying the migration and circularization rates. Runs terminated without an extended period of circularization in the absence of migration torques gave rise to either a collision, or a system close to a resonance. These were mostly first order with a few per cent terminating in second-order resonances. Both planetary eccentricities were small <0.1 and all resonant angles liberated. This type of survey produced only a limited range of period ratios and cannot reproduce Kepler observations. When circularization alone operates in the final stages, divergent migration occurs causing period ratios to increase. Depending on its strength the whole period ratio range between 1 and 2 can be obtained. A few systems close to second-order commensurabilities also occur. In contrast to when arising through convergent migration, resonant trapping does not occur and resonant angles circulate. Thus, the behaviour of the resonant angles may indicate the form of migration that led to near resonance.

  12. The Characteristics of the Post-midnight Plasma Irregularities in Low-to-mid Latitude during the Solar Minimum Period Observed by the DMSP and the CHAMP

    NASA Astrophysics Data System (ADS)

    Oh, S.; Kil, H.

    2011-12-01

    Plasma irregularities in mid-to-low latitude are a significant feature that can be responsible for the interference to radio communications and navigation systems. The characteristics of the plasma irregularities during the solar minimum period, significantly different from the previous studies during solar active period, have been revealed by the recent observations. The most distinguishing signature of the plasma irregularities during the solar minimum is the peak in occurrence frequency that appears in the post-midnight sector with the low level of background ionosphere density. Moreover, the plasma irregularities exist at the morning sector during the solar minimum period. However, the onset conditions and the mechanisms to explain the occurrence of those irregularities are still questionable. We investigate the post-midnight irregularities at solar minimum based on the in-situ measurement observations by the DMSP F13 and the CHAMP. The association of the occurrence pattern with the background ionospheric parameters such as the vertical drift velocity, the background density and the density gradient will be discussed.

  13. High energy X-ray observations of CYG X-3 from from OSO-8: Further evidence of a 34.1 day period

    NASA Technical Reports Server (NTRS)

    Dolan, J. F.; Crannell, C. J.; Dennis, B. R.; Frost, K. J.; Orwig, L. E.

    1981-01-01

    The X-ray source Cyg X-3 (=4U2030+40) was observed with the high energy X-ray spectrometer on OSO-8 for two weeks in 1975 and in 1976 and for one week in 1977. No change in spectral shape and intensity above 23 keV was observed from year to year. No correlation is observed between the source's intensity and the phase of the 34.1 day period discovered by Molteni, et al. (1980). The pulsed fraction of the 4.8 hour light curve between 23 and 73 keV varies from week to week, however, and the magnitude of the pulsed fraction appears to be correlated with the 34.1 day phase. No immediate explanation of this behavior is apparent in terms of previously proposed models of the source.

  14. Seasonal variations of diurnal and semidiurnal tidal-period perturbations in mesopause region temperature and zonal and meridional winds above Fort Collins, Colorado (40 degrees North, 105 degrees West) based on sodium-Lidar observation over full diurnal cycles

    NASA Astrophysics Data System (ADS)

    Yuan, Tao

    With continued efforts by all the members (past and present) in the Na-Lidar group at Colorado State University, the lidar system was capable of simultaneous measurement of mesopause region temperature and horizontal wind at night. Since May 2002, the CSU fluorescence lidar system has been able to perform these observations on 24-hour continuous basis for a long-period, weather permitting. The key factor, which makes lidar observation under sunlit conditions possible, is a pair of robust (reliable and stable) Faraday filters that reduces the sky background. To attain such a Faraday Filter, in this thesis we developed and implemented dual temperature control (to +/-0.1K) of sodium cell inside the filters, and of the cell's tip-off region. The dual control allows independent setting of cell temperature and the Na vapor pressure, thus stabilizing Na vapor density in the cell and the transmission function of the Faraday filter. This 24-hour continuous observation capability provided us with the first yearlong data set with campaigns of full diurnal cycle coverage leading to the first study of diurnal and semidiurnal tides of mesopause region temperature, zonal and meridional winds based on ground based observation. The yearlong data set include a total of 1,491 hours with 659 hours under sunlit conditions, within which there are 29 sets of 24-hour continuous observation. We binned these 29 data sets into bimonthly time series and performed harmonic analysis to deduce diurnal mean, diurnal and semidiurnal tidal-period oscillations of the mesopause region temperature, zonal and meridional winds over Fort Collins, CO. The resulting bimonthly tidal amplitudes and phases are compared to the predictions of Global Scale Wave Models (GSWM00 and GSWM02) and Thermosphere, Ionosphere, Mesosphere and Electrodynamics - General Circulation Model (TIME-GCM02). Other than diurnal temperatures in Nov--Dec, we found excellent agreement between observation and GSWM00 model for diurnal tides, suggesting that migrating solar tides dominate the observed oscillations. The observed diurnal temperature phase in Nov--Dec suggests the existence of midnight local heating, which requires further study. For non-winter months, all three models considerably underestimate the semidiurnal amplitudes, implicating the existence of considerable local wave perturbations at or near semidiurnal period. At the present, the causes for the discrepancy between observation and model prediction are not understood. For the bimonthly periods with significant discrepancy between observation and model predictions, analysis of more recent data taken during the same bimonthly periods showed general agreement between two data sets. Continued observation for two additional years is planned. At the end of that time, we should have enough data to determine not only tidal climatology but also tidal variability, revealing unexpected interactions between tides and gravity waves and planetary waves. Our results will provide complementary information to satellite observations which provide global but lack local-time coverage. In collaboration with modeling efforts at National Center for Atmospheric Research, our data set hopefully will play a significant role in advancing our understanding of solar tides and their roles in the structure and dynamics of the Mesosphere and Lower Thermosphere.

  15. Improved safety of biologic therapy for rheumatoid arthritis over the 8-year period since implementation in Japan: long-term results from a multicenter observational cohort study.

    PubMed

    Kojima, Toshihisa; Takahashi, Nobunori; Funahashi, Koji; Asai, Shuji; Terabe, Kenya; Kaneko, Atsushi; Hirano, Yuji; Hayashi, Masatoshi; Miyake, Hiroyuki; Oguchi, Takeshi; Takagi, Hideki; Kanayama, Yasuhide; Yabe, Yuichiro; Watanabe, Tsuyoshi; Fujibayashi, Takayoshi; Shioura, Tomone; Ito, Takayasu; Yoshioka, Yutaka; Ishikawa, Hisato; Asai, Nobuyuki; Takemoto, Toki; Kojima, Masayo; Ishiguro, Naoki

    2016-04-01

    This study aimed to compare the long-term safety of biologics by initiation year of treatment in patients with rheumatoid arthritis (RA) in Japan. RA patients who started their first biologics including infliximab, etanercept, adalimumab, and tocilizumab between 2003 and 2008 were identified in the Tsurumai Biologics Communication Registry (TBCR), multicenter observational cohort, and followed for 2 years or until discontinuation of the drugs. We identified baseline predictors for adverse events (AEs) resulting in discontinuation of the first TNFI using Cox proportional hazards regression analysis. A total of 874 cases (1,340 person-years) were observed. During the observation period, 96 AEs (4.7 events/100 person-years) occurred. From 2003 to 2008, there were significant changes in disease duration, Steinbrocker stage, and disease activity in those aged ≤64 years with no increase of incidence of AEs, whereas those aged >64 years had no significant changes in these variables. In the later initiation year of treatment with biologics, the fewer AEs were observed (log-rank, p = 0.017, 2008 vs. 2003-2005). Multivariate analysis showed that the initiation year significantly impacted the incidence of AEs 6 months into the observation period [initiation at 2008 (vs. 2003-2005): OR: 0.30, 95 % CI: (0.14-0.68)] after adjusting for variables at baseline. The decrease of AEs in the later initiation year was evident in those aged >64 years. The safety of biologic therapy improved over the course of the 8 years from its implementation in Japan. PMID:26846135

  16. Mortality coefficients among personnel of radiochemical plants of {open_quotes}Mayak{close_quotes}-Combine for 40-year period of observation

    SciTech Connect

    Koshurnikova, N.A.; Komleva, N.S.; Baisogolov, G.D.

    1993-12-31

    The results of the epidemiological research, conducted among the personnel of the radiochemical plants of {open_quotes}Mayak{close_quotes}. Combine are as follows: during the 40-year-period of observation the mortality rate from all and separate causes, except age, is lower, than the expected one, which is calculated on the basis of the National Statistics. Oncological mortality rate is reliably higher, than the expected one, which is conditioned by the high frequency of lung cancer and leucaemia. Internal {alpha}-irradiation plays the leading role in the induction of lung cancer, and the increase of mortality rate from leukemia is closely connected with external {gamma}-irradiation.

  17. Simultaneous Pc 1 observations by the synchronous satellite ATS-1 and ground stations - Implications concerning IPDP generation mechanisms. [Intervals of Pulsations Diminishing by Period

    NASA Technical Reports Server (NTRS)

    Bossen, M.; Mcpherron, R. L.; Russell, C. T.

    1976-01-01

    Results are presented for an experimental study designed to examine the properties of Pc 1 activity observed simultaneously at ATS 1 and two Canadian ground stations. The Pc 1 activity is found to follow substorm expansion phase onsets and to occur most frequently at dusk. Dynamic spectra waves at both ground stations are that of IPDP (Intervals of Pulsations Diminishing by Period) type Pc 1. A previously proposed mechanism to explain IPDP generation, which required a rapid increase in the equatorial magnetic field to produce IPDP, is inconsistent with the dynamic spectra and magnetic field observations. Either purely azimuthal or a combination of azimuthal and radial inward drift of energetic resonant protons is an equally plausible mechanism to explain IPDP generation.

  18. A high quality reprocessed ground-based GPS dataset for atmospheric process studies, radiosonde and model evaluation, and reanalysis of HYMEX Special Observing Period

    NASA Astrophysics Data System (ADS)

    BOCK, Olivier; Bosser, Pierre; Pacione, Rosa; Nuret, Mathieu; Fourrié, Nadia

    2015-04-01

    Data from more than 1000 ground-based GPS receivers in the north-western Mediterranean area have been reprocessed in a consistent way using GIPSY-OASIS II software for the period from 1st September 2012 to 31 March 2013 which encompasses the Special Observation Periods (SOPs) 1 and 2 of the HYMEX project. The reprocessed GPS ZTD data were screened converted to IWV. The ZTD data were used to assess the accuracy of the near real time ZTD data assimilated for operational weather forecasting. The mean of delay differences between the operational and reprocessed solutions is about 0 +/- 3 mm (mean +/- standard deviation of bias over all stations) and the standard deviation of delay differences ranges between 4 and 8 mm. Significant bias reduction is thus expected from a reanalysis ingesting the reprocessed delay data. Various methods and auxiliary data (surface pressure and weighted mean temperature) are investigated for the conversion of ZTD data into IWV. The final IWV dataset is used to evaluate radiosonde humidity observations and operational analyses produced with the AROME model. The spatial and temporal distribution of IWV is also studied with a focus on heavy precipitation events in the north-western Mediterranean area during the HYMEX SOP1.

  19. Operation of a digital seismic network on Mount St. Helens volcano and observations of long period seismic events that originate under the volcano

    SciTech Connect

    Fehler, M.; Chouet, B.

    1982-09-01

    A 9 station digital seismic array was operated on Mount St. Helens volcano in Washington State during 1981. One of the stations was placed inside the crater of the volcano, six were located on the flanks of the volcano within two km of the crater and two were approximately ten km from the crater. Four of the instruments recorded three components of motion and the remaining five recorded only the vertical component. A one day experiment was carried out during which the crater monitoring seismometer was complimented by the addition of two ink recording instruments. During the one day experiment six observers recorded times of rockfall, felt-earthquake occurrences, and changes in steam emissions from the dome in the crater. Using information obtained during the one day experiment seismic events recorded by the digital instruments were classified as earthquakes, rockfalls, helicopter noise and a type of event that is unique to volcanoes which is called long period. Waveforms of these long period events have a duration of up to 30 seconds and a spectrum that is peaked at approximately 2 Hz. The frequency at which the peak in the spectrum occurs is nearly the same at all stations which means that the unique waveform of long period events is due to a source effect, not a path effect. The peak frequency is fairly insensitive to the amplitude of the signal which means that the size of the source region is constant, independent of the signal amplitude. Long period events were not felt and were accompanied by no visible changes inside the crater which lead to the conclusion that they are some sort of seismic disturbance generated inside the Volcano.

  20. Quasi-periodic oscillations in short recurring bursts of magnetars SGR 180620 and SGR 1900+14 observed with RXTE

    SciTech Connect

    Huppenkothen, D.; Heil, L. M.; Watts, A. L.; G??, E.

    2014-11-10

    Quasi-periodic oscillations (QPOs) observed in the giant flares of magnetars are of particular interest due to their potential to open up a window into the neutron star interior via neutron star asteroseismology. However, only three giant flares have been observed. We therefore make use of the much larger data set of shorter, less energetic recurrent bursts. Here, we report on a search for QPOs in a large data set of bursts from the two most burst-active magnetars, SGR 1806-20 and SGR 1900+14, observed with Rossi X-ray Timing Explorer. We find a single detection in an averaged periodogram comprising 30 bursts from SGR 180620, with a frequency of 57 Hz and a width of 5 Hz, remarkably similar to a giant flare QPO observed from SGR 1900+14. This QPO fits naturally within the framework of global magneto-elastic torsional oscillations employed to explain giant flare QPOs. Additionally, we uncover a limit on the applicability of Fourier analysis for light curves with low background count rates and strong variability on short timescales. In this regime, standard Fourier methodology and more sophisticated Fourier analyses fail in equal parts by yielding an unacceptably large number of false-positive detections. This problem is not straightforward to solve in the Fourier domain. Instead, we show how simulations of light curves can offer a viable solution for QPO searches in these light curves.

  1. Auroral activities observed by SNPP VIIRS day/night band during a long period geomagnetic storm event on April 29-30, 2014

    NASA Astrophysics Data System (ADS)

    Shao, Xi; Cao, Changyong; Liu, Tung-chang; Zhang, Bin; Wang, Wenhui; Fung, Shing F.

    2015-10-01

    The Day/Night Band (DNB) of the Visible Infrared Imaging Radiometer Suite (VIIRS) onboard Suomi-NPP represents a major advancement in night time imaging capabilities. The DNB senses radiance that can span 7 orders of magnitude in one panchromatic (0.5-0.9 μm) reflective solar band and provides imagery of clouds and other Earth features over illumination levels ranging from full sunlight to quarter moon. When the satellite passes through the day-night terminator, the DNB sensor is affected by stray light due to solar illumination on the instrument. With the implementation of stray light correction, stray light-corrected DNB images enable the observation of aurora occurred in the high latitude regions during geomagnetic storms. In this paper, DNB observations of auroral activities are analyzed during a long period (> 20 hours) of geomagnetic storm event occurred on Apr. 29-30, 2014. The storm event has the Bz component of interplanetary magnetic field (IMF) pointing southward for more than 20 hours. During this event, the geomagnetic storm index Dst reached -67 nT and the geomagnetic auroral electrojet (AE) index increased and reached as high as 1200 nT with large amplitude fluctuations. The event occurred during new moon period and DNB observation has minimum moon light contamination. During this event, auroras are observed by DNB for each orbital pass on the night side (~local time 1:30am) in the southern hemisphere. DNB radiance data are processed to identify regions of aurora during each orbital pass. The evolution of aurora is characterized with time series of the poleward and equatorward boundary of aurora, area, peak radiance and total light emission of the aurora in DNB observation. These characteristic parameters are correlated with solar wind and geomagnetic index parameters. It is found that the evolution of total area-integrated radiance of auroral region over the southern hemisphere correlated well with the ground geomagnetic AE index with correlation coefficient = 0.71. DNB observations of aurora help understand the relations among solar wind variation, auroral activities and geomagnetic responses.

  2. Low Latitude Field-aligned Irregularities Observed In The E Region With The Piura Vhf Radar: Morphology, Long-term Periodicities and Their Relationship With Sporadic E Layers

    NASA Astrophysics Data System (ADS)

    Chau, J. L.; Haldoupis, C.

    Between 1991 and 1999, the Piura VHF radar (5.2S, 80.6W, 7.0N dip latitude) in northern Peru has been operated intermittently to observe coherent backscatter from 3-m E-region field-aligned irregularities. These echoes are detected by pointing the antenna beam to the north at 14 zenith angle, i.e., perpendicular to the magnetic field lines, in an area just outside the equatorial electrojet zone and far from mid latitudes. Studies of these observations have shown that the spectral and diurnal characteris- tics of backscatter are reminiscent of midlatitude E region irregularities rather than those at the equatorial electrojet. Since January 2000, "continuous" (2 minutes every 12 minutes) observations have been started in order to study in more detail the diur- nal and seasonal morphology of backscatter. In this paper, we analyze these data to study the morphology of the echoes (diurnal and seasonal) and compare it to the mor- phology of sporadic E (Es) layers observed in low latitude ionosonde stations. The results show the occurrence of the Piura E region irregularities to be in close relation with the characteristics of Es layers and their morphology. This indicates that E re- gion coherent backscatter even at very low latitudes is basically of the same nature as that observed at midlatitude, therefore it relates to plasma instabilities operating inside Es layers. In addition, we investigate the long-term (periods of days) variability seen in echo occurrence and intensity of the Piura backscatter and examine how these variations compare with similar ones measured at midlatitude, and also their possible relationship with planetary waves which are known to exist in the mesosphere and lower thermosphere.

  3. Observed trends in ambient concentrations of C 2-C 8 hydrocarbons in the United Kingdom over the period from 1993 to 2004

    NASA Astrophysics Data System (ADS)

    Dollard, G. J.; Dumitrean, P.; Telling, S.; Dixon, J.; Derwent, R. G.

    Hourly measurements of up to 26 C 2-C 8 hydrocarbons have been made at eight urban background sites, three urban-industrial sites, a kerbside and a rural site in the UK from 1993 onwards up until the end of December 2004. Average annual mean benzene and 1,3-butadiene concentrations at urban background locations have declined at about -20% per year and the observed declines have exactly mimicked the inferred declines in benzene and 1,3-butadiene emissions over the same period. Ninety-day rolling mean concentrations of ethylene, propylene, n- and i-butane, n- and i-pentane, isoprene and propane at urban and rural sites have also declined steadily by between -10% and -30% per year. Rolling mean concentrations of acetylene, 2- and 3-methylpentane, n-hexane, n-heptane, cis- and trans-but-2-ene, cis- and trans-pent-2-ene, toluene, ethylbenzene and o-, m- and p-xylene at a roadside location in London have all declined at between -14% and -21% per year. These declines demonstrate that motor vehicle exhaust catalysts and evaporative canisters have effectively and efficiently controlled vehicular emissions of hydrocarbons in the UK. Urban ethane concentrations arising largely from natural gas leakage have remained largely unchanged over this same period.

  4. Twenty-Four-Hour Raman Lidar Water Vapor Measurements During the Atmospheric Radiation Measurement Program's 1996 and 1997 Water Vapor Intensive Observation Periods

    SciTech Connect

    Turner, David D.; Goldsmith, JE M.

    1999-08-01

    Prior to the Atmospheric Radiation Measurement program's first water vapor intensive observation period (WVIOP) at the Cloud and Radiation Testbed site near Lamont, Oklahoma, an automated 24-h Raman lidar was delivered to the site. This instrument, which makes high-resolution measurements of water vapor both spatially and temporally, is capable of making these measurements with no operator interaction (other than initial startup) for days at a time. Water vapor measurements collected during the 1996 and 1997 WVIOPs are discussed here, illustrating both the nighttime and daytime capabilities of this system. System characteristics, calibration issues, and techniques are presented. Finally, detailed intercomparisons of the lidar's data with those from a microwave radiometer, radiosondes, an instrumented tower, a chilled mirror flown on both a tethersonde and a kite, and measurements from aircraft are shown and discussed, highlighting the accuracy and stability of this system for both nighttime and daytime measurements.

  5. A synoptic-scale overview of the TOGA COARE intensive observing period November 1992 to February 1993 based on analyses from US operational global data assimilation systems

    NASA Technical Reports Server (NTRS)

    Fiorino, M.; Lord, S. J.; Lau, W. K.-M.; Phoebus, P. A.; Strey, C. G.

    1993-01-01

    The operational global analyses from the two major U.S. numerical weather prediction centers, the Navy's Fleet Numerical Oceanography Center and the National Meteorological Center, are used to describe the synoptic-scale features of the 1 Nov. 1992 to 28 Feb. 1993 TOGA COARE intensive observing period (IOP). TOGA COARE is an international field experiment in which a large number of research scientists from the Goddard Laboratory for Atmospheres (Code 910) and the Laboratory for Hydrospheres (Code 970) participated. Two high-amplitude intraseasonal (30-60 day) oscillations passed through the TOGA COARE observational network located in the equatorial western Pacific. Associated with the oscillations were two 6-10 day periods of persistent westerly surface winds at the equator or 'westerly wind bursts.' These events are depicted through time series and time-longitude cross sections of divergence/velocity potential, surface winds, precipitation, ocean mixed-layer depth, and sea surface temperature. The high and low frequency components of the flow in which the intraseasonal oscillations were embedded are shown using seasonal, monthly, and 5-day averages of the surface, 850 and 200 mb winds, precipitation, and sea-level pressure, and a time-longitude cross section of tropical cyclone activity. Independent verification of precipitation comes from near real-time satellite estimates, and a reference climatology is given based on 9 years of ECMWF analyses. Daily 00 UTC analyses of surface winds and sea-level pressure for the entire western Pacific and Indian Ocean are provided to trace the evolution of individual synoptic events.

  6. FORMOSAT-3/COSMIC observations of seasonal and longitudinal variations of equatorial ionization anomaly and its interhemispheric asymmetry during the solar minimum period

    NASA Astrophysics Data System (ADS)

    Tulasi Ram, S.; Su, S.-Y.; Liu, C. H.

    2009-06-01

    Using an extremely valuable global data set from Formosa Satellite (FORMOSAT-3)/Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) radio occultation experiment, a comprehensive study has been carried out on the seasonal and longitudinal variations of equatorial ionization anomaly (EIA) and the temporal variation in the hemispheric asymmetry of EIA during the low solar activity period from November 2006 to October 2007. The interesting result observed from this investigation is the local-time-dependent variation in the hemispheric asymmetry of EIA. During the solstices, it has been consistently observed that the EIA crest in the winter hemisphere appears stronger than that in the summer hemisphere during morning to noon hours. In contrast to this, during noon to early afternoon hours, the ionization in the winter EIA crest decreases rapidly, and the crest in the summer hemisphere becomes more intensified than that in the winter hemisphere. Further, this transition of stronger EIA crest from winter hemisphere to summer hemisphere occurs around 1200-1300 LT during the December solstice months and is delayed by a couple of hours (seen around 1400 LT) during June solstice months. The causative neutral and electrodynamical mechanisms are discussed in light of relative contributions from the field-aligned plasma transport due to transequatorial interhemispheric neutral wind, the strength of the equatorial fountain process, and the ion drag effects during different local times and seasons. The results from the Sami2 is Another Model of the Ionosphere (SAMI2) model simulation also exhibit similar local-time-dependent variation in the hemispheric asymmetry of EIA, which further supports our argument. Also, it was observed that the large magnetic declination of the field lines and the four-peaked longitudinal structure of EIA can significantly modulate the interhemispheric asymmetry of EIA even during the equinoxes.

  7. Cloud Properties Derived From GOES-7 for Spring 1994 ARM Intensive Observing Period Using Version 1.0.0 of ARM Satellite Data Analysis Program

    NASA Technical Reports Server (NTRS)

    Minnis, Patrick; Smith, William L., Jr.; Garber, Donald P.; Ayers, J. Kirk; Doelling, David R.

    1995-01-01

    This document describes the initial formulation (Version 1.0.0) of the Atmospheric Radiation Measurement (ARM) program satellite data analysis procedures. Techniques are presented for calibrating geostationary satellite data with Sun synchronous satellite radiances and for converting narrowband radiances to top-of-the-atmosphere fluxes and albedos. A methodology is documented for combining geostationary visible and infrared radiances with surface-based temperature observations to derive cloud amount, optical depth, height, thickness, temperature, and albedo. The analysis is limited to two grids centered over the ARM Southern Great Plains central facility in north-central Oklahoma. Daytime data taken during 5 Apr. - 1 May 1994, were analyzed on the 0.3 deg and 0.5 deg latitude-longitude grids that cover areas of 0.9 deg x 0.9 deg and 10 deg x 14 deg, respectively. Conditions ranging from scattered low cumulus to thin cirrus and thick cumulonimbus occurred during the study period. Detailed comparisons with hourly surface observations indicate that the mean cloudiness is within a few percent of the surface-derived sky cover. Formats of the results are also provided. The data can be accessed through the World Wide Web computer network.

  8. On the spatiotemporal evolution of the ionospheric backscatter during magnetically disturbed periods as observed by the TIGER Bruny Island HF radar

    NASA Astrophysics Data System (ADS)

    Kumar, V. V.; Makarevich, R. A.; Kane, T. A.; Ye, H.; Devlin, J. C.; Dyson, P. L.

    2011-08-01

    The Superposed Epoch Analysis (SEA) method is used to examine a 4-year database (2000-2003) of the TIGER Bruny Island radar (MLON=226.78E, MLAT=55.06S) measurements to determine typical patterns of the spatiotemporal evolution of ionospheric backscatter during geomagnetically disturbed periods. SEA is performed separately for three disturbance categories: short-, medium-, and long-duration magnetic disturbances, based on the Dst index variation. Prior to SEA, the diurnal, seasonal, and solar cycle effects have been accounted for by subtracting the nominal quiet-time values. It is found that the occurrence of ionospheric HF backscatter exhibited strongest enhancements near t=0 h between 65S and 70S MLAT (range of 800-2500 km) during short-duration magnetic disturbance. In contrast, a reduction in echo occurrence first occurred near t=0 h at higher ranges (r?2500 km) and expanded equatorwards during the recovery phase of the magnetic disturbances. This reduction in occurrence became progressively stronger and prolonged for medium- and long-duration magnetic disturbances. These categories also showed clear enhancements in the E-region backscatter (r<765 km) commencing from t=0 h. These observations can be explained by three main factors: (1) an enhancement in the E-region densities due to high-energy particle precipitation during magnetically disturbed periods causing the HF radar waves to refract from smaller altitudes and closer ranges, (2) a variability in the F-region densities associated with magnetic disturbances also affecting the propagation of the HF radar waves, and (3) a short-lived strong enhancement in growth rate of decametre-scale ionospheric irregularities when IMF turned southwards causing the highest echo occurrence near t=0 h during SEA.

  9. Time evolution of monsoon low-level jet observed over an Indian tropical station during the peak monsoon period from high-resolution Doppler wind lidar measurements

    NASA Astrophysics Data System (ADS)

    Ruchith, R. D.; Raj, P. Ernest; Kalapureddy, M. C. R.; Deshpande, Sachin M.; Dani, K. K.

    2014-02-01

    Doppler wind lidar measurements of horizontal winds at an Indian tropical station, Mahbubnagar (16.73°N, 77.98°E, 445 m above mean sea level), were used to investigate the time evolution of the monsoon low-level jet (MLLJ) during the southwest monsoon season. Vertical profiles of zonal wind in the altitude range of 100 to 3000 m above surface (at every 50 m height interval and 5 min time averaged) obtained during the period 25 July to 23 August 2011 are considered for the analysis. The zonal winds in the altitude up to 3000 m above ground are predominantly westerly throughout the period and on almost all the days there is a westerly wind speed maximum around 500 m above ground during nighttime. Soon after local sunrise, the core of this wind speed maximum (jet) gets lifted up and by afternoon, the westerly wind maximum is shifted to a higher altitude of 2000 m-2500 m without much change in its magnitude. Analysis of the high-resolution lidar data strongly indicates that the same nocturnal LLJ seems to be moving up and evolving into a daytime westerly MLLJ reported in several previous studies. Wind speed and direction derived from the wind lidar agree reasonably well with simultaneously observed GPS upper air sounding wind measurements. Further analysis shows that the time-height evolution of the jet core is closely associated with daytime convection and boundary layer growth. The presence of clouds over the region seems to inhibit this type of time evolution.

  10. Multiwavelength optical observations of chromospherically active binary systems. V. FF UMa (2RE J0933+624): a system with orbital period variation

    NASA Astrophysics Data System (ADS)

    Glvez, M. C.; Montes, D.; Fernndez-Figueroa, M. J.; de Castro, E.; Cornide, M.

    2007-09-01

    Context: This is the fifth paper in a series aimed at studying the chromospheres of active binary systems using several optical spectroscopic indicators to obtain or improve orbital solution and fundamental stellar parameters. Aims: We present here the study of FF UMa (2RE J0933+624), a recently discovered, X-ray/EUV selected, active binary with strong H? emission. The objectives of this work are, to find orbital solutions and define stellar parameters from precise radial velocities and carry out an extensive study of the optical indicators of chromospheric activity. Methods: We obtained high resolution echelle spectroscopic observations during five observing runs from 1998 to 2004. We found radial velocities by cross correlation with radial velocity standard stars to achieve the best orbital solution. We also measured rotational velocity by cross-correlation techniques and have studied the kinematic by galactic space-velocity components (U, V, W) and Eggen criteria. Finally, we have determined the chromospheric contribution in optical spectroscopic indicators, from Ca ii H & K to Ca ii IRT lines, using the spectral subtraction technique. Results: We have found that this system presents an orbital period variation, higher than previously detected in other RS CVn systems. We determined an improved orbital solution, finding a circular orbit with a period of 3.274 days. We derived the stellar parameters, confirming the subgiant nature of the primary component (MP = 1.67 M? and R sin{i}_P=2.17 R?) and obtained rotational velocities (v sin{i}), of 33.57 0.45 km s-1 and 32.38 0.75 km s-1 for the primary and secondary components respectively. From our kinematic study, we can deduce its membership to the Castor moving group. Finally, the activity study has given us a better understanding of the possible mechanisms that produce the orbital period variation. Based on observations collected with the 2.2 m telescope at the Centro Astronmico Hispano Alemn (CAHA) at Calar Alto (Almera, Spain), operated jointly by the Max-Planck Institut fr Astronomie and the Instituto de Astrofsica de Andaluca (CSIC); with the Nordic Optical Telescope (NOT), operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway and Sweden, in the Spanish Observatorio del Roque de Los Muchachos of the Instituto de Astrofsica de Canarias; with the 2.1 m Otto Struve Telescope at McDonald Observatory of the University of Texas at Austin (USA) and with Hobby-Eberly Telescope, which is a joint project of the University of Texas at Austin, the Pennsylvania State University, Stanford University, Ludwig-Maximilians-Universitt Mnchen, and Georg-August-Universitt Gttingen. Tables 7 and 8 are only available in electronic form at http://www.aanda.org

  11. PM measurement campaign HOVERT in the Greater Berlin area: model evaluation with chemically specified particulate matter observations for a one year period

    NASA Astrophysics Data System (ADS)

    Beekmann, M.; Kerschbaumer, A.; Reimer, E.; Stern, R.; Mller, D.

    2007-01-01

    The HOVERT (HOrizontal and VERtical Transport of ozone and particulate matter) campaign held in the Berlin Brandenburg area in Eastern Germany from September 2001 to September 2002 allowed to collect a unique data set of the aerosol chemical speciation (daily averages) at traffic, urban and rural sites. These observations are used for a thorough evaluation of the aerosol part in the REM-CALGRID model (RCG) developed at the Free University of Berlin (FUB). For inorganic ions (sulphate, nitrate and ammonium), simulated annual averages agree to observations within 30% at more than half of the sites and always within a factor of two. Correlation coefficients are larger than in previous studies for SO42- and NH4+ (>0.7). For nitrate, less elevated correlations, 0.4-0.7 in the cold season, 0.2-0.4 in the warm season, are encountered. To our knowledge, this is one of the first comparisons of air quality model simulated elemental and organic carbon (EC and OC) with daily observations for a whole year. It suggests an overestimation of EC and OC emissions in the Berlin area (through a scaling techniques between EC, OC and NOx and when assuming correct NOx emissions), and an underestimation of EC and OC at rural sites. Secondary organic aerosol (SOA) formation, recently introduced into the model (SORGAM module, Schell et al., 2001), is simulated as a very variable process, SOA levels varying from close to zero for most days to more than 5 ?g/m3. Correlation between simulated SOA to observed OC is about 0.6, indicating that simulated variability partly corresponds to reality.

  12. PM measurement campaign HOVERT in the Greater Berlin area: model evaluation with chemically specified particulate matter observations for a one year period

    NASA Astrophysics Data System (ADS)

    Beekmann, M.; Kerschbaumer, A.; Reimer, E.; Stern, R.; Mller, D.

    2006-08-01

    The HOVERT (Horizontal and VERtical Transport of Ozone and particulate matter) campaign held in the Berlin Brandenburg area in Eastern Germany from September 2001 to September 2002 allowed to collect a unique data set of the aerosol chemical speciation (daily averages) at traffic, urban and rural sites. These observations are used for a thorough evaluation of the aerosol part in the REM-CALGRID model (RCG) developed at the Free University of Berlin (FUB). For inorganic ions (sulphate, nitrate and ammonium), simulated annual averages agree to observations within 30% at more than half of the sites and always within a factor of two. Correlation coefficients are larger than in previous studies for SO42- and NH4+ (>0.7). For nitrate, less elevated correlations, 0.4-0.7 in the cold season, 0.2-0.4 in the warm season, are encountered. To our knowledge, this is one of the first comparisons of air quality model simulated elemental carbon (EC and OC) with daily observations for a whole year. It suggests an overestimation of EC and OC emissions in the Berlin area (through a scaling techniques between EC, OC and NOx and when assuming correct NOx emissions), and an underestimation of EC and OC at rural sites. Secondary organic aerosol (SOA) formation, recently introduced into the model (SORGAM module, Schell et al., 2001), is simulated as a very variable process, SOA levels varying from close to zero for most days to more than 5 g/m3. Correlation between simulated SOA to observed OC is about 0.6, indicating that simulated variability partly corresponds to reality.

  13. Long-term MAX-DOAS network observations of NO2 in Russia and Asia (MADRAS) during the period 2007-2012: instrumentation, elucidation of climatology, and comparisons with OMI satellite observations and global model simulations

    NASA Astrophysics Data System (ADS)

    Kanaya, Y.; Irie, H.; Takashima, H.; Iwabuchi, H.; Akimoto, H.; Sudo, K.; Gu, M.; Chong, J.; Kim, Y. J.; Lee, H.; Li, A.; Si, F.; Xu, J.; Xie, P.-H.; Liu, W.-Q.; Dzhola, A.; Postylyakov, O.; Ivanov, V.; Grechko, E.; Terpugova, S.; Panchenko, M.

    2014-08-01

    We conducted long-term network observations using standardized Multi-Axis Differential optical absorption spectroscopy (MAX-DOAS) instruments in Russia and ASia (MADRAS) from 2007 onwards and made the first synthetic data analysis. At seven locations (Cape Hedo, Fukue and Yokosuka in Japan, Hefei in China, Gwangju in Korea, and Tomsk and Zvenigorod in Russia) with different levels of pollution, we obtained 80 927 retrievals of tropospheric NO2 vertical column density (TropoNO2VCD) and aerosol optical depth (AOD). In the technique, the optimal estimation of the TropoNO2VCD and its profile was performed using aerosol information derived from O4 absorbances simultaneously observed at 460-490 nm. This large data set was used to analyze NO2 climatology systematically, including temporal variations from the seasonal to the diurnal scale. The results were compared with Ozone Monitoring Instrument (OMI) satellite observations and global model simulations. Two NO2 retrievals of OMI satellite data (NASA ver. 2.1 and Dutch OMI NO2 (DOMINO) ver. 2.0) generally showed close correlations with those derived from MAX-DOAS observations, but had low biases of up to ~50%. The bias was distinct when NO2 was abundantly present near the surface and when the AOD was high, suggesting a possibility of incomplete accounting of NO2 near the surface under relatively high aerosol conditions for the satellite observations. Except for constant biases, the satellite observations showed nearly perfect seasonal agreement with MAX-DOAS observations, suggesting that the analysis of seasonal features of the satellite data were robust. Weekend reduction in the TropoNO2VCD found at Yokosuka and Gwangju was absent at Hefei, implying that the major sources had different weekly variation patterns. While the TropoNO2VCD generally decreased during the midday hours, it increased exceptionally at urban/suburban locations (Yokosuka, Gwangju, and Hefei) during winter. A global chemical transport model, MIROC-ESM-CHEM (Model for Interdisciplinary Research on Climate-Earth System Model-Chemistry), was validated for the first time with respect to background NO2 column densities during summer at Cape Hedo and Fukue in the clean marine atmosphere.

  14. Field observation of morpho-dynamic processes during storms at a Pacific beach, Japan: Role of long-period waves in storm-induced berm erosion

    PubMed Central

    MIZUGUCHI, Masaru; SEKI, Katsumi

    2015-01-01

    Many ultrasonic wave gages were placed with a small spacing across the swash zone to monitor either sand level or water level. Continuous monitoring conducted for a few years enabled the collection of data on the change in wave properties as well as swash-zone profiles. Data sets including two cases of large-scale berm erosion were analyzed. The results showed that 1) shoreline erosion started when high waves with significant power in long-period (1 to 2 min.) waves reached the top of a well-developed berm with the help of rising tide; 2) the beach in the swash zone was eroded with higher elevation being more depressed, while the bottom elevation just outside the swash zone remained almost unchanged; and 3) erosion stopped in a few hours after the berm was completely eroded or the swash-zone slope became uniformly mild. These findings strongly suggest that long waves play a dominant role in the swash-zone dynamics associated with these erosional events. PMID:25748583

  15. Should patients with implantable cardioverter-defibrillators be allowed to drive? Observations in 291 patients from a single center over an 11-year period.

    PubMed

    Trappe, H J; Wenzlaff, P; Grellman, G

    1998-06-01

    Motor-vehicle driving restrictions for patients with implantable cardioverter-defibrillators (ICDs) vary widely throughout the world because safety concerns have never been adequately resolved in this patient population. To address this issue, we examined the driving behavior of 291 ICD patients to correlate the frequency of device therapy during driving, the occurrence of syncopal symptoms, and the incidence of traffic accidents. Fifty of the 291 patients had never driven. Of the remaining 241 patients, 171 (59%) continued driving postimplant and 70 (24%) elected to stop prior to (n = 30) or at the time of ICD implantation (n = 40). Patients were followed for a mean of 38 +/- 26 months (range < 1-124). During this period, no patients died while driving. Of 11 accidents involving 11 driving patients (6%), only 1 was caused by the driver, and none was related to syncopal symptoms or ICD therapy. Although 2 accidents (8%) occurred within 12 months postimplant, the majority (50%) took place after more than 36 months. ICD therapy was delivered in 8 patients (5%) while driving: 13% (1 episode) of the discharges occurred within the first year postimplant, 13% (1 episode) occurred between 1-2 years, and 74% (6 episodes) occurred > 2 years. None of these patients experienced syncope before or during these episodes. A multivariate analysis was unable to identify any variables that might predict increased risk of ICD therapy (with or without sudden death) while driving and consequent motor vehicle accidents. Our data suggest that such events occur only rarely. PMID:9870013

  16. Field observation of morpho-dynamic processes during storms at a Pacific beach, Japan: role of long-period waves in storm-induced berm erosion.

    PubMed

    Mizuguchi, Masaru; Seki, Katsumi

    2015-01-01

    Many ultrasonic wave gages were placed with a small spacing across the swash zone to monitor either sand level or water level. Continuous monitoring conducted for a few years enabled the collection of data on the change in wave properties as well as swash-zone profiles. Data sets including two cases of large-scale berm erosion were analyzed. The results showed that 1) shoreline erosion started when high waves with significant power in long-period (1 to 2 min.) waves reached the top of a well-developed berm with the help of rising tide; 2) the beach in the swash zone was eroded with higher elevation being more depressed, while the bottom elevation just outside the swash zone remained almost unchanged; and 3) erosion stopped in a few hours after the berm was completely eroded or the swash-zone slope became uniformly mild. These findings strongly suggest that long waves play a dominant role in the swash-zone dynamics associated with these erosional events. PMID:25748583

  17. The role of nocturnal delivery and delivery during the holiday period in Finland on obstetric anal sphincter rupture rates- a population based observational study

    PubMed Central

    2010-01-01

    Background Obstetric anal sphincter rupture (OASR) is a serious complication of delivery, which frequently results in faecal incontinence despite primary repair and has serious implications for women's health. The objective of this study was to assess whether human factors, workload and staffing at night, at weekends and during holidays has an effect on the increasing OASR rates among all singleton vaginal deliveries (n = 514,741) having occurred between 1997 and 2007 in Finland. Women (n = 2,849) with OASR were compared in terms of possible risk factors to women without OASR using stepwise logistic regression analysis. Findings In Finland, the increase in OASR rate is striking, from 0.2% in 1997 to 0.9% in 2007. OASR rates varied from 0.49% to 0.58% (? 0.001) according to the time of day, and were lowest at night. After adjustment for patient-mix and the use of interventions, the risk of OASR was 11% lower (95% CI 3-18%) at night and 15% lower (95% CI 3-26%) in July - the main holiday month. Only 14% of the increased OASR risk during the day time (8-23.59) was attributable to vacuum assistance and birth weight, whereas the holiday period had no effect. Conclusions Decreased OASR rates at night and in July suggest that human factors such as decreased alertness due to fatigue or hospitals' administrative factors such as workload and staffing did not increase the rates of OASR. PMID:20205904

  18. Tectonomagnetic Anomaly Observed at Parkfield, California, from 1993 to the Present - Correspondence to Increased Shear Strain-Rate during the Same Period.

    NASA Astrophysics Data System (ADS)

    Johnston, M. J.; Mueller, R. J.

    2002-12-01

    Precise measurements of local magnetic fields have been obtained with a differentially connected array of seven synchronized proton magnetometers in the Parkfield region since 1984. The magnetometers are located along 60 km of the transition region of the San Andreas fault where fault creep changes from zero to about 15 mm/yr. To the south the fault last ruptured with a M8 earthquake in 1857. The central region has ruptured with M6 earthquakes in quasi-periodic manner from 1881 to 1966. Between 1992 and 1994, a significant increase in shear strain was observed on the 2-color geodimeter network and a small network of borehole tensor strainmeters in the central region. This strain change was accompanied by three M4.5-5 earthquakes roughly a year apart in 1992, 1993 and 1994 near the suspected nucleation point of M6+ earthquakes in this region. After correction for secular variation, it is apparent that an anomalous 0.2 nT/yr increase in the magnetic field has occurred from mid-1993 to the present on several magnetometers on the southeast side of the San Andreas Fault and smaller increases are observed on the northeast side of the fault. The strain data are consistent with increased slip in the central region near the hypocenters of the M5 earthquakes. The magnetic field data indicate that this change in slip occurred in a region larger than indicated by the 2-color EDM data. Magnetic field steps were not expected, nor were they observed, to accompany the M5 earthquakes. A simple rectangular-source piezomagnetic model with a width W of 6 km, a length L of 20 km, a depth of 3 km and variable slip change of up to 5 cm generates magnetic field perturbations of the same signs and amplitudes as those observed. If correct, this increased slip distribution indicatesa changing stress state in the region which may increase the likelihood of moderate magnitude earthquakes in the near future.

  19. Summary of Sonic Boom Rise Times Observed During FAA Community Response Studies over a 6-Month Period in the Oklahoma City Area

    NASA Technical Reports Server (NTRS)

    Maglieri, Domenic J.; Sothcott, Victor E.

    1990-01-01

    The sonic boom signature data acquired from about 1225 supersonic flights, over a 6-month period in 1964 in the Oklahoma City area, was enhanced with the addition of data relating to rise times and total signature duration. These later parameters, not available at the time of publication of the original report on the Oklahoma City sonic boom exposures, are listed in tabular form along with overpressure, positive impulse, positive duration, and waveform category. Airplane operating information along with the surface weather observations are also included. Sonic boom rise times include readings to the 1/2, 3/4, and maximum overpressure values. Rise time relative probabilities for various lateral locations from the ground track of 0, 5, and 10 miles are presented along with the variation of rise times with flight altitude. The tabulated signature data, along with corresponding airplane operating conditions and surface and upper level atmospheric information, are also available on electronic files to provide it in the format for more efficient and effective utilization.

  20. Inter-annual variability of aerosol optical depth over the tropical Atlantic Ocean based on MODIS-Aqua observations over the period 2002-2012

    NASA Astrophysics Data System (ADS)

    Gkikas, Antonis; Hatzianastassiou, Nikolaos

    2013-04-01

    The tropical Atlantic Ocean is affected by dust and biomass burning aerosol loads transported from the western parts of the Saharan desert and the sub-Sahel regions, respectively. The spatial and temporal patterns of this transport are determined by the aerosol emission rates, their deposition (wet and dry), by the latitudinal shift of the Intertropical Convergence Zone (ITCZ) and the prevailing wind fields. More specifically, in summer, Saharan dust aerosols are transported towards the Atlantic Ocean, even reaching the Gulf of Mexico, while in winter the Atlantic Ocean transport takes place in more southern latitudes, near the equator, sometimes reaching the northern parts of South America. In the later case, dust is mixed with biomass burning aerosols originating from agricultural activities in the sub-Sahel, associated with prevailing north-easterly airflow (Harmattan winds). Satellite observations are the appropriate tool for describing this African aerosol export, which is important to atmospheric, oceanic and climate processes, offering the advantage of complete spatial coverage. In the present study, we use satellite measurements of aerosol optical depth at 550nm (AOD550nm), on a daily and monthly basis, derived from MODIS-Aqua platform, at 1ox1o spatial resolution (Level 3), for the period 2002-2012. The primary objective is to determine the pixel-level and regional mean anomalies of AOD550nm over the entire study period. The regime of the anomalies of African export is interpreted in relation to the aerosol source areas, precipitation, wind patterns and temporal variability of the North Atlantic Oscillation Index (NAOI). In order to ensure availability of AOD over the Sahara desert, MODIS-Aqua Deep Blue products are also used. As for precipitation, Global Precipitation Climatology Project (GPCP) data at 2.5ox2.5o are used. The wind fields are taken from the National Center for Environmental Prediction (NCEP). Apart from the regime of African aerosol export in the northern tropical Atlantic Ocean, it is also attempted to examine possible relationships between African dust export and NAO, with emphasis on identifying possible effects of the former to the later. This might be possible since aerosols through their radiative effects are known to affect atmospheric dynamics, for example modifying precipitation or the tracks and intensity of cyclones. Of course, such aerosol feedbacks on atmospheric dynamics and teleconnections are certainly complex and difficult to study, requiring the use of climate models, which is planned in a next step of the study.

  1. X-ray, FUV, and UV Observations of ? Centauri B: Determination of Long-term Magnetic Activity Cycle and Rotation Period

    NASA Astrophysics Data System (ADS)

    DeWarf, L. E.; Datin, K. M.; Guinan, E. F.

    2010-10-01

    Over the last couple of decades we have been carrying out a study of stellar magnetic activity, dynamos, atmospheric physics, and spectral irradiances from a sample of solar-type G0-5 V stars with different ages. One of the major goals of this program is to study the evolution of the Sun's X-ray through NUV spectral irradiances with age. Of particular interest is the determination of the young Sun's elevated levels of high-energy fluxes because of the critical roles that X-ray (coronal) through FUV (transition region (TR), chromospheric) emissions play on the photochemical and photoionization evolution (and possible erosion) of early, young planetary atmospheres and ionospheres. Motivated by the current exoplanetary search missions (such as Kepler and CoRoT, along with the planned Space Interferometry Mission and Darwin/Terrestrial Planet Finder missions) that are hunting for Earth-size planets in the habitable zones (liquid water) of nearby main-sequence G-M stars, we are expanding our program to cooler, less luminous, but very importantly, much more numerous main-sequence K-type stars, such as ? Centauri B. The long life (2-3 longer than the Sun) and slow evolution of K stars provide nearly constant energy sources for possible hosted planets. This program parallels our "Sun in Time" program, but extends the study to stars with deeper convective zone depths. Presented here are X-ray (coronal; ROSAT, Chandra, XMM-Newton), UV (TR; International Ultraviolet Explorer (IUE)), NUV (chromospheric; IUE), and recently acquired FUV (TR/chromospheric; FUSE Cycles 7/8) observations of the K1 V star ? Cen B (HD 128621; V = 1.33; (B - V) = +0.88; ? = 5.6 0.6 Gyr). These combined high-energy measures provide a more complete look into the nature of ? Cen B's magnetic activity and X-ray-UV radiances. We find that ? Cen B has exhibited significant long-term variability in X-ray through NUV emission fluxes, indicating a solar-like long-term activity cycle of P cycle = 8.84 0.4 years. In addition, analysis of the short-term rotational modulation of mean light due to the effects of magnetically active regions has yielded a well-determined rotation period of P rotation = 36.2 1.4 days. ? Cen B is the only old main-sequence K star with a reliably determined age and rotation period, and for early K stars, as in the case of the Sun for G2 V stars, is an important calibrator for stellar age/rotation/activity relations.

  2. Ground-based observations of Saturn's auroral ionosphere over three days: Trends in H3+ temperature, density and emission with Saturn local time and planetary period oscillation

    NASA Astrophysics Data System (ADS)

    O'Donoghue, James; Melin, Henrik; Stallard, Tom S.; Provan, G.; Moore, Luke; Badman, Sarah V.; Cowley, Stan W. H.; Baines, Kevin H.; Miller, Steve; Blake, James S. D.

    2016-01-01

    On 19-21 April 2013, the ground-based 10-m W.M. Keck II telescope was used to simultaneously measure H3+ emissions from four regions of Saturn's auroral ionosphere: (1) the northern noon region of the main auroral oval; (2) the northern midnight main oval; (3) the northern polar cap and (4) the southern noon main oval. The H3+ emission from these regions was captured in the form of high resolution spectral images as the planet rotated. The results herein contain twenty-three H3+ temperatures, column densities and total emissions located in the aforementioned regions - ninety-two data points in total, spread over timescales of both hours and days. Thermospheric temperatures in the spring-time northern main oval are found to be cooler than their autumn-time southern counterparts by tens of K, consistent with the hypothesis that the total thermospheric heating rate is inversely proportional to magnetic field strength. The main oval H3+ density and emission is lower at northern midnight than it is at noon, in agreement with a nearby peak in the electron influx in the post-dawn sector and a minimum flux at midnight. Finally, when arranging the northern main oval H3+ parameters as a function of the oscillation period seen in Saturn's magnetic field - the planetary period oscillation (PPO) phase - we see a large peak in H3+ density and emission at ∼115° northern phase, with a full-width at half-maximum (FWHM) of ∼44°. This seems to indicate that the influx of electrons associated with the PPO phase at 90° is responsible at least in part for the behavior of all H3+ parameters. A combination of the H3+ production and loss timescales and the ±10° uncertainty in the location of a given PPO phase are likely, at least in part, to be responsible for the observed peaks in H3+ density and emission occurring at a later time than the peak precipitation expected at 90° PPO phase.

  3. Remission in schizophrenia: results of cross-sectional with 6-month follow-up period and 1-year observational therapeutic studies in an outpatient population

    PubMed Central

    2012-01-01

    Background A standardized definition of remission criteria in schizophrenia was proposed by the International group of NC Andreasen in 2005 (low symptom threshold for the eight core Positive and Negative Syndrome Scale (PANSS) symptoms for at least 6 consecutive months). Methods A cross-sectional study of remission rate, using a 6-month follow-up to assess symptomatic stability, was conducted in two healthcare districts (first and second) of an outpatient psychiatric service in Moscow. The key inclusion criteria were outpatients with an International Classification of Diseases, 10th edition (ICD-10) diagnosis of schizophrenia or schizoaffective disorder. Remission was assessed using modern criteria (severity and time criteria), PANSS and Global Assessment of Functioning (GAF). Patients who were stable but did not satisfied the symptomatic criteria were included in a further 1-year observational study, with the first group (first district) receiving risperidone (long-acting, injectable) (RLAI) and the second group (second district) continuing to receiving routine treatment. Symptoms were assessed with PANSS, social functioning with the personal and social performance scale, compliance with rating of medication influences scale, and extrapyramidal side effects with the Simpson-Angus scale. Results Only 64 (31.5%) of 203 outpatients met the criteria for symptomatic remission in the cross-sectional study, but at the end of the 6-month follow-up period, 158 (77.8%) were stable (irrespective of remission status). Among these only 53 (26.1%) patients fulfilled the remission criteria. The observational study had 42 stable patients in the RLAI group and 35 in the routine treatment group: 19.0% in the RLAI group and 5.7% in the control group met remission criteria after 12 months of therapy. Furthermore, reduction of PANSS total and subscale scores, as well as improvement in social functioning, was more significant in the first group. Conclusions Only around one-quarter of our outpatient schizophrenic population met full remission criteria. Use of RLAI gave a better remission rate than achieved in standard care with routine treatment. Criteria for remission should take into account clinical course and functioning to support clinical care. PMID:22221826

  4. Long-period tides observed with a superconducting gravimeter at Syowa Station, Antarctica, and their implication to global ocean tide modeling

    NASA Astrophysics Data System (ADS)

    Sato, Tadahiro; Ooe, Masatsugu; Nawa, Kazunari; Shibuya, Kazuo; Tamura, Yoshiaki; Kaminuma, Katsutada

    1997-10-01

    The long-period tides (Mf and Mm waves) were analyzed with the 2 years data obtained with a superconducting gravimeter (SG) installed at Syowa Station (69.0 S, 39.6 E), Antarctica. The observed amplitudes, phase lags and amplitude factors (? factors) were 11.642 0.035 ?Gal, -0.12 0.17 and 1.1218 0.0034 for the Mf wave, and 6.143 0.058 ?Gal, 0.33 0.54 and 1.1205 0.0106 for the Mm wave, respectively (1 ?Gal = 10 -8 m s -2). The ocean tide effects (effects of the attraction and loading due to the ocean mass) at the observation site were estimated using the five global ocean tide models: equilibrium ocean tide model, Schwiderski model (Schwiderski, E.W., 1980. On charting global ocean tides. Rev. Geophys. Space Phys. 18, 243-268.), Dickman model (Dickman, S.R., 1989. A complete spherical harmonic approach to luni-solar tides. Geophys. J. Int. 99, 457-468.), CSR model (Eanes, R.J., 1995. Private communication.), and Desai and Wahr model (Desai, S.H., Wahr, J.M., 1995. Empirical ocean tide models estimated from TOPEX/POSEIDON altimetry. J. Geophys. Res. 100, 25205-25228.). The averages of the five estimates are 0.433 ?Gal and 0.244 ?Gal in amplitude and 192.9 and 179.5 in phase for the Mf and Mm waves, respectively. The five estimates differ by a maximum of 0.104 ?Gal in amplitude and 18.8 in phase for the Mf wave, and by 0.033 ?Gal and 6.4 for the Mm wave. The estimated Mm phases are nearly 180 for the five models, and the variation of their values among the models is relatively small compared with that of the Mf phases. These indicate that the Mm wave is much closer to an equilibrium tide than the Mf wave. Due to the variation of the ocean tide corrections, the corrected ? factors were scattered within the ranges of 1.158 to 1.169 for the Mf wave and of 1.163 to 1.169 for the Mm wave. However, it is noted that the mean ? factors of the five ocean models, i.e. 1.162 0.023 for the Mf wave and 1.165 0.014 for the Mm wave, prefer slightly larger value rather than those estimated from the theory of the elastic tide.

  5. Motion of CMS detector and mechanical structures during Magnet Cycles and Stability Periods from 2008 to 2013 as observed by the Link Alignment System

    NASA Astrophysics Data System (ADS)

    Arce, P.; Barcala, J. M.; Calvo, E.; Ferrando, A.; Josa, M. I.; Molinero, A.; Navarrete, J.; Oller, J. C.; Brochero, J.; Calderón, A.; Fernández, M. G.; Gómez, G.; González-Sánchez, F. J.; Martínez-Rivero, C.; Matorras, F.; Rodrigo, T.; Scodellaro, L.; Sobrón, M.; Vila, I.; Virto, A. L.; Fernández, J.; Raics, P.; Szabó, Zs.; Trócsnyi, Z.; Ujvári, B.; Zilizi, Gy.; Béni, N.; Christian, G.; Imrek, J.; Molnar, J.; Novak, D.; Pálinkás, J.; Székely, G.; Szillási, Z.; Bencze, G. L.; Vestergombi, G.; Benettoni, M.; Gasparini, F.; Montecassiano, F.; Rampazzo, M.; Zago, M.; Benvenuti, A.; Reithler, H.; Ruiz-Árbol, P.; Jiang, C.

    2016-03-01

    Magnet Cycles and Stability Periods of the CMS Experiment are studied with the Alignment Link System data recorded along the 2008-2013 years of operation. The motions of the mechanical structures due to the magnetic field forces are studied and the mechanical stability of the detector during the physics data taking periods is verified.

  6. Period Cramps

    MedlinePLUS

    ... ago. She's learned to handle using pads and tampons, but the cramps are really bothering her. Sometimes ... Periods Getting Your Period at School Pads and Tampons Do Periods Ever End? All About Menstruation Contact ...

  7. Spectral Index and Quasi-Periodic Oscillation Frequency Correlation in Black Hole (BH) Sources: Observational Evidence of Two Phases and Phase Transition in BHs

    NASA Technical Reports Server (NTRS)

    Titarchuk, Lev; Fiorito, Ralph

    2004-01-01

    Recent studies have shown that strong correlations are observed between the low frequencies (1-10 Hz) of quasiperiodic oscillations (QPOs) and the spectral power law index of several Black Hole (BH) candidate sources, in low hard states, steep power-law (soft) states and in transition between these states. The observations indicate that the X-ray spectrum of such state (phases) show the presence of a power-law component and are sometimes related to simultaneous radio emission indicated the probable presence of a jet. Strong QPOs (less than 20% rms) are present in the power density spectrum in the spectral range where the power-law component is dominant ( i.e. 60-90% ). This evidence contradicts the dominant long standing interpretation of QPOs as a signature of the thermal accretion disk. We present the data from the literature and our own data to illustrate the dominance of power-law index-QPO frequency correlations. We provide a model, that identifies and explains the origin of the QPOs and how they are imprinted on the properties of power-law flux component. We argue the existence of a bounded compact coronal region which is a natural consequence of the adjustment of Keplerian disk flow to the innermost sub-Keplerian boundary conditions near the central object and that ultimately leads to the formation of a transition layer (TL) between the adjustment radius and the innermost boundary. The model predicts two phases or states dictated by the photon upscattering produced in the TL: (1) hard state, in which the TL is optically thin and very hot (kT approx. greater than 50 keV) producing photon upscattering via thermal Componization; the photon spectrum index Gamma appprox.1.5 for this state is dictated by gravitational energy release and Compton cooling in an optically thin shock near the adjustment radius; (2) a soft state which is optically thick and relatively cold (approx. less than 5 keV); the index for this state, Gamma approx. 2.8 is determined by soft-photon upscattering and photon trapping in converging flow into BH. In the TL model for corona the QPO frequency vnu(sub high) is related to the gravitational (close to Keplerian) frequency nu(sub K) at the outer (adjustment) radius and nu(sub low) is related to the TL s normal mode (magnetoacoustic) oscillation frequency nu(sub MA). The observed correlations between index and low and high QPO frequencies are readily explained in terms of this model. We also suggest a new method for evaluation of the BH mass using the index-frequency correlation.

  8. X-RAY, FUV, AND UV OBSERVATIONS OF {alpha} CENTAURI B: DETERMINATION OF LONG-TERM MAGNETIC ACTIVITY CYCLE AND ROTATION PERIOD

    SciTech Connect

    DeWarf, L. E.; Guinan, E. F.; Datin, K. M.

    2010-10-10

    Over the last couple of decades we have been carrying out a study of stellar magnetic activity, dynamos, atmospheric physics, and spectral irradiances from a sample of solar-type G0-5 V stars with different ages. One of the major goals of this program is to study the evolution of the Sun's X-ray through NUV spectral irradiances with age. Of particular interest is the determination of the young Sun's elevated levels of high-energy fluxes because of the critical roles that X-ray (coronal) through FUV (transition region (TR), chromospheric) emissions play on the photochemical and photoionization evolution (and possible erosion) of early, young planetary atmospheres and ionospheres. Motivated by the current exoplanetary search missions (such as Kepler and CoRoT, along with the planned Space Interferometry Mission and Darwin/Terrestrial Planet Finder missions) that are hunting for Earth-size planets in the habitable zones (liquid water) of nearby main-sequence G-M stars, we are expanding our program to cooler, less luminous, but very importantly, much more numerous main-sequence K-type stars, such as {alpha} Centauri B. The long life (2-3x longer than the Sun) and slow evolution of K stars provide nearly constant energy sources for possible hosted planets. This program parallels our 'Sun in Time' program, but extends the study to stars with deeper convective zone depths. Presented here are X-ray (coronal; ROSAT, Chandra, XMM-Newton), UV (TR; International Ultraviolet Explorer (IUE)), NUV (chromospheric; IUE), and recently acquired FUV (TR/chromospheric; FUSE Cycles 7/8) observations of the K1 V star {alpha} Cen B (HD 128621; V = 1.33; (B - V) = +0.88; {tau} = 5.6 {+-} 0.6 Gyr). These combined high-energy measures provide a more complete look into the nature of {alpha} Cen B's magnetic activity and X-ray-UV radiances. We find that {alpha} Cen B has exhibited significant long-term variability in X-ray through NUV emission fluxes, indicating a solar-like long-term activity cycle of P{sub cycle} = 8.84 {+-} 0.4 years. In addition, analysis of the short-term rotational modulation of mean light due to the effects of magnetically active regions has yielded a well-determined rotation period of P{sub rotation} = 36.2 {+-} 1.4 days. {alpha} Cen B is the only old main-sequence K star with a reliably determined age and rotation period, and for early K stars, as in the case of the Sun for G2 V stars, is an important calibrator for stellar age/rotation/activity relations.

  9. Randomized, observer-blind, split-face study to compare the irritation potential of 2 topical acne formulations over a 14-day treatment period.

    PubMed

    Ting, William

    2012-08-01

    This randomized, observer-blind, split-face study assessed the irritation potential and likelihood of continued use of clindamycin phosphate 1.2%--benzoyl peroxide (BPO) 2.5% gel or adapalene 0.1%--BPO 2.5% gel once daily over a 14-day treatment period in 21 participants (11 males; 10 females) with acne who were 18 years or older. Investigator clinical assessment (erythema and dryness) and self-assessment (dryness and burning/stinging) were performed at baseline and each study visit (days 1-14) using a 4-point scale (O = none; 3 = severe). Transepidermal water loss (TEWL) and corneometry measurements were performed at baseline and days 3, 5, 7, 9, 11, and 14. Lesions were counted at baseline and on day 14. Participant satisfaction questionnaires were completed on days 7 and 14. At the end of the study, investigators reported none or only mild erythema in 86% (18/21) of participants treated with clindamycin phosphate 1.2%--BPO 2.5% gel compared with 62% (13/21) of participants treated with adapalene 0.1%--BPO 2.5% gel. No severe erythema was reported with clindamycin phosphate 1.2%--BPO 2.5% gel. Adapalene 0.1%--BPO 2.5% gel was prematurely discontinued due to severe erythema in 1 participant on day 5 and a second participant on day 9. Additionally, 2 more participants reported severe erythema on day 14. Mean erythema scores were 0.9 (mean change from baseline, 0.7) with clindamycin phosphate 1.2%--BPO 2.5% gel and 1.4 (mean change from baseline, 1.3) with adapalene 0. 1%--BPO 2.5% gel on day 14 (P < .05 for days 6-14). Similar results were seen with dryness. Mean scores were 0.5 (mean change from baseline, 0.4) and 1.0 (mean change from baseline, 1.0), respectively (P < .05 for days 6-14). Self-assessment, TEWL, and corneometry results underscored the investigator clinical assessment. Participant preference and likelihood of continued usage was greater with clindamycin phosphate 1.2%--BPO 2.5% gel. Continued use and efficacy results for the treatment of acne were influenced by the potential of the product to cause irritation and the participant preferences. Irritation potential was more pronounced and severe with adapalene 0.1%--BPO 2.5% gel. Undoubtedly, as a result more participants preferred treatment with clindamycin phosphate 1.2%--BPO 2.5% gel and were more likely to continue to use the product. PMID:22988653

  10. Dynamics and evolution of tree populations and soil-vegetation relationships in Fogscapes: Observations over a period of 14 years at the experimental sites of Meija (Peru).

    NASA Astrophysics Data System (ADS)

    Salbitano, F.; Calamini, G.; Certini, G.; Ortega, A.; Pierguidi, A.; Villasante, L.; Caceres, R.; Coaguila, D.; Delgado, M.

    2010-07-01

    The Fogscapes, i.e. fog-dependent landscapes, and the sub mountain drylands of the Pacific Coast from Ecuador to Northern Chile are amongst the most fragile regions of the planet. The so-called "Lomas" (i.e. Hills) ecosystems are characterised by pre-desertic flora and vegetation where the plant phenological pattern coincides with the fog season from June to December every year. The occurance of ENSO (El Nio Southern Oscillation) affects these ecosystems inducing, occasionally, a sudden change in the characteristics of the vegetation. Relics of low-density woodlands dominated by Caesalpinea spinosa and scattered trees of the same species (which during the fog season appear as savannah-like ecosystems) are still present but becoming increasingly rare due to past and present overgrazing In the experimental site of Las Cuchillas, located on the coastal hills close to Meija (Dept. Arequipa, South Peru) trees of native species (Caesalpinaea spinosa and Prosopis pallida) and exotic species (Acacia saligna, Casuarina equisetifolia, Parkinsonia aculeata) were planted in 1996, in order to look at the rehabilitation potential of the degraded "lomas" ecosystems. This paper deals with the results observed over a period of 14 years of tree growth patterns and the related results concerning the soil and habitat dynamics. Among indigenous species Caesalpinea spinosa shows the heighest rate of survival even if the height increment is low and the tree crowns tend to dry out at a height of approximately two metres, followed by the appearance of new shoots produced during the course of the seasons. The exotic Acacia saligna shows the maximum height, diameter and crown volume increments. The habitat conditions, both in term of diversity / frequency of plant and animal populations, and plant cover (LAI estimated by processing fish-eye lens images) have changed substantially over the years. A number of samples from the top mineral soil and random samples from the forest floor were collected both from the reforested test site and from the adjacent control areas were no trees had been planted. The samples were analysed for organic carbon and total nitrogen. Overall, the tree-covered soil retained much more of both elements than the non-forested areas, thus demonstrating the efficiency of the intervention carried out in terms of combatting the greenhouse effect. The various tree species planted, however, showed greatly variable capacity to promote carbon sequestration at soil level. The results referred to above are critical in understanding the plant population dynamics of pre-desertic ecosystems in response to climate change and in assessing the potential of reforestation programmes and landscape conservation strategies for the purposes of carbon sequestration.

  11. Integrating the Desegregated School: Some Observations and Suggestions.

    ERIC Educational Resources Information Center

    Virag, Wayne F.

    The problem of the desegregation process in public schools, beginning with the Supreme Court decision Brown v the Board of Education of Topeka, Kansas, is that it is conceived of as an artificial climate imposed by ratios and busing rather than a learning situation wherein ethnocentricity is developed as a positive attribute. Integration, however,…

  12. YELLOW HYPERGIANTS SHOW LONG SECONDARY PERIODS?

    SciTech Connect

    Stothers, Richard B.

    2012-06-01

    There is observational evidence that intermittent long secondary periods of {approx}1000 days are present in the well-observed yellow hypergiants {rho} Cas and HR 8752. The long secondary period is interpreted here as the turnover time of giant convection cells in the convective envelope, as has been already suggested in the case of red giants and supergiants of high luminosity. The observed secondary periods and surface radial velocities of {rho} Cas and HR 8752 agree with the theoretical predictions, within the expected errors. These results support a theoretical interpretation that now covers the entire initial mass range from 1 to 50 M{sub Sun} for luminous cool stars.

  13. First observations of the fumarolic gas output from a restless caldera: Implications for the current period of unrest (2005-2013) at Campi Flegrei

    NASA Astrophysics Data System (ADS)

    Aiuppa, A.; Tamburello, G.; Napoli, R.; Cardellini, C.; Chiodini, G.; Giudice, G.; Grassa, F.; Pedone, M.

    2013-10-01

    The fumarolic gas output has not been quantified for any of the currently deforming calderas worldwide, due to the lack of suitable gas flux sensing techniques. In view of resumption of ground uplift (since 2005) and the associated variations in gas chemistry, Campi Flegrei, in southern Italy, is one of the restless calderas where gas flux observations are especially necessary. Here we report the first ever obtained estimate of the Campi Flegrei fumarolic gas output, based on a set of MultiGAS surveys (performed in 2012 and 2013) with an ad-hoc-designed measurement setup. We estimate that the current Campi Flegrei fumarolic sulphur (S) flux is low, on the order of 1.5-2.2 tons/day, suggesting substantial scrubbing of magmatic S by the hydrothermal system. However, the fumarolic carbon dioxide (CO2) output is ˜460±160 tons/day (mean±SD), which is surprisingly high for a dormant volcano in the hydrothermal stage of activity, and results in a combined (fumaroles + soil) CO2 output of ˜1560 tons/day. Assuming magma to be the predominant source, we propose that the current CO2 output can be supplied by either (i) a large (0.6-4.6 km3), deeply stored (>7 km) magmatic source with low CO2 contents (0.05-0.1 wt%) or (ii) by a small to medium-sized (˜0.01-0.1 km3) but CO2-rich (2 wt%) magma, possibly stored at pressures of ˜100 to 120 MPa. Independent geophysical evidence (e.g., inferred from geodetic and gravity data) is needed to distinguish between these two possibilities.

  14. Deepening Sleep by Hypnotic Suggestion

    PubMed Central

    Cordi, Maren J.; Schlarb, Angelika A.; Rasch, Björn

    2014-01-01

    Study Objectives: Slow wave sleep (SWS) plays a critical role in body restoration and promotes brain plasticity; however, it markedly declines across the lifespan. Despite its importance, effective tools to increase SWS are rare. Here we tested whether a hypnotic suggestion to “sleep deeper” extends the amount of SWS. Design: Within-subject, placebo-controlled crossover design. Setting: Sleep laboratory at the University of Zurich, Switzerland. Participants: Seventy healthy females 23.27 ± 3.17 y. Intervention: Participants listened to an auditory text with hypnotic suggestions or a control tape before napping for 90 min while high-density electroencephalography was recorded. Measurements and Results: After participants listened to the hypnotic suggestion to “sleep deeper” subsequent SWS was increased by 81% and time spent awake was reduced by 67% (with the amount of SWS or wake in the control condition set to 100%). Other sleep stages remained unaffected. Additionally, slow wave activity was significantly enhanced after hypnotic suggestions. During the hypnotic tape, parietal theta power increases predicted the hypnosis-induced extension of SWS. Additional experiments confirmed that the beneficial effect of hypnotic suggestions on SWS was specific to the hypnotic suggestion and did not occur in low suggestible participants. Conclusions: Our results demonstrate the effectiveness of hypnotic suggestions to specifically increase the amount and duration of slow wave sleep (SWS) in a midday nap using objective measures of sleep in young, healthy, suggestible females. Hypnotic suggestions might be a successful tool with a lower risk of adverse side effects than pharmacological treatments to extend SWS also in clinical and elderly populations. Citation: Cordi MJ, Schlarb AA, Rasch B. Deepening sleep by hypnotic suggestion. SLEEP 2014;37(6):1143-1152. PMID:24882909

  15. Interrogative suggestibility in opiate users.

    PubMed

    Murakami, A; Edelmann, R J; Davis, P E

    1996-09-01

    The present study investigated interrogative suggestibility in opiate users. A group of patients undergoing a methadone detoxification programme in an in-patient drug treatment unit (Detox group, n = 21), and a group of residents who had come off drugs and were no longer suffering from withdrawal syndrome (Rehab group, n = 19) were compared on interrogative suggestibility and various other psychological factors. Significant differences were found between the two groups, with the Detox group having more physical and psychological problems, and a higher total suggestibility score in comparison with the Rehab group. These findings are discussed in relation to the context of police interrogations and the reliability of confessions made by suspects and witnesses dependent on opiates. PMID:8854372

  16. 10 Suggestions for Enhancing Lecturing

    ERIC Educational Resources Information Center

    Heitzmann, Ray

    2010-01-01

    Criticism of the lecture method remains a staple of discussion and writing in academia--and most of the time it's deserved! Those interested in improving this aspect of their teaching might wish to consider some or all of the following suggestions for enhancing lectures. These include: (1) Lectures must start with a "grabber"; (2) Lectures must be

  17. Representational constraints on children's suggestibility.

    PubMed

    Ceci, Stephen J; Papierno, Paul B; Kulkofsky, Sarah

    2007-06-01

    In a multistage experiment, twelve 4- and 9-year-old children participated in a triad rating task. Their ratings were mapped with multidimensional scaling, from which euclidean distances were computed to operationalize semantic distance between items in target pairs. These children and age-mates then participated in an experiment that employed these target pairs in a story, which was followed by a misinformation manipulation. Analyses linked individual and developmental differences in suggestibility to children's representations of the target items. Semantic proximity was a strong predictor of differences in suggestibility: The closer a suggested distractor was to the original item's representation, the greater was the distractor's suggestive influence. The triad participants' semantic proximity subsequently served as the basis for correctly predicting memory performance in the larger group. Semantic proximity enabled a priori counterintuitive predictions of reverse age-related trends to be confirmed whenever the distance between representations of items in a target pair was greater for younger than for older children. PMID:17576263

  18. Operation of a digital seismic network on Mount St. Helens volcano and observations of long-period seismic events that originate under the volcano

    SciTech Connect

    Fehler, M.; Chouet, B.

    1982-01-01

    During the period May through October 1981, a nine station digital seismic array was operated on the flanks of Mount St. Helens volcano in the state of Washington. The purpose was to obtain high quality digital seismic data from a dense seismic array operating near and in the summit crater of the volcano to facilitate study of near field seismic waveforms generated under the volcano. Our goal is to investigate the source mechanism of volcanic tremor and seismic activity associated with magma intrusion, dome growth and steam-ash emissions occurring within the crater of Mount St. Helens.

  19. Observation of a quantum size effect with unusual long period by experiments of absorption of low energy electrons and by RHEED a simple physical model

    NASA Astrophysics Data System (ADS)

    Marlire, C.

    1992-05-01

    Absorption experiments of electrons of very low energy (few eV) have been done during deposition, at 80 K, of indium on polycrystalline and textured (111) gold films. The target current, for limited range of the energy (E) of the electrons, versus the indium thickness is modulated by damped oscillations with unexpectedly long period of which the value varies with the electronic energy. These results, as those obtained earlier by electrical resistance and work function measurements, can be well explained by a simple physical picture: an effect of vernier (i.e., a stroboscopic effect) between: (i) the quantization of the transverse electronic states in the indium layer in the case of the free electron model (giving a period of half the de Broglie wavelength for electrons of energy E); (ii) the almost perfect atomic layer by atomic layer growth of indium on the gold substrate (d(101) = 0.271 nm). Oscillations of the same type have been found with RHEED experiments by monitoring the variations of the specular intensity in the diffraction pattern.

  20. Trends in the prevalence of heart diseases over a ten-year period from single-center observations based on a large echocardiographic database*

    PubMed Central

    Lu, Hao; Pan, Wen-zhi; Wan, Quan; Cheng, Lei-lei; Shu, Xian-hong; Pan, Cui-zhen; Qian, Ju-ying; Ge, Jun-bo

    2016-01-01

    There is a paucity of data regarding trends in the incidence of heart disease in China during recent years. Using a large echocardiography database in our center, we analyzed trends in the prevalence of several common heart diseases from Dec. 2003. This study retrospectively analyzed the echocardiographic database in our Department from 2003 to 2012. A total of 385 682 cases were included in the study. The prevalence of rheumatic heart disease decreased over the 10-year period, from 4.04% in 2003 to 3.06% in 2012 (P<0.01). Infective endocarditis also decreased, from a mean prevalence of 0.37% in July 2003 to 0.27% in Dec. 2008 (P<0.001). The prevalence of hypertrophic cardiomyopathy, which includes 20% apical hypertrophic cardiomyopathy and 20% hypertrophic obstructive cardiomyopathy, was about 1.8%. The prevalence of the three most common adult congenital heart diseases (CHDs) decreased by about 10% from July 2003 to Dec. 2008 (all P<0.001). The prevalence of moderate pulmonary arterial hypertension (PAH) or left ventricular systolic dysfunction (LVSD) decreased during the 10-year period (P<0.001), but there was no change in the prevalence of severe PAH or LVSD (P>0.05). The present study indirectly demonstrates that the prevalence of several common heart diseases in China has declined in recent years. PMID:26739526

  1. Trends in the prevalence of heart diseases over a ten-year period from single-center observations based on a large echocardiographic database.

    PubMed

    Lu, Hao; Pan, Wen-Zhi; Wan, Quan; Cheng, Lei-Lei; Shu, Xian-Hong; Pan, Cui-Zhen; Qian, Ju-Ying; Ge, Jun-Bo

    2016-01-01

    There is a paucity of data regarding trends in the incidence of heart disease in China during recent years. Using a large echocardiography database in our center, we analyzed trends in the prevalence of several common heart diseases from Dec. 2003. This study retrospectively analyzed the echocardiographic database in our Department from 2003 to 2012. A total of 385 682 cases were included in the study. The prevalence of rheumatic heart disease decreased over the 10-year period, from 4.04% in 2003 to 3.06% in 2012 (P<0.01). Infective endocarditis also decreased, from a mean prevalence of 0.37% in July 2003 to 0.27% in Dec. 2008 (P<0.001). The prevalence of hypertrophic cardiomyopathy, which includes 20% apical hypertrophic cardiomyopathy and 20% hypertrophic obstructive cardiomyopathy, was about 1.8%. The prevalence of the three most common adult congenital heart diseases (CHDs) decreased by about 10% from July 2003 to Dec. 2008 (all P<0.001). The prevalence of moderate pulmonary arterial hypertension (PAH) or left ventricular systolic dysfunction (LVSD) decreased during the 10-year period (P<0.001), but there was no change in the prevalence of severe PAH or LVSD (P>0.05). The present study indirectly demonstrates that the prevalence of several common heart diseases in China has declined in recent years. PMID:26739526

  2. Suggested guidelines for platform presentations.

    PubMed

    Cina, S J; DiMaio, V; Smialek, J E

    1998-03-01

    A platform presentation at an academic meeting requires preparation, practice, and self-discipline. Our observations and discussions of presentations made at national meetings of forensic scientists over the past several years compelled us to review the essentials of public speaking in the academic arena. We translated this review into a compilation of recommendations for the prospective presenter. Application of these recommendations will result in more informative, efficient, and enjoyable platform presentations. PMID:9539392

  3. Suggestions for Popularizing Civil Aviation

    NASA Technical Reports Server (NTRS)

    1926-01-01

    The public generally is taking very little interest in the progress of Civil Aviation, and the time has come to educate the public in aeronautics and to make them realize the far-reaching importance of air transport. Briefly, the whole problem resolves itself into discovering and applying means for bringing some of the many aspects and effects of civil aviation into the everyday lives of the public. The report suggests three principal groups of methods: (1) Bring aviation into daily contact with the public. (2) Bring the public into daily contact with aviation. (3) General publicity.

  4. NIMBUS-7 SBUV (Solar Backscatter Ultraviolet) observations of solar UV spectral irradiance variations caused by solar rotation and active-region evolution for the period November 7, 1978 - November 1, 1980

    NASA Technical Reports Server (NTRS)

    Heath, D. F.; Repoff, T. P.; Donnelly, R. F.

    1984-01-01

    Observations of temporal variations of the solar UV spectral irradiance over several days to a few weeks in the 160-400 nm wavelength range are presented. Larger 28-day variations and a second episode of 13-day variations occurred during the second year of measurements. The thirteen day periodicity is not a harmonic of the 28-day periodicity. The 13-day periodicity dominates certain episodes of solar activity while others are dominated by 28-day periods accompanied by a week 14-day harmonic. Techniques for removing noise and long-term trends are described. Time series analysis results are presented for the Si II lines near 182 nm, the Al I continuum in the 190 nm to 205 nm range, the Mg I continuum in the 210 nm to 250 nm range, the MgII H & K lines at 280 nm, the Mg I line at 285 nm, and the Ca II K & H lines at 393 and 397 nm.

  5. Period Cramps

    MedlinePLUS

    ... and what to do if you're a girl who gets them. What Are Period Cramps? Lots of girls experience cramps before or during their periods. Cramps ... prostaglandins (say: pross-tuh-GLAN-dinz), chemicals a girl's body produces to make the muscles of the ...

  6. Revision of Suggested State Regulations.

    PubMed

    Winston, John P

    2016-02-01

    It is the mission of the Conference of Radiation Control Program Directors (CRCPD) to promote radiological health in all aspects and phases of implementation and to create a seamless and coherent regulatory structure across the United States. CRCPD currently has 25 committees charged with the development of Suggested State Regulations (SSRs) for everything from transportation and waste disposal to tanning and medical therapy. The SR-F Committee is responsible for the suggested regulations of the equipment and processes used in medical diagnostic and interventional x-ray procedures. Several states are required by law to adopt the SSR verbatim, making it vital that they are kept current. The current revision of SR-F brought together representatives from the state radiation control programs, the Food and Drug Administration, the American Association of Physicists in Medicine, American College of Radiology, and industry. Through the course of two meetings and multiple conference calls, the Committee finalized an updated draft. The CRCPD process for the development of SSR is well established and includes internal and external peer review, review by the state Director Members, approval by the Board of Directors, and concurrence from relevant federal agencies. Once final, an SSR allows a state radiation control program to proceed through the state's own regulatory process with a vetted set of regulations, making this difficult process more efficient and effective. PMID:26717174

  7. Study of the blazar AO 0235+164 during the multi-wavelength observation period from October 2008 to February 2009

    NASA Astrophysics Data System (ADS)

    Rain, S.; Madejski, G.; do Couto e Silva, E.; Gargano, F.; Reyes, L.; Nalewajko, K.; Sikora, M.

    2013-06-01

    AO 0235+164 is one of the most studied and monitored BL Lac objects in the sky. Since the launch of Fermi, the source has been monitored in the gamma-ray band by Fermi Large Area Telescope. Starting in October 2008, AO 0235+164 showed an increasing activity in gamma-rays that led to a multi-wavelength campaign with instruments in the radio, near-infrared, optical, UV and X-ray bands. We present here the results of the analysis of the multi-wavelength data collected during the flaring period: the high variability properties of this source and the SED built from radio frequencies to gamma-rays are shown, and are interpreted in the context of well-known blazar emission models [Ackermann, M. et al. 2012, ApJ 751, 159].

  8. STUDYING FREQUENCY RELATIONSHIPS OF KILOHERTZ QUASI-PERIODIC OSCILLATIONS FOR 4U 1636-53 AND Sco X-1: OBSERVATIONS CONFRONT THEORIES

    SciTech Connect

    Lin Yongfeng; Boutelier, Martin; Barret, Didier; Zhang Shuangnan

    2011-01-10

    By fitting the frequencies of simultaneous lower and upper kilohertz quasi-periodic oscillations (kHz QPOs) in two prototype neutron star (NS) QPO sources (4U 1636-53 and Sco X-1), we test the predictive power of all currently proposed QPO models. Models predict a linear, power law, or other relationship between the two frequencies. We found that for plausible NS parameters (mass and angular momentum), no model can satisfactorily reproduce the data, leading to very large chi-square values in our fittings. For both 4U 1636-53 and Sco X-1, this is largely due to the fact that the data significantly differ from a linear relationship. Some models perform relatively better but still have their own problems. Such a detailed comparison of data from models enables identification of routes for improving those models further.

  9. Long-term observations of saccharides in remote marine aerosols from the western North Pacific: A comparison between 1990-1993 and 2006-2009 periods

    NASA Astrophysics Data System (ADS)

    Chen, Jing; Kawamura, Kimitaka; Liu, Cong-Qiang; Fu, Pingqing

    2013-03-01

    Anhydrosugars (galactosan, mannosan and levoglucosan), sugars (xylose, fructose, glucose, sucrose and trehalose) and sugar alcohols (erythritol, arabitol, mannitol and inositol) were measured in the aerosol samples collected in a remote island (Chichi-Jima, Japan) in the western North Pacific from 1990 to 1993 and from 2006 to 2009. Total concentrations of anhydrosugars, the biomass burning tracers, were 0.01-5.57 ng m-3 (average 0.76 ng m-3) during 1990-1993 versus 0.01-7.19 ng m-3 (0.64 ng m-3) during 2006-2009. Their seasonal variations were characterized by winter/spring maxima and summer/fall minima. Such a seasonal pattern should be caused by the enhanced long-range atmospheric transport of biomass burning products and terrestrial organic matter (such as higher plant detritus and soil dust) from the Asian continent in winter/spring seasons, when the westerly or winter monsoon system prevails over the western North Pacific. Sugars and sugar alcohols showed different seasonal patterns. The monthly mean concentrations of erythritol, arabitol, mannitol, inositol, fructose, glucose and trehalose were found to be higher in spring/summer and lower in fall/winter during both 1990-1993 and 2006-2009 periods, indicating an enhanced biogenic emission of aerosols in warm seasons. Interestingly, saccharides showed a gradual decrease in their concentrations from 1991 to 1993 and an increase from 2006 to 2009. In addition, the monthly averaged concentrations of sugars and sugar alcohols showed maxima in early summer during 1990-1993, which occurred about 1-2 months earlier than those during 2006-2009. Such a clear seasonal shift may be attributable to the changes in the strength of westerly and trade wind systems during two periods.

  10. Hinode 7: Conference summary and future suggestions

    NASA Astrophysics Data System (ADS)

    Priest, Eric

    2014-12-01

    This conclusion to the seventh Hinode science meeting (2013 November in Takayama, Japan) attempts to summarise what we have learnt during the conference (mainly from the review talks) about new observations from Hinode and about theories stimulated by them. Suggestions for future study are also offered.

  11. The functional anatomy of suggested limb paralysis.

    PubMed

    Deeley, Quinton; Oakley, David A; Toone, Brian; Bell, Vaughan; Walsh, Eamonn; Marquand, Andre F; Giampietro, Vincent; Brammer, Michael J; Williams, Steven C R; Mehta, Mitul A; Halligan, Peter W

    2013-02-01

    Suggestions of limb paralysis in highly hypnotically suggestible subjects have been employed to successfully model conversion disorders, revealing similar patterns of brain activation associated with attempted movement of the affected limb. However, previous studies differ with regard to the executive regions involved during involuntary inhibition of the affected limb. This difference may have arisen as previous studies did not control for differences in hypnosis depth between conditions and/or include subjective measures to explore the experience of suggested paralysis. In the current study we employed functional magnetic resonance imaging (fMRI) to examine the functional anatomy of left and right upper limb movements in eight healthy subjects selected for high hypnotic suggestibility during (i) hypnosis (NORMAL) and (ii) attempted movement following additional left upper limb paralysis suggestions (PARALYSIS). Contrast of left upper limb motor function during NORMAL relative to PARALYSIS conditions revealed greater activation of contralateral M1/S1 and ipsilateral cerebellum, consistent with the engagement of these regions in the completion of movements. By contrast, two significant observations were noted in PARALYSIS relative to NORMAL conditions. In conjunction with reports of attempts to move the paralysed limb, greater supplementary motor area (SMA) activation was observed, a finding consistent with the role of SMA in motor intention and planning. The anterior cingulate cortex (ACC, BA 24) was also significantly more active in PARALYSIS relative to NORMAL conditions - suggesting that ACC (BA 24) may be implicated in involuntary, as well as voluntary inhibition of prepotent motor responses. PMID:23351848

  12. CONSTRAINTS ON LONG-PERIOD PLANETS FROM AN L'- AND M-BAND SURVEY OF NEARBY SUN-LIKE STARS: OBSERVATIONS

    SciTech Connect

    Heinze, A. N.; Hinz, Philip M.; Sivanandam, Suresh; Kenworthy, Matthew; Miller, Douglas; Meyer, Michael E-mail: phinz@as.arizona.ed E-mail: mkenworthy@as.arizona.ed E-mail: mmeyer@phys.ethz.c

    2010-05-10

    We present the observational results of an L'- and M-band adaptive optics imaging survey of 54 nearby, Sun-like stars for extrasolar planets, carried out using the Clio camera on the MMT. We have concentrated more strongly than all other planet-imaging surveys to date on very nearby F, G, and K stars, prioritizing stellar proximity higher than youth. Ours is also the first survey to include extensive observations in the M band, which supplement the primary L' observations. Models predict much better planet/star flux ratios at the L' and M bands than at more commonly used shorter wavelengths (i.e., the H band). We have carried out extensive blind simulations with fake planets inserted into the raw data to verify our sensitivity, and to establish a definitive relationship between source significance in {sigma} and survey completeness. We find 97% confident-detection completeness for 10{sigma} sources, but only 46% for 7{sigma} sources-raising concerns about the standard procedure of assuming high completeness at 5{sigma}, and demonstrating that blind sensitivity tests to establish the significance-completeness relation are an important analysis step for all planet-imaging surveys. We discovered a previously unknown {approx}0.15 M{sub sun} stellar companion to the F9 star GJ 3876, at a projected separation of about 80 AU. Twelve additional candidate faint companions are detected around other stars. Of these, 11 are confirmed to be background stars and one is a previously known brown dwarf. We obtained sensitivity to planetary-mass objects around almost all of our target stars, with sensitivity to objects below 3 M{sub Jup} in the best cases. Constraints on planet populations based on this null result are presented in our Modeling Results paper.

  13. Periodized wavelets

    SciTech Connect

    Schlossnagle, G.; Restrepo, J.M.; Leaf, G.K.

    1993-12-01

    The properties of periodized Daubechies wavelets on [0,1] are detailed and contrasted against their counterparts which form a basis for L{sup 2}(R). Numerical examples illustrate the analytical estimates for convergence and demonstrate by comparison with Fourier spectral methods the superiority of wavelet projection methods for approximations. The analytical solution to inner products of periodized wavelets and their derivatives, which are known as connection coefficients, is presented, and several tabulated values are included.

  14. Observations of runup and energy flux on a low-slope beach with high-energy, long-period ocean swell

    NASA Astrophysics Data System (ADS)

    Fiedler, Julia W.; Brodie, Katherine L.; McNinch, Jesse E.; Guza, Robert T.

    2015-11-01

    The transformation of surface gravity waves from 11 m depth to runup was observed on the low-sloped (1/80) Agate Beach, Oregon, with a cross-shore transect of current meters, pressure sensors, and a scanning lidar. Offshore wave heights H0 ranged from calm (0.5 m) to energetic (>7 m). Runup, measured with pressure sensors and a scanning lidar, increases linearly with (H0L0)1/2, with L0 the deep-water wavelength of the spectral peak. Runup saturation, in which runup oscillations plateau despite further increases in (H0L0)1/2, is not observed. Infragravity wave shoaling and nonlinear energy exchanges with short waves are included in an infragravity wave energy balance. This balance closes for high-infragravity frequencies (0.025-0.04 Hz) but not lower frequencies (0.003-0.025 Hz), possibly owing to unmodeled infragravity energy losses of wave breaking and/or bottom friction. Dissipative processes limit, but do not entirely damp, increases in runup excursions in response to increased incident wave forcing.

  15. Observations on changes in abundance of questing Ixodes ricinus, castor bean tick, over a 35-year period in the eastern part of its range (Russia, Tula region).

    PubMed

    Korotkov, Yu; Kozlova, T; Kozlovskaya, L

    2015-06-01

    Ixodes ricinus (Acari: Ixodidae) L. transmit a wide variety of pathogens to vertebrates including viruses, bacteria and protozoa. Understanding of the epidemiology of tick-borne infections requires basic knowledge of the regional and local factors influencing tick population dynamics. The present study describes the results of monitoring of a questing I. ricinus population, conducted over 35 years (1977-2011) in the eastern, poorly studied part of its range (Russia, Tula region). We have found that the multiannual average abundance of ticks is small and varies depending on the biotope and degree of urban transformation. Tick abundance for the first 14 years of observations (1977-1990) was at the lower limit of the sensitivity of our methods throughout the study area (0.1-0.9 specimens per 1-km transect). In the following 21 years (1991-2011), a manifold increase in abundance was observed, which reached 18.1 1.8 individuals per 1-km transect in moist floodplain terraces, and 4.8 0.9 in xerophylic hill woods. Long-term growth of tick abundance occurred in spite of a relatively constant abundance of small mammals and only minor fluctuations in the abundance of large wild animals. Climate and anthropogenic changes appear to be the main contributors to increased abundance of the tick. PMID:25631747

  16. Arctic Ocean circulation, processes and water masses: A description of observations and ideas with focus on the period prior to the International Polar Year 2007-2009

    NASA Astrophysics Data System (ADS)

    Rudels, Bert

    2015-03-01

    The evolving knowledge of the Arctic Ocean, its hydrography and its water masses and their transformations and circulation is reviewed starting with the observations made on Fram 1893-1896 and extending to the International Polar Year (IPY) 2007-2009. The expeditions and observations after Fram to the mid 20th century as well as the more extensive and systematic studies of water masses and circulation made from ice stations and airborne expeditions from the late 1940s to the late 1970s are briefly described. The early concepts of the connections and exchanges between the Arctic Ocean and the world ocean are also discussed. In the 1980s scientific icebreakers were beginning to enter the inner parts of the Arctic Ocean and large international programmes were launched, culminating in the IPY. The changes in the Arctic Ocean, first noted in the Atlantic layer in 1990 and shortly after in the upper layers, are described. The exchanges between the Arctic Ocean and the surrounding seas through the four main openings, Fram Strait, Barents Sea, Bering Strait and the Canadian Arctic Archipelago as well the volume and freshwater balances of the Arctic Ocean are examined.

  17. Periodic chiral structures

    NASA Technical Reports Server (NTRS)

    Jaggard, Dwight L.; Engheta, Nader; Pelet, Philippe; Liu, John C.; Kowarz, Marek W.; Kim, Yunjin

    1989-01-01

    The electromagnetic properties of a structure that is both chiral and periodic are investigated using coupled-mode equations. The periodicity is described by a sinusoidal perturbation of the permittivity, permeability, and chiral admittance. The coupled-mode equations are derived from physical considerations and used to examine bandgap structure and reflected and transmitted fields. Chirality is observed predominantly in transmission, whereas periodicity is present in both reflection and transmission.

  18. The state of the atmosphere as inferred from the FGGE satellite observing systems during SOP-1. [special observing period (SOP-1) of First Global Atmospheric Research Program Global Experiment (FGGE)

    NASA Technical Reports Server (NTRS)

    Halem, M.; Kalnay-Rivas, E.; Baker, W. E.; Atlas, R.

    1981-01-01

    The statistical properties, and coverage, of satellite temperature sounding data are described. Tropical regions are observed every two days, extratropics from one to four times a day. Oceans are covered two to three times a day. Asynoptic coverage is comparable to the U.S. rawinsonde network twice daily coverage. Lack of ground truth for data sparse areas makes accuracy difficult to assess. The rms differences of layer mean temperatures obtained from collocating rawinsonde observations with satellite temperature profiles in space and time differ from rms differences of layer mean satellite temperature soundings. The FGGE satellite systems can infer the three dimensional motion field and improve the representation of the large scale state of the atmosphere.

  19. Annual water-level measurements in observation wells, 1951-1955, and atlas of maps showing changes in water levels for various periods from beginning of record through 1954, New Mexico

    USGS Publications Warehouse

    Reeder, Harold O.

    1959-01-01

    This report tabulates the annual measurements of water level in the observation wells in the various irrigated areas, primarily from 1951 through 1955. It summarizes changes in water level by discussion and with an atlas of nearly all the maps of change of water level for the period of record to 1955 for each area in which observations are being made. Included also are hydrographs for the period of record through 1954 of several selected wells in the various areas irrigated from ground-water sources. The annual measurements of water level before 1951, seasonal measurements, and daily records of water levels in wells equipped with recording gages have been published in an annual series of U. S. Geological Survey water-supply papers.

  20. Rotation of Hyperion. I - Observations

    NASA Technical Reports Server (NTRS)

    Klavetter, James Jay

    1989-01-01

    Precise and well sampled observations of Hyperion over a long period of time have been performed to test the prediction of Wisdom et al. (1984) that the satellite is in a state of chaotic rotation. CCD data for a 13-week period were obtained in Chile and in Arizona. A phase-dispersion-minimization analysis of the light curve indicates that Hyperion is not in a periodic rotational state, thus suggesting that it is chaotic.

  1. Irregular Periods

    MedlinePLUS

    ... from Nemours for Parents for Kids for Teens Teens Home Body Mind Sexual Health Food & Fitness Diseases & Conditions Infections Q&A School & Jobs Drugs & Alcohol Staying Safe Recipes En Espaol Making a Change Your Personal Plan Hot ... > Irregular Periods Print A A A Text Size ...

  2. Periodic Polymers

    NASA Astrophysics Data System (ADS)

    Thomas, Edwin

    2013-03-01

    Periodic polymers can be made by self assembly, directed self assembly and by photolithography. Such materials provide a versatile platform for 1, 2 and 3D periodic nano-micro scale composites with either dielectric or impedance contrast or both, and these can serve for example, as photonic and or phononic crystals for electromagnetic and elastic waves as well as mechanical frames/trusses. Compared to electromagnetic waves, elastic waves are both less complex (longitudinal modes in fluids) and more complex (longitudinal, transverse in-plane and transverse out-of-plane modes in solids). Engineering of the dispersion relation between wave frequency w and wave vector, k enables the opening of band gaps in the density of modes and detailed shaping of w(k). Band gaps can be opened by Bragg scattering, anti-crossing of bands and discrete shape resonances. Current interest is in our group focuses using design - modeling, fabrication and measurement of polymer-based periodic materials for applications as tunable optics and control of phonon flow. Several examples will be described including the design of structures for multispectral band gaps for elastic waves to alter the phonon density of states, the creation of block polymer and bicontinuous metal-carbon nanoframes for structures that are robust against ballistic projectiles and quasi-crystalline solid/fluid structures that can steer shock waves.

  3. A Critical Period for Learning to Pronounce Foreign Languages?

    ERIC Educational Resources Information Center

    Flege, James Emil

    1987-01-01

    Examination of existing empirical and theoretical literature suggests there is no conclusive support for the existence of a critical period for human speech learning. Assumption of a critical period may inhibit the search for testable hypotheses concerning observed adult-child differences in second language production. (Author/LMO)

  4. Long-Period Solar Variability

    SciTech Connect

    GAUTHIER,JOHN H.

    2000-07-20

    Terrestrial climate records and historical observations of the Sun suggest that the Sun undergoes aperiodic oscillations in radiative output and size over time periods of centuries and millenia. Such behavior can be explained by the solar convective zone acting as a nonlinear oscillator, forced at the sunspot-cycle frequency by variations in heliomagnetic field strength. A forced variant of the Lorenz equations can generate a time series with the same characteristics as the solar and climate records. The timescales and magnitudes of oscillations that could be caused by this mechanism are consistent with what is known about the Sun and terrestrial climate.

  5. A suggested new bacteriophage genus: "Viunalikevirus".

    PubMed

    Adriaenssens, Evelien M; Ackermann, Hans-Wolfgang; Anany, Hany; Blasdel, Bob; Connerton, Ian F; Goulding, David; Griffiths, Mansel W; Hooton, Steven P; Kutter, Elizabeth M; Kropinski, Andrew M; Lee, Ju-Hoon; Maes, Martine; Pickard, Derek; Ryu, Sangryeol; Sepehrizadeh, Zargham; Shahrbabak, S Sabouri; Toribio, Ana L; Lavigne, Rob

    2012-10-01

    We suggest a bacteriophage genus, "Viunalikevirus", as a new genus within the family Myoviridae. To date, this genus includes seven sequenced members: Salmonella phages ViI, SFP10 and ?SH19; Escherichia phages CBA120 and PhaxI; Shigella phage phiSboM-AG3; and Dickeya phage LIMEstone1. Their shared myovirus morphology, with comparable head sizes and tail dimensions, and genome organization are considered distinguishing features. They appear to have conserved regulatory sequences, a horizontally acquired tRNA set and the probable substitution of an alternate base for thymine in the DNA. A close examination of the tail spike region in the DNA revealed four distinct tail spike proteins, an arrangement which might lead to the umbrella-like structures of the tails visible on electron micrographs. These properties set the suggested genus apart from the recently ratified subfamily Tevenvirinae, although a significant evolutionary relationship can be observed. PMID:22707043

  6. Mid-Term Quasi-Periodicities and Solar Cycle Variation of the White-Light Corona from 18.5 Years (1996.0 - 2014.5) of LASCO Observations

    NASA Astrophysics Data System (ADS)

    Barlyaeva, T.; Lamy, P.; Llebaria, A.

    2015-07-01

    We report on the analysis of the temporal evolution of the solar corona based on 18.5 years (1996.0 - 2014.5) of white-light observations with the SOHO/LASCO-C2 coronagraph. This evolution is quantified by generating spatially integrated values of the K-corona radiance, first globally, then in latitudinal sectors. The analysis considers time series of monthly values and 13-month running means of the radiance as well as several indices and proxies of solar activity. We study correlation, wavelet time-frequency spectra, and cross-coherence and phase spectra between these quantities. Our results give a detailed insight on how the corona responds to solar activity over timescales ranging from mid-term quasi-periodicities (also known as quasi-biennial oscillations or QBOs) to the long-term 11 year solar cycle. The amplitude of the variation between successive solar maxima and minima (modulation factor) very much depends upon the strength of the cycle and upon the heliographic latitude. An asymmetry is observed during the ascending phase of Solar Cycle 24, prominently in the royal and polar sectors, with north leading. Most prominent QBOs are a quasi-annual period during the maximum phase of Solar Cycle 23 and a shorter period, seven to eight months, in the ascending and maximum phases of Solar Cycle 24. They share the same properties as the solar QBOs: variable periodicity, intermittency, asymmetric development in the northern and southern solar hemispheres, and largest amplitudes during the maximum phase of solar cycles. The strongest correlation of the temporal variations of the coronal radiance - and consequently the coronal electron density - is found with the total magnetic flux. Considering that the morphology of the solar corona is also directly controlled by the topology of the magnetic field, this correlation reinforces the view that they are intimately connected, including their variability at all timescales.

  7. Pressure-driven reconnection and quasi periodical oscillations in plasmas

    NASA Astrophysics Data System (ADS)

    Paccagnella, R.

    2014-03-01

    This paper presents a model for an ohmically heated plasma in which a feedback exists between thermal conduction and transport, on one side, and the magneto-hydro-dynamical stability of the system, on the other side. In presence of a reconnection threshold for the magnetic field, a variety of periodical or quasi periodical oscillations for the physical quantities describing the system are evidenced. The model is employed to interpret the observed quasi periodical oscillations of electron temperature and perturbed magnetic field around the so called "Single Helical" state in the reversed field pinch, but its relevance for other periodical phenomena observed in magnetic confinement systems, especially in tokamaks, is suggested.

  8. Lidar observations of persistent gravity waves with periods of 3-10 h in the Antarctic middle and upper atmosphere at McMurdo (77.83°S, 166.67°E)

    NASA Astrophysics Data System (ADS)

    Chen, Cao; Chu, Xinzhao; Zhao, Jian; Roberts, Brendan R.; Yu, Zhibin; Fong, Weichun; Lu, Xian; Smith, John A.

    2016-02-01

    Persistent, dominant, and large-amplitude gravity waves with 3-10 h periods and vertical wavelengths ~20-30 km are observed in temperatures from the stratosphere to lower thermosphere with an Fe Boltzmann lidar at McMurdo, Antarctica. These waves exhibit characteristics of inertia-gravity waves in case studies, yet they are extremely persistent and have been present during every lidar observation. We characterize these 3-10 h waves in the mesosphere and lower thermosphere using lidar temperature data in June from 2011 to 2015. A new method is applied to identify the major wave events from every lidar run longer than 12 h. A continuous 65 h lidar run on 28-30 June 2014 exhibits a 7.5 h wave spanning ~60 h, and 6.5 h and 3.4 h waves spanning 40 and 45 h, respectively. Over the course of 5 years, 323 h of data in June reveal that the major wave periods occur in several groups centered from ~3.5 to 7.5 h, with vertical phase speeds of 0.8-2 m/s. These 3-10 h waves possess more than half of the spectral energy for ~93% of the time. A rigorous prewhitening, postcoloring technique is introduced for frequency power spectra investigation. The resulting spectral slopes are unusually steep (-2.7) below ~100 km but gradually become shallower with increasing altitude, reaching about -1.6 at 110 km. Two-dimensional fast Fourier transform spectra confirm that these waves have a uniform dominant vertical wavelength of 20-30 km across periods of 3.5-10 h. These statistical features shed light on the wave source and pave the way for future research.

  9. Periods found in heat measurements obtained by calorimetry

    SciTech Connect

    Jordan, K.C.

    1984-02-28

    During a span of 640 days, a periodicity of 1.5158 +- 0.0008 days was discovered in successive heater equilibria on Calorimeter No. 127. Measurements were taken at 12-h intervals, with occasional changes of exactly 3 or 6 h in the schedule of measurements. This schedule eliminated all other possible periods except a period of 0.150156 days. Periods of 1.519125 and 1.511283 days were discovered in data on the excess length of day as obtained by the US Naval Observatory over a period of 24 y. These two periods could equally well represent periods of 0.150189 and 0.150112 days, since measurements were obtained only once every 24 h. It is suggested that periods observed in sensitive calorimeters and in length of day data may be related. 1 reference, 6 figures, 5 tables.

  10. Charged particle periodicity in the Saturnian magnetosphere

    NASA Technical Reports Server (NTRS)

    Carbary, J. F.; Krimigis, S. M.

    1982-01-01

    The present investigation is concerned with the first definitive evidence for charged particle modulations near the magnetic rotation period at Saturn. This periodicity is apparent in the ratios (and spectra) of low energy charged particles in the Saturnian magnetosphere. Most of the data presented were taken during the Voyager 2 outbound portion of the Saturn encounter. During this time the spacecraft was at high latitudes (approximately 30 deg) in the southern hemisphere of the Saturnian magnetosphere. The probe's trajectory was approximately along the dawn meridian at an essentially constant local time. The observation that the charged particle modulation is consistent with the Saturn Kilometric Radiation (SKR) period provides a basic input for the resolution of a puzzle which has existed ever since the discovery of the SKR modulation. The charged particle periodicity identified suggests that a basic asymmetry must exist in the Saturnian magnetosphere.

  11. Continuous data assimilation experiments with the NMC eta model: A GALE IOP 1 case study. [NMC (National Meteorological Center); GALE IOP (Genesis of Atlantic Lows Experiment intensive observing period)

    SciTech Connect

    Ramamurthy, M.K.; Xu, T.Y. )

    1993-11-01

    The current major expansion in observational capability of the National Weather Service is principally in the volume of asynchronous data rather than synchronous observations at the standard synoptic times. Hence, the National Meteorological Center is considering a continuous data assimilation system to replace at some time the intermittent system now used by its regional and global operational models. We describe this system, based on the Newtonian relaxation technique, as developed for the eta model. Experiments are performed for the first intensive observing period of the Genesis of Atlantic Lows Experiment (GALE) in January 1986, when strong upper-level cyclogenesis occurred, with a pronounced tropopause fold but only modest surface development. The GALE level IIIb dataset was used for initializing and updating the model. Issues addressed in the experiments include choice of update variable, number, and length of update segments; need for updating moisture and surface pressure information; nudging along boundaries; and noise control. Assimilation of data from a single level was also studied. Use of a preforecast assimilation cycle was found to eliminate the spinup problem almost entirely. Multiple, shorter assimilation segments produced better forecasts than a single, longer cycle. Updating the mass field was less effective than nudging the wind field but assimilating both was best. Assimilation of moisture data, surprisingly, affected the spinup adversely, but nudging the surface pressure information reduced the spurious pillow effect. Assimilation of single-level information was ineffective unless accompanied by increased vertical coupling, obtained from a control integration. 52 refs., 19 figs., 1 tab.

  12. Predictability of antitumor efficacy of cetuximab plus irinotecan based on skin rash severity according to observation period in patients with metastatic colorectal cancer following failure of fluorouracil, irinotecan and oxaliplatin

    PubMed Central

    HORIE, YOSHIKI; YAMAZAKI, KENTARO; FUNAKOSHI, TARO; HAMAUCHI, SATOSHI; TANIGUCHI, HIROYA; TSUSHIMA, TAKAHIRO; TODAKA, AKIKO; MACHIDA, NOZOMU; TAKU, KEISEI; FUKUTOMI, AKIRA; ONOZAWA, YUSUKE; YASUI, HIROFUMI; MIZUKAMI, TAKURO; IZAWA, NAOKI; HIRAKAWA, MAMI; TSUDA, TAKASHI; NAKAJIMA, TAKAKO; BOKU, NARIKAZU

    2015-01-01

    The efficacy of cetuximab correlates with the severity of skin toxicity, although its onset may vary. The AIM of this retrospective study was to investigate the optimal observation period for skin rash as a predictor of the efficacy of cetuximab plus irinotecan. The subjects comprised 33 patients with KRAS wild-type metastatic colorectal cancer (mCRC) who had received prior chemotherapy with fluorouracil, irinotecan and oxaliplatin. The response rate (RR), progression-free survival (PFS) and overall survival (OS) were compared according to the presence or absence of ?grade 2 skin rash within 2, 4, 6, or 8 weeks following cetuximab initiation. The overall RR was 45% (15/33) and the median PFS and OS were 188 and 383 days, respectively. A total of 26 patients experienced ?grade 2 skin rash within 8 weeks. The proportion of responders among patients who developed ?grade 2 skin rash (severe group) decreased depending on the duration of the observation period (50% within 8 weeks), whereas the proportion of non-responders among patients with

  13. California foreshock sequences suggest underlying aseismic process

    NASA Astrophysics Data System (ADS)

    Chen, X.; Shearer, P. M.; Hauksson, E.

    2012-12-01

    Foreshocks are the clearest precursors to mainshocks, and understanding their characteristics is of great interest. In this study, we analyze immediate foreshock sequences (within 2 days and 5 km) for mainshocks in California using precisely relocated catalogs and find that 27 out of 61 mainshocks of M ? 5 have at least one immediate foreshock. Among the 27 foreshock sequences, 9 consist of just one event, 3 are aftershocks of a previous event, and 13 are swarm-like sequences (more than 4 events, not starting with the largest foreshock). For 5 swarm-like foreshock sequences (Landers, Hector Mine, El Mayor-Cucapah, Chalfant, Mt-Lewis earthquakes), there are enough events to determine that they exhibit significant spatial migration, with migration velocities comparable to swarms in southern California (e.g., Chen et al., 2011). To study if there are systematic changes between foreshocks and aftershocks, we apply an iterative deconvolution approach [Shearer et al., 2006] to obtain earthquake source spectra. We then estimate earthquake stress drops using a multi-event empirical Green's function (EGF) method. These 5 foreshock sequences have much lower median stress drops than aftershocks from the same region. To confirm this difference, we shift the source spectra along an f^-3 curve to facilitate a direct comparison of the frequency content of the source spectra for different sized events. The foreshocks have a stronger fall off at high frequencies compared to the aftershocks. We are currently studying, using a source-specific EGF approach, whether attenuation changes could explain some of these frequency differences. These observations of spatially migrating foreshock sequences and their apparently low stress drops indicate that there is likely an underlying aseismic process, such as fluid flow or slow slip, that triggers both the foreshocks and the mainshocks. Such aseismic processes are thought to drive many swarms and some observations have suggested that aseismic slip may occur prior to large earthquakes [e.g., Roeloffs, 2006].

  14. Periodicities of cardiac mechanics.

    PubMed

    Ben-Haim, S A; Fruchter, G; Hayam, G; Edoute, Y

    1991-08-01

    Using a finite-difference equation to model cardiac mechanics, we simulated the stable action of the left ventricle. This model describes the left ventricular end-diastolic volume as a function of the previous end-diastolic volume and several physiological parameters describing the mechanical properties and hemodynamic loading conditions of the heart. Our theoretical simulations demonstrated that transitions (bifurcations) can occur between different modes of dynamic organization of the isolated working heart as parameters are changed. Different regions in the parameter space are characterized by different stable limit cycle periodicities. Experimental studies carried out in an isolated working rat heart model verified the model predictions. The experimental studies showed that stable periodicities were invoked by changing the parameter values in the direction suggested by the theoretical analysis. We propose in the present work that mechanical periodicities of the heart action are an inherent part of its nonlinear nature. The model predictions and experimental results are compatible with previous experimental data but may contradict several hypotheses suggested to explain the phenomenon of cardiac periodicities. PMID:1877669

  15. Periodicity of extinction: A 1988 update

    NASA Technical Reports Server (NTRS)

    Sepkowski, J. John, Jr.

    1988-01-01

    The hypothesis that events of mass extinction recur periodically at approximately 26 my intervals is an empirical claim based on analysis of data from the fossil record. The hypothesis has become closely linked with catastrophism because several events in the periodic series are associated with evidence of extraterrestrial impacts, and terrestrial forcing mechanisms with long, periodic recurrences are not easily conceived. Astronomical mechanisms that have been hypothesized include undetected solar companions and solar oscillation about the galactic plane, which induce comet showers and result in impacts on Earth at regular intervals. Because these mechanisms are speculative, they have been the subject of considerable controversy, as has the hypothesis of periodicity of extinction. In response to criticisms and uncertainties, a data base was developed on times of extinction of marine animal genera. A time series is given and analyzed with 49 sample points for the per-genus extinction rate from the Late Permian to the Recent. An unexpected pattern in the data is the uniformity of magnitude of many of the periodic extinction events. Observations suggest that the sequence of extinction events might be the result of two sets of mechanisms: a periodic forcing that normally induces only moderate amounts of extinction, and independent incidents or catastrophes that, when coincident with the periodic forcing, amplify its signal and produce major-mass extinctions.

  16. Parenthood May Alter Immune System, Research Suggests

    MedlinePLUS

    ... medlineplus/news/fullstory_157316.html Parenthood May Alter Immune System, Research Suggests Raising a child seems to cause ... new research suggests it may also rewire the immune system. The study found that parenting seems to have ...

  17. Suggestibility, Reliability, and the Legal Process.

    ERIC Educational Resources Information Center

    Rosenthal, J. D. Robert

    2002-01-01

    Provides information to help lawyers and expert witnesses understand how well-established legal principles demand the exclusion of suggestion-induced accusation in child abuse cases just as they do suggestion-induced identifications. Discusses legal arguments that support the exclusion of accusations obtained through suggestion and provides an

  18. Evidentiality and Suggestibility: A New Research Venue

    ERIC Educational Resources Information Center

    Aydin, Cagla; Ceci, Stephen J.

    2009-01-01

    Recent research suggests that acquisition of mental-state language may influence conceptual development. We examine this possibility by investigating the conceptual links between evidentiality in language and suggestibility. Young children are disproportionately suggestible and tend to change their reports or memories when questioned. The authors

  19. Radar interferometry observations of surface displacements during pre- and coeruptive periods at Mount St. Helens, Washington, 1992-2005: Chapter 18 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

    USGS Publications Warehouse

    Poland, Michael; Lu, Zhong

    2008-01-01

    We analyzed hundreds of interferograms of Mount St. Helens produced from radar images acquired by the ERS-1/2, ENVISAT, and RADARSAT satellites during the 1992-2004 preeruptive and 2004-2005 coeruptive periods for signs of deformation associated with magmatic activity at depth. Individual interferograms were often contaminated by atmospheric delay anomalies; therefore, we employed stacking to amplify any deformation patterns that might exist while minimizing random noise. Preeruptive interferograms show no signs of volcanowide deformation between 1992 and the onset of eruptive activity in 2004. Several patches of subsidence in the 1980 debris-avalanche deposit were identified, however, and are thought to be caused by viscoelastic relaxation of loosely consolidated substrate, consolidation of water-saturated sediment, or melting of buried ice. Coeruptive interferometric stacks are dominated by atmospheric noise, probably because individual interferograms span only short time intervals in 2004 and 2005. Nevertheless, we are confident that at least one of the seven coeruptive stacks we constructed is reliable at about the 1-cm level. This stack suggests deflation of Mount St. Helens driven by contraction of a source beneath the volcano.

  20. Suggestive techniques connected to medical interventions

    PubMed Central

    2013-01-01

    The paper introduces a series of articles where several detailed clinical examples will be presented on the effectiveness of using suggestive techniques in various fields of interventional medicine. The aim of this series is to raise the attention to the patients heightened openness to suggestions. By recognizing the unavoidable nature of suggestive effects on one hand we can eliminate unfavourable, negative suggestions and on the other hand go on and consciously apply positive, helpful variations. Research materials, reviews and case study will describe the way suggestions can reduce anxiety and stress connected to medical intervention, improve subjective well-being and cooperation, and increase efficiency by reducing treatment costs. PMID:24265898

  1. Changing Periods of ST Puppis

    NASA Astrophysics Data System (ADS)

    Walker, S.; Butterworth, N.; Pearce, A.

    2015-12-01

    ST Puppis is a reasonably bright W Virginis variable star, a Type 2 Cepheid with a record of substantial and erratic period changes21 during the interval 1900 to 1985 with a range of magnitude from 17.4 to 19.2. It was observed as part of Variable Stars South's Cepheid project by Butterworth in 2014 and 2015 using DSLR photometry in BGR passbands and visually by Pearce in 2015. The known period changes are shown graphically and doubtful ones examined and discarded if necessary. With its period and amplitude with a frequently changing period it is a suitable and worthwhile object for visual observing.

  2. Animal Rights: Selected Resources and Suggestions for Further Study.

    ERIC Educational Resources Information Center

    Davidoff, Donald J.

    1989-01-01

    Presents an annotated list of selected resources intended to serve as a guide to the growing amount of material on animal rights. Suggestions to aid in additional research include subject headings used to find books, indexes used to locate periodical articles, sources for locating organizations, and a selected list of animal rights organizations.

  3. Animal Rights: Selected Resources and Suggestions for Further Study.

    ERIC Educational Resources Information Center

    Davidoff, Donald J.

    1989-01-01

    Presents an annotated list of selected resources intended to serve as a guide to the growing amount of material on animal rights. Suggestions to aid in additional research include subject headings used to find books, indexes used to locate periodical articles, sources for locating organizations, and a selected list of animal rights organizations.…

  4. Suggestions for the Classical Shelves of a School Library.

    ERIC Educational Resources Information Center

    Colebourn, R., Comp.; Cleeve, Marigold, Comp.

    This bibliography is suggested for use by students and teachers of Latin, Greek and ancient civilizations. Entries are compiled under the headings of: (1) bibliographies and journals including booklists, periodicals, and books for teachers; (2) reference works in literature, mythology, history and antiquities, and language; (3) texts and…

  5. Fuel Distribution Estimate via Spin Period to Precession Period Ratio for the Advanced Composition Explorer

    NASA Technical Reports Server (NTRS)

    DeHart, Russell; Smith, Eric; Lakin, John

    2015-01-01

    The spin period to precession period ratio of a non-axisymmetric spin-stabilized spacecraft, the Advanced Composition Explorer (ACE), was used to estimate the remaining mass and distribution of fuel within its propulsion system. This analysis was undertaken once telemetry suggested that two of the four fuel tanks had no propellant remaining, contrary to pre-launch expectations of the propulsion system performance. Numerical integration of possible fuel distributions was used to calculate moments of inertia for the spinning spacecraft. A Fast Fourier Transform (FFT) of output from a dynamics simulation was employed to relate calculated moments of inertia to spin and precession periods. The resulting modeled ratios were compared to the actual spin period to precession period ratio derived from the effect of post-maneuver nutation angle on sun sensor measurements. A Monte Carlo search was performed to tune free parameters using the observed spin period to precession period ratio over the life of the mission. This novel analysis of spin and precession periods indicates that at the time of launch, propellant was distributed unevenly between the two pairs of fuel tanks, with one pair having approximately 20% more propellant than the other pair. Furthermore, it indicates the pair of the tanks with less fuel expelled all of its propellant by 2014 and that approximately 46 kg of propellant remains in the other two tanks, an amount that closely matches the operational fuel accounting estimate. Keywords: Fuel Distribution, Moments of Inertia, Precession, Spin, Nutation

  6. Observation of coronal loop torsional oscillation

    NASA Astrophysics Data System (ADS)

    Zaqarashvili, T. V.

    2003-02-01

    We suggest that the global torsional oscillation of solar coronal loop may be observed by the periodical variation of a spectral line width. The amplitude of the variation must be maximal at the velocity antinodes and minimal at the nodes of the torsional oscillation. Then the spectroscopic observation as a time series at different heights above the active region at the solar limb may allow to determine the period and wavelength of global torsional oscillation and consequently the Alfvén speed in corona. From the analysis of early observation (Egan & Schneeberger \\cite{egan}) we suggest the value of coronal Alfvén speed as ~ 500 km s-1.

  7. Comparison of global synthetic seismograms calculated using the spherical 2.5-D finite-difference method with observed long-period waveforms including data from the intra-Antarctic region

    NASA Astrophysics Data System (ADS)

    Toyokuni, Genti; Takenaka, Hiroshi; Kanao, Masaki; Wiens, Douglas A.; Nyblade, Andrew

    2012-07-01

    We have been developing an accurate and efficient numerical scheme, which uses the finite-difference method (FDM) in spherical coordinates, for the computation of global seismic wave propagation through laterally heterogeneous realistic Earth models. In the field of global seismology, traditional axisymmetric modeling has been used widely as an efficient approach since it can solve the 3-D elastodynamic equation in spherical coordinates on a 2-D cross-section of the Earth, assuming structures to be invariant with respect to the axis through the seismic source. However, it has the severe disadvantages that asymmetric structures about the axis cannot be incorporated and the source mechanisms with arbitrary shear dislocation have not been attempted for a long time. Our scheme is based on the framework of axisymmetric modeling but has been extended to treat asymmetric structures, arbitrary moment-tensor point sources, anelastic attenuation, and the Earth center which is a singularity of wave equations in spherical coordinates. All these types of schemes which solve 3-D wavefields on a 2-D model cross-section are classified as 2.5-D modeling, so we have named our scheme the spherical 2.5-D FDM. In this study, we compare synthetic seismograms calculated using our FDM scheme with three-component observed long-period seismograms including data from stations newly installed in Antarctica in conjunction with the International Polar Year (IPY) 2007-2008. Seismic data from inland Antarctica are expected to reveal images of the Earth's deep interior with enhanced resolution because of the high signal-to-noise ratio and wide extent of this region, in addition to the rarity of sampling paths along the rotation axis of the Earth. We calculate synthetic seismograms through the preliminary reference earth model (PREM) including attenuation using a moment-tensor point source for the November 9, 2009 Fiji earthquake. Our results show quite good agreement between synthetic and observed seismograms, which indicates the accuracy of observations in the Antarctica, as well as the feasibility of the spherical 2.5-D modeling scheme.

  8. Equine hyperkalemic periodic paralysis: review and implications.

    PubMed Central

    Naylor, J M

    1994-01-01

    The purpose of this review is to present an up-to-date summary of the signs, diagnosis, treatment, and implications of equine hyperkalemic periodic paralysis. The review encompasses all original articles published between 1986 and early 1993. Hyperkalemic periodic paralysis is the result of a genetic mutation in the skeletal muscle sodium channel gene. It is inherited as an autosomal dominant trait; most affected horses are heterozygotes. The classical signs are muscle fasciculation, spasm, and weakness associated with hyperkalemia. However, these signs are only rarely observed in affected horses. Potential sequelae to attacks are abrasions and involuntary recumbency; these problems are not specific for hyperkalemic periodic paralysis, but they occur more frequently in hyperkalemic periodic paralysis-affected horses. It is also likely that hyperkalemic periodic paralysis results in greater muscle mass. There are suggestions that homozygotes may be more severely affected and show signs of upper respiratory obstruction as foals. The practitioner needs to be aware of the tests for hyperkalemic periodic paralysis, and their limitations, so that he can properly diagnose this condition. The industry has the difficult problem of deciding whether or not testing should be mandatory and the fate of positive horses. Images Figure 2. PMID:8050073

  9. Equine hyperkalemic periodic paralysis: review and implications.

    PubMed

    Naylor, J M

    1994-05-01

    The purpose of this review is to present an up-to-date summary of the signs, diagnosis, treatment, and implications of equine hyperkalemic periodic paralysis. The review encompasses all original articles published between 1986 and early 1993. Hyperkalemic periodic paralysis is the result of a genetic mutation in the skeletal muscle sodium channel gene. It is inherited as an autosomal dominant trait; most affected horses are heterozygotes. The classical signs are muscle fasciculation, spasm, and weakness associated with hyperkalemia. However, these signs are only rarely observed in affected horses. Potential sequelae to attacks are abrasions and involuntary recumbency; these problems are not specific for hyperkalemic periodic paralysis, but they occur more frequently in hyperkalemic periodic paralysis-affected horses. It is also likely that hyperkalemic periodic paralysis results in greater muscle mass. There are suggestions that homozygotes may be more severely affected and show signs of upper respiratory obstruction as foals. The practitioner needs to be aware of the tests for hyperkalemic periodic paralysis, and their limitations, so that he can properly diagnose this condition. The industry has the difficult problem of deciding whether or not testing should be mandatory and the fate of positive horses. PMID:8050073

  10. Instructional Suggestions from Abroad concerning Overseas Teaching.

    ERIC Educational Resources Information Center

    Mahan, James M.; Stachowski, Laura L.

    1989-01-01

    Interviews with 32 British and Irish supervisors of U.S. student teachers produced several suggestions for improving the preparation component of overseas practicum placements. Suggestions related to planning and preparation for teaching, basic teacher preparation courses, cultural preparation, content, arrangements and logistics, teacher image

  11. Suggested Learnings: Consumer and Homemaking Education.

    ERIC Educational Resources Information Center

    Edmondson, Dorothy Jean; Swanson, Bettye B.

    The guide presents suggested learning concepts, experiences, and references for home economics educators in the planning and organization of secondary level consumer and homemaking programs. The suggestions are based on questionnaires and interviews with teachers and administrators involved in this program. The guide's main focus is on the process

  12. Positive Suggestion: It Helps LD Students Learn.

    ERIC Educational Resources Information Center

    Oldridge, O. A. "Buff"

    1982-01-01

    The author reviews his experiences in remediating reading problems of learning disabled students through hypnotic and nonhypnotic suggestion. Research on the use of hypnosis is briefly summarized and recommendations on the use of nonhypnotic suggestion in the classroom are given. (CL)

  13. Maltreated Children's Memory: Accuracy, Suggestibility, and Psychopathology

    ERIC Educational Resources Information Center

    Eisen, Mitchell L.; Goodman, Gail S.; Qin, Jianjian; Davis, Suzanne; Crayton, John

    2007-01-01

    Memory, suggestibility, stress arousal, and trauma-related psychopathology were examined in 328 3- to 16-year-olds involved in forensic investigations of abuse and neglect. Children's memory and suggestibility were assessed for a medical examination and venipuncture. Being older and scoring higher in cognitive functioning were related to fewer…

  14. Mercury's Rotation Period: Photographic Confirmation.

    PubMed

    Smith, B A; Reese, E J

    1968-12-13

    Photographic measures of surface features on Mercury have led to a rotation period of 58.663 +/- 0.021 days, which is in good agreement with the 58.646-day period required by a predicted 2:3 resonance between the axial and orbital periods. The incorrect interpretation of earlier visual and photographic observations which supported an 88-day rotation period appears to be partially explained by peculiar characteristics associated with the observability of various hermo-graphic longitudes. The apparent contrast of most of the recorded surface features is marginal for visual observation when viewed through the terrestrial daytime sky. The intrinsic contrast of a relatively conspicuous feature was measured as 0.20, a value lower than that of typical markings observed on the moon and Mars. PMID:17756336

  15. [On suggestion and its related problems].

    PubMed

    Oka, Kazutaro

    2013-01-01

    Recently, intensive discussions about dissociative disorders have led to the rediscovery of the psychology of P. Janet, that has been under the shadow of Freud's psychoanalysis. Nevertheless, psychiatry, "Schulpsychiatrie" in German, has still paid little attention to the suggestion with which Janet has occupied himself throughout his long career. In this paper, the author examined suggestion from another point of view other than psychodynamic. It is presented that Freud reduced suggestion to a specific relation between an active subject and a passive object, as his precursors, F.A. Mesmer and R. de Puységur did the same. In contrast, Janet's early studies influenced by the philosophy of M. de Biran seem to focus on another aspect of suggestion. From this aspect, suggestion is based on a spontaneous intersubjective process that should be expressed by the middle voice. Referring to H. Bergson, with whom Janet corresponded, the author pointed out that one is not always one's own self that reflects one's whole life history, regardless of the presence/absence of mental abnormality, as is the case with a person under suggestion. Taking into account these factors of suggestion, i. e., the middle voice and fragile selfhood that is not firmly rooted in one's own life history, the author investigated hysteria as a distinct phenomenon that has a particularly close relation with suggestion. Furthermore, depersonalization and schizophrenia were discussed concerning their relation with hysteria. In this approach, the author suggested that the unconscious could be topographically localized not only in a deep portion of the mental apparatus, but also in its most superficial portion, unlike in the case of Freud's psychoanalysis. PMID:24228472

  16. Anxiety disorders and physical comorbidity: increased prevalence but reduced relevance of specific risk factors for hospital-based mortality during a 12.5-year observation period in general hospital admissions.

    PubMed

    Schoepf, Dieter; Heun, Reinhard

    2015-08-01

    Anxiety disorders (AD) are associated with an increase in physical comorbidities, but the effects of these diseases on hospital-based mortality are unclear. Consequently, we investigated whether the burden of physical comorbidity and its relevance on hospital-based mortality differed between individuals with and without AD during a 12.5-year observation period in general hospital admissions. During 1 January 2000 and 30 June 2012, 11,481 AD individuals were admitted to seven General Manchester Hospitals. All comorbidities with a prevalence ? 1 % were compared with those of 114,810 randomly selected and group-matched hospital controls of the same age and gender, regardless of priority of diagnoses or specialized treatments. Comorbidities that increased the risk of hospital-based mortality (but not mortality outside of the hospital) were identified using multivariate logistic regression analyses. AD individuals compared to controls had a substantial excess comorbidity, but a reduced hospital-based mortality rate. Twenty-two physical comorbidities were increased in AD individuals compared with controls, which included cardiovascular diseases and their risk factors. The most frequent physical comorbidities in AD individuals were hypertension, asthma, cataract, and ischaemic heart disease. Risk factors for hospital-based mortality in AD individuals were lung cancer, alcoholic liver disease, respiratory failure, heart failure, pneumonia, bronchitis, non-specific dementia, breast cancer, COPD, gallbladder calculus, atrial fibrillation, and angina. The impact of atrial fibrillation, angina, and gallbladder calculus on hospital-based mortality was higher in AD individuals than in controls. In contrast, other mortality risk factors had an equal or lower impact on hospital-based mortality in sample comparisons. Therefore AD individuals have a higher burden of physical comorbidity that is associated with a reduced risk of general hospital-based mortality. Atrial fibrillation, angina, and gallbladder calculus are major risk factors for general hospital-based mortality in AD individuals. PMID:25472881

  17. Global Two-Channel AVHRR Retrievals of Aerosol Properties over the Ocean for the Period of NOAA-9 Observations and Preliminary Retrievals Using NOAA-7 and NOAA-11 Data.

    NASA Astrophysics Data System (ADS)

    Geogdzhayev, Igor V.; Mishchenko, Michael I.; Rossow, William B.; Cairns, Brian; Lacis, Andrew A.

    2002-02-01

    Described is an improved algorithm that uses channel 1 and 2 radiances of the Advanced Very High Resolution Radiometer (AVHRR) to retrieve the aerosol optical thickness and ngstrm exponent over the ocean. Specifically discussed are recent changes in the algorithm as well as the results of a sensitivity study analyzing the effect of several sources of retrieval errors not addressed previously. Uncertainties in the AVHRR radiance calibration (particularly in the deep-space count value) may be among the major factors potentially limiting the retrieval accuracy. A change by one digital count may lead to a 50% change in the aerosol optical thickness and a change of 0.4 in the ngstrm exponent. On the other hand, the performance of two-channel algorithms weakly depends on a specific choice of the aerosol size distribution function with less than 10% changes in the optical thickness resulting from replacing a power law with a bimodal modified lognormal distribution. The updated algorithm is applied to a 10-yr period of observations (Jul 1983-Aug 1994), which includes data from NOAA-7, NOAA-9 (Feb 1985-Nov 1988), and NOAA-11 satellites. (The results are posted online at http://gacp.giss.nasa.gov/retrievals.)The NOAA-9 record reveals a seasonal cycle with maxima occurring around January-February and minima in June-July in the globally averaged aerosol optical thickness. The NOAA-7 data appear to show a residual effect of the El Chichn eruption (Mar 1982) as increased optical thickness values in the beginning of the record. The June 1991 eruption of Mt. Pinatubo resulted in a sharp increase in the aerosol load to more than double its normal value. The NOAA-9 record shows no discernible long-term trends in the global and hemisphere averages of the optical thickness and ngstrm exponent. On the other hand, there is a discontinuity in the ngstrm exponent values derived from NOAA-9 and NOAA-11 data and a significant temporal trend in the NOAA-11 record. The latter is unlikely to be related to the Mt. Pinatubo eruption and may be indicative of a serious calibration problem.The NOAA-9 record shows that the Northern Hemisphere mean optical thickness systematically exceeds that averaged over the Southern Hemisphere. Zonal means of the optical thickness exhibit an increase in the tropical regions of the Northern Hemisphere associated with annual desert dust outbursts and a springtime increase at middle latitudes of the Northern Hemisphere. Increased aerosol loads observed at middle latitudes of the Southern Hemisphere are probably associated with higher sea salt particle concentrations. Reliable extension of the retrieval record beyond the NOAA-9 lifetime will help to corroborate these findings.

  18. Electronic Reference Services: Some Suggested Guidelines.

    ERIC Educational Resources Information Center

    Sloan, Bernie

    1998-01-01

    Suggests guidelines to help libraries formalize their electronic reference services. Covers the following issues: administration/management (library division/department, library administration, campus administration, academic departments); services; primary clientele; personnel; infrastructure/facilities; finances; and evaluation. (AEF)

  19. On the Period-Amplitude and Amplitude-Period Relationships

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.; Hathaway, David H.

    2008-01-01

    Examined are Period-Amplitude and Amplitude-Period relationships based on the cyclic behavior of the 12-month moving averages of monthly mean sunspot numbers for cycles 0.23, both in terms of Fisher's exact tests for 2x2 contingency tables and linear regression analyses. Concerning the Period-Amplitude relationship (same cycle), because cycle 23's maximum amplitude is known to be 120.8, the inferred regressions (90-percent prediction intervals) suggest that its period will be 131 +/- 24 months (using all cycles) or 131 +/- 18 months (ignoring cycles 2 and 4, which have the extremes of period, 108 and 164 months, respectively). Because cycle 23 has already persisted for 142 months (May 1996 through February 2008), based on the latter prediction, it should end before September 2008. Concerning the Amplitude-Period relationship (following cycle maximum amplitude versus preceding cycle period), because cycle 23's period is known to be at least 142 months, the inferred regressions (90-percent prediction intervals) suggest that cycle 24's maximum amplitude will be about less than or equal to 96.1 +/- 55.0 (using all cycle pairs) or less than or equal to 91.0 +/- 36.7 (ignoring statistical outlier cycle pairs). Hence, cycle 24's maximum amplitude is expected to be less than 151, perhaps even less than 128, unless cycle pair 23/24 proves to be a statistical outlier.

  20. Hydrodynamics of periodic breathers.

    PubMed

    Chabchoub, A; Kibler, B; Dudley, J M; Akhmediev, N

    2014-10-28

    We report the first experimental observation of periodic breathers in water waves. One of them is Kuznetsov-Ma soliton and another one is Akhmediev breather. Each of them is a localized solution of the nonlinear Schrdinger equation (NLS) on a constant background. The difference is in localization which is either in time or in space. The experiments conducted in a water wave flume show results that are in good agreement with the NLS theory. Basic features of the breathers that include the maximal amplitudes and spectra are consistent with the theoretical predictions. PMID:25246673

  1. Periodic features in Saturn's F ring - Evidence for nearby moonlets

    NASA Technical Reports Server (NTRS)

    Kolvoord, Robert A.; Burns, Joseph A.; Showalter, Mark R.

    1990-01-01

    The Saturn F ring's shepherd satellites, Pandora and Prometheus, have been suspected of causing the periodicities observed in the ring. To test this idea, a selection of the best available Voyager images of the ring were examined by applying an FFT technique to azimuthal profiles from spacecraft ring images. Only a few distinct periodic signals, including one due to the inner shepherd, are visible. It is suggested that these periodic signatures provide evidence for so-far-undiscovered satellites next to this puzzling ring.

  2. Rationalization of Comet Halley's periods

    NASA Technical Reports Server (NTRS)

    Belton, Michael J. S.

    1990-01-01

    The sense of long axis orientation of Comet Halley during the Vega 1 encounter must be reversed from that deduced by Sagdeev et al. (1986) in order to harmonize the comet nucleus' Vega/Giotto-observed orientations with periodicities extracted from time-series brightness data. It is also demonstrated that Vega/Giotto observations can be satisfied by either a 2.2- or 3.7-day long-axis free precession period. A novel Fourier algorithm is used to reanalyze five independent data sets; strong evidence is adduced for periods harmonically related to a 7.4-day period. The preferred candidate models for Halley's nuclear rotation are characterized by a long-axis precession period of 3.7 days.

  3. Rationalization of Comet Halley's periods

    SciTech Connect

    Belton, M.J.S. )

    1990-07-01

    The sense of long axis orientation of Comet Halley during the Vega 1 encounter must be reversed from that deduced by Sagdeev et al. (1986) in order to harmonize the comet nucleus' Vega/Giotto-observed orientations with periodicities extracted from time-series brightness data. It is also demonstrated that Vega/Giotto observations can be satisfied by either a 2.2- or 3.7-day long-axis free precession period. A novel Fourier algorithm is used to reanalyze five independent data sets; strong evidence is adduced for periods harmonically related to a 7.4-day period. The preferred candidate models for Halley's nuclear rotation are characterized by a long-axis precession period of 3.7 days. 79 refs.

  4. Placebo-Suggestion Modulates Conflict Resolution in the Stroop Task

    PubMed Central

    Caspar, Emilie A.; Gevers, Wim; Cleeremans, Axel

    2013-01-01

    Here, we ask whether placebo-suggestion (without any form of hypnotic induction) can modulate the resolution of cognitive conflict. Nave participants performed a Stroop Task while wearing an EEG cap described as a brain wave machine. In Experiment 1, participants were made to believe that the EEG cap would either enhance or decrease their color perception and performance on the Stroop task. In Experiment 2, participants were explicitly asked to imagine that their color perception and performance would be enhanced or decreased (non-hypnotic imaginative suggestion). We observed effects of placebo-suggestion on Stroop interference on accuracy: interference was decreased with positive suggestion and increased with negative suggestion compared to baseline. Intra-individual variability was also increased under negative suggestion compared to baseline. Compliance with the instruction to imagine a modulation of performance, on the other hand, did not influence accuracy and only had a negative impact on response latencies and on intra-individual variability, especially in the congruent condition of the Stroop Task. Taken together, these results demonstrate that expectations induced by a placebo-suggestion can modulate our ability to resolve cognitive conflict, either facilitating or impairing response accuracy depending on the suggestions contents. Our results also demonstrate a dissociation between placebo-suggestion and non-hypnotic imaginative suggestion. PMID:24130735

  5. Evolution of periodicity in periodical cicadas

    PubMed Central

    Ito, Hiromu; Kakishima, Satoshi; Uehara, Takashi; Morita, Satoru; Koyama, Takuya; Sota, Teiji; Cooley, John R.; Yoshimura, Jin

    2015-01-01

    Periodical cicadas (Magicicada spp.) in the USA are famous for their unique prime-numbered life cycles of 13 and 17 years and their nearly perfectly synchronized mass emergences. Because almost all known species of cicada are non-periodical, periodicity is assumed to be a derived state. A leading hypothesis for the evolution of periodicity in Magicicada implicates the decline in average temperature during glacial periods. During the evolution of periodicity, the determinant of maturation in ancestral cicadas is hypothesized to have switched from size dependence to time (period) dependence. The selection for the prime-numbered cycles should have taken place only after the fixation of periodicity. Here, we build an individual-based model of cicadas under conditions of climatic cooling to explore the fixation of periodicity. In our model, under cold environments, extremely long juvenile stages lead to extremely low adult densities, limiting mating opportunities and favouring the evolution of synchronized emergence. Our results indicate that these changes, which were triggered by glacial cooling, could have led to the fixation of periodicity in the non-periodical ancestors. PMID:26365061

  6. Seasonal variation in the length of the daily activity period in buffy-headed marmosets (Callithrix flaviceps): an important consideration for the analysis of foraging strategies in observational field studies of primates.

    PubMed

    Ferrari, Stephen F; Hilário, Renato R

    2014-04-01

    Activity budgets are widely used in primate behavioral studies for the analysis of ecological strategies. In some cases, there is considerable seasonal variation in the length of the daily activity period. Here, activity budgets from two field studies of Callithrix flaviceps were compiled first by the traditional approach (proportion of scan sample records) and then by considering the proportion of time dedicated to each activity over the 24-hr cycle (adjusted budget). Both groups were almost invariably active for at least 1-2 hr less than the daylight period, with significantly shorter activity periods during the austral winter, when the daylight period was up to 2:35 hr shorter than in the summer. The adjustment of activity budgets provided a completely different perspective on foraging strategies. Whereas the basic budgets indicated a significant increase in foraging and moving during the resource-poor dry season (winter) months, the time-adjusted data revealed that the primary strategy was a time-minimizing one, with the animals simply spending more time at rest during the longer activity periods of summer days. While both groups followed the same pattern of relatively short activity periods, there were considerable differences between sites in the mean duration of the period in a given month, and in behavior patterns, although the analysis of the determining factors was beyond the scope of the present study. Overall, the results of the study indicate that the manipulation of the duration of the daily activity period may be an integral component of primate behavioral strategies, and that this parameter should be taken into account systematically when evaluating activity patterns, especially at sites at relatively high latitudes where day length may vary considerably over the course of the year. PMID:24323495

  7. Stellar evolution and period changes in RR Lyrae stars

    NASA Technical Reports Server (NTRS)

    Lee, Young-Wook

    1991-01-01

    The observed secular period changes of RR Lyrae stars in five globular clusters have been compared with those predicted by synthetic models of the horizontal branch (HB). It is shown that most of the observed number distributions of the period change rate beta could be attributed to evolutionary effects, if the random observational error is of order + or - 0.07 days/Myr in beta as suggested by the observers. The model calculations indicate that the mean rate of period change in RR Lyrae stars in globular clusters depends sensitively on their HB type, as is the case for the period shift at a given effective temperature. The distinct bias toward positive period changes in M15 and Omega Cen is evidence that most HB stars in the Oosterhoff group II clusters pass through the instability strip from blue to red toward the end of their core helium burning phase. If confirmed by future observations, this is strong support for the Lee et al. (1990) explanation of the Sandage (1957) period-shift effect.

  8. Excited-state quantum phase transitions and periodic dynamics

    NASA Astrophysics Data System (ADS)

    Engelhardt, G.; Bastidas, V. M.; Kopylov, W.; Brandes, T.

    2015-01-01

    We investigate signatures of the excited-state quantum phase transition in the periodic dynamics of the Lipkin-Meshkov-Glick model and the Tavis-Cummings model. In the thermodynamic limit, expectation values of observables in eigenstates of the system can be calculated using classical trajectories. Motivated by this, we suggest a method based on the time evolution of the finite-size system to find singularities in observables, which arise due to the excited-state quantum phase transition.

  9. Shipwreck rates and tree rings suggest reduced North Atlantic tropical cyclone activity during the Maunder Minimum.

    NASA Astrophysics Data System (ADS)

    Harley, G. L.; Trouet, V.; Dominguez Delmas, M.

    2014-12-01

    The observational record of North Atlantic TCs is too short to inform our understanding of decadal-scale climatic controls on TC regimes. We combined two new annual-resolution proxies of Atlantic storm activity to extend the observational TC record back to the 16th Century. A tree-growth suppression chronology (1707-2010 CE) from the Florida Keys, U.S.A. captures 91% of observed North Atlantic TCs (1850-2010 CE) and shares significant peak events with a documentary time series of Spanish shipwrecks in the Caribbean (1495-1820). Decadal-scale shipwreck rates were lowest during the Maunder Minimum (ca. 1645-1715), indicating that cooler Atlantic sea surface temperatures (SSTs) during this period reduced Caribbean TC activity. Our results support global-scale climate proxy data and suggest that cooler tropical Atlantic SSTs and a generally negative mode of the North Atlantic Oscillation during the Little Ice Age reduced TC frequency.

  10. Improving sleep and cognition by hypnotic suggestion in the elderly.

    PubMed

    Cordi, Maren Jasmin; Hirsiger, Sarah; Mrillat, Susan; Rasch, Bjrn

    2015-03-01

    Sleep quality markedly declines across the human lifespan. Particularly the amount of slow-wave sleep (SWS) decreases with age and this decrease is paralleled by a loss of cognitive functioning in the elderly. Here we show in healthy elderly females that the amount of SWS can be extended by a hypnotic suggestion "to sleep deeper" before sleep. In a placebo-controlled cross-over design, participants listened to hypnotic suggestions or a control tape before a midday nap while high density electroencephalography was recorded. After the hypnotic suggestion, we observed a 57% increase in SWS in females suggestible to hypnosis as compared to the control condition. Furthermore, left frontal slow-wave activity (SWA), characteristic for SWS, was significantly increased, followed by a significant improvement in prefrontal cognitive functioning after sleep. Our results suggest that hypnotic suggestions might be a successful alternative for widely-used sleep-enhancing medication to extend SWS and improve cognition in the elderly. PMID:25660206

  11. Current Research: 2013 Summer Reading Suggestions

    ERIC Educational Resources Information Center

    Journal of College Science Teaching, 2013

    2013-01-01

    To supplement the summer reading of National Science Teachers Association (NSTA) members, the NSTA Committee on Research in Science Education suggested a list of science education research articles that were published in the journals of NSTA's affiliates in 2012. These articles covered a variety of topics that include learning about…

  12. Leadership Theories--Managing Practices, Challenges, Suggestions

    ERIC Educational Resources Information Center

    Hawkins, Cheryl

    2009-01-01

    A shortage of community college executives due to the number of retirements occurring among current leaders is predicted. An examination of three leadership theories--servant-leadership, business leadership and transformational leadership--suggests techniques for potential community college leaders. Servant-leaders focus on the needs of their

  13. Technology Is Power: Suggestions for Beginning Teachers

    ERIC Educational Resources Information Center

    Shanklin, Nancy

    2010-01-01

    Shanklin knows it can be hard for new teachers to incorporate all they know about technology with the realities of a classroom. She suggests setting incremental, monthly technology goals; investing in equipment; assessing students' grasp of the technology at their disposal and their use of it in classroom projects; searching purposefully for

  14. Technology Is Power: Suggestions for Beginning Teachers

    ERIC Educational Resources Information Center

    Shanklin, Nancy

    2010-01-01

    Shanklin knows it can be hard for new teachers to incorporate all they know about technology with the realities of a classroom. She suggests setting incremental, monthly technology goals; investing in equipment; assessing students' grasp of the technology at their disposal and their use of it in classroom projects; searching purposefully for…

  15. Physics Courses--Some Suggested Case Studies

    ERIC Educational Resources Information Center

    Swetman, T. P.

    1972-01-01

    To communicate the relevance and excitement of science activity to students, the use of more imaginative, and even openly speculative, case studies in physics courses is suggested. Some useful examples are Magnetic Monopoles, Constants, Black Holes, Antimatter, Zero Mass Particles, Tachyons, and the Bootstrap Hypothesis. (DF)

  16. Family Living: Suggestions for Effective Parenting.

    ERIC Educational Resources Information Center

    Katz, Lilian G.; And Others

    Suggestions for effective parenting of preschool children are provided in 33 brief articles on children's feelings concerning self-esteem; fear; adopted children; the birth of a sibling; death; depression; and coping with stress, trauma, and divorce. Children's behavior is discussed in articles on toddlers' eating habits, punishment and

  17. Integrating Composition and Literature: Some Practical Suggestions.

    ERIC Educational Resources Information Center

    Daiker, Donald A.

    This paper suggests that it is possible to construct a course that integrates the teaching of composition with the teaching of literature without allowing the secondary goal of heightened literary understanding to overwhelm the primary goal of improved expository writing. It presents a syllabus for a four-week unit on Ernest Hemingway's "The Sun…

  18. Qualitative Research Articles: Guidelines, Suggestions and Needs

    ERIC Educational Resources Information Center

    Crescentini, Alberto; Mainardi, Giuditta

    2009-01-01

    Purpose: The purpose of this paper is to give ideas and suggestions to avoid some typical problems of qualitative articles. The aim is not to debate quality in qualitative research but to indicate some practical solutions. Design/methodology/approach: The paper discusses the design of qualitative research and the structure of a qualitative article

  19. Suggestions for a Course in Consumer Health.

    ERIC Educational Resources Information Center

    Young, Michael; Means, Richard K.

    1981-01-01

    Suggestions are given for the development of a college course in consumer health. The goals of such a course are: (1) to present information which will aid students in consumer decision-making skills; and (2) to assist students in developing effective strategies in consumer health education. (JN)

  20. Current Research: 2013 Summer Reading Suggestions

    ERIC Educational Resources Information Center

    Journal of College Science Teaching, 2013

    2013-01-01

    To supplement the summer reading of National Science Teachers Association (NSTA) members, the NSTA Committee on Research in Science Education suggested a list of science education research articles that were published in the journals of NSTA's affiliates in 2012. These articles covered a variety of topics that include learning about

  1. Accounting: Suggested Content for Postsecondary Tax Course

    ERIC Educational Resources Information Center

    King, Patricia H.; Morgan, Samuel D.

    1978-01-01

    Surveys of community college graduates and of certified public accountants were made to determine employment relevance of the accounting curriculum. The article suggests topics from the study data which should be included in taxation courses, e.g., income tax accounting, corporate taxation accounting, and tax law. (MF)

  2. Qualitative Research Articles: Guidelines, Suggestions and Needs

    ERIC Educational Resources Information Center

    Crescentini, Alberto; Mainardi, Giuditta

    2009-01-01

    Purpose: The purpose of this paper is to give ideas and suggestions to avoid some typical problems of qualitative articles. The aim is not to debate quality in qualitative research but to indicate some practical solutions. Design/methodology/approach: The paper discusses the design of qualitative research and the structure of a qualitative article…

  3. Leadership Theories--Managing Practices, Challenges, Suggestions

    ERIC Educational Resources Information Center

    Hawkins, Cheryl

    2009-01-01

    A shortage of community college executives due to the number of retirements occurring among current leaders is predicted. An examination of three leadership theories--servant-leadership, business leadership and transformational leadership--suggests techniques for potential community college leaders. Servant-leaders focus on the needs of their…

  4. Integrating Composition and Literature: Some Practical Suggestions.

    ERIC Educational Resources Information Center

    Daiker, Donald A.

    This paper suggests that it is possible to construct a course that integrates the teaching of composition with the teaching of literature without allowing the secondary goal of heightened literary understanding to overwhelm the primary goal of improved expository writing. It presents a syllabus for a four-week unit on Ernest Hemingway's "The Sun

  5. Suggestions for Structuring a Research Article

    ERIC Educational Resources Information Center

    Klein, James D.; Reiser, Robert A.

    2014-01-01

    Researchers often experience difficulty as they attempt to prepare journal articles that describe their work. The purpose of this article is to provide researchers in the field of education with a series of suggestions as to how to clearly structure each section of a research manuscript that they intend to submit for publication in a scholarly…

  6. Challenges and Suggestions for Safe Schools.

    ERIC Educational Resources Information Center

    Bucher, Katherine T.; Manning, M. Lee

    2003-01-01

    Looks at challenges to safe schools and offers eight suggestions for ensuring the safety of students and educators. Notes that school violence includes unacceptable social behavior ranging from aggression that threatens or harms others to bullying, threats, sexual harassment, gang violence, extortion, and other forms of intimidation. (SG)

  7. Assessment of Achievement Motives: Comments and Suggestions

    ERIC Educational Resources Information Center

    Nygard, Roald; Gjesme, Torgrim

    1973-01-01

    In this article some problems, such as the tests employed to assess motivation, are considered together with suggestions for developing an instrument more in accordance with the achievement motivation theory as represented by the McClelland-Atkinson tradition. (Author/RK)

  8. Seven Salutary Suggestions for Counselor Stamina

    ERIC Educational Resources Information Center

    Osborn, Cynthia J.

    2004-01-01

    Counselor stamina is deemed essential in the midst of a consistently challenging, complex, and changing mental health care environment. Rather than perpetuating conversations about "burnout" and "burnout prevention," this article provides a salutary or health-promoting perspective. Seven suggestions for counselor stamina are presented and

  9. Cable Television Report and Suggested Ordinance.

    ERIC Educational Resources Information Center

    League of California Cities, Sacramento.

    Guidelines and suggested ordinances for cable television regulation by local governments are comprehensively discussed in this report. The emphasis is placed on franchising the cable operator. Seventeen legal aspects of franchising are reviewed, and an exemplary ordinance is presented. In addition, current statistics about cable franchising in

  10. Suggestions for Structuring a Research Article

    ERIC Educational Resources Information Center

    Klein, James D.; Reiser, Robert A.

    2014-01-01

    Researchers often experience difficulty as they attempt to prepare journal articles that describe their work. The purpose of this article is to provide researchers in the field of education with a series of suggestions as to how to clearly structure each section of a research manuscript that they intend to submit for publication in a scholarly

  11. Structure of the solar oscillation with period near 160 minutes

    NASA Technical Reports Server (NTRS)

    Scherrer, P. H.; Wilcox, J. M.

    1982-01-01

    The solar oscillation with period near 160 minutes is found to be unique in a spectrum computed over the range of periods from about 71 to 278 minutes. A best estimate of the period is 160.0095 + or - 0.001 minutes, which is different from 160 minutes (one ninth of a day) by a highly significant amount. The width of the peak is approximately equal to the limiting resolution that can be obtained from an observation lasting 6 years, which suggests that the damping time of the oscillations is considerably longer than 6 years. A suggestion that this peak might be the result of a beating phenomenon between the five minute data averages and a solar oscillation with period near five minutes is shown to be incorrect by recomputing a portion of the spectrum using 15 second data averages.

  12. A Multi-period Oscillation in a Stellar Superflare

    NASA Astrophysics Data System (ADS)

    Pugh, C. E.; Nakariakov, V. M.; Broomhall, A.-M.

    2015-11-01

    Flares that are orders of magnitude larger than the most energetic solar flares are routinely observed on Sun-like stars, raising the question of whether the same physical processes are responsible for both solar and stellar flares. In this Letter, we present a white-light stellar superflare on the star KIC 9655129, observed by NASAs Kepler mission, with a rare multi-period quasi-periodic pulsation (QPP) pattern. Two significant periodic processes were detected using the wavelet and autocorrelation techniques, with periods of 78 12 minutes and 32 2 minutes. By comparing the phases and decay times of the two periodicities, the QPP signal was found to most likely be linear, suggesting that the two periodicities are independent, possibly corresponding either to different magnetohydrodynamic (MHD) modes of the flaring region or different spatial harmonics of the same mode. The presence of multiple periodicities is a good indication that the QPPs were caused by MHD oscillations and suggests that the physical processes in operation during stellar flares could be the same as those in solar flares.

  13. Quasi-periodic compressive waves in polar plumes

    NASA Technical Reports Server (NTRS)

    DeForest, C. E.; Gurman, J. B.

    1997-01-01

    The observation of polar plumes in the south polar coronal hole, carried out on 7 March 1996 by the Solar and Heliospheric Observatory (SOHO), are analyzed. These polar plumes are cool density structures that arise from morphologically unipolar magnetic footpoints. Data from the extreme ultraviolet imaging telescope show quasi-periodic perturbations in the brightness of the Fe IX and X line emissions at 171 A from polar plumes. The perturbations have periods of 10 to 15 min, and repeat for several cycles suggesting that they are compressive waves propagating through the plume at or near the Alfven speed. Possible explanations for the observed phenomenon are proposed.

  14. Log-periodic route to fractal functions

    NASA Astrophysics Data System (ADS)

    Gluzman, S.; Sornette, D.

    2002-03-01

    Log-periodic oscillations have been found to decorate the usual power-law behavior found to describe the approach to a critical point, when the continuous scale-invariance symmetry is partially broken into a discrete-scale invariance symmetry. For Ising or Potts spins with ferromagnetic interactions on hierarchical systems, the relative magnitude of the log-periodic corrections are usually very small, of order 10-5. In growth processes [diffusion limited aggregation (DLA)], rupture, earthquake, and financial crashes, log-periodic oscillations with amplitudes of the order of 10% have been reported. We suggest a ``technical'' explanation for this 4 order-of-magnitude difference based on the property of the ``regular function'' g(x) embodying the effect of the microscopic degrees of freedom summed over in a renormalization group (RG) approach F(x)=g(x)+?-1F(?x) of an observable F as a function of a control parameter x. For systems for which the RG equation has not been derived, the previous equation can be understood as a Jackson q integral, which is the natural tool for describing discrete-scale invariance. We classify the ``Weierstrass-type'' solutions of the RG into two classes characterized by the amplitudes An of the power-law series expansion. These two classes are separated by a novel ``critical'' point. Growth processes (DLA), rupture, earthquake, and financial crashes thus seem to be characterized by oscillatory or bounded regular microscopic functions that lead to a slow power-law decay of An, giving strong log-periodic amplitudes. If in addition, the phases of An are ergodic and mixing, the observable presents self-affine nondifferentiable properties. In contrast, the regular function of statistical physics models with ``ferromagnetic''-type interactions at equibrium involves unbound logarithms of polynomials of the control variable that lead to a fast exponential decay of An giving weak log-periodic amplitudes and smoothed observables.

  15. Suggested notation conventions for rotational seismology

    USGS Publications Warehouse

    Evans, J.R.

    2009-01-01

    We note substantial inconsistency among authors discussing rotational motions observed with inertial seismic sensors (and much more so in the broader topic of rotational phenomena). Working from physics and other precedents, we propose standard terminology and a preferred reference frame for inertial sensors (Fig. 1) that may be consistently used in discussions of both finite and infinitesimal observed rotational and translational motions in seismology and earthquake engineering. The scope of this article is limited to observations because there are significant differences in the analysis of finite and infinitesimal rotations, though such discussions should remain compatible with those presented here where possible. We recommend the general use of the notation conventions presented in this tutorial, and we recommend that any deviations or alternatives be explicitly defined.

  16. Period Determination for 1660 Wood

    NASA Astrophysics Data System (ADS)

    Oey, Julian; Alvarez, Eduardo Manuel

    2012-07-01

    Lightcurve analysis for asteroid 1660 Wood was performed in collaboration with observers in Australia and Uruguay from observations obtained during the asteroid's favorable opposition in 2012. The synodic rotation period was found to be 6.8090 0.0002 h and the lightcurve amplitude was 0.14 0.03 mag.

  17. Placebo-suggestion modulates conflict resolution in the Stroop Task.

    PubMed

    Magalhes De Saldanha da Gama, Pedro A; Slama, Hichem; Caspar, Emilie A; Gevers, Wim; Cleeremans, Axel

    2013-01-01

    Here, we ask whether placebo-suggestion (without any form of hypnotic induction) can modulate the resolution of cognitive conflict. Nave participants performed a Stroop Task while wearing an EEG cap described as a "brain wave" machine. In Experiment 1, participants were made to believe that the EEG cap would either enhance or decrease their color perception and performance on the Stroop task. In Experiment 2, participants were explicitly asked to imagine that their color perception and performance would be enhanced or decreased (non-hypnotic imaginative suggestion). We observed effects of placebo-suggestion on Stroop interference on accuracy: interference was decreased with positive suggestion and increased with negative suggestion compared to baseline. Intra-individual variability was also increased under negative suggestion compared to baseline. Compliance with the instruction to imagine a modulation of performance, on the other hand, did not influence accuracy and only had a negative impact on response latencies and on intra-individual variability, especially in the congruent condition of the Stroop Task. Taken together, these results demonstrate that expectations induced by a placebo-suggestion can modulate our ability to resolve cognitive conflict, either facilitating or impairing response accuracy depending on the suggestion's contents. Our results also demonstrate a dissociation between placebo-suggestion and non-hypnotic imaginative suggestion. PMID:24130735

  18. Cajal's brief experimentation with hypnotic suggestion.

    PubMed

    Stefanidou, Maria; Sol, Carme; Kouvelas, Elias; del Cerro, Manuel; Triarhou, Lazaros C

    2007-01-01

    Spanish histologist Santiago Ramn y Cajal, one of the most notable figures in Neuroscience, and winner, along with Camillo Golgi, of the 1906 Nobel Prize in Physiology or Medicine for his discoveries on the structure of the nervous system, did not escape experimenting with some of the psychiatric techniques available at the time, mainly hypnotic suggestion, albeit briefly. While a physician in his thirties, Cajal published a short article under the title, "Pains of labour considerably attenuated by hypnotic suggestion" in Gaceta Mdica Catalana. That study may be Cajal's only documented case in the field of experimental psychology. We here provide an English translation of the original Spanish text, placing it historically within Cajal's involvement with some of the key scientific and philosophical issues at the time. PMID:17966053

  19. Finding query suggestions for PubMed.

    PubMed

    Lu, Zhiyong; Wilbur, W John; McEntyre, Johanna R; Iskhakov, Alexey; Szilagyi, Lee

    2009-01-01

    It is common for PubMed users to repeatedly modify their queries (search terms) before retrieving documents relevant to their information needs. To assist users in reformulating their queries, we report the implementation and usage analysis of a new component in PubMed called Related Queries, which automatically produces query suggestions in response to the original user's input. The proposed method is based on query log analysis and focuses on finding popular queries that contain the initial user search term with a goal of helping users describe their information needs in a more precise manner. This work has been integrated into PubMed since January 2009. Automatic assessment using clickthrough data show that each day, the new feature is used consistently between 6% and 10% of the time when it is shown, suggesting that it has quickly become a popular new feature in PubMed. PMID:20351887

  20. Motivational factors in aphasia therapy: research suggestions.

    PubMed

    Shill, M A

    1979-11-01

    Following Wepman (1953), the process of recovery from aphasia is seen as involving stimulation, motivation, and facilitation. The most adequate studies of aphasia therapy outcome focus on facilitation to the virtual exclusion of stimulation and motivation, although clinical experience suggests their importance. Motivation includes both the subjective and experiential aspects of the patient's response to aphasic disablement (anxiety, feelings of inadequacy) and the quality of the speech-therapist/patient alliance during the treatment. Retrospective studies utilizing sufficiently improved aphasics and ratings of the patient-therapist alliance are suggested as preliminary means of defining "motivation" in this context more accurately. Research approaches are also outlined which would assess the importance of and interaction between the three factors implicated in recovery for therapeutic outcome. PMID:391834

  1. Mentoring in biostatistics: some suggestions for reform

    PubMed Central

    Odueyungbo, Adefowope; Thabane, Lehana

    2012-01-01

    Mentoring is routinely used as a tool to facilitate acquisition of skills by new professionals in fields like medicine, nursing, surgery, and business. While mentoring has been proposed as an effective strategy for knowledge and skills transfer in biostatistics and related fields, there is still much to be done to facilitate adoption by stakeholders, including academia and employers of biostatisticians. This is especially troubling given that biostatisticians play a key role in the success or otherwise of clinical research conducted for evidence-based decisions. In this paper, we offer suggestions on how mentoring can be applied in practice to advance the statistical training of future biostatisticians. In particular, we propose steps that academic statistics departments, professional statistical societies, and statistics organizations can take to advance the mentoring of young biostatisticians. Our suggestions also cover what mentors and mentees can do to facilitate a successful mentoring relationship. PMID:23093907

  2. Further suggestions for writing memorable geophysical papers

    NASA Astrophysics Data System (ADS)

    Baker, D. N.

    In an earlier article in Eos (December 21, 1982, p. 1219), I suggested that members of AGU had been seriously remiss in not forming proper author teams in order to write “memorable” geophysical research papers. A number of the original suggestions were rejected either on the grounds of good taste (see the “unabridged” preprint version of the paper, available from the author) or else because of political sensitivity (e.g., “Crooked magnetic field lines” by AGU members Agnew and Nixon). Nonetheless, several examples of what might be done survived censorship and appeared in the Eos article. In summary, it was concluded that geophysicists could be a lot more active in this area.

  3. [Suggestions to improve dentist-endodontist collaboration].

    PubMed

    Zabalegui, B; Zabalegui, I; Flores, L

    1989-01-01

    Referrals from the general dentist to the endodontist are in some occasions complicated with lack of proper communication among dentist-patient-specialist, resulting in the loss of confidence or even the patient. Suggestions to improve this communication are discussed, which will provide the patient a higher confidence in the indicated endodontic treatment and a better dental service. It will also enhance the prestige of the general dentists' and specialists' practice. PMID:2640034

  4. Promoting Good Statistical Practices: Some Suggestions.

    ERIC Educational Resources Information Center

    Kirk, Roger E.

    2001-01-01

    Makes the case that science is best served when researchers focus on the size of effects and their practical significance. Advocates the use of confidence intervals for deciding whether chance or sampling variability is an unlikely explanation for an observed effect. Calls for more emphasis on effect sizes in the next edition of the American

  5. Secular period decreasing of 17 detached chromospherically active binaries

    NASA Astrophysics Data System (ADS)

    Luo, C. Q.; Luo, Y. P.; Zhang, X. B.; Deng, L. C.; Luo, Z. Q.; Yang, S. Z.

    2008-10-01

    The long-term orbital period changes of detached chromospheric active binaries were surveyed. 17 of such systems are found to be undergoing secular period decreasing with the rates (dP/dt) of -3.05 10-9 to -3.77 10-5 days per year. The longer the orbital period, the more rapidly the period decreases. Following Stepien (1995), the period decreasing rate due to the angular momentum loss (AML) caused by magnetic wind is computed for each system. A comparison shows that the observed dP/dt's are obviously higher than that of the theoretical predictions by 1-3 orders of magnitude. It suggests that the magnetic wind is not likely the determinant mechanism driving the AML in close binaries.

  6. New evidence suggesting segmentation of Cocos Plate

    SciTech Connect

    Lew, L.R.; Sauermann, R.P.; De Boer, J.

    1985-02-01

    Compilation and analysis of geophysical and geological data indicate that the Cocos plate consists of three segments that have individual poles of rotation and independent motion vectors. Contoured heat-flow and gravity maps of the region delineate the boundaries of the segments within the Cocos plate. These segments have different focal-plane solutions along the Middle America Trench and different sedimentary-basin configurations within the Central America-Mexico island arc. Recent studies of seismic data from the region also have suggested that the subducted Cocos plate consists of three segments. The proposed northern and central segments are separated by the northeast-trending Siqueros-Tehuantepec Ridge fracture zone. The proposed central and southern segments are separated by the northeast-trending Costa Rica fracture zone that is located just northwest of the Cocos Ridge and extends from the Galapagos rift to the central valley of Costa Rica. Poles of rotation and relative motion vectors have been calculated with respect to the Caribbean plate for each segment. The northern segment is moving N75/sup 0/E, oblique to the trench; the central segment is moving N50/sup 0/E, perpendicular to the trench; the southern segment is moving north, perpendicular to the trench. The Siqueros-Tehuantepec and Costa Rice fracture zones appear to join with tectonized zones that dissect the Central America-Mexico island arc and extend across the Caribbean plate, suggesting that it too is segmented. Structural and stratigraphic data from the sedimentary basins on the island arc suggest that these fracture zones have existed throughout the Tertiary history of the region.

  7. Periodic bursts of Jovian non-Io decametric radio emission

    PubMed Central

    Panchenko, M.; Rucker, H.O.; Farrell, W.M.

    2013-01-01

    During the years 2000–2011 the radio instruments onboard Cassini, Wind and STEREO spacecraft have recorded a large amount of the Jovian decametric radio emission (DAM). In this paper we report on the analysis of the new type of Jovian periodic radio bursts recently revealed in the decametric frequency range. These bursts, which are non-Io component of DAM, are characterized by a strong periodic reoccurrence over several Jovian days with a period ≈1.5% longer than the rotation rate of the planet's magnetosphere (System III). The bursts are typically observed between 4 and 12 MHz and their occurrence probability has been found to be significantly higher in the sector of Jovian Central Meridian Longitude between 300° and 60° (via 360°). The stereoscopic multispacecraft observations have shown that the radio sources of the periodic bursts radiate in a non-axisymmetric hollow cone-like pattern and sub-corotate with Jupiter remaining active during several planet's rotations. The occurrence of the periodic non-Io DAM bursts is strongly correlated with pulses of the solar wind ram pressure at Jupiter. Moreover the periodic bursts exhibit a tendency to occur in groups every ∼25 days. The polarization measurements have shown that the periodic bursts are right hand polarized radio emission associated with the Northern magnetic hemisphere of Jupiter. We suggest that periodic non-Io DAM bursts may be connected with the interchange instability in Io plasma torus triggered by the solar wind. PMID:23585696

  8. Periodic bursts of Jovian non-Io decametric radio emission.

    PubMed

    Panchenko, M; Rucker, H O; Farrell, W M

    2013-03-01

    During the years 2000-2011 the radio instruments onboard Cassini, Wind and STEREO spacecraft have recorded a large amount of the Jovian decametric radio emission (DAM). In this paper we report on the analysis of the new type of Jovian periodic radio bursts recently revealed in the decametric frequency range. These bursts, which are non-Io component of DAM, are characterized by a strong periodic reoccurrence over several Jovian days with a period [Formula: see text] longer than the rotation rate of the planet's magnetosphere (System III). The bursts are typically observed between 4 and 12 MHz and their occurrence probability has been found to be significantly higher in the sector of Jovian Central Meridian Longitude between 300° and 60° (via 360°). The stereoscopic multispacecraft observations have shown that the radio sources of the periodic bursts radiate in a non-axisymmetric hollow cone-like pattern and sub-corotate with Jupiter remaining active during several planet's rotations. The occurrence of the periodic non-Io DAM bursts is strongly correlated with pulses of the solar wind ram pressure at Jupiter. Moreover the periodic bursts exhibit a tendency to occur in groups every [Formula: see text] days. The polarization measurements have shown that the periodic bursts are right hand polarized radio emission associated with the Northern magnetic hemisphere of Jupiter. We suggest that periodic non-Io DAM bursts may be connected with the interchange instability in Io plasma torus triggered by the solar wind. PMID:23585696

  9. Periodic Bursts of Jovian Non-Io Decametric Radio Emission

    NASA Technical Reports Server (NTRS)

    Panchenko, M.; Rucker, H O.; Farrell, W. M.

    2013-01-01

    During the years 2000-2011 the radio instruments onboard Cassini, Wind and STEREO spacecraft have Recorded a large amount of the Jovian decametric radio emission (DAM). In this paper we report on the analysis of the new type of Jovian periodic radio bursts recently revealed in the decametric frequency range. These bursts, which are non-Io component of DAM, are characterized by a strong periodic reoccurrence over several Jovian days with a period approx. = 1:5% longer than the rotation rate of the planet's magnetosphere (System III). The bursts are typically observed between 4 and 12 MHz and their occurrence probability has been found to be significantly higher in the sector of Jovian Central Meridian Longitude between 300 deg. and 60 deg. (via 360 deg.). The stereoscopic multispacecraft observations have shown that the radio sources of the periodic bursts radiate in a non-axisymmetric hollow cone-like pattern and sub-corotate with Jupiter remaining active during several planet's rotations. The occurrence of the periodic non-Io DAM bursts is strongly correlated with pulses of the solar wind ram pressure at Jupiter. Moreover the periodic bursts exhibit a tendency to occur in groups every approx. 25 days. The polarization measurements have shown that the periodic bursts are right hand polarized radio emission associated with the Northern magnetic hemisphere of Jupiter. We suggest that periodic non-Io DAM bursts may be connected with the interchange instability in Io plasma torus triggered by the solar wind.

  10. Dinosaur Peptides Suggest Mechanisms of Protein Survival

    SciTech Connect

    San Antonio, James D.; Schweitzer, Mary H.; Jensen, Shane T.; Kalluri, Raghu; Buckley, Michael; Orgel, Joseph P.R.O.

    2011-09-16

    Eleven collagen peptide sequences recovered from chemical extracts of dinosaur bones were mapped onto molecular models of the vertebrate collagen fibril derived from extant taxa. The dinosaur peptides localized to fibril regions protected by the close packing of collagen molecules, and contained few acidic amino acids. Four peptides mapped to collagen regions crucial for cell-collagen interactions and tissue development. Dinosaur peptides were not represented in more exposed parts of the collagen fibril or regions mediating intermolecular cross-linking. Thus functionally significant regions of collagen fibrils that are physically shielded within the fibril may be preferentially preserved in fossils. These results show empirically that structure-function relationships at the molecular level could contribute to selective preservation in fossilized vertebrate remains across geological time, suggest a 'preservation motif', and bolster current concepts linking collagen structure to biological function. This non-random distribution supports the hypothesis that the peptides are produced by the extinct organisms and suggests a chemical mechanism for survival.

  11. [Suggestions for buying medical equipment in hospitals].

    PubMed

    Trontzos, Christos

    2004-01-01

    TO THE EDITOR: Both in Greece and in other European countries there are plans to buy more medical equipment. If the whole procedure is not effective, it may result to a large deficit in the hospital budget. The total hospital deficit now in Greece is about 2.5 billion euros. It is suggested that in every hospital, the Authorized Committee for Medical Equipment Purchasing, should include the following: One Director of a Medical Department related to the equipment to be bought and another Director of a Medical Department, unrelated. One accountant. One legal advisor specialized in hospital affairs. One economical advisor specialized in banking who will be able to suggest leasing or other means of financing the purchase of the relevant equipment. A cost accounting analysis described by a detailed report, should be provided to secure that the equipment to be bought should be cost-effective and leaving a reasonable surplus after not more than 10 years from the time it is installed. Finally, the possibility of using one expensive equipment to cover the needs of more than one hospitals either by moving the equipment (i.e. the PET/CT camera by a large vehicle) or by transferring the patients to a central hospital, may be provided by the above Authorized Committee. PMID:15841294

  12. Hybrid simulation of whistler excitation by electron beams in two-dimensional non-periodic domains

    SciTech Connect

    Woodroffe, J.R. Streltsov, A.V.

    2014-11-01

    We present a two-dimensional hybrid fluid-PIC scheme for the simulation of whistler wave excitation by relativistic electron beams. This scheme includes a number of features which are novel to simulations of this type, including non-periodic boundary conditions and fresh particle injection. Results from our model suggest that non-periodicity of the simulation domain results in the development of fundamentally different wave characteristics than are observed in periodic domains.

  13. Chest magnetic resonance imaging: a protocol suggestion*

    PubMed Central

    Hochhegger, Bruno; de Souza, Vinícius Valério Silveira; Marchiori, Edson; Irion, Klaus Loureiro; Souza Jr., Arthur Soares; Elias Junior, Jorge; Rodrigues, Rosana Souza; Barreto, Miriam Menna; Escuissato, Dante Luiz; Mançano, Alexandre Dias; Araujo Neto, César Augusto; Guimarães, Marcos Duarte; Nin, Carlos Schuler; Santos, Marcel Koenigkam; Silva, Jorge Luiz Pereira e

    2015-01-01

    In the recent years, with the development of ultrafast sequences, magnetic resonance imaging (MRI) has been established as a valuable diagnostic modality in body imaging. Because of improvements in speed and image quality, MRI is now ready for routine clinical use also in the study of pulmonary diseases. The main advantage of MRI of the lungs is its unique combination of morphological and functional assessment in a single imaging session. In this article, the authors review most technical aspects and suggest a protocol for performing chest MRI. The authors also describe the three major clinical indications for MRI of the lungs: staging of lung tumors; evaluation of pulmonary vascular diseases; and investigation of pulmonary abnormalities in patients who should not be exposed to radiation. PMID:26811555

  14. Chest magnetic resonance imaging: a protocol suggestion.

    PubMed

    Hochhegger, Bruno; de Souza, Vinícius Valério Silveira; Marchiori, Edson; Irion, Klaus Loureiro; Souza, Arthur Soares; Elias Junior, Jorge; Rodrigues, Rosana Souza; Barreto, Miriam Menna; Escuissato, Dante Luiz; Mançano, Alexandre Dias; Araujo Neto, César Augusto; Guimarães, Marcos Duarte; Nin, Carlos Schuler; Santos, Marcel Koenigkam; Silva, Jorge Luiz Pereira E

    2015-01-01

    In the recent years, with the development of ultrafast sequences, magnetic resonance imaging (MRI) has been established as a valuable diagnostic modality in body imaging. Because of improvements in speed and image quality, MRI is now ready for routine clinical use also in the study of pulmonary diseases. The main advantage of MRI of the lungs is its unique combination of morphological and functional assessment in a single imaging session. In this article, the authors review most technical aspects and suggest a protocol for performing chest MRI. The authors also describe the three major clinical indications for MRI of the lungs: staging of lung tumors; evaluation of pulmonary vascular diseases; and investigation of pulmonary abnormalities in patients who should not be exposed to radiation. PMID:26811555

  15. Proactive and retroactive effects of negative suggestion.

    PubMed

    Brown, Alan S; Brown, Christine M; Mosbacher, Joy L; Dryden, W Erich

    2006-11-01

    The negative effects of false information presented either prior to (proactive interference; PI) or following (retroactive interference; RI) true information was examined with word definitions (Experiment 1) and trivia facts (Experiment 2). Participants were explicitly aware of which information was true and false when shown, and true-false discrimination was evaluated via multiple-choice tests. Negative suggestion, defined as poorer performance on interference items than noninterference (control) items, consistently occurred when the wrong information followed the correct information (RI) but not when it preceded the correct information (PI). These effects did not change as a function of retention interval (immediate, 1 week, or 3 weeks) or number of incorrect alternatives (1 or 3). Implications of this outcome for experiencing incorrect information in both academic and nonacademic situations are considered. PMID:17087580

  16. Pediatrics prescriptions with ontologies and treatment suggestions.

    PubMed

    Lup?e, Oana-Sorina; Stoicu-Tivadar, L?cr?mioara

    2014-01-01

    Diagnosis and treatment for children healthcare are very sensitive activities. The present work presents an ontology based model for a future information system to support these activities. The input data contains children health status, and drug characteristics. During clinical practice a database with what specialists mark as successful treatments is created. This database is gradually growing bigger and is built by physicians based on their good results related to a treatment for a certain health condition. The new ontology system proposed in this paper is supporting the e-prescription process. The relations are managed using the open source application Protg and for suggesting treatments, using the database with successful treatments, we developed a special module that offers to physicians a selection from which they can chose the best treatment for their current case. PMID:25160215

  17. Suggested noise criteria for plumbing systems

    NASA Astrophysics Data System (ADS)

    Lilly, Jerry

    2005-09-01

    The issue of noise that is generated by plumbing systems has been addressed in several articles and texts in the acoustic literature, but most of this information deals with a description of the various noise generation mechanisms and recommended methods of controlling noise from plumbing fixtures and piping. As with any noise source that has the potential for generating annoyance, the question of how much noise is too much noise eventually arises. Chapter 47 of the 2003 ASHRAE Applications Handbook contains newly published guidelines for plumbing noise criteria as it impacts building occupants. This paper discusses the ASHRAE guidelines, and it also suggests additional noise criteria for other plumbing-related sources of noise in multitenant buildings.

  18. Ten Suggestions for Including Gifted Education in Preservice Teacher Education.

    ERIC Educational Resources Information Center

    Clinkenbeard, Pamela R.; Kolloff, Penny Britton

    2001-01-01

    Ten suggestions for weaving information on gifted students into various preservice experiences include: a unit in other education courses, a guest lecture in colleagues' classes, a course project, guided reflections in observation and/or field experiences, short course for credit, independent study, workshops, local conference presentations,

  19. Neoron grouping suggested by a multiplicative learning model

    NASA Astrophysics Data System (ADS)

    Geszti, T.

    1986-03-01

    An approximate error analysis due to Hopfield and adapted to a multiplicative model of learning by synaptic plasticity, suggests that for preliminary information processing it is advantageous to devide a neural network into ganglia of few neutrons which is actually observed around sensory organs.

  20. The Orbital Period Distribution of Cataclysmic Variables Found by the SDSS

    NASA Astrophysics Data System (ADS)

    Southworth, John; Gnsicke, Boris T.; Breedt, Elm

    2012-04-01

    The orbital period is one of the most accessible observables of a cataclysmic variable. It has been a concern for many years that the orbital period distribution of the known systems does not match that predicted by evolutionary theory. The sample of objects discovered by the Sloan Digital Sky Survey has changed this: it shows the long-expected predominance of short-period objects termed the `period spike'. The minimum period remains in conflict with theory, suggesting that the angular momentum loss mechanisms are stronger than predicted.

  1. Temperature, periodicity and horizons

    NASA Astrophysics Data System (ADS)

    Fulling, S. A.; Ruijsenaars, S. N. M.

    1987-08-01

    We explain and explore the connections among the following propositions: (1) thermal equilibrium is characterized by the KMS condition, < At-i ?B> = < BAt>; (2) finite-temperature Green functions are periodic in imaginary time; (3) black holes are hot; and to an accelerating observer, empty space is hot. The KMS condition of quantum statistical mechanics is derived, with special attention to quantum field systems satisfying relativistic commutation relations and linear field equations. We display the analytic structure of the two-point function and show in what sense the KMS condition for such systems is a statement of periodicity. Then the application of these ideas to horizons in general-relativistic settings is reviewed. Other matters discussed include: the identification of the analytically continued two-point function with the Green function of an elliptic (Euclideanized) operator; the analogous relation between a nonrelativistic propagator and a parabolic operator; the construction of thermal two-point functions as image sums; the (in)significance of time ordering; simplications of the KMS condition in the presence of discrete symmetries; the appearance of a double Fock space (artificially in general statistical mechanics, but naturally in space-times with horizons); and complications associated with the infrared behavior of the particle spectrum.

  2. Enhancing business intelligence by means of suggestive reviews.

    PubMed

    Qazi, Atika; Raj, Ram Gopal; Tahir, Muhammad; Cambria, Erik; Syed, Karim Bux Shah

    2014-01-01

    Appropriate identification and classification of online reviews to satisfy the needs of current and potential users pose a critical challenge for the business environment. This paper focuses on a specific kind of reviews: the suggestive type. Suggestions have a significant influence on both consumers' choices and designers' understanding and, hence, they are key for tasks such as brand positioning and social media marketing. The proposed approach consists of three main steps: (1) classify comparative and suggestive sentences; (2) categorize suggestive sentences into different types, either explicit or implicit locutions; (3) perform sentiment analysis on the classified reviews. A range of supervised machine learning approaches and feature sets are evaluated to tackle the problem of suggestive opinion mining. Experimental results for all three tasks are obtained on a dataset of mobile phone reviews and demonstrate that extending a bag-of-words representation with suggestive and comparative patterns is ideal for distinguishing suggestive sentences. In particular, it is observed that classifying suggestive sentences into implicit and explicit locutions works best when using a mixed sequential rule feature representation. Sentiment analysis achieves maximum performance when employing additional preprocessing in the form of negation handling and target masking, combined with sentiment lexicons. PMID:25054188

  3. Enhancing Business Intelligence by Means of Suggestive Reviews

    PubMed Central

    Qazi, Atika

    2014-01-01

    Appropriate identification and classification of online reviews to satisfy the needs of current and potential users pose a critical challenge for the business environment. This paper focuses on a specific kind of reviews: the suggestive type. Suggestions have a significant influence on both consumers' choices and designers' understanding and, hence, they are key for tasks such as brand positioning and social media marketing. The proposed approach consists of three main steps: (1) classify comparative and suggestive sentences; (2) categorize suggestive sentences into different types, either explicit or implicit locutions; (3) perform sentiment analysis on the classified reviews. A range of supervised machine learning approaches and feature sets are evaluated to tackle the problem of suggestive opinion mining. Experimental results for all three tasks are obtained on a dataset of mobile phone reviews and demonstrate that extending a bag-of-words representation with suggestive and comparative patterns is ideal for distinguishing suggestive sentences. In particular, it is observed that classifying suggestive sentences into implicit and explicit locutions works best when using a mixed sequential rule feature representation. Sentiment analysis achieves maximum performance when employing additional preprocessing in the form of negation handling and target masking, combined with sentiment lexicons. PMID:25054188

  4. Secular period decreasing of detached chromospherically active binaries

    NASA Astrophysics Data System (ADS)

    Luo, Chang Qing; Zhang, Xiao Bin; Deng, Li Cai; Luo, Yang Ping; Luo, Zhi Quan; Yang, Shu Zheng

    2010-05-01

    The long-term orbital period changes of a large sample of detached chromospherically active binaries (CABs) were studied. Eleven such systems were found to be undergoing secular period decreases with the rates of -6.310-9 to -1.110-6 days per year. The period decreasing rates are found to vary depending on the orbital period. The longer the orbital period is, the more rapidly the period decreases. Following Stepien (Mon. Not. R. Astron. Soc. 274:1019, 1995), the period decreasing rate predicted by angular momentum loss (AML) caused by magnetic wind is computed for each system. A comparison between the observed and calculated period decreasing rates shows that the former values are obviously larger than the latter by 1-3 orders of magnitude. It suggests that the magnetic wind is not likely the determinant mechanism driving the AML in these systems. Finally, the orbital angular momentum (AM) and the rate of AML, dot{J} , are computed for each system. It shows that the AM have a similar change with the orbital period like d P/d t does, but logdot{J}/J presents no strict changing with the kinematical ages.

  5. Suggested criteria for evaluating systems engineering methodologies

    NASA Technical Reports Server (NTRS)

    Gates, Audrey; Paul, Arthur S.; Gill, Tepper L.

    1989-01-01

    Systems engineering is the application of mathematical and scientific principles to practical ends in the life-cycle of a system. A methodology for systems engineering is a carefully developed, relatively complex procedure or process for applying these mathematical and scientific principles. There are many systems engineering methodologies (or possibly many versions of a few methodologies) currently in use in government and industry. These methodologies are usually designed to meet the needs of a particular organization. It has been observed, however, that many technical and non-technical problems arise when inadequate systems engineering methodologies are applied by organizations to their systems development projects. Various criteria for evaluating systems engineering methodologies are discussed. Such criteria are developed to assist methodology-users in identifying and selecting methodologies that best fit the needs of the organization.

  6. Periodic exploding dissipative solitons

    NASA Astrophysics Data System (ADS)

    Cartes, Carlos; Descalzi, Orazio

    2016-03-01

    We show the existence of periodic exploding dissipative solitons. These nonchaotic explosions appear when higher-order nonlinear and dispersive effects are added to the complex cubic-quintic Ginzburg-Landau equation modeling fiber soliton lasers. This counterintuitive phenomenon is the result of period-halving bifurcations leading to order (periodic explosions), followed by period-doubling bifurcations leading to chaos (chaotic explosions).

  7. Suggested use of vaccines in diabetes.

    PubMed

    Kesavadev, Jothydev; Misra, Anoop; Das, Ashok Kumar; Saboo, Banshi; Basu, Debasis; Thomas, Nihal; Joshi, Shashank R; Unnikrishnan, A G; Shankar, Arun; Krishnan, Gopika; Unnikrishnan, Ranjit; Mohan, Viswanathan

    2012-11-01

    Diabetes has emerged as a disease of major public health importance in India affecting the rich and the poor alike. Conventionally, comprehensive diabetes management is aimed at preventing micro and macro vascular complications. However, morbidity and mortality due to infections are also significant. In developing countries like India, the concept of adult immunization is far from reality. Recently the H1N1 pandemic has triggered the necessity for considering immunization in all age groups for the prevention of vaccine-preventable fatal infectious diseases. Considering the economics of immunization in a developing country, providing free vaccines to all adults may not be a practical solution, although the free universal immunization program for children is in existence for several decades. There is no consensus on the use of vaccines in diabetes subjects in India. However, there are some clinics offering routine pneumococcal, influenza and other vaccinations. Patients with diabetes have a deranged immune system making them more prone for infections. Hospitalization and death due to pneumococcal disease and influenza are higher in diabetes patients. They, like other healthy individuals, have a normal humoral response to vaccination with clinically significant benefits. The American Diabetes Association, Advisory Committee on Immunization Practices, Centers for Disease Control and Prevention, World Health Organization, United Kingdom Guidelines and a number of other scientific organizations have well defined guidelines for vaccination in diabetes. In this article we make some suggestions for clinicians in India, regarding use of vaccines in subjects with diabetes. PMID:23226631

  8. [Evidence that suggest the reality of reincarnation].

    PubMed

    Bonilla, Ernesto

    2015-06-01

    Worldwide, children can be found who reported that they have memories of a previous life. More than 2,500 cases have been studied and their specifications have been published and preserved in the archives of the Division of Perceptual Studies at the University of Virginia (United States). Many of those children come from countries where the majority of the inhabitants believe in reincarnation, but others come from countries with different cultures and religions that reject it. In many cases, the revelations of the children have been verified and have corresponded to a particular individual, already dead. A good number of these children have marks and birth defects corresponding to wounds on the body of his previous personality. Many have behaviors related to their claims to their former life: phobias, philias, and attachments. Others seem to recognize people and places of his supposed previous life, and some of their assertions have been made under controlled conditions. The hypothesis of reincarnation is controversial. We can never say that it does not occur, or will obtain conclusive evidence that it happens. The cases that have been described so far, isolated or combined, do not provide irrefutable proof of reincarnation, but they supply evidence that suggest its reality. PMID:26299061

  9. Suggested guidelines for deposited ambient dust

    NASA Astrophysics Data System (ADS)

    Vallack, H. W.; Shillito, D. E.

    Despite deposited dust being one of the main causes of complaint about air pollution, no international or national (U.K.) standards or guidelines currently exist. Various difficulties in defining nuisance levels for deposited dust have militated against the use of guidelines on anything other than an ad hoc, site-specific basis. However, a need clearly exists for guidelines of wider relevance. A novel method of producing guidelines is proposed for monthly dustfall results based on the background levels normally expected. By adopting the concept of "likelihood of complaint", already used successfully for rating the impact of noise, the various difficulties inherent in defining dust nuisance standards per se are avoided. Monthly data for British Standard deposit gauges from the Warren Spring Laboratory (U.K.) National Survey of Air Pollution (grit and dust) have been re-analysed by the authors for gauges "sited to catch general deposit". Where local background data are limited or absent, it is suggested that summary statistics from this analysis of national background data could provide an appropriate basis for the proposed guidelines. Although this method is primarily applicable to British Standard and Frisbee-type deposit gauges, it could be adapted for use with other devices used for monitoring deposited dust.

  10. Babylonian observations

    NASA Astrophysics Data System (ADS)

    Brown, D.

    Very few cuneiform records survive from Mesopotamia of datable astronomical observations made prior to the mid-eighth century BC. Those that do record occasional eclipses, and in one isolated case the dates of the heliacal rising and setting of Venus over a few years sometime in the first half of the second millennium BC. After the mid-eighth century BC the situation changes dramatically. Incomplete records of daily observations of astronomical and meteorological events are preserved from c. 747 BC until the Christian Period. These records are without accompanying ominous interpretation, although it is highly probable that they were compiled by diviners for astrological purposes. They include numerous observations of use to historical astronomers, such as the times of eclipses and occultations, and the dates of comet appearances and meteor showers. The question arises as to why such records do not survive from earlier times; celestial divination was employed as far back as the third millenium BC. It is surely not without importance that the earliest known accurate astronomical predictions accompany the later records, and that the mid-eighth century BC ushered in a period of centralised Assyrian control of Mesopotamia and the concomitant employment by the Assyrian ruler of large numbers of professional celestial diviners. The programme of daily observations evidently began when a high premium was first set on the accurate astronomical prediction of ominous events. It is in this light that we must approach this valuable source material for historical astronomy.

  11. Quasi-periodic VLF emissions with short-period modulation and their relationship to whistlers: a case study

    NASA Astrophysics Data System (ADS)

    Titova, Elena; Demekhov, Andrei; Kozlovsky, Alexander; Manninen, Jyrki; Pasmanik, Dmitry

    We study properties of quasiperiodic (QP) VLF emissions recorded on December 24, 2011 during the VLF campaign in Northern Finland. The main attention is paid to interrelationships between different characteristic periods in the QP spectra. In particular, we analyze regular variations in the QP repetition intervals (1 - 10 min) during the event from 15:30 to 22 UT, their changes during substorms, and short periodic (several-second) modulation observed within separate QP elements. We explained the variations of periods of QP emissions in terms of the model of auto-oscillation regime of the cyclotron instability in the magnetosphere. During the considered event lasting about 7 hours we observed a regular increase in the time intervals between the QP elements. We relate this increase with weakening of the magnetospheric source of energetic electrons. Significant variations in the QP period occurred during substorms. These variations can be due to a substorm-related increase in the energetic-electron flux and/or due to the precipitation of these electrons into the ionosphere which changes the reflection coefficient of VLF waves. We analyze the fine structure of QP element spectra and reveal the periods related to the time scales of guided propagation of whistler-mode waves along the magnetic field line, which suggests that ducted propagation regime took place for the QP emissions. The periods were about 6--9 s for frequencies 3.5--1.2 kHz respectively, which was similar to the period of almost simultaneously observed two-hop whistlers In the low-frequency part of QP spectra periodic emissions with меньшими periods of about 3 s were observed. Analysis of fine structure of QP elements shows that their formation is affected by both linear effects (i.e., group-velocity dispersion) and nonlinear effects related

  12. AN INTERPRETATION OF THE ORBITAL PERIOD DIFFERENCE BETWEEN HOT JUPITERS AND GIANT PLANETS ON LONG-PERIOD ORBITS

    SciTech Connect

    Jin Liping

    2010-09-10

    It is believed that a hot Jupiter (giant planet with a short period less than 10 days) forms in the outer region of a protoplanetary disk, then migrates inward to an orbit with a short period around 3 days, and stops there by a final stopping mechanism. The prominent problem is why hot Jupiters migrate inward to short-period orbits, while other extrasolar giant planets and Jovian planets in our solar system exist on long-period orbits. Here we show that this difference in orbital periods is caused by two populations of protoplanetary disks. One population experiences gravitational instability during some periods of their lifetime (GI disks), while the other does not (No-GI disks). In GI disks, planets can quickly migrate inward to short-period orbits to become hot Jupiters. In No-GI disks, the migration is so slow that planets can exist on long-period orbits. Protoplanetary disks are classified into the two populations because of the differences in properties of molecular cloud cores, from which disks from. We specifically compare our theory with observations. Our theory is supported by observations of extrasolar planets. We analyze the current status of our solar system and find that our solar nebula belongs to the population with a low migration rate. This is consistent with the observation that Jupiter and Saturn are indeed on long-period orbits. Our results further suggest that, in the future observations, a hot Jupiter cannot be found around a star with mass below a critical mass (0.14-0.28 M {sub sun}).

  13. Metabolic brain activity suggestive of persistent pain in a rat model of neuropathic pain

    PubMed Central

    Thompson, Scott J; Millecamps, Magali; Aliaga, Antonio; Seminowicz, David A; Low, Lucie A; Bedell, Barry J; Stone, Laura S; Schweinhardt, Petra; Bushnell, M Catherine

    2014-01-01

    Persistent pain is a central characteristic of neuropathic pain conditions in humans. Knowing whether rodent models of neuropathic pain produce persistent pain is therefore crucial to their translational applicability. We investigated the Spared Nerve Injury (SNI) model of neuropathic pain and the formalin pain model in rats using Positron Emission Tomography (PET) with the metabolic tracer [18F]fluorodeoxyglucose (FDG) to determine if there is ongoing brain activity suggestive of persistent pain. For the formalin model, under brief anesthesia we injected one hindpaw with 5% formalin and the FDG tracer into a tail vein. We then allowed the animals to awaken and observed pain behavior for 30 min during the FDG uptake period. The rat was then anesthetized and placed in the scanner for static image acquisition, which took place between minutes 45 and 75 post-tracer injection. A single reference rat brain magnetic resonance image (MRI) was used to align the PET images with the Paxinos and Watson rat brain atlas. Increased glucose metabolism was observed in the somatosensory region associated with the injection site (S1 hindlimb contralateral), S1 jaw/upper lip and cingulate cortex. Decreases were observed in the prelimbic cortex and hippocampus. Second, SNI rats were scanned 3 weeks post-surgery using the same scanning paradigm, and region-of-interest analyses revealed increased metabolic activity in the contralateral S1 hindlimb. Finally, a second cohort of SNI rats were scanned while anesthetized during the tracer uptake period, and the S1 hindlimb increase was not observed. Increased brain activity in the somatosensory cortex of SNI rats resembled the activity produced with the injection of formalin, suggesting that the SNI model may produce persistent pain. The lack of increased activity in S1 hindlimb with general anesthetic demonstrates that this effect can be blocked, as well as highlights the importance of investigating brain activity in awake and behaving rodents. PMID:24462776

  14. The role of suggestibility in determinations of Miranda abilities: a study of the Gudjonsson Suggestibility Scales.

    PubMed

    Rogers, Richard; Harrison, Kimberly S; Rogstad, Jill E; LaFortune, Kathryn A; Hazelwood, Lisa L

    2010-02-01

    Traditionally, high levels of suggestibility have been widely assumed to be linked with diminished Miranda abilities, especially in relationship to the voluntariness of waivers. The current investigation examined suggestibility on the Gudjonsson Suggestibility Scales in a multisite study of pretrial defendants. One important finding was the inapplicability of British norms to American jurisdictions. Moreover, suggestibility appeared unrelated to Miranda comprehension, reasoning, and detainees' perceptions of police coercion. In testing rival hypotheses, defendants with high compliance had significantly lower Miranda comprehension and ability to reason about exercising Miranda rights than their counterparts with low compliance. Implications of these findings to forensic practice are examined. PMID:19462223

  15. Observations and Performances “with distinction” by Physical Therapy Students in Clinical Education: Analysis of Checkboxes on the Physical Therapist Clinical Performance Instrument (PT-CPI) over a 4-Year Period

    PubMed Central

    Booth, Randy

    2015-01-01

    ABSTRACT Purpose: To describe how often the 24 performance criteria of the Physical Therapist Clinical Performance Instrument (PT-CPI) were not observed and how often they were rated exceptionally well for physical therapy (PT) students in relation to clinical placement descriptors. Methods: Indicators of “not observed,” performance “with distinction,” and “significant concerns” were tabulated from 1,460 clinical placements between 2008 and 2012. The rates for these indicators were evaluated with respect to catchment area, practice setting (hospital/institutional or community-based), practice area (musculoskeletal, cardiorespiratory, neurology, paediatrics, geriatrics, or variety), and level (junior to senior). Results: Of the 24 PT-CPI criteria, 15 had observation rates >95%. Of the other nine criteria, some showed significant differences in observation rates across level, practice setting, and practice area. Ratings of “with distinction” were awarded most often for criteria related to professionalism and communication and were awarded more often in community-based settings than in hospital/institutional settings. For some criteria, “with distinction” was awarded more often in paediatrics placements than in other areas. The “significant concerns” checkboxes were rarely used. Conclusions: The overall observation rates were very similar to those reported elsewhere. The findings related to performance “with distinction” and observation rates relative to setting and practice area are new contributions to physical therapy knowledge. PMID:25931650

  16. Periodic Comet Machholz and its idiosyncrasies

    SciTech Connect

    Sekanina, Z. )

    1990-04-01

    The dynamics and physical characteristics of Comet P/Machholz are analyzed. The discovery of the comet (Machholz, 1986) is discussed, including the observational conditions and the theory that the comet is inactive over extensive periods of time. Consideration is given to observations of the two tails of Comet P/Machholz (Emerson, 1986), the brightness variations and light curve of the comet, and nuclear photometry of the comet (Green, 1987). It is suggested that the increase in activity beginning one day after perihelion was triggered by a discrete source within 15 deg of the rotation pole that became sunlit after perihelion. Also, the possibility that Comet P/Machholz is associated with a meteor stream is examined. 45 refs.

  17. Periodic Comet Machholz and its idiosyncrasies

    NASA Astrophysics Data System (ADS)

    Sekanina, Z.

    1990-04-01

    The dynamics and physical characteristics of Comet P/Machholz are analyzed. The discovery of the comet (Machholz, 1986) is discussed, including the observational conditions and the theory that the comet is inactive over extensive periods of time. Consideration is given to observations of the two tails of Comet P/Machholz (Emerson, 1986), the brightness variations and light curve of the comet, and nuclear photometry of the comet (Green, 1987). It is suggested that the increase in activity beginning one day after perihelion was triggered by a discrete source within 15 deg of the rotation pole that became sunlit after perihelion. Also, the possibility that Comet P/Machholz is associated with a meteor stream is examined.

  18. Relativistic timescale analysis suggests lunar theory revision

    NASA Technical Reports Server (NTRS)

    Deines, Steven D.; Williams, Carol A.

    1995-01-01

    The SI second of the atomic clock was calibrated to match the Ephemeris Time (ET) second in a mutual four year effort between the National Physical Laboratory (NPL) and the United States Naval Observatory (USNO). The ephemeris time is 'clocked' by observing the elapsed time it takes the Moon to cross two positions (usually occultation of stars relative to a position on Earth) and dividing that time span into the predicted seconds according to the lunar equations of motion. The last revision of the equations of motion was the Improved Lunar Ephemeris (ILE), which was based on E. W. Brown's lunar theory. Brown classically derived the lunar equations from a purely Newtonian gravity with no relativistic compensations. However, ET is very theory dependent and is affected by relativity, which was not included in the ILE. To investigate the relativistic effects, a new, noninertial metric for a gravitated, translationally accelerated and rotating reference frame has three sets of contributions, namely (1) Earth's velocity, (2) the static solar gravity field and (3) the centripetal acceleration from Earth's orbit. This last term can be characterized as a pseudogravitational acceleration. This metric predicts a time dilation calculated to be -0.787481 seconds in one year. The effect of this dilation would make the ET timescale run slower than had been originally determined. Interestingly, this value is within 2 percent of the average leap second insertion rate, which is the result of the divergence between International Atomic Time (TAI) and Earth's rotational time called Universal Time (UT or UTI). Because the predictions themselves are significant, regardless of the comparison to TAI and UT, the authors will be rederiving the lunar ephemeris model in the manner of Brown with the relativistic time dilation effects from the new metric to determine a revised, relativistic ephemeris timescale that could be used to determine UT free of leap second adjustments.

  19. Relativistic timescale analysis suggests lunar theory revision

    NASA Astrophysics Data System (ADS)

    Deines, Steven D.; Williams, Carol A.

    1995-05-01

    The SI second of the atomic clock was calibrated to match the Ephemeris Time (ET) second in a mutual four year effort between the National Physical Laboratory (NPL) and the United States Naval Observatory (USNO). The ephemeris time is 'clocked' by observing the elapsed time it takes the Moon to cross two positions (usually occultation of stars relative to a position on Earth) and dividing that time span into the predicted seconds according to the lunar equations of motion. The last revision of the equations of motion was the Improved Lunar Ephemeris (ILE), which was based on E. W. Brown's lunar theory. Brown classically derived the lunar equations from a purely Newtonian gravity with no relativistic compensations. However, ET is very theory dependent and is affected by relativity, which was not included in the ILE. To investigate the relativistic effects, a new, noninertial metric for a gravitated, translationally accelerated and rotating reference frame has three sets of contributions, namely (1) Earth's velocity, (2) the static solar gravity field and (3) the centripetal acceleration from Earth's orbit. This last term can be characterized as a pseudogravitational acceleration. This metric predicts a time dilation calculated to be -0.787481 seconds in one year. The effect of this dilation would make the ET timescale run slower than had been originally determined. Interestingly, this value is within 2 percent of the average leap second insertion rate, which is the result of the divergence between International Atomic Time (TAI) and Earth's rotational time called Universal Time (UT or UTI). Because the predictions themselves are significant, regardless of the comparison to TAI and UT, the authors will be rederiving the lunar ephemeris model in the manner of Brown with the relativistic time dilation effects from the new metric to determine a revised, relativistic ephemeris timescale that could be used to determine UT free of leap second adjustments.

  20. Frequency-modulated solar rotational periodicity of geomagnetic indices

    NASA Astrophysics Data System (ADS)

    Chang, Heon-Young

    2014-10-01

    Many attempts have been made to search for various timescales in the power spectrum of geomagnetic indices so that common periodicities in the solar activity and geomagnetic activity indices are identified. The spectral behavior of geomagnetic activity parameters may also provide invaluable information about physical processes involved. In this study we attempt to demonstrate that the frequency modulation associated with a long-term variation may cause extra sidelobes around the principal peak with a periodicity of 27 d in the observed power spectrum of geomagnetic activity indices, and/or may even split the peak into two adjacent peaks. We employ a straightforward model of an oscillation frequency-modulated by an arbitrary agent to consider the solar rotational periodicity of geomagnetic indices. As a result, we have found that the peak with the periodicity of 27 d in the observed power spectrum of geomagnetic indices seems likely frequency-modulated by the amount of 0.0026 d-1 which corresponds to a 1 yr period. We thus suggest that the fundamental period of the periodic perturbative agent is much longer than a year according to our analysis. Finally, we conclude by discussing the implications of what we have found.

  1. Adult survivors of childhood sexual abuse: suggestions for perinatal caregivers.

    PubMed

    Roussillon, J A

    1998-11-01

    As many as 1 in 4 women are survivors of childhood sexual abuse. This traumatic life event profoundly influences the care that advanced practice nurses provide throughout the life cycle, and particularly the care that is provided during times of physical and emotional stress. Despite the prevalence of sexual abuse, there has been little research on the experiences of survivors during the perinatal period, and few suggestions for interventions. This article reviews the literature on the implications of sexual abuse on a woman's experience of pregnancy, birth, and breastfeeding. It emphasizes the importance of routine screening for abuse, as well as assessment of a survivor's stage in the recovery process. Finally, this article suggests topics for appropriate perinatal anticipatory guidance for women who have a history of sexual abuse. PMID:12596835

  2. Review of magnetic field observations.

    NASA Technical Reports Server (NTRS)

    Ness, N. F.

    1972-01-01

    Recent observations in previously unexplored regions of the magnetosphere, particularly in the polar-cusp region, compliment and reinforce emphasis on particle access to the plasma sheet via the polar neutral points. Significant distortions of the geomagnetic field in the polar-cusp region suggest field-aligned currents at large geocentric distances which can be related to low-altitude polar-cap phenomena. Studies of the microstructure of the field reversal region of the plasma sheet embedded in the geomagnetic tail suggest a periodic structure of more complexity than earlier assumed simplified single neutral-line models.

  3. Suggestibility under Pressure: Theory of Mind, Executive Function, and Suggestibility in Preschoolers

    ERIC Educational Resources Information Center

    Karpinski, Aryn C.; Scullin, Matthew H.

    2009-01-01

    Eighty preschoolers, ages 3 to 5 years old, completed a 4-phase study in which they experienced a live event and received a pressured, suggestive interview about the event a week later. Children were also administered batteries of theory of mind and executive function tasks, as well as the Video Suggestibility Scale for Children (VSSC), which…

  4. [Individual prediction by the analysis of preflight ECG data of cardiac function disorders in cosmonauts during standard deorbit after long-term space flights and in the period of postflight observation].

    PubMed

    Kotovskaia, A R; Koloteva, M I; Luk'ianiuk, V Iu; Zhernavkov, A F; Kondratiuk, L L

    2008-01-01

    ECG records of 25 cosmonauts--members of 30 long-term Mir and ISS missions (73- to 197-day long) in the period of 1995-2007 were analyzed. The ECG records were made during medical selection, clinical-physiological investigations (KFO) before launch, insertion and standard descent, and post-flight KFO. No negative trends were discovered in 70% (n=21) of ECG records during insertion and descent of cosmonauts who had not have significant ECG deviations before flight. In 20% of ECG records (n=6) pre-launch individual properties of cardiac rhythm, conduction and end of the ventricular complex became more pronounced in the period of descent persisting after landing. In 10% of ECG records (n=3) the predicted ECG deviations were not found This was the first time when dynamic analysis of ECG records made on the stages of selection and pre-launch training was successful in predicting of 90% (n=27 of 30) of cardiac function deviations during descent. At the start of rehabilitation from long-term missions essentially each of the cosmonauts displayed ECG deviations which were more considerable as compared with the KFO and descent records. PMID:19140467

  5. Photographic observations of Theta-1 Orionis

    NASA Technical Reports Server (NTRS)

    Feibelman, W. A.; Gull, T. R.

    1979-01-01

    Photographic observations of the eclipsing binary Theta-1 Ori A suggest a secondary minimum near phase 0.64 of its 65.43233-day period. This minimum may be wavelength dependent. The star Theta-1 Ori E is suspected of being variable.

  6. Short-period comets

    NASA Technical Reports Server (NTRS)

    Weissman, Paul R.; Campins, Humberto

    1991-01-01

    The spacecraft flybys of Comet Halley in 1986 confirmed Whipple's icy conglomerate hypothesis for cometary nuclei and showed that comets are far richer in volatiles than any other class of solar system bodies. Water is the most abundant volatile, comprising roughly 80 percent of the gas flowing out from the nucleus. Carbon monoxide is next with a content of 15 percent relative to water, though with approximately half of that coming from an extended source in the cometary coma, i.e., hydrocarbon dust grains. The detection of large numbers of hydrocarbon CHON grains was one of the more significant discoveries of the Halley flybys, as was the ground-based observation that CN occurs in jets, again indicating an extended source. Evidence was also found for more complex hydrocarbons. Estimates of the total dust-to-gas ratio for Halley range as high as 2:1, indicating that a substantial fraction of the volatile material may be tied up in solid hydrocarbons rather than ices. The role of clathrates in trapping more volatile ices is not yet understood. If Halley can be taken to be representative of all short-period comets, then the short-period comets may provide a significant source of volatiles in near-earth space. This resource is more difficult to reach dynamically than the near-earth asteriods, but the high volatile content may justify the additional effort necessary. In addition, there is considerable evidence that at least some fraction of the near-earth asteriods are extinct cometary nuclei which have evolved into asteroid orbits, and which may contain significant volatiles buried beneath an insulating lag-deposit crust of nonvolatiles. Knowledge of comets will be greatly enhanced in the near future by the Comet Rendezvous Flyby mission now under development by NASA, and by the proposed Rosetta mission.

  7. Mammalian cycles: internally defined periods and interaction-driven amplitudes

    PubMed Central

    Krebs, CJ

    2015-01-01

    The cause of mammalian cyclesthe rise and fall of populations over a predictable period of timehas remained controversial since these patterns were first observed over a century ago. In spite of extensive work on observable mammalian cycles, the field has remained divided upon what the true cause is, with a majority of opinions attributing it to either predation or to intra-species mechanisms. Here we unite the eigenperiod hypothesis, which describes an internal, maternal effect-based mechanism to explain the cycles periods with a recent generalization explaining the amplitude of snowshoe hare cycles in northwestern North America based on initial predator abundance. By explaining the period and the amplitude of the cycle with separate mechanisms, a unified and consistent view of the causation of cycles is reached. Based on our suggested theory, we forecast the next snowshoe hare cycle (predicted peak in 2016) to be of extraordinarily low amplitude. PMID:26339557

  8. Mammalian cycles: internally defined periods and interaction-driven amplitudes.

    PubMed

    Ginzburg, L R; Krebs, C J

    2015-01-01

    The cause of mammalian cycles-the rise and fall of populations over a predictable period of time-has remained controversial since these patterns were first observed over a century ago. In spite of extensive work on observable mammalian cycles, the field has remained divided upon what the true cause is, with a majority of opinions attributing it to either predation or to intra-species mechanisms. Here we unite the eigenperiod hypothesis, which describes an internal, maternal effect-based mechanism to explain the cycles' periods with a recent generalization explaining the amplitude of snowshoe hare cycles in northwestern North America based on initial predator abundance. By explaining the period and the amplitude of the cycle with separate mechanisms, a unified and consistent view of the causation of cycles is reached. Based on our suggested theory, we forecast the next snowshoe hare cycle (predicted peak in 2016) to be of extraordinarily low amplitude. PMID:26339557

  9. Categorical spectral analysis of periodicity in nucleosomal DNA.

    PubMed

    Jin, Hu; Rube, H Tomas; Song, Jun S

    2016-03-18

    DNA helical twist imposes geometric constraints on the location of histone-DNA interaction sites along nucleosomal DNA. Certain 10.5-bp periodic nucleotides in phase with these geometric constraints have been suggested to facilitate nucleosome positioning. However, the extent of nucleotide periodicity in nucleosomal DNA and its significance in directing nucleosome positioning still remain unclear. We clarify these issues by applying categorical spectral analysis to high-resolution nucleosome maps in two yeast species. We find that only a small fraction of nucleosomal sequences contain significant 10.5-bp periodicity. We further develop a spectral decomposition method to show that the previously observed periodicity in aligned nucleosomal sequences mainly results from proper phasing among nucleosomal sequences, and not from a preponderant occurrence of periodicity within individual sequences. Importantly, we show that this phasing may arise from the histones' proclivity for putting preferred nucleotides at some of the evenly spaced histone-DNA contact points with respect to the dyad axis. We demonstrate that 10.5-bp periodicity, when present, significantl