Sample records for observation period suggesting

  1. Period measurement by accelerating observers

    E-print Network

    Bernhard Rothenstein; Stefan Popescu

    2006-07-04

    We consider the problem of the period measurement in the case of the following scenarios: stationary source of successive light signals and accelerating receiver, stationary receiver and accelerating source of successive light signals and stationary machine gun that fires successive bullets received by an accelerating receiver. The accelerated motion is the hyperbolic one.

  2. 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.

  3. Wavelet measurement suggests cause of period instability in mammalian circadian neurons.

    PubMed

    Meeker, Kirsten; Harang, Richard; Webb, Alexis B; Welsh, David K; Doyle, Francis J; Bonnet, Guillaume; Herzog, Erik D; Petzold, Linda R

    2011-08-01

    Cells in the suprachiasmatic nucleus (SCN) display remarkable precision, while either physically or chemically decoupling these cells from each other leads to a dramatic increase in period-to-period variability. Where previous studies have classified cells as either arrhythmic or circadian, our wavelet analysis reveals that individual cells, when removed from network interactions, intermittently express circadian and/or longer infradian periods. We reproduce the characteristic period distribution of uncoupled SCN cells with a stochastic model of the uncoupled SCN cell near a bifurcation in Bmal1 transcription repression. This suggests that the uncoupled cells may be switching between 2 oscillatory mechanisms: the indirect negative feedback of protein complex PER-CRY on the expression of Per and Cry genes, and the negative feedback of CLOCK-BMAL1 on the expression of the Bmal1 gene. The model is particularly sensitive near this bifurcation point, with only a small change in Bmal1 transcription repression needed to switch from the stable precision of coupled SCN cells to the unstable oscillations of decoupled individual cells, making this rate constant, an ideal target for cell signaling in the SCN. PMID:21775294

  4. Wavelet Measurement Suggests Cause of Period Instability in Mammalian Circadian Neurons

    PubMed Central

    Meeker, Kirsten; Harang, Richard; Webb, Alexis B.; Welsh, David K.; Doyle, Francis J.; Bonnet, Guillaume; Herzog, Erik D.; Petzold, Linda R.

    2012-01-01

    Cells in the suprachiasmatic nucleus (SCN) display remarkable precision, while either physically or chemically decoupling these cells from each other leads to a dramatic increase in period-to-period variability. Where previous studies have classified cells as either arrhythmic or circadian, our wavelet analysis reveals that individual cells, when removed from network interactions, intermittently express circadian and/or longer infradian periods. We reproduce the characteristic period distribution of uncoupled SCN cells with a stochastic model of the uncoupled SCN cell near a bifurcation in Bmal1 transcription repression. This suggests that the uncoupled cells may be switching between 2 oscillatory mechanisms: the indirect negative feedback of protein complex PER-CRY on the expression of Per and Cry genes, and the negative feedback of CLOCK-BMAL1 on the expression of the Bmal1 gene. The model is particularly sensitive near this bifurcation point, with only a small change in Bmal1 transcription repression needed to switch from the stable precision of coupled SCN cells to the unstable oscillations of decoupled individual cells, making this rate constant, an ideal target for cell signaling in the SCN. PMID:21775294

  5. Wavelet Measurement Suggests Cause of Period Instability in Mammalian Circadian Neurons

    Microsoft Academic Search

    Kirsten Meeker; Richard Harang; Alexis B. Webb; David K. Welsh; Francis J. Doyle; Guillaume Bonnet; Erik D. Herzog; Linda R. Petzold

    2011-01-01

    Cells in the suprachiasmatic nucleus (SCN) display remarkable precision, while either physically or chemically decoupling these cells from each other leads to a dramatic increase in period-to-period variability. Where previous studies have classified cells as either arrhythmic or circadian, our wavelet analysis reveals that individual cells, when removed from network interactions, intermittently express circadian and\\/or longer infradian periods. We reproduce

  6. Cassini and Galileo Observations of Quasi-periodic Radio Bursts

    NASA Astrophysics Data System (ADS)

    Hospodarsky, G. B.; Kurth, W. S.; Gurnett, D. A.; Kaiser, M. L.; Zarka, P.; Krupp, N.; Waite, J. H.

    Simultaneous measurements of many Jovian plasma and radio emissions were ob- tained by the Cassini and Galileo spacecraft during the Cassini flyby of Jupiter (clos- est approach was on December 30, 2000). Jovian type III radio emissions, also known as quasi-periodic (QP) emissions, were often detected by both spacecraft. This type of emission has been detected by Voyager, Ulysses, Galileo, and Cassini, with pe- riodicities ranging from about a minute to many tens of minutes (often around 40 minutes). Other quasi-periodic events have been detected in the energetic particle data of Ulysses, Galileo and Cassini and in the x-ray spectrum obtained by the Chandra spacecraft, usually with periodicities around 40 minutes. The multiple observations of similar quasi-periodic events suggests that there may be a common source for these phenomena. Many examples of simultaneous detection of the QP radio emissions were obtained by the Cassini and Galileo plasma wave and radio instruments. The charac- teristics of the QP emissions observed by each spacecraft are very similar, and when the difference in the travel time of a radio emission from Jupiter to each spacecraft is taken into account, the QP bursts are observed to occur simultaneously at each space- craft. These similar characteristics of the emissions, even when the two spacecraft are separated by many hours in local time and many degrees of system III longitude, sug- gest a broadly beamed 'strobe light' source for the emission, and not a narrow beam which rotates with the planet. The implications of these simultaneous observations will be discussed.

  7. Teaching Political Science in China: Observations and Suggestions from a Foreign Visitor.

    ERIC Educational Resources Information Center

    Petracca, Mark P.

    1990-01-01

    Describes teaching Western political theory at Beijing University (China) in 1987, a period of political modernization. Suggests changes to enhance education and scholarship in China concerning instructional pedagogy. Notes the need for critical writing skills, finds students limited in their ability to analyze scholarly writing, and recommends…

  8. Almost-periodic time observables for bound quantum systems

    E-print Network

    Michael J. W. Hall

    2008-04-22

    It is shown that a canonical time observable may be defined for any quantum system having a discrete set of energy eigenvalues, thus significantly generalising the known case of time observables for periodic quantum systems (such as the harmonic oscillator). The general case requires the introduction of almost-periodic probability operator measures (POMs), which allow the expectation value of any almost-periodic function to be calculated. An entropic uncertainty relation for energy and time is obtained which generalises the known uncertainty relation for periodic quantum systems. While non-periodic quantum systems with discrete energy spectra, such as hydrogen atoms, typically make poor clocks that yield no more than 1 bit of time information, the anisotropic oscillator provides an interesting exception. More generally, a canonically conjugate observable may be defined for any Hermitian operator having a discrete spectrum.

  9. 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.

  10. Time-periodic variations in stratospheric ozone from satellite observations

    NASA Technical Reports Server (NTRS)

    Wang, Pi-Huan; Mccormick, M. P.; Mcmaster, L. R.; Schaffner, S.; Woodbury, G. E.

    1989-01-01

    The time-periodic variations in stratospheric zonal mean ozone number density are examined with emphasis on annual and semi-annual oscillations. The data base for this analysis is the ozone observation from the SAGE II satellite instrument. A multiple linear regression method is adopted for the analysis. The results show that the amplitudes and phases of the time-periodic ozone variations are functions of altitude and latitude.

  11. 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

  12. Quantifying song bout production during zebra finch sensory-motor learning suggests a sensitive period for vocal practice

    PubMed Central

    Johnson, Frank; Soderstrom, Ken; Whitney, Osceola

    2014-01-01

    Using an event-triggered recording system, the quantity of daily song bout production was measured weekly in male zebra finches (Taeniopygia guttata) during sensory-motor learning and at one year of age. Our aim was to ask whether the development of a stereotyped vocal pattern involves a practice-driven component. If so, we hypothesized that juvenile males learning song should sing more often than adults reciting a vocal pattern they had already learned, and that greater levels of juvenile singing should be associated with improvement in the quality of the adult song. Across the period measured (36–365 days of age), subjects showed an inverted U-shaped pattern of daily song bout production. Song bout production was lowest during subsong, with increased production associated with plastic song and song crystallization, although individual differences were large. Daily song bout production decreased in adulthood. Higher levels of song bout production during plastic song correlated with fewer sequencing errors in adult song patterns (r2=0.77). In contrast, quantity of singing during song crystallization showed no relationship to vocal stereotypy (r2=0.002). Our data suggest a sensitive period for vocal practice during zebra finch sensory-motor learning with consequences for the note-sequence fidelity of the adult vocal pattern. PMID:11844572

  13. Earthquake nucleation mechanisms and periodic loading: Models, Experiments, and Observations

    NASA Astrophysics Data System (ADS)

    Dahmen, K.; Brinkman, B.; Tsekenis, G.; Ben-Zion, Y.; Uhl, J.

    2010-12-01

    The project has two main goals: (a) Improve the understanding of how earthquakes are nucleated ¬ with specific focus on seismic response to periodic stresses (such as tidal or seasonal variations) (b) Use the results of (a) to infer on the possible existence of precursory activity before large earthquakes. A number of mechanisms have been proposed for the nucleation of earthquakes, including frictional nucleation (Dieterich 1987) and fracture (Lockner 1999, Beeler 2003). We study the relation between the observed rates of triggered seismicity, the period and amplitude of cyclic loadings and whether the observed seismic activity in response to periodic stresses can be used to identify the correct nucleation mechanism (or combination of mechanisms). A generalized version of the Ben-Zion and Rice model for disordered fault zones and results from related recent studies on dislocation dynamics and magnetization avalanches in slowly magnetized materials are used in the analysis (Ben-Zion et al. 2010; Dahmen et al. 2009). The analysis makes predictions for the statistics of macroscopic failure events of sheared materials in the presence of added cyclic loading, as a function of the period, amplitude, and noise in the system. The employed tools include analytical methods from statistical physics, the theory of phase transitions, and numerical simulations. The results will be compared to laboratory experiments and observations. References: Beeler, N.M., D.A. Lockner (2003). Why earthquakes correlate weakly with the solid Earth tides: effects of periodic stress on the rate and probability of earthquake occurrence. J. Geophys. Res.-Solid Earth 108, 2391-2407. Ben-Zion, Y. (2008). Collective Behavior of Earthquakes and Faults: Continuum-Discrete Transitions, Evolutionary Changes and Corresponding Dynamic Regimes, Rev. Geophysics, 46, RG4006, doi:10.1029/2008RG000260. Ben-Zion, Y., Dahmen, K. A. and J. T. Uhl (2010). A unifying phase diagram for the dynamics of sheared solids and granular materials, Pure Appl. Geophys., in review, 2010. Dahmen, K.A., Y. Ben-Zion, and J.T. Uhl (2009). A micromechanical model for the deformation in solids with universal predictions for stress-strain curves and slip avalanches, Phys. Rev. Lett. 102, 175501/1-4. Dahmen , K.A. and Y. Ben-Zion (2009). The physics of jerky motion in slowly driven magnetic and earthquake fault systems. Encyclopedia of Complexity and System Science, R. Meyers (Eds.), Vol. 5, 5021-5037, Springer. Dieterich, J. H. (1987). Nucleation and triggering of earthquake slip: effect of periodic stresses, Tectonophysics 144, 127-139. Lockner, David A. and Nick M. Beeler (1999). Premonitory slip and tidal triggering of earthquakes, J. Geophys. Res. 104, 20,133-20,151.

  14. 313 New Asteroid Rotation Periods from Palomar Transient Factory Observations

    NASA Astrophysics Data System (ADS)

    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; Laher, Russ; Surace, Jason; Prince, Thomas. A.

    2014-06-01

    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 deg2 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-1. One superfast rotator candidate and two possible binary asteroids were also found in this work.

  15. 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-Bénard 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.

  16. Genetic diversity patterns at the human clock gene period 2 are suggestive of population-specific positive selection

    Microsoft Academic Search

    Fulvio Cruciani; Beniamino Trombetta; Damian Labuda; David Modiano; Antonio Torroni; Rodolfo Costa; Rosaria Scozzari

    2008-01-01

    Period 2 (PER2) is a key component of the mammalian circadian clock machinery. In humans, genetic variation of clock genes or chronic disturbance of circadian rhythmicity has been implied in the onset of several phenotypes, ranging from periodic insomnias to advanced or delayed sleep phases, to more severe disorders. Peculiar geographic diversity patterns in circadian genes might represent an adaptive

  17. Suggestions for an integrated observing system for the Atlantic meridional overturning circulation

    NASA Astrophysics Data System (ADS)

    Vellinga, M.; Wood, R. A.

    2003-04-01

    Currently, considerable resources and effort are devoted to the design of an operational observing system for the Atlantic meridional overturning circulation (`MOC') (NERC thematic programme `RAPID', web sit e: http://rapid.nerc.ac.uk/). Let us assume that the observing system is `perfect', in that it provides a continous time series of the strength of the Atlantic MOC at a particular latitude, say 24o N, from the moment of its deployme nt. Lack of historical data means that, should the observing system detect a decline in the MOC over a number of years, we will have difficulties telling if that constitutes a `normal' change (i.e. consisten t with natural, internal MOC variability) or an `unusual' MOC change (e.g. due to anthropogenic forcing, or a rapid, irreversible MOC change). Furthermore, background noise in the form of high-frequency oce an response to wind forcing projects onto the MOC, thereby increasing the time before an MOC reduction could be classified unusual. Here we use data from various simulations with the climate model HadCM3 to address the question if a choice of auxiliary observations, taken elsewhere in the ocean, in conjunction with the information obtained from the MOC observing system, can increase the capability of identifyin g unusual MOC changes. More specifically, we show that a particular set of hydrographic (model) observations makes it possible to generally classify MOC changes as either anthropogenic or natural. Secondl y, attempts are made, with some succes, to design an early-warning system of significant MOC changes using observations in the NADW formation regions. If perfected, such an early-warning system can assist in , for instance, adaptation to rapid climate change, of which large scale changes to the MOC can be a trigger.

  18. Modifications to the Water Vapor Continuum in the Microwave Suggested by Ground-Based 150GHz Observations

    Microsoft Academic Search

    David D. Turner; Maria P. Cadeddu; Ulrich Lohnert; Susanne Crewell; Andrew M. Vogelmann

    2009-01-01

    Ground-based observations from two different radiometers are used to evaluate commonly used microwave\\/millimeter-wave propagation models at 150 GHz. This frequency has strong sensitivity to changes in precipitable water vapor (PWV) and cloud liquid water. The observations were collected near Hesselbach, Germany, as part of the Atmospheric Radiation Measurement program's support of the General Observing Period and the Convective and Orographic

  19. 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…

  20. 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.

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

    SciTech Connect

    Erlandson, R.E.; Anderson, B.J.; Zanetti, L.J. [Johns Hopkins Univ., Laurel, MD (United States)

    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.

  2. Analysis of C3 Suggests Three Periods of Positive Selection Events and Different Evolutionary Patterns between Fish and Mammals

    PubMed Central

    Meng, Fanxing; Sun, Yuena; Liu, Xuezhu; Wang, Jianxin; Xu, Tianjun; Wang, Rixin

    2012-01-01

    Background The third complement component (C3) is a central protein of the complement system conserved from fish to mammals. It also showed distinct characteristics in different animal groups. Striking features of the fish complement system were unveiled, including prominent levels of extrahepatic expression and isotypic diversity of the complement components. The evidences of the involvement of complement system in the enhancement of B and T cell responses found in mammals indicated that the complement system also serves as a bridge between the innate and adaptive responses. For the reasons mentioned above, it is interesting to explore the evolutionary process of C3 genes and to investigate whether the huge differences between aquatic and terrestrial environments affected the C3 evolution between fish and mammals. Methodology/Principal Findings Analysis revealed that these two groups of animals had experienced different evolution patterns. The mammalian C3 genes were under purifying selection pressure while the positive selection pressure was detected in fish C3 genes. Three periods of positive selection events of C3 genes were also detected. Two happened on the ancestral lineages to all vertebrates and mammals, respectively, one happened on early period of fish evolutionary history. Conclusions/Significance Three periods of positive selection events had happened on C3 genes during history and the fish and mammals C3 genes experience different evolutionary patterns for their distinct living environments. PMID:22624039

  3. Observation of Periodic Orbits on Curved Two - dimensional Geometries

    E-print Network

    M. Avlund; C. Ellegaard; M. Oxborrow; T. Guhr; N. Sondergaard

    2010-04-26

    We measure elastomechanical spectra for a family of thin shells. We show that these spectra can be described by a "semiclassical" trace formula comprising periodic orbits on geodesics, with the periods of these orbits consistent with those extracted from experiment. The influence of periodic orbits on spectra in the case of two-dimensional curved geometries is thereby demonstrated, where the parameter corresponding to Planck's constant in quantum systems involves the wave number and the curvature radius. We use these findings to explain the marked clustering of levels when the shell is hemispherical.

  4. Drifting Quasi-Periodic Modulation of the Fast Magnetosonic Mode: Van Allen Probe Observations

    NASA Astrophysics Data System (ADS)

    Boardsen, S. A.; Hospodarsky, G. B.; Kletzing, C.; Pfaff, R. F., Jr.; Kurth, W. S.; Wygant, J. R.; MacDonald, E.

    2014-12-01

    The fast magnetosonic mode is one of the dominant wave modes in the Earth's radiation belts. These waves influence the ring current by scattering ions in energy in the 10's of keV range, and are believed to be a heat source for radiation belt electrons. The fast magnetosonic mode observed around the Earth's inner equatorial magnetosphere sometimes exhibits quasi-periodic modulation as detected by the Van Allen probes. During each modulation the wave frequency exhibits a strong drifting (dispersive) signature characterized by a rising tone. Each tone is composed of harmonics with spacing close to the proton cyclotron frequency. The tones are band limited in frequency and mainly observed above the 20th harmonic of the local proton cyclotron frequency. We observe this modulation mainly outside the plasmapause, but it has also been observed to penetrate down to 1.5 RE. The modulation is observed up to magnetic latitudes of ±17º, at all magnetic local times, but its signatures are more pronounced on the dayside. For events where lower frequency ULF waves are detected, the period of the ULF wave is about twice the modulation period of the fast magnetosonic mode, suggesting strong wave-wave interactions. The modulation period varies from 50 to 200 s and its duration ranges from 0.2 to 3 h, with the maximum duration limited by the spacecraft orbit. We hypothesize that the rising tone is produced by changing Alfven velocities created by steepened density fluctuations due to plasma modification by an underlying ULF wave.

  5. Ionospheric convection patterns observed during periods of steady magnetospheric convection

    NASA Astrophysics Data System (ADS)

    Hughes, J. M.; Bristow, W. A.

    2002-12-01

    We present a study of ionospheric convection patterns observed by the Super Dual Auroral Radar Network (SuperDARN) during two recent steady magnetospheric convection (SMC) events. Our analyses foucus on the region near the Harang discontinuity (HD) and show, in contrast to prevous SMC studies, that the HD is not an uncommon feature during SMC events. Although often observed during these events, the HD appears less extended than during a typical substorm growth phase and often forms at relatively high geomagnetic latitudes.

  6. Period Spacings of Most Red Giants Observed by Kepler

    NASA Astrophysics Data System (ADS)

    Stello, D.; Huber, D.; Bedding, T. R.; Benomar, O.; Bildsten, L.; Elsworth, Y.; Gilliland, R. L.; Mosser, B.; Paxton, B.; White, T. R.

    2013-12-01

    Of the more than 150 000 targets followed by the Kepler mission, about 10% were selected as red giants. Due to their high scientific value, in particular for Galaxy population studies and stellar structure and evolution, their Kepler light curves were made public in late 2011. More than 13 000 (over 85%) of these stars show intrinsic flux variability caused by solar-like oscillations making them ideal for large scale asteroseismic investigations. We automatically extracted individual frequencies and measured the period spacings of the dipole modes in nearly every red giant. These measurements naturally classify the stars into various populations, such as the Red Giant Branch, the low-mass (M / M? ? 1.8) helium-core-burning Red Clump, and the higher-mass (M / M? ? 1.8) secondary clump. The period spacings also reveal that a large fraction of the stars show rotationally induced frequency splittings. This sample of stars will undoubtedly provide an extremely valuable source for studying the stellar population in the direction of the Kepler field, in particular when combined with complementary spectroscopic surveys.

  7. STEREO observations of quasi-periodically driven high velocity outflows in polar plumes

    NASA Astrophysics Data System (ADS)

    McIntosh, S. W.; Innes, D. E.; de Pontieu, B.; Leamon, R. J.

    2010-02-01

    Context. Plumes are one of the most ubiquitous features seen at the limb in polar coronal holes and are considered to be a source of high density plasma streams to the fast solar wind. Aims: We analyze STEREO observations of plumes and aim to reinterpret and place observations with previous generations of EUV imagers within a new context that was recently developed from Hinode observations. Methods: We exploit the higher signal-to-noise, spatial and temporal resolution of the EUVI telescopes over that of SOHO/EIT to study the temporal variation of polar plumes in high detail. We employ recently developed insight from imaging (and spectral) diagnostics of active region, plage, and quiet Sun plasmas to identify the presence of apparent motions as high-speed upflows in magnetic regions as opposed to previous interpretations of propagating waves. Results: In almost all polar plumes observed at the limb in these STEREO sequences, in all coronal passbands, we observe high speed jets of plasma traveling along the structures with a mean velocity of 135 km s-1 at a range of temperatures from 0.5-1.5 MK. The jets have an apparent brightness enhancement of ~5% above that of the plumes they travel on and repeat quasi-periodically, with repeat-times ranging from five to twenty-five minutes. We also notice a very weak, fine scale, rapidly evolving, but ubiquitous companion of the plumes that covers the entire coronal hole limb. Conclusions: The observed jets are remarkably similar in intensity enhancement, periodicity and velocity to those observed in other magnetic regions of the solar atmosphere. They are multi-thermal in nature. We infer that the jets observed on the plumes are a source of heated mass to the fast solar wind. Further, based on the previous results that motivated this study, we suggest that these jets originated in the upper chromosphere. Five movies are only available in electronic form at http://www.aanda.org

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

    SciTech Connect

    D'Angelo, C. R.; Watts, A. L., E-mail: c.r.dangelo@uva.nl [Instituut Anton Pannekoek, University of Amsterdam, Amsterdam 1098 XH (Netherlands)

    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.

  9. CHARACTERIZING LONG-PERIOD TRANSITING PLANETS OBSERVED BY KEPLER Jennifer C. Yee and B. Scott Gaudi

    E-print Network

    Gaudi, B. Scott

    CHARACTERIZING LONG-PERIOD TRANSITING PLANETS OBSERVED BY KEPLER Jennifer C. Yee and B. Scott Gaudi a sufficient number of stars that it is likely to detect single transits of planets with periods longer than and assuming circular orbits, it is possible to estimate the periods of these transiting planets to better than

  10. Periodic magnetospheric substorms: Multiple space-based and ground-based instrumental observations

    E-print Network

    California at Berkeley, University of

    Periodic magnetospheric substorms: Multiple space-based and ground-based instrumental observations] Quasi-periodic, sawtooth-like variations of energetic plasma particle fluxes are often measured correspond to substorm onsets, and what mechanism is responsible for the generation of periodic particle

  11. Outbursts, State Transitions, and Periodicities Observed with the RXTE All-Sky Monitor

    E-print Network

    Alan M. Levine

    1998-08-28

    Results from the All-Sky Monitor (ASM) on the Rossi X-ray Timing Explorer are reviewed. A number of recurrent transient sources have been detected, while only a few previously unreported sources have been discovered. The ASM light curves show a wide variety of phenomena in general, and, in particular, those of transient sources show a wide range of properties. Examples are used to illustrate that the distinction between persistent and transient sources may be very unclear. The results of searches for periodicities in the ASM light curves are summarized, and other astrophysical investigations using ASM light curves are suggested. The latter include investigations of the possible causes of long-term quasiperiodic and chaotic variability, and comparative studies on the basis of the observed variability.

  12. Observation of flow processes in the vadose zone using ERT on different space and time scales: results, obstacles, and suggestions

    NASA Astrophysics Data System (ADS)

    Noell, Ursula; Ganz, Christina; Lamparter, Axel; Duijnisveld, Wilhelmus; Bachmann, Jörg

    2013-04-01

    Electrical resistivity tomography (ERT) observes the flow processes in the vadose zone indirectly. ERT has been used to estimate water flow in different soil types and under different flow conditions using active experiments or monitoring the natural process in many cases. Our experiments in sand and loess soil connected ERT with local soil probing using TDR devices and tensiometers in order to proof the reliability of the ERT inversion results in terms of infiltration velocity. Additionally, a colour tracer was used and sections through the infiltration zones were excavated in order to compare the shape of the dye -stained infiltration zone with the results of the ERT inversion. The data revealed the complicated infiltration pattern with a higher transport velocity in sand and a different shape than expected by classical soil hydraulic models. These results indicate the need for independent observations in order to correctly assess the water storage in the vadose zone with its hydrological consequences, the groundwater recharge and the contamination risk caused by rapid movement of water. ERT can be used for this purpose on different spatial- and time scales but for reliable results various obstacles need to be dealt with. Firstly, the ambiguity of the resistivity because soil resistivity depends on both, soil water content and electrical soil/water conductivity. This obstacle is less severe when the infiltration velocity is investigated, because then only the first onset of resistivity change is interpreted as the water arrival time. Our results show that the arrival of the water front as well as the final infiltration depth can be reliably detected. In contrast, this obstacle is very severe when the amount of water stored is observed using conductive tracer. The problem is not critical during a passive experiment when the natural rain fall and the waters fate through the vadose zone is monitored. The second obstacle is the limited resolution of ERT which deteriorates with depth. The resolution depends on the electrode distances and the depth resolution can be increased by using borehole electrodes. However, if one ha of land is to be observed with a reasonable number of electrodes (some 100) the resolution will be some 10 m. The structures, however, that influence the infiltration process, might be much smaller. Therefore, it is suggested to use ERT as the tool to observe and quantify the infiltration process with regard to time and space on a scale of some meters. For independent proof local TDR devices should be inserted within the investigated area for calibration. These results should then be used to establish a physical soil model that grasps the observed process correctly in time and space. The next step would then be to repeat these local measurements at different locations where the similarity of the processes is at doubt. Only when this is confirmed or discarded, further upscaling steps can be done reliably.

  13. Experimental Observation of a Periodically Oscillating Plasma Sphere in a Gridded Inertial Electrostatic Confinement Device

    Microsoft Academic Search

    R. A. Nebel; S. Stange; S. Krupakar Murali

    2005-01-01

    The periodically oscillating plasma sphere (POPS) [D. C. Barnes and R. A. Nebel, Phys. Plasmas 5, 2498 (1998).] oscillation has been observed in a gridded inertial electrostatic confinement device. In these experiments, ions in the virtual cathode exhibit resonant behavior when driven at the POPS frequency. Excellent agreement between the observed POPS resonance frequency and theoretical predictions has been observed

  14. The Trend in the Observation of Legacy Long Period Variable Stars (Poster abstract)

    NASA Astrophysics Data System (ADS)

    Dudley, R.

    2015-06-01

    (Abstract only) A decrease in the number of observers of the Legacy Long Period Variable Stars has been noted by the AAVSO. Amongst the observing community there is the perception that observers collecting digital data is making up for this gap. Data from the annual President's report (2002–2013) and the AAVSO International Data Base for the years 1993, 2003, and 2013 were analyzed. For the period of 2002 to 2013 the total number of observers remained fairly constant (816 ± 97) with a large bump in 2011. The number of observations has slowly declined since 2007 though there has recently been an increase in the number of observations. From the AID data the number of observations reached a maximum in 2003 and has slowly declined afterwards. These trends as well as other information gleamed from the data will be present and discussed.

  15. Periodicity in the most violent solar eruptions: recent observations of coronal mass ejections and flares revisited

    NASA Astrophysics Data System (ADS)

    Gao, Peng-Xin; Xie, Jing-Lan; Liang, Hong-Fei

    2012-03-01

    Using the Hilbert-Huang Transform method, we investigate the periodicity in the monthly occurrence numbers and monthly mean energy of coronal mass ejections (CMEs) observed by the Large Angle and Spectrometric Coronagraph Experiment on board the Solar and Heliographic Observatory from 1999 March to 2009 December. We also investigate the periodicity in the monthly occurrence numbers of H? flares and monthly mean flare indices from 1996 January to 2008 December. The results show the following. (1) The period of 5.66 yr is found to be statistically significant in the monthly occurrence numbers of CMEs; the period of 10.5 yr is found to be statistically significant in the monthly mean energy of CMEs. (2) The periods of 3.05 and 8.70yr are found to be statistically significant in the monthly occurrence numbers of H? flares; the period of 9.14yr is found to be statistically significant in the monthly mean flare indices.

  16. X-ray periodicities in sources observed by the RXTE ASM

    E-print Network

    Shivamoggi, Vasudha B

    2005-01-01

    The X-ray intensities measured from 230 X-ray sources observed by the RXTE All-Sky Monitor (ASM) were analyzed for periodic behavior. The ASM has been observing sources for nine years in the 1.5-12 keV energy range. In ...

  17. 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.; López-Puertas, M.

    2011-10-01

    An extensive observational data set, consisting of more than 106 SF6 vertical profiles distributed globally from MIPAS measurements 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.

  18. Determination of solar wind elemental abundances from M\\/Q observations during three periods in 1980

    Microsoft Academic Search

    S. Kunz; P. Bochsler; J. Geiss; K. W. Ogilvie; M. A. Coplan

    1983-01-01

    Mass spectra in the range 2 ? M\\/Q ? 3 provided by a high resolution mode of the ISEE-3 Plasma Composition Experiment were evaluated for three selected periods during early 1980. The observed Ne\\/O ratios are compatible with estimated solar abundance ratios. In two of the three periods, the He\\/Ne-ratios agree with the Apollo foil results. Freezing-in temperatures for oxygen

  19. Direct observation of induction period of MTO process with consecutive pulse reaction system

    Microsoft Academic Search

    Yingxu Wei; Dazhi Zhang; Fuxiang Chang; Zhongmin Liu

    2007-01-01

    The initial transformation of methanol over HZSM-5 catalyst was investigated by a consecutive pulse reaction system. The reactant–catalyst contact time influenced the initial methanol transformation and the performances implied methanol reaction in induction period or under steady-state condition. The induction period, in which an organic-free HZSM-5 catalyst could be transferred to a working catalyst, were directly observed. The analysis result

  20. A review of infrared limb observations of tenuous atmosphers. Suggestions for future work at the Jupiter system

    NASA Astrophysics Data System (ADS)

    Grassi, D.

    2012-01-01

    We review several historical observations of tenuous planetary atmospheres by IR spectroimager operating in limb scan mode. Limb observations are characterized by long optical paths and could detect very weak emission lines, often associated to the non-LTE conditions or photochemical phenomena encountered at low densities. Literature studies are used as a guideline to recommend observations by future Jupiter system missions, where oxygen in the atmospheres of Europa, Ganymede and Callisto is an obvious subject of interest. Integration of IR observations with the results of other payload components (Plasma and Particles Instrument/INMS) is also discussed, with possible synergies in defining the surface/space environment interactions that eventually lead to the formation of atmospheres of icy satellites.

  1. Ages of onset suggestive of genetic anticipation in rheumatoid arthritis multicase sibships can be explained by observational bias

    Microsoft Academic Search

    C. Deighton; L. A. Criswell; R. F. Lum; A. Silman

    2007-01-01

    Objectives. Previous work has suggested that features of genetic anticipation might be present in familial rheumatoid arthritis (RA), but bias is difficult to exclude when looking at disease in two consecutive generations. We used data from the North American Rheumatoid Arthritis Consortium (NARAC) and the Arthritis Research Campaign National repository for RA multicase pedigrees to determine whether differences in age

  2. Long-Period Oscillations of Sunspots Observed by SOHO/MDI

    NASA Astrophysics Data System (ADS)

    Efremov, V. I.; Parfinenko, L. D.; Solov'ev, A. A.; Kirichek, E. A.

    2014-06-01

    We processed magnetograms that were obtained with the Michaelson Doppler Imager onboard the Solar and Heliospheric Observatory (SOHO/MDI). The results confirm the basic properties of long-period oscillations of sunspots that have previously been established and also reveal new properties. We show that the limiting (lowest) eigenmode of low-frequency oscillations of a sunspot as a whole is the mode with a period of 10 - 12 up to 32 - 35 hours (depending on the sunspot's magnetic-field strength). This mode is observed consistently throughout an observation period of 5 - 7 days, but its amplitude is subject to quasi-cyclic changes, which are separated by about 1.5 - 2 days. As a result, the lower mode with a period of about 35 - 48 hours appears in the power spectrum of sunspot oscillations. But this lowest mode is apparently not an eigenmode of a sunspot because its period does not depend on the magnetic field of the sunspot. Perhaps the mode reflects the quasi-periodic sunspot perturbations caused by supergranulation cells that surround it. We also analyzed SOHO/MDI artifacts, which may affect the low-frequency power spectra of sunspots.

  3. Meteorology and dust in the central Sahara: Observations from Fennec supersite-1 during the June 2011 Intensive Observation Period

    NASA Astrophysics Data System (ADS)

    Marsham, J. H.; Hobby, M.; Allen, C. J. T.; Banks, J. R.; Bart, M.; Brooks, B. J.; Cavazos-Guerra, C.; Engelstaedter, S.; Gascoyne, M.; Lima, A. R.; Martins, J. V.; McQuaid, J. B.; O'Leary, A.; Ouchene, B.; Ouladichir, A.; Parker, D. J.; Saci, A.; Salah-Ferroudj, M.; Todd, M. C.; Washington, R.

    2013-05-01

    We describe observations from the Fennec supersite at Bordj Badji Mokhtar (BBM) made during the June 2011 Fennec Intensive Observation Period. These are the first detailed in situ observations of meteorology and dust from the central Sahara, close to the center of the Saharan heat low and the summertime dust maximum. Historically, a shortage of such Saharan observations has created problems for evaluating processes, models, and remote sensing. There was a monsoon influence at BBM before 8 June and after 12 June, with dry Harmattan winds in between. A split boundary layer, generated by ventilation from the Atlantic, persisted during the drier phase. Extensive cold pools (haboobs) and microburst-type events were regularly observed. Moisture reached BBM at night from the monsoon and the embedded haboobs. As well as the regularly occurring nocturnal low-level jet (LLJ), a Saharan upper boundary layer (650 hPa) jet was observed, where winds feel drag from dry convection in the afternoon. This jet is linked to the diurnal cycles of moisture and cloud. Most dust was observed in the cloudier monsoon-affected periods, and covarying dust and cloud amounts explain most of the variations in shortwave radiation that control the surface sensible flux. Dustiness is related to a standard parameterization of uplift using 10 m winds ("uplift potential"), and this is used to estimate uplift. Around 50% of uplift is nocturnal. Around 30% is from the LLJ, and 50% is from haboobs, which are mainly nocturnal. This demonstrates, for the first time from observations, the key role of haboobs, which are problematic for models.

  4. Experimental Observation of a Periodically Oscillating Plasma Sphere in a Gridded Inertial Electrostatic Confinement Device

    Microsoft Academic Search

    R. A. Nebel; S. Stange; S. Krupakar Murali

    2005-01-01

    The periodically oscillating plasma sphere (POPS) [D. C. Barnes and R. A. Nebel, Phys. Plasmas 5, 2498 (1998)., PHPAEN, 1070-664X, 10.1063\\/1.872933] oscillation has been observed in a gridded inertial electrostatic confinement device. In these experiments, ions in the virtual cathode exhibit resonant behavior when driven at the POPS frequency. Excellent agreement between the observed POPS resonance frequency and theoretical predictions

  5. Observations in APP Bitransgenic Mice Suggest that Diffuse and Compact Plaques Form via Independent Processes in Alzheimer's Disease

    PubMed Central

    Lord, Anna; Philipson, Ola; Klingstedt, Therése; Westermark, Gunilla; Hammarström, Per; Nilsson, K. Peter R.; Nilsson, Lars N.G.

    2011-01-01

    Studies of familial Alzheimer's disease suggest that misfolding and aggregation of amyloid-? (A?) peptides initiate the pathogenesis. The Arctic mutation of A? precursor protein (APP) results in AD, and Arctic A? is more prone to form A? protofibrils and extracellular deposits. Herein is demonstrated that the burden of diffuse A? deposits but not compact plaques is increased when tg-Swe mice are crossed with tg-ArcSwe mice synthesizing low levels of Arctic A?. The diffuse deposits in bitransgenic mice, which contain primarily wild-type A?42, accumulate in regions both with and without transgene expression. However, APP processing, when compared with tg-Swe, remains unchanged in young bitransgenic mice, whereas wild-type A?42 aggregation is accelerated and fibril architecture is altered in vitro and in vivo when a low level of Arctic A?42 is introduced. Thus, the increased number of diffuse deposits is likely due to physical interactions between Arctic A? and wild-type A?42. The selective increase of a single type of parenchymal A? deposit suggests that different pathways lead to formation of diffuse and compact plaques. These findings could have general implications for Alzheimer's disease pathogenesis and particular relevance to patients heterozygous for the Arctic APP mutation. Moreover, it further illustrates how A? neuropathologic features can be manipulated in vivo by mechanisms similar to those originally conceptualized in prion research. PMID:21514441

  6. LOW-FREQUENCY OBSERVATIONS OF TRANSIENT QUASI-PERIODIC RADIO EMISSION FROM THE SOLAR ATMOSPHERE

    SciTech Connect

    Sasikumar Raja, K.; Ramesh, R., E-mail: sasikumar@iiap.res.in [Indian Institute of Astrophysics, II Block, Koramangala, Bangalore 560 034 (India)

    2013-09-20

    We report low-frequency observations of quasi-periodic, circularly polarized, harmonic type III radio bursts whose associated sunspot active regions were located close to the solar limb. The measured periodicity of the bursts at 80 MHz was ?5.2 s, and their average degree of circular polarization (dcp) was ?0.12. We calculated the associated magnetic field B (1) using the empirical relationship between the dcp and B for the harmonic type III emission, and (2) from the observed quasi-periodicity of the bursts. Both the methods result in B ? 4.2 G at the location of the 80 MHz plasma level (radial distance r ? 1.3 R{sub ?}) in the active region corona.

  7. FUSE Observations of long-period pulsators among subdwarf B stars

    Microsoft Academic Search

    F. Wesemael

    2004-01-01

    We propose FUSE observations of a sample of 13 cool subdwarf B stars known to exhibit very low amplitude (lta 5 millimag), long-period 1000-5000 s), multiperiodic luminosity variations (the PG 1716 stars). These variations are interpreted as high radial order g modes. Current numbers indicate that the cool PG 1716 pulsators are much more common than their hotter counterparts, the

  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.; López-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.

  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.; López-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., Möbius, T., Bönisch, 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.

  10. 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: santanu@csp.res.in, E-mail: chakraba@bose.res.in, E-mail: dipak@csp.res.in [Indian Center for Space Physics, 43 Chalantika, Garia Station Road, Kolkata 700084 (India)

    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 ? 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.

  11. Experimental Observation of a Periodically Oscillating Plasma Sphere in a Gridded Inertial Electrostatic Confinement Device

    SciTech Connect

    Park, J.; Nebel, R.A.; Stange, S.; Murali, S. Krupakar [Los Alamos National Laboratory, Los Alamos, New Mexico 87544 (United States); University of Wisconsin, Madison, Wisconsin 53706 (United States)

    2005-07-01

    The periodically oscillating plasma sphere (POPS) [D. C. Barnes and R. A. Nebel, Phys. Plasmas 5, 2498 (1998).] oscillation has been observed in a gridded inertial electrostatic confinement device. In these experiments, ions in the virtual cathode exhibit resonant behavior when driven at the POPS frequency. Excellent agreement between the observed POPS resonance frequency and theoretical predictions has been observed for a wide range of potential well depths and for three different ion species. The results provide the first experimental validation of the POPS concept proposed by Barnes and Nebel [R. A. Nebel and D. C. Barnes, Fusion Technol. 34, 28 (1998).].

  12. Experimental observation of a periodically oscillating plasma sphere in a gridded inertial electrostatic confinement device.

    PubMed

    Park, J; Nebel, R A; Stange, S; Murali, S Krupakar

    2005-07-01

    The periodically oscillating plasma sphere (POPS) [D. C. Barnes and R. A. Nebel, Phys. Plasmas 5, 2498 (1998).] oscillation has been observed in a gridded inertial electrostatic confinement device. In these experiments, ions in the virtual cathode exhibit resonant behavior when driven at the POPS frequency. Excellent agreement between the observed POPS resonance frequency and theoretical predictions has been observed for a wide range of potential well depths and for three different ion species. The results provide the first experimental validation of the POPS concept proposed by Barnes and Nebel [R. A. Nebel and D. C. Barnes, Fusion Technol. 34, 28 (1998).]. PMID:16090625

  13. Imaging and Spectral Observations of Quasi-periodic Pulsations in a Solar Flare

    NASA Astrophysics Data System (ADS)

    Li, D.; Ning, Z. J.; Zhang, Q. M.

    2015-07-01

    We explore the quasi-periodic pulsations (QPPs) in a solar flare observed by Fermi Gamma-ray Burst Monitor, Solar Dynamics Observatory, Solar Terrestrial Relations Observatory, and Interface Region Imaging Spectrograph (IRIS) on 2014 September 10. QPPs are identified as the regular and periodic peaks on the rapidly varying components, which are the light curves after removing the slowly varying components. The QPPs display only three peaks at the beginning on the hard X-ray emissions, but 10 peaks on the chromospheric and coronal line emissions, and more than seven peaks (each peak corresponds to a type III burst on the dynamic spectra) at the radio emissions. A uniform quasi-period of about 4 minutes is detected among them. AIA imaging observations exhibit that the 4-minute QPPs originate from the flare ribbon and tend to appear on the ribbon front. IRIS spectral observations show that each peak of the QPPs tends to a broad line width and a red Doppler velocity at C i, O iv, Si iv, and Fe xxi lines. Our findings indicate that the QPPs are produced by the non-thermal electrons that are accelerated by the induced quasi-periodic magnetic reconnections in this flare.

  14. Determination of solar wind elemental abundances from M/Q observations during three periods in 1980

    NASA Technical Reports Server (NTRS)

    Kunz, S.; Bochsler, P.; Geiss, J.; Ogilvie, K. W.; Coplan, M. A.

    1983-01-01

    Mass spectra in the M/Q range from 2 to 3, provided by a high-resolution mode of the ISEE-3 Plasma Composition Experiment, were evaluated for three selected periods during early 1980. The observed Ne/O ratios are compatible with estimated solar abundance ratios. In two of the three periods, the He/Ne-ratios agree with the Apollo foil results. Freezing-in temperatures for oxygen are similar to those obtained by other groups. Possible reasons for an unexpectedly high flux at M/Q = 2.4 are discussed.

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

    NASA Astrophysics Data System (ADS)

    Kim, E.; Tedesco, M.; de Roo, R.; England, A. W.; Gu, H.; Pham, H.; Boprie, D.; Graf, T.; Koike, T.; Armstrong, R.; Brodzik, M.; Hardy, J.; Cline, D.

    2004-12-01

    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 3rd Intensive Observing Period (IOP3) period (February, 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 in 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.

  16. An Intercomparison of Cloud-Resolving Models with the Atmospheric Radiation Measurement Summer 1997 Intensive Observation Period Data

    NASA Astrophysics Data System (ADS)

    Xu, Kuan-Man; Cederwall, Richard T.; Donner, Leo J.; Grabowski, Wojciech W.; Guichard, Francoise; Johnson, Daniel E.; Khairoutdinov, Marat; Krueger, Steven K.; Petch, Jon C.; Randall, David A.

    2002-01-01

    This paper reports an intercomparison study of midlatitude continental cumulus convection simulated by eight two-dimensional and two three-dimensional cloud-resolving models (CRMs), driven by observed large-scale advective temperature and moisture tendencies, surface turbulent fluxes, and radiative-heating profiles during three sub-periods of the summer 1997 Intensive Observation Period of the US Department of Energy's Atmospheric Radiation Measurement (ARM) program. Each sub-period includes two or three precipitation events of various intensities over a span of 4 or 5 days. The results can be summarized as follows. CRMs can reasonably simulate midlatitude continental summer convection observed at the ARM Cloud and Radiation Testbed site in terms of the intensity of convective activity, and the temperature and specific-humidity evolution. Delayed occurrences of the initial precipitation events are a common feature for all three sub-cases among the models. Cloud mass fluxes, condensate mixing ratios and hydrometeor fractions produced by all CRMs are similar. Some of the simulated cloud properties such as cloud liquid-water path and hydrometeor fraction are rather similar to available observations. All CRMs produce large downdraught mass fluxes with magnitudes similar to those of updraughts, in contrast to CRM results for tropical convection. Some inter-model differences in cloud properties are likely to be related to those in the parametrizations of microphysical processes. There is generally a good agreement between the CRMs and observations with CRMs being significantly better than single-column models (SCMs), suggesting that current results are suitable for use in improving parametrizations in SCMs. However, improvements can still be made in the CRM simulations; these include the proper initialization of the CRMs and a more proper method of diagnosing cloud boundaries in model outputs for comparison with satellite and radar cloud observations.

  17. Optimal placement of a limited number of observations for period searches

    E-print Network

    Eric S. Saunders; Tim Naylor; Alasdair Allan

    2006-05-17

    Robotic telescopes present the opportunity for the sparse temporal placement of observations when period searching. We address the best way to place a limited number of observations to cover the dynamic range of frequencies required by an observer. We show that an observation distribution geometrically spaced in time can minimise aliasing effects arising from sparse sampling, substantially improving signal detection quality. The base of the geometric series is however a critical factor in the overall success of this strategy. Further, we show that for such an optimal distribution observations may be reordered, as long as the distribution of spacings is preserved, with almost no loss of quality. This implies that optimal observing strategies can retain significant flexibility in the face of scheduling constraints, by providing scope for on-the-fly adaptation. Finally, we present optimal geometric samplings for a wide range of common observing scenarios, with an emphasis on practical application by the observer at the telescope. Such a sampling represents the best practical empirical solution to the undersampling problem that we are aware of. The technique has applications to robotic telescope and satellite observing strategies, where target acquisition overheads mean that a greater total target exposure time (and hence signal-to-noise) can often in practice be achieved by limiting the number of observations.

  18. Observation of five-minute-period gravity waves in the solar photosphere

    NASA Astrophysics Data System (ADS)

    Stebbins, R. T.; Goode, Philip R.; Hill, Henry A.

    1983-01-01

    Vertically propagating traveling waves have been observed in the solar photosphere. These waves have a period of 278 ± 41 seconds and a vertical phase velocity of about 2 km s-1. It is noted that these waves also have approximately the same period as the well-studied five-minute-period acoustic mode, which is evanescent in the photosphere. The only consistent interpretation of the traveling waves implies that they are gravity waves. About half the time the gravity waves are outgoing, while the remainder of the time they are ingoing. The data were collected by Stebbins et al. (1980) to study the vertical structure of the photosphere. They examined velocity pertubations at nine altitudes in the photosphere using a Doppler shift technique. The current work represents a reanalysis of that data which uncovered the five-minute-period traveling waves. The mean velocity amplitude of disturbances at a given altitude, as registered in the observed Doppler shift, was found to be directly proportional to the mean velocity amplitude at the base of the photosphere. This was the expected relationship between the velocity amplitudes. It was not expected that the standard deviation of the velocity amplitude at a particular altitude would be independent of the velocity amplitude at the base of the photosphere. In addition, the phase difference between velocities at different altitudes is, unexpectedly, inversely proportional to the velocity amplitude at any altitude. These two traits of the data are consistent with a five-minute-period nonacoustic traveling wave being superimposed on the five-minute-period acoustic mode. This supposition is borne out by a detailed examination of the data in the complex plane of amplitude and phase and by a calculation of the power spectrum of the traveling waves as a function of their vertical wavenumber (see Hill et al., 1982).

  19. 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.

  20. 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.; Lopez-Puertas, M.

    2011-12-01

    According to model calculations, the meridional circulation is expected to intensify as a result of climate change, and mean age of stratospheric air is expected to decrease. However, an observational data set presented recently (Engel et al., 2009) and consisting of 27 balloon samples of the age of air tracers carbon dioxide and sulfur hexafluoride covering the years 1975 to 2005 did not confirm the model predictions. As a contribution to the ongoing discussion, an extensive observational data set, consisting of more than 1 Million SF6 vertical profiles distributed globally is presented here. It has been derived from the MIPAS instrument covering the period 2002 to 2010 and has been converted into mean age of stratospheric air by referring to a combined data set of in-situ and flask global mean tropospheric SF6 measurements provided by NOAA/ESRL. During conversion into age of air, the non-linearity of tropospheric SF6 increase has been corrected for by convolution with the age spectrum within an iterative approach. Monthly zonal means of mean age of air, binned at 10 deg latitude and 1-2 km altitude, were analyzed 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 the age-of-air 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. Reference: Engel, A., Möbius, T., Bönisch, 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.

  1. Observation of nonacoustic, 5 minute period, vertical traveling waves in the photosphere of the sun

    SciTech Connect

    Hill, H.A.; Goode, P.R.; Stebbins, R.T.

    1982-05-01

    Nonacoustic, radially propagating traveling waves have been observed in the solar photosphere. These traveling waves have a period of 278 +- 41 s. The vertical wavelength (approx.500 km) and phase velocity (approx.2 km s/sup -1/) of the waves are among their properties deduced from the data. It is also observed that the waves have outgoing phase part of the time and ingoing phase the remainder of the time. The traveling waves are interpreted to be gravity waves. Their role in the heating of the chromosphere is discussed.

  2. 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.

  3. 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.

  4. Techniques to determine the quiet day curve for a long period of subionospheric VLF observations

    NASA Astrophysics Data System (ADS)

    Cresswell-Moorcock, Kathy; Rodger, Craig J.; Clilverd, Mark A.; Milling, David K.

    2015-05-01

    Very low frequency (VLF) transmissions propagating between the conducting Earth's surface and lower edge of the ionosphere have been used for decades to study the effect of space weather events on the upper atmosphere. The VLF response to these events can only be quantified by comparison of the observed signal to the estimated quiet time or undisturbed signal levels, known as the quiet day curve (QDC). A common QDC calculation approach for periods of investigation of up to several weeks is to use observations made on quiet days close to the days of interest. This approach is invalid when conditions are not quiet around the days of interest. Longer-term QDCs have also been created from specifically identified quiet days within the period and knowledge of propagation characteristics. This approach is time consuming and can be subjective. We present three algorithmic techniques, which are based on either (1) a mean of previous days' observations, (2) principal component analysis, or (3) the fast Fourier transform (FFT), to calculate the QDC for a long-period VLF data set without identification of specific quiet days as a basis. We demonstrate the effectiveness of the techniques at identifying the true QDCs of synthetic data sets created to mimic patterns seen in actual VLF data including responses to space weather events. We find that the most successful technique is to use a smoothing method, developed within the study, on the data set and then use the developed FFT algorithm. This technique is then applied to multiyear data sets of actual VLF observations.

  5. 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

  6. Time Periods of Unusual Density Behavior Observed by GRACE and CHAMP

    NASA Astrophysics Data System (ADS)

    McLaughlin, C. A.; Fattig, E.; Mysore Krishna, D.; Locke, T.; Mehta, P. M.

    2011-12-01

    Time periods of low cross correlation between precision orbit ephemeris (POE) derived density and accelerometer density for CHAMP and GRACE are examined. In particular, the cross correlation for GRACE dropped from typical values near 0.9 to much lower values and then returned to typical over the time period of late October to late December of 2005. This time period includes a maneuver where GRACE-A and GRACE-B swapped positions. However, the drop in cross correlation begins and reaches its low point before the maneuvers begin. In addition, the densities were found using GRACE-A, but GRACE-B did most of the maneuvering. The time period is characterized by high frequency variations in accelerometer density of the same magnitude as the daylight to eclipse variations over the course of an orbit. However, the daylight to eclipse variations are particularly small during this time period because the orbit plane is near the terminator. Additionally, the difference between the accelerometer and POE derived densities are not unusually large during this time period. This implies the variations are not unusual, just more significant when the orbit plane is near terminator. Cyclical variations in correlation of the POE derived densities with accelerometer derived densities are seen for both GRACE and CHAMP, but the magnitude of the variations are much larger for GRACE, possibly because of the higher altitude of GRACE. The cycles seem to be phased so that low correlations occur with low beta angle when the orbit plane is near the terminator. The low correlation is possibly caused by the lower amplitude of the daylight to eclipse signal making higher frequency variations relatively more important. However, another possible explanation is terminator waves in density that propagate to the thermosphere from lower in the atmosphere. These waves have been observed in CHAMP accelerometer data and global circulation model simulations. Further investigation is needed to see if the variations correspond to terminator waves or if they represent typical high frequency signal from another source that is more apparent when the orbit plane is near the terminator. 1. C. A. McLaughlin, E. Fattig, D. Mysore Krishna, and P. M. Mehta, "Time Periods of Anomalous Density for GRACE and CHAMP," AAS/AIAA Astrodynamics Specialists Conference, AAS 11-613, Girdwood, AK, August 2011. 2. C. A. McLaughlin, A. Hiatt, and T. Lechtenberg, "Calibrating Precision Orbit Derived Total Density," Journal of Spacecraft and Rockets, Vol. 48, No. 1, January-February 2011, pp. 166-174.

  7. Chandra Observation of an Ultrasoft Active Galactic Nucleus with a 3.8 hr Periodicity

    NASA Astrophysics Data System (ADS)

    Lin, Dacheng

    2014-09-01

    Abstract: The source 2XMM J123103.2+110648 was recently discovered to show many intriguing properties, including being a strong candidate for a high Eddington-ratio true type 2 active galaxy lacking the broad line region, important for the standard Unified Model for active galactic nuclei, and showing a strong quasi-periodic X-ray oscillation, important for understanding the black hole scale invariance nature. To understand the origin of the very high luminosity emission we propose a deep Chandra follow-up observation, ten years after the previous XMM-Newton pointings, to determine its long-term evolution.

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

    SciTech Connect

    Pfeifer, T.; Downer, M. C. [Department of Physics, University of Texas at Austin, Austin, Texas 78712 (United States)

    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.

  9. ORIGINAL ARTICLE Pleistocene genetic legacy suggests incipient

    E-print Network

    Bernatchez, Louis

    ORIGINAL ARTICLE Pleistocene genetic legacy suggests incipient species of Sebastes mentella the Pleistocene glaciations followed by secondary contact. Although hybridization was observed between groups; Knowlton, 1993). The Pleistocene period is known as a period of intense speciation for a number of biota

  10. 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

  11. Quasi-periodic Oscillations Associated with Spectral Branches in RXTE Observations of Circinus X-1

    E-print Network

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

    1998-05-12

    We present Rossi X-ray Timing Explorer (RXTE) All-Sky Monitor observations of the X-ray binary Circinus X-1 which illustrate the variety of intensity profiles associated with the 16.55 d 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 which shifts in frequency between 6.8 Hz 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 which shift location in the CDs and HIDs over the course of the 16.55 d cycle. These results contradict a previous prediction, based on the hypothesis that Cir X-1 is a high-Mdot atoll source, that HBOs should never occur in this source (Oosterbroek et al. 1995; van der Klis 1994).

  12. 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 118.9±1.3 years with 68% confidence consistent with the value of Herbison-Evans et al. (1971), 124±11 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 = 9.24±0.01x10-5. (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.

  13. Deciphering IR Excess Observed by the Spitzer Space Telescope in Short Period Interacting Cataclysmic Binaries

    NASA Astrophysics Data System (ADS)

    Chun, Howard; Brinkworth, Carolyn; Ciardi, David; Hoard, Don; Howell, Steve; Stefaniak, Linda; Thomas, , Beth

    2006-03-01

    During the first year of the Spitzer Space Telescope Observing Program for Students and Teachers, our team observed a small sample of short orbital period interacting white dwarf binaries. Our scientific investigation was aimed at detection and characterization of the low mass, cool, brown dwarf-like mass donors in these systems. We used the Infrared Array Camera to obtain photometric observations of the polars EF Eri, GG Leo, V347 Pav, and RX J0154.0-5947 at 3.6, 4.5, 5.8, and 8.0 microns. In all our targets, we detected excess emission in the 3-8 micron region over that expected from a brown dwarf alone. One of the exciting discoveries we made with our IRAC observations is that the star EF Eri was found to be unexpectedly bright in the mid-IR (compared to its 2MASS magnitudes). This fact highlights an opportunity for us to observe EF Eri with the IRS as a follow-up proposal. EF Eri has a flux level of ~700 ?Jy at 8 microns. Thus, we are asking for time to obtain IRS data for only this star, our brightest source. We plan to obtain SL1 (7.4-14.5 microns) and SL2 (5.2-8.7 microns) spectroscopy only. We know the IRAC fluxes so our integration toies are well constrained and the spectral region covered by SL1, SL2 will yield sufficient S/N to differentiate between cool dust (rising BB like spectrum with PAH and other molecular features allowing us to determine dust size, temperature, and disk extent) and a T type dwarf showing characteristic spectral signatures and a falling Rayleigh-Jeans tail.

  14. Multi-periodicity of the Be star eta Centauri from spectroscopic and photometric observations

    NASA Astrophysics Data System (ADS)

    Janot-Pacheco, E.; Jankov, S.; Leister, N. V.; Hubert, A. M.; Floquet, M.

    1999-06-01

    We present photometric data and 209 high-resolution, high signal-to-noise ratio optical spectra of the Be star eta Centauri obtained in 1993 and 1995, respectively. Time series analysis of these and other data, performed using the CLEAN, CLEANEST and Fourier Doppler Imaging techniques, show the presence of multiperiodic variations. They are interpreted in terms of low and high order non-radial pulsation modes. A strong frequency of 1.29 c/d is detected in line profile and photometric variations. It is attributed to a mode with l = 2. Other high amplitude signals present in spectroscopic data are 1.78 c/d, 3.82 c/d and 4.51 c/d. A frequency of 1.48 c/d appearing in spectroscopic data is compatible with the 1.56 c/d periodicity largely dominant in observations taken prior to 1993. The corresponding ``superperiods" for four of the frequencies are commensurate at the 8% level. The star showed period and non-radial pulsation degree variations in timescales as short as ~ 1.5 hour. The dominant mode apparently alternates between l = 2 and l = 4 every other day during the eight day time span. This could be a modulation linked to the superperiod or to the stellar rotation. The main periodicities detected in our analysis are compatible with theoretical unstable g modes in SPB variables. Short time scale variability (1-3 hr), typical of high-order p modes is also systematically present.

  15. Period Status Codes: Please record only the highest hierarchical breeding status observed during each period (C supercedes P and O; P supercedes O), and the appropriate daily sub-codes (hierarchically listed) describing the behavior or observation

    E-print Network

    DeSante, David F.

    Period Status Codes: Please record only the highest hierarchical breeding status observed during the highest breeding status observed. C = Confirmed Breeder n = current year's nest found m = carrying nest BREEDING STATUS LIST List all species ever encountered at the station! Location: Station: OBSERVER

  16. Quasi-16-day period oscillations observed in middle atmospheric ozone and temperature in Antarctica

    NASA Astrophysics Data System (ADS)

    Demissie, T. D.; Kleinknecht, N. H.; Hibbins, R. E.; Espy, P. J.; Straub, C.

    2013-07-01

    Nightly averaged mesospheric temperature derived from the hydroxyl nightglow at Rothera station (67°34' S, 68°08' W) and nightly midnight measurements of ozone mixing ratio obtained from Troll station (72°01' S, 2°32' E) in Antarctica have been used to investigate the presence and vertical profile of the quasi-16-day planetary wave in the stratosphere and mesosphere during the Antarctic winter of 2009. The variations caused by planetary waves on the ozone mixing ratio and temperature are discussed, and spectral and cross-correlation analyses are performed to extract the wave amplitudes and to examine the vertical structure of the wave from 34 to 80 km. The results show that while planetary-wave signatures with periods 3-12 days are strong below the stratopause, the oscillations associated with the 16-day wave are the strongest and present in both the mesosphere and stratosphere. The period of the wave is found to increase below 42 km due to the Doppler shifting by the strong eastward zonal wind. The 16-day oscillation in the temperature is found to be correlated and phase coherent with the corresponding oscillation observed in O3 volume mixing ratio at all levels, and the wave is found to have vertical phase fronts consistent with a normal mode structure.

  17. "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%.

  18. 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.

  19. Vertical structure of the wind field during the special observing period I of the global weather experiment

    Microsoft Academic Search

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

    1984-01-01

    Summary 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 streamfunction 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

  20. Effects of confinement on short-period surface waves: Observations from a new dataset

    SciTech Connect

    Hooper, H.; Bonner, J.; Leidig, M. [Weston Geophysics Corp., Lexington, MA (United States)

    2006-04-15

    The Source Phenomenology Experiment (SPE) was conducted during the summer of 2003 in Arizona. Single-fired chemical shots were detonated and recorded at two locations, including a coal mine in the Black Mesa district of northern Arizona. This article reports on research into the effects of confinement on the generation of short-period, fundamental-mode Rayleigh waves (Rg), using a subset of the SPE data. Results show important differences between the Rg amplitudes of confined and unconfined explosions which must be understood to develop discriminants for mining explosions, which are an important aspect of nuclear test monitoring. Rg energy and frequency content depend on explosive weight and confinement, and unconfined explosions generate up to eight times less energy than equivalent confined explosions. For this reason, unconfined mining explosions cannot be simulated using a Mueller and Murphy (1971) source without including an empirical chemical decoupling factor. Rg chemical decoupling factors for unconfined shots vary from 0.5 to 8.2 at frequencies between 0.5 and 11 Hz. The effects of the bench free face are evident in radiation patterns. Explosions on the topographic bench show increased spectral energies for Rg (by a factor of 1.5) at azimuths behind the bench. This suggests that a discriminant based on the relative azimuthal spectral energies of Rg may be a possibility.

  1. Whole earth telescope observations of the white dwarf G29-38 - Phase variations of the 615 second period

    Microsoft Academic Search

    D. E. Winget; R. E. Nather; J. C. Clemens; J. Provencal; S. J. Kleinman; P. A. Bradley; M. A. Wood; C. F. Claver; E. L. Robinson; A. D. Grauer; B. P. Hine; G. Fontaine; N. Achilleos; T. M. K. Marar; S. Seetha; B. N. Ashoka; D. O'Donoghue; B. Warner; D. W. Kurtz; P. Martinez; G. Vauclair; M. Chevreton; A. Kanaan; S. O. Kepler; T. Augusteijn; J. van Paradijs; C. J. Hansen; James Liebert

    1990-01-01

    An extensive set of high-speed photometric observations obtained with the Whole Earth Telescope network is used to show that the complex light curve of the ZZ Zeti (DAV) star G29-38 is dominated by a single, constant amplitude period of 615 s during the time span of these observations. The pulse arrival times for this period exhibit a systematic variation in

  2. 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.

  3. Study on workloads of human care worker with the introduction of IT system - the characteristics of work loads by observational research and the suggestions for KAIZEN.

    PubMed

    Mizuno, Yuki; Yoshikawa, Toru; Matsuda, Fumiko; Takeuchi, Yuriko; Motegi, Nobuyuki; Ikegami, Thor; Sakai, Kazuhiro

    2012-01-01

    The purpose of this study was to clarify the characteristic of workloads on human care worker with the introduction of IT system, and suggested the support measures for KAIZEN in Japan. The investigation method is workflow line and hearing with a focus on work observation. The objects were 8 human care workers of the acute hospital that introduced an electronic system. By the introduction of the electronic chart, the nurse station sojourn time decreased, sickroom sojourn time increased, and time about direct nursing care to a patient increased. In addition, access to patient information became easy, and the offer of the health care service based on correct information came to be possible in real time. By The point of workflow line, it was effect that moving lengths decreased in order to install the electronic chart in patients' rooms. Though, it was a problem that it hasn't formed where to place the instruments such as sphygmomanometer, clinical thermometer and others. PMID:22317644

  4. Observation of periodic variable stars towards the Galactic spiral arms by EROS II

    NASA Astrophysics Data System (ADS)

    Derue, F.; Marquette, J.-B.; Lupone, S.; Afonso, C.; Alard, C.; Albert, J.-N.; Amadon, A.; Andersen, J.; Ansari, R.; Aubourg, É.; Bareyre, P.; Bauer, F.; Beaulieu, J.-P.; Blanc, G.; Bouquet, A.; Char, S.; Charlot, X.; Couchot, F.; Coutures, C.; Ferlet, R.; Fouqué, P.; Glicenstein, J.-F.; Goldman, B.; Gould, A.; Graff, D.; Gros, M.; Ha?ssinski, J.; Hamilton, J.-C.; Hardin, D.; de Kat, J.; Kim, A.; Lasserre, T.; Le Guillou, L.; Lesquoy, É.; Loup, C.; Magneville, C.; Mansoux, B.; Maurice, É.; Milsztajn, A.; Moniez, M.; Palanque-Delabrouille, N.; Perdereau, O.; Prévot, L.; Regnault, N.; Rich, J.; Spiro, M.; Vidal-Madjar, A.; Vigroux, L.; Zylberajch, S.; EROS Collaboration

    2002-07-01

    We present the results of a massive variability search based on a photometric survey of a six square degree region along the Galactic plane at (l = 305o, b = -0.8o) and (l = 330o, b = -2.5o). This survey was performed in the framework of the EROS II (Expérience de Recherche d'Objets Sombres) microlensing program. The variable stars were found among 1 913 576 stars that were monitored between April and June 1998 in two passbands, with an average of 60 measurements. A new period-search technique is proposed which makes use of a statistical variable that characterizes the overall regularity of the flux versus phase diagram. This method is well suited when the photometric data are unevenly distributed in time, as is our case. 1362 objects whose luminosity varies were selected. Among them we identified 9 Cepheids, 19 RR Lyræ, 34 Miras, 176 eclipsing binaries and 266 Semi-Regular stars. Most of them are newly identified objects. The cross-identification with known catalogues has been performed. The mean distance of the RR Lyræ is estimated to be ~ 4.9 +/- 0.3 kpc undergoing an average absorption of ~ 3.4 +/- 0.2 mag. This distance is in good agreement with that of disc stars that contribute to the microlensing source star population. Our catalogue and light curves are available electronically from the CDS, Strasbourg and from our Web site http://eros.in2p3.fr. Full Tables 4 and 5 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/389/149 This work is based on observations made with the MARLY telescope of the EROS collaboration at the European Southern Observatory, La Silla, Chile.

  5. 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.

  6. Ontogenesis of ultradian rhythm in the human fetus, observed through the alternation of eye movement and no eye movement periods

    Microsoft Academic Search

    Takashi Koyanagi; Naoki Horimoto; Takeshi Takashima; Shoji Satoh; Hirotaka Maeda; Hittoo Nakano

    1993-01-01

    To evaluate the ontogenesis of ultradian rhythm of alternating eye movement (EM) and no eye movement (NEM) period durations, a cross-sectional study was conducted on 240 human fetuses from 25 to 41 weeks of gestation, using real-time ultrasound to observe eye movements. Two critical points for the duration of the EM period were found at 29-30 and 37-38 weeks of

  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 Å, 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 Å 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. Some Observations on the Greek Military in the Inter-War Period, 1918-1935

    Microsoft Academic Search

    Thanos Veremis

    1978-01-01

    This article provides a historical description of the Greek military in the inter-war period (1918-1935), focusing on the self-image and professionalism of the officer corps as well as the civil-military relations of the period. The Greek military represented an institution different than other European nations, whose armed forces often grew out of an ancien regime or represented citizen armies like

  9. 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.

  10. Orbital periods of cataclysmic variables identified by the SDSS. V. VLT, NTT and Magellan observations of nine equatorial systems

    E-print Network

    John Southworth; B T Gaensicke; T R Marsh; M A P Torres; D Steeghs; P Hakala; C M Copperwheat; A Aungwerojwit; A Mukadam

    2008-09-10

    We present VLT and Magellan spectroscopy and NTT photometry of nine faint cataclysmic variables (CVs) which were spectroscopically identified by the SDSS. We measure orbital periods for five of these from the velocity variations of the cores and wings of their Halpha emission lines. Four of the five have orbital periods shorter than the 2-3 hour period gap observed in the known population of CVs. SDSS J004335.14-003729.8 has an orbital period of Porb = 82.325 +/- 0.088 min; Doppler maps show emission from the accretion disc, bright spot and the irradiated inner face of the secondary star. In its light curve we find a periodicity which may be attributable to pulsations of the white dwarf. SDSS J163722.21-001957.1 has Porb = 99.75 +/- 0.86 min. By combining this new measurement with a published superhump period we estimate a mass ratio of 0.16 and infer the physical properties and orbital inclination of the system. For SDSS J164248.52+134751.4 we find Porb = 113.60 +/- 1.5 min. The Doppler map of this CV shows an unusual brightness distribution in the accretion disc which would benefit from further observations. SDSS J165837.70+184727.4 had spectroscopic characteristics which were very different between the SDSS spectrum and our own VLT observations, despite only a small change in brightness. We measure Porb = 98.012 +/- 0.065 min from its narrow Halpha emission line. Finally, SDSS J223843.84+010820.7 has a comparatively longer period of Porb = 194.30 +/- 0.16 min. It contains a magnetic white dwarf and, with g = 18.15, is brighter than the other objects studied here. These results continue the trend for the fainter CVs identified by the SDSS to be almost exclusively shorter-period objects with low mass transfer rates.

  11. Water vapor measurements by Raman lidar during the ARM 1997 Water Vapor Intensive Observation Period

    Microsoft Academic Search

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

    1998-01-01

    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

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

    Microsoft Academic Search

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

    1998-01-01

    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

  13. Aerosol disturbances of the stratosphere over Tomsk according to data of lidar observations in volcanic activity period 2006-2011

    NASA Astrophysics Data System (ADS)

    Makeev, Andrey P.; Burlakov, Vladimir D.; Dolgii, Sergey I.; Nevzorov, Aleksey V.; Trifonov, Dimitar A.

    2012-11-01

    We summarize and analyze the lidar measurements (Tomsk: 56.5°N; 85.0°E) of the optical characteristics of the stratospheric aerosol layer (SAL) in the volcanic activity period 2006-2011. The background SAL state with minimal aerosol content, which was observed since 1997 under the conditions of long-term volcanically quiescent period, was interrupted in October 2006 by a series of explosive eruptions of volcanoes of the Pacific Ring of Fire: Rabaul (October 2006, New Guinea); Okmok and Kasatochi (July-August 2008, Aleutian Islands); Redoubt (March-April 2009, Alaska); Sarychev Peak (June 2009, Kuril Islands), and Grimsvötn (May 2011, Iceland). A short-term and minor disturbance of the lower stratosphere was also observed in April 2010 after eruption of the Icelandic volcano Eyjafjallajokull. The developed regional empirical model of the vertical distribution of background SAL optical characteristics was used to identify the periods of elevated stratospheric aerosol content after each of the volcanic eruptions.

  14. Observation of Periodic Fine Structure in Reflectance from Biological Tissue: A New Technique for Measuring Nuclear Size Distribution

    Microsoft Academic Search

    L. T. Perelman; V. Backman; M. Wallace; G. Zonios; R. Manoharan; A. Nusrat; S. Shields; M. Seiler; C. Lima; T. Hamano; I. Itzkan; J. Van Dam; J. M. Crawford; M. S. Feld

    1998-01-01

    We report observation of a fine structure component in backscattered light from mucosal tissue which is periodic in wavelength. This structure is ordinarily masked by a diffusive background. We have identified the origin of this component as being due to light which is Mie scattered by surface epithelial cell nuclei. By analyzing the amplitude and frequency of the fine structure,

  15. Simultaneous optical observations of long-period gravity waves during AIDA '89

    Microsoft Academic Search

    R. H. Wiens; S. P. Zhang; R. N. Peterson; G. G. Shepherd; C. A. Tepley; L. Kieffaber; R. Niciejewski; J. H. Hecht

    1993-01-01

    Ground-based optical instrumentation supported the AIDA 1989 wind measurement comparisons by describing the gravity waves affecting the 80-100 km altitude region during clear dark hours over Puerto Rico. This study tabulates the characteristics of gravity waves with fractional column emission rate amplitudes up to 30 percent and with periods greater than 45 min as seen in the O2 airglow layer

  16. Observations and seasonal periodicity of the benthic algae of Galveston Island, Texas 

    E-print Network

    Lowe, Glenn Curtis

    1975-01-01

    algal growth was found to be limited to winter populations of Phaeophytes and Chlorophytes w1th a rare 1solated Rhodophyte. From an investigation of the benthic algae of the Louisiana coast, Kapraun (1974}, encountered thirty species in monthly field.... , 1969. Field and cultural studies on the seasonal periodicity of growth and reproduction of selected Texas benthic marine algae. Contr. Mar. Sci. Univ. Texas 14: 59-114. 1970. Illustrated guide to the seaweeds and sea grasses in tile vicinity...

  17. 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.

  18. Observe an animation of an asteroid impact at the end of the Cretaceous period

    NSDL National Science Digital Library

    TERC. Center for Earth and Space Science Education

    2003-01-01

    This Earth science animation shows middle and high school students how an asteroid that struck the Earth at the end of the Cretaceous period may have caused a mass extinction that killed the dinosaurs. The introduction explains the basis of the asteroid theory of extinction. The animation depicts an artist's conception, presented from space, of an asteroid hitting the Gulf of Mexico and releasing a cloud that prevented sunlight from reaching the Earth. Movie controls allow students to repeat, pause, or step through the animation, which can give students more time to analyze the images. Copyright 2005 Eisenhower National Clearinghouse

  19. Measurement of filling factor 5/2 quasiparticle interference with observation of charge e/4 and e/2 period oscillations

    PubMed Central

    Willett, R. L.; Pfeiffer, L. N.; West, K. W.

    2009-01-01

    A standing problem in low-dimensional electron systems is the nature of the 5/2 fractional quantum Hall (FQH) state: Its elementary excitations are a focus for both elucidating the state's properties and as candidates in methods to perform topological quantum computation. Interferometric devices may be used to manipulate and measure quantum Hall edge excitations. Here we use a small-area edge state interferometer designed to observe quasiparticle interference effects. Oscillations consistent in detail with the Aharonov–Bohm effect are observed for integer quantum Hall and FQH states (filling factors ? = 2, 5/3, and 7/3) with periods corresponding to their respective charges and magnetic field positions. With these factors as charge calibrations, periodic transmission through the device consistent with quasiparticle charge e/4 is observed at ? = 5/2 and at lowest temperatures. The principal finding of this work is that, in addition to these e/4 oscillations, periodic structures corresponding to e/2 are also observed at 5/2 ? and at lowest temperatures. Properties of the e/4 and e/2 oscillations are examined with the device sensitivity sufficient to observe temperature evolution of the 5/2 quasiparticle interference. In the model of quasiparticle interference, this presence of an effective e/2 period may empirically reflect an e/2 quasiparticle charge or may reflect multiple passes of the e/4 quasiparticle around the interferometer. These results are discussed within a picture of e/4 quasiparticle excitations potentially possessing non-Abelian statistics. These studies demonstrate the capacity to perform interferometry on 5/2 excitations and reveal properties important for understanding this state and its excitations. PMID:19433804

  20. 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 Å) 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 Å channels. Simultaneously, AIA hot channels (94 and 131 Å) 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.

  1. Two types of ion energy dispersions observed in the nightside auroral regions during geomagnetically disturbed periods

    Microsoft Academic Search

    M. Hirahara; T. Mukai; T. Nagai; N. Kaya; H. Hayakawa; H. Fukunishi

    1996-01-01

    The Akebono satellite has observed two types of energy dispersion signatures of discrete ion precipitation event in the nightside auroral regions during active geomagnetic conditions. The charged particle experiments and electric and magnetic field detectors on board Akebono provide us with essential clues to characterize the source regions and acceleration and\\/or injection processes associated with these two types of ion

  2. Selecting broilers for low or high abdominal fat : observations on the hens during the breeding period

    E-print Network

    Paris-Sud XI, Université de

    Selecting broilers for low or high abdominal fat : observations on the hens during the breeding feed energy for lipid synthesis of yolk or adipose tissue. Introduction Modern strains of broilers and expensive compo- nent in broiler production. A divergent selection programme was undertaken to reduce

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

    SciTech Connect

    Turner, D.D. [Pacific Northwest National Lab., Richland, WA (United States); Goldsmith, J.E.M. [Sandia National Labs., Livermore, CA (United States)

    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.

  4. African Monsoon Multidisciplinary Analysis (AMMA) : The Special Observing Period of 2006

    NASA Astrophysics Data System (ADS)

    Polcher, J.; Cairo, F.; Fierli, F.; Höller, H.; Law, K.; Mari, C.; Reeves, C.; Schlager, H.

    2006-12-01

    The AMMA project aims at enhancing our understanding of the West African monsoon and its underlying physical, chemical and biological processes. This enhanced knowledge of the processes involved in the establishment and variability of the monsoon will be used to improve our capacity to predict it and evaluate the impacts on land-productivity, management of water resources and public health. The objective is to provide societies in Africa with improved tools to manage their dependence on environmental conditions. In the framework of AMMA a dense observational network has been established both as routine and campaign- based facilities. The aim is to provide a complete picture of the physical, chemical and biological processes over the ocean, the continent and in the atmosphere. The base network has been established over the last few year and covers surface states and surface flux monitoring in a number catchments over the climatic gradient of the region. The upper-air sounding network was upgraded and enhanced to improve the data available for operational weather forecasting. During 2006 AMMA supported a large field campaign to cover the dry season (SOP0), the monsoon onset (SOP1) and the wet season (SOP2). The enhancement to the observing system in 2006 included balloon borne instruments, a lightning network over northern Benin, 3 research vessels and 5 research aircraft stationed in the Niamey and Ouagadougou. Most of SOP2 observations were dedicated to the intense mesoscale convective systems which are generated in the region and travel to the West. Their impact on the circulation in the troposphere and lower stratosphere, the water cycle in the region and the transport of trace gases and aerosols have been observed at different stages of the life cycle of these systems. This talk will provide a overview of the AMMA project and the observations carried out in 2006, focusing on the most relevant events.

  5. A Comparison of Observationally Determined Radii with Theoretical Radius Predictions for Short-Period Transiting Extrasolar Planets

    Microsoft Academic Search

    Gregory Laughlin; Aaron Wolf; Tonny Vanmunster; Peter Bodenheimer; Debra Fischer; Geoff Marcy; Paul Butler; Steve Vogt

    2005-01-01

    Two extrasolar planets, HD 209458b and TrES-1, are currently known to transit bright parent stars for which physical properties can be accurately determined. The two transiting planets have very similar masses and periods and hence invite detailed comparisons between their observed and theoretically predicted properties. In this paper, we carry out these comparisons. We first report photometric and spectroscopic follow-up

  6. Overview of the Dust and Biomass-burning Experiment and African Monsoon Multidisciplinary Analysis Special Observing Period0

    Microsoft Academic Search

    J. M. Haywood; J. Pelon; P. Formenti; N. Bharmal; M. Brooks; G. Capes; P. Chazette; C. Chou; S. Christopher; H. Coe; J. Cuesta; Y. Derimian; K. Desboeufs; G. Greed; M. Harrison; B. Heese; E. J. Highwood; B. Johnson; M. Mallet; B. Marticorena; J. Marsham; S. Milton; G. Myhre; S. R. Osborne; D. J. Parker; J.-L. Rajot; M. Schulz; A. Slingo; D. Tanré; P. Tulet

    2008-01-01

    The African Monsoon Multidisciplinary Analysis (AMMA) is a major international campaign investigating far-reaching aspects of the African monsoon, climate and the hydrological cycle. A special observing period was established for the dry season (SOP0) with a focus on aerosol and radiation measurements. SOP0 took place during January and February 2006 and involved several ground-based measurement sites across west Africa. These

  7. Long period oscillations of microwave emission of solar active regions: observations with NoRH and SSRT

    Microsoft Academic Search

    I. A. Bakunina; V. E. Abramov-Maximov; S. V. Lesovoy; K. Shibasaki; A. A. Solov'ev; Yu. V. Tikhomirov

    2009-01-01

    In this work we present the first results of study and comparison of the parameters of quasi-periodic long-term oscillations of microwave emission of large (>0.7 arcmin) sunspots as a result of simultaneous observations with two radioheliographs - NoRH (17 GHz) and Siberian Solar Radio Telescope (SSRT) (5.7 GHz) with 1 minute cadence. Radioheliographs have been working with quite large time

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

    SciTech Connect

    Randall, D.A. [Colorado State Univ., Fort Collins, CO (United States); Cederwall, R.T. [Lawrence Livermore National Lab., CA (United States)

    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.

  9. He+ dominance in the plasmasphere during geomagnetically disturbed periods: 1. Observational results

    NASA Astrophysics Data System (ADS)

    Denton, M. H.; Bailey, G. J.; Wilford, C. R.; Rodger, A. S.; Venkatraman, S.

    2002-04-01

    Observations made by the DMSP F10 satellite during the recovery phase from geomagnetic disturbances in June 1991 show regions of He+ dominance around 830 km altitude at 09:00 MLT. These regions are co-located with a trough in ionisation observed around 55° in the winter hemisphere. Plasma temperature and concentration observations made during the severe geomagnetic storm of 24 March 1991 are used as a case study to determine the effects of geomagnetic disturbances along the orbit of the F10 satellite. Previous explanations for He+ dominance in this trough region relate to the part of the respective flux tubes that is in darkness. Such conditions are not relevant for this study, since the whole of the respective flux tubes are sunlit. A new mechanism is proposed to explain the He+ dominance in the trough region. This mechanism is based on plasma transport and chemical reaction effects in the F-region and topside ionosphere, and on the time scales for such chemical reactions. Flux tubes previously depleted by geomagnetic storm effects refill during the recovery phase from the ionosphere as a result of pressure differences along the flux tubes. Following a geomagnetic disturbance, the He+ ion recovers quickly via the rapid photoionisation of neutral helium, in the F-region and the topside. The recovery of the O+ and H+ ions is less rapid. This is proposed as a result of the respective charge exchange reactions with neutral atomic hydrogen and oxygen. Preliminary model calculations support the proposed mechanism.

  10. Plasma Wave Observations in the Cleft during a Period of Upflowing Ions

    NASA Astrophysics Data System (ADS)

    Lundberg, E. T.; Kintner, P. M.; Lynch, K.; Mella, M. R.; Sigernes, F.; Oksavik, K.; Ogawa, Y.

    2008-05-01

    On Jan 18th , 2008 at 0730 UT a high altitude sounding rocket, SCIFER-2 (Sounding of the Cleft Ion Fountain Energization Region-2), was launched into dayside cusp aurora from Andoya Rocket Range and closely over flew the EISCAT Svalbard Radar (ESR) and the Kjell Henrikson Observatory with an apogee of 1467 km. During flight ESR recorded upwelling ions with a flux of ~20*1012 m-2s-1 and velocity of ~400 m/s at 400 km altitude. Initial results from a 6m VLF wave receiver are presented. Strong wave signatures are observed between 3 kHz and 5 kHz with amplitudes of up to 40 mV/m peak to peak. These waves are roughly ordered by the hydrogen gyrofrequency indicating possible Bernstein mode waves over an altitude range from 1000 km to above 1400 km. Associated with these waves are measured ion populations between 50 and 100eV. At lower frequencies possible broadband ELF waves are observed above 1200 km at amplitudes of up to 20mV/m peak to peak. Additionally, banded waves are observed between 300 Hz and 600 Hz throughout the entire flight, from 300 Km to over 1400 km, with an amplitude of 5-20 mV/m peak to peak.

  11. 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.

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

    E-print Network

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

    2015-01-01

    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 sec 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 sh...

  13. 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

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

    SciTech Connect

    Corbet, Robin H. D. [University of Maryland, Baltimore County, Baltimore, MD 21250 (United States); Krimm, Hans A., E-mail: corbet@umbc.edu [Universities Space Research Association, 10211 Wincopin Circle, Suite 500, Columbia, MD 21044 (United States)

    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 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.

  15. Observing Evolution in the Supergranular Network Length Scale During Periods of Low Solar Activity

    NASA Astrophysics Data System (ADS)

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

    2011-03-01

    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 ~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.

  16. 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

    2015-06-01

    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.

  17. 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

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

    SciTech Connect

    Turner, D.D. [Pacific Northwest National Lab., Richland, WA (United States); Whiteman, D.N.; Schwemmer, G.K. [National Aeronautics and Space Administration, Greenbelt, MD (United States). Goddard Space Flight Center; Evans, K.D. [Univ. of Maryland, Baltimore, MD (United States)]|[National Aeronautics and Space Administration, Greenbelt, MD (United States). Goddard Space Flight Center; Melfi, S.H. [Univ. of Maryland, Baltimore, MD (United States); Goldsmith, J.E. [Sandia National Labs., Livermore, CA (United States)

    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.

  19. Periodic functions with variable period

    E-print Network

    M. V Pryjmak

    2010-06-08

    The examples of rhythmical signals with variable period are considered. The definition of periodic function with the variable period is given as a model of such signals. The examples of such functions are given and their variable periods are written in the explicit form. The system of trigonometric functions with the variable period is considered and its orthogonality is proved. The generalized system of trigonometric functions with the variable period is also suggested; some conditions of its existence are considered.

  20. 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.; Berresheim, H.; Elste, T.; Plass-Dülmer, C.; Stange, G.; Kleffmann, J.; Elshorbany, Y.; Schurath, U.

    2011-10-01

    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. OH and HO2 levels, observed by four and three instruments, respectively, 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. Adding isomerization of isoprene peroxy radicals to the model increased OH and HO2 by 43% and 48% on average. Although these are still only 15% and 21% higher than the observations made by one of the instruments, larger overestimations (>60%) occurred with respect to the observations made by the other three instruments, suggesting that the rates of the isomerization were not readily supported by the ensemble of radical observations. These model runs tend to underestimate observed OH reactivity which may be explained by unmeasured hydrocarbon species. By selecting hydrocarbon types to be added to the model in amounts that accounted for the missing fractions of observed OH reactivity, the gaps between HOx observations and model results with and without isomerization could be individually diminished to within uncertainty levels. In this case, however, the HO2/OH ratio rose on addition of hydrocarbons and diverged from observations. In the case where we used modeled HO2(*), 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, the model's overestimation for HO2 became evident (by factors of more than 1.8). These results strongly indicated 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 (and HO2(*)) with respect to observations made by the three instruments. We found that this tendency is associated with high NOx concentrations, suggesting that some HO2 production or HO2 regeneration processes under high NOx conditions were being overlooked; this might require revision of ozone production regimes.

  1. 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.

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

    E-print Network

    Kumar, Pankaj; Cho, Kyung-Suk

    2015-01-01

    We report decaying quasi-periodic intensity oscillations in the X-ray (6-12 keV) and extreme ultraviolet (EUV) channels (131, 94, 1600, 304 \\AA) observed by the Fermi GBM (Gamma-ray Burst Monitor) and SDO/AIA, respectively, during a C-class flare. The estimated period of oscillation and decay time in the X-ray channel (6-12 keV) was about 202 s and 154 s, respectively. A similar oscillation period was detected at the footpoint of the arcade loops in the AIA 1600 and 304 \\AA channels. Simultaneously, AIA hot channels (94 and 131 \\AA) 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 s and 1121 s, respectively. The characteristic phase speed of the wave is about 560 km/s for about 115 Mm loop length, which is roughly consistent with the sound speed at the temperature about 10-16 MK (480-608 km/s). These EUV oscillations are consistent with the SOHO/SUMER Doppler-shift oscillations interpreted as the...

  3. Periodic very high energy gamma-ray emission from LS I +61 303 observed with the MAGIC telescope

    E-print Network

    MAGIC Collaboration; J. Albert

    2008-06-11

    The MAGIC collaboration has recently reported the discovery of gamma-ray emission from the binary system LS I +61 303 in the TeV energy region. Here we present new observational results on this source in the energy range between 300 GeV and 3 TeV. In total 112 hours of data were taken between September and December 2006 covering 4 orbital cycles of this object. This large amount of data allowed us to produce an integral flux light curve covering for the first time all orbital phases of LS I +61 303. In addition, we also obtained a differential energy spectrum for two orbital phase bins covering the phase range 0.5LS I +61 303 was found to be variable at TeV energies on timescales of days. These new MAGIC measurements allowed us to search for intra-night variability of the VHE emission; however, no evidence for flux variability on timescales down to 30 minutes was found. To test for possible periodic structures in the light curve, we apply the formalism developed by Lomb and Scargle to the LS I +61 303 data taken in 2005 and 2006. We found the LS I +61 303 data set to be periodic with a period of (26.8+-0.2) days (with a post-trial chance probability of 10^{-7}), close to the orbital period.

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

    SciTech Connect

    Johannsen, Tim [Physics Department, University of Arizona, 1118 East 4th Street, Tucson, AZ 85721 (United States); Psaltis, Dimitrios, E-mail: timj@physics.arizona.edu, E-mail: dpsaltis@email.arizona.edu [Astronomy Department, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States)

    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.

  5. New observations of displacement steps associated with volcano seismic long-period events, constrained by step table experiments

    NASA Astrophysics Data System (ADS)

    Thun, Johannes; Lokmer, Ivan; Bean, Christopher J.

    2015-05-01

    Long-period (LP) volcano seismic events often precede volcanic eruptions and are viewed with considerable interest in hazard assessment. They are usually thought to be associated with resonating fluid-filled conduits although alternative models involving material failure have recently been proposed. Through recent field experiments, we uncovered a step-like displacement component associated with some LP events, outside the spectral range of the typically narrow-band analysis for this kind of event. Bespoke laboratory experiments with step tables show that steps of the order of a few micrometers can be extracted from seismograms, where long-period noise is estimated and removed with moving median filters. Using these constraints, we observe step-like ground deformation in LP recordings near the summits of Turrialba and Etna Volcanoes. This represents a previously unobserved static component in the source time history of LP events, with implications for the underlying source process.

  6. Observations of quasi-periodic oscillations from GX 5 - 1 and Cygnus X-2 with the Einstein (HEAO 2) Observatory

    NASA Technical Reports Server (NTRS)

    Elsner, R. F.; Weisskopf, M. C.; Darbro, W.; Ramsey, B. D.; Williams, A. C.

    1986-01-01

    The bright galactic bulge X-ray source GX 5 - 1 was observed in April 1979 with the Monitor Proportional Counter on board the Einstein (HEAO 2) Observatory. Analysis of the high time resolution data from the Time Interval Processor confirms the recent Exosat discovery of quasi-periodic oscillations in the X-ray emission from GX 5 - 1. In addition, the summed 0.4 s power spectrum shows the low-frequency red noise component also discovered in the Exosat data. Low-frequency structure is also clearly present in data taken from the bright galaxtic X-ray source Cyg X-2 in December 1978. The expected power spectrum for quasi-periodic oscillations was calculated, including the low-frequency red noise component, using a simple shot noise model with oscillating shots.

  7. Distributed Data Integration Prototype System for Coordinated Enhanced Observing Period (CEOP) Data

    NASA Astrophysics Data System (ADS)

    Miura, S. H.; Aizawa, K.

    2006-12-01

    The purpose of the JAXA Prototype for CEOP Distributed Data Integration Service is to provide user-friendly access to the CEOP (in-situ, satellite and global gridded model output) data. The system is distributed in the sense that, while the system is located in Tokyo, the data is located in archive centers which are globally distributed. The in-situ data is archived at the National Center for Atmospheric Research (NCAR) Earth Observing Laboratory (EOL) in Boulder, Colorado, USA. The NWP global gridded model output data is archived at the Max Planck Institute for Meteorology (MPIM) in cooperation with the World Data Center for Climate (WDC-Climate) in Hamburg, Germany. The satellite data is archived at the IIS (Institute of Industrial Science) at the University of Tokyo, in Tokyo, Japan. Other (non-CEOP) globally distributed data that is on DODS servers can be added in the future according to scientist's requests. The system is integrated in the sense that all of the data is temporally and geospatially coordinated and can be selected and viewed within the same system. The in-situ data are time series data and the global gridded model output data and satellite data are 4D (time series of 2D scenes at levels or in multiple frequency bands). The system knows the geolocation and time of all data sets and supports selection of the data through a uniform set of menus, by data type, reference site and station, and supports sub-setting according to time, area and height/depth. The basic concept for developing the JAXA prototype is " to use existing software where possible". Based on this concept, OPeNDAP, which is widely used in the ocean and atmospheric sciences, was chosen as the data access protocol to enable "access to distributed data". And also the open source Live Access Serve (LAS) was selected as the JAXA Prototype component to enable "integration service". Users can access the system at http://jaxa.ceos.org/wtf_ceop. This system has been online since June 1, 2005 and has more than 90 registered users as of July, 2006 (The site requires a brief registration to satisfy the CEOP data policy of keeping a record of users who receive CEOP data.). All in-situ data is available on the system while satellite and global gridded model output data are being added steadily. When fully established the system should include over 1,000,000 scenes of satellite data contributed by JAXA, NASA, ESA and Eumetsat, and a total of over 40-50 Terabytes of integrated in-situ, satellite and global gridded model output data.

  8. 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.

  9. 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.

  10. Occurrence of blowing snow events at an alpine site over a 10-year period: Observations and modelling

    NASA Astrophysics Data System (ADS)

    Vionnet, V.; Guyomarc'h, G.; Naaim Bouvet, F.; Martin, E.; Durand, Y.; Bellot, H.; Bel, C.; Puglièse, P.

    2013-05-01

    Blowing snow events control the evolution of the snow pack in mountainous areas and cause inhomogeneous snow distribution. The goal of this study is to identify the main features of blowing snow events at an alpine site and assess the ability of the detailed snowpack model Crocus to reproduce the occurrence of these events in a 1D configuration. We created a database of blowing snow events observed over 10 years at our experimental site. Occurrences of blowing snow events were divided into cases with and without concurrent falling snow. Overall, snow transport is observed during 10.5% of the time in winter and occurs with concurrent falling snow 37.3% of the time. Wind speed and snow age control the frequency of occurrence. Model results illustrate the necessity of taking the wind-dependence of falling snow grain characteristics into account to simulate periods of snow transport and mass fluxes satisfactorily during those periods. The high rate of false alarms produced by the model is investigated in detail for winter 2010/2011 using measurements from snow particle counters.

  11. FASTSAT-HSV01 synergistic observations of the magnetospheric response during active periods: MINI-ME, PISA and TTI

    NASA Astrophysics Data System (ADS)

    Casas, Joseph; Collier, Michael; Rowland, Douglas; Sigwarth, John; Boudreaux, Mark

    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 understand-ing 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 tech-niques and achieve necessary coordinated observation missions, NASA's Fast Affordable Sci-ence and Technology Satellite Huntsville 01 mission (FASTSAT-HSV01) scheduled for launch in 2010 will afford a highly synergistic solution which satisfies payload mission opportunities and launch requirements as well as contributing in 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 spec-trometer, 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.

  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. 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

  14. 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 Muḥy? al-D?n al-Maghrib?; 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 Jamsh?d Ghiy?th al-D?n al-K?sh? from K?sh?n (in central Iran). The results are that al-Maghrib?'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-K?sh?'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-Maghrib? achieved r = 5;12 and al-K?sh? 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.

  15. Suggestion Reduces the Stroop

    Microsoft Academic Search

    Irving Kirsch; Jessica Pollard; Yael Nitkin-Kaner

    We examined the effects of suggestion on Stroop interference in highly suggestible individuals. Participantscompleted the Stroop task with and without a suggestion to perceive Stroop words as meaningless sym- bols. Half the participants were given this suggestion in hypnosis, and half were given the suggestion without the induction of hypnosis. Suggestion produced a significant reduction in Stroop inhibition, accounting for

  16. 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.

  17. 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

  18. 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.

  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. 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.

  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. 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, É.; 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.

  3. 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.; Berresheim, H.; Elste, T.; Plass-Dülmer, C.; Stange, G.; Kleffmann, J.; Elshorbany, Y.; Schurath, U.

    2012-03-01

    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. This also indicates an overprediction of the HO2 to OH recycling. Together with the good model-measurement agreement for OH, it implies a missing OH source in the model. Modeled OH and HO2(*) could only be matched to the observations by addition of a strong unknown loss process for HO2(*) that recycles OH at a high yield. Adding to the base model, instead, the recently proposed isomerization mechanism of isoprene peroxy radicals (Peeters and Müller, 2010) increased OH and HO2(*) by 28% and 13% on average. Although these were 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. The overestimation in OH could be diminished only when reactive alkanes (HC8) were solely introduced to the model to explain the missing fraction of observed OH reactivity. Moreover, the overprediction of HO2(*) became even larger than in the base case. These analyses imply that the rates of the isomerization are not readily supported by the ensemble of radical 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.

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

    The main hydrological signal in gravity recordings by superconducting gravimeters (SGs) is typically seasonal. At the Metsähovi 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 Metsähovi 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.

  5. 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.

  6. 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.

  7. 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.

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

    PubMed

    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 phase-a phase where nongrowing bacteria can be quantitatively studied over several days in a reproducible manner-should contribute to a better understanding of this ubiquitous but overlooked physiological state of bacteria in nature. PMID:24344288

  9. Interannual variability of surface heat fluxes in the Adriatic Sea in the period 1998-2001 and comparison with observations.

    PubMed

    Chiggiato, Jacopo; Zavatarelli, Marco; Castellari, Sergio; Deserti, Marco

    2005-12-15

    Surface heat fluxes of the Adriatic Sea are estimated for the period 1998-2001 through bulk formulae with the goal to assess the uncertainties related to their estimations and to describe their interannual variability. In addition a comparison to observations is conducted. We computed the components of the sea surface heat budget by using two different operational meteorological data sets as inputs: the ECMWF operational analysis and the regional limited area model LAMBO operational forecast. Both results are consistent with previous long-term climatology and short-term analyses present in the literature. In both cases we obtained that the Adriatic Sea loses 26 W/m2 on average, that is consistent with the assessments found in the literature. Then we conducted a comparison with observations of the radiative components of the heat budget collected on offshore platforms and one coastal station. In the case of shortwave radiation, results show a little overestimation on the annual basis. Values obtained in this case are 172 W/m2 when using ECMWF data and 169 W/m2 when using LAMBO data. The use of either Schiano's or Gilman's and Garrett's corrections help to get even closer values. More difficult is to assess the comparison in the case of longwave radiation, with relative errors of an order of 10-20%. PMID:16318867

  10. 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.; García, R. A.; Turck-Chièze, S.; Jiménez, 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.

  11. Pulsations and Period Changes of the Non-Blazhko RR Lyrae Variable Y Oct Observed from Dome A, Antarctica

    NASA Astrophysics Data System (ADS)

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

    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-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, MV = 0.696 ± 0.014 mag, V-K = 1.182 ± 0.028 mag, log {{T}eff} = 3.802 ± 0.003 K, log g = 2.705 ± 0.004, log L/{{L}? } = 1.625 ± 0.013, and log M/{{M}? } = -0.240 ± 0.019.

  12. Correction of humidity bias for Vaisala RS80-A and MODEM sondes during AMMA 2006 observing period

    NASA Astrophysics Data System (ADS)

    Nuret, M.; Lafore, J. P.; Bock, O.; Guichard, F.

    2009-04-01

    During the African Monsoon Multidisciplinary Analyses (AMMA) program whose Special Observing Period took place over West Africa in 2006, a major effort has been devoted to monitor the atmosphere and its water cycle. The radiosoundings network has been upgraded and enhanced, and GPS receivers deployed. The various sondes used in the campaign exhibit a significant humidity bias: • dry bias for Vaisala RS80-A at daytime and nighttime, for RS92 and MODEM M2K2 at daytime only • moist bias for MODEM M2K2 and Vaisala RS92 at nighttime This presentation makes use of a simple but robust statistical approach to correct the bias. Validation against independent GPS data shows that a first correction (to be implemented in the database in early 2009), removes the night bias for MODEM and Vaisala RS-80A, and strongly reduces it for daytime RS80-A launches. The correction dramatically modifies the CAPE, which becomes much more in line with expected values over the region. A second correction (under development) will address the remaining daytime bias, thanks to an inter-comparison exercise performed in Niamey in September 2008.

  13. 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.

  14. Intestinal stoma in patients with colorectal cancer from the perspective of 20-year period of clinical observation

    PubMed Central

    Banaszkiewicz, Zbigniew; Woda, ?ukasz P.; Tojek, Krzysztof; Jarmocik, Pawe?; Jawie?, Arkadiusz

    2015-01-01

    Introduction Intestinal stoma is a procedure most often performed in patients with colorectal cancer. Aim To identify the percentage of patients with colorectal cancer in which the intestinal stoma was performed. Material and methods We retrospectively analysed 443 patients treated during a 20-year period (1994–2013) due to colorectal cancer, in which the intestinal stoma was made during the first surgical intervention. Results In the second analysed decade, a significant decrease in the percentage of created stomas, definitive stomas in particular, was observed. Stomas were made significantly more often in patients with a tumour located in the rectum, the left half of the colon, and in patients undergoing urgent surgeries. An increased incidence of intestinal stomas was associated with a higher severity of illness and higher proportion of unresectable and non-radical procedures. The definitive stomas were significantly more often made in men and in patients with tumours located in the rectum, whereas temporary stomas were created significantly more often in patients undergoing urgent operations. Conclusions In the last decade (2004–2013) the number of intestinal stomas in patients operated due to colorectal cancer was significantly reduced. PMID:25960811

  15. 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…

  16. Observations of SMC X-1 with the monitor proportional counter on the Einstein /HEAO 2/ X-ray Observatory - The pulse period and its history

    NASA Technical Reports Server (NTRS)

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

    1981-01-01

    The results of the sixth determination of the pulse period of the X-ray source SMC X-1 are presented. The observations were made in April 1979. The pulse period at this epoch was found to be (0.713683 + or - 0.000032) s referred to phase zero of the binary motion. This result together with all available historical data is utilized to quantify the observed trend toward spin-up. It is found that simple secular trends are not applicable. This finding is interpreted as evidence for additional variations in the pulse period. The obtained results are discussed in the context of present theoretical models for period variations in the binary pulsating X-ray sources. The apparent absence of spin-down episodes in the period history of SMC X-1 is also considered.

  17. 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

  18. 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.

  19. 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 [Department of Astronomy, Beijing Normal University, Beijing 100875 (China); M, Macri Lucas; Lifan, Wang [Mitchell Institute for Fundamental Physics and Astronomy, Department of Physics and Astronomy, Texas A and M University, College Station, TX (United States); Ashley, Michael C. B.; S, Lawrence Jon; Daniel, Luong-Van [School of Physics, University of New South Wales, NSW (Australia); Xiangqun, Cui; Long-Long, Feng; Xuefei, Gong; Qiang, Liu; Huigen, Yang; Xiangyan, Yuan; Xu, Zhou; Zhenxi, Zhu [Chinese Center for Antarctic Astronomy, Nanjing (China); R, Pennypacker Carl [Center for Astrophysics, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); G, York Donald, E-mail: jnfu@bnu.edu.cn [Department of Astronomy and Astrophysics and Enrico Fermi Institute, University of Chicago, Chicago, IL (United States)

    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.

  20. Origin of transient self-potential signals associated with very long period seismic pulses observed during the 2000 activity of Miyakejima volcano

    NASA Astrophysics Data System (ADS)

    Kuwano, Osamu; Yoshida, Shingo; Nakatani, Masao; Uyeshima, Makoto

    2015-05-01

    Origin of the previously reported transient geoelectrical (self-potential, SP) signals in the Miyakejima 2000 activity, that repeatedly occurred concurrently with very long period (VLP) seismic pulses, was investigated. SP waveforms stacked across repeated VLP events showed a step-like rise followed by a gradual decay at all stations spread over the island of 8 km diameter. Within a realistic range of hydrological diffusivity, the short time constants of the SP signals cannot be explained by the electrokinetic effect caused by fluid flow within a limited volume, proposed earlier as a fluid injection hypothesis. On the other hand, poroelasticity predicts an island-wide distributed flow field to occur almost instantaneously upon VLP events due to the step of strain field imposed by the mechanical event. We propose that the observed SP signals resulted from the streaming current by this island-wide flow field. Our quantitative model, assuming a vertical tensile crack as a mechanical source, which has been suggested by preceding seismic studies, can explain the time constants and the amplitude of the SP signals (both spatial pattern and absolute amplitude), within a reasonable range of rock properties and the scalar moment of the mechanical source (VLP event). Location and attitude of the mechanical source were well constrained by grid search and are consistent with those estimated earlier from other types of data.

  1. Whole Earth Telescope Observations of the subdwarf B star KPD 1930+2752: A rich, short period pulsator in a close binary

    Microsoft Academic Search

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

    2010-01-01

    KPD 1930+2752 is a short-period pulsating subdwarf B (sdB) star. It is also\\u000aan ellipsoidal variable with a known binary period just over two hours. The\\u000acompanion is most likely a white dwarf and the total mass of the system is\\u000aclose to the Chandresakhar limit. In this paper we report the results of Whole\\u000aEarth Telescope (WET) photometric observations

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

    Microsoft Academic Search

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

    2011-01-01

    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

  3. A Period Distribution of X-Ray Binaries Observed in the Central Region of M31 with Chandra and the Hubble Space Telescope

    NASA Astrophysics Data System (ADS)

    Barnard, R.; Galache, J. L.; Garcia, M. R.; Nooraee, N.; Callanan, P. J.; Zezas, A.; Murray, S. S.

    2012-09-01

    Almost all Galactic black hole (BH) binaries with low-mass donor stars are transient X-ray sources; we expect most of the X-ray transients observed in external galaxies to be BH binaries also. Obtaining period estimates for extragalactic transients is challenging, but the resulting period distribution is an important tool for modeling the evolution history of the host galaxy. We have obtained periods, or upper limits, for 12 transients in M31, using an updated relation between the optical and X-ray luminosities. We have monitored the central region of M31 with Chandra for the last ~12 years, and followed up promising transients with the Hubble Space Telescope; 4? B-magnitude limits for optical counterparts are 26-29, depending on crowding. We obtain period estimates for each transient for both neutron star and BH accretors. Periods range from <0.4 to 490 ± 90 hr (<0.97 to <175 hr if all are BH systems). These M31 transients appear to be somewhat skewed toward shorter periods than the Milky Way (MW) transients; indeed, comparing the M31 and MW transients with survival analysis techniques used to account for some data with only upper limits yields probabilities of ~0.02-0.08 that the two populations are drawn from the same distribution. We also checked for a correlation between orbital period and distance from the nucleus, finding a 12% probability of no correlation. Further observations of M31 transients will strengthen these results.

  4. 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.

  5. 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.

  6. Drift Effects and the Cosmic Ray Density Gradient in a Solar Rotation Period: First Observation with the Global Muon Detector Network (GMDN)

    Microsoft Academic Search

    Y. Okazaki; A. Fushishita; T. Narumi; C. Kato; S. Yasue; T. Kuwabara; J. W. Bieber; P. Evenson; M. R. Da Silva; A. Dal Lago; N. J. Schuch; Z. Fujii; M. L. Duldig; J. E. Humble; I. Sabbah; J. Kóta; K. Munakata

    2008-01-01

    We present for the first time hourly variations of the spatial density gradient of 50 GeV cosmic rays within a sample solar rotation period in 2006. By inversely solving the diffusive flux equation, including the drift, we deduce the gradient from the anisotropy that is derived from the observation made by the Global Muon Detector Network (GMDN). The anisotropy obtained

  7. Program Stars and Stellar Parameters Table. 1: Stellar parameters of the observed stars: spectral type (SpT), vsin(i) and photometric period

    E-print Network

    Complutense de Madrid, Universidad

    for spectroscopic binaries (singled lined (1) and double lined (2)) and T for triple star systems. The numberProgram Stars and Stellar Parameters Table. 1: Stellar parameters of the observed stars: spectral type (SpT), vsin(i) and photometric period (Pphot). The remark is -- for single stars, SB

  8. 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.

  9. 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.

  10. 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

  11. Inner magnetosphere variations after solar proton events. Observations on Mir space station in 1989-1994 time period.

    PubMed

    Dachev TsP; Semkova, J V; Matviichuk YuN; Tomov, B T; Koleva, R T; Baynov, P T; Petrov, V M; Shurshakov, V V; Ivanov, Y u

    1998-01-01

    Measurements on board the Mir space station have been used to study the dose rate and the particle flux distribution in the inner magnetosphere. The measurements have been performed with the Bulgarian-Russian dosimeter-radiometer Liulin. The paper concentrates on the dynamics of the observed "new" and "second" maxima which were created after Solar Proton Events (SPE) in the 1989-1994 time. The "second" belt was first observed after the SPE on October 20, 1989, and the last observation was after the SPE on February 20, 1994. The creation of the "new" belt is a unique phenomena seen in the Liulin data set after the SPE on March 23, 1991 and relates to the magnetic storm on March 24. The new belt fully disappears in the middle of 1993. PMID:11542781

  12. The winter anomaly in the middle-latitude F region during the solar minimum period observed by the Constellation Observing System for Meteorology, Ionosphere, and Climate

    Microsoft Academic Search

    W. K. Lee; H. Kil; Y.-S. Kwak; Q. Wu; S. Cho; J. U. Park

    2011-01-01

    The winter anomaly (or seasonal anomaly) at middle latitudes is a phenomenon during which the daytime plasma density at the F-peak height (NmF2) is greater in winter than in summer. Radio occultation measurements from the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) satellites provide a new data source for study of the winter anomaly on a global scale.

  13. 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 ?g C m(-3) (11.5-24.3), 9.4 ?g C m(-3) (7.0-12.7), and 1.2 ?g 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

  14. XMM-Newton observations of three short period polars: V347 Pav, GG Leo and EU UMa

    E-print Network

    Gavin Ramsay; Mark Cropper; K. O. Mason; F. A. Cordova; W. Priedhorsky

    2003-09-03

    We present phase-resolved XMM_Newton data of three short period polars: V347 Pav, GG Leo and EU UMa. All three systems show one dominant accretion region which is seen for approximately half of the orbital cycle. GG Leo shows a strong dip feature in its X-ray and UV light curves which is due to absorption of X-rays from the accretion site by the accretion stream. The emission in the case of EU UMa is dominated by soft X-rays: its soft/hard X-ray ratio is amongst the highest seen in these objects. In contrast, GG Leo and V347 Pav shows a ratio consistent with that predicted by the standard shock model. We infer the mass of the white dwarf and explore the affect of restricting the energy range on the derived parameters.

  15. 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 [Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Lim, Do Hoon [Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Lee, Jeeyun [Division of Hematology-Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Kang, Won Ki [Division of Hematology-Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)]. E-mail: wkkang@smc.samsung.co.kr; MacDonald, John S. [Gastrointestinal Oncology Service, Saint Vincent's Comprehensive Cancer Center, New York, NY (United States); Park, Chan Hyung [Center for the Improvement of Human Functioning International, Inc., Wichita, KS (United States); Park, Se Hoon [Division of Hematology-Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Lee, Se-Hoon [Division of Hematology-Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Kim, Kihyun [Division of Hematology-Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Park, Joon Oh; Kim, Won Seog; Jung, Chul Won; Park, Young Suk; Im, Young-Hyuck [Division of Hematology-Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Sohn, Tae Sung; Noh, Jae Hyung; Heo, Jin Seok; Kim, Yong Il [Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Park, Chul Keun [Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Park, Keunchil [Division of Hematology-Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    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.

  16. Comparison of modeled electron densities and electron and ion temperatures with Arecibo observations during undisturbed and geomagnetic storm periods of 7–11 September 2005

    Microsoft Academic Search

    A. V. Pavlov; N. M. Pavlova

    2011-01-01

    The electron density and the electron and ion temperatures measured by the Arecibo radar at 496 km altitude and NmF2 observed by the Puerto Rico ionosonde are compared with those produced by the model of the ionosphere and plasmasphere to study the time-dependent response of the ionosphere to geomagnetic forcing during the undisturbed and geomagnetic storm periods of 7–11 September

  17. Relationship between dominant periods of H/V of coda waves observed by MeSO-net and underground velocity structures in the Tokyo metropolitan area

    NASA Astrophysics Data System (ADS)

    Tsuno, S.; Yamanaka, H.; Sakai, S.; Hirata, N.; Kasahara, K.; Kimura, H.; Aketagawa, T.

    2010-12-01

    Recently, the high-density seismic observation network installed at more than 200 stations, called MeSO-net (Sakai and Hirata, 2009), have been being installed at an interval distance of about 5 km in the Tokyo metropolitan area. By comparing numerical predictions with earthquake ground motions observed by MeSO-net, we found that the previous 3-D underground velocity structural model in the Tokyo metropolitan area (Yamanaka and Yamada, 2006) was still not constrained enough to accurately predict the observed earthquake ground motions for long-periods. Therefore, to improve the 3-D underground velocity structural model especially for bedrock and/or a deep boundary between layers, we evaluated the relationship between dominant periods of H/V of earthquake ground motions observed by MeSO-net and underground velocity structures in the Tokyo metropolitan area. At first, we verified the stability of H/V of earthquake ground motions by applying a time-frequency analysis and understanding the differences of H/V calculated by several earthquake recording data. The results of those processes showed that coda waves were mainly composed of surface waves consisting of both Rayleigh waves and Love waves. The variability of H/V of coda waves induced by 9 earthquakes larger than M6.5 was quite small. Consequently, we concluded that dominant periods of H/V of coda waves would be useful for creating a 3-D underground velocity structural model to predict long-period ground motions. However, Love waves are contained in horizontal components as well as Rayleigh waves. In the case of using the amplitudes of H/V of coda waves, we would need to apply a radial component of coda waves for calculations of H/V to avoid the effect of Love waves. Finally, we compared dominant periods of H/V of coda waves obtained by MeSO-net with the velocity structures in the Tokyo metropolitan area (Yamanaka and Yamada, 2006). The dominant periods of H/V matched well for sites where shallow basin structures are located; however, dominant periods of H/V didn’t match well for sites where deep basin structures are located. In Yamanaka and Yamada’s model, which is based on phase velocities of Rayleigh waves obtained by array microtremors observations, there are still uncertainties in the data obtained from deep basin structures when phase velocities for long-periods are not obtained by array microtremors recording data. As a next step, we aim to improve the velocity structural model in the Tokyo metropolitan area, by applying the inversion of ellipticities of Rayleigh waves for H/V of coda waves observed by MeSO-net. Also, we will simulate long-periods of strong ground motions in the area, using the improved velocity structural model.

  18. Accelerating observers measure the period of the oscillations taking place in an acoustic wave (non-longitudinal case)

    E-print Network

    Popescu, S; Popescu, Stefan; Rothenstein, Bernhard

    2006-01-01

    We consider a scenario that involves a stationary source of acoustic waves located at the origin of the K(XOY) inertial reference frame and a receiver that performs the hyperbolic motion at a constant altitude. The observer measures the proper reception time of successive wave crests. We investigate its dependence on the propagation speed of the wave and on the altitude at which the motion takes place.

  19. Accelerating observers measure the period of the oscillations taking place in an acoustic wave (non-longitudinal case)

    E-print Network

    Stefan Popescu; Bernhard Rothenstein

    2006-08-01

    We consider a scenario that involves a stationary source of acoustic waves located at the origin of the K(XOY) inertial reference frame and a receiver that performs the hyperbolic motion at a constant altitude. The observer measures the proper reception time of successive wave crests. We investigate its dependence on the propagation speed of the wave and on the altitude at which the motion takes place.

  20. 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.

  1. Observed changes in the albedo of the Arctic sea-ice zone for the period 1982-2009

    NASA Astrophysics Data System (ADS)

    Riihelä, Aku; Manninen, Terhikki; Laine, Vesa

    2013-10-01

    The surface albedo of the Arctic sea-ice zone is a crucial component in the energy budget of the Arctic region. The treatment of sea-ice albedo has been identified as an important source of variability in the future sea-ice mass loss forecasts in coupled climate models. There is a clear need to establish data sets of Arctic sea-ice albedo to study the changes based on observational data and to aid future modelling efforts. Here we present an analysis of observed changes in the mean albedo of the Arctic sea-ice zone using a data set consisting of 28 years of homogenized satellite data. Along with the albedo reduction resulting from the well-known loss of late-summer sea-ice cover, we show that the mean albedo of the remaining Arctic sea-ice zone is decreasing. The change per decade in the mean August sea-ice zone albedo is -0.029+/-0.011. All albedo trends, except for the sea-ice zone in May, are significant with a 99% confidence interval. Variations in mean sea-ice albedo can be explained using sea-ice concentration, surface air temperature and elapsed time from onset of melt as drivers.

  2. Electrochemical Periodicities

    Microsoft Academic Search

    J. A. V. Butler; G. Armstrong

    1932-01-01

    IN the course of experiments on the anodic polarisation of platinum electrodes in dilute sulphuric acid solutions saturated with hydrogen, we have observed, at small current densities, some striking periodicities. The change of potential difference with time in a typical experiment is shown in Fig. 1. In this case the electrode potential falls continuously with a marked break at EH

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

    E-print Network

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

    2015-01-01

    Magnetic cataclysmic variables are close binary systems containing a strongly magnetized white dwarf that accretes matter coming from an M-dwarf companion. High-energy radiation coming from those objects is emitted from the accretion 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. 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. 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. The oscillation frequencies and amplitudes in the X-ray and optic...

  4. 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.

  5. 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.

  6. Hard X-ray pulse profile and period evolution of AO535 + 26 and GX 1 + 4 as observed by the Franco-Soviet Signe satellite experiments

    NASA Astrophysics Data System (ADS)

    Refloch, A.; Chambon, G.; Niel, M.; Vedrenne, G.; Rakhmaninov, Ch. Iu.

    1986-11-01

    The source GX 1 + 4 and an outburst from the recurrent X-ray transient A0535+26 were observed in 1977 December by collimated detectors aboard the Prognoz 6 satellite (Signe 2MP experiment) in the energy range 28-308 keV and aboard the Signe 3 satellite between 27 and 108 keV. The temporal evolution of the pulsation period of these sources (107.22 s and 103.89 s respectively), the variations of the pulsed and total fluxes, and the light curves are given. A temporary disk model for A0535+26 is proposed.

  7. XMM-Newton EPIC and OM Observations of Her X-1 over the 35 d Beat Period and an Anomalous Low State

    E-print Network

    S. Zane; G. Ramsay; M. A. Jimenez-Garate; J. W. den Herder; M. Still; P. T. Boyd; C. J. Hailey

    2005-03-10

    We present the results of a series of XMM-Newton EPIC and OM observations of Her X-1, spread over a wide range of the 35 d precession period. We confirm that the spin modulation of the neutron star is weak or absent in the low state - in marked contrast to the main or short-on states. The strong fluorescence emission line at ~6.4 keV is detected in all observations (apart from one taken in the middle of eclipse), with higher line energy, width and normalisation during the main-on state. In addition, we report the detection of a second line near 7 keV in 10 of the 15 observations taken during the low-intensity states of the system. We discuss these observations in the context of previous observations, investigate the origin of the soft and hard X-rays and consider the emission site of the 6.4keV and 7keV emission lines.

  8. Explorer 45 (S 3-A) observations of the magnetosphere and magnetopause during the 4-5 August 1972, magnetic storm period

    NASA Technical Reports Server (NTRS)

    Hoffman, R. A.; Cahill, L. J., Jr.; Anderson, R. R.; Maynard, N. C.; Smith, P. H.; Fritz, T. A.; Williams, D. J.; Konradi, A.; Gurnett, D. A.

    1974-01-01

    The Explorer 45 satellite performed extensive field and particle measurements in the heart of the magnetosphere during the double magnetic storm period of August 4-5, 1972. Both ground level magnetic records and the magnetic field deformations measured along the orbit by the satellite indicated the existence of only a moderate ring current. This was confirmed by the measurements of the total proton energy density less than those observed during the December 1971 and June 1972 magnetic storms. The plasmapause in the noon quadrant was eroded continuously from the onset of the first storm at the beginning of August 4 to an altitude below L = 2.07 at about 18 hours on August 5. During the orbit containing the second sudden commencement a large amount of low frequency electric and magnetic field noise was encountered throughout the entire orbit. A noteworthy observation during this orbit was the contraction of the magnetopause to distances inside the satellite at L = 5.2.

  9. Swift X-ray and ultraviolet observations of the shortest orbital period double-degenerate system RX J0806.3+1527 (HM Cnc)

    E-print Network

    Esposito, P; Dall'Osso, S; Covino, S

    2013-01-01

    RX J0806.3+1527 (HM Cnc) is a pulsating X-ray source with 100 per cent modulation on a period of 321.5 s (5.4 min). This period reflects the orbital motion of a close binary system consisting of two interacting white dwarfs. Here we present a series of simultaneous X-ray (0.2-10 keV) and near-ultraviolet (2600 angstrom and 1928 angstrom) observations carried out with the Swift satellite. In the near-ultraviolet the counterpart of RX J0806.3+1527 was detected at flux densities consistent with a blackbody with temperature 27E+3 K. We found that the emission at 2600 angstrom is modulated at the 321.5-s period, with the peak ahead of the X-ray one by 0.28 cycles and coincident, within 0.05 cycles, with the optical. This phase-shift measurement confirms that the X-ray hot spot (located on the primary white dwarf) is at about 80-100 degrees from the direction connecting the two white dwarfs. Albeit at lower significance, the 321.5-s signature is present also in the 1928-angstrom data; at this wavelength, however, t...

  10. 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.

  11. Swift X-ray and ultraviolet observations of the shortest orbital period double-degenerate system RX J0806.3+1527 (HM Cnc)

    NASA Astrophysics Data System (ADS)

    Esposito, Paolo; Israel, Gian Luca; Dall'Osso, Simone; Covino, Stefano

    2014-01-01

    The system RX J0806.3+1527 (HM Cnc) is a pulsating X-ray source with 100 per cent modulation on a period of 321.5 s (5.4 min). This period reflects the orbital motion of a close binary consisting of two interacting white dwarfs. Here we present a series of simultaneous X-ray (0.2-10 keV) and near-ultraviolet (2600 Å and 1928 Å) observations that were carried out with the Swift satellite. In the near-ultraviolet, the counterpart of RX J0806.3+1527 was detected at flux densities consistent with a blackbody with a temperature of (27 ± 8) × 103 K. We found that the emission at 2600 Å is modulated at the 321.5-s period with the peak ahead of the X-ray one by 0.28 ± 0.02 cycles and is coincident within ± 0.05 cycles with the optical. This phase-shift measurement confirms that the X-ray hot spot (located on the primary white dwarf) is at about 80°-100° from the direction that connects the two white dwarfs. Albeit at lower significance, the 321.5-s signature is also present in the 1928-Å data; at this wavelength, however, the pulse peak is better aligned with that observed at X-rays. We use the constraints on the source luminosity and the geometry of the emitting regions to discuss the merits and limits of the main models for RX J0806.3+1527.

  12. Quasi-Periodic Oscillations in Short Recurring Bursts of the magnetars SGR 1806-20 and SGR 1900+14 Observed With RXTE

    E-print Network

    Huppenkothen, D; Watts, A L; Gö?ü?, E

    2014-01-01

    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 the Rossi X-ray Timing Explorer (RXTE). We find a single detection in an averaged periodogram comprising 30 bursts from SGR 1806-20, 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 the giant flare QPOs. Additionally, we uncover a limit on the applicability of Fourier analysis for light curves with low background count rates and s...

  13. Quasi-periodic Oscillations in Short Recurring Bursts of Magnetars SGR 1806-20 and SGR 1900+14 Observed with RXTE

    NASA Astrophysics Data System (ADS)

    Huppenkothen, D.; Heil, L. M.; Watts, A. L.; Gö?ü?, E.

    2014-11-01

    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 1806-20, 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.

  14. Aerosol direct radiative forcing over Djougou (northern Benin) during the African Monsoon Multidisciplinary Analysis dry season experiment (Special Observation Period-0)

    NASA Astrophysics Data System (ADS)

    Mallet, M.; Pont, V.; Liousse, C.; Gomes, L.; Pelon, J.; Osborne, S.; Haywood, J.; Roger, J. C.; Dubuisson, P.; Mariscal, A.; Thouret, V.; Goloub, P.

    2008-12-01

    The purpose of this work is to investigate the direct radiative forcing of aerosols over the supersite of Djougou (northern Benin) during the African Monsoon Multidisciplinary Analyses dry season experiment. We focus our simulations on the top of atmosphere, bottom of atmosphere, and atmosphere radiative forcings. During the dry season period, Sun photometer measurements indicate a rather turbid atmosphere with a mean aerosol optical depth for the overall period of 0.78 ± 0.24 (at 440 nm). The aerosol absorption coefficient estimated at the surface ranged between 2.3 and 37.3 Mm-1 (mean value 15.2 ± 10.6 Mm-1 at 520 nm) and the scattering coefficient between 44.5 and 232.3 Mm-1 (mean 145 ± 59 Mm-1 at 520 nm). This leads to a single scattering albedo of between 0.81 and 0.98 (at 520 nm) with a mean (and standard deviation) value of 0.91 ± 0.05, indicating moderately absorbing aerosols. In parallel, micropulse lidar measurements indicate the presence of two distinct aerosol layers, with a first one located between the surface and 1 km and a second one located above 1.5-4.0 km. On the basis of surface and aircraft observations, sunphotometer measurements, lidar profiles, and Moderate Resolution Imagaing Spectroradiometer sensor an estimation of the daily clear sky direct radiative forcing has been estimated for the 17-24 January 2006 period. Simulations indicate that aerosols reduce significantly the solar energy reaching the surface (mean ?FBOA = -61.5 W/m2) by reflection to space (mean ?FTOA = -18.4 W/m2) but predominantly by absorption of the solar radiation into the atmosphere (mean ?FATM = +43.1 W/m2). The mean heating rate at the surface and within the elevated biomass burning layer is considerably enhanced by 1.50 and 1.90 K day-1, respectively.

  15. Suggestions for Early Motion Picture Research.

    ERIC Educational Resources Information Center

    Jowett, Garth S.

    Only by examining the motion picture as a mass medium, shaped and defined within a specific socio-cultural period in history, can we increase our understanding of the function and contribution of this entertainment form. This paper offers several suggestions for further research into early motion picture history. One glaring deficiency among…

  16. 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.

  17. The Promotion of Peace. I. Suggestions for the Observance of Peace Day (May 18) in Schools; II. Agencies and Associations for Peace. Bulletin, 1913, No. 12. Whole Number 519

    ERIC Educational Resources Information Center

    Andrews, Fannie Fern, Comp.

    1913-01-01

    Within the past few years the subjects of international peace and arbitration have come to have a place of importance in schools of all grades in the United States, and the interest in these subjects is increasing from year to year. As one means of fostering this interest many schools observe in a special way the 18th days of May, the anniversary…

  18. Explorer 45 /S3-A/ observations of the magnetosphere and magnetopause during the August 4-6, 1972, magnetic storm period

    NASA Technical Reports Server (NTRS)

    Hoffman, R. A.; Maynard, N. C.; Smith, P. H.; Cahill, L. J., Jr.; Anderson, R. R.; Gurnett, D. A.; Fritz, T. A.; Williams, D. J.; Konradi, A.

    1975-01-01

    The Explorer 45 (S3-A) satellite performed extensive field and particle measurements in the heart of the magnetosphere during the double magnetic storm period of August 4-6, 1972. Both the ground level magnetic records and the magnetic field deformations measured along the orbit by the satellite indicated the existence of only a moderate ring current. This was confirmed by the measurements of the total proton energy density by the on-board particle detectors, which showed a maximum energy density less than the densities observed during the December 1971 and June 1972 magnetic storms. The plasmapause in the noon quadrant was eroded continuously from the onset of the first storm at the beginning of August 4 to an altitude below L = 2.07 at about 1800 hours on August 5. Throughout the entire orbit during which the second sudden commencement occurred, a large amount of low-frequency electric and magnetic field noise was encountered. The most remarkable observation during this orbit was the contraction of the magnetopause to distances inside the satellite location at L = 5.2.

  19. The ~10 hour modulation of the relativistic electron spectrum as a result of the periodic motion of the Jovian outer magnetosphere layer: Ulysses observations

    NASA Astrophysics Data System (ADS)

    Anagnostopoulos, G. C.; Karanikola, I.; Marhavilas, P. K.

    2013-08-01

    We analyze relativistic (E>3 MeV) electron observations during the dayside inbound trajectory of Ulysses (day 33 to day 38, 1992) in the Jovian magnetosphere and we demonstrate that the continuous presence of a relativistic electron layer at higher north latitudes (Ulysses reached ~40° lat. during closest approach the planet). In particular, we evaluated the cross-B field anisotropy of relativistic (E>3 MeV) electrons intensity by the COSPIN/HET detector onboard Ulysses, and we found that between the times of plasma sheet crossings/approaches, when Ulysses was found far from the magnetodisc, at higher north latitudes, local increases in the relativistic electron intensity and intensity gradient in the northward direction were persistently observed. We also found that (1) the well known ~10 h separated relativistic electron spectral index peaks (spectral softening) and (2) the detection of relativistic electron intensity gradient in the northward direction are related phenomena. We infer that phenomenon 1 and 2 are explained by the ~10 h periodic upward-downward motion of the Jovian magnetosphere, and consequently of the outer magnetosphere relativistic electron layer. ?he above results extends earlier results for low energy electrons and energetic protons (Anagnostopoulos et al., 1998, 2001b) to relativistic electron phenomena, and provide strong evidence, for the first time, that the well known ~10 h rocking of the relativistic electron spectrum in the outer magnetosphere (the so called "clock phenomenon") is a spatial and not a temporal effect, as was earlier hypothesized (Simpson et al.,1992).

  20. Drift Effects and the Cosmic Ray Density Gradient in a Solar Rotation Period: First Observation with the Global Muon Detector Network (GMDN)

    NASA Astrophysics Data System (ADS)

    Okazaki, Y.; Fushishita, A.; Narumi, T.; Kato, C.; Yasue, S.; Kuwabara, T.; Bieber, J. W.; Evenson, P.; Da Silva, M. R.; Dal Lago, A.; Schuch, N. J.; Fujii, Z.; Duldig, M. L.; Humble, J. E.; Sabbah, I.; Kóta, J.; Munakata, K.

    2008-07-01

    We present for the first time hourly variations of the spatial density gradient of 50 GeV cosmic rays within a sample solar rotation period in 2006. By inversely solving the diffusive flux equation, including the drift, we deduce the gradient from the anisotropy that is derived from the observation made by the Global Muon Detector Network (GMDN). The anisotropy obtained by applying a new analysis method to the GMDN data is precise and free from atmospheric temperature effects on the muon count rate recorded by ground-based detectors. We find the derived north-south gradient perpendicular to the ecliptic plane is oriented toward the heliospheric current sheet (HCS; i.e., southward in the toward sector of the interplanetary magnetic field [IMF] and northward in the away sector). The orientation of the gradient component parallel to the ecliptic plane remains similar in both sectors, with an enhancement of its magnitude seen after the Earth crosses the HCS. These temporal features are interpreted in terms of a local maximum of the cosmic ray density at the HCS. This is consistent with the prediction of the drift model for the A<0 epoch. By comparing the observed gradient with the numerical prediction of a simple drift model, we conclude that particle drifts in the large-scale magnetic field play an important role in organizing the density gradient, at least in the present A<0 epoch. We also found that corotating interaction regions did not have such a notable effect. Observations with the GMDN provide us with a new tool for investigating cosmic-ray transport in the IMF.

  1. Long-period toroidal earth free oscillations from the great Sumatra-Andaman earthquake observed by paired laser extensometers in Gran Sasso, Italy

    NASA Astrophysics Data System (ADS)

    Park, J.; Amoruso, A.; Crescentini, L.; Boschi, E.

    2008-06-01

    Strain data recorded by two crossed laser extensometers operating in the Gran Sasso underground observatory recorded seismic free oscillations excited by the 2004 December 26 Sumatra-Andaman earthquake. The main source of instrumental noise can be mitigated by differencing data from the crossed strainmeter arms, so that the resulting differential strain data set offers an unprecedented resolution of the seismic toroidal free oscillations with periods T > 1000 s. We reconstruct the time evolution of selected free-oscillations for comparison with synthetic seismograms that include normal-mode coupling effects from Coriolis force, attenuation and ellipticity. Envelopes estimated for the Gran Sasso differential data set for free oscillations with period T < 1000 s (frequencies f > 1 mHz) are approximated adequately by a composite Centroid-Moment-Tensor (CMT) source with five subevents and an aggregate Mw = 9.3 moment-magnitude. Envelopes for several toroidal free oscillations with T > 1000 s are predicted less well. The amplitude of the rarely observed mode 0T2 is overpredicted at Gran Sasso by roughly a factor of two, and other modes are underpredicted. The amplitude discrepancy for 0T2 is confirmed at selected exceptionally low-noise seismic stations. Hypothetical explanations include a slow-slip component of the seismic moment release, errors in the composite-CMT source model, unmodelled coupling effects to Earth's secular modes and feedback from the Sumatra-Andaman tsunami on Indian Ocean coastlines. Of these hypotheses, either an extended-duration strain release or tsunami feedback seem most plausible. The viability of the tsunami-feedback mechansim deserves further investigation.

  2. 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

  3. 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

  4. 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.

  5. Drift effects and the cosmic ray density gradient in a solar rotation period: First observation with the Global Muon Detector Network (GMDN)

    E-print Network

    Okazaki, Y; Narumi, T; Kato, C; Yasue, S; Kuwabara, T; Bieber, J W; Evenson, P; Da Silva, M R; Lago, A Dal; Schuch, N J; Fujii, Z; Duldig, M L; Humble, J E; Sabbah, I; Kóta, J; Munakata, K

    2008-01-01

    We present for the first time hourly variations of the spatial density gradient of 50 GeV cosmic rays within a sample solar rotation period in 2006. By inversely solving the transport equation, including diffusion, we deduce the gradient from the anisotropy that is derived from the observation made by the Global Muon Detector Network (GMDN). The anisotropy obtained by applying a new analysis method to the GMDN data is precise and free from atmospheric temperature effects on the muon count rate recorded by ground based detectors. We find the derived north-south gradient perpendicular to the ecliptic plane is oriented toward the Helioshperic Current Sheet (HCS) (i.e. southward in the toward sector of the Interplanetary Magnetic Field (IMF) and northward in the away sector). The orientation of the gradient component parallel to the ecliptic plane remains similar in both sectors with an enhancement of its magnitude seen after the Earth crosses the HCS. These temporal features are interpreted in terms of a local m...

  6. Drift effects and the cosmic ray density gradient in a solar rotation period: First observation with the Global Muon Detector Network (GMDN)

    E-print Network

    Y. Okazaki; A. Fushishita; T. Narumi; C. Kato; S. Yasue; T. Kuwabara; J. W. Bieber; P. Evenson; M. R. Da Silva; A. Dal Lago; N. J. Schuch; Z. Fujii; M. L. Duldig; J. E. Humble; I. Sabbah; J. Kóta; K. Munakata

    2008-02-16

    We present for the first time hourly variations of the spatial density gradient of 50 GeV cosmic rays within a sample solar rotation period in 2006. By inversely solving the transport equation, including diffusion, we deduce the gradient from the anisotropy that is derived from the observation made by the Global Muon Detector Network (GMDN). The anisotropy obtained by applying a new analysis method to the GMDN data is precise and free from atmospheric temperature effects on the muon count rate recorded by ground based detectors. We find the derived north-south gradient perpendicular to the ecliptic plane is oriented toward the Helioshperic Current Sheet (HCS) (i.e. southward in the toward sector of the Interplanetary Magnetic Field (IMF) and northward in the away sector). The orientation of the gradient component parallel to the ecliptic plane remains similar in both sectors with an enhancement of its magnitude seen after the Earth crosses the HCS. These temporal features are interpreted in terms of a local maximum of the cosmic ray density at the HCS. This is consistent with the prediction of the drift model for the $AGMDN provide us with a new tool for investigating cosmic ray transport in the IMF.

  7. Summary of sonic boom rise times observed during FAA community response studies over a 6-month period in the Oklahoma City area

    NASA Astrophysics Data System (ADS)

    Maglieri, Domenic J.; Sothcott, Victor E.

    1990-04-01

    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.

  8. SUGGESTIONS FOR WEED CONTROL IN

    E-print Network

    Mukhtar, Saqib

    B-5038 10-98 SUGGESTIONS FOR WEED CONTROL IN PASTURES AND FORAGES Texas Agricultural Extension;4 Suggestions for Weed Control in Pastures and Forages Dr. Paul A. Baumann, Extension Weed Specialist Dr. David as a guide for controlling weeds in pasture and forages. Labeled rates and restrictions change constantly

  9. Rotation periods of 12 000 main-sequence Kepler stars: Dependence on stellar spectral type and comparison with v sin i observations

    NASA Astrophysics Data System (ADS)

    Nielsen, M. B.; Gizon, L.; Schunker, H.; Karoff, C.

    2013-09-01

    Aims: We aim to measure the starspot rotation periods of active stars in the Kepler field as a function of spectral type and to extend reliable rotation measurements from F-, G-, and K-type to M-type stars. Methods: Using the Lomb-Scargle periodogram we searched more than 150 000 stellar light curves for periodic brightness variations. We analyzed periods between 1 and 30 days in eight consecutive Kepler quarters, where 30 days is an estimated maximum for the validity of the PDC_MAP data correction pipeline. We selected stable rotation periods, i.e., periods that do not vary from the median by more than one day in at least six of the eight quarters. We averaged the periods for each stellar spectral class according to B - V color and compared the results to archival vsini data, using stellar radii estimates from the Kepler Input Catalog. Results: We report on the stable starspot rotation periods of 12 151 Kepler stars. We find good agreement between starspot velocities and vsini data for all F-, G- and early K-type stars. The 795 M-type stars in our sample have a median rotation period of 15.4 days. We find an excess of M-type stars with periods less than 7.5 days that are potentially fast-rotating and fully convective. Measuring photometric variability in multiple Kepler quarters appears to be a straightforward and reliable way to determine the rotation periods of a large sample of active stars, including late-type stars. Table 1 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/557/L10

  10. Hypnotic suggestion and cognitive neuroscience.

    PubMed

    Oakley, David A; Halligan, Peter W

    2009-06-01

    The growing acceptance of consciousness as a legitimate field of enquiry and the availability of functional imaging has rekindled research interest in the use of hypnosis and suggestion to manipulate subjective experience and to gain insights into healthy and pathological cognitive functioning. Current research forms two strands. The first comprises studies exploring the cognitive and neural nature of hypnosis itself. The second employs hypnosis to explore known psychological processes using specifically targeted suggestions. An extension of this second approach involves using hypnotic suggestion to create clinically informed analogues of established structural and functional neuropsychological disorders. With functional imaging, this type of experimental neuropsychopathology offers a productive means of investigating brain activity involved in many symptom-based disorders and their related phenomenology. PMID:19428287

  11. Time Series 14.1 Study Suggestions

    E-print Network

    Wardrop, Robert L.

    Chapter 14 Time Series 14.1 Study Suggestions Chapter 14 has a very modest goal, namely, to pro- vide a gentle introduction to the ideas of time series analysis. It is important to remember that autocorrelation and smoothing simply are descriptive techniques. In addition, since a time series is observational

  12. 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

  13. Period Cramps

    MedlinePLUS

    ... Games Kids' Medical Dictionary En Español What Other Kids Are Reading Girls and Puberty Boys and Puberty ... help push the blood out through a girl's vagina during her period . You probably know periods usually ...

  14. Betelgeuse Period Analysis Using VSTAR

    NASA Astrophysics Data System (ADS)

    Dempsey, F.

    2015-06-01

    (Abstract only) Betelgeuse was studied using the VSTAR software package and analysis of the observations in the AAVSO database. Period analysis derived a period of 376 days, in comparison with literature periods of 420 days using satellite UV data but significantly different from the VSX period of 2,335 days. The unique set of PEP observations of this star is also shown and advantage of PEP Johnson V observations is shown in comparison with the visual observations.

  15. Pressure-driven reconnection and quasi periodical oscillations in plasmas

    SciTech Connect

    Paccagnella, R., E-mail: roberto.paccagnella@igi.cnr.it [Consorzio RFX and Istituto Gas Ionizzati del Consiglio Nazionale delle Ricerche (CNR), Padova (Italy)

    2014-03-15

    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.

  16. 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.

  17. Ancient Crystals Suggest Earlier Ocean

    NSDL National Science Digital Library

    This report describes the findings of two scientists who studied the chemical makeup of crystals of zircon from rocks in Western Australia's Jack Hills. The zircon crystals are thought to be 4.5 billion years old, making them some of the oldest materials yet found on Earth. The ratios of oxygen isotopes found in the crystals suggest that conditions during the Hadean Eon, the first 500 million years of Earth's history when the crystals were formed, were cooler and wetter than previously thought. Links to a glossary are embedded in the text.

  18. A sunspot periodicity and the solar rotation

    NASA Technical Reports Server (NTRS)

    Knight, J. W.; Sturrock, P. A.; Schatten, K. H.

    1980-01-01

    A least squares power spectrum analysis of daily sunspot numbers for the last 122 years yielded a statistically significant peak at 12.0715 plus or minus .002 days period. This feature at 11.685 days (sidereal) of the sunspot spectrum is discussed in relation to the peak at 12.22 days (sidereal) which Dicke found in his oblateness data. The data is attributed to the Sun's core if the core rotates at either 12.0715 days or 24.1430 days period (synodic). It is suggested that spacecraft observations combined with correlative analysis of solar surface features between eastern and western hemispheres could further reveal a basic core periodicity. A Dicke type space oblateness experiment is discussed for providing better photospheric observations than a ground instrument to determine the core periodicity.

  19. 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.

  20. Periodic Table

    NSDL National Science Digital Library

    Using the Macromedia Shockwave Player, this American Chemical Society website offers three interactive periodic tables. Students can find the basic data on each element including its atomic radius, stable isotopes, melting point, and density in the first periodic table tab. The website identifies different elemental groups by color. Users can view the electron configuration by selecting elements on the periodic table in the second tab. The last tab offers plots of the elements' electronegativity, ionization energy, and other properties.

  1. 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.

  2. 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.

  3. Irregular Periods

    MedlinePLUS

    ... Date reviewed: October 2013 Back 1 ? 2 For Teens For Kids For Parents MORE ON THIS TOPIC Gyn Checkups I'm 14 and I Don't Have My Period Yet. Is This Normal? Can a Girl Get Pregnant if She Has Sex During Her Period? Birth Control Pill Coping With ...

  4. 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.

  5. Specific features of daytime long-period pulsations observed during the solar wind impulse against a background of the substorm of August 1, 1998

    NASA Astrophysics Data System (ADS)

    Klibanova, Yu. Yu.; Mishin, V. V.; Tsegmed, B.

    2014-11-01

    Long-period geomagnetic pulsations in the (1.7-6.7) mHz frequency range at 18.25-18.48 UT on August 1, 1998, caused by several successive sudden changes in the solar wind (SW) dynamic pressure, are studied against a background of substorm intensification. The data of the ground stations, which were near local noon (the CANOPUS Canadian network) and on the nightside (the auroral stations in Yakutia and at the IMAGE network), and the INTERBALL-1, ACE, WIND, and GOES 8, extramagnetospheric satellites are used. The effect of the SW plasma and IMF parameters, SW inhomogeneity front inclination, and geomagnetic activity on the pulsation propagation and polarization direction and amplitude is discussed. The properties of pulsations, recorded before the substorm, correspond to the pulsation excitation by the inhomogeneity front incident on the magnetopause during the magnetically quiet period: pulsations propagate from the contact point onto the nightside when the amplitude increases and the polarization sense of rotation is opposite on the dawn and dusk sides. Substorm intensification results in the propagation direction reversal and in a more complex behavior of the pulsation amplitude and polarization on the dayside.

  6. The Quasi-periodic Occurrence of Solar Radio Bursts, Auroral Kilometric Radiation, and Other Plasma Wave Phenomena Observed by the GEOTAIL Plasma Wave Investigation

    Microsoft Academic Search

    R. R. Anderson; I. Nagano; S. Yagitani; H. Matsumoto; K. Hashimoto; H. Kojima; H. Takano

    2004-01-01

    Type III solar radio bursts and auroral kilometric radiation (AKR) are among the most common phenomena observed by the GEOTAIL Plasma Wave Investigation in more than eleven years of operation. The occurrence of Type III bursts, generated in the solar wind by energetic electrons ejected from the sun by solar flares, varies from less than one per day to nearly

  7. The quasi-periodic occurrence of Type III solar radio bursts, auroral kilometric radiation, and other plasma wave phenomena observed by the GEOTAIL Plasma Wave Investigation

    Microsoft Academic Search

    R. R. Anderson; I. Nagano; S. Yagitani; H. Matsumoto; K. Hashimoto; H. Kojima; M. G. Henderson; M. F. Thomsen; G. D. Reeves

    2004-01-01

    Type III solar radio bursts and auroral kilometric radiation (AKR) are among the most common phenomena observed by the GEOTAIL Plasma Wave Investigation (PWI) in nearly twelve years of operation. The occurrence of Type III bursts, generated in the solar corona and solar wind at the fundamental and harmonics of the local electron plasma frequency by energetic electrons ejected from

  8. An investigation of time changes in clouds observed over the Gulf of Mexico and Caribbean Sea during the period 18 - 23 July 1961

    E-print Network

    Cramer, William Paul

    1963-01-01

    are isopleths of eights of total sky cover. The data in brackets are 1200 GCT observations Daily 1200 GCT positions of Hurricane ANNA, 19 through 24 July 1961 Frame No. 31, Orbit 133T, TIROS III. This photograph was taken at 1544 GCT, 21 July 1961 ix...

  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. Rotational Period of 5685 Sanenobufukui

    NASA Astrophysics Data System (ADS)

    Madden, Karl D.

    2015-07-01

    The asteroid 5685 Sanenobufukui was observed over eight nights in 2015 March in order to determine its previously unknown rotational period. Lightcurve analysis yielded a bimodal trend with a period of 3.388 ± 0.001 hours.

  11. 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.

  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 [Steward Observatory, University of Arizona, 933 N. Cherry Avenue, Tucson, AZ 85721 (United States); Meyer, Michael, E-mail: ariheinze@hotmail.co, E-mail: phinz@as.arizona.ed, E-mail: suresh@as.arizona.ed, E-mail: mkenworthy@as.arizona.ed, E-mail: dlmiller@as.arizona.ed, E-mail: mmeyer@phys.ethz.c [Department of Physics, Swiss Federal Institute of Technology (ETH-Zurich), ETH Honggerberg, CH-8093 Zurich (Switzerland)

    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. A MODULATED MULTIBAND Pc1 EVENT OBSERVED BY POLAR/EFI AROUND THE PLASMAPAUSE

    E-print Network

    California at Berkeley, University of

    in amplitude, corresponding to classical Pc1 pearls. The repetition period was the same on ground and in space. Moreover, the repetition period of Pc1 pearls coincided with the period of simultaneous Pc4 waves observed by POLAR and on ground. The observations suggest that Pc1 pearls (EMIC waves in general) are modulated

  14. Emergence of Carbapenem-Resistant Klebsiella pneumoniae: Progressive Spread and Four-Year Period of Observation in a Cardiac Surgery Division.

    PubMed

    Lombardi, Fortunata; Gaia, Paola; Valaperta, Rea; Cornetta, Maria; Tejada, Milvana Rosa; Di Girolamo, Luca; Moroni, Alessandra; Ramundo, Federica; Colombo, Alessio; Valisi, Massimiliano; Costa, Elena

    2015-01-01

    Frequent use of carbapenems has contributed to the increase to K. pneumoniae strains resistant to this class of antibiotics (CRKP), causing a problem in the clinical treatment of patients. This investigation reports the epidemiology, genetic diversity, and clinical implication of the resistance to drugs mediated by CRKP in our hospital. A total of 280 K. pneumoniae strains were collected; in particular 98/280 (35%) were CRKP. Sequencing analysis of CRKP isolated strains showed that 9/98 of MBL-producing strains carried the bla VIM-1 gene and 89/98 of the isolates were positive for bla KPC-2. Antimicrobial susceptibility tests revealed a complete resistance to third-generation cephalosporins and a moderate resistance to tigecycline, gentamicin, and fluoroquinolones with percentages of resistance of 61%, 64%, and 98%, respectively. A resistance of 31% was shown towards trimethoprim-sulfamethoxazole. Colistin was the most active agent against CRKP with 99% of susceptibility. Clonality was evaluated by PFGE and MLST: MLST showed the same clonal type, ST258, while PFGE analysis indicated the presence of a major clone, namely, pulsotype A. This finding indicates that the prevalent resistant isolates were genetically related, suggesting that the spread of these genes could be due to clonal dissemination as well as to genetic exchange between different clones. PMID:26064962

  15. Emergence of Carbapenem-Resistant Klebsiella pneumoniae: Progressive Spread and Four-Year Period of Observation in a Cardiac Surgery Division

    PubMed Central

    Gaia, Paola; Valaperta, Rea; Cornetta, Maria; Tejada, Milvana Rosa; Moroni, Alessandra; Ramundo, Federica; Colombo, Alessio

    2015-01-01

    Frequent use of carbapenems has contributed to the increase to K. pneumoniae strains resistant to this class of antibiotics (CRKP), causing a problem in the clinical treatment of patients. This investigation reports the epidemiology, genetic diversity, and clinical implication of the resistance to drugs mediated by CRKP in our hospital. A total of 280 K. pneumoniae strains were collected; in particular 98/280 (35%) were CRKP. Sequencing analysis of CRKP isolated strains showed that 9/98 of MBL-producing strains carried the blaVIM-1 gene and 89/98 of the isolates were positive for blaKPC-2. Antimicrobial susceptibility tests revealed a complete resistance to third-generation cephalosporins and a moderate resistance to tigecycline, gentamicin, and fluoroquinolones with percentages of resistance of 61%, 64%, and 98%, respectively. A resistance of 31% was shown towards trimethoprim-sulfamethoxazole. Colistin was the most active agent against CRKP with 99% of susceptibility. Clonality was evaluated by PFGE and MLST: MLST showed the same clonal type, ST258, while PFGE analysis indicated the presence of a major clone, namely, pulsotype A. This finding indicates that the prevalent resistant isolates were genetically related, suggesting that the spread of these genes could be due to clonal dissemination as well as to genetic exchange between different clones.

  16. 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)

    Microsoft Academic Search

    David Dolenc

    2006-01-01

    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

  17. Variations in the spawning periodicity of eight fish species in three English lowland rivers over a 6 year period, inferred from 0+ year fish length distributions

    Microsoft Academic Search

    A. D. Nunn; J. P. Harvey; I. G. Cowx

    2007-01-01

    The spawning periodicity of eight fish species was investigated in three English lowland rivers over a 6 year period from patterns in 0þ year fish standard length (LS) distributions. A single cohort of 0þ year dace Leuciscus leuciscus, roach Rutilus rutilus and perch Perca fluviatilis was observed each year, suggesting that these species spawned only once annually. By contrast, populations

  18. Results of a search for daily and annual variations of the Po-214 half-life at the two year observation period

    E-print Network

    Alexeyev, E N; Gangapshev, A M; Kazalov, V V; Kuzminov, V V; Panasenko, S I; Ratkevich, S S

    2015-01-01

    The brief description of installation TAU-2 intended for long-term monitoring of the half-life value $\\tau$ ($\\tau_{1/2}$) of the $^{214}$Po is presented. The methods of measurement and processing of collected data are reported. The results of analysis of time series values $\\tau$ with different time step are presented. Total of measurement time was equal to 590 days. Averaged value of the $^{214}$Po half-life was obtained $\\tau=163.46\\pm0.04$ $\\mu$s. The annual variation with an amplitude $A=(8.9\\pm2.3)\\cdot10^{-4}$, solar-daily variation with an amplitude $A_{So}=(7.5\\pm1.2)\\cdot10^{-4}$, lunar-daily variation with an amplitude $A_L=(6.9\\pm2.0)\\cdot10^{-4}$ and sidereal-daily variation with an amplitude $A_S=(7.2\\pm1.2)\\cdot10^{-4}$ were found in a series of $\\tau$ values. The maximal values of amplitude are observed at the moments when the projections of the installation Earth location velocity vectors toward the source of possible variation achieve its maximal magnitudes.

  19. Results of a search for daily and annual variations of the Po-214 half-life at the two year observation period

    E-print Network

    E. N. Alexeyev; Yu. M. Gavrilyuk; A. M. Gangapshev; V. V. Kazalov; V. V. Kuzminov; S. I. Panasenko; S. S. Ratkevich

    2015-05-07

    The brief description of installation TAU-2 intended for long-term monitoring of the half-life value $\\tau$ ($\\tau_{1/2}$) of the $^{214}$Po is presented. The methods of measurement and processing of collected data are reported. The results of analysis of time series values $\\tau$ with different time step are presented. Total of measurement time was equal to 590 days. Averaged value of the $^{214}$Po half-life was obtained $\\tau=163.46\\pm0.04$ $\\mu$s. The annual variation with an amplitude $A=(8.9\\pm2.3)\\cdot10^{-4}$, solar-daily variation with an amplitude $A_{So}=(7.5\\pm1.2)\\cdot10^{-4}$, lunar-daily variation with an amplitude $A_L=(6.9\\pm2.0)\\cdot10^{-4}$ and sidereal-daily variation with an amplitude $A_S=(7.2\\pm1.2)\\cdot10^{-4}$ were found in a series of $\\tau$ values. The maximal values of amplitude are observed at the moments when the projections of the installation Earth location velocity vectors toward the source of possible variation achieve its maximal magnitudes.

  20. Spectral Index and Quasi-Periodic Oscillation Frequency Correlation in Black Hole (BH) Sources: Observational Evidence of Two Phases and Phase Transition in BHs

    E-print Network

    Lev Titarchuk; Ralph Fiorito

    2004-05-19

    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 state, steep power-law (soft) state and in transition between these states. 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 ~ 50 keV) producing photon upscattering via thermal Componization; the photon spectrum index Gamma~1.7 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 (kT~5 keV); the index for this state, Gamma~2.8 is determined by soft-photon upscattering and photon trapping in converging flow into BH.

  1. Periodic Monopoles

    E-print Network

    R. S. Ward

    2005-12-28

    This paper deals with static BPS monopoles in three dimensions which are periodic either in one direction (monopole chains) or two directions (monopole sheets). The Nahm construction of the simplest monopole chain is implemented numerically, and the resulting family of solutions described. For monopole sheets, the Nahm transform in the U(1) case is computed explicitly, and this leads to a description of the SU(2) monopole sheet which arises as a deformation of the embedded U(1) solution.

  2. Light absorption-related optical properties of aerosol observed during episodic periods at Conghua, Guangdong Province, China during the 2008 PRD Campaign

    NASA Astrophysics Data System (ADS)

    Cayetano, M. G.; Jung, J.; Mueller, D.; Kim, Y. J.; Zhang, Y.; Liu, X.

    2010-12-01

    The magnitude of aerosol light absorption and its contribution to radiative forcing is subject to considerable uncertainty. Surface in-situ measurements of aerosol optical parameters were made at a continental background site in Conghua, Guangdong Province, China (23°39’0.7”N, 113°37’28.7” E) during the 2008 Pearl River Delta campaign in the fall of 2008. Aerosol absorption (Babs) and scattering (Bscatt) coefficients were measured using in- situ optical instruments, which were then used as combined input for an inversion algorithm for the retrieval of single scattering albedo (SSA) and complex refractive index, m (m=n-ik). Two episodic cases were identified from high aerosol loading events: Case 1 with air mass originating from the southeast (heavily industrialized PRD and Hong Kong) and Case 2 with air mass originating from northeast (Shanghai region). Two clean air mass cases with different aerosol characteristics were also identified: one with high SSA and the other with low SSA due to impact of local absorbing aerosols. Average Bscatt during the clean events was measured to be ~ 31.9 ± 7.3 Mm-1, while it increased to 306.1 ± 112.3 Mm-1 during the high aerosol loading episodic events. Angstrom exponent of Babs (?_abs) did not show large differences on episodic events. However, clear separation between episodic cases was observed for the imaginary part of the refractive index , k=0.005 for Case 1 and k=0.015-0.02 for Case 2, which can be used as indicator of aerosol types. Spectral absorption coefficient data showed a distinct peak at 880 nm, which is signature of soot particles. Spectral absorption characteristics of aerosols can provide additional information on the aerosol type and composition.

  3. Periodic changes in the distribution of species observed in the Ni(2+)-histidine equilibrium coupled to the BrO3(-)-SO3(2-) pH oscillator.

    PubMed

    Poros, Eszter; Kurin-Csörgei, Krisztina; Szalai, István; Horváth, Viktor; Orbán, Miklós

    2014-08-28

    The dynamical behavior of the system comprising of the pH-dependent complex formation between histidine and Ni(II) ions coupled to the BrO3(-)-SO3(2-) pH oscillator was studied. The pH oscillator was demonstrated to be capable of forcing the pH-sensitive nickel ion-histidine equilibrium to alternate periodically between the unreacted and the fully complexed states. The periodic interconversions gave rise to an oscillatory distribution of the species that participate in the equilibrium and resulted in oscillations in the free [Ni(2+)], [NiHis(+)], and [Ni(His)2]. The preconditions of the successful coupling of metal ion-amino acid complexes to a primary pH oscillator are briefly discussed. Model calculations were performed to simulate the dynamics observed in the BrO3(-)-SO3(2-) - Ni(2+)-His CSTR system. PMID:25072472

  4. Suggestions for Controlling Insects in Farm-Stored Grain. 

    E-print Network

    Hamman, Philip J.

    1982-01-01

    IUUL; Z TA24S.7 8873 NO.1410 Suggestions B-1410 for Controlling Insects ? In Farm-Stored Grain The Texas A&M University System ? Texas Agricultural Extension Service JUN 2 0 2002 Zerle L. Carpenter . Director College Station... be troublesome during the first season. Region 3, insects are troublesome every year. Region 4, insects are a serious problem throughout the storage period. (Courtesy USDA) 2 Suggestions for Controlling Insects in Farm-Stored Grain Philip J. Hamman * Texas...

  5. Are periodic bombardments real?

    NASA Astrophysics Data System (ADS)

    Weissman, P. R.

    1990-03-01

    Consideration is given to the hypothesis that showers of comets or asteroids strike the earth every 26 m yrs, causing climatic castastrophes and mass extinctions (Raup and Sepkoski, 1984). Possible explanations for the alleged periodicity are discussed, including the possibility that the sun has a small faint companion star and perturbations of the Oort cloud as the solar system passes through the Galactic plane. Also, the possible causes of the extinction at the K-T boundary are examined. The implications of these theories are noted and evidence suggesting that impacts do not have periodicity is presented.

  6. Rotation Period for 5110 Belgirate

    NASA Astrophysics Data System (ADS)

    Hayes-Gehrke, Melissa; Koester, Kenneth; Snyder, Christopher; Johnson, Anne; Gibson, Allison; Greenberg, Emily; Mehta, Sarth; Wells-Weitzner, Chris; Leung, Leo

    2014-04-01

    We present an updated rotation period for asteroid 5110 Belgirate, which we observed using the iTelescope.net T7 telescope in Nerpio, Spain, on 2013 October 24, 27, and November 3. The previously reported period is 11.04 hours with no uncertainty and based on fragmentary data. Through our observations and analysis, we found a period of 8.26 ± 0.02 h.

  7. Origin of long-period Alfv{é}n waves in the solar wind

    E-print Network

    T. V. Zaqarashvili; G. Belvedere

    2005-06-30

    We suggest that the observed long-period Alfv{\\'e}n waves in the solar wind may be generated in the solar interior due to the pulsation of the Sun in the fundamental radial mode. The period of this pulsation is about 1 hour. The pulsation causes a periodical variation of density and large-scale magnetic field, this affecting the Alfv{\\'e}n speed in the solar interior. Consequently the Alfv{\\'e}n waves with the half frequency of pulsation (i.e. with the double period) can be parametrically amplified in the interior below the convection zone due to the recently suggested swing wave-wave interaction. Therefore the amplified Alfv{\\'e}n waves have periods of several hours. The waves can propagate upwards through the convection zone to the solar atmosphere and cause the observed long-period Alfv{\\'e}n oscillations in the solar wind.

  8. 29 CFR 785.45 - Suggestion systems.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...INTERPRETATION NOT DIRECTLY RELATED TO REGULATIONS HOURS WORKED Application of Principles Adjusting Grievances, Medical Attention, Civic and Charitable Work, and Suggestion Systems § 785.45 Suggestion systems. Generally, time spent by...

  9. 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.

  10. Suggestions for Galaxy Workflow Design Using Semantically

    E-print Network

    Kissinger, Jessica

    Suggestions for Galaxy Workflow Design Using Semantically Annotated Services Alok Dhamanaskar Similarity 5. SSE Evaluation · Interfacing SSE with the Galaxy workflow editor 6. Summary and Future Work #12 Suggestions and Bi-directional Suggestions. SSE returns a ranked list of web service operations (from

  11. 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.

  12. The influence of suggestibility on memory.

    PubMed

    Nicolas, Serge; Collins, Thérèse; Gounden, Yannick; Roediger, Henry L

    2011-06-01

    We provide a translation of Binet and Henri's pioneering 1894 paper on the influence of suggestibility on memory. Alfred Binet (1857-1911) is famous as the author who created the IQ test that bears his name, but he is almost unknown as the psychological investigator who generated numerous original experiments and fascinating results in the study of memory. His experiments published in 1894 manipulated suggestibility in several ways to determine effects on remembering. Three particular modes of suggestion were employed to induce false recognitions: (1) indirect suggestion by a preconceived idea; (2) direct suggestion; and (3) collective suggestion. In the commentary we suggest that Binet and Henri's (1894) paper written over 115 years ago is still highly relevant even today. In particular, Binet's legacy lives on in modern research on misinformation effects in memory, in studies of conformity, and in experiments on the social contagion of memory. PMID:21144772

  13. 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. Naïve 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

  14. Hypnotizability, not suggestion, influences false memory development.

    PubMed

    Dasse, Michelle N; Elkins, Gary R; Weaver, Charles A

    2015-01-01

    Hypnotizability influences the development of false memories. In Experiment 1, participants heard a positive or negative suggestion regarding hypnosis and then listened to 8 Deese-Roediger-McDermott (DRM) false memory paradigm lists in a hypnotic state. Neither hypnosis nor prehypnotic suggestion affected memory. Highly hypnotizable participants were more accurate in recall and recognition. In Experiment 2, suggestions were delivered in the form of feedback. Participants heard a positive or negative suggestion about their performance prior to either the encoding or retrieval of 8 DRM lists. Neither accurate nor false memories were affected by the suggestion. Highly hypnotizable individuals recognized fewer critical lures if they received a negative suggestion about their performance. These results highlight the unusual role of hypnotizability in the creation of false memories. PMID:25365130

  15. Improving sleep and cognition by hypnotic suggestion in the elderly.

    PubMed

    Cordi, Maren Jasmin; Hirsiger, Sarah; Mérillat, Susan; Rasch, Björn

    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

  16. Two Suggestions for Improving Chemical Equilibrium Instruction

    E-print Network

    Yaron, David

    Two Suggestions for Improving Chemical Equilibrium Instruction Journal: Journal of Chemical to the Journal of Chemical Education #12;ed-20XX-XXXXXX Two Suggestions for Improving Chemical Equilibrium Chemical Equilibrium Instruction David Yaron*1, Jodi L. Davenport2, James Greeno3, Michael Karabinos1

  17. Cerebral Mechanisms of Hypnotic Induction and Suggestion

    Microsoft Academic Search

    Pierre Rainville; Robert K. Hofbauer; Tomáš Paus; Gary H. Duncan; M. Catherine Bushnell; Donald D. Price

    1999-01-01

    The neural mechanisms underlying hypnotic states and responses to hypnotic suggestions remain largely unknown and, to date, have been studied only with indirect methods. Here, the effects of hypnosis and suggestions to alter pain perception were investigated in hypnotizable subjects by using positron emission tomography (PET) measures of regional cerebral blood flow (rCBF) and electroencephalographic (EEG) measures of brain electrical

  18. 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…

  19. Period Determination of Mira Variables

    Microsoft Academic Search

    P. J. Benson; C. L. Ryan

    1999-01-01

    We have observed several Mira-type and suspected Mira variables for up to an eight-year span at Wellesley College's Whitin Observatory. Periods have been determined for 22 stars for which the period has not previously been determined. We note the presence of a rare \\

  20. 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.

  1. UCG environmental research: summary and suggested projections

    Microsoft Academic Search

    S. W. Mead; F. T. Wang; D. H. Stuermer

    1982-01-01

    Recent UCG experiments sponsored by Government and Industry have yielded a broad and comprehensive environmental data base. Groundwater modifications involving hydrologic effects and water quality changes have been carefully documented over a period of several years at a number of UCG test sites. The effects of cavity roof collapse, including aquifer interconnection and surface susidence, have also been investigated both

  2. SUGGESTED ANALYTIC APPROACH TO TRANSMISSION RELIABILITY MARGIN

    E-print Network

    SUGGESTED ANALYTIC APPROACH TO TRANSMISSION RELIABILITY MARGIN DRAFT REPORT JUNE 22 1999 Jianfeng Zhang Ian Dobson Fernando L. Alvarado POWER SYSTEMS ENGINEERING RESEARCH CENTER Electrical & Computer Engineering Dept. University of Wisconsin, Madison WI 53706 USA Abstract Transmission Reliability Margin (TRM

  3. Using suggestion to model different types of automatic writing.

    PubMed

    Walsh, E; Mehta, M A; Oakley, D A; Guilmette, D N; Gabay, A; Halligan, P W; Deeley, Q

    2014-05-01

    Our sense of self includes awareness of our thoughts and movements, and our control over them. This feeling can be altered or lost in neuropsychiatric disorders as well as in phenomena such as "automatic writing" whereby writing is attributed to an external source. Here, we employed suggestion in highly hypnotically suggestible participants to model various experiences of automatic writing during a sentence completion task. Results showed that the induction of hypnosis, without additional suggestion, was associated with a small but significant reduction of control, ownership, and awareness for writing. Targeted suggestions produced a double dissociation between thought and movement components of writing, for both feelings of control and ownership, and additionally, reduced awareness of writing. Overall, suggestion produced selective alterations in the control, ownership, and awareness of thought and motor components of writing, thus enabling key aspects of automatic writing, observed across different clinical and cultural settings, to be modelled. PMID:24657632

  4. AN INTERPRETATION OF THE ORBITAL PERIOD DIFFERENCE BETWEEN HOT JUPITERS AND GIANT PLANETS ON LONG-PERIOD ORBITS

    SciTech Connect

    Jin Liping, E-mail: jinlp@jlu.edu.c [College of Physics, Jilin University, Changchun, Jilin 130021 (China)

    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}).

  5. Periods, period changes and the nature of the microvariations of Luminous Blue Variables

    NASA Astrophysics Data System (ADS)

    Lamers, H. J. G. L. M.; Bastiaanse, M. V.; Aerts, C.; Spoon, H. W. W.

    1998-07-01

    We present period determinations of the microvariability of the six luminous blue variables AG Car, HR Car, 164 G Sco, S Dor, R 127, and R 71. In total, we were able to determine 22 periods in these stars, ranging from 18 days up to 195 days. All stars have period changes by up to a factor 4 within time scales of a few hundred days. For all stars the amplitude of the pulsations in V increases with increasing periods. The slope of the correlation between the amplitude and the period decreases with increasing luminosity. The values of the pulsation constant Q were determined. HR Car, 164 G Sco, R 71 and R 127 have Q-values in the range of 0.07 to 0.18 days. This is about a factor two larger than those of most other B-type supergiants, possibly because the LBVs have a higher L/M ratio as they have lost more mass. The most common value for the pulsational constant of LBVs is Q=0.07 +/- 0.01 days, but Q can increase temporarily by as much as a factor four. This is not related to a particular phase in the light curve. The long periods might be due to a beat of two frequencies. For the two stars R 71 and R 127, which showed significant changes in M_V, and hence in radius during the course of the observations, the pulsational period increased with increasing radius. The Q-values of R 71 and R 127 increase when the stars get brighter and their radii increase. This is probably due the changes in the density structure of the stars as their outer envelope expands. We compare the observed variations with those predicted for strange modes by Kiriakidis et al. (1993). The periods of the observed microvariations are orders of magnitudes longer than predicted for strange modes. A comparison with the variations of slowly pulsating B-stars (SPBs) suggests that the microvarions of LBVs are due to g-mode pulsations. A first attempt for mode identification, based on a simple linear pulsation model by means of the multicolour Stroemgren data, shows that none of the variations can be explained by means of a radial pulsation. The amplitude-wavelength relations suggest g-modes of low l.

  6. Impulsivity, self-control, and hypnotic suggestibility.

    PubMed

    Ludwig, V U; Stelzel, C; Krutiak, H; Prunkl, C E; Steimke, R; Paschke, L M; Kathmann, N; Walter, H

    2013-06-01

    Hypnotic responding might be due to attenuated frontal lobe functioning after the hypnotic induction. Little is known about whether personality traits linked with frontal functioning are associated with responsiveness to hypnotic suggestions. We assessed whether hypnotic suggestibility is related to the traits of self-control and impulsivity in 154 participants who completed the Brief Self-Control Scale, the Self-Regulation Scale, the Barratt Impulsiveness Scale (BIS-11), and the Harvard Group Scale of Hypnotic Susceptibility (HGSHS:A). BIS-11 non-planning impulsivity correlated positively with HGSHS:A (Bonferroni-corrected). Furthermore, in the best model emerging from a stepwise multiple regression, both non-planning impulsivity and self-control positively predicted hypnotic suggestibility, and there was an interaction of BIS-11 motor impulsivity with gender. For men only, motor impulsivity tended to predict hypnotic suggestibility. Hypnotic suggestibility is associated with personality traits linked with frontal functioning, and hypnotic responding in men and women might differ. PMID:23660477

  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. 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…

  9. 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)

  10. Our Hispano Heritage [Unit with Suggested Activities].

    ERIC Educational Resources Information Center

    Wilson, Jeanette

    This curriculum unit for elementary students, developed by the Montelores Studies Center, Cortez, Colorado, and funded by the Elementary and Secondary Education Act, Title III, presents a history of the Spanish Americans and Mexican Americans and suggests student activities. The history section outlines the historical development of the…

  11. Training in community policing : A suggested curriculum

    Microsoft Academic Search

    Michael J. Palmiotto; Michael L. Birzer; N. Prabha Unnithan

    2000-01-01

    The widespread acceptance of community policing necessitates the need for training of recruits into its philosophy and practices. We provide a suggested curriculum for such training after describing its three basic premises. This is followed by discussions of the rationale for the curriculum, and a promising training method that can be used in its implementation. All of the above are

  12. 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…

  13. Crowdsourcing suggestions to programming problems for dynamic

    E-print Network

    Hartmann, Björn

    Developers increasingly consult online examples and message boards to find solutions to common programming tasks. On the web, finding solutions to debugging problems is harder than searching for working code suggestions by presenting fixes to errors that peers have applied in the past. However, HelpMeOut only worked

  14. 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)

  15. Evidence from rhesus macaques suggests that

    E-print Network

    Little, Tony

    in primate female mate choice remains unknown. Adult male rhesus macaques undergo a hormonally regulatedEvidence from rhesus macaques suggests that male coloration plays a role in female primate mate: secondary sexual coloration; mate choice; primates; Macaca mulatta 1. INTRODUCTION Brilliant displays

  16. 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…

  17. Suggestions for Teaching the Migratory Pupil.

    ERIC Educational Resources Information Center

    Blanton, Dolly; And Others

    Suggestions for teachers of migrant children are offered in seven individual teaching guides which were developed as part of a research and curriculum development project to improve the teaching of migratory pupils. Levels of study include grades four, five, six, and seven, and one general unit deals with providing an effective learning…

  18. 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…

  19. 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)

  20. 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…

  1. 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…

  2. Allocation of Attentional Resources in Posthypnotic Suggestion

    Microsoft Academic Search

    Irene P. Tobis; John F. Kihlstrom

    2010-01-01

    Highly hypnotizable subjects received a nonhypnotic instruction to respond to a particular digit in a display and a posthypnotic suggestion to respond to a different digit. On some test trials, these 2 responses were tested separately; on others, they were placed in conflict. Overall, subjects were no more responsive to posthypnotic cues than to nonhypnotic cues, nor did their response

  3. On the mechanism of suggestion and hypnosis

    Microsoft Academic Search

    M. B. Arnold

    1946-01-01

    The nature of hypnosis is not adequately explained by conditioned responses or conditioned attitudes. The writer agrees with R. W. White that the hypnotized subject must be motivated, but not necessarily to behave like a hypnotized person. She postulates, rather, that suggestions are effective only if the subject actively strives to imagine himself in the situation described by the operator.

  4. Suggested References for Home Food Preservation

    E-print Network

    Suggested References for Home Food Preservation USDA and Cooperative Extension So Easy to Preserve Center for Home Food Preservation: http://homefoodpreservation.com USDA Complete Guide to Home Canning http://www.uga.edu/nchfp/publications/publications_usda.html Manufacturers of Home Food Preservation

  5. SUGGESTIONS FOR OPERATORS OF TUNA RECEIVING SHIPS

    E-print Network

    SUGGESTIONS FOR OPERATORS OF TUNA RECEIVING SHIPS · FISHER Y LEAFLET 301 FISH AND WILDLIFE SERVICE be anticipated in northern waters. Operators of tuna receiving ships may find it necessary to make arrangements is advisable to round out production. A receiving ship must have sustained and near capacity landings to prove

  6. 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.

  7. ULTRACAM observations of two accreting white dwarf pulsators

    E-print Network

    C. M. Copperwheat; T. R. Marsh; V. S. Dhillon; S. P. Littlefair; P. A. Woudt; B. Warner; D. Steeghs; B. T. Gaensicke; J. Southworth

    2008-10-30

    In this paper we present high time-resolution observations of GW Librae and SDSS J161033.64-010223.3 -- two cataclysmic variables which have shown periodic variations attributed to non-radial pulsations of the white dwarf. We observed both these systems in their quiescent states and detect the strong pulsations modes reported by previous authors. The identification of further periodicities in GW Lib is limited by the accretion-driven flickering of the source, but in the case of SDSS 1610 we identify several additional low-amplitude periodicities. In the case of SDSS 1610, there is evidence to suggest that the two primary signals have a different colour dependence, suggesting that they may be different spherical harmonic modes. We additionally observed GW Lib during several epochs following its 2007 dwarf nova outburst: the first time a dwarf nova containing a pulsating white dwarf has been observed in such a state. We do not observe any periodicities, suggesting that the heating of the white dwarf had either switched-off the pulsations entirely, or reduced their relative amplitude in flux to the point where they are undetectable. Further observations eleven months after the outburst still do not show the pulsation modes previously observed, but do show the emergence of two new periodic signals. In addition to the WD pulsations, our observations of GW Lib in quiescence show a larger-amplitude modulation in luminosity with a period of approximately 2.1 hours. This has been previously observed, and its origin is unclear: it is unrelated to the orbital period. We find this modulation to vary over the course of our observations in phase and/or period. Our data support the conclusion that this is an accretion-related phenomenon which originates in the accretion disc.

  8. Photometric Observations and Analysis of 1082 Pirola

    NASA Astrophysics Data System (ADS)

    Baker, Ronald E.; Pilcher, Frederick; Benishek, Vladimir

    2011-04-01

    CCD observations of the main-belt asteroid 1082 Pirola were recorded during the period 2010 October to 2011 January. Analysis of the lightcurve found a synodic period of P = 15.8525 ± 0.0005 h and amplitude A = 0.53 ± 0.01 mag. The phase curve referenced to mean magnitude suggests the absolute magnitude and phase slope parameter: H = 10.507 ± 0.014 mag; G = 0.080 ± 0.016. The phase curve referenced to maximum light suggests: H = 10.320 ± 0.013 mag; G = 0.107 ± 0.016.

  9. Latent period in clinical radiation myelopathy

    Microsoft Academic Search

    Timothy E. Schultheiss; Elizabeth M. Higgins; Anas M. El-Mahdi

    1984-01-01

    Seventy-seven papers containing data on more than 300 cases of radiation myelopathy have been analyzed. The data suggest that the latent periods are similar in the cervical and thoracic levels of the spinal cord and are bimodally distributed. Myelopathy of lumbar cord apparently has a shorter latent period. As in controlled animal experiments, the latent period decreases with increasing dose.

  10. Mentoring in biostatistics: some suggestions for reform.

    PubMed

    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

  11. 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

  12. Maltreated children's memory: accuracy, suggestibility, and psychopathology.

    PubMed

    Eisen, Mitchell L; Goodman, Gail S; Qin, Jianjian; Davis, Suzanne; Crayton, John

    2007-11-01

    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 inaccuracies. In addition, cortisol level and trauma symptoms in children who reported more dissociative tendencies were associated with increased memory error, whereas cortisol level and trauma symptoms were not associated with increased error for children who reported fewer dissociative tendencies. Sexual and/or physical abuse predicted greater accuracy. The study contributes important new information to scientific understanding of maltreatment, psychopathology, and eyewitness memory in children. PMID:18020811

  13. 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

  14. Relativistic timescale analysis suggests lunar theory revision

    Microsoft Academic Search

    Steven D. Deines; Carol A. Williams

    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

  15. UCG environmental research: summary and suggested projections

    SciTech Connect

    Mead, S.W.; Wang, F.T.; Stuermer, D.H.

    1982-08-09

    Recent UCG experiments sponsored by Government and Industry have yielded a broad and comprehensive environmental data base. Groundwater modifications involving hydrologic effects and water quality changes have been carefully documented over a period of several years at a number of UCG test sites. The effects of cavity roof collapse, including aquifer interconnection and surface susidence, have also been investigated both computationally and experimentally. The long term implications of these changes will require further study. Future research will also be guided by the need to extend our environmental knowledge to a broader range of hydrogeological conditions, to consider the application of available environmental knowledge to probable commercialization scenarios, and to explore the effectiveness of promising mitigation measures and control technologies. We have considered some specific problems at the Hoe Creek site that appear to need attention, and we discuss some general recommendations for environmental activities that we believe can help pave the way for a commercial UCG technology.

  16. Periodically oscillating plasma sphere

    SciTech Connect

    Park, J.; Nebel, R.A.; Stange, S.; Murali, S. Krupakar [Los Alamos National Laboratory, Los Alamos, New Mexico 87544 (United States); University of Wisconsin, Madison, Wisconsin 53706 (United States)

    2005-05-15

    The periodically oscillating plasma sphere, or POPS, is a novel fusion concept first proposed by D. C. Barnes and R. A. Nebel [Fusion Technol. 38, 28 (1998)]. POPS utilizes the self-similar collapse of an oscillating ion cloud in a spherical harmonic oscillator potential well formed by electron injection. Once the ions have been phase-locked, their coherent motion simultaneously produces very high densities and temperatures during the collapse phase of the oscillation. A requirement for POPS is that the electron injection produces a stable harmonic oscillator potential. This has been demonstrated in a gridded inertial electrostatic confinement device and verified by particle simulation. Also, the POPS oscillation has been confirmed experimentally through observation that the ions in the potential well exhibit resonance behavior when driven at the POPS frequency. Excellent agreement between the observed POPS frequencies and the theoretical predictions has been observed for a wide range of potential well depths and three different ion species. Practical applications of POPS require large plasma compressions. These large compressions have been observed in particle simulations, although space charge neutralization remains a major issue.

  17. 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

  18. Elastic wave scattering methods: assessments and suggestions

    SciTech Connect

    Gubernatis, J.E.

    1985-01-01

    The author was asked by the meeting organizers to review and assess the developments over the past ten or so years in elastic wave scattering methods and to suggest areas of future research opportunities. He highlights the developments, focusing on what he feels were distinct steps forward in our theoretical understanding of how elastic waves interact with flaws. For references and illustrative figures, he decided to use as his principal source the proceedings of the various annual Reviews of Progress in Quantitative Nondestructive Evaluation (NDE). These meetings have been the main forum not only for presenting results of theoretical research but also for demonstrating the relevance of the theoretical research for the design and interpretation of experiment. In his opinion a quantitative NDE is possible only if this relevance exists, and his major objective is to discuss and illustrate the degree to which relevance has developed.

  19. Recent Images Suggesting Liquid Water on Mars

    NSDL National Science Digital Library

    Recently, the press reported that the Mars Orbiter Camera (MOC) had captured compelling images of gullies and slope failures that might be associated with the presence of liquid water on Mars. Now you can see these famous images at Malin Space Science Systems' MOC Website. These sharp, beautiful, color images (.jpeg, .gif) are featured on pages containing descriptions of how such physical features are formed on earth. The images are available in two sizes (small = 360K, large = 690K). Highlights include the "gully landform" compared to channel and apron features on Mount Saint Helens on Earth, a 3-D image (3-D glasses required) of a "weeping" alcove in an impact crater, and clues suggesting that the suspected liquid water on Mars is relatively young.

  20. 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

  1. Periodic breathing in healthy humans at exercise in hypoxia.

    PubMed

    Hermand, Eric; Pichon, Aurélien; Lhuissier, François J; Richalet, Jean-Paul

    2015-01-01

    Periodic breathing is frequent in heart failure or ventilatory disorders during sleep, and common during sleep at high altitude, but has been rarely studied in wakefulness and during exercise. A retrospective analysis of ventilation from hypoxia exercise tests was realized in 82 healthy subjects separated into two groups with either high or low ventilatory response to hypoxia at exercise (HVRe). A fast Fourier transform spectral analysis of the breath-by-breath ventilation (V?e) signal, O2 saturation, and end-tidal PCO2 evidenced a periodic pattern with a period of 11.1 to 12.0 s. The peak power of the V?e spectrum was higher in the high HVRe group (P < 0.001). A prospective study (25 subjects) was performed to evaluate the influence of cardiorespiratory factors on the amplitude and period of oscillations in various conditions of exercise (20 to 40% maximal aerobic power) and hypoxia (0 to 4,000 m altitude). The period of V?e was shorter at exercise (vs. rest, P < 0.001) and hypoxia (vs. normoxia, P < 0.001), and inversely related with cardiac output and V?e (P < 0.001). V?e peak power was higher at exercise (P < 0.001) and hypoxia (P < 0.001), and was positively related with cardiac output and V?e (P < 0.001). V?e peak power in hypoxia was positively related with the ventilatory response to CO2 (HCVR). This novel observation suggests that healthy subjects demonstrate a spontaneous periodic breathing, not clearly observable at rest and in normoxia, but triggered by hypoxic exercise. The periodic pattern is enhanced in subjects with high HVRe and high HCVR, suggesting that oxygen and CO2 play synergistic roles in the modulation of these oscillations. PMID:25554800

  2. Enhanced entrainability of genetic oscillators by period mismatch

    PubMed Central

    Hasegawa, Yoshihiko; Arita, Masanori

    2013-01-01

    Biological oscillators coordinate individual cellular components so that they function coherently and collectively. They are typically composed of multiple feedback loops, and period mismatch is unavoidable in biological implementations. We investigated the advantageous effect of this period mismatch in terms of a synchronization response to external stimuli. Specifically, we considered two fundamental models of genetic circuits: smooth and relaxation oscillators. Using phase reduction and Floquet multipliers, we numerically analysed their entrainability under different coupling strengths and period ratios. We found that a period mismatch induces better entrainment in both types of oscillator; the enhancement occurs in the vicinity of the bifurcation on their limit cycles. In the smooth oscillator, the optimal period ratio for the enhancement coincides with the experimentally observed ratio, which suggests biological exploitation of the period mismatch. Although the origin of multiple feedback loops is often explained as a passive mechanism to ensure robustness against perturbation, we study the active benefits of the period mismatch, which include increasing the efficiency of the genetic oscillators. Our findings show a qualitatively different perspective for both the inherent advantages of multiple loops and their essentiality. PMID:23389900

  3. Evidence suggesting possible SCA1 gene involvement in schizophrenia

    SciTech Connect

    Diehl, S.R.; Wange, S.; Sun, C. [NIDR, Bethesda, MD (United States)] [and others

    1994-09-01

    Several findings suggest a possible role for the SCA1 gene on chromosome 6p in some cases of schizophrenia. First, linkage analyses in Irish pedigrees provided LOD scores up to 3.0 for one model tested using microsatellites closely linked to SCA1. Reanalysis of these data using affected sibpair methods yielded a significant result (p = 0.01) for one marker. An attempt to replicate this linkage finding was made using 44 NIMH families (206 individuals, 80 affected) and 12 Utah families (120 individuals, 49 affected). LOD scores were negative in these new families, even allowing for heterogeneity, as were results using affected sibpair methods. However, one Utah family provided a LOD score of 1.3. We also screened the SCA1 trinucleotide repeat to search for expansions characteristic of this disorder in these families and in 38 additional unrelated schizophrenics. We found 1 schizophrenic with 41 repeats, which is substantially larger than the maximum size of 36 repeats observed in previous studies of several hundred controls. We are now assessing whether the distribution of SCA1 repeats differs significantly in schizophrenia versus controls. Recent reports suggest possible anticipation in schizophrenia (also characteristic of SCA1) and a few cases of psychiatric symptoms suggesting schizophrenia have been observed in the highly related disorder DRPLA (SCA2), which is also based on trinucleotide repeat expansion. These findings suggest that further investigations of this gene and chromosome region may be a priority.

  4. Critical period for acoustic preference in mice

    PubMed Central

    Yang, Eun-Jin; Lin, Eric W.; Hensch, Takao K.

    2012-01-01

    Preference behaviors are often established during early life, but the underlying neural circuit mechanisms remain unknown. Adapting a unique nesting behavior assay, we confirmed a “critical period” for developing music preference in C57BL/6 mice. Early music exposure between postnatal days 15 and 24 reversed their innate bias for silent shelter, which typically could not be altered in adulthood. Instead, exposing adult mice treated acutely with valproic acid or carrying a targeted deletion of the Nogo receptor (NgR?/?) unmasked a strong plasticity of preference consistent with a reopening of the critical period as seen in other systems. Imaging of cFos expression revealed a prominent neuronal activation in response to the exposed music in the prelimbic and infralimbic medial prefrontal cortex only under conditions of open plasticity. Neither behavioral changes nor selective medial prefrontal cortex activation was observed in response to pure tone exposure, indicating a music-specific effect. Open-field center crossings were increased concomitant with shifts in music preference, suggesting a potential anxiolytic effect. Thus, music may offer both a unique window into the emotional state of mice and a potentially efficient assay for molecular “brakes” on critical period plasticity common to sensory and higher order brain areas. PMID:23045690

  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. Observations of Circinus X-1 from Uhuru

    NASA Technical Reports Server (NTRS)

    Jones, C.; Giacconi, R.; Forman, W.; Tananbaum, H.

    1974-01-01

    Analysis of Uhuru observations of the X-ray source Cir X-1 (3U 1516-56) suggests that the source may be a binary with a period longer than 15.0 days. Significant intensity variations have been observed on all time scales from 0.1 sec to days. Changes in the X-ray energy spectrum from 2 to 20 keV have also been found. A refined X-ray position, containing no obvious optical counterpart, is reported. The similarities between Cyg X-1 and Cir X-1 suggest that the X rays from Cir X-1 may be produced by accretion onto a massive, collapsed object.

  7. Periodicity of the Lorenz–Stenflo equations

    NASA Astrophysics Data System (ADS)

    Park, Junho; Lee, Hyunho; Jeon, Ye-Lim; Baik, Jong-Jin

    2015-06-01

    In this paper, we investigate periodic behaviors of the Lorenz–Stenflo equations in wide ranges of parameters. Regimes of periodic solutions and chaotic solutions are computed and distinguished by local maximum values of a dynamic variable Z. Complex behaviors of the periodic solutions are observed inside a regime of the chaotic solutions which is closed and surrounded by a regime of the periodic solutions where a feature of disconnected bifurcations is observed. It is found that not only a regime of fixed solutions but also regimes of solutions with period 1 and 2 remain for sufficiently large parameters.

  8. Procalcitonin elevation suggests a septic source.

    PubMed

    Friend, Kara E; Burgess, Jessica N; Britt, Rebecca C; Collins, Jay N; Weireter, Leonard N; Novosel, Timothy J; Britt, L D

    2014-09-01

    Procalcitonin is used as a marker for sepsis but there is little known about the correlation of the procalcitonin elevation with the causative organism in sepsis. All patients aged 18 to 80 years who were admitted to the surgery service from June 2010 to May 2012 and who had a procalcitonin drawn were evaluated. Culture data were reviewed to determine the causative organism. Infections analyzed included pneumonia, urinary tract infection (UTI), bloodstream infection, and Clostridium difficile. Other parameters assessed included reason for admission, body mass index, pressor use, antibiotic duration, and disposition. Two hundred thirty-two patient records were reviewed. Patients without a known infection/source of sepsis had a mean procalcitonin of 3.95. Those with pneumonia had a procalcitonin of 20.59 (P = 0.03). Those with a UTI had a mean procalcitonin of 66.84 (P = 0.0005). Patients with a bloodstream infection had a mean procalcitonin of 33.30 (P = 0.003). Those with C. difficile had a procalcitonin of 47.20 (P = 0.004). When broken down by causative organisms, those with Gram-positive sepsis had a procalcitonin of 23.10 (P = 0.02) compared with those with Gram-negative sepsis at 32.75 (P = 0.02). Those with fungal infections had a procalcitonin of 42.90 (P = 0.001). These data suggest that procalcitonin elevation can help guide treatment by indicating likely causative organism and infection type. These data may provide a good marker for initiation of antifungal therapy. PMID:25197879

  9. Employee suggestion programs: the rewards of involvement.

    PubMed

    Mishra, J M; McKendall, M

    1993-09-01

    Successful ESPs are the products of a great deal of effort by managers, administrators, teams, individuals, and reviewers, who are all striving to achieve the goals of increased profitability and enhanced employee involvement. A review of the literature indicates that there are several prescriptions that will increase the likelihood of a successful ESP (see the box). Today's American business prophets sound ceaseless calls to arms in the name of "world class performance," "global competitiveness," "total quality management," and a variety of other buzz terms. A burgeoning industry has evolved that promises, through speeches, teleconferences, seminars, and consulting contracts, to teach American organizations how to achieve excellence. In the face of a sputtering economy and unrelenting competitive pressure, today's managers must translate these laudatory ideals into hands-on reality without sacrificing the firm's profit margin to experimentation. If any idea can help an organization achieve improvement through a workable program, then that idea and that program deserve real consideration. An ESP represents an opportunity to tap the intelligence and resourcefulness of an organization's employees, and by doing so, reap significant cost savings. Those companies and managers that have an ESP program uniformly list economic advantages first when describing the benefits of their employee suggestion programs. But there is another deeper and longer term benefit inherent in an ESP. These programs allow employees to become involved in their organization; they drive deaccession to lower levels, they give employees more responsibility, they foster creative approaches to work, and they encourage creativity in pursuit of company goals.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:10127910

  10. Hemispheric asymmetry of the sun suggested by the annual variation of the aa index

    Microsoft Academic Search

    J. Oksman; E. Kataja

    1986-01-01

    The annual variation of Mayaud's (1973) aa index has been discovered to exhibit unequal spring and fall maxima, the relative dominance of the two equinoxes varying in a quasi-periodic way. This finding suggests that one magnetic hemisphere of the sun might predominate slightly over the other for several years in succession, the dominance then switching over in a quasi-periodic way.

  11. 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.

  12. Rotational Period of 1511 Dalera

    NASA Astrophysics Data System (ADS)

    Scardella, Maurizio; Franceschini, Francesco; Tomassini, Angelo

    2015-07-01

    Photometric observations of the asteroid 1511 Dalera were made on three nights in 2015 February and March. Analysis of the data has allowed to draw a lightcurve with a synodic period P = 3.880 ± 0.001 h with amplitude A = 0.18 mag.

  13. Analysis of the eclipsing binaries in the LMC discovered by OGLE: Period distribution and frequency of the short-period binaries

    E-print Network

    Tsevi Mazeh; Omer Tamuz; Pierre North

    2006-11-15

    We review the results of our analysis of the OGLE LMC eclipsing binaries (Mazeh, Tamuz & North 2006), using EBAS -- Eclipsing Binary Automated Solver, an automated algorithm to fit lightcurves of eclipsing binaries (Tamuz, Mazeh & North 2006). After being corrected for observational selection effects, the set of detected eclipsing binaries yielded the period distribution and the frequency of all LMC short-period binaries, and not just the eclipsing systems. Somewhat surprisingly, the period distribution is consistent with a flat distribution in log P between 2 and 10 days. The total number of binaries with periods shorter than 10 days in the LMC was estimated to be about 5000. This figure led us to suggest that (0.7 +- 0.4)% of the main-sequence A- and B-type stars are found in binaries with periods shorter than 10 days. This frequency is substantially smaller than the fraction of binaries found by small Galactic radial-velocity surveys of B stars.

  14. Latent period in clinical radiation myelopathy

    SciTech Connect

    Schultheiss, T.E.; Higgins, E.M.; El-Mahdi, A.M.

    1984-07-01

    Seventy-seven papers containing data on more than 300 cases of radiation myelopathy have been analyzed. The data suggest that the latent periods are similar in the cervical and thoracic levels of the spinal cord and are bimodally distributed. Myelopathy of lumbar cord apparently has a shorter latent period. As in controlled animal experiments, the latent period decreases with increasing dose. Furthermore, the variation in latent periods also decreases with dose. It is also seen that retreated patients and pediatric or adolescent patients have greatly reduced latent periods. The implications of these findings as they compare with the animal data are discussed.

  15. Clines of nuclear DNA markers suggest a largely Neolithic ancestry of the European gene pool

    PubMed Central

    Chikhi, Lounès; Destro-Bisol, Giovanni; Bertorelle, Giorgio; Pascali, Vincenzo; Barbujani, Guido

    1998-01-01

    Comparisons between archaeological findings and allele frequencies at protein loci suggest that most genes of current Europeans descend from populations that have been expanding in Europe in the last 10,000 years, in the Neolithic period. Recent mitochondrial data have been interpreted as indicating a much older, Paleolithic ancestry. In a spatial autocorrelation study at seven hypervariable loci in Europe (four microsatellites, two larger, tandem-repeat loci, and a sequence polymorphism) broad clinal patterns of DNA variation were recognized. The observed clines closely match those described at the protein level, in agreement with a possible Near Eastern origin for the ancestral population. Separation times between populations were estimated on the basis of a stepwise mutation model. Even assuming low mutation rates and long generation times, we found no evidence for population splits older than 10,000 years, with the predictable exception of Saami (Lapps). The simplest interpretation of these results is that the current nuclear gene pool largely reflects the westward and northward expansion of a Neolithic group. This conclusion is now supported by purely genetic evidence on the levels and patterns of microsatellite diversity, rather than by correlations of biological and nonbiological data. We argue that many mitochondrial lineages whose origin has been traced back to the Paleolithic period probably reached Europe at a later time. PMID:9671803

  16. Suggested posthypnotic amnesia in psychiatric patients and normals.

    PubMed

    Frischholz, Edward J; Lipman, Laurie S; Braun, Bennett G; Sachs, Roberta

    2015-01-01

    The present study examined both quantitative and qualitative hypnotizability differences among four psychiatric patient groups (dissociative disorder (n = 17), schizophrenic (n = 13), mood disorder (n = 14), and anxiety disorder (n = 14) patients), and normals (college students (n = 63)). Dissociative disorder patients earned significantly higher corrected total scores on the Stanford Hypnotic Susceptibility Scale, Form C (mean = 7.94), than all other groups. Likewise, dissociative disorder patients initially recalled significantly fewer items when the posthypnotic amnesia suggestion was in effect (mean = .41) and reversed significantly more items when the suggestion was canceled (mean = 3.82) than all other groups. In contrast, schizophrenic patients recalled significantly fewer items when the amnesia suggestion was in effect (mean = 1.85) and reversed significantly fewer items when it was canceled (mean = .77) than the remaining groups. This qualitative difference between schizophrenic patients and the other groups on the suggested posthypnotic amnesia item was observed even though there were no significant quantitative differences between groups in overall hypnotic responsivity. PMID:25928596

  17. Rhythm Generation through Period Concatenation in Rat Somatosensory Cortex

    PubMed Central

    Kramer, Mark A.; Roopun, Anita K.; Carracedo, Lucy M.; Traub, Roger D.; Whittington, Miles A.; Kopell, Nancy J.

    2008-01-01

    Rhythmic voltage oscillations resulting from the summed activity of neuronal populations occur in many nervous systems. Contemporary observations suggest that coexistent oscillations interact and, in time, may switch in dominance. We recently reported an example of these interactions recorded from in vitro preparations of rat somatosensory cortex. We found that following an initial interval of coexistent gamma (?25 ms period) and beta2 (?40 ms period) rhythms in the superficial and deep cortical layers, respectively, a transition to a synchronous beta1 (?65 ms period) rhythm in all cortical layers occurred. We proposed that the switch to beta1 activity resulted from the novel mechanism of period concatenation of the faster rhythms: gamma period (25 ms)+beta2 period (40 ms)?=?beta1 period (65 ms). In this article, we investigate in greater detail the fundamental mechanisms of the beta1 rhythm. To do so we describe additional in vitro experiments that constrain a biologically realistic, yet simplified, computational model of the activity. We use the model to suggest that the dynamic building blocks (or motifs) of the gamma and beta2 rhythms combine to produce a beta1 oscillation that exhibits cross-frequency interactions. Through the combined approach of in vitro experiments and mathematical modeling we isolate the specific components that promote or destroy each rhythm. We propose that mechanisms vital to establishing the beta1 oscillation include strengthened connections between a population of deep layer intrinsically bursting cells and a transition from antidromic to orthodromic spike generation in these cells. We conclude that neural activity in the superficial and deep cortical layers may temporally combine to generate a slower oscillation. PMID:18773075

  18. Thermospheric density oscillations due to periodic solar wind high-speed streams

    NASA Astrophysics Data System (ADS)

    Thayer, Jeffrey P.; Lei, Jiuhou; Forbes, Jeffrey M.; Sutton, Eric K.; Nerem, R. Steven

    2008-06-01

    We report on periodic oscillations in thermosphere density, measured by the accelerometer on the CHAMP satellite during 2006, and relate these periodicities to oscillations observed in solar wind speed and Kp index. Common periodic oscillations at 4-5, 6-7, and 9-11 day periods are observed in the neutral density at 400 km in the 2006 data set, with the 7 day period being the predominant oscillation. Spectral analysis reveals that similar periodicities are present in both the solar wind and the planetary magnetic index Kp but not in the EUV solar flux proxy F10.7. We suggest that the periodic oscillations observed in thermosphere density are a direct response to recurrent geomagnetic activity and associated high-speed streams in the solar wind. The lack of response in F10.7 at the 7 day period enables storm effects on the thermosphere density to be isolated from solar flux effects. The Kp index for these events correspond to moderate levels of geomagnetic activity, and the resultant perturbations in thermosphere density are ±20-30% of background levels. Although these levels of perturbation are small compared to major magnetic storms, their much higher occurrence frequency and characteristic long recovery time may lead to a cumulative effect on the state of the thermosphere and ionosphere.

  19. The Video Suggestibility Scale for Children: how generalizable is children's performance to other measures of suggestibility?

    PubMed

    McFarlane, Felicity; Powell, Martine B

    2002-01-01

    This study explored the generalizability of the Video Suggestibility Scale for Children (VSSC), which was developed by Scullin and colleagues (Scullin & Ceci, 2001; Scullin & Hembrooke, 1998) as a tool for discriminating among children (aged three to five years) who have different levels of suggestibility. The VSSC consists of two subscales; Yield (a measure of children's willingness to acquiesce to misleading questions) and Shift (a measure of children's tendency to change their responses after feedback from the interviewer). Children's (N = 77) performance on each of the subscales was compared with their performance using several other measures of suggestibility. These measures included children's willingness to assent to a false event as well as the number of false interviewer suggestions and false new details that the children provided when responding to cued-recall questions about an independent true-biased and an independent false (non-experienced) event. An independent samples t-test revealed that those children who assented to the false event generated higher scores on the Yield measure. Hierarchical regression analyses revealed that Yield was a significant predictor of the number of false details reported about the false activity, but not the true-biased activity. There was no significant relationship between the Shift subscale and any of the dependent variables. The potential contribution of the VSSC for forensic researchers and practitioners is discussed. PMID:12465135

  20. De novo origin of periodic proteins

    Microsoft Academic Search

    Martynas Y?as

    1972-01-01

    Summary Silk fibroin, collagen, “freezing point depressing” glycoproteins, keratin and protamines have periodic amino acid sequences which are unlikely to have arisen by amino acid replacements and internal duplications of non-periodic DNA. Evidence here discussed suggests that such proteins arise by a single evolutionary event, an iterativede novo synthesis of DNA.

  1. New Photometric Observations of sigma Ori E

    E-print Network

    Mary Oksala; Rich Townsend

    2005-11-15

    We present new UBVRI observations of the magnetic Bp star sigma Ori E. The basic features of the star's lightcurve have not changed since the previous monitoring by Hesser et al. (1977), indicating that the star's magnetosphere has remained stable over the past three decades. Interestingly, we find a rotation period that is slightly longer than in the Hesser et al. (1977) analysis, suggesting possible spindown of the star.

  2. Observational architectures for enabling earthquake forecasting

    Microsoft Academic Search

    Curtis W. Chen; Carol A. Raymond; SGren N. Madsen

    2003-01-01

    Observational architectures for allowing the eventual forecasting of earthquake are discussed. Current science requirements suggest that L-band InSAR systems with short repeat periods would be best suited to such measurements. Constellations of such sensors in orbits around 2000-5000 km altitude might provide optimal Earth coverage for interferometry, while higher orbits around 10,000 - 40,000 km might approach the goal of

  3. A slope variation in the period-luminosity relation for short period SMC Cepheids

    Microsoft Academic Search

    F. Bauer; C. Afonso; J. N. Albert; C. Alard; J. Andersen; R. Ansari; É. Aubourg; P. Bareyre; J. P. Beaulieu; A. Bouquet; S. Char; X. Charlot; F. Couchot; C. Coutures; F. Derue; R. Ferlet; C. Gaucherel; J. F. Glicenstein; B. Goldman; A. Gould; D. Graff; M. Gros; J. Haissinski; J. C. Hamilton; D. Hardin; J. de Kat; A. Kim; T. Lasserre; É. Lesquoy; C. Loup; C. Magneville; B. Mansoux; J. B. Marquette; É. Maurice; A. Milsztajn; M. Moniez; N. Palanque-Delabrouille; O. Perdereau; L. Prévot; C. Renault; N. Regnault; J. Rich; M. Spiro; A. Vidal-Madjar; L. Vigroux; S. Zylberajch

    1999-01-01

    We present the Period-Luminosity relations from 290 Cepheids towards the LMC and 590 Cepheids towards the SMC. The two data sets were obtained using the two wide field CCD cameras of the EROS 2 microlensing survey. We observe a significant slope change of the period-luminosity relation for the SMC fundamental mode Cepheids with periods shorter than 2 days. Many possible

  4. Application of the ex-Gaussian function to the effect of the word blindness suggestion on Stroop task performance suggests no word blindness

    PubMed Central

    Parris, Benjamin A.; Dienes, Zoltan; Hodgson, Timothy L.

    2013-01-01

    The aim of the present paper was to apply the ex-Gaussian function to data reported by Parris et al. (2012) given its utility in studies involving the Stroop task. Parris et al. showed an effect of the word blindness suggestion when Response-Stimulus Interval (RSI) was 500 ms but not when it was 3500 ms. Analysis revealed that: (1) The effect of the suggestion on interference is observed in ?, supporting converging evidence indicating the suggestion operates over response competition mechanisms; and, (2) Contrary to Parris et al. an effect of the suggestion was observed in ? when RSI was 3500 ms. The reanalysis of the data from Parris et al. (2012) supports the utility of ex-Gaussian analysis in revealing effects that might otherwise be thought of as absent. We suggest that word reading itself is not suppressed by the suggestion but instead that response conflict is dealt with more effectively. PMID:24065947

  5. On composites with periodic structure

    NASA Technical Reports Server (NTRS)

    Nemat-Nasser, S.; Iwakuma, T.; Hejazi, M.

    1982-01-01

    The overall moduli of a composite with an isotropic elastic matrix containing periodically distributed (anisotropic) inclusions or voids, can be expressed in terms of several infinite series which only depend on the geometry of the inclusions or voids, and hence can be computed once and for all for given geometries. For solids with periodic structures these infinite series play exactly the same role as does Eshelby's tensor for a single inclusion or void in an unbounded elastic medium. For spherical and circular-cylindrical geometries, the required infinite series are calculated and the results are tabulated. These are then used to estimate the overall elastic moduli when either the overall strains or the overall stresses are prescribed, obtaining the same results. These results are compared with other estimates and with experimental data. It is found that the model of composites with periodic structure yields estimates in excellent agreement with the experimental observations.

  6. Isolated periodic solutions of the Hodgkin-Huxley equations.

    PubMed

    Hassard, B D; Shiau, L J

    1989-02-01

    Periodic solutions of the current clamped Hodgkin-Huxley equations (Hodgkin & Huxley, 1952 J. Physiol. 117, 500) that arise by degenerate Hopf bifurcation were studied recently by Labouriau (1985 SIAM J. Math. Anal. 16, 1121, 1987 Degenerate Hopf Bifurcation and Nerve Impulse (Part II), in press). Two parameters, temperature T and sodium conductance gNa were varied from the original values obtained by Hodgkin & Huxley. Labouriau's work proved the existence of small amplitude periodic solution branches that do not connect locally to the stationary solution branch, and had not been previously computed. In this paper we compute these solution branches globally. We find families of isolas of periodic solutions (i.e. branches not connected to the stationary branch). For values of gNa in the range measured by Hodgkin & Huxley, and for physically reasonable temperatures, there are isolas containing orbitally asymptotically stable solutions. The presence of isolas of periodic solutions suggests that in certain current space clamped membrane experiments, action potentials could be observed even though the stationary state is stable for all current stimuli. Once produced, such action potentials will disappear suddenly if the current stimulus is either increased or decreased past certain values. Under some conditions, "jumping" between action potentials of different amplitudes might be observed. PMID:2811393

  7. 24 CFR 203.266 - Period covered by periodic MIP.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 false Period covered by periodic MIP. 203.266 Section 203.266 ...Obligations Mortgage Insurance Premiums-Periodic Payment § 203.266 Period covered by periodic MIP. The initial MIP shall...

  8. 24 CFR 203.266 - Period covered by periodic MIP.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 false Period covered by periodic MIP. 203.266 Section 203.266 ...Obligations Mortgage Insurance Premiums-Periodic Payment § 203.266 Period covered by periodic MIP. The initial MIP shall...

  9. 24 CFR 203.266 - Period covered by periodic MIP.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 false Period covered by periodic MIP. 203.266 Section 203.266 ...Obligations Mortgage Insurance Premiums-Periodic Payment § 203.266 Period covered by periodic MIP. The initial MIP shall...

  10. 24 CFR 203.266 - Period covered by periodic MIP.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 false Period covered by periodic MIP. 203.266 Section 203.266 ...Obligations Mortgage Insurance Premiums-Periodic Payment § 203.266 Period covered by periodic MIP. The initial MIP shall...

  11. 24 CFR 203.266 - Period covered by periodic MIP.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 false Period covered by periodic MIP. 203.266 Section 203.266 ...Obligations Mortgage Insurance Premiums-Periodic Payment § 203.266 Period covered by periodic MIP. The initial MIP shall...

  12. Statin therapy in the perioperative period.

    PubMed

    Lander, Jeffrey S; Coplan, Neil L

    2011-01-01

    Statins are frequently used as chronic therapy for reducing cardiovascular mortality and morbidity, but there has been less emphasis on the role of statins in the perioperative period. This review evaluates data regarding statin use in vascular and noncardiac surgery, the use of statins in combination with ?-blockers in the perioperative period, perioperative statin use in patients already treated with statins, and the safety of statin therapy in the perioperative period. Current recommendations state that patients who are prescribed statins as chronic therapy should continue treatment in the perioperative period, but data suggest that there may be benefit from the use of perioperative statins in a wider population. PMID:21546886

  13. VOLUME 85, NUMBER 17 P H Y S I C A L R E V I E W L E T T E R S 23 OCTOBER 2000 Discrete Periodic Melting Point Observations for Nanostructure Ensembles

    E-print Network

    Berry, R. Stephen

    Melting Point Observations for Nanostructure Ensembles M. Yu. Efremov,1 F. Schiettekatte,1 M. Zhang,1 E. A) and (b) size-dependent melting point depression of small particles. This area of research for clusters with a few atoms up to 22 000 atoms [7]. Size-dependent melting point depression is an important

  14. Period Determination for 4527 Schoenberg

    NASA Astrophysics Data System (ADS)

    Burkhonov, O. A.; Ehgamberdiev, Sh. A.; Ergashev, K. E.

    2013-10-01

    The main-belt asteroid 4527 Schoenberg (1982 OK) has been observed between June 28 and July 1, 2012 at Maidanak astronomical observatory of the Ulugh Beg Astronomical Institute (UBAI), Uzbekistan Academy of Sciences. On the basis of data analysis it is found a synodic rotation period of 2.6928" b0.0384 hour (0.1122±0.0016 day) and lightcurve amplitude of 0.31±0.05 mag.

  15. Composition and evolution of the continental crust as suggested by seismic observations

    USGS Publications Warehouse

    Pakiser, L.C.; Robinson, R.

    1966-01-01

    The average composition of the continental crust is more mafic than hitherto supposed. The conterminous United States can be divided, on the basis of seismic structure, into ten regions. The seven western and the three eastern regions can be termed western and eastern superprovinces. Seismic studies show that the crust is thinner and more silicic in tectonically active regions (western superprovince - average crustal thickness 34 km), than in stable regions (eastern superprovince - average crustal thickness 44 km). Mafic rocks are estimated to average 55% of the continental crust: 45% in the western and 59% in the eastern superprovince. These results express quantitatively the ideas expressed qualitatively by Pakiser and Zietz (1965). The computations of percentages of major oxides in the crust associate seismic velocities with rock compositions. ?? 1956.

  16. NATURE|Vol 435|9 June 2005 NEWS & VIEWS Some observations suggest that the fungal

    E-print Network

    Gomes, Carla P.

    . Yoneyama,K.,Takeuchi,Y.&Yokota,T.Physiol.Planta112, 25­30(2001). 11. Kosuta,S.etal.PlantPhysiol.131, Germany. e-mail: parniske@lmu.de 1. Akiyama,K.,Matsuzaki,K.-i.&Hayashi,H.Nature435, 824­827(2005). 2. Remy

  17. Mass-balance measurements in Alaska and suggestions for simplified observation programs

    USGS Publications Warehouse

    Trabant, D.C.; March, R.S.

    1999-01-01

    US Geological Survey glacier fieldwork in Alaska includes repetitious measurements, corrections for leaning or bending stakes, an ability to reliably measure seasonal snow as deep as 10 m, absolute identification of summer surfaces in the accumulation area, and annual evaluation of internal accumulation, internal ablation, and glacier-thickness changes. Prescribed field measurement and note-taking techniques help eliminate field errors and expedite the interpretative process. In the office, field notes are transferred to computerized spread-sheets for analysis, release on the World Wide Web, and archival storage. The spreadsheets have error traps to help eliminate note-taking and transcription errors. Rigorous error analysis ends when mass-balance measurements are extrapolated and integrated with area to determine glacier and basin mass balances. Unassessable errors in the glacier and basin mass-balance data reduce the value of the data set for correlations with climate change indices. The minimum glacier mass-balance program has at least three measurement sites on a glacier and the measurements must include the seasonal components of mass balance as well as the annual balance.

  18. The Spin Period of EX Hydrae

    E-print Network

    A. R. King; G. A. Wynn

    1999-09-17

    We show that the spin period of the white dwarf in the magnetic CV EX Hydrae represents an equilibrium state in which the corotation radius is comparable with the distance from the white dwarf to the inner Lagrange point. We also show that a continuum of spin equilibria exists at which Pspin is significantly longer than \\sim 0.1 Porb. Most systems occupying these equilibrium states should have orbital periods below the CV period gap, as observed.

  19. Photoelectric and Spectroscopic Observations Related to a Possible Optical Counterpart for Pulsar CP 1919+21.

    PubMed

    Lynds, R; Maran, S P; Trumbo, D E

    1968-07-01

    Spectroscopic observations of the two stars near the pulsar CP 1919+21 are not sufficiently conclusive to permit an identification of either object with the source of the radio pulses. However, our most extensive series of photometric observations of a region of sky near the radio source position, which region includes the brighter of the two stars, suggests an approximately sinusoidal variation. It is significant that the period of the variation is double the period of the radio pulsations. PMID:17756510

  20. The resistance to change of observing.

    PubMed Central

    Shahan, Timothy A; Magee, Adam; Dobberstein, Andria

    2003-01-01

    Observing responses produce contact with discriminative stimuli and have been considered analogous to attending. Many studies have examined the effects of reinforcement rate on the resistance to change of simple operant behavior, but nothing is known about the resistance to change of observing. Two experiments examined the effects of primary reinforcement rate on the resistance to change of observing behavior of pigeons. In Experiment 1, a multiple schedule of observing-response procedures was arranged. In a rich component, observing responses produced stimuli correlated with a high rate of random-interval (RI) reinforcement or extinction. In a lean component, observing responses produced stimuli correlated with a lower rate of RI reinforcement or extinction. In both components, observing responses produced the multiple-schedule stimuli on a fixed-interval 0.75-s schedule. In Experiment 2, a similar procedure was used, but observing in the rich and lean components produced schedule-correlated stimuli on an RI 15-s schedule. Observing in the rich component occurred at a higher rate and was more resistant to disruptions produced by presession feeding and response-independent food deliveries during intercomponent intervals. Despite more frequent observing during unsignaled periods of extinction than unsignaled periods of RI reinforcement, observing during extinction periods was less resistant to change. In addition, replicating the usual result, responding on the food key was generally more resistant to change in the presence of stimuli associated with higher reinforcement rates. These results suggest that quantitative descriptions of resistance to change derived with simple food-maintained responding may be applicable to observing, and perhaps by extension, to attending. PMID:14964708

  1. A suggested statistical test for measuring bivariate nonlinear dependence

    NASA Astrophysics Data System (ADS)

    Matsushita, Raul; Figueiredo, Annibal; Da Silva, Sergio

    2012-10-01

    We devise a new asymptotic statistical test to assess independence in bivariate continuous distributions. Our approach is based on the Cramér-von Mises test, in which the empirical process is viewed as the Kullback-Leibler divergence, that is, as the distance between the data under the independence hypothesis and the data empirically observed. We derive the theoretical characteristic function of the limit distribution of the test statistic and find the critical values through computer simulation. A Monte Carlo experiment is considered as assessing the validation and power performance of the test by assuming a bivariate nonlinear dependence structure with fat tails. Two extra examples, respectively, consider stationary and conditionally nonstationary series. Results confirm that our suggested test is consistent and powerful in the presence of bivariate nonlinear dependence even if the environment is non-Gaussian. Our case is illustrated with high-frequency data from stocks listed on the NYSE that recently experienced so-called mini-flash crashes.

  2. Membrane proteomics of phagosomes suggests a connection to autophagy

    SciTech Connect

    Shui, Wenqing; Sheu, Leslie; Liu, Jun; Smart, Brian; Petzold, Christopher J.; Hsieh, Tsung-yen; Pitcher, Austin; Keasling*, Jay D.; Bertozzi*, Carolyn R.

    2008-11-25

    Phagocytosis is the central process by which macrophage cellsinternalize and eliminate infectious microbes as well as apoptoticcells. During maturation, phagosomes containing engulfed particlesfuse with various endosomal compartments through theaction of regulatory molecules on the phagosomal membrane. Inthis study, we performed a proteomic analysis of the membranefraction from latex bead-containing (LBC) phagosomes isolatedfrom macrophages. The profile, which comprised 546 proteins,suggests diverse functions of the phagosome and potential connectionsto secretory processes, toll-like receptor signaling, andautophagy. Many identified proteins were not previously knownto reside in the phagosome. We characterized several proteins inLBC phagosomes that change in abundance on induction of autophagy,a process that has been previously implicated in the hostdefense against microbial pathogens. These observations suggestcrosstalk between autophagy and phagocytosis that may be relevantto the innate immune response of macrophages.

  3. Periodic table(3)

    NSDL National Science Digital Library

    Brian P. Reid

    This site not only provides a clickable-by-element resource for quickly finding physical properties of the elements (up to 109), but also provides students with puzzles to hone their ability to identify and place elements in their respective place in the periodic chart. Very useful for early learning of periodic placements.

  4. Active dust devils in Gusev crater, Mars: Observations from the Mars Exploration Rover Spirit

    Microsoft Academic Search

    Ronald Greeley; Patrick L. Whelley; Raymond E. Arvidson; Nathalie A. Cabrol; Daniel J. Foley; Brenda J. Franklin; Paul G. Geissler; Matthew P. Golombek; Ruslan O. Kuzmin; Geoffrey A. Landis; Mark T. Lemmon; Lynn D. V. Neakrase; Steven W. Squyres; Shane D. Thompson

    2006-01-01

    A full dust devil “season” was observed from Spirit from 10 March 2005 (sol 421, first active dust devil observed) to 12 December 2005 (sol 691, last dust devil seen); this corresponds to the period Ls 173.2° to 339.5°, or the southern spring and summer on Mars. Thermal Emission Spectrometer data suggest a correlation between high surface temperatures and a

  5. Rotation Period of Asteroid 4727 Ravel

    NASA Astrophysics Data System (ADS)

    Ergashev, K. E.; Ehgamberdiev, Sh. A.; Burkhonov, O. A.; Yoshida, Fumi

    2014-04-01

    The results of photometric observations of the main-belt asteroid 4727 Ravel (1979 UD1) from 2013 August 13- 16 at the Maidanak Astronomical Observatory of the Ulugh Beg Astronomical Institute (UBAI), Uzbekistan Academy of Sciences are presented. During the period of observations, the lightcurve amplitude was 0.32 ± 0.05 mag and the synodic rotation period was 0.185 ± 0.009 days (4.44 ± 0.22 h).

  6. Mitochondrial genomes suggest that hexapods and crustaceans are mutually paraphyletic

    PubMed Central

    Cook, Charles E; Yue, Qiaoyun; Akam, Michael

    2005-01-01

    For over a century the relationships between the four major groups of the phylum Arthropoda (Chelicerata, Crustacea, Hexapoda and Myriapoda) have been debated. Recent molecular evidence has confirmed a close relationship between the Crustacea and the Hexapoda, and has included the suggestion of a paraphyletic Hexapoda. To test this hypothesis we have sequenced the complete or near-complete mitochondrial genomes of three crustaceans (Parhyale hawaiensis, Squilla mantis and Triops longicaudatus), two collembolans (Onychiurus orientalis and Podura aquatica) and the insect Thermobia domestica. We observed rearrangement of transfer RNA genes only in O. orientalis, P. aquatica and P. hawaiensis. Of these, only the rearrangement in O. orientalis, an apparent autapomorphy for the collembolan family Onychiuridae, was phylogenetically informative. We aligned the nuclear and amino acid sequences from the mitochondrial protein-encoding genes of these taxa with their homologues from other arthropod taxa for phylogenetic analysis. Our dataset contains many more Crustacea than previous molecular phylogenetic analyses of the arthropods. Neighbour-joining, maximum-likelihood and Bayesian posterior probabilities all suggest that crustaceans and hexapods are mutually paraphyletic. A crustacean clade of Malacostraca and Branchiopoda emerges as sister to the Insecta sensu stricto and the Collembola group with the maxillopod crustaceans. Some, but not all, analyses strongly support this mutual paraphyly but statistical tests do not reject the null hypotheses of a monophyletic Hexapoda or a monophyletic Crustacea. The dual monophyly of the Hexapoda and Crustacea has rarely been questioned in recent years but the idea of both groups' paraphyly dates back to the nineteenth century. We suggest that the mutual paraphyly of both groups should seriously be considered. PMID:16024395

  7. Periodic Comet Showers, Mass Extinctions, and the Galaxy

    NASA Technical Reports Server (NTRS)

    Rampino, M. R.; Stothers, R. B.

    2000-01-01

    Geologic data on mass extinctions of life and evidence of large impacts on the Earth are thus far consistent with a quasi-periodic modulation of the flux of Oort cloud comets. Impacts of large comets and asteroids are capable of causing mass extinction of species, and the records of large impact craters and mass show a correlation. Impacts and extinctions display periods in the range of approximately 31 +/- 5 m.y., depending on dating methods, published time scales, length of record, and number of events analyzed. Statistical studies show that observed differences in the formal periodicity of extinctions and craters are to be expected, taking into consideration problems in dating and the likelihood that both records would be mixtures of periodic and random events. These results could be explained by quasi-periodic showers of Oort Cloud comets with a similar cycle. The best candidate for a pacemaker for comet showers is the Sun's vertical oscillation through the plane of the Galaxy, with a half-period over the last 250 million years in the same range. We originally suggested that the probability of encounters with molecular clouds that could perturb the Oort comet cloud and cause comet showers is modulated by the Sun's vertical motion through the galactic disk. Tidal forces produced by the overall gravitational field of the Galaxy can also cause perturbations of cometary orbits. Since these forces vary with the changing position of the solar system in the Galaxy, they provide a mechanism for the periodic variation in the flux of Oort cloud comets into the inner solar system. The cycle time and degree of modulation depend critically on the mass distribution in the galactic disk. Additional information is contained in the original extended abstract.

  8. Observations of discrete harmonics emerging from equatorial noise.

    PubMed

    Balikhin, Michael A; Shprits, Yuri Y; Walker, Simon N; Chen, Lunjin; Cornilleau-Wehrlin, Nicole; Dandouras, Iannis; Santolik, Ondrej; Carr, Christopher; Yearby, Keith H; Weiss, Benjamin

    2015-01-01

    A number of modes of oscillations of particles and fields can exist in space plasmas. Since the early 1970s, space missions have observed noise-like plasma waves near the geomagnetic equator known as 'equatorial noise'. Several theories were suggested, but clear observational evidence supported by realistic modelling has not been provided. Here we report on observations by the Cluster mission that clearly show the highly structured and periodic pattern of these waves. Very narrow-banded emissions at frequencies corresponding to exact multiples of the proton gyrofrequency (frequency of gyration around the field line) from the 17th up to the 30th harmonic are observed, indicating that these waves are generated by the proton distributions. Simultaneously with these coherent periodic structures in waves, the Cluster spacecraft observes 'ring' distributions of protons in velocity space that provide the free energy for the waves. Calculated wave growth based on ion distributions shows a very similar pattern to the observations. PMID:26169360

  9. Generating Many Majorana Modes via Periodic Driving: A Superconductor Model

    E-print Network

    Qing-Jun Tong; Jun-Hong An; Jiangbin Gong; Hong-Gang Luo; C. H. Oh

    2013-05-17

    Realizing Majorana modes (MMs) in condensed-matter systems is of vast experimental and theoretical interests, and some signatures of MMs have been measured already. To facilitate future experimental observations and to explore further applications of MMs, generating many MMs at ease in an experimentally accessible manner has become one important issue. This task is achieved here in a one-dimensional $p$-wave superconductor system with the nearest- and next-nearest-neighbor interactions. In particular, a periodic modulation of some system parameters can induce an effective long-range interaction (as suggested by the Baker-Campbell-Hausdorff formula) and may recover time-reversal symmetry already broken in undriven cases. By exploiting these two independent mechanisms at once we have established a general method in generating many Floquet MMs via periodic driving.

  10. Remote sensing requirements as suggested by watershed model sensitivity analyses

    NASA Technical Reports Server (NTRS)

    Salomonson, V. V.; Rango, A.; Ormsby, J. P.; Ambaruch, R.

    1975-01-01

    A continuous simulation watershed model has been used to perform sensitivity analyses that provide guidance in defining remote sensing requirements for the monitoring of watershed features and processes. The results show that out of 26 input parameters having meaningful effects on simulated runoff, 6 appear to be obtainable with existing remote sensing techniques. Of these six parameters, 3 require the measurement of the areal extent of surface features (impervious areas, water bodies, and the extent of forested area), two require the descrimination of land use that can be related to overland flow roughness coefficient or the density of vegetation so as to estimate the magnitude of precipitation interception, and one parameter requires the measurement of distance to get the length over which overland flow typically occurs. Observational goals are also suggested for monitoring such fundamental watershed processes as precipitation, soil moisture, and evapotranspiration. A case study on the Patuxent River in Maryland shows that runoff simulation is improved if recent satellite land use observations are used as model inputs as opposed to less timely topographic map information.

  11. SPECTROSCOPIC EVIDENCE FOR A 5.4 MINUTE ORBITAL PERIOD IN HM CANCRI

    SciTech Connect

    Roelofs, Gijs H. A. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Rau, Arne [Astronomy Department, California Institute of Technology, Pasadena, CA 91125 (United States); Marsh, Tom R.; Steeghs, Danny [Department of Physics, University of Warwick, Coventry, CV4 7AL (United Kingdom); Groot, Paul J.; Nelemans, Gijs [Department of Astrophysics, Radboud University Nijmegen, P.O. Box 9010, 6500 GL, Nijmegen (Netherlands)], E-mail: groelofs@cfa.harvard.edu, E-mail: arau@mpe.mpg.de

    2010-03-10

    HM Cancri is a candidate ultracompact binary white dwarf with an apparent orbital period of only 5.4 minutes, as suggested by X-ray and optical light-curve modulations on that period, and by the absence of longer-period variability. In this Letter, we present Keck-I spectroscopy which shows clear modulation of the helium emission lines in both radial velocity and amplitude on the 5.4 minute period and no other. The data strongly suggest that the binary is emitting He I 4471 from the irradiated face of the cooler, less massive star, and He II 4686 from a ring around the more massive star. From their relative radial velocities, we measure a mass ratio q = 0.50 {+-} 0.13. We conclude that the observed 5.4 minute period almost certainly represents the orbital period of an interacting binary white dwarf. We thus confirm that HM Cnc is the shortest period binary star known: a unique test for stellar evolution theory, and one of the strongest known sources of gravitational waves for LISA.

  12. Periodic structures in lipid monolayer phase transitions

    PubMed Central

    McConnell, Harden M.; Tamm, Lukas K.; Weis, Robert M.

    1984-01-01

    Periodic patterns are observed when supported lipid monolayers doped with low concentrations of fluorescent lipid probes are observed with epi-fluorescence microscopy. Monolayers of dipalmitoyl phosphatidylcholine were examined on air-water interfaces and also on alkylated glass coverslips. The patterns are formed by periodic arrays of solid-phase lipid domains in equilibrium with fluid-phase lipid under specified conditions of temperature and two-dimensional lipid pressure. Electrostatic forces may stabilize the periodic ordering of the solid domains. Images PMID:16593467

  13. Nonuniform Sampling and Periodic Signal Detection

    NASA Astrophysics Data System (ADS)

    Madore, Barry F.; Freedman, Wendy L.

    2005-09-01

    We discuss a search strategy for the discovery of periodically variable sources, using small numbers of observations (N<=20) distributed nonuniformly over a finite observing window that is comparable in size to the underlying periods. We explore such topics as sampling-induced errors, magnitude errors, and random and optimal sampling. We give the algorithm designed for optimal sampling as originally employed in the discovery of variables stars using the Hubble Space Telescope. We discuss in some detail a figure of merit designed to describe various sampling strategies and explore what is required to measure quantities such as the mean magnitudes and amplitudes of variables in addition to their periods.

  14. ULTRACAM observations of two accreting white dwarf pulsators

    NASA Astrophysics Data System (ADS)

    Copperwheat, C. M.; Marsh, T. R.; Dhillon, V. S.; Littlefair, S. P.; Woudt, P. A.; Warner, B.; Steeghs, D.; Gänsicke, B. T.; Southworth, J.

    2009-02-01

    In this paper, we present high time-resolution observations of GW Librae (GW Lib) and SDSS J161033.64-010223.3 (SDSS 1610) - two cataclysmic variables which have shown periodic variations attributed to non-radial pulsations of the white dwarf (WD). We observed both these systems in their quiescent states with ULTRACAM on the Very Large Telescope (VLT) and the University of Cape Town Photometer on the SAAO 1.9m telescope, and detect the strong pulsations modes reported by previous authors. The identification of further periodicities in GW Lib is limited by the accretion-driven flickering of the source, but in the case of SDSS 1610 we identify several additional low-amplitude periodicities. In both the sources, we find the pulsation modes to be stronger in amplitude at bluer wavelengths. In the case of SDSS 1610, there is evidence to suggest that the two primary signals have a different colour dependence, suggesting that they may be different spherical harmonic modes. We additionally observed GW Lib during several epochs following its 2007 dwarf nova outburst, using ULTRACAM on the VLT and the Auxiliary Port Imager on the William Herschel Telescope. This is the first time a dwarf nova containing a pulsating WD has been observed in such a state. We do not observe any periodicities, suggesting that the heating of the WD had either switched-off the pulsations entirely, or reduced their relative amplitude in flux to the point where they are undetectable. Further observations 11 months after the outburst taken with RATCam on the Liverpool Telescope still do not show the pulsation modes previously observed, but do show the emergence of two new periodic signals, one with a frequency of 74.86 +/- 0.68 cyclesd-1 (P = 1154s) and a g'-band amplitude of 2.20 per cent +/-0.18 and the other with a frequency of 292.05 +/- 1.11 cyclesd-1 (P = 296s) and a g' amplitude of 1.25 per cent +/-0.18. In addition to the WD pulsations, our observations of GW Lib in quiescence show a larger amplitude modulation in luminosity with a period of approximately 2.1 h. This has previously been observed, and its origin is unclear: it is unrelated to the orbital period. We find this modulation to vary over the course of our observations in phase and/or period. Our data support the conclusion that this is an accretion-related phenomenon, which originates in the accretion disc.

  15. Genealogy of periodic trajectories

    SciTech Connect

    de Adguiar, M.A.M.; Maldta, C.P.; de Passos, E.J.V.

    1986-05-20

    The periodic solutions of non-integrable classical Hamiltonian systems with two degrees of freedom are numerically investigated. Curves of periodic families are given in plots of energy vs. period. Results are presented for this Hamiltonian: H = 1/2(p/sub x//sup 2/ + p/sub y//sup 2/) + 1/2 x/sup 2/ + 3/2 y/sup 2/ - x/sup 2/y + 1/12 x/sup 4/. Properties of the families of curves are pointed out. (LEW)

  16. Periodic boundary conditions

    NSDL National Science Digital Library

    Iacovella, Christopher R.

    2006-09-24

    Schematic of periodic boundary conditions. When using periodic boundary conditions, a particle which exits the system on the right, will reappear on the left. In the schematic, our simulation volume is colored in red. As the yellow particle exits on the right, it will re-enter on the left. This can be thought of as having identical simulation boxes surrounding the system. As the yellow particle enters the next simulation on the right, a particle from the periodic image on the left will enter.

  17. A combined whelk watch suggests repeated TBT desorption pulses.

    PubMed

    Ruiz, J M; Albaina, N; Carro, B; Barreiro, R

    2015-01-01

    Environmental quality in coastal Europe has improved since the complete 2003 ban on the use of tributyltin (TBT) in antifouling paints. However, there is evidence that TBT is entering the water column, presumably from illegal practices. We determined the concentration of butyltins (BTs: TBT and derivatives) in populations of two gastropods, the rock snail Nucella lapillus (n=17) and the mud snail Nassarius reticulatus (n=18) at regular intervals from pre-ban times until 2009 and 2011, respectively, in NW Spain. Although a substantial decline in TBT occurred shortly after the ban, no significant changes were observed in either species over the last 3-year period of study. In addition, the proportion of TBT relative to the sum of BTs (a marker of recent pollution) in the most recent rock snail samples unexpectedly increased; this proportion therefore showed a generally decreasing but oscillatory trend over time. The results are consistent with the theoretical expectation of BT desorption from sediments; however, this natural phenomenon is now interpreted as a recurrent episode rather than a unique, transient event. Evidence of this subtle input improves our understanding of TBT persistence in the environment in Europe and worldwide. PMID:25260162

  18. MADS for periodic variables

    E-print Network

    Sébastien Le Digabel

    2009-05-19

    May 19, 2009 ... The effect of the treatment of periodic variables presented in this paper can be visualized in. Figure 5, that ... In all the numerical experiments conducted here, the new ... To appear in SIAM Journal on Optimization, 2009.

  19. The Cretaceous Period

    NSDL National Science Digital Library

    This resource discusses notable facts about the Cretaceous Period, the last portion of the "Age of Dinosaurs". The site covers Ceratopsians, such as the Tricerotops. It includes sections on stratigraphy, ancient life, localities and tectonics.

  20. Periodic multiresolution Lubeck, Germany

    E-print Network

    Potts, Daniel

    Periodic multiresolution J. Prestin L¨ubeck, Germany prestin@math.uni-luebeck.de One of the basic ideas of multiresolution and wavelet analysis consists in the investigation of shift-invariant function

  1. Interactive Periodic Table

    NSDL National Science Digital Library

    This interactive Periodic Table (application/applet) has been designed as a learning tool to help the beginning high school or undergraduate chemistry student gain insight. It could be used either as a lecture aid or distributed to students.

  2. Fourier series and periodicity

    E-print Network

    Donal F. Connon

    2014-12-07

    A large number of the classical texts dealing with Fourier series more or less state that the hypothesis of periodicity is required for pointwise convergence. In this paper, we highlight the fact that this condition is not necessary.

  3. Ecology of vector mosquitoes in Sri Lanka--suggestions for future mosquito control in rice ecosystems.

    PubMed

    Yasuoka, Junko; Levins, Richard

    2007-07-01

    Mosquito-borne diseases are a major public health threat in Asia. To explore effective mosquito control strategies in rice ecosystems from the ecological point of view, we carried out ecological analyses of vector mosquitoes in Sri Lanka. During the 18-month study period, 14 Anopheles, 11 Culex, 5 Aedes, 2 Mansonia, and 1 Armigeres species were collected, most of which are disease vectors for malaria, filariasis, Japanese encephalitis, or dengue in Sri Lanka and elsewhere in Asia. The density and occurrence of Anopheles and Culex species were the highest in seepage pools and paddy fields, where the majority of niche overlaps between larval mosquito and aquatic insect species were observed. All 7 aquatic insect species, which are larval mosquito predators, overlapped their niche with both Anopheles and Culex larvae. This suggests that conserving these aquatic insect species could be effective in controlling mosquito vectors in the study site. Correlations between several climatic factors and mosquito density were also analyzed, and weather conditions, including higher temperature, lower relative humidity, and higher wind velocity, were found to affect mosquito oviposition, propagation, and survival. These findings deepen our understanding of mosquito ecology and will strengthen future mosquito control strategies in rice ecosystems in Asia. PMID:17883002

  4. Periodical Cicada Page

    NSDL National Science Digital Library

    Cooley, John

    This site, from the University of Michigan's Museum of Zoology, provides a variety of short information entries about periodical cicadas including photos, and song clips. Information about cicada life cycles, broods and distribution, behavior, various species, and diseases and deformities can also be found here. For you "on the go types" who need basic information right now, there link to the "Quick periodical cicada FAQ."

  5. Effects of periodic discharges

    NASA Technical Reports Server (NTRS)

    Ford, F. E.

    1977-01-01

    Periodic capacity checks are assessed as well as the effects of periodic discharges on the cycle life and the performance of cells during the cycle life. Topics discussed include the effect of the amount of electrolyte on cell capacity at 35 C; battery design for spacecraft; electrolyte starvation theory; battery separator degradation; negative electrode stability; voltage regulation; operating temperatures; and integration of reconditioning systems using microprocessors.

  6. Suggestibility or Hypnosis: What do our Scales Really Measure?

    Microsoft Academic Search

    Irving Kirsch

    1997-01-01

    Conceptually, hypnotizability has always been defined as the increase in suggestibility produced by hypnosis. In practice, hypnotizability is measured as suggestibility following a hypnotic induction. The data indicate that these are different constructs. Although the induction of hypnosis inmases suggestibility to a substantial degree, the correlation between hypnotic and nonhypnotic suggestibility approximates the reliability coefficients of so-called hypnotizability scales. This

  7. Stable Isotope Analysis of Amphidromous Hawaiian Gobies Suggests Their Larvae Spend a Substantial Period of Time in Freshwater River Plumes

    Microsoft Academic Search

    Peter W. Sorensen; Keith A. Hobson

    2005-01-01

    We employed stable isotope analysis (?13C, ?15N) to evaluate the sources of nutrients used by amphidromous gobiid fishes (Lentipes concolor, Sicyopterus stimpsoni, Awaous guamensis) caught migrating into and living in Hakalau Stream, Hawaii. Although considerable variation amongst the stable isotope values of stream items was noted across all 4 years of our study, the relationships between the fishes were relatively constant.

  8. Clines of Nuclear DNA Markers Suggest a Largely Neolithic Ancestry of the European Gene Pool

    Microsoft Academic Search

    Lounes Chikhi; Giovanni Destro-Bisol; Giorgio Bertorelle; Vincenzo Pascali; Guido Barbujani

    1998-01-01

    Comparisons between archaeological findings and allele frequencies at protein loci suggest that most genes of current Europeans descend from populations that have been expanding in Europe in the last 10,000 years, in the Neolithic period. Recent mitochondrial data have been interpreted as indicating a much older, Paleolithic ancestry. In a spatial autocorrelation study at seven hypervariable loci in Europe (four

  9. Women Born Early at Greater Risk of Delivering Preemies, Study Suggests

    MedlinePLUS

    Women Born Early at Greater Risk of Delivering Preemies, Study Suggests But most of these women still have their babies at-term, researcher notes To use ... she said. "Even if 14.2 percent of women born before 32 weeks delivered prematurely during the study period, let's not forget that means 85 percent ...

  10. Power Laws in Real Estate Prices during Bubble Periods

    NASA Astrophysics Data System (ADS)

    Ohnishi, Takaaki; Mizuno, Takayuki; Shimizu, Chihiro; Watanabe, Tsutomu

    How can we detect real estate bubbles? In this paper, we propose making use of information on the cross-sectional dispersion of real estate prices. During bubble periods, prices tend to go up considerably for some properties, but less so for others, so that price inequality across properties increases. In other words, a key characteristic of real estate bubbles is not the rapid price hike itself but a rise in price dispersion. Given this, the purpose of this paper is to examine whether developments in the dispersion in real estate prices can be used to detect bubbles in property markets as they arise, using data from Japan and the U.S. First, we show that the land price distribution in Tokyo had a power-law tail during the bubble period in the late 1980s, while it was very close to a lognormal before and after the bubble period. Second, in the U.S. data we find that the tail of the house price distribution tends to be heavier in those states which experienced a housing bubble. We also provide evidence suggesting that the power-law tail observed during bubble periods arises due to the lack of price arbitrage across regions.

  11. Recent Maxima of 67 Short Period Pulsating Stars

    NASA Astrophysics Data System (ADS)

    Samolyk, G.

    2015-01-01

    This paper contains times of maxima for 67 short period pulsating stars (primarily RR Lyrae and d Scuti stars). These maxima represent the CCD observations received by the AAVSO Short Period Pulsator (SPP) section in 2014.

  12. Interplanetary magnetic field periodicity of ˜153 days

    NASA Astrophysics Data System (ADS)

    Cane, H. V.; Richardson, I. G.; von Rosenvinge, T. T.

    We report on the finding of a 153-day periodicity in the magnetic field strength and solar wind speed measured at 1 AU during the years 1978-1982. The period and the occurence epoch are consistent with the “154-day” periodicity previously reported for events occurring at the Sun. In particular, the variations in the field strength and the occurence rate of energetic (tens of MeV) solar particle events are in phase. The similar periodicities in the interplanetary field and solar phenomena are consistent with a global phenomenon. Whereas this periodicity is quite strong for the magnetic field magnitude, there is only a weak periodicity for the individual field components. The field magnitude shows essentially no periodicity at this period during the previous and following solar maxima. The lack of persistence, and of significant harmonic components of the observed periodicity, does not support the proposal of a solar “clock” mechanism. The most significant variations in the complete near-earth magnetic field data base (1963-1997) with periods of less than 200 days occur at 166 and 146 days.

  13. Periodic accretion from a circumbinary disk in the young binary UZ Tau E

    E-print Network

    Eric L. N. Jensen; Saurav Dhital; Keivan G. Stassun; Jenny Patience; William Herbst; Frederick M. Walter; Michal Simon; Gibor Basri; ;

    2007-05-03

    Close pre-main-sequence binary stars are expected to clear central holes in their protoplanetary disks, but the extent to which material can flow from the circumbinary disk across the gap onto the individual circumstellar disks has been unclear. In binaries with eccentric orbits, periodic perturbation of the outer disk is predicted to induce mass flow across the gap, resulting in accretion that varies with the binary period. This accretion may manifest itself observationally as periodic changes in luminosity. Here we present a search for such periodic accretion in the pre-main-sequence spectroscopic binary UZ Tau E. We present BVRI photometry spanning three years; we find that the brightness of UZ Tau E is clearly periodic, with a best-fit period of 19.16 +/- 0.04 days. This is consistent with the spectroscopic binary period of 19.13 days, refined here from analysis of new and existing radial velocity data. The brightness of UZ Tau E shows significant random variability, but the overall periodic pattern is a broad peak in enhanced brightness, spanning more than half the binary orbital period. The variability of the H-alpha line is not as clearly periodic, but given the sparseness of the data, some periodic component is not ruled out. The photometric variations are in good agreement with predictions from simulations of binaries with orbital parameters similar to those of UZ Tau E, suggesting that periodic accretion does occur from circumbinary disks, replenishing the inner disks and possibly extending the timescale over which they might form planets.

  14. A Further Investigation of Apparent Periodicities and the Rotational State of Comet 103P/Hartley 2 from Combined Coma Morphology and Lightcurve Datasets

    E-print Network

    Knight, Matthew M; Samarasinha, Nalin H; Schleicher, David G

    2015-01-01

    We present an analysis of Kitt Peak National Observatory and Lowell Observatory observations of comet 103P/Hartley 2 obtained from August through December 2010. The results are then compared with contemporaneous observations made by the EPOXI spacecraft. Each ground-based dataset has previously been investigated individually; the combined dataset has complementary coverage that reduces the time between observing runs and allows us to determine additional apparent periods at intermediate times. We compare CN coma morphology between ground-based datasets, making nine new measurements of apparent periods. The first five are consistent with the roughly linearly increasing apparent period during the apparition found by previous authors. The final four suggest that the change in apparent period slowed or stopped by late November. We also measure an inner coma lightcurve in both CN and R-band ground-based images, finding a single-peaked lightcurve which repeats in phase with the coma morphology. The apparent period ...

  15. Early Response of Mouse Joint Tissues to Noninvasive Knee Injury Suggests Treatment Targets

    PubMed Central

    Wu, P.; Holguin, N.; Silva, M. J.; Fu, M.; Liao, W.; Sandell, L. J.

    2015-01-01

    Objective Joint trauma can lead to a spectrum of acute lesions, including cartilage degradation, ligament or meniscus tears, and synovitis, all potentially associated with osteoarthritis. The goal of this study was to generate and validate a murine model of knee joint trauma following non-invasive controlled injurious compression in vivo and to investigate early molecular events. Methods The right knees of 8-week old mice were placed in a hyperflexed position and subjected to compressive joint loading at one of three peak forces (3, 6, 9 N) for 60 cycles in a single loading period and harvested at 5, 9 and 14 days post loading (n=3–5 mice for each time point and for each loading). The left knees were not loaded and served as the contralateral controls. Histological, immunohistochemical and ELISA analyses were performed to evaluate acute pathologic features in chondrocyte viability, cartilage matrix metabolism, synovial reaction, and serum COMP levels. Results Acute joint pathology was associated with increased injurious loads. All loading regimens induced chondrocyte apoptosis, cartilage matrix degradation, disruption of cartilage collagen fibril arrangement, and increased levels of serum COMP. We also observed that 6N loading induced mild synovitis by day 5 whereas at 9 N, with tearing of the anterior cruciate ligament, severe posttraumatic synovitis and ectopic cartilage formation were observed. Conclusion We have established and analyzed some early events in a murine model of knee joint trauma with different degrees of over-loading in vivo. These results suggest that immediate therapies particularly targeted to apoptosis and synovial cell proliferation could affect the acute posttraumatic reaction to potentially limit chronic consequences and osteoarthritis. PMID:24470303

  16. Habitat selection and movements of Piping Plover broods suggest a tradeoff between breeding stages

    USGS Publications Warehouse

    Wiltermuth, Mark T.; Anteau, Michael J.; Sherfy, Mark H.; Pearse, Aaron T.

    2015-01-01

    In precocial birds, adults select breeding areas using cues associated with habitat characteristics that are favorable for nesting success and chick survival, but there may be tradeoffs in habitat selection between these breeding stages. Here we describe habitat selection and intra-territory movements of 53 Piping Plover (Charadrius melodus) broods (320 observations) during the 2007–2008 breeding seasons on mainland- and island-shoreline habitats at Lake Sakakawea, North Dakota, USA. We used remotely sensed habitat characteristics to separately examine habitat selection and movements at two spatiotemporal scales to account for potential confounding effects of nest-site selection on brood-rearing habitat used. The scales used were (1) the entire brood-rearing period within available brood-rearing areas and (2) 2-day observation intervals within age-specific discrete habitat selection choice sets. Analyses at both scales indicated that broods selected areas which were non-vegetated, moderately level, and nearer to the shoreline. Rate of brood movement increased with age up to 5 days, then stabilized; broods that hatched >50 m away from the shoreline moved toward the shoreline. Brood movements were greater when they were in vegetated areas, when the brood-rearing area was of greater topographic complexity, and when broods aged 6–25 days were further away from the shoreline. Using inferences from our results and those of previously published work, we postulate how a potential tradeoff in habitat selection between nesting and brood-rearing can contribute to an ecological trap in a novel habitat. This work, in the context of published works, suggests that plover breeding habitat is a complex of both nesting and brood-rearing habitats and provides a basis for making remotely sensed abundance estimates of suitable breeding habitat for Piping Plovers.

  17. Statistical analysis of iron geochemical data suggests limited late Proterozoic oxygenation.

    PubMed

    Sperling, Erik A; Wolock, Charles J; Morgan, Alex S; Gill, Benjamin C; Kunzmann, Marcus; Halverson, Galen P; Macdonald, Francis A; Knoll, Andrew H; Johnston, David T

    2015-07-22

    Sedimentary rocks deposited across the Proterozoic-Phanerozoic transition record extreme climate fluctuations, a potential rise in atmospheric oxygen or re-organization of the seafloor redox landscape, and the initial diversification of animals. It is widely assumed that the inferred redox change facilitated the observed trends in biodiversity. Establishing this palaeoenvironmental context, however, requires that changes in marine redox structure be tracked by means of geochemical proxies and translated into estimates of atmospheric oxygen. Iron-based proxies are among the most effective tools for tracking the redox chemistry of ancient oceans. These proxies are inherently local, but have global implications when analysed collectively and statistically. Here we analyse about 4,700 iron-speciation measurements from shales 2,300 to 360 million years old. Our statistical analyses suggest that subsurface water masses in mid-Proterozoic oceans were predominantly anoxic and ferruginous (depleted in dissolved oxygen and iron-bearing), but with a tendency towards euxinia (sulfide-bearing) that is not observed in the Neoproterozoic era. Analyses further indicate that early animals did not experience appreciable benthic sulfide stress. Finally, unlike proxies based on redox-sensitive trace-metal abundances, iron geochemical data do not show a statistically significant change in oxygen content through the Ediacaran and Cambrian periods, sharply constraining the magnitude of the end-Proterozoic oxygen increase. Indeed, this re-analysis of trace-metal data is consistent with oxygenation continuing well into the Palaeozoic era. Therefore, if changing redox conditions facilitated animal diversification, it did so through a limited rise in oxygen past critical functional and ecological thresholds, as is seen in modern oxygen minimum zone benthic animal communities. PMID:26201598

  18. Rotational periods of asteroids II

    NASA Astrophysics Data System (ADS)

    Riccioli, D.; Blanco, C.; Cigna, M.

    2001-06-01

    In the framework of the photoelectric asteroid observational program undertaken at Catania University to collect lightcurves apt to apply the pole computational methods, the V-band lightcurves and the values of the synodic rotational period and of the average B- V colour index of 5 Astrea, 6 Hebe, 12 Victoria, 13 Egeria, 26 Proserpina, 34 Circe, 63 Ausonia, 66 Maja, 102 Miriam, 140 Siwa, 176 Iduna, 181 Eucaris, 241 Germania, 250 Bettina, 258 Tyche, 313 Chaldea, 335 Roberta, 352 Gisela, 419 Aurelia, 471 Papagena, 537 Pauly, 639 Latona and 984 Gretia are presented.

  19. Suggested visual hallucinations in and out of hypnosis.

    PubMed

    Mazzoni, Giuliana; Rotriquenz, Elisabetta; Carvalho, Claudia; Vannucci, Manila; Roberts, Kathrine; Kirsch, Irving

    2009-06-01

    We administered suggestions to see a gray-scale pattern as colored and a colored pattern in shades of gray to 30 high suggestible and eight low suggestible students. The suggestions were administered twice, once following the induction of hypnosis and once without an induction. Besides rating the degree of color they saw in the stimuli differently, participants also rated their states of consciousness as normal, relaxed, hypnotized, or deeply hypnotized. Reports of being hypnotized were limited to highly suggestible participants and only after the hypnotic induction had been administered. Reports of altered color perception were also limited to high suggestibles, but were roughly comparable regardless of whether hypnosis had been induced. These data indicate that suggestible individuals do not slip into a hypnotic state when given imaginative suggestions without the induction of hypnosis, but nevertheless report experiencing difficult suggestions for profound perceptual alterations that are pheonomenologically similar to what they report in hypnosis. PMID:19289292

  20. Pump-probe imaging of laser-induced periodic surface structures after ultrafast irradiation of Si

    SciTech Connect

    Murphy, Ryan D. [Applied Physics Program, University of Michigan, Ann Arbor, Michigan 48109 (United States)] [Applied Physics Program, University of Michigan, Ann Arbor, Michigan 48109 (United States); Torralva, Ben [Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, Michigan 48109 (United States)] [Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, Michigan 48109 (United States); Adams, David P. [Sandia National Laboratories, Albuquerque, New Mexico 87123 (United States)] [Sandia National Laboratories, Albuquerque, New Mexico 87123 (United States); Yalisove, Steven M. [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States)] [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States)

    2013-09-30

    Ultrafast pump-probe microscopy has been used to investigate laser-induced periodic surface structure (LIPSS) formation on polished Si surfaces. A crater forms on the surface after irradiation by a 150 fs laser pulse, and a second, subsequent pulse forms LIPSS within the crater. Sequentially delayed images show that LIPSS with a periodicity slightly less than the fundamental laser wavelength of 780 nm appear on Si surfaces ?50 ps after arrival of the second pump laser pulse, well after the onset of melting. LIPSS are observed on the same timescale as material removal, suggesting that their formation involves material ejection.

  1. February, 2003 Retinotopic mapping in awake monkeys suggests a different functional organization for

    E-print Network

    Faugeras, Olivier

    THEME 3 N° 4732 February, 2003 Retinotopic mapping in awake monkeys suggests a different functional0249-6399 #12;2 Retinotopic mapping in awake monkeys suggests a different functional organization the visual cortex of fixating monkeys. The observed retinotopy in V1, V2 and V3 was completely consistent

  2. Three failures of direct suggestion in psychogenic dermatitis followed by successful intervention.

    PubMed

    Iglesias, Alex

    2005-01-01

    Three adult cases of psychogenic dermatitis of atypical presentation were treated with direct suggestion under hypnosis (DSUH), which included suggestions for developing cooling, soothing and healing numbness in the affected areas. After a trial of 5 sessions over a period of 2 months, the results in all 3 cases were determined to be unappreciable and unsuccessful. The patients were subsequently treated with hypnoanalysis including ideomotor questioning, regression to onset, and reframing followed by direct suggestions under hypnosis (DSUH) for healing of all affected areas except a negotiated index finger on the nondominant hand. This technique proved an effective treatment that extinguished the flair-ups in 6 visits or less over a period of 2 months. These cases were followed at intervals of up to 1 year and no evidence of relapse found. PMID:15754865

  3. Periodic Ising Correlations

    E-print Network

    Grethe Hystad

    2010-11-09

    In this paper, we first rework B. Kaufman's 1949 paper, "Crystal Statistics. II. Partition Function Evaluated by Spinor Analysis", by using representation theory. Our approach leads to a simpler and more direct way of deriving the spectrum of the transfer matrix for the finite periodic Ising model. We then determine formulas for the spin correlation functions that depend on the matrix elements of the induced rotation associated with the spin operator in a basis of eigenvectors for the transfer matrix. The representation of the spin matrix elements is obtained by considering the spin operator as an intertwining map. We exhibit the "new" elements V+ and V- in the Bugrij-Lisovyy formula as part of a holomorphic factorization of the periodic and anti-periodic summability kernels on the spectral curve associated with the induced rotation for the transfer matrix.

  4. Modelling of Arabidopsis LAX3 expression suggests auxin homeostasis.

    PubMed

    Mellor, Nathan; Péret, Benjamin; Porco, Silvana; Sairanen, Ilkka; Ljung, Karin; Bennett, Malcolm; King, John

    2015-02-01

    Emergence of new lateral roots from within the primary root in Arabidopsis has been shown to be regulated by the phytohormone auxin, via the expression of the auxin influx carrier LAX3, mediated by the ARF7/19 IAA14 signalling module (Swarup et al., 2008). A single cell model of the LAX3 and IAA14 auxin response was formulated and used to demonstrate that hysteresis and bistability may explain the experimentally observed 'all-or-nothing' LAX3 spatial expression pattern in cortical cells containing a gradient of auxin concentrations. The model was tested further by using a parameter fitting algorithm to match model output with qRT-PCR mRNA expression data following exogenous auxin treatment. It was found that the model is able to show good agreement with the data, but only when the exogenous auxin signal is degraded over time, at a rate higher than that measured in the experimental medium, suggesting the triggering of an endogenous auxin homeostasis mechanism. Testing the model over a more physiologically relevant range of extracellular auxin shows bistability and hysteresis still occur when using the optimised parameters, providing the rate of LAX3 active auxin transport is sufficiently high relative to passive diffusion. PMID:25446711

  5. A study of the near-infrared modulation at spin and orbital periods in the intermediate polar WX Pyx

    NASA Astrophysics Data System (ADS)

    Joshi, V. H.; Ashok, N. M.; Banerjee, D. P. K.

    2011-06-01

    We present near-infrared J-band photometric observations of the intermediate polar WX Pyx. The frequency analysis indicates the presence of a period at 1559.2±0.2 sec which is attributed to the spin period of the white dwarf. The spin period inferred from the infrared data closely matches that determined from X-ray and optical observations. WX Pyx is a system whose orbital period has not been measured directly and which is not too well constrained. From the IR observations, a likely peak at 5.30±0.02 hr is seen in the power spectrum of the object. It is suggested that this corresponds to the orbital period of the system. In case this is indeed the true orbital period, some of the system physical parameters may be estimated. Our analysis indicates that the secondary star is of M2 spectral type and the distance to the object is 1.53 kpc. An upper limit of 30° for the angle of inclination of the system is suggested. The mass transfer rate and the magnetic moment of the white dwarf are estimated to be (0.95-1.6)×10-9 M? yr-1 and (1.9-2.4) × 1033 G cm3 respectively.

  6. 32 CFR 1901.04 - Suggestions and complaints.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...suggestions or complaints with regard to its administration of the Privacy Act. Many requesters will receive pre-paid, customer satisfaction survey cards. Letters of suggestion or complaint should identify the specific purpose and the issues for...

  7. 32 CFR 1901.04 - Suggestions and complaints.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...suggestions or complaints with regard to its administration of the Privacy Act. Many requesters will receive pre-paid, customer satisfaction survey cards. Letters of suggestion or complaint should identify the specific purpose and the issues for...

  8. SEMIREGULAR VARIABLES WITH PERIODS LYING BETWEEN THE PERIOD-LUMINOSITY SEQUENCES C', C, AND D

    SciTech Connect

    Soszynski, I. [Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa (Poland)] [Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa (Poland); Wood, P. R., E-mail: soszynsk@astrouw.edu.pl, E-mail: wood@mso.anu.edu.au [Research School of Astronomy and Astrophysics, Australian National University, Cotter Road, Weston Creek, ACT 2611 (Australia)

    2013-02-15

    We analyze the distribution of semiregular variables and Mira stars in the period-luminosity plane. Our sample consists of 6169 oxygen-rich long-period variables in the Large Magellanic Cloud included in the OGLE-III Catalog of Variable Stars. There are many stars with periods that lie between the well-known sequences C and C'. Most of these stars are multi-periodic and the period ratios suggest that these stars oscillate in the same mode as the sequence C stars. Models suggest that this mode is the fundamental radial pulsation mode. The stars with primary periods between sequences C and C' preferentially lie on an additional sequence (named F), and a large fraction of these stars also have long secondary periods (LSPs) that lie between sequences C and D. There are also a small number of stars with primary periods lying between sequences C and D. The origin of this long-period variability is unknown, as is the cause of sequence D variability. In addition, the origin of sequence F is unknown but we speculate that sequence F variability may be excited by the same phenomenon that causes the LSPs.

  9. THE RELATIONSHIP OF ALCOHOL WITHDRAWAL SYMPTOMS TO SUGGESTIBILITY AND COMPLIANCE

    Microsoft Academic Search

    Gisli H. Gudjonsson; Kristin Hannesdottir; Tomas Þor Agustsson; Jon F. Sigurdsson; Asa Gudmundsdottir; Þuridur Þordardottir; Þorarinn Tyrfingsson; Hannes Petursson

    2004-01-01

    People who are experiencing alcohol withdrawal are disadvantaged in terms of their ability to cope with leading questions and interrogative pressure (i.e. interrogative suggestibility). What had not been studied previously was the relationship of the severity of alcohol withdrawal symptoms with suggestibility and compliance. Suggestibility and compliance scores, obtained during the first week of hospital admission, were correlated with the

  10. Developmental Differences in Eyewitness Suggestibility and Memory for Source.

    ERIC Educational Resources Information Center

    Ackil, Jennifer K.; Zaragoza, Maria S.

    1995-01-01

    Examined children's ability to accurately monitor sources of suggested information. Age differences were found in the degree to which a misleading suggestion led subjects to believe they actually remembered seeing events that had in fact only been suggested to them. Proposes that these age differences reflect developmental differences in the…

  11. Field dependence, suggestibility and belief in paranormal phenomena

    Microsoft Academic Search

    Andreas Hergovich

    2003-01-01

    This paper examines the relationships between field dependence, suggestibility and belief in paranormal phenomena. In Experiment 1, 91 subjects underwent an hypnosis session to determine their suggestibility. They also completed a paranormal belief scale and a computer test of field dependence. It was shown that suggestibility and field dependence had positive and significant correlations with the belief in paranormal phenomena.

  12. TagAssist: Automatic Tag Suggestion for Blog Posts

    Microsoft Academic Search

    Sanjay C. Sood; Kristian J. Hammond; Sara H. Owsley; Larry Birnbaum

    2007-01-01

    In this paper, we describe a system called TagAssist that provides tag suggestions for new blog posts by utilizing existing tagged posts. The system is able to increase the quality of suggested tags by performing lossless compression over existing tag data. In addition, the system employs a set of metrics to evaluate the quality of a potential tag suggestion. Coupled

  13. Periods and Feynman integrals

    SciTech Connect

    Bogner, Christian [Institut fuer Physik, Universitaet Mainz, D-55099 Mainz (Germany); Department of Mathematical Sciences, University of Durham, Durham DH1 3LE (United Kingdom); Weinzierl, Stefan [Institut fuer Physik, Universitaet Mainz, D-55099 Mainz (Germany)

    2009-04-15

    We consider multiloop integrals in dimensional regularization and the corresponding Laurent series. We study the integral in the Euclidean region and where all ratios of invariants and masses have rational values. We prove that in this case all coefficients of the Laurent series are periods.

  14. Printable Periodic Tables

    NSDL National Science Digital Library

    This collection of periodic tables features a variety of styles, color or black and white versions, and several levels of information, from basic symbols, atomic number, and mass, to advanced versions that include melting point, boiling point, density, electronegativity, and electron configurations. The tables are provided in downloadable, printable format (PDF). Some versions feature links to additional information on the elements.

  15. Periodicity of Auroras

    Microsoft Academic Search

    A. S. Herschel

    1874-01-01

    ON my return to Newcastle-on-Tyne I take the opportunity of being able to recur to books of reference to reply to a question put by Mr. Procter, in NATURE (vol. x. p. 355), whether any complete catalogues of auroras have been constructed, and if they show indications of periodicity in its displays. Kæsemtz's ``Meteorology,'' in which almost every feature of

  16. The Cretaceous Period

    Microsoft Academic Search

    G. Henry Kinahan

    1871-01-01

    A QUARTER of a century ago, when first I began to study geology, it appeared to me that a predominance was given to the more recent rocks, such as the Pleistocene, Miocene, Eocene, Cretaceous, and the like, to which they were not entitled, when ranked as periods alongside such great groups as the Carboniferous the Silurian, the Cambro-silurian, and the

  17. Short Period Seismic Discrimination

    Microsoft Academic Search

    E. B. Manchee

    1972-01-01

    HERE I describe a method of utilizing the recognized differences in the short period (SP) spectra of earthquakes and underground explosions to aid in their discrimination. The method produces a dramatic increase in the separation between a suite of Nevada Test Site (NTS) explosion events and earthquakes in the Gulf of California area over that obtainable by the TMF (Third

  18. Magneto-Plasmons in Periodic Nanoporous Structures

    NASA Astrophysics Data System (ADS)

    Song, Yujun; Yin, Weiting; Wang, Ying-Hui; Zhang, Jun-Pei; Wang, Yan; Wang, Rongming; Han, Junbo; Wang, Wu; Nair, Selvakumar V.; Ruda, Harry E.

    2014-05-01

    We report on ordered nanoporous films exhibiting a unique magneto-plasmon based response, fabricated by nanosphere-assisted physical deposition. This work focuses on multi-layer Ag/CoFeB/Ag films as examples of such structures. Their microstructure dependent magnetic properties, localized surface plasmon resonance (LSPR) and magneto-optical Kerr effect were investigated. The observed effects of nanopores and Ag layers on the magnetic properties indicate the synergistic interaction between nanopores and Ag layers leading to an enhancement of the ferromagnetic character of the CoFeB film. LSPR spectra reveal that the introduction of Ag layers enhances the light transmission in the nanoporous CoFeB films (having pore sizes exceeding the wavelength of light) due to an enhanced interaction of light with surface plasmons. Periodic nanoporous Ag/CoFeB/Ag films covered by Ag capped nanospheres show a much larger extinction than uncovered nanoporous Ag/CoFeB/Ag films. The correlation between the magneto-optical Kerr effect and the nanostructures suggests a field-tunable Kerr effect owing to the magneto-electric coupling between the magnetic layer and the Ag layers, which is enhanced by the nanopores. These hybrid nanostructures are expected to offer potential applications in photovoltaic cells and for magneto-optic sensors.

  19. Periodic Reversals in Paenibacillus dendritiformis Swarming

    PubMed Central

    Strain, Shinji K.; Hernández, Roberto A.; Ben-Jacob, Eshel; Florin, E.-L.

    2013-01-01

    Bacterial swarming is a type of motility characterized by a rapid and collective migration of bacteria on surfaces. Most swarming species form densely packed dynamic clusters in the form of whirls and jets, in which hundreds of rod-shaped rigid cells move in circular and straight patterns, respectively. Recent studies have suggested that short-range steric interactions may dominate hydrodynamic interactions and that geometrical factors, such as a cell's aspect ratio, play an important role in bacterial swarming. Typically, the aspect ratio for most swarming species is only up to 5, and a detailed understanding of the role of much larger aspect ratios remains an open challenge. Here we study the dynamics of Paenibacillus dendritiformis C morphotype, a very long, hyperflagellated, straight (rigid), rod-shaped bacterium with an aspect ratio of ?20. We find that instead of swarming in whirls and jets as observed in most species, including the shorter T morphotype of P. dendritiformis, the C morphotype moves in densely packed straight but thin long lines. Within these lines, all bacteria show periodic reversals, with a typical reversal time of 20 s, which is independent of their neighbors, the initial nutrient level, agar rigidity, surfactant addition, humidity level, temperature, nutrient chemotaxis, oxygen level, illumination intensity or gradient, and cell length. The evolutionary advantage of this unique back-and-forth surface translocation remains unclear. PMID:23603739

  20. Periodic reversals in Paenibacillus dendritiformis swarming.

    PubMed

    Be'er, Avraham; Strain, Shinji K; Hernández, Roberto A; Ben-Jacob, Eshel; Florin, E-L

    2013-06-01

    Bacterial swarming is a type of motility characterized by a rapid and collective migration of bacteria on surfaces. Most swarming species form densely packed dynamic clusters in the form of whirls and jets, in which hundreds of rod-shaped rigid cells move in circular and straight patterns, respectively. Recent studies have suggested that short-range steric interactions may dominate hydrodynamic interactions and that geometrical factors, such as a cell's aspect ratio, play an important role in bacterial swarming. Typically, the aspect ratio for most swarming species is only up to 5, and a detailed understanding of the role of much larger aspect ratios remains an open challenge. Here we study the dynamics of Paenibacillus dendritiformis C morphotype, a very long, hyperflagellated, straight (rigid), rod-shaped bacterium with an aspect ratio of ~20. We find that instead of swarming in whirls and jets as observed in most species, including the shorter T morphotype of P. dendritiformis, the C morphotype moves in densely packed straight but thin long lines. Within these lines, all bacteria show periodic reversals, with a typical reversal time of 20 s, which is independent of their neighbors, the initial nutrient level, agar rigidity, surfactant addition, humidity level, temperature, nutrient chemotaxis, oxygen level, illumination intensity or gradient, and cell length. The evolutionary advantage of this unique back-and-forth surface translocation remains unclear. PMID:23603739

  1. Period Determination for 457 Alleghenia: Low Numbered Asteroid with No Previously Known Period

    NASA Astrophysics Data System (ADS)

    Alvarez, Eduardo Manuel; Pilcher, Frederick

    2015-01-01

    Lightcurve analysis for 457 Alleghenia was performed using observations during its 2014 opposition. The synodic rotation period was found to be 21.953 ± 0.001 h and the lightcurve amplitude was 0.20 ± 0.02 mag.

  2. ASCA Observations

    NASA Technical Reports Server (NTRS)

    Helfand, David J.

    1998-01-01

    This recently expired grant has supported the work of the PI, his students, and his collaborators on a variety of ASCA projects over the past four years. Annual reports have summarized much of the work accomplished; here we provide a brief review of the work resulting from this effort, and a summary of the personnel who have benefited from the grant's support. Starburst Galaxies with Extreme X-ray Luminosities This project began as a careful examination of the claims of Boller et al. (1992) that there were dozens of "normal" galaxies in the ROSAT All-Sky Survey that had X-ray luminosities in excess of 1042 erg sec, higher than that seen in the hundreds of non-AGN galaxies observed with Einstein. If true, this suggested that X-ray emission associated with star formation activity might have a significant contribution to make to the still unexplained cosmic X-ray background (XRB). Since some of our earlier work with the Einstein Observatory Deep Surveys had suggested a similar possibility and several sets of authors over the years had modelled the starburst XRB contribution, these claims were worth pursuing. Our work expanded the examination beyond the RASS to include earlier claims of high-luminosity galaxies powered by starburst emission (selected in this case on the basis of the far-IR luminosities). The result of extensive followup observations under several programs using ROSAT, ASCA, and ground-based facilities was to show that nearly all of these objects in fact have hidden AGN at their cores, and that their luminosities are not in any way extraordinary.

  3. CAN THE 62 DAY X-RAY PERIOD OF ULX M82 X-1 BE DUE TO A PRECESSING ACCRETION DISK?

    SciTech Connect

    Pasham, Dheeraj R. [Astronomy Department, University of Maryland, College Park, MD 20742 (United States); Strohmayer, Tod E., E-mail: dheeraj@astro.umd.edu, E-mail: tod.strohmayer@nasa.gov [Astrophysics Science Division, NASA's Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2013-09-10

    We have analyzed all archival Rossi X-Ray Timing Explorer/Proportional Counter Array monitoring observations of the ultraluminous X-ray source M82 X-1 in order to study the properties of its 62 day X-ray period, which was found by Kaaret and Feng in 2007. Based on its high coherence, it has been argued that the observed period is the orbital period of the binary. Utilizing a much longer data set than in previous studies, we find the following. (1) The phase-resolved X-ray (3-15 keV) spectra-modeled with a thermal accretion disk and a power law-suggest that the accretion disk's contribution to the total flux is strongly modulated with phase. (2) Suggestive evidence for a sudden phase shift of approximately 0.4 in phase (25 days) between the first and the second halves of the light curve separated by roughly 1000 days. If confirmed, the implied timescale to change the period is {approx}10 yr, which is exceptionally fast for an orbital phenomenon. These two independent pieces of evidence are consistent with the periodicity being due to a precessing accretion disk, similar to the super-orbital periods observed in systems like Her X-1, LMC X-4, and SS433. However, the timing evidence for a change in the period needs to be confirmed with additional observations. This should be possible with further monitoring of M82 with instruments such as the Swift X-Ray Telescope.

  4. Modeling of Laser Induced Periodic Surface Structures

    Microsoft Academic Search

    J. Z. P. Skolski; G. R. B. E. Römer; A. J. Huis in't Veld; V. S. Mitko; J. V. Obona; V. Ocelik; Hosson de J. Th. M

    2010-01-01

    In surfaces irradiated by short laser pulses, Laser Induced Periodic Surface Structures (LIPSS) have\\u000abeen observed on all kind of materials for over forty years. These LIPSS, also referred to as ripples,\\u000aconsist of wavy surfaces with periodicity equal or smaller than the wavelength of the laser radiation.\\u000aUnfortunately, the physical phenomena explaining ripple initiation, growth and transitions toward other

  5. Suggestion of EFS-small satellite system for impending earthquake forecast

    Microsoft Academic Search

    Zuji Qiang; Ainai Ma; Fangyun Chen; Junrong Zhang; Laixing Lin; Zhenlin Lu

    2000-01-01

    In the IAF Congress ’92 a multiple small satellite Earth observation system was put forward with sensors of visible and infrared\\u000a spectrums. The system could shorten the revisiting period so that any place on the world could be observed twice a day. Now\\u000a we extend the idea to the microwave remote sensing satellite system. The main purpose of the system

  6. PERIOD ERROR ESTIMATION FOR THE KEPLER ECLIPSING BINARY CATALOG

    SciTech Connect

    Mighell, Kenneth J. [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Plavchan, Peter [NASA Exoplanet Science Institute, California Institute of Technology, Pasadena, CA 91125 (United States)

    2013-06-15

    The Kepler Eclipsing Binary Catalog (KEBC) describes 2165 eclipsing binaries identified in the 115 deg{sup 2} Kepler Field based on observations from Kepler quarters Q0, Q1, and Q2. The periods in the KEBC are given in units of days out to six decimal places but no period errors are provided. We present the PEC (Period Error Calculator) algorithm, which can be used to estimate the period errors of strictly periodic variables observed by the Kepler Mission. The PEC algorithm is based on propagation of error theory and assumes that observation of every light curve peak/minimum in a long time-series observation can be unambiguously identified. The PEC algorithm can be efficiently programmed using just a few lines of C computer language code. The PEC algorithm was used to develop a simple model that provides period error estimates for eclipsing binaries in the KEBC with periods less than 62.5 days: log {sigma}{sub P} Almost-Equal-To - 5.8908 + 1.4425(1 + log P), where P is the period of an eclipsing binary in the KEBC in units of days. KEBC systems with periods {>=}62.5 days have KEBC period errors of {approx}0.0144 days. Periods and period errors of seven eclipsing binary systems in the KEBC were measured using the NASA Exoplanet Archive Periodogram Service and compared to period errors estimated using the PEC algorithm.

  7. Period Error Estimation for the Kepler Eclipsing Binary Catalog

    NASA Astrophysics Data System (ADS)

    Mighell, Kenneth J.; Plavchan, Peter

    2013-06-01

    The Kepler Eclipsing Binary Catalog (KEBC) describes 2165 eclipsing binaries identified in the 115 deg2 Kepler Field based on observations from Kepler quarters Q0, Q1, and Q2. The periods in the KEBC are given in units of days out to six decimal places but no period errors are provided. We present the PEC (Period Error Calculator) algorithm, which can be used to estimate the period errors of strictly periodic variables observed by the Kepler Mission. The PEC algorithm is based on propagation of error theory and assumes that observation of every light curve peak/minimum in a long time-series observation can be unambiguously identified. The PEC algorithm can be efficiently programmed using just a few lines of C computer language code. The PEC algorithm was used to develop a simple model that provides period error estimates for eclipsing binaries in the KEBC with periods less than 62.5 days: log ? P ? - 5.8908 + 1.4425(1 + log P), where P is the period of an eclipsing binary in the KEBC in units of days. KEBC systems with periods >=62.5 days have KEBC period errors of ~0.0144 days. Periods and period errors of seven eclipsing binary systems in the KEBC were measured using the NASA Exoplanet Archive Periodogram Service and compared to period errors estimated using the PEC algorithm.

  8. Interactives: The Periodic Table

    NSDL National Science Digital Library

    It can be tricky to remember the position of lanthanides within the periodic table of elements, but this interactive feature from Annenberg Media's "Interactive" series will keep students in the know about those so-called "rare earth" elements. This particular feature begins with "Atomic Basics", which provides an overview of the atom and its various functions. After completing this section, visitors can test their knowledge with the "Name That Atom" game. The game is full of protons, neutrons, and electrons, but it should be no problem for students who've been paying attention to this lively exploration of the atom. Moving on through the site, visitors will learn about the periodic table's organization, isotopes, and the groups within the table, all the way from the alkali metals to the boron family.

  9. Periodic mesoporous silica gels

    SciTech Connect

    Anderson, M.T.; Martin, J.E.; Odinek, J.G. [and others

    1996-06-01

    We have synthesized monolithic particulate gels of periodic mesoporous silica by adding tetramethoxysilane to a homogeneous alkaline micellar precursor solution. The gels exhibit 5 characteristic length scales over 4 orders of magnitude: fractal domains larger than the particle size (>500 nm), particles that are {approximately}150 to 500 nm in diameter, interparticle pores that are on the order of the particle size, a feature in the gas adsorption measurements that indicates pores {approximately}10-50 nm, and periodic hexagonal arrays of {approximately}3 nm channels within each particle. The wet gel monoliths exhibit calculated densities as low as {approximately}0.02 g/cc; the dried and calcined gels have bulk densities that range from {approximately}0.3-0.5 g/cc. The materials possess large interparticle ({approximately}1.0-2.3 cc/g) and intraparticle ({approximately}0.6 cc/g) porosities.

  10. Napoleonic Period Collection

    NSDL National Science Digital Library

    Napoleon Bonaparte never visited the part of North America that would later become Washington State, but he probably would have been intrigued by this online collection created by the good folks at the University of Washington Libraries Digital Collection project. This latest collection brings together 83 satirical drawings from the Napoleonic period, and there are a number of real gems amidst this visually arresting collection. As might be expected they all offer a variety of political commentary on various events during this period. The site includes information about the Napoleonic Era, complete with a nice timeline, and a comparison between the French and English drawings is included in this trove of visual ephemera. Finally, the site also contains a brief piece on the publishing scene of the late 18th and early 19th centuries, along with a very nice bibliography of additional resources.

  11. Periodic Table review

    NSDL National Science Digital Library

    Ms. Huntress

    2008-12-04

    See the videos we watched in class (or review for your next exam) here To play the game for lab PT Game To do some practice multiple choice questions, click below. (your user name is \\"slw- WHATEVER YOU USE AT SCHOOL\\" School Island To play the review game we will do in class, click below then click on Periodic Table Review Eureeka home To watch videos Sodium Video Element song Element song Alkali metal video Brainiac metals ...

  12. Dynamics of Periodic Monopoles

    E-print Network

    Derek Harland; R. S. Ward

    2009-04-22

    BPS monopoles which are periodic in one of the spatial directions correspond, via a generalized Nahm transform, to solutions of the Hitchin equations on a cylinder. A one-parameter family of solutions of these equations, representing a geodesic in the 2-monopole moduli space, is constructed numerically. It corresponds to a slow-motion dynamical evolution, in which two parallel monopole chains collide and scatter at right angles.

  13. The consequences of suggesting false childhood food events.

    PubMed

    Bernstein, Daniel M; Scoboria, Alan; Arnold, Robert

    2015-03-01

    We combined data across eight published experiments (N=1369) to examine the formation and consequences of false autobiographical beliefs and memories. Our path models revealed that the formation of false autobiographical belief fully mediated the pathway between suggesting to people that they had experienced a positive or negative food-related event in the past and current preference for that food. Suggestion indirectly affected intention to eat the food via change in autobiographical belief. The development of belief with and without memory produced similar changes in food preferences and behavior intention, indicating that belief in the event drives changes in suggestion-related attitudes. Finally, positive suggestions (e.g., "you loved asparagus the first time you tried it") yielded stronger effects than negative suggestions (e.g., "you got sick eating egg salad"). These findings show that false autobiographical suggestions lead to the development of autobiographical beliefs, which in turn, have consequences for one's attitudes and behaviors. PMID:25613303

  14. THE ORBITAL PERIOD OF SCORPIUS X-1

    SciTech Connect

    Hynes, Robert I.; Britt, Christopher T., E-mail: rih@phys.lsu.edu [Department of Physics and Astronomy, Louisiana State University, 202 Nicholson Hall, Tower Drive, Baton Rouge, LA 70803 (United States)

    2012-08-10

    The orbital period of Sco X-1 was first identified by Gottlieb et al. While this has been confirmed on multiple occasions, this work, based on nearly a century of photographic data, has remained the reference in defining the system ephemeris ever since. It was, however, called into question when Vanderlinde et al. claimed to find the one-year alias of the historical period in RXTE/All-Sky Monitor data and suggested that this was the true period rather than that of Gottlieb et al. We examine data from the All Sky Automated Survey (ASAS) spanning 2001-2009. We confirm that the period of Gottlieb et al. is in fact the correct one, at least in the optical, with the one-year alias strongly rejected by these data. We also provide a modern time of minimum light based on the ASAS data.

  15. On the Quarantine Period for Ebola Virus

    PubMed Central

    Haas, Charles N.

    2014-01-01

    Background: 21 days has been regarded as the appropriate quarantine period for holding individuals potentially exposed to Ebola Virus (EV) to reduce risk of contagion. There does not appear to be a systematic discussion of the basis for this period. Methods: The prior estimates for incubation time to EV were examined, along with data on the first 9 months of the current outbreak. These provided estimates of the distribution of incubation times. Results: A 21 day period for quarantine may result in the release of individuals with a 0.2 - 12% risk of release prior to full opportunity for the incubation to proceed. It is suggested that a detailed cost-benefit assessment, including considering full transmission risks, needs to occur in order to determine the appropriate quarantine period for potentially exposed individuals. PMID:25642371

  16. The Orbital Period of Scorpius X-1

    NASA Astrophysics Data System (ADS)

    Hynes, Robert I.; Britt, Christopher T.

    2012-08-01

    The orbital period of Sco X-1 was first identified by Gottlieb et al. While this has been confirmed on multiple occasions, this work, based on nearly a century of photographic data, has remained the reference in defining the system ephemeris ever since. It was, however, called into question when Vanderlinde et al. claimed to find the one-year alias of the historical period in RXTE/All-Sky Monitor data and suggested that this was the true period rather than that of Gottlieb et al. We examine data from the All Sky Automated Survey (ASAS) spanning 2001-2009. We confirm that the period of Gottlieb et al. is in fact the correct one, at least in the optical, with the one-year alias strongly rejected by these data. We also provide a modern time of minimum light based on the ASAS data.

  17. 76 FR 8325 - Periodic Reporting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-14

    ...Docket No. RM2011-7; Order No. 664] Periodic Reporting AGENCY: Postal Regulatory...consider certain temporary waivers from periodic reporting of service performance measurement...a request for temporary waivers from periodic reporting of service performance...

  18. 75 FR 65593 - Periodic Reporting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-26

    ...3020 [RM2011-1; Order No. 552] Periodic Reporting AGENCY: Postal Regulatory...waiver of rules requiring it to provide periodic reports on service performance for certain...a request for temporary waivers from periodic reporting of service performance...

  19. Molecular Genetic Diversity of Major Indian Rice Cultivars over Decadal Periods

    PubMed Central

    Deborah, Dondapati Annekitty; Vipparla, Abhilash; Anuradha, Ghanta; Siddiq, Ebrahimali Abubacker; Vemireddy, Lakshminarayana Reddy

    2013-01-01

    Genetic diversity in representative sets of high yielding varieties of rice released in India between 1970 and 2010 was studied at molecular level employing hypervariable microsatellite markers. Of 64 rice SSR primer pairs studied, 52 showed polymorphism, when screened in 100 rice genotypes. A total of 184 alleles was identified averaging 3.63 alleles per locus. Cluster analysis clearly grouped the 100 genotypes into their respective decadal periods i.e., 1970s, 1980s, 1990s and 2000s. The trend of diversity over the decadal periods estimated based on the number of alleles (Na), allelic richness (Rs), Nei’s genetic diversity index (He), observed heterozygosity (Ho) and polymorphism information content (PIC) revealed increase of diversity over the periods in year of releasewise and longevitywise classification of rice varieties. Analysis of molecular variance (AMOVA) suggested more variation in within the decadal periods than among the decades. Pairwise comparison of population differentiation (Fst) among decadal periods showed significant difference between all the pairs except a few. Analysis of trends of appearing and disappearing alleles over decadal periods showed an increase in the appearance of alleles and decrease in disappearance in both the categories of varieties. It was obvious from the present findings, that genetic diversity was progressively on the rise in the varieties released during the decadal periods, between 1970s and 2000s. PMID:23805204

  20. The role of suggestion in the psychoanalytic therapies.

    PubMed

    Campbell, L A

    The concept of suggestion in the psychoanalytic therapies is considered as it appears in the literature and in current practice. Bibring's definition of the technique of suggestion is extended differentiating overt and covert suggestion from the effects of unconscious transference fantasies. The use of suggestion as a technique is viewed as antithetical to the aims of exploratory psychoanalytic therapy and presents serious problems in the resolution of transference issues when it is used either inadvertently or as a parameter of the therapy. PMID:738805

  1. 32 CFR Enclosure - Suggested Format, Affidavit of Service by Mail

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...DEFENSE PERSONNEL, MILITARY AND CIVILIAN UNSATISFACTORY PERFORMANCE OF READY RESERVE OBLIGATION Definitions. Pt. 100, Encl. Enclosure—Suggested Format, Affidavit of Service by Mail State of _____ County of _____...

  2. 32 CFR Enclosure - Suggested Format, Affidavit of Service by Mail

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...DEFENSE PERSONNEL, MILITARY AND CIVILIAN UNSATISFACTORY PERFORMANCE OF READY RESERVE OBLIGATION Definitions. Pt. 100, Encl. Enclosure—Suggested Format, Affidavit of Service by Mail State of _____ County of _____...

  3. The effects of suspiciousness and anger on suggestibility.

    PubMed

    Gudjonsson, G H

    1989-07-01

    In this paper three criminal cases are presented where a suspicious 'cognitive set' or anger during experimental interrogation appeared to have a dramatic effect on their general tendency towards suggestibility. The subjects were used as their own control, as their susceptibility to suggestions had been tested objectively on two separate occasions; on one occasion they proved very resistant to suggestions, this being clearly associated with temporary suspiciousness or anger; on the other occasion, when no obvious suspiciousness or anger was evident, they proved highly suggestible. The theoretical and forensic implications of the findings are discussed. PMID:2770473

  4. The neural organization of semantic memory: Electrophysiological activity suggests

    E-print Network

    Coulson, Seana

    DTD 5 The neural organization of semantic memory: Electrophysiological activity suggests feature semantic information is coded within a unitary neural system. Below we outline each of these theoretical

  5. The period derivative of Cygnus X-3

    NASA Technical Reports Server (NTRS)

    Lamb, R. C.; Dower, R. G.; Fickle, R. K.

    1979-01-01

    X-rays from Cygnus X-3 have been observed during early 1978 with the detectors of the SAS 3 satellite. These observations, in conjunction with earlier Uhuru and ANS data, indicate that the 4.8 hr period of Cygnus X-3 is increasing at a rate of (5.1 + or - 1.3) times to the -6th per year. The sign and magnitude for this change are incompatible with a rotation model for the period and are in reasonable agreement with model predictions for orbital changes associated with mass loss and transfer in a binary system.

  6. Dynamics of the Bingham Canyon mine landslides from long-period and short-period seismic signal analysis

    NASA Astrophysics Data System (ADS)

    Hibert, C.; Ekstrom, G.; Stark, C. P.

    2013-12-01

    On April 10, 2013, one of the largest landslides observed in North America occurred at the Bingham Canyon copper mine near Salt Lake City, Utah. Seismic waves recorded by the Global Seismographic Network suggest that two major slope failures occurred: at 03:31UT and at 05:06UT with long-period surface-wave magnitudes of Msw~5.1 and Msw~4.9 respectively. The combined debris of these landslides has been estimated at 150 million tonnes. We used long-period surface wave data to invert for the Landslide Force History (LFH) of each of the two events, allowing us to infer the trajectories of landslide motion and their average dynamic properties [1]. These inferred runout paths are broadly consistent with those deduced from analysis of the landslide scar using air photographs, satellite imagery and differential topographic maps. However, the total mass obtained from the LFH analysis is less consistent: using the observed runout distances for calibration [1], our inversions suggest a total landslide mass 50% less than that reported by the mining company. A further complexity, possibly related, is revealed by analysis of the short-period seismic waves, which indicates that the 05:06UT detection is in fact the composite signal of two distinct landslide seismic sources. Usually, high-frequency (HF, >1Hz) seismic signals generated by landslides are hard to observe because of their strong scattering and attenuation with distance. However, a very dense network of broadband seismic stations exists in the vicinity of the Bingham Canyon mine. Thus, we were able to compare the LFH, long-period and HF seismic signals for both events. Joint analysis of the inverted trajectory and the HF seismic signal recorded at the closest stations shows that, for the first 03:31UT event, a backward movement of the mass center started just after a final burst in the very high-frequency (VHF, >20Hz) signal. After this final burst, a tremor-like signal is observed in the VHF. This tremor-like signal may be related to reverse flow over the primary deposit associated with the observed backward movement of the mass center. For the second 05:06UT event, no clear backward movement of the mass center is observed. While analysis of the seismic energy of the HF signal, which is related to the landslides mass [2], suggests that the second events mass is approximately 13% less that the first landslide, the mass deduced from the LFH of the second event is half that of the first event. In the VHF signal recorded at one of the closest stations (CWU), the second event appears to be composed of two sub-events occurring 20s apart. The first sub-event lasts approximately 40s while the second lasts only 20s. The impact of the complex dynamics of the 05:06UT event on the LFH inversion is discussed. The broad implication of our work is the evident utility of performing joint analysis of long-period and high-frequency seismic waves in the study of large landslide dynamics. [1] Ekström G. and Stark C. P. (2013), Science, 339: 1416-1419. DOI: 10.1126/science.1232887. [2] Hibert et al. (2011), Journal of Geophysical Research, 116, F04032, DOI:10.1029/2011JF002038.

  7. Energetic ion (>~50kev) and electron (>~40kev) bursts observed by ULYSSES near Jupiter

    Microsoft Academic Search

    G. C. Anagnostopoulos; A. Aggelis; I. Karanikola; P. K. Marhavilas

    2001-01-01

    A careful analysis of data collected by the HISCALE experiment on board Ulysses suggests that the quasi-periodic (Q-P) modulation of several or tens of minutes in flux and\\/or anisotropy\\/spectral observations is an almost permanent characteristic of the energetic (>~50 keV) ion population in the outer and the high latitude middle magnetosphere of Jupiter. In most cases a periodicity of ~5-20

  8. Early events following experimental infection with Peste-Des-Petits ruminants virus suggest immune cell targeting.

    PubMed

    Pope, Robert A; Parida, Satya; Bailey, Dalan; Brownlie, Joe; Barrett, Thomas; Banyard, Ashley C

    2013-01-01

    Peste-des-petits ruminants virus (PPRV) is a viral pathogen that causes a devastating plague of small ruminants. PPRV is an economically significant disease that continues to be a major obstacle to the development of sustainable agriculture across the developing world. The current understanding of PPRV pathogenesis has been heavily assumed from the closely related rinderpest virus (RPV) and other morbillivirus infections alongside data derived from field outbreaks. There have been few studies reported that have focused on the pathogenesis of PPRV and very little is known about the processes underlying the early stages of infection. In the present study, 15 goats were challenged by the intranasal route with a virulent PPRV isolate, Côte d'Ivoire '89 (CI/89) and sacrificed at strategically defined time-points post infection to enable pre- and post-mortem sampling. This approach enabled precise monitoring of the progress and distribution of virus throughout the infection from the time of challenge, through peak viraemia and into a period of convalescence. Observations were then related to findings of previous field studies and experimental models of PPRV to develop a clinical scoring system for PPRV. Importantly, histopathological investigations demonstrated that the initial site for virus replication is not within the epithelial cells of the respiratory mucosa, as has been previously reported, but is within the tonsillar tissue and lymph nodes draining the site of inoculation. We propose that virus is taken up by immune cells within the respiratory mucosa which then transport virus to lymphoid tissues where primary virus replication occurs, and from where virus enters circulation. Based on these findings we propose a novel clinical scoring methodology for PPRV pathogenesis and suggest a fundamental shift away from the conventional model of PPRV pathogenesis. PMID:23418464

  9. Early Events following Experimental Infection with Peste-Des-Petits Ruminants Virus Suggest Immune Cell Targeting

    PubMed Central

    Pope, Robert A.; Parida, Satya; Bailey, Dalan; Brownlie, Joe; Barrett, Thomas; Banyard, Ashley C.

    2013-01-01

    Peste-des-petits ruminants virus (PPRV) is a viral pathogen that causes a devastating plague of small ruminants. PPRV is an economically significant disease that continues to be a major obstacle to the development of sustainable agriculture across the developing world. The current understanding of PPRV pathogenesis has been heavily assumed from the closely related rinderpest virus (RPV) and other morbillivirus infections alongside data derived from field outbreaks. There have been few studies reported that have focused on the pathogenesis of PPRV and very little is known about the processes underlying the early stages of infection. In the present study, 15 goats were challenged by the intranasal route with a virulent PPRV isolate, Côte d’Ivoire ’89 (CI/89) and sacrificed at strategically defined time-points post infection to enable pre- and post-mortem sampling. This approach enabled precise monitoring of the progress and distribution of virus throughout the infection from the time of challenge, through peak viraemia and into a period of convalescence. Observations were then related to findings of previous field studies and experimental models of PPRV to develop a clinical scoring system for PPRV. Importantly, histopathological investigations demonstrated that the initial site for virus replication is not within the epithelial cells of the respiratory mucosa, as has been previously reported, but is within the tonsillar tissue and lymph nodes draining the site of inoculation. We propose that virus is taken up by immune cells within the respiratory mucosa which then transport virus to lymphoid tissues where primary virus replication occurs, and from where virus enters circulation. Based on these findings we propose a novel clinical scoring methodology for PPRV pathogenesis and suggest a fundamental shift away from the conventional model of PPRV pathogenesis. PMID:23418464

  10. Geyser periodicity and the response of geysers to deformation

    USGS Publications Warehouse

    Ingebritsen, S.E.; Rojstaczer, S.A.

    1996-01-01

    Numerical simulations of multiphase fluid and heat transport through a porous medium define combinations of rock properties and boundary conditions which lead to geyser-like periodic discharge. Within the rather narrow range of conditions that allow geyser-like behavior, eruption frequency and discharge are highly sensitive to the intrinsic permeabilities of the geyser conduit and the surrounding rock matrix, to the relative permeability functions assumed, and to pressure gradients in the matrix. In theory, heats pipes (concomitant upward flow of steam and downward flow of liquid) can exist under similar conditions, but our simulations suggest that the periodic solution is more stable. Simulated time series of geyser discharge are chaotic, but integrated quantities such as eruption frequency and mass discharge per eruption are free of chaos. These results may explain the observed sensitivity of natural geysers to small strains such as those caused by remote earthquakes, if ground motion is sufficient to induce permeability changes. Changes in geyser behavior caused by minor preseismic deformation, periodic surface loading, and Earth tides are more difficult to explain in the context of our current model. Copyright 1996 by the American Geophysical Union.

  11. Coded Strobing Photography: Compressive Sensing of High Speed Periodic Videos

    E-print Network

    Mellor-Crummey, John

    Coded Strobing Photography: Compressive Sensing of High Speed Periodic Videos Ashok Veeraraghavan, via temporal modulation, one can observe and capture a high-speed periodic video well beyond reconstruct a high-speed video of the high-frequency periodic process. Strobing is used in entertainment

  12. Senate Panel Suggests Teams To Penetrate Private Sector Computers

    Microsoft Academic Search

    Wayne Madsen

    2000-01-01

    At a 6 October 1999 hearing of the Senate Subcommittee on Technology, Terrorism, and Government Information, Senator Bob Bennett of Utah and the chair of the Senate’s Y2K Committee, suggested that Department of Defense penetration ‘Red Teams’ should be used to try to break into the computers of certain private industry areas. That suggestion prompted Michael Vatis, the director of

  13. Query suggestions for mobile search: understanding usage patterns

    Microsoft Academic Search

    Maryam Kamvar; Shumeet Baluja

    2008-01-01

    Entering search terms on mobile phones is a time consuming and cumbersome task. In this paper, we explore the usage patterns of query entry interfaces that display suggestions. Our primary goal is to build a usage model of query suggestions in order to provide user interface guidelines for mobile text prediction interfaces. We find that users who were asked to

  14. Query Suggestions for Mobile Search: Understanding Usage Patterns

    E-print Network

    Tomkins, Andrew

    Inc 1600 Amphitheatre Parkway, Mountain View, CA shumeet@google.com ABSTRACT Entering search terms that users who were asked to enter queries on a search interface with query suggestions rated their workload heavily on suggestions if they are provided. Users who were asked to enter queries on a search interface

  15. A Temporal Discriminability Account of Children's Eyewitness Suggestibility

    ERIC Educational Resources Information Center

    Bright-Paul, Alexandra; Jarrold, Christopher

    2009-01-01

    Children's suggestibility is typically measured using a three-stage "event-misinformation-test" procedure. We examined whether suggestibility is influenced by the time delays imposed between these stages, and in particular whether the temporal discriminability of sources (event and misinformation) predicts performance. In a novel approach, the…

  16. Involuntary Experiencing and the Performance of Hypnotic Test Suggestions

    Microsoft Academic Search

    Paul F. Cunningham; Philip Ramos

    2012-01-01

    This experimental study examined 2 questions: (a) Does the Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A) tap the “classic suggestion effect” and (b) does the wording of postexperimental questions bias subjective reports of hypnotic subjects? Results indicated that a significant minority of individuals who “passed” test suggestions by objective behavioral criteria reported performance as occurring voluntarily, and participants

  17. Suggested Subjects of Composition for Lower-Division Technical Writing.

    ERIC Educational Resources Information Center

    Henson, Leigh

    Intended for use with students in lower division technical writing courses, this list of over 800 suggested composition subjects is drawn from surveys of technical writing teachers as well as from teachers of science and technology. The suggested subjects pertain to 16 types of papers commonly presented in textbooks and articles dealing with…

  18. Students' Suggestions for Eliminating Bullying at a University

    ERIC Educational Resources Information Center

    Meriläinen, Matti; Puhakka, Helena; Sinkkonen, Hanna-Maija

    2015-01-01

    Students' suggestions for how to eliminate bullying at universities were gathered as part of an e-questionnaire sent to each university student (N = 10,551) at a Finnish university. The suggestions (n = 2804) regarding how to address bullying at universities were divided into the following four classes: support (944), punishment (78), support and…

  19. Query suggestion by constructing term-transition graphs

    Microsoft Academic Search

    Yang Song; Dengyong Zhou; Li-wei He

    2012-01-01

    Query suggestion is an interactive approach for search engines to better understand users information need. In this paper, we propose a novel query suggestion framework which leverages user re-query feedbacks from search engine logs. Specifically, we mined user query reformulation activities where the user only modifies part of the query by (1) adding terms after the query, (2) deleting terms

  20. MATH 5620 CLASS PROJECT SUGGESTIONS NUMERICAL ANALYSIS II

    E-print Network

    Guevara-Vasquez, Fernando

    MATH 5620 CLASS PROJECT SUGGESTIONS NUMERICAL ANALYSIS II 1. Project guidelines · It is possible to approximate the solution in each element are of degree n). You need to demonstrate the efficacy of your code well with this one. 1 #12;2 MATH 5620 CLASS PROJECT SUGGESTIONS NUMERICAL ANALYSIS II 7. (**) The two

  1. 29 CFR 778.333 - Suggestion system awards.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...OVERTIME COMPENSATION Special Problems Prizes As Bonuses § 778.333 Suggestion...may be generally stated, however, that prizes paid pursuant to a bona fide suggestion...fact that: (a) The amount of the prize has no relation to the earnings of...

  2. MESSENGER Plasma Wave Observations in Mercury's Magnetosphere

    NASA Astrophysics Data System (ADS)

    Boardsen, S. A.; Slavin, J. A.; Anderson, B. J.; Korth, H.; Raines, J. M.; Solomon, S. C.; Gloeckler, G.; Zurbuchen, T.

    2010-12-01

    The three Mercury flybys by the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft occurred on 14 January 2008, 6 October 2008, and 29 September 2009. MESSENGER will be inserted into a polar orbit about Mercury on 18 March 2011. For all flybys the spacecraft followed similar equatorial trajectories, entering the dusk side of the magnetosphere downstream of the planet and exiting just sunward of the dawn terminator. The first flyby (M1) occurred during steady northward interplanetary magnetic field (IMF) and showed no evidence of reconnection or substorm activity. In contrast, the second flyby (M2) occurred during steady southward IMF, and intense reconnection was observed in the magnetotail and at the dawn-side magnetopause. The third flyby (M3) occurred during a period marked by intermittent northward and southward IMF. During M3, no magnetic field data were collected after closest approach (CA). Despite the different IMF geometry during M1 and M2, bursts of narrow-band waves at frequencies in the range between the He+ and H+ cyclotron frequencies (~1 Hz) were observed during both flybys. These bursts were seen almost continuously from a few minutes before CA to the dawn-side magnetopause crossing. Outbound from CA, trends in wave power, wave-normal angle, and ellipticity were similar for both flybys. Also, during both flybys a dawn-side "boundary layer" (BL) was marked by a step decrease in magnetic field strength but no change in field orientation. During both flybys an order-of-magnitude increase in wave power was observed in this BL relative to that before BL entrance. Overall wave power was about 4 times larger during M2 than during M1. For both flybys the wave-normal angles were generally greater than 45°, and power parallel to the local magnetic field was often greater than power in the perpendicular direction, suggesting a strong magnetosonic component for these waves. At lower frequencies, quasi-periodic (~20-30-s period) oscillations were observed near CA during M2. In contrast, no such oscillations were observed near CA during M1. These quasi-periodic oscillations were strongly compressional, with a fractional change in magnetic field magnitude, ?B/B, of ~3%. The oscillation period was near and above the local Na+ cyclotron period, and these oscillations were strongly linear, with ellipticities near zero. We assess whether this low-frequency oscillation was more likely the result of Na+ pickup-ion instabilities, Kelvin-Helmholtz waves on the magnetopause, or quasi-periodic intense reconnection events in the magnetotail.

  3. Polar kicks and the spin period - eccentricity relation in double neutron stars

    E-print Network

    B. Willems; J. Andrews; V. Kalogera; K. Belczynski

    2007-10-01

    We present results of a population synthesis study aimed at examining the role of spin-kick alignment in producing a correlation between the spin period of the first-born neutron star and the orbital eccentricity of observed double neutron star binaries in the Galactic disk. We find spin-kick alignment to be compatible with the observed correlation, but not to alleviate the requirements for low kick velocities suggested in previous population synthesis studies. Our results furthermore suggest low- and high-eccentricity systems may form through two distinct formation channels distinguished by the presence or absence of a stable mass transfer phase before the formation of the second neutron star. The presence of highly eccentric systems in the observed sample of double neutron stars may furthermore support the notion that neutron stars accrete matter when moving through the envelope of a giant companion.

  4. Femtosecond laser induced periodic nanostructures on titanium dioxide film for improving biocompatibility

    NASA Astrophysics Data System (ADS)

    Shinonaga, T.; Horiguchi, N.; Tsukamoto, M.; Nagai, A.; Yamashita, K.; Hanawa, T.; Matsushita, N.; Guoqiang, X.; Abe, N.

    2013-03-01

    Periodic nanostructures formation on Titanium dioxide (TiO2) film by scanning of femtosecond laser beam spot at fundamental and second harmonic wave is reported. Titanium (Ti) is one of the most widely used for biomaterials, because of its excellent anti-corrosion and high mechanical properties. However, Ti implant is typically artificial materials and has no biofunction. Hence, it is necessary for improving the bioactivity of Ti. Recently, coating of TiO2 film on Ti plate surface is useful methods to improve biocompatibility of Ti plate. Then, if periodic nanostructures were formed on the film surface, cell spreading might be controlled at one direction. We propose periodic nanostructures formation on TiO2 film by femtosecond laser irradiation. Cell spread could be controlled along the grooves of periodic nanostructures. In the experiments, the film was formed on Ti plate with an aerosol beam. A commercial femtosecond Ti : sapphire laser system was employed in our experiments. Periodic nanostructures, lying perpendicular to the laser electric field polarization vector, were formed on the film at fundamental and second harmonic wave. Periodic nanostructures were also produced on Ti plate with femtosecond laser. The period of periodic nanostructures on the film was much shorter than that on Ti plate. By cell test, there was a region of cell spreading along the grooves of periodic nanostructures on the film formed with femtosecond laser at fundamental wave. On bare film surface, cell spreading was observed at all direction. These results suggest that direction of cell spread could be controlled by periodic nanostructures formation on the film.

  5. Periodical Cicada Survival

    NSDL National Science Digital Library

    Science Netlinks

    2004-05-26

    In this lesson, from Science NetLinks, students explore defense mechanisms involved in predatory/prey relationships. The periodical cicadas that emerge in various parts of the United States every 13 or 17 years provide an excellent opportunity to engage students in a discussion about predatory/prey interactions. Students reflect on the life cycle and behavior of the cicada and develop understandings about how their unique life cycle and behavior actually helps them to reproduce and survive in spite of the fact that they have very few typical defense mechanisms.

  6. Controls on geyser periodicity

    USGS Publications Warehouse

    Ingebritsen, S.E.; Rojstaczer, S.A.

    1993-01-01

    Geyser eruption frequency is not constant over time and has been shown to vary with small (???10-6) strains induced by seismic events, atmospheric loading, and Earth tides. The geyser system is approximated as a permeable conduit of intensely fractured rock surrounded by a less permeable rock matrix. Numerical simulation of this conceptual model yields a set of parameters that controls geyser existence and periodicity. Much of the responsiveness to remote seismicity and other small strains in the Earth can be explained in terms of variations in permeability and lateral recharge rates.

  7. Controls on geyser periodicity.

    PubMed

    Ingebritsen, S E; Rojstaczer, S A

    1993-11-01

    Geyser eruption frequency is not constant over time and has been shown to vary with small (periodicity. Much of the responsiveness to remote seismicity and other small strains in the Earth can be explained in terms of variations in permeability and lateral recharge rates. PMID:17757358

  8. Structure of Dnmt3a bound to Dnmt3L suggests a model for de novo DNA methylation

    PubMed Central

    Jia, Da; Jurkowska, Renata Z.; Zhang, Xing; Jeltsch, Albert; Cheng, Xiaodong

    2009-01-01

    Genetic imprinting, found in flowering plants and placental mammals, uses DNA methylation to yield gene expression that is dependent on the parent of origin1. DNA methyltransferase 3a (Dnmt3a) and its regulatory factor, DNA methyltransferase 3-like protein (Dnmt3L), are both required for the de novo DNA methylation of imprinted genes in mammalian germ cells. Dnmt3L interacts specifically with unmethylated lysine 4 of histone H3 through its amino-terminal PHD (plant homeodomain)-like domain2. Here we show, with the use of crystallography, that the carboxy-terminal domain of human Dnmt3L interacts with the catalytic domain of Dnmt3a, demonstrating that Dnmt3L has dual functions of binding the unmethylated histone tail and activating DNA methyltransferase. The complexed C-terminal domains of Dnmt3a and Dnmt3L showed further dimerization through Dnmt3a–Dnmt3a interaction, forming a tetrameric complex with two active sites. Substitution of key non-catalytic residues at the Dnmt3a–Dnmt3L interface or the Dnmt3a–Dnmt3a interface eliminated enzymatic activity. Molecular modelling of a DNA–Dnmt3a dimer indicated that the two active sites are separated by about one DNA helical turn. The C-terminal domain of Dnmt3a oligomerizes on DNA to form a nucleoprotein filament. A periodicity in the activity of Dnmt3a on long DNA revealed a correlation of methylated CpG sites at distances of eight to ten base pairs, indicating that oligomerization leads Dnmt3a to methylate DNA in a periodic pattern. A similar periodicity is observed for the frequency of CpG sites in the differentially methylated regions of 12 maternally imprinted mouse genes. These results suggest a basis for the recognition and methylation of differentially methylated regions in imprinted genes, involving the detection of both nucleosome modification and CpG spacing. PMID:17713477

  9. PERIODIC SOLUTIONS OF A PERIODIC DELAY PREDATOR-PREY SYSTEM

    Microsoft Academic Search

    LI YONGKUN

    The existence of a positive periodic solution for (dH(t) dt = r(t)H(t) h 1 H(t (t)) K(t) i (t)H(t)P(t); dP(t) dt = b(t)P(t )+ ( t ) P ( t ) H ( t ( t)) is established, where r, K, , b, are positive periodic continuous functions with period !> 0, and , are periodic continuous functions with period

  10. Flame propagation through periodic vortices

    SciTech Connect

    Dold, J.W.; Kerr, O.S. [Univ. of Bristol (United Kingdom). School of Mathematics] [Univ. of Bristol (United Kingdom). School of Mathematics; Nikolova, I.P. [Inst. of Mechanics and Biomechanics, Sofia (Bulgaria)] [Inst. of Mechanics and Biomechanics, Sofia (Bulgaria)

    1995-02-01

    The discovery of a new class of Navier-Stokes solutions representing steady periodic stretched vortices offers a useful test-bed for examining interactions between flames and complex flow-fields. After briefly describing these vortex solutions and their wide-ranging parameterization in terms of wavelength and amplitude, this article examines their effect on flames of constant normal propagation speed as observed through numerical solutions of an eikonal equation. Over certain ranges of vortex amplitude and flame-speed, a corridor of enhanced flame passage is seen to be created as a leading flame-tip managers to leap-frog between successive vortices. However, for large enough amplitudes of vorticity or small enough flame-speeds, the flame fails to be able to benefit from the advection due to the vortices. It is shown that the leading tips of such flames are effectively trapped by the stretched vortices.

  11. Are Mantle Plumes Periodic?

    NASA Astrophysics Data System (ADS)

    Rampino, Michael R.; Prokoph, Andreas

    2013-03-01

    In the past few years, researchers have uncovered evidence that several kinds of geological and biological events seem to show regular cycles of similar lengths. For example, Rohde and Muller [2005] looked at the record of diversity of marine organisms over the past 540 million years and found evidence for two cycles in the data—a roughly 62-million-year cycle and a longer cycle of about 140 million years. This was followed by reports of an approximately 56-million-year cycle in long-term stratigraphic sequences in sedimentary basins [Meyers and Peters, 2011] and a 59-million-year period in the marine strontium-isotope record [Melott et al., 2012]. A similar period may even exist in atmospheric carbon dioxide over the past 542 million years of the Phanerozoic [Franks et al., 2012]. A cycle of about 140 million years was reported by Veizer et al. [2000] and Mayhew et al. [2008] in long-term fluctuations in global climate.

  12. Structural and functional correlates of hypnotic depth and suggestibility.

    PubMed

    McGeown, William Jonathan; Mazzoni, Giuliana; Vannucci, Manila; Venneri, Annalena

    2015-02-28

    This study explores whether self-reported depth of hypnosis and hypnotic suggestibility are associated with individual differences in neuroanatomy and/or levels of functional connectivity. Twenty-nine people varying in suggestibility were recruited and underwent structural, and after a hypnotic induction, functional magnetic resonance imaging at rest. We used voxel-based morphometry to assess the correlation of grey matter (GM) and white matter (WM) against the independent variables: depth of hypnosis, level of relaxation and hypnotic suggestibility. Functional networks identified with independent components analysis were regressed with the independent variables. Hypnotic depth ratings were positively correlated with GM volume in the frontal cortex and the anterior cingulate cortex (ACC). Hypnotic suggestibility was positively correlated with GM volume in the left temporal-occipital cortex. Relaxation ratings did not correlate significantly with GM volume and none of the independent variables correlated with regional WM volume measures. Self-reported deeper levels of hypnosis were associated with less connectivity within the anterior default mode network. Taken together, the results suggest that the greater GM volume in the medial frontal cortex and ACC, and lower connectivity in the DMN during hypnosis facilitate experiences of greater hypnotic depth. The patterns of results suggest that hypnotic depth and hypnotic suggestibility should not be considered synonyms. PMID:25557062

  13. Hipparcos parallaxes for Mira-like long-period variables

    Microsoft Academic Search

    Patricia Whitelock; Michael Feast

    2000-01-01

    This paper concerns the calibration of the K period-luminosity relation for Mira variables using Hipparcos parallaxes. K magnitudes are available for 255 Mira-like variables which were observed by Hipparcos. Period-luminosity zero-points are evaluated for various subgroups of data. The best solution for oxygen-rich Miras, which uses 180 stars, omitting the short-period red group (which had different kinematics from the short-period

  14. A comparison of period finding algorithms

    NASA Astrophysics Data System (ADS)

    Graham, Matthew J.; Drake, Andrew J.; Djorgovski, S. G.; Mahabal, Ashish A.; Donalek, Ciro; Duan, Victor; Maker, Allison

    2013-10-01

    This paper presents a comparison of popular period finding algorithms applied to the light curves of variable stars from the Catalina Real-Time Transient Survey, MACHO and ASAS data sets. We analyse the accuracy of the methods against magnitude, sampling rates, quoted period, quality measures (signal-to-noise and number of observations), variability and object classes. We find that measure of dispersion-based techniques - analysis of variance with harmonics and conditional entropy - consistently give the best results but there are clear dependences on object class and light-curve quality. Period aliasing and identifying a period harmonic also remain significant issues. We consider the performance of the algorithms and show that a new conditional entropy-based algorithm is the most optimal in terms of completeness and speed. We also consider a simple ensemble approach and find that it performs no better than individual algorithms.

  15. Practical Suggestions to Internationalize the General Education Curriculum

    ERIC Educational Resources Information Center

    Galvan, Javier A.

    2006-01-01

    This article is based on the work that the author carried out at Santa Ana College (SAC) during a period of 2 years using two federal grants. SAC is a Hispanic-serving institution with an average yearly enrollment of 25,000 students. An average of 45% of the student population is Latino, with the majority being Mexican American. The author's aim…

  16. Injuries in Female Gymnasts: Trends Suggest Prevention Tactics.

    ERIC Educational Resources Information Center

    Mackie, Susan J.; Taunton, Jack E.

    1994-01-01

    Survey of 100 young female gymnasts examined injuries over a 40-month period. Injury rates were similar to those found in other studies of female competitive gymnasts, but there were several notable findings regarding injury patterns. Prevention methods to reduce injury include modifying mat design and prescribing strengthening and stretching…

  17. The Incubation Periods of Dengue Viruses

    PubMed Central

    Chan, Miranda; Johansson, Michael A.

    2012-01-01

    Dengue viruses are major contributors to illness and death globally. Here we analyze the extrinsic and intrinsic incubation periods (EIP and IIP), in the mosquito and human, respectively. We identified 146 EIP observations from 8 studies and 204 IIP observations from 35 studies. These data were fitted with censored Bayesian time-to-event models. The best-fitting temperature-dependent EIP model estimated that 95% of EIPs are between 5 and 33 days at 25°C, and 2 and 15 days at 30°C, with means of 15 and 6.5 days, respectively. The mean IIP estimate was 5.9 days, with 95% expected between days 3 and 10. Differences between serotypes were not identified for either incubation period. These incubation period models should be useful in clinical diagnosis, outbreak investigation, prevention and control efforts, and mathematical modeling of dengue virus transmission. PMID:23226436

  18. Stellar evolution in real time: Period variations in galactic RR Lyr stars

    E-print Network

    E. Poretti; J. F. Le Borgne; J. Vandenbroere; A. Paschke; A. Klotz; M. Boer; Y. Damerdji; M. Martignoni; F. Acerbi

    2007-11-27

    The times of maximum brightness collected in the GEOS RR Lyr database allowed us to trace the period variations of a sample of 123 galactic RRab variables. These data span a time baseline exceeding 100 years. Clear evidence of period increases or decreases at constant rates has been found, suggesting evolutionary effects. The observed rates are slightly larger than those predicted by theoretical models; moreover, there is an unexpected large percentage of RRab stars showing a period decrease. The new possibilities offered by the use of robotic telecopes (TAROTs, REM) and of data from satellite (CoRoT) are expected to speed up the project to measure stellar evolution in real time. It is noteworthy that the outlines of this project have been sketched during several GEOS meetings, where the different knowledge of amateur and professional astronomers found a very profitable synthesis.

  19. Long-period surface motion of the multipatch Mw9.0 Tohoku-Oki earthquake

    NASA Astrophysics Data System (ADS)

    Psimoulis, Panos A.; Houlié, Nicolas; Michel, Clotaire; Meindl, Michael; Rothacher, Markus

    2014-11-01

    We show that it is possible to capture the oscillatory ground motion induced by the Tohoku-Oki event for periods ranging from 3 to 100 s using precise point positioning. We find that the ground motions of the sedimentary basins of Japan were large (respectively >0.15 m s-1 and >0.15 m s-2 for velocity and acceleration) even for periods larger than 3 s. We compare geodetic observables with a ground motion prediction equation designed for Japan seismicity and find that the spectral acceleration is well estimated for periods larger than 3 s and distances ranging from 100 to 500 km. At last, through the analysis of the displacement attenuation plots, we show that the 2011 Tohoku-Oki event is likely composed of multiple rupture patches as suggested before by time-reversal inversions of seismic data.

  20. The effects of concurrent resistance and endurance training follow a detraining period in elementary school students.

    PubMed

    Santos, Albano P; Marinho, Daniel A; Costa, Aldo M; Izquierdo, Mikel; Marques, Mário C

    2012-06-01

    The purpose of this study was to compare the effects of an 8-week training period of resistance training alone (GR), or combined resistance and endurance training (GCOM), followed by 12 weeks of detraining (DT) on body composition, explosive strength, and ·VO?max adaptations in a large sample of adolescent school boys. Forty-two healthy boys recruited from a Portuguese public high school (age: 13.3 ± 1.04 years) were assigned to 2 experimental groups to train twice a week for 8 weeks: GR (n = 15), GCOM (n = 15), and a control group (GC: n = 12; no training program). Significant training-induced differences were observed in 1- and 3-kg medicine ball throw gains (GR: +10.3 and +9.8%, respectively; GCOM: +14.4 and +7%, respectively), whereas no significant changes were observed after a DT period in both the experimental groups. Significant training-induced gains in the height and length of the countermovement (vertical-and-horizontal) jumps were observed in both the experimental groups. No differences were perceived after a DT period in lower limb power. Time at 20 m decreased significantly for both intervention programs (GR: -11.5% and GCOM: -12.4%, <0.00), but either GR or GCOM groups kept the running speed after a DT period of 12 weeks. After training, the ·VO?max increased only significantly for GCOM (4.6%, p = 0.01). A significant loss was observed after a DT period in GR but not in GCOM. Performing resistance and endurance training in the same workout does not impair strength development in young school boys. As expected, strength training by itself does not improve aerobic capacity. Our results also suggest that training program effects even persist at the end of the DT period. PMID:21912296

  1. Using Neurolinguistic Programming: Some Suggestions for the Remedial Teacher.

    ERIC Educational Resources Information Center

    Burton, Grace M.

    1986-01-01

    The use of neurolinguistic programming techniques is suggested as a means of enhancing rapport with students. Mirroring, digital mirroring, analog mirroring, metaphors, knowing persons, and how these aid in presenting content are each discussed. (MNS)

  2. 32 CFR 1908.04 - Suggestions and complaints.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...declassification review program established under Executive Order 12958. Many requesters will receive pre-paid, customer satisfaction survey cards. Letters of suggestion or complaint should identify the specific purpose and the issues for...

  3. 32 CFR 1908.04 - Suggestions and complaints.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...declassification review program established under Executive Order 12958. Many requesters will receive pre-paid, customer satisfaction survey cards. Letters of suggestion or complaint should identify the specific purpose and the issues for...

  4. 32 CFR 1900.04 - Suggestions and complaints.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...complaints with regard to its administration of the Freedom of Information Act. Many requesters will receive pre-paid, customer satisfaction survey cards. Letters of suggestion or complaint should identify the specific purpose and the issues for...

  5. 37 CFR 41.202 - Suggesting an interference.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...OFFICE, DEPARTMENT OF COMMERCE PRACTICE BEFORE THE PATENT TRIAL AND APPEAL BOARD Patent Interferences § 41.202 Suggesting...disclosure provides a constructive reduction to practice within the scope of the interfering subject matter. (b) Patentee....

  6. 37 CFR 41.202 - Suggesting an interference.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...OFFICE, DEPARTMENT OF COMMERCE PRACTICE BEFORE THE PATENT TRIAL AND APPEAL BOARD Patent Interferences § 41.202 Suggesting...disclosure provides a constructive reduction to practice within the scope of the interfering subject matter. (b) Patentee....

  7. Statins Pose No Greater Harm to Memory, Study Suggests

    MedlinePLUS

    ... 152965.html Statins Pose No Greater Harm to Memory, Study Suggests Review of more than a million ... who take statin drugs might experience short-term memory loss, a large new study finds they are ...

  8. 'Green Space' At School May Help Kids Learn, Study Suggests

    MedlinePLUS

    ... physical activity is good for child growth and development." The findings suggest that the whole family can benefit from spending time together in natural environments, she added. "It may also have the added ...

  9. Oxygen Chamber Therapy May Ease Fibromyalgia, Study Suggests

    MedlinePLUS

    Oxygen Chamber Therapy May Ease Fibromyalgia, Study Suggests But treatment isn't FDA-approved, so insurance companies ... majority of women with fibromyalgia who underwent hyperbaric oxygen therapy -- best known for treating "the bends" in ...

  10. Breast-Feeding May Have Dental Benefits, Study Suggests

    MedlinePLUS

    Breast-Feeding May Have Dental Benefits, Study Suggests But kids also had fewer 'misaligned' teeth if they reduced ... that potential benefit, even if the children are breast-feeding, the Australian researchers said. "While most benefits of ...

  11. Poor Health as Teen, Poor Job Prospects Later, Study Suggests

    MedlinePLUS

    Poor Health as Teen, Poor Job Prospects Later, Study Suggests Chronic mental or physical problems were tied to worse education, employment goals in ... News) -- Mental or physical health problems during the teen years may make it harder to get a ...

  12. 29 CFR 778.333 - Suggestion system awards.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR STATEMENTS OF GENERAL POLICY OR INTERPRETATION NOT DIRECTLY RELATED TO REGULATIONS OVERTIME COMPENSATION Special Problems Prizes As Bonuses § 778.333 Suggestion system...

  13. Enhanced third harmonic generation in periodic structures

    Microsoft Academic Search

    V. Mahalakshmi; Jolly Jose; S Dutta Gupta

    1996-01-01

    We consider third harmonic generation in a periodic layered medium with alternate nonlinear media. We show enhanced third\\u000a harmonic generation when the fundamental frequency matches one of the mode frequencies of the distributed feedback structure.\\u000a The observed feature is explained in terms of large local field enhancement for the fundamental wave.

  14. Periodicity and chaos in coupled nonlinear oscillators.

    PubMed

    Gollub, J P; Brunner, T O; Danly, B G

    1978-04-01

    A system of coupled tunnel diode relaxation oscillators shows a variety of complex periodic states as the external voltage is varied. The existence of chaotic or nonperiodic states is more dependent on the nature of the coupling than on the number of degrees of freedom. A simple but accurate numerical model shows many of the phenomena observed experimentally. PMID:17847328

  15. Long Secondary Periods in variable red giants

    Microsoft Academic Search

    C. P. Nicholls; P. R. Wood; M.-R. L. Cioni; I. Soszynski

    2009-01-01

    We present a study of a sample of Large Magellanic Cloud red giants exhibiting Long Secondary Periods (LSPs). We use radial velocities obtained from VLT spectral observations and MACHO and OGLE light curves to examine properties of the stars and to evaluate models for the cause of LSPs. This sample is much larger than the combined previous studies of Hinkle

  16. Multiscale periodic structure in the Io wake

    NASA Astrophysics Data System (ADS)

    Smith, P. R.; Wright, A. N.

    1989-06-01

    Preliminary results from an eigenmode synthesis of the Alfven waves launched by Io are presented. It is found that several important periodicities emerge. Observations of the decametric emission reveal fine, medium, and large-scale radio structure. These simulations can provide structure on each of these scales, unlike earlier models.

  17. Rotation Period Determination for 3395 Jitka

    NASA Astrophysics Data System (ADS)

    Marchini, Alessandro; Salvaggio, Fabio

    2015-07-01

    Analysis of photometric observations of the main-belt asteroid 3395 Jitka performed by the authors in February 2015 revealed a bimodal lightcurve with a synodic rotation period of 18.293 ± 0.006 hours as the most likely solution.

  18. 3382 Cassidy: A Short Period Asteroid

    NASA Astrophysics Data System (ADS)

    Risley, Ethan

    2013-04-01

    The asteroid 3382 Cassidy was observed from the Etscorn Campus Observatory (ECO, 2012) at New Mexico Institute of Mining and Technology in Socorro, NM, on nine nights over a span of 43 days in 2012 September-November. A bimodal synodic period of 4.254 ± 0.002 h and an amplitude of 0.15 ± 0.02 mag were obtained.

  19. Training, Quality Assurance Factors, and Tools Investigation: a Work Report and Suggestions on Software Quality Assurance

    NASA Technical Reports Server (NTRS)

    Lee, Pen-Nan

    1991-01-01

    Previously, several research tasks have been conducted, some observations were obtained, and several possible suggestions have been contemplated involving software quality assurance engineering at NASA Johnson. These research tasks are briefly described. Also, a brief discussion is given on the role of software quality assurance in software engineering along with some observations and suggestions. A brief discussion on a training program for software quality assurance engineers is provided. A list of assurance factors as well as quality factors are also included. Finally, a process model which can be used for searching and collecting software quality assurance tools is presented.

  20. UTEP Computer Science Suggested 4 Year Plan of Study

    E-print Network

    Ward, Karen

    _precalc_090707_2007781.xls 14 17 Second Year Fall Hours Spring Hours Summer Hours Calculus II 3 Data Structures 3Study-Suggested4Yr_2008-120_hr_precalc_090707_2007781.xls #12;UTEP Computer Science Suggested 4 Year Plan of Study_2007781.xls 16 14 Fourth Year Fall Hours Spring Hours Summer Hours Software Eng. I 3 Software Eng. II 3 Design

  1. UHURU observations of the galactic plane in 1970, 1971, and 1972

    Microsoft Academic Search

    W. Forman; H. Tananbaum; C. Jones

    1976-01-01

    Uhuru observations of the galactic plane in 1970, 1971, and 1972 are analyzed. The great majority of the galactic X-ray sources are not 'transient'. Some of the so-called transient sources persist for long periods of time at an intensity of a few percent of their peak values. The data suggest that the transient sources may be quite similar to the

  2. Multicomponent periodic nanoparticle superlattices.

    SciTech Connect

    Podsiadlo, P.; Krylova, G. V.; Demortiere, A.; Shevchenko, E. V. (Center for Nanoscale Materials)

    2011-01-01

    In this article, we review the state-of-the-art in the preparation and characterization of multicomponent self-assembled superlattices of colloidal nanoparticles with core sizes in the range of 2-20 nm and interparticle spacing less than 2 nm down to intimate contact stemming from sintering. Several aspects of the field are discussed, including: structural organization, the role of particle size distribution, key interparticle forces at play, and methods of investigation of the structures. Contrary to the extensively studied colloidal crystals composed of microscale particles, the nanoparticles possess unique size-dependent properties, such as electronic, optical, or magnetic, which when combined into periodic structures can potentially lead to new collective states stemming from precise positioning of the nanocolloids. As such, we examine a number of emerging applications of this new class of metamaterials. Finally, we speculate on the potential impact of these materials, the new directions, and the challenges for the researchers.

  3. Periodically Driven Holographic Superconductor

    E-print Network

    Wei-Jia Li; Yu Tian; Hongbao Zhang

    2013-06-21

    As a first step towards our holographic investigation of the far-from-equilibrium physics of periodically driven systems at strong coupling, we explore the real time dynamics of holographic superconductor driven by a monochromatically alternating electric field with various frequencies. As a result, our holographic superconductor is driven to the final oscillating state, where the condensate is suppressed and the oscillation frequency is controlled by twice of the driving frequency. In particular, in the large frequency limit, the three distinct channels towards the final steady state are found, namely under damped to superconducting phase, over damped to superconducting and normal phase, which can be captured essentially by the low lying spectrum of quasi-normal modes in the time averaged approximation, reminiscent of the effective field theory perspective.

  4. Periodically Driven Holographic Superconductor

    E-print Network

    Li, Wei-Jia; Zhang, Hongbao

    2013-01-01

    As a first step towards our holographic investigation of the far-from-equilibrium physics of periodically driven systems at strong coupling, we explore the real time dynamics of holographic superconductor driven by a monochromatically alternating electric field with various frequencies. As a result, our holographic superconductor is driven to the final oscillating state, where the condensate is suppressed and the oscillation frequency is controlled by twice of the driving frequency. In particular, in the large frequency limit, the three distinct channels towards the final steady state are found, namely under damped to superconducting phase, over damped to superconducting and normal phase, which can be captured essentially by the low lying spectrum of quasi-normal modes in the time averaged approximation, reminiscent of the effective field theory perspective.

  5. Toxicogenomic analysis suggests chemical-induced sexual dimorphism in the expression of metabolic genes in zebrafish liver.

    PubMed

    Zhang, Xun; Ung, Choong Yong; Lam, Siew Hong; Ma, Jing; Chen, Yu Zong; Zhang, Louxin; Gong, Zhiyuan; Li, Baowen

    2012-01-01

    Differential gene expression in two sexes is widespread throughout the animal kingdom, giving rise to sex-dimorphic gene activities and sex-dependent adaptability to environmental cues, diets, growth and development as well as susceptibility to diseases. Here, we present a study using a toxicogenomic approach to investigate metabolic genes that show sex-dimorphic expression in the zebrafish liver triggered by several chemicals. Our analysis revealed that, besides the known genes for xenobiotic metabolism, many functionally diverse metabolic genes, such as ELOVL fatty acid elongase, DNA-directed RNA polymerase, and hydroxysteroid dehydrogenase, were also sex-dimorphic in their response to chemical treatments. Moreover, sex-dimorphic responses were also observed at the pathway level. Pathways belonging to xenobiotic metabolism, lipid metabolism, and nucleotide metabolism were enriched with sex-dimorphically expressed genes. We also observed temporal differences of the sex-dimorphic responses, suggesting that both genes and pathways are differently correlated during different periods of chemical perturbation. The ubiquity of sex-dimorphic activities at different biological hierarchies indicate the importance and the need of considering the sex factor in many areas of biological researches, especially in toxicology and pathology. PMID:23272195

  6. Discovery of four periodic methanol masers and updated light curve for a further one

    E-print Network

    Szymczak, M; Bartkiewicz, A

    2015-01-01

    We report the discovery of 6.7 GHz methanol maser periodic flares in four massive star forming regions and the updated light curve for the known periodic source G22.357+0.066. The observations were carried out with the Torun 32 m radio telescope between June 2009 and April 2014. Flux density variations with period of 120 to 245 d were detected for some or all spectral features. A variability pattern with a fast rise and relatively slow fall on time-scale of 30-60 d dominated. A reverse pattern was observed for some features of G22.357+0.066, while sinusoidal-like variations were detected in G25.411+0.105. A weak burst lasting ~520 d with the velocity drift of 0.24 km/s/yr occurred in G22.357+0.066. For three sources for which high resolution maps are available, we found that the features with periodic behaviour are separated by more than 500 au from those without any periodicity. This suggests that the maser flares are not triggered by large-scale homogeneous variations in either the background seed photon fl...

  7. Spectrophotometry and period analysis of the sdB eclipsing binary HW Virginis

    E-print Network

    L. L. Kiss; B. Csak; K. Szatmary; G. Furesz; K. Sziladi

    2000-10-23

    New CCD observations of the pre-cataclysmic binary HW Virginis are presented and discussed. The R-filtered CCD photometry was supplemented with medium-band (Cousins VRI) spectrophotometry based on low-resolution objective-prism spectra. The period variation is reanalysed by means of the standard O-C technique. The new data support the conclusions of Kilkenny et al. (2000) on the strong and continuous period change. The long-term period variation can be described approximately with two linear branches in the O-C diagram corresponding to a sudden period jump between two constant periods around JD 2448500 (1991). Additional smooth small-scale changes in the period distort the linearity. The present data do not support the hypothetical light-time effect of Cakirli & Devlen (1999). The eclipse depths in V, R, and I do not show colour dependence, which suggests negligible continuum variations due to the cool secondary component in the far-red region (up to 8800 AA). The magnitude of the reflection effect was used to estimate the mean effective temperature of the illuminated hemisphere of the secondary. The result is 13300\\pm200 K or 11000\\pm200 K, depending on the primary temperature (35000 K or 26000 K). An albedo near unity is implied for the cool component.

  8. Spectrophotometry and period analysis of the sdB eclipsing binary HW Virginis

    NASA Astrophysics Data System (ADS)

    Kiss, L. L.; Csák, B.; Szatmáry, K.; Furész, G.; Sziládi, K.

    2000-12-01

    New CCD observations of the pre-cataclysmic binary HW Virginis are presented and discussed. The R-filtered CCD photometry was supplemented with medium-band (Cousins VRI) spectrophotometry based on low-resolution objective-prism spectra. The period variation is reanalysed by means of the standard O-C technique. The new data support the conclusions of Kilkenny et al. (2000) on the strong and continuous period change. The long-term period variation can be described approximately with two linear branches in the O-C diagram corresponding to a sudden period jump between two constant periods around JD 2448500 (1991). Additional smooth small-scale changes in the period distort the linearity. The present data do not support the hypothetical light-time effect of Çakirli & Devlen (1999). The eclipse depths in V, R, and I do not show colour dependence, which suggests negligible continuum variations due to the cool secondary component in the far-red region (up to 8800 Å). The magnitude of the reflection effect was used to estimate the mean effective temperature of the illuminated hemisphere of the secondary. The result is 13300+/-200 K or 11000+/-200 K, depending on the primary temperature (35000 K or 26000 K). An albedo near unity is implied for the cool component.

  9. Periodic extinction of families and genera

    NASA Technical Reports Server (NTRS)

    Raup, D. M.; Sepkoski, J. J. Jr; Sepkoski JJ, J. r. (Principal Investigator)

    1986-01-01

    Eight major episodes of biological extinction of marine families over the past 250 million years stand significantly above local background (P < 0.05). These events are more pronounced when analyzed at the level of genus, and generic data exhibit additional apparent extinction events in the Aptian (Cretaceous) and Pliocene (Tertiary) Stages. Time-series analysis of these records strongly suggests a 26-million-year periodicity. This conclusion is robust even when adjusted for simultaneous testing of many trial periods. When the time series is limited to the four best-dated events (Cenomanian, Maestrichtian, upper Eocene, and middle Miocene), the hypothesis of randomness is also rejected for the 26-million-year period (P < 0.0002).

  10. Periodic extinction of families and genera

    NASA Technical Reports Server (NTRS)

    Raup, David M.; Sepkoski, J. John, Jr.

    1987-01-01

    Eight major episodes of biological extinction of marine families over the past 250 million years stand significantly above local background (P less than 0.05). These events are more pronounced when analyzed at the level of genus, and generic data exhibit additional apparent extinction events in the Aptian (Cretaceous) and Pliocene (Tertiary) Stages. Time-series analysis of these records strongly suggests a 26-million-year periodicity. This conclusion is robust even when adjusted for simultaneous testing of many trial periods. When the time series is limited to the four best-dated events (Cenomanian, Maestrichtian, upper Eocene, and middle Miocene), the hypothesis of randomness is also rejected for the 26-million-year period (P less than 0.0002).

  11. Periodicities in the IUE particle radiation data

    NASA Astrophysics Data System (ADS)

    Arquilla, Richard

    1993-06-01

    The magnetospheric charged particle flux measured serendipitously by the IUE satellite during perigee passages from 1978 February to 1989 February has been searched for periodicities using Fourier transform and correlation techniques. The analysis uncovers persistent modulations of the particle flux with periods of 28-33 days and 15-17 days. The particle flux seen by IUE in the outer van Allen belt is modulated to a significant extent by the magnetosphere's interaction with high-speed solar wind streams from coronal holes, in agreement with analyses of fluxes at other altitudes and of geomagnetic disturbance indices. It is suggested that recurrent global solar-surface activity, such as the 25.8-day periodicity discussed by Bai and Sturrock (1991) and the solar 'hot spots' reported by Bai (1987, 1988, 1990), may play a role in modulating the particle flux near solar maximum.

  12. ESTROGEN NEUROPROTECTION AND THE CRITICAL PERIOD HYPOTHESIS

    PubMed Central

    Scott, Erin; Zhang, Quan-guang; Wang, Ruimin; Vadlamudi, Ratna; Brann, Darrell

    2011-01-01

    17?-estradiol (estradiol or E2) is implicated as a neurodegenerative disorders. This review focuses on the mechanisms underlying E2 neuroprotection in cerebral ischemia, as well as emerging evidence from basic science and clinical studies, which suggests that there is a “critical period” for estradiol's beneficial effect in the brain. Potential mechanisms underlying the critical period are discussed, as are the neurological consequences of long-term E2 deprivation (LTED) in animals and in humans after natural menopause or surgical menopause. We also summarize the major clinical trials concerning postmenopausal hormone therapy (HT), comparing their outcomes with respect to cardiovascular and neurological disease and discussing their relevance to the critical period hypothesis. Finally, potential caveats, controversies and future directions for the field are highlighted and discussed throughout the review. PMID:22079780

  13. Possible Observational Criteria for Distinguishing Brown Dwarfs From Planets

    NASA Technical Reports Server (NTRS)

    Black, David C.

    1997-01-01

    The difference in formation process between binary stars and planetary systems is reflected in their composition, as well as orbital architecture, particularly in their orbital eccentricity as a function of orbital period. It is suggested here that this difference can be used as an observational criterion to distinguish between brown dwarfs and planets. Application of the orbital criterion suggests that, with three possible exceptions, all of the recently discovered substellar companions may be brown dwarfs and not planets. These criterion may be used as a guide for interpretation of the nature of substellar-mass companions to stars in the future.

  14. Hypnosis, suggestion, and placebo in the reduction of experimental pain.

    PubMed

    Spanos, N P; Perlini, A H; Robertson, L A

    1989-08-01

    Two experiments compared placebo and hypnotic analgesia in high and low hypnotizable subjects. Experiment 1 demonstrated that hypnotic and placebo analgesia were equally ineffective in low hypnotizables, but that hypnotic analgesia was much more effective than placebo analgesia in high hypnotizables. Experiment 2 replicated these results, but also included low and high hypnotizables who were given a nonhypnotic suggestion for analgesia. Both the low and high hypnotizables in this group reported greater suggested than placebo analgesia and as much suggested analgesia as high hypnotizable hypnotic subjects. Both experiments found substantial discrepancies between the amount of pain reduction subjects expected from the various treatments and the amount of pain reduction they actually reported following exposure to those treatments. In Experiment 2, subjects in all treatments who reduced reported pain engaged in more cognitive coping and less catastrophizing than those who did not reduce pain. Theoretical implications are discussed. PMID:2768664

  15. Quasi-Periodic Pulsations in Solar Flares

    NASA Astrophysics Data System (ADS)

    Nakariakov, V. M.; Melnikov, V. F.

    2009-12-01

    Quasi-periodic pulsations (QPP) are a common feature of flaring energy releases in the solar atmosphere, observed in all bands, from radio to hard X-ray. In this review we concentrate on QPP with the periods longer than one second. Physical mechanisms responsible for the generation of long QPP split into two groups: “load/unload” mechanisms and MHD oscillations. Load/unload mechanisms are repetitive regimes of flaring energy releases by magnetic reconnection or by other means. MHD oscillations can affect all elements of the flaring emission generation: triggering of reconnection and modulation of its rate, acceleration and dynamics of non-thermal electrons, and physical conditions in the emitting plasmas. In the case of MHD oscillations, the periodicity of QPP is determined either by the presence of some resonances, e.g. standing modes of plasma structures, or by wave dispersion. Periods and other parameters of QPP are linked with properties of flaring plasmas and their morphology. Observational investigation of the QPP generation mechanisms based upon the use of spatial information, broadband spectral coverage and multi-periodicity is discussed.

  16. Midterm periods of solar filaments

    NASA Astrophysics Data System (ADS)

    Zou, Peng; Li, Qixiu

    2014-12-01

    On the basis of the Carte Synoptique catalogue of solar filaments from March 1919 to December 1989, we measure power spectra of detrended full-disk (FSFNs, latitudinal bands: 0?-90?), low-latitude (LSFNs, latitudinal bands: <50?), and high-latitude (HSFNs, latitudinal bands: ?50?) solar filament numbers by Maximum Entropy Method (MEM) and Continuous wavelet transform to detect midterm periods. It is found as the following: (1) FSFNs and LSFNs have the same midterm periodicity, while HSFNs show a different midrange periodicity. Some periods frequently mentioned in other solar indices are also detected from the solar filament numbers, such as 2-3 year period (quasi-biennial oscillation—QBO), ˜1.7 year, ˜1.3 year, ˜1 year, 150-157 day period (Rieger period), and 6.0-6.4 months (Rieger-type period). These periods are intermittent during considered time span. Some of them are missing in some solar cycles. (2) QBO is detected from total data and most solar cycles of FSFNs, LSFNs, and HSFNs. It may be related to oscillation of magnetic field of solar surface. (3) Approximately 1.3 year period occasionally appears, but ˜1.7 year period is hardly seen. These two periods probably are seasonal effects. (4) Approximately 1 year period is detected from both total data and every solar cycle of FSFNs and LSFNs but hardly detected from HSFNs. It is perhaps connected with sunspot activity. (5) Rieger period of 5.0-5.2 months is detected in total data and even solar cycles of HSFNs. Rieger-type period of 6.0-6.4 months is found in total data and most solar cycles, except cycle 18 of LSFNs and FSFNs. These periods seem to be subharmonics of ˜11 year period.

  17. The effect of stellar evolution upon Population II Contact Binaries in the Period-Color Relation. I. Equal-Mass, Marginal Contact Systems

    E-print Network

    Eric P. Rubenstein

    2001-02-15

    Field W UMa binaries observe a well known Period-Color Relation such that systems containing more massive stars are bluer and have longer orbital periods than those systems with lower mass components. However, it has been known for a decade that metal-poor W UMa's are too blue, have too short an orbital period, or both. Correcting the observed color for the reduced line blanketing in the atmosphere of a Pop II star only accounts for part of the observed discrepancy. As others have suggested, and Rucinski (2000) show, the smaller radii of Pop II stars and the correspondingly shorter orbital periods are responsible for the remainder. In this paper I investigate the effect of evolution upon the location in the period-color plane. This paper addresses the restricted case of equal mass components in critical contact with their inner Roche lobes, but should be applicable to the more general cases to the extent that the relative sizes of stellar components are preserved with metallicity changes. The calculated metallicity-age dependent Period-Color Relations substantially agree with Rucinski & Duerbeck's (1997) empirically derived corrections to the Period-Color Relation over most of the investigated range of periods. However, our predictions deviate to a greater degree as stellar age increases since their parameterization does not include the effect of evolution.

  18. Periodicity in the occurrence of equatorial plasma bubbles

    NASA Astrophysics Data System (ADS)

    Choi, J.; Kim, Y.; Kil, H.; Kwak, Y.; Lee, W.

    2013-12-01

    The observations of equatorial plasma bubbles by low-inclination orbit satellites show periodic occurrence of bubbles along satellite orbits. The periodicity in the bubble occurrence provides a useful tool for identifying the role of gravity waves in the creation of bubbles. In this study, we investigate the variability of the periodicity in the bubble occurrence by analyzing the observations of Communication/Navigation Outage Forecasting System (C/NOFS) and the first Republic of China satellite (ROCSAT-1). Here the periodicity indicates spatial periodicity and is derived by applying a Fourier analysis to the electron densities projected onto the magnetic apex height. Our preliminary results show an occurrence of significant amplitudes of periodicity peaks on the spatial scale range of 50-1000 km. The periodicity on small scales may be associated with the bifurcation of bubbles or to the creation of multiple bubbles for one wave seeding. The periodicity on larger scales is considered to be related with the scale size of a seeding mechanism. We present statistics of the periodicity and the coincident satellite observations of periodic bubbles with ground observations.

  19. Organization of periodic structures in a damped-forced oscillator

    NASA Astrophysics Data System (ADS)

    Prants, Fabiola G.; Rech, Paulo C.

    2014-09-01

    We report on the dynamics in a parameter plane of a continuous-time damped system driven by a periodic forcing. The dynamics is characterized by considering the Lyapunov exponents spectrum and conventional bifurcation diagrams, to discriminate periodic, quasiperiodic, and chaotic behaviors for each point in this parameter plane, according two parameters are simultaneously varied. Periodic structures born in a quasiperiodic region and embedded in a chaotic region, the so-called Arnold tongues, are observed. We show that the Arnold tongues periodic distribution is highly organized in a mixed set of two period-adding sequences. Other three typical periodic structures born and embedded in a chaotic region were observed, also individually organized in a mixed set of two period-adding sequences.

  20. Periodicities of solar irradiance and solar activity indices

    Microsoft Academic Search

    Judit Pap; S. David Bouwer; W. Kent Tobiska

    1990-01-01

    The present FFT time-series analysis indicates the presence of an 8-11 month periodicity in solar total and UV irradiances, sunspot-blocking function, 10.7-cm radio flux, and Ca-K plage index. While the 51-day period is the dominant one in the projected areas of developing complex sunspot groups, it is missing from the old, decaying sunspot areas, thereby suggesting that the 51-day period