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1

Infrared Observations of Periodic Comets.  

National Technical Information Service (NTIS)

Selected comets are observed in the infrared with the NASA Infrared Telescope Facility (IRTF) and other telescopes as appropriate. The scientific objectives are to characterize the thermal emission from the dust coma, derive dust productions rates, detect...

S. Hanner

1988-01-01

2

Rational reduction of periodic propagators for off-period observations.  

PubMed

Many common solid-state nuclear magnetic resonance problems take advantage of the periodicity of the underlying Hamiltonian to simplify the computation of an observation. Most of the time-domain methods used, however, require the time step between observations to be some integer or reciprocal-integer multiple of the period, thereby restricting the observation bandwidth. Calculations of off-period observations are usually reduced to brute force direct methods resulting in many demanding matrix multiplications. For large spin systems, the matrix multiplication becomes the limiting step. A simple method that can dramatically reduce the number of matrix multiplications required to calculate the time evolution when the observation time step is some rational fraction of the period of the Hamiltonian is presented. The algorithm implements two different optimization routines. One uses pattern matching and additional memory storage, while the other recursively generates the propagators via time shifting. The net result is a significant speed improvement for some types of time-domain calculations. PMID:14729029

Blanton, Wyndham B; Logan, John W; Pines, Alexander

2004-02-01

3

Some Suggestions for Writing up Asteroid Lightcurve Observations for Publication  

NASA Astrophysics Data System (ADS)

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

Harris, A. W.

2005-05-01

4

Collider shot setup for Run 2 observations and suggestions  

SciTech Connect

This note is intended to provoke discussion on Collider Run II shot setup. We hope this is a start of activities that will converge on a functional description of what is needed for shot setups in Collider Run II. We will draw on observations of the present shot setup to raise questions and make suggestions for the next Collider run. It is assumed that the reader has some familiarity with the Collider operational issues. Shot setup is defined to be the time between the end of a store and the time the Main Control Room declares colliding beams. This is the time between Tevatron clock events SCE and SCB. This definition does not consider the time experiments use to turn on their detectors. This analysis was suggested by David Finley. The operational scenarios for Run II will require higher levels of reliability and speed for shot setup. See Appendix I and II. For example, we estimate that a loss of 3 pb{sup {minus}1}/week (with 8 hour stores) will occur if shot setups take 90 minutes instead of 30 minutes. In other words: If you do 12 shots for one week and accept an added delay of one minute in each shot, you will loose more than 60 nb{sup {minus}1} for that week alone (based on a normal shot setup of 30 minutes). These demands should lead us to be much more pedantic about all the factors that affect shot setups. Shot setup will be viewed as a distinct process that is composed of several inter- dependent `components`: procedures, hardware, controls, and sociology. These components don`t directly align with the different Accelerator Division departments, but are topical groupings of the needed accelerator functions. Defining these components, and categorizing our suggestions within them, are part of the goal of this document. Of course, some suggestions span several of these components.

Annala, J.; Joshel, B.

1996-01-31

5

STEREO observations of long period variables  

NASA Astrophysics Data System (ADS)

Observations from the Heliospheric Imagers (HI-1) on both the STEREO spacecrafts have been analysed to search for very long period large amplitude stellar variability, finding six new candidates. A total of 85 objects, mostly previously known Mira variables, were found to show convincing variability on time-scales of over a 100 days. These objects range in peak brightness from about fourth magnitude to 10th magnitude in R and have periods between about 170 and 490 d. There is a period gap between 200 and 300 d where no objects were found and this is discussed. 15 of the Miras in the sample are previously recorded as having variable periods and the possibility for these and two other stars to have undergone a period change or to be irregular is discussed. In addition to the six stars in the sample not previously recorded as variable, another seven are recorded as variable but with no classification. Our period determination is the first to be made for 19 of these 85 stars. The sample represents a set of very long period variables that would be challenging to monitor from the Earth, or even from Earth orbit, owing to their position on the ecliptic plane and that their periods are often close to a year or an integer fraction thereof. The possibility for the new candidates to possess circumstellar shells is discussed.

Wraight, K. T.; Bewsher, D.; White, Glenn J.; Nowotny, W.; Norton, A. J.; Paladini, C.

2012-10-01

6

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

ERIC Educational Resources Information Center

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

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

2012-01-01

7

OBSERVED POLARIZATION OF BROWN DWARFS SUGGESTS LOW SURFACE GRAVITY  

SciTech Connect

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

Sengupta, Sujan [Indian Institute of Astrophysics, Koramangala 2nd Block, Bangalore 560 034 (India); Marley, Mark S., E-mail: sujan@iiap.res.i, E-mail: Mark.S.Marley@NASA.go [NASA Ames Research Center, MS-245-3, Moffett Field, CA 94035 (United States)

2010-10-20

8

The international seismological observing period in Africa  

USGS Publications Warehouse

The International Seismological Observing Period (ISOP) is a specific time interval designated for enhanced international cooperation in the collection and dissemination of observatory measurements from the global seismographic network. The primary purpose of the ISOP is to strengthen the international infrastructure that supports current seismological practice and increase the cooperation among nations that operate seismological observatories. Measurements, reported by the existing global network and compiled by agencies such as the International Seismological Centre (ISC), are providing new information about earthquakes and the structure of the Earth of fundamental importance to the Earth sciences. However, these data represent but a small fraction of the information contained in the seismograms. One of the goals of the ISOP is to collect improved sets of data. In particular, the measurement and reporting of later-arriving phases, during a fixed ISOP period, from earthquakes selected for detailed observation by the cooperating stations will be encouraged. The use of advanced, digital instrumentation provides an unprecedented opportunity for enhancing the methods of seismogram interpretation and seismic parameter extraction, by the implementation of digital processing methods at seismic observatories worldwide. It must be ensured that this new information will be available to the entire seismological community. It is believed that this purpose is best served with an ISOP that promotes increased on-site processing at digital stations in Africa and elsewhere. Improvements in seismology require truly international cooperation and the educational aspects of seismological practice form one of the goals of the ISOP. Thus, workshops will be needed in Africa to train analysts in ISOP procedures and to introduce them to modern techniques and applications of the data. Participants will, thus, benefit from theoretical results and practical experience that are of direct relevance to their own work. ?? 1992.

Engdahl, E. R.; Bergman, E. A.

1992-01-01

9

Experimental observation of modes in a periodically segmented waveguide  

NASA Astrophysics Data System (ADS)

We present an experimental observation and numerical simulation of the evolution of the mode field profile in a Periodic Segmented Waveguide. A good agreement between the experimental and the numerical results is observed.

Aschieri, P.; Chanvillard, L.; Baldi, Pascal; de Micheli, Marc P.; Ostrowsky, Daniel B.; Bellanca, Gaetano; Bassi, Paolo; Thyagarajan, K.; Shenoy, M. R.; Rastogi, V.

1999-04-01

10

Freja UV imager observations of spatially periodic auroral distortions  

SciTech Connect

The authors present measurements made using a UV imager on Freja of distortions in the arc structure within auroral arcs. The authors see periodic intensifications, with typical periods of 150 km, and no observations with spacings less than 100 km. These periodic spacings were observed to have no apparent relationship to MLT. If they invoke shear flow regimes to attempt to account for these features, the measurements are seen to at least not be inconsistent with such models.

Murphree, J.S.; Johnson, M.L.; Cogger, L.L.; Hearn, D.J. [Univ. of Calgary, Alberta (Canada)

1994-08-15

11

Suggestive evidence for association of the circadian genes PERIOD3 and ARNTL with bipolar disorder  

PubMed Central

Bipolar affective disorder (BPAD) is suspected to arise in part from malfunctions of the circadian system, a system which enables adaptation to a daily and seasonally cycling environment. Genetic variations altering functions of genes involved with the input to the circadian clock, in the molecular feedback loops constituting the circadian oscillatory mechanism itself, or in the regulatory output systems could influence BPAD as a result. Several human circadian system genes have been identified and localized recently, and a comparison with linkage hotspots for BPAD has revealed some correspondences. We have assessed evidence for linkage and association involving polymorphisms in ten circadian clock genes (ARNTL, CLOCK, CRY2, CSNK1?, DBP, GSK3?, NPAS2, PER1, PER2, and PER3) to BPAD. Linkage analysis in 52 affected families showed suggestive evidence for linkage to CSNK1?. This finding was not substantiated in the association study. 52 SNPs in ten clock genes were genotyped in 185 parent proband triads. Single SNP TDT analyses showed no evidence for association to BPAD. However, more powerful haplotype analyses suggest two candidates deserving further studies. Haplotypes in ARNTL and PER3 were found to be significantly associated with BPAD via single-gene permutation tests (PG=0.025 and 0.008, respectively). The most suggestive haplotypes in PER3 showed a Bonferroni-corrected p-value of PGC=0.07. These two genes have previously been implicated in circadian rhythm sleep disorders and affective disorders. With correction for the number of genes considered and tests conducted, these data do not provide statistically significant evidence for association. However, the trends for ARNTL and PER3 are suggestive of their involvement in bipolar disorder and warrant further study in a larger sample.

Nievergelt, Caroline M.; Kripke, Daniel F.; Barrett, Thomas B.; Burg, Elyssa; Remick, Ronald A.; Sadovnick, A. Dessa; McElroy, Susan L.; Keck, Paul E.; Schork, Nicholas J.; Kelsoe, John R.

2008-01-01

12

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

NASA Astrophysics Data System (ADS)

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

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

2013-04-01

13

Characteristics of quasi-periodic scintillations observed at low latitude  

NASA Astrophysics Data System (ADS)

Quasi-periodic scintillations are characterized as primary deep fadeout in field strength, associated with regular ringing patterns before and after it. In this paper, observations of quasi-periodic scintillations using geostationary satellite (FLEETSAT) transmissions operating at frequency 250 MHz at low-latitude ground station, Varanasi (geomagnetic latitude 14°55'N, longitude 153°59'E), are reported. The results indicate that the quasi-periodic scintillations are most likely produced by plasma blobs/bubbles present in the E and F regions of the ionosphere which are helpful in identifying the generation mechanism of the associated irregularities. The various characteristic features of the different types of quasi-periodic scintillations observed at low latitude are discussed for the first time in detail based on a highly comprehensive analysis of longer data sets using autocorrelation, power spectrum, and scintillation index analysis. The computed horizontal scale size of the quasi-periodic scintillations producing irregularity varies from 100 to 1300 m which shows that the irregularities are of intermediate-scale sizes. The spectral index obtained from the slopes of power spectrum varies from -2 to -8. All of these observed results are important for identifying the generation mechanism of ionospheric irregularities associated with quasi-periodic scintillations. The observed fading patterns, especially the modulation of the diffraction patterns (fading envelopes), can be explained by considering an obstacle called radio lens in the ionosphere elongated in one direction. For the first time, we have successfully simulated the amplitude versus time plots of almost all types of quasi-periodic scintillation patches and found that our modeled and observed characteristics of quasi-periodic scintillation patches compare well with each other.

Patel, Kalpana; Singh, Ashutosh K.; Singh, A. K.; Singh, R. P.

2009-12-01

14

Probing Evolutionary Trends in Close Binaries from Observed Period Changes  

NASA Astrophysics Data System (ADS)

O-C diagrams analysis offers an opportunity to view the very late orbital evolution history (about 100 yrs) of nearly synchronized close binaries. The orbital period function P(E) becomes known in this way and hence it can be related with the most important physical mechanisms that modulate the orbital period of such binary systems through J - P (angular momentum - orbital period relations). Given the P(E) function and a variety of the implemented parameters, analytic parametric solutions can be sought in order to have estimations of the action of the most important of the physical mechanisms driving the observed orbital period variation trends. Preliminary analytic parametric solutions of such a generalized (non-conservative) J - P equation involving mass loss, magnetic braking and tidal evolution are presented here for some detached synchronized pairs (mainly members of the RS CVn group) whose orbital period variations are known by O-C diagram analysis.

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

2010-12-01

15

Array Observations of Short Period Pdiff Coda Waves  

NASA Astrophysics Data System (ADS)

There have been several reports of short-period, coherent coda waves following Pdiff at distances of approximately 95° -120°. Early interpretations favored topographical scattering at the core-mantle boundary or strong volumetric scattering in the lowermost mantle (D"). However, a recent study suggested these observations can be explained by relatively mild, uniform scattering throughout the lower mantle. In this study, we present a new data set that can be used to test the competing hypotheses for the generation of short-period Pdiff coda waves. We downloaded data for 824 earthquakes with magnitudes of 5.7 mb - 7.9 mb, depths shallower than 100~km, and at distances of 50° - 120° from the Yellowknife array (YKA) in Western Canada. YKA is a medium-aperture (20~km) array, with 19 short-period, vertical-component seismometers arranged in a cross. By using an array we can increase signal-to-noise ratio and infer the directions from which the coda waves are arriving. We included earthquakes at distances smaller than 90° so that we can test the vertical change in heterogeneity strength as waves approach D". The earthquakes are clustered in three regions: Asia, South America, and Tonga-Fiji. For each event, we used a sliding window slowness analysis technique to estimate the beam power as a function of time. Then we normalized each beam envelope by PP amplitude and corrected the amplitudes for radiation pattern effects, eliminating those data in which P, Pdiff, or PP was close to a nodal plane. We then stacked the data in 2° bins, and fit a log-linear relationship between energy and time to determine the coda decay rate (CDR). The CDRs show a clear distance dependence. Asia and South America have the same pattern above D": high CDR from 50° to 70°, low CDR in the range 72°-80°, followed by a CDR increase. At distances after 90° the coda decay rates in the three clusters show significant variations, with events from Asia having the highest CDR. We are currently experimenting with various methods for simulating Pdiff coda waves including a frequency-wavenumber integration technique for 1D stochastic models and a single-scattering ray theory based technique, modified to account for diffraction induced amplitude decay.

Xu, Y.; Koper, K. D.

2007-12-01

16

Fremsprachliche Unterrichtsstunde. Ein Vorschlag zu ihrer Analyse (The Foreign Language Class Period. A Suggestion for an Analysis).  

ERIC Educational Resources Information Center

Discusses the possibilities and limitations of a procedure devised at the University of Marburg for objectively evaluating foreign language class instruction. Ten criteria used in observing are explained in detail. By means of an example, procedure is demonstrated for observing a 45-minute class period. (IFS/WGA)

Freudenstein, Reinhold; Puerschel, Heiner

1978-01-01

17

Observations of long period earthquakes accompanying hydraulic fracturing  

Microsoft Academic Search

Waveforms of most seismic events accompanying hydraulic fracturing have been reported to contain clear P and S waves and have fault plane solutions consistent with shear displacement across a fault. This observation is surprising since classical hydraulic fracturing theory predicts the creation of a tensile opening of a cavity in response to fluid pressure. Very small long period events, similar

Dorthe Bame; Michael Fehler

1986-01-01

18

Periodic bursts observed in Jovian decametric radio emission  

NASA Astrophysics Data System (ADS)

Dynamic radio spectra of Jovian decametric radio emission (DAM) acquired by STEREO/ WAVES, Wind/WAVES and Cassini/RPWS instruments have been analyzed in a frequency range from few MHz up to ˜16 MHz during the time interval between the years 2002-2008. The non-Io component of the DAM, which is the subject of our study, appears mainly in a form of arcs in time-frequency coordinates and is generally modulated by the Jovian ˜9.925 - hour rotation period (System III). Nevertheless, we have found several unusual episodes when non-Io related bursts recurred with a period of ˜10.07 hour which is ˜1.5% longer than the System III and shorter than the period of System IV (System III + 3%). The bursts were observed in a frequency range from ˜4-5 MHz to ˜12-16 MHz. Typically, the bursts recurred very periodically during several Jovian days with decreasing intensity and displayed negative drift in time-frequency domain. All bursts were detected within the same sector of Jovian Central Meridian Longitude (III), between 300° and 60° (via 360°) of CML (III), close to the region of non-Io-C source. The absence of any correlation with the position of Io has been found. Since the bursts were observed sequentially by STEREO-A and STEREO-B, as well as by Wind and Cassini during several Jovian rotations with proper time delay we can conclude that the source of the periodic bursts sub-corotates with Jupiter and it may be active during longer periods of time. The possible relation between the Io plasma torus and ˜10.07-hour periodic bursts of the DAM is discussed.

Panchenko, M.; Rucker, H. O.; Kaiser, M. L.; Bougeret, J. L.; Gurnett, D. A.

2009-12-01

19

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

NASA Astrophysics Data System (ADS)

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.

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

2010-12-01

20

Coronal Field Opens at Lower Height During the Solar Cycles 22 and 23 Minimum Periods: IMF Comparison Suggests the Source Surface Should Be Lowered  

NASA Astrophysics Data System (ADS)

The solar cycle 23 minimum period has been characterized by a weaker solar and interplanetary magnetic field. This provides an ideal time to study how the strength of the photospheric field affects the interplanetary magnetic flux and, in particular, how much the observed interplanetary fields of different cycle minima can be understood simply from differences in the areas of the coronal holes, as opposed to differences in the surface fields within them. In this study, we invoke smaller source surface radii in the potential-field source-surface (PFSS) model to construct a consistent picture of the observed coronal holes and the near-Earth interplanetary field strength as well as polarity measurements for the cycles 23 and 22 minimum periods. Although the source surface value of 2.5 R ? is typically used in PFSS applications, earlier studies have shown that using smaller source surface heights generates results that better match observations during low solar activity periods. We use photospheric field synoptic maps from Mount Wilson Observatory (MWO) and find that the values of ? 1.9 R ? and ? 1.8 R ? for the cycles 22 and 23 minimum periods, respectively, produce the best results. The larger coronal holes obtained for the smaller source surface radius of cycle 23 somewhat offsets the interplanetary consequences of the lower magnetic field at their photospheric footpoints. For comparison, we also use observations from the Michelson Doppler Imager (MDI) and find that the source surface radius of ? 1.5 R ? produces better results for cycle 23, rather than ? 1.8 R ? as suggested from MWO observations. Despite this difference, our results obtained from MWO and MDI observations show a qualitative consistency regarding the origins of the interplanetary field and suggest that users of PFSS models may want to consider using these smaller values for their source surface heights as long as the solar activity is low.

Lee, C. O.; Luhmann, J. G.; Hoeksema, J. T.; Sun, X.; Arge, C. N.; de Pater, I.

2011-04-01

21

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

NASA Astrophysics Data System (ADS)

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

Nelson, R. M.

2008-12-01

22

HF radar observations of ionospheric backscatter during geomagnetically quiet periods  

NASA Astrophysics Data System (ADS)

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

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

2012-01-01

23

''Very Carefully Managed'': Advice and Suggestions in Post-Observation Meetings  

ERIC Educational Resources Information Center

This study examined the discourse of teacher supervision/mentoring, specifically within the context of the post-observation meeting. The analysis of six transcripts of post-observation meetings from one semester in a small university Intensive English Program revealed a variety of politeness strategies employed by supervisors in the delivery of…

Vasquez, Camilla

2004-01-01

24

''Very Carefully Managed'': Advice and Suggestions in Post-Observation Meetings  

ERIC Educational Resources Information Center

|This study examined the discourse of teacher supervision/mentoring, specifically within the context of the post-observation meeting. The analysis of six transcripts of post-observation meetings from one semester in a small university Intensive English Program revealed a variety of politeness strategies employed by supervisors in the delivery of…

Vasquez, Camilla

2004-01-01

25

Observations of elevated formaldehyde over a forest canopy suggest missing sources from rapid oxidation of arboreal hydrocarbons  

NASA Astrophysics Data System (ADS)

To better understand the processing of biogenic VOCs (BVOCs) in the pine forests of the U.S. Sierra Nevada, we measured HCHO at Blodgett Research Station using Quantum Cascade Laser Spectroscopy (QCLS) during the Biosphere Effects on Aerosols and Photochemistry Experiment (BEARPEX) of late summer 2007. Four days of the experiment exhibited particularly copious HCHO, with midday peaks between 15-20 ppbv, while the other days developed delayed maxima between 8-14 ppbv in the early evening. From the expansive photochemical data set, we attempt to explain the observed HCHO concentrations by quantifying the various known photochemical production and loss terms in its chemical budget. Overall, known chemistry predicts a factor of 3-5 times less HCHO than observed. By examining diurnal patterns of the various budget terms we conclude that, during the high HCHO period, local, highly reactive oxidation chemistry produces an abundance of formaldehyde at the site. The results support the hypothesis of previous work at Blodgett Forest suggesting that large quantities of BVOC oxidation products, observed directly above the ponderosa pine canopy, are evidence of profuse emissions of very reactive volatile organic compounds (VR-VOCs) from the forest. However, on the majority of days, under generally cooler and more moist conditions, lower levels of HCHO develop primarily influenced by the influx of precursors transported into the region along with the Sacramento plume.

Choi, W.; Faloona, I. C.; Bouvier-Brown, N. C.; McKay, M.; Goldstein, A. H.; Mao, J.; Brune, W. H.; Lafranchi, B. W.; Cohen, R. C.; Wolfe, G. M.; Thornton, J. A.; Sonnenfroh, D. M.; Millet, D. B.

2010-04-01

26

Observations of elevated formaldehyde over a forest canopy suggest missing sources from rapid oxidation of arboreal hydrocarbons  

NASA Astrophysics Data System (ADS)

To better understand the processing of biogenic VOCs (BVOCs) in the pine forests of the US Sierra Nevada, we measured HCHO at Blodgett Research Station using Quantum Cascade Laser Spectroscopy (QCLS) during the Biosphere Effects on Aerosols and Photochemistry Experiment (BEARPEX) of late summer 2007. Four days of the experiment exhibited particularly copious HCHO, with midday peaks between 15-20 ppbv, while the other days developed delayed maxima between 8-14 ppbv in the early evening. From the expansive photochemical data set, we attempt to explain the observed HCHO concentrations by quantifying the various known photochemical production and loss terms in its chemical budget. Overall, known chemistry predicts a factor of 3-5 times less HCHO than observed. By examining diurnal patterns of the various budget terms we conclude that, during the high HCHO period, local, highly reactive oxidation chemistry produces an abundance of formaldehyde at the site. The results support the hypothesis of previous work at Blodgett Forest suggesting that large quantities of oxidation products, observed directly above the ponderosa pine canopy, are evidence of profuse emissions of very reactive volatile organic compounds (VR-VOCs) from the forest. However, on the majority of days, under generally cooler and more moist conditions, lower levels of HCHO develop primarily influenced by the influx of precursors transported into the region along with the Sacramento plume.

Choi, W.; Faloona, I. C.; Bouvier-Brown, N. C.; McKay, M.; Goldstein, A. H.; Mao, J.; Brune, W. H.; Lafranchi, B. W.; Cohen, R. C.; Wolfe, G. M.; Thornton, J. A.; Sonnenfroh, D. M.; Millet, D. B.

2010-09-01

27

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

ERIC Educational Resources Information Center

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

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

2004-01-01

28

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

Microsoft Academic Search

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

Eric Stice; Melissa Fisher; Michael R. Lowe

2004-01-01

29

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

ERIC Educational Resources Information Center

|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…

Darda, David M.

2010-01-01

30

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

Microsoft Academic Search

The ability of systems to be anticipatory seems to be intricate connected with the ability to observe and to cognate by reducing complexity through signification. The semantic capacity of living systems, the cognitive ability to assign meaning to differences perturbating the system's self-organization, seems to be the prerequisite for the phenomenon of communication, language and consciousness. In cybernetics Bateson developed

Soren Brier

1998-01-01

31

A Relationship between Mean Rotation Period in Lower Main-Sequence Stars and Its Observed Range  

NASA Astrophysics Data System (ADS)

Chromospheric Ca II H and K fluxes have been measured in a sample of ~100 stars on or near the main sequence at Mount Wilson Observatory. Observations were made several times a week and span more than ten years. Within an observing season, many stars show periodic variations due to rotation. Thirty-six of the stars have highly-significant periods in at least five seasons. We compute the range in the observed period, Delta P, and suggest that it is a measure of, and a lower limit to, the surface differential rotation (SDR). Several physical and selection effects can affect the measured Delta P value. An analysis of the cumulative variance distribution at various time scales, however, demonstrates that Ca II variations due to active region growth and decay are of longer period and smaller amplitude than those due to rotation. We argue that other effects (e.g., multiple active regions, latitude bands) are either small, or primarily act to reduce the measured Delta P relative to its true value. Including results for the Sun, we find that Delta P depends on the mean seasonal rotation period , such that Delta P is proportional to to the power of 1.3 +/- 0.1, independent of mass. We briefly discuss this in the context of dynamo models, and other observations of surface differential rotation and active region structure.

Donahue, Robert A.; Saar, Steven H.; Baliunas, Sallie L.

1996-07-01

32

Evidence suggesting fluid flow beneath Japan due to periodic seismic triggering from the 2004 Sumatra-Andaman earthquake  

Microsoft Academic Search

We show that very large surface waves from the 2004 Sumatra-Andaman earthquake (M9.2) triggered deep low-frequency (DLF) seismic tremors beneath Japan over a 500 km wide region. The triggered seismicity was periodically excited, synchronized with the amplitudes and phases of the oscillatory surface waves incident on the region. Periodic excitation implies that the specific phase of the surface waves plays

Masatoshi Miyazawa; Jim Mori

2006-01-01

33

Stratospheric hydroxyl radical concentrations: new limitations suggested by observations of gaseous and particulate sulfur  

SciTech Connect

A one-dimensional aerosol model is used to investigate the sensitivity of the stratospheric distributions of gaseous sulfur compounds and sulfate aerosol particles to changes in OH and CS/sub 2/ concentrations, in eddy diffusion coefficients, and in key chemical rate constants. By comparing model predictions with recent observational data for So/sub 2/, OCS, and particulates, the following conclusions are reached. With regard to atmospheric sulfur, it appears that CS/sub 2/ is only a secondary source of sulfur for the stratosphere relative to OCS and that background tropospheric CS/sub 2/ concentrations are likely to be <70 pptv. It is also found that under stratospheric conditions, the rate coefficients for the reactions of OH with OCS and CS/sub 2/ may be substantially smaller than the room temperature laboratory values of Kurylo (1978). The most important conclusion of the present study, however, is that OH concentrations below 30 km may be over-estimated by a factor of 3 or more in current photochemical models. Plausibility arguments for lower atmospheric OH concentrations are supported by recent laboratory studies of the pressure, the temperature, and the humidity dependences of OH an HO/sub 2/ chemical kinetic systems. New reaction rate data bearing on this problem are reviewed. A reduced level of stratospheric OH has strong implications for ozone perturbations attributable to aircraft NO/sub x/ emissions, to nitrogen fertilizer usage, and to halocarbon releases. Such ozone perturbations are simulated using a one-dimensional atmospheric photochemistry model in which the OH concentrations are reduced in accordance with the sulfur sensitivity tests highlighted above. Owing to the reduction in OH, SST NO/sub x/ injections at 20 km act to decrease ozone, not increase it as had been thought previously. Nitrous oxide produced by fertilizer decomposition is also found to be more destructive of ozone. On the other hand, fluorocarbon-induced ozone depletions are somewhat smaller.

Turco, R.P.; Whitten, R.C.; Toon, O.B.; Inn, E.C.Y.; Hamill, P.

1981-02-20

34

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

NASA Astrophysics Data System (ADS)

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

Brier, Soren

1998-07-01

35

Periodic correlations in DNA sequences and evidence suggesting their evolutionary origin in a comma-less genetic code  

Microsoft Academic Search

Summary Strong rhythms with a period of three bases have been seen while correlating the relative positions of purines and pyrimidines and of the four individual bases in the complete DNA sequence of the viruses øX174, G4 and fd. Generally weaker variations of the same type have been found in the DNA virus SV40, the plasmid pBR322, the RNA virus

John C. W. Shepherd

1981-01-01

36

Strong post-midnight Equatorial Ionospheric Anomaly and Equatorial spread F Observations during magnetically quiet period  

NASA Astrophysics Data System (ADS)

Post sunset equatorial ionospheric irregularities, especially during magnetically active periods, have been a subject of many studies. The most prominent irregularities often observed right after sunset are the resurgence of the equatorial ionospheric anomaly (EIA) and equatorial spread F (ESF). It is well understood and documented that pre-reversal enhancement, due to the ionospheric conductivity gradient at the dusk, is one of the prime triggering mechanisms for the post-sunset irregularities in the equatorial region. However, less attention has been given to the equatorial irregularities (EIA and ESF) that often occur in post-midnight, especially during magnetically quiet periods. It has been suggested that the primary process responsible for the dramatic post-midnight ESF during magnetically active periods is the change in magnitude and direction of the usual equatorial electric field. Earlier studies speculated that during magnetically active post-midnight periods the change in electric field direction from westward to eastward for a short intervals cause an upward E × B drift, resulting in increased h'F and decreased electron densities at the magnetic equator. Individual scans of Jicamarca vertical drift also often observe significant upward drift during post-midnight periods. We present a case of post-midnight strong equatorial ionospheric anomaly during a magnetically quiet (Kp < 3) period using TOPEX altimeter TEC data. Simultaneously, the ionosonde station at S.J. Campos (23.2°S, 45.9°W; dip lat. 17.6°S) observed strong ESF and unusual h'F height rise during post-midnight period, where TOPEX detected strong EIA. At the same time ROCSAT-1 and DMSP satellites also clearly show existence of EIA during post-midnight period at their orbiting altitude. The former satellite also detected post-midnight in situ density irregularities (such as bubbles) at the same time as strong EIA and ESF. The questions here are what triggers these post-midnight equatorial ionospheric irregularities? Are these post-midnight EIAs related to dusk side pre-reversal EIA? If so, what causes the post-midnight ESF and bubble formation? If, as suggested before, the electric field shifted direction from westward to eastward during post-midnight period, how does this happen and what is the physics behind this direction shift?

Moldwin, M. B.; Yizengaw, E.; Sahai, Y.

2008-12-01

37

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

PubMed Central

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.

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

2012-01-01

38

Periodicities Within the Frequency Spectra of ? Scuti Stars Observed by Kepler  

NASA Astrophysics Data System (ADS)

We showed in previous works that a periodic pattern could be found in the frequency set of ? Sct stars observed by CoRoT. We related that pattern with a value of the large separation. However, are these stars particular cases? We present here preliminary results of our work aimed at answering this and related questions. We looked for periodicities in the frequency spectrum of a sub-sample of 153 ? Sct pulsators observed by Kepler. We have determined that ˜ 50% of the sub-sample shows a clear pattern. Moreover, we found three objects with almost the same KIC physical parameters showing the same value of the pattern. We suggest that the pattern is a sign of a large-separation-like structure.

García Hernández, A.; Pascual-Granado, J.; Grigahcène, A.; Uytterhoeven, K.; Moya, A.; Garrido, R.; Suárez, J. C.; Gutiérrez-Soto, J.; Martín-Ruiz, S.

39

The Observed Period and Q of The Chandler Wobble  

NASA Astrophysics Data System (ADS)

We have analyzed Titan observations performed by the Infrared Space Observatory (ISO) in the 7-30 micron range (Coustenis et al., 2002, submitted for publication). The spectra obtained by three of the instruments on board the mission (the Short Wavelength Spectrometer, the Photometer and the Camera) were combined to provide a new and more precise thermal and compositional knowledge of Titan's stratosphere. With the high spectral resolution achieved by the SWS (much higher than that of the Voyager IRIS spectrometer), we were able to detect and separate the contribution of most of the atmospheric gases present on Titan and to determine disk-averaged mole fractions. Our latest analysis allowed us to detect the HC3N feature at 633 cm-1 and also, tentatively and for the first time, benzene (C6H6) at 674 cm-1. We have also tested vertical distributions for C2H2, HCN, HC3N and CO2. We have inferred a new D/H isotopic abundance of 8.75 +3.2 × 10-4. Finally, we have inferred upper limits -1.9 for a number of molecules proposed as likely candidates on Titan (such as allene and other more complex hydrocarbons and nitriles).

Gross, R. S.

40

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

SciTech Connect

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

Su, J. T.; Mao, X. J. [Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Science, Beijing 100012 (China); Shen, Y. D.; Liu, Y. [National Astronomical Observatories/Yunnan Observatory, Chinese Academy of Sciences, Kunming 650011 (China); Liu, Y. [W. W. Hansen Experimental Physical Laboratory, Stanford University, Stanford, CA 94305 (United States)

2012-08-20

41

Spectroscopy of Centaurs Asbolus and Chiron: Observations over a full rotational period  

NASA Astrophysics Data System (ADS)

Spectroscopic observations of the centaurs Asbolus and Chiron were obtained in June 2001 at the Very Large Telescope (ESO, Chile). For each centaur, several spectra were recorded in order to find possible changes in the spectrum over a rotational period. Such a study is particularly important for Asbolus. Although Barucci et al. (2000 A&A 357) and Brown et al. (2000 AJ 119) did not observe any feature in spectra of Asbolus, Kern et al. (2000 ApJ 542) obtained two HST-NICMOS spectra of Asbolus over a 1.7 h interval, one with a strong absorption feature at 1.6 micron attributed to water ice, and the other without. They suggested that one side of Asbolus would contain a large amount of water ice, whereas the other side would show no water ice absorption feature. Our observations were performed in the near-infrared range (1.1-2.5 microns) using the ISAAC IR spectro-imager. Three near-infrared spectra of Chiron, and six spectra of Asbolus have been obtained, covering a wide part of the rotational period of each Centaur (full period for Asbolus). Asbolus spectra do not show any obvious water ice absorption feature around 1.6 and 2 microns. Since the full rotational period has been covered, this would mean that there is no strong water ice absorption on any side of Asbolus. This is not at all consistent with observations from Kern et al. However, their observations were obtained in 1998, whereas ours come 3 years later. May water ice absorption features have ``disappeared" from Asbolus surface between 1998 and 2001 ? Chiron spectra show some kind of absorption features in the K band, especially a strong decrease beyond 2.3 microns. Preliminary results would indicate that this feature varies from one spectrum to the other. However no clear evidence of water ice absorption can be seen on these spectra.

Romon-Martin, J.; Barucci, M. A.; de Bergh, C.; Peixinho, N.

2001-11-01

42

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

SciTech Connect

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

Harrison, Thomas E.; McNamara, Bernard J.; Bornak, Jillian [Department of Astronomy, New Mexico State University, Las Cruces, NM 88003-8001 (United States); Gelino, Dawn M. [NASA Exoplanet Science Institute, California Institute of Technology, Pasadena, CA 91125 (United States); Wachter, Stefanie [Spitzer Science Center, Caltech M/S 220-6, Pasadena, CA 91125 (United States); Rupen, Michael P. [National Radio Astronomy Observatory, Socorro, NM 87801 (United States); Gelino, Christopher R., E-mail: tharriso@nmsu.edu, E-mail: bmcnamar@nmsu.edu, E-mail: jbornak@nmsu.edu, E-mail: dawn@ipac.caltech.edu, E-mail: wachter@ipac.caltech.edu, E-mail: mrupen@aoc.nrao.edu, E-mail: cgelino@ipac.caltech.edu [Infrared Processing and Analysis Center, Caltech M/S 220-6, Pasadena, CA 91125 (United States)

2011-07-20

43

An Observational Investigation of Long Period Oscillations in the Apparent Solar Diameter.  

National Technical Information Service (NTIS)

Observations of the apparent solar diameter were undertaken to determine whether long period oscillations might be present. The observations discussed consist of 11 time series of the solar diameter, averaging 7 h in length. Power spectrum analyses of the...

T. M. Brown

1977-01-01

44

An observational investigation of long period oscillations in the apparent solar diameter. Doctoral thesis  

Microsoft Academic Search

Observations of the apparent solar diameter were undertaken to determine whether long-period oscillations might be present. The observations discussed consist of 11 time series of the solar diameter, averaging 7 h in length. Power spectrum analyses of these time series reveal oscillations throughout the 3 to 7 min period range, with typical amplitudes of 2 X 10-⁶ of the solar

1977-01-01

45

Empirical sea ice thickness retrieval during the freeze up period from SMOS high incident angle observations  

NASA Astrophysics Data System (ADS)

Sea ice thickness information is needed for climate modeling and ship operations. Here a method to detect the thickness of sea ice up to 50 cm during the freezeup season based on high incidence angle observations of the Soil Moisture and Ocean Salinity (SMOS) satellite working at 1.4 GHz is suggested. By comparison of thermodynamic ice growth data with SMOS brightness temperatures, a high correlation to intensity and an anti correlation to the difference between vertically and horizontally polarised brightness temperatures at incidence angles between 40 and 50 ° are found and used to develop an empirical retrieval sensitive to thin sea ice up to 50 cm thickness. It shows high correlations with ice thickness data from airborne measurements and reasonable ice thickness patterns for the Arctic freeze up period.

Huntemann, M.; Heygster, G.; Kaleschke, L.; Krumpen, T.; Mäkynen, M.; Drusch, M.

2013-08-01

46

Validation of a 6-hour observation period for cocaine body stuffers  

PubMed Central

Often, patients are brought in to the emergency room after ingesting large amounts of cocaine in an attempt to conceal it. This act is known as “body stuffing.” The observation period required to recognize potential toxic side effects in these patients is not well described in the literature. We sought to validate a treatment algorithm for asymptomatic cocaine body stuffers utilizing a 6-hour observation period by observing the clinical course of cocaine body stuffers over a 24-hour period. A retrospective chart review was performed on all patients evaluated for witnessed or suspected stuffing over two years utilizing a standardized protocol. 106 patients met final inclusion criteria as adult cocaine stuffers. No patients developed life-threatening symptoms and no patients died during observation. In our medical setting, stuffers could be discharged after a 6- hour observation period if there was either complete resolution or absence of clinical symptoms.

Moreira, Maria; Buchanan, Jennie; Heard, Kennon

2010-01-01

47

Periodicity  

NSDL National Science Digital Library

In thinking about a title for this chapter, the word periodicity came to mind. I was sure this had some kind of pop culture reference. After discussing this with my wife, we figured I was thinking of synchronicity, which is a reference to music by the band, The Police. Looking the word Periodicity up on the internet, I found that I was, in fact, a science geek and had not made a hip reference. Periodicity refers mainly to the Periodic Table, which is a focus of this chapter. No music, just science.

Robertson, William C.

2007-01-01

48

Periodic Crossings of Saturn's Current Sheet by Cassini: Observations and Modeling  

Microsoft Academic Search

Cassini continues to provide exciting new observations from the magnetosphere of Saturn. These observations are helping us understand the structure and dynamics of this rotationally dominant magnetosphere. One of the puzzling observations from the latest magnetotail passes is the occurrence of periodic current sheet crossings in a magnetosphere known for its almost axis-symmetric magnetic field. In these crossings, the radial

K. K. Khurana; C. S. Arridge; M. K. Dougherty; C. T. Russell

2006-01-01

49

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

Microsoft Academic Search

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

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

2005-01-01

50

Experimental Observation of Longitudinal Modulation of Mode Fields in Periodically Segmented Waveguides  

NASA Astrophysics Data System (ADS)

We present what is to our knowledge the first experimental observation by fluorescent visualization, of the evolution of the mode field profile in a periodically segmented waveguide. The experimental observations are then compared with the numerical results obtained by a finite-difference beam propagation method. Good agreement between experimental and numerical results is observed.

Aschiéri, Pierre; Rastogi, Vipul; Chanvillard, Loic; Baldi, Pascal; de Micheli, Marc P.; Ostrowsky, Daniel B.; Bellanca, Gaetano; Bassi, Paolo; Thyagarajan, Krishna; Shenoy, Mangalpady R.

1999-09-01

51

Simultaneous observations of quasi-periodic ELF/VLF wave emissions and electron precipitation by DEMETER satellite: A case study  

NASA Astrophysics Data System (ADS)

We present results of case studies of quasi-periodic (QP) ELF/VLF hiss emissions detected onboard the DEMETER satellite. Three events with simultaneous periodic modulation in VLF wave intensity and energetic electron precipitation are found. In each event we observe exact coincidence of one or two busts of VLF wave intensity with energetic electron precipitation peaks. To our knowledge, such observations made onboard satellites have not been reported earlier. All events are observed at fairly quiet geomagnetic conditions (Kp <3). The dynamic spectrum of the VLF waves in these QP events was characterized by a regular frequency increase in each burst, and the repetition period was less than or about 20 s. These features allow us to suggest that the observed events belong to the QP2-class, i.e., events which are not associated with geomagnetic pulsations. We also analyze energetic electron data from NOAA-17 spacecraft which has helio-synchronous circular orbit similar to DEMETER spacecraft and measured in the same region of the magnetosphere within 30 min for the analyzed events. NOAA-17 data confirm that the QP emissions were detected by DEMETER in the region of isotropization of energetic electrons, which is typically associated with the development of the cyclotron instability. Modulation of electron flux with a period close to the QP emission period is observed in two events. Based on the observed correlation between bursts of wave intensity and energetic particle flux, we estimate the location and spatial extent of the source region for QP emissions.

Hayosh, M.; Pasmanik, D. L.; Demekhov, A. G.; Santolik, O.; Parrot, M.; Titova, E. E.

2013-07-01

52

10s-period volcanic tremors observed over a wide area in southwestern Japan  

Microsoft Academic Search

Unusual seismic oscillations with a period of 10 seconds were observed over a wide area of southwestern Japan. Several lines of evidence indicate that the origin of these 10s waves must be around the Aso volcano, located in the central part of Kyushu Island, Japan. Although a 10s period is unusually long for a volcanic tremor and no corresponding surface

Hitoshi Kawakatsu; Takao Ohminato; Hisao Ito

1994-01-01

53

10s-Period volcanic tremors observed over a wide area in southwestern Japan  

Microsoft Academic Search

Unusual seismic oscillations with a period of 10 seconds were observed over a wide area of southwestern Japan. Several lines of evidence indicate that the origin of these 10s waves must be around the Aso volcano, located in the central part of Kyushu Island, Japan. Although a 10s period is unusually long for a volcanic tremor and no corresponding surface

Hitoshi Kawakatsu; Takao Ohminato; Hisao Ito

1994-01-01

54

Two-Way Coupled Atmospher-Ocean Modeling Of The PhilEx Intensive Observational Periods.  

National Technical Information Service (NTIS)

High-resolution coupled atmosphere-ocean simulations of the Philippines show the regional and local nature of atmospheric patterns and ocean response during Intensive Observational Period cruises in January- February 2008 (IOP-08) and February-March 2009 ...

J. D. Doyle J. D. Pullen L. T. David P. W. May

2011-01-01

55

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

NASA Astrophysics Data System (ADS)

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.

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

2012-03-01

56

Ionospheric disturbances observed during the period of Mount Pinatubo eruptions in June 1991  

SciTech Connect

A series of climatic eruptions of Mount Pinatubo occurred in June 1991. Many quasi-periodic ionospheric disturbances were observed in the virtual height variations of the ionosphere at Chungli, in the total electron content variations at Lunping, Kaohsiung, and Chihpen, and in the differential Doppler shift data recorded at Lunping. These ionospheric disturbances were characterized by quasi-periodic wavelike trains lasting for several cycles with periods around 16 to 30 min, wavelengths between 160 and 435 km, and propagation speeds ranging from 131 to 259 m/s from the direction of Mount Pinatubo to the observation sites. The oscillation periods, downward movement of distortion, and inclined phase fronts all show that these ionospheric disturbances were manifested by the gravity waves that arrived from the direction of Mount Pinatubo. By use of a simplified isothermal atmosphere model, the propagation mode is interpreted as the freely propagating gravity waves. 26 refs.

Cheng, Kang; Huang, Yinnnien (Lunping Observatory, Taoyuan (Taiwan, Province of China) Ministry of Transportation and Communications, Taipei (Taiwan, Province of China))

1992-11-01

57

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

NASA Astrophysics Data System (ADS)

In order to understand mechanisms that maintain and drive the evolution of the Earth's magnetic field, a characterization of its behavior on time scales of centuries to millennia is required. We have conducted a search for periodicities in Holocene sediment magnetic records, by applying three techniques: multitaper spectral estimation, wavelet analysis and empirical mode decomposition. When records are grouped according to their geographical locations, we find encouraging consistency amongst the observed periods, especially in nearby inclination records. No evidence was obtained for discrete, globally observed, periods. Rather we find a continuous broadband spectrum, with a slope corresponding to a power law with exponent of ?2.3±0.6 for the period range between 300 and 4000 yr. This is consistent with the hypothesis that chaotic convection in the outer core drives the majority of secular variation.

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

2013-10-01

58

Spectroscopic observations of the short-period, RS CVn-type star SV Cam  

Microsoft Academic Search

Spectroscopic observations of the eclipsing, short-period RS CVn-star SV Cam in the range 6500-6700 Å, covering the whole orbital period are presented. The absorption profiles of the lines Halpha and FeI 6678 are doubled out of the eclipses. The relative contribution of the secondary star is stronger in the FeI 6678 line than in Halpha . We determined K1=123.1+\\/-1.2 km

D. P. Kjurkchieva; D. V. Marchev; S. Zola

2002-01-01

59

Observations of Geomagnetic Fluctuations in the Period Range 0.3 to 120 Seconds  

Microsoft Academic Search

Data are presented from a 5-year series of observations of geomagnetic fluctua- tions in the period range 0.3 to 120 seconds, approximately. These were carried on with flux rate .variographs using pickup coils with 1-second-period galvanometers recording photo- graphically at a trace speed of I mm\\/sec with maximum sensitivities of 0.05 gamma\\/sec per trace millimeter. Four characteristic types of oscillations

Hugo Benioff

1960-01-01

60

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

NASA Astrophysics Data System (ADS)

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

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

2013-09-01

61

Observability of periodic lines in three-dimensional lid-driven cylindrical cavity flows.  

PubMed

This study employs three-dimensional particle-tracking velocimetry (3D-PTV) for experimental investigation of the existence and properties of periodic lines in 3D lid-driven time-periodic flows inside a cylindrical cavity. These periodic lines, consisting of material points that periodically return to their initial position, play a central role in the transport properties of laminar flows, yet their existence has so far been demonstrated only in numerical simulations. The formation and characteristics of periodic lines are inextricably linked with spatiotemporal symmetries of the flow. 3D-PTV measurements determined that relevant symmetries, identified with previous symmetry analyses, are satisfied within experimental error bounds. These measurements subsequently isolated periodic lines in the designated symmetry planes, thus offering first experimental evidence of their physical existence and their fundamental reliance on symmetries. Experimental periodic lines are topologically equivalent to those in simulated flows with identical symmetries and exhibit the same response to changes in forcing conditions. The laboratory experiments by these observations bridge the gap from theoretical and numerical predictions on periodic lines to real 3D flows. PMID:23005219

Znaien, J; Speetjens, M F M; Trieling, R R; Clercx, H J H

2012-06-25

62

Observability of periodic lines in three-dimensional lid-driven cylindrical cavity flows  

NASA Astrophysics Data System (ADS)

This study employs three-dimensional particle-tracking velocimetry (3D-PTV) for experimental investigation of the existence and properties of periodic lines in 3D lid-driven time-periodic flows inside a cylindrical cavity. These periodic lines, consisting of material points that periodically return to their initial position, play a central role in the transport properties of laminar flows, yet their existence has so far been demonstrated only in numerical simulations. The formation and characteristics of periodic lines are inextricably linked with spatiotemporal symmetries of the flow. 3D-PTV measurements determined that relevant symmetries, identified with previous symmetry analyses, are satisfied within experimental error bounds. These measurements subsequently isolated periodic lines in the designated symmetry planes, thus offering first experimental evidence of their physical existence and their fundamental reliance on symmetries. Experimental periodic lines are topologically equivalent to those in simulated flows with identical symmetries and exhibit the same response to changes in forcing conditions. The laboratory experiments by these observations bridge the gap from theoretical and numerical predictions on periodic lines to real 3D flows.

Znaien, J.; Speetjens, M. F. M.; Trieling, R. R.; Clercx, H. J. H.

2012-06-01

63

Spectroscopic and photometric observations of the short-period RS CVn-type star CG Cyg  

Microsoft Academic Search

Spectroscopic observations around the Halpha line and BVR photometry of the eclipsing short-period RS CVn-star CG Cyg are presented. The solutions of the radial velocity curves and the light curves yielded the following masses and radii of the star components: M1=0.97 Msun, M2=0.80 Msun, R1=1.00 Rsun, R2=0.83 Rsun. The measured rotational broadenings of the observed lines correspond to equatorial velocities

D. P. Kjurkchieva; D. V. Marchev; W. Ogloza

2003-01-01

64

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

Microsoft Academic Search

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

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

2005-01-01

65

Simultaneous observations of Jovian quasi-periodic radio emissions by the Galileo and Cassini spacecraft  

Microsoft Academic Search

The gravity-assist flyby by Cassini of Jupiter on 30 December 2000 and the extended Galileo orbital mission provided a unique opportunity to obtain simultaneous measurements with two spacecraft of many Jovian plasma wave and radio emissions. One of these emissions is Jovian type III radio emissions, also known as Jovian quasi-periodic (QP) emissions. The simultaneous observations of the QP emissions

G. B. Hospodarsky; W. S. Kurth; B. Cecconi; D. A. Gurnett; M. L. Kaiser; M. D. Desch; P. Zarka

2004-01-01

66

10s-Period volcanic tremors observed over a wide area in southwestern Japan  

NASA Astrophysics Data System (ADS)

Unusual seismic oscillations with a period of 10 seconds were observed over a wide area of southwestern Japan. Several lines of evidence indicate that the origin of these 10s waves must be around the Aso volcano, located in the central part of Kyushu Island, Japan. Although a 10s period is unusually long for a volcanic tremor and no corresponding surface activity at the crater was reported by the local observatory, the volcanic origin of the tremor is indisputable. A further astonishing aspects of the observation is that there exists a strong correlation between the onset of 10s waves observed remotely and cessation of high-frequency (greater than 1Hz) volcanic tremors at the Aso volcano. The Aso volcano appears to be trembling with a 10s period without this having been noticed. Since seismic monitoring of the volcanic activity is limited to high frequencies (above 1 Hz) at the most of the volcanoes in the world, long-period tremors of the type observed here might be a widespread phenomenon that has been overlooked.

Kawakatsu, Hitoshi; Ohminato, Takao; Ito, Hisao

1994-09-01

67

Observation of solitary filaments and spatially periodic patterns in a dc gas-discharge system  

NASA Astrophysics Data System (ADS)

In a planar gas-discharge system consisting of a metal and a high ohmic semiconductor electrode we observe experimentally the generation of stationary current density filaments, a discontinuous device characteristic with hysteresis and the bifurcation from a homogeneous discharge into a spatially periodic discharge pattern.

Willebrand, H.; Radehaus, C.; Niedernostheide, F.-J.; Dohmen, R.; Purwins, H.-G.

1990-09-01

68

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

NASA Astrophysics Data System (ADS)

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.

Grassi, D.

2012-01-01

69

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

NASA Astrophysics Data System (ADS)

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

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

2013-09-01

70

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

NASA Astrophysics Data System (ADS)

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.

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

71

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

PubMed

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

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

2005-06-29

72

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

SciTech Connect

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).].

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

73

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

SciTech Connect

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

Hasegawa, Yasuhiro [Department of Physics and Astronomy, McMaster University, Hamilton, ON L8S 4M1 (Canada); Pudritz, Ralph E., E-mail: hasegay@physics.mcmaster.ca, E-mail: pudritz@physics.mcmaster.ca [Origins Institute, McMaster University, Hamilton, ON L8S 4M1 (Canada)

2012-12-01

74

Coastal observations of weather features in Senegal during the African Monsoon Multidisciplinary Analysis Special Observing Period 3  

NASA Astrophysics Data System (ADS)

During 15 August through 30 September 2006 (Special Observing Period 3, SOP3), key weather measurements are obtained from ground and aircraft platforms during the African Monsoon Multidisciplinary Analysis campaign. Key measurements are aimed at investigating African easterly waves (AEWs) and mesoscale convective systems in a coastal environment as they transition to the eastern Atlantic Ocean. Ground and aircraft instruments include polarimetric radar, a coarse and a high-density rain gauge network, surface chemical measurements, 12 m meteorological measurement, broadband IR, solar and microwave measurements, rawinsonde, aircraft dropsonde, lidar, and cloud radar measurements. Ground observations during SOP3 show that Senegal was influenced by 5 squall lines, 6 Saharan air layer intrusions, and 10 AEWs. Downstream tropical cyclones developed were associated with the passage of four AEWs. FA-20 aircraft measurements of microphysical aspects of 22 September squall line and several nondeveloping AEWs over the extreme eastern Atlantic Ocean are presented.

Jenkins, G.; Kucera, P.; Joseph, E.; Fuentes, J.; Gaye, A.; Gerlach, J.; Roux, F.; Viltard, N.; Papazzoni, M.; Protat, A.; Bouniol, D.; Reynolds, A.; Arnault, J.; Badiane, D.; Kebe, F.; Camara, M.; Sall, S.; Ndiaye, S. A.; Deme, A.

2010-09-01

75

Observing fluctuating spectral density of subdiffusive overdamped Brownian particles in periodic potentials  

NASA Astrophysics Data System (ADS)

The aim of this paper is to develop a simple and efficient method for observing the fluctuating spectral density of subdiffusive Brownian motion in an overdamped periodic potential for exploring the subdiffusive property in frequency domain. Based on the general frame of linear response theory for subdiffusive fractional Fokker-Planck equation systems, an explicit relation between fluctuating spectral density and linear dynamical susceptibility is deduced, and then a method of moments based on the expansion of trigonometric functions is proposed for calculating the linear dynamic susceptibility. With the linear dynamic susceptibility available, the fluctuating spectral density is finally obtained. The numerical results demonstrate that subdiffusion weakens coherent oscillations in the periodic system, but enhances aperiodic components. Our observation embodies the fact of the Mittag-Leffler residence time distribution with an infinite mean in the subdiffusive process from the frequency domain.

Kang, Yan-Mei; Jiang, Jun; Xie, Yong

2011-01-01

76

Photoelectric observations of long-period RS CVn binary CQ aurigae  

Microsoft Academic Search

Long-period RS CVn-type binary CQ Aur was observed in 1987 and 1988.B andV light curves for the 1987 and 1988 epochs have been analyzed for the photometric solution by the modified Wilson and Devinney computing code with adjustable spot parameters. One-spot fit is good enough for the 1987 epoch while a wider distribution of spots in longitude is required for

Young Woon Kang

1993-01-01

77

Investigation of observed day-to-day variability in September mesopause region tidal-period perturbations  

Microsoft Academic Search

Simultaneous observations of the tidal-period perturbations (diurnal, semidiurnal, .etc) of temperature, zonal wind, and meridional wind in the mesopause region (80km-105km) by the CSU two-beam Na lidar system in Fort Collins, Colorado between UT day 264 and 272, September 2003 (a 9-day continuous campaign) indicate a dramatic day-to-day variability on tidal amplitudes. Further analysis on the dataset with best fit

T. Li; B. P. Williams; C. She; H. Liu

2004-01-01

78

Lidar observations of polar stratospheric clouds over northern Greenland in the period 1990-1997  

Microsoft Academic Search

Observations of the stratosphere were carried out at Thule (76.5°N, 68.8°W), Greenland, in the period 1990-1997 with an elastic backscatter\\/depolarization lidar. Polar stratospheric clouds (PSCs) were never detected during the winters 1991, 1992, 1993, and 1994. Small nondepolarizing PSCs could have been masked, however, by the large volcanic aerosol cloud that was in the stratosphere during 1992, 1993, and 1994.

A. di Sarra; M. Cacciani; G. Fiocco; D. Fuà; T. S. Jørgensen

2002-01-01

79

Lidar observations of polar stratospheric clouds over northern Greenland in the period 1990–1997  

Microsoft Academic Search

Observations of the stratosphere were carried out at Thule (76.5°N, 68.8°W), Greenland, in the period 1990–1997 with an elastic backscatter\\/depolarization lidar. Polar stratospheric clouds (PSCs) were never detected during the winters 1991, 1992, 1993, and 1994. Small nondepolarizing PSCs could have been masked, however, by the large volcanic aerosol cloud that was in the stratosphere during 1992, 1993, and 1994.

A. di Sarra; M. Cacciani; G. Fiocco; D. Fuà; T. S. Jørgensen

2002-01-01

80

Observed Temporal Evolution of Global Mean Age of Stratospheric Air for the 2002 to 2010 Period  

NASA Astrophysics Data System (ADS)

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.

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

81

Photometric observations and orbital period variations of HS 0705 + 6700 and NY Vir  

NASA Astrophysics Data System (ADS)

We present photometric observations of two post-common-envelope stars, NY Vir (=PG 1336-018) and HS 0705 + 6700. The V band CCD observation of NY Vir was performed by a 40 cm telescope at Ege University Observatory and the R band observations of HS 0705 + 6700 were performed by 100 cm telescope at TÜB?TAK National Observatory. The new light curves were analyzed by the WD code and the physical parameters of stars were determined. We obtained new mid-eclipse timings for HS 0705 + 6700 and combined them with those previously published data. The analysis of the O-C residuals yields a period of about 8.06 ± 0.28 yr and an amplitude of 98.5 s for the system HS 0705 + 6700, which is attributed to the third star physically bounded to the evolved eclipsing pair. A mass function of 1.2 × 10 -4 M? for the third star is obtained. The existence of a third star is also confirmed by the light curve analysis, indicating light contribution of about 0.043 at phase 0.25 in R-bandpass of the eclipsing pair. Using mass-luminosity relationship of the low mass stars we estimate a mass of 0.12 M? with an orbital inclination of about 20°. The O-C residuals obtained for the system NY Vir were represented by a downward parabola which indicates orbital period decrease in the system. Using the coefficient of quadratic term we calculate a rate of orbital period decrease of about dP/ dt = -4.09 × 10 -8days yr -1. The period decrease we have measured in NY Vir may be explained by angular momentum loss from the binary system.

Çamurdan, C. M.; Zengin Çamurdan, D.; ?banog?lu, C.

2012-04-01

82

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

NASA Astrophysics Data System (ADS)

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 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)., FUSTE8, 0748-1896].

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

2005-06-01

83

Infrared Spectroscopic Observations of the Secondary Stars of Short-period Sub-gap Cataclysmic Variables  

NASA Astrophysics Data System (ADS)

We present K-band spectroscopy of short-period, "sub-gap" cataclysmic variable (CV) systems obtained using ISAAC on the Very Large Telescope. We show the infrared (IR) spectra for nine systems below the 2-3 hr period gap: V2051 Oph, V436 Cen, EX Hya, VW Hyi, Z Cha, WX Hyi, V893 Sco, RZ Leo, and TY PsA. We are able to clearly detect the secondary star in all but WX Hyi, V893 Sco, and TY PsA. We present the first direct detection of the secondary stars of V2051 Oph, V436 Cen, and determine new spectral classifications for EX Hya, VW Hyi, Z Cha, and RZ Leo. We find that the CO band strengths of all but Z Cha appear normal for their spectral types, in contrast to their longer period cousins above the period gap. This brings the total number of CVs and pre-CVs with moderate resolution (R >~ 1500) IR spectroscopy to 61 systems: 19 pre-CVs, 31 non-magnetic systems, and 11 magnetic or partially magnetic systems. We discuss the trends seen in the IR abundance patterns thus far and highlight a potential link between anomalous abundances seen in the IR with the C IV/N V anomaly seen in the ultraviolet. We present a compilation of all systems with sufficient resolution IR observations to assess the CO band strengths and, by proxy, obtain an estimate on the C abundance on the secondary star.

Hamilton, Ryan T.; Harrison, Thomas E.; Tappert, Claus; Howell, Steve B.

2011-02-01

84

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

NASA Astrophysics Data System (ADS)

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

El Fady Morcos, Abd

2012-07-01

85

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

NASA Astrophysics Data System (ADS)

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.

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

86

Observations of Long-Period Rotational Ground Motions: From Ambient Noise to Earth's Free Oscillations  

NASA Astrophysics Data System (ADS)

After some technical improvements to the ring laser system measuring the vertical component of rotation rate at Wettzell, Germany, in 2009 a marked improvement of the signal-to-noise ratio for the broad-band frequency range of seismic observations could be achieved. This led to the first direct observation of rotational ground motions induced by toroidal free oscillations of the Earth, following the Mw=8.1 Samoa earthquake on September 29, 2009 and the Mw=8.8 Chile earthquake on February 27, 2010. Observations are compared with synthetic seismograms computed by summing normal modes. Amplitude spectra of real and synthetic data are analyzed to interpret the observations. We show that several toroidal modes can be detected in the ring laser data and that our observations are in reasonable agreement with the synthetic spectra. This indicates that long-period seismology can benefit from measurements of rotational ground motion measurements using ring lasers in the future. In addition, analysis of earthquake-free time windows of the ring laser records leads us to the conclusion that we consistently observe Love waves generated in the two ocean-generated microseismic frequency bands and that the azimuth of the source areas can be estimated from joint analysis with translation records from a collocated broadband seismometer.

Igel, H.; Kurrle, D.; Ferreira, A. M.; Wassermann, J. M.; Gaebler, P.; Schreiber, K. U.

2010-12-01

87

SOHO/SWAN OBSERVATIONS OF SHORT-PERIOD SPACECRAFT TARGET COMETS  

SciTech Connect

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

Combi, M. R.; Lee, Y.; Patel, T. S. [Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, 2455 Hayward Street, Ann Arbor, MI 48109-2143 (United States); Maekinen, J. T. T. [Finnish Meteorological Institute, P.O. Box 503, SF-00101 Helsinki (Finland); Bertaux, J.-L.; Quemerais, E., E-mail: mcombi@umich.edu [LATMOS, CNRS/INSU, Universite de Versailles Saint-Quentin, 11 Bd d'Alembert, 78280 Guyancourt (France)

2011-04-15

88

Impact of Asian dust and continental pollutants on cloud chemistry observed in northern Taiwan during the experimental period of ABC\\/EAREX 2005  

Microsoft Academic Search

Observations of particulate matter (PM), vertical cloud and aerosol structure and cloud water chemistry in northern Taiwan were conducted during the ABC\\/EAREX 2005 period. Five Asian continental outflow regimes reaching Taiwan were identified. One was coupled with a dust storm observed not only at Gosan, Korea, but also over Taiwan, suggesting the scope of its regional impact. The arrival of

Sheng-Hsiang Wang; Neng-Huei Lin; Chang-Feng OuYang; Jia-Lin Wang; James R. Campbell; Chi-Ming Peng; Chung-Te Lee; Guey-Rong Sheu; Si-Chee Tsay

2010-01-01

89

Observed low-salinity plume off Gulf of Khambhat, India, during post-monsoon period  

NASA Astrophysics Data System (ADS)

Freshwater outflow from river systems, joining the northeastern Arabian Sea suggests that the discharge is maximum during summer monsoon and least during other seasons. However, analysis of climatological monthly salinity and ARGO data indicate, low-saline plumes off Gulf of Khambhat during post-monsoon, despite the fact that there is no river discharge during this period. It is puzzling to understand the existence of relatively low-saline waters in the region that warrants further investigation. Simulations from three-dimensional Princeton Ocean Model (POM) suggest that the opposing winds and the associated onshore coastal currents during July seem to trap the freshwater in the gulf region. As the monsoon withdraws by September, the currents change their direction that would help in releasing the low-saline waters to open ocean. Winter cooling of the freshwater also enhances the prospects of temperature inversions.

Rao, A. D.; Joshi, Madhu; Ravichandran, M.

2009-02-01

90

Spectroscopic and photometric observations of the short-period RS CVn-type star WY Cnc  

Microsoft Academic Search

High-resolution spectroscopic observations around the H\\\\alpha line and BVRI photometry of the eclipsing short-period RS CVn star WY Cnc are presented. The solutions of our radial velocity curves and light curves yielded the following values for masses and radii of the components: M1=0.84 M&sun;, M2=0.46 M&sun;, R1=1.06 R&sun;, R2= 0.65 R&sun;. The measured rotational broadenings of the spectral lines correspond

D. Kjurkchieva; D. Marchev; W. Ogloza

2004-01-01

91

Spectroscopic and photometric observations of the short-period RS CVn star RT And  

Microsoft Academic Search

Spectroscopic observations in the range 6500-6700 Å and BVRI photometry of the eclipsing short-period RS CVn-star RT And are presented. We determined K1=130 km s-1 and K2=175.8 km s-1 by measurement of the double profiles of the lines Halpha and FeI 6678, and obtained the mass ratio q=0.74 and masses of the star components M1=1.23 Msun and M2=0.91 Msun. It

D. P. Kjurkchieva; D. V. Marchev; W. Ogloza

2001-01-01

92

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

NASA Astrophysics Data System (ADS)

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

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

1980-10-01

93

Coordinated Observations of Rotational Modulation in Long Period RS CVn Systems  

NASA Astrophysics Data System (ADS)

This proposal requests IUE time to obtain SWP low dispersion spectra during 10 US2 shifts during the Fall of 1985. The targets are all late G or early K giants in long period active chromosphere RS Canum Venaticorum binary systems. The research goal is to discern the spatial relationship and extent of the surface active regions in both the horizontal and vertical directions. Ground based observations will be obtained contemporaneously over the fall season. We will use the C IV line as the primary activity indicator in the stellar transition region, whereas ground based observations will supply information on the chromosphere and photosphere. We will particularly be seeking information on the relative shape and phase lead or lag of the transition region emission relative to the chromospheric and photospheric rotational phase behavior.

Ramsey, Lawrence

94

Quasi-periodic frequency fluctuations observed during coronal radio sounding experiments 1991-2009  

NASA Astrophysics Data System (ADS)

Coronal radio sounding experiments were carried out using the dual-frequency signals of the spacecraft Ulysses, Galileo, Mars Express, Venus Express, and Rosetta. The change in differential frequency recorded at the NASA and ESA ground stations, a quantity sensitive only to the plasma along the radio ray path from spacecraft to receiver, has been analyzed in this work. This large volume of observational data provides evidence for the occasional presence of a quasi-periodic component (QPC) in the derived frequency fluctuation spectra. First seen in data from the Mars Express conjunction in 2004, further evidence for the QPC has now been found in data recorded at other solar conjunction opportunities from 1991 to 2009, thereby better defining the statistical characteristics of the QPC. The level of QPC spectral density is a factor of three higher than the expected power-law background level. The characteristic frequency of the spectral density maximum is roughly 4 mHz, corresponding to a QPC fluctuation period of about 4 min. The bandwidth of the spectral line is comparable to the maximum frequency. The QPC are observed at heliocentric distances between 3 and 40 solar radii, both in equatorial regions and at high heliolatitudes. The QPC is detected with an occurrence frequency of about 20% and is occasionally accompanied by its second harmonic. The most likely progenitors of the QPC are quasi-periodic electron density fluctuations associated with magnetosonic waves, which are generated locally from nonlinear interactions of 5-min band Alfvén waves propagating from the coronal base.

Efimov, A. I.; Lukanina, L. A.; Samoznaev, L. N.; Rudash, V. K.; Chashei, I. V.; Bird, M. K.; Pätzold, M.; MEX, VEX, ROS Radio Science Team

2012-02-01

95

Observations and predictions of eclipse times by astronomers in the pre-telescopic period.  

NASA Astrophysics Data System (ADS)

Eclipses of the Sun and Moon are among the most impressive of celestial events. It is therefore unsurprising that they have played an important role in the astronomy and astrology of most early cultures. Many hundreds of references to eclipses are found in the writings of the chroniclers and astronomers of the pre-telescopic world. In particular, the astronomers of Babylon, Ancient Greece, the Islamic Near East. Later Medieval and Renaissance Europe, China, and Japan, recorded a large number of observations and predictions of the time of an eclipse. The present study contains an extensive compilation of all known timed reports of eclipse observations and predictions made by astronomers in the pre-telescopic period. By performing a basic analysis of the recorded times, it has been possible to trace the gradual development of the techniques used by the astronomers to observe and predict eclipses. In order to conduct this analysis, it has been necessary to investigate a number of other problems including the dating of damaged observational accounts, the units of time used by the early astronomers, and the methods by which the Babylonians predicted eclipses. Many of these questions have not previously been answered. Therefore, the results of this study provide important information regarding the astronomies of these early cultures.

Steele, J. M.

96

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

NASA Astrophysics Data System (ADS)

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

Taberka, A. N.

2009-12-01

97

The 67-min X-ray period of EX Hydrae observed with the Einstein observatory  

NASA Astrophysics Data System (ADS)

The cataclysmic variable EX Hydrae has been observed in X-rays with the high resolution imager (HRI), IPC, and monitor proportional counter (MPC) of the Einstein observatory on two occasions. The X-ray spectra indicate multiple spectral components. A constant hard X-ray flux is found in the high-energy channels of the MPC. In the lower energy channels of the MPC and in the IPC a variable softer component is observed with a period of 67 min. The modulation is approximately in phase with the stable 67-min modulation in the optical brightness. The IPC X-ray spectrum changes slightly with the 67 min phase. The X-ray observations of EX Hya, recently interpreted as an intermediate polar, exhibit many features characteristic of AM Her-type stars. The constant hard X-ray source, e.g., is expected from an AM Her-type star with suitable orientation of the magnetic axis with respect to the inclination angle. The AM Her-type X-ray properties of EX Hya and the possible absence of a standard accretion disk in the system are discussed.

Heise, J.; Mewe, R.; Kruszewski, A.; Chlebowski, T.

1987-09-01

98

Climatic changes over the Republic of Belarus during the period of instrumental observations  

NASA Astrophysics Data System (ADS)

Contemporary meteorological observations over the territory of Belarus commenced in the early 19th century. It is however a common practice to begin climatological analyses of surface air temperature changes over the nation from 1881 and of precipitation from 1891 respectively, when standard thermometer and rain gauge installations and observational procedures were developed. For the Republic of Belarus, we present analyses of nationwide changes in mean monthly temperature and precipitation during these more than century-long periods that span up to summer of 2009. We focus on the past two decades when unprecedented global climatic changes have occurred and assess their regional impact on the nation climate and found a significant increase in surface air temperatures with the largest changes (up to 3.5K) in the cold season. Nationwide annual surface air temperature has increased by 1K. Geographically, strongest warming was observed in the northern and eastern parts of the nation. This warming was accompanied by a significant decrease in the near surface wind speed across the nation in all seasons (a 15 to 20 percent decrease) and a weak increase (by 6 percent) of the nationwide annual precipitation. Temperature increases in March-April resulted in the earlier snow cover retreat and earlier spring onset. This onset is occurring now by 10-15 days earlier than in the past.

Komarovskaya, Elena; Taberka, Andrei; Chekan, Grigoriy; Groisman, Pavel

2010-05-01

99

Use of Statistical Models to Analyze Periodic Seismicity Observed for Clusters in the Kanto Region, Central Japan  

Microsoft Academic Search

A periodic pattern of seismicity has been reported for the Kinugawa cluster in the Kanto region, where several earthquake clusters are observed at depths between 40 and 90 km. To analyze this periodicity, statistical studies are performed for the Kinugawa cluster together with eight other clusters. Hypocentral parameters of the earthquakes with magnitudes 4.5 and larger for the period between

M. Imoto; K. Maeda; A. Yoshida

1999-01-01

100

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

SciTech Connect

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%.

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

2006-04-01

101

Observations of ultra-long period normal modes from the 2004 Sumatra-Andaman earthquake  

NASA Astrophysics Data System (ADS)

The great December 2004 Sumatra-Andaman earthquake was the first “giant” or “extreme” (moment magnitude Mw ? 9) earthquake recorded by broadband digital seismometers whose data were rapidly available to investigators worldwide. As a result, analysis of the earth's longest period normal modes became a primary tool for studying the earthquake, rather than an elegant afterthought. The mode data provided the first evidence that the earthquake was much larger (Mw ? 9.3) than initially inferred from surface wave data and involved slip on a much longer fault than initially inferred from body wave data. These observations in turn yielded important insight into the likely recurrence of similar earthquakes and the resulting tsunamis both on the segment of the trench that ruptured and on neighboring segments. The normal mode data are more numerous and much higher quality than previously available. They thus provide the first direct evidence for effects that had been theoretically predicted, such as the control of the splitting pattern by receiver latitude and the splitting of torsional modes. They similarly yield better results for mode properties such as the attenuation of the longest period radial modes, found in agreement with existing models of intrinsic Earth attenuation.

Okal, Emile A.; Stein, Seth

2009-06-01

102

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

NASA Astrophysics Data System (ADS)

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

Paulus, Richard A.

1995-02-01

103

Multipoint observations of quasi-periodic substorms associated with ULF pulsations  

NASA Astrophysics Data System (ADS)

Using auroral images from the IMAGE WIC instrument, geomagnetic data from various ground stations, and geosynchronous particle data, we have identified six consecutive substorms separated by about 45 min to 1.6 hr on November 8, 2000. Most of these substorms are of small to medium size and occurred under a weakly northward IMF condition: IMF Bz was near zero to about +5 nT prior to each substorm. IMF By was also weak, being within about ¢®¨ú3 nT. Most interestingly, we have found that for most of the substorms, about 10-15 min period ULF pulsation begins to amplify prior to each onset and tends to decline near the time of onset. The pulsation features are clearly seen at auroral zone and some higher latitude stations of the CANOPUS magnetic network when they cover morning side MLT regions. Similar features are also seen in the GOES magnetic field observations in similar MLT regions. For the first two substorms, the IMAGE magnetic network stations were at postnoon MLT regions and indicated similar ULF pulsation features. The SuperDARN data show that for most of the substorms, the ionospheric convection within the polar cap shows high-amplitude oscillations with a period of about 15 min that tend to amplify prior to onset and to decline after the onset. Based on the results, we will discuss the possible association between substorm triggering and convection associated with large-amplitude ULF pulsations.

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

2007-12-01

104

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

NASA Astrophysics Data System (ADS)

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

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

2013-04-01

105

Research Experience for Teachers at NRAO-Green Bank: Predicting Good Observing Periods for High Frequency Radio Astronomy  

NASA Astrophysics Data System (ADS)

High frequency observations with the NRAO Green Bank Telescope are affected by atmospheric conditions. Water vapor and the atmospheric stability influence radio waves by increasing the opacity of the atmosphere and degrading the quality of the "seeing." Although Green Bank is located in a temperate climate, preliminary studies using data from an 86 GHz tipping radiometer and a 12 GHz phase monitoring interferometer suggest that about 30% of the time ( 100 days/year) conditions will be excellent for observations at 100 GHz. This project attempts to determine in detail what atmospheric conditions produce simultaneously optimal seeing and opacity. We examined fifty-one periods of good observing that occurred over a period of 100 days. The analysis looks for patterns between twenty-five different weather parameters, drawn from a combination of surface, satellite, and vertical atmospheric measurements. Our preliminary results indicate that conditions of good opacity and good seeing do occur simultaneously and we can frequently predict good observing conditions from a combination of temperature, wind direction, pressure, and water vapor. >From this research, two high school projects were developed for students taking an introductory one semester astronomy course. In the first, students use data from the Observatory and four surrounding weather stations, as well as geographical and climatic information of the area, to create and test an interpolated vertical profile of the atmosphere over Green Bank. In the second, students analyze weather parameters on a set of poor observing days and compare their results with those of the good-weather study described above.

Maciolek, A. A.; Maddalena, R. J.

2000-12-01

106

Changes in ENACW observed in the Bay of Biscay over the period 1975–2010  

NASA Astrophysics Data System (ADS)

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

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

2013-08-01

107

Ground-water levels in Alabama. For observation wells measured periodically, August 1952-July 1977. Circular 105  

SciTech Connect

A systematic observation well network in Alabama was started in 1940. This report summarizes the general relationship between geology and groundwater availability. Unpublished water-level data collected periodically since 1952 at 254 observation wells are listed along with the location description and general information on construction of the observation wells. Publications containing water-level data from selected observation wells are also listed.

Davis, M.E.

1981-03-05

108

Search for periodicity in the observational data by means of artificial neuron networks  

NASA Astrophysics Data System (ADS)

The possibility of application of artificial neural networks is considered for two classical model problems of observational data reduction: (i) the identification of periodic oscillations in noisy time series and (ii) assessment of the frequency of this oscillation (on the existing time series). On the inputs of the neural networks the values of the time series are given, and on the output, respectively, we have either an indicatior of the presence of signal (from 0 to 1), or the assessment of its frequency. It is shown that the theoretical limit, which a neural network can achieve in the training to solve such problems, corresponds to the Bayesian theory of estimation and testing of statistical hypotheses. Training of the neural network was carried out with a help of means of open-source package FANN. The best results were achieved using the algorithm Cascade2, which allows finding the optimal number of network neurons (not just the weight of the connection between them). In comparison with traditional methods based on the periodogram, which require long calculations, the trained neural network works almost instantly. Thus, artificial neural networks are very promising for the processing of large data sets. However, the threshold of signal detection so far failed to bring to Bayesian theoretical limit. In addition, it is not yet possible to train the neural network to analyze time-series with arbitrarily-uneven distribution of observations. This indicates on a need for further investigations to improve the efficiency of the method.

Baluev, R.

2012-05-01

109

On the Flux-Rope Topology of Ejecta Observed in the Period 1997 - 2006  

NASA Astrophysics Data System (ADS)

In the following study our aim is to analyse the magnetic flux-rope topology of some events observed in the interplanetary medium related to ejecta. The magnetic field structures associated with interplanetary coronal mass ejections are globally classified in magnetic clouds and ejecta. One of the main questions regarding these phenomena concerns their flux-rope or non-flux-rope magnetic field line configuration. From the experimental measurements the only way to elucidate such a question is analysing the corresponding data by means of a flux-rope physical model. After selecting the ejecta events observed during the period 1997 - 2006, we have analysed them in light of an analytical model with that topology for the magnetic field components, initially developed for magnetic clouds, and with a non-force-free character; then, incorporating the expansion of the magnetic structure during their evolution in the interplanetary medium. Different parameters obtained from the fitting of the model are related to the orientation of the axis of the magnetic flux-rope structure and, additionally, the closest distance approach of the spacecraft to its axis. One of the main conclusions achieved concerns the fact that the axes of most of those structures are close to the Sun-Earth line, which implies that the passage of the spacecraft through the corresponding ejecta event is by its flank. In general, we show a rough procedure for the analysis and classification of ejecta in terms of their magnetic field topology.

Hidalgo, M. A.; Nieves-Chinchilla, T.; Blanco, J. J.

2013-05-01

110

Rotation periods of binary asteroids with large separations - Confronting the Escaping Ejecta Binaries model with observations  

NASA Astrophysics Data System (ADS)

Durda et al. (Durda, D.D., Bottke, W.F., Enke, B.L., Merline, W.J., Asphaug, E., Richardson, D.C., Leinhardt, Z.M. [2004]. Icarus 170, 243-257), using numerical models, suggested that binary asteroids with large separation, called Escaping Ejecta Binaries (EEBs), can be created by fragments ejected from a disruptive impact event. It is thought that six binary asteroids recently discovered might be EEBs because of the high separation between their components (˜100 > a/ R p > ˜20). However, the rotation periods of four out of the six objects measured by our group and others and presented here show that these suspected EEBs have fast rotation rates of 2.5-4 h. Because of the small size of the components of these binary asteroids, linked with this fast spinning, we conclude that the rotational-fission mechanism, which is a result of the thermal YORP effect, is the most likely formation scenario. Moreover, scaling the YORP effect for these objects shows that its timescale is shorter than the estimated ages of the three relevant Hirayama families hosting these binary asteroids. Therefore, only the largest ( D ˜ 19 km) suspected asteroid, (317) Roxane, could be, in fact, the only known EEB. In addition, our results confirm the triple nature of (3749) Balam by measuring mutual events on its lightcurve that match the orbital period of a nearby satellite in addition to its distant companion. Measurements of (1509) Esclangona at different apparitions show a unique shape of the lightcurve that might be explained by color variations.

Polishook, D.; Brosch, N.; Prialnik, D.

2011-03-01

111

Ground-based observations during the period between two strong November 2004 storms attributed to steady magnetospheric convection  

NASA Astrophysics Data System (ADS)

Strong geomagnetic storms are of great scientific interest because they drive the magnetosphere to an extreme state and result in nontypical magnetosphere-ionosphere coupling. The present study examines the ground-based signatures of the magnetosphere-ionosphere disturbances during the recovery phase of the very intense storm on 7-8 November 2004. The recovery phase took place under steady and slightly negative (˜-5 nT) values of the IMF Bz. We compare this event with previously documented storm recovery phases occurring under positive IMF Bz and accompanied by morning Pc5 geomagnetic pulsations. During the period studied in this article the strongest pulsation activity was recorded in the evening and midnight sectors of the Earth. We analyze observations from the Scandinavian multipoint ground-based instrumentation: (1) geomagnetic variations and pulsations, (2) auroras in visual wavelengths, and (3) energetic particle precipitation (riometer data). We show that several enhancements in electrojet, auroral, and energetic precipitation activity were recorded at auroral latitudes. The activations lasted 0.5-2 hours, and the associated negative magnetic field deviations were often more than 1000 nT. Only one of these activations shows typical substorm behavior (poleward expansion and geostationary particle injection). We demonstrate remarkably good correlation between the magnetic variations and cosmic noise absorption variations (in pulsations and slower variations) as well as between the optical auroras and cosmic noise absorption (Imaging Riometer for Ionospheric Studies riometer system) both in time and in space. Thus the auroral precipitation revealed a very coherent behavior over a wide energy range (˜1-40 keV) during the analyzed period. The images acquired by the network of MIRACLE all-sky cameras show that the auroral distribution exhibited double oval configuration during our event. Double oval is often observed during so-called Steady Magnetospheric Convection (SMC) episodes. Furthermore, multiple auroral streamers were recorded, implying probable occurrence of bursty bulk flows (BBFs) in the magnetotail. The absence of recurrent geostationary injections, the wide oval configuration, and BBF signatures lead us to suggest that the intermediate period between the two November 2004 superstorms can be attributed to a SMC period. Mapping the motion of ionospheric signatures to the magnetotail with the Tsyganenko 96 models suggests BBF earthward speeds of ˜600-800 km/s. We suppose that the main drivers for the above described recurrent and intensive ionospheric phenomena are energy input from the solar wind due to slightly negative values of IMF Bz as well as huge energy storage in the magnetotail due to the previous storm main phase.

Manninen, J.; Kleimenova, N. G.; Kozyreva, O. V.; Ranta, A.; Kauristie, K.; MäKinen, S.; Kornilova, T. A.

2008-03-01

112

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

SciTech Connect

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.

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

2006-04-15

113

RApid Temporal Survey (RATS) - II. Followup observations of four newly discovered short-period variables  

NASA Astrophysics Data System (ADS)

The Rapid Temporal Survey (RATS) is a survey to detect objects whose optical intensity varies on time-scales of less than ~70 min. In our pilot data set taken with the Isaac Newton Telescope and the Wide Field Camera in 2003 November, we discovered nearly 50 new variable objects. Many of these varied on time-scales much longer than 1 h. However, only four objects showed a modulation on a time-scale of 1 h or less. This paper presents followup optical photometry and spectroscopy of these four objects. We find that RATJ0455 + 1305 is a pulsating (on a period of 374 s) subdwarf B star of the EC14026 type. We have modelled its spectrum and determine Teff = 29200 +/- 1900K and logg = 5.2 +/- 0.3 which locates it on the cool edge of the EC14026 instability strip. It has a modulation amplitude which is one of the highest of any known EC14026 star. Based on their spectra, photometric variability and their infrared colours, we find that RATJ0449 + 1756, J0455 + 1254 and J0807 + 1510 are likely to be SX Phe stars - dwarf ? Sct stars. Our results show that our observing strategy is a good method for finding rare pulsating stars.

Ramsay, Gavin; Napiwotzki, Ralf; Hakala, Pasi; Lehto, Harry

2006-09-01

114

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

SciTech Connect

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

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

2011-07-01

115

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

NASA Astrophysics Data System (ADS)

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 overlap (about 5 hours) and have the high spatial resolution: 10 arcsec (NoRH) and 20 arcsec (SSRT). We have found that quasi-periodic long-term oscillations are surely observed at both frequencies with the periods in the range of 20-150 min. We detected common periods for common time of observations with two radioheliographs and interpret this as the consequence of the vertical-radial quasi-periodic displacements of sunspot as a whole structure.

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

2009-03-01

116

Bayesian statistical inference to remove periodic noise in the optical observations aboard a spacecraft  

Microsoft Academic Search

A statistical technique that discriminates between random and periodic noise is proposed to reduce data errors from data containing a periodic modulation due to the spin motion of a rocket. The method is based on the concept of entropy maximization and it provides a best-fit solution to the data. The criterion of fit employed is the logarithmic likelihood of a

Tomoyuki Higuchi; K. Kita; Toshihiro Ogawa

1988-01-01

117

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

NASA Astrophysics Data System (ADS)

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

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

2013-06-01

118

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

Microsoft Academic Search

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

Thanos Veremis

1978-01-01

119

Local time distributions of the repetition period of rising-tone chorus elements: THEMIS Observations  

NASA Astrophysics Data System (ADS)

Whistler-mode chorus waves most likely occur in the dayside, dawnside, and nightside sectors of the inner magnetosphere owing to the co-location of the drift trajectories of energetic electrons. When the chorus waves are excited by electron anisotropy in the minimum magnetic field region, they propagate along the field lines, possibly interacting with charged particles under some resonance conditions. The most noticeable property of chorus waves is discrete elements. The repetition period of chorus waves is defined as the generation time delay between two consecutive discrete chorus elements. Here we utilize in situ high-resolution magnetic fields from the THEMIS mission to obtain distributions of the repetition period of chorus elements for various local time sectors. These distributions have a peak at lower repetition periods and a long tail at higher repetition periods. We find that the average repetition periods for the dawnside (3 < MLT < 8) and the nightside (22 < MLT < 3) sectors are 0.56 and 0.68 s, respectively. The repetition periods for the dayside (8 < MLT < 14) and the duskside (14 < MLT < 22) sectors are about two times of those for the dawnside and nightside sectors. The distributions derived from this study are important to a modeling of wave-particle interactions for radiation belt electrons.

Hsieh, Yikai; Shue, Jih-Hong; Wing-Yee Tam, Sunny; Wang, Kaiti; Fu, Hui-Shan; Bortnik, Jacob

2013-04-01

120

Indications of a Lunar Synodical Period in the Sunshine Observations for Boston, Massachusetts, and Columbia, Missouri.  

National Technical Information Service (NTIS)

An analysis of 25,201 days of sunchine observations at Boston, Mass., and 21,184 days of observations at Columbia, Missouri, shows that below average sunchine is observed between New Moon and First Quarter and between Full Moon and Last Quarter while abov...

I. A. Lund

1964-01-01

121

[Statistical study of dermatomycosis - observations in Sendai National Hospital over a 30 year period].  

PubMed

A statistical 30-year study of dermatomycosis in Sendai National Hospital (1968-1997) revealed many changes in the prevalent diseases: Tinea pedis and tinea unguium constantly increased during this period, and the ratio of the former associated with nail infection finally reached 30% of all tinea pedis patients. On the contrary, tinea corporis and cruris showed a remarkable decreasing tendency. Patient age distribution of each disease also showed distinctive changes, generally increasing in the older generation and decreasing in the younger. The number of patients with tinea pedis and unguium gradually increased among the middle and older generations, with the peak of the age-distribution curve shifting upward year after year. On the other hand, cases of tinea cruris among the younger generation were few in the latest years, and middle-age patients remained at a low number. In the first stage of this study the kinds of atiologic dermatophytes consisted of multiple species, but after middle period the isolation of Epidermaphyton floccosum decreased. Microsporum canis appeared first in 1976 but in the recent several years has completely disappeared. In the last few years of the period studied Trichophyton rubrum and Trichophyton mentagrophytes were the only isolates found from among all types of dermatophytoses. Infantile candidiasis remarkably increased in 1970-1975 but thereafter decreased rapidlly. Candidial intertrigo also increased in the same period but did not decrease as much thereafter and continued at the same intermediate level. The number of other types of candidiases were not greatly changed throughout the 30-year period. Malassezia infection also showed no remarkable changes, and only 20 cases of sporothrichosis were found. One case of the deep seated form of cutaneous aspergillosis was found, and this was also true of chromomycosis caused by Fonceaea pedrosoi. PMID:16465134

Kasai, Tatsuya

2006-01-01

122

Daily observations of a large period jump of the VELA pulsar  

Microsoft Academic Search

The decay and recovery of the pulse arrival times of signals from the Vela pulsar PSRO833-45 are analyzed for indications of the structure of the object. A 102 nsec decrease was found to occur over a day's observations at 646 MHz. Six weeks of relatively continuous observations showed that a recovery from the decay occurred. Time constants for an exponential

P. M. McCulloch; P. A. Hamilton; G. W. R. Royle; R. N. Manchester

1983-01-01

123

Brightness of long-period comets observed at large heliocentric distances (III. The computer catalogue for 1959 - 1976)  

NASA Astrophysics Data System (ADS)

The paper is a compilation of 3327 magnitude estimates of 21 long-period comets observed at the heliocentric distances larger than 2.5 AU with the well determined orbits which passed the perihelion from 1959 to 1976. This is the third part of the catalogue of long-period comets. The first two parts (covering 1861-1957) were published before. The catalogue can serve as a supplement to the short-period CLICC/A catalolgue compiled by Kamél and ICQ archive compiled by Green et al. The catalogue exists only in computer version and can be downloaded from the author's www homepage.

Svore?, J.

2002-11-01

124

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

NASA Astrophysics Data System (ADS)

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 phase readily explained by light-travel time effects produced by reflex orbital motion about an unseen companion. The best-fit model to the observations indicates a highly eccentric orbit, a period of 109 + or - 13 days and a minimum mass of 0.5 solar mass for the companion.

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

1990-07-01

125

Microlidar observations of biomass burning aerosol over Djougou (Benin) during African Monsoon Multidisciplinary Analysis Special Observation Period 0: Dust and Biomass-Burning Experiment  

Microsoft Academic Search

Microlidar observations have been performed at the Djougou-Nangatchori site in northern Benin during the African Monsoon Multidisciplinary Analysis (AMMA) Special Observation Period 0 in the dry season, combined with the Dust and Biomass-Burning Experiment (DABEX) from mid-January to mid-February 2006. During the dry season, the Djougou area is a region where biomass burning aerosols are heavily produced from agriculture fires.

J. Pelon; M. Mallet; A. Mariscal; P. Goloub; D. Tanré; D. Bou Karam; C. Flamant; J. Haywood; B. Pospichal; S. Victori

2008-01-01

126

Observations and one-dimensional modeling of the atmospheric boundary layer during the afternoon-evening transition time period  

NASA Astrophysics Data System (ADS)

A more complete understanding of the afternoon-evening transition (AET) of the atmospheric boundary layer and the phenomena that occur during this time period is developed through the utilization of a diverse set of tools, including a 1-D boundary layer model and observational assets. The use of a multi-sensor approach to analyze the clear air boundary layer transition provides a more comprehensive description of the AET than has been previously available. An analysis of 82 cases during summer 2007 and autumn 2008 provides an in-depth examination of the boundary layer transition with and without the presence of boundaries and deep convection. The multi-sensor approach illustrates that the most significant changes during the AET occur near the surface, including a significant decrease in 10 m wind speeds. This decrease in wind speeds is hypothesized to produce a decrease in surface layer convergence, and an increase in convergence above the surface layer in association with accelerating winds during the AET. The observations of outflow boundaries and gust fronts during the AET showed that the evolution of the boundaries themselves made it difficult to determine the effect of the AET on the boundaries. Observations of CI cases also appeared to provide little evidence regarding the AET influence, likely due to the strong signal associated with convective-scale motions. Observations from cases where cold fronts and drylines were present give reason to believe that the AET plays a role in CI. A non-convective dryline case from 22 May 2002 during IHOP showed that convergence increased during the AET, providing support to the hypothesis that convergence within pre-existing boundaries increases during the AET. Evidence of an increase in convergence prior to CI was also observed for two cold front cases. The convective signal possibly overwhelms the signal for other active CI cases. The similar timing of all of the different events suggests that the AET plays a role in the evolution of boundaries and convective initiation during the early evening hours. The results of this study provide support for the hypotheses being investigated.

Busse, Jessica Lynn

127

DMS photochemistry during the Asian dust-storm period in the Spring of 2001: model simulations vs. field observations.  

PubMed

This study examines the local/regional DMS oxidation chemistry on Jeju Island (33.17 degrees N, 126.10 degrees E) during the Asian dust-storm (ADS) period of April 2001. Three ADS events were observed during the periods of April 10-12, 13-14, and 25-26, respectively. For comparative purposes, a non-Asian-dust-storm (NADS) period was also considered in this study, which represents the entire measurement periods in April except the ADS events. The atmospheric concentrations of DMS and SO2 were measured at a ground station on Jeju Island, Korea, as part of the ACE-Asia intensive operation. DMS (means of 34-52 pptv) and SO2 (means of 0.96-1.14 ppbv) levels measured during the ADS period were higher than those (mean of 0.45 ppbv) during the NADS period. The enhanced DMS levels during the ADS period were likely due to the increase in DMS flux under reduced oxidant levels (OH and NO3). SO2 levels between the two contrasting periods were affected sensitively by some factors such as air mass origins. The diurnal variation patterns of DMS observed during the two periods were largely different from those seen in the background environment (e.g., the marine boundary layer (MBL)). In contrast to the MBL, the maximum DMS value during the ADS period was seen in the late afternoon at about sunset; this reversed pattern appears to be regulated by certain factors (e.g., enhanced NO3 oxidation). The sea-to-air fluxes of DMS between the ADS and NADS periods were calculated based on the mass-balance photochemical-modeling approach; their results were clearly distinguished with the values of 4.4 and 2.4 micromole m(-2) day(-1), respectively. This study confirmed that the contribution of DMS oxidation to observed SO2 levels on Jeju Island was not significant during our study period regardless of ADS or NADS periods. PMID:15571747

Shon, Zang-Ho; Kim, Ki-Hyun; Swan, Hilton; Lee, Gangwoong; Kim, Yoo-Keun

2005-01-01

128

Periodic variability of surface ozone concentration over western and central Europe from observational data  

Microsoft Academic Search

Characteristics of periodic variability of surface ozone concentration at 98 western and central European stations participating\\u000a in the EMEP program for at least 7 (up to 14) years are determined. Daily and hourly model concentrations of surface ozone\\u000a for each station are given in an analytical form that presents a sum of a constant constituent and basic harmonics that determine

A. M. Zvyagintsev; G. Kakadzhanova; G. M. Kruchenitskii; O. A. Tarasova

2008-01-01

129

Periodic variable stars in CoRoT field LRa02 observed with BEST II  

Microsoft Academic Search

Context: The Berlin Exoplanet Search Telescope II (BEST II) is a small wide field-of-view photometric survey telescope system located at the Observatorio Cerro Armazones, Chile. The high duty cycle combined with excellent observing conditions and millimagnitude photometric precision makes this instrument suitable for ground based support observations for the CoRoT space mission. Aims: Photometric data of the CoRoT LRa02 target

P. Kabath; A. Erikson; H. Rauer; T. Pasternacki; Sz. Csizmadia; R. Chini; R. Lemke; M. Murphy; T. Fruth; R. Titz; P. Eigmüller

2009-01-01

130

Shear instability as a source of the daytime quasi-periodic radar echoes observed by the Gadanki VHF radar  

NASA Astrophysics Data System (ADS)

High-resolution observations of the daytime quasi-periodic (QP) structures of the lower E region irregularities made using the Gadanki VHF radar are presented. The structures are found to display striations with negative altitude rates of ~10 m s-1 and periods of 1-3 minutes. More importantly, these structures are found to be associated with a descending irregularity layer having descent rate of ~0.3 m s-1. The characteristics of these structures although resemble closely to that of nighttime low altitude structures observed earlier at Gadanki as well as at mid-latitudes, the periodicities observed during daytime are found to be higher than that observed during nighttime. The Doppler velocities are mostly in the range -20-10 m s-1 and exhibit remarkable shear corresponding to the echoes of larger periodicities. The echoes being mostly confined to the collision dominated lower E region, it is possible to derive meridional neutral wind and the derived wind shows remarkable shear. It is proposed that the Kelvin-Helmholtz instability is the most likely mechanism responsible for the observed structures presented in this paper.

Sripathi, S.; Patra, A. K.; Sivakumar, V.; Rao, P. B.

2003-11-01

131

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

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

132

DEMETER ULF observations of turbulence during the period before large earthquakes  

NASA Astrophysics Data System (ADS)

During the period before a major earthquake, the electrical properties of the crust change as the stresses increase. These changes can generate perturbations in the electric and magnetic fields, generating waves which may propagate through the atmosphere, resulting in perturbations of the ionosphere. In this present paper, data from the DEMETER satellite is analysed to search for enhancements in ULF wave activity in the vicinity of earthquakes as a prelude to the seismic event. Results are presented for two seismic events, the Sichuan event in 2008 and l'Aquila 2009 which show enhancements in wave activity with frequencies f~0.05Hz during the build up to a major earthquake.

Walker, S. N.; Balikhin, M. A.; Pokhotelov, O. A.; Parrott, M.

2012-04-01

133

Short-period Variations of the Earth Rotation Parameters Observed by Very Long Baseline Interferometry  

NASA Astrophysics Data System (ADS)

High-frequency polar motion and universal time variations are obtained from Very Long Baseline Interferometry (VLBI). The goal is to detect short-period and episodic events with signatures below the 100 microarcseconds (7.5 microseconds) level. Ter-diurnal variations in the order of 40 microarcseconds in polar motion have been reported during the VLBI campaign CONT02, from October 16 to 31, 2002. But, no geophysical explanation with similar amplitudes was provided. To resolve this enigma, we re-processed the VLBI data obtained during the CONT96, CONT02, and CONT05 campaigns using identical an the most recent reduction models. Two independent software packages were used, OCCAM61E and CALC SOLVE, to assure robustness of the Earth rotation parameters (ERP) estimated with semi-hourly resolution over the fortnightly data sets. The long wavelength signal was removed by a smooth function from the final ERP. Jumps in the ERP values at session boundaries were identified. A heuristic and Fourier frequency analysis shows no significant ter-diurnal periods. In addition, this high-frequency analysis allows to detect incorrect daily ERP values in the International Earth Rotation and reference Systems (IERS) C04 series.

Schuh, H.; Artz, T.; Nothnagel, A.; Mendes Cerveira, P. J.

2007-05-01

134

High-order quantum resonances observed in a periodically kicked Bose-Einstein condensate.  

PubMed

We have observed high-order quantum resonances in a realization of the quantum delta-kicked rotor, using Bose-condensed Na atoms subjected to a pulsed standing wave of laser light. These resonances occur for pulse intervals that are rational fractions of the Talbot time, and are characterized by ballistic momentum transfer to the atoms. The condensate's narrow momentum distribution not only permits the observation of the quantum resonances at 3/4 and 1/3 of the Talbot time, but also allows us to study scaling laws for the resonance width in quasimomentum and pulse interval. PMID:16712208

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

2006-04-27

135

Modeling and experimental observation of parametric fluorescence in periodically poled lithium niobate waveguides  

NASA Astrophysics Data System (ADS)

We present a theoretical and experimental study of parametric generation in a guided wave quasi-phase-matched configuration. A numerical model taking into account inverted domain shape, electrooptic and photorefractive effects, as well as waveguide profiles allows calculation of the observed phase matching curves. The observed parametric fluorescence efficiencies can be explained by assuming a slight reduction of nonlinear coefficient and/or a partial degradation of the nonlinear grating. Optimization of the grating depth profile would permit room temperature parametric oscillation using pump wavelengths and powers attainable with diode lasers.

Baldi, P.; Aschieri, P.; Nouh, S.; de Micheli, M.; Ostrowsky, D. B.; Delacourt, D.; Papuchon, M.

1995-06-01

136

Estimation of individual in-cynlinder air mass flow via periodic observer in Takagi-Sugeno form  

Microsoft Academic Search

In this paper, we propose to estimate the individual in-cylinder air mass flow for a gasoline IC engine. In order to achieve this goal a periodic observer for a class of non-linear models in the discrete Takagi-Sugeno form is designed. The adopted framework to prove the stability of the observer is based on the Lyapunov theory and uses linear matrix

H. Kerkeni; J. Lauber; T. M. Guerra

2010-01-01

137

Optimal Inventory Decisions in the Multi-period Newsvendor Problem with Partial-Observed Markovian Supply Capacities  

Microsoft Academic Search

This paper considers a multi-period news-vendor problem with partially observed supply capacity information which evolves as a Markovian Process. The supply capacity is fully observed by the buyer when the capacity is smaller than buyer's ordering quantity. With a dynamic programming formulation, we prove the existence of a unique optimal ordering policy. In a two-state Markovian capacity case, we further

Haifeng Wang; Houmin Yan

138

LONG PERIOD GROUND MOTION OBSERVED IN SENBOKU PLAIN, MIYAGI PREFECTURE DURING THE 2008 IWATE-MIYAGI NAIRIKU EARTHQUAKE  

NASA Astrophysics Data System (ADS)

During the 2008 Iwate-Miyagi Nairiku Earthquake, long period ground motion with a period of three to four second is observed in Senboku plain, Miyagi prefecture, Japan. In this paper, to characterize these ground motions, following points are studied. At first, we compare these motions and past records those abound in the long-period component using Fourier spectra. Spectral amplitudes of these event motions are almost coincident with those of past records. And stability of peak frequency at K-NET MYG006 station is studied. The result shows that predominant frequency of each event is almost the same. Finally, propagation direction is studied. Results come from this study indicate that long period ground motion is comprised of surface wave excited by deep plain structure.

Kataoka, Shunichi

139

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

Microsoft Academic Search

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

R. F. Elsner; M. C. Weisskopf; W. Darbro; B. D. Ramsey; A. C. Williams; P. G. Sutherland; J. E. Grindlay

1986-01-01

140

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

Microsoft Academic Search

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

Jacopo Chiggiato; Marco Zavatarelli; Sergio Castellari; Marco Deserti

2005-01-01

141

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

Microsoft Academic Search

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,

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

142

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

Microsoft Academic Search

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

R. G. Lawford

2003-01-01

143

Observation of period doubling and chaos in spin-wave instabilities in yttrium iron garnet  

Microsoft Academic Search

Ferromagnetic resonance in a polished 0.047-cm-radius sphere of gallium-doped yttrium iron garnet is studied at 1.3 GHz in a magnetic field of 460 G. A second-order Suhl instability is observed, owing to the nonlinear coupling of the precessing uniform magnetization with spin waves. This is detected by the onset of auto-oscillations of the magnetization. One of these modes with frequency

George Gibson; Carson Jeffries

1984-01-01

144

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

NASA Astrophysics Data System (ADS)

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.

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

2002-04-01

145

Observations of quasi-inertial and short-period internal waves from stationary platform in the Black Sea  

NASA Astrophysics Data System (ADS)

It is well known that the major factor of the generation of the intensive internal waves on the shelves of the oceans and open seas is barotropic tide. Despite of the Black sea is closed and free-tidal sea nevertheless there are exist quite intense internal wave field in here. The results of long-term observations of long- and short-period internal waves measured in the Black Sea are analyzed. These studies were carried out from the stationary platform of the Marine Hydrophysical Institute of the National Academy of Sciences of Ukraine in the summer 2010 and 2011. The platform is situated on the Southern coast of Crimea in 600 m from the shore, where sea depth is about 30 m. The measurements were taken by acoustic Doppler current profilometer (ADCP) "Rio Grande 600 kHz", thermistor chain of ten sensors "Star-Oddi" and oceanographic mini profiler «MiniSVP» with measuring parameters of sound velocity and temperature. We observed the well-defined temporal thermocline oscillations with period close to local inertial (17.2 hours) period. At the same time the clockwise rotation of the vector of currents with the inertial period was detected. During the expedition in 2011 the whole water column synchronous oscillations of the first-mode were observed for the first 5 days, which than changed into the second-mode oscillations. Observations of 2011 were for conditions when thermocline was in the middle of water column. Observed oscillations of inertial waves in 2010 were for conditions of bottom thermocline. The amplitudes of thermocline oscillations were up to 10 -12 m. Also intense short-period waves with period from 2 to 20 minutes and heights from 1 to 6 m were registered. Several cases of second mode short-period internal waves were observed. Also several passages of solitary internal waves were noticed. The peaks of inertial and high-frequency oscillations were revealed by the spectral analysis of current data and temperature records. This work was partly supported by the Russian Foundation for Basic Research.

Khymchenko, Ielizaveta; Serebryany, Andrey

2013-04-01

146

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

NASA Astrophysics Data System (ADS)

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.

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

2011-03-01

147

Bistatic-radar observation of long-period, directional ocean-wave spectra with loran a.  

PubMed

Bistatic-radar scattering from medium- to long-wavelength (80 to 200 meters) ocean waves has been observed with the use of loran A (1.85 megahertz) transmissions and a receiver located 280 kilometers away. The received echoes have been converted into a time-delay, Doppler-frequency map in which the effects of anisotropies in the ocean-wave spectra are clearly shown. The distribution of the echoes in delay-Doppler space is consistent with Bragg scattering from trains of dispersed ocean waves. PMID:17833495

Peterson, A M; Teague, C C; Tyler, G L

1970-10-01

148

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

SciTech Connect

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

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

2011-12-01

149

Observations and modelling of winds and waves during the surface wave dynamics experiment. Report 2. Intensive observation period IOP-3, 25 February-9 March 1991. Technical report  

SciTech Connect

This report describes the compilation of observed and modelled wind, wave and current parameters during the third intensive observation period (IOP-3) from February 25 to March 9, 1991, of the Surface Wave Dynamics Experiment. The measurements include wind speed and direction, wave heights and periods, air and sea temperatures, and atmospheric pressures from four directional wave buoys, two meteorological buoys, and several routinely operated buoys from the National Data Buoy Center (NDBC). Examples of directional wave spectra obtained from two airborne radars and from a Swath ship are presented along with surface currents from airborne expendable current profilers (AXCP) and acoustic doppler current profilers (ADCP). In addition, a summary of directional wave spectra is presented for this period. The model data include examples of wind fields from six numerical weather prediction models and the corresponding wave height maps as derived from the 3G-WAM ocean wave model. Estimated surface current velocities and directions from the Fleet Numerical Oceanographic Center (FNOC) model and selected satellite images of sea surface temperature fields are also presented for this time period.

Caruso, M.J.; Graber, H.C.; Jensen, R.E.; Donelan, M.A.

1994-03-01

150

Jovian periodicities (˜10 h, ˜40 min) on Ulysses’ Distant Jupiter Encounter observations around the Halloween CIR events  

NASA Astrophysics Data System (ADS)

We analyzed data from four different instruments (HI-SCALE, URAP, SWOOPS, VHM/FGM) onboard Ulysses spacecraft (s/c) and we searched for possible evidence of Jovian emissions when the s/c approached Jupiter during the times of Halloween events (closest time approach/position to Jupiter: February 5, 2004/ R = 1683 R J, ? = ˜49°). In particular, we analyzed extensively the low energy ion measurements obtained by the HI-SCALE experiment in order to examine whether low energy ion/electron emissions show a symmetry, and whether they are observed at north high latitudes upstream from the jovian bow shock, as is known to occur in the region upstream from the south bow shock as well ( Marhavilas et al., 2001). We studied the period from October 2003 to March 2004, as Ulysses moved at distances 0.8-1.2 AU from the planet at north Jovicentric latitudes <75°, and we present here an example of characteristic Jovian periodicities in the measurements around a CIR observed by Ulysses on days ˜348-349/2003 ( R = 1894 R J, ? = 72°). We show that Ulysses observed low energy ion (˜0.055-4.7 MeV) and electron (>˜40 keV) flux and/or spectral modulation with the Jupiter rotation period (˜10 h) as well as variations with the same period in solar wind parameters, radio and magnetic field directional data. In addition, characteristic strong ˜40 min periodic variations were found superimposed on the ˜10 h ion spectral modulation. Both the ˜10 h and ˜40 min ion periodicities in HI-SCALE measurements were present in several cases during the whole period examined (October 2003 to March 2004) and were found to be more evident during some special conditions, for instance during enhanced fluxes around the start (forward shock) and the end (reverse shock) of CIRs. We infer that the Jovian magnetosphere was triggered by the impact of the CIRs, after the Halloween events, and it was (a) a principal source of forward and reverse shock-associated ion flux structures and (b) the cause of generation of ˜10 h quasi-periodic magnetic field and plasma modulation observed by Ulysses at those times.

Anagnostopoulos, G. C.; Louri, I.; Marhavilas, P.; Sarris, E. T.

2009-02-01

151

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

PubMed

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

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

2013-07-02

152

Observational studies of Cepheid amplitudes. I. Period-amplitude relationships for Galactic Cepheids and interrelation of amplitudes  

NASA Astrophysics Data System (ADS)

Context: The dependence of amplitude on the pulsation period differs from other Cepheid-related relationships. Aims: We attempt to revise the period-amplitude (P-A) relationship of Galactic Cepheids based on multi-colour photometric and radial velocity data. Reliable P-A graphs for Galactic Cepheids constructed for the U, B, V, R_C, and IC photometric bands and pulsational radial velocity variations facilitate investigations of previously poorly studied interrelations between observable amplitudes. The effects of both binarity and metallicity on the observed amplitude, and the dichotomy between short- and long-period Cepheids can both be studied. Methods: A homogeneous data set was created that contains basic physical and phenomenological properties of 369 Galactic Cepheids. Pulsation periods were revised and amplitudes were determined by the Fourier method. P-A graphs were constructed and an upper envelope to the data points was determined in each graph. Correlations between various amplitudes and amplitude-related parameters were searched for, using Cepheids without known companions. Results: Large amplitude Cepheids with companions exhibit smaller photometric amplitudes on average than solitary ones, as expected, while s-Cepheids pulsate with an arbitrary (although small) amplitude. The ratio of the observed radial velocity to blue photometric amplitudes, AV_RAD/A_B, is not as good an indicator of the pulsation mode as predicted theoretically. This may be caused by an incorrect mode assignment to a number of small amplitude Cepheids, which are not necessarily first overtone pulsators. The dependence of the pulsation amplitudes on wavelength is used to identify duplicity of Cepheids. More than twenty stars previously classified as solitary Cepheids are now suspected to have a companion. The ratio of photometric amplitudes observed in various bands confirms the existence of a dichotomy among normal amplitude Cepheids. The limiting period separating short- and long-period Cepheids is 10.47 days. Conclusions: Interdependences of pulsational amplitudes, the period dependence of the amplitude parameters, and the dichotomy have to be taken into account as constraints in modelling the structure and pulsation of Cepheids. Studies of the P-L relationship must comply with the break at 10.47° instead of the currently used “convenient” value of 10 days. Table 1 is 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/504/959

Klagyivik, P.; Szabados, L.

2009-09-01

153

Breaking of Thunderstorm-Generated Gravity Waves as a Source of Short-Period Ducted Waves Observed at Mesopause Altitudes  

NASA Astrophysics Data System (ADS)

Atmospheric gravity waves with periods of 5 to 8 minutes have been observed at airglow altitudes [Taylor et al., GRL, 22, 2849, 1995; Walterscheid et al., JASTP, 61, 461, 1999; Hecht et al., JGR, 106, 5181, 2001; and references cited therein]. These waves are believed to propagate as thermally-ducted wave modes, trapped in the Brunt-Väisälä frequency minimum of the upper mesosphere and lower thermosphere [e.g., Walterscheid et al., 1999]. Many of these recently observed waves have been traced to thunderstorm activity located hundreds of kilometers from the point of observation. However, these gravity waves would be evanescent in most regions of atmosphere, where their frequency exceeds the local Brunt-Väisälä frequency. It is therefore improbable that the observed waves with short periods (? ˜=5 min) would be able to propagate freely from a tropospheric convective source to the lower thermosphere. Thunderstorms are known radiators of gravity waves, with typical forcing periods of 10 to 16 minutes (approximately equal to the Brunt-Väisälä period of the upper troposphere) [e.g., Pierce and Coroniti, Nature, 210(5042), 1209, 1966]. Recent numerical studies have demonstrated that the breaking of low frequency gravity waves can excite harmonic secondary waves, with frequencies and horizontal wavenumbers approximately twice that of the primary waves [e.g., Franke and Robinson, J. Atmos. Sci., 56, 3010, 1999, Zhou et al., JGR, 107(D7), doi:10.1029/2001JD001204, 2002]. It has also been proposed that these radiated secondary waves may be subject to ducting near the breaking region [Vadas et al., J. Atmos. Sci., 60, 194, 2003]. It can thus be predicted that if thunderstorm-generated gravity waves, with periods of 10 to 16 minutes, were to break near mesopause, they may excite secondary waves with short periods of 5 to 8 minutes. These waves would be trapped in the lower thermospheric duct. Using a high-resolution, two-dimensional, nonlinear numerical model, we examine this process in a thermally-realistic atmosphere for a tropospheric oscillatory source modeling the effects of convection. Simulated results demonstrate that breaking thunderstorm-generated gravity waves may be able to excite quasi-monochromatic, short-period, thermally ducted wave modes at airglow altitudes. These results will be compared with linear mechanisms (such as ``kissing" modes [e.g., Walterscheid et al. JGR, 106, 31825, 2001]); the applicability and limitations of the different mechanisms will be discussed.

Snively, J. B.; Pasko, V. P.

2003-12-01

154

Periodic variation in the water production of comet C/2001 Q4 (NEAT) observed with the Odin satellite  

NASA Astrophysics Data System (ADS)

Context: Comet C/2001 Q4 (NEAT) was extensively studied with the 1.1-m submillimetre telescope of the Odin satellite. The H2O line at 557 GHz was regularly observed from 6 March to 16 May 2004 and nearly continuously monitored during 3 periods between 26 April and 2 May 2004. Aims: This last set of data shows periodic variations in the line intensity, and we looked for characterising the long- and short-term behaviour of this comet. Methods: We used the variance ratio method and ?2 minimization to find the period of variation in the water production rate and simulations to infer its amplitude at the nucleus surface. Results: A 40% periodic variation in the water production rate is measured with a period of 0.816±0.004 day (19.58±0.1 h). The comet also exhibits a seasonal effect with a mean peak of outgassing around 2.7×1029 molec. s-1 taking place about 18 days before perihelion. Odin is a Swedish-led satellite project funded jointly by the Swedish National Space Board (SNSB), the Canadian Space Agency (CSA), the National Technology Agency of Finland (Tekes) and the Centre National d'Études Spatiales (CNES, France). The Swedish Space Corporation is the prime contractor, also responsible for Odin operations.

Biver, N.; Bockelée-Morvan, D.; Colom, P.; Crovisier, J.; Lecacheux, A.; Frisk, U.; Hjalmarson, Å.; Olberg, M.; Sandqvist, Aa.

2009-07-01

155

Observations of Inertial Period Waves and Vertical Velocities in the Tropical Middle Atmosphere Using the MST Radar Technique  

Microsoft Academic Search

The UHF radar at Arecibo, Puerto Rico (18.3 ^circN) and VHF radar at Jicamarca, Peru (11^circS) have been used as Mesospheric-Stratospheric-Tropospheric (MST) radar wind profilers to observe winds and waves in the tropical middle atmosphere. Velocity measurements over Arecibo indicate the presence of one or more wave modes near the local inertial period of 38.1 hours in the lower stratosphere.

Charles Robert Cornish

1987-01-01

156

[Report of a lateral collum femoris fracture in childhood with observations spanning a 32-year-period (author's transl)].  

PubMed

On the basis of a 32-year-observation-period (radiologically controlled) of a lateral collum femoris fracture which occurred when the patient was 8 years of age, it could be ascertained that surprisingly good results were achieved in the sense of self healing in spite of basic treatment errors, pseudarthrosis of the collum femoris and traumatic loosening of the femur head with subsequent alterations. PMID:997742

Bengert, O

1976-10-01

157

Simultaneous observations of quasi-periodic ELF/VLF wave emissions and energetic-electron precipitation by DEMETER  

NASA Astrophysics Data System (ADS)

One of the proposed explanations of the quasi-periodic (QP) VLF wave observed in the ionosphere is based on their generation by energetic electrons in the equatorial region of the magnetosphere. These electrons then precipitate into the ionosphere and their flux should be modulated with the same period as the QP emissions. The main attention in our study is paid to the correlation between both features. We use the DEMETER spacecraft data for this purpose. We have analyzed more than two hundred events of the QP wave measurements by DEMETER. In this large data set, we have found several cases where precipitated electrons are highly correlated with the QP wave bursts. To our knowledge, such observations made onboard satellites have not been reported earlier. We have found the cases at both low (L < 4) and high (L > 4) McIlwain parameter, however characteristics of the QP emissions (the frequencies, the dynamic spectrums, the periods) differ for different latitudes. Energetic particle data from the DEMETER satellite are supplemented by data from the NOAA-17 satellite. The orbit of this spacecraft is very similar to the orbit of DEMETER. We discuss mechanisms of removal of energetic electrons from a generation region and we compare the parameters of the observed events with the cyclotron maser model of the QP emissions.

Hayosh, M.; Pasmanik, D.; Demekhov, A.; Santolík, O.; Titova, E.; Parrot, M.

2012-04-01

158

Effect of Ovaprim doses and latency periods on induced spawning of Clarias batrachus: observation on larval deformity.  

PubMed

Induced spawning of C. batrachus was conducted at different Ovaprim dose and latency period combinations to observe the deformed larvae among the hatchlings. For the purpose, four doses of Ovaprim (0.5, 1.0, 1.5 and 2.0 ml/kg body weight) and five latency periods (11, 14, 17, 20 and 23 hr) were considered in 20 different combinations. There were no deformed larvae in the females injected with all four doses and stripped at 11 hr latency, as the eggs did not hatch. The percentage of deformed larvae (4-7%) did not vary significantly at 1.0-2.0 ml dose level in combination with 14-17 hr latency periods. While increasing the latency period beyond 17 hr at 1-1.5 ml dose level, the percentage of deformed larvae increased significantly and touched as high as 11%. The results indicated that 1-1.5 ml dose in combination with 14-17 hr latency are suitable to reduce the deformed larvae among the hatchlings during induced spawning of C. batrachus. PMID:17948742

Sahoo, S K; Giri, S S; Chandra, S; Sahu, A K

2007-10-01

159

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)

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.

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

2012-06-01

160

Current state of the Altai glaciers (Russia) and trends over the period of instrumental observations 1952-2008.  

PubMed

Results of research into climate and glacier dynamics in the Altai Mountains (Russia) over the period of instrumental observations (1952-2008) are presented in this article. About 1030 glaciers with a total area of 805 km2 and volume of 42.5 km3 have been recorded in the Altai Region. The average summer air temperature in different regions of the Altai has increased during the study period from about 0.2 degrees C (Aktru) to 1.1 degrees C (Akkem). The annual atmospheric precipitation rate has also increased, by 8-10%. Since 1952, the glacier area in different regions of the Altai has decreased by 9-27%, and volume by 12-24%. By 2008, as a result of degradation, the total number of glaciers was 953 with an area of 724 km2 and volume of 38 km3. PMID:21954721

Narozhniy, Yuriy; Zemtsov, Valeriy

2011-09-01

161

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

SciTech Connect

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

Skyllingstad, E.D. [Pacific Northwest Lab., Sequim, WA (United States); Wijesekera, H.W.; Gregg, M.C. [Univ. of Washington, Seattle, WA (United States). Applied Physics Lab.] [and others

1995-03-01

162

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

NASA Astrophysics Data System (ADS)

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

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

2013-01-01

163

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

NASA Astrophysics Data System (ADS)

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

Kotrlová, A.; Stuchlík, Z.; Török, G.

2013-06-01

164

Swift Observations of the High-mass X-Ray Binary IGR J16283-4838 Unveil a 288 Day Orbital Period  

NASA Astrophysics Data System (ADS)

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

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

2013-09-01

165

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

NASA Astrophysics Data System (ADS)

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.

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

2013-05-01

166

Determining earth's rotation from laser observations of LAGEOS artificial earth satellite (during period of main merit campaign)  

NASA Astrophysics Data System (ADS)

An additional contribution is made to determine the parameters of the earth's rotation by laser determinations of the LAGEOS artificial earth satellite as observed during the main campaign of the MERIT program. Ways to solve the many problems involved were outlined in the MERIT standards. However, the traditional algorithm to determine the parameters of the earth's rotation do not take into account the erroneousness or neglecting of parameters of the earth's rotation arising in the numerical integration of the equations of motion of a satellite, although this influence may be significant when making highly precise observations. This article gives the results of a series of determinations of parameters of the earth's rotation obtained during the period 1 September 1983 to 31 October 1984 using a new algorithm which takes this influence into account. A table gives the parameters of the earth's rotation for 89 arcs. Four solutions were obtained by the processing of 49,506 normal points of laser observations distributed in a 14-month interval. An improved method is proposed for more precise determination of sidereal time on the basis of laser observations of artificial earth satellites.

Tsyupak, I. M.

1988-02-01

167

Black Sea thermo-haline characteristics during the period 2002-2008: State estimates based on modelling and observations  

NASA Astrophysics Data System (ADS)

We present an investigation of the thermo-haline characteristics in the Black Sea during the period 2002-2008 using analysis and intercomparison of data from ocean modelling and observations like satellite altimetry, Argo floats and AVHRR. The ocean model set-up is based on the Nucleus of European Modelling of the Ocean (NEMO) framework. It reproduces reasonably well most important features of the Black Sea processes such as the seasonal variability of the rim current, cold intermediate water formation and evolution of the seasonal pycnocline. The main novelty of the employed model setup is its capability to estimate the transport through the Bosporus Straits from the water conservation equation constrained by altimeter data, which can be understand as an assimilation of the altimetric mean sea level signal (MSL) in the model. Main attention in the analysis of simulations is been paid to the dominating characteristics of physical fields at seasonal and inter-annual time scales. Therefore we use empirical orthogonal function (EOF) analysis of temperature, salinity and steric heights from ocean model and investigate their consistence with the modelled and observed sea surface anomaly (SLA), the later is an indicator of the propagation of thermo-haline signals. Results from the EOF analysis show that the major part of SLA variability during the examined period can be express through the first two EOF modes which explain approximately 83.5% of total variance and are well know to be connected to the general evolution of MSL (1-st mode) and the seasonal cycle of rim current intensification (2-nd mode). Higher degree EOF modes show more complex processes which are very interesting because these processes could not be found in older versions of altimeter observations and are mainly controlled by the distribution of water fluxes, in particular from rivers and transport through the Bosporus Strait.

Grayek, S.; Stanev, E. V.

2009-04-01

168

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

NASA Astrophysics Data System (ADS)

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

Ferretti, Rossella

2013-04-01

169

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

NASA Astrophysics Data System (ADS)

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.

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

2007-12-01

170

Observation of three-dimensional structures of quasi-periodic echoes associated with mid-latitude sporadic-E layers by MU radar ultra-multi-channel system  

NASA Astrophysics Data System (ADS)

Quasi-periodic (QP) backscatter observed by VHF radars associated with the mid-latitude Sporadic-E (Es) layers is characterized by distinct striations on range-time-intensity (RTI) plots. Two competing models claim to explain the structure of unstable regions that scatter the radar waves: horizontally drifting patches at an almost constant altitude and unstable regions elongated in altitude along the geomagnetic field line. We have conducted interferometric imaging observations of QP radar echoes to investigate spatial structures of QP echoes, precisely. Kyoto University's newly developed ultra-multi-channel receiving system of middle and upper atmosphere (MU) radar was used. We used 19 independent channels for the radar imaging, and determined the three-dimensional structure and the motion of the QP echoes. During the observation from 30 May to 02 June 2005, well-defined QP echoes were observed on the nights of 31 May, 01 June, and 02 June 2005. Some of QP echoes were found at altitudes higher than 120 km and appeared to descend in altitude as they approached the radar. This result suggests that backscatter regions are developed along the geomagnetic field line from Es layer altitudes to as high as 130 km and that the fluctuations in plasma density and electric field observed by Pfaff et al. (2005) using in-situ measurements form a part of QP echoes.

Saito, S.; Yamamoto, M.; Hashiguchi, H.; Maegawa, A.

2006-07-01

171

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

NASA Astrophysics Data System (ADS)

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

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

2008-12-01

172

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

PubMed

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

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

2005-11-28

173

Quasi-periodic Oscillations of Solar Active Regions in Connection with Their Flare Activity - NoRH Observations  

NASA Astrophysics Data System (ADS)

The sunspot-associated sources at the frequency of 17 GHz give information on plasma parameters in the regions of magnetic field about B=2000 G at the level of the chromosphere-corona transition region. The observations of short period (from one to ten minutes) oscillations in sunspots reflect propagation of magnetohydrodynamic (MHD) waves in the magnetic flux tubes of the sunspots. We investigate the oscillation parameters in active regions in connection with their flare activity. We confirm the existence of a link between the oscillation spectrum and flare activity. We find differences in the oscillations between pre-flare and post-flare phases. In particular, we demonstrate a case of powerful three-minute oscillations that start just before the burst. This event is similar to the cases of the precursors investigated by Sych et al. ( Astron. Astrophys. 505, 791, 2009). We also found well-defined eight-minute oscillations of microwave emission from sunspot. We interpret our observations in terms of a relationship between MHD waves propagating from sunspots and flare processes.

Abramov-Maximov, V. E.; Gelfreikh, G. B.; Shibasaki, K.

2011-11-01

174

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

NASA Astrophysics Data System (ADS)

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.

Lawford, R. G.

2003-12-01

175

Far Eastern Pacific Fresh Pool surface salinity variability observed by SMOS and Aquarius sensors over the period 2010-2012  

NASA Astrophysics Data System (ADS)

The seasonal and interannual variability of the Sea Surface Salinity (SSS) deduced from SMOS and Aquarius/SAC-D satellite missions are analyzed over the period 2010-2012 in the Far Eastern Pacific Fresh Pool. The lowest values of salinity in surface layers (<33) in the tropical Pacific Ocean are found in this region of intense precipitation, associated with the northward migration of the Intertropical Convergence Zone (ITCZ) over Central America (Alory et al., 2012). During the boreal winter, as the ITCZ moves southward, the north-easterly Panama gap wind creates a south-westward jet-like current in its path with a dipole of Ekman pumping/eddies on its flanks. As a result, upwelling in the Panama Bight brings cold and salty waters to the surface which erode the fresh pool on its eastern side while surface currents stretch the pool westward. The present study focuses on the fresh pool patterns ranging from the seasonal and interannual variability over the last 3 year period. Each year, satellite SSS products reveal the erosion of the fresh pool by the Panama upwelling. Compared to the SSS climatology from the World Ocean Atlas, satellite SSS data systematically exhibit fresher surface water (by ~0.5 to 1 unit in SSS) just after the occurrence of the maximum SSS reached in the region during the Panama upwelling events (April-May). Using Tropical Rainfall Measuring Mission (TRMM) data, we found that these fresh anomalies coincide with local excess precipitation. Moreover, except during the boreal winter 2011, saltier surface waters than in the climatology were observed during the intensification phase of the Panama upwelling events (Fev-March). Using ASCAT sensor surface winds, TRMM data, surface current deduced from altimeter data combined with the satellite SSS, the study will analyze how these observed SSS anomalies could be related to the interannual variability in the dominant physical mechanisms involved in the freshpool dynamics. A particular focus will be set on the consistency between SMOS and Aquarius observations and on the potential role of the surface freshwater induced-barrier layer processes in modulating the interannual signals.

Reul, Nicolas; Alory, Gael; Maes, Christophe; Illig, Serena; Chapron, Bertrand

2013-04-01

176

Time Delays in Quasi-periodic Pulsations Observed during the X2.2 Solar Flare on 2011 February 15  

NASA Astrophysics Data System (ADS)

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

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

2012-04-01

177

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

NASA Astrophysics Data System (ADS)

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.

Simoniello, R.; Finsterle, W.; Salabert, D.; García, R. A.; Turck-Chièze, S.; Jiménez, A.; Roth, M.

2012-03-01

178

Detecting multiple periodicities in observational data with the multifrequency periodogram - I. Analytic assessment of the statistical significance  

NASA Astrophysics Data System (ADS)

We consider the `multifrequency' periodogram, in which the putative signal is modelled as a sum of two or more sinusoidal harmonics with independent frequencies. It is useful in cases when the data may contain several periodic components, especially when their interaction with each other and with the data sampling patterns might produce misleading results. Although the multifrequency statistic itself was constructed earlier, for example by G. Foster in his CLEANest algorithm, its probabilistic properties (the detection significance levels) are still poorly known and much of what is deemed known is not rigorous. These detection levels are nonetheless important for data analysis. We argue that to prove the simultaneous existence of all n components revealed in a multiperiodic variation, it is mandatory to apply at least 2n - 1 significance tests, among which most involve various multifrequency statistics, and only n tests are single-frequency ones. The main result of this paper is an analytic estimation of the statistical significance of the frequency tuples that the multifrequency periodogram can reveal. Using the theory of extreme values of random fields (the generalized Rice method), we find a useful approximation to the relevant false alarm probability. For the double-frequency periodogram, this approximation is given by the elementary formula (?/16)W2e- zz2, where W denotes the normalized width of the settled frequency range, and z is the observed periodogram maximum. We carried out intensive Monte Carlo simulations to show that the practical quality of this approximation is satisfactory. A similar analytic expression for the general multifrequency periodogram is also given, although with less numerical verification.

Baluev, Roman V.

2013-11-01

179

Detecting multiple periodicities in observational data with the multifrequency periodogram - I. Analytic assessment of the statistical significance  

NASA Astrophysics Data System (ADS)

We consider the `multifrequency' periodogram, in which the putative signal is modelled as a sum of two or more sinusoidal harmonics with independent frequencies. It is useful in cases when the data may contain several periodic components, especially when their interaction with each other and with the data sampling patterns might produce misleading results. Although the multifrequency statistic itself was constructed earlier, for example by G. Foster in his CLEANest algorithm, its probabilistic properties (the detection significance levels) are still poorly known and much of what is deemed known is not rigorous. These detection levels are nonetheless important for data analysis. We argue that to prove the simultaneous existence of all n components revealed in a multiperiodic variation, it is mandatory to apply at least 2n - 1 significance tests, among which most involve various multifrequency statistics, and only n tests are single-frequency ones. The main result of this paper is an analytic estimation of the statistical significance of the frequency tuples that the multifrequency periodogram can reveal. Using the theory of extreme values of random fields (the generalized Rice method), we find a useful approximation to the relevant false alarm probability. For the double-frequency periodogram, this approximation is given by the elementary formula (?/16)W2e- zz2, where W denotes the normalized width of the settled frequency range, and z is the observed periodogram maximum. We carried out intensive Monte Carlo simulations to show that the practical quality of this approximation is satisfactory. A similar analytic expression for the general multifrequency periodogram is also given, although with less numerical verification.

Baluev, Roman V.

2013-09-01

180

Application of radar-measured rain data in hydrological processes modeling during the intensified observation period of HUBEX  

NASA Astrophysics Data System (ADS)

On the basis of Digital Elevation Model data, the raster flow vectors, watershed delineation, and spatial topological relationship are generated by the Martz and Garbrecht method for the upper area of Huangnizhuang station in the Shihe Catchment with 805 km(2) of area, an intensified observation field for the HUBEX/GAME Project. Then, the Xin'anjiang Model is applied for runoff production in each grid element where rain data measured by radar at Fuyang station is utilized as the input of the hydrological model. The elements are connected by flow vectors to the outlet of the drainage catchment where runoff is routed by the Muskingum method from each grid element to the outlet according to the length between each grid and the outlet. The Nash-Sutcliffe model efficiency coefficient is 92.41% from 31 May to 3 August 1998, and 85.64%, 86.62%, 92.57%, and 83.91%, respectively for the 1st, 2nd, 3rd, and 4th flood events during the whole computational period. As compared with the case where rain-gauge data axe used in simulating the hourly hydrograph at Huangnizhuang station in the Shihe Catchment, the index of model efficiency improvement is positive, ranging from 27.56 % to 69.39 %. This justifies the claim that radar-measured data are superior to rain-gauge data as inputs to hydrological modeling. As a result, the grid-based hydrological model provides a good platform for runoff computation when radar-measured rain data with highly spatiotemporal resolution axe taken as the input of the hydrological model.

Ren, L. L.; Li, C. H.; Wang, M. R.

2003-03-01

181

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

NASA Astrophysics Data System (ADS)

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 observations of TrES-1, and we use these observations to obtain improved estimates for the planetary radius, Rpl=(1.08+/-0.05)RJ, and the planetary mass, Mpl=(0.729+/-0.036)MJ. We also confirm that the inclination estimate of the planetary orbit as i=88.2d. These values agree with those obtained by Alonso et al. in their discovery paper, but the uncertainty in the planet radius has been improved as a result of both high-cadence photometry of two full transits and from independent radius determinations for the V=11.8 K0 V parent star. We derive estimates for the TrES-1 stellar parameters of R*/Rsolar=0.83+/-0.03 (by combining independent estimates from stellar models, high-resolution spectra, and transit light curve fitting) M*/Msolar=0.87+/-0.05 (via fitting to evolutionary tracks), Teff=5214+/-23K, [Me/H]=0.001+/-0.04, rotational velocity Vsin(i)=1.08+/-0.3kms-1, logg=4.52+/-0.05dex, logL*/Lsolar=-0.32, d=157+/-6pc, and an age of ?=4+/-2Gyr. These estimates of the physical properties of the system allow us to compute evolutionary models for the planet that result in a predicted radius of Rpl=1.05RJ for a model that contains an incompressible 20 M? core and a radius Rpl=1.09RJ for a model without a core. We use our grids of planetary evolution models to show that, with standard assumptions, our code also obtains good agreement with the observed radii of the other recently discovered transiting planets, including OGLE-TR-56b, OGLE-TR-111b, OGLE-TR-113b, and OGLE-TR-132b. We report an updated radius for HD 209458b of Rpl=(1.32+/-0.05)RJ, based on a new radius estimate of R*=1.12Rsolar for the parent star. Our theoretical predictions for the radius of HD 209458b are Rpl=1.05RJ and 1.09RJ for models with and without cores. HD 209458b is therefore the only transiting planet whose radius does not agree well with our theoretical models. We argue that tidal heating stemming from dynamical interaction with a second planet is currently the most viable explanation for its inflated size.

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

2005-03-01

182

Radon observations by Gamma Detectors “PM-4 and PM-2” during the seismic period (January - April 2009) in L’Aquila Basin. (Invited)  

NASA Astrophysics Data System (ADS)

The measures of 222Radon from gamma detectors PM-4 and PM-2 in L’Aquila Basin have been analysed during the whole period of major seismic activities in January to April 2009.The primary scope of our observations was to study in systematic fashion the Radon variability related to the earthquakes occurrence .One of the outcome is to evaluate the possibility of using the “PM-4 and PM-2” methodology in Rn observation to study the cycles in the earthquake occurrences in the L’Aquila region. Three stations have been in operation during the period of December 2008 - April 2009: Coppito (Lat. +42° 22’N Long. +13° 20’E); Gran Sasso (Lat. 42° 25’N Long. +13° 30’E); and De Amicis (Lat. +42° 21’N Long. +13° 24’E;). The distance between Coppito and Gran Sasso it’s 20Km; Gran Sasso and De Amicis it’s 15Km; Coppito and De Amicis it’s 8Km. All of the stations are equipped with gamma detectors (PM-4 and PM-2) continuously measure the Radon coming vertically from subsoil. They consists of an NE110 or NE102 Plastic Scintillator of 800/600 cm3 seen by 4 or 2 photomultiplier Photonis xp3462b with a gain of ? 2 * 106, inserted into an airtight container of lead. The lead container is 7 cm thick. All of the detectors are installed 3 metres under the ground surface. At the detector is fixed in a window energy of 351 KeV and 609 KeV, which allows to counts gamma rays of 214Pb and 214Bi. The analogue signal, converted into digital signal, is sent to a counter that returns the value in counting rate, in an acquisition time of 600 sec and 7200 sec (2 hours). We are presenting a comprehensive overview of our observations and the statistical trend during the seismic period of January - April 2009 in L’Aquila Basin,. Our findings suggest that Rn counts significantly increases in several hours up to two days, in advance to the major earthquakes occurrence in the region. Based on our experimental results, we argue that rapid changes in the concentration of radon, measured from gamma detectors, could be considered as a potential earthquake precursor for the L’Aquila region. We are recommending similar measurements to be performed and in other seismogenetic areas in order to crosscheck and validate our findings and to enable this methodology for the future multi disciplinary early warning systems.

Giuliani, G. G.; Giuliani, R.; Totani, G.; Eusani, G.; Totani, F.

2009-12-01

183

Assessment of DMS Photochemistry at Jeju Island During the Asian Dust-Storm Period of Spring 2001: Comparison of Model Simulation with Field Observations  

NASA Astrophysics Data System (ADS)

This study examines the influence of long-range transport of dust particles and air pollutants on both local/regional DMS oxidation chemistry and the distribution of sulfur compounds at Jeju Island (33.17°N, 126.10°E) during the Asian dust-storm (ADS) period in April 2001. The atmospheric concentrations of these sulfur species were measured at a ground station on Jeju Island, Korea as part of the ACE-Asia intensive operation. Three ADS events were observed during the periods of 10-12, 13-14, and 25-26 April, respectively. The concentrations of DMS and CS2 were higher during the ADS period than during the non-Asian-dust-storm (NADS) period. Conversely, a difference in SO2 levels during the ADS period was not distinguishable from those measured during the NADS period. The diurnal variation pattern of DMS observed was largely different from that in the remote marine boundary layer. DMS loss by NO3 in the atmospheric boundary layer was dominant due to significantly high NOx levels influenced by the long-range transport of pollutants from East Asia to Jeju Island. The DMS maximum during the ADS period was observed in the late afternoon. The oceanic fluxes of DMS during the ADS and NADS periods were estimated to be 5.7 +/- 2.3 and 2.9 (+2.8/-1.5) ? mole m^{-2} day-1, respectively.

Shon, Z.; Swan, H.; Bower, K.; Kim, K.; Lee, G.; Kim, J.

2002-12-01

184

Characterization of ambient aerosol from measurements of cloud condensation nuclei during the 2003 Atmospheric Radiation Measurement Aerosol Intensive Observational Period at the Southern Great Plains site in Oklahoma  

Microsoft Academic Search

Measurements were made by a new cloud condensation nuclei (CCN) instrument (CCNC3) during the Atmospheric Radiation Measurement (ARM) Program's Aerosol Intensive Observational Period (IOP) in May 2003 in Lamont, Oklahoma. An inverse aerosol\\/CCN closure study is undertaken, in which the predicted number concentration of particles available for activation (NP) at the CCNC3 operating supersaturations is compared to that observed (NO).

T. A. Rissman; T. M. VanReken; J. Wang; R. Gasparini; D. R. Collins; H. H. Jonsson; F. J. Brechtel; R. C. Flagan; J. H. Seinfeld

2006-01-01

185

Evaluating trends in tropospheric ozone observations from TES with sonde data for the period 2005-2010  

NASA Astrophysics Data System (ADS)

Tropospheric ozone is a global air pollutant and an important greenhouse gas. It is mainly produced by the photochemical reaction of short wave radiation with precursor molecules such as NOx and VOC's originating from anthropogenic pollution and biogenic sources. Besides that, intrusions of stratospheric ozone into the higher troposphere contribute to the ozone abundance in the lower atmosphere. Balloon soundings are one way of measuring ozone. These sondes provide in situ measurements of temperature, pressure, humidity and ozone from balloons launched from stations located all over the world. As the distribution of ozone in the troposphere is not uniform both temporal as well as spatial variability in ozone concentrations must be considered. In contrast to the poor spatial sampling by sondes, spaceborne sensors provide a much better coverage and a fixed time retrieval of ozone enabling the understanding of patterns and origins of tropospheric ozone. These sensors, for instance TES (Tropospheric Emission Spectrometer onboard NASA's EOS-Aura satellite), however need to be evaluated with independent data, such as worldwide sonde ozone data (i.e. World Ozone and Ultraviolet Data Center, WOUDC). The objective of this study is to investigate any tropospheric ozone trends when evaluating the TES v4 data record with the worldwide WOUDC sonde dataset for the period 2005-2010. A comparison between the TES and the WOUDC data provides a detailed consistency check of the ozone spatial distribution as well as the seasonal and multi-year patterns in TES and sonde ozone. We used a maximum range of 300 km and a maximum time difference of ± 9 hours between the version 4 TES and sonde ozone data as coincidence criteria to increase the probability that the same air parcels are sampled. To ensure a valid comparison, the TES averaging kernel was applied on the sonde data. Validation of TES tropospheric ozone is conducted at the lower (surface - 500 hPa) and upper (> 500 hPa) troposphere (cfr. two degrees of freedom of TES in the tropospheric region), per season, year, station, latitudinal zone and for some specific regions. First validation results for all seasons and all stations show better agreement between TES v4 and sonde ozone in the upper troposphere (r = 0.9) than in the lower troposphere (r < 0.8), consistent with the better sensitivity of the satellite instrument higher up in the troposphere. Generally, TES is biased high by 7-15 ppbv in the upper troposphere, in line with earlier reports on the validation of TES v2 retrievals with sondes. A first analysis of TES v4 time series indicate a increasing trend of tropospheric ozone at the 464 hPa level in eastern Asia, more specific in NE China. Further research will focus on an in-depth analysis of these trends and will explore the potential to map and correct for the observed bias between TES and sonde ozone data.

Verstraeten, W. W.; Zörner, J.; Boersma, K. F.

2012-04-01

186

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

Microsoft Academic Search

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

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

187

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)

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.

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

2012-09-01

188

Satellite based observations of LIS and OTD: A comparative study of flash count during the overlapping period  

Microsoft Academic Search

The optical measurements of lightning activity recorded by the sensors viz. LIS and OTD, in the form of flash count, during overlapping period (1998 and 99) have been analysed over the Indian landmass (8°-33° N and 73°- 86° E). The spatial resolution is 0.5° X 0.5° grid (~55km X 55km). Along with this, their diurnal and annual variation is also

S. S. KandalgaonkarA; A. Indian; Homi Bhabha; M. K. Kulkarni

189

A periodic table of ion charge-state distributions observed in the transition region between vacuum sparks and vacuum arcs  

Microsoft Academic Search

Ion charge-state distributions have been measured with high time resolution for short (20 ?s) and long (250 ?s) vacuum discharges of 300 A. Charge-state data for 3 ?s after discharge ignition and quasi-steady-state values are given for most conductive elements in a Periodic Table, including data for a few elements (rhodium, europium, and terbium) that were never before reported in

André Anders

2001-01-01

190

Comparison of UV-RSS spectral measurements and TUV model runs for clear skies for the May 2003 ARM aerosol intensive observation period  

NASA Astrophysics Data System (ADS)

The first successful deployment of the fully-operational ultraviolet rotating shadow-band spectroradiometer occurred during the May 2003 US Department of Energy's Atmospheric Radiation Measurement program's Aerosol Intensive Observation Period. The aerosol properties in the visible range were characterized using redundant measurements with several instruments to determine the column aerosol optical depth, the single scattering albedo, and the asymmetry parameter needed as input for radiative transfer calculations of the downwelling direct normal and diffuse horizontal solar irradiance in clear-sky conditions. The Tropospheric Ultraviolet and Visible (TUV) radiative transfer model developed by Madronich and his colleagues at the US National Center for Atmospheric Research was used for the calculations of the spectral irradiance between 300-360 nm. Since there are few ultraviolet measurements of aerosol properties, most of the input aerosol data for the radiative transfer model are based on the assumption that UV input parameters can be extrapolated from the visible portion of the spectrum. Disagreements among available extraterrestrial spectra, which are discussed briefly, suggested that instead of comparing irradiances, measured and modeled spectral transmittances between 300-360 nm should be compared for the seven cases studied. Transmittance was calculated by taking the ratios of the measured irradiances to the Langley-derived, top-of-the-atmosphere irradiances. The cases studied included low to moderate aerosol loads and low to high solar-zenith angles. A procedure for retrieving single scattering albedo in the ultraviolet based on the comparisons of direct and diffuse transmittance is outlined.

Michalsky, J. J.; Kiedron, P. W.

2008-03-01

191

Comparison of UV-RSS spectral measurements and TUV model runs for clear skies for the May 2003 ARM aerosol intensive observation period  

NASA Astrophysics Data System (ADS)

The first successful deployment of the fully-operational ultraviolet rotating shadow-band spectroradiometer occurred during the May 2003 U.S. Department of Energy's Atmospheric Radiation Measurement program's Aerosol Intensive Observation Period. The aerosol properties in the visible range were characterized using redundant measurements with several instruments to determine the column aerosol optical depth, the single scattering albedo, and the asymmetry parameter needed as input for radiative transfer calculations of the downwelling direct normal and diffuse horizontal solar irradiance in clear-sky conditions. The Tropospheric Ultraviolet and Visible (TUV) radiative transfer model developed by Madronich and his colleagues at the U.S. National Center for Atmospheric Research was used for the calculations of the spectral irradiance between 300-360 nm. Since there are few ultraviolet measurements of aerosol properties, most of the input aerosol data for the radiative transfer model are based on the assumption that UV input parameters can be extrapolated from the visible portion of the spectrum. Disagreements between available extraterrestrial spectra, which are discussed briefly, suggested that instead of comparing irradiances that measured and modeled spectral transmittances between 300-360 nm should be compared for the seven cases studied. These cases included low to moderate aerosol loads and low to high solar-zenith angles. A procedure for retrieving single scattering albedo in the ultraviolet based on the comparisons of direct and diffuse transmittance is outlined.

Michalsky, J. J.; Kiedron, P. W.

2007-11-01

192

Babesia ovis infections: detailed clinical and laboratory observations in the pre- and post-treatment periods of 97 field cases.  

PubMed

Ovine babesiosis, caused by Babesia ovis, is of major economic importance in Turkey. The changes in the blood profile of infected animals are informative about the course of infection. The aim of the present study was to evaluate the hematological and biochemical changes in the pre- and post-treatment periods of the natural B. ovis infections. The presence of the parasites was confirmed by microscopy and polymerase chain reaction (PCR) analysis. On the basis of the clinical and laboratory findings, the infections were categorized into different groups according to the degree of anemia and the level of parasitemia. All infected sheep were treated with imidocarb dipropionate (IMDP). The blood pictures in the pre- and post-treatment periods were compared. Pancytopenia occurred in animals with severe anemia and very high parasitemia, and bicytopenia in the other groups. The platelet count (PLT), plateletcrit (PCT) and mean platelet volume (MPV) returned to the normal ranges after treatment, except those in the group with severe anemia. In the biochemical profile, B. ovis infection caused an increase in blood urea nitrogen and total bilirubin, and these parameters returned to normal levels after treatment. The indirect fluorescein antibody test (IFAT) results showed that 38.1% of the cases raised specific antibodies during the period of infection, with titers ranging from 1/160 to 1/640. All of 45 animals re-examined after treatment were seropositive, with high titers that rose up to 1/5120. PMID:22889552

Sevinc, Ferda; Sevinc, Mutlu; Ekici, Ozlem Derinbay; Yildiz, Ramazan; Isik, Nermin; Aydogdu, Ugur

2012-07-31

193

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

NASA Astrophysics Data System (ADS)

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.

Baluev, Roman V.

2013-05-01

194

Observation of a Metastable Periodic Structure for the (001) Surface of KTaO{sub 3} after Cleaving In Situ  

SciTech Connect

Helium atom diffraction experiments carried out under ultrahigh vacuum conditions on a freshly cleaved (001) surface of KTaO{sub 3} reveal metastable features which decay over a period of several hours. The initial He diffraction pattern contains large scattering intensity satellite peaks very close to the specular reflection beam. As time from cleaving elapses, the satellite intensities diminish virtually to zero while the specular intensity increases, and the diffraction pattern evolves into one consistent with the (1x1) bulk termination surface. The data are compared with model calculations for scattering from a series of terraces at two heights with a distribution of terrace lengths [Surf.Sci. 384, 15 (1997)].

Li, Jaime A.; Akhadov, E. A.; Baker, Jeff; Boatner, L. A.; Bonart, D.; Flaherty, F. A.; Fritsch, J.; Safron, S. A.; Schro''der, U.; Skofronick, J. G. (and others)

2001-05-21

195

Cluster observation of inverted-V structures above the polar caps during prolonged periods of northward IMF  

NASA Astrophysics Data System (ADS)

During periods of northward IMF and above the polar caps, the Cluster spacecraft detect outflowing ion beams with typical inverted V structures. These structures are thin in the dawn-dusk direction (about 30 km at ionospheric altitude) and elongated in the day-night direction. A recent statistical study based on the analysis of a database of 185 events detected by the Cluster spacecraft gives new insight on these structures. This study shows that the delay between a northward/southward turning of IMF and the appearance/disappearance of these structures is respectively of about 2 hours and 15 minutes. Furthermore, it reveals that 40% of the beams are detected together with hot isotropic plasma clouds located inside the magnetospheric lobes. When detected together, there is a strong spatial correlation between these two plasma populations. The polar cap ion beams may thus be the consequence of processes occurring in the distant magnetosphere and a signature of the global magnetospheric configuration during prolonged periods of northward IMF. We analyze in more details some events extracted from this database. We will describe the associated field aligned currents characteristics and the particle and fields properties. We will also discuss the possible mechanisms that can bring isotropic plasma clouds inside the lobes and their connection to ion outflows.

Maggiolo, Romain; Echim, Marius; de Keyser, Johan

196

Type III Radio Bursts Observed with Radio Spectrograph ARTEMIS IV within the Intense Active Period of October-November 2003  

NASA Astrophysics Data System (ADS)

We investigate the relationship of metric type III radio bursts obtained with radio spectrograph ARTEMIS IV (20-650 MHz) in Thermopylae, to GOES SXR/Ha and SOHO/LASCO CMEs within the period of intense activity 20 October to 5 November 2003. Our sample consists of 123 type III radio bursts, 115 SXR Flares (mostly C-type) and 12 CMEs. 69% of type III bursts are coincident in time with SXR Flares, while the rest 31% were detected between successive SXR flux maxima and though not always in the same active region as the SXR Flare, thereby labeled as SXR Less. The lack of SXR enhancement in SXR less type III bursts was probably the result of increased SXR background which prevented detection. It is found also, that 62% of the Flares are associated with type III radio bursts. Furthermore, we study the characteristic type III parameters i.e. start frequency, frequency band and duration as well as the SXR Flare parameters i.e. Flux, Duration, Apparent Area, rise time, decay time and their ratio. Finally, we tried to investigate any characteristic variation occurred because of the different morphology of the three major active regions, 484, 486 and 488 of that period.

Thanasa, M.; Preka-Papadima, P.; Moussas, X.; Tsitsipis, P.; Kontogeorgos, A.

2010-01-01

197

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

PubMed

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

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

198

Open to Suggestion.  

ERIC Educational Resources Information Center

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

Journal of Reading, 1987

1987-01-01

199

Suicidality and Interrogative Suggestibility  

Microsoft Academic Search

All people are subject to memory suggestibility, but suicidal individuals may be especially so. The link between suidality and suggestibility is unclear given mixed findings and methodological weaknesses of past research. To test the link between suidality and interrogative suggestibility, 149 undergraduates answered questions about suicidal thoughts and reasons for living, and participated in a direct suggestibility procedure. As expected,

Lea Pritchard-Boone; Lillian M. Range

2005-01-01

200

Testing the No-hair Theorem with Observations in the Electromagnetic Spectrum. III. Quasi-periodic Variability  

Microsoft Academic Search

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

Tim Johannsen; Dimitrios Psaltis

2011-01-01

201

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

National Technical Information Service (NTIS)

Recent studies have shown that strong correlations are observed between the low frequencies (1-10 Hz) of quasi-periodic oscillations (QPOs) and the spectral power law index of several black hole (BH) candidate sources, in low (hard) states, steep power la...

L. Titarchuk R. Fiorito

2004-01-01

202

Constraining the unexplored period between the dark ages and reionization with observations of the global 21 cm signal  

SciTech Connect

Observations of the frequency dependence of the global brightness temperature of the redshifted 21 cm line of neutral hydrogen may be possible with single dipole experiments. In this paper, we develop a Fisher matrix formalism for calculating the sensitivity of such instruments to the 21 cm signal from reionization and the dark ages. We show that rapid reionization histories with duration {Delta}z < or approx. 2 can be constrained, provided that local foregrounds can be well modeled by low order polynomials. It is then shown that observations in the range {nu}=50-100 MHz can feasibly constrain the Ly{alpha} and x-ray emissivity of the first stars forming at z{approx}15-25, provided that systematic temperature residuals can be controlled to less than 1 mK. Finally, we demonstrate the difficulty of detecting the 21 cm signal from the dark ages before star formation.

Pritchard, Jonathan R.; Loeb, Abraham [Harvard-Smithsonian Center for Astrophysics, MS-51, 60 Garden St, Cambridge, Massachusetts 02138 (United States)

2010-07-15

203

Satellite observations of atmospheric SO 2 from volcanic eruptions during the time-period of 1996-2002  

NASA Astrophysics Data System (ADS)

In this article, we present satellite observations of atmospheric sulfur dioxide (SO 2) from volcanic eruptions. Global ozone monitoring experiment (GOME) data for the years 1996-2002 is analyzed using a DOAS based algorithm with the aim of retrieving SO 2 slant column densities (SCD). The retrieval of SO 2 SCD in the UV spectral region is difficult due to strong and interfering ozone absorptions. It is also likely affected by instrumental effects. We investigated these effects in detail to obviate systematic biases in the SO 2 retrieval. A quantitative study of about 20 volcanoes from Italy, Iceland, Congo/Zaire, Ecuador, Japan, Vanuatu Island and Mexico is presented. The focus is on both eruption and out gassing scenarios. We prepared a 7-year mean map (1996-2002) of SO 2 SCD observed by GOME and tabulated the ratios of the maximum SO 2 SCD observed to the average SO 2 SCD as seen in the 7-year mean map. The further aim of this study is to provide information about unknown volcanic eruptions, e.g., Bandai Honshu Japan, Central Islands Vanuatu, Piton de la Fournaise Réunion Island France, Kamchatka region of Russia and from Indonesia especially. The results demonstrate a high sensitivity of the GOME instrument towards SO 2 emissions during both eruption and degassing episodes.

Khokhar, M. F.; Frankenberg, C.; Van Roozendael, M.; Beirle, S.; Kühl, S.; Richter, A.; Platt, U.; Wagner, T.

204

Hypnosis and Suggestion.  

National Technical Information Service (NTIS)

The report contains a description of the use of hypnosis and suggestion and examines the physiological foundation. It includes a determination of the degree of susceptibility to suggestion and hypnosis, the techniques to hypnosis, and the reactions of pat...

P. I. Bul

1975-01-01

205

Suggesting a Memory Screening  

MedlinePLUS

Suggesting a Memory Screening... Text Size: Email This Post Print This Post Suggesting a Memory Screening By Kevin Gault It can be a ... cognitive abilities, want to suggest screening for possible memory deficit, but aren’t sure how to go ...

206

Theories of Suggestion  

PubMed Central

The word “suggestion” has been used in educational, scientific and medical literature in slightly different senses. In psychological medicine the use of suggestion has developed out of the earlier use of hypnotic influence. Charcot defined hypnosis as an artificial hysteria, Bernheim as an artificially increased suggestibility. The two definitions need to be combined to give an adequate account of hypnosis. Moreover, due allowance should be made for the factors of dissociation and of rapport in hypnotic phenomena. The relationships between dissociation, suggestibility, and hypnotizability. Theories of suggestion propounded by Pierre Janet, Freud, McDougall, Pawlow and others. Ernest Jones's theory of the nature of auto-suggestion. Janet explains suggestion in terms of ideo-motor action in which the suggested idea, because of the inactivity of competing ideas, produces its maximum effect. Freud explains rapport in terms of the sex instinct “inhibited in its aim” (transference) and brings in his distinction of “ego” and “ego-ideal” (or “super-ego”) to supplement the theory. Jones explains auto-suggestion in terms of narcissism. McDougall explains hypnotic suggestion in terms of the instinct of self-abasement. But different instincts may supply the driving power to produce suggestion-effects in different circumstances. Such instincts as those of self-preservation (fear) and gregariousness may play their part. Auto-suggestion as a therapeutic factor is badly named. It supplements, but does not supplant the will, and makes complete volition possible.

Brown, William

1928-01-01

207

The Life of Suggestions  

ERIC Educational Resources Information Center

|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…

Pearce, Cathie

2010-01-01

208

Observed Tail Current Systems Associated with Bursty Bulk Flows and Auroral Streamers During a Period of Multiple Substorms  

NASA Astrophysics Data System (ADS)

We present a multi-instrument study of a substorm bursty bulk flow (BBF) and auroral streamer. During a substorm on the 25 August 2003, which was one of a series of substorms that occurred between 00:00 and 05:00~UT, the Cluster spacecraft encountered a BBF event travelling Earthwards and duskwards with a velocity of ~500~{km~s-1} some nine minutes after the onset of the substorm. Coincident with this event the IMAGE spacecraft detected an auroral streamer in the substorm auroral bulge in the southern hemisphere near the footpoints of the Cluster spacecraft. Using FluxGate Magnetometer (FGM) data from the four Cluster spacecraft, we determine the field-aligned currents in the BBF, using the curlometer technique, to have been ~5~{mA~km-2}. When projected into the ionosphere, these currents give ionospheric field-aligned currents of ~ 18~{A~km-2}, which is comparable with previously observed ionospheric field-aligned current associated with BBFs and auroral streamers. The observations of the BBF are consistent with the plasma "bubble" model of Chen and Wolf (1993) and with the reconnection of open field-lines Earthward of the substorm associated near-Earth neutral line for the creation of BBFs.

Forsyth, C.; Lester, M.; Cowley, S. W.; Dandouras, I.; Fazakerley, A. N.; Fear, R. C.; Frey, H. U.; Grocott, A.; Kadokura, A.; Lucek, E. A.; Réme, H.; Milan, S. E.; Watermann, J.

2007-12-01

209

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

NASA Astrophysics Data System (ADS)

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.

Riihelä, Aku; Manninen, Terhikki; Laine, Vesa

2013-10-01

210

Periodic faceting on TaC(110): Observations using high-resolution low-energy electron diffraction and scanning tunneling microscopy  

SciTech Connect

Unidirectional alternating (100)-(010) faceting has been observed for the clean TaC(110) surface using both high-resolution low-energy electron diffraction and scanning tunneling microscopy. Facets propagate periodically along the [1[bar 1]0] direction and form a ridge-and-valley grating, characterized by an average periodicity of [similar to]6 lattice spacings in the [1[bar 1]0] direction, where (110) terraces are completely absent. This faceted surface is shown to be an energetically favored structure.

Zuo, J.; Warmack, R.J.; Zehner, D.M.; Wendelken, J.F. (Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6024 (United States))

1993-04-15

211

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

NASA Astrophysics Data System (ADS)

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

Oh, Suyeon; Kang, Jeongsoo

2013-09-01

212

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

USGS Publications Warehouse

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

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

2006-01-01

213

Imaging Observations of X-Ray Quasi-periodic Oscillations at 3 - 6 keV in the 26 December 2002 Solar Flare  

NASA Astrophysics Data System (ADS)

Quasi-periodic oscillations in soft X-rays (SXR) are not well known due to the instrument limitations, especially the absence of imaging observations of SXR oscillations. We explore the quasi-periodic oscillations of SXR at 3 - 6 keV in a solar flare observed by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) on 26 December 2002. This was a B8.1 class event and showed three X-ray sources (S1, S2, and S3) at 3 - 6 keV and two sources (S1 and S2) at 12 - 25 keV. The light curves of the total fluxes display a two-minute oscillation at 3 - 6 keV, but not in the energy bands above 8 keV. To investigate imaging observations of the oscillations, we prepared CLEAN images at seven energy bands between 3 keV and 20 keV with an eight-second integration. The light curves of three sources were analyzed after integrating the flux of each source region. We used the Fourier method to decompose each source light curve into rapidly varying and slowly varying components. The rapidly varying components show seven individual peaks which are well fitted with a sine function. Then we used the wavelet method to analyze the periods in the rapidly varying component of each source. The results show that three sources display damped quasi-periodic oscillations with a similar two-minute period. The damped oscillations timescale varies between 2.5 to 6 minutes. Source S1 oscillates with the same phase as S3, but is almost in anti-phase with S2. Analyzing the flaring images in more detail, we found that these oscillation peaks are well consistent with the appearance of S3, which seems to split from or merge with S2 with a period of two minutes. The flare images with a high cadence of one second at 3 - 6 keV show that source S3 appears with a rapid period of 25 seconds. The two-minute oscillation shows the highest spectral power. Source S3 seems to shift its position along the flare loop with a mean speed of 130 km s-1, which is of the same order as the local sound speed. This connection between the oscillation peaks and emission enhancement appears to be an observational constraint on the emission mechanism at 3 - 6 keV.

Ning, Zongjun

2013-10-01

214

Non-typical ground-based quasi-periodic VLF emissions observed at L˜5.3 under quiet geomagnetic conditions at night  

NASA Astrophysics Data System (ADS)

Non-typical long lasting quasi-periodic (QP) VLF emissions have been recorded in Northern Finland at L˜5.3 during the recent Finnish VLF campaign held in December 2011. Contrary to the typical daytime QP emissions, the night-time and early morning (00-05UT) event reported here for the first time is a sequence of 1.5-3.5kHz noise bursts lasting for several tens of seconds with an unusually long repetition period which gradually decreases from ˜700s to ˜50s. These QP emissions were observed under conditions of very quiet geomagnetic activity (Kp=0). In spite of that, the interplanetary magnetic field generally had a small southward component, and a high-latitude substorm occurred on the night-side. After this substorm, the repetition period of the VLF bursts suddenly dropped from ˜200s to˜60s and the spectral structure of QP wave changed. We attribute these QP emissions to auto-oscillations of the cyclotron instability of the Earth's radiation belts. According to the theory, the repetition period of the QP should be inversely proportional to the flux of the gyroresonant energetic electrons. Thus the increased flux of energetic electrons injected by the substorm probably led to the decreasing QP repetition periods.

Manninen, J.; Kleimenova, N. G.; Kozyreva, O. V.; Bespalov, P. A.; Kozlovsky, A. E.

2013-07-01

215

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)

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.

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

2010-12-01

216

Early Periods May Signal Greater Diabetes Risk, Study Suggests  

MedlinePLUS

... 2013 Related MedlinePlus Pages Diabetes Type 2 Menstruation Puberty THURSDAY, Oct. 24 (HealthDay News) -- Girls who start ... eight European countries doesn't confirm that early puberty causes diabetes, but it does point to an ...

217

Diurnal variations in suggestibility  

Microsoft Academic Search

The size-weight illusion was used in an effort to get a measure of suggestibility. 15 subjects, 10 men and 5 women, were given the test five times daily for 26 days. The standard (large) block weighed 55 grams. From the array of smaller blocks one was, at each test, selected as equal to the standard. After 16 days the curve

H. L. Hollingworth

1931-01-01

218

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

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.

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

219

Spectral observations of CH Cygni. IV - June 1983 to May 1984, the period prior to the end of the active phase  

NASA Astrophysics Data System (ADS)

Spectral observations of Cygni IV from June 1983 to May 1984 indicated that the changes that occurred in its spectrum during this period preceded the end of the activity phase that set in with a sudden drop of the star's brightness in July 1984. The intensity of the blue continuum reached its highest value in the middle of 1983 and then began to decrease rapidly. The absorption lines of the ions with high ionization potentials weakened, while the lines of Sr II, which has a lower ionization potential, grew stronger, indicating a decrease of the ionization temperature in the envelope.

Rodriguez, M. H.

1991-06-01

220

Observation of high-order quasi-one-dimensional periodic orbit resonance in (DMET)2I3 and its fermi surface  

NASA Astrophysics Data System (ADS)

Magneto-optical measurements of a quasi-one-dimensional (q1D) organic superconductor (DMET)2I3 has been performed by using a cavity perturbation technique. Several resonant absorption lines, which can be attributed to the q1D periodic orbit resonance (q1D POR), as well as the quite unusual high-order q1D POR coming from the corrugated Fermi surface (FS) in the interlayer direction were observed. Moreover, other harmonic resonances are also observed when the AC electric field is applied along the c*-axis. We will also show its estimated q1D FS from the data analysis where the estimated FS clearly shows why there is no spin-density-wave or charge-density-wave transition in (DMET)2I3 despite having a q1D FS.

Oshima, Y.; Kimata, M.; Kishigi, K.; Ohta, H.; Koyama, K.; Motokawa, M.; Nishikawa, H.; Kikuchi, K.; Ikemoto, I.

2004-04-01

221

SDO/AIA Observations of Quasi-periodic Fast (~1000 km/s) Propagating (QFP) Waves as Evidence of Fast-mode Magnetosonic Waves in the Low Corona: Statistics and Implications  

NASA Astrophysics Data System (ADS)

Recent EUV imaging observations from SDO/AIA led to the discovery of quasi-periodic fast (~2000 km/s) propagating (QFP) waves in active regions (Liu et al. 2011). They were interpreted as fast-mode magnetosonic waves and reproduced in 3D MHD simulations (Ofman et al. 2011). Since then, we have extended our study to a sample of more than a dozen such waves observed during the SDO mission (2010/04-now). We will present the statistical properties of these waves including: (1) Their projected speeds measured in the plane of the sky are about 400-2200 km/s, which, as the lower limits of their true speeds in 3D space, fall in the expected range of coronal Alfven or fast-mode speeds. (2) They usually originate near flare kernels, often in the wake of a coronal mass ejection, and propagate in narrow funnels of coronal loops that serve as waveguides. (3) These waves are launched repeatedly with quasi-periodicities in the 30-200 seconds range, often lasting for more than one hour; some frequencies coincide with those of the quasi-periodic pulsations (QPPs) in the accompanying flare, suggestive a common excitation mechanism. We obtained the k-omega diagrams and dispersion relations of these waves using Fourier analysis. We estimate their energy fluxes and discuss their contribution to coronal heating as well as their diagnostic potential for coronal seismology.

Liu, W.; Ofman, L.; Title, A. M.; Zhao, J.; Aschwanden, M. J.

2011-12-01

222

Hypnosuggestive Therapy (Treatment by Suggestion in Hypnosis).  

National Technical Information Service (NTIS)

Contents: A brief history of hypnosis; The theoretical foundations of hypnosis; The method of hypnotizing and verbal suggestion in hypnosis; Indications for treatment by hypnotic suggestion; Clinical observations; The role of hypno suggestive therapy in e...

K. M. Varshavskii

1974-01-01

223

The serotypes of Bordetella pertussis isolated in Great Britain between 1941 and 1968 and a comparison with the serotypes observed in other countries over this period.  

PubMed Central

Classification, by agglutinogens, of 634 isolates of Bordetella pertussis collected from 1971 to 1968 in Great Britain demonstrated that a change from a predominantly 1,2,0,4 serotype (75% of those examined during 1941-4) to a predominantly 1,0,3,0 serotype (73% of those examined during 1966-8) occurred sometime after 1953. Furthermore, evidence from the examination of isolates collected between 1941 and 1953 suggests that the change may have been gradual. Isolates of serotype 1,2,3,4 made up 20-30% of the total of our cross-country selection for the periods 1941-4, 1946-9, 1950-3 and 1966-8, but over shorter periods in individual areas the percentage varied from negligible to as high as half of those isolated. Results from other countries show a similar drift towards a 1,0,3 sertype but more often from a 1,2,3 than from 1,2,0 serotype. The value, in epidemiological studies, of extended information obtained by monospecific typing sera to all six, rather than only two or three agglutinogens, and confirmation of the results by agglutinin production is demonstrated: for instance not all 1,0,3 isolates were identical.

Bronne-Shanbury, C.; Miller, D.; Standfast, A. F.

1976-01-01

224

Observed trends in ambient concentrations of C 2-C 8 hydrocarbons in the United Kingdom over the period from 1993 to 2004  

NASA Astrophysics Data System (ADS)

Hourly measurements of up to 26 C 2-C 8 hydrocarbons have been made at eight urban background sites, three urban-industrial sites, a kerbside and a rural site in the UK from 1993 onwards up until the end of December 2004. Average annual mean benzene and 1,3-butadiene concentrations at urban background locations have declined at about -20% per year and the observed declines have exactly mimicked the inferred declines in benzene and 1,3-butadiene emissions over the same period. Ninety-day rolling mean concentrations of ethylene, propylene, n- and i-butane, n- and i-pentane, isoprene and propane at urban and rural sites have also declined steadily by between -10% and -30% per year. Rolling mean concentrations of acetylene, 2- and 3-methylpentane, n-hexane, n-heptane, cis- and trans-but-2-ene, cis- and trans-pent-2-ene, toluene, ethylbenzene and o-, m- and p-xylene at a roadside location in London have all declined at between -14% and -21% per year. These declines demonstrate that motor vehicle exhaust catalysts and evaporative canisters have effectively and efficiently controlled vehicular emissions of hydrocarbons in the UK. Urban ethane concentrations arising largely from natural gas leakage have remained largely unchanged over this same period.

Dollard, G. J.; Dumitrean, P.; Telling, S.; Dixon, J.; Derwent, R. G.

225

Characteristics and implications of Doppler spectra of E region quasi-periodic echoes observed by the multibeam middle and upper atmosphere radar  

NASA Astrophysics Data System (ADS)

We present multibeam middle and upper atmosphere (MU) radar observations of quasi-periodic (QP) echoes from 3.2-m field-aligned irregularities associated with plasma patches in the nighttime midlatitude sporadic E (Es) layers over Shigaraki, Japan, to give a cohesive view of the QP echo characteristics. Echo regions with zonal scales less than 50 km moved westward at altitudes near 105 km with trace velocities of 110-120 m s-1 and crossed the radar beams successively. Doppler spectra of the echoes changed in time, range, and azimuth and exhibited mostly type 2 echoes with Doppler velocities between -200 and +200 m s-1 and occasionally type 1 echoes due to the two-stream instability ("the first type 1 echo detection by the MU radar"). We find that the spectra near the middle of the drifting echo region have two type 2 peaks, one at positive Doppler velocity (motion away from the radar) and the other at negative one (motion toward the radar) and that the spectra in the west and east parts of the echo region have single type 2 peak at positive and negative Doppler velocities, respectively. Interestingly, the type 1 echoes lasting for about 4 min on a fixed beam were located near the middle of the echo region. Their Doppler shifts between 250 and 320 m s-1 are very consistent with those from previous type 1 echo observations at other midlatitude locations. Occasionally, type 1 and type 2 echoes coexisted in the same range gates. On the basis of recent observations, theories, and simulations related to QP echoes, we propose a simple model of an Es plasma patch to explain the observations. In the model, polarization electric fields with opposite polarity inside and outside the patch, elongated along the NW-SE direction, play a predominant role in exciting type 1 and type 2 echoes, and cause a variety of Doppler spectra.

Ogawa, Tadahiko; Otsuka, Yuichi; Yamamoto, Mamoru

2006-05-01

226

Seasonal variations of midlatitude mesospheric Na layer and their tidal period perturbations based on full diurnal cycle Na lidar observations of 2002-2008  

NASA Astrophysics Data System (ADS)

The Na lidar facility at Colorado State University (41°N, 105°W) started the full diurnal cycle observations of mesopause region temperature and zonal and meridional winds as well as mesospheric Na density in May 2002. In this paper, monthly means and seasonal variations of the density of mesospheric Na based on lidar observations from May 2002 to December 2008 are reported along with the amplitude and phase of tidal period perturbations. The revealed seasonal behaviors of mesospheric Na layer are generally consistent with published nocturnal climatology, with thick layers and high abundance in winter but thin layers and low abundance near summer. Tidal amplitudes of Na density are large in February-April and August-November with a dominant peak between 85 and 90 km; they are weak in summer months (May-July). The Na density tidal phase profiles, while showing downward progression, show a significant and abrupt phase shift (ideally 180 degrees). The center altitude of this phase shifting (termed switching altitude) is found to coincide with the fractional tidal amplitude (tidal amplitude over diurnal mean) minimum about 2-4 km above the centroid altitude of the associated Na layer. Taking advantage of the established temperature tidal climatology deduced from the same data set, the tidal phase behaviors between temperature and Na density and associated fractional Na density tidal amplitudes are discussed in terms of the theoretical prediction by Gardner and Shelton (1985).

Yuan, Tao; She, C.-Y.; Kawahara, Takuya D.; Krueger, D. A.

2012-06-01

227

Analytical microscopy observations of rat enterocytes after oral administration of soluble salts of lanthanides, actinides and elements of group III-A of the periodic chart.  

PubMed

The behavior in the intestinal barrier of nine elements (three of the group III-A, four lanthanides and two actinides), absorbed as soluble salts, has been studied by two microanalytical methods: electron probe X-ray micro analysis (EPMA) and secondary ion mass spectrometry (SIMS). It has been shown that the three elements of group III-A, aluminium, gallium and indium; and the four lanthanides, lanthanum, cerium, europium and thulium, are selectively concentrated and precipitated as non-soluble form in enterocytes of proximal part of the intestinal tract. SIMS microscopy has shown that these elements are concentrated as a number of submicroscopic precipitates, most of them localized in the apical part of the duodenum enterocytes, where they are observed from one hour to 48 hr after a single intragastric administration. No precipitate is observed after three days. It is suggested that this mechanism of local concentration limits the diffusion of these elements through the digestive barrier, some of them being toxic and none of them having a recognized physiological role. Additionally, the precipitation in duodenal enterocytes, the life time of which is on the order of 2-3 days, allows the elements absorbed as soluble form to be eliminated as a non-soluble form in the digestive lumen along with the desquamation of the apoptotic enterocytes. The intracytoplasmic localization of the precipitates are supposed to be the lysosomes although no direct evidence could be given here due to the very small sizes of the lysosomes of enterocytes. The same results were not observed with the two studied actinides. After administration of thorium, only some very sparse microprecipitates could be observed in intestinal mucosa and, after administration of uranium, no precipitates were observed with the exception of some in the conjunctive part of the duodenal villi. PMID:11441948

Floren, C; Tekaya, L; Escaig, F; Labejof, L; Mouthon, G; Galle, P

2001-05-01

228

On the spatiotemporal evolution of the ionospheric backscatter during magnetically disturbed periods as observed by the TIGER Bruny Island HF radar  

NASA Astrophysics Data System (ADS)

The Superposed Epoch Analysis (SEA) method is used to examine a 4-year database (2000-2003) of the TIGER Bruny Island radar (MLON=226.78°E, MLAT=55.06°S) measurements to determine typical patterns of the spatiotemporal evolution of ionospheric backscatter during geomagnetically disturbed periods. SEA is performed separately for three disturbance categories: short-, medium-, and long-duration magnetic disturbances, based on the Dst index variation. Prior to SEA, the diurnal, seasonal, and solar cycle effects have been accounted for by subtracting the nominal quiet-time values. It is found that the occurrence of ionospheric HF backscatter exhibited strongest enhancements near t=0 h between 65°S and 70°S MLAT (range of 800-2500 km) during short-duration magnetic disturbance. In contrast, a reduction in echo occurrence first occurred near t=0 h at higher ranges (r?2500 km) and expanded equatorwards during the recovery phase of the magnetic disturbances. This reduction in occurrence became progressively stronger and prolonged for medium- and long-duration magnetic disturbances. These categories also showed clear enhancements in the E-region backscatter (r<765 km) commencing from t=0 h. These observations can be explained by three main factors: (1) an enhancement in the E-region densities due to high-energy particle precipitation during magnetically disturbed periods causing the HF radar waves to refract from smaller altitudes and closer ranges, (2) a variability in the F-region densities associated with magnetic disturbances also affecting the propagation of the HF radar waves, and (3) a short-lived strong enhancement in growth rate of decametre-scale ionospheric irregularities when IMF turned southwards causing the highest echo occurrence near t=0 h during SEA.

Kumar, V. V.; Makarevich, R. A.; Kane, T. A.; Ye, H.; Devlin, J. C.; Dyson, P. L.

2011-08-01

229

Retrospective analysis of prosthetic complications of implant-supported fixed partial dentures after an observation period of 5 to 10 years.  

PubMed

Purpose: The purpose of this study was to evaluate the incidence of the most common technical problems with implant-supported fixed partial dentures (FPDs) and to assess the survival and success rates (event-free survival) after 5 to 10 years of function. Materials and Methods: All of the implants evaluated in this study were from a single manufacturer (Institut Straumann). Follow-up examinations were scheduled 1 week after suprastructure placement, 6 months later, and annually thereafter. Prosthesis-based data on survival/failure rates and technical complications were analyzed. Results: In 95 partially edentulous patients, 231 Straumann implants were placed and restored with 177 implant-supported prostheses (125 single crowns, 18 splinted crowns on two adjacent implants, and 34 three-unit FPDs). One hundred thirty one solid abutments and 100 synOcta abutments were inserted. The survival rate of prostheses supported by implants was 97.7%. The prosthetic success rate (event-free survival) was 96.05%. After an observation period of 5 years, the cumulative incidence of screw loosening was 0%. Fracture of the veneering porcelain occurred in 3.95% of all restorations. Fractures of the superstructure framework were not observed. The overall incidence of complications after 5 years was highest for splinted crowns, which showed the lowest success rate (94.4%), followed by three-unit FPDs (96%) and single crowns (98.4%). Conclusions: Single-unit restorations or short-span FPDs supported by both synOcta and solid abutments on Straumann implants showed low rates of technical complications, the most common being fracture of the veneering porcelain. PMID:24066321

Vanl?oglu, Burçin; Ozkan, Yasar; Kulak-Özkan, Yasemin

230

X-ray, FUV, and UV Observations of ? Centauri B: Determination of Long-term Magnetic Activity Cycle and Rotation Period  

NASA Astrophysics Data System (ADS)

Over the last couple of decades we have been carrying out a study of stellar magnetic activity, dynamos, atmospheric physics, and spectral irradiances from a sample of solar-type G0-5 V stars with different ages. One of the major goals of this program is to study the evolution of the Sun's X-ray through NUV spectral irradiances with age. Of particular interest is the determination of the young Sun's elevated levels of high-energy fluxes because of the critical roles that X-ray (coronal) through FUV (transition region (TR), chromospheric) emissions play on the photochemical and photoionization evolution (and possible erosion) of early, young planetary atmospheres and ionospheres. Motivated by the current exoplanetary search missions (such as Kepler and CoRoT, along with the planned Space Interferometry Mission and Darwin/Terrestrial Planet Finder missions) that are hunting for Earth-size planets in the habitable zones (liquid water) of nearby main-sequence G-M stars, we are expanding our program to cooler, less luminous, but very importantly, much more numerous main-sequence K-type stars, such as ? Centauri B. The long life (2-3× longer than the Sun) and slow evolution of K stars provide nearly constant energy sources for possible hosted planets. This program parallels our "Sun in Time" program, but extends the study to stars with deeper convective zone depths. Presented here are X-ray (coronal; ROSAT, Chandra, XMM-Newton), UV (TR; International Ultraviolet Explorer (IUE)), NUV (chromospheric; IUE), and recently acquired FUV (TR/chromospheric; FUSE Cycles 7/8) observations of the K1 V star ? Cen B (HD 128621; V = 1.33; (B - V) = +0.88; ? = 5.6 ± 0.6 Gyr). These combined high-energy measures provide a more complete look into the nature of ? Cen B's magnetic activity and X-ray-UV radiances. We find that ? Cen B has exhibited significant long-term variability in X-ray through NUV emission fluxes, indicating a solar-like long-term activity cycle of P cycle = 8.84 ± 0.4 years. In addition, analysis of the short-term rotational modulation of mean light due to the effects of magnetically active regions has yielded a well-determined rotation period of P rotation = 36.2 ± 1.4 days. ? Cen B is the only old main-sequence K star with a reliably determined age and rotation period, and for early K stars, as in the case of the Sun for G2 V stars, is an important calibrator for stellar age/rotation/activity relations.

DeWarf, L. E.; Datin, K. M.; Guinan, E. F.

2010-10-01

231

Long-period tides observed with a superconducting gravimeter at Syowa Station, Antarctica, and their implication to global ocean tide modeling  

NASA Astrophysics Data System (ADS)

The long-period tides (Mf and Mm waves) were analyzed with the 2 years data obtained with a superconducting gravimeter (SG) installed at Syowa Station (69.0° S, 39.6° E), Antarctica. The observed amplitudes, phase lags and amplitude factors (? factors) were 11.642 +/- 0.035 ?Gal, -0.12° +/- 0.17° and 1.1218 +/- 0.0034 for the Mf wave, and 6.143 +/- 0.058 ?Gal, 0.33° +/- 0.54° and 1.1205 +/- 0.0106 for the Mm wave, respectively (1 ?Gal = 10-8 m s-2). The ocean tide effects (effects of the attraction and loading due to the ocean mass) at the observation site were estimated using the five global ocean tide models: equilibrium ocean tide model, Schwiderski model, Dickman model, CSR model, and Desai and Wahr model. The averages of the five estimates are 0.433 ?Gal and 0.244 ?Gal in amplitude and 192.9° and 179.5° in phase for the Mf and Mm waves, respectively. The five estimates differ by a maximum of 0.104 ?Gal in amplitude and 18.8° in phase for the Mf wave, and by 0.033 ?Gal and 6.4° for the Mm wave. The estimated Mm phases are nearly 180° for the five models, and the variation of their values among the models is relatively small compared with that of the Mf phases. These indicate that the Mm wave is much closer to an equilibrium tide than the Mf wave. Due to the variation of the ocean tide corrections, the corrected ? factors were scattered within the ranges of 1.158 to 1.169 for the Mf wave and 1.163 to 1.169 for the Mm wave. However, it is noted that the mean ? factors of the five ocean models, i.e. 1.162 +/- 0.023 for the Mf wave and 1.165 +/- 0.014 for the Mm wave, prefer slightly larger value rather than those estimated from the theory of the elastic tide.

Sato, Tadahiro; Ooe, Masatsugu; Nawa, Kazunari; Shibuya, Kazuo; Tamura, Yoshiaki; Kaminuma, Katsutada

1997-10-01

232

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)

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

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

2013-09-01

233

Short-period fluctuations of the diurnal tide observed with low-latitude MF and meteor radars during CADRE: Evidence for gravity wave/tidal interactions  

NASA Astrophysics Data System (ADS)

MF and meteor radar data from four equatorial and subtropical sites (Hawaii, Christmas Island, Jakarta, and Adelaide) are used to examine diurnal tide amplitude and phase variability at mesosphere and lower thermosphere altitudes. All sites exhibit significant seasonal variability, with the largest amplitude fluctuations occurring at Hawaii and Adelaide. Shorter-term variability is found to occur primarily on timescales of ˜5 to 30 days. Amplitude and phase fluctuations are well correlated among different sites on occasion, but in general, the amplitude and phase coherences are low and suggest significant local influences on the tidal structures. The temporal behavior of height variations of the diurnal tide amplitude and phase is also examined. Cross correlations and cross spectra of these tidal parameters, especially between the amplitude and phase, are examined closely. The tendency for phase maxima to lead amplitude maxima is consistent with tidal modulation of gravity wave propagation and momentum fluxes, with a corresponding feedback by the gravity wave momentum flux divergences on the observed tidal structures. These results substantially extend previous more limited studies of gravity wave/tidal interactions and provide a statistical basis for the possible importance of this interaction and its influences on the diurnal tidal structure.

Nakamura, T.; Fritts, D. C.; Isler, J. R.; Tsuda, T.; Vincent, R. A.; Reid, I. M.

1997-11-01

234

X-RAY, FUV, AND UV OBSERVATIONS OF {alpha} CENTAURI B: DETERMINATION OF LONG-TERM MAGNETIC ACTIVITY CYCLE AND ROTATION PERIOD  

SciTech Connect

Over the last couple of decades we have been carrying out a study of stellar magnetic activity, dynamos, atmospheric physics, and spectral irradiances from a sample of solar-type G0-5 V stars with different ages. One of the major goals of this program is to study the evolution of the Sun's X-ray through NUV spectral irradiances with age. Of particular interest is the determination of the young Sun's elevated levels of high-energy fluxes because of the critical roles that X-ray (coronal) through FUV (transition region (TR), chromospheric) emissions play on the photochemical and photoionization evolution (and possible erosion) of early, young planetary atmospheres and ionospheres. Motivated by the current exoplanetary search missions (such as Kepler and CoRoT, along with the planned Space Interferometry Mission and Darwin/Terrestrial Planet Finder missions) that are hunting for Earth-size planets in the habitable zones (liquid water) of nearby main-sequence G-M stars, we are expanding our program to cooler, less luminous, but very importantly, much more numerous main-sequence K-type stars, such as {alpha} Centauri B. The long life (2-3x longer than the Sun) and slow evolution of K stars provide nearly constant energy sources for possible hosted planets. This program parallels our 'Sun in Time' program, but extends the study to stars with deeper convective zone depths. Presented here are X-ray (coronal; ROSAT, Chandra, XMM-Newton), UV (TR; International Ultraviolet Explorer (IUE)), NUV (chromospheric; IUE), and recently acquired FUV (TR/chromospheric; FUSE Cycles 7/8) observations of the K1 V star {alpha} Cen B (HD 128621; V = 1.33; (B - V) = +0.88; {tau} = 5.6 {+-} 0.6 Gyr). These combined high-energy measures provide a more complete look into the nature of {alpha} Cen B's magnetic activity and X-ray-UV radiances. We find that {alpha} Cen B has exhibited significant long-term variability in X-ray through NUV emission fluxes, indicating a solar-like long-term activity cycle of P{sub cycle} = 8.84 {+-} 0.4 years. In addition, analysis of the short-term rotational modulation of mean light due to the effects of magnetically active regions has yielded a well-determined rotation period of P{sub rotation} = 36.2 {+-} 1.4 days. {alpha} Cen B is the only old main-sequence K star with a reliably determined age and rotation period, and for early K stars, as in the case of the Sun for G2 V stars, is an important calibrator for stellar age/rotation/activity relations.

DeWarf, L. E.; Guinan, E. F.; Datin, K. M., E-mail: Laurence.DeWarf@Villanova.ed [Department of Astronomy and Astrophysics, Villanova University, 800 Lancaster Avenue, Villanova, PA 19085 (United States)

2010-10-10

235

Dynamics and evolution of tree populations and soil-vegetation relationships in Fogscapes: Observations over a period of 14 years at the experimental sites of Meija (Peru).  

NASA Astrophysics Data System (ADS)

The Fogscapes, i.e. fog-dependent landscapes, and the sub mountain drylands of the Pacific Coast from Ecuador to Northern Chile are amongst the most fragile regions of the planet. The so-called "Lomas" (i.e. Hills) ecosystems are characterised by pre-desertic flora and vegetation where the plant phenological pattern coincides with the fog season from June to December every year. The occurance of ENSO (El Niño Southern Oscillation) affects these ecosystems inducing, occasionally, a sudden change in the characteristics of the vegetation. Relics of low-density woodlands dominated by Caesalpinea spinosa and scattered trees of the same species (which during the fog season appear as savannah-like ecosystems) are still present but becoming increasingly rare due to past and present overgrazing In the experimental site of Las Cuchillas, located on the coastal hills close to Meija (Dept. Arequipa, South Peru) trees of native species (Caesalpinaea spinosa and Prosopis pallida) and exotic species (Acacia saligna, Casuarina equisetifolia, Parkinsonia aculeata) were planted in 1996, in order to look at the rehabilitation potential of the degraded "lomas" ecosystems. This paper deals with the results observed over a period of 14 years’ of tree growth patterns and the related results concerning the soil and habitat dynamics. Among indigenous species Caesalpinea spinosa shows the heighest rate of survival even if the height increment is low and the tree crowns tend to dry out at a height of approximately two metres, followed by the appearance of new shoots produced during the course of the seasons. The exotic Acacia saligna shows the maximum height, diameter and crown volume increments. The habitat conditions, both in term of diversity / frequency of plant and animal populations, and plant cover (LAI estimated by processing fish-eye lens images) have changed substantially over the years. A number of samples from the top mineral soil and random samples from the forest floor were collected both from the reforested test site and from the adjacent control areas were no trees had been planted. The samples were analysed for organic carbon and total nitrogen. Overall, the tree-covered soil retained much more of both elements than the non-forested areas, thus demonstrating the efficiency of the intervention carried out in terms of combatting the greenhouse effect. The various tree species planted, however, showed greatly variable capacity to promote carbon sequestration at soil level. The results referred to above are critical in understanding the plant population dynamics of pre-desertic ecosystems in response to climate change and in assessing the potential of reforestation programmes and landscape conservation strategies for the purposes of carbon sequestration.

Salbitano, F.; Calamini, G.; Certini, G.; Ortega, A.; Pierguidi, A.; Villasante, L.; Caceres, R.; Coaguila, D.; Delgado, M.

2010-07-01

236

Suggestion Reduces the Stroop Effect  

Microsoft Academic Search

ABSTRACT—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 about 45% of the variance in Stroop responding,

Amir Raz; Irving Kirsch; Jessica Pollard; Yael Nitkin-kaner

2006-01-01

237

PEC: Period Error Calculator  

NASA Astrophysics Data System (ADS)

The PEC (Period Error Calculator) algorithm estimates the period error for eclipsing binaries observed by the Kepler Mission. The 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. A simple C implementation of the PEC algorithm is available.

Mighell, Kenneth J.

2013-04-01

238

Types of Suggestibility: Relationships Among Compliance, Indirect, and Direct Suggestibility  

Microsoft Academic Search

It is commonly believed that direct suggestibility, referring to overt influence, and indirect suggestibility, in which the intention to influence is hidden, correlate poorly. This study demonstrates that they are substantially related, provided that they tap similar areas of influence. Test results from 103 students, 55 women and 48 men, were entered into regression analyses. Indirect suggestibility, as measured by

Romuald Polczyk; Tomasz Pasek

2006-01-01

239

Climatology of short-period gravity waves observed over northern Australia during the Darwin Area Wave Experiment (DAWEX) and their dominant source regions  

Microsoft Academic Search

The Darwin Area Wave Experiment (DAWEX) was designed to investigate the generation and propagation of gravity waves from intense regions of localized convection that occur regularly over northern Australia (in the vicinity of Darwin) during the premonsoon period. This multinational program was conducted during the austral spring 2001 using a range of coordinated optical, radar, and in situ balloon measurements.

P.-D. Pautet; M. J. Taylor; A. Z. Liu; G. R. Swenson

2005-01-01

240

Observation of backward effective third-harmonic generation by cascading completely quasi-phase-matched backward second-harmonic and sum-frequency generation in periodically-poled potassium titanyl phosphate waveguide  

Microsoft Academic Search

Summary form only given. Recently, we achieved backward second-harmonic generation (SHG) in periodically-poled bulk LiNbO3 (PPLN). We have improved the conversion efficiency by about an order of magnitude by using long laser pulses. Here, we report our new results of backward SHG by using periodically-poled potassium titanyl phosphate (PPKTP) waveguide. More importantly, we report our results on first observation of

Xinhua Gu; M. Makarov; Y. J. Ding; J. B. Khurgin; W. P. Risk

1999-01-01

241

Field and laboratory observations of spawning periodicity and behavior of a northern population of the Atlantic silverside, Menidia menidia (Pisces: Atherinidae)  

Microsoft Academic Search

Synopsis  The spawning periodicity and mating behavior of a northern population of the Atlantic silverside, Menidia menidia, was studied both in the field (Salem Harbor, Massachusetts) and in laboratory experiments. Spawning in the field coincided\\u000a with new and full moons. Under conditions of unlimited food availability in artificial outdoor pools that received natural\\u000a celestial illumination or in indoor aquaria receiving no

David O. Conover; Boyd E. Kynard

1984-01-01

242

Enhancement and depletion of lower/middle tropospheric ozone in Senegal during pre-monsoon and monsoon periods of summer 2008: observations and model results  

NASA Astrophysics Data System (ADS)

During the summer (8 June through 3 September) of 2008, nine ozonesondes are launched from Dakar, Senegal (14.75° N, 17.49° W) to investigate the impact of the Saharan Dust Layer (SAL) on ozone (O3) concentrations in the lower troposphere. Results during June (pre-monsoon period) show a reduction in O3, especially in the 850-700 hPa layer with SAL events. However, O3 concentrations are increased in the 950-900 hPa layer where the peak of the inversion is found and presumably the highest dust concentrations. We use the WRF-CHEM model to explore the causes of elevated O3 concentrations that appear to have a stratospheric contribution. During July and August (monsoon period), with the exception of one SAL outbreak, vertical profiles of O3 are well mixed with concentrations not exceeding 55 ppb between the surface and 550 hPa. In the transition period between 26 June and 2 July lower tropospheric (925-600 hPa) O3 concentrations are likely enhanced by enhanced biogenic NOx emissions from the Saharan desert and Sahelian soils following several rain events on 28 June and 1 July.

Jenkins, G. S.; Ndiaye, S.; Gueye, M.; Fitzhugh, R.; Smith, J. W.; Kebe, A.

2011-03-01

243

Suggestions for Early Motion Picture Research.  

ERIC Educational Resources Information Center

|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…

Jowett, Garth S.

244

Three-field photometer observations of short-period gravity wave intrinsic parameters in the 80 to 100 km height region  

NASA Astrophysics Data System (ADS)

A three-field photometer (3FP) for making observations of airglow in the Mesosphere Lower Thermosphere (MLT) region has been operated at the center of the large MF aerial array located near Adelaide (138°E, 35°S) since 1993. Observations of the 557.7 nm airglow intensity emitted by atomic oxygen (OI) at heights near 97 km and the 730.0 nm airglow intensity emitted by hydroxyl (OH) near 87 km have been made simultaneously with MF spaced antenna observations of wind velocities in the 80-100 km height region. The 3FP measures the intensity of the 557.7 nm airglow in three fields separated by about 13 km at heights near 97 km, and then the intensity of the 730 nm airglow in three fields separated by about 12 km at heights near 87 km, on a 60 s cycle. These data have been analyzed to yield gravity wave observed phase speeds and horizontal wavelengths. Simultaneous MF radar data have been analyzed to yield measurements of the neutral wind velocity in 2 km height steps in the 80-100 km height interval every 2 min, and these have been used together with the observed wave parameters to calculate intrinsic gravity wave parameters. This paper presents a very brief overview of the system, the motivation for the work, and preliminary analysis of the data from 1995 until 2000.

Reid, I. M.; Woithe, J. M.

2005-11-01

245

The quality of suggested memories  

Microsoft Academic Search

Alarge number of studies have demonstrated that participants could be led to report suggested events that were never witnessed (Loftus & Palmer, 1974). The present study attempts to explore the quality of such suggested memories. Thirty?six participants were exposed to a live event of brief duration (20 s). They were then misled about certain aspects of the event. Memory was assessed

Vanita Sondhi; Ashum Gupta

2007-01-01

246

Study of the blazar AO 0235+164 during the multi-wavelength observation period from October 2008 to February 2009  

NASA Astrophysics Data System (ADS)

AO 0235+164 is one of the most studied and monitored BL Lac objects in the sky. Since the launch of Fermi, the source has been monitored in the gamma-ray band by Fermi Large Area Telescope. Starting in October 2008, AO 0235+164 showed an increasing activity in gamma-rays that led to a multi-wavelength campaign with instruments in the radio, near-infrared, optical, UV and X-ray bands. We present here the results of the analysis of the multi-wavelength data collected during the flaring period: the high variability properties of this source and the SED built from radio frequencies to gamma-rays are shown, and are interpreted in the context of well-known blazar emission models [Ackermann, M. et al. 2012, ApJ 751, 159].

Rainò, S.; Madejski, G.; do Couto e Silva, E.; Gargano, F.; Reyes, L.; Nalewajko, K.; Sikora, M.

2013-06-01

247

The impact of systemic vascular resistance on the accuracy of the FloTrac/Vigileo™ system in the perioperative period of cardiac surgery: a prospective observational comparison study.  

PubMed

FloTrac/Vigileo™ system is based on arterial pressure waveform analysis arterial pressure-based CO (APCO). Therefore, systemic vascular resistance (SVR) can influence the accuracy of APCO. The purpose of this study is to evaluate the relationship between SVR and the accuracy of APCO. We managed 50 consecutive patients in the perioperative period of cardiac surgery with FloTrac/Vigileo™ system (v. 3.02) and Swan-Ganz catheter/Vigilance™ system pulmonary artery catheter-based CO (PAC-CO) simultaneously. Continuous hemodynamic measurement using both methods was performed every 20 s from the induction of anesthesia to PAC removal 4 h after extubation. A total of 11,092 (intraoperative), 38,455 (postoperative, pre-extubation), and 44,235 (postoperative, post-extubation) data pairs were finally analyzed. Bland-Altman analysis revealed that in the intraoperative [postoperative pre-extubation, post-extubation] period, the bias was 0.5 [0.1, 0.0] L/min and the limits of agreement ranged from -2.4 to 3.3 [-2.2 to 2.4, -2.4 to 2.3] L/min. The percentage error was 60.3 [54.5, 48.5] %. Regression analysis of the systemic vascular resistance index (SVRI) and the bias between APCO and PAC-CO showed that the bias was positively correlated to the SVRI. Subanalysis based on SVR with Lin's concordance correlation coefficient revealed that relatively satisfactory concordance was found in the normal-SVR group (concordance correlation coefficient ? c = 0.51-0.56) regardless of vasoactive agent use. The accuracy of the FloTrac/Vigileo™ System (v. 3.02) is relatively satisfactory in the condition with normal SVR regardless of vasoactive agent use. Positive correlation between the bias and SVR can be the clue to the more effective use of FloTrac/Vigileo™ system. PMID:23748600

Sotomi, Yohei; Iwakura, Katsuomi; Higuchi, Yoshiharu; Abe, Kazuo; Yoshida, Junko; Masai, Takafumi; Fujii, Kenshi

2013-06-01

248

Current Research: Summer Reading Suggestions  

NSDL National Science Digital Library

To supplement your summer reading, NSTA's affiliates would like to suggest some recent articles on education research. These articles cover a variety of topics that include diversity, technology, and science teacher retention. The abstracts of these impor

2009-07-01

249

Observations of GW\\/TID oscillations in the F2 layer at low latitude during high and low solar activity, geomagnetic quiet and disturbed periods  

Microsoft Academic Search

Ionospheric vertical sounding observations, using a digital ionosonde, are being carried out on a routine basis at Sao Jose dos Campos (23.2°S, 45.9°W; dip latitude 17.6°S, hereafter referred to as SJC), Brazil, located under the southern crest of the equatorial ionization anomaly (EIA), since August 2000. In this paper, we present and discuss the seasonal variation of gravity wave (GW)

V. Klausner; P. R. Fagundes; Y. Sahai; C. M. Wrasse; V. G. Pillat; F. Becker-Guedes

2009-01-01

250

The spectrum and light curve of Mrk-501 during its low activity period from 1998 2000 as observed with the HEGRA Cherenkov telescope CT1  

NASA Astrophysics Data System (ADS)

The BL Lac Object Mrk-501 was observed during its low activity state in the years 1998 until 2000 with the Cherenkov telescope CT1 of the HEGRA-Collaboration. Part of the data were also taken during moonshine thus providing a nearly continuous coverage for this object in the TeV-range. Preliminary results for the spectrum and light curve will be presented.

Siems, M.; Mang, O.; Schilling, M.

2001-08-01

251

Space-nadir observations of formaldehyde columns in the 1995-2008 period and their use for inferring NMVOC emissions through inverse modelling.  

NASA Astrophysics Data System (ADS)

Non-methane volatile organic compounds (NMVOCs) of both natural and anthropogenic origin play an important role in the formation of tropospheric ozone. Despite recent efforts to improve existing databases of NMVOC emissions, large uncertainties still remain mainly due to the diversity of the sources and the complexity of the mechanisms involved. Satellite observations of formaldehyde (CH2O) provide useful information to test and improve bottom-up inventories of NMVOC emissions because CH2O is an intermediate product in the oxidation of a large number of NMVOCs and its lifetime is only a few hours. Since 1995, global distributions of CH2O columns have been retrieved from the GOME, SCIAMACHY, OMI and GOME-2 UV-Vis nadir sounders. The retrieval of CH2O by differential absorption spectroscopy (DOAS) is challenging mainly due to the overall faintness of the CH2O signal, but also due to uncertainties in the calculation of air mass factors. To ensure the coherence of long time series of observations based on the combination of different satellite sounders, retrieval settings must be homogenized while taking into account instrumental specificities and eventual limitations of each sounder. Currently, one of the main limitations of the CH2O retrieval from UV-Vis satellites is the random error of the slant column. For single pixels, this error dominates the other sources of uncertainty. It can be reduced by averaging a large number of observations and to this regard, new instruments like OMI and GOME-2, which offer a much better global coverage of the earth, have the capacity to improve the statistics on the CH2O columns and to allow for more selective cloud screening. Recent achievements but also problems and limitations of the currently available sounders are highlighted. This points to the need for improved satellite instruments, both from LEO and GEO orbital configurations. We finally illustrate the potential of satellite CH2O observations for the inverse modelling of NMVOCs emissions, based on the use of the IMAGESv2 global tropospheric chemistry transport model. Results are shown for biogenic and pyrogenic emissions of VOCs. Anthropogenic emissions are currently more difficult to constrain because of the low signal to noise ratio of the CH2O columns in polluted regions. We discuss the interest and potential of combining CH2O observations with glyoxal measurements from the same sensors.

de Smedt, I.; van Roozendael, M.; Lerot, C.; Müller, J.-F.; Stavrakou, T.; Kurosu, T.; Wittrock, F.

2009-04-01

252

CONSTRAINTS ON LONG-PERIOD PLANETS FROM AN L'- AND M-BAND SURVEY OF NEARBY SUN-LIKE STARS: OBSERVATIONS  

SciTech Connect

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.

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

253

Periodicity analysis of Jovian quasi-periodic radio bursts based on Lomb-Scargle periodograms  

NASA Astrophysics Data System (ADS)

The Jovian polar magnetosphere has relativistic particle accelerations with quasi-periodicity (hereafter QP accelerations) that are accompanied by periodic auroral emissions and low-frequency radio bursts called quasi-periodic (QP) bursts. Some previous observations suggested a possible physical relationship between the QP accelerations and QP radio bursts. However, the cause of the QP accelerations has not been revealed yet. This study investigated the generation process of QP radio bursts that constrain the QP acceleration process. The statistical features of QP bursts' periodicity were investigated by applying Lomb-Scargle periodogram analysis to the variations of the QP bursts' spectral densities observed by the Galileo and Ulysses spacecraft. The Lomb-Scargle analysis revealed remarkable characteristics: QP bursts have statistically large amplitudes with periods of 30-50 min at all latitudes. This result suggests that 30-50 min is an "eigenfrequency" of the QP accelerations which is close to the 45 min periodicity of the pulsating X-ray hot spot in the polar cap region. In addition, it was also revealed that successive pulses sometimes exhibit periodicity transition. We discussed one possible scenario which links Jovian periodic accelerations to those in the terrestrial magnetosphere. The scenario is that particles are energized within the period of the dispersive Alfvén waves with field-aligned electric fields that obliquely propagate between the northern and southern ionospheres. The observed eigenfrequency and periodicity transition of QP bursts are consistent with the Alfvénic acceleration scenario.

Kimura, Tomoki; Tsuchiya, Fuminori; Misawa, Hiroaki; Morioka, Akira; Nozawa, Hiromasa; Fujimoto, Masaki

2011-03-01

254

Revisiting the Brazilian scenario of registry and protection of cultivars: an analysis of the period from 1998 to 2010, its dynamics and legal observations.  

PubMed

During the last 20 years, the national production of grains has increased 156.1%; productivity increased 93.8% and there has been an increase of 29.1% in cultivated area. Currently, agribusiness is responsible for 40% of Brazilian exports. Nevertheless, there is little quantitative information on the main plant species of economic interest that have been registered and protected in the Agriculture, Fisheries and Food Supply Ministry (MAPA) by public and private companies, as well as by public-private partnerships. Consequently, we investigated the registry and protection of 27 species of economic interest, including the 15 that are the basis of the Brazilian diet, based on the information available on the site CultivarWeb, of MAPA, for the period from 1998 to August 30, 2010. We also examined the legislation that regulates registration and protection procedures and its implications for plant breeding and plant product development. It was found that the private sector controls 73.1% of the registrations and 53.56% of the protections, while 10.73% of the protections were of material developed overseas. Public-private partnerships contributed little to the development of new cultivars, with 0.5% of the registries and 3.61% of the protections. We conclude that plant protection directed private investment to development of wheat and rice varieties, with the greatest public investments directed to corn and sorghum. After the Cultivar Protection Law was implemented, there was restriction of access to germplasm banks, which could inhibit advances in Brazilian plant breeding programs, indicating a need for revision of this legal barrier. PMID:21563073

Marinho, C D; Martins, F J O; Amaral, S C S; Amaral Júnior, A T; Gonçalves, L S A; de Mello, M P

2011-05-03

255

Estimation of radial gradients of phase space density from POLAR observations during a quiet period prior to a sudden solar wind dynamic pressure enhancement  

NASA Astrophysics Data System (ADS)

We have analyzed POLAR electron flux data to estimate the radial gradients of electron phase space density (PSD) immediately prior to a sudden solar wind dynamic pressure enhancement at ˜1135 UT on 12 August 2001. In this event, the instantaneous flux changes from the magnetospheric compression at L ˜ 7.6 in the postmidnight magnetic local time sector are observed to be both energy and pitch angle (PA) dependent: a substantial flux increase for lower energies (<˜200 keV) particularly at smaller local PA (<˜50°) and a large flux decrease for relativistic energies that is more pronounced for a larger PA. For this event, because of the extremely steady and quiet solar wind conditions prior to the pressure impact, we can reasonably assume that the temporal variation is negligible and so deduce the spatial and pitch angle distribution of initial electron fluxes to construct the event-specific electron flux model for a localized region of the nightside outer radiation belt. PSD radial profiles are then estimated for 6.5 < L < 8.5 using the constructed electron flux model and Tsyganenko magnetospheric model for quiet times. The estimates show a positive PSD gradient for low energies (<˜a few 100 s keV at the POLAR location right after the pressure impact) and a negative gradient for relativistic energies. In addition, a rather gradual transition of the radial gradient from highly positive to more negative is found with increasing energy. The expected immediate flux responses using these estimated PSD radial gradients are qualitatively consistent with those observed, partially validating the veracity of the estimated profiles.

Kim, H.-J.; Zesta, E.; Kim, K.-C.; Shprits, Y.; Shi, Y.; Lyons, L. R.

2010-12-01

256

10 Suggestions for Enhancing Lecturing  

ERIC Educational Resources Information Center

Criticism of the lecture method remains a staple of discussion and writing in academia--and most of the time it's deserved! Those interested in improving this aspect of their teaching might wish to consider some or all of the following suggestions for enhancing lectures. These include: (1) Lectures must start with a "grabber"; (2) Lectures must be…

Heitzmann, Ray

2010-01-01

257

Spontaneous and Suggested Posthypnotic Amnesia.  

National Technical Information Service (NTIS)

The investigation was carried out to obtain comparable figures on the prevalence of spontaneous and suggested posthypnotic amnesia. Ninety-one introductory psychology students were randomly assigned to 1 of 2 groups, and were required to serve as Ss for t...

E. R. Hilgard L. M. Cooper

1965-01-01

258

A suggestion for the IRS  

Microsoft Academic Search

Suggests that private psychology practitioners, hospitals, and psychological centers should be allowed to deduct discounts given to clients who are unable to pay or who are unable to pay the full fee. Currently, the Internal Revenue Service (IRS) does not permit such deductions. (0 ref)

William P. Hill

1971-01-01

259

Suggestions for Library Network Design.  

ERIC Educational Resources Information Center

Various approaches to the design of automatic library systems are described, suggestions for the design of rational and effective automated library processes are posed, and an attempt is made to assess the importance and effect of library network systems on library operations and library effectiveness. (Author/CWM)

Salton, Gerald

1979-01-01

260

The upcoming apparition of Periodic Comet de Vico (1846 IV)  

NASA Astrophysics Data System (ADS)

Periodic Comet de Vico was last seen in 1846; it eluded observation at its expected 1921-22 passage but is due back soon. Discussed here is the history of the comet, various orbital calculations, search suggestions, and search ephemerides.

Machholz, Don

1994-10-01

261

Period Cramps  

MedlinePLUS

... ago. She's learned to handle using pads and tampons, but the cramps are really bothering her. Sometimes ... THIS TOPIC Do Periods Ever End? Pads and Tampons How Do Pain Relievers Work? Five Things Girls ...

262

Periodic Pegboard  

NSDL National Science Digital Library

In this activity, learners use pegboard and straws to build a three-dimensional model of the periodic table. This model helps learners visualize trends in the chemical properties of the elements, including electronegativity, ionization energy, atomic radii, and mass.

Johnsen, Jill

2006-01-01

263

SUGGESTIONS FOR CALCULATING NEST SUCCESS  

Microsoft Academic Search

Reports of nesting success that do not take into account the time span of observation for each nest usually understate losses, and sometimes the error can be very large. More than a decade ago I pointed out this problem and proposed a way of dealing with it (Mayfield 1960:192-204; 1961). Since that time many field students have used the method,

HAROLD F. MAYFIELD

1975-01-01

264

Period Variations of RT Persei  

NASA Astrophysics Data System (ADS)

RT Per has been known as a close binary of which the orbital period has unpredictably varied so far. Although there are no agreements with the working mechanism for the changes of the period, two interpretations have been suggested and waiting for to be tested: 1)light-time effects due to the unseen 3rd and 4th bodies(Panchatsaram 1981), 2)Abrupt period-change due to internal variations of the system(e.q. mass transfer or mass loss) superimposing to the light-times effect by a 3rd body(Frieboes-Conde&Herczeg 1973). In the point of view that the former interprepation models could predict the behavior of the changes of the orbital period theoretically, we checked whether the recent observed times of minimum lights follow the predictions by the first model or not. We confirmed that the observed times of minimum lights have followed the variations calculated by the light-times effects due to 3rd and 4th bodies suggested by Panchatsaram. In this paper a total of 626 times of minimum lights were reanalyzed in terms of the light-time effects by the 3rd and 4th bodies. We concluded that the eclipsing pair in SV Cam system moves in an elliptic orbit about center of mass of the triple system with a period of about 42.y2, while the mass center of the triplet is in light-time orbit about the center of mass of the quadruple system with a period of 120y. The mean masses deduced for the 3rd and 4th bodies were 0.89m and 0.82m , respectively.

Kim, Chun-Hwey

1995-12-01

265

Annual water-level measurements in observation wells, 1951-1955, and atlas of maps showing changes in water levels for various periods from beginning of record through 1954, New Mexico  

USGS Publications Warehouse

This report tabulates the annual measurements of water level in the observation wells in the various irrigated areas, primarily from 1951 through 1955. It summarizes changes in water level by discussion and with an atlas of nearly all the maps of change of water level for the period of record to 1955 for each area in which observations are being made. Included also are hydrographs for the period of record through 1954 of several selected wells in the various areas irrigated from ground-water sources. The annual measurements of water level before 1951, seasonal measurements, and daily records of water levels in wells equipped with recording gages have been published in an annual series of U. S. Geological Survey water-supply papers.

Reeder, Harold O.

1959-01-01

266

Unstationary aspects of foehn in a large valley part I: operational setup, scientific objectives and analysis of the cases during the special observing period of the MAP subprogramme FORM  

Microsoft Academic Search

Summary  The Rhine valley, which stretches from the main Alpine crest to the Lake of Constance, was chosen as the target area to study\\u000a unstationary aspects of foehn during the Special Observing Period (SOP) of the Mesoscale Alpine Programme (MAP). This large\\u000a valley is up to 10?km wide and has some of the highest foehn frequencies in the European Alps. The

H. Richner; K. Baumann-Stanzer; B. Benech; H. Berger; B. Chimani; M. Dorninger; P. Drobinski; M. Furger; S. Gubser; T. Gutermann; C. Häberli; E. Häller; M. Lothon; V. Mitev; D. Ruffieux; G. Seiz; R. Steinacker; S. Tschannett; S. Vogt; R. Werner

2006-01-01

267

Size distribution, shape, and composition of mineral dust aerosols collected during the African Monsoon Multidisciplinary Analysis Special Observation Period 0: Dust and Biomass-Burning Experiment field campaign in Niger, January 2006  

Microsoft Academic Search

Dust samples were collected onboard the UK community BAe-146 research aircraft of the Facility for Airborne Atmospheric Measurements (FAAM) operated over Niger during the winter Special Observation Period of the African Monsoon Multidisciplinary Analysis project (AMMA SOP0\\/DABEX). Particle size, morphology, and composition were assessed using single-particle analysis by analytical scanning and transmission electron microscopy. The aerosol was found to be

Cédric Chou; Paola Formenti; Michel Maille; Patrick Ausset; Günter Helas; Mark Harrison; Simon Osborne

2008-01-01

268

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.

269

Studies Suggest Exercise Improves Colorectal Cancer Outcomes  

Cancer.gov

The results of two new prospective, observational studies offer compelling evidence to suggest that regular physical activity in the months following treatment may decrease the risk of cancer recurrence and death from colorectal cancer, according to the Aug. 1, 2006, issue of the Journal of Clinical Oncology.

270

The functional anatomy of suggested limb paralysis.  

PubMed

Suggestions of limb paralysis in highly hypnotically suggestible subjects have been employed to successfully model conversion disorders, revealing similar patterns of brain activation associated with attempted movement of the affected limb. However, previous studies differ with regard to the executive regions involved during involuntary inhibition of the affected limb. This difference may have arisen as previous studies did not control for differences in hypnosis depth between conditions and/or include subjective measures to explore the experience of suggested paralysis. In the current study we employed functional magnetic resonance imaging (fMRI) to examine the functional anatomy of left and right upper limb movements in eight healthy subjects selected for high hypnotic suggestibility during (i) hypnosis (NORMAL) and (ii) attempted movement following additional left upper limb paralysis suggestions (PARALYSIS). Contrast of left upper limb motor function during NORMAL relative to PARALYSIS conditions revealed greater activation of contralateral M1/S1 and ipsilateral cerebellum, consistent with the engagement of these regions in the completion of movements. By contrast, two significant observations were noted in PARALYSIS relative to NORMAL conditions. In conjunction with reports of attempts to move the paralysed limb, greater supplementary motor area (SMA) activation was observed, a finding consistent with the role of SMA in motor intention and planning. The anterior cingulate cortex (ACC, BA 24) was also significantly more active in PARALYSIS relative to NORMAL conditions - suggesting that ACC (BA 24) may be implicated in involuntary, as well as voluntary inhibition of prepotent motor responses. PMID:23351848

Deeley, Quinton; Oakley, David A; Toone, Brian; Bell, Vaughan; Walsh, Eamonn; Marquand, Andre F; Giampietro, Vincent; Brammer, Michael J; Williams, Steven C R; Mehta, Mitul A; Halligan, Peter W

2012-12-21

271

Suggestion in the treatment of depression.  

PubMed

Meta-analyses consistently reveal that most of the response to antidepressant treatment can be obtained by placebo, and the difference between response to the drug and the response to any treatment is not clinically significant for most individuals diagnosed with major depressive disorder. Furthermore, the best predictor of antidepressant efficacy is the response to placebo during the so-called placebo run-in period. It can also be shown that a significant portion of the placebo effect is expectancy. These data thus indicate that suggestion is a central factor in treating depression. Therefore, the use of hypnosis, which is based on suggestion, as a treatment adjunct can be expected to enhance treatment outcome. PMID:23488249

Kirsch, Irving; Low, Carol B

2013-01-01

272

Periodic Polymers  

NASA Astrophysics Data System (ADS)

Periodic polymers can be made by self assembly, directed self assembly and by photolithography. Such materials provide a versatile platform for 1, 2 and 3D periodic nano-micro scale composites with either dielectric or impedance contrast or both, and these can serve for example, as photonic and or phononic crystals for electromagnetic and elastic waves as well as mechanical frames/trusses. Compared to electromagnetic waves, elastic waves are both less complex (longitudinal modes in fluids) and more complex (longitudinal, transverse in-plane and transverse out-of-plane modes in solids). Engineering of the dispersion relation between wave frequency w and wave vector, k enables the opening of band gaps in the density of modes and detailed shaping of w(k). Band gaps can be opened by Bragg scattering, anti-crossing of bands and discrete shape resonances. Current interest is in our group focuses using design - modeling, fabrication and measurement of polymer-based periodic materials for applications as tunable optics and control of phonon flow. Several examples will be described including the design of structures for multispectral band gaps for elastic waves to alter the phonon density of states, the creation of block polymer and bicontinuous metal-carbon nanoframes for structures that are robust against ballistic projectiles and quasi-crystalline solid/fluid structures that can steer shock waves.

Thomas, Edwin

2013-03-01

273

Post-equinox periodicities in Saturn's energetic electrons  

NASA Astrophysics Data System (ADS)

Since Saturn's vernal equinox in August 2009 (day 223), energetic electrons (110-365 keV) have exhibited a variety of periodic and aperiodic behavior within a spectral window of 5-15 hours. From late 2009 through the end of 2010, when the observed at dusk, a single period near 10.7 hours dominated the Lomb spectra of these particles. Near the end of 2010, however, the energetic electrons displayed multiple periods, with the strongest at 10.65 hours. The periodicity observed after equinox has a mean value of 10.69 ± 0.06 hours and agreed closely with that of Saturn kilometric radio (south) emissions. By early 2011, when the observer had moved to the dayside, the periodicities abruptly disappeared and the Lomb spectra show no periodicity. This behavior may suggest changes in Saturn's ionosphere as a result of seasonal change, or may alternately imply a local time dependence of periodicity caused by magnetodisk thickness asymmetry.

Carbary, J. F.; Mitchell, D. G.; Krimigis, S. M.; Krupp, N.

2011-12-01

274

Long-Period Solar Variability  

SciTech Connect

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.

GAUTHIER,JOHN H.

2000-07-20

275

Radio rotation period of jupiter.  

PubMed

The results of observations of Jupiter at 18 megacycles per second indicate that the apparent rotation period drifts cyclically about a constant mean value. The most probable drift period appears to be 11.9 years, Jupiter's orbital period. The mean rotation period during one orbital period is about 0.3 second longer than that of the system III (1957.0) period. This is in close agreement with the rotation period deduced from decimetric observations and probably represents the true rotation period of the magnetic field. The cyclic drift in the rotation period of source A at 18 megacycles per second is explained on the basis of beaming of the escaping radiation at an angle 6 degrees north of the magnetic equator. The apparent rotation period of source A depends on the rate of change of the Jovicentric declination of Earth. PMID:17810304

Gulkis, S; Carr, T D

1966-10-14

276

Unstable periodic orbits in human epileptic activity  

NASA Astrophysics Data System (ADS)

We examine in detail subdural recordings from a patient with an epileptic focal seizure, highly unusual in the ongoing nature of the discharges and in the lack of cognitive impairment. We applied a recent method for detecting unstable periodic orbits to the series of time intervals between successive spike discharges, and report that a few unstable fixed points exist within their apparent random fluctuations. The statistical significance of this underlying deterministic dynamics is assessed using surrogate data. In particular, the approaches of trajectories toward the unstable periodic patterns are observed in the sequences immediately following the perceptual tasks. This suggests that the act of perception contributes in a highly specific manner to pulling the epileptic activities towards particular unstable periodic orbits, which closely resemble the technique called chaos control for stabilization of unstable periodic orbits.

Le van Quyen, Michel; Martinerie, Jacques; Adam, Claude; Baulac, Michel; Varela, Francisco J.

1997-09-01

277

On the pre-main sequence circularization period  

NASA Astrophysics Data System (ADS)

In this paper we present an updated compilation of the currently known pre-main sequence (PMS) spectroscopic binaries (SB) for which orbital elements have been determined. In particular we report our results for and discuss the case of the bona-fide PMS system RX J1603.9-3938, which has a circular orbit and a period of 7.56 days. This is the longest orbital period for a circular orbit found among the bona-fide PMS spectroscopic binaries so far, and we suggest that this system may be thus considered to now set the PMS circularization period. The longer period is compatible with the circularization periods already known for older binary populations such as the Hyades and Praesepe. When considered in the context of the circularization periods for other binary populations of different ages, the new PMS circularization period strongly supports the suggestion of Mathieu et al. (\\cite{M92}) that a hybrid scenario (tidal circularization occurring on both PMS phase and on MS phase) could explain the observed circularization periods as a function of age. The apparently circular orbit observed in another PMS system, RX J1301.0-7654a, with an orbital period of nearly 13 days, may perhaps change this picture when the orbit is improved and the system is better understood. Based on observations carried out at the Swiss Euler Telescope at ESO, La Silla, Chile.

Melo, C. H. F.; Covino, E.; Alcalá, J. M.; Torres, G.

2001-11-01

278

Eu Tauri: An S-cepheid With A Changing Period  

NASA Astrophysics Data System (ADS)

The short period Cepheid EU Tauri ( = HD38321 = HIP27183; V = 7.94) was on the observing program of the Four College Consortium APT for several years. We were observing it based on the suggestion that it was a multimode Cepheid. We obtained approximately 194 UBVRI observations on 112 nights from JD 2448276 through JD 2448988. When EU Tauri was shown to be pulsating in only one mode, both by our observations and those of others, this star was dropped from out observing program. Recently however it has been brought to our attention that short period, s-type Cepheids show period changes over relatively short time scales. We have combined our data with published data extending over 35 years and determined an average period from the entire data set of 2.10248 days. We then used this period to determine the Fourier coefficients for each data subsets in order to find any phase shifts between sets which would be indicative of a changing period. These phase shifts were indicative of such a period change. We also used both our data and a contemporaneous radial velocity set in an attempt to determine the radius of EU Tau. Finally EU Tauri has been returned to the APT observing program. Fall observations will be included in this presentation. This work has been supported by NSF Grants 86-116362, AST-91-15114, and AST-050755 to the College of Charleston.

Boyer, Kirk; Lewandowski, C.; Dukes, R. J., Jr.

2007-12-01

279

California foreshock sequences suggest aseismic triggering process  

NASA Astrophysics Data System (ADS)

Foreshocks are one of the few well-documented precursors to large earthquakes; therefore, understanding their nature is very important for earthquake prediction and hazard mitigation. However, the triggering role of foreshocks is not yet clear. It is possible that foreshocks are a self-triggering cascade of events that simply happen to trigger an unusually large aftershock; alternatively, foreshocks might originate from an external aseismic process that ultimately triggers the mainshock. In the former case, the foreshocks will have limited utility for forecasting. The latter case has been observed for several individual large earthquakes; however, it remains unclear how common it is and how to distinguish foreshock sequences from other seismicity clusters that do not lead to large earthquakes. Here we analyze foreshocks of three M>7 mainshocks in southern California. These foreshock sequences appear similar to earthquake swarms, in that they do not start with their largest events and they exhibit spatial migration of seismicity. Analysis of source spectra shows that all three foreshock sequences feature lower average stress drops and depletion of high-frequency energy compared with the aftershocks of their corresponding mainshocks. Using a longer-term stress-drop catalog, we find that the average stress drop of the Landers and Hector Mine foreshock sequences is comparable to nearby swarms. Our observations suggest that these foreshock sequences are manifestations of aseismic transients occurring close to the mainshock hypocenters, possibly related to localized fault zone complexity, which have promoted the occurrence of both the foreshocks and the eventual mainshock.

Chen, Xiaowei; Shearer, Peter M.

2013-06-01

280

Planetary period oscillations at Saturn  

NASA Astrophysics Data System (ADS)

Saturn's magnetosphere chimes with oscillations at periods close to the planetary rotation period. The oscillatory period changes slowly over time [Galopeau and Lecacheux, 2000; Gurnett et al., 2005, Kurth et al., 2007, 2008], with slightly different periods being observed in the Northern and southern hemispheres [Gurnett et al., 2009a, Lamy, 2011]. Both periods are observed in the equatorial plane [Provan et al., 2011]. This talk aims to explore the periodicity, phase and polarization of magnetic field oscillations on closed and open field lines, and show how these oscillations are related to the variations in the UV auroral power as observed by the Hubble spacecraft [Nichols et al., 2010a], the location of the UV auroral oval [Nichols et al., 2008,2010b, Provan et al., 2009], the position of the magnetopause and bow shock [Clarke et al., 2006, 2010a,b] and the vertical displacement and thickness of Saturn's plasma sheet.

Provan, G.; Andrews, D. J.; Cowley, S. W.

2011-12-01

281

Magnetospheric Periodicities at Saturn Equinox  

NASA Astrophysics Data System (ADS)

For several years before equinox, the energetic charged and neutral particles in Saturn’s magnetosphere displayed strong periodicities near 10.8 hours, the same period observed in radio emissions and magnetic fields. These particle periodicities have now been observed at equinox in electrons, protons, oxygen ions, and neutral hydrogen and oxygen atoms at all energies greater than ~3 keV, the lowest energies measured by the Magnetospheric IMaging Instrument (MIMI) on the Cassini spacecraft. The equinoctial electrons exhibit a very strong period at 10.72 hours, while the protons have essentially no periodicity at all. Water group ions display a notable period at 10.73 hours. Both the electrons and the ions have curious overtones in their spectral structure that may be related to solar wind modulation. The energetic neutral hydrogen and oxygen atoms have strong periods of 10.79 hours at equinox. Within the uncertainties of the measurements, the ENA periods are slightly longer than the charged particle periods, although they cover a somewhat different time interval. For comparison, the Cassini magnetometer observed periodicities in Saturn’s magnetic field of 10.65 hours during the same equinoctial interval. These observations will be interpreted in terms of a wavy magnetodisk model.

Carbary, J. F.; Mitchell, D. G.; Roelof, E.; Paranicas, C.; Krimigis, S. M.; Krupp, N.; Hamilton, D. C.; Dougherty, M. K.

2010-12-01

282

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

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

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

2007-01-01

283

Hypnotic suggestibility predicts the magnitude of the imaginative word blindness suggestion effect in a non-hypnotic context.  

PubMed

The present study investigated how the magnitude the word blindness suggestion effect on Stroop interference depended on hypnotic suggestibility when given as an imaginative suggestion (i.e. not post-hypnotic suggestion) and under conditions in which hypnosis was not mentioned. Hypnotic suggestibility is shown to be a significant predictor of the magnitude of the imaginative word blindness suggestion effect under these conditions. This is therefore the first study to show a linear relationship between the imaginative word blindness suggestion effect and hypnotic suggestibility across the whole hypnotizability spectrum. The results replicate previous findings showing that highs respond to the word blindness suggestion to a greater extent than lows but extend previous work by showing that the advantage for those higher on the hypnotizability spectrum occurs even in a non-hypnotic context. Negative attitudes about hypnosis may not explain the failure to observe similar effects of the word blindness suggestion in less hypnotizable individuals. PMID:23778018

Parris, Benjamin A; Dienes, Zoltan

2013-06-15

284

Periodicities in gamma ray bursts  

SciTech Connect

Gamma ray burst models based on magnetic neutron stars face a problem of account for the scarcity of observed periods. Both this scarcity and the typical period found when any is detected are explained if the neutron stars are accreting in binary systems

Wood, K.S.

1984-05-26

285

Periodic paralysis with cardiac arrhythmia  

Microsoft Academic Search

In 1963, Klein et al. first described two girls with normokalemic periodic paralysis and cardiac arrhythmia. We have observed a 15-year-old girl with cardiac arrhythmia and normokalemia but with some features of hyperkalemic, periodic paralysis. The patient showed a waddling gait and Gower's sign. She had atrophy of the proximal muscles and deep tendon reflexes were reduced. Her ECG showed

T. Yoshimura; M. Kaneuji; T. Okuno; M. Yoshioka; T. Ueda; H. Mikawa; T. Kowata; T. Kamiya

1983-01-01

286

Animal Rights: Selected Resources and Suggestions for Further Study.  

ERIC Educational Resources Information Center

|Presents an annotated list of selected resources intended to serve as a guide to the growing amount of material on animal rights. Suggestions to aid in additional research include subject headings used to find books, indexes used to locate periodical articles, sources for locating organizations, and a selected list of animal rights organizations.…

Davidoff, Donald J.

1989-01-01

287

Suggestions for the Classical Shelves of a School Library.  

ERIC Educational Resources Information Center

This bibliography is suggested for use by students and teachers of Latin, Greek and ancient civilizations. Entries are compiled under the headings of: (1) bibliographies and journals including booklists, periodicals, and books for teachers; (2) reference works in literature, mythology, history and antiquities, and language; (3) texts and…

Colebourn, R., Comp.; Cleeve, Marigold, Comp.

288

Suggestions for the Classical Shelves of a School Library.  

ERIC Educational Resources Information Center

|This bibliography is suggested for use by students and teachers of Latin, Greek and ancient civilizations. Entries are compiled under the headings of: (1) bibliographies and journals including booklists, periodicals, and books for teachers; (2) reference works in literature, mythology, history and antiquities, and language; (3) texts and…

Colebourn, R., Comp.; Cleeve, Marigold, Comp.

289

Ionospheric effects of major magnetic storms during the international space weather period of September and October 1999: GPS observations, VHF/UHF scintillations, and in situ density structures at middle and equatorial latitudes  

NASA Astrophysics Data System (ADS)

In this paper we present a study of the ionospheric effects of a halo coronal mass ejection (CME) initiated on the Sun on September 20, 1999, and causing the largest magnetic storm during this month on September 22-23, 1999, with the hourly Dst index being -167 nT at ~2400 UT on September 22. The recurrent CME on October 18 caused an even larger magnetic storm on October 22, 1999, with Dst of -231 nT at ~0700 UT. The ionospheric effects of these two major magnetic storms are studied through their effects on a prototype of a Global Positioning System (GPS)-based navigation system called Wide Area Augmentation System (WAAS) being developed by the Federal Aviation Administration for use in the continental United States and their impact on global VHF/UHF communication systems. It is shown that the penetration of transient magnetospheric electric fields equatorward of the shielding region at midlatitudes, which have been well-correlated in the past with rapid changes in the well-known Dst index (or through its recently available high resolution 1-min counterpart the SYM-H index), can cause large increases of total electron content (TEC), TEC fluctuations, and saturated 250-MHz scintillation, and these, in turn, may have significant impacts on WAAS. The local time of Dst changes (and not just Dst magnitude) was found to be very important for WAAS, since the largest effects on TEC are seen near dusk. The prompt penetration of these magnetospheric electric fields all the way to the magnetic equator causes augmentation or inhibition of equatorial spread F. The global ionospheric response to these storms has been obtained from ground-based TEC observations with a GPS network and space-based in situ density and electric field measurements using the Republic of China Satellite-1 (ROCSAT-1) and several Defense Meteorological Satellite Program satellites. These prompt penetration electric fields cause VHF/UHF scintillations and GPS TEC variations at low latitudes in the specific longitude sector for which the early evening period corresponds to the time of rapid Dst variations and maximum Dst phase. The effects of the delayed ionospheric disturbance dynamo and those of decreased magnetospheric convection on postmidnight irregularity generation are shown to be confined to a part of the same longitude range that actively responded to the prompt penetration of electric fields in the early evening sector.

Basu, Sunanda; Basu, Santimay; Valladares, C. E.; Yeh, H.-C.; Su, S.-Y.; MacKenzie, E.; Sultan, P. J.; Aarons, J.; Rich, F. J.; Doherty, P.; Groves, K. M.; Bullett, T. W.

2001-12-01

290

Rationalization of Comet Halley's periods  

SciTech Connect

The sense of long axis orientation of Comet Halley during the Vega 1 encounter must be reversed from that deduced by Sagdeev et al. (1986) in order to harmonize the comet nucleus' Vega/Giotto-observed orientations with periodicities extracted from time-series brightness data. It is also demonstrated that Vega/Giotto observations can be satisfied by either a 2.2- or 3.7-day long-axis free precession period. A novel Fourier algorithm is used to reanalyze five independent data sets; strong evidence is adduced for periods harmonically related to a 7.4-day period. The preferred candidate models for Halley's nuclear rotation are characterized by a long-axis precession period of 3.7 days. 79 refs.

Belton, M.J.S. (National Optical Astronomy Observatories, Tucson, AZ (USA))

1990-07-01

291

Are Dual Periodicities at Saturn Really, Really Real?  

NASA Astrophysics Data System (ADS)

Since the discovery of dual periodicities in Saturn's kilometric radiation (SKR), similar dual periods have been putatively observed in energetic charged particles, energetic neutral atoms, low energy plasma, and magnetic field oscillations. Ostensibly, one period (~10.8 hours) derives from a source in the southern hemisphere, while the second period (~10.6 hours) derives from a source in the northern hemisphere. Recent work on SKR, however, has demonstrated that at least southern SKR simultaneously oscillates at both frequencies. Recent work in the magnetic field oscillations further indicates that dual periodicities can sporadically arise from "beating" of Cassini's orbit with the single southern period. A rotating spiral configuration of the plasma sheet can readily produce dual periods in energetic particle data when considered along the Cassini trajectory. Furthermore, solar wind modulation at ~26 days of any "carrier" phenomena at ~10.7 hours will generate a dual frequency spectrum very similar to that observed in the SKR, as well as Saturn's particles and fields. This presentation suggests that Saturn's magnetosphere really has only one fundamental (carrier) period and that dual (or even multiple) periodicities arise when this fundamental is amplitude-modulated by an external driver such as the solar wind, Titan, or even the orbit of Cassini!

Carbary, J. F.

2011-12-01

292

Maltreated Children's Memory: Accuracy, Suggestibility, and Psychopathology  

ERIC Educational Resources Information Center

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…

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

2007-01-01

293

UCG environmental research: summary and suggested projections  

Microsoft Academic Search

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

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

1982-01-01

294

The role of the dwarf nova period distribution in understanding the evolution of cataclysmic variables  

NASA Astrophysics Data System (ADS)

The dwarf nova period distribution is used to constrain the variation of mass transfer with orbital period. For orbital periods above the gap, agreement between the observed dwarf nova period distribution with those constructed from various magnetic braking models is generally poor. The most promising braking law is that of Mestel and Spruit (1987). Under certain conditions this braking law is able to produce a relatively flat M-dot(P) relation, but the braking law is not entirely satisfactory because it offers no explanation for the complete dominance of stable over unstable accretors immediately above the period gap. Speculative ideas are presented that may eventually provide a complete and satisfactory explanation for the lack of dwarf novae with periods between 3 and about 4 hr. It is suggested that the dwarf nova period distribution, and not only the overall period distribution, should be considered when applying observational constraints to theories of mass transfer in cataclysmic variables.

Shafter, Allen W.

1992-07-01

295

Period Determination for 1660 Wood  

NASA Astrophysics Data System (ADS)

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.

Oey, Julian; Alvarez, Eduardo Manuel

2012-07-01

296

Periodically oscillating plasma sphere  

SciTech Connect

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.

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

297

The period variation of DY Hercules  

NASA Astrophysics Data System (ADS)

In this paper the researchers collected 28 times of maximum light including 4 times of those observed at the Xinglong station, the National Astronomical Observation of China between May 27, 2004 and June 1, 2004 and 1 time of maximum light from a 60 cm telescope on May 4, 1984. It found that the O-C point distribution was more completely compared than in any papers published before. The period is decreasing at the rate of about (1.4±0.1)×10-8 per year, which should not be caused by stellar evolution. It might be only part of a binary orbital light-time variation or other unknown reason. The time scale is longer than Pocs and Szeidl’s suggestion; the star needs more observations before we can be certain of the exact light-time variation.

Boonyarak, Chayan; Jiang, Shi Yang

2007-08-01

298

Suggestions for Documenting SOA-Based Systems.  

National Technical Information Service (NTIS)

This report provides suggestions for documenting service-oriented architecture-based systems based on the Views & Beyond (V&B) software documentation approach. The V&B documentation approach is a lightweight and flexible approach to documenting software a...

S. Bellomo

2010-01-01

299

Suggested Minimum Cataloging Standards for Arizona.  

ERIC Educational Resources Information Center

|Notes problems with cataloging library materials in the small and medium sized public library and suggests interpretations of the Anglo-American cataloging rules, with recommendations for their adaptation to smaller libraries. (CWM)|

Scott, Sharon

1979-01-01

300

Suggestions for an Updated Fusion Power Program.  

National Technical Information Service (NTIS)

This document contains suggestions for a revised CTR Program strategy which should allow us to achieve equivalent goals while operating within the above constraints. The revised program is designed around three major facilities. The first is an upgrading ...

J. F. Clarke

1976-01-01

301

Hypnotic suggestion: opportunities for cognitive neuroscience.  

PubMed

Hypnosis uses the powerful effects of attention and suggestion to produce, modify and enhance a broad range of subjectively compelling experiences and behaviours. For more than a century, hypnotic suggestion has been used successfully as an adjunctive procedure to treat a wide range of clinical conditions. More recently, hypnosis has attracted a growing interest from a cognitive neuroscience perspective. Recent studies using hypnotic suggestion show how manipulating subjective awareness in the laboratory can provide insights into brain mechanisms involved in attention, motor control, pain perception, beliefs and volition. Moreover, they indicate that hypnotic suggestion can create informative analogues of clinical conditions that may be useful for understanding these conditions and their treatments. PMID:23860312

Oakley, David A; Halligan, Peter W

2013-07-17

302

Babylonian observations  

NASA Astrophysics Data System (ADS)

Very few cuneiform records survive from Mesopotamia of datable astronomical observations made prior to the mid-eighth century BC. Those that do record occasional eclipses, and in one isolated case the dates of the heliacal rising and setting of Venus over a few years sometime in the first half of the second millennium BC. After the mid-eighth century BC the situation changes dramatically. Incomplete records of daily observations of astronomical and meteorological events are preserved from c. 747 BC until the Christian Period. These records are without accompanying ominous interpretation, although it is highly probable that they were compiled by diviners for astrological purposes. They include numerous observations of use to historical astronomers, such as the times of eclipses and occultations, and the dates of comet appearances and meteor showers. The question arises as to why such records do not survive from earlier times; celestial divination was employed as far back as the third millenium BC. It is surely not without importance that the earliest known accurate astronomical predictions accompany the later records, and that the mid-eighth century BC ushered in a period of centralised Assyrian control of Mesopotamia and the concomitant employment by the Assyrian ruler of large numbers of professional celestial diviners. The programme of daily observations evidently began when a high premium was first set on the accurate astronomical prediction of ominous events. It is in this light that we must approach this valuable source material for historical astronomy.

Brown, D.

303

SEM Microanalysis of Particles: Concerns and Suggestions  

NASA Astrophysics Data System (ADS)

The scanning electron microscope (SEM) is well suited to examine and characterize small (i.e. <10 micron) particles. Particles can be imaged and sizes and shapes determined. With energy dispersive x-ray spectrometers (EDS), chemical compositions can be determined quickly. Despite the ease in acquiring x-ray spectra and chemical compositions, there are potentially major sources of error to be recognized. Problems with EDS analyses of small particles: Qualitive estimates of composition (e.g. stating that Si>Al>Ca>Fe plus O) are easy. However, to be able to have confidence that a chemical composition is accurate, several issues should be examined. (1) Particle Mass Effect: Is the accelerating voltage appropriate for the specimen size? Are all the incident electrons remaining inside the particle, and not traveling out of the sample side or bottom? (2) Particle Absorption Effect: What is the geometric relationship of the beam impact point to the x-ray detector? The x-ray intensity will vary by significant amounts for the same material if the grains are irregular and the path out of the sample in the direction of the detector is longer or shorter. (3) Particle Fluorescence Effect: This is generally a smaller error, but should be considered: for small particles, using large standards, there will be a few % less x-rays generated in a small particle relative to one of the same composition and 50-100 times larger. Also, if the sample sits on a grid of a particular composition (e.g. Si wafer) potentially several % of Si could appear in the analysis. (4) In a increasing number of laboratories, with environmental or variable pressure SEMs, the Gas Skirt Effect is operating against you: here the incident electron beam scatters in the gas in the chamber, with less electrons impacting the target spot and some others hitting grains 100s of microns away, producing spectra that could be faulty. (5) Inclusion of measured oxygen: if the measured oxygen x-ray counts are utilized, significant errors can be introduced by differential absorption of this low energy x-ray. (6) Standardless Analysis: This typical method of doing EDS analysis has a major pitfall: the printed analysis is normalized to 100 wt%, thereby eliminating an important clue to analytical error. Suggestions: (1) Use lower voltage, e.g. 10 kV, reducing effects 1,2,3 above. (2) Use standards--traditional flat polished ones--and don't initially normalize totals. Discrepancies can be observed and addressed, not ignored. (3) Alway include oxygen by stoichometry, not measured. (4) Experimental simulation. Using material of constant composition (e.g. NIST glass K-411, or other homogeneous multi-element material with the elements of interest), grind into fragments of similar size to your unknowns, and see what is the analytical error for measurements of these known particles. Analyses of your unknown material will be no better, and probably worse than that, particularly if the grains are smaller. The results of this experiment should be reported whenever discussing measurements on the unknown materials. (5) Monte Carlo simulation. Programs such PENEPMA allows creation of complex geometry samples (and samples on substrates) and resulting EDS spectra can be generated. This allows estimation of errors for representative cases. It is slow, however; other simulations such as DTSA-II promise faster simulations with some limitations. (6) EBSD: this is a perfectly suited for some problems with SEM identification of small particles, e.g. distinguishing magnetite (Fe3O4) from hematite (Fe2O3), which is virtually impossible to do by EDS. With the appropriate hardware and software, electron diffraction patterns on particles can be gathered and the crystal type determined.

Fournelle, J.

2008-12-01

304

Secular period decreasing of 17 detached chromospherically active binaries  

NASA Astrophysics Data System (ADS)

The long-term orbital period changes of detached chromospheric active binaries were surveyed. 17 of such systems are found to be undergoing secular period decreasing with the rates (dP/dt) of -3.05 × 10-9 to -3.77 × 10-5 days per year. The longer the orbital period, the more rapidly the period decreases. Following Stepien (1995), the period decreasing rate due to the angular momentum loss (AML) caused by magnetic wind is computed for each system. A comparison shows that the observed dP/dt's are obviously higher than that of the theoretical predictions by 1-3 orders of magnitude. It suggests that the magnetic wind is not likely the determinant mechanism driving the AML in close binaries.

Luo, C. Q.; Luo, Y. P.; Zhang, X. B.; Deng, L. C.; Luo, Z. Q.; Yang, S. Z.

2008-10-01

305

So Many Periodic Tables!  

NSDL National Science Digital Library

Periodic tables come in a variety of shapes and formats. Some periodic tables have a flair of creativity! Take a look at these different versions of Periodic Tables at the following websites. You will be asked to reflect on the theme of periodicity after exploring these websites. 1. Some Periodic Tables provide a wealth of information about each element. Compare 2 different elements on the following Periodic Tables. Periodic Table Alive WebElements 2. Periodic Tables can be organized in unique and unusual 2-dimensional and 3-dimensional formats. Analyse the organization of periodicity in some of the following Periodic Tables. Presentation Forms of the Periodic Table Universal Periodic Table 3. Sometimes the designer ...

Suggs, Mrs.

2007-11-30

306

Familial Periodic Paralyses  

MedlinePLUS

NINDS Familial Periodic Paralyses Information Page Synonym(s): Periodic Paralyses Table of Contents (click to jump to sections) What are Familial Periodic Paralyses? Is there any treatment? What is the prognosis? What research is ...

307

Periodic bursts of Jovian non-Io decametric radio emission  

NASA Astrophysics Data System (ADS)

During the years 2000-2011 the radio instruments onboard Cassini, Wind and STEREO spacecraft have recorded a large amount of the Jovian decametric radio emission (DAM). In this paper we report on the analysis of the new type of Jovian periodic radio bursts recently revealed in the decametric frequency range. These bursts, which are non-Io component of DAM, are characterized by a strong periodic reoccurrence over several Jovian days with a period ?1.5% longer than the rotation rate of the planet's magnetosphere (System III). The bursts are typically observed between 4 and 12 MHz and their occurrence probability has been found to be significantly higher in the sector of Jovian Central Meridian Longitude between 300° and 60° (via 360°). The stereoscopic multispacecraft observations have shown that the radio sources of the periodic bursts radiate in a non-axisymmetric hollow cone-like pattern and sub-corotate with Jupiter remaining active during several planet's rotations. The occurrence of the periodic non-Io DAM bursts is strongly correlated with pulses of the solar wind ram pressure at Jupiter. Moreover the periodic bursts exhibit a tendency to occur in groups every ˜25 days. The polarization measurements have shown that the periodic bursts are right hand polarized radio emission associated with the Northern magnetic hemisphere of Jupiter. We suggest that periodic non-Io DAM bursts may be connected with the interchange instability in Io plasma torus triggered by the solar wind.

Panchenko, M.; Rucker, H. O.; Farrell, W. M.

2013-03-01

308

Periodic bursts of Jovian non-Io decametric radio emission.  

PubMed

During the years 2000-2011 the radio instruments onboard Cassini, Wind and STEREO spacecraft have recorded a large amount of the Jovian decametric radio emission (DAM). In this paper we report on the analysis of the new type of Jovian periodic radio bursts recently revealed in the decametric frequency range. These bursts, which are non-Io component of DAM, are characterized by a strong periodic reoccurrence over several Jovian days with a period [Formula: see text] longer than the rotation rate of the planet's magnetosphere (System III). The bursts are typically observed between 4 and 12 MHz and their occurrence probability has been found to be significantly higher in the sector of Jovian Central Meridian Longitude between 300° and 60° (via 360°). The stereoscopic multispacecraft observations have shown that the radio sources of the periodic bursts radiate in a non-axisymmetric hollow cone-like pattern and sub-corotate with Jupiter remaining active during several planet's rotations. The occurrence of the periodic non-Io DAM bursts is strongly correlated with pulses of the solar wind ram pressure at Jupiter. Moreover the periodic bursts exhibit a tendency to occur in groups every [Formula: see text] days. The polarization measurements have shown that the periodic bursts are right hand polarized radio emission associated with the Northern magnetic hemisphere of Jupiter. We suggest that periodic non-Io DAM bursts may be connected with the interchange instability in Io plasma torus triggered by the solar wind. PMID:23585696

Panchenko, M; Rucker, H O; Farrell, W M

2013-03-01

309

Detection of three periodicities in a single oscillating coronal loop  

NASA Astrophysics Data System (ADS)

Context: TRACE 171 Å observations of transverse loop oscillations on May 13, 2001 have been studied by De Moortel & Brady (2007). They found hints of 3 periodicities present in this event. Aims: The aim of this article is to improve the analysis, and measure the periodicities more accurately in order to do coronal seismology. Methods: We create multiple (x,t)-slices across the loop, and determine the oscillatory parameters within those slices. We then use statistical methods to reduce the errors on the measured oscillations parameters. Results: We find two populations with a clearly distinct period. The population at the loop top has a period of 895±2~s, while the population in the loop leg has a period of 452±1~s. The fact that the ratio of these two periods is roughly 2 and the geometry of the problem suggests that two harmonics are observed. In the residues, we confirm the presence of a 3rd harmonic with period 309±15~s using two separate data analysis techniques. The three periods are then used to do a seismological estimate of the loop expansion and the density scale height.

van Doorsselaere, T.; Birtill, D. C. C.; Evans, G. R.

2009-12-01

310

Placebo-Suggestion Modulates Conflict Resolution in the Stroop Task  

PubMed Central

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.

Caspar, Emilie A.; Gevers, Wim; Cleeremans, Axel

2013-01-01

311

NMR Shielding and the Periodic Table  

NASA Astrophysics Data System (ADS)

The object of this article is to find periodic, structurally significant observables that can be correlated to the nuclear shielding or alternatively to investigate whether chemical shift can be used to intensify the periodic disposition of valence electrons.

Gerothanassis, I. P.; Kalodimos, C. G.

1996-08-01

312

NMR Shielding and the Periodic Table  

Microsoft Academic Search

The object of this article is to find periodic, structurally significant observables that can be correlated to the nuclear shielding or alternatively to investigate whether chemical shift can be used to intensify the periodic disposition of valence electrons.

I. P. Gerothanassis; C. G. Kalodimos

1996-01-01

313

Integrating Composition and Literature: Some Practical Suggestions.  

ERIC Educational Resources Information Center

This paper suggests that it is possible to construct a course that integrates the teaching of composition with the teaching of literature without allowing the secondary goal of heightened literary understanding to overwhelm the primary goal of improved expository writing. It presents a syllabus for a four-week unit on Ernest Hemingway's "The Sun…

Daiker, Donald A.

314

Web Service Composition Using Service Suggestions  

Microsoft Academic Search

This paper presents a semi-automatic Web service composition approach. This approach ranks all available candidate Web service operations based on semantic annotations and suggests service operations to a human designer during the process of Web service composition. The ranking scores are based on data mediation, functionality and formal service specifications. A formal graph model, an IODAG, is defined to formalize

Rui Wang; Chaitanya Guttula; Maryam Panahiazar; Haseeb Yousaf; John A. Miller; Eileen T. Kraemer; Jessica C. Kissinger

2011-01-01

315

Qualitative Research Articles: Guidelines, Suggestions and Needs  

ERIC Educational Resources Information Center

|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…

Crescentini, Alberto; Mainardi, Giuditta

2009-01-01

316

Spontaneous and Suggested Posthypnotic Source Amnesia.  

National Technical Information Service (NTIS)

The occurrence of spontaneous and/or suggested posthypnotic source amnesia was investigated in a sample of 93 introductory psychology students. Ss were randomly assigned to one of two groups, and served as Ss on 2 successive days. The standard induction o...

L. M. Cooper

1965-01-01

317

Suggested nuclear waste management radiological performance objectives  

Microsoft Academic Search

Development of criteria for the safe disposal of nuclear wastes in geologic media requires the establishment of definitive objectives against which the adequacy of various waste management methods may be judged. Certain guidelines are suggested that might serve as first approximations pending promulgation of official criteria. These include: the allowable radiation dose to individuals should be related to the predicted

J. Cohen

1978-01-01

318

Assessment of Achievement Motives: Comments and Suggestions  

Microsoft Academic Search

Nygård, R. & Gjesme, T. 1973. Assessment of Achievement Motives: Comments and Suggestions. Scand. J. educ. Res. 17, 39?46. Measuring instruments usually employed in achievement motivation research are reviewed and appraised. The following conclusions are drawn; (a) the validity of the need for achievement tests, especially when used among females, is questionable; (b) the objective tests assumed to indicate the

Roald Nygård; Torgrim Gjesme

1973-01-01

319

Technology Is Power: Suggestions for Beginning Teachers  

ERIC Educational Resources Information Center

|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…

Shanklin, Nancy

2010-01-01

320

SUGGESTED SCHOOL HEALTH POLICIES. FOURTH EDITION.  

ERIC Educational Resources Information Center

|THE FOURTH EDITION OF A GUIDE FIRST PUBLISHED IN 1940 OUTLINES IMPORTANT FEATURES OF AN ACCEPTABLE SCHOOL HEALTH PROGRAM. HEALTH EDUCATION IS DEFINED AS AN APPLIED SCIENCE CONCERNED WITH MAN'S UNDERSTANDING OF HIMSELF IN RELATION TO HEALTH MATTERS IN A CHANGING SOCIETY. SUGGESTIONS ARE GIVEN FOR DEVELOPING A HEALTH EDUCATION CURRICULUM. POLICIES…

REICHERT, JOHN L.; AND OTHERS

321

Integrating Composition and Literature: Some Practical Suggestions.  

ERIC Educational Resources Information Center

|This paper suggests that it is possible to construct a course that integrates the teaching of composition with the teaching of literature without allowing the secondary goal of heightened literary understanding to overwhelm the primary goal of improved expository writing. It presents a syllabus for a four-week unit on Ernest Hemingway's "The Sun…

Daiker, Donald A.

322

Physics Courses--Some Suggested Case Studies  

ERIC Educational Resources Information Center

|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)|

Swetman, T. P.

1972-01-01

323

A Suggested Model for a Working Cyberschool.  

ERIC Educational Resources Information Center

|Suggests a model for a working cyberschool based on a case study of Kamiak Cyberschool (Washington), a technology-driven public high school. Topics include flexible hours; one-to-one interaction with teachers; a supportive school environment; use of computers, interactive media, and online resources; and self-paced, project-based learning.…

Javid, Mahnaz A.

2000-01-01

324

Suggestibility of Children's Memory: Psycholegal Implications  

Microsoft Academic Search

Historically, there has been a bias in the American judicial system against relying on eyewitness accounts of young children. Some of the apprehension about the veracity of children's recollections has arisen from a concern over the testimony provided by children during the Salem Witch Trials and been fueled further by research carried out around the turn of the century suggesting

Stephen J. Ceci; David F. Ross; Michael P. Toglia

1987-01-01

325

Preliminary suggested readings in forensic psychology.  

PubMed

ABBP Diplomates in forensic psychology were surveyed to identify lists of "suggested readings" for their field. The return rate was 28% of 162 total Diplomates. Four of 117 books and five of 56 journals met the inclusion criterion of being endorsed by > or = 25% of the respondents. The present survey provides a preliminary reading guide for undergraduate and graduate students. PMID:12841440

Ryan, Joseph J; Fletcher, Jessica

2003-06-01

326

Polarimetric observations of 51 NEMAUSA during its 1991 apparition  

NASA Astrophysics Data System (ADS)

We present the results of polarimetric observations of astroid 51 Nemausa obtained during 4 nights in December 1991. This object has been found to show a rotational modulation of polarization, but with a period equal to a third of the rotational period, suggesting a complex variegation of the surface.

Broglia, P.; Manara, A.

1994-01-01

327

Placebo-suggestion modulates conflict resolution in the stroop task.  

PubMed

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

Magalhães De Saldanha da Gama, Pedro A; Slama, Hichem; Caspar, Emilie A; Gevers, Wim; Cleeremans, Axel

2013-10-09

328

Suggested new modes in supersymmetric proton decay  

Microsoft Academic Search

We show that in supersymmetric unified theories such as SO(10), implementation of the see–saw mechanism for neutrino masses introduces a new set of color triplet fields and thereby a new source of d=5 proton decay operators. For neutrino masses in a plausible range, these operators are found to have the right strength to yield observable, but not yet excluded, proton

K. S. Babu; Jogesh C. Pati; Frank Wilczek

1998-01-01

329

Suggested new modes in supersymmetric proton decay  

Microsoft Academic Search

We show that in supersymmetric unified theories such as SO(10), implementation of the see-saw mechanism for neutrino masses introduces a new set of color triplet fields and thereby a new source of d=5 proton decay operators. For neutrino masses in a plausible range, these operators are found to have the right strength to yield observable, but not yet excluded, proton

K. S. Babu; Jogesh C. Pati; Frank Wilczek

1998-01-01

330

Secular period decreasing of detached chromospherically active binaries  

NASA Astrophysics Data System (ADS)

The long-term orbital period changes of a large sample of detached chromospherically active binaries (CABs) were studied. Eleven such systems were found to be undergoing secular period decreases with the rates of -6.3×10-9 to -1.1×10-6 days per year. The period decreasing rates are found to vary depending on the orbital period. The longer the orbital period is, the more rapidly the period decreases. Following Stepien (Mon. Not. R. Astron. Soc. 274:1019, 1995), the period decreasing rate predicted by angular momentum loss (AML) caused by magnetic wind is computed for each system. A comparison between the observed and calculated period decreasing rates shows that the former values are obviously larger than the latter by 1-3 orders of magnitude. It suggests that the magnetic wind is not likely the determinant mechanism driving the AML in these systems. Finally, the orbital angular momentum (AM) and the rate of AML, dot{J} , are computed for each system. It shows that the AM have a similar change with the orbital period like d P/d t does, but logdot{J}/J presents no strict changing with the kinematical ages.

Luo, Chang Qing; Zhang, Xiao Bin; Deng, Li Cai; Luo, Yang Ping; Luo, Zhi Quan; Yang, Shu Zheng

2010-05-01

331

Mentoring in biostatistics: some suggestions for reform.  

PubMed

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

Odueyungbo, Adefowope; Thabane, Lehana

2012-10-15

332

UCG environmental research: summary and suggested projections  

SciTech Connect

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.

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

1982-08-09

333

Preschoolers' understanding of mind: implications for suggestibility  

Microsoft Academic Search

Fifty-seven 3- to 5- I\\/2-year-olds listened to a story accompanied by pictures of target items. After a short delay, an interviewer asked children questions about the story and suggested information that conflicted with the original details. Story memory was assessed 5-l 1 days later using a two-alternative, picture recognition test. Children completed theory of mind (TOM) tasks that indexed an

Melissa K. Welch-Ross

1999-01-01

334

Describing Baseline Conditions: Suggestions for Study Reports  

Microsoft Academic Search

Experimental research involves comparing two or more conditions. One of those conditions in single subject research is often\\u000a the baseline. Adequate description of the baseline conditions is necessary for evaluating the effects of independent variables,\\u000a drawing generalizations from studies, and providing information for subsequent replication studies. Suggestions are made about\\u000a the types of information to include when describing baseline conditions

Mark Wolery; Brian Reichow; Leslie Rogers

2007-01-01

335

A Suggestion for a Fast Multiplier  

Microsoft Academic Search

It is suggested that the economics of present large-scale scientific computers could benefit from a greater investment in hardware to mechanize multiplication and division than is now common. As a move in this direction, a design is developed for a multiplier which generates the product of two numbers using purely combinational logic, i.e., in one gating step. Using straightforward diode-transistor

C. S. Wallace

1964-01-01

336

In vitro circadian period is associated with circadian/sleep preference.  

PubMed

Evaluation of circadian phenotypes is crucial for understanding the pathophysiology of diseases associated with disturbed biological rhythms such as circadian rhythm sleep disorders (CRSDs). We measured clock gene expression in fibroblasts from individual subjects and observed circadian rhythms in the cells (in vitro rhythms). Period length of the in vitro rhythm (in vitro period) was compared with the intrinsic circadian period, ?, measured under a forced desynchrony protocol (in vivo period) and circadian/sleep parameters evaluated by questionnaires, sleep log, and actigraphy. Although no significant correlation was observed between the in vitro and in vivo periods, the in vitro period was correlated with chronotype, habitual sleep time, and preferred sleep time. Our data demonstrate that the in vitro period is significantly correlated with circadian/sleep preference. The findings suggest that fibroblasts from individual patients can be utilized for in vitro screening of therapeutic agents to provide personalized therapeutic regimens for CRSD patients. PMID:23797865

Hida, Akiko; Kitamura, Shingo; Ohsawa, Yosuke; Enomoto, Minori; Katayose, Yasuko; Motomura, Yuki; Moriguchi, Yoshiya; Nozaki, Kentaro; Watanabe, Makiko; Aritake, Sayaka; Higuchi, Shigekazu; Kato, Mie; Kamei, Yuichi; Yamazaki, Shin; Goto, Yu-Ichi; Ikeda, Masaaki; Mishima, Kazuo

2013-01-01

337

An Interpretation of the Orbital Period Difference Between Hot Jupiters and Giant Planets on Long-period Orbits  

NASA Astrophysics Data System (ADS)

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 sun).

Jin, Liping

2010-09-01

338

Geometric Laws in the Periodic Table of Elements  

Microsoft Academic Search

Despite many versions of the Periodic table of Elements were suggested, no one discussed the problem how the elements are connected to each other inside the Groups and Periods of the Table. As is known, the Groups are joined along the vertical (18 Groups in total), while the Periods are joined along the horizontal (7 Periods; we also suggest Period

Albert Khazan

2011-01-01

339

Anomalous ocean tide loading displacements in western Europe suggest mantle anelasticity  

NASA Astrophysics Data System (ADS)

Using GPS data from over 200 continuously-operating sites in western Europe, at a range of latitudes and distances from the coast, we observe ocean tide loading displacements (OTLD) at a selection of semi-diurnal and diurnal tidal periods. Our processing strategy uses the GIPSY-OASIS II software with reprocessed satellite orbits and clocks, and either (1) 24-hour batch solutions with 3-d harmonic motions estimated at fixed tidal periods and later combined over the 2+ year data span, or (2) kinematic solutions from which 3-d harmonic motions are later estimated over the whole data span. Excepting the K1 and K2 tidal periods which are problematic because of their coincidence with the sidereal rotation period and GPS satellite geometry repeat interval, and GPS orbital period, we obtain good (better than 0.5 mm) agreement between these two strategies, with little sensitivity to the quality of a priori OTLD model used. Compared with OTLD computed from modern numerical ocean tide models convolved with Green's functions derived from the PREM global Earth model, we observe differences in the vertical component of OTLD for the M2 tidal constituent approaching 3 mm in SW England and NW France (nearly 10 per cent of the signal amplitude). These differences are too large to be explained by errors in the numerical ocean tide models, which show good agreement with each other and with local tide gauge data, and too large and widespread to be explained by plausible changes to the Green's functions reflecting regional crustal structure. Instead, they show clear correlation with the contribution to OTLD from ocean tidal signals at distances of 100-200 km, suggesting an asthenospheric upper mantle origin for the discrepancy. OTLD offers a window onto the possible anelastic behaviour of the upper mantle at tidal timescales, which cannot be detected by solid Earth tides that are largely sensitive to lower mantle rheology.

Clarke, P. J.; Bos, M. S.; Penna, N. T.; Keshin, M.; Baker, T. F.

2011-12-01

340

Further observations on canine spirocercosis in Kenya  

Microsoft Academic Search

The close association of the parasite Spirocerca lupi with oesophageal sarcomas suggests aetiological involvement of S lupi. Further investigations may yield results of significance with respect to comparative oncology. This paper records detailed observations made over an 11 year period, on the incidence and pathological variations of S lupi infections in Kenya.

JG Wandera

1976-01-01

341

Further observations on canine spirocercosis in Kenya.  

PubMed

The close association of the parasite Spirocerca lupi with oesophageal sarcomas suggests aetiological involvement of S lupi. Further investigations may yield results of significance with respect to comparative oncology. This paper records detailed observations made over an 11 year period, on the incidence and pathological variations of S lupi infections in Kenya. PMID:1069399

Wandera, J G

1976-10-30

342

Cross-sectional and longitudinal observations of activity level and sustained attention in a normative sample  

Microsoft Academic Search

This study examined developmental changes in playroom observations of activity level and sustained attention among 47 elementary school-age boys. The boys were observed at two different times, approximately 2 years apart. The playroom observations consisted of two 15-minute periods, a relatively unstructured freeplay period and a structured restricted academic period. In general, both cross-sectional and longitudinal analyses suggested developmental improvements

Richard Milich

1984-01-01

343

New evidence suggesting segmentation of Cocos Plate  

SciTech Connect

Compilation and analysis of geophysical and geological data indicate that the Cocos plate consists of three segments that have individual poles of rotation and independent motion vectors. Contoured heat-flow and gravity maps of the region delineate the boundaries of the segments within the Cocos plate. These segments have different focal-plane solutions along the Middle America Trench and different sedimentary-basin configurations within the Central America-Mexico island arc. Recent studies of seismic data from the region also have suggested that the subducted Cocos plate consists of three segments. The proposed northern and central segments are separated by the northeast-trending Siqueros-Tehuantepec Ridge fracture zone. The proposed central and southern segments are separated by the northeast-trending Costa Rica fracture zone that is located just northwest of the Cocos Ridge and extends from the Galapagos rift to the central valley of Costa Rica. Poles of rotation and relative motion vectors have been calculated with respect to the Caribbean plate for each segment. The northern segment is moving N75/sup 0/E, oblique to the trench; the central segment is moving N50/sup 0/E, perpendicular to the trench; the southern segment is moving north, perpendicular to the trench. The Siqueros-Tehuantepec and Costa Rice fracture zones appear to join with tectonized zones that dissect the Central America-Mexico island arc and extend across the Caribbean plate, suggesting that it too is segmented. Structural and stratigraphic data from the sedimentary basins on the island arc suggest that these fracture zones have existed throughout the Tertiary history of the region.

Lew, L.R.; Sauermann, R.P.; De Boer, J.

1985-02-01

344

About the Solar Activity Rotation Periods  

NASA Astrophysics Data System (ADS)

The purpose of this paper is to evidence, from a statistical point of view, the different periods of solar activity. The well known period is that of 150-160 days, but many others were detected between 9 and 4750 days (length of solar cycle). We tabulated 49 articles revealing 231 periods. In order to explain them, different hypotheses were suggested.

Mouradian, Zadig

2007-03-01

345

A Periodic Table of Elementary Particles  

Microsoft Academic Search

We will present a poster that represents a periodic table of all the ground-state elementary particles - quarks, leptons, mesons and baryons. This will be the first time, a comprehensive periodic table of all these elementary particles (similar to the periodic table of the elements) will be shown to the public. We welcome your comments and suggestions.

Allan Figueroa; Akhtar Mahmood

2001-01-01

346

Halloween Costumes May Suggest Influence of Violent Models on Children.  

ERIC Educational Resources Information Center

Halloween costumes may be used to examine the influence violent models have on children. On Halloween evening observers recorded the frequency of violent and nonviolent costumes worn by children. When all of the data are inspected they suggest that children confronted with several aggressive models may be more likely to identify with the "good…

Owen, John W.; Sterling, Bruce S.

347

Halloween Costumes May Suggest Influence of Violent Models on Children.  

ERIC Educational Resources Information Center

|Halloween costumes may be used to examine the influence violent models have on children. On Halloween evening observers recorded the frequency of violent and nonviolent costumes worn by children. When all of the data are inspected they suggest that children confronted with several aggressive models may be more likely to identify with the "good…

Owen, John W.; Sterling, Bruce S.

348

Modifying Behavior: Suggestions for Teachers of the Handicapped.  

ERIC Educational Resources Information Center

Behavior modification from the teacher's point of view is explored. Means of identifying pupils with special needs are discussed (observation, records, family contact, tests, resource personnel). Needs of children influencing their behavior are examined. Suggestions for working with behavior problems cover children who are aggressive, withdrawn,…

Iowa Univ., Iowa City. Special Education Curriculum Development Center.

349

Suggestibility and salience in people with intellectual disabilities: An experimental critique of the Gudjonsson Suggestibility Scale  

Microsoft Academic Search

Aim: The Gudjonsson Suggestibility Scale (GSS) assesses suggestibility by asking respondents to recall a short story, using leading questions and pressure to change their responses. Suggestibility, as assessed by the GSS, is elevated in people with intellectual disabilities. Unlike real life incidents, the information presented is of no personal significance to the respondent. The aim of the present study was

Richard White; Paul Willner

2005-01-01

350

Bacterial survival strategies suggest rethinking cancer cooperativity.  

PubMed

Despite decades of a much improved understanding of cancer biology, we are still baffled by questions regarding the deadliest traits of malignancy: metastatic colonization, dormancy and relapse, and the rapid evolution of multiple drug and immune resistance. New ideas are needed to resolve these critical issues. Relying on finding and demonstrating parallels between collective behavior capabilities of cancer cells and that of bacteria, we suggest communal behaviors of bacteria as a valuable model system for new perspectives and research directions. Understanding the ways in which bacteria thrive in competitive habitats and their cooperative strategies for surviving extreme stress can shed light on cooperativity in tumorigenesis and portray tumors as societies of smart communicating cells. This may translate into progress in fathoming cancer pathogenesis. We outline new experiments to test the cancer cooperativity hypothesis and reason that cancer may be outsmarted through its own 'social intelligence'. PMID:22750098

Ben-Jacob, Eshel; Coffey, Donald S; Levine, Herbert

2012-06-29

351

Proactive and retroactive effects of negative suggestion.  

PubMed

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

Brown, Alan S; Brown, Christine M; Mosbacher, Joy L; Dryden, W Erich

2006-11-01

352

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.

353

Elastic wave scattering methods: assessments and suggestions  

SciTech Connect

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.

Gubernatis, J.E.

1985-01-01

354

Suggested noise criteria for plumbing systems  

NASA Astrophysics Data System (ADS)

The issue of noise that is generated by plumbing systems has been addressed in several articles and texts in the acoustic literature, but most of this information deals with a description of the various noise generation mechanisms and recommended methods of controlling noise from plumbing fixtures and piping. As with any noise source that has the potential for generating annoyance, the question of how much noise is too much noise eventually arises. Chapter 47 of the 2003 ASHRAE Applications Handbook contains newly published guidelines for plumbing noise criteria as it impacts building occupants. This paper discusses the ASHRAE guidelines, and it also suggests additional noise criteria for other plumbing-related sources of noise in multitenant buildings.

Lilly, Jerry

2005-09-01

355

Period meter for reactors  

DOEpatents

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

Rusch, Gordon K. (Downers Grove, IL)

1976-01-06

356

Functions of tropomyosin's periodic repeats.  

PubMed

Tropomyosin binds along actin filaments and regulates actin-myosin interaction in muscle and nonmuscle cells. Seven periodic amino acid repeats are proposed to correspond to actin binding sites, and the middle periods are important for cooperative activation of actin by myosin. The functional contributions of individual periods were studied in mutants in which periods 2-6 were individually deleted from rat striated muscle alphaalpha-tropomyosin or replaced with a leucine zipper sequence. Unacetylated recombinant tropomyosins were assayed for actin binding, regulation of the actomyosin ATPase with troponin, cooperative myosin S1-induced binding to actin, and thermal stability. Tropomyosin function is relatively insensitive to deletion of period 2, but loss increases as the deletion is shifted toward the C-terminus. Retention of function upon deletion of the periodic repeats is in the order of 2 > 3 approximately 4 approximately 6 > 5. Internal periods are important for specific functions and are not quasiequivalent. Deletion of period 5 (residues 166-207), and especially deletion or replacement of residues 166-188, a constitutively expressed region encoded by exon 5, had severe consequences on actin affinity and cooperative myosin S1-induced binding to actin. Period 6, residues 208-242, part of the troponin binding site, is required for full inhibition of the actomyosin ATPase in the absence of calcium. The effect of the deletion can depend on its context, suggesting that sequence alone is not the only factor important for function. We propose that the local structure and stability, and consequent flexibility, of the coiled coil are major determinants of actin affinity. PMID:12475253

Hitchcock-DeGregori, Sarah E; Song, Yuhua; Greenfield, Norma J

2002-12-17

357

Periodic growth of bacterial colonies  

NASA Astrophysics Data System (ADS)

The formation of concentric ring colonies by bacterial species Bacillus subtilis and Proteus mirabilis has been investigated experimentally, focusing our attention on the dependence of local cell density upon the bacterial motility. It has been confirmed that these concentric ring colonies reflect the periodic change of the bacterial motility between motile cell state and immotile cell state. We conclude that this periodic change is macroscopically determined neither by biological factors (i.e., biological clock) nor by chemical factors (chemotaxis as inhibitor). And our experimental results strongly suggest that the essential factor for the change of the bacterial motility during concentric ring formation is the local cell density.

Yamazaki, Yoshihiro; Ikeda, Takemasa; Shimada, Hirotoshi; Hiramatsu, Fumiko; Kobayashi, Naoki; Wakita, Jun-Ichi; Itoh, Hiroto; Kurosu, Sayuri; Nakatsuchi, Michio; Matsuyama, Tohey; Matsushita, Mitsugu

2005-06-01

358

The Periodic Spectroscopic Variability of FU Orionis  

NASA Astrophysics Data System (ADS)

FU Orionis systems are young stars undergoing outbursts of disc accretion and where the optical spectrum contains lines associated with both the disc photosphere and a wind component. Previous observations of the prototype FU Orionis by Herbig et al. (2003) have suggested that the wind lines and the photospheric lines are modulated with periods of 14.54 and 3.54 d respectively. We have re-observed the system at higher spectral resolution, by monitoring variations of optical line profiles over 21 nights in 2007 and have found periods of 13.48 and 3.6 d in the wind and disc components, consistent with the above: this implies variability mechanisms that are stable over at least a decade. In addition we have found: i) that the variations in the photospheric absorption lines are confined to the blue wing of the line (centered on velocity -9 km s-1): we tentatively ascribe this to an orbiting hotspot in the disc, which is obscured by a disc warp during its receding phase. ii) The wind period is manifested not only in blue-shifted H? absorption, (as found by Herbig et al. 2003) but also in red-shifted emission of H? and H? as well as in blue-shifted absorption of Na I D, Li I and Fe II ?5018. iii) We find that the periodic modulation of blue-shifted H? absorption (at a velocity of around -100 km s-1) is phase lagged with respect to variations in the other lines by around 1.8 d. This is consistent with a picture in which variations at the wind base first affect chromospheric emission and then low velocity blue-shifted absorption, followed - after a lag equal to the propagation time of disturbances across the wind's acceleration region - by a response in high velocity blue-shifted absorption. Such arguments constrain the size of the acceleration region to be ~1012 cm. We suggest possible mechanisms for periodic variations within the innermost 0.1 AU of the disc, including the possibility that these variations indicate the presence of an embedded hot Jupiter in this object.

Powell, Stacie; Irwin, M.; Bouvier, J.; Clarke, C. J.

2013-01-01

359

Relativistic timescale analysis suggests lunar theory revision  

NASA Astrophysics Data System (ADS)

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.

Deines, Steven D.; Williams, Carol A.

1995-05-01

360

Latitudinal dependence of the seasonal variation of particulate extinction in the UTLS over the Indian longitude sector during volcanically quiescent period based on lidar and SAGE-II observations  

NASA Astrophysics Data System (ADS)

The altitude profiles of particulate extinction in the upper troposphere and lower stratosphere (UTLS) obtained from SAGE-II in the latitude region 0-30°N over the Indian longitude sector (70-90°E) are used to study the latitudinal variation of its annual pattern in this region during the volcanically quiescent period of 1998-2003. The SAGE-II data is compared with the lidar measurements from Gadanki (13.5°N, 79.2°E) when the satellite had an overhead occultation pass over a small geographical grid centered at this location. The particulate optical depth (?p) in the UT region shows a general decrease with increase in latitude and a pronounced summer-winter contrast with relatively low values during winter and high values during summer. In general, these variations are in accordance with the latitudinal variation of convective available potential energy (CAPE) and thunderstorm activity, which are good representative indices of tropospheric convection. While the particulate extinction (and ?p) in the 18-21 km (LS1) region is relatively low in the equatorial region up to 15°N, it shows an increase in the off-equatorial region, beyond 15°N. While the annual variation of ?p in the LS1 region is almost insignificant near the equator, it is rather well pronounced in latitude region between 10 and 15°N with relatively high values during winter and low values during summer. Beyond 20°N, this shows a prominent peak during summer. At a higher altitude, the 21-30 km (LS2) region, the latitude variation of ?p shows a different pattern with high values near the equator and low values in the off-equatorial region confirming the existence of a stratospheric aerosol reservoir. Low values of ?p at lower regime (LS1) near the equator could be due to rapid transport of particulates from the near equatorial region to higher latitudes, while the equatorial high at upper regime (LS2) could be due to lofting and subsequent accumulation.

Parameswaran, K.; Thampi, Bijoy V.; Sunilkumar, S. V.

2010-08-01

361

Testing Increases Suggestibility for Narrative-based Misinformation but Reduces Suggestibility for Question-based Misinformation.  

PubMed

A number of recent studies have found that recalling details of an event following its occurrence can increase people's suggestibility to later presented misinformation. However, several other studies have reported the opposite result, whereby earlier retrieval can reduce subsequent eyewitness suggestibility. In the present study, we investigated whether differences in the way misinformation is presented can modulate the effects of testing on suggestibility. Participants watched a video of a robbery and some were questioned about the event immediately afterwards. Later, participants were exposed to misinformation in a narrative (Experiment 1) or in questions (Experiment 2). Consistent with previous studies, we found that testing increased suggestibility when misinformation was presented via a narrative. Remarkably, when misinformation was presented in questions, testing decreased suggestibility. Copyright © 2013 John Wiley & Sons, Ltd. PMID:24105926

Lapaglia, Jessica A; Chan, Jason C K

2013-09-16

362

The periodic spectroscopic variability of FU Orionis  

NASA Astrophysics Data System (ADS)

FU Orionis systems are young stars undergoing outbursts of disc accretion and where the optical spectrum contains lines associated with both the disc photosphere and a wind component. Previous observations of the prototype FU Orionis by Herbig et al., suggested that the wind lines and the photospheric lines are modulated with periods of 14.54 and 3.54 d, respectively. We have re-observed the system at higher spectral resolution, by monitoring variations of optical line profiles over 21 nights in 2007 and have found periods of 13.48 and 3.6 d in the wind and disc components, consistent with the above: this implies variability mechanisms that are stable over at least a decade. In addition, we have found (i) that the variations in the photospheric absorption lines are confined to the blue wing of the line (centred on velocity ˜ -9 km s-1): we tentatively ascribe this to an orbiting hotspot in the disc, which is obscured by a disc warp during its receding phase. (ii) The wind period is manifested not only in blueshifted H? absorption (as found by Herbig et al.), but also in redshifted emission of H? and H?, as well as in blueshifted absorption of Na I D, Li I and Fe II ?5018. (iii) We find that the periodic modulation of blueshifted H? absorption (at a velocity of around -100 km s-1) is phase lagged with respect to variations in the other lines by around 1.8 d. This is consistent with a picture in which variations at the wind base first affect chromospheric emission and then low-velocity blueshifted absorption, followed - after a lag equal to the propagation time of disturbances across the wind's acceleration region - by a response in high-velocity blueshifted absorption. Such arguments constrain the size of the acceleration region to be ˜1012 cm. We discuss possible mechanisms for periodic variations within the innermost 0.1 au of the disc, including the possibility that these variations indicate the presence of an embedded hot Jupiter in this object. Based on observations made at Observatoire de Haute-Provence (CNRS), France, with the SOPHIE spectrograph.

Powell, Stacie L.; Irwin, Mike; Bouvier, Jerome; Clarke, Cathie J.

2012-11-01

363

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

USGS Publications Warehouse

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.

Pakiser, L. C.; Robinson, R.

1966-01-01

364

Advice for Advisors: Suggestions and Observations from Lawrence to the Present.  

National Technical Information Service (NTIS)

While always a mission for some Army units, advising indigenous forces has become a major task for many Army units and for thousands of Soldiers, both Active and Reserve. The Combat Studies Institute is publishing this occasional paper as a supplement to ...

I. R. Ramsey

2006-01-01

365

The use (and misuse) of sediment traps in coral reef environments: theory, observations, and suggested protocols  

NASA Astrophysics Data System (ADS)

Sediment traps are commonly used as standard tools for monitoring "sedimentation" in coral reef environments. In much of the literature where sediment traps were used to measure the effects of "sedimentation" on corals, it is clear from deployment descriptions and interpretations of the resulting data that information derived from sediment traps has frequently been misinterpreted or misapplied. Despite their widespread use in this setting, sediment traps do not provide quantitative information about "sedimentation" on coral surfaces. Traps can provide useful information about the relative magnitude of sediment dynamics if trap deployment standards are used. This conclusion is based first on a brief review of the state of knowledge of sediment trap dynamics, which has primarily focused on traps deployed high above the seabed in relatively deep water, followed by our understanding of near-bed sediment dynamics in shallow-water environments that characterize coral reefs. This overview is followed by the first synthesis of near-bed sediment trap data collected with concurrent hydrodynamic information in coral reef environments. This collective information is utilized to develop nine protocols for using sediment traps in coral reef environments, which focus on trap parameters that researchers can control such as trap height ( H), trap mouth diameter ( D), the height of the trap mouth above the substrate ( z o ), and the spacing between traps. The hydrodynamic behavior of sediment traps and the limitations of data derived from these traps should be forefront when interpreting sediment trap data to infer sediment transport processes in coral reef environments.

Storlazzi, C. D.; Field, M. E.; Bothner, M. H.

2011-03-01

366

The use (and misuse) of sediment traps in coral reef environments: Theory, observations, and suggested protocols  

USGS Publications Warehouse

Sediment traps are commonly used as standard tools for monitoring “sedimentation” in coral reef environments. In much of the literature where sediment traps were used to measure the effects of “sedimentation” on corals, it is clear from deployment descriptions and interpretations of the resulting data that information derived from sediment traps has frequently been misinterpreted or misapplied. Despite their widespread use in this setting, sediment traps do not provide quantitative information about “sedimentation” on coral surfaces. Traps can provide useful information about the relative magnitude of sediment dynamics if trap deployment standards are used. This conclusion is based first on a brief review of the state of knowledge of sediment trap dynamics, which has primarily focused on traps deployed high above the seabed in relatively deep water, followed by our understanding of near-bed sediment dynamics in shallow-water environments that characterize coral reefs. This overview is followed by the first synthesis of near-bed sediment trap data collected with concurrent hydrodynamic information in coral reef environments. This collective information is utilized to develop nine protocols for using sediment traps in coral reef environments, which focus on trap parameters that researchers can control such as trap height (H), trap mouth diameter (D), the height of the trap mouth above the substrate (z o ), and the spacing between traps. The hydrodynamic behavior of sediment traps and the limitations of data derived from these traps should be forefront when interpreting sediment trap data to infer sediment transport processes in coral reef environments.

Storlazzi, C. D.; Field, M. E.; Bothner, M. H.

2011-01-01

367

The use (and misuse) of sediment traps in coral reef environments: theory, observations, and suggested protocols  

Microsoft Academic Search

Sediment traps are commonly used as standard tools for monitoring “sedimentation” in coral reef environments. In much of the\\u000a literature where sediment traps were used to measure the effects of “sedimentation” on corals, it is clear from deployment\\u000a descriptions and interpretations of the resulting data that information derived from sediment traps has frequently been misinterpreted\\u000a or misapplied. Despite their widespread

C. D. Storlazzi; M. E. Field; M. H. Bothner

2011-01-01

368

The Observed Association between Maternal Anxiety and Adolescent Asthma: Children of Twin Design Suggest Familial Effects  

PubMed Central

Background Previous studies indicate that maternal anxiety is associated with asthma in the adolescent child, but mechanisms are unclear. Objective To investigate the association between maternal anxiety and maternal, self- and register-based report of asthma in the adolescent child, and whether the association remains after control of familial confounding (shared environmental and genetic factors). Method From the Twin and Offspring Study of Sweden, 1691 mothers (1058 twins) and their adolescent child were included. The association between maternal self-reported anxiety (Beck Anxiety Inventory (BAI) and Karolinska Scales of Personality (KSP) somatic or psychic anxiety) and asthma based on subjective (maternal or child report) or objective (register-based diagnosis and medication) measures were analysed using logistic regression. The children-of-twins design was used to explore whether genes or environment contribute to the association. Results Maternal BAI anxiety (OR 2.02, CI 1.15–3.55) was significantly associated with adolescent asthma reported by the mother. Maternal KSP somatic anxiety (OR 1.74, CI 1.04–2.91) and psychic anxiety (OR 1.74, CI 1.05–2.86) was significantly associated with breathlessness reported by the adolescent child. In contrast, maternal anxiety was not associated with increased risk for the register-based outcomes of asthma diagnosis or medication. The results remained also after adjusting for covariates and the children-of-twins analyses which indicate that the association was due to familial confounding. Conclusions We found some associations between maternal anxiety and subjectively reported offspring asthma or breathlessness which may be due to familial effects. A likely candidate for explaining this familial confounding is heritable personality traits associated with both anxiety and subjective measures of asthma.

Havland, Ida; Lundholm, Cecilia; Lichtenstein, Paul; Neiderhiser, Jenae M.; Ganiban, Jody M.; Spotts, Erica L.; Walum, Hasse; Reiss, David; Almqvist, Catarina

2013-01-01

369

[Scientific periodicals: quality criteria].  

PubMed

This paper presents a historical literature review on the evaluation of periodicals and the methodology employed for their evaluation. It emphasizes the attention that should be given to the contents of the periodicals and their format based on technical standards in order to reach a global quality of the publications. This paper includes a summary of the most important aspects of the technical standards for periodicals and scientific articles. PMID:12937744

Ferreira, Maria Cecilia Gonzaga; Krzyzanowski, Rosaly Favero

2003-08-14

370

Before Misinformation is Encountered: Source Monitoring Decreases Child Witness Suggestibility  

Microsoft Academic Search

This research examines whether young children are less suggestible if they monitor the source of acquired information. Events from 2 sources—live and videotaped sci- ence demonstrations—were observed by 3- to 4-year-olds (n = 39) and 5- to 6-year- olds (n = 36) in Experiment 1. One half of the children in each age group were admin- istered a source-monitoring (SM)

Karen L. Thierry; Melanie J. Spence; Amina Memon

2001-01-01

371

The Periodic Table  

NSDL National Science Digital Library

The following will provide you with a brief overview of the Periodic Table of Elements, as well as some interesting facts about the elements. There are also some games which will help you practice the names and symbols of the elements. A worksheet may be provided for you to record your newfound knowledge. Please follow the directions and links below to enlighten yourself on the wonders of the Periodic Table. If provided, don't forget to fill in your worksheet as you go... Part A: Who, what, where and when? Read a brief History of the Periodic Table:History of the PT2. Part B: Interactive Periodic Tables: Find physical ...

Cutting, Mrs.

2011-01-05

372

Enhanced entrainability of genetic oscillators by period mismatch.  

PubMed

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

Hasegawa, Yoshihiko; Arita, Masanori

2013-02-06

373

Periodic solar wind density structures  

NASA Astrophysics Data System (ADS)

This dissertation addresses a specific aspect of the Sun-Earth connection: we show that coronal activity creates periodic density structures in the solar wind which convect radially outward and interact with Earth's magnetosphere. First, we analyze 11 years (1995-2005) of in situ solar wind density observations from the Wind spacecraft and find that periodic density structures occur at particular sets of radial length-scales more often than others. This indicates that these density fluctuations, which have radial length-scales of hundreds of megameters, cannot be attributed entirely to turbulence. Next, we analyze their effect on Earth's magnetosphere. Though these structures are not waves in the solar wind rest frame, they appear at discrete frequencies in Earth's reference frame. They compress the magnetosphere as they convect past, driving global magnetospheric oscillations at the same discrete frequencies as the periodic density structures. Last, we investigate source regions and mechanisms of the periodic solar wind density structures. We analyze the alpha particle to proton abundance ratio during events of periodic density structures. In many events, the proton and alpha density fluctuations are anti- correlated, which strongly argues for either temporally or spatially varying coronal source plasma. We examine white light images of the solar wind taken with SECCHI HI1 on the STEREO spacecraft and find periodic density structures as near to the Sun as 15 solar radii. The smallest resolvable periodic structures that we identify are of comparable length to those found at 1 AU, providing further evidence that at least some periodic density structures are generated in the solar corona as the solar wind is formed. Guided by the properties observed during previous studies and the characteristics established through the work presented here, we examine possible candidate mechanisms in the solar corona that can form periodic density structures. We conclude that: coronal activity creates coherent structures in the solar wind at smaller size scales than previously thought; corona-formed coherent structures persist to 1 AU largely intact; finally, a significant amount of discrete frequency wave power in Earth's magnetosphere is directly driven by these structures once they reach Earth.

Viall, Nicholeen Mary

2010-01-01

374

Retrospective Conversion of Periodicals  

Microsoft Academic Search

To participate in automated serials check-in systems or online catalogs, libraries must convert their manual periodicals records into machine-readable form. This article describes retrospective conversion, using OCLC and currently available staff and resources, of an uncataloged periodicals collection. Various phases of the conversion project, including planning, staffing, training, inventorying, editing procedures and updating, are discussed, as are problems encountered and

Rita Broadway; Jane Qualls

1988-01-01

375

Wavelet periodicity detection algorithms  

NASA Astrophysics Data System (ADS)

This paper deals with the analysis of time series with respect to certain known periodicities. In particular, we shall present a fast method aimed at detecting periodic behavior inherent in noise data. The method is composed of three steps: (1) Non-noisy data are analyzed through spectral and wavelet methods to extract specific periodic patterns of interest. (2) Using these patterns, we construct an optimal piecewise constant wavelet designed to detect the underlying periodicities. (3) We introduce a fast discretized version of the continuous wavelet transform, as well as waveletgram averaging techniques, to detect occurrence and period of these periodicities. The algorithm is formulated to provide real time implementation. Our procedure is generally applicable to detect locally periodic components in signals s which can be modeled as s(t) equals A(t)F(h(t)) + N(t) for t in I, where F is a periodic signal, A is a non-negative slowly varying function, and h is strictly increasing with h' slowly varying, N denotes background activity. For example, the method can be applied in the context of epileptic seizure detection. In this case, we try to detect seizure periodics in EEG and ECoG data. In the case of ECoG data, N is essentially 1/f noise. In the case of EEG data and for t in I,N includes noise due to cranial geometry and densities. In both cases N also includes standard low frequency rhythms. Periodicity detection has other applications including ocean wave prediction, cockpit motion sickness prediction, and minefield detection.

Benedetto, John J.; Pfander, Goetz E.

1998-10-01

376

Periodicities in Jupiter's magnetotail  

NASA Astrophysics Data System (ADS)

The New Horizons spacecraft had a close flyby of Jupiter in 2007. The Pluto energetic particle spectrometer science investigation (PEPSSI) made measurements beginning early in the same year. It obtained data as the spacecraft flew inward through closest approach and out down Jupiter's magnetotail. Measurements of ions and electrons were obtained to tail distances of over 1 AU. General surveys of electron data from PEPSSI revealed increases in intensity at approximately the spin period of the planet. These periodic variations were obtained well down the tail. It is not completely understood whether there is a periodic source of particles that remain coherent to large distances or whether the planet's period is somehow communicated down the tail. In this work, we will discuss the PEPSSI data by species to study the periodicities in the data and to constrain the source of these phenomena. In the past, other spacecraft data have revealed multiple periodicities much closer to the planet. These have been associated with both the planet's rotation and the periodic release of plasma down the tail.

Paranicas, C.; Haggerty, D. K.; Khurana, K. K.; Bagenal, F.

2011-12-01

377

On the Period Variations of BH Virginis  

NASA Astrophysics Data System (ADS)

In the present work, 17 new times of the light minimum for BHVir were derived from observations by Kjurkchieva etal. (2004, A&A, 424, 993). Combining the new determined eclipse times with others compiled from the literature, the behavior of their O-C variation was investigated. It has been found that the orbital period of BHVir shows some cyclic variations with three different periods: a long-period variation of 51.7years, and two short-period variations of 9.2years and 11.8years, respectively. The mechanisms that could explain the period changes of the system are discussed.

Tian, Yong-Po; Xiang, Fu-Yuan; Tao, Xia

2008-06-01

378

Calculation of periodic trajectories  

SciTech Connect

Methods are presented for calculating classical periodic trajectories in a two-dimensional non-integrable potential problem. The main one is the monodromy method, which consists in refining an approximate solution by using a ''once-around-the-trajectory'' procedure. This can be done either for a given period or for a given energy. Other methods proceed by searching on the initial conditions until the trajectory closes. We also discuss how to find new periodic families, particularly branchings from already known families, and how to get started when no families are known.

Baranger, M.; Davies, K.T.R.; Mahoney, J.H.

1988-08-15

379

Periodically poled silicon  

NASA Astrophysics Data System (ADS)

We propose a new class of photonic devices based on periodic stress fields in silicon that enable second-order nonlinearity as well as quasi-phase matching. Periodically poled silicon (PePSi) adds the periodic poling capability to silicon photonics and allows the excellent crystal quality and advanced manufacturing capabilities of silicon to be harnessed for devices based on second-order nonlinear effects. As an example of the utility of the PePSi technology, we present simulations showing that midwave infrared radiation can be efficiently generated through difference frequency generation from near-infrared with a conversion efficiency of 50%.

Hon, Nick K.; Tsia, Kevin K.; Solli, Daniel R.; Jalali, Bahram

2009-03-01

380

The Arm Program's Water Vapor Intensive Observation Periods  

Microsoft Academic Search

forward modeling) are continuing.The paper concludes by outlining the objectives of the recent 2000 WVIOP and the ARM-First International Satellite Cloud Climatology Project (ISCCP) Regional Experiment (FIRE) Water Vapor Experiment (AFWEX), the latter of which switched the focus to characterizing upper-tropospheric humidity measurements.

Henry E. Revercomb; David D. Turner; D. C. Tobin; Robert O. Knuteson; W. F. Feltz; James C. Barnard; J. Bösenberg; Shepard A. Clough; D. Cook; Richard Ferrare; John E M. Goldsmith; S. Gutman; R. N. Halthore; B. M. Lesht; James C. Liljegren; H. Linné; Joseph J. Michalsky; Victor R. Morris; William Porch; S. Richardson; B. Schmid; M. E. Splitt; T. van Hove; Ed R. Westwater; David N. Whiteman

2003-01-01

381

Periodic Slug Tests in a Sandstone Bedding Plane Fracture  

NASA Astrophysics Data System (ADS)

Periodic aquifer tests are conducted by varying the flow and/or head in a well at repeated intervals. The primary difference between periodic tests and traditional slug and pump tests is that the well is kept in a continuously transient state. Increased hydraulic transience leads to unique interpretations of aquifer storage as water is alternately withdrawn from and returned to the formation. We show results from period slug tests conducted in a sandstone bedding-plane fracture. A sinusoidal head variation is induced in a well by oscillating a slug with a programmed step motor. Head in four observation wells is monitored. All wells are 7 meters from the disturbed well and the fracture is isolated using inflatable packers. In spite of the fact that all wells are isolated in single fracture and are in close proximity, the observation wells exhibit a wide variation in both amplitude and phase response to head oscillations. Cross-hole pumping tests in the same well set show similar response in 3 of 4 monitoring wells, indicating that the periodic tests may be more sensitive to local changes in hydraulic conductivity and/or storativity. Independent hydraulic, tracer, and GPR experiments in this formation suggest that the periodic tests may be responding to flow channels that develop in response to hydraulic disturbance in the formation.

Becker, M. W.; Guiltinan, E.

2009-12-01

382

Lorenz Attractor Periodic Orbits  

NSDL National Science Digital Library

The butterfly-like Lorenz attractor is a simplified model of two-dimensional convective fluid flow and is one of the best known images of chaos. Embedded in this attractor are unstable periodic orbits described by Viswanath and this model computes a number of these orbits. Each periodic orbit is classified by the number of times the trajectory orbits the A and B fixed points before it repeats. Note that because the attractor is chaotic and because of numerical errors and the finite precision of the initial conditions, errors accumulate and the trajectory leaves the vicinity of a periodic orbit after a half dozen cycles. The Lorenz Attractor Periodic Orbits Model was created using the Easy Java Simulations (EJS) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the ejs_chaos_LorenzAttractor.jar file will run the program if Java is installed.

Christian, Wolfgang

2009-05-20

383

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.

384

Periodized Daubechies wavelets.  

National Technical Information Service (NTIS)

The properties of periodized Daubechies wavelets on (0,1) are detailed and counterparts which form a basis for L(sup 2)(R). Numerical examples illustrate the analytical estimates for convergence and demonstrated by comparison with Fourier spectral methods...

J. M. Restrepo G. K. Leaf G. Schlossnagle

1996-01-01

385

Quasi-biennial periodicity in the solar neutrino flux and its relation to the solar structure  

Microsoft Academic Search

By analysing the observed results on the neutrino flux from the Sun for the years 1970–1978, it is shown that the production rate of the neutrinos at the central core of the Sun had been varying with a period almost equal to 26 months for these years. This so-called ‘quasi-biennial’ periodicity in this rate suggests that the physical state of

Kunitomo Sakurai

1981-01-01

386

Periodical Cicada Page  

NSDL National Science Digital Library

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."

Cooley, John; Marshall, David

2008-01-14

387

A New Periodicity Lemma  

Microsoft Academic Search

Abstract. Given a string x = x[1..n], a repetition of period p in x is a substring u, is a repetition, t is a proper prefix of u, and no repetition of period p begins at position i 1 of x or ends at position i+rp+|t|. In 2000 Kolpakov and Kucherov [J. Discrete Algorithms, 1 (2000), pp. 159?186] showed that

Kangmin Fan; William F. Smyth; R. J. Simpson

2005-01-01

388

Imaging of periodic dielectrics  

Microsoft Academic Search

We consider imaging of periodic penetrable structures from measurements of scattered electromagnetic waves. The importance\\u000a of this problem stems from the decreasing size of periodic structures in photonic devices, together with an increasing demand\\u000a in fast non-destructive testing. This demand makes qualitative inverse scattering techniques particularly attractive since\\u000a they do not use time consuming optimization techniques for reconstruction but rather

Armin Lechleiter

2010-01-01

389

Periodization Research and an Example Application.  

ERIC Educational Resources Information Center

|Describes periodization in strength training (the cycling of specificity, intensity, and volume of training to achieve peak levels of performance for the most important conditions), suggesting that well-designed periodized programs will allow superior performance at the appropriate time, reduction in overtraining potential, systematic control…

Graham, John

2002-01-01

390

Children's Memory for Their Mother's Murder: Accuracy, Suggestibility, and Resistance to Suggestion.  

PubMed

From its inception, child eyewitness memory research has been guided by dramatic legal cases that turn on the testimony of children. Decades of scientific research reveal that, under many conditions, children can provide veracious accounts of traumatic experiences. Scientific studies also document factors that lead children to make false statements. In this paper we describe a legal case in which children testified about their mother's murder. We discuss factors that may have influenced the accuracy of the children's eyewitness memory. Children's suggestibility and resistance to suggestion are illustrated. Expert testimony, based on scientific research, can aid the trier of fact when children provide crucial evidence in criminal investigations and courtroom trials about tragic events. PMID:23362807

McWilliams, Kelly; Narr, Rachel; Goodman, Gail S; Ruiz, Sandra; Mendoza, Macaria

2013-01-31

391

The effect of women's suggestive clothing on men's behavior and judgment: a field study.  

PubMed

Numerous studies have shown that men overestimate the sexual intent of women based on their clothing style; however, this hypothesis has not been assessed empirically in a natural setting. This small field study measured the time it took for men to approach two female confederates sitting in a tavern, one wearing suggestive clothes and one wearing more conservative clothes. The behavior of 108 men was observed over 54 periods on 16 different nights in two different taverns. The time it took for the men to approach after initial eye contact was significantly shorter in the suggestive clothing condition. The men were also asked by male confederates to rate the likelihood of having a date with the women, and having sex on the first date. The men rated their chances to have a date and to have sex significantly higher in the suggestive clothing condition. Results are discussed with respect to men's possible misinterpretation that women's clothing indicates sexual interest, and the risks associated with the misinterpretation. PMID:22238861

Guéguen, Nicolas

2011-10-01

392

ASCA Observations  

NASA Astrophysics Data System (ADS)

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.

Helfand, David J.

1998-10-01

393

Rocket observations  

NASA Astrophysics Data System (ADS)

The Institute of Space and Astronautical Science (ISAS) sounding rocket experiments were carried out during the periods of August to September, 1982, January to February and August to September, 1983 and January to February, 1984 with sounding rockets. Among 9 rockets, 3 were K-9M, 1 was S-210, 3 were S-310 and 2 were S-520. Two scientific satellites were launched on February 20, 1983 for solar physics and on February 14, 1984 for X-ray astronomy. These satellites were named as TENMA and OHZORA and designated as 1983-011A and 1984-015A, respectively. Their initial orbital elements are also described. A payload recovery was successfully carried out by S-520-6 rocket as a part of MINIX (Microwave Ionosphere Non-linear Interaction Experiment) which is a scientific study of nonlinear plasma phenomena in conjunction with the environmental assessment study for the future SPS project. Near IR observation of the background sky shows a more intense flux than expected possibly coming from some extragalactic origin and this may be related to the evolution of the universe. US-Japan cooperative program of Tether Experiment was done on board US rocket.

1984-05-01

394

Suggested Revised H Values of Selected Asteroids: Report Number 3  

NASA Astrophysics Data System (ADS)

We report results obtained by the “Magnitude Alert Project” (MAP) during the first ten years of activity, from 1996 to 2006. As of December 31, 2006 the MAP Database contained 430 asteroids and 4927 measures. 16 minor planets, for which visual and CCD measures indicate an average difference of H magnitude from the current predicted values, have been observed at least during three oppositions. These confirmed discrepancies are from 0.3 to 2.6 magnitudes. We suggest a revision of their catalogued H magnitude to permit better predicted magnitudes in ephemerides of these objects, notably by the Minor Planet Center.

Faure, Gerard; Garret, Lawrence

2007-12-01

395

Suggested Revised H Values of Selected Asteroids: Report Number 4  

NASA Astrophysics Data System (ADS)

We report the main results obtained by the “Magnitude Alert Project” (MAP) from 2007 to mid-2009. On 2009 May 31 the MAP Database contained 495 asteroids and 5541 measures. Observations were made of 19 minor planets on at least three oppositions for which visual and CCD measures indicated a significant difference from the predicted value. These discrepancies ranged from 0.2 to 1.7 magnitudes. We suggest a revision of their catalogued H magnitude to permit better predicted magnitudes in the future ephemerides of these objects, notably by the Minor Planet Center.

Faure, Gerard; Garrett, Lawrence

2009-10-01

396

A Revised Period For AY Aur  

NASA Astrophysics Data System (ADS)

The period of the Mira variable AY Aur has been determined to be longer than that published in the GCVS 4th Edition. Fourier and CLEANEST analysis of AAVSO data determines the period to be 389.8 days. The discrepancy may have been caused by the effects of large gaps in observational data magnified by the close proximity of the star's period in relation to the length of the solar cycle.

Price, A.; Templeton, M. R.; Mattei, J. A.

2003-02-01

397

Biperiodic orbital period modulation of the W UMa binary system CK Bootis  

NASA Astrophysics Data System (ADS)

A study of the orbital period variation of the W UMa system CK Bootis is made using an extended observational time base. The biperiodicity of the orbital period modulation is emphasized. Both detected periodicities (24.14 yr and 10.62 yr) cannot be explained through the light-time effect unless the companion would be a white dwarf as suggested by other authors, too. Moreover, we also argue that, nowadays at least, it seems that there is no causal relation between the orbital period variation and the recently discovered visual companion. Consequently, we infer that at least one of the two periodicities may be related to the magnetic activity cycles in the component stars of CK Boo, while the other periodicity could be related to the presence of a fourth companion in the system.

Pop, Alexandru; Vamo?, C?lin

2012-10-01

398

David's Understanding of Functions and Periodicity  

ERIC Educational Resources Information Center

|This is a study of David, a senior enrolled in a high school precalculus course. David's understandings of functions and periodicity was explored, through clinical interviews and contextualized through classroom observations. Although David's precalculus class was traditional his understanding of periodic functions was unconventional David…

Gerson, Hope

2008-01-01

399

The Periodic Table: An Eight Period Table For The 21 st Centrury  

Microsoft Academic Search

Throughout most of the 20th century, an eight-period periodic table (also known as an electron-configuration table) was offered as an improvement over the ubiquitous seven-period format of wall charts and textbooks. The eight-period version has never achieved wide acceptance although it has significant advantages. Many observers have questioned the way helium is displayed in this format. Now, a reinterpretation of

Gary Katz

2001-01-01

400

Period and Styles  

NSDL National Science Digital Library

Designed by Tulane University Professor Hugh Lester to complement his courses for advanced theater design students, this collection of teaching modules and images will appeal to anyone with an interest in architecture or historical design. The modules offer varying levels of detail about historical time periods from Ancient Egypt to Modern. The image collection offers photos and information on a variety of architectural, decorative and furniture styles. Typical entries include a thumbnail image, location, name of architect or designer, and date of construction. Some provide commentary on the design and its place in the period. Access to images varies in terms of how it is organized in the module and image sections.

401

ACS Periodic Table  

NSDL National Science Digital Library

This Web site from the American Chemical Society features an interactive Periodic Table with the use of Shockwave. The information presented is divided into three sections. In the first, Periodic Table, students will find attributes such as melting point and molar heat capacity for the elements. The second part illustrates the electron configurations of each of the elements, helping students to better understand the concept. The last section allows users to plot data based on the elements' attributes including atomic radius and electro negativity. Working with this site, high school and college students are able to improve their chemical knowledge.

402

Periodic Table Live!  

NSDL National Science Digital Library

Periodic Table Live!, produced by the Division of Chemical Education at the University of Wisconsin-Madison, allows users "to explore a broad range of information about the elements, their reactions, their properties, their structures and their histories." After selecting an element from the periodic table, users can access a myriad of information divided into three sections: Description, Physical, and Atomic. Students can view short videos of many of the elements' reactions with air, water, acids, and bases. The website is equipped with a helpful glossary and images of the elements, scientists, and other related items.

403

Early Infancy as a Critical Period for Development of Obesity and Related Conditions  

Microsoft Academic Search

The current obesity epidemic has affected even the youngest children in our societies, including those in the first months of life. Animal experiments suggest that the early postnatal period may be critical to development of healthful energy homeostasis and thus prevention of obesity. In humans, observational studies and follow-up of randomized feeding trials show that rapid weight gain in the

Matthew W. Gillman

2010-01-01

404

Diurnal Variations of Quasi-Periodic and Periodic VLF emissions in the Outer Magnetosphere  

NASA Astrophysics Data System (ADS)

ELF-VLF receiver and search coil magnetometer data from four Antarctic stations during 1998 have been analyzed to study quasi-periodic emissions (QPs) and periodic emissions (PEs), which occur as ULF-range modulations of ELF-VLF signals between 0.5 kHz and ˜4 kHz. QPs are modulated at frequencies of 15-50 mHz, and PEs are modulated at frequencies of 100-500 mHz. The stations used covered a range of magnetic latitudes from -62° (Halley) to -74° (South Pole Station); two automated geophysical observatories (AGOs) were located at intermediate latitudes. Consistent with earlier studies, most QPs were observed with magnetic pulsations of identical period in the Pc 3-4 range (type I QPs). Of those QPs not observed with simultaneous magnetic pulsations (type II QPs), nearly all were accompanied by PEs. It is also notable that no PE events simultaneous with Pc 3-4 magnetic pulsations but without QPs were observed during the entire year at any station. Diurnal patterns of all categories of QP events show occurrence maxima in the noon or post-noon sectors. The total absence of type I QP occurrences without PEs on the nightside is consistent with the expected absence of Pc 3-4 pulsations there, because of their origin at the upstream bow shock. PEs, on the other hand, could be seen at all local times. Diurnal profiles showed no latitudinal or seasonal differences for most categories, except for a clear reversal of the profile of PE occurrence with latitude. In every multistation event studied, we have found QP and/or PE modulations to be simultaneous at all stations to within the 1-s sampling time of the data. This suggests that all such events originate a single, localized region, most probably near the plasmapause. In contrast, the magnetic pulsations showed little or no detailed correlation between stations. Both statistical and single event studies support the hypothesis that highly localized field-aligned currents stimulated by echoing whistlers (PEs) may be responsible for producing type II QPs on the same flux tubes, typically in the subauroral or auroral regions. In addition, we have noted that the small number of type II QP events we have observed without accompanying PEs is tightly clustered near local noon. The existence of a set of equatorially-localized, near-noon, compressional Pc 3-4 waves that evidently do not appear in ground records suggests that this category as well might be generated by ULF wave modulation of equatorial ELF/VLF wave growth.

Engebretson, M. J.; Posch, J. L.; Shelburne, G. A.; Halford, A. J.; Smith, A. J.; Spasojevich, M.; Inan, U. S.; Arnoldy, R. L.

2003-12-01

405

SCIENCE PERIODICALS USE STUDY  

Microsoft Academic Search

A two-semester study of science periodicals usage at State University of New York at Albany was conducted to identify little used titles for storage or possibly discard. Even in this large multidisciplinary collection a small core of journals accounted for a large percentage of use. Use patterns over time were also recorded and are reported for selected titles. Use rankings

Barbara A. Rice

1979-01-01

406

Indexing of Feminist Periodicals  

Microsoft Academic Search

During the last twelve years there has been a phenomenal increase in the number of periodicals focusing on women's studies and feminism. Initially these titles were ignored by most indexing and abstracting services. The earliest indexing, by the Alternative Press Index and Women Studies Abstracts appeared in 1971 and 1972. Since 1975 there has been a marked increase in the

Mary Alice Sanguinetti

1984-01-01

407

Scheduling: Seven Period Day  

ERIC Educational Resources Information Center

|Driven by stable or declining financial resources many school districts are considering the costs and benefits of a seven-period day. While there is limited evidence that any particular scheduling model has a greater impact on student learning than any other, it is clear that the school schedule is a tool that can significantly impact teacher…

Williamson, Ronald

2010-01-01

408

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.

409

Adaptive periodic IIR filters  

Microsoft Academic Search

We consider adaptive periodic IIR filtering and present an extension of the hyperstable adaptive recursive filter (HARF). We give conditions for convergence of the parameter estimate error, involving passivity of certain operators in the identification loop, identifiability of the system parameters, and persistent excitation (PE). A necessary and sufficient condition for identifiability is given and subject to its satisfaction, input-only

J. W. Whikehart; S. Dasgupta

1997-01-01

410

Long-Period Variability in o Ceti  

NASA Astrophysics Data System (ADS)

We carried out a new and sensitive search for long-period variability in the prototype of the Mira class of long-period pulsating variables, o Ceti (Mira A), the closest and brightest Mira variable. We conducted this search using an unbroken light curve from 1902 to the present, assembled from the visual data archives of five major variable star observing organizations from around the world. We applied several time-series analysis techniques to search for two specific kinds of variability: long secondary periods (LSPs) longer than the dominant pulsation period of ~333 days, and long-term period variation in the dominant pulsation period itself. The data quality is sufficient to detect coherent periodic variations with photometric amplitudes of 0.05 mag or less. We do not find evidence for coherent LSPs in o Ceti to a limit of 0.1 mag, where the amplitude limit is set by intrinsic, stochastic, low-frequency variability of approximately 0.1 mag. We marginally detect a slight modulation of the pulsation period similar in timescale to that observed in the Miras with meandering periods, but with a much lower period amplitude of ±2 days. However, we do find clear evidence of a low-frequency power-law component in the Fourier spectrum of o Ceti's long-term light curve. The amplitude of this stochastic variability is approximately 0.1 mag at a period of 1000 days, and it exhibits a turnover for periods longer than this. This spectrum is similar to the red noise spectra observed in red supergiants.

Templeton, Matthew R.; Karovska, Margarita

2009-02-01

411

Mauna Kea Observatory Infrared Observations.  

National Technical Information Service (NTIS)

Galactic and solar system infrared observations are reported using a broad variety of radiometric and spectroscopic instrumentation. Infrared programs and papers published during this period are listed.

J. T. Jefferies

1974-01-01

412

Periodic radio variabilities in NRAO 530: a jet-disc connection?  

NASA Astrophysics Data System (ADS)

Time series analysis techniques, Lomb-Scargle periodogram and weighted wavelet Z-transform, have been employed to search for year-time-scale periodicities from the radio light curves of a typical blazar NRAO 530. The periodicity analysis using the two methods show consistent results: two strong and persistent periods of ˜10 and ˜6 yr are prominent at all three wavelengths; three other weaker periodicities with shorter time-scales (˜5, ˜3.5 and ˜3 yr) were also seen; in addition, the 14.5-GHz WWZ power spectrum revealed a ˜2-yr periodic component during the time interval 1983-1990. Statistical significance analysis suggests that these periodicities might result from physically periodic process. The characteristic frequencies of these periodicities seem to have a harmonic relationship, and the fundamental frequency, i.e. the first-order harmonic, is about 0.05 yr-1 (P0 = 20 yr). But the fundamental frequency was not pronounced. The multiplicity and apparent harmonic relationship of the periodicities could be interpreted by the global p-mode oscillation of the accretion disc, if the jet and disc are coupled. In this scenario, the periodic fluctuations in the accretion rate consequently lead to the observed periodic variabilities of the radio luminosity.

An, Tao; Baan, Willem A.; Wang, Jun-Yi; Wang, Yu; Hong, Xiao-Yu

2013-10-01

413

Rotational periods of asteroids II  

NASA Astrophysics Data System (ADS)

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.

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

2001-06-01