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

Energy Technology Data Exchange (ETDEWEB)

Burton, J. R.; Watson, C. A.; Fitzsimmons, A.; Moulds, V. [Astrophysics Research Centre, Queen' s University Belfast, Belfast BT7 1NN (United Kingdom); Pollacco, D.; Wheatley, P. J. [Department of Physics and Astronomy, University of Warwick, Coventry CV4 7AL (United Kingdom); Littlefair, S. P., E-mail: jburton04@qub.ac.uk [Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH (United Kingdom)

2014-07-10

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

High-Resolution Observations of a Filament showing Activated Barb

Science.gov (United States)

Joshi, Anand; Martin, Sara F.; Mathew, Shibu; Srivastava, Nandita

2012-07-01

Analysis of a filament showing an activated barb using observations from the Dutch Open Telescope (DOT) on 2010 August 20 are presented. The DOT takes Doppler images in Hα, among other wavelengths, in a region about 110 × 110 arcsec^{2} in area, at a cadence of 30~seconds. The offline image restoration technique of speckle reconstruction is applied to obtain diffraction limited images. The filament developed a new barb in 10~minutes, which disappeared within the next 35~minutes. Such a rapid formation and disappearance of a filament barb is unusual, and has not been reported earlier. Line-of-sight velocity maps were constructed from the Doppler images of the target filament. We observe flows in the filament spine towards the barb location prior to its formation, and flows in the barb towards the spine during its disappearance. Photospheric magnetograms from Heliospheric Magnetic Imager on board the Solar Dynamics Observatory, at a cadence of 45~seconds, were used to determine the changes in magnetic flux in the region surrounding the barb location. The variation of magnetic flux in this duration supports the view that barbs are rooted in minor magnetic polarity. Our analysis shows that barbs can be short-lived and formation and disappearance of the barb was associated with cancellation of magnetic flux.

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

DEFF Research Database (Denmark)

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

2013-01-01

, 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......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...

Climatic trends in Estonia during the period of instrumental observations and climate scenarios

International Nuclear Information System (INIS)

Jaagus, J.

1996-01-01

Weather conditions in Estonia are quite variable. Long-term periodical fluctuations have been observed in meteorological values. At the same time, the climate change during the last 100-150 years is marked. As a general tendency, the climate has become more maritime. Air pressure is characterized by an increasing trend in spring and summer, and by a decreasing trend in autumn and winter. Mean air temperature has increased, particularly over the colder half of the year. Precipitation area totals have risen, most of all in autumn and winter. Snow cover duration has decreased significantly. General circulation model-based climate change scenarios expect a general increase in air temperature in Estonia with warming in winter more significant than that in summer. Moreover, they indicate an increase in precipitation, but the results of the individual models are quite variable. The transient scenario shows that the main increase in precipitation will not occur during next decades, but only at the end of the transient period, around 2070. It can be stated that observed tendencies of climate change in Estonia concur with expected changes caused by global warming. According to the long-term fluctuations of meteorological values in Estonia, changes different from general trends can take place during the next decade. An increase in mean air pressure, sunshine duration and snow cover duration, as well as a decrease in mean air temperature and precipitation is expected in the following years

Observation of quasi-periodic solar radio bursts associated with propagating fast-mode waves

Science.gov (United States)

Goddard, C. R.; Nisticò, G.; Nakariakov, V. M.; Zimovets, I. V.; White, S. M.

2016-10-01

Aims: Radio emission observations from the Learmonth and Bruny Island radio spectrographs are analysed to determine the nature of a train of discrete, periodic radio "sparks" (finite-bandwidth, short-duration isolated radio features) which precede a type II burst. We analyse extreme ultraviolet (EUV) imaging from SDO/AIA at multiple wavelengths and identify a series of quasi-periodic rapidly-propagating enhancements, which we interpret as a fast wave train, and link these to the detected radio features. Methods: The speeds and positions of the periodic rapidly propagating fast waves and the coronal mass ejection (CME) were recorded using running-difference images and time-distance analysis. From the frequency of the radio sparks the local electron density at the emission location was estimated for each. Using an empirical model for the scaling of density in the corona, the calculated electron density was used to obtain the height above the surface at which the emission occurs, and the propagation velocity of the emission location. Results: The period of the radio sparks, δtr = 1.78 ± 0.04 min, matches the period of the fast wave train observed at 171 Å, δtEUV = 1.7 ± 0.2 min. The inferred speed of the emission location of the radio sparks, 630 km s-1, is comparable to the measured speed of the CME leading edge, 500 km s-1, and the speeds derived from the drifting of the type II lanes. The calculated height of the radio emission (obtained from the density) matches the observed location of the CME leading edge. From the above evidence we propose that the radio sparks are caused by the quasi-periodic fast waves, and the emission is generated as they catch up and interact with the leading edge of the CME. The movie associated to Fig. 2 is available at http://www.aanda.org

Overview of the first HyMeX special observation period over Croatia

Science.gov (United States)

Ivančan-Picek, Branka; Tudor, Martina; Horvath, Kristian; Stanešić, Antonio; Ivatek-Šahdan, Stjepan

2016-12-01

The HYdrological cycle in the Mediterranean EXperiment (HyMeX) is intended to improve the capabilities of predicting high-impact weather events. Within its framework, the aim of the first special observation period (SOP1), 5 September to 6 November 2012, was to study heavy precipitation events and flash floods. Here, we present high-impact weather events over Croatia that occurred during SOP1. Particular attention is given to eight intense observation periods (IOPs), during which high precipitation occurred over the eastern Adriatic and Dinaric Alps. During the entire SOP1, the operational model forecasts generally well represented medium intensity precipitation, but heavy precipitation was frequently underestimated by the ALADIN model at an 8 km grid spacing and was overestimated at a higher resolution (2 km grid spacing). During IOP2, intensive rainfall occurred over a wider area around the city of Rijeka in the northern Adriatic. The short-range maximum rainfall totals were the largest ever recorded at the Rijeka station since the beginning of measurements in 1958. The rainfall amounts measured in intervals of 20, 30 and 40 min were exceptional, with return periods that exceeded a thousand, a few hundred and one hundred years, respectively. The operational precipitation forecast using the ALADIN model at an 8 km grid spacing provided guidance regarding the event but underestimated the rainfall intensity. An evaluation of numerical sensitivity experiments suggested that the forecast was slightly enhanced by improving the initial conditions through variational data assimilation. The operational non-hydrostatic run at a 2 km grid spacing using a configuration with the ALARO physics package further improved the forecast. This article highlights the need for an intensive observation period in the future over the Adriatic region to validate the simulated mechanisms and improve numerical weather predictions via data assimilation and model improvements in descriptions

Period Study and Analyses of 2017 Observations of the Totally Eclipsing, Solar Type Binary, MT Camelopardalis

Science.gov (United States)

Faulkner, Danny R.; Samec, Ronald G.; Caton, Daniel B.

2018-06-01

We report here on a period study and the analysis of BVRcIc light curves (taken in 2017) of MT Cam (GSC03737-01085), which is a solar type (T ~ 5500K) eclipsing binary. D. Caton observed MT Cam on 05, 14, 15, 16, and 17, December 2017 with the 0.81-m reflector at Dark Sky Observatory. Six times of minimum light were calculated from four primary eclipses and two secondary eclipses:HJD I = 24 58092.4937±0.0002, 2458102.74600±0.0021, 2458104.5769±0.0002, 2458104.9434±0.0029HJD II = 2458103.6610±0.0001, 2458104.7607±0.0020,Six times of minimum light were also calculated from data taken by Terrell, Gross, and Cooney, in their 2016 and 2004 observations (reported in IBVS #6166; TGC, hereafter). In addition, six more times of minimum light were taken from the literature. From all 18 times of minimum light, we determined the following light elements:JD Hel Min I=2458102.7460(4) + 0.36613937(5) EWe found the orbital period was constant over the 14 years spanning all observations. We note that TGC found a slightly increasing period. However, our results were obtained from a period study rather than comparison of observations from only two epochs by the Wilson-Devinney (W-D) Program. A BVRcIc Johnson-Cousins filtered simultaneous W-D Program solution gives a mass ratio (0.3385±0.0014) very nearly the same as TGC’s (0.347±0.003), and a component temperature difference of only ~40 K. As with TGC, no spot was needed in the modeling. Our modeling (beginning with Binary Maker 3.0 fits) was done without prior knowledge of TGC’s. This shows the agreement achieved when independent analyses are done with the W-D code. The present observations were taken 1.8 years later than the last curves by TGC, so some variation is expected.The Roche Lobe fill-out of the binary is ~13% and the inclination is ~83.5 degrees. The system is a shallow contact W-type W UMa Binary, albeit, the amplitudes of the primary and secondary eclipse are very nearly identical. An eclipse duration of ~21

Dinosaur incubation periods directly determined from growth-line counts in embryonic teeth show reptilian-grade development.

Science.gov (United States)

Erickson, Gregory M; Zelenitsky, Darla K; Kay, David Ian; Norell, Mark A

2017-01-17

Birds stand out from other egg-laying amniotes by producing relatively small numbers of large eggs with very short incubation periods (average 11-85 d). This aspect promotes high survivorship by limiting exposure to predation and environmental perturbation, allows for larger more fit young, and facilitates rapid attainment of adult size. Birds are living dinosaurs; their rapid development has been considered to reflect the primitive dinosaurian condition. Here, nonavian dinosaurian incubation periods in both small and large ornithischian taxa are empirically determined through growth-line counts in embryonic teeth. Our results show unexpectedly slow incubation (2.8 and 5.8 mo) like those of outgroup reptiles. Developmental and physiological constraints would have rendered tooth formation and incubation inherently slow in other dinosaur lineages and basal birds. The capacity to determine incubation periods in extinct egg-laying amniotes has implications for dinosaurian embryology, life history strategies, and survivorship across the Cretaceous-Paleogene mass extinction event.

Aerosol chemical composition at Cabauw, The Netherlands as observed in two intensive periods in May 2008 and March 2009

Science.gov (United States)

Mensah, A. A.; Holzinger, R.; Otjes, R.; Trimborn, A.; Mentel, Th. F.; ten Brink, H.; Henzing, B.; Kiendler-Scharr, A.

2012-05-01

Observations of aerosol chemical composition in Cabauw, the Netherlands, are presented for two intensive measurement periods in May 2008 and March 2009. Sub-micron aerosol chemical composition was measured by an Aerodyne Aerosol Mass Spectrometer (AMS) and is compared to observations from aerosol size distribution measurements as well as composition measurements with a Monitor for AeRosol and GAses (MARGA) based instrument and a Thermal-Desorption Proton-Transfer-Reaction Mass-Spectrometer (TD-PTR-MS). An overview of the data is presented and the data quality is discussed. In May 2008 enhanced pollution was observed with organics contributing 40% to the PM1 mass. In contrast the observed average mass loading was lower in March 2009 and a dominance of ammonium nitrate (42%) was observed. The semi-volatile nature of ammonium nitrate is evident in the diurnal cycles with maximum concentrations observed in the morning hours in May 2008 and little diurnal variation observed in March 2009. Size dependent composition data from AMS measurements are presented and show a dominance of organics in the size range below 200 nm. A higher O:C ratio of the organics is observed for May 2008 than for March 2009. Together with the time series of individual tracer ions this shows the dominance of OOA over HOA in May 2008.

Long Period Seismological Research Program

Science.gov (United States)

1974-10-31

in central Asia as observed at the high-gain long- period sites. Preliminary results from observations at Chiang Mai (CHG) show that the complexity...Preliminary results from observations at Chiang Mai (CHG) show that the complexity of the surface wave signals from many events in the Tadzhik-Kirgiz...and receivers. A number of Interesting features can be illustrated by examining portions of three selsmograms recorded at Chiang Mai (CHO

Short-Period Binary Stars: Observations, Analyses, and Results

CERN Document Server

Milone, Eugene F; Hobill, David W

2008-01-01

Short-period binaries run the gamut from widely separated stars to black-hole pairs; in between are systems that include neutron stars and white dwarfs, and partially evolved systems such as tidally distorted and over-contact systems. These objects represent stages of evolution of binary stars, and their degrees of separation provide critical clues to how their evolutionary paths differ from that of single stars. The widest and least distorted systems provide astronomers with the essential precise data needed to study all stars: mass and radius. The interactions of binary star components, on the other hand, provide a natural laboratory to observe how the matter in these stars behaves under different and often varying physical conditions. Thus, cataclysmic variables with and without overpoweringly strong magnetic fields, and stars with densities from that found in the Sun to the degenerate matter of white dwarfs and the ultra-compact states of neutron stars and black holes are all discussed. The extensive inde...

Experimental observation of parametric effects near period doubling in a loss-modulated CO2 laser

OpenAIRE

Chizhevsky, V. N.

1996-01-01

A number of parametric effects, such as suppression of period doubling, shift of the bifurcation point, scaling law relating the shift and the perturbation amplitude, influence of the detuning on the suppression, reaching of the maximum gain between the original and shifted bifurcation points, and scaling law for idler power are experimentally observed near period doubling bifurcation in a loss-driven CO2 laser that is subjected to periodic loss perturbations at a frequency that is close to a...

Aerosol chemical composition at Cabauw, The Netherlands as observed in two intensive periods in May 2008 and March 2009

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A. A. Mensah

2012-05-01

Full Text Available Observations of aerosol chemical composition in Cabauw, the Netherlands, are presented for two intensive measurement periods in May 2008 and March 2009. Sub-micron aerosol chemical composition was measured by an Aerodyne Aerosol Mass Spectrometer (AMS and is compared to observations from aerosol size distribution measurements as well as composition measurements with a Monitor for AeRosol and GAses (MARGA based instrument and a Thermal-Desorption Proton-Transfer-Reaction Mass-Spectrometer (TD-PTR-MS. An overview of the data is presented and the data quality is discussed. In May 2008 enhanced pollution was observed with organics contributing 40% to the PM₁ mass. In contrast the observed average mass loading was lower in March 2009 and a dominance of ammonium nitrate (42% was observed. The semi-volatile nature of ammonium nitrate is evident in the diurnal cycles with maximum concentrations observed in the morning hours in May 2008 and little diurnal variation observed in March 2009. Size dependent composition data from AMS measurements are presented and show a dominance of organics in the size range below 200 nm. A higher O:C ratio of the organics is observed for May 2008 than for March 2009. Together with the time series of individual tracer ions this shows the dominance of OOA over HOA in May 2008.

Summer weather characteristics and periodicity observed over the period 1888-2013 in the region of Belgrade, Serbia

Science.gov (United States)

Vujović, Dragana; Todorović, Nedeljko; Paskota, Mira

2018-04-01

With the goal of finding summer climate patterns in the region of Belgrade (Serbia) over the period 1888-2013, different techniques of multivariate statistical analysis were used in order to analyze the simultaneous changes of a number of climatologic parameters. An increasing trend of the mean daily minimum temperature was detected. In the recent decades (1960-2013), this increase was much more pronounced. The number of days with the daily minimum temperature greater or equal to 20 °C also increased significantly. Precipitation had no statistically significant trend. Spectral analysis showed a repetitive nature of the climatologic parameters which had periods that roughly can be classified into three groups, with the durations of the following: (1) 6 to 7 years, (2) 10 to 18 years, and (3) 21, 31, and 41 years. The temperature variables mainly had one period of repetitiveness of 5 to 7 years. Among other variables, the correlations of regional fluctuations of the temperature and precipitation and atmospheric circulation indices were analyzed. The North Atlantic oscillation index had the same periodicity as that of the precipitation, and it was not correlated to the temperature variables. Atlantic multidecadal oscillation index correlated well to the summer mean daily minimum and summer mean temperatures. The underlying structure of the data was analyzed by principal component analysis, which detected the following four easily interpreted dimensions: More sunshine-Higher temperature, Precipitation, Extreme heats, and Changeable summer.

STS-39 Earth observation of Earth's limb at sunset shows atmospheric layers

Science.gov (United States)

1991-01-01

STS-39 Earth observation taken aboard Discovery, Orbiter Vehicle (OV) 103, shows the Earth's limb at sunset with numerous atmospheric scattering layers highlighted. The layers consist of fine particles suspended in very stable layers of the atmosphere. The layers act as a prism for the sunlight.

On the observed excess of retrograde orbits among long-period comets

International Nuclear Information System (INIS)

Fernandez, J.A.

1981-01-01

The distribution of orbital inclinations of the observed long-period comets is analysed. An excess of retrograde orbits is found which increases with the perihelion distance, except for the range 1.1 10 3 A U) has the same behaviour as the total sample. It is thus suggested that the excess of retrograde orbits among long-period comets is related to an already existent excess among the incoming new comets (i.e. comets driven into the planetary region by stellar perturbations). Using theoretical considerations and a numerical model it is proposed that an important fraction of the so-called new comets are actually repeating passages through the planetary region. Nearly a half of the new comets with q > 2 A U may be repeating passages. An important consequence of the presence of comets repeating passages among the new ones is the production of an excess of retrograde orbits in the whole sample. (author)

Periodic and quasiperiodic revivals in periodically driven interacting quantum systems

Science.gov (United States)

Luitz, David J.; Lazarides, Achilleas; Bar Lev, Yevgeny

2018-01-01

Recently it has been shown that interparticle interactions generically destroy dynamical localization in periodically driven systems, resulting in diffusive transport and heating. In this Rapid Communication we rigorously construct a family of interacting driven systems which are dynamically localized and effectively decoupled from the external driving potential. We show that these systems exhibit tunable periodic or quasiperiodic revivals of the many-body wave function and thus of all physical observables. By numerically examining spinless fermions on a one-dimensional lattice we show that the analytically obtained revivals of such systems remain stable for finite systems with open boundary conditions while having a finite lifetime in the presence of static spatial disorder. We find this lifetime to be inversely proportional to the disorder strength.

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

Energy Technology Data Exchange (ETDEWEB)

Demissie, T.D.; Hibbins, R.E.; Espy, P.J. [Norwegian Univ. of Science and Technology (NTNU), Trondheim (Norway); Birkeland Centre for Space Science, Bergen (Norway); Kleinknecht, N.H.; Straub, C. [Norwegian Univ. of Science and Technology (NTNU), Trondheim (Norway)

2013-09-01

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

Travelling Ionospheric Disturbances Observed During Sudden Stratospheric Warming, Equinox and Solstice Periods with Kharkiv and Millstone Hill Incoherent Scatter Radars

Science.gov (United States)

Goncharenko, L. P.; Panasenko, S.; Aksonova, K.; Erickson, P. J.; Domnin, I. F.

2016-12-01

Travelling ionospheric disturbances (TIDs) play a key role in the coupling of different ionospheric regions through momentum an energy transfer. They are thought to be mostly associated with atmospheric gravity waves and are known to strongly affect radio propagation conditions. The incoherent scatter (IS) method enables TIDs detection in such ionospheric parameters as electron density, ion and electron temperatures, and plasma velocity along radar beam, thus providing critical information needed to examine different hypothesis about association of TIDs with their sources. In 2016, several joint measuring campaigns were conducted using Kharkiv (49.6 N, 36.4 E) and Millstone Hill (42.6 N, 288.5 E) IS radars. These campaigns covered the periods of sudden stratospheric warnings (SSW) in February, vernal equinox and summer solstice. For consistency, the data acquired by radars were processed using the same data analysis methods. The results obtained show the TIDs to be detected throughout all observation intervals in February measurements. The differences found in the behavior of TIDs over Kharkiv and Millstone Hill sites may be partially explained by variations in stratospheric wind velocity vectors during SSW period. As for March equinox and June solstice, the prevailing TIDs are observed near solar terminators. Their periods vary mostly in the range of 40 - 80 minutes, relative amplitudes are about 0.05 - 0.3 of the background electron density, and the maximum values are observed at the heights of 200 - 250 km. Systematic long-term observations of wave processes in the ionosphere with multiple IS facilities can reveal interhemispheric variability in TID parameters, give better understanding the mechanisms of TID generation and propagation, and improve regional and global ionospheric models.

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

Science.gov (United States)

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

2005-01-01

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.

The period of the magnetic star HD 133 029

International Nuclear Information System (INIS)

Panov, K.; Schoeneich, W.

1976-01-01

The period of 0.741285 days for the light variability of the magnetic star HD 133 029 was obtained from UBV observations. The observations of the effective magnetic field by Babcock show variations with a period of 0.7447 days. A small change of the period and a slow change of the magnitude of this magnetic star seems to be present. (author)

Postaccident changes in heath status of the Chornobyl cleanup workers 1986-1987 (period of observation 1988-2012)

International Nuclear Information System (INIS)

Buzunov, V.O.; Vojchulene, Yu.S.; Domashevs'ka, T.Je.; Khabarova, T.P.; Kortushyin, G.Yi.

2015-01-01

Long-term cohort epidemiological study (period of observation 1988-2012) has been conducted using data of the State Registry of Ukraine of Persons Affected by the Chornobyl Accident. Study cohort - 196,423 males-participants of the Chornobyl recovery operations in 1986-1987. Epidemiological and mathematical- and-statistical methods were used. We have found a dramatic deterioration of the Chornobyl cleanup workers' health due to the growth of wide range of nontumor diseases, especially circulatory, digestive, respiratory, endocrine, genitourinary and nervous system diseases. In postaccident period, disability and mortality have increased significantly due to nontumor diseases. Circulatory diseases make major contribution to the structure of causes of disability and death. When studying the dynamics of nontumor incidence, we have found that in 1988-1992 the highest, throughout postaccident period, rate of mental and behavioral disorders, diseases of the nervous system was mainly due to disorders of the autonomic nervous system. Since 1993-1997, rate of this pathology has significantly reduced and remained stable in subsequent years of observation. Thus, we can assume that in the early postaccident period, stress factor in combination with radiation one had the greatest impact on health of cleanup workers, resulting in the development of other nontumor diseases in the remote postaccident period. The study revealed an evident increase in nontumor incidence, disability and mortality from nontumor diseases among Chornobyl cleanup workers 1986-1987; the highest rate of nontumor incidence was observed 12-21 years after the Chornobyl accident

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

Science.gov (United States)

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

2008-02-01

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

Experimental observation of chaotic phase synchronization of a periodically pump-modulated multimode microchip Nd:YVO{sub 4} laser

Energy Technology Data Exchange (ETDEWEB)

Lin, Chien-Hui; Kuo, Chie-Tong [Department of Physics, National Sun Yat-Sen University, Kaohsiung 804, Taiwan, ROC (China); Hsu, Tzu-Fang, E-mail: tfhsu@mail.npue.edu.tw [Department of Applied Physics, National Pingtung University of Education, Pingtung 900, Taiwan, ROC (China); Jan, Hengtai; Han, Shiang-Yi [Department of Physics, National Kaohsiung Normal University, No. 62, Shenjhong Rd., Yanchao District, Kaohsiung City 824, Taiwan, ROC (China); Ho, Ming-Chung, E-mail: t1603@nknucc.nknu.edu.tw [Department of Physics, National Kaohsiung Normal University, No. 62, Shenjhong Rd., Yanchao District, Kaohsiung City 824, Taiwan, ROC (China); Jiang, I-Min [Department of Physics, National Sun Yat-Sen University, Kaohsiung 804, Taiwan, ROC (China)

2012-03-12

In this Letter we demonstrate the experimental observation of chaotic phase synchronization (CPS) in a periodically pump-modulated multimode microchip Nd:YVO{sub 4} laser. PS transition is displayed via the stroboscopic technique. We apply the recurrence probability and correlation probability of recurrence to estimate the degree of PS. The degree of PS is studied taking into account the modulation amplitude and modulation frequency. We also propose an experimental compatible numerical simulation to reflect the fact that the Arnold tongues are experimentally and numerically exhibited in the periodically pump-modulated multimode microchip Nd:YVO{sub 4} laser. -- Highlights: ► We show chaotic phase synchronization in a pump-modulated microchip Nd:YVO{sub 4} laser. ► Phase synchronization (PS) transition is displayed via the stroboscopic technique. ► The degree of PS is studied taking into account the modulation parameters. ► The Arnold tongues are experimentally and numerically exhibited in the laser.

Subarcsecond bright points and quasi-periodic upflows below a quiescent filament observed by IRIS

Science.gov (United States)

Li, T.; Zhang, J.

2016-05-01

Context. The new Interface Region Imaging Spectrograph (IRIS) mission provides high-resolution observations of UV spectra and slit-jaw images (SJIs). These data have become available for investigating the dynamic features in the transition region (TR) below the on-disk filaments. Aims: The driver of "counter-streaming" flows along the filament spine is still unknown yet. The magnetic structures and the upflows at the footpoints of the filaments and their relations with the filament mainbody have not been well understood. We study the dynamic evolution at the footpoints of filaments in order to find some clues for solving these questions. Methods: Using UV spectra and SJIs from the IRIS, along with coronal images and magnetograms from the Solar Dynamics Observatory (SDO), we present the new features in a quiescent filament channel: subarcsecond bright points (BPs) and quasi-periodic upflows. Results: The BPs in the TR have a spatial scale of about 350-580 km and lifetimes of more than several tens of minutes. They are located at stronger magnetic structures in the filament channel with a magnetic flux of about 1017-1018 Mx. Quasi-periodic brightenings and upflows are observed in the BPs, and the period is about 4-5 min. The BP and the associated jet-like upflow comprise a "tadpole-shaped" structure. The upflows move along bright filament threads, and their directions are almost parallel to the spine of the filament. The upflows initiated from the BPs with opposite polarity magnetic fields have opposite directions. The velocity of the upflows in the plane of sky is about 5-50 km s-1. The emission line of Si IV 1402.77 Å at the locations of upflows exhibits obvious blueshifts of about 5-30 km s-1, and the line profile is broadened with the width of more than 20 km s-1. Conclusions: The BPs seem to be the bases of filament threads, and the upflows are able to convey mass for the dynamic balance of the filament. The "counter-streaming" flows in previous observations

Desertification, resilience, and re-greening in the African Sahel - a matter of the observation period?

Science.gov (United States)

Kusserow, Hannelore

2017-12-01

Since the turn of the millennium various scientific publications have been discussing a re-greening of the Sahel after the 1980s drought mainly based on coarse-resolution satellite data. However, the author's own field studies suggest that the situation is far more complex and that both paradigms, the encroaching Sahara and the re-greening Sahel, need to be questioned.This paper discusses the concepts of desertification, resilience, and re-greening by addressing four main aspects: (i) the relevance of edaphic factors for a vegetation re-greening, (ii-iii) the importance of the selected observation period in the debate on Sahel greening or browning, and (iv) modifications in the vegetation pattern as possible indicators of ecosystem changes (shift from originally diffuse to contracted vegetation patterns).The data referred to in this paper cover a time period of more than 150 years and include the author's own research results from the early 1980s until today. A special emphasis, apart from fieldwork data and remote sensing data, is laid on the historical documents.The key findings summarised at the end show the following: (i) vegetation recovery predominantly depends on soil types; (ii) when discussing Sahel greening vs. Sahel browning, the majority of research papers only focus on post-drought conditions. Taking pre-drought conditions (before the 1980s) into account, however, is essential to fully understand the situation. Botanical investigations and remote-sensing-based time series clearly show a substantial decline in woody species diversity and cover density compared to pre-drought conditions; (iii) the self-organised patchiness of vegetation is considered to be an important indicator of ecosystem changes.

Quasi-periodicity in deep redshift surveys

International Nuclear Information System (INIS)

Weygaert, R. van de

1991-01-01

The recent result by Broadhurst et al., (1990. Nature 343, 726) showing a striking, nearly periodic, galaxy redshift distribution in a narrow pencil-beam survey, is explained within the Voronoi cellular model of clustering of galaxies. Galaxies, whose luminosities are selected from a Schechter luminosity function, are placed randomly within the walls of this cellular model. Narrow and deep, magnitude-limited, pencil-beam surveys through these structures are simulated. Some 15 per cent of these beams show that observed regular pattern, with a spacing between the peaks of the order of 105 h -1 -150 h -1 Mpc, but most pencil-beams show peaks in the redshift distribution without periodicity, so we may conclude that, even within a cellular universe, periodicity is not a common phenomenon. (author)

Estimating interevent time distributions from finite observation periods in communication networks

Science.gov (United States)

Kivelä, Mikko; Porter, Mason A.

2015-11-01

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

On the Diurnal Periodicity of Representative Earthquakes in Greece: Comparison of Data from Different Observation Systems

Science.gov (United States)

Desherevskii, A. V.; Sidorin, A. Ya.

2017-12-01

Due to the initiation of the Hellenic Unified Seismic Network (HUSN) in late 2007, the quality of observation significantly improved by 2011. For example, the representative magnitude level considerably has decreased and the number of annually recorded events has increased. The new observational system highly expanded the possibilities for studying regularities in seismicity. In view of this, the authors revisited their studies of the diurnal periodicity of representative earthquakes in Greece that was revealed earlier in the earthquake catalog before 2011. We use 18 samples of earthquakes of different magnitudes taken from the catalog of Greek earthquakes from 2011 to June 2016 to derive a series of the number of earthquakes for each of them and calculate its average diurnal course. To increase the reliability of the results, we compared the data for two regions. With a high degree of statistical significance, we have obtained that no diurnal periodicity can be found for strongly representative earthquakes. This finding differs from the estimates obtained earlier from an analysis of the catalog of earthquakes at the same area for 1995-2004 and 2005-2010, i.e., before the initiation of the Hellenic Unified Seismic Network. The new results are consistent with the hypothesis of noise discrimination (observational selection) explaining the cause of the diurnal variation of earthquakes with different sensitivity of the seismic network in daytime and nighttime periods.

Clinical outcomes with olanzapine long-acting injection: impact of the 3-hour observation period on patient satisfaction and well-being

Directory of Open Access Journals (Sweden)

Anand E

2016-10-01

Full Text Available Ernie Anand,1 Lovisa Berggren,2 John Landry,3 Ágoston Tóth,4 Holland C Detke5 1Neuroscience Medical Affairs, Eli Lilly & Company Ltd, Windlesham, UK; 2Global Statistical Sciences, Lilly Deutschland GmbH, Bad Homburg, Germany; 3Global Statistical Sciences, Eli Lilly Canada Inc., Toronto, ON, Canada; 4Neuroscience, Lilly Hungary, Budapest, Hungary; 5Psychiatry and Pain Disorders, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA Background: The objective of the present analysis is to determine the impact of the 3-hour observation period for olanzapine long-acting injection (LAI on patient satisfaction and well-being by comparing data collected before and after its implementation. Methods: This is a post hoc analysis of patients treated with olanzapine LAI in 1 a 6-month fixed-dose randomized controlled trial and/or 2 a 6-year open-label safety study. This analysis was limited to patients with schizophrenia who were treated with olanzapine LAI consistent with the approved indication and dosing recommendations of the European Union Summary of Product Characteristics (N=966. Of the 966 patients, the analysis further focused only on those patients who received both 1 at least one injection before the implementation of the 3-hour observation period and 2 at least one injection after implementation of the 3-hour observation period (N=487. Patient satisfaction was assessed with the three-item Patient Satisfaction with Medication Questionnaire-Modified. Responses were averaged across all postbaseline visits occurring before (ie, without the implementation of the 3-hour observation period and across all postbaseline visits occurring after (ie, with the implementation of the 3-hour observation period. In addition, the rate of postinjection delirium/sedation syndrome events was calculated. Results: There was no meaningful change after implementation of the 3-hour observation period in satisfaction (before: mean [SD] =4.0 [1.02] and

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

Science.gov (United States)

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

2004-12-01

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

Physicians' attentional performance following a 24-hour observation period: do we need to regulate sleep prior to work?

Science.gov (United States)

Smyth, P; Maximova, K; Jirsch, J D

2017-08-01

The tradition of physicians working while sleep deprived is increasingly criticised. Medical regulatory bodies have restricted resident physician duty-hours, not addressing the greater population of physicians. We aimed to assess factors such as sleep duration prior to a 24-hour observation period on physicians' attention. We studied 70 physicians (mean age 38 years old (SD 10.8 years)): 36 residents and 34 faculty from call rosters at the University of Alberta. Among 70 physicians, 52 (74%) performed overnight call; 18 did not perform overnight call and were recruited to control for the learning effect of repetitive neuropsychological testing. Attentional Network Test (ANT) measured physicians' attention at the beginning and end of the 24-hour observation period. Participants self-reported ideal sleep needs, sleep duration in the 24 hours prior to (ie, baseline) and during the 24-hour observation period (ie, follow-up). Median regression models examined effects on ANT parameters. Sleep deprivation at follow-up was associated with reduced attentional accuracy following the 24-hour observation period, but only for physicians more sleep deprived at baseline. Other components of attention were not associated with sleep deprivation after adjusting for repetitive testing. Age, years since medical school and caffeine use did not impact changes in ANT parameters. Our study suggests that baseline sleep before 24 hours of observation impacts the accuracy of physicians' attentional testing at 24 hours. Further study is required to determine if optimising physician sleep prior to overnight call shifts is a sustainable strategy to mitigate the effects of sleep deprivation. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Beam-induced and cosmic-ray backgrounds observed in the ATLAS detector during the LHC 2012 proton-proton running period

International Nuclear Information System (INIS)

Aad, G.; Abbott, B.; Abdallah, J.; Abdinov, O.; Abeloos, B.; Aben, R.; Abolins, M.; AbouZeid, O.S.; Abraham, N.L.; Abramowicz, H.; Abreu, H.; Abreu, R.; Abulaiti, Y.; Acharya, B.S.; Adamczyk, L.; Adams, D.L.; Adelman, J.

2016-01-01

This paper discusses various observations on beam-induced and cosmic-ray backgrounds in the ATLAS detector during the LHC 2012 proton-proton run. Building on published results based on 2011 data, the correlations between background and residual pressure of the beam vacuum are revisited. Ghost charge evolution over 2012 and its role for backgrounds are evaluated. New methods to monitor ghost charge with beam-gas rates are presented and observations of LHC abort gap population by ghost charge are discussed in detail. Fake jets from colliding bunches and from ghost charge are analysed with improved methods, showing that ghost charge in individual radio-frequency buckets of the LHC can be resolved. Some results of two short periods of dedicated cosmic-ray background data-taking are shown; in particular cosmic-ray muon induced fake jet rates are compared to Monte Carlo simulations and to the fake jet rates from beam background. A thorough analysis of a particular LHC fill, where abnormally high background was observed, is presented. Correlations between backgrounds and beam intensity losses in special fills with very high β * are studied.

Observed hierarchy of student proficiency with period, frequency, and angular frequency

Directory of Open Access Journals (Sweden)

Nicholas T. Young

2018-01-01

Full Text Available In the context of a generic harmonic oscillator, we investigated students’ accuracy in determining the period, frequency, and angular frequency from mathematical and graphical representations. In a series of studies including interviews, free response tests, and multiple choice tests developed in an iterative process, we assessed students in both algebra-based and calculus-based, traditionally instructed university-level introductory physics courses. Using the results, we categorized nine skills necessary for proficiency in determining period, frequency, and angular frequency. Overall results reveal that, postinstruction, proficiency is quite low: only about 20%–40% of students mastered most of the nine skills. Next, we used a semiquantitative, intuitive method to investigate the hierarchical structure of the nine skills. We also employed the more formal item tree analysis method to verify this structure and found that the skills form a multilevel, nonlinear hierarchy, with mastery of some skills being prerequisite for mastery in other skills. Finally, we implemented a targeted, 30-min group-work activity to improve proficiency in these skills and found a 1 standard deviation gain in accuracy. Overall, the results suggest that many students currently lack these essential skills, targeted practice may lead to required mastery, and that the observed hierarchical structure in the skills suggests that instruction should especially attend to the skills lower in the hierarchy.

Detecting atmospheric normal modes with periods less than 6 h by barometric observations

Science.gov (United States)

Ermolenko, S. I.; Shved, G. M.; Jacobi, Ch.

2018-04-01

The theory of atmospheric normal modes (ANMs) predicts the existence of relatively short-period gravity-inertia ANMs. Simultaneous observations of surface air-pressure variations by barometers at distant stations of the Global Geodynamics Project network during an interval of 6 months were used to detect individual gravity-inertia ANMs with periods of ∼2-5 h. Evidence was found for five ANMs with a lifetime of ∼10 days. The data of the stations, which are close in both latitude and longitude, were utilized for deriving the phases of the detected ANMs. The phases revealed wave propagation to the west and increase of zonal wavenumbers with frequency. As all the detected gravity-inertia ANMs are westward propagating, they are suggested to be generated due to the breakdown of migrating solar tides and/or large-scale Rossby waves. The existence of an ANM background will complicate the detection of the translational motions of the Earth's inner core.

Inflation from periodic extra dimensions

Energy Technology Data Exchange (ETDEWEB)

Higaki, Tetsutaro [Department of Physics, Keio University, Kanagawa 223-8522 (Japan); Tatsuta, Yoshiyuki, E-mail: thigaki@rk.phys.keio.ac.jp, E-mail: y_tatsuta@akane.waseda.jp [Department of Physics, Waseda University, Tokyo 169-8555 (Japan)

2017-07-01

We discuss a realization of a small field inflation based on string inspired supergravities. In theories accompanying extra dimensions, compactification of them with small radii is required for realistic situations. Since the extra dimension can have a periodicity, there will appear (quasi-)periodic functions under transformations of moduli of the extra dimensions in low energy scales. Such a periodic property can lead to a UV completion of so-called multi-natural inflation model where inflaton potential consists of a sum of multiple sinusoidal functions with a decay constant smaller than the Planck scale. As an illustration, we construct a SUSY breaking model, and then show that such an inflaton potential can be generated by a sum of world sheet instantons in intersecting brane models on extra dimensions containing orbifold. We show also predictions of cosmic observables by numerical analyzes.

Maximizing the TESS Mission’s Yield of Long-Period Planets

Science.gov (United States)

Dragomir, Diana; Gaudi, B. Scott; Villanueva, Steven; Crossfield, Ian; Huang, Xu; Ribas, Ignasi; Quinn, Samuel

2018-01-01

The upcoming TESS mission will discover thousands of transiting planets around bright stars. However, during its primary mission the satellite will observe most of the sky for just 27 days (and for at most one year even in its continuous viewing zones near the ecliptic poles), thus limiting the mission’s yield of long-period planets that show three or more transits in the TESS light curves. By also pursuing single- and double-transit events, we can increase by several hundred the number of planets with periods longer than 10 days that TESS will discover. I will show how strategic planning and the judicious use of follow-up observations can confirm these planets and refine their ephemerides. Through this program, we will generate a sample of long-period planets transiting bright stars that are ripe for detailed characterization studies such as mass measurements and atmospheric observations. In turn, these studies will provide important constraints on the composition and formation of long-period planets.

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

Science.gov (United States)

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

2009-06-02

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

Global Scale Periodic Responses in Saturn’s Magnetosphere

Science.gov (United States)

Jia, Xianzhe; Kivelson, Margaret G.

2017-10-01

Despite having an axisymmetric internal magnetic field, Saturn’s magnetosphere exhibits periodic modulations in a variety of properties at periods close to the planetary rotation period. While the source of the periodicity remains unidentified, it is evident from Cassini observations that much of Saturn’s magnetospheric structure and dynamics is dominated by global-scale responses to the driving source of the periodicity. We have developed a global MHD model in which a rotating field-aligned current system is introduced by imposing vortical flows in the high-latitude ionosphere in order to simulate the magnetospheric periodicities. The model has been utilized to quantitatively characterize various periodic responses in the magnetosphere, such as the displacement of the magnetopause and bow shock and flapping of the tail plasma sheet, all of which show quantitative agreement with Cassini observations. One of our model predictions is periodic release of plasmoids in the tail that occurs preferentially in the midnight-to-dawn local time sector during each rotation cycle. Here we present detailed analysis of the periodic responses seen in our simulations focusing on the properties of plasmoids predicted by the model, including their spatial distribution, occurrence frequency, and mass loss rate. We will compare these modeled parameters with published Cassini observations, and discuss their implications for interpreting in-situ measurements.

The academic trend of Oriental Medicine during the Japanese colonial period as observed through the publication of medical books

Directory of Open Access Journals (Sweden)

KIM Nam-il

2006-06-01

Full Text Available This thesis examines the academical trend of Oriental Medicine in the Japanese colonial period observed through medical books published during the Japanese colonial period.This is a period in which Western Medicine was introduced,and due to the lean-to-one-side policy by the Japanese, Western Medicine became the mainstream medical science while Oriental Medicine was pushed to the outskirts.Even after all this,the academic activity was flourishing during this period compared to any other periods. This article is divided into various chapters each with its own theme in order to understand the academic trend of Oriental Medicine during the Japanese colonial period.Focusing on the publication of medical books, this article is divided and observed according to various themes such as the study of Dong-Eui-Bo-Gam(東醫寶鑑,the study of Bang-Yak-Hap- Pyeun(方藥合編,the study of Sang-Han-Ron(傷寒論,the study of Sa-sang (四象constitutional medicine,the study of Eui-Hak-Ip-Mun (醫學入門,the study about Bu-Yang-Ron(扶陽論,On-Bo-Ron(溫補論,and pediatrics, compromise between Western and Oriental Medicine,the study of experience medicine,the study of acupuncture and moxibustion,and etc.

Beam-induced and cosmic-ray backgrounds observed in the ATLAS detector during the LHC 2012 proton-proton running period

CERN Document Server

Aad, Georges; Abdallah, Jalal; Abdinov, Ovsat; Abeloos, Baptiste; Aben, Rosemarie; Abolins, Maris; AbouZeid, Ossama; Abraham, Nicola; Abramowicz, Halina; Abreu, Henso; Abreu, Ricardo; Abulaiti, Yiming; Acharya, Bobby Samir; Adamczyk, Leszek; Adams, David; Adelman, Jahred; Adomeit, Stefanie; Adye, Tim; Affolder, Tony; Agatonovic-Jovin, Tatjana; Agricola, Johannes; Aguilar-Saavedra, Juan Antonio; Ahlen, Steven; Ahmadov, Faig; Aielli, Giulio; Akerstedt, Henrik; Åkesson, Torsten Paul Ake; Akimov, Andrei; Alberghi, Gian Luigi; Albert, Justin; Albrand, Solveig; Alconada Verzini, Maria Josefina; Aleksa, Martin; Aleksandrov, Igor; Alexa, Calin; Alexander, Gideon; Alexopoulos, Theodoros; Alhroob, Muhammad; Aliev, Malik; Alimonti, Gianluca; Alison, John; Alkire, Steven Patrick; Allbrooke, Benedict; Allen, Benjamin William; Allport, Phillip; Aloisio, Alberto; Alonso, Alejandro; Alonso, Francisco; Alpigiani, Cristiano; Alvarez Gonzalez, Barbara; Άlvarez Piqueras, Damián; Alviggi, Mariagrazia; Amadio, Brian Thomas; Amako, Katsuya; Amaral Coutinho, Yara; Amelung, Christoph; Amidei, Dante; Amor Dos Santos, Susana Patricia; Amorim, Antonio; Amoroso, Simone; Amram, Nir; Amundsen, Glenn; Anastopoulos, Christos; Ancu, Lucian Stefan; Andari, Nansi; Andeen, Timothy; Anders, Christoph Falk; Anders, Gabriel; Anders, John Kenneth; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Angelidakis, Stylianos; Angelozzi, Ivan; Anger, Philipp; Angerami, Aaron; Anghinolfi, Francis; Anisenkov, Alexey; Anjos, Nuno; Annovi, Alberto; Antonelli, Mario; Antonov, Alexey; Antos, Jaroslav; Anulli, Fabio; Aoki, Masato; Aperio Bella, Ludovica; Arabidze, Giorgi; Arai, Yasuo; Araque, Juan Pedro; Arce, Ayana; Arduh, Francisco Anuar; Arduini, Gianluigi; Arguin, Jean-Francois; Argyropoulos, Spyridon; Arik, Metin; Armbruster, Aaron James; Armitage, Lewis James; Arnaez, Olivier; Arnold, Hannah; Arratia, Miguel; Arslan, Ozan; Artamonov, Andrei; Artoni, Giacomo; Artz, Sebastian; Asai, Shoji; Asbah, Nedaa; Ashkenazi, Adi; Åsman, Barbro; Asquith, Lily; Assamagan, Ketevi; Astalos, Robert; Atkinson, Markus; Atlay, Naim Bora; Augsten, Kamil; Avolio, Giuseppe; Axen, Bradley; Ayoub, Mohamad Kassem; Azuelos, Georges; Baak, Max; Baas, Alessandra; Baca, Matthew John; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Backhaus, Malte; Bagiacchi, Paolo; Bagnaia, Paolo; Bai, Yu; Baines, John; Baker, Oliver Keith; Baldin, Evgenii; Balek, Petr; Balestri, Thomas; Balli, Fabrice; Balunas, William Keaton; Banas, Elzbieta; Banerjee, Swagato; Bannoura, Arwa A E; Barak, Liron; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Barillari, Teresa; Barklow, Timothy; Barlow, Nick; Barnes, Sarah Louise; Barnett, Bruce; Barnett, Michael; Barnovska, Zuzana; Baroncelli, Antonio; Barone, Gaetano; Barr, Alan; Barranco Navarro, Laura; Barreiro, Fernando; Barreiro Guimarães da Costa, João; Bartoldus, Rainer; Barton, Adam Edward; Bartos, Pavol; Basalaev, Artem; Bassalat, Ahmed; Basye, Austin; Bates, Richard; Batista, Santiago Juan; Batley, Richard; Battaglia, Marco; Bauce, Matteo; Bauer, Florian; Bawa, Harinder Singh; Beacham, James Baker; Beattie, Michael David; Beau, Tristan; Beauchemin, Pierre-Hugues; Bechtle, Philip; Beck, Hans~Peter; Becker, Kathrin; Becker, Maurice; Beckingham, Matthew; Becot, Cyril; Beddall, Andrew; Beddall, Ayda; Bednyakov, Vadim; Bedognetti, Matteo; Bee, Christopher; Beemster, Lars; Beermann, Thomas; Begel, Michael; Behr, Janna Katharina; Belanger-Champagne, Camille; Bell, Andrew Stuart; Bella, Gideon; Bellagamba, Lorenzo; Bellerive, Alain; Bellomo, Massimiliano; Belotskiy, Konstantin; Beltramello, Olga; Belyaev, Nikita; Benary, Odette; Benchekroun, Driss; Bender, Michael; Bendtz, Katarina; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez, Jose; Benitez Garcia, Jorge-Armando; Benjamin, Douglas; Bensinger, James; Bentvelsen, Stan; Beresford, Lydia; Beretta, Matteo; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Berghaus, Frank; Beringer, Jürg; Berlendis, Simon; Bernard, Nathan Rogers; Bernius, Catrin; Bernlochner, Florian Urs; Berry, Tracey; Berta, Peter; Bertella, Claudia; Bertoli, Gabriele; Bertolucci, Federico; Bertram, Iain Alexander; Bertsche, Carolyn; Bertsche, David; Besjes, Geert-Jan; Bessidskaia Bylund, Olga; Bessner, Martin Florian; Besson, Nathalie; Betancourt, Christopher; Bethke, Siegfried; Bevan, Adrian John; Bhimji, Wahid; Bianchi, Riccardo-Maria; Bianchini, Louis; Bianco, Michele; Biebel, Otmar; Biedermann, Dustin; Bielski, Rafal; Biesuz, Nicolo Vladi; Biglietti, Michela; Bilbao De Mendizabal, Javier; Bilokon, Halina; Bindi, Marcello; Binet, Sebastien; Bingul, Ahmet; Bini, Cesare; Biondi, Silvia; Bjergaard, David Martin; Black, Curtis; Black, James; Black, Kevin; Blackburn, Daniel; Blair, Robert; Blanchard, Jean-Baptiste; Blanco, Jacobo Ezequiel; Blazek, Tomas; Bloch, Ingo; Blocker, Craig; Blum, Walter; Blumenschein, Ulrike; Blunier, Sylvain; Bobbink, Gerjan; Bobrovnikov, Victor; Bocchetta, Simona Serena; Bocci, Andrea; Bock, Christopher; Boehler, Michael; Boerner, Daniela; Bogaerts, Joannes Andreas; Bogavac, Danijela; Bogdanchikov, Alexander; Bohm, Christian; Boisvert, Veronique; Bold, Tomasz; Boldea, Venera; Boldyrev, Alexey; Bomben, Marco; Bona, Marcella; Boonekamp, Maarten; Borisov, Anatoly; Borissov, Guennadi; Bortfeldt, Jonathan; Bortoletto, Daniela; Bortolotto, Valerio; Bos, Kors; Boscherini, Davide; Bosman, Martine; Bossio Sola, Jonathan David; Boudreau, Joseph; Bouffard, Julian; Bouhova-Thacker, Evelina Vassileva; Boumediene, Djamel Eddine; Bourdarios, Claire; Boutle, Sarah Kate; Boveia, Antonio; Boyd, James; Boyko, Igor; Bracinik, Juraj; Brandt, Andrew; Brandt, Gerhard; Brandt, Oleg; Bratzler, Uwe; Brau, Benjamin; Brau, James; Braun, Helmut; Breaden Madden, William Dmitri; Brendlinger, Kurt; Brennan, Amelia Jean; Brenner, Lydia; Brenner, Richard; Bressler, Shikma; Bristow, Timothy Michael; Britton, Dave; Britzger, Daniel; Brochu, Frederic; Brock, Ian; Brock, Raymond; Brooijmans, Gustaaf; Brooks, Timothy; Brooks, William; Brosamer, Jacquelyn; Brost, Elizabeth; Broughton, James; Bruce, Roderik; Bruckman de Renstrom, Pawel; Bruncko, Dusan; Bruneliere, Renaud; Bruni, Alessia; Bruni, Graziano; Brunt, Benjamin; Bruschi, Marco; Bruscino, Nello; Bryant, Patrick; Bryngemark, Lene; Buanes, Trygve; Buat, Quentin; Buchholz, Peter; Buckley, Andrew; Budagov, Ioulian; Buehrer, Felix; Bugge, Magnar Kopangen; Bulekov, Oleg; Bullock, Daniel; Burckhart, Helfried; Burdin, Sergey; Burgard, Carsten Daniel; Burghgrave, Blake; Burka, Klaudia; Burke, Stephen; Burmeister, Ingo; Busato, Emmanuel; Büscher, Daniel; Büscher, Volker; Bussey, Peter; Butler, John; Butt, Aatif Imtiaz; Buttar, Craig; Butterworth, Jonathan; Butti, Pierfrancesco; Buttinger, William; Buzatu, Adrian; Buzykaev, Aleksey; Cabrera Urbán, Susana; Caforio, Davide; Cairo, Valentina; Cakir, Orhan; Calace, Noemi; Calafiura, Paolo; Calandri, Alessandro; Calderini, Giovanni; Calfayan, Philippe; Caloba, Luiz; Calvet, David; Calvet, Samuel; Calvet, Thomas Philippe; Camacho Toro, Reina; Camarda, Stefano; Camarri, Paolo; Cameron, David; Caminal Armadans, Roger; Camincher, Clement; Campana, Simone; Campanelli, Mario; Campoverde, Angel; Canale, Vincenzo; Canepa, Anadi; Cano Bret, Marc; Cantero, Josu; Cantrill, Robert; Cao, Tingting; Capeans Garrido, Maria Del Mar; Caprini, Irinel; Caprini, Mihai; Capua, Marcella; Caputo, Regina; Carbone, Ryne Michael; Cardarelli, Roberto; Cardillo, Fabio; Carli, Tancredi; Carlino, Gianpaolo; Carminati, Leonardo; Caron, Sascha; Carquin, Edson; Carrillo-Montoya, German D; Carter, Janet; Carvalho, João; Casadei, Diego; Casado, Maria Pilar; Casolino, Mirkoantonio; Casper, David William; Castaneda-Miranda, Elizabeth; Castelli, Angelantonio; Castillo Gimenez, Victoria; Castro, Nuno Filipe; Catinaccio, Andrea; Catmore, James; Cattai, Ariella; Caudron, Julien; Cavaliere, Viviana; Cavallaro, Emanuele; Cavalli, Donatella; Cavalli-Sforza, Matteo; Cavasinni, Vincenzo; Ceradini, Filippo; Cerda Alberich, Leonor; Cerio, Benjamin; Santiago Cerqueira, Augusto; Cerri, Alessandro; Cerrito, Lucio; Cerutti, Fabio; Cerv, Matevz; Cervelli, Alberto; Cetin, Serkant Ali; Chafaq, Aziz; Chakraborty, Dhiman; Chalupkova, Ina; Chan, Stephen Kam-wah; Chan, Yat Long; Chang, Philip; Chapman, John Derek; Charlton, Dave; Chatterjee, Avishek; Chau, Chav Chhiv; Chavez Barajas, Carlos Alberto; Che, Siinn; Cheatham, Susan; Chegwidden, Andrew; Chekanov, Sergei; Chekulaev, Sergey; Chelkov, Gueorgui; Chelstowska, Magda Anna; Chen, Chunhui; Chen, Hucheng; Chen, Karen; Chen, Shenjian; Chen, Shion; Chen, Xin; Chen, Ye; Cheng, Hok Chuen; Cheng, Huajie; Cheng, Yangyang; Cheplakov, Alexander; Cheremushkina, Evgenia; Cherkaoui El Moursli, Rajaa; Chernyatin, Valeriy; Cheu, Elliott; Chevalier, Laurent; Chiarella, Vitaliano; Chiarelli, Giorgio; Chiodini, Gabriele; Chisholm, Andrew; Chitan, Adrian; Chizhov, Mihail; Choi, Kyungeon; Chomont, Arthur Rene; Chouridou, Sofia; Chow, Bonnie Kar Bo; Christodoulou, Valentinos; Chromek-Burckhart, Doris; Chudoba, Jiri; Chuinard, Annabelle Julia; Chwastowski, Janusz; Chytka, Ladislav; Ciapetti, Guido; Ciftci, Abbas Kenan; Cinca, Diane; Cindro, Vladimir; Cioara, Irina Antonela; Ciocio, Alessandra; Cirotto, Francesco; Citron, Zvi Hirsh; Ciubancan, Mihai; Clark, Allan G; Clark, Brian Lee; Clark, Michael; Clark, Philip James; Clarke, Robert; Clement, Christophe; Coadou, Yann; Cobal, Marina; Coccaro, Andrea; Cochran, James H; Coffey, Laurel; Colasurdo, Luca; Cole, Brian; Cole, Stephen; Colijn, Auke-Pieter; Collot, Johann; Colombo, Tommaso; Compostella, Gabriele; Conde Muiño, Patricia; Coniavitis, Elias; Connell, Simon Henry; Connelly, Ian; Consorti, Valerio; Constantinescu, Serban; Conta, Claudio; Conti, Geraldine; Conventi, Francesco; Cooke, Mark; Cooper, Ben; Cooper-Sarkar, Amanda; Cornelissen, Thijs; Corradi, Massimo; Corriveau, Francois; Corso-Radu, Alina; Cortes-Gonzalez, Arely; Cortiana, Giorgio; Costa, Giuseppe; Costa, María José; Costanzo, Davide; Cottin, Giovanna; Cowan, Glen; Cox, Brian; Cranmer, Kyle; Crawley, Samuel Joseph; Cree, Graham; Crépé-Renaudin, Sabine; Crescioli, Francesco; Cribbs, Wayne Allen; Crispin Ortuzar, Mireia; Cristinziani, Markus; Croft, Vince; Crosetti, Giovanni; Cuhadar Donszelmann, Tulay; Cummings, Jane; Curatolo, Maria; Cúth, Jakub; Cuthbert, Cameron; Czirr, Hendrik; Czodrowski, Patrick; D'Auria, Saverio; D'Onofrio, Monica; Da Cunha Sargedas De Sousa, Mario Jose; Da Via, Cinzia; Dabrowski, Wladyslaw; Dai, Tiesheng; Dale, Orjan; Dallaire, Frederick; Dallapiccola, Carlo; Dam, Mogens; Dandoy, Jeffrey Rogers; Dang, Nguyen Phuong; Daniells, Andrew Christopher; Dann, Nicholas Stuart; Danninger, Matthias; Dano Hoffmann, Maria; Dao, Valerio; Darbo, Giovanni; Darmora, Smita; Dassoulas, James; Dattagupta, Aparajita; Davey, Will; David, Claire; Davidek, Tomas; Davies, Merlin; Davison, Peter; Davygora, Yuriy; Dawe, Edmund; Dawson, Ian; Daya-Ishmukhametova, Rozmin; De, Kaushik; de Asmundis, Riccardo; De Benedetti, Abraham; De Castro, Stefano; De Cecco, Sandro; De Groot, Nicolo; de Jong, Paul; De la Torre, Hector; De Lorenzi, Francesco; De Pedis, Daniele; De Salvo, Alessandro; De Sanctis, Umberto; De Santo, Antonella; De Vivie De Regie, Jean-Baptiste; Dearnaley, William James; Debbe, Ramiro; Debenedetti, Chiara; Dedovich, Dmitri; Deigaard, Ingrid; Del Peso, Jose; Del Prete, Tarcisio; Delgove, David; Deliot, Frederic; Delitzsch, Chris Malena; Deliyergiyev, Maksym; Dell'Acqua, Andrea; Dell'Asta, Lidia; Dell'Orso, Mauro; Della Pietra, Massimo; della Volpe, Domenico; Delmastro, Marco; Delsart, Pierre-Antoine; Deluca, Carolina; DeMarco, David; Demers, Sarah; Demichev, Mikhail; Demilly, Aurelien; Denisov, Sergey; Denysiuk, Denys; Derendarz, Dominik; Derkaoui, Jamal Eddine; Derue, Frederic; Dervan, Paul; Desch, Klaus Kurt; Deterre, Cecile; Dette, Karola; Deviveiros, Pier-Olivier; Dewhurst, Alastair; Dhaliwal, Saminder; Di Ciaccio, Anna; Di Ciaccio, Lucia; Di Clemente, William Kennedy; Di Donato, Camilla; Di Girolamo, Alessandro; Di Girolamo, Beniamino; Di Micco, Biagio; Di Nardo, Roberto; Di Simone, Andrea; Di Sipio, Riccardo; Di Valentino, David; Diaconu, Cristinel; Diamond, Miriam; Dias, Flavia; Diaz, Marco Aurelio; Diehl, Edward; Dietrich, Janet; Diglio, Sara; Dimitrievska, Aleksandra; Dingfelder, Jochen; Dita, Petre; Dita, Sanda; Dittus, Fridolin; Djama, Fares; Djobava, Tamar; Djuvsland, Julia Isabell; Barros do Vale, Maria Aline; Dobos, Daniel; Dobre, Monica; Doglioni, Caterina; Dohmae, Takeshi; Dolejsi, Jiri; Dolezal, Zdenek; Dolgoshein, Boris; Donadelli, Marisilvia; Donati, Simone; Dondero, Paolo; Donini, Julien; Dopke, Jens; Doria, Alessandra; Dova, Maria-Teresa; Doyle, Tony; Drechsler, Eric; Dris, Manolis; Du, Yanyan; Duarte-Campderros, Jorge; Duchovni, Ehud; Duckeck, Guenter; Ducu, Otilia Anamaria; Duda, Dominik; Dudarev, Alexey; Duflot, Laurent; Duguid, Liam; Dührssen, Michael; Dunford, Monica; Duran Yildiz, Hatice; Düren, Michael; Durglishvili, Archil; Duschinger, Dirk; Dutta, Baishali; Dyndal, Mateusz; Eckardt, Christoph; Ecker, Katharina Maria; Edgar, Ryan Christopher; Edson, William; Edwards, Nicholas Charles; Eifert, Till; Eigen, Gerald; Einsweiler, Kevin; Ekelof, Tord; El Kacimi, Mohamed; Ellajosyula, Venugopal; Ellert, Mattias; Elles, Sabine; Ellinghaus, Frank; Elliot, Alison; Ellis, Nicolas; Elmsheuser, Johannes; Elsing, Markus; Emeliyanov, Dmitry; Enari, Yuji; Endner, Oliver Chris; Endo, Masaki; Ennis, Joseph Stanford; Erdmann, Johannes; Ereditato, Antonio; Ernis, Gunar; Ernst, Jesse; Ernst, Michael; Errede, Steven; Ertel, Eugen; Escalier, Marc; Esch, Hendrik; Escobar, Carlos; Esposito, Bellisario; Etienvre, Anne-Isabelle; Etzion, Erez; Evans, Hal; Ezhilov, Alexey; Fabbri, Federica; Fabbri, Laura; Facini, Gabriel; Fakhrutdinov, Rinat; Falciano, Speranza; Falla, Rebecca Jane; Faltova, Jana; Fang, Yaquan; Fanti, Marcello; Farbin, Amir; Farilla, Addolorata; Farina, Christian; Farooque, Trisha; Farrell, Steven; Farrington, Sinead; Farthouat, Philippe; Fassi, Farida; Fassnacht, Patrick; Fassouliotis, Dimitrios; Faucci Giannelli, Michele; Favareto, Andrea; Fawcett, William James; Fayard, Louis; Fedin, Oleg; Fedorko, Wojciech; Feigl, Simon; Feligioni, Lorenzo; Feng, Cunfeng; Feng, Eric; Feng, Haolu; Fenyuk, Alexander; Feremenga, Last; Fernandez Martinez, Patricia; Fernandez Perez, Sonia; Ferrando, James; Ferrari, Arnaud; Ferrari, Pamela; Ferrari, Roberto; Ferreira de Lima, Danilo Enoque; Ferrer, Antonio; Ferrere, Didier; Ferretti, Claudio; Ferretto Parodi, Andrea; Fiedler, Frank; Filipčič, Andrej; Filipuzzi, Marco; Filthaut, Frank; Fincke-Keeler, Margret; Finelli, Kevin Daniel; Fiolhais, Miguel; Fiorini, Luca; Firan, Ana; Fischer, Adam; Fischer, Cora; Fischer, Julia; Fisher, Wade Cameron; Flaschel, Nils; Fleck, Ivor; Fleischmann, Philipp; Fletcher, Gareth Thomas; Fletcher, Gregory; Fletcher, Rob Roy MacGregor; Flick, Tobias; Floderus, Anders; Flores Castillo, Luis; Flowerdew, Michael; Forcolin, Giulio Tiziano; Formica, Andrea; Forti, Alessandra; Foster, Andrew Geoffrey; Fournier, Daniel; Fox, Harald; Fracchia, Silvia; Francavilla, Paolo; Franchini, Matteo; Francis, David; Franconi, Laura; Franklin, Melissa; Frate, Meghan; Fraternali, Marco; Freeborn, David; Fressard-Batraneanu, Silvia; Friedrich, Felix; Froidevaux, Daniel; Frost, James; Fukunaga, Chikara; Fullana Torregrosa, Esteban; Fusayasu, Takahiro; Fuster, Juan; Gabaldon, Carolina; Gabizon, Ofir; Gabrielli, Alessandro; Gabrielli, Andrea; Gach, Grzegorz; Gadatsch, Stefan; Gadomski, Szymon; Gagliardi, Guido; Gagnon, Louis Guillaume; Gagnon, Pauline; Galea, Cristina; Galhardo, Bruno; Gallas, Elizabeth; Gallop, Bruce; Gallus, Petr; Galster, Gorm Aske Gram Krohn; Gan, KK; Gao, Jun; Gao, Yanyan; Gao, Yongsheng; Garay Walls, Francisca; García, Carmen; García Navarro, José Enrique; Garcia-Sciveres, Maurice; Gardner, Robert; Garelli, Nicoletta; Garonne, Vincent; Gascon Bravo, Alberto; Gatti, Claudio; Gaudiello, Andrea; Gaudio, Gabriella; Gaur, Bakul; Gauthier, Lea; Gavrilenko, Igor; Gay, Colin; Gaycken, Goetz; Gazis, Evangelos; Gecse, Zoltan; Gee, Norman; Geich-Gimbel, Christoph; Geisler, Manuel Patrice; Gemme, Claudia; Genest, Marie-Hélène; Geng, Cong; Gentile, Simonetta; George, Simon; Gerbaudo, Davide; Gershon, Avi; Ghasemi, Sara; Ghazlane, Hamid; Ghneimat, Mazuza; Giacobbe, Benedetto; Giagu, Stefano; Giannetti, Paola; Gibbard, Bruce; Gibson, Stephen; Gignac, Matthew; Gilchriese, Murdock; Gillam, Thomas; Gillberg, Dag; Gilles, Geoffrey; Gingrich, Douglas; Giokaris, Nikos; Giordani, MarioPaolo; Giorgi, Filippo Maria; Giorgi, Francesco Michelangelo; Giraud, Pierre-Francois; Giromini, Paolo; Giugni, Danilo; Giuli, Francesco; Giuliani, Claudia; Giulini, Maddalena; Gjelsten, Børge Kile; Gkaitatzis, Stamatios; Gkialas, Ioannis; Gkougkousis, Evangelos Leonidas; Gladilin, Leonid; Glasman, Claudia; Glatzer, Julian; Glaysher, Paul; Glazov, Alexandre; Goblirsch-Kolb, Maximilian; Godlewski, Jan; Goldfarb, Steven; Golling, Tobias; Golubkov, Dmitry; Gomes, Agostinho; Gonçalo, Ricardo; Goncalves Pinto Firmino Da Costa, Joao; Gonella, Laura; Gongadze, Alexi; González de la Hoz, Santiago; Gonzalez Parra, Garoe; Gonzalez-Sevilla, Sergio; Goossens, Luc; Gorbounov, Petr Andreevich; Gordon, Howard; Gorelov, Igor; Gorini, Benedetto; Gorini, Edoardo; Gorišek, Andrej; Gornicki, Edward; Goshaw, Alfred; Gössling, Claus; Gostkin, Mikhail Ivanovitch; Goudet, Christophe Raymond; Goujdami, Driss; Goussiou, Anna; Govender, Nicolin; Gozani, Eitan; Graber, Lars; Grabowska-Bold, Iwona; Gradin, Per Olov Joakim; Grafström, Per; Gramling, Johanna; Gramstad, Eirik; Grancagnolo, Sergio; Gratchev, Vadim; Gray, Heather; Graziani, Enrico; Greenwood, Zeno Dixon; Grefe, Christian; Gregersen, Kristian; Gregor, Ingrid-Maria; Grenier, Philippe; Grevtsov, Kirill; Griffiths, Justin; Grillo, Alexander; Grimm, Kathryn; Grinstein, Sebastian; Gris, Philippe Luc Yves; Grivaz, Jean-Francois; Groh, Sabrina; Grohs, Johannes Philipp; Gross, Eilam; Grosse-Knetter, Joern; Grossi, Giulio Cornelio; Grout, Zara Jane; Guan, Liang; Guan, Wen; Guenther, Jaroslav; Guescini, Francesco; Guest, Daniel; Gueta, Orel; Guido, Elisa; Guillemin, Thibault; Guindon, Stefan; Gul, Umar; Gumpert, Christian; Guo, Jun; Guo, Yicheng; Gupta, Shaun; Gustavino, Giuliano; Gutierrez, Phillip; Gutierrez Ortiz, Nicolas Gilberto; Gutschow, Christian; Guyot, Claude; Gwenlan, Claire; Gwilliam, Carl; Haas, Andy; Haber, Carl; Hadavand, Haleh Khani; Haddad, Nacim; Hadef, Asma; Haefner, Petra; Hageböck, Stephan; Hajduk, Zbigniew; Hakobyan, Hrachya; Haleem, Mahsana; Haley, Joseph; Hall, David; Halladjian, Garabed; Hallewell, Gregory David; Hamacher, Klaus; Hamal, Petr; Hamano, Kenji; Hamilton, Andrew; Hamity, Guillermo Nicolas; Hamnett, Phillip George; Han, Liang; Hanagaki, Kazunori; Hanawa, Keita; Hance, Michael; Haney, Bijan; Hanke, Paul; Hanna, Remie; Hansen, Jørgen Beck; Hansen, Jorn Dines; Hansen, Maike Christina; Hansen, Peter Henrik; Hara, Kazuhiko; Hard, Andrew; Harenberg, Torsten; Hariri, Faten; Harkusha, Siarhei; Harrington, Robert; Harrison, Paul Fraser; Hartjes, Fred; Hasegawa, Makoto; Hasegawa, Yoji; Hasib, A; Hassani, Samira; Haug, Sigve; Hauser, Reiner; Hauswald, Lorenz; Havranek, Miroslav; Hawkes, Christopher; Hawkings, Richard John; Hawkins, Anthony David; Hayden, Daniel; Hays, Chris; Hays, Jonathan Michael; Hayward, Helen; Haywood, Stephen; Head, Simon; Heck, Tobias; Hedberg, Vincent; Heelan, Louise; Heim, Sarah; Heim, Timon; Heinemann, Beate; Heinrich, Jochen Jens; Heinrich, Lukas; Heinz, Christian; Hejbal, Jiri; Helary, Louis; Hellman, Sten; Helsens, Clement; Henderson, James; Henderson, Robert; Heng, Yang; Henkelmann, Steffen; Henriques Correia, Ana Maria; Henrot-Versille, Sophie; Herbert, Geoffrey Henry; Hernández Jiménez, Yesenia; Herten, Gregor; Hertenberger, Ralf; Hervas, Luis; Hesketh, Gavin Grant; Hessey, Nigel; Hetherly, Jeffrey Wayne; Hickling, Robert; Higón-Rodriguez, Emilio; Hill, Ewan; Hill, John; Hiller, Karl Heinz; Hillier, Stephen; Hinchliffe, Ian; Hines, Elizabeth; Hinman, Rachel Reisner; Hirose, Minoru; Hirschbuehl, Dominic; Hobbs, John; Hod, Noam; Hodgkinson, Mark; Hodgson, Paul; Hoecker, Andreas; Hoeferkamp, Martin; Hoenig, Friedrich; Hohlfeld, Marc; Hohn, David; Holmes, Tova Ray; Homann, Michael; Hong, Tae Min; Hooberman, Benjamin Henry; Hopkins, Walter; Horii, Yasuyuki; Horton, Arthur James; Hostachy, Jean-Yves; Hou, Suen; Hoummada, Abdeslam; Howard, Jacob; Howarth, James; Hrabovsky, Miroslav; Hristova, Ivana; Hrivnac, Julius; Hryn'ova, Tetiana; Hrynevich, Aliaksei; Hsu, Catherine; Hsu, Pai-hsien Jennifer; Hsu, Shih-Chieh; Hu, Diedi; Hu, Qipeng; Huang, Yanping; Hubacek, Zdenek; Hubaut, Fabrice; Huegging, Fabian; Huffman, Todd Brian; Hughes, Emlyn; Hughes, Gareth; Huhtinen, Mika; Hülsing, Tobias Alexander; Huseynov, Nazim; Huston, Joey; Huth, John; Iacobucci, Giuseppe; Iakovidis, Georgios; Ibragimov, Iskander; Iconomidou-Fayard, Lydia; Ideal, Emma; Idrissi, Zineb; Iengo, Paolo; Igonkina, Olga; Iizawa, Tomoya; Ikegami, Yoichi; Ikeno, Masahiro; Ilchenko, Iurii; Iliadis, Dimitrios; Ilic, Nikolina; Ince, Tayfun; Introzzi, Gianluca; Ioannou, Pavlos; Iodice, Mauro; Iordanidou, Kalliopi; Ippolito, Valerio; Irles Quiles, Adrian; Isaksson, Charlie; Ishino, Masaya; Ishitsuka, Masaki; Ishmukhametov, Renat; Issever, Cigdem; Istin, Serhat; Ito, Fumiaki; Iturbe Ponce, Julia Mariana; Iuppa, Roberto; Ivarsson, Jenny; Iwanski, Wieslaw; Iwasaki, Hiroyuki; Izen, Joseph; Izzo, Vincenzo; Jabbar, Samina; Jackson, Brett; Jackson, Matthew; Jackson, Paul; Jain, Vivek; Jakobi, Katharina Bianca; Jakobs, Karl; Jakobsen, Sune; Jakoubek, Tomas; Jamin, David Olivier; Jana, Dilip; Jansen, Eric; Jansky, Roland; Janssen, Jens; Janus, Michel; Jarlskog, Göran; Javadov, Namig; Javůrek, Tomáš; Jeanneau, Fabien; Jeanty, Laura; Jejelava, Juansher; Jeng, Geng-yuan; Jennens, David; Jenni, Peter; Jentzsch, Jennifer; Jeske, Carl; Jézéquel, Stéphane; Ji, Haoshuang; Jia, Jiangyong; Jiang, Hai; Jiang, Yi; Jiggins, Stephen; Jimenez Pena, Javier; Jin, Shan; Jinaru, Adam; Jinnouchi, Osamu; Johansson, Per; Johns, Kenneth; Johnson, William Joseph; Jon-And, Kerstin; Jones, Graham; Jones, Roger; Jones, Sarah; Jones, Tim; Jongmanns, Jan; Jorge, Pedro; Jovicevic, Jelena; Ju, Xiangyang; Juste Rozas, Aurelio; Köhler, Markus Konrad; Kaczmarska, Anna; Kado, Marumi; Kagan, Harris; Kagan, Michael; Kahn, Sebastien Jonathan; Kajomovitz, Enrique; Kalderon, Charles William; Kaluza, Adam; Kama, Sami; Kamenshchikov, Andrey; Kanaya, Naoko; Kaneti, Steven; Kantserov, Vadim; Kanzaki, Junichi; Kaplan, Benjamin; Kaplan, Laser Seymour; Kapliy, Anton; Kar, Deepak; Karakostas, Konstantinos; Karamaoun, Andrew; Karastathis, Nikolaos; Kareem, Mohammad Jawad; Karentzos, Efstathios; Karnevskiy, Mikhail; Karpov, Sergey; Karpova, Zoya; Karthik, Krishnaiyengar; Kartvelishvili, Vakhtang; Karyukhin, Andrey; Kasahara, Kota; Kashif, Lashkar; Kass, Richard; Kastanas, Alex; Kataoka, Yousuke; Kato, Chikuma; Katre, Akshay; Katzy, Judith; Kawagoe, Kiyotomo; Kawamoto, Tatsuo; Kawamura, Gen; Kazama, Shingo; Kazanin, Vassili; Keeler, Richard; Kehoe, Robert; Keller, John; Kempster, Jacob Julian; Kentaro, Kawade; Keoshkerian, Houry; Kepka, Oldrich; Kerševan, Borut Paul; Kersten, Susanne; Keyes, Robert; Khalil-zada, Farkhad; Khandanyan, Hovhannes; Khanov, Alexander; Kharlamov, Alexey; Khoo, Teng Jian; Khovanskiy, Valery; Khramov, Evgeniy; Khubua, Jemal; Kido, Shogo; Kim, Hee Yeun; Kim, Shinhong; Kim, Young-Kee; Kimura, Naoki; Kind, Oliver Maria; King, Barry; King, Matthew; King, Samuel Burton; Kirk, Julie; Kiryunin, Andrey; Kishimoto, Tomoe; Kisielewska, Danuta; Kiss, Florian; Kiuchi, Kenji; Kivernyk, Oleh; Kladiva, Eduard; Klein, Matthew Henry; Klein, Max; Klein, Uta; Kleinknecht, Konrad; Klimek, Pawel; Klimentov, Alexei; Klingenberg, Reiner; Klinger, Joel Alexander; Klioutchnikova, Tatiana; Kluge, Eike-Erik; Kluit, Peter; Kluth, Stefan; Knapik, Joanna; Kneringer, Emmerich; Knoops, Edith; Knue, Andrea; Kobayashi, Aine; Kobayashi, Dai; Kobayashi, Tomio; Kobel, Michael; Kocian, Martin; Kodys, Peter; Koffas, Thomas; Koffeman, Els; Kogan, Lucy Anne; Koi, Tatsumi; Kolanoski, Hermann; Kolb, Mathis; Koletsou, Iro; Komar, Aston; Komori, Yuto; Kondo, Takahiko; Kondrashova, Nataliia; Köneke, Karsten; König, Adriaan; Kono, Takanori; Konoplich, Rostislav; Konstantinidis, Nikolaos; Kopeliansky, Revital; Koperny, Stefan; Köpke, Lutz; Kopp, Anna Katharina; Korcyl, Krzysztof; Kordas, Kostantinos; Korn, Andreas; Korol, Aleksandr; Korolkov, Ilya; Korolkova, Elena; Kortner, Oliver; Kortner, Sandra; Kosek, Tomas; Kostyukhin, Vadim; Kotwal, Ashutosh; Kourkoumeli-Charalampidi, Athina; Kourkoumelis, Christine; Kouskoura, Vasiliki; Koutsman, Alex; Kowalewska, Anna Bozena; Kowalewski, Robert Victor; Kowalski, Tadeusz; Kozanecki, Witold; Kozhin, Anatoly; Kramarenko, Viktor; Kramberger, Gregor; Krasnopevtsev, Dimitriy; Krasny, Mieczyslaw Witold; Krasznahorkay, Attila; Kraus, Jana; Kravchenko, Anton; Kretz, Moritz; Kretzschmar, Jan; Kreutzfeldt, Kristof; Krieger, Peter; Krizka, Karol; Kroeninger, Kevin; Kroha, Hubert; Kroll, Joe; Kroseberg, Juergen; Krstic, Jelena; Kruchonak, Uladzimir; Krüger, Hans; Krumnack, Nils; Kruse, Amanda; Kruse, Mark; Kruskal, Michael; Kubota, Takashi; Kucuk, Hilal; Kuday, Sinan; Kuechler, Jan Thomas; Kuehn, Susanne; Kugel, Andreas; Kuger, Fabian; Kuhl, Andrew; Kuhl, Thorsten; Kukhtin, Victor; Kukla, Romain; Kulchitsky, Yuri; Kuleshov, Sergey; Kuna, Marine; Kunigo, Takuto; Kupco, Alexander; Kurashige, Hisaya; Kurochkin, Yurii; Kus, Vlastimil; Kuwertz, Emma Sian; Kuze, Masahiro; Kvita, Jiri; Kwan, Tony; Kyriazopoulos, Dimitrios; La Rosa, Alessandro; La Rosa Navarro, Jose Luis; La Rotonda, Laura; Lacasta, Carlos; Lacava, Francesco; Lacey, James; Lacker, Heiko; Lacour, Didier; Lacuesta, Vicente Ramón; Ladygin, Evgueni; Lafaye, Remi; Laforge, Bertrand; Lagouri, Theodota; Lai, Stanley; Lammers, Sabine; Lampl, Walter; Lançon, Eric; Landgraf, Ulrich; Landon, Murrough; Lang, Valerie Susanne; Lange, J örn Christian; Lankford, Andrew; Lanni, Francesco; Lantzsch, Kerstin; Lanza, Agostino; Laplace, Sandrine; Lapoire, Cecile; Laporte, Jean-Francois; Lari, Tommaso; Lasagni Manghi, Federico; Lassnig, Mario; Laurelli, Paolo; Lavrijsen, Wim; Law, Alexander; Laycock, Paul; Lazovich, Tomo; Lazzaroni, Massimo; Le Dortz, Olivier; Le Guirriec, Emmanuel; Le Menedeu, Eve; Le Quilleuc, Eloi; LeBlanc, Matthew Edgar; LeCompte, Thomas; Ledroit-Guillon, Fabienne Agnes Marie; Lee, Claire Alexandra; Lee, Shih-Chang; Lee, Lawrence; Lefebvre, Guillaume; Lefebvre, Michel; Legger, Federica; Leggett, Charles; Lehan, Allan; Lehmann Miotto, Giovanna; Lei, Xiaowen; Leight, William Axel; Leisos, Antonios; Leister, Andrew Gerard; Leite, Marco Aurelio Lisboa; Leitner, Rupert; Lellouch, Daniel; Lemmer, Boris; Leney, Katharine; Lenz, Tatjana; Lenzi, Bruno; Leone, Robert; Leone, Sandra; Leonidopoulos, Christos; Leontsinis, Stefanos; Lerner, Giuseppe; Leroy, Claude; Lesage, Arthur; Lester, Christopher; Levchenko, Mikhail; Levêque, Jessica; Levin, Daniel; Levinson, Lorne; Levy, Mark; Leyko, Agnieszka; Leyton, Michael; Li, Bing; Li, Haifeng; Li, Ho Ling; Li, Lei; Li, Liang; Li, Qi; Li, Shu; Li, Xingguo; Li, Yichen; Liang, Zhijun; Liao, Hongbo; Liberti, Barbara; Liblong, Aaron; Lichard, Peter; Lie, Ki; Liebal, Jessica; Liebig, Wolfgang; Limbach, Christian; Limosani, Antonio; Lin, Simon; Lin, Tai-Hua; Lindquist, Brian Edward; Lipeles, Elliot; Lipniacka, Anna; Lisovyi, Mykhailo; Liss, Tony; Lissauer, David; Lister, Alison; Litke, Alan; Liu, Bo; Liu, Dong; Liu, Hao; Liu, Hongbin; Liu, Jian; Liu, Jianbei; Liu, Kun; Liu, Lulu; Liu, Miaoyuan; Liu, Minghui; Liu, Yanlin; Liu, Yanwen; Livan, Michele; Lleres, Annick; Llorente Merino, Javier; Lloyd, Stephen; Lo Sterzo, Francesco; Lobodzinska, Ewelina; Loch, Peter; Lockman, William; Loebinger, Fred; Loevschall-Jensen, Ask Emil; Loew, Kevin Michael; Loginov, Andrey; Lohse, Thomas; Lohwasser, Kristin; Lokajicek, Milos; Long, Brian Alexander; Long, Jonathan David; Long, Robin Eamonn; Longo, Luigi; Looper, Kristina Anne; Lopes, Lourenco; Lopez Mateos, David; Lopez Paredes, Brais; Lopez Paz, Ivan; Lopez Solis, Alvaro; Lorenz, Jeanette; Lorenzo Martinez, Narei; Losada, Marta; Lösel, Philipp Jonathan; Lou, XinChou; Lounis, Abdenour; Love, Jeremy; Love, Peter; Lu, Haonan; Lu, Nan; Lubatti, Henry; Luci, Claudio; Lucotte, Arnaud; Luedtke, Christian; Luehring, Frederick; Lukas, Wolfgang; Luminari, Lamberto; Lundberg, Olof; Lund-Jensen, Bengt; Lynn, David; Lysak, Roman; Lytken, Else; Lyubushkin, Vladimir; Ma, Hong; Ma, Lian Liang; Ma, Yanhui; Maccarrone, Giovanni; Macchiolo, Anna; Macdonald, Calum Michael; Maček, Boštjan; Machado Miguens, Joana; Madaffari, Daniele; Madar, Romain; Maddocks, Harvey Jonathan; Mader, Wolfgang; Madsen, Alexander; Maeda, Junpei; Maeland, Steffen; Maeno, Tadashi; Maevskiy, Artem; Magradze, Erekle; Mahlstedt, Joern; Maiani, Camilla; Maidantchik, Carmen; Maier, Andreas Alexander; Maier, Thomas; Maio, Amélia; Majewski, Stephanie; Makida, Yasuhiro; Makovec, Nikola; Malaescu, Bogdan; Malecki, Pawel; Maleev, Victor; Malek, Fairouz; Mallik, Usha; Malon, David; Malone, Caitlin; Maltezos, Stavros; Malyukov, Sergei; Mamuzic, Judita; Mancini, Giada; Mandelli, Beatrice; Mandelli, Luciano; Mandić, Igor; Maneira, José; Manhaes de Andrade Filho, Luciano; Manjarres Ramos, Joany; Mann, Alexander; Mansoulie, Bruno; Mantifel, Rodger; Mantoani, Matteo; Manzoni, Stefano; Mapelli, Livio; Marceca, Gino; March, Luis; Marchiori, Giovanni; Marcisovsky, Michal; Marjanovic, Marija; Marley, Daniel; Marroquim, Fernando; Marsden, Stephen Philip; Marshall, Zach; Marti, Lukas Fritz; Marti-Garcia, Salvador; Martin, Brian Thomas; Martin, Tim; Martin, Victoria Jane; Martin dit Latour, Bertrand; Martinez, Mario; Martin-Haugh, Stewart; Martoiu, Victor Sorin; Martyniuk, Alex; Marx, Marilyn; Marzano, Francesco; Marzin, Antoine; Masetti, Lucia; Mashimo, Tetsuro; Mashinistov, Ruslan; Masik, Jiri; Maslennikov, Alexey; Massa, Ignazio; Massa, Lorenzo; Mastrandrea, Paolo; Mastroberardino, Anna; Masubuchi, Tatsuya; Mättig, Peter; Mattmann, Johannes; Maurer, Julien; Maxfield, Stephen; Maximov, Dmitriy; Mazini, Rachid; Mazza, Simone Michele; Mc Fadden, Neil Christopher; Mc Goldrick, Garrin; Mc Kee, Shawn Patrick; McCarn, Allison; McCarthy, Robert; McCarthy, Tom; McClymont, Laurie; McFarlane, Kenneth; Mcfayden, Josh; Mchedlidze, Gvantsa; McMahon, Steve; McPherson, Robert; Medinnis, Michael; Meehan, Samuel; Mehlhase, Sascha; Mehta, Andrew; Meier, Karlheinz; Meineck, Christian; Meirose, Bernhard; Mellado Garcia, Bruce Rafael; Meloni, Federico; Mengarelli, Alberto; Menke, Sven; Meoni, Evelin; Mercurio, Kevin Michael; Mergelmeyer, Sebastian; Mermod, Philippe; Merola, Leonardo; Meroni, Chiara; Merritt, Frank; Messina, Andrea; Metcalfe, Jessica; Mete, Alaettin Serhan; Meyer, Carsten; Meyer, Christopher; Meyer, Jean-Pierre; Meyer, Jochen; Meyer Zu Theenhausen, Hanno; Middleton, Robin; Miglioranzi, Silvia; Mijović, Liza; Mikenberg, Giora; Mikestikova, Marcela; Mikuž, Marko; Milesi, Marco; Milic, Adriana; Miller, David; Mills, Corrinne; Milov, Alexander; Milstead, David; Minaenko, Andrey; Minami, Yuto; Minashvili, Irakli; Mincer, Allen; Mindur, Bartosz; Mineev, Mikhail; Ming, Yao; Mir, Lluisa-Maria; Mistry, Khilesh; Mitani, Takashi; Mitrevski, Jovan; Mitsou, Vasiliki A; Miucci, Antonio; Miyagawa, Paul; Mjörnmark, Jan-Ulf; Moa, Torbjoern; Mochizuki, Kazuya; Mohapatra, Soumya; Mohr, Wolfgang; Molander, Simon; Moles-Valls, Regina; Monden, Ryutaro; Mondragon, Matthew Craig; Mönig, Klaus; Monk, James; Monnier, Emmanuel; Montalbano, Alyssa; Montejo Berlingen, Javier; Monticelli, Fernando; Monzani, Simone; Moore, Roger; Morange, Nicolas; Moreno, Deywis; Moreno Llácer, María; Morettini, Paolo; Mori, Daniel; Mori, Tatsuya; Morii, Masahiro; Morinaga, Masahiro; Morisbak, Vanja; Moritz, Sebastian; Morley, Anthony Keith; Mornacchi, Giuseppe; Morris, John; Mortensen, Simon Stark; Morvaj, Ljiljana; Mosidze, Maia; Moss, Josh; Motohashi, Kazuki; Mount, Richard; Mountricha, Eleni; Mouraviev, Sergei; Moyse, Edward; Muanza, Steve; Mudd, Richard; Mueller, Felix; Mueller, James; Mueller, Ralph Soeren Peter; Mueller, Thibaut; Muenstermann, Daniel; Mullen, Paul; Mullier, Geoffrey; Munoz Sanchez, Francisca Javiela; Murillo Quijada, Javier Alberto; Murray, Bill; Musheghyan, Haykuhi; Muskinja, Miha; Myagkov, Alexey; Myska, Miroslav; Nachman, Benjamin Philip; Nackenhorst, Olaf; Nadal, Jordi; Nagai, Koichi; Nagai, Ryo; Nagano, Kunihiro; Nagasaka, Yasushi; Nagata, Kazuki; Nagel, Martin; Nagy, Elemer; Nairz, Armin Michael; Nakahama, Yu; Nakamura, Koji; Nakamura, Tomoaki; Nakano, Itsuo; Namasivayam, Harisankar; Naranjo Garcia, Roger Felipe; Narayan, Rohin; Narrias Villar, Daniel Isaac; Naryshkin, Iouri; Naumann, Thomas; Navarro, Gabriela; Nayyar, Ruchika; Neal, Homer; Nechaeva, Polina; Neep, Thomas James; Nef, Pascal Daniel; Negri, Andrea; Negrini, Matteo; Nektarijevic, Snezana; Nellist, Clara; Nelson, Andrew; Nemecek, Stanislav; Nemethy, Peter; Nepomuceno, Andre Asevedo; Nessi, Marzio; Neubauer, Mark; Neumann, Manuel; Neves, Ricardo; Nevski, Pavel; Newman, Paul; Nguyen, Duong Hai; Nickerson, Richard; Nicolaidou, Rosy; Nicquevert, Bertrand; Nielsen, Jason; Nikiforov, Andriy; Nikolaenko, Vladimir; Nikolic-Audit, Irena; Nikolopoulos, Konstantinos; Nilsen, Jon Kerr; Nilsson, Paul; Ninomiya, Yoichi; Nisati, Aleandro; Nisius, Richard; Nobe, Takuya; Nodulman, Lawrence; Nomachi, Masaharu; Nomidis, Ioannis; Nooney, Tamsin; Norberg, Scarlet; Nordberg, Markus; Norjoharuddeen, Nurfikri; Novgorodova, Olga; Nowak, Sebastian; Nozaki, Mitsuaki; Nozka, Libor; Ntekas, Konstantinos; Nurse, Emily; Nuti, Francesco; O'grady, Fionnbarr; O'Neil, Dugan; O'Rourke, Abigail Alexandra; O'Shea, Val; Oakham, Gerald; Oberlack, Horst; Obermann, Theresa; Ocariz, Jose; Ochi, Atsuhiko; Ochoa, Ines; Ochoa-Ricoux, Juan Pedro; Oda, Susumu; Odaka, Shigeru; Ogren, Harold; Oh, Alexander; Oh, Seog; Ohm, Christian; Ohman, Henrik; Oide, Hideyuki; Okawa, Hideki; Okumura, Yasuyuki; Okuyama, Toyonobu; Olariu, Albert; Oleiro Seabra, Luis Filipe; Olivares Pino, Sebastian Andres; Oliveira Damazio, Denis; Olszewski, Andrzej; Olszowska, Jolanta; Onofre, António; Onogi, Kouta; Onyisi, Peter; Oram, Christopher; Oreglia, Mark; Oren, Yona; Orestano, Domizia; Orlando, Nicola; Orr, Robert; Osculati, Bianca; Ospanov, Rustem; Otero y Garzon, Gustavo; Otono, Hidetoshi; Ouchrif, Mohamed; Ould-Saada, Farid; Ouraou, Ahmimed; Oussoren, Koen Pieter; Ouyang, Qun; Ovcharova, Ana; Owen, Mark; Owen, Rhys Edward; Ozcan, Veysi Erkcan; Ozturk, Nurcan; Pachal, Katherine; Pacheco Pages, Andres; Padilla Aranda, Cristobal; Pagáčová, Martina; Pagan Griso, Simone; Paige, Frank; Pais, Preema; Pajchel, Katarina; Palacino, Gabriel; Palestini, Sandro; Palka, Marek; Pallin, Dominique; Palm, Marcus; Palma, Alberto; Panagiotopoulou, Evgenia; Pandini, Carlo Enrico; Panduro Vazquez, William; Pani, Priscilla; Panitkin, Sergey; Pantea, Dan; Paolozzi, Lorenzo; Papadopoulou, Theodora; Papageorgiou, Konstantinos; Paramonov, Alexander; Paredes Hernandez, Daniela; Parker, Adam Jackson; Parker, Michael Andrew; Parker, Kerry Ann; Parodi, Fabrizio; Parsons, John; Parzefall, Ulrich; Pascuzzi, Vincent; Pasqualucci, Enrico; Passaggio, Stefano; Pastore, Fernanda; Pastore, Francesca; Pásztor, Gabriella; Pataraia, Sophio; Patel, Nikhul; Pater, Joleen; Pauly, Thilo; Pearce, James; Pearson, Benjamin; Pedersen, Lars Egholm; Pedersen, Maiken; Pedraza Lopez, Sebastian; Pedro, Rute; Peleganchuk, Sergey; Pelikan, Daniel; Penc, Ondrej; Peng, Cong; Peng, Haiping; Penwell, John; Peralva, Bernardo; Perego, Marta Maria; Perepelitsa, Dennis; Perez Codina, Estel; Perini, Laura; Pernegger, Heinz; Perrella, Sabrina; Peschke, Richard; Peshekhonov, Vladimir; Peters, Krisztian; Peters, Yvonne; Petersen, Brian; Petersen, Troels; Petit, Elisabeth; Petridis, Andreas; Petridou, Chariclia; Petroff, Pierre; Petrolo, Emilio; Petrov, Mariyan; Petrucci, Fabrizio; Pettersson, Nora Emilia; Peyaud, Alan; Pezoa, Raquel; Phillips, Peter William; Piacquadio, Giacinto; Pianori, Elisabetta; Picazio, Attilio; Piccaro, Elisa; Piccinini, Maurizio; Pickering, Mark Andrew; Piegaia, Ricardo; Pilcher, James; Pilkington, Andrew; Pin, Arnaud Willy J; Pina, João Antonio; Pinamonti, Michele; Pinfold, James; Pingel, Almut; Pires, Sylvestre; Pirumov, Hayk; Pitt, Michael; Plazak, Lukas; Pleier, Marc-Andre; Pleskot, Vojtech; Plotnikova, Elena; Plucinski, Pawel; Pluth, Daniel; Poettgen, Ruth; Poggioli, Luc; Pohl, David-leon; Polesello, Giacomo; Poley, Anne-luise; Policicchio, Antonio; Polifka, Richard; Polini, Alessandro; Pollard, Christopher Samuel; Polychronakos, Venetios; Pommès, Kathy; Pontecorvo, Ludovico; Pope, Bernard; Popeneciu, Gabriel Alexandru; Popovic, Dragan; Poppleton, Alan; Pospisil, Stanislav; Potamianos, Karolos; Potrap, Igor; Potter, Christina; Potter, Christopher; Poulard, Gilbert; Poveda, Joaquin; Pozdnyakov, Valery; Pozo Astigarraga, Mikel Eukeni; Pralavorio, Pascal; Pranko, Aliaksandr; Prell, Soeren; Price, Darren; Price, Lawrence; Primavera, Margherita; Prince, Sebastien; Proissl, Manuel; Prokofiev, Kirill; Prokoshin, Fedor; Protopopescu, Serban; Proudfoot, James; Przybycien, Mariusz; Puddu, Daniele; Puldon, David; Purohit, Milind; Puzo, Patrick; Qian, Jianming; Qin, Gang; Qin, Yang; Quadt, Arnulf; Quayle, William; Queitsch-Maitland, Michaela; Quilty, Donnchadha; Raddum, Silje; Radeka, Veljko; Radescu, Voica; Radhakrishnan, Sooraj Krishnan; Radloff, Peter; Rados, Pere; Ragusa, Francesco; Rahal, Ghita; Raine, John Andrew; Rajagopalan, Srinivasan; Rammensee, Michael; Rangel-Smith, Camila; Ratti, Maria Giulia; Rauscher, Felix; Rave, Stefan; Ravenscroft, Thomas; Raymond, Michel; Read, Alexander Lincoln; Readioff, Nathan Peter; Rebuzzi, Daniela; Redelbach, Andreas; Redlinger, George; Reece, Ryan; Reeves, Kendall; Rehnisch, Laura; Reichert, Joseph; Reisin, Hernan; Rembser, Christoph; Ren, Huan; Rescigno, Marco; Resconi, Silvia; Rezanova, Olga; Reznicek, Pavel; Rezvani, Reyhaneh; Richter, Robert; Richter, Stefan; Richter-Was, Elzbieta; Ricken, Oliver; Ridel, Melissa; Rieck, Patrick; Riegel, Christian Johann; Rieger, Julia; Rifki, Othmane; Rijssenbeek, Michael; Rimoldi, Adele; Rinaldi, Lorenzo; Ristić, Branislav; Ritsch, Elmar; Riu, Imma; Rizatdinova, Flera; Rizvi, Eram; Rizzi, Chiara; Robertson, Steven; Robichaud-Veronneau, Andree; Robinson, Dave; Robinson, James; Robson, Aidan; Roda, Chiara; Rodina, Yulia; Rodriguez Perez, Andrea; Rodriguez Rodriguez, Daniel; Roe, Shaun; Rogan, Christopher Sean; Røhne, Ole; Romaniouk, Anatoli; Romano, Marino; Romano Saez, Silvestre Marino; Romero Adam, Elena; Rompotis, Nikolaos; Ronzani, Manfredi; Roos, Lydia; Ros, Eduardo; Rosati, Stefano; Rosbach, Kilian; Rose, Peyton; Rosenthal, Oliver; Rossetti, Valerio; Rossi, Elvira; Rossi, Leonardo Paolo; Rosten, Jonatan; Rosten, Rachel; Rotaru, Marina; Roth, Itamar; Rothberg, Joseph; Rousseau, David; Royon, Christophe; Rozanov, Alexandre; Rozen, Yoram; Ruan, Xifeng; Rubbo, Francesco; Rubinskiy, Igor; Rud, Viacheslav; Rudolph, Matthew Scott; Rühr, Frederik; Ruiz-Martinez, Aranzazu; Rurikova, Zuzana; Rusakovich, Nikolai; Ruschke, Alexander; Russell, Heather; Rutherfoord, John; Ruthmann, Nils; Ryabov, Yury; Rybar, Martin; Rybkin, Grigori; Ryu, Soo; Ryzhov, Andrey; Saavedra, Aldo; Sabato, Gabriele; Sacerdoti, Sabrina; Sadrozinski, Hartmut; Sadykov, Renat; Safai Tehrani, Francesco; Saha, Puja; Sahinsoy, Merve; Saimpert, Matthias; Saito, Tomoyuki; Sakamoto, Hiroshi; Sakurai, Yuki; Salamanna, Giuseppe; Salamon, Andrea; Salazar Loyola, Javier Esteban; Salek, David; Sales De Bruin, Pedro Henrique; Salihagic, Denis; Salnikov, Andrei; Salt, José; Salvatore, Daniela; Salvatore, Pasquale Fabrizio; Salvucci, Antonio; Salzburger, Andreas; Sammel, Dirk; Sampsonidis, Dimitrios; Sanchez, Arturo; Sánchez, Javier; Sanchez Martinez, Victoria; Sandaker, Heidi; Sandbach, Ruth Laura; Sander, Heinz Georg; Sanders, Michiel; Sandhoff, Marisa; Sandoval, Carlos; Sandstroem, Rikard; Sankey, Dave; Sannino, Mario; Sansoni, Andrea; Santoni, Claudio; Santonico, Rinaldo; Santos, Helena; Santoyo Castillo, Itzebelt; Sapp, Kevin; Sapronov, Andrey; Saraiva, João; Sarrazin, Bjorn; Sasaki, Osamu; Sasaki, Yuichi; Sato, Koji; Sauvage, Gilles; Sauvan, Emmanuel; Savage, Graham; Savard, Pierre; Sawyer, Craig; Sawyer, Lee; Saxon, James; Sbarra, Carla; Sbrizzi, Antonio; Scanlon, Tim; Scannicchio, Diana; Scarcella, Mark; Scarfone, Valerio; Schaarschmidt, Jana; Schacht, Peter; Schaefer, Douglas; Schaefer, Ralph; Schaeffer, Jan; Schaepe, Steffen; Schaetzel, Sebastian; Schäfer, Uli; Schaffer, Arthur; Schaile, Dorothee; Schamberger, R Dean; Scharf, Veit; Schegelsky, Valery; Scheirich, Daniel; Schernau, Michael; Schiavi, Carlo; Schillo, Christian; Schioppa, Marco; Schlenker, Stefan; Schmieden, Kristof; Schmitt, Christian; Schmitt, Stefan; Schmitz, Simon; Schneider, Basil; Schnellbach, Yan Jie; Schnoor, Ulrike; Schoeffel, Laurent; Schoening, Andre; Schoenrock, Bradley Daniel; Schopf, Elisabeth; Schorlemmer, Andre Lukas; Schott, Matthias; Schovancova, Jaroslava; Schramm, Steven; Schreyer, Manuel; Schuh, Natascha; Schultens, Martin Johannes; Schultz-Coulon, Hans-Christian; Schulz, Holger; Schumacher, Markus; Schumm, Bruce; Schune, Philippe; Schwanenberger, Christian; Schwartzman, Ariel; Schwarz, Thomas Andrew; Schwegler, Philipp; Schweiger, Hansdieter; Schwemling, Philippe; Schwienhorst, Reinhard; Schwindling, Jerome; Schwindt, Thomas; Sciolla, Gabriella; Scuri, Fabrizio; Scutti, Federico; Searcy, Jacob; Seema, Pienpen; Seidel, Sally; Seiden, Abraham; Seifert, Frank; Seixas, José; Sekhniaidze, Givi; Sekhon, Karishma; Sekula, Stephen; Seliverstov, Dmitry; Semprini-Cesari, Nicola; Serfon, Cedric; Serin, Laurent; Serkin, Leonid; Sessa, Marco; Seuster, Rolf; Severini, Horst; Sfiligoj, Tina; Sforza, Federico; Sfyrla, Anna; Shabalina, Elizaveta; Shaikh, Nabila Wahab; Shan, Lianyou; Shang, Ruo-yu; Shank, James; Shapiro, Marjorie; Shatalov, Pavel; Shaw, Kate; Shaw, Savanna Marie; Shcherbakova, Anna; Shehu, Ciwake Yusufu; Sherwood, Peter; Shi, Liaoshan; Shimizu, Shima; Shimmin, Chase Owen; Shimojima, Makoto; Shiyakova, Mariya; Shmeleva, Alevtina; Shoaleh Saadi, Diane; Shochet, Mel; Shojaii, Seyedruhollah; Shrestha, Suyog; Shulga, Evgeny; Shupe, Michael; Sicho, Petr; Sidebo, Per Edvin; Sidiropoulou, Ourania; Sidorov, Dmitri; Sidoti, Antonio; Siegert, Frank; Sijacki, Djordje; Silva, José; Silverstein, Samuel; Simak, Vladislav; Simard, Olivier; Simic, Ljiljana; Simion, Stefan; Simioni, Eduard; Simmons, Brinick; Simon, Dorian; Simon, Manuel; Sinervo, Pekka; Sinev, Nikolai; Sioli, Maximiliano; Siragusa, Giovanni; Sivoklokov, Serguei; Sjölin, Jörgen; Sjursen, Therese; Skinner, Malcolm Bruce; Skottowe, Hugh Philip; Skubic, Patrick; Slater, Mark; Slavicek, Tomas; Slawinska, Magdalena; Sliwa, Krzysztof; Slovak, Radim; Smakhtin, Vladimir; Smart, Ben; Smestad, Lillian; Smirnov, Sergei; Smirnov, Yury; Smirnova, Lidia; Smirnova, Oxana; Smith, Matthew; Smith, Russell; Smizanska, Maria; Smolek, Karel; Snesarev, Andrei; Snidero, Giacomo; Snyder, Scott; Sobie, Randall; Socher, Felix; Soffer, Abner; Soh, Dart-yin; Sokhrannyi, Grygorii; Solans Sanchez, Carlos; Solar, Michael; Soldatov, Evgeny; Soldevila, Urmila; Solodkov, Alexander; Soloshenko, Alexei; Solovyanov, Oleg; Solovyev, Victor; Sommer, Philip; Son, Hyungsuk; Song, Hong Ye; Sood, Alexander; Sopczak, Andre; Sopko, Vit; Sorin, Veronica; Sosa, David; Sotiropoulou, Calliope Louisa; Soualah, Rachik; Soukharev, Andrey; South, David; Sowden, Benjamin; Spagnolo, Stefania; Spalla, Margherita; Spangenberg, Martin; Spanò, Francesco; Sperlich, Dennis; Spettel, Fabian; Spighi, Roberto; Spigo, Giancarlo; Spiller, Laurence Anthony; Spousta, Martin; St Denis, Richard Dante; Stabile, Alberto; Stahlman, Jonathan; Stamen, Rainer; Stamm, Soren; Stanecka, Ewa; Stanek, Robert; Stanescu, Cristian; Stanescu-Bellu, Madalina; Stanitzki, Marcel Michael; Stapnes, Steinar; Starchenko, Evgeny; Stark, Giordon; Stark, Jan; Staroba, Pavel; Starovoitov, Pavel; Stärz, Steffen; Staszewski, Rafal; Steinberg, Peter; Stelzer, Bernd; Stelzer, Harald Joerg; Stelzer-Chilton, Oliver; Stenzel, Hasko; Stewart, Graeme; Stillings, Jan Andre; Stockton, Mark; Stoebe, Michael; Stoicea, Gabriel; Stolte, Philipp; Stonjek, Stefan; Stradling, Alden; Straessner, Arno; Stramaglia, Maria Elena; Strandberg, Jonas; Strandberg, Sara; Strandlie, Are; Strauss, Michael; Strizenec, Pavol; Ströhmer, Raimund; Strom, David; Stroynowski, Ryszard; Strubig, Antonia; Stucci, Stefania Antonia; Stugu, Bjarne; Styles, Nicholas Adam; Su, Dong; Su, Jun; Subramaniam, Rajivalochan; Suchek, Stanislav; Sugaya, Yorihito; Suk, Michal; Sulin, Vladimir; Sultansoy, Saleh; Sumida, Toshi; Sun, Siyuan; Sun, Xiaohu; Sundermann, Jan Erik; Suruliz, Kerim; Susinno, Giancarlo; Sutton, Mark; Suzuki, Shota; Svatos, Michal; Swiatlowski, Maximilian; Sykora, Ivan; Sykora, Tomas; Ta, Duc; Taccini, Cecilia; Tackmann, Kerstin; Taenzer, Joe; Taffard, Anyes; Tafirout, Reda; Taiblum, Nimrod; Takai, Helio; Takashima, Ryuichi; Takeda, Hiroshi; Takeshita, Tohru; Takubo, Yosuke; Talby, Mossadek; Talyshev, Alexey; Tam, Jason; Tan, Kong Guan; Tanaka, Junichi; Tanaka, Reisaburo; Tanaka, Shuji; Tannenwald, Benjamin Bordy; Tapia Araya, Sebastian; Tapprogge, Stefan; Tarem, Shlomit; Tartarelli, Giuseppe Francesco; Tas, Petr; Tasevsky, Marek; Tashiro, Takuya; Tassi, Enrico; Tavares Delgado, Ademar; Tayalati, Yahya; Taylor, Aaron; Taylor, Geoffrey; Taylor, Pierre Thor Elliot; Taylor, Wendy; Teischinger, Florian Alfred; Teixeira-Dias, Pedro; Temming, Kim Katrin; Temple, Darren; Ten Kate, Herman; Teng, Ping-Kun; Teoh, Jia Jian; Tepel, Fabian-Phillipp; Terada, Susumu; Terashi, Koji; Terron, Juan; Terzo, Stefano; Testa, Marianna; Teuscher, Richard; Theveneaux-Pelzer, Timothée; Thomas, Juergen; Thomas-Wilsker, Joshuha; Thompson, Emily; Thompson, Paul; Thompson, Ray; Thompson, Stan; Thomsen, Lotte Ansgaard; Thomson, Evelyn; Thomson, Mark; Tibbetts, Mark James; Ticse Torres, Royer Edson; Tikhomirov, Vladimir; Tikhonov, Yury; Timoshenko, Sergey; Tipton, Paul; Tisserant, Sylvain; Todome, Kazuki; Todorov, Theodore; Todorova-Nova, Sharka; Tojo, Junji; Tokár, Stanislav; Tokushuku, Katsuo; Tolley, Emma; Tomlinson, Lee; Tomoto, Makoto; Tompkins, Lauren; Toms, Konstantin; Tong, Baojia(Tony); Torrence, Eric; Torres, Heberth; Torró Pastor, Emma; Toth, Jozsef; Touchard, Francois; Tovey, Daniel; Trefzger, Thomas; Tricoli, Alessandro; Trigger, Isabel Marian; Trincaz-Duvoid, Sophie; Tripiana, Martin; Trischuk, William; Trocmé, Benjamin; Trofymov, Artur; Troncon, Clara; Trottier-McDonald, Michel; Trovatelli, Monica; Truong, Loan; Trzebinski, Maciej; Trzupek, Adam; Tseng, Jeffrey; Tsiareshka, Pavel; Tsipolitis, Georgios; Tsirintanis, Nikolaos; Tsiskaridze, Shota; Tsiskaridze, Vakhtang; Tskhadadze, Edisher; Tsui, Ka Ming; Tsukerman, Ilya; Tsulaia, Vakhtang; Tsuno, Soshi; Tsybychev, Dmitri; Tudorache, Alexandra; Tudorache, Valentina; Tuna, Alexander Naip; Tupputi, Salvatore; Turchikhin, Semen; Turecek, Daniel; Turgeman, Daniel; Turra, Ruggero; Turvey, Andrew John; Tuts, Michael; Tyndel, Mike; Ucchielli, Giulia; Ueda, Ikuo; Ueno, Ryuichi; Ughetto, Michael; Ukegawa, Fumihiko; Unal, Guillaume; Undrus, Alexander; Unel, Gokhan; Ungaro, Francesca; Unno, Yoshinobu; Unverdorben, Christopher; Urban, Jozef; Urquijo, Phillip; Urrejola, Pedro; Usai, Giulio; Usanova, Anna; Vacavant, Laurent; Vacek, Vaclav; Vachon, Brigitte; Valderanis, Chrysostomos; Valdes Santurio, Eduardo; Valencic, Nika; Valentinetti, Sara; Valero, Alberto; Valery, Loic; Valkar, Stefan; Vallecorsa, Sofia; Valls Ferrer, Juan Antonio; Van Den Wollenberg, Wouter; Van Der Deijl, Pieter; van der Geer, Rogier; van der Graaf, Harry; van Eldik, Niels; van Gemmeren, Peter; Van Nieuwkoop, Jacobus; van Vulpen, Ivo; van Woerden, Marius Cornelis; Vanadia, Marco; Vandelli, Wainer; Vanguri, Rami; Vaniachine, Alexandre; Vankov, Peter; Vardanyan, Gagik; Vari, Riccardo; Varnes, Erich; Varol, Tulin; Varouchas, Dimitris; Vartapetian, Armen; Varvell, Kevin; Vasquez, Jared Gregory; Vazeille, Francois; Vazquez Schroeder, Tamara; Veatch, Jason; Veloce, Laurelle Maria; Veloso, Filipe; Veneziano, Stefano; Ventura, Andrea; Venturi, Manuela; Venturi, Nicola; Venturini, Alessio; Vercesi, Valerio; Verducci, Monica; Verkerke, Wouter; Vermeulen, Jos; Vest, Anja; Vetterli, Michel; Viazlo, Oleksandr; Vichou, Irene; Vickey, Trevor; Vickey Boeriu, Oana Elena; Viehhauser, Georg; Viel, Simon; Vigani, Luigi; Vigne, Ralph; Villa, Mauro; Villaplana Perez, Miguel; Vilucchi, Elisabetta; Vincter, Manuella; Vinogradov, Vladimir; Vittori, Camilla; Vivarelli, Iacopo; Vlachos, Sotirios; Vlasak, Michal; Vogel, Marcelo; Vokac, Petr; Volpi, Guido; Volpi, Matteo; von der Schmitt, Hans; von Toerne, Eckhard; Vorobel, Vit; Vorobev, Konstantin; Vos, Marcel; Voss, Rudiger; Vossebeld, Joost; Vranjes, Nenad; Vranjes Milosavljevic, Marija; Vrba, Vaclav; Vreeswijk, Marcel; Vuillermet, Raphael; Vukotic, Ilija; Vykydal, Zdenek; Wagner, Peter; Wagner, Wolfgang; Wahlberg, Hernan; Wahrmund, Sebastian; Wakabayashi, Jun; Walder, James; Walker, Rodney; Walkowiak, Wolfgang; Wallangen, Veronica; Wang, Chao; Wang, Chao; Wang, Fuquan; Wang, Haichen; Wang, Hulin; Wang, Jike; Wang, Jin; Wang, Kuhan; Wang, Rui; Wang, Song-Ming; Wang, Tan; Wang, Tingting; Wang, Xiaoxiao; Wanotayaroj, Chaowaroj; Warburton, Andreas; Ward, Patricia; Wardrope, David Robert; Washbrook, Andrew; Watkins, Peter; Watson, Alan; Watson, Ian; Watson, Miriam; Watts, Gordon; Watts, Stephen; Waugh, Ben; Webb, Samuel; Weber, Michele; Weber, Stefan Wolf; Webster, Jordan S; Weidberg, Anthony; Weinert, Benjamin; Weingarten, Jens; Weiser, Christian; Weits, Hartger; Wells, Phillippa; Wenaus, Torre; Wengler, Thorsten; Wenig, Siegfried; Wermes, Norbert; Werner, Matthias; Werner, Per; Wessels, Martin; Wetter, Jeffrey; Whalen, Kathleen; Whallon, Nikola Lazar; Wharton, Andrew Mark; White, Andrew; White, Martin; White, Ryan; White, Sebastian; Whiteson, Daniel; Wickens, Fred; Wiedenmann, Werner; Wielers, Monika; Wienemann, Peter; Wiglesworth, Craig; Wiik-Fuchs, Liv Antje Mari; Wildauer, Andreas; Wilk, Fabian; Wilkens, Henric George; Williams, Hugh; Williams, Sarah; Willis, Christopher; Willocq, Stephane; Wilson, John; Wingerter-Seez, Isabelle; Winklmeier, Frank; Winston, Oliver James; Winter, Benedict Tobias; Wittgen, Matthias; Wittkowski, Josephine; Wollstadt, Simon Jakob; Wolter, Marcin Wladyslaw; Wolters, Helmut; Wosiek, Barbara; Wotschack, Jorg; Woudstra, Martin; Wozniak, Krzysztof; Wu, Mengqing; Wu, Miles; Wu, Sau Lan; Wu, Xin; Wu, Yusheng; Wyatt, Terry Richard; Wynne, Benjamin; Xella, Stefania; Xu, Da; Xu, Lailin; Yabsley, Bruce; Yacoob, Sahal; Yakabe, Ryota; Yamaguchi, Daiki; Yamaguchi, Yohei; Yamamoto, Akira; Yamamoto, Shimpei; Yamanaka, Takashi; Yamauchi, Katsuya; Yamazaki, Yuji; Yan, Zhen; Yang, Haijun; Yang, Hongtao; Yang, Yi; Yang, Zongchang; Yao, Weiming; Yap, Yee Chinn; Yasu, Yoshiji; Yatsenko, Elena; Yau Wong, Kaven Henry; Ye, Jingbo; Ye, Shuwei; Yeletskikh, Ivan; Yen, Andy L; Yildirim, Eda; Yorita, Kohei; Yoshida, Rikutaro; Yoshihara, Keisuke; Young, Charles; Young, Christopher John; Youssef, Saul; Yu, David Ren-Hwa; Yu, Jaehoon; Yu, Jiaming; Yu, Jie; Yuan, Li; Yuen, Stephanie P; Yusuff, Imran; Zabinski, Bartlomiej; Zaidan, Remi; Zaitsev, Alexander; Zakharchuk, Nataliia; Zalieckas, Justas; Zaman, Aungshuman; Zambito, Stefano; Zanello, Lucia; Zanzi, Daniele; Zeitnitz, Christian; Zeman, Martin; Zemla, Andrzej; Zeng, Jian Cong; Zeng, Qi; Zengel, Keith; Zenin, Oleg; Ženiš, Tibor; Zerwas, Dirk; Zhang, Dongliang; Zhang, Fangzhou; Zhang, Guangyi; Zhang, Huijun; Zhang, Jinlong; Zhang, Lei; Zhang, Rui; Zhang, Ruiqi; Zhang, Xueyao; Zhang, Zhiqing; Zhao, Xiandong; Zhao, Yongke; Zhao, Zhengguo; Zhemchugov, Alexey; Zhong, Jiahang; Zhou, Bing; Zhou, Chen; Zhou, Lei; Zhou, Li; Zhou, Mingliang; Zhou, Ning; Zhu, Cheng Guang; Zhu, Hongbo; Zhu, Junjie; Zhu, Yingchun; Zhuang, Xuai; Zhukov, Konstantin; Zibell, Andre; Zieminska, Daria; Zimine, Nikolai; Zimmermann, Christoph; Zimmermann, Stephanie; Zinonos, Zinonas; Zinser, Markus; Ziolkowski, Michael; Živković, Lidija; Zobernig, Georg; Zoccoli, Antonio; zur Nedden, Martin; Zurzolo, Giovanni; Zwalinski, Lukasz

2016-05-20

This paper discusses various observations on beam-induced and cosmic-ray backgrounds in the ATLAS detector during the LHC 2012 proton-proton run. Building on published results based on 2011 data, the correlations between background and residual pressure of the beam vacuum are revisited. Ghost charge evolution over 2012 and its role for backgrounds are evaluated. New methods to monitor ghost charge with beam-gas rates are presented and observations of LHC abort gap population by ghost charge are discussed in detail. Fake jets from colliding bunches and from ghost charge are analysed with improved methods, showing that ghost charge in individual radio-frequency buckets of the LHC can be resolved. Some results of two short periods of dedicated cosmic-ray background data-taking are shown; in particular cosmic-ray muon induced fake jet rates are compared to Monte Carlo simulations and to the fake jet rates from beam background. A thorough analysis of a particular LHC fill, where abnormally high background was obse...

X-RAY AND EUV OBSERVATIONS OF SIMULTANEOUS SHORT AND LONG PERIOD OSCILLATIONS IN HOT CORONAL ARCADE LOOPS

International Nuclear Information System (INIS)

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

2015-01-01

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

X-RAY AND EUV OBSERVATIONS OF SIMULTANEOUS SHORT AND LONG PERIOD OSCILLATIONS IN HOT CORONAL ARCADE LOOPS

Energy Technology Data Exchange (ETDEWEB)

Kumar, Pankaj; Cho, Kyung-Suk [Korea Astronomy and Space Science Institute (KASI), Daejeon, 305-348 (Korea, Republic of); Nakariakov, Valery M., E-mail: pankaj@kasi.re.kr [Centre for Fusion, Space and Astrophysics, Department of Physics, University of Warwick, CV4 7AL (United Kingdom)

2015-05-01

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

Aerosol chemical composition at Cabauw, the Netherlands as observed in two intensive periods in May 2008 and March 2009

NARCIS (Netherlands)

Mensah, A.A.; Holzinger, R.; Otjes, R.; Trimborn, A.; Mentel, T.F.; Brink, H. ten; Henzing, B.; Kiendler-Scharr, A.

2012-01-01

Observations of aerosol chemical composition in Cabauw, the Netherlands, are presented for two intensive measurement periods in May 2008 and March 2009. Sub-micron aerosol chemical composition was measured by an Aerodyne Aerosol Mass Spectrometer (AMS) and is compared to observations from aerosol

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

Directory of Open Access Journals (Sweden)

Seyedmohammad Shayestehaminzadeh

2015-11-01

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

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

Science.gov (United States)

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

2013-08-01

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

X-ray and optical observations of the ultrashort period dwarf nova SW Ursae Majoris - A likely new DQ Herculis star

Science.gov (United States)

Shafter, A. W.; Szkody, P.; Thorstensen, J. R.

1986-01-01

Time-resolved X-ray and optical photometric and optical spectroscopic observations of the ultrashort period cataclysmic variable SW UMa are reported. The spectroscopic observations reveal the presence of an s-wave component which is almost in phase with the extreme line wings and presumably the white dwarf. This very unusual phasing in conjunction with the available optical and X-ray data seems to indicate that a region of enhanced emission exists on the opposite side of the disk from the expected location of the hot spot. The photometric observations reveal the presence of a hump in the light curve occurring at an orbital phase which is consistent with the phase at which the region of enhanced line emission is most favorably seen. Changes in the hump amplitude are seen from night to night, and a 15.9 min periodicity is evident in the light curve. The optical and X-ray periodicities suggest that SW UMa is a member of the DQ Her class of cataclysmic variables.

Aerial Observation; A Bibliography of Periodical Articles.

Science.gov (United States)

1982-04-01

99,90, Jan 1944. ’If not an Air OP why not locatinc7," 2CRA, ?0:115-123, Apr 1953. Jackson , I-ian E. "FDC an- the Artillery Air Observer," FM, 34...194, 1886. Thom.pson, Percy N;. "Organization and ’aneuver of Ficld Artillery Observation," .*IL RVW, 25:53-60, Apr 1945. "To See or not to see," JORA

Subjective and objective observation of skin graft recovery on Indonesian local cat with different periods of transplantation time.

Science.gov (United States)

Erwin; Gunanti; Handharyani, Ekowati; Noviana, Deni

2016-05-01

The success of a skin graft in a cat is highly dependent on the granulation formed by the base of recipient bed. Granulation by the base of recipient bed will form after several days after injury. This research aimed to observe subjective and objective profile of skin graft recovery on forelimb of cats with different periods of donor skin placement. Nine male Indonesian local cats aged 1-2 years old, weighing 3-4 kg were divided into three groups. The first surgery for creating defect wound of 2 cm×2 cm in size was performed in the whole group. The wound was left for several days with the respective interval for each group, respectively: Group I (for 2 days), Group II (for 4 days), and Group III (for 6 days). In the whole group, the second surgery was done by the harvesting skin of thoracic area which then applied on recipient bed of respective groups. The donor skin on Group II was accepted faster compared to Group I and Group III. The donor skin did not show color differences compared to surrounding skin, painless, bright red in bleeding test had faster both hair growth and drug absorption. Test toward the size of donor skin and the effect of drugs did not show a significant difference between each group. The observe subjective and objective profile of skin graft recovery on forelimb of cats on Group II were accepted faster compared to Group I and III.

Behaviour of 7Be air concentration observed during a period of 13 years and comparison with sun activity

International Nuclear Information System (INIS)

Cannizzaro, F.; Greco, G.; Raneli, M.; Spitale, M.C.; Tomarchio, E.

1995-01-01

The study reported in this work is addressed to review the time variations of the air-borne concentration of cosmogenic 7 Be obtained in the period January 1982-December 1994. Among other things, the observation of a long-term modulation present in the average monthly concentrations led us to perform a comparison with the behaviour in the same period of solar activity owing to its important influence on cosmic rays, from which the 7 Be production originates. (author)

Regulatory T Cells Show Dynamic Behavior During Late Pregnancy, Delivery, and the Postpartum Period.

Science.gov (United States)

Lima, Jorge; Martins, Catarina; Nunes, Glória; Sousa, Maria-José; Branco, Jorge C; Borrego, Luís-Miguel

2017-07-01

Regulatory T cells (Tregs) are critical immunomodulators during early pregnancy by preventing maternal T-cell activation against fetal cells. However, how populations of maternal Tregs vary during and after pregnancy in humans is still unclear. Therefore, we investigated Treg subsets in the peripheral blood of pregnant women from late pregnancy through the postpartum period. To accomplish this, the following circulating Treg subsets were analyzed in 43 healthy pregnant women and 35 nonpregnant women by flow cytometry during the third trimester, on the day of delivery, and postpartum: CD4 Dim CD25 Hi , CD4 + CD25 Hi Foxp3 + , and CD4 + CD25 Hi CD127 -/dim . Additionally, the expression levels of the transcription factor Foxp3 in CD4 Dim CD25 Hi Treg were analyzed. We have found that CD4 Dim CD25 Hi Treg subset significantly decreased in the pregnant women on the day of delivery relative to the third trimester ( P postpartum compared to the third trimester and the day of delivery ( P postpartum compared to the third trimester and the day of delivery ( P postpartum period. Our results offer an explanation for the possible effects of pregnancy on the clinical outcomes of some autoimmune diseases during the postpartum period.

Planetary perturbations and the origins of short-period comets

International Nuclear Information System (INIS)

Quinn, T.; Tremaine, S.; Duncan, M.

1990-01-01

To investigate the dynamical plausibility of possible sources for the short-period comets, a representative sample of comet orbits in the field of the sun and the giant planets was integrated, with the aim to determine whether the distribution of orbits from a proposed source that reach observable perihelia (q less than 2.5 AU) matches the observed distribution of short-period orbits. It is found that the majority of the short-period comets, those with orbital period P less than 20 yr (the Jupiter family), cannot arise from isotropic orbits with perihelia near Jupiter's orbit, because the resulting observable comet orbits have the wrong distribution in period, inclination, and argument of perihelion. The simulations also show that Jupiter-family comets cannot arise from isotropic orbits with perihelia in the Uranus-Neptune region. On the other hand, a source of low-inclination Neptune-crossing orbits yields a distribution of observable Jupiter-family comets that is consistent with the data in all respects. These results imply that the Jupiter-family comets arise from a disk source in the outer solar system rather than from the Oort comet cloud. 30 refs

Possible signature of the magnetic fields related to quasi-periodic oscillations observed in microquasars

Science.gov (United States)

Kološ, Martin; Tursunov, Arman; Stuchlík, Zdeněk

2017-12-01

The study of quasi-periodic oscillations (QPOs) of X-ray flux observed in the stellar-mass black hole binaries can provide a powerful tool for testing of the phenomena occurring in the strong gravity regime. Magnetized versions of the standard geodesic models of QPOs can explain the observationally fixed data from the three microquasars. We perform a successful fitting of the HF QPOs observed for three microquasars, GRS 1915+105, XTE 1550-564 and GRO 1655-40, containing black holes, for magnetized versions of both epicyclic resonance and relativistic precession models and discuss the corresponding constraints of parameters of the model, which are the mass and spin of the black hole and the parameter related to the external magnetic field. The estimated magnetic field intensity strongly depends on the type of objects giving the observed HF QPOs. It can be as small as 10^{-5} G if electron oscillatory motion is relevant, but it can be by many orders higher for protons or ions (0.02-1 G), or even higher for charged dust or such exotic objects as lighting balls, etc. On the other hand, if we know by any means the magnetic field intensity, our model implies strong limit on the character of the oscillating matter, namely its specific charge.

Possible signature of the magnetic fields related to quasi-periodic oscillations observed in microquasars

Energy Technology Data Exchange (ETDEWEB)

Kolos, Martin; Tursunov, Arman; Stuchlik, Zdenek [Silesian University in Opava, Institute of Physics and Research Centre of Theoretical Physics and Astrophysics, Faculty of Philosophy and Science, Opava (Czech Republic)

2017-12-15

The study of quasi-periodic oscillations (QPOs) of X-ray flux observed in the stellar-mass black hole binaries can provide a powerful tool for testing of the phenomena occurring in the strong gravity regime. Magnetized versions of the standard geodesic models of QPOs can explain the observationally fixed data from the three microquasars. We perform a successful fitting of the HF QPOs observed for three microquasars, GRS 1915+105, XTE 1550-564 and GRO 1655-40, containing black holes, for magnetized versions of both epicyclic resonance and relativistic precession models and discuss the corresponding constraints of parameters of the model, which are the mass and spin of the black hole and the parameter related to the external magnetic field. The estimated magnetic field intensity strongly depends on the type of objects giving the observed HF QPOs. It can be as small as 10{sup -5} G if electron oscillatory motion is relevant, but it can be by many orders higher for protons or ions (0.02-1 G), or even higher for charged dust or such exotic objects as lighting balls, etc. On the other hand, if we know by any means the magnetic field intensity, our model implies strong limit on the character of the oscillating matter, namely its specific charge. (orig.)

Multimedia Based on Scientific Approach for Periodic System of Element

Science.gov (United States)

Sari, S.; Aryana, D. M.; Subarkah, C. Z.; Ramdhani, M. A.

2018-01-01

This study aims to describe the application of interactive multimedia on the concept of the periodic system of elements. The study was conducted by using the one-shot case study design. The subjects in this study were 35 high school students of class XI IPA. Results showed that the stages of observing, questioning, data collecting (experimenting), and communicating are all considered very good. This shows that multimedia can assist students in explaining the development of the periodic system of elements, ranging from Triade doberrainer, Newland Octarchic Law, Mendeleyev, and the modern periodic, as well as atomic radius, ionization energy, and electronegativity of an element in the periodic system.

On the quasi-periodic nature of magnetopause flux transfer events

International Nuclear Information System (INIS)

Lockwood, M.; Wild, M.N.

1993-01-01

The authors look at the interpretation of magnetopause flux transfer events (FTE), which claims to show that these events are quasi periodic with a mean period of about 8 minutes. FTE are characteristic signatures in the magnetic field observed by satellites in or near the magnetopause. They are mainly observed when the interplanetary magnetic field is southward, as is supported by a wide range of experimental evidence. There are several theoretical models which try to explain these events. The most successful to date is based upon a suggestion made by Saunders and Biernat, et al. This model has the advantage of accounting for some of the ground based observations of these events. It has been suggested that FTE represent bursts of enhanced magnetic reconnection, and may be the dominant mechanism of this solar wind-magnetosphere coupling. The authors also look at the variability of the IMF B z component as a potential source of the periodic FTE. Data from the ISEE 1 and 2 spacecraft taken during 1977 to 1979 were statistically surveyed for this report. The spacecraft crossed the magnetopause more than 172 times, and could observe FTE for typically 1 hr per pass. Data for the IMF came from the IMP8 spacecraft. Little data was available for the period of interest, but for the subsequent phase of the solar cycle there was considerable coverage. The data analysis shows a highly skewed recurrence period, with a mode of 3 min., and a lower and upper decile of 1.5 and 18.5 min. No significant peak is observed at 8 minutes. The shape of the distribution does not lend itself to any natural period of the magnetosphere-ionosphere system. There may be a correlation with the B z component of the IMF, but the correlation suffers most from the variability of the IMF dataset

Survival of inlays and partial crowns made of IPS empress after a 10-year observation period and in relation to various treatment parameters.

Science.gov (United States)

Stoll, Richard; Cappel, I; Jablonski-Momeni, Anahita; Pieper, K; Stachniss, V

2007-01-01

This study evaluated the long-term survival of inlays and partial crowns made of IPS Empress. For this purpose, the patient data of a prospective study were examined in retrospect and statistically evaluated. All of the inlays and partial crowns fabricated of IPS-Empress within the Department of Operative Dentistry at the School of Dental Medicine of Philipps University, Marburg, Germany were systematically recorded in a database between 1991 and 2001. The corresponding patient files were revised at the end of 2001. The information gathered in this way was used to evaluate the survival of the restorations using the method described by Kaplan and Meyer. A total of n = 1624 restorations were fabricated of IPS-Empress within the observation period. During this time, n = 53 failures were recorded. The remaining restorations were observed for a mean period of 18.77 months. The failures were mainly attributed to fractures, endodontic problems and cementation errors. The last failure was established after 82 months. At this stage, a cumulative survival probability of p = 0.81 was registered with a standard error of 0.04. At this time, n = 30 restorations were still being observed. Restorations on vital teeth (n = 1588) showed 46 failures, with a cumulative survival probability of p = 0.82. Restorations performed on non-vital teeth (n = 36) showed seven failures, with a cumulative survival probability of p = 0.53. Highly significant differences were found between the two groups (p < 0.0001) in a log-rank test. No significant difference (p = 0.41) was found between the patients treated by students (n = 909) and those treated by qualified dentists (n = 715). Likewise, no difference (p = 0.13) was established between the restorations seated with a high viscosity cement (n = 295) and those placed with a low viscosity cement (n = 1329).

Chaos to periodicity and periodicity to chaos by periodic perturbations in the Belousov-Zhabotinsky reaction

International Nuclear Information System (INIS)

Li Qianshu; Zhu Rui

2004-01-01

A three-variable model of the Belousov-Zhabotinsky reaction system subject to external sinusoidal perturbations is investigated by means of frequency spectrum analysis. In the period-1 window of the model, the transitions from periodicity to chaos are observed; in the chaotic window, the transitions from chaos to periodicity are found. The former might be understood by the circle map of two coupled oscillators, and the latter is partly explained by the resonance between the main frequency of the chaos and the frequency of the external periodic perturbations

Subjective and objective observation of skin graft recovery on Indonesian local cat with different periods of transplantation time

Directory of Open Access Journals (Sweden)

Erwin

2016-05-01

Full Text Available Aim: The success of a skin graft in a cat is highly dependent on the granulation formed by the base of recipient bed. Granulation by the base of recipient bed will form after several days after injury. This research aimed to observe subjective and objective profile of skin graft recovery on forelimb of cats with different periods of donor skin placement. Materials and Methods: Nine male Indonesian local cats aged 1-2 years old, weighing 3-4 kg were divided into three groups. The first surgery for creating defect wound of 2 cm×2 cm in size was performed in the whole group. The wound was left for several days with the respective interval for each group, respectively: Group I (for 2 days, Group II (for 4 days, and Group III (for 6 days. In the whole group, the second surgery was done by the harvesting skin of thoracic area which then applied on recipient bed of respective groups. Result: The donor skin on Group II was accepted faster compared to Group I and Group III. The donor skin did not show color differences compared to surrounding skin, painless, bright red in bleeding test had faster both hair growth and drug absorption. Test toward the size of donor skin and the effect of drugs did not show a significant difference between each group. Conclusion: The observe subjective and objective profile of skin graft recovery on forelimb of cats on Group II were accepted faster compared to Group I and III.

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

Science.gov (United States)

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

2013-05-01

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

Complexity analyses show two distinct types of nonlinear dynamics in short heart period variability recordings

Science.gov (United States)

Porta, Alberto; Bari, Vlasta; Marchi, Andrea; De Maria, Beatrice; Cysarz, Dirk; Van Leeuwen, Peter; Takahashi, Anielle C. M.; Catai, Aparecida M.; Gnecchi-Ruscone, Tomaso

2015-01-01

Two diverse complexity metrics quantifying time irreversibility and local prediction, in connection with a surrogate data approach, were utilized to detect nonlinear dynamics in short heart period (HP) variability series recorded in fetuses, as a function of the gestational period, and in healthy humans, as a function of the magnitude of the orthostatic challenge. The metrics indicated the presence of two distinct types of nonlinear HP dynamics characterized by diverse ranges of time scales. These findings stress the need to render more specific the analysis of nonlinear components of HP dynamics by accounting for different temporal scales. PMID:25806002

On the number of observable customers, served during he busy period of GI/GI/infinity queue

International Nuclear Information System (INIS)

Dvurechenskij, A.

1982-01-01

It is proved that the number of observable customers, served during the busy period of the GI/GI infinity queue with infinitely many servers has a geometric distribution. The parameter of this distribution is determined, too. It is shown that the normalized distributions converge to the exponential distribution. As a particular result is obtained that the distribution of the number of nonabsorbing streamers in a streamer blob has a geometric distribution

A0535+26: Refined position measurement and new pulse period data

International Nuclear Information System (INIS)

Li, F.; Rappaport, S.; Clark, G.W.; Jernigan, J.G.

1979-01-01

The hard, pulsing, transient X-ray source A0535+26 has been observed with SAS 3 on three occasions during 1977--1978. These observations have yielded a precise position measurement (20'' error radius) which renders the identification of A0535+26 with the Be star HDE 245770 virtually certain. The pulse phase was tracked for approx.9 days in 1978 April and clearly showed both first and second derivatives in the pulse period. An analysis of these new timing data, combined with data from previous observations, leads to the following conclusions: (1) a significant fraction of the observed changes in pulse period is probably intrinsic to the compact X-ray stae (e.g., accretion torques on a neutron star), and (2) conservative limits on binary orbital parameters tend to further confirm a long orbital period

Dirofilaria immitis and D. repens show circadian co-periodicity in naturally co-infected dogs

Czech Academy of Sciences Publication Activity Database

Ionică, A.M.; Matei, I.A.; D'Amico, G.; Bel, L.; Dumitrache, M.O.; Modrý, David; Mihalca, A. D.

2017-01-01

Roč. 10, FEB 28 (2017), č. článku 116. ISSN 1756-3305 Institutional support: RVO:60077344 Keywords : periodicity * microfilariae * co-infection * Dirofilaria immitis * Dirofilaria repens Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine OBOR OECD: Veterinary science Impact factor: 3.080, year: 2016

Extreme value analysis of meterological parameters observed at Narora during the period 1989-2001

International Nuclear Information System (INIS)

Varakhedkar, V.K.; Dube, B.; Gurg, R.P.

2002-08-01

The design of engineering structures requires an understanding of extreme weather conditions that may occur at the site of interest, which is very essential, so that the structures can be designed to withstand weather stresses. In this report an analysis of extreme values of meteorological parameters observed at Narora for the period 1989- 2001 is described. The parameters considered are maximum and minimum air temperature, minimum relative humidity, maximum wind speed, maximum rainfall in a day and month, and annual rainfall. The extreme value analysis reveals that the variables such as annual maximum air temperature, minimum relative humidity and monthly maximum rainfall obey Fisher -Tippet Type -I extreme value distribution where as annual minimum air temperature, maximum hourly wind speed, daily maximum rainfall and maximum and minimum annual rainfall, obey Fisher -Tippet Type -2 extreme value distribution function. Various distribution function parameters for each variable are determined. Extreme values corresponding to return periods of 50 years and 100 years are worked out. These derived extreme values are particularly useful for arriving at suitable design values to ensure the safety of any civil structure in Narora area with respect to stresses due to weather conditions. (author)

QUASI-PERIODIC ACCELERATION OF ELECTRONS IN THE FLARE ON 2012 JULY 19

Energy Technology Data Exchange (ETDEWEB)

Huang, Jing [Key Laboratory of Solar Activities, National Astronomical Observatories, Chinese Academy of Sciences, Beijing, 100012 (China); Kontar, Eduard P. [School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Nakariakov, Valery M. [Physics Department, University of Warwick, Coventry CV4 7AL (United Kingdom); Gao, Guannan, E-mail: huangj@bao.ac.cn [Yunnan Observatory, Chinese Academy of Sciences, Kunming, Yunnan 650011 (China)

2016-11-10

Quasi-periodic pulsations (QPPs) of nonthermal emission in an M7.7 class flare on 2012 July 19 are investigated with spatially resolved observations at microwave and HXR bands and with spectral observations at decimetric, metric waves. Microwave emission at 17 GHz of two footpoints, HXR emission at 20–50 keV of the north footpoint and loop top, and type III bursts at 0.7–3 GHz show prominent in-phase oscillations at 270 s. The microwave emission of the loop leg has less pulsation but stronger emission. Through the estimation of plasma density around the loop top from EUV observations, we find that the local plasma frequency would be 1.5 GHz or even higher. Thus, type III bursts at 700 MHz originate above the loop top. Quasi-periodic acceleration or injection of energetic electrons is proposed to dominate these in-phase QPPs of nonthermal emission from footpoints, loop top, and above. In the overlying region, drifting pulsations (DPS) at 200–600 MHz oscillate at a distinct period (200 s). Its global structure drifts toward lower frequency, which is closely related to upward plasmoids observed simultaneously from EUV emission. Hence, nonthermal emission from overlying plasmoids and underlying flaring loops show different oscillating periods. Two individual systems of quasi-periodic acceleration of electrons are proposed to coincide in the bi-direction outflows from the reconnection region.

Short-Period Surface Wave Based Seismic Event Relocation

Science.gov (United States)

White-Gaynor, A.; Cleveland, M.; Nyblade, A.; Kintner, J. A.; Homman, K.; Ammon, C. J.

2017-12-01

Accurate and precise seismic event locations are essential for a broad range of geophysical investigations. Superior location accuracy generally requires calibration with ground truth information, but superb relative location precision is often achievable independently. In explosion seismology, low-yield explosion monitoring relies on near-source observations, which results in a limited number of observations that challenges our ability to estimate any locations. Incorporating more distant observations means relying on data with lower signal-to-noise ratios. For small, shallow events, the short-period (roughly 1/2 to 8 s period) fundamental-mode and higher-mode Rayleigh waves (including Rg) are often the most stable and visible portion of the waveform at local distances. Cleveland and Ammon [2013] have shown that teleseismic surface waves are valuable observations for constructing precise, relative event relocations. We extend the teleseismic surface wave relocation method, and apply them to near-source distances using Rg observations from the Bighorn Arche Seismic Experiment (BASE) and the Earth Scope USArray Transportable Array (TA) seismic stations. Specifically, we present relocation results using short-period fundamental- and higher-mode Rayleigh waves (Rg) in a double-difference relative event relocation for 45 delay-fired mine blasts and 21 borehole chemical explosions. Our preliminary efforts are to explore the sensitivity of the short-period surface waves to local geologic structure, source depth, explosion magnitude (yield), and explosion characteristics (single-shot vs. distributed source, etc.). Our results show that Rg and the first few higher-mode Rayleigh wave observations can be used to constrain the relative locations of shallow low-yield events.

The transition mechanism from a symmetric single period discharge to a period-doubling discharge in atmospheric helium dielectric-barrier discharge

International Nuclear Information System (INIS)

Zhang, Dingzong; Wang, Yanhui; Wang, Dezhen

2013-01-01

Period-doubling and chaos phenomenon have been frequently observed in atmospheric-pressure dielectric-barrier discharges. However, how a normal single period discharge bifurcates into period-doubling state is still unclear. In this paper, by changing the driving frequency, we study numerically the transition mechanisms from a normal single period discharge to a period-doubling state using a one-dimensional self-consistent fluid model. The results show that before a discharge bifurcates into a period-doubling state, it first deviates from its normal operation and transforms into an asymmetric single period discharge mode. Then the weaker discharge in this asymmetric discharge will be enhanced gradually with increasing of the frequency until it makes the subsequent discharge weaken and results in the discharge entering a period-doubling state. In the whole transition process, the spatial distribution of the charged particle density and the electric field plays a definitive role. The conclusions are further confirmed by changing the gap width and the amplitude of the applied voltage

The transition mechanism from a symmetric single period discharge to a period-doubling discharge in atmospheric helium dielectric-barrier discharge

Energy Technology Data Exchange (ETDEWEB)

Zhang, Dingzong; Wang, Yanhui; Wang, Dezhen [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)

2013-06-15

Period-doubling and chaos phenomenon have been frequently observed in atmospheric-pressure dielectric-barrier discharges. However, how a normal single period discharge bifurcates into period-doubling state is still unclear. In this paper, by changing the driving frequency, we study numerically the transition mechanisms from a normal single period discharge to a period-doubling state using a one-dimensional self-consistent fluid model. The results show that before a discharge bifurcates into a period-doubling state, it first deviates from its normal operation and transforms into an asymmetric single period discharge mode. Then the weaker discharge in this asymmetric discharge will be enhanced gradually with increasing of the frequency until it makes the subsequent discharge weaken and results in the discharge entering a period-doubling state. In the whole transition process, the spatial distribution of the charged particle density and the electric field plays a definitive role. The conclusions are further confirmed by changing the gap width and the amplitude of the applied voltage.

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

Energy Technology Data Exchange (ETDEWEB)

Dolla, L.; Marque, C.; Seaton, D. B.; Dominique, M.; Berghmans, D.; Cabanas, C.; De Groof, A.; Verdini, A.; West, M. J.; Zhukov, A. N. [Solar-Terrestrial Center of Excellence, Royal Observatory of Belgium, Avenue Circulaire 3, B-1180 Brussels (Belgium); Van Doorsselaere, T. [Centrum voor Plasma-Astrofysica, Department of Mathematics, KULeuven, Celestijnenlaan 200B bus 2400, B-3001 Leuven (Belgium); Schmutz, W. [Physikalisch-Meteorologisches Observatorium Davos, World Radiation Center, Davos Dorf (Switzerland); Zender, J., E-mail: dolla@sidc.be [European Space Agency, ESTEC, Keplerlaan 1, 2201 AZ Noordwijk (Netherlands)

2012-04-10

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

Periods, poles, and shapes of Saturn's irregular moons

Science.gov (United States)

Denk, Tilmann; Mottola, Stefano

2016-10-01

We report rotational-lightcurve observations of irregular moons of Saturn based on disk-integrated observations with the Narrow-Angle Camera of the Cassini spacecraft. From 24 measured rotation periods, 20 are now known with an accuracy of ~2% or better. The numbers are as follows (in hours; an '*' marks the less reliable periods): Hati 5.42; Mundilfari 6.74; Loge 6.94*; Skoll 7.26; Kari 7.70; Suttungr 7.82*, Bergelmir 8.13; Phoebe 9.274; Siarnaq 10.188; Narvi 10.21; Tarvos 10.69; Skathi 11.30; Ymir 11.922; Hyrrokkin 12.76; Greip 12.79*; Ijiraq 13.03; Albiorix 13.32; Bestla 14.624; Bebhionn 16.40; Paaliaq 18.75; Kiviuq 21.96; Erriapus 28.15; Thrymr 35 or >45* Tarqeq 76.8.More recent data strengthen the notion that objects in orbits with an inclination supplemental angle i' > 27° have significantly slower spin rates than those at i' 27°, Siarnaq, stands opposed to at least eight objects with faster spins and i' 27° bin contains all nine known prograde moons and four retrograde objects.A total of 25 out of 38 known outer moons has been observed with Cassini, and there is no chance to observe the 13 missing objects until end-of-mission. However, all unobserved objects are part of the i' 27° are known, and none of them is a fast rotator, with no exception.Several objects were observed repeatedly to determine pole directions, sidereal periods, and convex shapes. A few lightcurves have been observed to show three maxima and three minima even at low phase angles, suggesting objects with a triangular equatorial cross-section. Some objects with 2 maxima/ 2 minima are probably quite elongated. One moon even shows lightcurves with 4 maxima/ 4 minima.

Photometrical Observations "SBIRS GEO-2"

Science.gov (United States)

Sukhov, P. P.; Epishev, V. P.; Karpenko, G. F.; Sukhov, K. P.; Kudak, V. I.

2015-08-01

Photometrical observations GSS "SBIRS GEO 2" in B,V,R filters were carried near the equinoxes 2014-2015. Used velocity electrophotometer based on the FEU-79 in the pulse-counting mode. Received more than 25 light curves. From the known dimensions are defined; effective reflecting area - Sγλ, the spectral reflectance index - γλ, periods of light variation. Color-indices showed that in the reflected light flux from the GSS prevails "red" component. In the light curves are periodically dips and specular flash. This shows that GSS orbit is not in a static position specified triaxial orientation as in dynamic motion. Assumed following dynamics of the satellite "SBIRS GEO 2" in orbit. Helical scanning the Earth's surface visible infrared sensors satellite occurs with a period P1 = 15.66 sec. and swinging of the GSS about the direction of the motion vector of the satellite in an orbit with P2 = 62.64 sec., from the northern to the southern pole. Thus, during the period of swinging GSS going on 2 scan the visible part of the northern and southern hemispheres. In some dates observations dynamics work satellite in orbit changed.

Polarization of a periodic solar microwave burst

Energy Technology Data Exchange (ETDEWEB)

Kaufmann, P [Universidade Mackenzie, Sao Paulo (Brazil). Centro de Radio-Astronomia e Astrofisica

1976-09-01

No fluctuations in polarization have been found during a 7 GHz solar burst showing 17s periodic pulses in intensity. Polarization effects can be produced by the propagation media in the active centre, which are not affected directly by the burst source, but situated more deeply than the observed heights at that microwave frequency.

The Drop of the Coherence of the Lower Kilohertz Quasi-periodic Brightness Variations is Also Observed in XTE J1701-462

Science.gov (United States)

Barret, D.; Bachetti, M.; Miller, M. Coleman

2011-02-01

We investigate the quality factor and root mean square (rms) amplitude of the lower kilohertz quasi-periodic brightness variations (kHz QPOs) from XTE J1701-462, a unique X-ray source which was observed in both the so-called Z and atoll states. Correcting for the frequency drift of the QPO, we show that, as in all sources for which such a correction can be applied, the quality factor and rms amplitude drops sharply above a critical frequency. For XTE J1701-462, this frequency is estimated to be ~800 Hz, where the quality factor reaches a maximum of ~200 (e.g., a value consistent with the one observed from more classical systems, such as 4U 1636-536). Such a drop has been interpreted as the signature of the innermost stable circular orbit, and that interpretation is consistent with the observations we report here. The kHz QPOs in the Z state are much less coherent and lower amplitude than they are in the atoll state. We argue that the change of the QPO properties between the two source states is related to the change of the scale height of the accretion disk; a prediction of the toy model proposed by Barret et al. As a by-product of our analysis, we also increased the significance of the upper kHz QPO detected in the atoll phase up to 4.8σ (single trial significance) and show that the frequency separation (266.5 ± 13.1 Hz) is comparable with the one measured from simultaneous twin QPOs in the Z phase.

The Colorado Ultraviolet Transit Experiment (CUTE): Observing Mass Loss on Short-Period Exoplanets

Science.gov (United States)

Egan, Arika; Fleming, Brian; France, Kevin

2018-06-01

The Colorado Ultraviolet Transit Experiment (CUTE) is an NUV spectrograph packaged into a 6U CubeSat, designed to characterize the interaction between exoplanetary atmospheres and their host stars. CUTE will conduct a transit spectroscopy survey, gathering data over multiple transits on more than 12 short-period exoplanets with a range of masses and radii. The instrument will characterize the spectral properties of the transit light curves to atomic and molecular absorption features predicted to exist in the upper atmospheres of these planets, including Mg I, Mg II, Fe II, and OH. The shape and evolution of these spectral light curves will be used to quantify mass loss rates, the stellar drives of that mass loss, and the possible existence of exoplanetary magnetic fiends. This poster presents the science motivation for CUTE, planned observation and data analysis methods, and expected results.

Observed ozone exceedances in Italy: statistical analysis and modelling in the period 2002-2015

Science.gov (United States)

Falasca, Serena; Curci, Gabriele; Candeloro, Luca; Conte, Annamaria; Ippoliti, Carla

2017-04-01

Local ambient air quality is strongly influenced by anthropogenic emissions and meteorological conditions. The year 2015 is considered by NASA scientists as one of the hottest at the global scale since 1880. Furthermore, in Europe it was the first summer after the introduction of Euro6 regulation, the latest emission standard for passenger vehicles. The goal of this study is twofold: (1) the investigation of the impact of the heat wave occurred in the summer of 2015 on ozone levels and (2) the exploration of the weight of temperature as driver of high-level ozone events with respect to other variables. We performed a quantitative examination of the ozone seasons (May-September) for the period 2002-2015 using ozone concentration and weather data from 24 stations across Italy. The number of exceedances of limit values set by the European directive was calculated for each year, and compared with the trend of ozone concentration and temperature. Furthermore, the data were grouped in clusters of consecutive days of ozone exceedances in order to characterize the duration and the intensity of high ozone events. Finally, we developed a multivariate logistic regression model to investigate the role of a set of independent variables (meteorological, and temporal variables, altitude, number of inhabitants, vehicle emission standard) on the probability of exceedances. Results show that 2015 is one of the hottest years after 2003. During the period 2002-2015, the average number of exceedances per station of the daily maximum 8-hour average is often higher than the limit established by the European directive (25 per year). The highest number of exceedances was 65 per station, reached in 2003. The Po Valley is confirmed as a hot spot for pollution, with more frequent exceedances and a higher sensitivity to temperature, especially at urban sites. Ozone events in 2015 were fewer than recent years, but of longer duration (on average 4 days against 3 days), and with similar mean

[Evaluation of the interdependence between homocystein and folic acid levels in patients after kidney transplantation during a 2 year observation period].

Science.gov (United States)

Janda, Katarzyna; Aksamit, Dariusz; Krzanowski, Marcin; Kuzniewski, Marek; Sułowicz, Władysław

2013-01-01

Patients on maintenance dialysis have increased heomocystein (Hcy) serum levels. The aim of the study was to evaluate the interdependence between Hcy and folic acid (FA) levels in renal transplant patients (pts) at various time periods during a two year observation period after kidney transplantation (Ktx). The study included 51 pts (17 F, 34 M) aged 15-62 years (median 38.1) after deceased donors Ktx. Before Ktx, 46 pts were treated with maintenance hemodialysis (HD), while 5 by peritoneal dialysis (PD). The mean observation period equaled 21.2 months (6-24 months); while total observation period was 90 person/years. Hcy level was measured using high performance liquid chromatography (HPLC). FA level was measured using chemiluminesence method (standard methods) using the Immulite 2000 analyzer. Patients blood was drawn before Ktx and 3, 6, 9, 12, 15, 18, 21 and 24 months after procedure. An increased Hcy level (>15 micromol/l) - mean 28.5 +/- 17.8 micromol/l (range from 10.2 micromol/l to 116.8 micromol/I) was noted in the blood of 44 pts before Ktx (86.3% of the examined population). In 31 pts after Ktx (60.8% of the examined population), mean Hcy level remained increased above 15 micromol/I (mean Hcy - 19.2 +/- 5.8 micromol/I). A negative correlation was found between the levels of Hcy and FA directly before Ktx (R= -0.28, p15 micromol/l (36.4 ng/ml vs. 62.5 ng/ml). Statistically significant decrease of Hcy concentration was observed after Ktx as compare with values before procedure, however not reached normal values. Significant decrease of FA concentration after Ktx is most likely associated with the discontinuation of FA supplementation, as well as due to the restoration of the erythropoietic line.

Metabolic observations during the treatment of obese patients by periods of total starvation

NARCIS (Netherlands)

Riet, H.G. van; Schwarz, F.; Kinderen, P.J. der; Veeman, W.

Ten very obese female patients were treated by periods of total starvation lasting 10 days each. In the interval between these starvation periods, a diet of 600 calories was given. Twenty-one periods were completed, 6 patients went through 3 periods each. The fasting was generally well tolerated;

The first orbital parameters and period variation of the short-period eclipsing binary AQ Boo

Science.gov (United States)

Wang, Shuai; Zhang, Liyun; Pi, Qingfeng; Han, Xianming L.; Zhang, Xiliang; Lu, Hongpeng; Wang, Daimei; Li, TongAn

2016-10-01

We obtained the first VRI CCD light curves of the short-period contact eclipsing binary AQ Boo, which was observed on March 22 and April 19 in 2014 at Xinglong station of National Astronomical Observatories, and on January 20, 21 and February 28 in 2015 at Kunming station of Yunnan Observatories of Chinese Academy of Sciences, China. Using our six newly obtained minima and the minima that other authors obtained previously, we revised the ephemeris of AQ Boo. By fitting the O-C (observed minus calculated) values of the minima, the orbital period of AQ Boo shows a decreasing tendency P˙ = - 1.47(0.17) ×10-7 days/year. We interpret the phenomenon by mass transfer from the secondary (more massive) component to the primary (less massive) one. By using the updated Wilson & Devinney program, we also derived the photometric orbital parameters of AQ Boo for the first time. We conclude that AQ Boo is a near contact binary with a low contact factor of 14.43%, and will become an over-contact system as the mass transfer continues.

CLATHRATE HYDRATES FORMATION IN SHORT-PERIOD COMETS

International Nuclear Information System (INIS)

Marboeuf, Ulysse; Mousis, Olivier; Petit, Jean-Marc; Schmitt, Bernard

2010-01-01

The initial composition of current models of cometary nuclei is only based on two forms of ice: crystalline ice for long-period comets and amorphous ice for short-period comets. A third form of ice, i.e., clathrate hydrate, could exist within the short-period cometary nuclei, but the area of formation of this crystalline structure in these objects has never been studied. Here, we show that the thermodynamic conditions in the interior of short-period comets allow the existence of clathrate hydrates in Halley-type comets. We show that their existence is viable in the Jupiter family comets only when the equilibrium pressure of CO clathrate hydrate is at least 1 order of magnitude lower than the usually assumed theoretical value. We calculate that the amount of volatiles that could be trapped in the clathrate hydrate layer may be orders of magnitude greater than the daily amount of gas released at the surface of the nucleus at perihelion. The formation and the destruction of the clathrate hydrate cages could then explain the diversity of composition of volatiles observed in comets, as well as some pre-perihelion outbursts. We finally show that the potential clathrate hydrate layer in comet 67P/Churyumov-Gerasimenko would, unfortunately, be deep inside the nucleus, out of reach of the Rosetta lander. However, such a clathrate hydrate layer would show up by the gas composition of the coma.

Unveiling Quasiperiodicity through Nonlinear Wave Mixing in Periodic Media

International Nuclear Information System (INIS)

Bahabad, Alon; Arie, Ady; Voloch, Noa; Bruner, Ariel; Eger, David

2007-01-01

Quasiperiodicity is the concept of order without translation symmetry. The discovery of quasiperiodic order in natural materials transformed the way scientists examine and define ordered structure. We show and verify experimentally that quasiperiodicity can be observed by scattering processes from a periodic structure, provided the interaction area is of finite width. This is made through a momentum conservation condition, physically realizing a geometrical method used to model quasiperiodic structures by projecting a periodic structure of a higher dimension

Turbulence kinetic energy budget during the afternoon transition - Part 1: Observed surface TKE budget and boundary layer description for 10 intensive observation period days

Science.gov (United States)

Nilsson, Erik; Lohou, Fabienne; Lothon, Marie; Pardyjak, Eric; Mahrt, Larry; Darbieu, Clara

2016-07-01

The decay of turbulence kinetic energy (TKE) and its budget in the afternoon period from midday until zero-buoyancy flux at the surface is studied in a two-part paper by means of measurements from the Boundary Layer Late Afternoon and Sunset Turbulence (BLLAST) field campaign for 10 intensive observation period days. Here, in Part 1, near-surface measurements from a small tower are used to estimate a TKE budget. The overall boundary layer characteristics and mesoscale situation at the site are also described based upon taller tower measurements, radiosoundings and remote sensing instrumentation. Analysis of the TKE budget during the afternoon transition reveals a variety of different surface layer dynamics in terms of TKE and TKE decay. This is largely attributed to variations in the 8 m wind speed, which is responsible for different amounts of near-surface shear production on different afternoons and variations within some of the afternoon periods. The partitioning of near-surface production into local dissipation and transport in neutral and unstably stratified conditions was investigated. Although variations exist both between and within afternoons, as a rule of thumb, our results suggest that about 50 % of the near-surface production of TKE is compensated for by local dissipation near the surface, leaving about 50 % available for transport. This result indicates that it is important to also consider TKE transport as a factor influencing the near-surface TKE decay rate, which in many earlier studies has mainly been linked with the production terms of TKE by buoyancy and wind shear. We also conclude that the TKE tendency is smaller than the other budget terms, indicating a quasi-stationary evolution of TKE in the afternoon transition. Even though the TKE tendency was observed to be small, a strong correlation to mean buoyancy production of -0.69 was found for the afternoon period. For comparison with previous results, the TKE budget terms are normalized with

Rationalization of Comet Halley's periods

Science.gov (United States)

Belton, Michael J. S.

1990-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2006-04-01

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

Improvement of the Management of Infants, Children and Adults with a Molecular Diagnosis of Enterovirus Meningitis during Two Observational Study Periods

Science.gov (United States)

Archimbaud, Christine; Ouchchane, Lemlih; Mirand, Audrey; Chambon, Martine; Demeocq, François; Labbé, André; Laurichesse, Henri; Schmidt, Jeannot; Clavelou, Pierre; Aumaître, Olivier; Regagnon, Christel; Bailly, Jean-Luc; Henquell, Cécile; Peigue-Lafeuille, Hélène

2013-01-01

Enteroviruses (EVs) are a major cause of aseptic meningitis, and RNA detection using molecular assay is the gold standard diagnostic test. The aim of this study was to assess the impact of an EV positive diagnosis on the clinical management of patients admitted for meningitis over the course of two observational study periods (2005 and 2008–09) in the same clinical departments. We further investigated in multivariate analysis various factors possibly associated with hospital length of stay (LOS) in all age groups (infants, children, and adults). The results showed an overall improvement in the management of patients (n = 142) between the study periods, resulting in a significantly shorter hospital LOS for adults and children, and a shorter duration of antibiotic use for adults and infants. In multivariate analysis, we observed that the time from molecular test results to discharge of patients and the median duration of antibiotic treatment were associated with an increase in LOS in all age groups. In addition, among adults, the turnaround time of the molecular assay was significantly correlated with LOS. The use of CT scan in children and hospital admission outside the peak of EV prevalence in infants tended to increase LOS. In conclusion, the shorter length of stay of patients with meningitis in this study was due to various factors including the rapidity of the EV molecular test (particularly in adults), greater physician responsiveness after a positive result (in adults and children), and greater experience on the part of physicians in handling EV meningitis, as evidenced by the shorter duration of antibiotic use in adults and infants. PMID:23874676

Improvement of the management of infants, children and adults with a molecular diagnosis of Enterovirus meningitis during two observational study periods.

Directory of Open Access Journals (Sweden)

Christine Archimbaud

Full Text Available Enteroviruses (EVs are a major cause of aseptic meningitis, and RNA detection using molecular assay is the gold standard diagnostic test. The aim of this study was to assess the impact of an EV positive diagnosis on the clinical management of patients admitted for meningitis over the course of two observational study periods (2005 and 2008-09 in the same clinical departments. We further investigated in multivariate analysis various factors possibly associated with hospital length of stay (LOS in all age groups (infants, children, and adults. The results showed an overall improvement in the management of patients (n = 142 between the study periods, resulting in a significantly shorter hospital LOS for adults and children, and a shorter duration of antibiotic use for adults and infants. In multivariate analysis, we observed that the time from molecular test results to discharge of patients and the median duration of antibiotic treatment were associated with an increase in LOS in all age groups. In addition, among adults, the turnaround time of the molecular assay was significantly correlated with LOS. The use of CT scan in children and hospital admission outside the peak of EV prevalence in infants tended to increase LOS. In conclusion, the shorter length of stay of patients with meningitis in this study was due to various factors including the rapidity of the EV molecular test (particularly in adults, greater physician responsiveness after a positive result (in adults and children, and greater experience on the part of physicians in handling EV meningitis, as evidenced by the shorter duration of antibiotic use in adults and infants.

Coexisting chaotic and multi-periodic dynamics in a model of cardiac alternans

Energy Technology Data Exchange (ETDEWEB)

Skardal, Per Sebastian, E-mail: skardals@gmail.com [Departament d' Enginyeria Informàtica i Matemàtiques, Universitat Rovira i Virgili, 43007 Tarragona (Spain); Restrepo, Juan G., E-mail: juanga@colorado.edu [Department of Applied Mathematics, University of Colorado, Boulder, Colorado 80309 (United States)

2014-12-15

The spatiotemporal dynamics of cardiac tissue is an active area of research for biologists, physicists, and mathematicians. Of particular interest is the study of period-doubling bifurcations and chaos due to their link with cardiac arrhythmogenesis. In this paper, we study the spatiotemporal dynamics of a recently developed model for calcium-driven alternans in a one dimensional cable of tissue. In particular, we observe in the cable coexistence of regions with chaotic and multi-periodic dynamics over wide ranges of parameters. We study these dynamics using global and local Lyapunov exponents and spatial trajectory correlations. Interestingly, near nodes—or phase reversals—low-periodic dynamics prevail, while away from the nodes, the dynamics tend to be higher-periodic and eventually chaotic. Finally, we show that similar coexisting multi-periodic and chaotic dynamics can also be observed in a detailed ionic model.

Clinical observations over 20 years period of Bikini victims

International Nuclear Information System (INIS)

Kumatori, Toshiyuki

1976-01-01

The author outlined the results of medical examinations performed in a period of 20 years on the Japanese fishermen who were exposed at Bikini in 1954. Exposure doses were estimated, and the progress of medical examinations for skin injury, hematological changes, cytogenetic changes, and spermatogenetic disturbance was described. In view of internal exposure, none of the long half-life nuclides was retained in the body. The victims were compared with the victims exposed in Marshall Islands. (Serizawa, K.)

Quasi-periodic VLF emissions observed during daytime at a low ...

Indian Academy of Sciences (India)

at a low latitude Indian ground station Jammu. K K Singh1, J .... Figure 4. Typical example of pulsing VLF hiss emission of longer period recorded during daytime at Jammu on 20 ..... Further,. Ward (1983) also paid attention to a certain simi-.

Probing the (empirical quantum structure embedded in the periodic table with an effective Bohr model

Directory of Open Access Journals (Sweden)

Wellington Nardin Favaro

2013-01-01

Full Text Available The atomic shell structure can be observed by inspecting the experimental periodic properties of the Periodic Table. The (quantum shell structure emerges from these properties and in this way quantum mechanics can be explicitly shown considering the (semi-quantitative periodic properties. These periodic properties can be obtained with a simple effective Bohr model. An effective Bohr model with an effective quantum defect (u was considered as a probe in order to show the quantum structure embedded in the Periodic Table. u(Z shows a quasi-smoothed dependence of Z, i.e., u(Z ≈ Z2/5 - 1.

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

Science.gov (United States)

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

2010-01-01

Understanding the complex processes within the inner magnetosphere of Earth particularly during storm periods requires coordinated observations of the particle and field environment using both in-situ and remote sensing techniques. In fact in order to gain a better understanding of our Heliophysics and potentially improve our space weather forecasting capabilities, new observation mission approaches and new instrument technologies which can provide both cost effective and robust regular observations of magnetospheric activity and other space weather related phenomenon are necessary. As part of the effort to demonstrate new instrument techniques and achieve necessary coordinated observation missions, NASA's Fast Affordable Science and Technology Satellite Huntsville 01 mission (FASTSAT-HSVOI) scheduled for launch in 2010 will afford a highly synergistic solution which satisfies payload mission opportunities and launch requirements as well as contributing iri the near term to our improved understanding of Heliophysics. NASA's FASTSAT-HSV01 spacecraft on the DoD Space Test Program-S26 (STP-S26) Mission is a multi-payload mission executed by the DoD Space Test Program (STP) at the Space Development and Test Wing (SDTW), Kirtland AFB, NM. and is an example of a responsive and economical breakthrough in providing new possibilities for small space technology-driven and research missions. FASTSAT-HSV is a unique spacecraft platform that can carry multiple small instruments or experiments to low-Earth orbit on a wide range of expendable launch vehicles for a fraction of the cost traditionally required for such missions. The FASTSAT-HSV01 mission allows NASA to mature and transition a technical capability to industry while increasing low-cost access to space for small science and technology (ST) payloads. The FASTSAT-HSV01 payload includes three NASA Goddard Space Flight Center (GSFC) new technology built instruments that will study the terrestrial space environment and

Minimum period and the gap in periods of Cataclysmic binaries

International Nuclear Information System (INIS)

Paczynski, B.; Sienkiewicz, R.

1983-01-01

The 81 minute cutoff to the orbital periods of hydrogen-rich cataclysmic binaries is consistent with evolution of those systems being dominated by angular momentum losses due to gravitational radiation. Unfortunately, many uncertainties, mainly poorly known atmospheric opacities below 2000 K, make is physically impossible to verify the quadrupole formula for gravitational radiation by using the observed cutoff at 81 minutes. The upper boundary of the gap in orbital periods observed at about 3 hours is almost certainly due to enhanced angular momentum losses from cataclysmic binaries which have longer periods. The physical mechanism of those losses is not identified, but a possible importance of stellar winds is pointed out. The lower boundary of the gap may be explained with the oldest cataclysmic binaries, whose periods evolved past the minimum at 81 minutes and reached the value of 2 hours within about 12 x 10 9 years after the binary had formed. Those binaries should have secondary components of only 0.02 solar masses, and their periods could be used to estimate ages of the oldest cataclysmic stars, and presumably the age of Galaxy. An alternative explanation for the gap requires that binaries should be detached while crossing the gap. A possible mechanism for this phenomenon is discussed. It requires the secondary components to be about 0.2 solar masses in the binaries just below the gap

Periodic Recurrence Patterns In X-Ray Solar Flare Appearances

Science.gov (United States)

Gyenge, N.; Erdélyi, R.

2018-06-01

The temporal recurrence of micro-flare events is studied for a time interval before and after of major solar flares. Our sample is based on the X-ray flare observations by the Geostationary Operational Environmental Satellite (GOES) and Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI). The analyzed data contain 1330/301 M-class and X-class GOES/RHESSI energetic solar flares and 4062/4119 GOES/RHESSI micro-flares covering the period elapse since 2002. The temporal analysis of recurrence, by Fast Fourier Transform, of the micro-flares, shows multiple significant periods. Based on the GOES and RHESSI data, the temporal analysis also demonstrates that multiple periods manifest simultaneously in both statistical samples without any significant shift over time. In the GOES sample, the detected significant periods are: 11.33, 5.61, 3.75, 2.80, and 2.24 minutes. The RHESSI data show similar significant periods at 8.54, 5.28, 3.66, 2.88, and 2.19 minutes. The periods are interpreted as signatures of standing oscillations, with the longest period (P 1) being the fundamental and others being higher harmonic modes. The period ratio of the fundamental and higher harmonics (P 1/P N ) is also analyzed. The standing modes may be signatures of global oscillations of the entire solar atmosphere encompassing magnetized plasma from the photosphere to the corona in active regions.

Propagation dynamics for a spatially periodic integrodifference competition model

Science.gov (United States)

Wu, Ruiwen; Zhao, Xiao-Qiang

2018-05-01

In this paper, we study the propagation dynamics for a class of integrodifference competition models in a periodic habitat. An interesting feature of such a system is that multiple spreading speeds can be observed, which biologically means different species may have different spreading speeds. We show that the model system admits a single spreading speed, and it coincides with the minimal wave speed of the spatially periodic traveling waves. A set of sufficient conditions for linear determinacy of the spreading speed is also given.

Replicate periodic windows in the parameter space of driven oscillators

Energy Technology Data Exchange (ETDEWEB)

Medeiros, E.S., E-mail: esm@if.usp.br [Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo (Brazil); Souza, S.L.T. de [Universidade Federal de Sao Joao del-Rei, Campus Alto Paraopeba, Minas Gerais (Brazil); Medrano-T, R.O. [Departamento de Ciencias Exatas e da Terra, Universidade Federal de Sao Paulo, Diadema, Sao Paulo (Brazil); Caldas, I.L. [Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo (Brazil)

2011-11-15

Highlights: > We apply a weak harmonic perturbation to control chaos in two driven oscillators. > We find replicate periodic windows in the driven oscillator parameter space. > We find that the periodic window replication is associated with the chaos control. - Abstract: In the bi-dimensional parameter space of driven oscillators, shrimp-shaped periodic windows are immersed in chaotic regions. For two of these oscillators, namely, Duffing and Josephson junction, we show that a weak harmonic perturbation replicates these periodic windows giving rise to parameter regions correspondent to periodic orbits. The new windows are composed of parameters whose periodic orbits have the same periodicity and pattern of stable and unstable periodic orbits already existent for the unperturbed oscillator. Moreover, these unstable periodic orbits are embedded in chaotic attractors in phase space regions where the new stable orbits are identified. Thus, the observed periodic window replication is an effective oscillator control process, once chaotic orbits are replaced by regular ones.

Sparsely-Observed Pulsating Red Giants in the AAVSO Observing Program

Science.gov (United States)

Percy, J. R.

2018-06-01

This paper reports on time-series analysis of 156 pulsating red giants (21 SRa, 52 SRb, 33 SR, 50 Lb) in the AAVSO observing program for which there are no more than 150-250 observations in total. Some results were obtained for 68 of these stars: 17 SRa, 14 SRb, 20 SR, and 17 Lb. These results generally include only an average period and amplitude. Many, if not most of the stars are undoubtedly more complex; pulsating red giants are known to have wandering periods, variable amplitudes, and often multiple periods including "long secondary periods" of unknown origin. These results (or lack thereof) raise the question of how the AAVSO should best manage the observation of these and other sparsely-observed pulsating red giants.

Quasi-Periodic Pulse Amplitude Modulation in the Accreting Millisecond Pulsar IGR J00291+5934

Science.gov (United States)

Bult, Peter; van Doesburgh, Marieke; van der Klis, Michiel

2017-01-01

We introduce a new method for analyzing the a periodic variability of coherent pulsations in accreting millisecond X-ray pulsars (AMXPs). Our method involves applying a complex frequency correction to the time-domain lightcurve, allowing for the aperiodic modulation of the pulse amplitude to be robustly extracted in the frequency domain. We discuss the statistical properties of the resulting modulation spectrum and show how it can be correlated with the non-pulsed emission to determine if the periodic and a periodic variability are coupled processes. Using this method, we study the 598.88 Hz coherent pulsations of the AMXP IGR J00291+5934 as observed with the Rossi X-ray Timing Explorer and XMM-Newton. We demonstrate that our method easily confirms the known coupling between the pulsations and a strong 8 mHz quasi-periodic oscillation (QPO) in XMM-Newton observations. Applying our method to the RXTE observations, we further show, for the first time, that the much weaker 20 mHz QPO and its harmonic are also coupled with the pulsations. We discuss the implications of this coupling and indicate how it may be used to extract new information on the underlying accretion process.

Quasi-periodic 1-hour pulsations in the Saturn's outer magnetosphere

Science.gov (United States)

Rusaitis, L.; Khurana, K. K.; Walker, R. J.; Kivelson, M.

2017-12-01

Pulsations in the Saturn's magnetic field and particle fluxes of approximately 1-hour periodicity have been frequently detected in the outer Saturnian magnetosphere by the Cassini spacecraft since 2004. These particle and magnetic field enhancements have been typically observed more often in the dusk sector of the planet, and mid to high latitudes. We investigate nearly 200 of these events as detected by the magnetometer and the Cassini Low-Energy Magnetospheric Measurement System detector (LEMMS) data during the 2004-2015 time frame to characterize these pulsations and suggest their origin. The mechanism needed to produce these observed enhancements needs to permit the acceleration of the energetic electrons to a few MeV and a variable periodicity of enhancements from 40 to 90 minutes. We examine the relation of the oscillations to the periodic power modulations in Saturn kilometric radiation (SKR), using the SKR phase model of Kurth et al. [2007] and Provan et al. [2011]. Finally, we show that similar pulsations can also be observed at 2.5-D MHD simulations of Saturn's magnetosphere.

IUE observations of long period eclipsing binaries: a study of accretion onto non-degenerate stars

International Nuclear Information System (INIS)

Plavec, M.J.

1980-01-01

It has long been thought that β Lyrae is a unique system, by virtue of its UV spectrum and its nature. The author argues that a whole class of interacting long-period binaries exists, similar to β Lyrae. According to IUE observations made in 1978-79 this group comprises: RX Cas, SX Cas, V 367 Cyg, W Cru, β Lyr, and W Ser. AR Pav is a transition case linking them with the symbiotics. The author also suggests that HD 218393 (KX And), HD 72754, and HD 51480 are their non-eclipsing counterparts. The whole group is called the W Serpentis stars. These systems are mass-transfering binaries (case B) in which the mass transfer rate is relatively high, probably on the order 10 -6 to 10 -4 solar masses/year. They display an ultraviolet continuum with a color temperature definitely higher than the one observed in the optical region. Even more characteristical is the presence of strong emission lines of N V, C IV, Si IV, Fe III, Al III, and lower ions of C and Si. The author discusses these phenomena on the assumption that they are due to accretion onto non-degenerate stars. (Auth.)

Non-equilibrium ionization by a periodic electron beam. I. Synthetic coronal spectra and implications for interpretation of observations

Science.gov (United States)

Dzifčáková, E.; Dudík, J.; Mackovjak, Š.

2016-05-01

Context. Coronal heating is currently thought to proceed via the mechanism of nanoflares, small-scale and possibly recurring heating events that release magnetic energy. Aims: We investigate the effects of a periodic high-energy electron beam on the synthetic spectra of coronal Fe ions. Methods: Initially, the coronal plasma is assumed to be Maxwellian with a temperature of 1 MK. The high-energy beam, described by a κ-distribution, is then switched on every period P for the duration of P/ 2. The periods are on the order of several tens of seconds, similar to exposure times or cadences of space-borne spectrometers. Ionization, recombination, and excitation rates for the respective distributions are used to calculate the resulting non-equilibrium ionization state of Fe and the instantaneous and period-averaged synthetic spectra. Results: Under the presence of the periodic electron beam, the plasma is out of ionization equilibrium at all times. The resulting spectra averaged over one period are almost always multithermal if interpreted in terms of ionization equilibrium for either a Maxwellian or a κ-distribution. Exceptions occur, however; the EM-loci curves appear to have a nearly isothermal crossing-point for some values of κs. The instantaneous spectra show fast changes in intensities of some lines, especially those formed outside of the peak of the respective EM(T) distributions if the ionization equilibrium is assumed. Movies 1-5 are available in electronic form at http://www.aanda.org

Long-Period Variability in o Ceti

Science.gov (United States)

Templeton, Matthew R.; Karovska, Margarita

2009-02-01

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.

Physical interpretation of geysering phenomena and periodic boiling instability at low flows

International Nuclear Information System (INIS)

Duffey, R.B.; Rohatgi, U.S.

1996-01-01

Over 30 years ago, Griffith showed that unstable and periodic initial boiling occurred in stagnant liquids in heated pipes coupled to a cooler or condensing plenum volume. This was called ''geysering'', and is a similar phenomenon to the rapid nucleation and voiding observed in tubes filled with superheated liquid. It is also called ''bumping'' when non-uniformly heated water or a chemical suddenly boils in laboratory glassware. In engineering, the stability and predictability has importance to the onset of bulk boiling in a natural and forced circulation loops. The latest available data show the observed stability and periodicity of the onset of boiling flow when there is a plenum, multiple heated channels, and a sustained subcooling in a circulating loop. We examine the available data, both old and new, and develop a new theory to illustrate the simple physics causing the observed periodicity of the flow. We examine the validity of the theory by comparison to all the geysering data, and develop a useful and simple correlation. We illustrate the equivalence of the onset of geysering to the onset of static instability in subcooled boiling. We also derive the stability boundary for geysering, utilizing turbulent transport analysis to determine the effects of pressure and other key parameters. This new result explains the greater stability region observed at higher pressures. The paper builds on the 30 years of quite independent thermal hydraulic work that is still fresh and useful today. We discuss the physical interpretation of geysering onset with a consistent theory, and show where refinements would be useful to the data correlations

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

Directory of Open Access Journals (Sweden)

C. R. Wilford

Full Text Available 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.Key words. Magnetospheric physics (storms and sub-storms, plasmasphere

On the relationship between period and cohort mortality

Directory of Open Access Journals (Sweden)

John R. Wilmoth

2005-11-01

Full Text Available In this paper I explore the formal relationship between period and cohort mortality, focusing on a comparison of measures of mean lifespan. I consider not only the usual measures (life expectancy at birth for time periods and birth cohorts but also some alternative measures that have been proposed recently. I examine (and reject the claim made by Bongaarts and Feeney that the level of period is distorted, or biased, due to changes in the timing of mortality. I show that their proposed alternative measure, called "tempo-adjusted" life expectancy, is exactly equivalent in its generalized form to a measure proposed by both Brouard and Guillot, the cross-sectional average length of life (or CAL, which substitutes cohort survival probabilities for their period counterparts in the calculation of mean lifespan. I conclude that this measure does not in any sense correct for a distortion in period life expectancy at birth, but rather offers an alternative measure of mean lifespan that is approximately equal to two analytically interesting quantities: 1 the mean age at death in a given year for a hypothetical population subject to observed historical mortality conditions but with a constant annual number of births; and 2 the mean age at death, , for a cohort born years ago. However, I also observe that the trend in period does indeed offer a biased depiction of the pace of change in mean lifespan from cohort to cohort. Holding other factors constant, an historical increase in life expectancy at birth is somewhat faster when viewed from the perspective of cohorts (i.e., year of birth than from the perspective of periods (i.e., year of death.

The Periodic Flapping and Breathing of Saturn's Magnetodisk During Equinox

Science.gov (United States)

Sorba, A. M.; Achilleos, N.; Guio, P.; Arridge, C. S.; Dougherty, M. K.; Sergis, N.

2017-12-01

Periodic variations have been observed in many field and particle properties in Saturn's magnetosphere, modulated at a period close to the planetary rotation rate. Magnetic field observations by Cassini's magnetometer instrument suggest that in the outer magnetosphere (beyond 12 Saturn radii) Saturn's current sheet is periodically displaced with respect to the rotational equator, to a first approximation acting as a rotating, tilted disk. This manifests as a `flapping' mode when observed by the spacecraft. Recent studies suggest the magnetosphere also has a `breathing' mode, expanding and contracting with a period close to the planetary rotation rate. We model these two modes in tandem by combining a global, geometrical model of a tilted and rippled current sheet with a local, force-balance model of Saturn's magnetodisk, accounting for the magnetospheric size and hot plasma content. We simulate the breathing behavior by introducing an azimuthal dependence of the system size. We fit Cassini magnetometer data acquired on equatorial orbits from 23 Oct - 17 Dec 2009 (Revs 120-122), close to Saturn equinox, in order that seasonal effects on the current sheet are minimised. We find that our model characterises well the amplitude and phase of the oscillations in the data, for those passes that show clear periodic signatures in the field. In particular, the Bθ (meridional) component can only be characterised when the breathing mode is included. This study introduces calculations for an oscillating boundary under conditions of constant solar wind dynamic pressure, which provide a good basis for understanding the complex relationship between current sheet dynamics and the periodic field perturbations.

Interspecific studies of circadian genes period and timeless in Drosophila.

Science.gov (United States)

Noreen, Shumaila; Pegoraro, Mirko; Nouroz, Faisal; Tauber, Eran; Kyriacou, Charalambos P

2018-03-30

The level of rescue of clock function in genetically arrhythmic Drosophila melanogaster hosts using interspecific clock gene transformation was used to study the putative intermolecular coevolution between interacting clock proteins. Among them PER and TIM are the two important negative regulators of the circadian clock feedback loop. We transformed either the D. pseudoobscura per or tim transgenes into the corresponding arrhythmic D. melanogaster mutant (per01 or tim01) and observed >50% rhythmicity but the period of activity rhythm was either longer (D. pseudoobscura-per) or shorter than 24 h (D. pseudoobscura-tim) compared to controls. By introducing both transgenes simultaneously into double mutants, we observed that the period of the activity rhythm was rescued by the pair of hemizygous transgenes (~24 h). These flies also showed a more optimal level of temperature compensation for the period. Under LD 12:12 these flies have a D. pseudoobscura like activity profile with the absence of morning anticipation as well as a very prominent earlier evening peak of activity rhythm. These observation are consistent with the view that TIM and PER form a heterospecific coevolved module at least for the circadian period of activity rhythms. However the strength of rhythmicity was reduced by having both transgenes present, so while evidence for a coevolution between PER and TIM is observed for some characters it is not for others. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Turbulence kinetic energy budget during the afternoon transition – Part 1: Observed surface TKE budget and boundary layer description for 10 intensive observation period days

Directory of Open Access Journals (Sweden)

E. Nilsson

2016-07-01

Full Text Available The decay of turbulence kinetic energy (TKE and its budget in the afternoon period from midday until zero-buoyancy flux at the surface is studied in a two-part paper by means of measurements from the Boundary Layer Late Afternoon and Sunset Turbulence (BLLAST field campaign for 10 intensive observation period days. Here, in Part 1, near-surface measurements from a small tower are used to estimate a TKE budget. The overall boundary layer characteristics and mesoscale situation at the site are also described based upon taller tower measurements, radiosoundings and remote sensing instrumentation. Analysis of the TKE budget during the afternoon transition reveals a variety of different surface layer dynamics in terms of TKE and TKE decay. This is largely attributed to variations in the 8 m wind speed, which is responsible for different amounts of near-surface shear production on different afternoons and variations within some of the afternoon periods. The partitioning of near-surface production into local dissipation and transport in neutral and unstably stratified conditions was investigated. Although variations exist both between and within afternoons, as a rule of thumb, our results suggest that about 50 % of the near-surface production of TKE is compensated for by local dissipation near the surface, leaving about 50 % available for transport. This result indicates that it is important to also consider TKE transport as a factor influencing the near-surface TKE decay rate, which in many earlier studies has mainly been linked with the production terms of TKE by buoyancy and wind shear. We also conclude that the TKE tendency is smaller than the other budget terms, indicating a quasi-stationary evolution of TKE in the afternoon transition. Even though the TKE tendency was observed to be small, a strong correlation to mean buoyancy production of −0.69 was found for the afternoon period. For comparison with previous results, the TKE

Formation of laser-induced periodic surface structures on niobium by femtosecond laser irradiation

International Nuclear Information System (INIS)

Pan, A.; Dias, A.; Gomez-Aranzadi, M.; Olaizola, S. M.; Rodriguez, A.

2014-01-01

The surface morphology of a Niobium sample, irradiated in air by a femtosecond laser with a wavelength of 800 nm and pulse duration of 100 fs, was examined. The period of the micro/nanostructures, parallel and perpendicularly oriented to the linearly polarized fs-laser beam, was studied by means of 2D Fast Fourier Transform analysis. The observed Laser-Induced Periodic Surface Structures (LIPSS) were classified as Low Spatial Frequency LIPSS (periods about 600 nm) and High Spatial Frequency LIPSS, showing a periodicity around 300 nm, both of them perpendicularly oriented to the polarization of the incident laser wave. Moreover, parallel high spatial frequency LIPSS were observed with periods around 100 nm located at the peripheral areas of the laser fingerprint and overwritten on the perpendicular periodic gratings. The results indicate that this method of micro/nanostructuring allows controlling the Niobium grating period by the number of pulses applied, so the scan speed and not the fluence is the key parameter of control. A discussion on the mechanism of the surface topology evolution was also introduced

Formation of laser-induced periodic surface structures on niobium by femtosecond laser irradiation

Energy Technology Data Exchange (ETDEWEB)

Pan, A.; Dias, A.; Gomez-Aranzadi, M.; Olaizola, S. M. [CIC microGUNE, Goiru Kalea 9 Polo Innovación Garaia, 20500 Arrasate-Mondragón (Spain); CEIT-IK4 and Tecnun, University of Navarra, Manuel Lardizábal 15, 20018 San Sebastián (Spain); Rodriguez, A. [CIC microGUNE, Goiru Kalea 9 Polo Innovación Garaia, 20500 Arrasate-Mondragón (Spain)

2014-05-07

The surface morphology of a Niobium sample, irradiated in air by a femtosecond laser with a wavelength of 800 nm and pulse duration of 100 fs, was examined. The period of the micro/nanostructures, parallel and perpendicularly oriented to the linearly polarized fs-laser beam, was studied by means of 2D Fast Fourier Transform analysis. The observed Laser-Induced Periodic Surface Structures (LIPSS) were classified as Low Spatial Frequency LIPSS (periods about 600 nm) and High Spatial Frequency LIPSS, showing a periodicity around 300 nm, both of them perpendicularly oriented to the polarization of the incident laser wave. Moreover, parallel high spatial frequency LIPSS were observed with periods around 100 nm located at the peripheral areas of the laser fingerprint and overwritten on the perpendicular periodic gratings. The results indicate that this method of micro/nanostructuring allows controlling the Niobium grating period by the number of pulses applied, so the scan speed and not the fluence is the key parameter of control. A discussion on the mechanism of the surface topology evolution was also introduced.

QUASI-PERIODIC FLUCTUATIONS AND CHROMOSPHERIC EVAPORATION IN A SOLAR FLARE RIBBON OBSERVED BY HINODE /EIS, IRIS , AND RHESSI

Energy Technology Data Exchange (ETDEWEB)

Brosius, Jeffrey W.; Inglis, Andrew R. [Catholic University of America at NASA Goddard Space Flight Center, Solar Physics Laboratory, Code 671, Greenbelt, MD 20771 (United States); Daw, Adrian N., E-mail: Jeffrey.W.Brosius@nasa.gov [NASA Goddard Space Flight Center, Solar Physics Laboratory, Code 671, Greenbelt, MD 20771 (United States)

2016-10-20

The Hinode /Extreme-ultraviolet Imaging Spectrometer (EIS) obtained rapid cadence (11.2 s) EUV stare spectra of an M7.3 flare ribbon in AR 12036 on 2014 April 18. Quasi-periodic ( P ≈ 75.6 ± 9.2 s) intensity fluctuations occurred in emission lines of O iv, Mg vi, Mg vii, Si vii, Fe xiv, and Fe xvi during the flare's impulsive rise, and ended when the maximum intensity in Fe xxiii was reached. The profiles of the O iv–Fe xvi lines reveal that they were all redshifted during most of the interval of quasi-periodic intensity fluctuations, while the Fe xxiii profile revealed multiple components including one or two highly blueshifted ones. This indicates that the flare underwent explosive chromospheric evaporation during its impulsive rise. Fluctuations in the relative Doppler velocities were seen, but their amplitudes were too subtle to extract significant quasi-periodicities. RHESSI detected 25–100 keV hard-X-ray sources in the ribbon near the EIS slit's pointing position during the peaks in the EIS intensity fluctuations. The observations are consistent with a series of energy injections into the chromosphere by nonthermal particle beams. Electron densities derived with Fe xiv (4.6 × 10{sup 10} cm{sup −3}) and Mg vii (7.8 × 10{sup 9} cm{sup −3}) average line intensity ratios during the interval of quasi-periodic intensity fluctuations, combined with the radiative loss function of an optically thin plasma, yield radiative cooling times of 32 s at 2.0 × 10{sup 6} K, and 46 s at 6.3 × 10{sup 5} K (about half the quasi-period); assuming Fe xiv's density for Fe xxiii yields a radiative cooling time of 10{sup 3} s (13 times the quasi-period) at 1.4 × 10{sup 7} K.

EARLY OPTICAL OBSERVATIONS OF GAMMA-RAY BURSTS BY THE TAROT TELESCOPES: PERIOD 2001-2008

International Nuclear Information System (INIS)

Klotz, A.; Boer, M.; Atteia, J. L.; Gendre, B.

2009-01-01

The Telescopes a Action Rapide pour les Objets Transitoires telescopes are two robotic observatories designed to observe the prompt optical emission counterpart and the early afterglow of gamma-ray bursts (GRBs). We present data acquired between 2001 and 2008 and discuss the properties of the optical emission of GRBs, noting various interesting results. The optical emission observed during the prompt GRB phase is rarely very bright: we estimate that 5%-20% of GRBs exhibit a bright optical flash (R < 14) during the prompt gamma-ray emission, and that more than 50% of the GRBs have an optical emission fainter than R = 15.5 when the gamma-ray emission is active. We study the apparent optical brightness distribution of GRBs at 1000 s showing that our observations confirm the distribution derived by other groups. The combination of these results with those obtained by other rapid slewing telescopes allows us to better characterize the early optical emission of GRBs and to emphasize the importance of very early multiwavelength GRB studies for the understanding of the physics of the ejecta.

Studying Short-Period Comets and Long-Period Comets Detected by WISE/NEOWISE

Science.gov (United States)

Kramer, Emily A.; Fernández, Yanga R.; Bauer, James M.; Stevenson, Rachel; Mainzer, Amy K.; Grav, Tommy; Masiero, Joseph; Walker, Russell G.; Lisse, Carey M.

2014-11-01

The Wide-field Infrared Survey Explorer (WISE) mission surveyed the sky in four infrared wavelength bands (3.4, 4.6, 12 and 22-micron) between January 2010 and February 2011 [1, 2]. During the mission, WISE serendipitously observed 160 comets, including 21 newly discovered objects. About 89 of the comets observed by WISE displayed a significant dust tail in the 12 and 22-micron (thermal emission) bands, showing a wide range of activity levels and dust morphology. Since the observed objects are a mix of both long-period comets (LPCs) and short-period comets (SPCs), differences in their activity can be used to better understand the thermal evolution that each of these populations has undergone. For the comets that displayed a significant dust tail, we have estimated the sizes and ages of the particles using dynamical models based on the Finson-Probstein method [3, 4]. For a selection of 40 comets, we have then compared these models to the data using a novel tail-fitting method that allows the best-fit model to be chosen analytically rather than subjectively. For comets that were observed multiple times by WISE, the dust tail particle properties were estimated separately, and then compared. We find that the dust tails of both LPCs and SPCs are primarily comprised of ~mm to cm sized particles, which were the result of emission that occurred several months to several years prior to the observations. The LPCs nearly all have strong dust emission close to the comet's perihelion distance, and the SPCs mostly have strong dust emission close to perihelion, but some have strong dust emission well before perihelion. Acknowledgments: This publication makes use of data products from (1) WISE, which is a joint project of UCLA and JPL/Caltech, funded by NASA; and (2) NEOWISE, which is a project of JPL/Caltech, funded by the Planetary Science Division of NASA. EK was supported by a NASA Earth and Space Sciences Fellowship. RS gratefully acknowledges support from the NASA

Observations of short period seismic scattered waves by small seismic arrays

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M. Simini

1997-06-01

Full Text Available The most recent observations of well correlated seismic phases in the high frequency coda of local earthquakes recorded throughout the world are reported. In particular the main results, obtained on two active volcanoes, Teide and Deception, using small array are described. The ZLC (Zero Lag Cross-correlation method and polarization analysis have been applied to the data in order to distinguish the main phases in the recorded seismograms and their azimuths and apparent velocities. The results obtained at the Teide volcano demonstrate that the uncorrelated part of the seismograms may be produced by multiple scattering from randomly distributed heterogeneity, while the well correlated part, showing SH type polarization or the possible presence of Rayleigh surface waves, may be generated by single scattering by strong scatterers. At the Deception Volcano strong scattering, strongly focused in a precise direction, is deduced from the data. In that case, all the coda radiation is composed of surface waves.

Temporal Variation in Oscillatory Characteristics of Long-period Tremor at Aso Volcano, Japan.

Science.gov (United States)

Yamamoto, M.; Ohkura, T.; Kaneshima, S.; Kawakatsu, H.

2017-12-01

At Aso volcano, Japan, various kinds of volcanic signals with broad frequency contents have been observed since 1930s. One of these signals is long-period tremor (LPT) with a dominant period of around 15 s, which is intermittently emitted from the volcano regardless of the surface activity. Our broadband seismic observations have revealed that LPTs are a kind of resonance oscillation of a crack-like conduit beneath the crater. In this study, aiming to detect a temporal variation of volcanic system, we analyze the long-term variation of LPTs from 1994 to the present.We first examine the temporal variation of dominant periods of LPTs (fundamental mode of around 15 s and the first overtone of around 7 s) using the continuous data recorded at broadband stations close to the active crater. The result shows a clear temporal change in the dominant periods of LPTs in 2003-2005 and 2014-2015. In 2003-2005, the periods of the two modes show correlated temporal change, and it can be interpreted as compositional and/or thermal change of hydrothermal fluids. On the other hand, in 2014-2015, the period of first overtone is almost constant at around 8 s, while that of the fundamental mode shows relatively large temporal fluctuations between 16 s and 12 s. To explain the different behavior among the two resonant modes, we examine the oscillatory characteristics of a fluid-filled crack having linearly varying thickness. With this model, we find that the ratio between resonance periods becomes smaller than that in the case of a flat crack having constant thickness. This behavior can be understood by considering the effective thickness of the crack depends on the wavelength of each resonant mode. Based on these results, the different temporal variation of dominant periods can be interpreted by depth-dependent thickness of the crack-like conduit which may be caused by pressurization and/or intrusion of magma at deeper portion of the conduit. These results suggest the importance of

Period Variations for the Cepheid VZ Cyg

Science.gov (United States)

Sirorattanakul, Krittanon; Engle, Scott; Pepper, Joshua; Wells, Mark; Laney, Clifton D.; Rodriguez, Joseph E.; Stassun, Keivan G.

2017-12-01

The Cepheid Period-Luminosity law is a key rung on the extragalactic distance ladder. However, numerous Cepheids are known to undergo period variations. Monitoring, refining, and understanding these period variations allows us to better determine the parameters of the Cepheids themselves and of the instability strip in which they reside, and to test models of stellar evolution. VZ Cyg, a classical Cepheid pulsating at ˜4.864 days, has been observed for over 100 years. Combining data from literature observations, the Kilodegree Extremely Little Telescope (KELT) transit survey, and new targeted observations with the Robotically Controlled Telescope (RCT) at Kitt Peak, we find a period change rate of dP/dt = -0.0642 ± 0.0018 s yr-1. However, when only the recent observations are examined, we find a much higher period change rate of dP/dt = -0.0923 ± 0.0110 s yr-1. This higher rate could be due to an apparent long-term (P ≈ 26.5 years) cyclic period variation. The possible interpretations of this single Cepheid’s complex period variations underscore both the need to regularly monitor pulsating variables and the important benefits that photometric surveys such as KELT can have on the field. Further monitoring of this interesting example of Cepheid variability is recommended to confirm and better understand the possible cyclic period variations. Further, Cepheid timing analyses are necessary to fully understand their current behaviors and parameters, as well as their evolutionary histories.

Multiple bifurcations and periodic 'bubbling' in a delay population model

International Nuclear Information System (INIS)

Peng Mingshu

2005-01-01

In this paper, the flip bifurcation and periodic doubling bifurcations of a discrete population model without delay influence is firstly studied and the phenomenon of Feigenbaum's cascade of periodic doublings is also observed. Secondly, we explored the Neimark-Sacker bifurcation in the delay population model (two-dimension discrete dynamical systems) and the unique stable closed invariant curve which bifurcates from the nontrivial fixed point. Finally, a computer-assisted study for the delay population model is also delved into. Our computer simulation shows that the introduction of delay effect in a nonlinear difference equation derived from the logistic map leads to much richer dynamic behavior, such as stable node → stable focus → an lower-dimensional closed invariant curve (quasi-periodic solution, limit cycle) or/and stable periodic solutions → chaotic attractor by cascading bubbles (the combination of potential period doubling and reverse period-doubling) and the sudden change between two different attractors, etc

STELLAR PULSATIONS AND PERIOD CHANGES IN THE SX PHOENICIS STAR XX CYGNI

International Nuclear Information System (INIS)

Yang, X. H.; Fu, J. N.; Zha, Q.

2012-01-01

Time-series photometric observations were made for the SX Phoenicis star XX Cyg between 2007 and 2011 at the Xinglong Station of National Astronomical Observatories of China. With the light curves derived from the new observations, we do not detect any secondary maximum in the descending portion of the light curves of XX Cyg, as reported in some previous work. Frequency analysis of the light curves confirms a fundamental frequency f 0 = 7.4148 cycles day –1 and up to 19 harmonics, 11 of which are newly detected. However, no secondary mode of pulsation is detected from the light curves. The O–C diagram, produced from 46 newly determined times of maximum light combined with those derived from the literature, reveals a continuous period increase with the rate of (1/P)(dP/dt) = 1.19(13) × 10 –8 yr -1 . Theoretical rates of period change due to the stellar evolution were calculated with a modeling code. The result shows that the observed rate of period change is fully consistent with period change caused by evolutionary behavior predicted by standard theoretical models.

Period-doubling bifurcation cascade observed in a ferromagnetic nanoparticle under the action of a spin-polarized current

Energy Technology Data Exchange (ETDEWEB)

Horley, Paul P., E-mail: paul.horley@cimav.edu.mx [Centro de Investigación en Materiales Avanzados, S.C. (CIMAV), Chihuahua/Monterrey, 120 Avenida Miguel de Cervantes, 31109 Chihuahua (Mexico); Kushnir, Mykola Ya. [Yuri Fedkovych Chernivtsi National University, 2 Kotsyubynsky str., 58012 Chernivtsi (Ukraine); Morales-Meza, Mishel [Centro de Investigación en Materiales Avanzados, S.C. (CIMAV), Chihuahua/Monterrey, 120 Avenida Miguel de Cervantes, 31109 Chihuahua (Mexico); Sukhov, Alexander [Institut für Physik, Martin-Luther Universität Halle-Wittenberg, 06120 Halle (Saale) (Germany); Rusyn, Volodymyr [Yuri Fedkovych Chernivtsi National University, 2 Kotsyubynsky str., 58012 Chernivtsi (Ukraine)

2016-04-01

We report on complex magnetization dynamics in a forced spin valve oscillator subjected to a varying magnetic field and a constant spin-polarized current. The transition from periodic to chaotic magnetic motion was illustrated with bifurcation diagrams and Hausdorff dimension – the methods developed for dissipative self-organizing systems. It was shown that bifurcation cascades can be obtained either by tuning the injected spin-polarized current or by changing the magnitude of applied magnetic field. The order–chaos transition in magnetization dynamics can be also directly observed from the hysteresis curves. The resulting complex oscillations are useful for development of spin-valve devices operating in harmonic and chaotic modes.

Observed Hierarchy of Student Proficiency with Period, Frequency, and Angular Frequency

Science.gov (United States)

Young, Nicholas T.; Heckler, Andrew F.

2018-01-01

In the context of a generic harmonic oscillator, we investigated students' accuracy in determining the period, frequency, and angular frequency from mathematical and graphical representations. In a series of studies including interviews, free response tests, and multiple-choice tests developed in an iterative process, we assessed students in both…

The physiological period length of the human circadian clock in vivo is directly proportional to period in human fibroblasts.

Directory of Open Access Journals (Sweden)

Lucia Pagani

Full Text Available BACKGROUND: Diurnal behavior in humans is governed by the period length of a circadian clock in the suprachiasmatic nuclei of the brain hypothalamus. Nevertheless, the cell-intrinsic mechanism of this clock is present in most cells of the body. We have shown previously that for individuals of extreme chronotype ("larks" and "owls", clock properties measured in human fibroblasts correlated with extreme diurnal behavior. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we have measured circadian period in human primary fibroblasts taken from normal individuals and, for the first time, compared it directly with physiological period measured in vivo in the same subjects. Human physiological period length was estimated via the secretion pattern of the hormone melatonin in two different groups of sighted subjects and one group of totally blind subjects, each using different methods. Fibroblast period length was measured via cyclical expression of a lentivirally delivered circadian reporter. Within each group, a positive linear correlation was observed between circadian period length in physiology and in fibroblast gene expression. Interestingly, although blind individuals showed on average the same fibroblast clock properties as sighted ones, their physiological periods were significantly longer. CONCLUSIONS/SIGNIFICANCE: We conclude that the period of human circadian behaviour is mostly driven by cellular clock properties in normal individuals and can be approximated by measurement in peripheral cells such as fibroblasts. Based upon differences among sighted and blind subjects, we also speculate that period can be modified by prolonged unusual conditions such as the total light deprivation of blindness.

Periodicities in the X-ray Emission from the Solar Corona: SphinX and SOXS Observations

Science.gov (United States)

Steślicki, M.; Awasthi, A. K.; Gryciuk, M.; Jain, R.

The structure and evolution of the solar magnetic field is driven by a magnetohydrodynamic dynamo operating in the solar interior, which induces various solar activities that exhibit periodic variations on different timescales. Therefore, probing the periodic nature of emission originating from the solar corona may provide insights of the convection-zone-photosphere-corona coupling processes. We present the study of the mid-range periodicities, between rotation period (˜27 days) and the Schwabe cycle period (˜11 yr), in the solar soft X-ray emission, based on the data obtained by two instruments: SphinX and SOXS in various energy bands.

Unmanned observatory for auroral physics study on the Antarctic Continent-Multipoint ground-based observations during the IMS period (1976-1978-

Directory of Open Access Journals (Sweden)

Masaru Ayukawa

1999-07-01

Full Text Available The International Magnetospheric Study (IMS was carried out for three years from 1976. The Japanese Antarctic Research Expedition (JARE participated in this IMS project. The main purpose of the IMS project in JARE was the synthetic observation of polar magnetic substorms. In order to study polar magnetic substorms, a multipoint ground observation network was planned around Syowa, including unmanned stations. In the construction of an unmanned observatory system in Antarctica, there have been difficulties, such as insuffcient information about enviromental conditions, the construction support capability, power supply and others. During the IMS period, the U. S. A., former Soviet Union, Australia and the United Kingdom also started to develop unmanned observation systems. In this report, we describe the development of a JARE unmanned observatory for upper atmosphere physics and also the scientific results.

Extreme values of meteorological parameters observed at Kalpakkam during the period 1968-1999

International Nuclear Information System (INIS)

Balagurunathan, M.R.; Chandresekharan, E.; Rajan, M.P.; Gurg, R.P.

2001-05-01

In the design phase of engineering structures, an understanding of extreme weather conditions that may occur at the site of interest is very essential, so that the structures can be designed to withstand climatological stresses during its life time. In this report an analysis of extreme values of meteorological parameters at Kalpakkam for the period 1968-99, which provide an insight into such situations is described. The extreme value analysis reveals that all the variables obey Fisher-Tippet Type-I extreme value distribution function. Parameter values of extreme value analysis functions are presented for the variables studied and the 50- and 100- year return period extreme values are arrived at. Frequency distribution of rainfall parameters is investigated. Time series of annual rainfall data suggests a cycle of 2-3 years period. (author)

Spectral sum rules and search for periodicities in DNA sequences

International Nuclear Information System (INIS)

Chechetkin, V.R.

2011-01-01

Periodic patterns play the important regulatory and structural roles in genomic DNA sequences. Commonly, the underlying periodicities should be understood in a broad statistical sense, since the corresponding periodic patterns have been strongly distorted by the random point mutations and insertions/deletions during molecular evolution. The latent periodicities in DNA sequences can be efficiently displayed by Fourier transform. The criteria of significance for observed periodicities are obtained via the comparison versus the counterpart characteristics of the reference random sequences. We show that the restrictions imposed on the significance criteria by the rigorous spectral sum rules can be rationally described with De Finetti distribution. This distribution provides the convenient intermediate asymptotic form between Rayleigh distribution and exact combinatoric theory. - Highlights: → We study the significance criteria for latent periodicities in DNA sequences. → The constraints imposed by sum rules can be described with De Finetti distribution. → It is intermediate between Rayleigh distribution and exact combinatoric theory. → Theory is applicable to the study of correlations between different periodicities. → The approach can be generalized to the arbitrary discrete Fourier transform.

Quantum-classical correspondence in the vicinity of periodic orbits

Science.gov (United States)

Kumari, Meenu; Ghose, Shohini

2018-05-01

Quantum-classical correspondence in chaotic systems is a long-standing problem. We describe a method to quantify Bohr's correspondence principle and calculate the size of quantum numbers for which we can expect to observe quantum-classical correspondence near periodic orbits of Floquet systems. Our method shows how the stability of classical periodic orbits affects quantum dynamics. We demonstrate our method by analyzing quantum-classical correspondence in the quantum kicked top (QKT), which exhibits both regular and chaotic behavior. We use our correspondence conditions to identify signatures of classical bifurcations even in a deep quantum regime. Our method can be used to explain the breakdown of quantum-classical correspondence in chaotic systems.

Observations of long-period waves in the nearshore waters of central west coast of India during the fall inter-monsoon period

Digital Repository Service at National Institute of Oceanography (India)

Amrutha, M.M.; SanilKumar, V.; Jesbin, G.

variability in both long period waves and short period waves need more detailed study. Acknowledgments The authors acknowledge the Earth System Science Organization, Ministry of Earth Sciences, New Delhi for providing the financial support to conduct part... Geraldton. Proceedings of the 2009 Pacific Coasts and Ports Conference, Wellington, New Zealand. Mehta, A. V., & Krishnamurti, T. N., 1988. Interannual variability of the 30 to 50 day wave motions. Journal of the Meteorological Society of Japan, 66...

Synchronous observations of long-periodic geomagnetic pulsations on the ATS-6 satellite and on the Earth surface

International Nuclear Information System (INIS)

Barfild, Dzh.N.; Bondarenko, N.M.; Buloshnikov, A.M.; Gokhberg, M.B.; Kalisher, A.L.; Mak-Ferron, R.L.; Troitskaya, V.A.

1977-01-01

Geomagnetic pulsations of the Pi2 and Pc4 types recorded by the ATS-6 geostationary satellite and by observatories located near the geomagnetic longitude of the space satellite from the 24th of May, 1974 to the 1st of September, 1976 are compared. The periods of the Pi2 pulsations measured by the space satellite and on the Earth practically coincide, dynamic spectra and spectral densities are similar. The amplitude of the Pi2 pulsations recorded in auroral latitudes is several times wider than the amplitude measured by the ATS-6 while in middle latitudes the amplitude is much smaller than on the satellite. The Pc4 pulsations are not practically observed on the Earth for they are probably excited in narrow local areas of the magnitosphere. In order to arrive to the single-valued solution of the problem of the mechanism of the generation and localization of the pulsation source it is necessary to carry out simultaneous observations on the Earth and in the magnitosphere

The first coordinated observations of mid-latitude E-region quasi-periodic radar echoes and lower thermospheric 557.7-nm airglow

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T. Ogawa

2005-10-01

Full Text Available We present the first coordinated observations of quasi-periodic (QP radar echoes from sporadic-E (Es field-aligned irregularities (FAIs, OI 557.7-nm airglow, and neutral winds in a common volume over Shigaraki, Japan (34.9° N, 136.1° E on the night of 5 August 2002 during the SEEK-2 campaign. QP echo altitudes of 90-110 km were lower than usual by 10 km, enabling us to make a detailed comparison among QP echoes, airglow intensity, and neutral wind at around 96 km altitude. Eastward movement of the QP echo regions is consistent with the motions of neutral winds, airglow structures, and FAIs, suggesting that the electrodynamics of Es-layers is fundamentally controlled by the neutral atmospheric dynamics. During the QP echo event, the echo altitudes clearly went up (down in harmony with an airglow enhancement (subsidence that also moved to the east. This fact suggests that the eastward-moving enhanced airglow region included an upward (downward component of neutral winds to raise (lower the altitude of the wind-shear node responsible for the Es formation. The airglow intensity, echo intensity, and Doppler velocity of FAIs at around 96 km altitude fluctuated with periods from 10 min to 1h, indicating that these parameters were modulated with short-period atmospheric disturbances. Some QP echo regions below 100km altitude contained small-scale QP structures in which very strong neutral winds exceeding 100 m/s existed. The results are compared with recent observations, theories, and simulations of QP echoes. Keywords. Ionosphere (Ionosphere-atmosphere interactions; Ionospheric irregularities; Mid-latitude ionosphere

Long-period ground motions at near-regional distances caused by the PL wave from, inland earthquakes: Observation and numerical simulation of the 2004 Mid-Niigata, Japan, Mw6.6 earthquake

Science.gov (United States)

Furumura, T.; Kennett, B. L. N.

2017-12-01

We examine the development of large, long-period ground motions at near-regional distances (D=50-200 km) generated by the PL wave from large, shallow inland earthquakes, based on the analysis of strong motion records and finite-difference method (FDM) simulations of seismic wave propagation. PL wave can be represented as leaking modes of the crustal waveguide and are commonly observed at regional distances between 300 to 1000 km as a dispersed, long-period signal with a dominant period of about 20 s. However, observations of recent earthquakes at the dense K-NET and KiK-net strong motion networks in Japan demonstrate the dominance of the PL wave at near-regional (D=50-200 km) distances as, e.g., for the 2004 Mid Niigata, Japan, earthquake (Mw6.6; h=13 km). The observed PL wave signal between P and S wave shows a large, dispersed wave packet with dominant period of about T=4-10 s with amplitude almost comparable to or larger than the later arrival of the S and surface waves. Thus, the early arrivals of the long-period PL wave immediately after P wave can enhance resonance with large-scale constructions such as high-rise buildings and large oil-storage tanks etc. with potential for disaster. Such strong effects often occurred during the 2004 Mid Niigata earthquakes and other large earthquakes which occurred nearby the Kanto (Tokyo) basin. FDM simulation of seismic wave propagation employing realistic 3-D sedimentary structure models demonstrates the process by which the PL wave develops at near-regional distances from shallow, crustal earthquakes by constructive interference of the P wave in the long-period band. The amplitude of the PL wave is very sensitive to low-velocity structure in the near-surface. Lowered velocities help to develop large SV-to-P conversion and weaken the P-to-SV conversion at the free surface. Both effects enhance the multiple P reflections in the crustal waveguide and prevent the leakage of seismic energy into the mantle. However, a very

Difference in Striae Periodicity of Heilongjiang and Singaporean Chinese Teeth

Directory of Open Access Journals (Sweden)

Sharon H. X. Tan

2017-06-01

Full Text Available Striae periodicity refers to the number of cross-striations between successive lines of Retzius in tooth enamel. A regular time dependency of striae periodicity, known as the circaseptan interval, has been proposed. Previous studies on striae periodicity have been carried out on both modern and early humans given its potential applications in forensic age estimations and anthropology. Nevertheless, research comparing striae periodicities across gender groups and populations in different geographical locations, particularly in Asia, is lacking. In this study, we compared the striae periodicities of Heilongjiang and Singaporean Chinese, as well as that of Singaporean Chinese males and females. Results showed that while the median striae periodicity counts of Heilongjiang Chinese and Singaporean Chinese teeth are both 7, Heilongjiang Chinese tend to have lower striae periodicity counts than Singaporean Chinese (p < 0.01. No significant gender difference was observed between the median striae periodicity of Singaporean Chinese Female and Singaporean Chinese Male teeth (p = 0.511. We concluded that the median striae periodicity may statistically differ with geographical location, but not gender, provided that ethnicity and geographical location are held constant. Further studies are required to examine the causes for variation in striae periodicities between geographical locations, as well as to verify the other bio-environmental determinants of striae periodicity.

Enormous periodic doppler shifts in SS 433

International Nuclear Information System (INIS)

Margon, B.; Ford, H.C.; Grandi, S.A.; Stone, R.P.S.

1979-01-01

We have previously reported prominent ''moving' emission lines in the visible spectrum of Stephenson-Sanduleak 433, the optical counterpart of a variable radio and X-ray source. Further observations show that despite the implausible velocities and changes in velocities implied if the moving features are interpreted as Doppler-shifted Balmer lines, this explanation is indeed correct. Spectroscopy of SS 433 on 51 mights in 1978--1979 reveals that the unidentified features are two sets of Balmer and He I lines, one with large and changing redshift, and the other with large and changing blueshift. Combining our data with published earlier observations, we obtain Doppler shifts on 80 nights in the period 1978 June to 1979 June. These data indicate that the velocity variations are cyclical, repeating in both the blueshift and redshift systems with a period of 164 +- 3 days. The two systems have thus far been observed to reach maximum positive and negative radial velocities of +50,000 and -35,000 km s -1 , respectively, are always symmetric about redshift z=0.04, and follow roughly sinusoidal velocity curves. We discuss in addition a variety of interesting short-term spectroscopic details, including minor but highly significant deviations of the radial velocity from the sinusoid, and nightly line profile changes, sometimes appearing as mirror-image events in the redshift and blueshift systems. The behavior of SS 433 is unprecedented

Periodic instantons and scattering amplitudes

International Nuclear Information System (INIS)

Khlebnikov, S.Yu.; Rubakov, V.A.; Tinyakov, P.G.

1991-04-01

We discuss the role of periodic euclidean solutions with two turning points and zero winding number (periodic instantons) in instanton induced processes below the sphaleron energy E sph . We find that the periodic instantons describe certain multiparticle scattering events leading to the transitions between topologically distinct vacua. Both the semiclassical amplitudes and inital and final states of these transitions are determined by the periodic instantons. Furthermore, the corresponding probabilities are maximal among all states of given energy. We show that at E ≤ E sph , the periodic instantons can be approximated by infinite chains of ordinary instantons and anti-instantons, and they naturally emerge as deformations of the zero energy instanton. In the framework of 2d abelian Higgs model and 4d electroweak theory we show, however, that there is not obvious relation between periodic instantons and two-particle scattering amplitudes. (orig.)

Period adding cascades: experiment and modeling in air bubbling.

Science.gov (United States)

Pereira, Felipe Augusto Cardoso; Colli, Eduardo; Sartorelli, José Carlos

2012-03-01

Period adding cascades have been observed experimentally/numerically in the dynamics of neurons and pancreatic cells, lasers, electric circuits, chemical reactions, oceanic internal waves, and also in air bubbling. We show that the period adding cascades appearing in bubbling from a nozzle submerged in a viscous liquid can be reproduced by a simple model, based on some hydrodynamical principles, dealing with the time evolution of two variables, bubble position and pressure of the air chamber, through a system of differential equations with a rule of detachment based on force balance. The model further reduces to an iterating one-dimensional map giving the pressures at the detachments, where time between bubbles come out as an observable of the dynamics. The model has not only good agreement with experimental data, but is also able to predict the influence of the main parameters involved, like the length of the hose connecting the air supplier with the needle, the needle radius and the needle length.

[Vaginitis and vaginosis. Comparison of two periods].

Science.gov (United States)

Ceruti, M; Canestrelli, M; Piantelli, G; Amone, F; Condemi, V; De Paolis, P; Ludovici, G; Somenzi, P

1993-10-01

Vaginitis is the most frequent gynecological disease. It is characterized by objective and subjective signs of inflammation and differs from bacterial vaginosis (BV) which is an abnormal condition of the vaginal ecosystem caused by the excessive growth of aerobic and anaerobic flora normally present in the vagina with an increased risk of pelvic inflammatory disease (PID). The authors report the results of a study carried out at the Centre for Gynecological Infections at the Clinic of Obstetrics and Gynecology of the University of Parma. 828 patients were enrolled in the study during the period 1985-86 and 1559 patients during the two-year period 1991-92. The aim of the study was to evaluate variations in epidemiological data for vaginitis and bacterial vaginosis in the two periods examined. No significant changes were observed (p > 0.05) with regard to the prevalence of Ca, Tv and BV forms. On the other hand, there was a significant reduction (p vaginitis and BV showed a reduction of other microorganisms and an increase in negative vaginal swabs in adults (> 20 years old).

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

Science.gov (United States)

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

1981-01-01

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

A new sentinel surveillance system for severe influenza in England shows a shift in age distribution of hospitalised cases in the post-pandemic period.

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Shelly Bolotin

Full Text Available BACKGROUND: The World Health Organization and European Centre for Disease Prevention and Control have highlighted the importance of establishing systems to monitor severe influenza. Following the H1N1 (2009 influenza pandemic, a sentinel network of 23 Trusts, the UK Severe Influenza Surveillance System (USISS, was established to monitor hospitalisations due to confirmed seasonal influenza in England. This article presents the results of the first season of operation of USISS in 2010/11. METHODOLOGY/PRINCIPAL FINDINGS: A case was defined as a person hospitalised with confirmed influenza of any type. Weekly aggregate numbers of hospitalised influenza cases, broken down by flu type and level of care, were submitted by participating Trusts. Cases in 2010/11 were compared to cases during the 2009 pandemic in hospitals with available surveillance data for both time periods (n = 19. An unexpected resurgence in seasonal A/H1N1 (2009 influenza activity in England was observed in December 2010 with reports of severe disease. Reported cases over the period of 4 October 2010 to 13 February 2011 were mostly due to influenza A/H1N1 (2009. One thousand and seventy-one cases of influenza A/H1N1 (2009 occurred over this period compared to 409 at the same Trusts over the 2009/10 pandemic period (1 April 2009 to 6 January 2010. Median age of influenza A/H1N1 (2009 cases in 2010/11 was 35 years, compared with 20 years during the pandemic (p = <0.0001. CONCLUSIONS/SIGNIFICANCE: The Health Protection Agency successfully established a sentinel surveillance system for severe influenza in 2010/11, detecting a rise in influenza cases mirroring other surveillance indicators. The data indicate an upward shift in the age-distribution of influenza A/H1N1 (2009 during the 2010/11 influenza season as compared to the 2009/10 pandemic. Systems to enable the ongoing surveillance of severe influenza will be a key component in understanding and responding to the evolving

A study of 3-dimensionally periodic carbon nanostructures

Science.gov (United States)

Yin, Ming; Bleiweiss, Michael; Amirzadeh, Jafar; Datta, Timir; Arammash, Fouzi

2012-02-01

Electronic structures with intricate periodic 3-dimensional arrangements at the submicron scale were investigated. These may be fabricated using artificial porous opal substrates as the templates in which the targeted conducting medium is introduced. In the past these materials were reported to show interesting electronic behaviors. [Michael Bleiweiss, et al ``Localization and Related Phenomena in Multiply Connected Nanostructured,'' BAPS, Z30.011, Nanostructured Materials Session, March 2001, Seattle]. Several materials were studied in particular disordered carbon which has been reported to show quantum transport including fractional hall steps. The results of these measurements, including the observation of localization phenomena, will be discussed. Comparisons will be made with literature data.

The period-luminosity relation for Cepheids

International Nuclear Information System (INIS)

Brodie, J.P.

1980-01-01

Numerical simulations of the empirical determination of the period-luminosity-colour relation for classical Cepheids are presented. In this study the quantitative effects of random errors, reddening, sample size and the presence of both colour and period cut-offs (imposed by the finite extent of the instability strip) on the observational redetermination of the original relation are evaluated. Both random errors in the photometry and correlated errors in the reddening corrections are shown to have systematic effects. Especially sensitive to these errors is the colour coefficient in the period-luminosity-colour relation, where the ratio of the error to the width of the instability strip is the determining factor. With present observations only broad confidence limits can be placed on present knowledge of the intrinsic period-luminosity-colour relation and/or its variations from galaxy to galaxy. (author)

Comparison of land surface humidity between observations and CMIP5 models

Science.gov (United States)

Dunn, Robert J. H.; Willett, Kate M.; Ciavarella, Andrew; Stott, Peter A.

2017-08-01

We compare the latest observational land surface humidity dataset, HadISDH, with the latest generation of climate models extracted from the CMIP5 archive and the ERA-Interim reanalysis over the period 1973 to present. The globally averaged behaviour of HadISDH and ERA-Interim are very similar in both humidity measures and air temperature, on decadal and interannual timescales. The global average relative humidity shows a gradual increase from 1973 to 2000, followed by a steep decline in recent years. The observed specific humidity shows a steady increase in the global average during the early period but in the later period it remains approximately constant. None of the CMIP5 models or experiments capture the observed behaviour of the relative or specific humidity over the entire study period. When using an atmosphere-only model, driven by observed sea surface temperatures and radiative forcing changes, the behaviour of regional average temperature and specific humidity are better captured, but there is little improvement in the relative humidity. Comparing the observed climatologies with those from historical model runs shows that the models are generally cooler everywhere, are drier and less saturated in the tropics and extra-tropics, and have comparable moisture levels but are more saturated in the high latitudes. The spatial pattern of linear trends is relatively similar between the models and HadISDH for temperature and specific humidity, but there are large differences for relative humidity, with less moistening shown in the models over the tropics and very little at high latitudes. The observed drying in mid-latitudes is present at a much lower magnitude in the CMIP5 models. Relationships between temperature and humidity anomalies (T-q and T-rh) show good agreement for specific humidity between models and observations, and between the models themselves, but much poorer for relative humidity. The T-q correlation from the models is more steeply positive than

Numerical study of two disks settling in an Oldroyd-B fluid: From periodic interaction to chaining

Science.gov (United States)

Pan, Tsorng-Whay; Glowinski, Roland

2017-12-01

In this article, we present a numerical study of the dynamics of two disks sedimenting in a narrow vertical channel filled with an Oldroyd-B fluid. Two kinds of particle dynamics are observed: (i) a periodic interaction between the two disks, and (ii) the formation of a two-disk chain. For the periodic interaction of the two disks, two different motions are observed: (a) the two disks stay far apart and interact periodically, and (b) the two disks interact closely and then far apart in a periodic way, like the drafting, kissing, and tumbling of two disks sedimenting in a Newtonian fluid, due to a weak elastic force. Concerning the formation of a two-disk chain occurring at higher values of the elasticity number, either a tilted chain or a vertical chain is observed. Our simulations show that, as expected, the values of the elasticity and Mach numbers are the determining factors concerning the particle chain formation and its orientation.

Charged particle periodicity in the Saturnian magnetosphere

International Nuclear Information System (INIS)

Carbary, J.F.; Krimigis, S.M.

1982-01-01

The low energy charged particles (LECP) experiments on the Voyager 1 and 2 spacecraft performed measurements of electrons (approx.22 keV to approx.20 MeV) and ions (approx.28 keV to approx.150 MeV) during the Saturn encounters in 1980 and 1981. Count rate ratios of two of the low energy electron (22 to 35 keV and 183 to 500 keV) and ion (43 to 80 keV and 137 to 215 keV) channels exhibit an approximation 10 hour periodicity in the outer Saturnian magnetosphere beyond the orbit of Titan. Electron ratios vary from approx.50 to approx.300; ion ratios vary from approx.3 to approx.20. Similar but less pronounced periodicities are observed for higher and lower energy electron and ion spectral indices. Three complete cycles were observed during the Voyager 2 outbound portion of the encounter from which were determined an electron ratio period of 10/sup h/21/sup m/ +- 48/sup m/ and an ion ratio period of 9/sup h/49/sup m/ +- 59/sup m/. Using Saturn Kilometric Radiation (SKR) and Saturn Electrostatic Discharge (SED) periods, extrapolation backward from Voyager 2 to Voyager 1 suggests that the periodicities are Saturnian rather than Jovian in nature, and that they persist in phase for time intervals at least as long as 287 days. Ratio minima, or spectral hardenings, occur in the same hemisphere as do auroral brightenings, SKR activity, and spoke enhanement. We interpret the observations as prima facie evidence of an asymmetry in the Saturian magnetic field and the root cause of the observed SKR periodicity

The Discrete Beverton-Holt Model with Periodic Harvesting in a Periodically Fluctuating Environment

Directory of Open Access Journals (Sweden)

Ziyad AlSharawi

2010-01-01

Full Text Available We investigate the effect of constant and periodic harvesting on the Beverton-Holt model in a periodically fluctuating environment. We show that in a periodically fluctuating environment, periodic harvesting gives a better maximum sustainable yield compared to constant harvesting. However, if one can also fix the environment, then constant harvesting in a constant environment can be a better option, especially for sufficiently large initial populations. Also, we investigate the combinatorial structure of the periodic sequence of carrying capacities and its effect on the maximum sustainable yield. Finally, we leave some questions worth further investigations.

Dependence of spectrum on period and twist effect of the pulsars magnetic field

International Nuclear Information System (INIS)

Shitov, Yu.P.

1983-01-01

The analysis of flux depsities at 102, 408 and 2700 MHz shows that the mean spectral radio luminosity of pUlsars anti Lsub(ν) depends on their period P. The radio luminosity on the average, decreases with the increasing period at all three freqUercies. The character and power of the period dependence anti Lsub(ν)(P) are different at different freqUencies caUsing the corresponding period dependence of the mean radio spectrUm and, particularly, of the spectral index anti αsub(1-4)(102-408 MHz), anti αsub(1-4)(P) varies as Psup(1.7) for P 408 (P) varies as Psup(-1.3) in the period interval 0.3 408 and the period derivatives P, between αsub(1-4) and P. In this connection, the arthor draws the conclusion that period dependences of the spectral radio luminosity and of the spectrum of pulsars are caused by geometrical factors. Quantitative estimates show that the twist effect of magnetic field lines caused by the reaction of magnetic-dipole radiation may be such a geometrical factor, which increases the field line curvatUre (as compared to the dipole field). The twist curvature rhosub(rot)sup(-1) varies as PsUp(-3)xrsup(2) (r is the radial distance from a star) causes the observed period dependence anti Lsub(ν)(P) owing to the curvature emission mechanism. The twist effect of the magnetic field gives the possibility to estimate height levels r of the radio emission regions in a pulsar from the observed function anti Lsub(π)(P). At 408 MHz for an ''average statistic'' pulsar with P> or approximately 0.3 s the level r 408 =1x10 9 cm

Planetary period oscillations in Saturn's magnetosphere: New results from the F-ring and proximal orbits

Science.gov (United States)

Provan, G.; Cowley, S. W. H.; Bunce, E. J.; Hunt, G. J.; Dougherty, M. K.

2017-12-01

We investigate planetary period oscillations (PPOs) in Saturn's magnetosphere using Cassini magnetic field data during the high cadence ( 7 days) F-ring and proximal orbits. Previous results have shown that there are two PPO systems, one in each hemisphere. Both PPO periods show seasonal dependence, and since mid-2014 the Northern PPO period has been 10.8 h and the Southern PPO period 10.7 h. The beat period of the two oscillations is 45 days. Previous results demonstrated that in the Northern (Southern) polar region only pure Northern (Southern) oscillations can be observed, whilst in the equatorial region both oscillations are present and constructively and destructively interfere over the beat-cycle of the two oscillations. The PPOs are believed to be driven by twin-cell convection patterns in the polar ionosphere/thermosphere regions, with two systems of field-aligned currents transmitting the PPO flows to the magnetospheric plasma.The F-ring and proximal orbits uniquely observe the PPOs over 6 orbits during each PPO beat cycle. This high-cadence data demonstrates that over a beat cycle both the periods and amplitudes of the PPO observed within the each polar region are modulated by the PPO system from the opposite hemisphere. When the two oscillations are in phase (anti-phase) the `drag' of one system on the other acts to decrease (increase) the amplitude of the oscillations and the two PPO periods diverge (converge). We present a theoretical model showing that this coupling is due to the PPO flows from one hemisphere not just being communicated to the magnetosphere as previously assumed, but also to the opposite hemisphere. The result is inter-hemispheric coupling of the PPO flow systems within the ionosphere/thermosphere system, so that the northern PPO system drives a northern twin-cell convection pattern in the southern hemisphere, and vice versa, thus leading to the observed polar modulations of the PPOs.We will also present PPO phase models determined

Lidar Observations of Aerosol Disturbances of the Stratosphere over Tomsk (56.5∘N; 85.0∘E in Volcanic Activity Period 2006–2011

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Oleg E. Bazhenov

2012-01-01

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

Viral infection model with periodic lytic immune response

International Nuclear Information System (INIS)

Wang Kaifa; Wang Wendi; Liu Xianning

2006-01-01

Dynamical behavior and bifurcation structure of a viral infection model are studied under the assumption that the lytic immune response is periodic in time. The infection-free equilibrium is globally asymptotically stable when the basic reproductive ratio of virus is less than or equal to one. There is a non-constant periodic solution if the basic reproductive ratio of the virus is greater than one. It is found that period doubling bifurcations occur as the amplitude of lytic component is increased. For intermediate birth rates, the period triplication occurs and then period doubling cascades proceed gradually toward chaotic cycles. For large birth rate, the period doubling cascade proceeds gradually toward chaotic cycles without the period triplication, and the inverse period doubling can be observed. These results can be used to explain the oscillation behaviors of virus population, which was observed in chronic HBV or HCV carriers

Long-period Intensity Pulsations in Coronal Loops Explained by Thermal Non-equilibrium Cycles

Energy Technology Data Exchange (ETDEWEB)

Froment, C.; Auchère, F.; Bocchialini, K.; Buchlin, E.; Solomon, J. [Institut d’Astrophysique Spatiale, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Bât. 121, F-91405 Orsay cedex (France); Aulanier, G. [LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 06, Univ. Paris Diderot, Sorbonne Paris Cité, 5 place Jules Janssen, F-92195 Meudon (France); Mikić, Z., E-mail: clara.froment@astro.uio.no [Predictive Science, Inc., San Diego, CA 92121 (United States)

2017-02-01

In solar coronal loops, thermal non-equilibrium (TNE) is a phenomenon that can occur when the heating is both highly stratified and quasi-constant. Unambiguous observational identification of TNE would thus permit us to strongly constrain heating scenarios. While TNE is currently the standard interpretation of coronal rain, the long-term periodic evolution predicted by simulations has never been observed. However, the detection of long-period intensity pulsations (periods of several hours) has been recently reported with the Solar and Heliospheric Observatory /EIT, and this phenomenon appears to be very common in loops. Moreover, the three intensity-pulsation events that we recently studied with the Solar Dynamics Observatory /Atmospheric Imaging Assembly (AIA) show strong evidence for TNE in warm loops. In this paper, a realistic loop geometry from linear force-free field (LFFF) extrapolations is used as input to 1D hydrodynamic simulations. Our simulations show that, for the present loop geometry, the heating has to be asymmetrical to produce TNE. We analyze in detail one particular simulation that reproduces the average thermal behavior of one of the pulsating loop bundle observed with AIA. We compare the properties of this simulation with those deduced from the observations. The magnetic topology of the LFFF extrapolations points to the presence of sites of preferred reconnection at one footpoint, supporting the presence of asymmetric heating. In addition, we can reproduce the temporal large-scale intensity properties of the pulsating loops. This simulation further strengthens the interpretation of the observed pulsations as signatures of TNE. This consequently provides important information on the heating localization and timescale for these loops.

Cavitation bubble oscillation period as a process diagnostic during the laser shock peening process

CSIR Research Space (South Africa)

Glaser, Daniel

2017-09-01

Full Text Available bubble can be used to characterize effective and repeatable energy delivery to the target. High-speed shadowgraphy is implemented to show that variations in the bubble period occur before visual observations of dielectric breakdown in water...

Detecting periodicities with Gaussian processes

Directory of Open Access Journals (Sweden)

Nicolas Durrande

2016-04-01

Full Text Available We consider the problem of detecting and quantifying the periodic component of a function given noise-corrupted observations of a limited number of input/output tuples. Our approach is based on Gaussian process regression, which provides a flexible non-parametric framework for modelling periodic data. We introduce a novel decomposition of the covariance function as the sum of periodic and aperiodic kernels. This decomposition allows for the creation of sub-models which capture the periodic nature of the signal and its complement. To quantify the periodicity of the signal, we derive a periodicity ratio which reflects the uncertainty in the fitted sub-models. Although the method can be applied to many kernels, we give a special emphasis to the Matérn family, from the expression of the reproducing kernel Hilbert space inner product to the implementation of the associated periodic kernels in a Gaussian process toolkit. The proposed method is illustrated by considering the detection of periodically expressed genes in the arabidopsis genome.

Mathematical observations on the relation between eclosion periods and the copulation rate of cicadas.

Science.gov (United States)

Saisho, Yasumasa

2010-04-01

In many species of cicadas the peak of eclosion of males precedes that of females. In this paper, we construct a stochastic model and consider whether this sexual difference of eclosion periods works against mating or not. We also discuss the relation between the peak period of copulations and the development of population number by using this model.

High-latitude long-period pulsations in the atmospheric electricity according to observations at Schpitzbergen

International Nuclear Information System (INIS)

Klejmenova, N.G.; Kozyreva, O.V.; Mikhnovski, S.; Shimanski, A.; Ermolenko, D.Yu.

1992-01-01

The spectrum of long-period oscillations in the electric and magnetic fields is investigated for the first time using the data on simultaneous digital recording in the high altitudes at Schpitzbergen. It is established that during both tranquil and perturbed period at any time of the day, spectrum variation in electric and magnetic fields feature a decline discrete nature

Debris flow recurrence periods and multi-temporal observations of colluvial fan evolution in central Spitsbergen (Svalbard)

Science.gov (United States)

Bernhardt, H.; Reiss, D.; Hiesinger, H.; Hauber, E.; Johnsson, A.

2017-11-01

Fan-shaped accumulations of debris flow deposits are common landforms in polar regions such as Svalbard. Although depositional processes in these environments are of high interest to climate as well as Mars-analog research, several parameters, e.g., debris flow recurrence periods, remain poorly constrained. Here, we present an investigation based on remote sensing as well as in situ data of a 0.4 km2 large colluvial fan in Hanaskogdalen, central Spitsbergen. We analyzed high resolution satellite and aerial images covering five decades from 1961 to 2014 and correlated them with lichenometric dating as well as meteorological data. Image analyses and lichenometry deliver consistent results and show that the recurrence period of large debris flows (≥ 400 m3) is about 5 to 10 years, with smaller flows averaging at two per year in the period from 2008 to 2013. While this is up to two orders of magnitude shorter than previous estimates for Svalbard (80 to 500 years), we found the average volume of 220 m3 per individual flow to be similar to previous estimates for the region. Image data also reveal that an avulsion took place between 1961 and 1976, when the active part of the fan moved from its eastern to its western portion. A case study of the effects of a light rain event ( 5 mm/day) in the rainy summer of 2013, which triggered a large debris flow, further shows that even light precipitation can trigger major flows. This is made possible by multiple light rain events or gradual snow melt pre-saturating the permafrost ground and has to be taken into account when predicting the likelihood of potentially hazardous mass wasting in polar regions. Furthermore, our findings imply a current net deposition rate on the colluvial fan of 480 m3/year, which is slightly less than the integrated net deposition rate of 576 to 720 m3/year resulting from the current fan volume divided by the 12,500 to 10,000 years since the onset of fan build-up after the area's deglaciation. However

Mean-periodic functions

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Carlos A. Berenstein

1980-01-01

Full Text Available We show that any mean-periodic function f can be represented in terms of exponential-polynomial solutions of the same convolution equation f satisfies, i.e., u∗f=0(μ∈E′(ℝn. This extends to n-variables the work of L. Schwartz on mean-periodicity and also extends L. Ehrenpreis' work on partial differential equations with constant coefficients to arbitrary convolutors. We also answer a number of open questions about mean-periodic functions of one variable. The basic ingredient is our work on interpolation by entire functions in one and several complex variables.

Long-period polar rain variations, solar wind and hemispherically symmetric polar rain

International Nuclear Information System (INIS)

Makita, K.; Meng, C.

1987-01-01

On the basic of electron data obtained by the Defense Meteorological Satellite Program (DMSP) F2 satellite the long-period variations of the polar rain flux are examined for four consecutive solar rotations. It is clearly demonstrated that the asymmetric enhancement of the polar rain flux is strongly controlled by the sector structure of the interplanetary magnetic field (IMF). However, the orbit-to-orbit and day-to-day variations of the polar rain flux are detected even during a very stable sector period, and the polar rain flux does not have any clear relationship to the magnitude of the IMF B/sub x/ or B/sub y/. Thus the polarity of B/sub x/ controls only the accessibility of a polar region. It is also noticed that the intensity of polar rain fluxes does not show any relationship to the density of the solar wind, suggesting that the origin of the polar rain electrons is different from the commonly observed part of the solar wind electron distribution function. In addition to the asymmetric polar rain distribution, increasing polar rain fluxes of similar high intensity are sometimes detected over both polar caps. An examination of more than 1 year's data from the DMSP F2 and F4 satellites shows that simultaneous intense uniform precipitations (>10 7 electrons/cm 2 s sr) over both polar caps are not coincidental; it also shows that the spectra are similar. The occurrence of hemispherically symmetric events is not common. They generally are observed after an IMF sector transition period, during unstable periods in the sector structure, and while the solar wind density is high. copyright American Geophysical Union 1987

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-01-01

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

Observations of Equatorial Kelvin Wave Modes in FORMOSAT-3/COSMIC GPS RO Temperature Profiles

Directory of Open Access Journals (Sweden)

Potula Sree Brahmanandam

2010-01-01

Full Text Available In this study, we analyze FORMOSAT-3/COSMIC (F3/C GPS radio occultation (RO derived temperature components for the period September 2006 to February 2008. Results show the presence of slow Kelvin waves (wave period > 10 days with higher zonal wavenumbers (either one or two in the upper troposphere and lower stratosphere (UTLS. The vertical wavelengths of these waves are found to be in the range of 5 - 12 km. The predominant Kelvin waves observed in the temperature fluctuations are in the altitude range between 15 and 28 km and centered on the tropical tropopause. The downward phase progression of these waves suggests that the derived waves are propagating upward, with the source region located at lower altitudes possibly due to tropical convective heating. The zonal winds retrieved using radiosonde observations over Singapore (1¢XN, 104¢XE during this period show a periodicity of ~24 - 26 months in the stratosphere, and quasi-biennial oscillation (QBO characteristics with eastward zonal winds from March 2006 to May 2007 and westward winds from June 2007 to July 2008 respectively. Our results further show that the Kelvin wave characteristics are enhanced during the westward phase of QBO and diminish during the eastward phase, in line with the previous reported results. Furthermore, an examination of outgoing longwave radiation (OLR data shows that deep convection activity is developed episodically over the Indonesian archipelago during the observation period, thereby indicating that the Kelvin wave events observed in temperature fluctuations are either driven by convective activity (convectively coupled waves or by a broad spectrum of convective variability (free waves over the Indonesian region.

Chromospheric activity of periodic variable stars (including eclipsing binaries) observed in DR2 LAMOST stellar spectral survey

Science.gov (United States)

Zhang, Liyun; Lu, Hongpeng; Han, Xianming L.; Jiang, Linyan; Li, Zhongmu; Zhang, Yong; Hou, Yonghui; Wang, Yuefei; Cao, Zihuang

2018-05-01

The LAMOST spectral survey provides a rich databases for studying stellar spectroscopic properties and chromospheric activity. We cross-matched a total of 105,287 periodic variable stars from several photometric surveys and databases (CSS, LINEAR, Kepler, a recently updated eclipsing star catalogue, ASAS, NSVS, some part of SuperWASP survey, variable stars from the Tsinghua University-NAOC Transient Survey, and other objects from some new references) with four million stellar spectra published in the LAMOST data release 2 (DR2). We found 15,955 spectra for 11,469 stars (including 5398 eclipsing binaries). We calculated their equivalent widths (EWs) of their Hα, Hβ, Hγ, Hδ and Caii H lines. Using the Hα line EW, we found 447 spectra with emission above continuum for a total of 316 stars (178 eclipsing binaries). We identified 86 active stars (including 44 eclipsing binaries) with repeated LAMOST spectra. A total of 68 stars (including 34 eclipsing binaries) show chromospheric activity variability. We also found LAMOST spectra of 12 cataclysmic variables, five of which show chromospheric activity variability. We also made photometric follow-up studies of three short period targets (DY CVn, HAT-192-0001481, and LAMOST J164933.24+141255.0) using the Xinglong 60-cm telescope and the SARA 90-cm and 1-m telescopes, and obtained new BVRI CCD light curves. We analyzed these light curves and obtained orbital and starspot parameters. We detected the first flare event with a huge brightness increase of more than about 1.5 magnitudes in R filter in LAMOST J164933.24+141255.0.

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

Science.gov (United States)

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

2015-07-01

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

Response to various periods of mechanical stimuli in Physarum plasmodium

International Nuclear Information System (INIS)

Umedachi, Takuya; Ito, Kentaro; Kobayashi, Ryo; Ishiguro, Akio; Nakagaki, Toshiyuki

2017-01-01

Response to mechanical stimuli is a fundamental and critical ability for living cells to survive in hazardous conditions or to form adaptive and functional structures against force(s) from the environment. Although this ability has been extensively studied by molecular biology strategies, it is also important to investigate the ability from the viewpoint of biological rhythm phenomena so as to reveal the mechanisms that underlie these phenomena. Here, we use the plasmodium of the true slime mold Physarum polycephalum as the experimental system for investigating this ability. The plasmodium was repetitively stretched for various periods during which its locomotion speed was observed. Since the plasmodium has inherent oscillation cycles of protoplasmic streaming and thickness variation, how the plasmodium responds to various periods of external stretching stimuli can shed light on the other biological rhythm phenomena. The experimental results show that the plasmodium exhibits response to periodic mechanical stimulation and changes its locomotion speed depending on the period of the stretching stimuli. (paper)

V2492 Cygni: Optical BVRI Variability During the Period 2010-2017

Science.gov (United States)

Ibryamov, Sunay I.; Semkov, Evgeni H.; Peneva, Stoyanka P.

2018-02-01

Results from BVRI photometric observations of the young stellar object V2492 Cyg collected during the period from August 2010 to December 2017 are presented. The star is located in the field of the Pelican Nebula and it was discovered in 2010 due to its remarkable increase in the brightness by more than 5 mag in R-band. According to the first hypothesis of the variability, V2492 Cyg is an FUor candidate. During subsequent observations, it was reported that the star shows the characteristics inherent to EXor- and UXor-type variables. The optical data show that during the whole time of observations the star exhibits multiple large amplitude increases and drops in the brightness. In the beginning of 2017, we registered a significant increase in the optical brightness of V2492 Cyg, which seriously exceeds the maximal magnitudes registered after 2010.

A Bayesian test for periodic signals in red noise

Science.gov (United States)

Vaughan, S.

2010-02-01

Many astrophysical sources, especially compact accreting sources, show strong, random brightness fluctuations with broad power spectra in addition to periodic or quasi-periodic oscillations (QPOs) that have narrower spectra. The random nature of the dominant source of variance greatly complicates the process of searching for possible weak periodic signals. We have addressed this problem using the tools of Bayesian statistics; in particular, using Markov Chain Monte Carlo techniques to approximate the posterior distribution of model parameters, and posterior predictive model checking to assess model fits and search for periodogram outliers that may represent periodic signals. The methods developed are applied to two example data sets, both long XMM-Newton observations of highly variable Seyfert 1 galaxies: RE J1034 + 396 and Mrk 766. In both cases, a bend (or break) in the power spectrum is evident. In the case of RE J1034 + 396, the previously reported QPO is found but with somewhat weaker statistical significance than reported in previous analyses. The difference is due partly to the improved continuum modelling, better treatment of nuisance parameters and partly to different data selection methods.

Extreme value analysis of meteorological parameters observed during the period 1994-2001 at Kakrapar Atomic Power Station

International Nuclear Information System (INIS)

Ramkumar, S.; Dole, M.L.; Nankar, D.P.; Rajan, M.P.; Gurg, R.P.

2003-01-01

In the design of engineering structures, an understanding of extreme weather conditions that may occur at the site of interest is very essential, so that the structures can be designed to withstand such situations. In this report an analysis of extreme values of meteorological parameters observed at Kakrapar Atomic Power Station site for the period 1994 -2001 is described. The parameters considered are maximum and minimum air temperature, maximum wind speed and gust, and maximum rainfall in a month, in a day, in an hour and annual rainfall. The extreme value analysis reveals that annual rainfall, maximum monthly rainfall, minimum air temperature and maximum wind speed at 10 m obey Fisher-Tippet Type -1 distribution whereas maximum daily rainfall, maximum hourly rainfall, maxinlum air temperature and maximum wind speed at 30 m obey Fisher-Tippet Type -2 distribution function. There is no difference in correlation coefficients and fit both extreme value distribution function. Co-efficients of the distribution functions for each variable are established. Extreme values of parameters corresponding to return periods of 50 and 100 years are derived. These derived extreme values are particularly useful for arriving at suitable design basis values to ensure the safety of any civil structure in and around Kakrapar Atomic Power Station site with respect to stresses due to weather conditions. (author)

Periodic pulling of the drift instability in a thermal plasma

International Nuclear Information System (INIS)

Abrams, R.H. Jr.

1970-01-01

The primary objective of this thesis is to show that a mode of oscillation in a plasma can be represented by a van der Pol oscillator. The results of an experiment performed on a drift wave in a Q-machine are interpreted in terms of a mechanism developed by Lashinsky. The mechanism, called periodic pulling, predicts a specific kind of spectrum for certain experimental conditions when a van der Pol oscillator is perturbed by a small signal. The observed spectrum, along with other observations, lends credence to the van der Pol oscillator model of a plasma mode

Multiple-wavelength Variability and Quasi-periodic Oscillation of PMN J0948+0022

Energy Technology Data Exchange (ETDEWEB)

Zhang, Jin [Key Laboratory of Space Astronomy and Technology, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China); Zhang, Hai-Ming; Zhu, Yong-Kai; Lu, Rui-Jing; Liang, En-Wei [Guangxi Key Laboratory for Relativistic Astrophysics, Department of Physics, Guangxi University, Nanning 530004 (China); Yi, Ting-Feng [Department of Physics, Yunnan Normal University, Kunming 650500 (China); Yao, Su, E-mail: jinzhang@bao.ac.cn [Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871 (China)

2017-11-01

We present a comprehensive analysis of multiple-wavelength observational data of the first GeV-selected narrow-line Seyfert 1 galaxy PMN J0948+0022. We derive its light curves in the γ -ray and X-ray bands from the data observed with Fermi /LAT and Swift /XRT, and generate the optical and radio light curves by collecting the data from the literature. These light curves show significant flux variations. With the LAT data we show that this source is analogous to typical flat spectrum radio quasars in the L {sub γ} –Γ {sub γ} plane, where L {sub γ} and Γ {sub γ} are the luminosity and spectral index in the LAT energy band. The γ -ray flux is correlated with the V-band flux with a lag of ∼44 days, and a moderate quasi-periodic oscillation (QPO) with a periodicity of ∼490 days observed in the LAT light curve. A similar QPO signature is also found in the V-band light curve. The γ -ray flux is not correlated with the radio flux in 15 GHz, and no similar QPO signature is found at a confidence level of 95%. Possible mechanisms of the QPO are discussed. We propose that gravitational-wave observations in the future may clarify the current plausible models for the QPO.

Conjugate observations of quasi-periodic emissions by Cluster and DEMETER spacecraft

Czech Academy of Sciences Publication Activity Database

Němec, F.; Santolík, Ondřej; Parrot, M.; Pickett, J. S.; Hayosh, Mykhaylo; Cornilleau-Wehrlin, N.

2013-01-01

Roč. 118, č. 1 (2013), s. 198-208 ISSN 2169-9380 R&D Projects: GA ČR GAP205/10/2279; GA ČR(CZ) GAP209/11/2280 Grant - others:GA ČR(CZ) GPP209/12/P658 Program:GP Institutional support: RVO:68378289 Keywords : quasi-periodic * QP emissions Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 3.440, year: 2013 http://onlinelibrary.wiley.com/doi/10.1029/2012JA018380/abstract

Sensitive periods in human development: evidence from musical training.

Science.gov (United States)

Penhune, Virginia B

2011-10-01

One of the primary goals of cognitive neuroscience is to understand the interaction between genes, development and specific experience. A particularly fascinating example of this interaction is a sensitive period - a time during development when experience has a differential effect on behavior and the brain. Behavioral and brain imaging studies in musicians have provided suggestive evidence for a possible sensitive period for musical training; showing that musicians who began training early show better task performance and greater changes in auditory and motor regions of the brain. However, these studies have not controlled for likely differences between early- (ET) and late-trained (LT) musicians in the number of years of musical experience. This review presents behavioral work from our laboratory comparing the performance of ET (before age seven) and LT musicians who were matched for years of experience on the ability to tap in synchrony with auditory and visual rhythms. The results demonstrate the existence of a possible sensitive period for musical training that has its greatest impact on measures of sensorimotor integration. Work on motor learning in children and how this might relate to the observed sensitive period effect is also reviewed. These studies are described in the context of what is currently known about sensitive periods in animals and humans; drawing on evidence from anatomy and physiology, studies of deafness, as well as structural and functional neuroimaging studies in trained musicians. The possible mechanisms underlying sensitive periods for musical training are discussed based on current theories describing the influence of both low-level features of sensory experience and higher-level cognitive processing. Copyright © 2011 Elsevier Srl. All rights reserved.

David's Understanding of Functions and Periodicity

Science.gov (United States)

Gerson, Hope

2008-01-01

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 engaged…

Observed Sea-Level Changes along the Norwegian Coast

Directory of Open Access Journals (Sweden)

Kristian Breili

2017-07-01

Full Text Available Norway’s national sea level observing system consists of an extensive array of tide gauges, permanent GNSS stations, and lines of repeated levelling. Here, we make use of this observation system to calculate relative sea-level rates and rates corrected for glacial isostatic adjustment (GIA along the Norwegian coast for three different periods, i.e., 1960 to 2010, 1984 to 2014, and 1993 to 2016. For all periods, the relative sea-level rates show considerable spatial variations that are largely due to differences in vertical land motion due to GIA. The variation is reduced by applying corrections for vertical land motion and associated gravitational effects on sea level. For 1960 to 2010 and 1984 to 2014, the coastal average GIA-corrected rates for Norway are 2.0 ± 0.6 mm/year and 2.2 ± 0.6 mm/year, respectively. This is close to the rate of global sea-level rise for the same periods. For the most recent period, 1993 to 2016, the GIA-corrected coastal average is 3.5 ± 0.6 mm/year and 3.2 ± 0.6 mm/year with and without inverse barometer (IB corrections, respectively, which is significantly higher than for the two earlier periods. For 1993 to 2016, the coastal average IB-corrected rates show broad agreement with two independent sets of altimetry. This suggests that there is no systematic error in the vertical land motion corrections applied to the tide-gauge data. At the same time, altimetry does not capture the spatial variation identified in the tide-gauge records. This could be an effect of using altimetry observations off the coast instead of directly at each tide gauge. Finally, we note that, owing to natural variability in the climate system, our estimates are highly sensitive to the selected study period. For example, using a 30-year moving window, we find that the estimated rates may change by up to 1 mm/year when shifting the start epoch by only one year.

Genetic connections between dressage and show-jumping horses in Dutch Warmblood horses

DEFF Research Database (Denmark)

Rovere, Gabriel; Madsen, Per; Norberg, Elise

2014-01-01

During the last decades, the breeding practice within the Dutch Warmblood studbook (KWPN) has resulted in an increasing specialisation of horses into show-jumping (JH) and dressage (DH). The objective of this study was to describe the effect of the specialisation on the connectedness between...... and within subpopulations were analysed in three periods of time to describe changes in genetic connectedness between subpopulations. A decline in GS (0.97–0.45), GC0.5 (0.69–0.13) and r (0.018–0.014) in the recent years was observed. Both subpopulations have a common genetic pool; however...

Thyrotoxic periodic paralysis

OpenAIRE

Rojith Karandode Balakrishnan; Suresh Rama Chandran; Geetha Thirumalnesan; Nedumaran Doraisamy

2011-01-01

This article aims at highlighting the importance of suspecting thyrotoxicosis in cases of recurrent periodic flaccid paralysis; especially in Asian men to facilitate early diagnosis of the former condition. A case report of a 28 year old male patient with recurrent periodic flaccid paralysis has been presented. Hypokalemia secondary to thyrotoxicosis was diagnosed as the cause of the paralysis. The patient was given oral potassium intervention over 24 hours. The patient showed complete recove...

RIEGER-TYPE PERIODICITY DURING SOLAR CYCLES 14–24: ESTIMATION OF DYNAMO MAGNETIC FIELD STRENGTH IN THE SOLAR INTERIOR

Energy Technology Data Exchange (ETDEWEB)

Gurgenashvili, Eka; Zaqarashvili, Teimuraz V.; Kukhianidze, Vasil; Ramishvili, Giorgi; Shergelashvili, Bidzina [Abastumani Astrophysical Observatory at Ilia State University, Tbilisi, Georgia (United States); Oliver, Ramon; Ballester, Jose Luis [Departament de Física, Universitat de les Illes Balears, E-07122, Palma de Mallorca (Spain); Hanslmeier, Arnold [IGAM, Institute of Physics, University of Graz, Universitätsplatz 5, A-8010 Graz (Austria); Poedts, Stefaan, E-mail: teimuraz.zaqarashvili@uni-graz.at [Centre for Mathematical Plasma Astrophysics, Department of Mathematics, KU Leuven, Celestijnenlaan 200B, B-3001, Leuven (Belgium)

2016-07-20

Solar activity undergoes a variation over timescales of several months known as Rieger-type periodicity, which usually occurs near maxima of sunspot cycles. An early analysis showed that the periodicity appears only in some cycles and is absent in other cycles. But the appearance/absence during different cycles has not been explained. We performed a wavelet analysis of sunspot data from the Greenwich Royal Observatory and the Royal Observatory of Belgium during cycles 14–24. We found that the Rieger-type periods occur in all cycles, but they are cycle dependent: shorter periods occur during stronger cycles. Our analysis revealed a periodicity of 185–195 days during the weak cycles 14–15 and 24 and a periodicity of 155–165 days during the stronger cycles 16–23. We derived the dispersion relation of the spherical harmonics of the magnetic Rossby waves in the presence of differential rotation and a toroidal magnetic field in the dynamo layer near the base of the convection zone. This showed that the harmonics of fast Rossby waves with m = 1 and n = 4, where m ( n ) indicates the toroidal (poloidal) wavenumbers, perfectly fit with the observed periodicity. The variation of the toroidal field strength from weaker to stronger cycles may lead to the different periods found in those cycles, which explains the observed enigmatic feature of the Rieger-type periodicity. Finally, we used the observed periodicity to estimate the dynamo field strength during cycles 14–24. Our estimations suggest a field strength of ∼40 kG for the stronger cycles and ∼20 kG for the weaker cycles.

Superorbital Period in the high mass X-ray binary 2S 0114+650

Science.gov (United States)

Farrell, S.; Sood, R.; O'Neill, P.

2004-05-01

We report the identification of a superorbital period in the high mass X-ray binary 2S 0114+650. RXTE ASM observations of this object from 1996 Jan 5 to 2003 May 26 show the presence of a modulation at a period of 30.7 +/- 0.2 days. This period is detected using a Lomb-Scargle periodogram, and has a false-alarm probability of 5E-12. Epoch folding of the data gives an ephemeris of JD 2450079.4 (+/- 0.7) +30.7 (+/- 0.2)N, where N is the cycle number, with phase zero defined as the modulation minimum, and a full amplitude of 60 +/- 20%.

Stress perception among patients in pre-colonoscopy period and those undergoing chemotherapy treatment

Directory of Open Access Journals (Sweden)

Graziela de Souza Alves da Silva

2015-05-01

Full Text Available Objective: comparing the perception of stress among patients with colorectal cancer undergoing chemotherapy with those in pre-colonoscopy period. Methods: a comparative descriptive study developed with 144 people receiving chemotherapy and 100 patients in the pre-colonoscopy period, using biosocial and clinical data, Stress Assessment Tool and Perceived Stress Scale. Results: a predominance of females (73%, aged over 65 (50% were predominant for the pre-colonoscopy period patients. In patients receiving chemotherapy, gender parity with ages ranging from 40-64 years (68.1% was observed. Pre-colonoscopy patients showed higher perceived stress compared to those receiving chemotherapy (p <0.001. Conclusion: the phase of diagnostic definition represents greater stress to patients in comparison to period of treatment, even despite the characteristic manifestations of chemotherapy.

Thyroid Cancer Incidences From Selected South America Population-Based Cancer Registries: An Age-Period-Cohort Study

Directory of Open Access Journals (Sweden)

Anne Karin da Mota Borges

2017-08-01

Full Text Available Purpose: The incidence of thyroid cancer (TC has increased substantially worldwide. However, there is a lack of knowledge about age-period-cohort (APC effects on incidence rates in South American countries. This study describes the TC incidence trends and analyzes APC effects in Cali, Colombia; Costa Rica; Goiânia, Brazil; and Quito, Ecuador. Materials and Methods: Data were obtained from the Cancer Incidence in Five Continents series, and the crude and age-standardized incidence rates were calculated. Trends were assessed using the estimated annual percentage change, and APC models were estimated using Poisson regression for individuals between age 20 and 79 years. Results: An increasing trend in age-standardized incidence rates was observed among women from Goiânia (9.2%, Costa Rica (5.7%, Quito (4.0%, and Cali (3.4%, and in men from Goiânia (10.0% and Costa Rica (3.4%. The APC modeling showed that there was a period effect in all regions and for both sexes. Increasing rate ratios were observed among women over the periods. The best fit model was the APC model in women from all regions and in men from Quito, whereas the age-cohort model showed a better fit in men from Cali and Costa Rica, and the age-drift model showed a better fit among men from Goiânia. Conclusion: These findings suggest that overdiagnosis is a possible explanation for the observed increasing pattern of TC incidence. However, some environmental exposures may also have contributed to the observed increase.

Spatial Heterodyne Observations of Water (SHOW) vapour in the upper troposphere and lower stratosphere from a high altitude aircraft: Modelling and sensitivity analysis

Science.gov (United States)

Langille, J. A.; Letros, D.; Zawada, D.; Bourassa, A.; Degenstein, D.; Solheim, B.

2018-04-01

A spatial heterodyne spectrometer (SHS) has been developed to measure the vertical distribution of water vapour in the upper troposphere and the lower stratosphere with a high vertical resolution (∼500 m). The Spatial Heterodyne Observations of Water (SHOW) instrument combines an imaging system with a monolithic field-widened SHS to observe limb scattered sunlight in a vibrational band of water (1363 nm-1366 nm). The instrument has been optimized for observations from NASA's ER-2 aircraft as a proof-of-concept for a future low earth orbit satellite deployment. A robust model has been developed to simulate SHOW ER-2 limb measurements and retrievals. This paper presents the simulation of the SHOW ER-2 limb measurements along a hypothetical flight track and examines the sensitivity of the measurement and retrieval approach. Water vapour fields from an Environment and Climate Change Canada forecast model are used to represent realistic spatial variability along the flight path. High spectral resolution limb scattered radiances are simulated using the SASKTRAN radiative transfer model. It is shown that the SHOW instrument onboard the ER-2 is capable of resolving the water vapour variability in the UTLS from approximately 12 km - 18 km with ±1 ppm accuracy. Vertical resolutions between 500 m and 1 km are feasible. The along track sampling capability of the instrument is also discussed.

Long-period Ground Motion Simulation in the Osaka Basin during the 2011 Great Tohoku Earthquake

Science.gov (United States)

Iwata, T.; Kubo, H.; Asano, K.; Sato, K.; Aoi, S.

2014-12-01

Large amplitude long-period ground motions (1-10s) with long duration were observed in the Osaka sedimentary basin during the 2011 Tohoku earthquake (Mw9.0) and its aftershock (Ibaraki-Oki, Mw7.7), which is about 600 km away from the source regions. Sato et al. (2013) analyzed strong ground motion records from the source region to the Osaka basin and showed the following characteristics. (1) In the period range of 1 to 10s, the amplitude of horizontal components of the ground motion at the site-specific period is amplified in the Osaka basin sites. The predominant period is about 7s in the bay area where the largest pSv were observed. (2) The velocity Fourier amplitude spectra with their predominant period of around 7s are observed at the bedrock sites surrounding the Osaka basin. Those characteristics were observed during both of the mainshock and the largest aftershock. Therefore, large long-period ground motions in the Osaka basin are generated by the combination of propagation-path and basin effects. They simulated ground motions due to the largest aftershock as a simple point source model using three-dimensional FDM (GMS; Aoi and Fujiwara, 1999). They used a three-dimensional velocity structure based on the Japan Integrated Velocity Structure Model (JIVSM, Koketsu et al., 2012), with the minimum effective period of the computation of 3s. Their simulation result reproduced the observation characteristics well and it validates the applicability of the JIVSM for the long period ground motion simulation. In this study, we try to simulate long-period ground motions during the mainshock. The source model we used for the simulation is based on the SMGA model obtained by Asano and Iwata (2012). We succeed to simulate long-period ground motion propagation from Kanto area to the Osaka basin fairly well. The long-period ground motion simulations with the several Osaka basin velocity structure models are done for improving the model applicability. We used strong motion

Stable one-dimensional periodic waves in Kerr-type saturable and quadratic nonlinear media

International Nuclear Information System (INIS)

Kartashov, Yaroslav V; Egorov, Alexey A; Vysloukh, Victor A; Torner, Lluis

2004-01-01

We review the latest progress and properties of the families of bright and dark one-dimensional periodic waves propagating in saturable Kerr-type and quadratic nonlinear media. We show how saturation of the nonlinear response results in the appearance of stability (instability) bands in a focusing (defocusing) medium, which is in sharp contrast with the properties of periodic waves in Kerr media. One of the key results discovered is the stabilization of multicolour periodic waves in quadratic media. In particular, dark-type waves are shown to be metastable, while bright-type waves are completely stable in a broad range of energy flows and material parameters. This yields the first known example of completely stable periodic wave patterns propagating in conservative uniform media supporting bright solitons. Such results open the way to the experimental observation of the corresponding self-sustained periodic wave patterns

Correlated wave and particle observations upstream of the earth's bow shock

International Nuclear Information System (INIS)

Harvey, C.C.; Bavassano-Cattaneo, M.B.; Dobrowolny, M.; Orsini, S.; Mangeney, A.; Russell, C.T.

1981-01-01

Data from three ISEE experiments has been analyzed during several periods of turbulence observed in the solar wind upstream of the earth's quasi-parallel bow shock. Radio observations are used to validate a shock model, which is subsequently used to compute various geometrical parameters during all the periods studied. One typical 9-hour period on November 4, 1977, is discussed in some detail to illustrate the parameters studied and the correlations found. It is shown that during this period, the radio noise spectrum has two components, one centered around the local electron plasma frequency and the other at somewhat lower frequencies; the latter component has a shorter wavelength and correlates with the level of MHD turbulence. A multivariate canonical statistical analysis of particle and MHD data during a 2-week period shows that the proton anisotropy and turbulence level correlate well with the minimum backstreaming proton parallel velocity p/sub min/ which, as defined here, is a purely geometrical parameter. Trivariate analysis shows that the correlation of particles and turbulence with the angle between the magnetic field and the shock normal have their sense reversed when allowance is made for the strong correlations with p/sub min/. A very good correlation has been found between power and compressibility in magnetic fluctuations

Mortality coefficients among personnel of radiochemical plants of open-quotes Mayakclose quotes-Combine for 40-year period of observation

International Nuclear Information System (INIS)

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

1993-01-01

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

Finding hidden periodic signals in time series - an application to stock prices

Science.gov (United States)

O'Shea, Michael

2014-03-01

Data in the form of time series appear in many areas of science. In cases where the periodicity is apparent and the only other contribution to the time series is stochastic in origin, the data can be `folded' to improve signal to noise and this has been done for light curves of variable stars with the folding resulting in a cleaner light curve signal. Stock index prices versus time are classic examples of time series. Repeating patterns have been claimed by many workers and include unusually large returns on small-cap stocks during the month of January, and small returns on the Dow Jones Industrial average (DJIA) in the months June through September compared to the rest of the year. Such observations imply that these prices have a periodic component. We investigate this for the DJIA. If such a component exists it is hidden in a large non-periodic variation and a large stochastic variation. We show how to extract this periodic component and for the first time reveal its yearly (averaged) shape. This periodic component leads directly to the `Sell in May and buy at Halloween' adage. We also drill down and show that this yearly variation emerges from approximately half of the underlying stocks making up the DJIA index.

Periodic auroral forms and geomagnetic field oscillations in the 1400 MLT region

International Nuclear Information System (INIS)

Potemra, T.A.; Vo, H.; Venkatesan, D.; Cogger, L.L.; Erlandson, R.E.; Zanetti, L.J.; Bythrow, P.F.; Anderson, B.J.

1990-01-01

The UV images obtained with the Viking satellite often show bright features which resemble beads or pearls aligned in the east-west direction between noon and 1800 MLT. Viking acquired a series of 25 UV images during a 28-min period on July 29, 1986, which showed a distinct series of periodic bright features in this region. Magnetic field and hot plasma measurements obtained by Viking confirm that the UV emissions are colocated with the field line projection of an upward-flowing region 1 Birkeland current and precipitating energetic (∼200 eV) electrons. The magnetic field and electric field measurements show transverse oscillations with a nearly constant period of about 3.5 min from 67 degree invariant latitude equatorward up to the location of the large-scale Birkeland current system near 76 degree invariant latitude. The electric field oscillations lead the magnetic field oscillations by about a quarter-period. The authors interpret the observed oscillations as standing Alfven waves driven at a frequency near the local resonance frequency by a large-scale wave in the boundary layer. They propose that the energy flux of the precipitating low-energy electrons in this afternoon region is modulated by this boundary wave and produces the periodic UV emission features. The results of this study support the view that large-scale oscillations of magnetospheric boundaries, possibly associated with the Kelvin-Helmholtz instability, can modulate currents, particles, and auroral forms

Periodic precursors of nonlinear dynamical transitions

International Nuclear Information System (INIS)

Jiang Yu; Dong Shihai; Lozada-Cassou, M.

2004-01-01

We study the resonant response of a nonlinear system to external periodic perturbations. We show by numerical simulation that the periodic resonance curve may anticipate the dynamical instability of the unperturbed nonlinear periodic system, at parameter values far away from the bifurcation points. In the presence of noise, the buried intrinsic periodic dynamics can be picked out by analyzing the system's response to periodic modulation of appropriate intensity

X ray spectra of X Per. [oso-8 observations

Science.gov (United States)

Becker, R. H.; Boldt, E. A.; Holt, S. S.; Pravdo, S. H.; Robinson-Saba, J.; Serlemitsos, P. J.; Swank, J. H.

1978-01-01

The cosmic X-ray spectroscopy experiment on OSO-8 observed X Per for twenty days during two observations in Feb. 1976 and Feb. 1977. The spectrum of X Per varies in phase with its 13.9 min period, hardening significantly at X-ray minimum. Unlike other X-ray binary pulsar spectra, X Per's spectra do not exhibit iron line emission or strong absorption features. The data show no evidence for a 22 hour periodicity in the X-ray intensity of X Per. These results indicate that the X-ray emission from X Per may be originating from a neutron star in a low density region far from the optically identified Be star.

Toward 2D Seismic Wavefield Monitoring: Seismic Gradiometry for Long-Period Seismogram and Short-Period Seismogram Envelope applied to the Hi-net Array

Science.gov (United States)

Maeda, T.; Nishida, K.; Takagi, R.; Obara, K.

2015-12-01

The high-sensitive seismograph network Japan (Hi-net) operated by National Research Institute for Earth Science and Disaster Prevention (NIED) has about 800 stations with average separation of 20 km. We can observe long-period seismic wave propagation as a 2D wavefield with station separations shorter than wavelength. In contrast, short-period waves are quite incoherent at stations, however, their envelope shapes resemble at neighbor stations. Therefore, we may be able to extract seismic wave energy propagation by seismogram envelope analysis. We attempted to characterize seismic waveform at long-period and its envelope at short-period as 2D wavefield by applying seismic gradiometry. We applied the seismic gradiometry to a synthetic long-period (20-50s) dataset prepared by numerical simulation in realistic 3D medium at the Hi-net station layout. Wave amplitude and its spatial derivatives are estimated by using data at nearby stations. The slowness vector, the radiation pattern and the geometrical spreading are extracted from estimated velocity, displacement and its spatial derivatives. For short-periods at shorter than 1 s, seismogram envelope shows temporal and spatial broadening through scattering by medium heterogeneity. It is expected that envelope shape may be coherent among nearby stations. Based on this idea, we applied the same method to the time-integration of seismogram envelope to estimate its spatial derivatives. Together with seismogram envelope, we succeeded in estimating the slowness vector from the seismogram envelope as well as long-period waveforms by synthetic test, without using phase information. Our preliminarily results show that the seismic gradiometry suits the Hi-net to extract wave propagation characteristics both at long and short periods. This method is appealing that it can estimate waves at homogeneous grid to monitor seismic wave as a wavefield. It is promising to obtain phase velocity variation from direct waves, and to grasp wave

Entropy method of measuring and evaluating periodicity of quasi-periodic trajectories

Science.gov (United States)

Ni, Yanshuo; Turitsyn, Konstantin; Baoyin, Hexi; Junfeng, Li

2018-06-01

This paper presents a method for measuring the periodicity of quasi-periodic trajectories by applying discrete Fourier transform (DFT) to the trajectories and analyzing the frequency domain within the concept of entropy. Having introduced the concept of entropy, analytical derivation and numerical results indicate that entropies increase as a logarithmic function of time. Periodic trajectories typically have higher entropies, and trajectories with higher entropies mean the periodicities of the motions are stronger. Theoretical differences between two trajectories expressed as summations of trigonometric functions are also derived analytically. Trajectories in the Henon-Heiles system and the circular restricted three-body problem (CRTBP) are analyzed with the indicator entropy and compared with orthogonal fast Lyapunov indicator (OFLI). The results show that entropy is a better tool for discriminating periodicity in quasiperiodic trajectories than OFLI and can detect periodicity while excluding the spirals that are judged as periodic cases by OFLI. Finally, trajectories in the vicinity of 243 Ida and 6489 Golevka are considered as examples, and the numerical results verify these conclusions. Some trajectories near asteroids look irregular, but their higher entropy values as analyzed by this method serve as evidence of frequency regularity in three directions. Moreover, these results indicate that applying DFT to the trajectories in the vicinity of irregular small bodies and calculating their entropy in the frequency domain provides a useful quantitative analysis method for evaluating orderliness in the periodicity of quasi-periodic trajectories within a given time interval.

Periodic disruptions in the MT-1 tokamak

International Nuclear Information System (INIS)

Zoletnik, S.

1988-11-01

Disruptive instabilities are common phenomena in toroidal devices, especially in tokamaks. Three types can be distinguished: internal, minor and major disruptions. Periodic minor disruptions in the MT-1 tokamak were measured systematically with values of the limiter safety factor between 4 and 10. The density limit as a function of plasma current and horizontal displacement was investigated. Precursor oscillations always appear before the instability with increasing amplitude but can be observed at the density limit with quasi-stationary amplitude. Phase correlation between precursor oscillations were measured with Mirnov coils and x-ray detectors, and they show good agreement with a simple magnetic island model. (R.P.) 11 refs.; 6 figs

Influence of storage period on properties of biopolymer packaging materials and pouches

Directory of Open Access Journals (Sweden)

Bulut Sandra N.

2017-01-01

Full Text Available Bilayer biodegradable films based on pumpkin oil cake (PuOC and zein, as well as pouches made from these materials, were prepared, and the changes of their mechanical, physicochemical and barrier properties were analyzed during four weeks of storage. Heat seal quality of formed pouches and composition of the gas atmosphere in the pouches were also monitored. The results showed that the bilayer film had a thickness of 300 ± 10 (μm, and no its changes were observed during the storage time. The tensile strength of the tested film increased slightly in the third week, but the elongation at break showed a decreasing trend during the whole storage period. The decreases in the moisture content, total soluble matter and swelling of the obtained film, were also observed. After one month of storage, the O2 transmission rate of tested films, increased from 27 to 64 (ml/m2 24h 1 bar, and the CO2 gas transmission rate from 147 to 188 (ml/m2 24h 1 bar. The heat seal strength of the PuOC/Zein pouches decreased during the whole storage period. The percentage of O2 in PuOC/Zein pouches increased up to 7 times during the storage period; however, the percentage of CO2 decreased up to 18 times already after one week, and then remained stable in the rest of the storage period. These results are, to a smaller extent, due to the gas transmission rate through the material, especially for CO2 , and to a greater extent, due to the low heat seal strength, which decreased through the storage period, and probably influenced the content of the gases in the pouches.[Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 46010

Optical observation of comets

International Nuclear Information System (INIS)

Tanabe, Hiroyoshi

1974-01-01

The observation of comets is proposed to study the state of interplanetary space. The behavior of the tails of comets shows the state of solar wind. On July 4, 1964, large bending was seen in the tail of the Tomita-Gerber-Handa comet. Then, on July 7, 1964, geomagnetic disturbance was observed. Disturbance in the tail of Kohoutek comet was seen on Jan. 19, 1974, and Ksub(p)--5 on the ground on Jan. 25. The effort for the quantitative measurement of the parameters of solar wind has been continued in various countries. Recently, the large scale observation of the Kohoutek comet was carried out in the world. Preliminary report is presented in this paper. Waving in the type 1 tail of the comet was seen, and this phenomenon may show some instability due to the interaction between the tail and the solar wind. Periodic variation of the direction of the tail has been reported. The present result also confirmed this report. In case of small comets, flare-up occurs and original luminous intensity is regained after several days. Measurement of the spectrum at the time of flare-up may show information concerning temporary variation of the state of interplanetary space. For the tracking of time variation of comets, cooperation of a number of stations at different positions is required. (Kato, T.)

Observations of TT Ari requested in support of MOST observations

Science.gov (United States)

Waagen, Elizabeth O.

2012-08-01

Dr. Nikolaus Vogt (Universidad de Valparaiso, Chile) requested simultaneous photometry and spectroscopy of the novalike (VY Scl subtype) cataclysmic variable TT Ari in support of upcoming observations with the Canadian Microvariability and Oscillations of Stars (MOST) satellite 2012 September 13 through October 20. The Departamento de Fisica y Astronomia of the Valparaiso University will carry out photometry with small telescopes in central Chile but the assistance of other observers, particularly in other latitudes and longitudes, is requested. The observations are being carried out to study superhump behavior, which is still not well understood despite the amount of research done in all classes of cataclysmic variables. TT Ari exibits superhumps - both positive (the superhump period is longer than the orbital period) and negative (the superhump period is shorter than the orbital period). While positive superhumps are thought probably to be the result of an eccentric configuration in the accretion disk, the mechanism for negative superhumps is not yet understood except that it may be related to the disk's being warped out of the orbital plane, leading to complex torque phenomena. TT Ari, one of the brightest cataclysmic variables, exhibits occasional fadings of several magnitudes, from its usual high-state (maximum) magnitude of ~10.5V to a low-state magnitude as faint as 16V. These fadings occur every 20-25 years, and last between 500 and 1000 days. According to observations in the AAVSO International Database, TT Ari is currently magnitude 10.5V. Finder charts with sequence may be created using the AAVSO Variable Star Plotter (http://www.aavso.org/vsp). Observations should be submitted to the AAVSO International Database. See full Alert Notice for more details, particularly regarding goals of the campaign, and observing instructions.

Reliability of P mode event classification using contemporaneous BiSON and GOLF observations

International Nuclear Information System (INIS)

Simoniello, R; Chaplin, W J; Elsworth, Y P; Garcia, R A

2008-01-01

We carried out a comparison of the signals seen in contemporaneous BiSON and GOLF data sets. Both instruments perform Doppler shift velocity measurements in integrated sunlight, although BiSON perform measurements from the two wings of potassium absorption line and GOLF from one wing of the NaD1 line. Discrepancies between the two datasets have been observed. We show,in fact, that the relative power depends on the wing in which GOLF data observes. During the blue wing period, the relative power is mugh higher than in BiSON datasets, while a good agreement has been observed during the red period.

Orbital periods of recurrent novae

International Nuclear Information System (INIS)

Schaefer, B.E.

1990-01-01

The class of recurrent novae (RN) with thermonuclear runaways contains only three systems (T Pyx, U Sco, and V394 CrA), for which no orbital periods are known. This paper presents a series of photometric observations where the orbital periods for all three systems are discovered. T Pyx is found to have sinusoidal modulation with an amplitude of 0.08 mag and a period of 2.3783 h (with a possible alias of 2.6403 h). U Sco is found to be an eclipsing system with an eclipse amplitude of roughly 1.5 mag and an orbital period of 1.2344 days. V394 CrA is found to have sinusoidal modulation with an amplitude of 0.5 mag and a period of 0.7577 days. Thus two out of three RN with thermonuclear runaways (or five out of six for all RN) have evolved companions. 16 refs

Holonomic systems for period mappings

Energy Technology Data Exchange (ETDEWEB)

Chen, Jingyue, E-mail: jychen@brandeis.edu [Department of Mathematics, Brandeis University, Waltham, MA 02454 (United States); Huang, An, E-mail: anhuang@math.harvard.edu [Department of Mathematics, Harvard University, Cambridge, MA 02138 (United States); Lian, Bong H., E-mail: lian@brandeis.edu [Department of Mathematics, Brandeis University, Waltham, MA 02454 (United States)

2015-09-15

Period mappings were introduced in the sixties [4] to study variation of complex structures of families of algebraic varieties. The theory of tautological systems was introduced recently [7,8] to understand period integrals of algebraic manifolds. In this paper, we give an explicit construction of a tautological system for each component of a period mapping. We also show that the D-module associated with the tautological system gives rise to many interesting vanishing conditions for period integrals at certain special points of the parameter space.

Quasi-periodic Pulse Amplitude Modulation in the Accreting Millisecond Pulsar IGR J00291+5934

Energy Technology Data Exchange (ETDEWEB)

Bult, Peter [Astrophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Doesburgh, Marieke van; Klis, Michiel van der [Anton Pannekoek Institute, University of Amsterdam, Postbus 94249, 1090 GE Amsterdam (Netherlands)

2017-08-20

We introduce a new method for analyzing the aperiodic variability of coherent pulsations in accreting millisecond X-ray pulsars (AMXPs). Our method involves applying a complex frequency correction to the time-domain light curve, allowing for the aperiodic modulation of the pulse amplitude to be robustly extracted in the frequency domain. We discuss the statistical properties of the resulting modulation spectrum and show how it can be correlated with the non-pulsed emission to determine if the periodic and aperiodic variability are coupled processes. Using this method, we study the 598.88 Hz coherent pulsations of the AMXP IGR J00291+5934 as observed with the Rossi X-ray Timing Explorer and XMM-Newton . We demonstrate that our method easily confirms the known coupling between the pulsations and a strong 8 mHz quasi-periodic oscillation (QPO) in XMM-Newton observations. Applying our method to the RXTE observations, we further show, for the first time, that the much weaker 20 mHz QPO and its harmonic are also coupled with the pulsations. We discuss the implications of this coupling and indicate how it may be used to extract new information on the underlying accretion process.

Lagrangian structures in time-periodic vortical flows

Directory of Open Access Journals (Sweden)

S. V. Kostrykin

2006-01-01

Full Text Available The Lagrangian trajectories of fluid particles are experimentally studied in an oscillating four-vortex velocity field. The oscillations occur due to a loss of stability of a steady flow and result in a regular reclosure of streamlines between the vortices of the same sign. The Eulerian velocity field is visualized by tracer displacements over a short time period. The obtained data on tracer motions during a number of oscillation periods show that the Lagrangian trajectories form quasi-regular structures. The destruction of these structures is determined by two characteristic time scales: the tracers are redistributed sufficiently fast between the vortices of the same sign and much more slowly transported into the vortices of opposite sign. The observed behavior of the Lagrangian trajectories is quantitatively reproduced in a new numerical experiment with two-dimensional model of the velocity field with a small number of spatial harmonics. A qualitative interpretation of phenomena observed on the basis of the theory of adiabatic chaos in the Hamiltonian systems is given. The Lagrangian trajectories are numerically simulated under varying flow parameters. It is shown that the spatial-temporal characteristics of the Lagrangian structures depend on the properties of temporal change in the streamlines topology and on the adiabatic parameter corresponding to the flow. The condition for the occurrence of traps (the regions where the Lagrangian particles reside for a long time is obtained.

Anomalous short period geomagnetic variations at two stations in Sri Lanka

International Nuclear Information System (INIS)

Kunaratnam, K.

1986-08-01

An analysis of the rates of change in the geomagnetic field components in the period range 20-600 sec recorded at Kondavil and Hikkaduwa, two stations in the equatorial electrojet belt near the northern and south western coasts respectively of Sri Lanka, shows anomalous variations. The results confirm induced current concentration in the Palk Strait and deflection of induced currents around the southerncoast of Sri Lanka postulated by earlier workers from observations of SSC and Bay events at Indian stations and from analogue and numerical model studies. At Kondavil, which is situated close to the geomagnetic equator, no appreciable difference in the night-time and day-time values of ΔZ/ΔH and ΔD/ΔH ratios was noticed while at Hikkaduwa, a station situated under the edge of the equatorial electrojet belt, a day-time enhancement of ΔZ/ΔH ratios was found at all periods in the observed range. An enhancement of the H component at Colombo over that at Hikkaduwa was also found at short periods, the enhancement being greater at day-time. The day-time enhancement in the ΔZ/ΔH ratios at Hikkaduwa and in the ratio of the H components at Colombo and Hikkaduwa could be due to the effect of the equatorial electrojet on the short period variations. (author)

Evaluating Surface Radiation Fluxes Observed From Satellites in the Southeastern Pacific Ocean

Science.gov (United States)

Pinker, R. T.; Zhang, B.; Weller, R. A.; Chen, W.

2018-03-01

This study is focused on evaluation of current satellite and reanalysis estimates of surface radiative fluxes in a climatically important region. It uses unique observations from the STRATUS Ocean Reference Station buoy in a region of persistent marine stratus clouds 1,500 km off northern Chile during 2000-2012. The study shows that current satellite estimates are in better agreement with buoy observations than model outputs at a daily time scale and that satellite data depict well the observed annual cycle in both shortwave and longwave surface radiative fluxes. Also, buoy and satellite estimates do not show any significant trend over the period of overlap or any interannual variability. This verifies the stability and reliability of the satellite data and should make them useful to examine El Niño-Southern Oscillation variability influences on surface radiative fluxes at the STRATUS site for longer periods for which satellite record is available.

Bias magnetic field and test period dependences of direct and converse magnetoelectric hysteresis of tri-layered magnetoelectric composite

Science.gov (United States)

Zhou, Yun; Li, Xiao-Hong; Wang, Jian-Feng; Zhou, Hao-Miao; Cao, Dan; Jiao, Zhi-Wei; Xu, Long; Li, Qi-Hao

2018-04-01

The direct and converse magnetoelectric hysteresis behavior for a tri-layered composite has been comparatively investigated and significant similarities have been observed. The results show that both the direct and converse magnetoelectric hysteresis is deeply affected by the bias magnetic field and test period. The test time hysteresis caused by a fast varying bias magnetic field can be reduced by prolonging the test period. The observed coercive field, remanence, and ratio of remanence of the direct and converse magnetoelectric effects with the test period obey an exponential decay law. A hysteretic nonlinear magnetoelectric theoretical model for the symmetrical tri-layered structure has been proposed based on a nonlinear constitutive model and pinning effect. The numerical calculation shows that the theoretical results are in good agreement with the experimental results. These findings not only provide insight into the examination and practical applications of magnetoelectric materials, but also propose a theoretical frame for studying the hysteretic characteristics of the magnetoelectric effect.

Direct observation during surgery shows preservation of cerebral microcirculation in patients with traumatic brain injury

NARCIS (Netherlands)

Pérez-Bárcena, Jon; Romay, Eduardo; Llompart-Pou, Juan Antonio; Ibáñez, Javier; Brell, Marta; Llinás, Pedro; González, Elsa; Merenda, Amedeo; Ince, Can; Bullock, Ross

2015-01-01

To describe the alterations of the cortical microcirculation of the brain (blood flow and vessel density) in TBI patients who and compare them with a control group. Prospective and observational study in a third-level university hospital. Cortical microcirculation in the brain was directly observed

PULSAR OBSERVATIONS OF EXTREME SCATTERING EVENTS

International Nuclear Information System (INIS)

Coles, W. A.; Kerr, M.; Shannon, R. M.; Hobbs, G. B.; Manchester, R. N.; Dai, S.; Ravi, V.; Reardon, D.; Toomey, L.; Zhu, X. J.; You, X.-P.; Bailes, M.; Straten, W. van; Bhat, N. D. R.; Burke-Spolaor, S.; Keith, M. J.; Levin, Y.; Osłowski, S.; Wang, J. B.; Wen, L.

2015-01-01

Extreme scattering events (ESEs) in the interstellar medium (ISM) were first observed in regular flux measurements of compact extragalactic sources. They are characterized by a flux variation over a period of weeks, suggesting the passage of a “diverging plasma lens” across the line of sight (LOS). Modeling the refraction of such a lens indicates that the structure size must be of the order of AU and the electron density of the order of 10s of cm −3 . Similar structures have been observed in measurements of pulsar intensity scintillation and group delay. Here we report observations of two ESEs, showing increases in both intensity scintillation and dispersion made with the Parkes Pulsar Timing Array. These allow us to make more complete models of the ESE, including an estimate of the “outer-scale” of the turbulence in the plasma lens. These observations clearly show that the ESE structure is fully turbulent on an AU scale. They provide some support for the idea that the structures are extended along the LOS, such as would be the case for a scattering shell. The dispersion measurements also show a variety of AU scale structures that would not be called ESEs, yet involve electron density variations typical of ESEs and likely have the same origin

Pulsar Observations of Extreme Scattering Events

Science.gov (United States)

Coles, W. A.; Kerr, M.; Shannon, R. M.; Hobbs, G. B.; Manchester, R. N.; You, X.-P.; Bailes, M.; Bhat, N. D. R.; Burke-Spolaor, S.; Dai, S.; Keith, M. J.; Levin, Y.; Osłowski, S.; Ravi, V.; Reardon, D.; Toomey, L.; van Straten, W.; Wang, J. B.; Wen, L.; Zhu, X. J.

2015-08-01

Extreme scattering events (ESEs) in the interstellar medium (ISM) were first observed in regular flux measurements of compact extragalactic sources. They are characterized by a flux variation over a period of weeks, suggesting the passage of a “diverging plasma lens” across the line of sight (LOS). Modeling the refraction of such a lens indicates that the structure size must be of the order of AU and the electron density of the order of 10s of cm-3. Similar structures have been observed in measurements of pulsar intensity scintillation and group delay. Here we report observations of two ESEs, showing increases in both intensity scintillation and dispersion made with the Parkes Pulsar Timing Array. These allow us to make more complete models of the ESE, including an estimate of the “outer-scale” of the turbulence in the plasma lens. These observations clearly show that the ESE structure is fully turbulent on an AU scale. They provide some support for the idea that the structures are extended along the LOS, such as would be the case for a scattering shell. The dispersion measurements also show a variety of AU scale structures that would not be called ESEs, yet involve electron density variations typical of ESEs and likely have the same origin.

PULSAR OBSERVATIONS OF EXTREME SCATTERING EVENTS

Energy Technology Data Exchange (ETDEWEB)

Coles, W. A. [ECE Department, University of California at San Diego, La Jolla, CA, 92093-0407 (United States); Kerr, M.; Shannon, R. M.; Hobbs, G. B.; Manchester, R. N.; Dai, S.; Ravi, V.; Reardon, D.; Toomey, L.; Zhu, X. J. [ATNF, CSIRO Astronomy and Space Science, P.O. Box 76, Epping, NSW 1710 (Australia); You, X.-P. [Southwest University, Chongqing (China); Bailes, M.; Straten, W. van [Centre for Astrophysics and Supercomputing, Swinburne University of Technology, P.O. Box 218, Hawthorn, VIC 3122 (Australia); Bhat, N. D. R. [International Centre for Radio Astronomy Research, Curtin University, Bentley, WA 6102 (Australia); Burke-Spolaor, S. [California Institute of Technology, Pasadena, 1200 E California Boulevard, CA 91125 (United States); Keith, M. J. [Jodrell Bank Centre for Astrophysics, School of Physics and Astronomy, The University of Manchester, Manchester M13 9PL (United Kingdom); Levin, Y. [Monash Center for Astrophysics, School of Physics and Astronomy, Monash University, Vic 3800 (Australia); Osłowski, S. [Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany); Wang, J. B. [Xinjiang Astronomical Observatory, Chinese Academy of Science, 150 Science 1-Street, Urumqi, Xinjiang, 830011 (China); Wen, L., E-mail: bcoles@ucsd.edu [University of Western Australia, 35 Stirling Highway, Crawley, WA 6009 (Australia)

2015-08-01

Extreme scattering events (ESEs) in the interstellar medium (ISM) were first observed in regular flux measurements of compact extragalactic sources. They are characterized by a flux variation over a period of weeks, suggesting the passage of a “diverging plasma lens” across the line of sight (LOS). Modeling the refraction of such a lens indicates that the structure size must be of the order of AU and the electron density of the order of 10s of cm{sup −3}. Similar structures have been observed in measurements of pulsar intensity scintillation and group delay. Here we report observations of two ESEs, showing increases in both intensity scintillation and dispersion made with the Parkes Pulsar Timing Array. These allow us to make more complete models of the ESE, including an estimate of the “outer-scale” of the turbulence in the plasma lens. These observations clearly show that the ESE structure is fully turbulent on an AU scale. They provide some support for the idea that the structures are extended along the LOS, such as would be the case for a scattering shell. The dispersion measurements also show a variety of AU scale structures that would not be called ESEs, yet involve electron density variations typical of ESEs and likely have the same origin.

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

Directory of Open Access Journals (Sweden)

G. P. Stiller

2012-04-01

Full Text Available An extensive observational data set, consisting of more than 10⁶ SF₆ vertical profiles from MIPAS measurements distributed over the whole globe has been condensed into monthly zonal means of mean age of air for the period September 2002 to January 2010, binned at 10° latitude and 1–2 km altitude. The data were analysed with respect to their temporal variation by fitting a regression model consisting of a constant and a linear increase term, 2 proxies for the QBO variation, sinusoidal terms for the seasonal and semi-annual variation and overtones for the correction of the shapes to the observed data set. The impact of subsidence of mesospheric SF₆-depleted air and in-mixing into non-polar latitudes on mid-latitudinal absolute age of air and its linear increase was assessed and found to be small.

The linear increase of mean age of stratospheric air was found to be positive and partly larger than the trend derived by Engel et al. (2009 for most of the Northern mid-latitudes, the middle stratosphere in the tropics, and parts of the Southern mid-latitudes, as well as for the Southern polar upper stratosphere. Multi-year decrease of age of air was found for the lowermost and the upper stratospheric tropics, for parts of Southern mid-latitudes, and for the Northern polar regions. Analysis of the amplitudes and phases of the seasonal variation shed light on the coupling of stratospheric regions to each other. In particular, the Northern mid-latitude stratosphere is well coupled to the tropics, while the Northern lowermost mid-latitudinal stratosphere is decoupled, confirming the separation of the shallow branch of the Brewer-Dobson circulation from the deep branch. We suggest an overall increased tropical upwelling, together with weakening of mixing barriers, especially in the Northern Hemisphere, as a hypothetical model to explain the observed pattern of linear multi-year increase/decrease, and amplitudes

Estimation of cortical silent period following transcranial magnetic stimulation using a computerised cumulative sum method.

Science.gov (United States)

King, Nicolas K K; Kuppuswamy, Annapoorna; Strutton, Paul H; Davey, Nick J

2006-01-15

The cortical silent period (CSP) following transcranial magnetic stimulation (TMS) of the motor cortex can be used to measure intra-cortical inhibition and changes in a number of important pathologies affecting the central nervous system. The main drawback of this technique has been the difficulty in accurately identifying the onset and offset of the cortical silent period leading to inter-observer variability. We developed an automated method based on the cumulative sum (Cusum) technique to improve the determination of the duration and area of the cortical silent period. This was compared with experienced raters and two other automated methods. We showed that the automated Cusum method reliably correlated with the experienced raters for both duration and area of CSP. Compared with the automated methods, the Cusum also showed the strongest correlation with the experienced raters. Our results show the Cusum method to be a simple, graphical and powerful method of detecting low-intensity CSP that can be easily automated using standard software.

Publication Trend of Clinical Trials with Negative Results Funded by Pharmaceutical Industries for the 2007-2012 Period

Directory of Open Access Journals (Sweden)

Evert A. Jiménez-Cotes

2015-01-01

Full Text Available Abstract: Objective: To evaluate the results of clinical trials financed by the pharmaceutical industries during the period 2007-2012 in a general medical journal. Materials and methods: We performed an observational cross sectional study where originals clinical trials financed by the pharmaceutical industry published between 2007 and 2012 in the journal The New England Journal of Medicine (http://www.nejm.org were reviewed. Trend Chi2 test was used to evaluate the results of studies over the years. A database was created with different variables, identifying the number of publications and the period of greater publishing negatives studies, as well as the medical specialty and pharmaceutical industry funding. Results: 321 clinical trials were analyzed. The Odds Ratio was calculated for each year evaluated, finding a Chi2 of linear trend in negatives studies of 2.91 with value p 0.08 and positive studies of 1.16 with value p 0.28. It was found that in the period 2007-2009 123 studies were published, 40 % of which presented negative results; unlike the 2010-2012 period in which 198 clinical trials where published, 142 of them, showed positive results, OR 1.68, 95 % CI (1.02-2.78 value p 0.03. The highest figures of negative results were published in 2007: 44.7 %. Conclusions: A progressive decrease in the number of publications with annual general negative results has been observed. A statistically significant difference in the publication of negative studies per year was not found between the periods 2007-2012. The medical specialty that showed the largest number of total and negative publications in both periods was cardiology. The pharmaceutical industry that sponsored most total clinical trials with negative results in both periods did so through Merck, Glaxo SmithKline, and Sanofi-Aventis. 50% of neurology publications showed negative results.

Dark matter as a trigger for periodic comet impacts.

Science.gov (United States)

Randall, Lisa; Reece, Matthew

2014-04-25

Although statistical evidence is not overwhelming, possible support for an approximately 35×106  yr periodicity in the crater record on Earth could indicate a nonrandom underlying enhancement of meteorite impacts at regular intervals. A proposed explanation in terms of tidal effects on Oort cloud comet perturbations as the Solar System passes through the galactic midplane is hampered by lack of an underlying cause for sufficiently enhanced gravitational effects over a sufficiently short time interval and by the time frame between such possible enhancements. We show that a smooth dark disk in the galactic midplane would address both these issues and create a periodic enhancement of the sort that has potentially been observed. Such a disk is motivated by a novel dark matter component with dissipative cooling that we considered in earlier work. We show how to evaluate the statistical evidence for periodicity by input of appropriate measured priors from the galactic model, justifying or ruling out periodic cratering with more confidence than by evaluating the data without an underlying model. We find that, marginalizing over astrophysical uncertainties, the likelihood ratio for such a model relative to one with a constant cratering rate is 3.0, which moderately favors the dark disk model. Our analysis furthermore yields a posterior distribution that, based on current crater data, singles out a dark matter disk surface density of approximately 10M⊙/pc2. The geological record thereby motivates a particular model of dark matter that will be probed in the near future.

Remote Cloud Sensing Intensive Observation Period (RCS-IOP) millimeter-wave radar calibration and data intercomparison

Energy Technology Data Exchange (ETDEWEB)

Sekelsky, S.M.; Firda, J.M.; McIntosh, R.E. [Univ. of Massachusetts, Amherst, MA (United States)] [and others

1996-04-01

During April 1994, the University of Massachusetts (UMass) and the Pennsylvania State University (Penn State) fielded two millimeter-wave atmospheric radars in the Atmospheric Radiation Measurement Remote Cloud Sensing Intensive Operation Period (RCS-IOP) experiment. The UMass Cloud Profiling Radar System (CPRS) operates simultaneously at 33.12 GHz and 94.92 GHz through a single antenna. The Penn State radar operates at 93.95 GHz and has separate transmitting and receiving antennas. The two systems were separated by approximately 75 meters and simultaneously observed a variety of cloud types at verticle incidence over the course of the experiment. This abstract presents some initial results from our calibration efforts. An absolute calibration of the UMass radar was made from radar measurements of a trihedral corner reflector, which has a known radar cross-section. A relative calibration of between the Penn State and UMass radars is made from the statistical comparison of zenith pointing measurements of low altitude liquid clouds. Attenuation is removed with the aid of radiosonde data, and the difference in the calibration between the UMass and Penn State radars is determined by comparing the ratio of 94-GHz and 95-GHz reflectivity values to a model that accounts for parallax effects of the two antennas used in the Penn State system.

Pattern of cerebral glucose metabolism on F-18 FDG brain PET during vomiting and symptom free periods in cyclic vomiting syndrome

International Nuclear Information System (INIS)

Kim, Yu Kyeong; Lee, Dong Soo; Kang, Eun Joo; Seo, Jeong Kee; Yeo, Jeong Seok; Chung, June Key; Lee, Myung Chul

2001-01-01

Cyclic Vomiting Syndrome (CVS) is characterized by recurrent, periodic, self-limiting vomiting. However, its pathogenesis is not yet established. We investigated the changes of the cerebral glucose metabolism using F-18 FDG during the vomiting attack and symptom free period in two children with CVS. FDG PET study showed the markedly increased metabolism in both temporal lobes and also in the medulla and cerebellum during the vomiting period. Also, FDG PET showed the decreased metabolism in the parieto-occipital and occipital areas during the in vomiting period. The area with decreased metabolism seemed to be related with the region showing abnormalities in EEG and perfusion SPECT studies. We expect that what we observed would be a helpful finding in clarifying the pathogenesis of the CVS

Mid-Term Quasi-Periodicities and Solar Cycle Variation of the White-Light Corona from 18.5 Years (1996.0 - 2014.5) of LASCO Observations

Science.gov (United States)

Barlyaeva, T.; Lamy, P.; Llebaria, A.

2015-07-01

We report on the analysis of the temporal evolution of the solar corona based on 18.5 years (1996.0 - 2014.5) of white-light observations with the SOHO/LASCO-C2 coronagraph. This evolution is quantified by generating spatially integrated values of the K-corona radiance, first globally, then in latitudinal sectors. The analysis considers time series of monthly values and 13-month running means of the radiance as well as several indices and proxies of solar activity. We study correlation, wavelet time-frequency spectra, and cross-coherence and phase spectra between these quantities. Our results give a detailed insight on how the corona responds to solar activity over timescales ranging from mid-term quasi-periodicities (also known as quasi-biennial oscillations or QBOs) to the long-term 11 year solar cycle. The amplitude of the variation between successive solar maxima and minima (modulation factor) very much depends upon the strength of the cycle and upon the heliographic latitude. An asymmetry is observed during the ascending phase of Solar Cycle 24, prominently in the royal and polar sectors, with north leading. Most prominent QBOs are a quasi-annual period during the maximum phase of Solar Cycle 23 and a shorter period, seven to eight months, in the ascending and maximum phases of Solar Cycle 24. They share the same properties as the solar QBOs: variable periodicity, intermittency, asymmetric development in the northern and southern solar hemispheres, and largest amplitudes during the maximum phase of solar cycles. The strongest correlation of the temporal variations of the coronal radiance - and consequently the coronal electron density - is found with the total magnetic flux. Considering that the morphology of the solar corona is also directly controlled by the topology of the magnetic field, this correlation reinforces the view that they are intimately connected, including their variability at all timescales.

Solar Rotational Periodicities and the Semiannual Variation in the Solar Wind, Radiation Belt, and Aurora

Science.gov (United States)

Emery, Barbara A.; Richardson, Ian G.; Evans, David S.; Rich, Frederick J.; Wilson, Gordon R.

2011-01-01

The behavior of a number of solar wind, radiation belt, auroral and geomagnetic parameters is examined during the recent extended solar minimum and previous solar cycles, covering the period from January 1972 to July 2010. This period includes most of the solar minimum between Cycles 23 and 24, which was more extended than recent solar minima, with historically low values of most of these parameters in 2009. Solar rotational periodicities from S to 27 days were found from daily averages over 81 days for the parameters. There were very strong 9-day periodicities in many variables in 2005 -2008, triggered by recurring corotating high-speed streams (HSS). All rotational amplitudes were relatively large in the descending and early minimum phases of the solar cycle, when HSS are the predominant solar wind structures. There were minima in the amplitudes of all solar rotational periodicities near the end of each solar minimum, as well as at the start of the reversal of the solar magnetic field polarity at solar maximum (approx.1980, approx.1990, and approx. 2001) when the occurrence frequency of HSS is relatively low. Semiannual equinoctial periodicities, which were relatively strong in the 1995-1997 solar minimum, were found to be primarily the result of the changing amplitudes of the 13.5- and 27-day periodicities, where 13.5-day amplitudes were better correlated with heliospheric daily observations and 27-day amplitudes correlated better with Earth-based daily observations. The equinoctial rotational amplitudes of the Earth-based parameters were probably enhanced by a combination of the Russell-McPherron effect and a reduction in the solar wind-magnetosphere coupling efficiency during solstices. The rotational amplitudes were cross-correlated with each other, where the 27 -day amplitudes showed some of the weakest cross-correlations. The rotational amplitudes of the > 2 MeV radiation belt electron number fluxes were progressively weaker from 27- to 5-day periods

SPECTROSCOPIC ORBITAL PERIODS FOR 29 CATACLYSMIC VARIABLES FROM THE SLOAN DIGITAL SKY SURVEY

Energy Technology Data Exchange (ETDEWEB)

Thorstensen, John R.; Taylor, Cynthia J.; Peters, Christopher S.; Skinner, Julie N. [Department of Physics and Astronomy 6127 Wilder Laboratory, Dartmouth College Hanover, NH 03755-3528 (United States); Southworth, John [Astrophysics Group Keele University Staffordshire ST5 5BG (United Kingdom); Gänsicke, Boris T. [Department of Physics University of Warwick Coventry CV4 7AL (United Kingdom)

2015-04-15

We report follow-up spectroscopy of 29 cataclysmic variables from the Sloan Digital Sky Survey (SDSS), 22 of which were discovered by SDSS and seven of which are previously known systems that were recovered in SDSS. The periods for 16 of these objects were included in the tabulation by Gänsicke et al. While most of the systems have periods less than 2 hr, only one has a period in the 80–86 minutes “spike” found by Gänsicke et al., and 11 have periods longer than 3 hr, indicating that the present sample is skewed toward longer-period, higher-luminosity objects. Seven of the objects have spectra resembling dwarf novae, but have apparently never been observed in outburst, suggesting that many cataclysmics with relatively low variability amplitude remain to be discovered. Some of the objects are notable. SDSS J07568+0858 and SDSS J08129+1911 were previously known to have deep eclipses; in addition to spectroscopy, we use archival data from the Catalina Real Time Transient Survey to refine their periods. We give a parallax-based distance of 195 (+54, −39) pc for LV Cnc (SDSS J09197+0857), which at P{sub orb} = 81 m has the shortest orbital period in our sample. SDSS J08091+3814 shows both the spectroscopic phase offset and phase-dependent absorption found in SW Sextantis stars. The average spectra of SDSS J08055+0720 and SDSS J16191+1351 show contributions from K-type secondaries, and SDSS J080440+0239 shows a contribution from an early M star. We use these to constrain the distances. SDSS J09459+2922 has characteristics typical of a magnetic system. SDSS11324+6249 may be a novalike variable, and if so, its orbital period (99 minutes) is unusually short for that subclass.

Turing patterns in parabolic systems of conservation laws and numerically observed stability of periodic waves

Science.gov (United States)

Barker, Blake; Jung, Soyeun; Zumbrun, Kevin

2018-03-01

Turing patterns on unbounded domains have been widely studied in systems of reaction-diffusion equations. However, up to now, they have not been studied for systems of conservation laws. Here, we (i) derive conditions for Turing instability in conservation laws and (ii) use these conditions to find families of periodic solutions bifurcating from uniform states, numerically continuing these families into the large-amplitude regime. For the examples studied, numerical stability analysis suggests that stable periodic waves can emerge either from supercritical Turing bifurcations or, via secondary bifurcation as amplitude is increased, from subcritical Turing bifurcations. This answers in the affirmative a question of Oh-Zumbrun whether stable periodic solutions of conservation laws can occur. Determination of a full small-amplitude stability diagram - specifically, determination of rigorous Eckhaus-type stability conditions - remains an interesting open problem.

ASASSN-16dt and ASASSN-16hg: Promising candidate period bouncers

Science.gov (United States)

Kimura, Mariko; Isogai, Keisuke; Kato, Taichi; Taguchi, Kenta; Wakamatsu, Yasuyuki; Hambsch, Franz-Josef; Monard, Berto; Myers, Gordon; Dvorak, Shawn; Starr, Peter; Brincat, Stephen M.; de Miguel, Enrique; Ulowetz, Joseph; Itoh, Hiroshi; Stone, Geoff; Nogami, Daisaku

2018-04-01

We present optical photometry of superoutbursts that occurred in 2016 of two WZ Sge-type dwarf novae (DNe), ASASSN-16dt and ASASSN-16hg. Their light curves showed a dip in brightness between the first plateau stage with no ordinary superhumps (or early superhumps) and the second plateau stage with ordinary superhumps. We find that the dip is produced by the slow evolution of the 3 : 1 resonance tidal instability and that it would likely be observed in low mass-ratio objects. An estimated mass ratio (q ≡ M2/M1) from the period of developing (stage A) superhumps [0.06420(3) d] was 0.036(2) in ASASSN-16dt. Additionally, its superoutburst has many properties similar to those in other low-q WZ Sge-type DNe: long-lasting stage-A superhumps, small superhump amplitudes, long delay of ordinary-superhump appearances, and a slow decline rate in the plateau stage with superhumps. Its very small mass ratio and observational characteristics suggest that this system is one of the best candidates for a period bouncer—a binary accounting for the missing population of post-period minimum cataclysmic variables. Although it is not clearly verified due to the lack of detection of stage-A superhumps, ASASSN-16hg might be a possible candidate for period bouncers on the basis of the morphology of its light curves and the small superhump amplitudes. Many outburst properties of period bouncer candidates would originate from the small tidal effects of their secondary stars.

R Aqr observing campaign

Science.gov (United States)

Waagen, Elizabeth O.

2016-01-01

Dr. George Wallerstein (University of Washington) has requested AAVSO coverage of the long period/symbiotic variable R Aquarii beginning immediately in support of high resolution spectroscopic observations planned for 2016 January 19 and 21. Several other astronomers, including Drs. Lee Anne Willson (Iowa State University), Ulisse Munari (INAF, Astronomical Observatory of Padua, Italy), and Fred Walter (Stony Brook University) are studying R Aqr closely and additional spectroscopic and other observations are planned for the near future. R Aqr is both a Mira (M) and a symbiotic (ZAND) - it is a close binary system consisting of a hot star and a late-type star (the Mira), both enveloped in nebulosity. As a result, the very interesting light curve shows not only the Mira pulsation but also complex eclipse behavior as the two stars interact. The period of Mira variation is 387.0 days; the eclipse period is 43.6-44 years. The cause of the eclipse is unknown; several theories h! ave been proposed, including a focused accretion stream, a disk or cloud around the secondary, and a triggered mass loss that produces an opaque cloud. Careful investigation of this upcoming event should help to resolve this question. The last eclipse of R Aqr was in 1978. The next eclipse is predicted for 2022, but may be early. The current behavior of R Aqr suggests that the eclipse, which lasts for several years, may either be beginning or its beginning may be imminent. R Aqr was at minimum in early December 2015 at magnitude V=11.4, and is currently at visual magnitude 11.0. During this phase of the approximately 44-year eclipse cycle, at maximum it may be as bright as V 6.0-6.5 but is not expected to become brighter. Beginning immediately, nightly BVRI CCD and DSLR photometry and visual observations are requested. As R Aqr brightens towards maximum and is in range, PEP observations are also requested. Ongoing spectroscopy over the next several years will be interesting to see as the system

Cephalometric standards for Slovenians in the mixed dentition period.

Science.gov (United States)

Drevensek, Martina; Farcnik, Franc; Vidmar, Gaj

2006-02-01

The aim of this study was to develop standard cephalometric values for Slovenians in the period of the mixed dentition. Eighty-eight children were included in the study (46 girls and 42 boys, mean age 9.31 +/- 1.52 years). The selection criteria were: in the mixed dentition, a score of the modified Eismann method for an objective assessment of malocclusion of less than 15 points, the absence of aplasia and supernumerary teeth, no congential anomalies and no previous orthodontic treatment. Twenty-five cephalometric measurements were performed twice to analyse the size and shape of the craniofacial complex. The reliability of the measurements was assessed by correlation coefficients, regression, and analysis of inter-subject differences; satisfactory results were obtained. The differences between boys and girls and between those in the early and late mixed dentition period were tested with a two-way analysis of variance. The most pronounced changes between the early and late mixed dentition were observed in the vertical skeletal relationships: a decrease in mandibular inclination, interbasal angle and gonial angle, and an increase in anterior and posterior face height. Sagittal skeletal relationships remained constant from the early to the late mixed dentition. No significant differences were found between the observed developmental stages. Significant differences between genders were found only for anterior and posterior face height, with boys showing larger values (P mixed dentition, the mean measurement values of the total sample can be used as cephalometric standards for Slovenians in the mixed dentition period.

Dairy cows affected by ketosis show alterations in innate immunity and lipid and carbohydrate metabolism during the dry off period and postpartum.

Science.gov (United States)

Zhang, Guanshi; Hailemariam, Dagnachew; Dervishi, Elda; Goldansaz, Seyed Ali; Deng, Qilan; Dunn, Suzanna M; Ametaj, Burim N

2016-08-01

The objective of this investigation was to search for alterations in blood variables related to innate immunity and carbohydrate and lipid metabolism during the transition period in cows affected by ketosis. One hundred multiparous Holstein dairy cows were involved in the study. Blood samples were collected at -8, -4, week of disease diagnosis (+1 to +3weeks), and +4weeks relative to parturition from 6 healthy cows (CON) and 6 cows with ketosis and were analyzed for serum variables. Results showed that cows with ketosis had greater concentrations of serum β-hydroxybutyric acid (BHBA), interleukin (IL)-6, tumor necrosis factor (TNF), serum amyloid A (SAA), and lactate in comparison with the CON animals. Serum concentrations of BHBA, IL-6, TNF, and lactate were greater starting at -8 and -4weeks prior to parturition in cows with ketosis vs those of CON group. Cows with ketosis also had lower DMI and milk production vs CON cows. Milk fat also was lower in ketotic cows at diagnosis of disease. Cows affected by ketosis showed an activated innate immunity and altered carbohydrate and lipid metabolism several weeks prior to diagnosis of disease. Serum IL-6 and lactate were the strongest discriminators between ketosis cows and CON ones before the occurrence of ketosis, which might be useful as predictive biomarkers of the disease state. Copyright © 2016 Elsevier Ltd. All rights reserved.

Long-period structures in gold-copper alloys; Structures a longues periodes dans les alliages or-cuivre

Energy Technology Data Exchange (ETDEWEB)

Jehanno, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1965-07-01

We first proceed to reevaluation of the gold-copper equilibrium diagram for alloys between Au{sub 20}Cu{sub 80} and Au{sub 65}Cu{sub 35}. The identification of the various phases was performed by X-rays diffraction on quenched polycrystalline samples. We next study the structure of the phase AuCuII. X-ray data collected from bulk single crystals show that this long-period structure must be described with the help of two correlated periodic functions: an 'order function' and a 'displacement function'. The 'order function' conciliates the non-integer value of the period with its rigorous definition. The 'displacement function' accounts for the dis-symmetries of the observed intensities for the antiphase homologous reflections as the appearance of satellites around the fundamental reflections. These two functions are remarkably well defined at long distance in carefully annealed samples and, in some conditions, can be obtained independently. We observe that the improvement of the degree of order increases the 'modulation of position'. In the case of non stoichiometric alloys, the excess of gold atoms (gold rich alloys) is distributed at random whereas the excess of copper (copper rich alloys) is distributed in a preferential manner close to the antiphase boundaries. (author) [French] Nous procedons, tout d'abord, a une reevaluation du diagramme d'equilibre des alliages or-cuivre compris entre Au{sub 20}Cu{sub 80} et Au{sub 65}Cu{sub 35}. L'identification des differentes phases s'est faite par diffraction de rayons X sur des echantillons polycristallins trempes. Nous etudions ensuite, aux rayons X, la structure de la phase AuCuII. Les donnees rassemblees sur monocristaux massifs indiquent que cette structure a longue periode doit etre decrite a l'aide de deux fonctions periodiques correlees: une fonction d'ordre et une fonction de deplacement des atomes. La fonction d'ordre concilie le caractere non entier de la periode avec sa rigoureuse definition. La fonction de

Satellite-derived SIF and CO2 Observations Show Coherent Responses to Interannual Climate Variations

Science.gov (United States)

Butterfield, Z.; Hogikyan, A.; Kulawik, S. S.; Keppel-Aleks, G.

2017-12-01

Gross primary production (GPP) is the single largest carbon flux in the Earth system, but its sensitivity to changes in climate is subject to significant uncertainty. Satellite measurements of solar-induced chlorophyll fluorescence (SIF) offer insight into spatial and temporal patterns in GPP at a global scale and, combined with other satellite-derived datasets, provide unprecedented opportunity to explore interactions between atmospheric CO2, GPP, and climate variability. To explore potential drivers of GPP in the Northern Hemisphere (NH), we compare monthly-averaged SIF data from the Global Ozone Monitoring Experiment 2 (GOME-2) with observed anomalies in temperature (T; CRU-TS), liquid water equivalent (LWE) from the Gravity Recovery and Climate Experiment (GRACE), and photosynthetically active radiation (PAR; CERES SYN1deg). Using observations from 2007 through 2015 for several NH regions, we calculate month-specific sensitivities of SIF to variability in T, LWE, and PAR. These sensitivities provide insight into the seasonal progression of how productivity is affected by climate variability and can be used to effectively model the observed SIF signal. In general, we find that high temperatures are beneficial to productivity in the spring, but detrimental in the summer. The influences of PAR and LWE are more heterogeneous between regions; for example, higher LWE in North American temperate forest leads to decreased springtime productivity, while exhibiting a contrasting effect in water-limited regions. Lastly, we assess the influence of variations in terrestrial productivity on atmospheric carbon using a new lower tropospheric CO2 product derived from the Greenhouse Gases Observing Satellite (GOSAT). Together, these data shed light on the drivers of interannual variability in the annual cycle of NH atmospheric CO2, and may provide improved constraints on projections of long-term carbon cycle responses to climate change.

Heat waves and warm periods in Slovakia

Science.gov (United States)

Faško, Pavel; Bochníček, Oliver; Markovič, Ladislav; Švec, Marek

2016-04-01

The scenarios of climate change caused by human activity show that frequency of occurrence and extent of heat waves in the interior of Europe is increasing. Among the most exposed regions in this regard should the area of southeastern and eastern Austria and south-western Slovakia. The relatively faster increase in the number of heat waves in this area is related also to potential desertification in this region just east of the Alps, since during summer, weather fronts advancing from the west are consequently losing their original features and moderating influence. Summer weather patterns for this area should in the future more closely remind climate typical for some inland areas of southwestern, southern and southeastern Europe. A certain shift of climate zones from south to north should thus modify future climate and Slovakia. Despite the complex natural conditions the existing trends derived from results of meteorological measurements and observations are clear and they confirm warming of climate in this region. Observations and measurements in the recent years of the 21st century confirm, that heat waves are no longer rare phenomenon during summer, but are systematically appearing even in colder regions of northern Slovakia. What is very remarkable and will be necessary to pay more attention to, is the fact that these heat waves are expanding into previously unaffected areas, associated with the lack of rainfall and drought, on larger regional scale. In this study heat wave periods and individual heat events and days are statistically identified in the time series characteristics of air temperature at selected meteorological stations for the period from the mid-20th century until 2015, in case of available historical data even for longer period.

Quasi-periodic recurrence of large earthquakes on the southern San Andreas fault

Science.gov (United States)

Scharer, Katherine M.; Biasi, Glenn P.; Weldon, Ray J.; Fumal, Tom E.

2010-01-01

It has been 153 yr since the last large earthquake on the southern San Andreas fault (California, United States), but the average interseismic interval is only ~100 yr. If the recurrence of large earthquakes is periodic, rather than random or clustered, the length of this period is notable and would generally increase the risk estimated in probabilistic seismic hazard analyses. Unfortunately, robust characterization of a distribution describing earthquake recurrence on a single fault is limited by the brevity of most earthquake records. Here we use statistical tests on a 3000 yr combined record of 29 ground-rupturing earthquakes from Wrightwood, California. We show that earthquake recurrence there is more regular than expected from a Poisson distribution and is not clustered, leading us to conclude that recurrence is quasi-periodic. The observation of unimodal time dependence is persistent across an observationally based sensitivity analysis that critically examines alternative interpretations of the geologic record. The results support formal forecast efforts that use renewal models to estimate probabilities of future earthquakes on the southern San Andreas fault. Only four intervals (15%) from the record are longer than the present open interval, highlighting the current hazard posed by this fault.

Slow-light dynamics in nonlinear periodic waveguides couplers

DEFF Research Database (Denmark)

Sukhorukov, A.A.; Ha, S.; Powell, D.A.

2009-01-01

We predict pulse switching and reshaping through nonlinear mixing of two slow-light states with different phase velocities in the same frequency range, and report on the first experimental observation of slow-light tunneling between coupled periodic waveguides.......We predict pulse switching and reshaping through nonlinear mixing of two slow-light states with different phase velocities in the same frequency range, and report on the first experimental observation of slow-light tunneling between coupled periodic waveguides....

Daytime descending intermediate layers observed over a sub-tropical Indian station Waltair during low-solar activity period

Directory of Open Access Journals (Sweden)

K. Niranjan

2010-03-01

Full Text Available Study on daytime descending intermediate layer over subtropical Indian station Waltair (17.7° N, 83.3° E geographic, 6.4° N, 10° E geomagnetic, 20° N dip located in the equatorial anomaly transition region, using an IPS 42 Digital Ionosonde during the low solar activity year 2004 showed that the layers occur in the altitude range of 140–160 km with maximum occurrence during winter solstice. The layers observed during daytime occur with a double peak variation throughout the year with less occurrence probability and shorter duration presence during forenoon hours. The morning layer descent was associated with a density increase where as during afternoon hours a decrease in density was observed. The downward drift velocity was about 8 km/h during morning hours and between 7–11 km/h during afternoon hours, with a low descent rate of around 4.5 km/h during summer morning hours. The results indicate the presence of a 6 h tide at this location as observed from the characteristics of the descending layers, unlike at majority of locations where a significant semi diurnal trend is observed. The study brings out the complex nature of the tidal interaction at different locations.

Evolution of periodicity in periodical cicadas.

Science.gov (United States)

Ito, Hiromu; Kakishima, Satoshi; Uehara, Takashi; Morita, Satoru; Koyama, Takuya; Sota, Teiji; Cooley, John R; Yoshimura, Jin

2015-09-14

Periodical cicadas (Magicicada spp.) in the USA are famous for their unique prime-numbered life cycles of 13 and 17 years and their nearly perfectly synchronized mass emergences. Because almost all known species of cicada are non-periodical, periodicity is assumed to be a derived state. A leading hypothesis for the evolution of periodicity in Magicicada implicates the decline in average temperature during glacial periods. During the evolution of periodicity, the determinant of maturation in ancestral cicadas is hypothesized to have switched from size dependence to time (period) dependence. The selection for the prime-numbered cycles should have taken place only after the fixation of periodicity. Here, we build an individual-based model of cicadas under conditions of climatic cooling to explore the fixation of periodicity. In our model, under cold environments, extremely long juvenile stages lead to extremely low adult densities, limiting mating opportunities and favouring the evolution of synchronized emergence. Our results indicate that these changes, which were triggered by glacial cooling, could have led to the fixation of periodicity in the non-periodical ancestors.

Periodic patterning of silicon by direct nanosecond laser interference ablation

International Nuclear Information System (INIS)

Tavera, T.; Pérez, N.; Rodríguez, A.; Yurrita, P.; Olaizola, S.M.; Castaño, E.

2011-01-01

The production of periodic structures in silicon wafers by four-beam is presented. Because laser interference ablation is a single-step and cost-effective process, there is a great technological interest in the fabrication of these structures for their use as antireflection surfaces. Three different laser fluences are used to modify the silicon surface (0.8 J cm -2 , 1.3 J cm -2 , 2.0 J cm -2 ) creating bumps in the rim of the irradiated area. Laser induced periodic surface structures (LIPSS), in particular micro and nano-ripples, are also observed. Measurements of the reflectivity show a decrease in the reflectance for the samples processed with a laser fluence of 2.0 J cm -2 , probably caused by the appearance of the nano-ripples in the structured area, while bumps start to deteriorate.

Periodic and stochastic thermal modulation of protein folding kinetics.

Science.gov (United States)

Platkov, Max; Gruebele, Martin

2014-07-21

Chemical reactions are usually observed either by relaxation of a bulk sample after applying a sudden external perturbation, or by intrinsic fluctuations of a few molecules. Here we show that the two ideas can be combined to measure protein folding kinetics, either by periodic thermal modulation, or by creating artificial thermal noise that greatly exceeds natural thermal fluctuations. We study the folding reaction of the enzyme phosphoglycerate kinase driven by periodic temperature waveforms. As the temperature waveform unfolds and refolds the protein, its fluorescence color changes due to FRET (Förster resonant Energy Transfer) of two donor/acceptor fluorophores labeling the protein. We adapt a simple model of periodically driven kinetics that nicely fits the data at all temperatures and driving frequencies: The phase shifts of the periodic donor and acceptor fluorescence signals as a function of driving frequency reveal reaction rates. We also drive the reaction with stochastic temperature waveforms that produce thermal fluctuations much greater than natural fluctuations in the bulk. Such artificial thermal noise allows the recovery of weak underlying signals due to protein folding kinetics. This opens up the possibility for future detection of a stochastic resonance for protein folding subject to noise with controllable amplitude.

Diffraction Theory and Almost Periodic Distributions

Science.gov (United States)

Strungaru, Nicolae; Terauds, Venta

2016-09-01

We introduce and study the notions of translation bounded tempered distributions, and autocorrelation for a tempered distribution. We further introduce the spaces of weakly, strongly and null weakly almost periodic tempered distributions and show that for weakly almost periodic tempered distributions the Eberlein decomposition holds. For translation bounded measures all these notions coincide with the classical ones. We show that tempered distributions with measure Fourier transform are weakly almost periodic and that for this class, the Eberlein decomposition is exactly the Fourier dual of the Lebesgue decomposition, with the Fourier-Bohr coefficients specifying the pure point part of the Fourier transform. We complete the project by looking at few interesting examples.

Can oscillating physics explain an apparently periodic universe?

International Nuclear Information System (INIS)

Hill, C.T.; Steinhardt, P.J.; Turner, M.S.; Chicago Univ., IL; Fermi National Accelerator Lab., Batavia, IL

1990-01-01

Recently, Broadhurst et al. have reported an apparent periodicity in a north-south pencil-beam red-shift survey of galaxies. We consider whether the periodicity may be an illusion caused by the oscillations of physical constants. Should the periodicity be disproven by subsequent observations, the same analysis can be used to derive new, stringent limits on the variations of physical constants. (orig.)

Pulsation properties of Mira long period variables

International Nuclear Information System (INIS)

Cahn, J.H.

1980-01-01

A matter of great interest to variable star students concerns the mode of pulsation of Mira long period variables. In this report we first give observational evidence for the pulsation constant Q. We then compare the observations with calculations. Next, we review two interesting groups of papers dealing with hydrodynamic properties of long period variables. In the first, a fully dynamic nonlinear calculation maps out the Mira instability domain. In the second, special attention is paid to shock propagation beyond the photosphere which in large measure accounts for the complex spectra from this region. (orig./WL)

Biliary atresia: evaluation on two distinct periods at a reference pediatric service.

Science.gov (United States)

Queiroz, Thais Costa Nascentes; Ferreira, Alexandre Rodrigues; Fagundes, Eleonora Druve Tavares; Roquete, Mariza Leitão Valadares; Penna, Francisco José

2014-01-01

Biliary atresia is a progressive, idiopathic, fibro-obliterative disease of the extrahepatic biliary tree that presents with biliary obstruction exclusively in the neonatal period. To assess the differences regarding age at referral, age at surgery, duration of propaedeutics and waiting time for surgery between two groups of infants in different periods. Retrospective study of infants diagnosed with biliary atresia on two periods: 1983-1993 and 1998-2011. Biliary atresia was diagnosed in 129 infants, being 48 in casuistic I and 81 in casuistic II. The median age at admission was 94 and 60 days, respectively (P = 0.0001). On evaluating patients who had undergone portoenterostomy before 120 days of age, no difference was observed regarding the duration of propaedeutics or waiting time for surgery (P = 0.15), but difference was found when comparing the age at surgery (P = 0.002). Among those infants with no biliary flow and without liver transplantation or death after 18 post-operative months, the estimated probability of survival was 44.6% and 38.7% in casuistics I and II, respectively. In casuistic I, all infants who showed biliary flow were alive during the observation period and, in casuistic II, 80.3% were alive after 7 years of follow-up. Even though patients were admitted and treated earlier, it is clear that surgery could be done sooner. Delay in referral and timely propaedeutics were the main contributors.

Quasi-periodic Pulsations in the Most Powerful Solar Flare of Cycle 24

Science.gov (United States)

Kolotkov, Dmitrii Y.; Pugh, Chloe E.; Broomhall, Anne-Marie; Nakariakov, Valery M.

2018-05-01

Quasi-periodic pulsations (QPPs) are common in solar flares and are now regularly observed in stellar flares. We present the detection of two different types of QPP signals in the thermal emission light curves of the X9.3-class solar flare SOL2017-09-06T12:02, which is the most powerful flare of Cycle 24. The period of the shorter-period QPP drifts from about 12 to 25 s during the flare. The observed properties of this QPP are consistent with a sausage oscillation of a plasma loop in the flaring active region. The period of the longer-period QPP is about 4 to 5 minutes. Its properties are compatible with standing slow magnetoacoustic oscillations, which are often detected in coronal loops. For both QPP signals, other mechanisms such as repetitive reconnection cannot be ruled out, however. The studied solar flare has an energy in the realm of observed stellar flares, and the fact that there is evidence of a short-period QPP signal typical of solar flares along with a long-period QPP signal more typical of stellar flares suggests that the different ranges of QPP periods typically observed in solar and stellar flares is likely due to observational constraints, and that similar physical processes may be occurring in solar and stellar flares.

Microprocessor controlled digital period meter

International Nuclear Information System (INIS)

Keefe, D.J.; McDowell, W.P.; Rusch, G.K.

1980-01-01

A microprocessor controlled digital period meter has been developed and tested operationally on a reactor at Argonne National Laboratory. The principle of operation is the mathematical relationship between asymptotic periods and pulse counting circuitry. This relationship is used to calculate and display the reactor periods over a range of /plus or minus/1 second to /plus or minus/999 seconds. The time interval required to update each measurement automatically varies from 8 seconds at the lowest counting rates to 2 seconds at higher counting rates. The paper will describe hardware and software design details and show the advantages of this type of Period Meter over the conventional circuits. 1 ref

Multi-band photometric study of the short-period eclipsing binary GR Boo

Science.gov (United States)

Wang, Daimei; Zhang, Liyun; Han, Xianming L.; Lu, Hongpeng

2017-05-01

We present BVRI light curves with complete phase coverage for the short-period (p = 0.377day) eclipsing binary star GR Boo. We carried out the observations using the SARA 90 cm telescope located at Kitt Peak National Observatory. We obtained six new light curve minimum times. By fitting all of the available O-C minimum times, we obtained an updated ephemeris that shows the orbital period of GR Boo is decreasing at a rate of P˙ = - 2.36 ×10-7 days/year. This decrease in its period can be explained by either mass transfer from the more massive component to the less massive one, or angular momentum exchange due to magnetic activities. We also obtained a set of revised orbital parameters using the Wilson & Devinney program. And finally, we concluded that GR Boo is a contact binary with a dark spot.

Circatrigintan instead of lunar periodicity of larval release in a brooding coral species.

Science.gov (United States)

Linden, Bart; Huisman, Jef; Rinkevich, Baruch

2018-04-04

Larval release by brooding corals is often assumed to display lunar periodicity. Here, we show that larval release of individual Stylophora pistillata colonies does not comply with the assumed tight entrainment by the lunar cycle, and can better be classified as a circatrigintan pattern. The colonies exhibited three distinct reproductive patterns, characterized by short intervals, long intervals and no periodicity between reproductive peaks, respectively. Cross correlation between the lunar cycle and larval release of the periodic colonies revealed an approximately 30-day periodicity with a variable lag of 5 to 10 days after full moon. The observed variability indicates that the lunar cycle does not provide a strict zeitgeber. Other factors such as water temperature and solar radiation did not correlate significantly with the larval release. The circatrigintan patterns displayed by S. pistillata supports the plasticity of corals and sheds new light on discussions on the fecundity of brooding coral species.

Results of Joint Observations of Jupiter's Atmosphere by Juno and a Network of Earth-Based Observing Stations

Science.gov (United States)

Orton, G. S.; Momary, T.; Tabataba-Vakili, F.; Bolton, S.; Levin, S.; Adriani, A.; Gladstone, G. R.; Hansen, C. J.; Janssen, M.

2017-09-01

Well over sixty investigator/instrument investigations are actively engaged in the support of the Juno mission. These observations range from X-ray to the radio wavelengths and involve both space- and ground-based astronomical facilities. These observations enhance and expand Juno measurements by (1) providing a context that expands the area covered by often narrow spatial coverage of Juno's instruments, (2) providing a temporal context that shows how phenomena evolve over Juno's 53-day orbit period, (3) providing observations in spectral ranges not covered by Juno's instruments, and (4) monitoring the behavior of external influences to Jupiter's magnetosphere. Intercommunication between the Juno scientists and the support program is maintained by reference to a Google table that describes the observation and its current status, as well as by occasional group emails. A non-interactive version of this invitation-only site is mirrored in a public site. Several sets of these supporting observations are described at this meeting.

Scaling Limit of Symmetric Random Walk in High-Contrast Periodic Environment

Science.gov (United States)

Piatnitski, A.; Zhizhina, E.

2017-11-01

The paper deals with the asymptotic properties of a symmetric random walk in a high contrast periodic medium in Z^d, d≥1. From the existing homogenization results it follows that under diffusive scaling the limit behaviour of this random walk need not be Markovian. The goal of this work is to show that if in addition to the coordinate of the random walk in Z^d we introduce an extra variable that characterizes the position of the random walk inside the period then the limit dynamics of this two-component process is Markov. We describe the limit process and observe that the components of the limit process are coupled. We also prove the convergence in the path space for the said random walk.

This research is to study the factors which influence the business success of small business ‘processed rotan’. The data employed in the study are primary data within the period of July to August 2013, 30 research observations through census method. Method of analysis used in the study is multiple linear regressions. The results of analysis showed that the factors of labor, innovation and promotion have positive and significant influence on the business success of small business ‘processed rotan’ simultaneously. The analysis also showed that partially labor has positive and significant influence on the business success, yet innovation and promotion have insignificant and positive influence on the business success.

OpenAIRE

Nasution, Inggrita Gusti Sari; Muchtar, Yasmin Chairunnisa

2013-01-01

This research is to study the factors which influence the business success of small business ‘processed rotan’. The data employed in the study are primary data within the period of July to August 2013, 30 research observations through census method. Method of analysis used in the study is multiple linear regressions. The results of analysis showed that the factors of labor, innovation and promotion have positive and significant influence on the business success of small busine...

Economic comparison of a sixty day dry period with no dry period on Dutch dairy farms

NARCIS (Netherlands)

Heeren, J.A.H.; Steeneveld, W.; Berentsen, P.B.M.

2014-01-01

In the Netherlands it is general practice that dairy cows have a dry period of six to eight weeks. Research, however, shows that omission of the dry period avoids the negative energy balance after calving with its potential negative effects on metabolic disorders, infectious diseases, and fertility.

An Iberian climatology of solar radiation obtained from WRF regional climate simulations for 1950-2010 period

Science.gov (United States)

Perdigão, João; Salgado, Rui; Magarreiro, Clarisse; Soares, Pedro M. M.; Costa, Maria João; Dasari, Hari Prasad

2017-12-01

The mesoscale Weather Research and Forecasting (WRF) Model is used over the Iberian Peninsula to generate 60 years (1950-2010) of climate data, at 5 km resolution, in order to evaluate and characterize the incident shortwave downward radiation at the surface (SW ↓), in present climate. The simulated values of SW ↓ in the period 2000-2009 were compared with data measured in Spanish and Portuguese meteorological stations before and a statistical BIAS correction was applied using data from Clouds and the Earth's Radiant Energy System (CERES), on board four different satellites. The spatial and temporal comparison between WRF results and observations show a good agreement for the analyzed period, although the model overestimates observations. This overestimation has a mean normalized bias of about 7% after BIAS correction (or 17% for original WRF output). Additionally, the present simulation was confronted against another previously validated WRF simulation performed with different resolution and set of parametrizations, showing comparable results. WRF adequately reproduces the observational features of SW ↓ with correlation coefficients above 0.8 in annual and seasonal basis. 60 years of simulated SW ↓ over the Iberian Peninsula were produced, which showed annual mean values that range from 130 W/m2, in the northern regions, to a maximum of around 230 W/m2 in the southeast of the Iberian Peninsula (IP). SW ↓ over IP shows a positive gradient from north to south and from west to east, with local effects influenced by topography and distance to the coast. The analysis of the simulated cloud fraction indicates that clear sky days are found in > 30% of the period at the southern area of IP, particularly in the Algarve (Portugal) and Andalusia (Spain), and this value increases significantly in the summer season for values above 80%.

Hydrological long-term dry and wet periods in the Xijiang River basin, South China

Directory of Open Access Journals (Sweden)

T. Fischer

2013-01-01

Full Text Available In this study, hydrological long-term dry and wet periods are analyzed for the Xijiang River basin in South China. Daily precipitation data of 118 stations and data on daily discharge at Gaoyao hydrological station at the mouth of the Xijiang River for the period 1961–2007 are used. At a 24-month timescale, the standardized precipitation index (SPI-24 for the six sub-basins of the Xijiang River and the standardized discharge index (SDI-24 for Gaoyao station are applied. The monthly values of the SPI-24 averaged for the Xijiang River basin correlate highly with the monthly values of the SDI-24. Distinct long-term dry and wet sequences can be detected.

The principal component analysis is applied and shows spatial disparities in dry and wet periods for the six sub-basins. The correlation between the SPI-24 of the six sub-basins and the first principal component score shows that 67% of the variability within the sub-basins can be explained by dry and wet periods in the east of the Xijiang River basin. The spatial dipole conditions (second and third principal component explain spatiotemporal disparities in the variability of dry and wet periods. All sub-basins contribute to hydrological dry periods, while mainly the northeastern sub-basins cause wet periods in the Xijiang River. We can also conclude that long-term dry events are larger in spatial extent and cover all sub-basins while long-term wet events are regional phenomena.

A spectral analysis is applied for the SPI-24 and the SDI-24. The results show significant peaks in periodicities of 11–14.7 yr, 2.8 yr, 3.4–3.7 yr, and 6.3–7.3 yr. The same periodic cycles can be found in the SPI-24 of the six sub-basins but with some variability in the mean magnitude. A wavelet analysis shows that significant periodicities have been stable over time since the 1980s. Extrapolations of the reconstructed SPI-24 and SDI-24 represent the continuation of observed significant periodicities

Handgun waiting periods reduce gun deaths.

Science.gov (United States)

Luca, Michael; Malhotra, Deepak; Poliquin, Christopher

2017-11-14

Handgun waiting periods are laws that impose a delay between the initiation of a purchase and final acquisition of a firearm. We show that waiting periods, which create a "cooling off" period among buyers, significantly reduce the incidence of gun violence. We estimate the impact of waiting periods on gun deaths, exploiting all changes to state-level policies in the Unites States since 1970. We find that waiting periods reduce gun homicides by roughly 17%. We provide further support for the causal impact of waiting periods on homicides by exploiting a natural experiment resulting from a federal law in 1994 that imposed a temporary waiting period on a subset of states. Copyright © 2017 the Author(s). Published by PNAS.

Period Changes of 23 Field RR Lyrae Stars

Directory of Open Access Journals (Sweden)

Soo-Chang Rey

1994-12-01

Full Text Available The secular period behavior of 23 field RR Lyrae stars is studied in order to determine if the observed period changes could be attributed, at least in the mean, to stellar evolution. The sample of stars is subdivided into two Oosterhoff groups based on the metallicity and period-shift. Despite the small sample size, we found a distinct bias toward positive period changes in the group variables. The period changes of the group variables in globular clusters. This provides yet another support for the Lee, Demarque, and Zinn(1990 evolutionary models of RR Lyrae stars and their explanation of the Sandage period-shift effect.

Periodic Density Structures and the Origin of the Slow Solar Wind

Science.gov (United States)

Viall-Kepko, Nicholeen M.; Vourlidas, Angelos

2015-01-01

The source of the slow solar wind has challenged scientists for years. Periodic density structures (PDSs), observed regularly in the solar wind at 1 AU (Astronomical Unit), can be used to address this challenge. These structures have length scales of hundreds to several thousands of megameters and frequencies of tens to hundreds of minutes. Two lines of evidence indicate that PDSs are formed in the solar corona as part of the slow solar wind release and/or acceleration processes. The first is corresponding changes in compositional data in situ, and the second is PDSs observed in the inner Heliospheric Imaging data on board the Solar Terrestrial Relations Observatory (STEREO)/Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI) suite. The periodic nature of these density structures is both a useful identifier as well as an important physical constraint on their origin. In this paper, we present the results of tracking periodic structures identified in the inner Heliospheric Imager in SECCHI back in time through the corresponding outer coronagraph (COR2) images. We demonstrate that the PDSs are formed around or below 2.5 solar radii-the inner edge of the COR2 field of view. We compute the occurrence rates of PDSs in 10 days of COR2 images both as a function of their periodicity and location in the solar corona, and we find that this set of PDSs occurs preferentially with a periodicity of approximately 90 minutes and occurs near streamers. Lastly, we show that their acceleration and expansion through COR2 is self-similar, thus their frequency is constant at distances beyond 2.5 solar radii.

Observations and modeling of post-midnight uplifts near the magnetic equator

Directory of Open Access Journals (Sweden)

M. J. Nicolls

2006-07-01

Full Text Available We report here on post-midnight uplifts near the magnetic equator. We present observational evidence from digital ionosondes in Brazil, a digisonde in Peru, and other measurements at the Jicamarca Radio Observatory that show that these uplifts occur fairly regularly in the post-midnight period, raising the ionosphere by tens of kilometers in the most mild events and by over a hundred kilometers in the most severe events. We show that in general the uplifts are not the result of a zonal electric field reversal, and demonstrate instead that the uplifts occur as the ionospheric response to a decreasing westward electric field in conjunction with sufficient recombination and plasma flux. The decreasing westward electric field may be caused by a change in the wind system related to the midnight pressure bulge, which is associated with the midnight temperature maximum. In order to agree with observations from Jicamarca and Palmas, Brazil, it is shown that there must exist sufficient horizontal plasma flux associated with the pressure bulge. In addition, we show that the uplifts may be correlated with a secondary maximum in the spread-F occurrence rate in the post-midnight period. The uplifts are strongly seasonally dependent, presumably according to the seasonal dependence of the midnight pressure bulge, which leads to the necessary small westward field in the post-midnight period during certain seasons. We also discuss the enhancement of the uplifts associated with increased geomagnetic activity, which may be related to disturbance dynamo winds. Finally, we show that it is possible using simple numerical techniques to estimate the horizontal plasma flux and the vertical drift velocity from electron density measurements in the post-midnight period.

May flood-poor periods be more dangerous than flood-rich periods?

Science.gov (United States)

Salinas, Jose Luis; Di Baldassarre, Giuliano; Viglione, Alberto; Kuil, Linda; Bloeschl, Guenter

2014-05-01

River floods are among the most devastating natural hazards experienced by populations that, since the earliest recorded civilisations, have settled in floodplains because they offer favourable conditions for trade, agriculture, and economic development. The occurrence of a flood may cause loss of lives and tremendous economic damages and, therefore, is rightly seen as a very negative event by the communities involved. Occurrence of many floods in a row is, of course, even more frustrating and is rightly considered a unbearable calamity. Unfortunately, the occurrence of many floods in a limited number of consecutive years is not unusual. In many places in the world, it has been observed that extreme floods do not arrive randomly but cluster in time into flood-poor and flood-rich periods consistent with the Hurst effect. If this is the case, when are the people more in danger? When should people be more scared? In flood-poor or flood-rich periods? In this work, a Socio-Hydrology model (Di Baldassarre et al., 2013; Viglione et al., 2014) is used to show that, maybe counter-intuitively, flood-poor periods may be more dangerous than flood-rich periods. The model is a conceptualisation of a hypothetical setting of a city at a river where a community evolves, making choices between flood management options on the floodplain. The most important feedbacks between the economic, political, technological and hydrological processes of the evolution of that community are represented in the model. In particular, the model also accounts in a dynamic way for the evolution of the the community awareness to flood risk. Occurrence of floods tends to increase peoples' recognition that their property is in an area that is potentially at risk of flooding, both at the scales of individuals and communities, which is one of the main reasons why flood coping actions are taken. It is shown through examples that frequent flood events may result in moderate damages because they ensure that the

ACTIVITY OF 50 LONG-PERIOD COMETS BEYOND 5.2 au

Energy Technology Data Exchange (ETDEWEB)

Sárneczky, K.; Szabó, Gy. M.; Csák, B.; Kelemen, J.; Pál, A.; Szakáts, R.; Szegedi-Elek, E.; Vida, K.; Vinkó, J.; Kiss, L. L. [Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Hungarian Academy of Sciences, H-1121 Budapest, Konkoly Thege Miklós út 15-17 (Hungary); Marschalkó, G. [Eötvös Loránd Tudományegyetem, H-1117 Pázmány Péter sétány 1/A, Budapest (Hungary); Szalai, T. [Department of Optics and Quantum Electronics, University of Szeged, H-6720 Szeged, Dóm tér 9 (Hungary); Székely, P. [Department of Experimental Physics, University of Szeged, Szeged H-6720, Dóm tér 9 (Hungary)

2016-12-01

Remote investigations of ancient matter in the solar system have traditionally been carried out through observations of long-period (LP) comets, which are less affected by solar irradiation than their short-period counterparts orbiting much closer to the Sun. Here we summarize the results of our decade-long survey of the distant activity of LP comets. We found that the most important separation in the data set is based on the dynamical nature of the objects. Dynamically new comets are characterized by a higher level of activity on average: the most active new comets in our sample can be characterized by Afρ values >3–4, higher than those for our most active returning comets. New comets develop more symmetric comae, suggesting a generally isotropic outflow. In contrast to this, the comae of recurrent comets can be less symmetrical, ocassionally exhibiting negative slope parameters, which suggest sudden variations in matter production. The morphological appearance of the observed comets is rather diverse. A surprisingly large fraction of the comets have long, tenuous tails, but the presence of impressive tails does not show a clear correlation with the brightness of the comets.

ACTIVITY OF 50 LONG-PERIOD COMETS BEYOND 5.2 au

International Nuclear Information System (INIS)

Sárneczky, K.; Szabó, Gy. M.; Csák, B.; Kelemen, J.; Pál, A.; Szakáts, R.; Szegedi-Elek, E.; Vida, K.; Vinkó, J.; Kiss, L. L.; Marschalkó, G.; Szalai, T.; Székely, P.

2016-01-01

Remote investigations of ancient matter in the solar system have traditionally been carried out through observations of long-period (LP) comets, which are less affected by solar irradiation than their short-period counterparts orbiting much closer to the Sun. Here we summarize the results of our decade-long survey of the distant activity of LP comets. We found that the most important separation in the data set is based on the dynamical nature of the objects. Dynamically new comets are characterized by a higher level of activity on average: the most active new comets in our sample can be characterized by Afρ values >3–4, higher than those for our most active returning comets. New comets develop more symmetric comae, suggesting a generally isotropic outflow. In contrast to this, the comae of recurrent comets can be less symmetrical, ocassionally exhibiting negative slope parameters, which suggest sudden variations in matter production. The morphological appearance of the observed comets is rather diverse. A surprisingly large fraction of the comets have long, tenuous tails, but the presence of impressive tails does not show a clear correlation with the brightness of the comets.

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

Science.gov (United States)

Banaszkiewicz, Zbigniew; Woda, Łukasz P; Zwoliński, Tomasz; Tojek, Krzysztof; Jarmocik, Paweł; Jawień, Arkadiusz

2015-01-01

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

Phonon heat transport through periodically stubbed waveguides

International Nuclear Information System (INIS)

Li Wenxia; Chen Keqiu

2006-01-01

We investigate the acoustic phonon band structure, transmission spectrum and thermal conductance in a periodically stubbed waveguide structure by use of the transfer matrix method and the scattering matrix method. We find that the existence of stop-frequencies or dips in the transmission spectrum, which corresponds to the stop bands or gaps in the acoustic band structure. The dependence of the stop band width and the dip width on the stub height is also demonstrated. We also find that the universal quantum thermal conductance can be clearly observed and the thermal conductance increases monotonically with increasing temperature. Our results show that the acoustic phonon band structure, transmission spectrum and thermal conductance can be artificially controlled by adjusting the height of the stub

Day-to-day thermosphere parameter variation as deduced from Millstone Hill incoherent scatter radar observations during March 16-22, 1990 magnetic storm period

Directory of Open Access Journals (Sweden)

A. V. Mikhailov

1997-11-01

Full Text Available A self-consistent method for day-time F2-region modelling was applied to the analysis of Millstone Hill incoherent scatter observations during the storm period of March 16-22, 1990. The method allows us to calculate in a self-consistent way neutral composition, temperature and meridional wind as well as the ionized species height distribution. Theoretically calculated Ne(h profiles fit the observed daytime ones with great accuracy in the whole range of heights above 150 km for both quiet and disturbed days. The overall increase in Tex by 270 K from March 16 to March 22 reflects the increase of solar activity level during the period in question. A 30% decrease in [O] and a two-fold increase in [N2] are calculated for the disturbed day of March 22 relative to quiet time prestorm conditions. Only a small reaction to the first geomagnetic disturbance on March 18 and the initial phase of the second storm on March 20 was found in [O] and [N2] variations. The meridional neutral wind inferred from plasma vertical drift clearly demonstrates the dependence on the geomagnetic activity level being more equatorward on disturbed days. Small positive F2-layer storm effects on March 18 and 20 are totally attributed to the decrease in the northward neutral wind but not to changes in neutral composition. A moderate (by a factor of 1.5 O/N2 ratio decrease relative to the MSIS-83 model prediction is required to describe the observed NmF2 decrease on the most disturbed day of March 22, but virtually no change of this ratio is needed for March 21.

Water vapour inter-comparison effort in the framework of the hydrological cycle in the mediterranean experiment - special observation period (hymex-sop1)

Science.gov (United States)

Summa, Donato; Di Girolamo, Paolo; Flamant, Cyrille; De Rosa, Benedetto; Cacciani, Marco; Stelitano, Dario

2018-04-01

Accurate measurements of the vertical profiles of water vapour are of paramount importance for most key areas of atmospheric sciences. A comprehensive inter-comparison between different remote sensing and in-situ sensors has been carried out in the frame work of the first Special Observing Period of the Hydrological cycle in the Mediterranean Experiment for the purpose of obtaining accurate error estimates for these sensors. The inter-comparison involves a ground-based Raman lidar (BASIL), an airborne DIAL (LEANDRE2), a microwave radiometer, radiosondes and aircraft in-situ sensors.

Time trends for prostate cancer mortality in Brazil and its geographic regions: An age-period-cohort analysis.

Science.gov (United States)

Braga, Sonia Faria Mendes; de Souza, Mirian Carvalho; Cherchiglia, Mariangela Leal

2017-10-01

In the 1980s, an increase in mortality rates for prostate cancer was observed in North America and developed European countries. In the 1990s, however, mortality rates decreased for these countries, an outcome related to early detection of the disease. Conversely, an upward trend in mortality rates was observed in Brazil. This study describe the trends in mortality for prostate cancer in Brazil and geographic regions (North, Northeast, South, Southeast, and Central-West) between 1980 until 2014 and analyze the influence of age, period, and cohort effects on mortality rates. This time-series study used data from the Mortality Information System (SIM) and population data from Brazilian Institute for Geography and Statistics (IBGE). The effects on mortality rates were examined using age-period-cohort (APC) models. Crude and standardized mortality rates showed an upward trend for Brazil and its regions more than 2-fold the last 30 years. Age effects showed an increased risk of death in all regions. Period effects showed a higher risk of death in the finals periods for the North and Northeast. Cohort effects showed risk of death was higher for younger than older generations in Brazil and regions, mainly Northeast (RR Adjusted =3.12, 95% CI 1.29-1.41; RR Adjusted =0.28, 95% CI 0.26-0.30, respectively). The increase in prostate cancer mortality rates in Brazil and its regions was mainly due to population aging. The differences in mortality rates and APC effects between regions are related to demographic differences and access of health services across the country. Copyright © 2017 Elsevier Ltd. All rights reserved.

Tapir: A web interface for transit/eclipse observability

Science.gov (United States)

Jensen, Eric

2013-06-01

Tapir is a set of tools, written in Perl, that provides a web interface for showing the observability of periodic astronomical events, such as exoplanet transits or eclipsing binaries. The package provides tools for creating finding charts for each target and airmass plots for each event. The code can access target lists that are stored on-line in a Google spreadsheet or in a local text file.

The nature and nurture of high IQ: an extended sensitive period for intellectual development.

Science.gov (United States)

Brant, Angela M; Munakata, Yuko; Boomsma, Dorret I; Defries, John C; Haworth, Claire M A; Keller, Matthew C; Martin, Nicholas G; McGue, Matthew; Petrill, Stephen A; Plomin, Robert; Wadsworth, Sally J; Wright, Margaret J; Hewitt, John K

2013-08-01

IQ predicts many measures of life success, as well as trajectories of brain development. Prolonged cortical thickening observed in individuals with high IQ might reflect an extended period of synaptogenesis and high environmental sensitivity or plasticity. We tested this hypothesis by examining the timing of changes in the magnitude of genetic and environmental influences on IQ as a function of IQ score. We found that individuals with high IQ show high environmental influence on IQ into adolescence (resembling younger children), whereas individuals with low IQ show high heritability of IQ in adolescence (resembling adults), a pattern consistent with an extended sensitive period for intellectual development in more-intelligent individuals. The pattern held across a cross-sectional sample of almost 11,000 twin pairs and a longitudinal sample of twins, biological siblings, and adoptive siblings.

[Evaluation of immunosuppressive treatment on homocystein levels in patients after kidney transplantation during a 2 year observation period].

Science.gov (United States)

Aksamit, Dariusz; Janda, Katarzyna; Kuźniewski, Marek; Krzanowski, Marcin; Ignacak, Ewa; Betkowska-Prokop, Alina; Chowaniec, Eve; Sułowicz, Wladysław

2012-01-01

The aim of the study was to evaluate the influence of the type of prescribed immunosuppression: cyclosporine A (CsA) vs. tacrolimus (Tac) on remote homocystein levels in patients (pts) after kidney transplantation (Ktx). The study included 51 pts (17 F, 34 M) aged 15 to 62 years (mean 38.1) after cadaver Ktx. The mean observation period equaled 21.2 months (6 -24); while total observation period was 90 personlyears. Before Ktx, 46 pts were treated with maintenance hemodialysis (HD), while 5 by peritoneal dialysis (PD). After Ktx, patients had immunosuppression prescribed according to the following schemes: prednisone (P) + CsA + azathioprine (AZA) - 12 pts; P + CsA + mycophenolate mofetil (MMF) -26 pts; P + Tac + MMF - 11 pts; and P + Tac + AZA - 2 pts. Hcy level was measured using high performance liquid chromatography (HPLC). Serum creatinine level was measured by standard method using the Hitachi 917 analyzer. Creatinine clearance was calculated based on the Cockcroft-Gault formula. Patient's blood was drawn before Ktx and 3, 6, 9, 12,15, 18, 21 and 24 months post procedure. Delayed graft function (DGF) after Ktx was diagnosed in 29 pts (56.9%) and this group required from 4 to 28 HD sessions (mean 14 sessions). Hcy level did not significantly differ between pts requiring (29 pts) and not requiring (22 pts) HD treatment after Ktx. It was also noted that the number of performed HD sessions did not significantly correlate with Hcy levels 24 months after Ktx (R =0.04, p=0.81). No relationship was found (non-parametric Spearman test) between the drop in Hcy level 3 months after Ktx as compare with value before Ktx and ischemia time (R=0.09, p=0.49), number of compatible HLA A and B (R=0.07, p=0.63), and DR antigens (R=0.09, p=0.51). Decrease in Hcy level (before Ktx and 24 months after Ktx) did not significantly correlate with the above parameters, respectively: R=-0.14, p=0.40; R=0.06, p=0.73; R=0.12, p=0.45; R=0.11, p=0.50. Decrease in Hcy level (before Ktx and 3

Time variability of X-ray binaries: observations with INTEGRAL. Modeling

International Nuclear Information System (INIS)

Cabanac, Clement

2007-01-01

The exact origin of the observed X and Gamma ray variability in X-ray binaries is still an open debate in high energy astrophysics. Among others, these objects are showing aperiodic and quasi-periodic luminosity variations on timescales as small as the millisecond. This erratic behavior must put constraints on the proposed emission processes occurring in the vicinity of the neutrons star or the stellar mass black-hole held by these objects. We propose here to study their behavior following 3 different ways: first we examine the evolution of a particular X-ray source discovered by INTEGRAL, IGR J19140+0951. Using timing and spectral data given by different instruments, we show that the source type is plausibly consistent with a High Mass X-ray Binary hosting a neutrons star. Subsequently, we propose a new method dedicated to the study of timing data coming from coded mask aperture instruments. Using it on INTEGRAL/ISGRI real data, we detect the presence of periodic and quasi-periodic features in some pulsars and micro-quasars at energies as high as a hundred keV. Finally, we suggest a model designed to describe the low frequency variability of X-ray binaries in their hardest state. This model is based on thermal comptonization of soft photons by a warm corona in which a pressure wave is propagating in cylindrical geometry. By computing both numerical simulations and analytical solution, we show that this model should be suitable to describe some of the typical features observed in X-ray binaries power spectra in their hard state and their evolution such as aperiodic noise and low frequency quasi-periodic oscillations. (author) [fr

Best in show but not best shape: a photographic assessment of show dog body condition.

Science.gov (United States)

Such, Z R; German, A J

2015-08-01

Previous studies suggest that owners often wrongly perceive overweight dogs to be in normal condition. The body shape of dogs attending shows might influence owners' perceptions, with online images of overweight show winners having a negative effect. This was an observational in silico study of canine body condition. 14 obese-prone breeds and 14 matched non-obese-probe breeds were first selected, and one operator then used an online search engine to identify 40 images, per breed, of dogs that had appeared at a major national UK show (Crufts). After images were anonymised and coded, a second observer subjectively assessed body condition, in a single sitting, using a previously validated method. Of 1120 photographs initially identified, 960 were suitable for assessing body condition, with all unsuitable images being from longhaired breeds. None of the dogs (0 per cent) were underweight, 708 (74 per cent) were in ideal condition and 252 (26 per cent) were overweight. Pugs, basset hounds and Labrador retrievers were most likely to be overweight, while standard poodles, Rhodesian ridgebacks, Hungarian vizslas and Dobermanns were least likely to be overweight. Given the proportion of show dogs from some breeds that are overweight, breed standards should be redefined to be consistent with a dog in optimal body condition. British Veterinary Association.

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

Science.gov (United States)

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

2013-04-01

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

Thyrotoxic periodic paralysis

Directory of Open Access Journals (Sweden)

Rojith Karandode Balakrishnan

2011-01-01

Full Text Available This article aims at highlighting the importance of suspecting thyrotoxicosis in cases of recurrent periodic flaccid paralysis; especially in Asian men to facilitate early diagnosis of the former condition. A case report of a 28 year old male patient with recurrent periodic flaccid paralysis has been presented. Hypokalemia secondary to thyrotoxicosis was diagnosed as the cause of the paralysis. The patient was given oral potassium intervention over 24 hours. The patient showed complete recovery after the medical intervention and was discharged after 24 hours with no residual paralysis. Thyrotoxic periodic paralysis (TPP is a complication of thyrotoxicosis, more common amongst males in Asia. It presents as acute flaccid paralysis in a case of hyperthyroidism with associated hypokalemia. The features of thyrotoxicosis may be subtle or absent. Thus, in cases of recurrent or acute flaccid muscle paralysis, it is important to consider thyrotoxicosis as one of the possible causes, and take measures accordingly.

Improved nonparametric inference for multiple correlated periodic sequences

KAUST Repository

Sun, Ying

2013-08-26

This paper proposes a cross-validation method for estimating the period as well as the values of multiple correlated periodic sequences when data are observed at evenly spaced time points. The period of interest is estimated conditional on the other correlated sequences. An alternative method for period estimation based on Akaike\\'s information criterion is also discussed. The improvement of the period estimation performance is investigated both theoretically and by simulation. We apply the multivariate cross-validation method to the temperature data obtained from multiple ice cores, investigating the periodicity of the El Niño effect. Our methodology is also illustrated by estimating patients\\' cardiac cycle from different physiological signals, including arterial blood pressure, electrocardiography, and fingertip plethysmograph.

Influence of periodic external fields in multiagent models with language dynamics

Science.gov (United States)

Palombi, Filippo; Ferriani, Stefano; Toti, Simona

2017-12-01

We investigate large-scale effects induced by external fields, phenomenologically interpreted as mass media, in multiagent models evolving with the microscopic dynamics of the binary naming game. In particular, we show that a single external field, broadcasting information at regular time intervals, can reverse the majority opinion of the population, provided the frequency and the effectiveness of the sent messages lie above well-defined thresholds. We study the phase structure of the model in the mean field approximation and in numerical simulations with several network topologies. We also investigate the influence on the agent dynamics of two competing external fields, periodically broadcasting different messages. In finite regions of the parameter space we observe periodic equilibrium states in which the average opinion densities are reversed with respect to naive expectations. Such equilibria occur in two cases: (i) when the frequencies of the competing messages are different but close to each other; (ii) when the frequencies are equal and the relative time shift of the messages does not exceed half a period. We interpret the observed phenomena as a result of the interplay between the external fields and the internal dynamics of the agents and conclude that, depending on the model parameters, the naming game is consistent with scenarios of first- or second-mover advantage (to borrow an expression from the jargon of business strategy).

A Case of Carcinoma Showing Thymus-Like Differentiation with a Rapidly Lethal Course

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Tomohiro Nogami

2014-12-01

Full Text Available A 55-year-old woman underwent a total thyroidectomy for carcinoma showing thymus-like differentiation (CASTLE. The patient was referred to our hospital after the tumor was found to have directly invaded the cervical esophagus and the entire circumference of the trachea. A total thyroidectomy was performed, followed by end-to-end anastomosis of the trachea, suprahyoid release and dissection of bilateral pulmonary ligaments. No major complications, including anastomotic dehiscence or stenosis, were observed. The patient experienced some swallowing disturbances and hoarseness during the perioperative period but fully recovered. Radiotherapy to the neck was performed as an adjuvant therapy. Eleven months after surgery, lower back pain and right leg numbness developed and led to gait inability. Multiple lung and bone recurrences were observed, but no local recurrence. Palliative radiotherapy to the bone metastasis was performed. The patient died of pleural metastasis 14 months after the initial diagnosis of CASTLE.

Uruguay - Surface Weather Observations

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Surface weather observation forms for 26 stations in Uruguay. Period of record 1896-2005, with two to eight observations per day. Files created through a...

Periodically modulated single-photon transport in one-dimensional waveguide

Science.gov (United States)

Li, Xingmin; Wei, L. F.

2018-03-01

Single-photon transport along a one-dimension waveguide interacting with a quantum system (e.g., two-level atom) is a very useful and meaningful simplified model of the waveguide-based optical quantum devices. Thus, how to modulate the transport of the photons in the waveguide structures by adjusting certain external parameters should be particularly important. In this paper, we discuss how such a modulation could be implemented by periodically driving the energy splitting of the interacting atom and the atom-photon coupling strength. By generalizing the well developed time-independent full quantum mechanical theory in real space to the time-dependent one, we show that various sideband-transmission phenomena could be observed. This means that, with these modulations the photon has certain probabilities to transmit through the scattering atom in the other energy sidebands. Inversely, by controlling the sideband transmission the periodic modulations of the single photon waveguide devices could be designed for the future optical quantum information processing applications.

Prospective Epidemiological Observations on the Course of the Disease in Fibromyalgia Patients

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Sprott Haiko

2003-08-01

Full Text Available Abstract Objectives The aim of the study was to carry out a survey in patients with fibromyalgia (FM, to examine their general health status and work incapacity (disability-pension status, and their views on the effectiveness of therapy received, over a two-year observation period. Methods 48 patients diagnosed with FM, according to the American College of Rheumatology (ACR criteria, took part in the study. At baseline, and on average two years later, the patients underwent clinical investigation (dolorimetry, laboratory diagnostics, medical history taking and completed the Fibromyalgia questionnaire (Dettmer and Chrostek 1. Results 27/48 (56% patients participated in the two-year follow-up. In general, the patients showed no improvement in their symptoms over the observation period, regardless of the type of therapy they had received. General satisfaction with quality of life improved, as did satisfaction regarding health status and the family situation, although the degree of pain experienced remain unchanged. In comparison with the initial examination, there was no change in either work-capacity or disability-pension status. Conclusions The FM patients showed no improvement in pain, despite the many various treatments received over the two-year period. The increase in general satisfaction over the observation period was believed to be the result of patient instruction and education about the disease. To what extent a population of patients with FM would show similar outcomes if they did not receive any instruction/education about their disorder, cannot be ascertained from the present study; and, indeed, the undertaking of a study to investigate this would be ethically questionable. As present, no conclusions can be made regarding the influence of therapy on the primary and secondary costs associated with FM.

Transient periodic x-ray source in Taurus, A0535+26

International Nuclear Information System (INIS)

Bradt, H.; Mayer, W.; Buff, J.; Clark, G.W.; Doxsey, R.; Hearn, D.; Jernigan, G.; Joss, P.C.; Laufer, B.; Lewin, W.; Li, F.; Matilsky, T.; McClintock, J.; Primini, F.; Rappaport, S.; Schnopper, H.

1976-01-01

Light curves of the 104 s periodicity in the transient X-ray source in Taurus (A0535+26) are presented for six energy intervals in the range 1-35 keV for the period 1975 May 30-June 2. The pulse structure ranges from an apparently simple modulation at higher energies to a very complex pattern at lower energies. No Doppler shift is observed in the 104 s pulse period during the three days of observations. This places severe constraints upon possible binary orbital motion. Upper limits on the power at other periodicities are approximately-less-than10 percent for 2 ms-2s and approximately-less-than2 percent for 2 s-2000 s

Photoelectric observations of CH Cygni

Energy Technology Data Exchange (ETDEWEB)

Luud, L; Ruusalepp, M; Vennik, Ya

1977-01-01

UBV observations of the peculiar variable star CH Cygni from 1968 up to 1974 are presented. HD 182691 served as a comparison star. It turned out that the colours are in accordance with a model for a symbiotic star. The colour-magnitude diagrams of CH Cygni allow dividing the period of the observations into two parts in dependence on the activity of CH Cygni. Observed brightness variations are analyzed by using autocorrelation, crosscorrelation, and power spectral density functions. It has been found that brightness variations have some periods which are given.

Time trend and age-period-cohort effect on kidney cancer mortality in Europe, 1981–2000

Directory of Open Access Journals (Sweden)

López-Abente Gonzalo

2006-05-01

Full Text Available Abstract Background The incorporation of diagnostic and therapeutic improvements, as well as the different smoking patterns, may have had an influence on the observed variability in renal cancer mortality across Europe. This study examined time trends in kidney cancer mortality in fourteen European countries during the last two decades of the 20th century. Methods Kidney cancer deaths and population estimates for each country during the period 1981–2000 were drawn from the World Health Organization Mortality Database. Age- and period-adjusted mortality rates, as well as annual percentage changes in age-adjusted mortality rates, were calculated for each country and geographical region. Log-linear Poisson models were also fitted to study the effect of age, death period, and birth cohort on kidney cancer mortality rates within each country. Results For men, the overall standardized kidney cancer mortality rates in the eastern, western, and northern European countries were 20, 25, and 53% higher than those for the southern European countries, respectively. However, age-adjusted mortality rates showed a significant annual decrease of -0.7% in the north of Europe, a moderate rise of 0.7% in the west, and substantial increases of 1.4% in the south and 2.0% in the east. This trend was similar among women, but with lower mortality rates. Age-period-cohort models showed three different birth-cohort patterns for both men and women: a decrease in mortality trend for those generations born after 1920 in the Nordic countries, a similar but lagged decline for cohorts born after 1930 in western and southern European countries, and a continuous increase throughout all birth cohorts in eastern Europe. Similar but more heterogeneous regional patterns were observed for period effects. Conclusion Kidney cancer mortality trends in Europe showed a clear north-south pattern, with high rates on a downward trend in the north, intermediate rates on a more marked rising

BILIARY ATRESIA: evaluation on two distinct periods at a reference pediatric service

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Thais Costa Nascentes QUEIROZ

2014-03-01

Full Text Available Context Biliary atresia is a progressive, idiopathic, fibro-obliterative disease of the extrahepatic biliary tree that pre­sents with biliary obstruction exclusively in the neonatal period. Objectives To assess the differences regarding age at referral, age at surgery, duration of propaedeutics and waiting time for surgery between two groups of infants in different periods. Methods Retrospective study of infants diagnosed with biliary atresia on two periods: 1983-1993 and 1998-2011. Results Biliary atresia was diagnosed in 129 infants, being 48 in casuistic I and 81 in casuistic II. The median age at admission was 94 and 60 days, respectively (P = 0.0001. On evaluating patients who had undergone portoenterostomy before 120 days of age, no difference was observed regarding the duration of propaedeutics or waiting time for surgery (P = 0.15, but difference was found when comparing the age at surgery (P = 0.002. Among those infants with no biliary flow and without liver transplantation or death after 18 post-operative months, the estimated probability of survival was 44.6% and 38.7% in casuistics I and II, respectively. In casuistic I, all infants who showed biliary flow were alive during the observation period and, in casuistic II, 80.3% were alive after 7 years of follow-up. Conclusions Even though patients were admitted and treated earlier, it is clear that surgery could be done sooner. Delay in referral and timely propaedeutics were the main contributors.

An Iberian climatology of solar radiation obtained from WRF regional climate simulations for 1950–2010 period

KAUST Repository

Perdigão, João

2017-08-15

The mesoscale Weather Research and Forecasting (WRF) Model is used over the Iberian Peninsula to generate 60years (1950–2010) of climate data, at 5km resolution, in order to evaluate and characterize the incident shortwave downward radiation at the surface (SW↓), in present climate.The simulated values of SW↓ in the period 2000–2009 were compared with data measured in Spanish and Portuguese meteorological stations before and a statistical BIAS correction was applied using data from Clouds and the Earth\\'s Radiant Energy System (CERES), on board four different satellites. The spatial and temporal comparison between WRF results and observations show a good agreement for the analyzed period, although the model overestimates observations. This overestimation has a mean normalized bias of about 7% after BIAS correction (or 17% for original WRF output). Additionally, the present simulation was confronted against another previously validated WRF simulation performed with different resolution and set of parametrizations, showing comparable results. WRF adequately reproduces the observational features of SW↓ with correlation coefficients above 0.8 in annual and seasonal basis.60years of simulated SW↓ over the Iberian Peninsula were produced, which showed annual mean values that range from 130W/m2, in the northern regions, to a maximum of around 230W/m2 in the southeast of the Iberian Peninsula (IP). SW↓ over IP shows a positive gradient from north to south and from west to east, with local effects influenced by topography and distance to the coast.The analysis of the simulated cloud fraction indicates that clear sky days are found in >30% of the period at the southern area of IP, particularly in the Algarve (Portugal) and Andalusia (Spain), and this value increases significantly in the summer season for values above 80%.

An Iberian climatology of solar radiation obtained from WRF regional climate simulations for 1950–2010 period

KAUST Repository

Perdigã o, Joã o; Salgado, Rui; Magarreiro, Clarisse; Soares, Pedro M.M.; Costa, Maria Joã o; Dasari, Hari Prasad

2017-01-01

The mesoscale Weather Research and Forecasting (WRF) Model is used over the Iberian Peninsula to generate 60years (1950–2010) of climate data, at 5km resolution, in order to evaluate and characterize the incident shortwave downward radiation at the surface (SW↓), in present climate.The simulated values of SW↓ in the period 2000–2009 were compared with data measured in Spanish and Portuguese meteorological stations before and a statistical BIAS correction was applied using data from Clouds and the Earth's Radiant Energy System (CERES), on board four different satellites. The spatial and temporal comparison between WRF results and observations show a good agreement for the analyzed period, although the model overestimates observations. This overestimation has a mean normalized bias of about 7% after BIAS correction (or 17% for original WRF output). Additionally, the present simulation was confronted against another previously validated WRF simulation performed with different resolution and set of parametrizations, showing comparable results. WRF adequately reproduces the observational features of SW↓ with correlation coefficients above 0.8 in annual and seasonal basis.60years of simulated SW↓ over the Iberian Peninsula were produced, which showed annual mean values that range from 130W/m2, in the northern regions, to a maximum of around 230W/m2 in the southeast of the Iberian Peninsula (IP). SW↓ over IP shows a positive gradient from north to south and from west to east, with local effects influenced by topography and distance to the coast.The analysis of the simulated cloud fraction indicates that clear sky days are found in >30% of the period at the southern area of IP, particularly in the Algarve (Portugal) and Andalusia (Spain), and this value increases significantly in the summer season for values above 80%.

Periods found in heat measurements obtained by calorimetry

International Nuclear Information System (INIS)

Jordan, K.C.

1984-01-01

During a span of 640 days, a periodicity of 1.5158 +- 0.0008 days was discovered in successive heater equilibria on Calorimeter No. 127. Measurements were taken at 12-h intervals, with occasional changes of exactly 3 or 6 h in the schedule of measurements. This schedule eliminated all other possible periods except a period of 0.150156 days. Periods of 1.519125 and 1.511283 days were discovered in data on the excess length of day as obtained by the US Naval Observatory over a period of 24 y. These two periods could equally well represent periods of 0.150189 and 0.150112 days, since measurements were obtained only once every 24 h. It is suggested that periods observed in sensitive calorimeters and in length of day data may be related. 1 reference, 6 figures, 5 tables

Simulating suppressed and active convection periods during TOGA COARE

CSIR Research Space (South Africa)

Bopape, Mary-Jane M

2013-09-01

Full Text Available The two-dimensional Non-hydrostatic s-coordinate Model (NSM) is used to simulate two twelve day periods and an eight day period observed during the Tropical Oceans Global Atmosphere Coupled Ocean-Atmosphere Response Experiment (TOGA COARE...

Observations and modeling of post-midnight uplifts near the magnetic equator

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M. J. Nicolls

2006-07-01

Full Text Available We report here on post-midnight uplifts near the magnetic equator. We present observational evidence from digital ionosondes in Brazil, a digisonde in Peru, and other measurements at the Jicamarca Radio Observatory that show that these uplifts occur fairly regularly in the post-midnight period, raising the ionosphere by tens of kilometers in the most mild events and by over a hundred kilometers in the most severe events. We show that in general the uplifts are not the result of a zonal electric field reversal, and demonstrate instead that the uplifts occur as the ionospheric response to a decreasing westward electric field in conjunction with sufficient recombination and plasma flux. The decreasing westward electric field may be caused by a change in the wind system related to the midnight pressure bulge, which is associated with the midnight temperature maximum. In order to agree with observations from Jicamarca and Palmas, Brazil, it is shown that there must exist sufficient horizontal plasma flux associated with the pressure bulge. In addition, we show that the uplifts may be correlated with a secondary maximum in the spread-F occurrence rate in the post-midnight period. The uplifts are strongly seasonally dependent, presumably according to the seasonal dependence of the midnight pressure bulge, which leads to the necessary small westward field in the post-midnight period during certain seasons. We also discuss the enhancement of the uplifts associated with increased geomagnetic activity, which may be related to disturbance dynamo winds. Finally, we show that it is possible using simple numerical techniques to estimate the horizontal plasma flux and the vertical drift velocity from electron density measurements in the post-midnight period.

Long-term periodicities in the sunspot record

International Nuclear Information System (INIS)

Wilson, R.M.

1984-07-01

Sunspot records are systematically maintained, with the knowledge that an 11 year average period exists since about 1850. Thus, the sunspot record of highest quality and considered to be the most reliable is that of cycle eight through the present. On the basis of cycles 8 through 20, various combinations of sine curves were used to approximate the observed R sub MAX values (where R sub MAX is the smoothed sunspot number at cycle maximum). It is found that a three component sinusoidal function, having an 11 cycle and a 2 cycle variation on a 90 cycle periodicity, yields computed R sub MAX values which fit, reasonably well, observed R sub MAX values for the modern sunspot cycles. Extrapolation of the empirical functions forward in time allows for the projection of values of R sub MAX for cycles 21 and 22. For cycle 21, the function projects a value of 157.3, very close to the actually observed value of 164.5. For cycle 22, the function projects a value of about 107. Linear regressions applied to cycle 22 indicate a long-period cycle (cycle duration 132 months). An extensive bibliography on techniques used to estimate the time dependent behavior of sunspot cycles is provided

NuSTAR Observation of the Symbiotic System GX 1+4

Science.gov (United States)

Wolff, Michael Thomas; Becker, Peter A.; Enoto, Teruaki; Pottschmidt, Katja; Wood, Kent

2017-08-01

We report on a NuSTAR observation of the symbiotic binary system GX 1+4. GX 1+4 is one of a small number of systems with a red giant mass donor and a magnetic neutron star in orbit around each other. The accreting pulsar in GX 1+4 has a spin period of ~150 seconds with epochs of both spin-up and spin-down. The orbital period that has not been determined. Magnetic accretion theory in such systems suggests that the neutron star has a magnetic field in the range 1013-1014 Gauss although this is not settled because no cyclotron absorption feature has been observed in the X-ray spectrum. The NuSTAR spectrum shows broad Fe-line emission near ~6.5 keV and also shows a broad power law shape detected up to ~60 keV. We analyze and discuss the NuSTAR X-ray data with particular attention to the question of what can the spectrum tell us about the structure of the accretion flow onto the neutron star and the magnetic field strength.

Periodic solutions of nonlinear vibrating beams

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J. Berkovits

2003-01-01

Full Text Available The aim of this paper is to prove new existence and multiplicity results for periodic semilinear beam equation with a nonlinear time-independent perturbation in case the period is not prescribed. Since the spectrum of the linear part varies with the period, the solvability of the equation depends crucially on the period which can be chosen as a free parameter. Since the period of the external forcing is generally unknown a priori, we consider the following natural problem. For a given time-independent nonlinearity, find periods T for which the equation is solvable for any T-periodic forcing. We will also deal with the existence of multiple solutions when the nonlinearity interacts with the spectrum of the linear part. We show that under certain conditions multiple solutions do exist for any small forcing term with suitable period T. The results are obtained via generalized Leray-Schauder degree and reductions to invariant subspaces.

Period--luminosity--color relations and pulsation modes of pulsating variable stars

International Nuclear Information System (INIS)

Breger, M.; Bregman, J.N.

1975-01-01

The periods of delta Scuti, RR Lyrae, dwarf Cepheid, and W Virginis variables have been investigated for their dependence on luminosity, color, mass, and pulsation modes. A maximum-likelihood method, which includes consideration of the observational errors in each coordinate, has been applied to obtain observational period-luminosity-color (P-L-C) relations

Magnetospheric Truncation, Tidal Inspiral, and the Creation of Short-period and Ultra-short-period Planets

Energy Technology Data Exchange (ETDEWEB)

Lee, Eve J.; Chiang, Eugene, E-mail: evelee@berkeley.edu [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States)

2017-06-10

Sub-Neptunes around FGKM dwarfs are evenly distributed in log orbital period down to ∼10 days, but dwindle in number at shorter periods. Both the break at ∼10 days and the slope of the occurrence rate down to ∼1 day can be attributed to the truncation of protoplanetary disks by their host star magnetospheres at corotation. We demonstrate this by deriving planet occurrence rate profiles from empirical distributions of pre-main-sequence stellar rotation periods. Observed profiles are better reproduced when planets are distributed randomly in disks—as might be expected if planets formed in situ—rather than piled up near disk edges, as would be the case if they migrated in by disk torques. Planets can be brought from disk edges to ultra-short (<1 day) periods by asynchronous equilibrium tides raised on their stars. Tidal migration can account for how ultra-short-period planets are more widely spaced than their longer-period counterparts. Our picture provides a starting point for understanding why the sub-Neptune population drops at ∼10 days regardless of whether the host star is of type FGK or early M. We predict planet occurrence rates around A stars to also break at short periods, but at ∼1 day instead of ∼10 days because A stars rotate faster than stars with lower masses (this prediction presumes that the planetesimal building blocks of planets can drift inside the dust sublimation radius).

Magnetospheric Truncation, Tidal Inspiral, and the Creation of Short-period and Ultra-short-period Planets

International Nuclear Information System (INIS)

Lee, Eve J.; Chiang, Eugene

2017-01-01

Sub-Neptunes around FGKM dwarfs are evenly distributed in log orbital period down to ∼10 days, but dwindle in number at shorter periods. Both the break at ∼10 days and the slope of the occurrence rate down to ∼1 day can be attributed to the truncation of protoplanetary disks by their host star magnetospheres at corotation. We demonstrate this by deriving planet occurrence rate profiles from empirical distributions of pre-main-sequence stellar rotation periods. Observed profiles are better reproduced when planets are distributed randomly in disks—as might be expected if planets formed in situ—rather than piled up near disk edges, as would be the case if they migrated in by disk torques. Planets can be brought from disk edges to ultra-short (<1 day) periods by asynchronous equilibrium tides raised on their stars. Tidal migration can account for how ultra-short-period planets are more widely spaced than their longer-period counterparts. Our picture provides a starting point for understanding why the sub-Neptune population drops at ∼10 days regardless of whether the host star is of type FGK or early M. We predict planet occurrence rates around A stars to also break at short periods, but at ∼1 day instead of ∼10 days because A stars rotate faster than stars with lower masses (this prediction presumes that the planetesimal building blocks of planets can drift inside the dust sublimation radius).

A comparative study on chaoticity of equatorial/low latitude ionosphere over Indian subcontinent during geomagnetically quiet and disturbed periods

Directory of Open Access Journals (Sweden)

K. Unnikrishnan

2010-12-01

Full Text Available In the present study, the latitudinal aspect of chaotic behaviour of ionosphere during quiet and storm periods are analyzed and compared by using GPS TEC time series measured at equatorial trough, crest and outside crest stations over Indian subcontinent, by employing the chaotic quantifiers like Lyapunov exponent (LE, correlation dimension (CD, entropy and nonlinear prediction error (NPE. It is observed that the values of LE are low for storm periods compared to those of quiet periods for all the stations considered here. The lowest value of LE is observed at the trough station, Agatti (2.38° N, Geomagnetically, and highest at crest station, Mumbai (10.09° N, Geomagnetically for both quiet and storm periods. The values of correlation dimension computed for TEC time series are in the range 2.23–2.74 for quiet period, which indicate that equatorial ionosphere may be described with three variables during quiet period. But the crest station Mumbai shows a higher value of CD (3.373 during storm time, which asserts that four variables are necessary to describe the system during storm period. The values of non linear prediction error (NPE are lower for Agatti (2.38° N, Geomagnetically and Jodhpur (18.3° N, Geomagnetically, during storm period, compared to those of quiet period, mainly because of the predominance of non linear aspects during storm periods The surrogate data test is carried out and on the basis of the significance of difference of the original data and surrogates for various aspects, the surrogate data test rejects the null hypothesis that the time series of TEC during storm and quiet times represent a linear stochastic process. It is also observed that using state space model, detrended TEC can be predicted, which reasonably reproduces the observed data. Based on the values of the above quantifiers, the features of chaotic behaviour of equatorial trough crest and outside the crest regions of ionosphere during geomagnetically

Deciphering Periodic Methanol Masers

Science.gov (United States)

Stecklum, Bringfried; Caratti o Garatti, Alessio; Henning, Thomas; Hodapp, Klaus; Hopp, Ulrich; Kraus, Alex; Linz, Hendrik; Sanna, Alberto; Sobolev, Andrej; Wolf, Verena

2018-05-01

Impressive progress has been made in recent years on massive star formation, yet the involved high optical depths even at submm/mm wavelengths make it difficult to reveal its details. Recently, accretion bursts of massive YSOs have been identified to cause flares of Class II methanol masers (methanol masers for short) due to enhanced mid-IR pumping. This opens a new window to protostellar accretion variability, and implies that periodic methanol masers hint at cyclic accretion. Pinning down the cause of the periodicity requires joint IR and radio monitoring. We derived the first IR light curve of a periodic maser host from NEOWISE data. The source, G107.298+5.639, is an intermediate-mass YSO hosting methanol and water masers which flare every 34.5 days. Our recent joint K-band and radio observations yielded first but marginal evidence for a phase lag between the rise of IR and maser emission, respectively, and revealed that both NEOWISE and K-band light curves are strongly affected by the light echo from the ambient dust. Both the superior resolution of IRAC over NEOWISE and the longer wavelengths compared to our ground-based imaging are required to inhibit the distractive contamination by the light echo. Thus, we ask for IRAC monitoring of G107 to cover one flare cycle, in tandem with 100-m Effelsberg and 2-m Wendelstein radio and NIR observations to obtain the first high-quality synoptic measurements of this kind of sources. The IR-maser phase lag, the intrinsic shape of the IR light curves and their possible color variation during the cycle allow us to constrain models for the periodic maser excitation. Since methanol masers are signposts of intermediate-mass and massive YSOs, deciphering their variability offers a clue to the dynamics of the accretion-mediated growth of massive stars and their feedback onto the immediate natal environment. The Spitzer light curve of such a maser-hosting YSO would be a legacy science product of the mission.

Drought periods in non-mountainous part of South Bulgaria on the background of climate change

Directory of Open Access Journals (Sweden)

Nikolova Nina

2012-01-01

Full Text Available The scientific investigations and various analyses show a trend towards a significant extension of water scarcity across Europe. Decreasing of precipitation totals and increasing of drought periods are characteristic for many regions of Bulgaria. Often high temperatures, strong winds and low relative humidity occur in conjunction with the drought. This makes the drought very strong expressed. The present work aims to analyze drought periods in South Bulgaria in terms of its temporal variability, intensity, seasonal and territorial differences. The study areas are one of the main agricultural areas in Bulgaria and because of this investigation of drought in this region is very important. Drought periods are investigated on the base of seasonal precipitation totals and precipitation indices. The data for monthly precipitation from nine meteorological stations situated at the regions with different geographical conditions are used. The deviations of the seasonal and annual precipitation from normal (precipitation for the period 1961-1990 are used to determine drought periods in investigated stations. The duration of drought event is determined by Cumulative Precipitation Anomalies (CA. The Standardized Precipitation Indices (SPI are calculated in order to determine moisture conditions and occurrence of drought periods in the investigated stations. The results from the research show that drought was widespread in 1945 and 1949. The years with dry seasons are more often during 80’s and 90’s but drought during these periods was observed in a few of the investigated stations.

Sediment transport drives tidewater glacier periodicity.

Science.gov (United States)

Brinkerhoff, Douglas; Truffer, Martin; Aschwanden, Andy

2017-07-21

Most of Earth's glaciers are retreating, but some tidewater glaciers are advancing despite increasing temperatures and contrary to their neighbors. This can be explained by the coupling of ice and sediment dynamics: a shoal forms at the glacier terminus, reducing ice discharge and causing advance towards an unstable configuration followed by abrupt retreat, in a process known as the tidewater glacier cycle. Here we use a numerical model calibrated with observations to show that interactions between ice flow, glacial erosion, and sediment transport drive these cycles, which occur independent of climate variations. Water availability controls cycle period and amplitude, and enhanced melt from future warming could trigger advance even in glaciers that are steady or retreating, complicating interpretations of glacier response to climate change. The resulting shifts in sediment and meltwater delivery from changes in glacier configuration may impact interpretations of marine sediments, fjord geochemistry, and marine ecosystems.The reason some of the Earth's tidewater glaciers are advancing despite increasing temperatures is not entirely clear. Here, using a numerical model that simulates both ice and sediment dynamics, the authors show that internal dynamics drive glacier variability independent of climate.

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

Science.gov (United States)

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

2011-12-01

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.

Century Scale Evaporation Trend: An Observational Study

Science.gov (United States)

Bounoui, Lahouari

2012-01-01

Several climate models with different complexity indicate that under increased CO2 forcing, runoff would increase faster than precipitation overland. However, observations over large U.S watersheds indicate otherwise. This inconsistency between models and observations suggests that there may be important feedbacks between climate and land surface unaccounted for in the present generation of models. We have analyzed century-scale observed annual runoff and precipitation time-series over several United States Geological Survey hydrological units covering large forested regions of the Eastern United States not affected by irrigation. Both time-series exhibit a positive long-term trend; however, in contrast to model results, these historic data records show that the rate of precipitation increases at roughly double the rate of runoff increase. We considered several hydrological processes to close the water budget and found that none of these processes acting alone could account for the total water excess generated by the observed difference between precipitation and runoff. We conclude that evaporation has increased over the period of observations and show that the increasing trend in precipitation minus runoff is correlated to observed increase in vegetation density based on the longest available global satellite record. The increase in vegetation density has important implications for climate; it slows but does not alleviate the projected warming associated with greenhouse gases emission.

Chaos synchronization based on intermittent state observer

Institute of Scientific and Technical Information of China (English)

Li Guo-Hui; Zhou Shi-Ping; Xu De-Ming

2004-01-01

This paper describes the method of synchronizing slave to the master trajectory using an intermittent state observer by constructing a synchronizer which drives the response system globally tracing the driving system asymptotically. It has been shown from the theory of synchronization error-analysis that a satisfactory result of chaos synchronization is expected under an appropriate intermittent period and state observer. Compared with continuous control method,the proposed intermittent method can target the desired orbit more efficiently. The application of the method is demonstrated on the hyperchaotic Rossler systems. Numerical simulations show that the length of the synchronization interval rs is of crucial importance for our scheme, and the method is robust with respect to parameter mismatch.

Ovarian activity and embryo yield in relation to the postpartum period in superovulated dairy cows

Directory of Open Access Journals (Sweden)

Luděk Stádník

2017-01-01

Full Text Available The aim of this study was to evaluate superovulation response in cows at various postpartum periods (early postpartum period up to 3.5 months; middle postpartum period 3.7–7 months; later postpartum period above 7.5 months after calving. The data included observation of 55 Holstein cows superovulated at one farm in the Czech Republic during the years 2010 and 2013. Reproduction traits (dependent variable were represented as number of the corpora lutea, number of transferable embryos, morulae, blastocysts, total number of embryos and embryo recovery. For statistical evaluation we used the PROC GLM of SAS® with fixed effect - breeding value of milk production. The study results show significant differences (P < 0.05–0.01 in the three postpartum periods (early, middle, and later postpartum periods and the number of corpora lutea (4.6; 7.4; 10.8, number of total embryos (3.2; 2.9; 6.5 and transferable embryos (1.8; 1.7; 4.4. Effective timing of embryo transfer in the later postpartum period resulted in greater ovarian activity and embryo yield compared to early lactation periods.

Cometary ion dynamics observed in the close vicinity of comet 67P/Churyumov-Gerasimenko during the intermediate activity period

Science.gov (United States)

Berčič, L.; Behar, E.; Nilsson, H.; Nicolaou, G.; Wieser, G. Stenberg; Wieser, M.; Goetz, C.

2018-06-01

Aims: Cometary ions are constantly produced in the coma, and once produced they are accelerated and eventually escape the coma. We describe and interpret the dynamics of the cometary ion flow, of an intermediate active comet, very close to the nucleus and in the terminator plane. Methods: We analysed in situ ion and magnetic field measurements, and characterise the velocity distribution functions (mostly using plasma moments). We propose a statistical approach over a period of one month. Results: On average, two populations were observed, separated in phase space. The motion of the first is governed by its interaction with the solar wind farther upstream, while the second one is accelerated in the inner coma and displays characteristics compatible with an ambipolar electric field. Both populations display a consistent anti-sunward velocity component. Conclusions: Cometary ions born in different regions of the coma are seen close to the nucleus of comet 67P/Churyumov-Gerasimenko with distinct motions governed in one case by the solar wind electric field and in the other case by the position relative to the nucleus. A consistent anti-sunward component is observed for all cometary ions. An asymmetry is found in the average cometary ion density in a solar wind electric field reference frame, with higher density in the negative (south) electric field hemisphere. There is no corresponding signature in the average magnetic field strength.

Water vapour inter-comparison effort in the framework of the hydrological cycle in the mediterranean experiment – special observation period (hymex-sop1

Directory of Open Access Journals (Sweden)

Summa Donato

2018-01-01

Full Text Available Accurate measurements of the vertical profiles of water vapour are of paramount importance for most key areas of atmospheric sciences. A comprehensive inter-comparison between different remote sensing and in-situ sensors has been carried out in the frame work of the first Special Observing Period of the Hydrological cycle in the Mediterranean Experiment for the purpose of obtaining accurate error estimates for these sensors. The inter-comparison involves a ground-based Raman lidar (BASIL, an airborne DIAL (LEANDRE2, a microwave radiometer, radiosondes and aircraft in-situ sensors.

Tropical temperature altitude amplification in the hiatus period (1998-2012

Directory of Open Access Journals (Sweden)

Ducić Vladan D.

2015-01-01

Full Text Available In the period 1998-2012 there was a stagnation in temperature rise, despite the GHGs radiation forcing is increased (hiatus period. According to Global Circulation Models simulations, expected response on the rise of GHGs forcing is tropical temperature altitude amplification - temperature increases faster in higher troposphere than in lower troposphere. In this paper, two satellite data sets, UAH MSU and RSS, were used to test altitude temperature amplification in tropic (20°N-20°S in the hiatus period. We compared data from satellite data sets from lower troposphere (TLT and middle troposphere (TMT in general and particularly for land and ocean (for UAH MSU. The results from both satellite measurements showed the presence of hiatus, i.e. slowdown of the temperature rise in the period 1998-2012 compared to period 1979-2012 (UAH MSU and temperature fall for RSS data. Smaller increase, i.e. temperature fall over ocean showed that hiatus is an ocean phenomenon above all. Data for UAH MSU showed that temperature altitude amplification in tropic was not present either for period 1979-2012, or 1998-2012. RSS data set also do not show temperature altitude amplification either for longer (1979-2012, or for shorter period (1998-2012. RSS data for successive 15-year periods from 1979-1993 till 1998-2012 does not show tropical temperature altitude amplification and in one case negative trend is registered in TLT and in two cases in TMT. In general, our results do not show presence of temperature altitude amplification in tropic in the hiatus period. [Projekat Ministarstva nauke Republike Srbije, br. III47007

Bicritical behaviors observed in coupled diode resonators

International Nuclear Information System (INIS)

Kim, Youngtae

2004-01-01

We have investigated bicritical behaviors of unidirectionally coupled diode resonators having a period doubling route to chaos. Depending on the dynamical states of the drive subsystem, the response subsystem showed a dynamical behavior other than that of the uncoupled system. The experimental results agreed well with the results obtained from the simulation of unidirectionally coupled logistic maps and oscillators. A new type of scaling behavior and a power spectrum of the hyperchaotic attractor appearing near a bicritical point were also observed.

Statistical analysis of MMS observations of energetic electron escape observed at/beyond the dayside magnetopause

Science.gov (United States)

Cohen, Ian J.; Mauk, Barry H.; Anderson, Brian J.; Westlake, Joseph H.; Sibeck, David G.; Turner, Drew L.; Fennell, Joseph F.; Blake, J. Bern; Jaynes, Allison N.; Leonard, Trevor W.; Baker, Daniel N.; Spence, Harlan E.; Reeves, Geoff D.; Giles, Barbara J.; Strangeway, Robert J.; Torbert, Roy B.; Burch, James L.

2017-09-01

Observations from the Energetic Particle Detector (EPD) instrument suite aboard the Magnetospheric Multiscale (MMS) spacecraft show that energetic (greater than tens of keV) magnetospheric particle escape into the magnetosheath occurs commonly across the dayside. This includes the surprisingly frequent observation of magnetospheric electrons in the duskside magnetosheath, an unexpected result given assumptions regarding magnetic drift shadowing. The 238 events identified in the 40 keV electron energy channel during the first MMS dayside season that exhibit strongly anisotropic pitch angle distributions indicating monohemispheric field-aligned streaming away from the magnetopause. A review of the extremely rich literature of energetic electron observations beyond the magnetopause is provided to place these new observations into historical context. Despite the extensive history of such research, these new observations provide a more comprehensive data set that includes unprecedented magnetic local time (MLT) coverage of the dayside equatorial magnetopause/magnetosheath. These data clearly highlight the common escape of energetic electrons along magnetic field lines concluded to have been reconnected across the magnetopause. While these streaming escape events agree with prior studies which show strong correlation with geomagnetic activity (suggesting a magnetotail source) and occur most frequently during periods of southward IMF, the high number of duskside events is unexpected and previously unobserved. Although the lowest electron energy channel was the focus of this study, the events reported here exhibit pitch angle anisotropies indicative of streaming up to 200 keV, which could represent the magnetopause loss of >1 MeV electrons from the outer radiation belt.

Statistical analysis of MMS observations of energetic electron escape observed at/beyond the dayside magnetopause

International Nuclear Information System (INIS)

Cohen, Ian J.; Mauk, Barry H.; Anderson, Brian J.; Westlake, Joseph H.; Sibeck, David G.

2017-01-01

Here, observations from the Energetic Particle Detector (EPD) instrument suite aboard the Magnetospheric Multiscale (MMS) spacecraft show that energetic (greater than tens of keV) magnetospheric particle escape into the magnetosheath occurs commonly across the dayside. This includes the surprisingly frequent observation of magnetospheric electrons in the duskside magnetosheath, an unexpected result given assumptions regarding magnetic drift shadowing. The 238 events identified in the 40 keV electron energy channel during the first MMS dayside season that exhibit strongly anisotropic pitch angle distributions indicating monohemispheric field-aligned streaming away from the magnetopause. A review of the extremely rich literature of energetic electron observations beyond the magnetopause is provided to place these new observations into historical context. Despite the extensive history of such research, these new observations provide a more comprehensive data set that includes unprecedented magnetic local time (MLT) coverage of the dayside equatorial magnetopause/magnetosheath. These data clearly highlight the common escape of energetic electrons along magnetic field lines concluded to have been reconnected across the magnetopause. While these streaming escape events agree with prior studies which show strong correlation with geomagnetic activity (suggesting a magnetotail source) and occur most frequently during periods of southward IMF, the high number of duskside events is unexpected and previously unobserved. Although the lowest electron energy channel was the focus of this study, the events reported here exhibit pitch angle anisotropies indicative of streaming up to 200 keV, which could represent the magnetopause loss of >1 MeV electrons from the outer radiation belt.

Do pregnancy, postpartum period and lactation predispose to recurrent toxoplasmic retinochoroiditis?

Science.gov (United States)

Brydak-Godowska, Joanna; Borkowski, Piotr Karol; Rabczenko, Daniel; Moneta-Wielgoś, Joanna; Kęcik, Dariusz

2015-02-23

The aim of the study was a statistical analysis of the possible effects of pregnancy, postpartum period, and lactation on increased risk for reactivation of toxoplasmic retinochoroiditis. A retrospective study was undertaken of the clinical records of 661 patients referred with the diagnosis of acute toxoplasmic retinochoroiditis to the Department of Zoonoses and Tropical Diseases, Medical University of Warsaw and to the Department of Ophthalmology, Medical University of Warsaw in the years 1994-2014. This group of inpatients consisted of 213 women of child-bearing age (18 to 40 years). Reactivation of toxoplasmic retinochoroiditis was observed in 24 women aged 15 to 39 years who were pregnant, in the postpartum period, or lactating. To compare the rate of the relapses in pregnant/lactating patients vs. non-pregnant/non-lactating patients, the Fisher exact test was used. Calculations were performed with WinPepi software (Abramson JH (2004) WINPEPI (PEPI-for-Windows) for epidemiologists. Epidemiologic Perspectives & Innovations, 2005, 1: 6). A total of 28 reactivations of toxoplasmic retinochoroiditis were observed (16 episodes in pregnancy, 4 in the postpartum period, and 8 during lactation) in 24 women aged 15 to 39 years. In 3 women, multiple episodes were reported (in early pregnancy and the postpartum period in 2 women, and during 2 pregnancies and lactation in 1 woman). Statistical analysis showed that the risk of an episode of toxoplasmic retinochoroiditis is 7.4-fold higher in pregnancy compared to the non-pregnant/non-lactating women (p<0.0001). Women of childbearing age with toxoplasma ocular lesions should be informed by their doctors about possible active recurrences during pregnancy and should be followed carefully by an ophthalmologist when pregnant.

The periodic table of elementary particles

International Nuclear Information System (INIS)

Bhattacharjee, B.J.

1994-01-01

It is shown that a periodic classification of elementary particles (eps) may be done with the basic properties of eps: viz. mass, spin and parity. Further application of spacing rule and GMO mass formulae show repetitions at very regular intervals. It is found that properties of eps are periodic function of rest mass. (author). 17 refs., 6 tabs

The periodic table of elementary particles

Energy Technology Data Exchange (ETDEWEB)

Bhattacharjee, B J [St. Anthony' s College, Shillong (India). Dept. of Physics

1994-01-01

It is shown that a periodic classification of elementary particles (eps) may be done with the basic properties of eps: viz. mass, spin and parity. Further application of spacing rule and GMO mass formulae show repetitions at very regular intervals. It is found that properties of eps are periodic function of rest mass. (author). 17 refs., 6 tabs.

Recurrent mass ejections observed in H-alpha and CIV

International Nuclear Information System (INIS)

Schmieder, B.; Simon, G.

1984-01-01

Time sequences of recurrent mass ejections have been observed during a coordinated SMY program (Sept. 1, 1980 - Sept. 23, 1980 - Oct. 2, 1980). Comparison of the temporal evolution of H-alpha and CIV brightnesses shows a weak phase lag between H-alpha and CIV maxima, in the case of homologous flares, with CIV brightness maxima preceding H-alpha maxima. The analysis of the variation of the ejection velocities is expected to lead to the determination of an energy balance. Such recurrent ejections could be due to periodic energy storage and periodic reorganization of magnetic field as envisaged to occur for flares, but at lower energy levels

Periodic solutions of dissipative systems revisited

Directory of Open Access Journals (Sweden)

Górniewicz Lech

2006-01-01

Full Text Available We reprove in an extremely simple way the classical theorem that time periodic dissipative systems imply the existence of harmonic periodic solutions, in the case of uniqueness. We will also show that, in the lack of uniqueness, the existence of harmonics is implied by uniform dissipativity. The localization of starting points and multiplicity of periodic solutions will be established, under suitable additional assumptions, as well. The arguments are based on the application of various asymptotic fixed point theorems of the Lefschetz and Nielsen type.

Periodic solutions of dissipative systems revisited

Directory of Open Access Journals (Sweden)

Lech Górniewicz

2006-05-01

Full Text Available We reprove in an extremely simple way the classical theorem that time periodic dissipative systems imply the existence of harmonic periodic solutions, in the case of uniqueness. We will also show that, in the lack of uniqueness, the existence of harmonics is implied by uniform dissipativity. The localization of starting points and multiplicity of periodic solutions will be established, under suitable additional assumptions, as well. The arguments are based on the application of various asymptotic fixed point theorems of the Lefschetz and Nielsen type.

DETECTION OF POLARIZED QUASI-PERIODIC MICROSTRUCTURE EMISSION IN MILLISECOND PULSARS

Energy Technology Data Exchange (ETDEWEB)

De, Kishalay; Sharma, Prateek [Department of Physics, Indian Institute of Science, Bangalore 560012 (India); Gupta, Yashwant, E-mail: kde@caltech.edu [National Centre for Radio Astrophysics, TIFR, Pune University Campus, Post Bag 3, Pune 411007 (India)

2016-12-10

Microstructure emission, involving short timescale, often quasi-periodic, intensity fluctuations in subpulse emission, is well known in normal period pulsars. In this Letter, we present the first detections of quasi-periodic microstructure emission from millisecond pulsars (MSPs), from Giant Metrewave Radio Telescope observations of two MSPs at 325 and 610 MHz. Similar to the characteristics of microstructure observed in normal period pulsars, we find that these features are often highly polarized and exhibit quasi-periodic behavior on top of broader subpulse emission, with periods of the order of a few μ s. By measuring their widths and periodicities from single pulse intensity profiles and their autocorrelation functions, we extend the microstructure timescale–rotation period relationship by more than an order of magnitude down to rotation periods ∼5 ms, and find it to be consistent with the relationship derived earlier for normal pulsars. The similarity of behavior is remarkable, given the significantly different physical properties of MSPs and normal period pulsars, and rules out several previous speculations about the possible different characteristics of microstructure in MSP radio emission. We discuss the possible reasons for the non-detection of these features in previous high time resolution MSP studies along with the physical implications of our results, both in terms of a geometric beam sweeping model and temporal modulation model for micropulse production.

Observation and excitation of magnetohydrodynamic waves in numerical models of Earth's core

Science.gov (United States)

Teed, R.; Hori, K.; Tobias, S.; Jones, C. A.

2017-12-01

Several types of magnetohydrodynamic waves are theorised to operate in Earth's outer core but their detection is limited by the inability to probe the fluid core directly. Secular variation data and periodic changes in Earth's length-of-day provide evidence for the possible existence of waves. Numerical simulations of core dynamics enable us to search directly for waves and determine their properties. With this information it is possible to consider whether they can be the origin of features observed in observational data. We focus on two types of wave identified in our numerical experiments: i) torsional waves and ii) slow magnetic Rossby waves. Our models display periodic, Earth-like torsional waves that travel outwards from the tangent cylinder circumscribing the inner core. We discuss the properties of these waves and their similarites to observational data. Excitation is via a matching of the Alfvén frequency with that of small modes of convection focused at the tangent cylinder. The slow magnetic Rossby waves observed in our simulations show that these waves may account for some geomagnetic westward drifts observed at mid-latitudes. We present analysis showing excitation of waves by the convective instability and we discuss how the detection of these waves could also provide an estimate of the strength of the toroidal component of the magnetic field within the planetary fluid core.

The HyMeX Special Observation Period in Central Italy: precipitation measurements, retrieval techniques and preliminary results

Science.gov (United States)

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

2013-04-01

The Mediterranean area concentrates the major natural risks related to the water cycle, including heavy precipitation and flash-flooding during the fall season. The capability to predict such high-impact events remains weak because of the contribution of very fine-scale processes and their non-linear interactions with the larger scale processes. These societal and science issues motivate the HyMeX (Hydrological cycle in the Mediterranean Experiment, http://www.hymex.org/) experimental programme. HyMeX aims at a better quantification and understanding of the water cycle in the Mediterranean with emphasis on intense events. The observation strategy of HyMEX is organized in a long-term (4 years) Enhanced Observation Periods (EOP) and short-term (2 months) Special Observation Periods (SOP). HyMEX has identified 3 main Mediterranean target areas: North-West (NW), Adriatic (A) and South-East (SE). Within each target area several hydrometeorological sites for heavy rainfall and flash flooding have been set up. The hydrometeorological site in Central Italy (CI) is interested by both western and eastern fronts coming from the Atlantic Ocean and Siberia, respectively. Orographic precipitations play an important role due to the central Apennine range, which reaches nearly 3000 m (Gran Sasso peak). Moreover, convective systems commonly develop in CI during late summer and beginning of autumn, often causing localized hailstorms with cluster organized cells. Western fronts may heavily hit the Tiber basin crossing large urban areas (Rome), whereas eastern fronts can cause flash floods along the Adriatic coastline. Two major basins are involved within CI region: Tiber basin (1000 km long) and its tributary Aniene and the Aterno-Pescara basin (300 km long). The first HyMeX SOP1.1 was carried out from Sept. till Nov. 2012 in the NW target area. The Italian SOP1.1 was coordinated by the Centre of Excellence CETEMPS, University of L'Aquila, a city located in the CI heart. The CI area

Meteorological circumstances during the 'Chernobyl-period'

International Nuclear Information System (INIS)

Ivens, R.; Lablans, W.N.; Wessels, H.R.A.

1987-01-01

The progress of the meteorological circumstances and air flows in Europe from 26th April up to 8th May 1986, which caused the spread of contaminated air originating from Chernobyl is outlined and mapped out. Furthermore a global survey is presented of the precipitation in the Netherlands during the period 2nd May to 10th May based on observations of various observation stations of the Royal Dutch Meteorologic Institute (KNMI). 11 figs.; 1 table (H.W.)

Time domain phenomena of wave propagation in rapidly created plasma of periodic distribution

International Nuclear Information System (INIS)

Kuo, S P

2007-01-01

Theories, experiments and numerical simulations on the interaction of electromagnetic waves with rapidly created unmagnetized plasmas are presented. In the case that plasma is created uniformly, the frequency of a propagating electromagnetic wave is upshifted. An opposite propagation wave of the same frequency is also generated. In addition, a static current supporting a wiggler magnetic field is also produced in the plasma. When a spatially periodic structure is introduced to the rapidly created plasma, the theory and numerical simulation results show that both frequency-upshifted and downshifted waves are generated. If the plasma has a large but finite dimension in the incident wave propagation direction and is created rapidly rather than instantaneously, the frequency downshifted waves are found to be trapped by the plasma when the plasma frequency is larger than the wave frequency. The wave trapping results in accumulating the frequency-downshifted waves during the finite transient period of plasma creation. Indeed, in the experimental observations the frequency downshifted signals were detected repetitively with considerably enhanced spectral intensities, confirming the results of the numerical simulations. The missing of frequency upshifted signals in the experimental observations is explained by the modal field distributions in the periodic structure, indicating that the frequency upshifted modes experience heavier collisional damping of the plasma than the frequency downshifted modes

Can the periodic spectral modulations observed in 236 Sloan Sky Survey stars be due to dark matter effects?

Science.gov (United States)

Tamburini, Fabrizio; Licata, Ignazio

2017-09-01

The search for dark matter (DM) is one of the most active and challenging areas of current research. Possible DM candidates are ultralight fields such as axions and weak interacting massive particles (WIMPs). Axions piled up in the center of stars are supposed to generate matter/DM configurations with oscillating geometries at a very rapid frequency, which is a multiple of the axion mass m B (Brito et al (2015); Brito et al (2016)). Borra and Trottier (2016) recently found peculiar ultrafast periodic spectral modulations in 236 main sequence stars in the sample of 2.5 million spectra of galactic halo stars of the Sloan Digital Sky Survey (˜1% of main sequence stars in the F-K spectral range) that were interpreted as optical signals from extraterrestrial civilizations, suggesting them as possible candidates for the search for extraterrestrial intelligence (SETI) program. We argue, instead, that this could be the first indirect evidence of bosonic axion-like DM fields inside main sequence stars, with a stable radiative nucleus, where a stable DM core can be hosted. These oscillations were not observed in earlier stellar spectral classes probably because of the impossibility of starting a stable oscillatory regime due to the presence of chaotic motions in their convective nuclei. The axion mass values, (50< {m}B< 2.4× {10}3) μ {eV}, obtained from the frequency range observed by Borra and Trottier, (0.6070< f< 0.6077) THz, agree with the recent theoretical results from high-temperature lattice quantum chromodynamics (Borsanyi et al (2016); Borsanyi et al (2016b)).

Optical resonance analysis of reflected long period fiber gratings with metal film overlay

Science.gov (United States)

Zhang, Guiju; Cao, Bing; Wang, Chinua; Zhao, Minfu

2008-11-01

We present the experimental results of a novel single-ended reflecting surface plasma resonance (SPR) based long period fiber grating (LPFG) sensor. A long period fiber grating sensing device is properly designed and fabricated with a pulsed CO2 laser writing system. Different nm-thick thin metal films are deposited on the fiber cladding and the fiber end facet for the excitation of surface plasma waves (SPWs) and the reflection of the transmission spectrum of the LPFG with doubled interaction between metal-dielectric interfaces of the fiber to enhance the SPW of the all-fiber SPR-LPFG sensing system. Different thin metal films with different thicknesses are investigated. The effect of the excited SPW transmission along the fiber cladding-metal interface with silver and aluminum films is observed. It is found that different thicknesses of the metal overlay show different resonant behaviors in terms of resonance peak situation, bandwidth and energy loss. Within a certain range, thinner metal film shows narrower bandwidth and deeper peak loss.

Prolonged hypoxia increases survival even in Zebrafish (Danio rerio showing cardiac arrhythmia.

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Renate Kopp

Full Text Available Tolerance towards hypoxia is highly pronounced in zebrafish. In this study even beneficial effects of hypoxia, specifically enhanced survival of zebrafish larvae, could be demonstrated. This effect was actually more pronounced in breakdance mutants, which phenotypically show cardiac arrhythmia. Breakdance mutants (bre are characterized by chronically reduced cardiac output. Despite an about 50% heart rate reduction, they become adults, but survival rate significantly drops to 40%. Normoxic bre animals demonstrate increased hypoxia inducible factor 1 a (Hif-1α expression, which indicates an activated hypoxic signaling pathway. Consequently, cardiovascular acclimation, like cardiac hypertrophy and increased erythrocyte concentration, occurs. Thus, it was hypothesized, that under hypoxic conditions survival might be even more reduced. When bre mutants were exposed to hypoxic conditions, they surprisingly showed higher survival rates than under normoxic conditions and even reached wildtype values. In hypoxic wildtype zebrafish, survival yet exceeded normoxic control values. To specify physiological acclimation, cardiovascular and metabolic parameters were measured before hypoxia started (3 dpf, when the first differences in survival rate occurred (7 dpf and when survival rate plateaued (15 dpf. Hypoxic animals expectedly demonstrated Hif-1α accumulation and consequently enhanced convective oxygen carrying capacity. Moreover, bre animals showed a significantly enhanced heart rate under hypoxic conditions, which reached normoxic wildtype values. This improvement in convective oxygen transport ensured a sufficient oxygen and nutrient supply and was also reflected in the significantly higher mitochondrial activity. The highly optimized energy metabolism observed in hypoxic zebrafish larvae might be decisive for periods of higher energy demand due to organ development, growth and increased activity. However, hypoxia increased survival only during a

Observational and Dynamical Wave Climatologies. VOS vs Satellite Data

Science.gov (United States)

Grigorieva, Victoria; Badulin, Sergei; Chernyshova, Anna

2013-04-01

The understanding physics of wind-driven waves is crucially important for fundamental science and practical applications. This is why experimental efforts are targeted at both getting reliable information on sea state and elaborating effective tools of the sea wave forecasting. The global Visual Wave Observations and satellite data from the GLOBWAVE project of the European Space Agency are analyzed in the context of these two viewpoints. Within the first "observational" aspect we re-analyze conventional climatologies of all basic wave parameters for the last decades [5]. An alternative "dynamical" climatology is introduced as a tool of prediction of dynamical features of sea waves on global scales. The features of wave dynamics are studied in terms of one-parametric dependencies of wave heights on wave periods following the theoretical concept of self-similar wind-driven seas [3, 1, 4] and recently proposed approach to analysis of Voluntary Observing Ship (VOS) data [2]. Traditional "observational" climatologies based on VOS and satellite data collections demonstrate extremely consistent pictures for significant wave heights and dominant periods. On the other hand, collocated satellite and VOS data show significant differences in wave heights, wind speeds and, especially, in wave periods. Uncertainties of visual wave observations can explain these differences only partially. We see the key reason of this inconsistency in the methods of satellite data processing which are based on formal application of data interpolation methods rather than on up-to-date physics of wind-driven waves. The problem is considered within the alternative climatology approach where dynamical criteria of wave height-to-period linkage are used for retrieving wave periods and constructing physically consistent dynamical climatology. The key dynamical parameter - exponent R of one-parametric dependence Hs ~ TR shows dramatically less pronounced latitudinal dependence as compared to observed Hs

THE ROTATION PERIOD OF C/2014 Q2 (LOVEJOY)

Energy Technology Data Exchange (ETDEWEB)

Serra-Ricart, Miquel; Licandro, Javier, E-mail: mserra@iac.es, E-mail: jlicandr@iac.es [Instituto de Astrofísica de Canarias, c/Vía Láctea, s/n, E-38200 La Laguna, Tenerife (Spain)

2015-11-20

C/2014 Q2 (Lovejoy) was observed around perihelion (2015 January 30) on 15 nights between 2015 January 21 and February 11 using the TADer 0.3-m astrograph telescope at Teide Observatory (IAC, Tenerife, Spain). Two large spiral jet structures were observed over several cometary rotations. A new method of searching for periodicities in the PA of spiral jets in the coma region at a fixed distance (20,624 km) from the cometary optocenter is presented and used to determine a nuclear rotation period of 17.89 ± 0.17 hr.

[Studies on flomoxef in the perinatal period].

Science.gov (United States)

Cho, N; Fukunaga, K; Kunii, K; Kobayashi, I

1991-06-01

Pharmacokinetic, bacteriological and clinical studies on flomoxef (FMOX) in the perinatal period were carried out with the following summary of the results. Antibacterial effects of FMOX on the growth of methicillin-resistant Staphylococcus aureus (MRSA, MIC 400 micrograms/ml), methicillin-sensitive S. aureus (MSSA, MIC 0.78 microgram/ml), Escherichia coli (MIC 3.13 micrograms/ml and MIC 0.20 microgram/ml) in amniotic fluid were determined and it was found that the activity of FMOX was enhanced in the amniotic fluid. FMOX rapidly penetrated into tissues and sera of pregnant women upon intravenous injection and its maternal serum concentrations reached their peak levels shortly after administration. Placental penetration of FMOX to the fetus was good and, after single intravenous injection of 1 g, the concentrations of FMOX in the umbilical cord serum and amniotic fluid exceeded MICs against major causative organisms of perinatal infections. These results indicate that single intravenous injection of FMOX 1 g twice a day is effective for the treatment and prophylaxis of perinatal infections. Injection of FMOX for the treatment of 14 cases of puerperal infections showed excellent clinical effectiveness with 100% clinical effect and 81.8% bacteriological response. No side-effect was observed in any case. All of these results suggested clinical usefulness of FMOX in the perinatal period.

Distributed Fusion Estimation for Multisensor Multirate Systems with Stochastic Observation Multiplicative Noises

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Peng Fangfang

2014-01-01

Full Text Available This paper studies the fusion estimation problem of a class of multisensor multirate systems with observation multiplicative noises. The dynamic system is sampled uniformly. Sampling period of each sensor is uniform and the integer multiple of the state update period. Moreover, different sensors have the different sampling rates and observations of sensors are subject to the stochastic uncertainties of multiplicative noises. At first, local filters at the observation sampling points are obtained based on the observations of each sensor. Further, local estimators at the state update points are obtained by predictions of local filters at the observation sampling points. They have the reduced computational cost and a good real-time property. Then, the cross-covariance matrices between any two local estimators are derived at the state update points. At last, using the matrix weighted optimal fusion estimation algorithm in the linear minimum variance sense, the distributed optimal fusion estimator is obtained based on the local estimators and the cross-covariance matrices. An example shows the effectiveness of the proposed algorithms.

Trends and periodicity of daily temperature and precipitation extremes during 1960-2013 in Hunan Province, central south China

Science.gov (United States)

Chen, Ajiao; He, Xinguang; Guan, Huade; Cai, Yi

2018-04-01

In this study, the trends and periodicity in climate extremes are examined in Hunan Province over the period 1960-2013 on the basis of 27 extreme climate indices calculated from daily temperature and precipitation records at 89 meteorological stations. The results show that in the whole province, temperature extremes exhibit a warming trend with more than 50% stations being statistically significant for 7 out of 16 temperature indices, and the nighttime temperature increases faster than the daytime temperature at the annual scale. The changes in most extreme temperature indices show strongly coherent spatial patterns. Moreover, the change rates of almost all temperature indices in north Hunan are greater than those of other regions. However, the statistically significant changes in indices of extreme precipitation are observed at fewer stations than in extreme temperature indices, forming less spatially coherent patterns. Positive trends in indices of extreme precipitation show that the amount and intensity of extreme precipitation events are generally increasing in both annual and seasonal scales, whereas the significant downward trend in consecutive wet days indicates that the precipitation becomes more even over the study period. Analysis of changes in probability distributions of extreme indices for 1960-1986 and 1987-2013 also demonstrates a remarkable shift toward warmer condition and increasing tendency in the amount and intensity of extreme precipitation during the past decades. The variations in extreme climate indices exhibit inconstant frequencies in the wavelet power spectrum. Among the 16 temperature indices, 2 of them show significant 1-year periodic oscillation and 7 of them exhibit significant 4-year cycle during some certain periods. However, significant periodic oscillations can be found in all of the precipitation indices. Wet-day precipitation and three absolute precipitation indices show significant 1-year cycle and other seven provide

Observation of γ rays > 1015 eV from Cygnus X-3

International Nuclear Information System (INIS)

Lloyd-Evans, J.; Coy, R.N.; Lambert, A.; Lapikens, J.; Patel, M.; Reid, R.J.O.; Watson, A.A.

1983-01-01

The X-ray binary system Cygnus X-3 is a source of particular interest. As well as emitting X-rays which are modulated with a 4.8-h period, it has been observed in 30-100 MeV γ rays by the SAS II satellite and several groups have detected γ rays in the TeV range showing the same period. Most recently, using the small extensive air shower array at Kiel, workers have found that the γ-ray spectrum of Cygnus X-3 extends above 2 x 10 15 eV, with an integral flux of (7.4 +- 3.2) x 10 -14 cm -2 s -1 . This paper confirms the Kiel observations and presents evidence that the γ-ray spectrum of Cygnus X-3 steepens above 10 16 eV. (author)

Observation of Dynamical Super-Efimovian Expansion in a Unitary Fermi Gas

Science.gov (United States)

Deng, Shujin; Diao, Pengpeng; Li, Fang; Yu, Qianli; Yu, Shi; Wu, Haibin

2018-03-01

We report an observation of a dynamical super Efimovian expansion in a strongly interacting Fermi gas by engineering time dependent external harmonic trap frequencies. When the trap frequency is tailored as [1 /4 t2+1 /t2λ log2(t /t*)]1/2, where t* and λ are two controllable parameters, and the change is faster than a critical value, the expansion of such a quantum gas shows novel dynamics that share the same characteristics as the super Efimov effect. A clear double-log periodicity with discrete geometric scaling emerges for the cloud size in the expansion. The universality of such scaling dynamics is verified both in the noninteracting and in the unitarity limit of Fermi gas. Moreover, the measured energy scaling reveals that the potential and internal energy also show double-log periodicity with a π /2 phase difference, but the total energy is monotonically decreased. Observing super Efimovian evolution represents a paradigm in probing universal properties and allows us in a new way to study many-body nonequilibrium dynamics with experiments.

Heat flux variations over sea ice observed at the coastal area of the Sejong Station, Antarctica

Science.gov (United States)

Park, Sang-Jong; Choi, Tae-Jin; Kim, Seong-Joong

2013-08-01

This study presents variations of sensible heat flux and latent heat flux over sea ice observed in 2011 from the 10-m flux tower located at the coast of the Sejong Station on King George Island, Antarctica. A period from July to September was selected as a sea ice period based on daily record of sea state and hourly photos looking at the Marian Cove in front of the Sejong Station. For the sea ice period, mean sensible heat flux is about -11 Wm-2, latent heat flux is about +2 W m-2, net radiation is -12 W m-2, and residual energy is -3 W m-2 with clear diurnal variations. Estimated mean values of surface exchange coefficients for momentum, heat and moisture are 5.15 × 10-3, 1.19 × 10-3, and 1.87 × 10-3, respectively. The observed exchange coefficients of heat shows clear diurnal variations while those of momentum and moisture do not show diurnal variation. The parameterized exchange coefficients of heat and moisture produces heat fluxes which compare well with the observed diurnal variations of heat fluxes.

Surface plasmon enhanced absorption and suppressed transmission in periodic arrays of graphene ribbons

Science.gov (United States)

Nikitin, A. Yu.; Guinea, F.; Garcia-Vidal, F. J.; Martin-Moreno, L.

2012-02-01

Resonance diffraction in the periodic array of graphene microribbons is theoretically studied following a recent experiment [L. Ju , Nature Nanotech.1748-338710.1038/nnano.2011.146 6, 630 (2011)]. Systematic studies over a wide range of parameters are presented. It is shown that a much richer resonant picture would be observable for higher relaxation times of charge carriers: More resonances appear and transmission can be totally suppressed. The comparison with the absorption cross-section of a single ribbon shows that the resonant features of the periodic array are associated with leaky plasmonic modes. The longest-wavelength resonance provides the highest visibility of the transmission dip and has the strongest spectral shift and broadening with respect to the single-ribbon resonance, due to collective effects.

Theoretical consideration of the use of mode entangled states to beat the minimal period of an interference pattern

International Nuclear Information System (INIS)

Podoshvedov, Sergey A

2005-01-01

We propose to use multi-photon mode entangled states to beat the minimal period of an interference pattern. Using the multi-photon mode entangled states, we show that it is possible to observe an interference effect with a period of minimum size λ/2N in an N-photon absorbing substrate. In the framework of the method developed, we propose a simple scheme for a quantum encoder with a two-photon quantum channel for producing a desired N-photon mode entangled state on which to write an interference pattern with a smaller period, as compared with the one in the case of the use of classical light

[Gender and age characteristics and the trends in prevalence of obesity in the adult population in Russia during the 1994-2012 period].

Science.gov (United States)

Martinchik, A N; Baturin, A K; Keshabyants, E E; Peskova, E V

2015-01-01

The analysis of the prevalence of overweight and obesity in adult age and sex groups of the Russian population in the dynamics of observation from 1994 to 2012 was based on anthropometric measurements of weight and height in Russian Longitudinal Monitoring Survey. The mean values of body mass index (BMI) and the frequency of obesity (BMI > 30.0) of the entire population have been increased during the observation period. The analyzing the data by gender revealed a significant increase in the frequency of obesity mainly among men, especially in the period 2005-2012, whereas among women increased incidence of obesity was negligible. The most rapid increase in the frequency of overweight and obesity in men noted in the age period of 20-30 years, and further increase in frequency of overweight and obesity with age were negligible. The rate of overweight and obesity in women had almost linear increase in the age period of 20-60 years. Comparative analysis of the prevalence of obesity showed that the obtained values for the 2000-2012 period were close to those characteristic of the developed world in recent decades. The growth of obesity rate in the general adult population in 2000-2005 and the 2005-2012 was 0.4% per year. At the same time, men showed a significant acceleration of the growth rate of obesity in the period 2005 to 2012 (0.61% per year) compared with the period 2000-2005 (0.44% per year). Increase in the frequency of obesity was observed in all regions in 2000 to 2012. The data should be considered as a rationale for research into the causes of gender differences in the prevalence of overweight and obesity in the first place to find differences in the peculiarities of dietary intake between men and women at different ages of life, leading to the development of overweight and obesity.

MRI and morphological observation in C6 glioma model rats and significance

International Nuclear Information System (INIS)

Zhou Ying; Yuan Bo; Wang Hao; Lu Jin; Yuan Changji; Ma Yue; Tong Dan; Zhang Kun; Gao Feng; Wu Xiaogang

2013-01-01

Objective: To establish stable and reliable rat C6 glioma model, and to perform MRI dynamic observation and pathomorphological observation in model animal brain, and to provide experimental basis for pharmaceutical research on anti-glioma drugs. Methods: The C6 glioma cells were cultured and 20 μL cultural fluid containing 1×10 6 C6 cells was sterotactically implanted into the left caudate nuclei in 10 male Wistar rats, respectively. The changes in the behavior of the rats after implantation were observed and recorded. MRI dynamic scanning was performed in 10 rats 2, 3 and 4 weeks after implantation and the brain tissues were taken for general and pathological examination when the 10 rats were naturally dead. The survival period of tumor-bearing rats was calculated. Results: 2 weeks after implantation the rats showed decreased activities and food intake, fur lackluster, and conjunctival congestion and so on; 3 weeks later, some rats appeared nerve symptoms such as body twitch, body hemiplegy, body distortion, rotation and so on. All the 10 rats died in 8-30 d. The median survival period of the tumor-bearing rats was 18 d, the average survival period was (18.3±7.3) d. The pathological examination showed that the tumor cells were arranged irregularly closely and karyokinesis was easy to see; tumor vascular tissue proliferation and tumor invasive growth into surrounding normal tissues were found. The expression of glial fibrillary acidic protein (GFAP) was positive in the tumors. Conclusion: A stable animal model of intracranial glioma is successfully established by stereotactic implantation of C6 cells into the rat caudate nucleus. The results of MRI dynamic observation and pathohistological observation on the model animal brain tissue. Can provide experimental basis for selecting the appropriate time window to perform the pharmaceutical research on anti-glioma drugs. (authors)

Systematic Onset of Periodic Patterns in Random Disk Packings

Science.gov (United States)

Topic, Nikola; Pöschel, Thorsten; Gallas, Jason A. C.

2018-04-01

We report evidence of a surprising systematic onset of periodic patterns in very tall piles of disks deposited randomly between rigid walls. Independently of the pile width, periodic structures are always observed in monodisperse deposits containing up to 1 07 disks. The probability density function of the lengths of disordered transient phases that precede the onset of periodicity displays an approximately exponential tail. These disordered transients may become very large when the channel width grows without bound. For narrow channels, the probability density of finding periodic patterns of a given period displays a series of discrete peaks, which, however, are washed out completely when the channel width grows.

A critical period of progesterone withdrawal precedes menstruation in macaques

Science.gov (United States)

Slayden, Ov D; Brenner, Robert M

2006-01-01

Macaques are menstruating nonhuman primates that provide important animal models for studies of hormonal regulation in the uterus. In women and macaques the decline of progesterone (P) at the end of the cycle triggers endometrial expression of a variety of matrix metalloproteinase (MMP) enzymes that participate in tissue breakdown and menstrual sloughing. To determine the minimal duration of P withdrawal required to induce menses, we assessed the effects of adding P back at various time points after P withdrawal on both frank bleeding patterns and endometrial MMP expression. Artificial menstrual cycles were induced by treating the animals sequentially with implants releasing estradiol (E2) and progesterone (P). To assess bleeding patterns, P implants were removed at the end of a cycle and then added back at 12, 24, 30, 36, 40, 48, 60, or 72 hours (h) after the initial P withdrawal. Observational analysis of frank bleeding patterns showed that P replacement at 12 and 24 h blocked menses, replacement at 36 h reduced menses but replacement after 36 h failed to block menses. These data indicate that in macaques, a critical period of P withdrawal exists and lasts approximately 36 h. In other similarly cycled animals, we withdrew P and then added P back either during (12–24 h) or after (48 h) the critical period, removed the uterus 24 h after P add back and evaluated endometrial MMP expression. Immunocytochemistry showed that replacement of P during the critical period suppressed MMP-1, -2 and -3 expression along with menses, but replacement of P at 48 h, which failed to suppress mense, suppressed MMP-1 and MMP-3 but did not block MMP-2. We concluded that upregulation of MMPs is essential to menses induction, but that after the critical period, menses will occur even if some MMPs are experimentally blocked. PMID:17118170

Observations and Numerical Modeling of the Jovian Ribbon

Science.gov (United States)

Cosentino, R. G.; Simon, A.; Morales-Juberias, R.; Sayanagi, K. M.

2015-01-01

Multiple wavelength observations made by the Hubble Space Telescope in early 2007 show the presence of a wavy, high-contrast feature in Jupiter's atmosphere near 30 degrees North. The "Jovian Ribbon," best seen at 410 nanometers, irregularly undulates in latitude and is time-variable in appearance. A meridional intensity gradient algorithm was applied to the observations to track the Ribbon's contour. Spectral analysis of the contour revealed that the Ribbon's structure is a combination of several wavenumbers ranging from k equals 8-40. The Ribbon is a dynamic structure that has been observed to have spectral power for dominant wavenumbers which vary over a time period of one month. The presence of the Ribbon correlates with periods when the velocity of the westward jet at the same location is highest. We conducted numerical simulations to investigate the stability of westward jets of varying speed, vertical shear, and background static stability to different perturbations. A Ribbon-like morphology was best reproduced with a 35 per millisecond westward jet that decreases in amplitude for pressures greater than 700 hectopascals and a background static stability of N equals 0.005 per second perturbed by heat pulses constrained to latitudes south of 30 degrees North. Additionally, the simulated feature had wavenumbers that qualitatively matched observations and evolved throughout the simulation reproducing the Jovian Ribbon's dynamic structure.

Planet X as the source of the periodic and steady-state flux of short period comets

International Nuclear Information System (INIS)

Matese, J.J.; Whitmire, D.P.

1986-01-01

The cratering and fossil records suggest that impacts on the earth have been modulated with a period of roughly 30 Myr. In the Planet X model, this modulation is the result of the interaction of Planet X with a primordial disk of planetesimals lying beyond the orbit of Neptune. In this paper, observational and theoretical evidence supporting the existence of Planet X and the planetesimal disk is briefly reviewed, and the constraints on the orbit parameters of Planet X and the disk parameters which must be satisfied to ensure consistency with observational limits are discussed

Observations of magnetic flux ropes during magnetic reconnection in the Earth's magnetotail

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A. L. Borg

2012-05-01

Full Text Available We present an investigation of magnetic flux ropes observed by the four Cluster spacecraft during periods of magnetic reconnection in the Earth's magnetotail. Using a list of 21 Cluster encounters with the reconnection process in the period 2001–2006 identified in Borg et al. (2012, we present the distribution and characteristics of the flux ropes. We find 27 flux ropes embedded in the reconnection outflows of only 11 of the 21 reconnection encounters. Reconnection processes associated with no flux rope observations were not distinguishable from those where flux ropes were observed. Only 7 of the 27 flux ropes show evidence of enhanced energetic electron flux above 50 keV, and there was no clear signature of the flux rope in the thermal particle measurements. We found no clear correlation between the flux rope core field and the prevailing IMF By direction.

Periodic Boundary Motion in Thermal Turbulence

International Nuclear Information System (INIS)

Zhang, Jun; Libchaber, Albert

2000-01-01

A free-floating plate is introduced in a Benard convection cell with an open surface. It partially covers the cell and distorts the local heat flux, inducing a coherent flow that in turn moves the plate. Remarkably, the plate can be driven to a periodic motion even under the action of a turbulent fluid. The period of the oscillation depends on the coverage ratio, and on the Rayleigh number of the convective system. The plate oscillatory behavior observed in this experiment may be related to a geological model, in which continents drift in a quasiperiodic fashion. (c) 2000 The American Physical Society

Swift/BAT and RXTE Observations of the Peculiar X-ray Binary 4U 2206+54 - Disappearance of the 9.6 Day Modulation

Science.gov (United States)

Corbet, R. H. D.; Markwardt, C.; Tueller, J.

2007-01-01

Observations of the high-mass X-ray binary 4U 2206+54 with the Swift Burst Alert Telescope (BAT) do not show modulation at the previously reported period of 9.6 days found from observations made with the Rossi X-ray Timing Explorer (RXTE) All-Sky Monitor (ASM). Instead, the strongest peak in the power spectrum of the BAT light curve occurs at a period of 19.25+/-0.08 days, twice the period found with the RXTE ASM. The maximum of the folded BAT light curve is also delayed compared to the maximum of the folded ASM light curve. The most recent ASM data folded on twice the 9.6 day period show 'similar morphology to the folded BAT light curve. This suggests that the apparent period doubling is a recent secular change rather than an energy-dependent effect. The 9.6 day period is thus not a permanent strong feature of the light curve. We suggest that the orbital period of 4U 2206+54 may be twice the previously proposed value.

Longitudinal differences observed in the ionospheric F-region during the major geomagnetic storm of 31 March 2001

Directory of Open Access Journals (Sweden)

Y. Sahai

2004-09-01

Full Text Available A new ionospheric sounding station using a Canadian Advanced Digital Ionosonde (CADI was established for routine measurements by the "Universidade do Vale do Paraiba (UNIVAP" at São José dos Campos (23.2° S, 45.9° W, Brazil, in August 2000. A major geomagnetic storm with gradual commencement at about 01:00 UT was observed on 31 March 2001. In this paper, we present and discuss salient features from the ionospheric sounding measurements carried out at S. J. Campos on the three consecutive UT days 30 March (quiet, 31 March (disturbed and 1 April (recovery 2001. During most of the storm period, the foF2 values showed negative phase, whereas during the two storm-time peaks, large F-region height variations were observed. In order to study the longitudinal differences observed in the F-region during the storm, the simultaneous ionospheric sounding measurements carried out at S. J. Campos, El Arenosillo (37.1° N, 6.7° W, Spain, Okinawa (26.3° N, 127.8° E, Japan and Wakkanai (45.5° N, 141.7° E, Japan, during the period 30 March-1 April 2001, have been analyzed. A comparison of the observed ionospheric parameters (h'F and foF2 in the two longitudinal zones (1. Japanese and 2. Brazilian-Spanish shows both similarities and differences associated with the geomagnetic disturbances. Some latitudinal differences are also observed in the two longitudinal zones. In addition, global ionospheric TEC maps from the worldwide network of GPS receivers are presented, showing widespread TEC changes during both the main and recovery phases of the storm. The ionospheric sounding measurements are compared with the ASPEN-TIMEGCM model runs appropriate for the storm conditions. The model results produce better agreement during the quiet period. During the disturbed period, some of the observed F-region height variations are well reproduced by the model results. The model foF2 and TEC results differ considerably during the recovery period and indicate much

Longitudinal differences observed in the ionospheric F-region during the major geomagnetic storm of 31 March 2001

Directory of Open Access Journals (Sweden)

Y. Sahai

2004-09-01

Full Text Available A new ionospheric sounding station using a Canadian Advanced Digital Ionosonde (CADI was established for routine measurements by the "Universidade do Vale do Paraiba (UNIVAP" at São José dos Campos (23.2° S, 45.9° W, Brazil, in August 2000. A major geomagnetic storm with gradual commencement at about 01:00 UT was observed on 31 March 2001. In this paper, we present and discuss salient features from the ionospheric sounding measurements carried out at S. J. Campos on the three consecutive UT days 30 March (quiet, 31 March (disturbed and 1 April (recovery 2001. During most of the storm period, the foF2 values showed negative phase, whereas during the two storm-time peaks, large F-region height variations were observed. In order to study the longitudinal differences observed in the F-region during the storm, the simultaneous ionospheric sounding measurements carried out at S. J. Campos, El Arenosillo (37.1° N, 6.7° W, Spain, Okinawa (26.3° N, 127.8° E, Japan and Wakkanai (45.5° N, 141.7° E, Japan, during the period 30 March-1 April 2001, have been analyzed. A comparison of the observed ionospheric parameters (h'F and foF2 in the two longitudinal zones (1. Japanese and 2. Brazilian-Spanish shows both similarities and differences associated with the geomagnetic disturbances. Some latitudinal differences are also observed in the two longitudinal zones. In addition, global ionospheric TEC maps from the worldwide network of GPS receivers are presented, showing widespread TEC changes during both the main and recovery phases of the storm. The ionospheric sounding measurements are compared with the ASPEN-TIMEGCM model runs appropriate for the storm conditions. The model results produce better agreement during the quiet period. During the disturbed period, some of the observed F-region height variations are well reproduced by the model results. The model foF2 and TEC results differ considerably during the

Diverse Long-term Variability of Five Candidate High-mass X-Ray Binaries from Swift Burst Alert Telescope Observations

Energy Technology Data Exchange (ETDEWEB)

Corbet, Robin H. D. [University of Maryland, Baltimore County, MD 21250 (United States); Coley, Joel B. [NASA Postdoctoral Program, and Astroparticle Physics Laboratory, Code 661 NASA Goddard Space Flight Center, Greenbelt Road, MD 20771 (United States); Krimm, Hans A., E-mail: corbet@umbc.edu [Universities Space Research Association, 10211 Wincopin Circle, Suite 500, Columbia, MD 21044 (United States)

2017-09-10

We present an investigation of long-term modulation in the X-ray light curves of five little-studied candidate high-mass X-ray binaries using the Swift Burst Alert Telescope. IGR J14488-5942 and AX J1700.2-4220 show strong modulation at periods of 49.6 and 44 days, respectively, which are interpreted as orbital periods of Be star systems. For IGR J14488-5942, observations with the Swift X-ray Telescope show a hint of pulsations at 33.4 s. For AX J1700.2-4220, 54 s pulsations were previously found with XMM-Newton . Swift J1816.7-1613 exhibits complicated behavior. The strongest peak in the power spectrum is at a period near 150 days, but this conflicts with a determination of a period of 118.5 days by La Parola et al. AX J1820.5-1434 has been proposed to exhibit modulation near 54 days, but the extended BAT observations suggest modulation at slightly longer than double this at approximately 111 days. There appears to be a long-term change in the shape of the modulation near 111 days, which may explain the apparent discrepancy. The X-ray pulsar XTE J1906+090, which was previously proposed to be a Be star system with an orbital period of ∼30 days from pulse timing, shows peaks in the power spectrum at 81 and 173 days. The origins of these periods are unclear, although they might be the orbital period and a superorbital period respectively. For all five sources, the long-term variability, together with the combination of orbital and proposed pulse periods, suggests that the sources contain Be star mass donors.

A technique to detect periodic and non-periodic ultra-rapid flux time variations with standard radio-astronomical data

Science.gov (United States)

Borra, Ermanno F.; Romney, Jonathan D.; Trottier, Eric

2018-06-01

We demonstrate that extremely rapid and weak periodic and non-periodic signals can easily be detected by using the autocorrelation of intensity as a function of time. We use standard radio-astronomical observations that have artificial periodic and non-periodic signals generated by the electronics of terrestrial origin. The autocorrelation detects weak signals that have small amplitudes because it averages over long integration times. Another advantage is that it allows a direct visualization of the shape of the signals, while it is difficult to see the shape with a Fourier transform. Although Fourier transforms can also detect periodic signals, a novelty of this work is that we demonstrate another major advantage of the autocorrelation, that it can detect non-periodic signals while the Fourier transform cannot. Another major novelty of our work is that we use electric fields taken in a standard format with standard instrumentation at a radio observatory and therefore no specialized instrumentation is needed. Because the electric fields are sampled every 15.625 ns, they therefore allow detection of very rapid time variations. Notwithstanding the long integration times, the autocorrelation detects very rapid intensity variations as a function of time. The autocorrelation could also detect messages from Extraterrestrial Intelligence as non-periodic signals.

Small flow rate can supply inwardly migrating shortest-period planets

Directory of Open Access Journals (Sweden)

Taylor S.F.

2013-04-01

Full Text Available The number of exoplanets found with periods as short as one day and less was surprising given how fast these planets had been expected to migrate into the star due to the tides raised on the star by planets at such close distances. It has been seen as improbable that we would find planets in such a small final fraction of their lives [1]. The favored solution has been that the tidal dissipation is much weaker than expected, which would mean that the final infall would be a larger fraction of the planets’ life. We find no reason, however, to exclude the explanation that a small number of planets are continuously sent migrating inwards such that these planets indeed are in the last fraction of their lives. Following the observation that the distribution of medium planets disfavors tidal dissipation being significantly weaker than has been found from observations of binary stars [2], we now show that the numbers of planets in such a “flow” of excess planets migrating inwards is low enough that even depletion of the three-day pileup is a plausible source. Then the shortest period occurrence distribution would be shaped by planets continuously being sent into the star, which may explain the depletion of the pileup in the Kepler field relative to the solar neighborhood [3]. Because Kepler observes above the galactic plan, [3] suggested the Kepler field may include an older population of stars. The tidal dissipation strength in stars due to giant planets may be not greatly weaker than it is in binary stars.

Observations of volcanic earthquakes and tremor at Deception Island - Antarctica

Directory of Open Access Journals (Sweden)

J. Morales

1999-06-01

Full Text Available Deception Island - South Shetlands, Antarctica is site of active volcanism. Since 1988 field surveys have been carried out with the aim of seismic monitoring, and in 1994 a seismic array was set up near the site of the Spanish summer base in order to better constrain the source location and spectral properties of the seismic events related to the volcanic activity. The array was maintained during the Antarctic summer of 1995 and the last field survey was carried out in 1996. Data show the existence of three different groups (or families of seismic events: 1 long period events, with a quasi-monochromatic spectral content (1-3 Hz peak frequency and a duration of more than 50 s, often occurring in small swarms lasting from several minutes to some day; 2 volcanic tremor, with a spectral shape similar to the long period events but with a duration of several minutes (2-10; 3 hybrid events, with a waveform characterised by the presence of a high frequency initial phase, followed by a low frequency phase with characteristics similar to those of the long period events. The high frequency phase of the hybrid events was analysed using polarisation techniques, showing the presence of P waves. This phase is presumably located at short epicentral distances and shallow source depth. All the analysed seismic events show back-azimuths between 120 and 330 degrees from north (corresponding to zones of volcanic activity showing no seismic activity in the middle of the caldera. Particle motion, Fourier spectral and spectrogram analysis show that the low frequency part of the three groups of the seismic signals have similar patterns. Moreover careful observations show that the high frequency phase which characterises the hybrid events is present in the long period and in the tremor events, even with lower signal to noise ratios. This evidence suggests that long period events are events in which the high frequency part is simply difficult to observe, due to a very

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

Science.gov (United States)

Guliyev, Ayyub; Nabiyev, Shaig

2015-12-01

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

Comparison of human and electronic observation for the measurement of compliance with hand hygiene.

Science.gov (United States)

Filho, Miguel Almeida O; Marra, Alexandre R; Magnus, Thyago Pereira; Rodrigues, Rodrigo Dias; Prado, Marcelo; de Souza Santini, Tales Roberto; da Silva Victor, Elivane; Ishibe, Eder Issao; Pavão Dos Santos, Oscar Fernando; Edmond, Michael B

2014-11-01

Monitoring of hand hygiene is an important part of the improvement of hospital quality indicators. This study was prospectively performed over a 14-week (electronic observer) period from December 3, 2013-March 9, 2014, to evaluate hand hygiene compliance in an adult step-down unit. We compared electronic handwash counters with the application of radiofrequency identification (RFID - ZigBee; i-Healthsys, São Carlos, Brazil) (electronic observer), which counts each activation of the alcohol gel dispenser to direct observation (human observer) using the iScrub application. For the overall time period of simultaneous electronic and human observation, we found that the electronic observer identified 414 hand hygiene episodes, whereas the human observers identified 448 episodes. Therefore, we found 92% (95% confidence interval [CI], 90%-95%) overall concordance (414/448), with an intraclass correlation coefficient of .87 (95% CI, 0.77-0.92). Our RFID (ZigBee) system showed good accuracy (92%) and is a useful method to monitor hand hygiene compliance. Copyright © 2014 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Periodically poled silicon

Science.gov (United States)

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

2010-02-01

Bulk centrosymmetric silicon lacks second-order optical nonlinearity χ(2) - a foundational component of nonlinear optics. Here, we propose a new class of photonic device which enables χ(2) as well as quasi-phase matching based on periodic stress fields in silicon - periodically-poled silicon (PePSi). This concept 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 χ(2)) effects. The concept can also be simply achieved by having periodic arrangement of stressed thin films along a silicon waveguide. As an example of the utility, we present simulations showing that mid-wave infrared radiation can be efficiently generated through difference frequency generation from near-infrared with a conversion efficiency of 50% based on χ(2) values measurements for strained silicon reported in the literature [Jacobson et al. Nature 441, 199 (2006)]. The use of PePSi for frequency conversion can also be extended to terahertz generation. With integrated piezoelectric material, dynamically control of χ(2)nonlinearity in PePSi waveguide may also be achieved. The successful realization of PePSi based devices depends on the strength of the stress induced χ(2) in silicon. Presently, there exists a significant discrepancy in the literature between the theoretical and experimentally measured values. We present a simple theoretical model that produces result consistent with prior theoretical works and use this model to identify possible reasons for this discrepancy.

US Daily Pilot Balloon Observations

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Pilot Balloon observational forms for the United States. Taken by Weather Bureau and U.S. Army observers. Period of record 1918-1960. Records scanned from the NCDC...

Observed tail current systems associated with bursty bulk flows and auroral streamers during a period of multiple substorms

Directory of Open Access Journals (Sweden)

C. Forsyth

2008-02-01

Full Text Available We present a multi-instrument study of a substorm bursty bulk flow (BBF and auroral streamer. During a substorm on 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 currents associated with BBFs and auroral streamers. The observations of the BBF are consistent with the plasma "bubble" model of Chen and Wolf (1993. Furthermore, we show that the observations of the BBF are consistent with the creation of the BBF by the reconnection of open field lines Earthward of a substorm associated near-Earth neutral line.

Seismic isolation of two dimensional periodic foundations

International Nuclear Information System (INIS)

Yan, Y.; Mo, Y. L.; Laskar, A.; Cheng, Z.; Shi, Z.; Menq, F.; Tang, Y.

2014-01-01

Phononic crystal is now used to control acoustic waves. When the crystal goes to a larger scale, it is called periodic structure. The band gaps of the periodic structure can be reduced to range from 0.5 Hz to 50 Hz. Therefore, the periodic structure has potential applications in seismic wave reflection. In civil engineering, the periodic structure can be served as the foundation of upper structure. This type of foundation consisting of periodic structure is called periodic foundation. When the frequency of seismic waves falls into the band gaps of the periodic foundation, the seismic wave can be blocked. Field experiments of a scaled two dimensional (2D) periodic foundation with an upper structure were conducted to verify the band gap effects. Test results showed the 2D periodic foundation can effectively reduce the response of the upper structure for excitations with frequencies within the frequency band gaps. When the experimental and the finite element analysis results are compared, they agree well with each other, indicating that 2D periodic foundation is a feasible way of reducing seismic vibrations.

Precessional Periods of Long and Short Foucault Pendulums

Science.gov (United States)

Soga, Michitoshi

1978-01-01

Derives the precessional period of a Foucault pendulum without using small oscillation amplitudes. Shows that if the path of the pendulum passes through the origin, the periods for differing amplitudes are essentially the same. (GA)

Periodic table of elements

International Nuclear Information System (INIS)

Fluck, E.; Heumann, K.G.

1985-01-01

Following a recommendation by the International Union for Pure and Applied Chemistry (IUPAC), the groups of the periodic table shall be numbered from 1 to 18, instead of I to VIII as before. The recommendations has been approved of by the Committee on Nomenclature of the American Chemical Society. The new system abandons the distinction between main groups (a) and auxiliary groups (b), which in the past frequently has been the reason for misunderstandings between European and American chemists, due to different handling. The publishing house VCH Verlagsgesellschaft recently produced a new periodic table that shows the old and the new numbering system together at a glance, so that chemists will have time to get familiar with the new system. In addition the new periodic table represents an extensive data compilation arranged by elements. The front page lists the chemical properties of elements, the back page their physical properties. (orig./EF) [de

Plasma jets and FTE Dayside Generation for Northward IMF on 8 June 2007: THEMIS Observations

Science.gov (United States)

Eriksson, S.; Cully, C. M.; Ergun, R. E.; Gosling, J. T.; Angelopoulos, V.; Bonnell, J. W.; McFadden, J. P.; Glassmeier, K.; Roux, A.; Auster, H.; Le Contel, O.

2007-12-01

Five-spacecraft THEMIS (TH) observations are presented for a 15.5 MLT equatorial magnetopause crossing on 8 June 2007 when the upstream IMF was predominantly northward with a negative IMF By component at Wind. During the 0650-0855 UT period on this day TH-B was the most tailward probe while TH-A was the most sunward probe. TH-E was closest to TH-A with a maximum separation of only 0.71 RE. The maximum TH-A to TH-B GSM separation was 1.85 RE. TH-B showed a clean magnetopause crossing into the magnetosphere as the magnetopause expanded over the probes while TH-A spent this 2-hour period within a boundary layer inside the magnetopause with frequent transitions between a magnetosheath-like and a magnetosphere-like plasma as previously seen by Cluster at high-latitudes for southward IMF [Wild et al., 2003]. TH-E observed similar activity for a shorter period of time. Many of the sheath-like transitions showed evidence of plasma jets at TH-A with enhanced speed in the tailward and/or duskward direction suggesting a subsolar component merging region. Some jets were related to frequent bipolar FTE signatures in the normal BN component with enhanced total pressure observed at their centers. The more common ±BN sequence suggests that TH-A observed tailward propagating FTEs on the sheath side of the magnetopause. We compare TH-E ExB velocities with the enhanced jet velocities observed by TH-A and discuss whether the jets observed within this boundary layer were caused by subsolar magnetopause reconnection. We also compare these low-latitude northward IMF observations with prior Cluster FTE observations at high-latitude for southward IMF.

Anomalous periodic disruptions in tokamak plasma

International Nuclear Information System (INIS)

Montvai, A.; Tegze, M.; Valyi, I.

1982-09-01

Anomalously strong, periodic instabilities were observed in the MT-1 tokamak. Characteristics of these instabilities were partly similar to those of internal disruptions, but there were features making them different from the normal relaxational oscillations. Basic characteristics of the phenomenon were studied with the aid of generally used diagnostics. (author)

USA Observation of Spectral and Timing Evolution During the 2000 Outburst of XTE J1550--564

Energy Technology Data Exchange (ETDEWEB)

Reilly, Kaice T

2002-12-06

We report on timing and spectral observations of the 2000 outburst of XTE J1550--564 made by the Unconventional Stellar Aspect (USA) Experiment on board the Advanced Research and Global Observation Satellite (ARGOS). We observe a low-frequency quasi-periodic oscillation (LFQPO) with a centroid frequency that tends to increase with increasing flux and a fractional rms amplitude which is correlated with the hardness ratio. Several high-frequency quasi-periodic oscillations (HFQPO) were detected by RXTE, during periods where the LFQPO is seen to be weakening or not detectable at all. The evolution of the hardness ratio (4-16 keV/1-4 keV) with time and source flux is examined. The hardness-intensity diagram (HID) shows a cyclical movement in the counterclockwise direction and possibly indicates the presence of two independent accretion flows: a thin disk and a hot sub-Keplerian flow.

The Alberta smoke plume observation study

Directory of Open Access Journals (Sweden)

K. Anderson

2018-02-01

Full Text Available A field project was conducted to observe and measure smoke plumes from wildland fires in Alberta. This study used handheld inclinometer measurements and photos taken at lookout towers in the province. Observations of 222 plumes were collected from 21 lookout towers over a 6-year period from 2010 to 2015. Observers reported the equilibrium and maximum plume heights based on the plumes' final levelling heights and the maximum lofting heights, respectively. Observations were tabulated at the end of each year and matched to reported fires. Fire sizes at assessment times and forest fuel types were reported by the province. Fire weather conditions were obtained from the Canadian Wildland Fire Information System (CWFIS. Assessed fire sizes were adjusted to the appropriate size at plume observation time using elliptical fire-growth projections. Though a logical method to collect plume observations in principle, many unanticipated issues were uncovered as the project developed. Instrument limitations and environmental conditions presented challenges to the investigators, whereas human error and the subjectivity of observations affected data quality. Despite these problems, the data set showed that responses to fire behaviour conditions were consistent with the physical processes leading to plume rise. The Alberta smoke plume observation study data can be found on the Canadian Wildland Fire Information System datamart (Natural Resources Canada, 2018 at http://cwfis.cfs.nrcan.gc.ca/datamart.

The Alberta smoke plume observation study

Science.gov (United States)

Anderson, Kerry; Pankratz, Al; Mooney, Curtis; Fleetham, Kelly

2018-02-01

A field project was conducted to observe and measure smoke plumes from wildland fires in Alberta. This study used handheld inclinometer measurements and photos taken at lookout towers in the province. Observations of 222 plumes were collected from 21 lookout towers over a 6-year period from 2010 to 2015. Observers reported the equilibrium and maximum plume heights based on the plumes' final levelling heights and the maximum lofting heights, respectively. Observations were tabulated at the end of each year and matched to reported fires. Fire sizes at assessment times and forest fuel types were reported by the province. Fire weather conditions were obtained from the Canadian Wildland Fire Information System (CWFIS). Assessed fire sizes were adjusted to the appropriate size at plume observation time using elliptical fire-growth projections. Though a logical method to collect plume observations in principle, many unanticipated issues were uncovered as the project developed. Instrument limitations and environmental conditions presented challenges to the investigators, whereas human error and the subjectivity of observations affected data quality. Despite these problems, the data set showed that responses to fire behaviour conditions were consistent with the physical processes leading to plume rise. The Alberta smoke plume observation study data can be found on the Canadian Wildland Fire Information System datamart (Natural Resources Canada, 2018) at http://cwfis.cfs.nrcan.gc.ca/datamart.

Glass Waveguides for Periodic Poling

DEFF Research Database (Denmark)

Fage-Pedersen, Jacob; Jacobsen, Rune Shim; Kristensen, Martin

2005-01-01

Planar silica-based waveguide devices have been developed for second-harmonic generation by poling with periodic electrodes. We show that detrimental charge transport can occur along interfaces, but with proper choice of fabrication, high-quality devices are obtained....

Origin of very-short orbital-period binary systems

International Nuclear Information System (INIS)

Miyaji, S.

1983-01-01

Recent observations of four close binaries have established that there is a group of very-short orbital-period (VSOP) binaries whose orbital periods are less than 60 minutes. The VSOP binaries consist of both X-ray close binaries and cataclysmic variables. Their orbital periods are too short to have a main-sequence companion. However, four binaries, none of which belongs to any globular cluster, are too abundant to be explained by the capturing mechanism of a white dwarf. Therefore it seemed to be worthwhile to present an evolutionary scenario from an original binary system which can be applied for all VSOP binaries. (Auth.)

MAGNETIC ROSSBY WAVES IN THE SOLAR TACHOCLINE AND RIEGER-TYPE PERIODICITIES

International Nuclear Information System (INIS)

Zaqarashvili, Teimuraz V.; Carbonell, Marc; Oliver, Ramon; Ballester, Jose Luis

2010-01-01

Apart from the eleven-year solar cycle, another periodicity around 155-160 days was discovered during solar cycle 21 in high-energy solar flares, and its presence in sunspot areas and strong magnetic flux has been also reported. This periodicity has an elusive and enigmatic character, since it usually appears only near the maxima of solar cycles, and seems to be related with a periodic emergence of strong magnetic flux at the solar surface. Therefore, it is probably connected with the tachocline, a thin layer located near the base of the solar convection zone, where a strong dynamo magnetic field is stored. We study the dynamics of Rossby waves in the tachocline in the presence of a toroidal magnetic field and latitudinal differential rotation. Our analysis shows that the magnetic Rossby waves are generally unstable and that the growth rates are sensitive to the magnetic field strength and to the latitudinal differential rotation parameters. Variation of the differential rotation and the magnetic field strength throughout the solar cycle enhance the growth rate of a particular harmonic in the upper part of the tachocline around the maximum of the solar cycle. This harmonic is symmetric with respect to the equator and has a period of 155-160 days. A rapid increase of the wave amplitude could give rise to a magnetic flux emergence leading to observed periodicities in solar activity indicators related to magnetic flux.

From the Mendeleev periodic table to particle physics and back to the periodic table

International Nuclear Information System (INIS)

Kibler, Maurice R.

2006-11-01

We briefly describe in this paper the passage from Mendeleev's chemistry (1869) to atomic physics (in the 1900's), nuclear physics (in the 1932's) and particle physics (from 1953 to 2006). We show how the consideration of symmetries, largely used in physics since the end of the 1920's, gave rise to a new format of the periodic table in the 1970's. More specifically, this paper is concerned with the application of the group SO(4,2)xSU(2) to the periodic table of chemical elements. It is shown how the Madelung rule of the atomic shell model can be used for setting up a periodic table that can be further rationalized via the group SO(4,2)xSU(2) and some of its subgroups. Qualitative results are obtained from this nonstandard table. (author)

Quasi-periodic Radio Bursts Associated with Fast-mode Waves near a Magnetic Null Point

Energy Technology Data Exchange (ETDEWEB)

Kumar, Pankaj [Heliophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Nakariakov, Valery M. [Centre for Fusion, Space and Astrophysics, Department of Physics, University of Warwick, CV4 7AL (United Kingdom); Cho, Kyung-Suk, E-mail: pankaj.kumar@nasa.gov [Korea Astronomy and Space Science Institute (KASI), Daejeon, 305-348 (Korea, Republic of)

2017-08-01

This paper presents an observation of quasi-periodic rapidly propagating waves observed in the Atmospheric Image Assembly (AIA) 171/193 Å channels during the impulsive phase of an M1.9 flare that occurred on 2012 May 7. The instant period was found to decrease from 240 to 120 s, and the speed of the wavefronts was in the range of ∼664–1416 km s{sup −1}. Almost simultaneously, quasi-periodic bursts with similar instant periods, ∼70 and ∼140 s, occur in the microwave emission and in decimetric type IV and type III radio bursts, and in the soft X-ray emission. The magnetic field configuration of the flare site was consistent with a breakout topology, i.e., a quadrupolar field along with a magnetic null point. The quasi-periodic rapidly propagating wavefronts of the EUV emission are interpreted as a fast magnetoacoustic wave train. The observations suggest that the fast-mode waves are generated during the quasi-periodic magnetic reconnection in the cusp region above the flare arcade loops. For the first time, we provide evidence of a tadpole wavelet signature at about 70–140 s in decimetric (245/610 MHz) radio bursts, along with the direct observation of a coronal fast-mode wave train in EUV. In addition, at AIA 131/193 Å we observed quasi-periodic EUV disturbances with periods of 95 and 240 s propagating downward at apparent speeds of 172–273 km s{sup −1}. The nature of these downward propagating disturbances is not revealed, but they could be connected to magnetoacoustic waves or periodically shrinking loops.

Quasi-periodic Radio Bursts Associated with Fast-mode Waves near a Magnetic Null Point

International Nuclear Information System (INIS)

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

2017-01-01

This paper presents an observation of quasi-periodic rapidly propagating waves observed in the Atmospheric Image Assembly (AIA) 171/193 Å channels during the impulsive phase of an M1.9 flare that occurred on 2012 May 7. The instant period was found to decrease from 240 to 120 s, and the speed of the wavefronts was in the range of ∼664–1416 km s −1 . Almost simultaneously, quasi-periodic bursts with similar instant periods, ∼70 and ∼140 s, occur in the microwave emission and in decimetric type IV and type III radio bursts, and in the soft X-ray emission. The magnetic field configuration of the flare site was consistent with a breakout topology, i.e., a quadrupolar field along with a magnetic null point. The quasi-periodic rapidly propagating wavefronts of the EUV emission are interpreted as a fast magnetoacoustic wave train. The observations suggest that the fast-mode waves are generated during the quasi-periodic magnetic reconnection in the cusp region above the flare arcade loops. For the first time, we provide evidence of a tadpole wavelet signature at about 70–140 s in decimetric (245/610 MHz) radio bursts, along with the direct observation of a coronal fast-mode wave train in EUV. In addition, at AIA 131/193 Å we observed quasi-periodic EUV disturbances with periods of 95 and 240 s propagating downward at apparent speeds of 172–273 km s −1 . The nature of these downward propagating disturbances is not revealed, but they could be connected to magnetoacoustic waves or periodically shrinking loops.

Effects of age, gender, and stimulus presentation period on visual short-term memory.

Science.gov (United States)

Kunimi, Mitsunobu

2016-01-01

This study focused on age-related changes in visual short-term memory using visual stimuli that did not allow verbal encoding. Experiment 1 examined the effects of age and the length of the stimulus presentation period on visual short-term memory function. Experiment 2 examined the effects of age, gender, and the length of the stimulus presentation period on visual short-term memory function. The worst memory performance and the largest performance difference between the age groups were observed in the shortest stimulus presentation period conditions. The performance difference between the age groups became smaller as the stimulus presentation period became longer; however, it did not completely disappear. Although gender did not have a significant effect on d' regardless of the presentation period in the young group, a significant gender-based difference was observed for stimulus presentation periods of 500 ms and 1,000 ms in the older group. This study indicates that the decline in visual short-term memory observed in the older group is due to the interaction of several factors.

Intrinsic periodic and aperiodic stochastic resonance in an electrochemical cell

Science.gov (United States)

Tiwari, Ishant; Phogat, Richa; Parmananda, P.; Ocampo-Espindola, J. L.; Rivera, M.

2016-08-01

In this paper we show the interaction of a composite of a periodic or aperiodic signal and intrinsic electrochemical noise with the nonlinear dynamics of an electrochemical cell configured to study the corrosion of iron in an acidic media. The anodic voltage setpoint (V0) in the cell is chosen such that the anodic current (I ) exhibits excitable fixed point behavior in the absence of noise. The subthreshold periodic (aperiodic) signal consists of a train of rectangular pulses with a fixed amplitude and width, separated by regular (irregular) time intervals. The irregular time intervals chosen are of deterministic and stochastic origins. The amplitude of the intrinsic internal noise, regulated by the concentration of chloride ions, is then monotonically increased, and the provoked dynamics are analyzed. The signal to noise ratio and the cross-correlation coefficient versus the chloride ions' concentration curves have a unimodal shape indicating the emergence of an intrinsic periodic or aperiodic stochastic resonance. The abscissa for the maxima of these unimodal curves correspond to the optimum value of intrinsic noise where maximum regularity of the invoked dynamics is observed. In the particular case of the intrinsic periodic stochastic resonance, the scanning electron microscope images for the electrode metal surfaces are shown for certain values of chloride ions' concentrations. These images, qualitatively, corroborate the emergence of order as a result of the interaction between the nonlinear dynamics and the composite signal.

Assessing trends in observed and modelled climate extremes over Australia in relation to future projections

International Nuclear Information System (INIS)

Alexander, Lisa

2007-01-01

Full text: Nine global coupled climate models were assessed for their ability to reproduce observed trends in a set of indices representing temperature and precipitation extremes over Australia. Observed trends for 1957-1999 were compared with individual and multi-modelled trends calculated over the same period. When averaged across Australia the magnitude of trends and interannual variability of temperature extremes were well simulated by most models, particularly for the warm nights index. Except for consecutive dry days, the majority of models also reproduced the correct sign of trend for precipitation extremes. A bootstrapping technique was used to show that most models produce plausible trends when averaged over Australia, although only heavy precipitation days simulated from the multi-model ensemble showed significant skill at reproducing the observed spatial pattern of trends. Two of the models with output from different forcings showed that only with anthropogenic forcing included could the models capture the observed areally averaged trend for some of the temperature indices, but the forcing made little difference to the models' ability to reproduce the spatial pattern of trends over Australia. Future projected changes in extremes using three emissions scenarios were also analysed. Australia shows a shift towards significant warming of temperature extremes with much longer dry spells interspersed with periods of increased extreme precipitation irrespective of the scenario used. More work is required to determine whether regional projected changes over Australia are robust

Hydrometeorological aspects of the Real-Time Ultrafinescale Forecast Support during the Special Observing Period of the MAP*

Directory of Open Access Journals (Sweden)

R. Benoit

2003-01-01

Full Text Available During the Special Observation Period (SOP, 7 September–15 November, 1999 of the Mesoscale Alpine Programme (MAP, the Canadian Mesoscale Compressible Community Model (MC2 was run in real time at a horizontal resolution of 3 km on a computational domain of 350☓300☓50 grid points, covering the whole of the Alpine region. The WATFLOOD model was passively coupled to the MC2; the former is an integrated set of computer programs to forecast flood flows, using all available data, for catchments with response times ranging from one hour to several weeks. The unique aspect of this contribution is the operational application of numerical weather prediction data to forecast flows over a very large, multinational domain. An overview of the system performance from the hydrometeorological aspect is presented, mostly for the real-time results, but also from subsequent analyses. A streamflow validation of the precipitation is included for large basins covering upper parts of the Rhine and the Rhone, and parts of the Po and of the Danube. In general, the MC2/WATFLOOD model underestimated the total runoff because of the under-prediction of precipitation by MC2 during the MAP SOP. After the field experiment, a coding error in the cloud microphysics scheme of MC2 explains this underestimation to a large extent. A sensitivity study revealed that the simulated flows reproduce the major features of the observed flow record for most of the flow stations. The experiment was considered successful because two out of three possible flood events in the Swiss-Italian border region were predicted correctly by data from the numerical weather models linked to the hydrological model and no flow events were missed. This study has demonstrated that a flow forecast from a coupled atmospheric-hydrological model can serve as a useful first alert and quantitative forecast. Keywords: mesoscale atmospheric model, hydrological model, flood forecasting, Alps

Chandra Observations of a Collisionally and Optically Thin Charge Exchange System - Comet 2P/Encke 2003

Science.gov (United States)

Christian, D. J.; Lisse, C. M.; Dennerl, K.; Wolk, S. J.; Bodewits, D.; Combi, M. R.; Hoekstra, R.; Makinen, J. T. T.; Weaver, H. A.

2004-11-01

The highly favorable perigee passage of the x-ray bright comet 2P/Encke in late 2003 provided an excellent opportunity to use Chandra's high spatial, spectral, and temporal resolution to study cometary x-ray emission in the low neutral target density, low x-ray flux regime. The 1997 ROSAT/EUVE observations of Encke (Lisse et al. 1999) and the nucleus rotation studies of Luu and Jewitt (1990, most likely rotation period = 15 hours) suggested a simple Chandra experiment - continuous ACIS-S observations of Encke over 15 hours during the time of its closest approach to Earth. Here we report initial results from our X-ray observations. X-ray emission from comet Encke was found only in a small, asymmetric region between 1500 km - 40,000 km from the nucleus. The Encke ACIS-S3 200 -- 1000 eV spectrum shows many of the same x-ray emission lines previously observed from comets (C+5, O+6,O+7), including confirmation of several emission lines in the 800 to 1000 eV range. However, the Encke spectrum shows very different line ratios in the 200 - 700 eV range than any previous comet. A lightcurve with peak-to-peak amplitude of 20% and period 11.7 hours was found over the 15 hour observing period. Comparing the observations to contemporaneous measurements of the coma and solar wind made by other means, we find the combination of a low density, collisionally thin (to charge exchange) coma and a post-massive X-flare, high temperature, moderate density solar wind can explain our unusual Encke x-ray observations.

High-resolution vertical velocities and their power spectrum observed with the MAARSY radar - Part 1: frequency spectrum

Science.gov (United States)

Li, Qiang; Rapp, Markus; Stober, Gunter; Latteck, Ralph

2018-04-01

The Middle Atmosphere Alomar Radar System (MAARSY) installed at the island of Andøya has been run for continuous probing of atmospheric winds in the upper troposphere and lower stratosphere (UTLS) region. In the current study, we present high-resolution wind measurements during the period between 2010 and 2013 with MAARSY. The spectral analysis applying the Lomb-Scargle periodogram method has been carried out to determine the frequency spectra of vertical wind velocity. From a total of 522 days of observations, the statistics of the spectral slope have been derived and show a dependence on the background wind conditions. It is a general feature that the observed spectra of vertical velocity during active periods (with wind velocity > 10 m s-1) are much steeper than during quiet periods (with wind velocity wind conditions considered together the general spectra are obtained and their slopes are compared with the background horizontal winds. The comparisons show that the observed spectra become steeper with increasing wind velocities under quiet conditions, approach a spectral slope of -5/3 at a wind velocity of 10 m s-1 and then roughly maintain this slope (-5/3) for even stronger winds. Our findings show an overall agreement with previous studies; furthermore, they provide a more complete climatology of frequency spectra of vertical wind velocities under different wind conditions.

TWO NEW LONG-PERIOD HOT SUBDWARF BINARIES WITH DWARF COMPANIONS

Energy Technology Data Exchange (ETDEWEB)

Barlow, Brad N.; Wade, Richard A. [Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States); Liss, Sandra E. [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904-4325 (United States); Green, Elizabeth M., E-mail: bbarlow@psu.edu [Steward Observatory, University of Arizona, 933 N. Cherry Avenue, Tucson, AZ 85721 (United States)

2013-07-01

Hot subdwarf stars with F-K main sequence binary companions have been known for decades, but the first orbital periods for such systems were published just recently. Current observations suggest that most have long periods, on the order of years, and that some are or once were hierarchical triple systems. As part of a survey with the Hobby-Eberly Telescope, we have been monitoring the radial velocities of several composite-spectra binaries since 2005 in order to determine their periods, velocities, and eccentricities. Here we present observations and orbital solutions for two of these systems, PG 1449+653 and PG 1701+359. Similar to the other sdB+F/G/K binaries with solved orbits, their periods are long, 909 and 734 days, respectively, and pose a challenge to current binary population synthesis models of hot subdwarf stars. Intrigued by their relatively large systemic velocities, we also present a kinematical analysis of both targets and find that neither is likely a member of the Galactic thin disk.

TWO NEW LONG-PERIOD HOT SUBDWARF BINARIES WITH DWARF COMPANIONS

International Nuclear Information System (INIS)

Barlow, Brad N.; Wade, Richard A.; Liss, Sandra E.; Green, Elizabeth M.

2013-01-01

Hot subdwarf stars with F-K main sequence binary companions have been known for decades, but the first orbital periods for such systems were published just recently. Current observations suggest that most have long periods, on the order of years, and that some are or once were hierarchical triple systems. As part of a survey with the Hobby-Eberly Telescope, we have been monitoring the radial velocities of several composite-spectra binaries since 2005 in order to determine their periods, velocities, and eccentricities. Here we present observations and orbital solutions for two of these systems, PG 1449+653 and PG 1701+359. Similar to the other sdB+F/G/K binaries with solved orbits, their periods are long, 909 and 734 days, respectively, and pose a challenge to current binary population synthesis models of hot subdwarf stars. Intrigued by their relatively large systemic velocities, we also present a kinematical analysis of both targets and find that neither is likely a member of the Galactic thin disk.

X-Ray Timing Analysis of Cyg X-3 Using AstroSat/LAXPC: Detection of Milli-hertz Quasi-periodic Oscillations during the Flaring Hard X-Ray State

Energy Technology Data Exchange (ETDEWEB)

Pahari, Mayukh; Misra, Ranjeev [Inter-University Center for Astronomy and Astrophysics, Ganeshkhind, Pune 411007 (India); Antia, H M; Yadav, J S; Chauhan, Jai Verdhan; Chitnis, V R; Dedhia, Dhiraj; Katoch, Tilak; Madhwani, P; Shah, Parag [Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005 (India); Agrawal, P C [UM-DAE Center of Excellence for Basic Sciences, University of Mumbai, Kalina, Mumbai 400098 (India); Manchanda, R K [University of Mumbai, Kalina, Mumbai 400098 (India); Paul, B, E-mail: mayukh@iucaa.in [Department of Astronomy and Astrophysics, Raman Research Institute, Bengaluru 560080 (India)

2017-11-01

We present here results from the X-ray timing and spectral analysis of the X-ray binary Cyg X-3 using observations from the Large Area X-ray proportional Counter on board AstroSat . Consecutive light curves observed over a period of one year show the binary orbital period of 17253.56 ± 0.19 s. Another low-amplitude, slow periodicity of the order of 35.8 ± 1.4 days is observed, which may be due to the orbital precession as suggested earlier by Molteni et al. During the rising binary phase, power density spectra from different observations during the flaring hard X-ray state show quasi-periodic oscillations (QPOs) at ∼5–8 mHz, ∼12–14 mHz, and ∼18–24 mHz frequencies at the minimum confidence of 99%. However, during the consecutive binary decay phase, no QPO is detected up to 2 σ significance. Energy-dependent time-lag spectra show soft lag (soft photons lag hard photons) at the mHz QPO frequency and the fractional rms of the QPO increases with the photon energy. During the binary motion, the observation of mHz QPOs during the rising phase of the flaring hard state may be linked to the increase in the supply of the accreting material in the disk and corona via stellar wind from the companion star. During the decay phase, the compact source moves in the outer wind region causing the decrease in supply of material for accretion. This may cause weakening of the mHz QPOs below the detection limit. This is also consistent with the preliminary analysis of the orbital phase-resolved energy spectra presented in this paper.

The period-age relation for cepheids

International Nuclear Information System (INIS)

Efremov, Yu.N.

1978-01-01

The list of 119 cepheid-members of 55 clusters and associations of the Magellanic Clouds, the Galaxy, and M31 is given. The period-age relation is found from the data on 64 cepheids in 29 clusters for which the age determinations are available, the ages of extragalactic clusters were determined mainly from their integral colours. The U-B colours are found to be of much better age parameters than the B-V ones. The composite period-age relation agrees well with the theoretical one. The observed dispersion of the period-age relation leads to an estimate of the age dispersion about 1x10 7 years in the associations. Some peculiarities of the cepheids with the shortest periods amongst others in the same clusters are probably explained if they are overtone pulsators. The period-age relation may be used for an investigation of the recent history of star formation in the galaxies. This relation allows to determine the age gradient across the spiral arm in M31 which is in agreement with the density wave theory predictions. The distribution of cepheids in our Galaxy and neighbouring galaxies is consistent with the conception of star formation lasting for some dozen million years in cells with a dimension of some hundreds of parsecs

Reproductive periods of Lucina pectinata (BIVALVE; LUCINIDAE in the Paranaguá Estuarine Complex, Paraná - Brazil

Directory of Open Access Journals (Sweden)

S. W. Christo

Full Text Available Abstract The objectives of the present study is to describe the size for exploitation and gonadal maturation of L. pectinata in Peças Island in Paraná coast. Twenty two individuals were sampled every month, from an intertidal flat of the Peças River, Municipality of Guaraqueçaba, during two periods – summer/autumn and winter of the 2009. Environmental parameter data was obtained at the same time of the biological sampling: temperature, salinity and seawater transparency at the Peças River mouth. The animals’ height, length, width, gross weight, wet weight of meat and dry weight of meat were measured at the lab. The gonad development stages (GDS, condition index (CI and yield index (Y were calculated. Sex identification was conducted by direct observation of the gonads and gametes under an optic microscope. Individuals were classified as males (M, females (F or undetermined (U. The medium height observed was of 49.62 ± 6.84 mm. Period of more expressive gonad repletion were observed in summer when water temperature was higher. Results of GDS in both periods showed a predominance of partially filled gonad stages. This may be related with the fact that L. pectinata has intense gametogenesis activity, that is, the organisms do not have a resting interval, but go back to gonad restructuring rapidly after releasing the gametes. The continuity of the reproductive cycle of the specimens found in both studied periods could demonstrate a possible continuous reproduction of the species and a size for exploitation above 40.00 mm of height.

Resonantly-enhanced transmission through a periodic array of subwavelength apertures in heavily-doped conducting polymer films

Science.gov (United States)

Matsui, Tatsunosuke; Vardeny, Z. Valy; Agrawal, Amit; Nahata, Ajay; Menon, Reghu

2006-02-01

We observed resonantly-enhanced terahertz transmission through two-dimensional (2D) periodic arrays of subwavelength apertures with various periodicities fabricated on metallic organic conducting polymer films of polypyrrole heavily doped with PF6 molecules [PPy(PF6)]. The "anomalous transmission" spectra are in good agreement with a model involving surface plasmon polariton excitations on the film surfaces. We also found that the `anomalous transmission' peaks are broader in the exotic metallic PPy (PF6) films compared to those formed in 2D aperture array in regular metallic films such as silver, showing that the surface plasmon polaritons on the PPy (PF6) film surfaces have higher attenuation.

Swift observations of GS 1826-238

Science.gov (United States)

Ji, L.; Santangelo, A.; Zhang, S.; Ducci, L.; Suleimanov, V.

2018-02-01

GS 1826-238 is a well-studied low-mass X-ray binary neutron star. This source was in a persistent hard state since its discovery in 1988 and until 2014 June. After that, the source exhibited several softer periods of enhanced intensity in the energy range 2-20 keV. We studied the long-term light curves of MAXI (Monitor of All Sky X-ray Image) and Swift/BAT, and found clearly two branches in the MAXI-BAT and hardness-intensity diagrams, which correspond to the persistent state and softer periods, respectively. We analysed 21 Swift/XRT observations, of which four were located in the persistent state while the others were in softer periods or in a state between them. The XRT spectra could be generally fitted by using an absorbed Comptonization model with no other components required. We found a peculiar relationship between the luminosity and the hardness in the energy range of 0.6-10 keV: when the luminosity is larger (smaller) than 4 per cent-6 per cent Ledd, the hardness is anti-correlated (correlated) with luminosity. We also estimated the variability for each observation by using the fractional rms in the 0.1-10 Hz range. We found that the observations in the persistent state had a large fractional rms of ˜25 per cent, similar to other low-mass X-ray binaries. However, the variability is mainly found in the range of 5 per cent-20 per cent during softer periods. We suggest that GS 1826-238 did not evolve into the soft state of atoll sources, and all the observed XRT observations during the softer periods resemble a peculiar intermediate state of atoll sources.

Observed tail current systems associated with bursty bulk flows and auroral streamers during a period of multiple substorms

Directory of Open Access Journals (Sweden)

C. Forsyth

2008-02-01

Full Text Available We present a multi-instrument study of a substorm bursty bulk flow (BBF and auroral streamer. During a substorm on 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 currents associated with BBFs and auroral streamers. The observations of the BBF are consistent with the plasma "bubble" model of Chen and Wolf (1993. Furthermore, we show that the observations of the BBF are consistent with the creation of the BBF by the reconnection of open field lines Earthward of a substorm associated near-Earth neutral line.

Four-atom period in the conductance of monatomic al wires

DEFF Research Database (Denmark)

Thygesen, Kristian Sommer; Jacobsen, Karsten Wedel

2003-01-01

We present first-principles calculations based on density functional theory for the conductance of monatomic Al wires between Al(111) electrodes. In contrast to the even-odd oscillations observed in other metallic wires, the conductance of the Al wires is found to oscillate with a period of four ...... atoms as the length of the wire is varied. Although local charge neutrality can account for the observed period, it leads to an incorrect phase. We explain the conductance behavior using a resonant transport model based on the electronic structure of the infinite wire....

Periodic tests: a human factors analysis of documentary aspects

International Nuclear Information System (INIS)

Perinet, Romuald; Rousseau, Jean-Marie

2007-01-01

Periodic tests are technical inspections aimed at verifying the availability of the safety-related systems during operation. The French licensee, Electricite de France (EDF), manages periodic tests according to procedures, methods of examination and a frequency, which were defined when the systems were designed. These requirements are defined by national authorities of EDF in a reference document composed of rules of testing and tables containing the reference values to be respected. This reference document is analyzed and transformed by each 'Centre Nucleaire de Production d'Electricite' (CNPE) into station-specific operating ranges of periodic tests. In 2003, the IRSN noted that significant events for safety (ESS) involving periodic tests represented more than 20% of ESS between 2000 and 2002. Thus, 340 ESS were related to non-compliance with the conditions of the test and errors in the implementation of the procedures. A first analysis showed that almost 26% of all ESSs from 2000 to 2002 were related to periodic tests. For many of them, the national reference document and the operating ranges of tests were involved. In this context, the 'Direction Generale de la Surete Nucleaire' (DGSNR), requested the 'Institut de Radioprotection et de Surete Nucleaire' (IRSN) to examine the process of definition and implementation of the periodic tests. The IRSN analyzed about thirty French Licensee event reports occurring during the considered period (2000-2002). The IRSN also interviewed the main persons responsible for the processes and observed the performance of 3 periodic tests. The results of this analysis were presented to a group of experts ('Groupe Permanent') charged with delivering advice to the DGSNR about the origin of the problems identified and the improvements to be implemented. The main conclusions of the IRSN addressed the quality of the prescriptive documents. In this context, EDF decided to carry out a thorough analysis of the whole process. The first

Two New Long-period Hot Subdwarf Binaries with Dwarf Companions

Science.gov (United States)

Barlow, Brad N.; Liss, Sandra E.; Wade, Richard A.; Green, Elizabeth M.

2013-07-01

Hot subdwarf stars with F-K main sequence binary companions have been known for decades, but the first orbital periods for such systems were published just recently. Current observations suggest that most have long periods, on the order of years, and that some are or once were hierarchical triple systems. As part of a survey with the Hobby-Eberly Telescope, we have been monitoring the radial velocities of several composite-spectra binaries since 2005 in order to determine their periods, velocities, and eccentricities. Here we present observations and orbital solutions for two of these systems, PG 1449+653 and PG 1701+359. Similar to the other sdB+F/G/K binaries with solved orbits, their periods are long, 909 and 734 days, respectively, and pose a challenge to current binary population synthesis models of hot subdwarf stars. Intrigued by their relatively large systemic velocities, we also present a kinematical analysis of both targets and find that neither is likely a member of the Galactic thin disk. Based on observations obtained with the Hobby-Eberly Telescope, which is a joint project of the University of Texas at Austin, the Pennsylvania State University, Stanford University, Ludwig-Maximilians-Universität München, and Georg-August-Universität Göttingen.

Predicting Changes of Rainfed Barley (Hordeum vulgare L. Farming Calendar using Downscaling LARS-WG and HadCM3 Models in Lorestan Province in 2011-2030 period

Directory of Open Access Journals (Sweden)

Mahmoud Ahmadi

2017-10-01

Full Text Available Introduction The results of climate change studies in recent years confirm this phenomenon occurrence in Iran. The climatic characteristics (potential and limitations of climate are considered in the long run, to determine the pattern of cultivation and distribution of different plant species. Unfortunately, the agricultural sector due to the low speed and power compliance, will suffer the greatest impact of climate change. General circulation models provide accurate tools to predict future climatic conditions, and the necessary data for the implementation of simulation models and the development of crops under climate change conditions. The study of the effects of climate change on the agricultural sector seems to be necessary due to increase the demand for agricultural production. The aim of this study was to investigate the effects of climate change on the rainfed barley farming calendar in Lorestan province as an effective pole in cereal cultivation in Iran. Materials and methods In order to study the effects of climate change on the rainfed barley farming calendar, outputs from the HadCM3 model simulations were used. After evaluating the LARS-WG stochastic weather generator model using performance indicators and ensure the suitability of the model, this model was applied to downscale HadCM3 model outputs. A2 scenario was chosen to evaluate climate impacts for the period 2011–2030. In this study, due to the suitable temperature for germination in the region, has been emphasized only on the precipitation to find the most suitable time for barley cultivation. Planting date was calculated by Weibull probability with 50 and 75% confidence intervals. Growing degree days (GDD were used to calculate the phenological stages. For the forecast period, the same method was used to determine the farming calendar. Results Discussion The results showed that in the observation period, the earliest planting date was observed in northern province in

Statistical characteristics of sudden stratospheric warming as observed over the observatoire de Haute Provence (44°N, 6°E) during the 1981-2001 period

CSIR Research Space (South Africa)

Sivakumar, V

2006-04-01

Full Text Available of stratospheric sudden warming as observed over the Observatoire de Haute Provence (44°N, 6°E) during the period 1981-2001 D.V. Acharyulu, V. Sivakumar*, H. Bencherif, B. Morel, Laboratoire de l’Atmosphère et des Cyclones (LACy), CNRS–UMR 8105, Université de... La Réunion, FRANCE. * Also at National Laser Centre, Council for Scientific and Industrial Research (CSIR), Pretoria, SOUTH AFRICA. A. Hauchecorne Service d’Aéronomie, CNRS, Paris, FRANCE. D.N. Rao National Atmosphere Research Laboratory...

Evolutionary dynamics of incubation periods.

Science.gov (United States)

Ottino-Loffler, Bertrand; Scott, Jacob G; Strogatz, Steven H

2017-12-21

The incubation period for typhoid, polio, measles, leukemia and many other diseases follows a right-skewed, approximately lognormal distribution. Although this pattern was discovered more than sixty years ago, it remains an open question to explain its ubiquity. Here, we propose an explanation based on evolutionary dynamics on graphs. For simple models of a mutant or pathogen invading a network-structured population of healthy cells, we show that skewed distributions of incubation periods emerge for a wide range of assumptions about invader fitness, competition dynamics, and network structure. The skewness stems from stochastic mechanisms associated with two classic problems in probability theory: the coupon collector and the random walk. Unlike previous explanations that rely crucially on heterogeneity, our results hold even for homogeneous populations. Thus, we predict that two equally healthy individuals subjected to equal doses of equally pathogenic agents may, by chance alone, show remarkably different time courses of disease.

From the Mendeleev periodic table to particle physics and back to the periodic table

Energy Technology Data Exchange (ETDEWEB)

Kibler, Maurice R. [Universite de Lyon, Institut de Physique Nucleaire, Universite Lyon 1 and CNRS/IN2P3, 43 Bd du 11 Novembre 1918, F-69622 Villeurbanne Cedex (France)

2006-11-15

We briefly describe in this paper the passage from Mendeleev's chemistry (1869) to atomic physics (in the 1900's), nuclear physics (in the 1932's) and particle physics (from 1953 to 2006). We show how the consideration of symmetries, largely used in physics since the end of the 1920's, gave rise to a new format of the periodic table in the 1970's. More specifically, this paper is concerned with the application of the group SO(4,2)xSU(2) to the periodic table of chemical elements. It is shown how the Madelung rule of the atomic shell model can be used for setting up a periodic table that can be further rationalized via the group SO(4,2)xSU(2) and some of its subgroups. Qualitative results are obtained from this nonstandard table. (author)

Coherent Phonon Dynamics in Short-Period InAs/GaSb Superlattices

OpenAIRE

Noe, G. T.; Haugan, H. J.; Brown, G. J.; Sanders, G. D.; Stanton, C. J.; Kono, J.

2011-01-01

We have performed ultrafast pump-probe spectroscopy studies on a series of InAs/GaSb-based short-period superlattice (SL) samples with periods ranging from 46 \\AA to 71 \\AA. We observe two types of oscillations in the differential reflectivity with fast ($\\sim$ 1- 2 ps) and slow ($\\sim$ 24 ps) periods. The period of the fast oscillations changes with the SL period and can be explained as coherent acoustic phonons generated from carriers photoexcited within the SL. This mode provides an accura...

Quantum mechanical analysis of fractal conductance fluctuations: a picture using self-similar periodic orbits

International Nuclear Information System (INIS)

Ogura, Tatsuo; Miyamoto, Masanori; Budiyono, Agung; Nakamura, Katsuhiro

2007-01-01

Fractal magnetoconductance fluctuations are often observed in experiments on ballistic quantum dots. Although the analysis of the exact self-affine fractal has been given by the semiclassical theory using self-similar periodic orbits in systems with a soft-walled potential with a saddle, there has been no corresponding quantum mechanical investigation. We numerically calculate the quantum conductance with use of the recursive Green's function method applied to open cavities characterized by a Henon-Heiles type potential. The conductance fluctuations show exact self-affinity just as in some of the experimental observations. The enlargement factor for the horizontal axis can be explained by the scaling factor of the area of self-similar periodic orbits, and therefore be attributed to the curvature of the saddle in the cavity potential. The fractal dimension obtained through the box counting method agrees with those evaluated with use of the Hurst exponent, and coincides with the semiclassical prediction. We further investigate the variation of the fractal dimension by changing the control parameters between the classical and quantum domains. (fast track communication)

Correlation between the luminosity and spin-period changes during outbursts of 12 Be binary pulsars observed by the MAXI/GSC and the Fermi/GBM

Science.gov (United States)

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

2017-12-01

To study observationally the spin-period changes of accreting pulsars caused by the accretion torque, the present work analyzes X-ray light curves of 12 Be binary pulsars obtained by the MAXI Gas-Slit Camera all-sky survey and their pulse periods measured by the Fermi Gamma-ray Burst Monitor pulsar project, both covering more than six years, from 2009 August to 2016 March. The 12 objects were selected because they are accompanied by clear optical identification and accurate measurements of surface magnetic fields. The luminosity L and the spin-frequency derivatives \\dot{ν}, measured during large outbursts with L ≳ 1 × 1037 erg s-1, were found to follow approximately the theoretical relations in the accretion torque models, represented by \\dot{ν} ∝ L^{α} (α ≃ 1), and the coefficient of proportionality between \\dot{ν} and Lα agrees, within a factor of ˜3, with that proposed by Ghosh and Lamb (1979b, ApJ, 234, 296). In the course of the present study, the orbital elements of several sources were refined.

ASSOCIATING LONG-TERM γ-RAY VARIABILITY WITH THE SUPERORBITAL PERIOD OF LS I +61°303

International Nuclear Information System (INIS)

Ackermann, M.; Buehler, R.; Ajello, M.; Ballet, J.; Casandjian, J. M.; Barbiellini, G.; Bastieri, D.; Buson, S.; Bellazzini, R.; Bregeon, J.; Bonamente, E.; Cecchi, C.; Brandt, T. J.; Brigida, M.; Bruel, P.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Cavazzuti, E.; Chekhtman, A.

2013-01-01

Gamma-ray binaries are stellar systems for which the spectral energy distribution (discounting the thermal stellar emission) peaks at high energies. Detected from radio to TeV gamma rays, the γ-ray binary LS I +61°303 is highly variable across all frequencies. One aspect of this system's variability is the modulation of its emission with the timescale set by the ∼26.4960 day orbital period. Here we show that, during the time of our observations, the γ-ray emission of LS I +61°303 also presents a sinusoidal variability consistent with the previously known superorbital period of 1667 days. This modulation is more prominently seen at orbital phases around apastron, whereas it does not introduce a visible change close to periastron. It is also found in the appearance and disappearance of variability at the orbital period in the power spectrum of the data. This behavior could be explained by a quasi-cyclical evolution of the equatorial outflow of the Be companion star, whose features influence the conditions for generating gamma rays. These findings open the possibility to use γ-ray observations to study the outflows of massive stars in eccentric binary systems

Long-term analyses of snow dynamics within the french Alps on the 1900-2100 period. Analyses of historical snow water equivalent observations, modelisations and projections of a hundred of snow courses.

Science.gov (United States)

Mathevet, T.; Joel, G.; Gottardi, F.; Nemoz, B.

2017-12-01

The aim of this communication is to present analyses of climate variability and change on snow water equivalent (SWE) observations, reconstructions (1900-2016) and scenarii (2020-2100) of a hundred of snow courses dissiminated within the french Alps. This issue became particularly important since a decade, in regions where snow variability had a large impact on water resources availability, poor snow conditions in ski resorts and artificial snow production. As a water resources manager in french mountainuous regions, EDF (french hydropower company) has developed and managed a hydrometeorological network since 1950. A recent data rescue research allowed to digitize long term SWE manual measurments of a hundred of snow courses within the french Alps. EDF have been operating an automatic SWE sensors network, complementary to the snow course network. Based on numerous SWE observations time-series and snow accumulation and melt model (Garavaglia et al., 2017), continuous daily historical SWE time-series have been reconstructed within the 1950-2016 period. These reconstructions have been extented to 1900 using 20 CR reanalyses (ANATEM method, Kuentz et al., 2015) and up to 2100 using GIEC Climate Change scenarii. Considering various mountainous areas within the french Alps, this communication focuses on : (1) long term (1900-2016) analyses of variability and trend of total precipitation, air temperature, snow water equivalent, snow line altitude, snow season length , (2) long term variability of hydrological regime of snow dominated watersheds and (3) future trends (2020 -2100) using GIEC Climate Change scenarii. Comparing historical period (1950-1984) to recent period (1984-2016), quantitative results within a region in the north Alps (Maurienne) shows an increase of air temperature by 1.2 °C, an increase of snow line height by 200m, a reduction of SWE by 200 mm/year and a reduction of snow season length by 15 days. These analyses will be extended from north to south

An RR Lyrae period shift in terms of the Fourier parameter Phi sub 31

Science.gov (United States)

Clement, Christine M.; Jankulak, Michael; Simon, Norman R.

1992-01-01

The Fourier phase parameter Phi sub 31 has been determined for RRc stars in five globular clusters, NGC 6171, M5, M3, M53, and M15. The results indicate that the RRc stars in a given cluster show a sequence of Phi sub 31 increasing with period, and that the higher the cluster metallicity, the higher the sequence lies in a plot of Phi sub 31 with period. The Phi sub 31 values for the stars in NGC 6171 and M5 presented here are based on observations made with the University of Toronto 0.61 m telescope at Las Campanas, Chile, while those for M3, M53, and M15 are based on published data. A bootstrap procedure has been used to establish the uncertainties in the Fourier parameters. The physical significance of the relationship among Phi sub 31, period, and metallicity is not yet understood. It will need to be tested with hydrodynamic pulsation models computed with new opacities.

Linear theory period ratios for surface helium enhanced double-mode Cepheids

International Nuclear Information System (INIS)

Cox, A.N.; Hodson, S.W.; King, D.S.

1979-01-01

Linear nonadiabatic theory period ratios for models of double-mode Cepheids with their two periods between 1 and 7 days have been computed, assuming differing amounts and depths of surface helium enhancement. Evolution theory masses and luminosities are found to be consistent with the observed periods. All models give Pi 1 /Pi 0 approx. =0.70 as observed for the 11 known variables, contrary to previous theoretical conclusions. The composition structure that best fits the period ratios has the helium mass fraction in the outer 10 -3 of the stellar mass (T< or =250,000 K) as 0.65, similar to a previous model for the triple-mode pulsator AC And. This enrichment can be established by a Cepheid wind and downward inverted μ gradient instability mixing in the lifetime of these low-mass classical Cepheids

Availability of periodically tested systems

International Nuclear Information System (INIS)

Signoret, J.P.

1979-01-01

There is at the present time a need in accurate models to asess the availability of periodically tested stand-by systems. This paper shows how to improve the well known 'saw-tooth curve' model in order to take into account various reliability parameters. A model is developed to assess the pointwise and the mean availabilities of periodically tested stand-by systems. Exact and approxination formulae are given. In addition, the model developed herein leads to optimize the test interval in order to minimize the mean unavailability. A safety diesel in a nuclear power plant is given as an example

Periodic depuration of anthracene metabolites by rainbow trout

International Nuclear Information System (INIS)

Linder, G.; Bergman, H.L.

1984-01-01

Rainbow trout Salmo gairdneri, statically exposed to 36 μg/liter anthracene (including 9- 14 C-C anthracene), bioconcentrated the polynuclear aromatic hydrocarbon 200 times the exposure concentration over 18 hours. Then, during a 96-hour clearance periods, mass-balance analysis of fish and water samples indicated that anthracene was rapidly converted to polar metabolites(s), then eliminated periodically. Maximum depuration occurred during the dark phase of a 16-hour-light: 8-hour-dark photocycle. Of the 2-3% contribution of 14 C metabolites(s) to the total 14 C residue, nearly half came from the bile. This periodic depuration may be circadian, although this requires confirmation by further work; to the extent it affects metabolic fate of bioconcentrated organics, periodic depuration undoubtedly contributes to differences between predicted and observed bioconcentration factors

Exotic supersymmetry of the kink-antikink crystal, and the infinite period limit

International Nuclear Information System (INIS)

Plyushchay, Mikhail S.; Arancibia, Adrian; Nieto, Luis-Miguel

2011-01-01

Some time ago, Thies et al. showed that the Gross-Neveu model with a bare mass term possesses a kink-antikink crystalline phase. Corresponding self-consistent solutions, known earlier in polymer physics, are described by a self-isospectral pair of one-gap periodic Lame potentials with a Darboux displacement depending on the bare mass. We study an unusual supersymmetry of such a second-order Lame system, and show that the associated first-order Bogoliubov-de Gennes Hamiltonian possesses its own nonlinear supersymmetry. The Witten index is ascertained to be zero for both of the related exotic supersymmetric structures, each of which admits several alternatives for the choice of a grading operator. A restoration of the discrete chiral symmetry at zero value of the bare mass, when the kink-antikink crystalline condensate transforms into the kink crystal, is shown to be accompanied by structural changes in both of the supersymmetries. We find that the infinite period limit may or may not change the index. We also explain the origin of the Darboux-dressing phenomenon recently observed in a nonperiodic self-isospectral one-gap Poeschl-Teller system, which describes the Dashen, Hasslacher, and Neveu kink-antikink baryons.

Light Curve Periodic Variability of Cyg X-1 using Jurkevich Method

Indian Academy of Sciences (India)

The Jurkevich method is a useful method to explore periodicity in the unevenly sampled observational data. In this work, we adopted the method to the light curve of Cyg X-1 from 1996 to 2012, and found that there is an interesting period of 370 days, which appears in both low/hard and high/soft states. That period may be ...

KIC 3240411 - the hottest known SPB star with the asymptotic g-mode period spacing

Science.gov (United States)

Szewczuk, Wojciech; Daszyńska-Daszkiewicz, Jadwiga

2018-05-01

We report the discovery of the hottest hybrid B-type pulsator, KIC 3240411, that exhibits the period spacing in the low-frequency range. This pattern is associated with asymptotic properties of high-order gravity (g-) modes. Our seismic modelling made simultaneously with the mode identification shows that dipole axisymmetric modes best fit the observations. Evolutionary models are computed with MESA code and pulsational models with the linear non-adiabatic code employing the traditional approximation to include the effects of rotation. The problem of mode excitation is discussed. We confirm that significant modification is indispensable to explain an instability of both pressure and gravity modes in the observed frequency ranges of KIC 3240411.

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

Science.gov (United States)

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

2006-01-01

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

Computing return times or return periods with rare event algorithms

Science.gov (United States)

Lestang, Thibault; Ragone, Francesco; Bréhier, Charles-Edouard; Herbert, Corentin; Bouchet, Freddy

2018-04-01

The average time between two occurrences of the same event, referred to as its return time (or return period), is a useful statistical concept for practical applications. For instance insurances or public agencies may be interested by the return time of a 10 m flood of the Seine river in Paris. However, due to their scarcity, reliably estimating return times for rare events is very difficult using either observational data or direct numerical simulations. For rare events, an estimator for return times can be built from the extrema of the observable on trajectory blocks. Here, we show that this estimator can be improved to remain accurate for return times of the order of the block size. More importantly, we show that this approach can be generalised to estimate return times from numerical algorithms specifically designed to sample rare events. So far those algorithms often compute probabilities, rather than return times. The approach we propose provides a computationally extremely efficient way to estimate numerically the return times of rare events for a dynamical system, gaining several orders of magnitude of computational costs. We illustrate the method on two kinds of observables, instantaneous and time-averaged, using two different rare event algorithms, for a simple stochastic process, the Ornstein–Uhlenbeck process. As an example of realistic applications to complex systems, we finally discuss extreme values of the drag on an object in a turbulent flow.

Explosive dome eruptions modulated by periodic gas-driven inflation

Science.gov (United States)

Johnson, Jeffrey B.; Lyons, John; Andrews, B. J.; Lees, J.M.

2014-01-01

Volcan Santiaguito (Guatemala) “breathes” with extraordinary regularity as the edifice's conduit system accumulates free gas, which periodically vents to the atmosphere. Periodic pressurization controls explosion timing, which nearly always occurs at peak inflation, as detected with tiltmeters. Tilt cycles in January 2012 reveal regular 26 ± 6 min inflation/deflation cycles corresponding to at least ~101 kg/s of gas fluxing the system. Very long period (VLP) earthquakes presage explosions and occur during cycles when inflation rates are most rapid. VLPs locate ~300 m below the vent and indicate mobilization of volatiles, which ascend at ~50 m/s. Rapid gas ascent feeds pyroclast-laden eruptions lasting several minutes and rising to ~1 km. VLPs are not observed during less rapid inflation episodes; instead, gas vents passively through the conduit producing no infrasound and no explosion. These observations intimate that steady gas exsolution and accumulation in shallow reservoirs may drive inflation cycles at open-vent silicic volcanoes.

Mammalian cycles: internally defined periods and interaction-driven amplitudes

Directory of Open Access Journals (Sweden)

LR Ginzburg

2015-08-01

Full Text Available The cause of mammalian cycles—the rise and fall of populations over a predictable period of time—has remained controversial since these patterns were first observed over a century ago. In spite of extensive work on observable mammalian cycles, the field has remained divided upon what the true cause is, with a majority of opinions attributing it to either predation or to intra-species mechanisms. Here we unite the eigenperiod hypothesis, which describes an internal, maternal effect-based mechanism to explain the cycles’ periods with a recent generalization explaining the amplitude of snowshoe hare cycles in northwestern North America based on initial predator abundance. By explaining the period and the amplitude of the cycle with separate mechanisms, a unified and consistent view of the causation of cycles is reached. Based on our suggested theory, we forecast the next snowshoe hare cycle (predicted peak in 2016 to be of extraordinarily low amplitude.

Influence of composite period and date of observation on phenological metrics extracted from MODIS data

CSIR Research Space (South Africa)

Wessels, Konrad J

2009-05-01

Full Text Available ) The 8-day, 500m MODIS data (MOD09) for the Skukuza EOS site were downloaded from the MODIS ASCII Subsets website (http://daac.ornl.gov/cgi-bin/MODIS/GR_1/button.slim.pl). The data comprised 14 x 14 pixels of data covering a 7x7 km area for the period...

Magnetomechanically induced long period fiber gratings

International Nuclear Information System (INIS)

Causado-Buelvas, Jesus D.; Gomez-Cardona, Nelson D.; Torres, Pedro

2008-01-01

In this work, we report a simple, flexible method to create long period fiber gratings mechanically by controlling the repulsion/attraction force between two magnets that pressing a plate with a periodic array of small glass cylinders to a short length of optical fiber. Via the photoelastic effect, the pressure points induce the required periodic refractive index modulation to create the LPFG. We found that the induced device exhibits spectral characteristics similar to those of other types of LPFG. As the optical properties of LPFGs are directly related to the nature of the applied perturbations, we show, to our knowledge for the frrst time, how is the evolution of birefringence effects in mechanically induced LPFGs

Impact of a standardized nurse observation protocol including MEWS after Intensive Care Unit discharge.

Science.gov (United States)

De Meester, K; Das, T; Hellemans, K; Verbrugghe, W; Jorens, P G; Verpooten, G A; Van Bogaert, P

2013-02-01

Analysis of in-hospital mortality after serious adverse events (SAE's) in our hospital showed the need for more frequent observation in medical and surgical wards. We hypothesized that the incidence of SAE's could be decreased by introducing a standard nurse observation protocol. To investigate the effect of a standard nurse observation protocol implementing the Modified Early Warning Score (MEWS) and a color graphic observation chart. Pre- and post-intervention study by analysis of patients records for a 5-day period after Intensive Care Unit (ICU) discharge to 14 medical and surgical wards before (n=530) and after (n=509) the intervention. For the total study population the mean Patient Observation Frequency Per Nursing Shift (POFPNS) during the 5-day period after ICU discharge increased from .9993 (95% C.I. .9637-1.0350) in the pre-intervention period to 1.0732 (95% C.I. 1.0362-1.1101) (p=.005) in the post-intervention period. There was an increased risk of a SAE in patients with MEWS 4 or higher in the present nursing shift (HR 8.25; 95% C.I. 2.88-23.62) and the previous nursing shift (HR 12.83;95% C.I. 4.45-36.99). There was an absolute risk reduction for SAE's within 120h after ICU discharge of 2.2% (95% C.I. -0.4-4.67%) from 5.7% to 3.5%. The intervention had a positive impact on the observation frequency. MEWS had a predictive value for SAE's in patients after ICU discharge. The drop in SAE's was substantial but did not reach statistical significance. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

On the short periods oscillation in relativistic stars

International Nuclear Information System (INIS)

Aquilano, R.; Morales, S.; Navone, H.; Sevilla, D.; Zorzi, A.

2009-01-01

We expand the study of neutron and strange matter stars with general relativistic formalism. We analyze the correlation with the observational data short periods oscillations in these stars, and we intend to discriminate between them.

The Last Great American Picture Show : New Hollywood Cinema in the 1970s

NARCIS (Netherlands)

2004-01-01

In The Last Great American Picture Show wordt de veranderende herwaardering in kaart gebracht voor de Amerikaanse film in de jaren zeventig. Deze periode, vroeger aangeduid als het decennium van de 'lost generation', wordt meer en meer erkend als het eerste 'Nieuwe Hollywood'. In deze periode werd

Pulse periods and the long-term variations of the X-ray pulsars VELA X-1 and Centaurus X-3

Science.gov (United States)

Tsunemi, Hiroshi

The paper reports recent determinations of the pulse period for two X-ray pulsars, Vela X-1 and Cen X-3, made in 1987 with the All Sky Monitor (ASM) on board the Ginga satellite. The heliocentric pulse periods are 283.09 + or - 0.01 s and 4.8229 + or - 0.0001 s, respectively. These are the longest and shortest values in their respective observational histories. The random walk model for the Vela X-1 pulsar can explain this result as well as those obtained previously. It is also noted that the pulse-period change for the Cen X-3 system shows a 9-yr periodicity. This is probably due to the activity of the companion star rather than to Doppler-shift variations due to a third body or the precession of the neutron star.

Periodic feedback stabilization for linear periodic evolution equations

CERN Document Server

Wang, Gengsheng

2016-01-01

This book introduces a number of recent advances regarding periodic feedback stabilization for linear and time periodic evolution equations. First, it presents selected connections between linear quadratic optimal control theory and feedback stabilization theory for linear periodic evolution equations. Secondly, it identifies several criteria for the periodic feedback stabilization from the perspective of geometry, algebra and analyses respectively. Next, it describes several ways to design periodic feedback laws. Lastly, the book introduces readers to key methods for designing the control machines. Given its coverage and scope, it offers a helpful guide for graduate students and researchers in the areas of control theory and applied mathematics.

The period function of the generalized Lotka-Volterra centers

Science.gov (United States)

Villadelprat, J.

2008-05-01

The present paper deals with the period function of the quadratic centers. In the literature different terminologies are used to classify these centers, but essentially there are four families: Hamiltonian, reversible , codimension four Q4 and generalized Lotka-Volterra systems . Chicone [C. Chicone, Review in MathSciNet, Ref. 94h:58072] conjectured that the reversible centers have at most two critical periods, and that the centers of the three other families have a monotonic period function. With regard to the second part of this conjecture, only the monotonicity of the Hamiltonian and Q4 families [W.A. Coppel, L. Gavrilov, The period function of a Hamiltonian quadratic system, Differential Integral Equations 6 (1993) 1357-1365; Y. Zhao, The monotonicity of period function for codimension four quadratic system Q4, J. Differential Equations 185 (2002) 370-387] has been proved. Concerning the family, no substantial progress has been made since the middle 80s, when several authors showed independently the monotonicity of the classical Lotka-Volterra centers [F. Rothe, The periods of the Volterra-Lokta system, J. Reine Angew. Math. 355 (1985) 129-138; R. Schaaf, Global behaviour of solution branches for some Neumann problems depending on one or several parameters, J. Reine Angew. Math. 346 (1984) 1-31; J. Waldvogel, The period in the Lotka-Volterra system is monotonic, J. Math. Anal. Appl. 114 (1986) 178-184]. By means of the first period constant one can easily conclude that the period function of the centers in the family is monotone increasing near the inner boundary of its period annulus (i.e., the center itself). Thus, according to Chicone's conjecture, it should be also monotone increasing near the outer boundary, which in the Poincaré disc is a polycycle. In this paper we show that this is true. In addition we prove that, except for a zero measure subset of the parameter plane, there is no bifurcation of critical periods from the outer boundary. Finally we

Three dimensional periodic foundations for base seismic isolation

International Nuclear Information System (INIS)

Yan, Y; Mo, Y L; Cheng, Z; Shi, Z; Menq, F; Tang, Y

2015-01-01

Based on the concept of phononic crystals, periodic foundations made of periodic materials are investigated in this paper. The periodic foundations can provide low frequency band gaps, which cover the main frequency ranges of seismic waves. Therefore, the periodic foundations are able to protect the upper structures during earthquake events. In this paper, the basic theory of three dimensional periodic foundations is studied and the finite element method was used to conduct the sensitivity study. A simplified three-dimensional periodic foundation with a superstructure was tested in the field and the feasibility of three dimensional periodic foundations was proved. The test results showed that the response of the upper structure with the three dimensional periodic foundation was reduced under excitation waves with the main frequency falling in the attenuation zones. The finite element analysis results are consistent with the experimental data, indicating that three dimensional periodic foundations are a feasible way of reducing seismic vibrations. (paper)

Seasonal Variations of Mesospheric Gravity Waves Observed with an Airglow All-sky Camera at Mt. Bohyun, Korea (36° N

Directory of Open Access Journals (Sweden)

Yong Ha Kim

2010-09-01

Full Text Available We have carried out all-sky imaging of OH Meinel, O2 atmospheric and OI 557.7 nm airglow layers in the period from July of 2001 through September of 2005 at Mt. Bohyun, Korea (36.2° N, 128.9° E, Alt = 1,124 m. We analyzed the images observed during a total of 153 clear moonless nights and found 97 events of band-type waves. The characteristics of the observed waves (wavelengths, periods, and phase speeds are consistent with internal gravity waves. The wave occurrence shows an approximately semi-annual variation, with maxima near solstices and minima near equinoxes, which is consistent with other studies of airglow wave observations, but not with those of mesospheric radar/lidar observations. The observed waves tended to propagate westward during fall and winter, and eastward during spring and summer. Our ray tracing study of the observed waves shows that majority of the observed waves seemed to originate from mesospheric altitudes. The preferential directions and the apparent source altitudes can be explained if the observed waves are secondary waves generated from primary waves that have been selected by the filtering process and break up at the mesospheric altitudes.

The long view: Causes of climate change over the instrumental period

Science.gov (United States)

Hegerl, G. C.; Schurer, A. P.; Polson, D.; Iles, C. E.; Bronnimann, S.

2016-12-01

The period of instrumentally recorded data has seen remarkable changes in climate, with periods of rapid warming, and periods of stagnation or cooling. A recent analysis of the observed temperature change from the instrumental record confirms that most of the warming recorded since the middle of the 20rst century has been caused by human influences, but shows large uncertainty in separating greenhouse gas from aerosol response if accounting for model uncertainty. The contribution by natural forcing and internal variability to the recent warming is estimated to be small, but becomes more important when analysing climate change over earlier or shorter time periods. For example, the enigmatic early 20th century warming was a period of strong climate anomalies, including the US dustbowl drought and exceptional heat waves, and pronounced Arctic warming. Attribution results suggests that about half of the global warming 1901-1950 was forced by greenhouse gases increases, with an anomalously strong contribution by climate variability, and contributions by natural forcing. Long term variations in circulation are important for some regional climate anomalies. Precipitation is important for impacts of climate change and precipitation changes are uncertain in models. Analysis of the instrumental record suggests a human influence on mean and heavy precipitation, and supports climate model estimates of the spatial pattern of precipitation sensitivity to warming. Broadly, and particularly over ocean, wet regions are getting wetter and dry regions are getting drier. In conclusion, the historical record provides evidence for a strong response to external forcings, supports climate models, and raises questions about multi-decadal variability.

An Online Observer for Minimization of Pulsating Torque in SMPM Motors

Science.gov (United States)

Roșca, Lucian

2016-01-01

A persistent problem of surface mounted permanent magnet (SMPM) motors is the non-uniformity of the developed torque. Either the motor design or the motor control needs to be improved in order to minimize the periodic disturbances. This paper proposes a new control technique for reducing periodic disturbances in permanent magnet (PM) electro-mechanical actuators, by advancing a new observer/estimator paradigm. A recursive estimation algorithm is implemented for online control. The compensating signal is identified and added as feedback to the control signal of the servo motor. Compensation is evaluated for different values of the input signal, to show robustness of the proposed method. PMID:27089182

Changes in effective moisture on the Tibetan Plateau during the period 1981-2010

Science.gov (United States)

Yin, Y.; Wu, S.; Zhao, D.

2013-12-01

Observed evaporative demand has decreased worldwide during the past several decades. This trend is also noted on the Tibetan Plateau, a region that is particularly sensitive to climate change. However, actual evapotranspiration trends and their relationship to drought stress on the Tibetan Plateau are poorly understood. We analyzed the spatiotemporal changes in potential evapotranspiration(PET), actual evapotranspiration(AET) and effective moisture (defined as AET/PET) during 1981-2010. Climate data from 80 meteorological stations on the Tibetan Plateau were compiled for the period 1981-2010. New plant functional types were defined for the Tibetan Plateau and evapotranspiration is simulated by the modified Lund-Potsdam-Jena Dynamic Global Vegetation Model (LPJ). The results show regional trends towards decreasing PET and statistically significant increases in AET (p < 0.05) and effective moisture (p < 0.001) during the period 1981-2010. A transition from significant negative to positive PET occurred in 1997. Additionally, a pronounced increase in effective moisture occurred during the period 1981-1997 because of significant decreased PET before 1997.