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Sample records for timing variation ttv

  1. EXTRACTING PLANET MASS AND ECCENTRICITY FROM TTV DATA

    International Nuclear Information System (INIS)

    Lithwick, Yoram; Xie Jiwei; Wu Yanqin

    2012-01-01

    Most planet pairs in the Kepler data that have measured transit time variations (TTVs) are near first-order mean-motion resonances. We derive analytical formulae for their TTV signals. We separate planet eccentricity into free and forced parts, where the forced part is purely due to the planets' proximity to resonance. This separation yields simple analytical formulae. The phase of the TTV depends sensitively on the presence of free eccentricity: if the free eccentricity vanishes, the TTV will be in phase with the longitude of conjunctions. This effect is easily detectable in current TTV data. The amplitude of the TTV depends on planet mass and free eccentricity, and it determines planet mass uniquely only when the free eccentricity is sufficiently small. We analyze the TTV signals of six short-period Kepler pairs. We find that three of these pairs (Kepler 18, 24, 25) have a TTV phase consistent with zero. The other three (Kepler 23, 28, 32) have small TTV phases, but ones that are distinctly non-zero. We deduce that the free eccentricities of the planets are small, ∼< 0.01, but not always vanishing. Furthermore, as a consequence of this, we deduce that the true masses of the planets are fairly accurately determined by the TTV amplitudes, within a factor of ∼< 2. The smallness of the free eccentricities suggests that the planets have experienced substantial dissipation. This is consistent with the hypothesis that the observed pile-up of Kepler pairs near mean-motion resonances is caused by resonant repulsion. But the fact that some of the planets have non-vanishing free eccentricity suggests that after resonant repulsion occurred there was a subsequent phase in the planets' evolution when their eccentricities were modestly excited, perhaps by interplanetary interactions.

  2. Transit timing observations from Kepler. V. Transit timing variation candidates in the first sixteen months from polynomial models

    DEFF Research Database (Denmark)

    Ford, E.B.; Ragozzine, D.; Holman, M.J.

    2012-01-01

    Transit timing variations provide a powerful tool for confirming and characterizing transiting planets, as well as detecting non-transiting planets. We report the results of an updated transit timing variation (TTV) analysis for 1481 planet candidates based on transit times measured during...... that several of these planet candidates could be confirmed and perhaps characterized with more detailed TTV analyses using publicly available Kepler observations. For many others, Kepler has observed a long-term TTV trend, but an extended Kepler mission will be required to characterize the system via TTVs. We...

  3. TRANSIT TIMING VARIATIONS FOR INCLINED AND RETROGRADE EXOPLANETARY SYSTEMS

    International Nuclear Information System (INIS)

    Payne, Matthew J.; Ford, Eric B.; Veras, Dimitri

    2010-01-01

    We perform numerical calculations of the expected transit timing variations (TTVs) induced on a hot-Jupiter by an Earth-mass perturber. Motivated by the recent discoveries of retrograde transiting planets, we concentrate on an investigation of the effect of varying relative planetary inclinations, up to and including completely retrograde systems. We find that planets in low-order (e.g., 2:1) mean-motion resonances (MMRs) retain approximately constant TTV amplitudes for 0 deg. 170 deg. Systems in higher order MMRs (e.g., 5:1) increase in TTV amplitude as inclinations increase toward 45 deg., becoming approximately constant for 45 deg. 135 deg. Planets away from resonance slowly decrease in TTV amplitude as inclinations increase from 0 deg. to 180 deg., whereas planets adjacent to resonances can exhibit a huge range of variability in TTV amplitude as a function of both eccentricity and inclination. For highly retrograde systems (135 deg. < i ≤ 180 deg.), TTV signals will be undetectable across almost the entirety of parameter space, with the exceptions occurring when the perturber has high eccentricity or is very close to an MMR. This high inclination decrease in TTV amplitude (on and away from resonance) is important for the analysis of the known retrograde and multi-planet transiting systems, as inclination effects need to be considered if TTVs are to be used to exclude the presence of any putative planetary companions: absence of evidence is not evidence of absence.

  4. TTV as A Risk Factor in Hemodialysis Process

    International Nuclear Information System (INIS)

    Ibrahim, I.M.

    2010-01-01

    The association of TTV (transfusion transmitted virus) with both cryptogenic chronic liver diseases and post-transfusion hepatitis has been reported. Hemodialysis patients are at high risk for viral hepatitis due to blood born viral agents. The few data available concerning TTV infection among hemodialysis patients shows a high prevalence. This study was conducted on one hundred patients with end-stage renal disease (ESRD). They were attending the hemodialysis (HD) unit of Naser institute for performing hemodialysis for the first time (as a control group) and the same patients after recurrent HD for at least six months of regular HD (as a HD patient group). Patients and controls were subjected to the following laboratory investigations; 1) TTV DNA detection by PCR. 2) HBs Ag by ELISA technique. 3) HCV Ab by ELISA technique. 4) Liver enzymes include ALT, AST and γGT. The study was done to detect TTV DNA by PCR in hemodialysis patients and to evaluate its clinical impacts, taking into account co-infection with other hepatitis viruses. The results of this work are:- 1- TTV is remarkably prevalent in HD patients. The prevalence of TTV infection in HD Egyptian patients was 45% and 9% in healthy volunteer from the same geographical area. 2- HCV was found to have highly significant association with HD patients while there was no association between HD patients and HBs Ag. 3- TTV infection was not found to be more prevalent in HD patients infected with HCV. 4- Abnormal liver enzymes were uncommon in HD patients infected with TTV alone, in contrast to patients with known hepatotropic viruses such as HCV. 5- TTV did not play a role in liver injury, but it might aggravate liver diseases caused by HCV.

  5. TRANSIT TIMING OBSERVATIONS FROM KEPLER. V. TRANSIT TIMING VARIATION CANDIDATES IN THE FIRST SIXTEEN MONTHS FROM POLYNOMIAL MODELS

    Energy Technology Data Exchange (ETDEWEB)

    Ford, Eric B. [Astronomy Department, University of Florida, 211 Bryant Space Sciences Center, Gainesville, FL 32111 (United States); Ragozzine, Darin; Holman, Matthew J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Rowe, Jason F.; Barclay, Thomas; Borucki, William J.; Bryson, Stephen T.; Caldwell, Douglas A.; Kinemuchi, Karen; Koch, David G.; Lissauer, Jack J.; Still, Martin; Tenenbaum, Peter [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Steffen, Jason H. [Fermilab Center for Particle Astrophysics, P.O. Box 500, MS 127, Batavia, IL 60510 (United States); Batalha, Natalie M. [Department of Physics and Astronomy, San Jose State University, San Jose, CA 95192 (United States); Fabrycky, Daniel C. [UCO/Lick Observatory, University of California, Santa Cruz, CA 95064 (United States); Gautier, Thomas N. [Jet Propulsion Laboratory/California Institute of Technology, Pasadena, CA 91109 (United States); Ibrahim, Khadeejah A.; Uddin, Kamal [Orbital Sciences Corporation/NASA Ames Research Center, Moffett Field, CA 94035 (United States); Kjeldsen, Hans, E-mail: eford@astro.ufl.edu [Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C (Denmark); and others

    2012-09-10

    Transit timing variations provide a powerful tool for confirming and characterizing transiting planets, as well as detecting non-transiting planets. We report the results of an updated transit timing variation (TTV) analysis for 1481 planet candidates based on transit times measured during the first sixteen months of Kepler observations. We present 39 strong TTV candidates based on long-term trends (2.8% of suitable data sets). We present another 136 weaker TTV candidates (9.8% of suitable data sets) based on the excess scatter of TTV measurements about a linear ephemeris. We anticipate that several of these planet candidates could be confirmed and perhaps characterized with more detailed TTV analyses using publicly available Kepler observations. For many others, Kepler has observed a long-term TTV trend, but an extended Kepler mission will be required to characterize the system via TTVs. We find that the occurrence rate of planet candidates that show TTVs is significantly increased ({approx}68%) for planet candidates transiting stars with multiple transiting planet candidates when compared to planet candidates transiting stars with a single transiting planet candidate.

  6. TTV and HPV co-infection in cervical smears of patients with cervical lesions

    Directory of Open Access Journals (Sweden)

    Tachezy Ruth

    2009-07-01

    Full Text Available Abstract Background The female lower genital tract is a gateway for pathogens entering the host through the mucous membrane. One of the prevalent human viruses is Torque teno virus (TTV. The major reported routes of TTV transmission are fecal-oral and parenteral. Furthermore, other modes of transmission, e.g. sexual contact, are suggested. To investigate the sexual route of TTV transmission, cervical smears of healthy women and those with cervical lesions were screened for the presence of TTV DNA. Methods TTV DNA was studied in cervical smears of 95 patients with cervical lesions and 55 healthy women. Paired serum samples were available from 55 and 42 women, respectively. All healthy women had normal cytology while 44 patients had histologically confirmed low-grade lesion (LGL and 51 high-grade lesion (HGL. TTV DNA was detected with primers specific for the non-coding region. In 40 paired cervical smears and serum samples, the phylogenetic group of TTV isolates was determined. The presence of HPV DNA in cervical smears was detected by means of PCR with MY09/11 primers. Results The prevalence of TTV DNA in cervical smears of healthy women was 52.7% and was comparable with that in paired serum samples (50%. Symptomatic women had significantly higher prevalence of TTV DNA in cervical smears (74.7% than healthy controls. The TTV DNA prevalence in patient serum samples was 51%. The phylogenetic groups of TTV serum isolates were concordant with those of TTV from cervical smears of the same subjects. In cervical smears, a wider variety of TTV isolates was found. The viral loads in cervical smears were 10 to 1000 times as high as in sera. The HPV-positive study subjects had significantly higher TTV DNA prevalence than HPV negatives. The prevalence of TTV was not associated with disease severity. Conclusion High prevalence of TTV in cervical smears suggests that sexual transmission is another mode of expansion of TTV infection among the population. The

  7. A search for transit timing variation

    Directory of Open Access Journals (Sweden)

    Kramm U.

    2011-02-01

    Full Text Available Photometric follow-ups of transiting exoplanets (TEPs may lead to discoveries of additional, less massive bodies in extrasolar systems. This is possible by detecting and then analysing variations in transit timing of transiting exoplanets. In 2009 we launched an international observing campaign, the aim of which is to detect and characterise signals of transit timing variation (TTV in selected TEPs. The programme is realised by collecting data from 0.6-2.2-m telescopes spread worldwide at different longitudes. We present our observing strategy and summarise first results for WASP-3b with evidence for a 15 Earth-mass perturber in an outer 2:1 orbital resonance.

  8. The prevalence of transfusion-transmitted virus (TTV) infection in ...

    African Journals Online (AJOL)

    Transfusion-transmitted virus (TTV) is an unenveloped circular single-stranded DNA virus with a diameter of 30 to 32 nm that was first described in 1997 in Japan. TTV was detected in various populations without proven pathology, including blood donors and in patients with chronic hepatitis B virus (HBV) and hepatitis C ...

  9. Densities and eccentricities of 139 Kepler planets from transit time variations

    Energy Technology Data Exchange (ETDEWEB)

    Hadden, Sam; Lithwick, Yoram [Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208 (United States)

    2014-05-20

    We extract densities and eccentricities of 139 sub-Jovian planets by analyzing transit time variations (TTVs) obtained by the Kepler mission through Quarter 12. We partially circumvent the degeneracies that plague TTV inversion with the help of an analytical formula for the TTV. From the observed TTV phases, we find that most of these planets have eccentricities of the order of a few percent. More precisely, the rms eccentricity is 0.018{sub −0.004}{sup +0.005}, and planets smaller than 2.5 R {sub ⊕} are around twice as eccentric as those bigger than 2.5 R {sub ⊕}. We also find a best-fit density-radius relationship ρ ≈ 3 g cm{sup –3} × (R/3 R {sub ⊕}){sup –2.3} for the 56 planets that likely have small eccentricity and hence small statistical correction to their masses. Many planets larger than 2.5 R {sub ⊕} are less dense than water, implying that their radii are largely set by a massive hydrogen atmosphere.

  10. Detection of TTV-DNA in PBMC using digoxigenin labelled probe by in situ hybridization

    International Nuclear Information System (INIS)

    Liu Yang; Qi Qige

    2002-01-01

    To determine TTV-DNA in PBMC in patients with viral hepatitis, a study of in situ hybridization using digoxigenin labelled probe by PCR method to the TTV ORF1 region was performed on PBMC. Results showed that the detection rate of TTV-DNA using double-stranded probe in TTV-DNA positive group in sera was 58.06 (18/31), and the detection rate of TTV-DNA using double-stranded probe in TTV-DNA negative group in sera was 27.59 (8/29). For TTV-DNA positive group detected by double- stranded probe, then we use negative- stranded probe to detect their replication. The detection rate was 22.2%(4/18). Conclusions: TTV can infect PBMC and replicate in PBMC

  11. The prevalence of transfusion-transmitted virus (TTV) infection in ...

    African Journals Online (AJOL)

    Administrator

    2011-06-08

    Jun 8, 2011 ... diameter of 30 to 32 nm that was first described in 1997 in Japan. TTV was detected in ... serum of a Japanese patient with fulminant hepatitis and chronic liver ..... Molecular cloning and characterization of a novel DNA virus ...

  12. PREVALENCE OF ''TTV'' IN PATIENTS WITH CHRONIC VIRAL HEPATITIS ''B'' AND ''C''

    International Nuclear Information System (INIS)

    NOSSEIR, N.M.; MANSOUR, H.H.; FAHMY, N.M.

    2007-01-01

    Transfusion transmitted virus (TTV) is an enveloped single strand virus discovered in serum of patients with post-transfusion hepatitis of unknown etiology in Japan and designated as TT virus (TTV). To investigate the frequency of TTV infection in patients with viral hepatitis B or C, 25 Egyptian patients with hepatitis C virus (HCV) aged 8-40 years and 25 patients with B virus (HBV) aged 8-57 years were tested. Detection of TTV-DNA was performed by semi-nested polymerase chain reaction (PCR) using TTV-specific primers. Serum levels of transaminases were tested. The prevalence of TTV in patients with chronic viral hepatitis B or C was frequent and the co-infection of TTV with HCV or HBV was accompanied by a high level of transaminases as compared to that of HBV or HCV alone. The present study confirms and extends that infection alone doesn't cause significant liver damage

  13. The Transiting System GJ1214: High-Precision Defocused Transit Observations and a Search for Evidence of Transit Timing Variation

    DEFF Research Database (Denmark)

    Harpsøe, Kennet Bomann West; Hardis, S.; Hinse, T. C.

    2012-01-01

    Aims: We present 11 high-precision photometric transit observations of the transiting super-Earth planet GJ1214b. Combining these data with observations from other authors, we investigate the ephemeris for possible signs of transit timing variations (TTVs) using a Bayesian approach. Methods......: The observations were obtained using telescope-defocusing techniques, and achieve a high precision with random errors in the photometry as low as 1mmag per point. To investigate the possibility of TTVs in the light curve, we calculate the overall probability of a TTV signal using Bayesian methods. Results...

  14. Transit timing observations from Kepler. VI. Potentially interesting candidate systems from fourier-based statistical tests

    DEFF Research Database (Denmark)

    Steffen, J.H.; Ford, E.B.; Rowe, J.F.

    2012-01-01

    We analyze the deviations of transit times from a linear ephemeris for the Kepler Objects of Interest (KOI) through quarter six of science data. We conduct two statistical tests for all KOIs and a related statistical test for all pairs of KOIs in multi-transiting systems. These tests identify...... several systems which show potentially interesting transit timing variations (TTVs). Strong TTV systems have been valuable for the confirmation of planets and their mass measurements. Many of the systems identified in this study should prove fruitful for detailed TTV studies....

  15. TRANSIT TIMING OBSERVATIONS FROM KEPLER. VI. POTENTIALLY INTERESTING CANDIDATE SYSTEMS FROM FOURIER-BASED STATISTICAL TESTS

    International Nuclear Information System (INIS)

    Steffen, Jason H.; Ford, Eric B.; Rowe, Jason F.; Borucki, William J.; Bryson, Steve; Caldwell, Douglas A.; Jenkins, Jon M.; Koch, David G.; Sanderfer, Dwight T.; Seader, Shawn; Twicken, Joseph D.; Fabrycky, Daniel C.; Holman, Matthew J.; Welsh, William F.; Batalha, Natalie M.; Ciardi, David R.; Kjeldsen, Hans; Prša, Andrej

    2012-01-01

    We analyze the deviations of transit times from a linear ephemeris for the Kepler Objects of Interest (KOI) through quarter six of science data. We conduct two statistical tests for all KOIs and a related statistical test for all pairs of KOIs in multi-transiting systems. These tests identify several systems which show potentially interesting transit timing variations (TTVs). Strong TTV systems have been valuable for the confirmation of planets and their mass measurements. Many of the systems identified in this study should prove fruitful for detailed TTV studies.

  16. Time variations in geomagnetic intensity

    Science.gov (United States)

    Valet, Jean-Pierre

    2003-03-01

    After many years spent by paleomagnetists studying the directional behavior of the Earth's magnetic field at all possible timescales, detailed measurements of field intensity are now needed to document the variations of the entire vector and to analyze the time evolution of the field components. A significant step has been achieved by combining intensity records derived from archeological materials and from lava flows in order to extract the global field changes over the past 12 kyr. A second significant step was due to the emergence of coherent records of relative paleointensity using the remanent magnetization of sediments to retrace the evolution of the dipole field. A third step was the juxtaposition of these signals with those derived from cosmogenic isotopes. Contemporaneous with the acquisition of records, new techniques have been developed to constrain the geomagnetic origin of the signals. Much activity has also been devoted to improving the quality of determinations of absolute paleointensity from volcanic rocks with new materials, proper selection of samples, and investigations of complex changes in magnetization during laboratory experiments. Altogether these developments brought us from a situation where the field changes were restricted to the past 40 kyr to the emergence of a coherent picture of the changes in the geomagnetic dipole moment for at least the past 1 Myr. On longer timescales the field variability and its average behavior is relatively well documented for the past 400 Myr. Section 3 gives a summary of most methods and techniques that are presently used to track the field intensity changes in the past. In each case, current limits and potential promises are discussed. The section 4 describes the field variations measured so far over various timescales covered by the archeomagnetic and the paleomagnetic records. Preference has always been given to composite records and databases in order to extract and discuss major and global geomagnetic

  17. Transit Timing Variation analysis with Kepler light curves of KOI 227 and Kepler 93b

    Science.gov (United States)

    Dulz, Shannon; Reed, Mike

    2017-01-01

    By searching for transit signals in approximately 150,000 stars, NASA’s Kepler Space telescope found thousands of exoplanets over its primary mission from 2009 to 2013 (Tenenbaum et al. 2014, ApJS, 211, 6). Yet, a detailed follow-up examination of Kepler light curves may contribute more evidence on system dynamics and planetary atmospheres of these objects. Kepler’s continuous observing of these systems over the mission duration produced light curves of sufficient duration to allow for the search for transit timing variations. Transit timing variations over the course of many orbits may indicate a precessing orbit or the existence of a non-transiting third body such as another exoplanet. Flux contributions of the planet just prior to secondary eclipse may provide a measurement of bond albedo from the day-side of the transiting planet. Any asymmetries of the transit shape may indicate thermal asymmetries which can measure upper atmosphere motion of the planet. These two factors can constrain atmospheric models of close orbiting exoplanets. We first establish our procedure with the well-documented TTV system, KOI 227 (Nesvorny et al. 2014, ApJ, 790, 31). Using the test case of KOI 227, we analyze Kepler-93b for TTVs and day-side flux contributions. Kepler-93b is likely a rocky planet with R = 1.50 ± 0.03 Earth Radii and M = 2.59 ± 2.0 Earth Masses (Marcy et al. 2014, ApJS, 210, 20). This research is funded by a NASA EPSCoR grant.

  18. TRANSIT TIMING OBSERVATIONS FROM KEPLER. VIII. CATALOG OF TRANSIT TIMING MEASUREMENTS OF THE FIRST TWELVE QUARTERS

    Energy Technology Data Exchange (ETDEWEB)

    Mazeh, Tsevi; Nachmani, Gil; Holczer, Tomer; Sokol, Gil [School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978 (Israel); Fabrycky, Daniel C. [Department of Astronomy and Astrophysics, University of Chicago, 5640 Ellis Ave., Chicago, IL 60637 (United States); Ford, Eric B.; Ragozzine, Darin [Astronomy Department, University of Florida, Gainesville, FL 32111 (United States); Sanchis-Ojeda, Roberto [Department of Physics and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Rowe, Jason F.; Lissauer, Jack J. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Zucker, Shay [Department of Geophysical, Atmospheric and Planetary Sciences, Raymond and Beverly Sackler Faculty of Exact Sciences Tel Aviv University, 69978 Tel Aviv (Israel); Agol, Eric [Department of Astronomy, Box 351580, University of Washington, Seattle, WA 98195 (United States); Carter, Joshua A. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Quintana, Elisa V. [SETI Institute, 189 Bernardo Ave, Suite 100, Mountain View, CA 94043 (United States); Steffen, Jason H. [Fermilab Center for Particle Astrophysics, P.O. Box 500, MS 127, Batavia, IL 60510 (United States); Welsh, William [Astronomy Department, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182 (United States)

    2013-10-01

    Following the works of Ford et al. and Steffen et al. we derived the transit timing of 1960 Kepler objects of interest (KOIs) using the pre-search data conditioning light curves of the first twelve quarters of the Kepler data. For 721 KOIs with large enough signal-to-noise ratios, we obtained also the duration and depth of each transit. The results are presented as a catalog for the community to use. We derived a few statistics of our results that could be used to indicate significant variations. Including systems found by previous works, we have found 130 KOIs that showed highly significant times of transit variations (TTVs) and 13 that had short-period TTV modulations with small amplitudes. We consider two effects that could cause apparent periodic TTV—the finite sampling of the observations and the interference with the stellar activity, stellar spots in particular. We briefly discuss some statistical aspects of our detected TTVs. We show that the TTV period is correlated with the orbital period of the planet and with the TTV amplitude.

  19. Modelling systematics of ground-based transit photometry I. Implications on transit timing variations

    DEFF Research Database (Denmark)

    von Essen, C.; Cellone, S.; Mallonn, M.

    2016-01-01

    introduced a perturbation in the mid-transit times of the hot Jupiter, caused by an Earth-sized planet in a 3:2 mean motion resonance. Analyzing the synthetic light curves produced after certain epochs, we attempt to recover the synthetically added TTV signal by means of usual primary transit fitting...... we attempt to reproduce, by means of physically and empirically motivated relationships, the effects caused by the Earth's atmosphere and the instrumental setup on the synthetic light curves. Therefore, the synthetic data present different photometric quality and transit coverage. In addition, we...

  20. Detection and genotyping of torque teno virus (TTV) in healthy blood donors and patients infected with HBV or HCV in Qatar.

    Science.gov (United States)

    AbuOdeh, Raed; Al-Mawlawi, Naema; Al-Qahtani, Ahmed A; Bohol, Marie Fe F; Al-Ahdal, Mohammed N; Hasan, Haydar A; AbuOdeh, Lamees; Nasrallah, Gheyath K

    2015-07-01

    Torque Teno virus (TTV) has been associated with non A-G hepatitis. The goal of this study was to estimate the infection rates and genotypic characteristics of TTV in the State of Qatar. A total of 644 blood samples representing different nationalities: (i) Qatari (118) and (ii) non-Qatari (526) nationals (mostly from Arab and South Eeast Asia countries) were tested for the presence of TTV DNA by nested PCR. The majority (573) of the blood samples belonged to healthy blood donors, whereas 54 and 53 of the blood samples belonged to patients infected with hepatitis B virus (HBV) and hepatitis C virus (HCV), respectively. The results obtained showed that the TTV infection rates in the healthy blood donors, and those infected with HBV or HCV patients were 81.4, 90.75 and 84.9%, respectively. Significant association between TTV viremia and age, or nationality was observed. Sequence analysis of PCR fragments amplified from the 5'-untranslated region (5'-UTR) of all (531) TTV positive samples showed that 65.5% (348/531) of the PCR fragment sequences were classified into main genogroup 3, followed by main genogroups 5 (24%), 2 (5.8%), and 1 (4.7%). Genogroup 4 was not detected among the our studied subjects. Phylogenetic and pairwise analyses using sequences from TTV viremic samples also showed an overall close similarity to the main genogroup 3. In conclusion, there was no significant difference in the rates of TTV detection among Qataris and non-Qataris and several genotypes, mainly genotype 3, were isolated. © 2015 Wiley Periodicals, Inc.

  1. Transiting Exoplanet Monitoring Project (TEMP). IV. Refined System Parameters, Transit Timing Variations, and Orbital Stability of the Transiting Planetary System HAT-P-25

    Science.gov (United States)

    Wang, Xian-Yu; Wang, Songhu; Hinse, Tobias C.; Li, Kai; Wang, Yong-Hao; Laughlin, Gregory; Liu, Hui-Gen; Zhang, Hui; Wu, Zhen-Yu; Zhou, Xu; Zhou, Ji-Lin; Hu, Shao-Ming; Wu, Dong-Hong; Peng, Xi-Yan; Chen, Yuan-Yuan

    2018-06-01

    We present eight new light curves of the transiting extra-solar planet HAT-P-25b obtained from 2013 to 2016 with three telescopes at two observatories. We use the new light curves, along with recent literature material, to estimate the physical and orbital parameters of the transiting planet. Specifically, we determine the mid-transit times (T C ) and update the linear ephemeris, T C[0] = 2456418.80996 ± 0.00025 [BJDTDB] and P = 3.65281572 ± 0.00000095 days. We carry out a search for transit timing variations (TTVs), and find no significant TTV signal at the ΔT = 80 s-level, placing a limit on the possible strength of planet–planet interactions (TTVG). In the course of our analysis, we calculate the upper mass-limits of the potential nearby perturbers. Near the 1:2, 2:1, and 3:1 resonances with HAT-P-25b, perturbers with masses greater than 0.5, 0.3, and 0.5 M ⊕ respectively, can be excluded. Furthermore, based on the analysis of TTVs caused by light travel time effect (LTTE) we also eliminate the possibility that a long-period perturber exists with M p > 3000 MJ within a = 11.2 au of the parent star.

  2. KOI-142, the king of transit variations, is a pair of planets near the 2:1 resonance

    DEFF Research Database (Denmark)

    Nesvorný, David; Kipping, David; Terrell, Dirk

    2013-01-01

    The transit timing variations (TTVs) can be used as a diagnostic of gravitational interactions between planets in a multi-planet system. Many Kepler Objects of Interest (KOIs) exhibit significant TTVs, but KOI-142.01 stands out among them with an unrivaled ≃12 hr TTV amplitude. Here we report...... mass inferred from the transit variations is consistent with the measured transit depth, suggesting a Neptune-class planet (KOI-142b). The orbital period ratio P /P = 2.03 indicates that the two planets are just wide of the 2:1 resonance. The present dynamics of this system, characterized here...

  3. Timing Variations in Two Balkan Percussion Performances

    Directory of Open Access Journals (Sweden)

    Daniel Goldberg

    2016-01-01

    Full Text Available Many songs and dance pieces from the Balkan Peninsula employ aksak meter, in which two categorically different durations, long and short, coexist in the sequence of beats that performers emphasize and listeners move to. This paper analyzes the durations of aksak beats and measures in two recorded percussion performances that use a particular aksak beat sequence, long-short-short. The results suggest that the timing of beats varies in conjunction with factors including melodic grouping and interaction among members of a performing ensemble and audience. Timing variation linked to melodic groups occurs on a solo recording of a Macedonian Romani folk song. The performer, Muzafer Bizlim, taps an ostinato while singing, and the timing of his taps seems to mark some local and large-scale group boundaries. Melodic organization also seems relevant to the timing of beats and measures on a recording of Bulgarian percussionist Mitko Popov playing the tŭpan, a double-headed bass drum, in a small folk music ensemble. In Popov’s performance, however, timing differences might be related to characteristics of the ensemble dynamic, such as the coordination of multiple musical participants. These interpretations generate possibilities for future study of timing variations in relation to rhythm and meter.

  4. Deterministic Chaos in Radon Time Variation

    International Nuclear Information System (INIS)

    Planinic, J.; Vukovic, B.; Radolic, V.; Faj, Z.; Stanic, D.

    2003-01-01

    Radon concentrations were continuously measured outdoors, in living room and basement in 10-minute intervals for a month. The radon time series were analyzed by comparing algorithms to extract phase-space dynamical information. The application of fractal methods enabled to explore the chaotic nature of radon in the atmosphere. The computed fractal dimensions, such as Hurst exponent (H) from the rescaled range analysis, Lyapunov exponent (λ ) and attractor dimension, provided estimates of the degree of chaotic behavior. The obtained low values of the Hurst exponent (0< H<0.5) indicated anti-persistent behavior (non random changes) of the time series, but the positive values of the λ pointed out the grate sensitivity on initial conditions and appearing deterministic chaos by radon time variations. The calculated fractal dimensions of attractors indicated more influencing (meteorological) parameters on radon in the atmosphere. (author)

  5. Radon time variations and deterministic chaos

    Energy Technology Data Exchange (ETDEWEB)

    Planinic, J. E-mail: planinic@pedos.hr; Vukovic, B.; Radolic, V

    2004-07-01

    Radon concentrations were continuously measured outdoors, in the living room and in the basement at 10 min intervals for a month. Radon time series were analyzed by comparing algorithms to extract phase space dynamical information. The application of fractal methods enabled exploration of the chaotic nature of radon in atmosphere. The computed fractal dimensions, such as the Hurst exponent (H) from the rescaled range analysis, Lyapunov exponent ({lambda}) and attractor dimension, provided estimates of the degree of chaotic behavior. The obtained low values of the Hurst exponent (0time series, but the positive values of {lambda} pointed out the grate sensitivity on initial conditions and the deterministic chaos that appeared due to radon time variations. The calculated fractal dimensions of attractors indicated more influencing (meteorological) parameters on radon in the atmosphere.

  6. Radon time variations and deterministic chaos

    International Nuclear Information System (INIS)

    Planinic, J.; Vukovic, B.; Radolic, V.

    2004-01-01

    Radon concentrations were continuously measured outdoors, in the living room and in the basement at 10 min intervals for a month. Radon time series were analyzed by comparing algorithms to extract phase space dynamical information. The application of fractal methods enabled exploration of the chaotic nature of radon in atmosphere. The computed fractal dimensions, such as the Hurst exponent (H) from the rescaled range analysis, Lyapunov exponent (λ) and attractor dimension, provided estimates of the degree of chaotic behavior. The obtained low values of the Hurst exponent (0< H<0.5) indicated anti-persistent behavior (non-random changes) of the time series, but the positive values of λ pointed out the grate sensitivity on initial conditions and the deterministic chaos that appeared due to radon time variations. The calculated fractal dimensions of attractors indicated more influencing (meteorological) parameters on radon in the atmosphere

  7. Time dependent variational method in quantum mechanics

    International Nuclear Information System (INIS)

    Torres del Castillo, G.F.

    1987-01-01

    Using the fact that the solutions to the time-dependent Schodinger equation can be obtained from a variational principle, by restricting the evolution of the state vector to some surface in the corresponding Hilbert space, approximations to the exact solutions can be obtained, which are determined by equations similar to Hamilton's equations. It is shown that, in order for the approximate evolution to be well defined on a given surface, the imaginary part of the inner product restricted to the surface must be non-singular. (author)

  8. Time-Dependent Variations of Accretion Disk

    Directory of Open Access Journals (Sweden)

    Hye-Weon Na

    1987-06-01

    Full Text Available In dward nova we assume the primary star as a white dwarf and the secondary as the late type star which filled Roche lobe. Mass flow from the secondary star leads to the formation of thin accretion disk around the white dwarf. We use the α parameter as viscosity to maintain the disk form and propose that the outburst in dwarf nova cause the steep increase of source term. With these assumptions we solve the basic equations of stellar structure using Newton-Raphson method. We show the physical parameters like temperature, density, pressure, opacity, surface density, height and flux to the radius of disk. Changing the value of α, we compare several parameters when mass flow rate is constant with those of when luminosity of disk is brightest. At the same time, we obtain time-dependent variations of luminosity and mass of disk. We propose the suitable range of α is 0.15-0.18 to the difference of luminosity. We compare several parameters of disk with those of the normal late type stars which have the same molecular weight of disk is lower. Maybe the outburst in dwarf nova is due to the variation of the α value instead of increment of mass flow from the secondary star.

  9. Principles of time-of-flight tomography

    International Nuclear Information System (INIS)

    Campagnolo, R.; Garderet, P.; Lecomte, J.L.; Bouvier, A.; Darier, P.; Soussaline, F.

    1983-03-01

    After a short introduction to the physics of time-of-flight positron tomography, the various aspects of this technique are presented. The characteristics including data acquisition and image reconstruction system of a positron tomograph (TTV01) which uses time-of-flight information, are described. The preliminary results obtained with TTV01, such as resolution and sensitivity, as well as phantom images, are presented [fr

  10. Time variations of hf induced plasma waves

    International Nuclear Information System (INIS)

    Showen, R.L.

    1976-01-01

    Intense plasma waves are generated by an HF pump wave in an ionospheric heating experiment at the Arecibo Observatory. These plasma waves can be observed as enhancements to the ion and plasma lines of the incoherent backscatter echo. The enhancements can be three or four orders of magnitude more intense than the unenhanced lines, and tend to fluctuate wildly. Both the purely growing and the decay mode parametric instabilities are present. When the pump wave is turned on abruptly the enhancements develop in time in a repeatable manner. A rather remarkable feature on time scales of seconds is an overshoot in instability power. These overshoots occur frequently but not universally and last for 1 to 6 seconds. They can have a magnitude from ten to hundreds of times the average instability level. Field aligned irregularities may be the cause of the overshoots. The overshoots appear definitely related to an unusually rapid rise in measured electron temperature that cannot be understood in terms of ohmic energy deposition. On time scales of milliseconds there is a ''mini-overshoot'' before the growth of the instability to a large value. The spectral details also change in a striking manner. The instabilities can first be detected 2 to 4 msec after the pump wave turn-on. The decay mode is present as well as a broad featureless ''noise bump'', which partially sharpens into a line as time progresses. These changes of the spectra in time seem to run counter to the currently accepted theories of plasma wave saturation

  11. Time variations of stellar water masers

    International Nuclear Information System (INIS)

    Cox, G.G.; Parker, E.A.

    1979-01-01

    The 22-GHz H 2 O spectra of the stars RS Vir, RT Vir, R Aql, W Hya, U Her, S Cr B, Rx Boo, R Crt and VY CMa have been observed at intervals during the period 1974 September -1977 May. Optical and infrared measurements have also been made. New components have been observed in the H 2 O spectra of most of the stars, and the flux density of W Hya reached 2000 Jy near Jd 2442700. The intensities of the three main groups of components in VY CMa varied in phase consistent with a central pump source. In several stars the intensities were very different from those found by earlier observers, showing that stellar H 2 O masers are often not stable for more than a few cycles of the stellar luminosity. For part of the time the H 2 O and infrared intensities of R Aql and RS Vir were anticorrelated. (author)

  12. REFINED SYSTEM PARAMETERS AND TTV STUDY OF TRANSITING EXOPLANETARY SYSTEM HAT-P-20

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Leilei; Gu, Shenghong; Wang, Xiaobin; Cao, Dongtao; Wang, Yibo; Xiang, Yue [Yunnan Observatories, Chinese Academy of Sciences, Kunming 650011 (China); Cameron, Andrew Collier [School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS (United Kingdom); Hui, Ho-Keung; Kwok, Chi-Tai [Ho Koon Nature Education cum Astronomical Centre, Sik Sik Yuen, Hong Kong (China); Yeung, Bill; Ng, Eric [Hong Kong Astronomical Society, Hong Kong (China); Horta, Ferran Grau, E-mail: wangxb@ynao.ac.cn [Observatori Ca l’Ou, C/de Dalt 18, Sant Martí Sesgueioles (Spain)

    2017-01-01

    We report new photometric observations of the transiting exoplanetary system HAT-P-20, obtained using CCD cameras at Yunnan Observatories and Ho Koon Nature Education cum Astronomical Centre, China, from 2010 to 2013, and Observatori Ca l’Ou, Sant Marti Sesgueioles, Spain, from 2013 to 2015. The observed data are corrected for systematic errors according to the coarse de-correlation and SYSREM algorithms, so as to enhance the signal of the transit events. In order to consistently model the star spots and transits of this exoplanetary system, we develop a highly efficient tool STMT based on the analytic models of Mandel and Agol and Montalto et al. The physical parameters of HAT-P-20 are refined by homogeneously analyzing our new data, the radial velocity data, and the earlier photometric data in the literature with the Markov chain Monte Carlo technique. New radii and masses of both host star and planet are larger than those in the discovery paper due to the discrepancy of the radius among K-dwarfs between predicted values by standard stellar models and empirical calibration from observations. Through the analysis of all available mid-transit times calculated with the normal model and spotted model, we conclude that the periodic transit timing variations in these transit events revealed by employing the normal model are probably induced by spot crossing events. From the analysis of the distribution of occulted spots by HAT-P-20b, we constrain the misaligned architecture between the planetary orbit and the spin of the host star.

  13. Prevalence of anelloviruses (TTV, TTMDV, and TTMV) in healthy blood donors and in patients infected with HBV or HCV in Qatar.

    Science.gov (United States)

    Al-Qahtani, Ahmed A; Alabsi, Enas S; AbuOdeh, Raed; Thalib, Lukman; El Zowalaty, Mohamed E; Nasrallah, Gheyath K

    2016-12-28

    Anelloviruses (TTV, TTMV, and TTMDV) have been associated with non A-G hepatitis. The goal of the current study was to estimate the prevalence of these anelloviruses in Qatar. A total of 607 blood samples (500 healthy donors, and 53 HBV-and 54 HCV-positive patients) representing different nationalities were tested for the presence of TTV, TTMV, and TTMDV DNA by nested PCR. Prevalence rates for the three viruses were high in all studied groups, and exceeding 95% in the HBV group (for TTV and TTMDV). Infection with more than one type of viruses was common and significant in most of the positive patients (p nationality, or gender (p > 0.05) albeit the detection of higher infection rates among females and Qatari subjects. This was the first published study to look at prevalence of Anellowviruses in the Middle East. High prevalence rates of the three viruses in all studied groups was noted. Further studies are needed to explore and compare the different genotypes of these viruses in the region.

  14. Continuous radon measurements in schools: time variations and related parameters

    International Nuclear Information System (INIS)

    Giovani, C.; Cappelletto, C.; Garavaglia, M.; Pividore, S.; Villalta, R.

    2004-01-01

    Some results are reported of observations made within a four-year survey, during different seasons and in different conditions of school building use. Natural radon variations (day-night cycles, seasonal and temperature dependent variations etc..) and artificial ones (opening of windows, weekends and vacations, deployment of air conditioning or heating systems. etc.) were investigated as parameters affecting time dependent radon concentrations. (P.A.)

  15. Time variation of fundamental couplings and dynamical dark energy

    International Nuclear Information System (INIS)

    Dent, Thomas; Stern, Steffen; Wetterich, Christof

    2009-01-01

    Scalar field dynamics may give rise to a nonzero cosmological variation of fundamental constants. Within different scenarios based on the unification of gauge couplings, the various claimed observations and bounds may be combined in order to trace or restrict the time history of the couplings and masses. If the scalar field is responsible for a dynamical dark energy or quintessence, cosmological information becomes available for its time evolution. Combining this information with the time variation of couplings, one can determine the interaction strength between the scalar and atoms, which may be observed by tests of the Weak Equivalence Principle. We compute bounds on the present rate of coupling variation from experiments testing the differential accelerations for bodies with equal mass and different composition and compare the sensitivity of various methods. In particular, we discuss two specific models of scalar evolution: crossover quintessence and growing neutrino models

  16. Time Variations of Macrostickies and Extractable Stickies Concentrations in Deinking

    OpenAIRE

    MacNeil, Donald; Miranda Carreño, Rubén; Monte Lara, María Concepción; Blanco Suárez, Ángeles; Sundberg, Anna

    2010-01-01

    The stickies content, both macrostickies and stickies extractable in a solvent, was determined for samples taken at short time intervals from deinking lines, producing deinked pulp for newsprint production. The study was carried out at three mills on different continents, with each having a different source of recycled paper as raw material. The short-term variations in extractable stickies in the incoming raw material were quite extreme, with differences of 100% being seen within hours. Desp...

  17. Time variations of macro and extractable stickies concentrations in deinking

    OpenAIRE

    McNeil, Donald; Miranda Carreño, Rubén; Concepción Lara, María Concepción; Blanco Suárez, Ángeles; Sundberg, Anna

    2010-01-01

    The stickies content, both macrostickies and stickies extractable in a solvent, was determined for samples taken at short time intervals from deinking lines producing deinked pulp for newsprint production. The study was carried out at three mills on different continents, with each having a different source of recycled paper as raw material. The short-term variations in extractable stickies in the incoming raw material were quite extreme, with differences of 100% being seen within hours. Despi...

  18. Variation in Part-Time Work among Pediatric Subspecialties.

    Science.gov (United States)

    Freed, Gary L; Boyer, Debra M; Van, Kenton D; Macy, Michelle L; McCormick, Julie; Leslie, Laurel K

    2018-04-01

    To assess the part-time workforce and average hours worked per week among pediatric subspecialists in the 15 medical subspecialties certified by the American Board of Pediatrics. We examined data from pediatric subspecialists who enrolled in Maintenance of Certification with the American Board of Pediatrics from 2009 to 2015. Data were collected via an online survey. Providers indicated whether they worked full time or part time and estimated the average number of hours worked per week in clinical, research, education, and administrative tasks, excluding time on call. We calculated and compared the range of hours worked by those in full- and part-time positions overall, by demographic characteristics, and by subspecialty. Overall, 9.6% of subspecialists worked part time. There was significant variation in part-time employment rates between subspecialties, ranging from 3.8% among critical care pediatricians to 22.9% among developmental-behavioral pediatricians. Women, American medical graduates, and physicians older than 70 years of age reported higher rates of part-time employment than men, international medical graduates, and younger physicians. There was marked variation in the number of hours worked across subspecialties. Most, but not all, full-time subspecialists reported working at least 40 hours per week. More than one-half of physicians working part time in hematology and oncology, pulmonology, and transplant hepatology reported working at least 40 hours per week. There are unique patterns of part-time employment and hours worked per week among pediatric medical subspecialists that make simple head counts inadequate to determine the effective workforce. Our findings are limited to the 15 American Board of Pediatrics-certified medical subspecialties. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Oscillation effects and time variation of the supernova neutrino signal

    Science.gov (United States)

    Kneller, James P.; McLaughlin, Gail C.; Brockman, Justin

    2008-02-01

    The neutrinos detected from the next galactic core-collapse supernova will contain valuable information on the internal dynamics of the explosion. One mechanism leading to a temporal evolution of the neutrino signal is the variation of the induced neutrino flavor mixing driven by changes in the density profile. With one and two-dimensional hydrodynamical simulations we identify the behavior and properties of prominent features of the explosion. Using these results we demonstrate the time variation of the neutrino crossing probabilities due to changes in the Mikheyev-Smirnov-Wolfenstein (MSW) neutrino transformations as the star explodes by using the S-matrix—Monte Carlo—approach to neutrino propagation. After adopting spectra for the neutrinos emitted from the proto-neutron star we calculate for a galactic supernova the evolution of the positron spectra within a water Cerenkov detector and find that this signal allows us to probe of a number of explosion features.

  20. Time variation of fluorescence lifetime in enhanced cyan fluorescence protein

    International Nuclear Information System (INIS)

    Lee, Soonhyouk; Kim, Soo Yong; Park, Kyoungsook; Jeong, Jinyoung; Chung, Bong Hyun; Kim, Sok Won

    2010-01-01

    The lifetime variations of enhanced cyan fluorescence protein (ECFP) in relatively short integration time bins were studied via time-correlated single photon counting (TCSPC) measurement. We observed that minimum photon counts are necessary for the lifetime estimation to achieve a certain range of variance. The conditions to decrease the variance of lifetime were investigated and the channel width of the measurement of TCSPC data was found to be another important factor for the variance of lifetime. Though the lifetime of ECFP is best fit by a double exponential, a mono exponential fit for the same integration time is more stable. The results may be useful in the analysis of photophysical dynamics for ensemble molecules in short measurement time windows.

  1. No variations in transit times for Qatar-1 b

    Science.gov (United States)

    Maciejewski, G.; Fernández, M.; Aceituno, F. J.; Ohlert, J.; Puchalski, D.; Dimitrov, D.; Seeliger, M.; Kitze, M.; Raetz, St.; Errmann, R.; Gilbert, H.; Pannicke, A.; Schmidt, J.-G.; Neuhäuser, R.

    2015-05-01

    Aims: The transiting hot-Jupiter planet Qatar-1 b exhibits variations in transit times that could be perturbative. A hot Jupiter with a planetary companion on a nearby orbit would constitute an unprecedented planetary configuration, which is important for theories of the formation and evolution of planetary systems. We performed a photometric follow-up campaign to confirm or refute transit timing variations. Methods: We extend the baseline of transit observations by acquiring 18 new transit light curves acquired with 0.6-2.0 m telescopes. These photometric time series, together with data available in the literature, were analyzed in a homogenous way to derive reliable transit parameters and their uncertainties. Results: We show that the dataset of transit times is consistent with a linear ephemeris leaving no hint of any periodic variations with a range of 1 min. We find no compelling evidence of a close-in planetary companion to Qatar-1 b. This finding is in line with a paradigm that hot Jupiters are not components of compact multiplanetary systems. Based on dynamical simulations, we place tighter constraints on the mass of any fictitious nearby planet in the system. Furthermore, new transit light curves allowed us to redetermine system parameters with better precision than reported in previous studies. Our values generally agree with previous determinations. Partly based on (1) data collected with telescopes at the Rozhen National Astronomical Observatory and (2) observations obtained with telescopes of the University Observatory Jena, which is operated by the Astrophysical Institute of the Friedrich-Schiller-University.Tables of light curve data are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/577/A109

  2. Novel crystal timing calibration method based on total variation

    Science.gov (United States)

    Yu, Xingjian; Isobe, Takashi; Watanabe, Mitsuo; Liu, Huafeng

    2016-11-01

    A novel crystal timing calibration method based on total variation (TV), abbreviated as ‘TV merge’, has been developed for a high-resolution positron emission tomography (PET) system. The proposed method was developed for a system with a large number of crystals, it can provide timing calibration at the crystal level. In the proposed method, the timing calibration process was formulated as a linear problem. To robustly optimize the timing resolution, a TV constraint was added to the linear equation. Moreover, to solve the computer memory problem associated with the calculation of the timing calibration factors for systems with a large number of crystals, the merge component was used for obtaining the crystal level timing calibration values. Compared with other conventional methods, the data measured from a standard cylindrical phantom filled with a radioisotope solution was sufficient for performing a high-precision crystal-level timing calibration. In this paper, both simulation and experimental studies were performed to demonstrate the effectiveness and robustness of the TV merge method. We compare the timing resolutions of a 22Na point source, which was located in the field of view (FOV) of the brain PET system, with various calibration techniques. After implementing the TV merge method, the timing resolution improved from 3.34 ns at full width at half maximum (FWHM) to 2.31 ns FWHM.

  3. How travellers’ schedule their trips under uncertain travel times

    DEFF Research Database (Denmark)

    Hjorth, Katrine

    Travel times play an important role when people decide where, when and how much to travel. But travel times are not always predictable from the traveller’s point of view: They may vary from day to day due to demand fluctuations, weather conditions, accidents and other unforeseen events that cause...... road capacity to decrease. We refer to this uncertainty as travel time variability (TTV). TTV is likely to affect how travellers schedule their trips, since it affects their probability of arriving late at their destination. We would like to account for TTV in traffic models and cost-benefit analyses......, but in practice there are limits to the kinds of behaviour that can be accommodated in such applications. For that reason, we are not solely interested in explaining travellers’ behaviour, but also in whether this behaviour can be approximated by behavioural models that are simple enough to be applied in traffic...

  4. Time and space variations of trophosherive carbon dioxide over Japan

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, M.; Nakazawa, T.; Aoki, S.

    Aircraft measurements of atmospheric CO/sub 2/ concentration over Japan, initiated in January 1979, have been continued to the present. The average seasonal variation of atmospheric CO/sub 2/ showed maximum concentration early in April and early in May, and minimum concentration in mid-August and mid-September for the lower-most and the upper-most layers of the troposphere, respectively. The peak-to-peak amplitudes of the seasonal variation were 14.5, 9.0 and 7.8 ppmv for the lower, middle and upper tropospheres, respectively. The average rate of annual increase of the CO/sub 2/ concentration over the last 6 years was about 1.3 ppmv yr/sup -1/ with considerable variation with time. The vertical profile of the annual mean value of the CO/sub 2/ concentration was almost the same from year to year; the CO/sub 2/ concentrations decreased gradually with height and the concentration difference between the lowest and highest layers of the troposphere was about 2 ppmv. (authors).

  5. On time variation of fundamental constants in superstring theories

    International Nuclear Information System (INIS)

    Maeda, K.I.

    1988-01-01

    Assuming the action from the string theory and taking into account the dynamical freedom of a dilaton and its coupling to matter fluid, the authors show that fundamental 'constants' in string theories are independent of the 'radius' of the internal space. Since the scalar related to the 'constants' is coupled to the 4-dimensional gravity and matter fluid in the same way as in the Jordan-Brans Dicke theory with ω = -1, it must be massive and can get a mass easily through some symmetry breaking mechanism (e.g. the SUSY breaking due to a gluino condensation). Consequently, time variation of fundamental constants is too small to be observed

  6. Variation of explosive force at different times of day

    Directory of Open Access Journals (Sweden)

    R Pereira

    2011-03-01

    Full Text Available AIM: The purpose of this study was to compare the explosive force and electromyographic (EMG activity at three different times of the day. METHODS: Thirty healthy subjects took part in the study, and carried out two maximum isometric voluntary knee extensions to measure explosive force, through contractile impulse (CI and rate of force development (RFD, and myoelectric signals from quadriceps muscles in the following periods: 07:30-09:30, 13:30-15:30 and 19:30-21:30 (called morning, afternoon and night respectively, on three non-consecutive days. RESULTS: The body temperature was lower in the morning than in the afternoon and night periods. The explosive force, evaluated through contractile impulse (CI and rate of force development (RFD, was greater at night than in the morning, without differences in the myoelectric signal. CONCLUSION: The ability to produce explosive force varies throughout different times of the day without variation in muscular recruitment, indicating that peripheral and not neural mechanisms could be responsible for this variation.

  7. Time variations of the angular momentum of the sun

    International Nuclear Information System (INIS)

    Schatten, K.H.

    1977-01-01

    Time variations of density models of the Sun are investigated. This is an attempt to estimate the changing moment of inertia of the Sun in order to calculate the internal solar angular velocity based upon Newton's equation of motion. Previous estimates of dI/dt disagree with those based upon central densities in a homologously contracting model. It is shown that the homologously contracting model leads to large errors in dI/dt. Based upon an integration of Sears's solar model, dI/dt=-5.5 x 10 34 gm cm 2 s -1 . This suggests a core angular velocity of /sub thetar-italic/ = (0.15 +- 0.03) x 10 -3 s -1 , corresponding to a period of 0.5 +- 0.1 days, assuming a constant angular velocity with time. The brackets indicate a weighting which is discussed

  8. Study of long-time variations of cosmic rays

    International Nuclear Information System (INIS)

    Dergachev, V.A.

    1979-01-01

    Discussed are some problems of the investigation into the cosmic rays intensity in the past via the contents of cosmogenic isotopes in the samples of known age, mainly measuring the activity of radiocarbon in the samples dated by the dendrochronological method. The necessity of production of the multicentury dendrochronological scales with absolute dating for decoding of the information contained in the annual rings during the large time scale is pointed out. The dendrochronologic studies supplemented by the radiocarbon dating would permit to study the variations in radiocarbon content and to determine the factors, which influence this content, during large time intervals. The different factors - the solar activity, the supernovae flares et cetera - influencing the radiocarbon concentration are considered

  9. Algebraic time-dependent variational approach to dynamical calculations

    International Nuclear Information System (INIS)

    Shi, S.; Rabitz, H.

    1988-01-01

    A set of time-dependent basis states is obtained with a group of unitary transformations generated by a Lie algebra. Applying the time-dependent variational principle to the trial function subspace constructed from the linear combination of the time-dependent basis states gives rise to a set of ''classical'' equations of motion for the group parameters and the expansion coefficients from which the time evolution of the system state can be determined. The formulation is developed for a general Lie algebra as well as for the commonly encountered algebra containing homogeneous polynominal products of the coordinate Q and momentum P operators (or equivalently the boson creation a/sup dagger/ and annihilation a operators) of order 0, 1, and 2. Explicit expressions for the transition amplitudes are derived by virtue of the cannonical transformation properties of the unitary transformation. The applicability of the present formalism in a variety of problems is implied by two illustrative examples: (a) a parametric amplifier; (b) the collinear collision of an atom with a Morse oscillator

  10. Time dependent variation of carrying capacity of prestressed precast beam

    Science.gov (United States)

    Le, Tuan D.; Konečný, Petr; Matečková, Pavlína

    2018-04-01

    The article deals with the evaluation of the precast concrete element time dependent carrying capacity. The variation of the resistance is inherited property of laboratory as well as in-situ members. Thus the specification of highest, yet possible, laboratory sample resistance is important with respect to evaluation of laboratory experiments based on the test machine loading capabilities. The ultimate capacity is evaluated through the bending moment resistance of a simply supported prestressed concrete beam. The probabilistic assessment is applied. Scatter of random variables of compressive strength of concrete and effective height of the cross section is considered. Monte Carlo simulation technique is used to investigate the performance of the cross section of the beam with changes of tendons’ positions and compressive strength of concrete.

  11. Modeling of electron time variations in the radiation belts

    International Nuclear Information System (INIS)

    Chan, K.W.; Teague, M.J.; Schofield, N.J.; Vette, J.I.

    1979-01-01

    A review of the temporal variation in the trapped electron population of the inner and outer radiation zones is presented. Techniques presently used for modeling these zones are discussed and their deficiencies identified. An intermediate region is indicated between the zones in which the present modeling techniques are inadequate due to the magnitude and frequency of magnetic storms. Future trends are examined, and it is suggested that modeling of individual magnetic storms may be required in certain L bands. An analysis of seven magnetic storms is presented, establishing the independence of the depletion time of the storm flux and the storm magnitude. Provisional correlation between the storm magnitude and the Dst index is demonstrated

  12. Variation in aluminium patch test reactivity over time.

    Science.gov (United States)

    Siemund, Ingrid; Mowitz, Martin; Zimerson, Erik; Bruze, Magnus; Hindsén, Monica

    2017-11-01

    Contact allergy to aluminium has been reported more frequently in recent years. It has been pointed out that positive patch test reactions to aluminium may not be reproducible on retesting. To investigate possible variations in patch test reactivity to aluminium over time. Twenty-one adults, who had previously reacted positively to aluminium, were patch tested with equimolar dilution series in pet. of aluminium chloride hexahydrate and aluminium lactate, four times over a period of 8 months. Thirty-six of 84 (43%) serial dilution tests with aluminium chloride hexahydrate and 49 of 84 (58%) serial dilution tests with aluminium lactate gave negative results. The range of reactivity varied between a negative reaction to aluminium chloride hexahydrate at 10% and/or to aluminium lactate at 12%, and a positive reaction to aluminium chloride hexahydrate at 0.1% and/or to aluminium lactate at 0.12%. The highest individual difference in test reactivity noticed was 320-fold when the two most divergent minimal eliciting concentrations were compared. The patch test reactivity to aluminium varies over time. Aluminium-allergic individuals may have false-negative reactions. Therefore, retesting with aluminium should be considered when there is a strong suspicion of aluminium contact allergy. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Divorce risk factors and their variation over time in Spain

    Directory of Open Access Journals (Sweden)

    Fabrizio Bernardi

    2011-05-01

    Full Text Available The aim of this article is to analyse the determinants of marriage dissolution in Spain and their variation over time for women married between 1949 and 2006. Data are drawn from the Survey of Fertility, Family and Values of 2006. The article analyses the transition from first marriage to marital dissolution for couples who married in two eras: one prior to the Divorce Law of 1981, during which social and legal barriers to dissolution were many, and one in the period after the law was introduced, during which barriers to marriage dissolution were far fewer. Analyses are conducted using a continuous time event history model. The results indicate some similarities between Spain and other countries, such as the positive relationship between the typical features of unconventional families and marital dissolution, but also some specific differences, such as an increase in the importance of premarital pregnancy and/or not having children. It is also important to stress the declining importance of socio-economic variables, such as education and the labour market situation of women.

  14. Result Variation and Efficiency Kinetics in Real-Time PCR

    Directory of Open Access Journals (Sweden)

    Reza Shahsiah

    2010-10-01

    Full Text Available Fluorescent monitoring of DNA amplification is the basis of real-time PCR. Absolute quantification can be achieved using a standard curve method. The standard curve is constructed by amplifying known amounts of standards under identical conditions to that of the samples.The objective of the current study is to propose a mathematical model to assess the acceptability of PCR resulys.Four commercial standards for HCV-RNA (hepatitis C virus RNA along with 6 patient samples were measured by real-time PCR, using two different RT-PCR reagents. The standard deviation of regression (Sy,x was calculated for each group of standard and compared by F-Test. The efficiency kinetics was computed by logistic regression, c2 goodness of fit test was preformed to assess the appropriateness of the efficiency curves.Calculated efficiencies were not significantly different from the value predicted by logistic regression model. Reactions with more variation showed less stable efficiency curves, with wider range of amplification efficiencies.Amplification efficiency kinetics can be computed by fitting a logistic regression curve to the gathered fluorescent data of each reaction. This model can be employed to assess the acceptability of PCR results calculated by standard curve method.

  15. Time-causal decomposition of geomagnetic time series into secular variation, solar quiet, and disturbance signals

    Science.gov (United States)

    Rigler, E. Joshua

    2017-04-26

    A theoretical basis and prototype numerical algorithm are provided that decompose regular time series of geomagnetic observations into three components: secular variation; solar quiet, and disturbance. Respectively, these three components correspond roughly to slow changes in the Earth’s internal magnetic field, periodic daily variations caused by quasi-stationary (with respect to the sun) electrical current systems in the Earth’s magnetosphere, and episodic perturbations to the geomagnetic baseline that are typically driven by fluctuations in a solar wind that interacts electromagnetically with the Earth’s magnetosphere. In contrast to similar algorithms applied to geomagnetic data in the past, this one addresses the issue of real time data acquisition directly by applying a time-causal, exponential smoother with “seasonal corrections” to the data as soon as they become available.

  16. New Insights on Planet Formation in WASP-47 from a Simultaneous Analysis of Radial Velocities and Transit Timing Variations

    Science.gov (United States)

    Weiss, Lauren M.; Deck, Katherine M.; Sinukoff, Evan; Petigura, Erik A.; Agol, Eric; Lee, Eve J.; Becker, Juliette C.; Howard, Andrew W.; Isaacson, Howard; Crossfield, Ian J. M.; Fulton, Benjamin J.; Hirsch, Lea; Benneke, Björn

    2017-06-01

    Measuring precise planet masses, densities, and orbital dynamics in individual planetary systems is an important pathway toward understanding planet formation. The WASP-47 system has an unusual architecture that motivates a complex formation theory. The system includes a hot Jupiter (“b”) neighbored by interior (“e”) and exterior (“d”) sub-Neptunes, and a long-period eccentric giant planet (“c”). We simultaneously modeled transit times from the Kepler K2 mission and 118 radial velocities to determine the precise masses, densities, and Keplerian orbital elements of the WASP-47 planets. Combining RVs and TTVs provides a better estimate of the mass of planet d (13.6+/- 2.0 {M}\\oplus ) than that obtained with only RVs (12.75+/- 2.70 {M}\\oplus ) or TTVs (16.1+/- 3.8 {M}\\oplus ). Planets e and d have high densities for their size, consistent with a history of photoevaporation and/or formation in a volatile-poor environment. Through our RV and TTV analysis, we find that the planetary orbits have eccentricities similar to the solar system planets. The WASP-47 system has three similarities to our own solar system: (1) the planetary orbits are nearly circular and coplanar, (2) the planets are not trapped in mean motion resonances, and (3) the planets have diverse compositions. None of the current single-process exoplanet formation theories adequately reproduce these three characteristics of the WASP-47 system (or our solar system). We propose that WASP-47, like the solar system, formed in two stages: first, the giant planets formed in a gas-rich disk and migrated to their present locations, and second, the high-density sub-Neptunes formed in situ in a gas-poor environment.

  17. Beach morphological variations over micro-time scales

    Digital Repository Service at National Institute of Oceanography (India)

    Murty, C.S.; Veerayya, M.; Sastry, J.S.; Varadachari, V.V.R.

    formation, variations in the profiles show anomalous behaviour. The differences in grain-size distribution of the sediments of these 2 beaches are attributed to the available wave energies at these 2 locations...

  18. Variations of extreme rainfall in space and time

    DEFF Research Database (Denmark)

    Gregersen, Ida Bülow; Madsen, H.; Rosbjerg, Dan

    2012-01-01

    variation, whereas annual variations are related to changes in the average Danish summer precipitation, the average Danish summer temperature and the East Atlantic pattern. The spatio-temporal Poisson regression model was found to be a helpful tool when comparing the internal importance of these variables......In the ongoing climate change discussion, methods for identification of variability governed by climate change are important tools. The magnitude of variables that can describe this variability should be compared with magnitudes of variables describing variability in a stationary setting....... This study focuses on variations of extreme rainfall events, observed at 70 different locations in Denmark over a period of 31 years. The aim is to identify and compare variables, both spatially and temporally, which can explain different parts of the variability in this data set. Assuming that the number...

  19. Time variation of the fine structure constant driven by quintessence

    International Nuclear Information System (INIS)

    Anchordoqui, Luis; Goldberg, Haim

    2003-01-01

    There are indications from the study of quasar absorption spectra that the fine structure constant α may have been measurably smaller for redshifts z>2. Analyses of other data ( 149 Sm fission rate for the Oklo natural reactor, variation of 187 Re β-decay rate in meteorite studies, atomic clock measurements) which probe variations of α in the more recent past imply much smaller deviations from its present value. In this work we tie the variation of α to the evolution of the quintessence field proposed by Albrecht and Skordis, and show that agreement with all these data, as well as consistency with Wilkinson Microwave Anisotropy Probe observations, can be achieved for a range of parameters. Some definite predictions follow for upcoming space missions searching for violations of the equivalence principle

  20. Short-time variations of the ground water level

    International Nuclear Information System (INIS)

    Nilsson, Lars Y.

    1977-09-01

    Investigations have demonstrated that the ground water level of aquifers in the Swedish bedrock shows shorttime variations without changing their water content. The ground water level is among other things affected by regular tidal movements occuring in the ''solid'' crust of the earth variations in the atmospheric pressure strong earthquakes occuring in different parts of the world These effects proves that the system of fissures in the bedrock are not stable and that the ground water flow is influenced by both water- and airfilled fissures

  1. Variational extension of the time-dependent mean field approach

    International Nuclear Information System (INIS)

    Flocard, H.

    1989-01-01

    We investigate an application of the variational principle of Balian and Veneroni for density operators and observables. Our choice for the trial spaces incorporates correlations in the density operator. It allows one to calculate the expectation values of both one-body and two-body observables. We derive a set of coupled equations which extends the TDHF formalism, and determines the evolution of the partition function, the one-body density and the second cumulant (it corresponds also to a truncation of the quantal counterpart of the BBKGY equations). By restricting further the trial space for the two-body observables, the variational principle generates simpler equations which still include the effects of a selected class of correlations on the evolution of the one-body density

  2. Determining Time Variation of Cable Tension Forces in Suspended Bridges Using Time-Frequency Analysis

    Directory of Open Access Journals (Sweden)

    Gannon Stromquist-LeVoir

    2018-01-01

    Full Text Available A feasibility study was conducted to develop a novel method to determine the temporal changes of tensile forces in bridge suspender cables using time-frequency analysis of ambient vibration measurements. An analytical model of the suspender cables was developed to evaluate the power spectral density (PSD function of a cable with consideration of cable flexural stiffness. Discrete-time, short-time Fourier transform (STFT was utilized to analyze the recorded acceleration histories in both time and frequency domains. A mathematical convolution of the analytical PSD function and time-frequency data was completed to evaluate changes in cable tension force over time. The method was implemented using acceleration measurements collected from an in-service steel arch bridge with a suspended deck to calculate the temporal variation in cable forces from the vibration measurements. The observations served as proof of concept that the proposed method may be used for cable fatigue life calculations and bridge weigh-in-motion studies.

  3. Time dependency of local cerebral blood flow measurements caused by regional variations in tissue transit time

    International Nuclear Information System (INIS)

    Lear, J.L.; Kasliwal, R.; Feyerabend, A.

    1990-01-01

    Calculated values of local cerebral blood flow (LCBF) using the diffusible tracer model are assumed to be independent of time as long as experiments are brief enough to prevent tissue saturation. This paper investigates the effects of CTT variation on LCBF measurements. Using double-label quantitative digital autoradiography, we compared iodoantipyrine (IAP)-based LCBF measurements obtained with tracer infusions of different lengths of time. Lightly anesthetized rats were given simultaneous ramp infusions of C-14 IAP (45 seconds) and I-123 IAP (15 seconds) and immediately sacrificed. Two autoradiograms of each brain section, one representing I-123 and the other representing C-14, were produced, digitized, and converted into images of LCBF based on the 15- and 45-second infusion periods. The LCBF image pairs were compared on a pixel-by-pixel basis

  4. High-Cadence Transit Timing Variation Monitoring of Extrasolar Planets

    Directory of Open Access Journals (Sweden)

    Naef D.

    2011-02-01

    Full Text Available We report ground-based high-cadence transit timing observations of the extrasolar planet WASP-2b. We achieve a typical timing error of 15-30 sec. The data show no significant deviations from the predicted ephemeris.

  5. variation of reverberation time with quantity of absorbers in an ...

    African Journals Online (AJOL)

    DJFLEX

    broadcasting and recording studios, reverberation time can be simply controlled to achieve desired results. KEY WORDS: ..... Positions and Actual sizes and Numbers of. Absorbers Used. Measured. Reverberation. Times (s). Calculated with. Sabine Formula. Calculated with. Arau-Puchades. Formula. 500. (Hz). 1000. (Hz).

  6. Variational derivation of a time-dependent Hartree-Fock Hamiltonian

    International Nuclear Information System (INIS)

    Lichtner, P.C.; Griffin, J.J.; Schultheis, H.; Schultheis, R.; Volkov, A.B.

    1979-01-01

    The variational derivation of the time-dependent Hartree-Fock equation is reviewed. When norm-violating variations are included, a unique time-dependent Hartree-Fock Hamiltonian, which differs from that customarily used in time-dependent Hartree-Fock analyses, is implied. This variationally ''true'' Hartree-Fock Hamiltonian has the same expectation value as the exact Hamiltonian, equal to the average energy of the system. Since this quantity remains constant under time-dependent Hartree-Fock time evolution, we suggest the label ''constant '' for this form of time-dependent Hartree-Fock theory

  7. Speech Timing Deficit of Stuttering: Evidence from Contingent Negative Variations.

    Directory of Open Access Journals (Sweden)

    Ning Ning

    Full Text Available The aim of the present study was to investigate the speech preparation processes of adults who stutter (AWS. Fifteen AWS and fifteen adults with fluent speech (AFS participated in the experiment. The event-related potentials (ERPs were recorded in a foreperiod paradigm. The warning signal (S1 was a color square, and the following imperative stimulus (S2 was either a white square (the Go signal that required participants to name the color of S1 or a white dot (the NoGo signal that prevents participants from speaking. Three differences were found between AWS and AFS. First, the mean amplitude of the ERP component parietal positivity elicited by S1 (S1-P3 was smaller in AWS than in AFS, which implies that AWS may have deficits in investing working memory on phonological programming. Second, the topographic shift from the early phase to the late phase of contingent negative variation occurred earlier for AWS than for AFS, thus suggesting that the motor preparation process is promoted in AWS. Third, the NoGo effect in the ERP component parietal positivity elicited by S2 (S2-P3 was larger for AFS than for AWS, indicating that AWS have difficulties in inhibiting a planned speech response. These results provide a full picture of the speech preparation and response inhibition processes of AWS. The relationship among these three findings is discussed. However, as stuttering was not manipulated in this study, it is still unclear whether the effects are the causes or the results of stuttering. Further studies are suggested to explore the relationship between stuttering and the effects found in the present study.

  8. Geographic Variations and Time Trends in Cancer Treatments in Taiwan.

    Science.gov (United States)

    Hsu, Jason C; Chang, Sheng-Mao; Lu, Christine Y

    2017-08-02

    Targeted therapies have become important treatment options for cancer care in many countries. This study aimed to examine recent trends in utilization of antineoplastic drugs, particularly the use of targeted therapies for treatment of cancer, by geographic region in Taiwan (northern, midwestern, southern, and eastern regions and the outer islands). This was a retrospective observational study of antineoplastic agents using 2009-2012 quarterly claims data from Taiwan's National Health Insurance Research Database. Yearly market shares by prescription volume and costs for targeted therapies among total antineoplastic agents by region were estimated. We used multivariate regression model and ANOVA to examine variations in utilization of targeted therapies between geographic regions and used ARIMA models to estimate longitudinal trends. Population-adjusted use and costs of antineoplastic drugs (including targeted therapies) were highest in the southern region of Taiwan and lowest in the outer islands. We found a 4-fold difference in use of antineoplastic drugs and a 49-fold difference in use of targeted therapies between regions if the outer islands were included. There were minimal differences in use of antineoplastic drugs between other regions with about a 2-fold difference in use of targeted therapies. Without considering the outer islands, the market share by prescription volume and costs of targeted therapies increased almost 2-fold (1.84-1.90) and 1.5-fold (1.26-1.61) respectively between 2009 and 2012. Furthermore, region was not significantly associated with use of antineoplastic agents or use of targeted therapies after adjusting for confounders. Region was associated with costs of antineoplastic agents but it was not associated with costs of targeted therapies after confounding adjustments. Use of antineoplastic drugs overall and use of targeted therapies for treatment of cancer varied somewhat between regions in Taiwan; use was notably low in the outer

  9. Transducer frequency response variations investigated by time reversal calibration

    Czech Academy of Sciences Publication Activity Database

    Kober, Jan; Převorovský, Zdeněk

    2016-01-01

    Roč. 26, č. 2 (2016), A16-A16 ISSN 1213-3825. [Europen Conference on Acoustic Emission Testing /32./. 07.09.2016-09.09.2016, Praha] Institutional support: RVO:61388998 Keywords : calibration * time reversal * transducer * frequency response Subject RIV: BI - Acoustics

  10. Variation of tumour radiosensitivity with time after anaesthetic

    Energy Technology Data Exchange (ETDEWEB)

    Nias, A.H.W.; Perry, P.M. (Saint Thomas' Hospital, London (UK). Richard Dimbleby Research Lab.)

    1989-10-01

    Transplanted C{sub 3}H mouse mammary tumours were given single doses of X irradiation in air or oxygen at 1 atmosphere (atm) with or without anaesthesia of recipient mice by ketamine and diazepam. The radiation response to single doses of 25 Gy was determined in terms of time taken to reach 3.5 times the treatment volume. Under all conditions there was more growth delay in tumours irradiated in pure oxygen than in air. In air and oxygen, the radiation response for anaestheitized animals tended to fall below the level for non-anaesthetized ones when only 10 min had elapsed after administration of anaesthesia. After 25 min, the response in air was back to the level for non-anaesthetized animals but the oxygen group then showed significant sensitization compared with the oxygen without anaesthetic group. After 40 min, the air group showed slight sensitization and the oxygen group still showed significant sensitization by the anaesthetic. (author).

  11. Assessment of variations in control of asthma over time.

    Science.gov (United States)

    Combescure, C; Chanez, P; Saint-Pierre, P; Daurès, J P; Proudhon, H; Godard, P

    2003-08-01

    Control and severity of asthma are two different but complementary concepts. The severity of asthma could influence the control over time. The aim of this study was to demonstrate this relationship. A total 365 patients with persistent asthma (severity) were enrolled and followed-up prospectively. Data were analysed using a continuous time homogeneous Markov model of the natural history of asthma. Control of asthma was defined according to three health states which were qualified: optimal, suboptimal and unacceptable control (states 1, 2 and 3). Transition forces (denoted lambda(ij) from state i to state j) and transition probabilities between control states were assessed and the results stratified by asthma severity were compared. Models were validated by comparing expected and observed numbers of patients in the different states. Transition probabilities stabilised between 100-250 days and more rapidly in patients with mild-to-moderate asthma. Patients with mild-to-moderate asthma in suboptimal or unacceptable control had a high probability of transition directly to optimal control. Patients with severe asthma had a tendency to remain in unacceptable control. A Markov model is a useful tool to model the control of asthma over time. Severity modified clearly the health states. It could be used to compare the performance of different approaches to asthma management.

  12. A Simple Approach for Monitoring Business Service Time Variation

    Directory of Open Access Journals (Sweden)

    Su-Fen Yang

    2014-01-01

    Full Text Available Control charts are effective tools for signal detection in both manufacturing processes and service processes. Much of the data in service industries comes from processes having nonnormal or unknown distributions. The commonly used Shewhart variable control charts, which depend heavily on the normality assumption, are not appropriately used here. In this paper, we propose a new asymmetric EWMA variance chart (EWMA-AV chart and an asymmetric EWMA mean chart (EWMA-AM chart based on two simple statistics to monitor process variance and mean shifts simultaneously. Further, we explore the sampling properties of the new monitoring statistics and calculate the average run lengths when using both the EWMA-AV chart and the EWMA-AM chart. The performance of the EWMA-AV and EWMA-AM charts and that of some existing variance and mean charts are compared. A numerical example involving nonnormal service times from the service system of a bank branch in Taiwan is used to illustrate the applications of the EWMA-AV and EWMA-AM charts and to compare them with the existing variance (or standard deviation and mean charts. The proposed EWMA-AV chart and EWMA-AM charts show superior detection performance compared to the existing variance and mean charts. The EWMA-AV chart and EWMA-AM chart are thus recommended.

  13. A simple approach for monitoring business service time variation.

    Science.gov (United States)

    Yang, Su-Fen; Arnold, Barry C

    2014-01-01

    Control charts are effective tools for signal detection in both manufacturing processes and service processes. Much of the data in service industries comes from processes having nonnormal or unknown distributions. The commonly used Shewhart variable control charts, which depend heavily on the normality assumption, are not appropriately used here. In this paper, we propose a new asymmetric EWMA variance chart (EWMA-AV chart) and an asymmetric EWMA mean chart (EWMA-AM chart) based on two simple statistics to monitor process variance and mean shifts simultaneously. Further, we explore the sampling properties of the new monitoring statistics and calculate the average run lengths when using both the EWMA-AV chart and the EWMA-AM chart. The performance of the EWMA-AV and EWMA-AM charts and that of some existing variance and mean charts are compared. A numerical example involving nonnormal service times from the service system of a bank branch in Taiwan is used to illustrate the applications of the EWMA-AV and EWMA-AM charts and to compare them with the existing variance (or standard deviation) and mean charts. The proposed EWMA-AV chart and EWMA-AM charts show superior detection performance compared to the existing variance and mean charts. The EWMA-AV chart and EWMA-AM chart are thus recommended.

  14. Biological variation in tPA-induced plasma clot lysis time.

    Science.gov (United States)

    Talens, Simone; Malfliet, Joyce J M C; Rudež, Goran; Spronk, Henri M H; Janssen, Nicole A H; Meijer, Piet; Kluft, Cornelis; de Maat, Moniek P M; Rijken, Dingeman C

    2012-10-01

    Hypofibrinolysis is a risk factor for venous and arterial thrombosis, and can be assessed by using a turbidimetric tPA-induced clot lysis time (CLT) assay. Biological variation in clot lysis time may affect the interpretation and usefulness of CLT as a risk factor for thrombosis. Sufficient information about assay variation and biological variation in CLT is not yet available. Thus, this study aimed to determine the analytical, within-subject and between-subject variation in CLT. We collected blood samples from 40 healthy individuals throughout a period of one year (average 11.8 visits) and determined the CLT of each plasma sample in duplicate. The mean (± SD) CLT was 83.8 (± 11.1) minutes. The coefficients of variation for total variation, analytical variation, within-subject variation and between-subject variation were 13.4%, 2.6%, 8.2% and 10.2%, respectively. One measurement can estimate the CLT that does not deviate more than 20% from its true value. The contribution of analytical variation to the within-subject variation was 5.0%, the index of individuality was 0.84 and the reference change value was 23.8%. The CLT was longer in the morning compared to the afternoon and was slightly longer in older individuals (> 40 years) compared to younger (≤40 years) individuals. There was no seasonal variation in CLT and no association with air pollution. CLT correlated weakly with fibrinogen, C-reactive protein, prothrombin time and thrombin generation. This study provides insight into the biological variation of CLT, which can be used in future studies testing CLT as a potential risk factor for thrombosis.

  15. Modelling the quiet-time geomagnetic daily variations using observatory data

    OpenAIRE

    Hamilton, Brian; Macmillan, Susan

    2008-01-01

    We present on-going work towards building a global model of the quiet-time geomagnetic daily variation using bservatory data. We select hourly mean data during June 2006 (solar minimum). We fit Fourier series in time, with a fundamental period of 24 hours, to the data at each observatory. We then use global spherical harmonic expansions to separate the daily variation signal, as characterised by the Fourier coefficients in time, into external and induced internal contributions. The mode...

  16. Pattern and Variation in the Timing of Aksak Meter: Commentary on Goldberg

    OpenAIRE

    Rainer Polak

    2016-01-01

    Daniel Goldberg (2015, this issue) explores relations between timing variations, grouping structure, and musical form in the percussive accompaniment of Balkan folk dance music. A chronometric re-analysis of one of the target article’s two audio samples finds a regular metric timing pattern to consistently underlie the variations Goldberg uncovered. Read together, the target article and this commentary demonstrate the complex interplay of a regular timing pattern with several levels of nuance...

  17. Inter-temporal variation in the travel time and travel cost parameters of transport models

    OpenAIRE

    Börjesson, Maria

    2012-01-01

    The parameters for travel time and travel cost are central in travel demand forecasting models. Since valuation of infrastructure investments requires prediction of travel demand for future evaluation years, inter-temporal variation of the travel time and travel cost parameters is a key issue in forecasting. Using two identical stated choice experiments conducted among Swedish drivers with an interval of 13 years, 1994 and 2007, this paper estimates the inter-temporal variation in travel time...

  18. Developmental stage of strongyle eggs affects the outcome variations of real-time PCR analysis

    DEFF Research Database (Denmark)

    Andersen, Ulla Vestergaard; Haakansson, I. T.; Roust, Tina

    2013-01-01

    extent developmental stages can affect the variation of diagnostic test results. This study investigated the influence of developmental stages of strongyle eggs on the variation real-time polymerase chain reaction (PCR) results. Mixed species strongyle eggs were obtained from the faeces of a naturally...

  19. Standardised Resting Time Prior to Blood Sampling and Diurnal Variation Associated with Risk of Patient Misclassification

    DEFF Research Database (Denmark)

    Bøgh Andersen, Ida; Brasen, Claus L.; Christensen, Henry

    2015-01-01

    .9×10-7) and sodium (p = 8.7×10-16). Only TSH and albumin were clinically significantly influenced by diurnal variation. Resting time had no clinically significant effect. CONCLUSIONS: We found no need for resting 15 minutes prior to blood sampling. However, diurnal variation was found to have a significant......BACKGROUND: According to current recommendations, blood samples should be taken in the morning after 15 minutes' resting time. Some components exhibit diurnal variation and in response to pressures to expand opening hours and reduce waiting time, the aims of this study were to investigate...... the impact of resting time prior to blood sampling and diurnal variation on biochemical components, including albumin, thyrotropin (TSH), total calcium and sodium in plasma. METHODS: All patients referred to an outpatient clinic for blood sampling were included in the period Nov 2011 until June 2014 (opening...

  20. Fast solution of Cahn–Hilliard variational inequalities using implicit time discretization and finite elements

    KAUST Repository

    Bosch, Jessica; Stoll, Martin; Benner, Peter

    2014-01-01

    We consider the efficient solution of the Cahn-Hilliard variational inequality using an implicit time discretization, which is formulated as an optimal control problem with pointwise constraints on the control. By applying a semi-smooth Newton

  1. Variation in the timing of reproduction of the four-striped field mouse ...

    African Journals Online (AJOL)

    Variation in the timing of reproduction of the four-striped field mouse, Rhabdomys pumilio , in ... Open Access DOWNLOAD FULL TEXT ... We used the four-striped field mouse, Rhabdomys pumilio (Sparrmann, 1784), to test the hypothesis that ...

  2. Feynman’s clock, a new variational principle, and parallel-in-time quantum dynamics

    Science.gov (United States)

    McClean, Jarrod R.; Parkhill, John A.; Aspuru-Guzik, Alán

    2013-01-01

    We introduce a discrete-time variational principle inspired by the quantum clock originally proposed by Feynman and use it to write down quantum evolution as a ground-state eigenvalue problem. The construction allows one to apply ground-state quantum many-body theory to quantum dynamics, extending the reach of many highly developed tools from this fertile research area. Moreover, this formalism naturally leads to an algorithm to parallelize quantum simulation over time. We draw an explicit connection between previously known time-dependent variational principles and the time-embedded variational principle presented. Sample calculations are presented, applying the idea to a hydrogen molecule and the spin degrees of freedom of a model inorganic compound, demonstrating the parallel speedup of our method as well as its flexibility in applying ground-state methodologies. Finally, we take advantage of the unique perspective of this variational principle to examine the error of basis approximations in quantum dynamics. PMID:24062428

  3. Nonlinear Variation of Parameters Formula for Impulsive Differential Equations with Initial Time Difference and Application

    Directory of Open Access Journals (Sweden)

    Peiguang Wang

    2014-01-01

    Full Text Available This paper establishes variation of parameters formula for impulsive differential equations with initial time difference. As an application, one of the results is used to investigate stability properties of solutions.

  4. Training and evaluation of neural networks for multi-variate time series processing

    DEFF Research Database (Denmark)

    Fog, Torben L.; Larsen, Jan; Hansen, Lars Kai

    1995-01-01

    We study the training and generalization for multi-variate time series processing. It is suggested to used a quasi-maximum likelihood approach rather than the standard sum of squared errors, thus taking dependencies among the errors of the individual time series into account. This may lead...... to improved generalization performance. Further, we extend the optimal brain damage pruning technique to the multi-variate case. A key ingredient is an algebraic expression for the generalization ability of a multi-variate model. The variability of the suggested techniques are successfully demonstrated...

  5. Handheld mechanical nociceptive threshold testing in dairy cows - intra-individual variation, inter-observer agreement and variation over time.

    Science.gov (United States)

    Raundal, Peter M; Andersen, Pia H; Toft, Nils; Forkman, Björn; Munksgaard, Lene; Herskin, Mette S

    2014-11-01

    To examine the use of handheld methodology to assess mechanical nociceptive threshold (MNT) on cows kept loose-housed. Prospective randomized partial cross-over experimental study. A one-factor (test day) design was used to evaluate MNT over time. One hundred and fifteen healthy, loose-housed Danish Holstein cattle. We evaluated intra-individual variation, inter-observer agreement and variation over time of MNT using two handheld devices and two stimulation sites. Mechanical, ramped stimulations were performed with an algometer (6.5 mm diameter steel probe, 0-10.0 kgf) or an electronic von Frey device (plastic tip with diameter 0.8 mm, 0-1000 gf). Each cow received 5-6 consecutive stimulations within a 2 × 5 cm skin area on the dorsal or lateral aspect of the left third metatarsus until an avoidance reaction occurred. We investigated the difference in precision [expressed as coefficient of variation (CV)] between the combinations of devices and stimulation sites. The inter-observer agreement and the difference in MNT between test day 1, 3, 7, 10 and 24 were investigated for selected combinations. Data were analysed in mixed models and Bland-Altman as relevant. The CVs did not differ [range 0.34-0.52 (p = 0.1)]. Difference between observers (95% limits) was 0.2 kgf (2.8) and 4 gf (369) for the algometer and von Frey device, respectively. Mechanical nociceptive threshold increased from 361 on test day one to 495 gf on test day 24 (p < 0.01). All methods showed a high degree of intra-individual variation, and no combination of device and stimulation site showed superior precision. Mean difference between observers was low, and MNT was not consistent over time. Further development of the methods is required before they can be used in research to investigate possible relations between claw lesions and hyperalgesia. © 2014 The Authors Veterinary Anaesthesia and Analgesia published by John Wiley & Sons Ltd on behalf of Association of Veterinary Anaesthetists and the

  6. Study of time variation of terrestrial gamma radiation due to depth distribution of soil moisture content

    International Nuclear Information System (INIS)

    Yoshioka, Katsuhiro

    1994-01-01

    An empirical equation was deduced from studies of time variations of terrestrial gamma exposure rate and soil moisture content with depth distribution in the surface layer. It was definitely suggested that the variation of terrestrial gamma exposure rate is most strongly influenced by the change of soil moisture content at 5 cm depth. The seasonal variation with a relative maximum in early autumn and a relative minimum in early spring was clearly obtained in the consequence of long time measurements of terrestrial gamma exposure rate and degree of soil dryness. The diurnal change and phase difference due to the effect of depth were also obtained in the dynamic characteristics of soil moisture content at 3 different depths. From the comparison between measured terrestrial gamma exposure rate and that evaluated from soil moisture content using the empirical equation, it was seen that seasonal variations of the both agreed fairly well as a whole. (author)

  7. Variations in automatically recorded rumination time as explained by variations in intake of dietary fractions and milk production, and between-cow variation.

    Science.gov (United States)

    Byskov, M V; Nadeau, E; Johansson, B E O; Nørgaard, P

    2015-06-01

    Individual recording of rumination time (RT) is now possible in commercial dairy herds, through development of a microphone-based sensor, which is able to record RT by the sound of rumination activity. The objectives of this study were to examine the relationship between daily RT and intakes of different dietary fractions, the relationship between RT in minutes per kilogram of dry matter intake (DMI) and milk production, and to examine the variation in RT within and between mid-lactating dairy cows. Data from 3 production trials were used in which a total of 27 different diets were fed. The data contained 761, 290, and 203 daily recordings of RT, milk yield, milk components, DMI, and intake of dietary fractions recorded on 29, 26, and 24 Holstein and Swedish Red cows from trials 1, 2, and 3, respectively. The dietary fractions included forage neutral detergent fiber (NDF), concentrate NDF, crude protein, sugar, starch, and the remaining fraction represented by organic matter--(forage NDF+concentrate NDF+crude protein+sugar+starch). The relationship between the dietary fractions and RT was analyzed in 2 steps. In step 1, the dietary fractions, which were significantly related to RT, were selected and simultaneously checked for multicollinearity between the dietary components; in step 2, a multivariate model, including the effect of repeated measurements, the main effect of the selected dietary fractions from step 1, random effects of cow(trial) and trial, and information on breed, days in milk, and parity was used to analyze the relationship between RT and the selected dietary fractions. Relationships between RT in minutes per kilogram of DMI and milk yield and milk components were analyzed, using the same multivariate model as in step 2. Approximately 32% of the variation in daily RT could be explained by variations in intakes of the dietary fractions, whereas 48% of the total variation in RT was accounted for by individual variations between cows. Intakes of

  8. Dynamics of Gaussian Wigner functions derived from a time-dependent variational principle

    Directory of Open Access Journals (Sweden)

    Jens Aage Poulsen

    2017-11-01

    Full Text Available By using a time-dependent variational principle formulated for Wigner phase-space functions, we obtain the optimal time-evolution for two classes of Gaussian Wigner functions, namely those of either thawed real-valued or frozen but complex Gaussians. It is shown that tunneling effects are approximately included in both schemes.

  9. Reducing lumber thickness variation using real-time statistical process control

    Science.gov (United States)

    Thomas M. Young; Brian H. Bond; Jan Wiedenbeck

    2002-01-01

    A technology feasibility study for reducing lumber thickness variation was conducted from April 2001 until March 2002 at two sawmills located in the southern U.S. A real-time statistical process control (SPC) system was developed that featured Wonderware human machine interface technology (HMI) with distributed real-time control charts for all sawing centers and...

  10. Running vacuum in the Universe and the time variation of the fundamental constants of Nature

    Energy Technology Data Exchange (ETDEWEB)

    Fritzsch, Harald [Nanyang Technological University, Institute for Advanced Study, Singapore (Singapore); Universitaet Muenchen, Physik-Department, Munich (Germany); Sola, Joan [Nanyang Technological University, Institute for Advanced Study, Singapore (Singapore); Universitat de Barcelona, Departament de Fisica Quantica i Astrofisica, Barcelona, Catalonia (Spain); Universitat de Barcelona (ICCUB), Institute of Cosmos Sciences, Barcelona, Catalonia (Spain); Nunes, Rafael C. [Universidade Federal de Juiz de Fora, Dept. de Fisica, Juiz de Fora, MG (Brazil)

    2017-03-15

    We compute the time variation of the fundamental constants (such as the ratio of the proton mass to the electron mass, the strong coupling constant, the fine-structure constant and Newton's constant) within the context of the so-called running vacuum models (RVMs) of the cosmic evolution. Recently, compelling evidence has been provided that these models are able to fit the main cosmological data (SNIa+BAO+H(z)+LSS+BBN+CMB) significantly better than the concordance ΛCDM model. Specifically, the vacuum parameters of the RVM (i.e. those responsible for the dynamics of the vacuum energy) prove to be nonzero at a confidence level >or similar 3σ. Here we use such remarkable status of the RVMs to make definite predictions on the cosmic time variation of the fundamental constants. It turns out that the predicted variations are close to the present observational limits. Furthermore, we find that the time evolution of the dark matter particle masses should be crucially involved in the total mass variation of our Universe. A positive measurement of this kind of effects could be interpreted as strong support to the ''micro-macro connection'' (viz. the dynamical feedback between the evolution of the cosmological parameters and the time variation of the fundamental constants of the microscopic world), previously proposed by two of us (HF and JS). (orig.)

  11. Time variations in the mechanical characteristics of local crustal segments according to seismic observations

    Science.gov (United States)

    Kocharyan, G. G.; Gamburtseva, N. G.; Sanina, I. A.; Danilova, T. V.; Nesterkina, M. A.; Gorbunova, E. M.; Ivanchenko, G. N.

    2011-04-01

    The results of the seismic observations made with two different experimental setups are presented. In the first case, the signals produced by underground nuclear explosions at the Semipalatinsk Test Site were measured on a linear profile, which allowed one to definitely outline the areas where the mechanical properties of rocks experienced considerable time variations. In the second case, the waves excited by the open-pit mine blasts recorded at a small-aperture seismic array at the Mikhnevo Geophysical Station (Institute of Geosphere Dynamics, Russian Academy of Sciences) on the East European Platform favored the estimation of variations in the integral characteristics of the seismic path. Measurements in aseismic regions characterized by diverse geological structure and different tectonic conditions revealed similar effects of the strong dependency of seismic parameters on the time of explosions. Here, the variations experienced by the maximum amplitudes of oscillations and irrelevant to seasonal changes or local conditions reached a factor of two. The generic periods of these variations including the distinct annual rhythm are probably the fragments of a lower-frequency process. The obtained results suggest that these variations are due to changes in the stressstrain state of active fault zones, which, in turn, can be associated with the macroscale motion of large blocks triggered by tidal strains, tectonic forces and, possibly, variations in the rate of the Earth's rotation.

  12. Controlling cyclic combustion timing variations using a symbol-statistics predictive approach in an HCCI engine

    International Nuclear Information System (INIS)

    Ghazimirsaied, Ahmad; Koch, Charles Robert

    2012-01-01

    Highlights: ► Misfire reduction in a combustion engine based on chaotic theory methods. ► Chaotic theory analysis of cyclic variation of a HCCI engine near misfire. ► Symbol sequence approach is used to predict ignition timing one cycle-ahead. ► Prediction is combined with feedback control to lower HCCI combustion variation. ► Feedback control extends the HCCI operating range into the misfire region. -- Abstract: Cyclic variation of a Homogeneous Charge Compression Ignition (HCCI) engine near misfire is analyzed using chaotic theory methods and feedback control is used to stabilize high cyclic variations. Variation of consecutive cycles of θ Pmax (the crank angle of maximum cylinder pressure over an engine cycle) for a Primary Reference Fuel engine is analyzed near misfire operation for five test points with similar conditions but different octane numbers. The return map of the time series of θ Pmax at each combustion cycle reveals the deterministic and random portions of the dynamics near misfire for this HCCI engine. A symbol-statistic approach is used to predict θ Pmax one cycle-ahead. Predicted θ Pmax has similar dynamical behavior to the experimental measurements. Based on this cycle ahead prediction, and using fuel octane as the input, feedback control is used to stabilize the instability of θ Pmax variations at this engine condition near misfire.

  13. Temporal and spatial variations of travel-time residuals in central California for Novaya Zemlya events

    International Nuclear Information System (INIS)

    Robinson, R.; Iyer, H.M.

    1976-01-01

    Eight large nuclear explosions in Novaya Zemlya from October 1969 through November 1974 were used to monitor long-term variations in crustal seismic velocity near the San Andreas fault in central California. Relative P-wave travel-time residuals appear to be accurate to approximately +-0.1 sec. Of the over 100 stations used, none show clearly significant temporal variations in residual greater than this amount, corresponding to about a 4 percent change in velocity in the upper crust. Average relative residuals at individual stations show a large spatial variation of about 1.5 sec. These variations reflect both a complex crustal geology and changes in crustal thickness and provide a potentially powerful tool for studying crustal structure

  14. Stability Analysis and Variational Integrator for Real-Time Formation Based on Potential Field

    Directory of Open Access Journals (Sweden)

    Shengqing Yang

    2014-01-01

    Full Text Available This paper investigates a framework of real-time formation of autonomous vehicles by using potential field and variational integrator. Real-time formation requires vehicles to have coordinated motion and efficient computation. Interactions described by potential field can meet the former requirement which results in a nonlinear system. Stability analysis of such nonlinear system is difficult. Our methodology of stability analysis is discussed in error dynamic system. Transformation of coordinates from inertial frame to body frame can help the stability analysis focus on the structure instead of particular coordinates. Then, the Jacobian of reduced system can be calculated. It can be proved that the formation is stable at the equilibrium point of error dynamic system with the effect of damping force. For consideration of calculation, variational integrator is introduced. It is equivalent to solving algebraic equations. Forced Euler-Lagrange equation in discrete expression is used to construct a forced variational integrator for vehicles in potential field and obstacle environment. By applying forced variational integrator on computation of vehicles' motion, real-time formation of vehicles in obstacle environment can be implemented. Algorithm based on forced variational integrator is designed for a leader-follower formation.

  15. Own-wage labor supply elasticities: variation across time and estimation methods

    Directory of Open Access Journals (Sweden)

    Olivier Bargain

    2016-10-01

    Full Text Available Abstract There is a huge variation in the size of labor supply elasticities in the literature, which hampers policy analysis. While recent studies show that preference heterogeneity across countries explains little of this variation, we focus on two other important features: observation period and estimation method. We start with a thorough survey of existing evidence for both Western Europe and the USA, over a long period and from different empirical approaches. Then, our meta-analysis attempts to disentangle the role of time changes and estimation methods. We highlight the key role of time changes, documenting the incredible fall in labor supply elasticities since the 1980s not only for the USA but also in the EU. In contrast, we find no compelling evidence that the choice of estimation method explains variation in elasticity estimates. From our analysis, we derive important guidelines for policy simulations.

  16. Co-gradient variation in growth rate and development time of a broadly distributed butterfly.

    Directory of Open Access Journals (Sweden)

    Madeleine Barton

    Full Text Available Widespread species often show geographic variation in thermally-sensitive traits, providing insight into how species respond to shifts in temperature through time. Such patterns may arise from phenotypic plasticity, genetic adaptation, or their interaction. In some cases, the effects of genotype and temperature may act together to reduce, or to exacerbate, phenotypic variation in fitness-related traits across varying thermal environments. We find evidence for such interactions in life-history traits of Heteronympha merope, a butterfly distributed across a broad latitudinal gradient in south-eastern Australia. We show that body size in this butterfly is negatively related to developmental temperature in the laboratory, in accordance with the temperature-size rule, but not in the field, despite very strong temperature gradients. A common garden experiment on larval thermal responses, spanning the environmental extremes of H. merope's distribution, revealed that butterflies from low latitude (warmer climate populations have relatively fast intrinsic growth and development rates compared to those from cooler climates. These synergistic effects of genotype and temperature across the landscape (co-gradient variation are likely to accentuate phenotypic variation in these traits, and this interaction must be accounted for when predicting how H. merope will respond to temperature change through time. These results highlight the importance of understanding how variation in life-history traits may arise in response to environmental change. Without this knowledge, we may fail to detect whether organisms are tracking environmental change, and if they are, whether it is by plasticity, adaptation or both.

  17. Controlling spark timing for consecutive cycles to reduce the cyclic variations of SI engines

    International Nuclear Information System (INIS)

    Kaleli, Alirıza; Ceviz, Mehmet Akif; Erenturk, Köksal

    2015-01-01

    Minimization of the cyclic variations is one of the most important design goal for spark-ignited engines. Primary motivation of this study is to reduce the cyclic variations in spark ignition engines by controlling the spark timing for consecutive cycles. A stochastic model was performed between spark timing and in–cylinder maximum pressure by using the system identification techniques. The incylinder maximum pressure of the next cycle was predicted with this model. Minimum variance and generalized minimum variance controllers were designed to regulate the in–cylinder maximum pressure by changing the spark timing for consecutive cycles of the test engine. The produced control algorithms were built in LabView environment and installed to the Field Programmable Gate Arrays (FPGA) chassis. According to the test results, the in–cylinder maximum pressure of the next pressure cycle can be predicted fairly well, and the spark timing can be regulated to keep the in–cylinder maximum pressure in a desired band to reduce the cyclic variations. At fixed spark timing experiments, the COV Pmax and COV imep were 3.764 and 0.677%, whereas they decreased to 3.208 and 0.533% when GMV controller was applied, respectively. - Highlights: • Cycle per cycle spark timing control was carried out. • A stochastic process model was described between P max and the spark timing. • The cyclic variations in P max was decreased by keeping it in a desired band. • Different controllers were used to adjust spark timing signal of the next cycle. • COV Pmax was decreased by about 15% by using GMV controller

  18. Simple model of variation of the signature of a space-time metric

    International Nuclear Information System (INIS)

    Konstantinov, M.Yu.

    2004-01-01

    The problem on the changes in the space-time signature metrics is discussed. The simple model, wherein the space-time metrics signature is determined by the nonlinear scalar field, is proposed. It is shown that both classical and quantum description of changes in the metrics signature is possible within the frames of the considered model; the most characteristic peculiarities and variations of the classical and quantum descriptions are also briefly noted [ru

  19. Identifying significant temporal variation in time course microarray data without replicates

    Directory of Open Access Journals (Sweden)

    Porter Weston

    2009-03-01

    Full Text Available Abstract Background An important component of time course microarray studies is the identification of genes that demonstrate significant time-dependent variation in their expression levels. Until recently, available methods for performing such significance tests required replicates of individual time points. This paper describes a replicate-free method that was developed as part of a study of the estrous cycle in the rat mammary gland in which no replicate data was collected. Results A temporal test statistic is proposed that is based on the degree to which data are smoothed when fit by a spline function. An algorithm is presented that uses this test statistic together with a false discovery rate method to identify genes whose expression profiles exhibit significant temporal variation. The algorithm is tested on simulated data, and is compared with another recently published replicate-free method. The simulated data consists both of genes with known temporal dependencies, and genes from a null distribution. The proposed algorithm identifies a larger percentage of the time-dependent genes for a given false discovery rate. Use of the algorithm in a study of the estrous cycle in the rat mammary gland resulted in the identification of genes exhibiting distinct circadian variation. These results were confirmed in follow-up laboratory experiments. Conclusion The proposed algorithm provides a new approach for identifying expression profiles with significant temporal variation without relying on replicates. When compared with a recently published algorithm on simulated data, the proposed algorithm appears to identify a larger percentage of time-dependent genes for a given false discovery rate. The development of the algorithm was instrumental in revealing the presence of circadian variation in the virgin rat mammary gland during the estrous cycle.

  20. Preferences for travel time variability – A study of Danish car drivers

    DEFF Research Database (Denmark)

    Hjorth, Katrine; Rich, Jeppe

    Travel time variability (TTV) is a measure of the extent of unpredictability in travel times. It is generally accepted that TTV has a negative effect on travellers’ wellbeing and overall utility of travelling, and valuation of variability is an important issue in transport demand modelling...... preferences, to exclude non-traders, and to avoid complicated issues related to scheduled public transport services. The survey uses customised Internet questionnaires, containing a series of questions related to the traveller’s most recent morning trip to work, e.g.: • Travel time experienced on this day......, • Number of stops along the way, their duration, and whether these stops involved restrictions on time of day, • Restrictions regarding departure time from home or arrival time at work, • How often such a trip was made within the last month and the range of experienced travel times, • What the traveller...

  1. An explicit solution for a renewal process with waiting time and its variational principle

    International Nuclear Information System (INIS)

    Lewins, J.D.

    2001-01-01

    The forward and backward equations for the conditional probability density are derived for a reliability system consisting of a single component whose repair is subject to a delay time in providing a spare part but whose mean rate of repair is otherwise constant and whose time to failure is exponentially distributed. Exact solutions are quoted. These equations are then shown to be an adjoint pair that provide stationary conditions for a variational principle, in elementary form, from which all properties of the systems can be predicted with an accuracy greater than that implied by the trial functions or approximations used. A second or specific form of variational principle provides specific estimates to questions at hand. The second or adjoint field in the first elementary principle is the backward Kolmogorov solution and the in the specific form is the importance function, as used in nuclear reactor theory. The solutions are given for long-time and in a recurrence relation form valid for all times so that approximate solutions can be checked. Approximations suitable for variational trial functions are given. Two examples give the effect of a change of delay time for a steady state and an initial transient, respectively

  2. Temporal variation in bat-fruit interactions: Foraging strategies influence network structure over time

    Science.gov (United States)

    Zapata-Mesa, Natalya; Montoya-Bustamante, Sebastián; Murillo-García, Oscar E.

    2017-11-01

    Mutualistic interactions, such as seed dispersal, are important for the maintenance of structure and stability of tropical communities. However, there is a lack of information about spatial and temporal variation in plant-animal interaction networks. Thus, our goal was to assess the effect of bat's foraging strategies on temporal variation in the structure and robustness of bat-fruit networks in both a dry and a rain tropical forest. We evaluated monthly variation in bat-fruit networks by using seven structure metrics: network size, average path length, nestedness, modularity, complementary specialization, normalized degree and betweenness centrality. Seed dispersal networks showed variations in size, species composition and modularity; did not present nested structures and their complementary specialization was high compared to other studies. Both networks presented short path lengths, and a constantly high robustness, despite their monthly variations. Sedentary bat species were recorded during all the study periods and occupied more central positions than nomadic species. We conclude that foraging strategies are important structuring factors that affect the dynamic of networks by determining the functional roles of frugivorous bats over time; thus sedentary bats are more important than nomadic species for the maintenance of the network structure, and their conservation is a must.

  3. Simulation of the Universal-Time Diurnal Variation of the Global Electric Circuit Charging Rate

    Science.gov (United States)

    Mackerras, D.; Darvenzia, M.; Orville, R. E.; Williams, E. R.; Goodman, S. J.

    1999-01-01

    A global lightning model that includes diurnal and annual lightning variation, and total flash density versus latitude for each major land and ocean, has been used as the basis for simulating the global electric circuit charging rate. A particular objective has been to reconcile the difference in amplitude ratios [AR=(max-min)/mean] between global lightning diurnal variation (AR approx. = 0.8) and the diurnal variation of typical atmospheric potential gradient curves (AR approx. = 0.35). A constraint on the simulation is that the annual mean charging current should be about 1000 A. The global lightning model shows that negative ground flashes can contribute, at most, about 10-15% of the required current. For the purpose of the charging rate simulation, it was assumed that each ground flash contributes 5 C to the charging process. It was necessary to assume that all electrified clouds contribute to charging by means other than lightning, that the total flash rate can serve as an indirect indicator of the rate of charge transfer, and that oceanic electrified clouds contribute to charging even though they are relatively inefficient in producing lightning. It was also found necessary to add a diurnally invariant charging current component. By trial and error it was found that charging rate diurnal variation curves in Universal time (UT) could be produced with amplitude ratios and general shapes similar to those of the potential gradient diurnal variation curves measured over ocean and arctic regions during voyages of the Carnegie Institute research vessels.

  4. Hybrid model for forecasting time series with trend, seasonal and salendar variation patterns

    Science.gov (United States)

    Suhartono; Rahayu, S. P.; Prastyo, D. D.; Wijayanti, D. G. P.; Juliyanto

    2017-09-01

    Most of the monthly time series data in economics and business in Indonesia and other Moslem countries not only contain trend and seasonal, but also affected by two types of calendar variation effects, i.e. the effect of the number of working days or trading and holiday effects. The purpose of this research is to develop a hybrid model or a combination of several forecasting models to predict time series that contain trend, seasonal and calendar variation patterns. This hybrid model is a combination of classical models (namely time series regression and ARIMA model) and/or modern methods (artificial intelligence method, i.e. Artificial Neural Networks). A simulation study was used to show that the proposed procedure for building the hybrid model could work well for forecasting time series with trend, seasonal and calendar variation patterns. Furthermore, the proposed hybrid model is applied for forecasting real data, i.e. monthly data about inflow and outflow of currency at Bank Indonesia. The results show that the hybrid model tend to provide more accurate forecasts than individual forecasting models. Moreover, this result is also in line with the third results of the M3 competition, i.e. the hybrid model on average provides a more accurate forecast than the individual model.

  5. Pattern and Variation in the Timing of Aksak Meter: Commentary on Goldberg

    Directory of Open Access Journals (Sweden)

    Rainer Polak

    2016-01-01

    Full Text Available Daniel Goldberg (2015, this issue explores relations between timing variations, grouping structure, and musical form in the percussive accompaniment of Balkan folk dance music. A chronometric re-analysis of one of the target article’s two audio samples finds a regular metric timing pattern to consistently underlie the variations Goldberg uncovered. Read together, the target article and this commentary demonstrate the complex interplay of a regular timing pattern with several levels of nuanced variation to be performed with fluency, flexibility, and accuracy. This might appear commonplace, but here it is observed in the context of an asymmetric rhythmic mode, non-isochronous beat sequence, and asymmetric metric hierarchy. This context evidently does not represent a constraint of any sort in respect to the rhythmic timing performance, which casts doubts on the deep-seated assumption that metric regularity depends on iso-periodicity and vertical symmetry. This assumption is sometimes explicitly and often implicitly taken as universal; this comment suggests that, on the contrary, it might well be culturally biased.

  6. Storm time variation of radiative cooling of thermosphere by nitric oxide emission

    Science.gov (United States)

    Krishna, M. V. Sunil; Bag, Tikemani; Bharti, Gaurav

    2016-07-01

    The fundamental vibration-rotation band emission (Δν=1, Δ j=0,± 1) by nitric oxide (NO) at 5.3 µm is one of the most important cooling mechanisms in thermosphere. The collisional vibrational excitation of NO(ν=0) by impact with atomic oxygen is the main source of vibrationally excited nitric oxide. The variation of NO density depends on latitude, longitude and season. The present study aims to understand how the radiative flux gets influenced by the severe geomagnetic storm conditions. The variation of Nitric Oxide (NO) radiative flux exiting thermosphere is studied during the superstorm event of 7-12 November, 2004. The observations of TIMED/SABER suggest a strong anti-correlation with the O/N_2 ratio observed by GUVI during the same period. On a global scale the NO radiative flux showed an enhancement during the main phase on 8 November, 2004, whereas maximum depletion in O/N_2 is observed on 10 November, 2004. Both O/N_2 and NO radiative flux were found to propagate equatorward due to the effect of meridional wind resulting from joule and particle heating in polar region. Larger penetrations is observed in western longitude sectors. These observed variations are effectively connected to the variations in neutral densities. In the equatorial sectors, O/N_2 shows enhancement but almost no variation in radiative flux is observed. The possible reasons for the observed variations in NO radiative emission and O/N_2 ratios are discussed in the light of equator ward increase in the densities and prompt penetration.

  7. Population growth enhances the mean fixation time of neutral mutations and the persistence of neutral variation.

    Science.gov (United States)

    Waxman, D

    2012-06-01

    A fundamental result of population genetics states that a new mutation, at an unlinked neutral locus in a randomly mating diploid population, has a mean time of fixation of ∼4N(e) generations, where N(e) is the effective population size. This result is based on an assumption of fixed population size, which does not universally hold in natural populations. Here, we analyze such neutral fixations in populations of changing size within the framework of the diffusion approximation. General expressions are derived for the mean and variance of the fixation time in changing populations. Some explicit results are given for two cases: (i) the effective population size undergoes a sudden change, representing a sudden population expansion or a sudden bottleneck; (ii) the effective population changes linearly for a limited period of time and then remains constant. Additionally, a lower bound for the mean time of fixation is obtained for an effective population size that increases with time, and this is applied to exponentially growing populations. The results obtained in this work show, among other things, that for populations that increase in size, the mean time of fixation can be enhanced, sometimes substantially so, over 4N(e,0) generations, where N(e,0) is the effective population size at the time the mutation arises. Such an enhancement is associated with (i) an increased probability of neutral polymorphism in a population and (ii) an enhanced persistence of high-frequency neutral variation, which is the variation most likely to be observed.

  8. Dynamics of the sub-Ohmic spin-boson model: A time-dependent variational study

    International Nuclear Information System (INIS)

    Wu Ning; Duan Liwei; Zhao Yang; Li Xin

    2013-01-01

    The Dirac-Frenkel time-dependent variation is employed to probe the dynamics of the zero temperature sub-Ohmic spin-boson model with strong friction utilizing the Davydov D 1 ansatz. It is shown that initial conditions of the phonon bath have considerable influence on the dynamics. Counterintuitively, even in the very strong coupling regime, quantum coherence features still manage to survive under the polarized bath initial condition, while such features are absent under the factorized bath initial condition. In addition, a coherent-incoherent transition is found at a critical coupling strength α≈ 0.1 for s= 0.25 under the factorized bath initial condition. We quantify how faithfully our ansatz follows the Schrödinger equation, finding that the time-dependent variational approach is robust for strong dissipation and deep sub-Ohmic baths (s≪ 1).

  9. TIME VARIATION OF AV AND RV FOR TYPE Ia SUPERNOVAE BEHIND INTERSTELLAR DUST

    Science.gov (United States)

    Huang, Xiaosheng; Biederman, M.; Herger, B.; Aldering, G. S.

    2014-01-01

    TIME VARIATION OF AV AND RV FOR TYPE Ia SUPERNOVAE BEHIND NON-UNIFORM INTERSTELLAR DUST ABSTRACT We investigate the time variation of the visual extinction, AV, and the total-to-selective extinction ratio, RV, resulting from interstellar dust in front of an expanding photospheric disk of a type Ia supernova (SN Ia). We simulate interstellar dust clouds according to a power law power spectrum and produce extinction maps that either follow a pseudo-Gaussian distribution or a lognormal distribution. The RV maps are produced through a correlation between AV and RV. With maps of AV and RV generated in each case (pseudo-Gaussian and lognormal), we then compute the effective AV and RV for a SN as its photospheric disk expands behind the dust screen. We find for a small percentage of SNe the AV and RV values can vary by a large factor from day to day in the first 40 days after explosion.

  10. Time-variations of the regional evapotranspiration rate from GRACE satellite gravimetry

    OpenAIRE

    Ramillien , Guillaume; Frappart , Frédéric; Güntner , Andreas; Ngo-Duc , Thanh; Cazenave , Anny; Laval , Katia

    2006-01-01

    International audience; Since its launch in March 2002, the GRACE mission is measuring the global time variations of the Earth's gravity field with a current resolution of ~500 km. Especially over the continents, these measurements represent the integrated land water mass including surface waters (lakes, wetlands and rivers), soil moisture, groundwater and snow cover. In this study, we use the GRACE land water solutions computed by Ramillien et al. (2005a) through an iterative inversion of mo...

  11. TIME VARIATION AND ASYMMETRY IN THE WORLD PRICE OF COVARIANCE RISK: THE IMPLICATIONS FOR INTERNATIONAL DIVERSIFICATION

    OpenAIRE

    Olan T. Henry; Nilss Olekalns; Kalvinder Shields

    2004-01-01

    The International Capital Asset Pricing Model measures country risk in terms of the conditional covariance of national returns with the world return. Using impulse responses from a multivariate nonlinear model we provide evidence of time variation and asymmetry in the measure of country risk. and the implied benefit to international diversification. The evidence implies that the price of risk and the benefits from diversification may differ in a statistically and economically meaningful fashi...

  12. Boundedness and almost Periodicity in Time of Solutions of Evolutionary Variational Inequalities

    Science.gov (United States)

    Pankov, A. A.

    1983-04-01

    In this paper existence theorems are obtained for the solutions of abstract parabolic variational inequalities, which are bounded with respect to time (in the Stepanov and L^\\infty norms). The regularity and almost periodicity properties of such solutions are studied. Theorems are also established concerning their solvability in spaces of Besicovitch almost periodic functions. The majority of the results are obtained without any compactness assumptions. Bibliography: 30 titles.

  13. Time variations of geomagnetic activity indices Kp and Ap: an update

    Directory of Open Access Journals (Sweden)

    G. K. Rangarajan

    1997-10-01

    Full Text Available Kp and Ap indices covering the period 1932 to 1995 are analysed in a fashion similar to that attempted by Bartels for the 1932–1961 epoch to examine the time variations in their characteristics. Modern analysis techniques on the extended data base are used for further insight. The relative frequencies of occurrence of Kp with different magnitudes and the seasonal and solar cycle dependences are seen to be remarkably consistent despite the addition of 35 years of observations. Many of the earlier features seen in the indices and special intervals are shown to be replicated in the present analysis. Time variations in the occurrence of prolonged periods of geomagnetic calm or of enhanced activity are presented and their relation to solar activity highlighted. It is shown that in the declining phase the occurrence frequencies of Kp = 4–5 (consecutively over 4 intervals can be used as a precursor for the maximum sunspot number to be expected in the next cycle. The semi-annual variation in geomagnetic activity is re-examined utilising not only the Ap index but also the occurrence frequencies of Kp index with different magnitudes. Lack of dependence of the amplitude of semi-annual variation on sunspot number is emphasised. Singular spectrum analysis of the mean monthly Ap index shows some distinct periodic components. The temporal evolution of ~44 month, ~21 month and ~16 month oscillations are examined and it is postulated that while QBO and the 16 month oscillations could be attributed to solar wind and IMF oscillations with analogous periodicity, the 44 month variation is associated with a similar periodicity in recurrent high speed stream caused by sector boundary passage. It is reconfirmed that there could have been only one epoch around 1940 when solar wind speed could have exhibited a 1.3-year periodicity comparable to that seen during the post-1986 period.

  14. Time variations of geomagnetic activity indices Kp and Ap: an update

    Directory of Open Access Journals (Sweden)

    G. K. Rangarajan

    Full Text Available Kp and Ap indices covering the period 1932 to 1995 are analysed in a fashion similar to that attempted by Bartels for the 1932–1961 epoch to examine the time variations in their characteristics. Modern analysis techniques on the extended data base are used for further insight. The relative frequencies of occurrence of Kp with different magnitudes and the seasonal and solar cycle dependences are seen to be remarkably consistent despite the addition of 35 years of observations. Many of the earlier features seen in the indices and special intervals are shown to be replicated in the present analysis. Time variations in the occurrence of prolonged periods of geomagnetic calm or of enhanced activity are presented and their relation to solar activity highlighted. It is shown that in the declining phase the occurrence frequencies of Kp = 4–5 (consecutively over 4 intervals can be used as a precursor for the maximum sunspot number to be expected in the next cycle. The semi-annual variation in geomagnetic activity is re-examined utilising not only the Ap index but also the occurrence frequencies of Kp index with different magnitudes. Lack of dependence of the amplitude of semi-annual variation on sunspot number is emphasised. Singular spectrum analysis of the mean monthly Ap index shows some distinct periodic components. The temporal evolution of ~44 month, ~21 month and ~16 month oscillations are examined and it is postulated that while QBO and the 16 month oscillations could be attributed to solar wind and IMF oscillations with analogous periodicity, the 44 month variation is associated with a similar periodicity in recurrent high speed stream caused by sector boundary passage. It is reconfirmed that there could have been only one epoch around 1940 when solar wind speed could have exhibited a 1.3-year periodicity comparable to that seen during the post-1986 period.

  15. SABER (TIMED) and MLS (UARS) Temperature Observations of Mesospheric and Stratospheric QBO and Related Tidal Variations

    Science.gov (United States)

    Huang, Frank T.; Mayr, Hans G.; Reber, Carl A.; Russell, James; Mlynczak, Marty; Mengel, John

    2006-01-01

    More than three years of temperature observations from the SABER (TIMED) and MLS WARS) instruments are analyzed to study the annual and inter-annual variations extending from the stratosphere into the upper mesosphere. The SABER measurements provide data from a wide altitude range (15 to 95 km) for the years 2002 to 2004, while the MLS data were taken in the 16 to 55 km altitude range a decade earlier. Because of the sampling properties of SABER and MLS, the variations with local solar time must be accounted for when estimating the zonal mean variations. An algorithm is thus applied that delineates with Fourier analysis the year-long variations of the migrating tides and zonal mean component. The amplitude of the diurnal tide near the equator shows a strong semiannual periodicity with maxima near equinox, which vary from year to year to indicate the influence from the Quasi-biennial Oscillation (QBO) in the zonal circulation. The zonal mean QBO temperature variations are analyzed over a range of latitudes and altitudes, and the results are presented for latitudes from 48"s to 48"N. New results are obtained for the QBO, especially in the upper stratosphere and mesosphere, and at mid-latitudes. At Equatorial latitudes, the QBO amplitudes show local peaks, albeit small, that occur at different altitudes. From about 20 to 40 km, and within about 15" of the Equator, the amplitudes can approach 3S K for the stratospheric QBO or SQBO. For the mesospheric QBO or MQBO, we find peaks near 70 km, with temperature amplitudes reaching 3.5"K, and near 85 km, the amplitudes approach 2.5OK. Morphologically, the amplitude and phase variations derived from the SABER and MLS measurements are in qualitative agreement. The QBO amplitudes tend to peak at the Equator but then increase again pole-ward of about 15" to 20'. The phase progression with altitude varies more gradually at the Equator than at mid-latitudes. A comparison of the observations with results from the Numerical Spectral

  16. Observed variations in U.S. frost timing linked to atmospheric circulation patterns.

    Science.gov (United States)

    Strong, Courtenay; McCabe, Gregory J

    2017-05-23

    Several studies document lengthening of the frost-free season within the conterminous United States (U.S.) over the past century, and report trends in spring and fall frost timing that could stem from hemispheric warming. In the absence of warming, theory and case studies link anomalous frost timing to atmospheric circulation anomalies. However, recent efforts to relate a century of observed changes in U.S. frost timing to various atmospheric circulations yielded only modest correlations, leaving the relative importance of circulation and warming unclear. Here, we objectively partition the U.S. into four regions and uncover atmospheric circulations that account for 25-48% of spring and fall-frost timing. These circulations appear responsive to historical warming, and they consistently account for more frost timing variability than hemispheric or regional temperature indices. Reliable projections of future variations in growing season length depend on the fidelity of these circulation patterns in global climate models.

  17. Variations in the small-scale galactic magnetic field and short time-scale intensity variations of extragalactic radio sources

    International Nuclear Information System (INIS)

    Simonetti, J.H.

    1985-01-01

    Structure functions of the Faraday rotation measures (RMs) of extragalactic radio sources are used to investigate variations in the interstellar magnetic field on length scales of approx.0.01 to 100 pc. Model structure functions derived assuming a power-law power spectrum of irregularities in n/sub e/B, are compared with those observed. The results indicate an outer angular scale for RM variations of approximately less than or equal to 5 0 and evidence for RM variations on scales as small as 1'. Differences in the variance of n/sub e/B fluctuations for various lines of sight through the Galaxy are found. Comparison of pulsar scintillations in right- and left-circular polarizations yield an upper limit to the variations in n/sub e/ on a length scale of approx.10 11 cm. RMs were determined through high-velocity molecular flows in galactic star-formation regions, with the goal of constraining magnetic fields in and near the flows. RMs of 7 extragalactic sources with a approx.20 arcmin wide area seen through Cep A, fall in two groups separated by approx.150 rad m -2 - large given our knowledge of RM variations on small angular scales and possibly a result of the anisotropy of the high-velocity material

  18. Time Variations of the Spectral Indices of the Suprathermal Distribution as observed by WIND/STICS

    Science.gov (United States)

    Gruesbeck, J. R.; Christian, E. R.; Lepri, S. T.; Thomas, J.; Zurbuchen, T.; Gloeckler, G.

    2011-12-01

    Suprathermal particle spectra, measured in various regions of the heliosphere and heliosheath by Ulysses, ACE and Voyager, have recently been reported. In many cases long accumulation times had to be used to obtain sufficient statistical accuracy, and corrections were necessary, since only a fraction of phase space was measured. The SupraThermal Ion Composition Spectrometer (STICS), onboard Wind, enables observations of the suprathermal plasma in the solar wind at much higher time resolution. In addition, the STICS samples nearly full three-dimensional phase space, enabling measurements of anisotropies. We present a multi-year investigation of the spectral index of the suprathermal distribution, accumulated over 1 day and less, where we see significant time variation. An average lower bound value of the spectral index is at ~ -5, however, there are time periods during which the observed distributions steepen. We will also present an analysis of time and spatial variations of the suprathermal particle fluxes, observed by STICS and other instruments. In particular, we will compare the observed variability with predictions from a model by Bochsler and Moebius, based on data of the Interstellar Boundary Explorer (IBEX), who postulated that energetic neutral atoms, from outside of the heliosheath, which then penetrate the inner heliosphere and are finally ionized, could be a source of the very suprathermal populations we observe.

  19. Derivation of an adiabatic time-dependent Hartree-Fock formalism from a variational principle

    International Nuclear Information System (INIS)

    Brink, D.M.; Giannoni, M.J.; Veneroni, M.

    1975-10-01

    A derivation of the adiabatic time-dependent Hartree-Fock formalism is given, which is based on a variational principle analogous to Hamilton's principle in classical mechanics. The method leads to a Hamiltonian for collective motion which separates into a potential and a kinetic energy and gives mass and potential parameters in terms of the nucleon-nucleon interaction. The adiabatic approximation assumes slow motion but not small amplitudes and can therefore describe anharmonic effects. The RPA is a limiting case where both amplitudes and velocities are small. The variational approach provides a consistent way of extracting coordinated and momenta from the density matrix and of obtaining equations of motion when particular trial forms for this density matrix are chosen. One such choice leads to Thouless-Valatin formula. An other choice leads to irrotational hydrodynamics [fr

  20. Variation of CRE with exponents of time and number of fractions

    International Nuclear Information System (INIS)

    Supe, S.J.; Rao, S.M.; Sawant, S.G.; Bisht, J.S.

    1976-01-01

    The concept of NSD has been modified into TDF's by Orton and Ellis and CRE's by Kirk et al. It was aimed to study the variability of these new concepts on the exponents of time and number of fractions. It was found that TDF has larger variation with the exponents compared to that of CRE. The use of CRE and NSD for solving the treatment scheduling problems or for intercomparison of various regimes has been simplified by providing readymade estimation of CRE for various doses/fraction with increasing number of fractions. As there is increasing evidence for the change of exponents J and H, nomograms are presented to determine the CRE for various values of J and H. The variation of decay correction factors with the exponent H is also evaluated and is presented. This will help various radiotherapists to use CRE and the decay correction factors consistent with their clinical findings. (orig.) [de

  1. Removing tidal-period variations from time-series data using low-pass digital filters

    Science.gov (United States)

    Walters, Roy A.; Heston, Cynthia

    1982-01-01

    Several low-pass, digital filters are examined for their ability to remove tidal Period Variations from a time-series of water surface elevation for San Francisco Bay. The most efficient filter is the one which is applied to the Fourier coefficients of the transformed data, and the filtered data recovered through an inverse transform. The ability of the filters to remove the tidal components increased in the following order: 1) cosine-Lanczos filter, 2) cosine-Lanczos squared filter; 3) Godin filter; and 4) a transform fitter. The Godin fitter is not sufficiently sharp to prevent severe attenuation of 2–3 day variations in surface elevation resulting from weather events.

  2. Chernobyl derived activity in sheep: variation within a single flock and with time

    International Nuclear Information System (INIS)

    Walters, B.

    1988-01-01

    The continuous monitoring of the caesium contents of sheep grazing a high fell in Cumbria, UK, is described. The technique of in-vivo monitoring, using portable NaI crystal detectors, is shown to be robust and capable of producing accurate quantitative data. Results are presented from the monitoring of 100 sheep at fortnightly intervals over a period of 13 weeks. The peak average activity (1300 Bq kg -1 ) was reached five weeks after introduction of the sheep to grazing land with up to 2000 Bq kg -1 in herbage. Activity had fallen, on average, to 68% of the peak value after eight weeks. The variation in activity between individual sheep is large and usually symmetrically distributed. The temporal trend of activity in the whole flock is a combination of the many disparate individual trends. The technique has allowed the variation between animals and individual time trends to be followed. (author)

  3. Long-term and transient time variation of cosmic ray fluxes detected in Argentina by CARPET cosmic ray detector

    Science.gov (United States)

    De Mendonça, R. R. S.; Raulin, J.-P.; Bertoni, F. C. P.; Echer, E.; Makhmutov, V. S.; Fernandez, G.

    2011-07-01

    We present results obtained at El Leoncito (CASLEO, San Juan, Argentina) with the CARPET charged particles detector installed in April 2006. The observed modulation of the cosmic ray flux is discussed as a function of its time variability and it is related to longer solar activity variations and to shorter variations during solar and geomagnetic transient activity. Short period (few minutes, few hours) cosmic ray modulation events are observed during rain time (precipitation) and significant variations of the atmospheric electric field. Complementary observations of the atmospheric electric field indicate that its time variations play an important role in the detected cosmic ray event.

  4. New constraints on time-dependent variations of fundamental constants using Planck data

    Science.gov (United States)

    Hart, Luke; Chluba, Jens

    2018-02-01

    Observations of the cosmic microwave background (CMB) today allow us to answer detailed questions about the properties of our Universe, targeting both standard and non-standard physics. In this paper, we study the effects of varying fundamental constants (i.e. the fine-structure constant, αEM, and electron rest mass, me) around last scattering using the recombination codes COSMOREC and RECFAST++. We approach the problem in a pedagogical manner, illustrating the importance of various effects on the free electron fraction, Thomson visibility function and CMB power spectra, highlighting various degeneracies. We demonstrate that the simpler RECFAST++ treatment (based on a three-level atom approach) can be used to accurately represent the full computation of COSMOREC. We also include explicit time-dependent variations using a phenomenological power-law description. We reproduce previous Planck 2013 results in our analysis. Assuming constant variations relative to the standard values, we find the improved constraints αEM/αEM, 0 = 0.9993 ± 0.0025 (CMB only) and me/me, 0 = 1.0039 ± 0.0074 (including BAO) using Planck 2015 data. For a redshift-dependent variation, αEM(z) = αEM(z0) [(1 + z)/1100]p with αEM(z0) ≡ αEM, 0 at z0 = 1100, we obtain p = 0.0008 ± 0.0025. Allowing simultaneous variations of αEM(z0) and p yields αEM(z0)/αEM, 0 = 0.9998 ± 0.0036 and p = 0.0006 ± 0.0036. We also discuss combined limits on αEM and me. Our analysis shows that existing data are not only sensitive to the value of the fundamental constants around recombination but also its first time derivative. This suggests that a wider class of varying fundamental constant models can be probed using the CMB.

  5. Benchmarking the stochastic time-dependent variational approach for excitation dynamics in molecular aggregates

    Energy Technology Data Exchange (ETDEWEB)

    Chorošajev, Vladimir [Department of Theoretical Physics, Faculty of Physics, Vilnius University, Sauletekio 9-III, 10222 Vilnius (Lithuania); Gelzinis, Andrius; Valkunas, Leonas [Department of Theoretical Physics, Faculty of Physics, Vilnius University, Sauletekio 9-III, 10222 Vilnius (Lithuania); Department of Molecular Compound Physics, Center for Physical Sciences and Technology, Sauletekio 3, 10222 Vilnius (Lithuania); Abramavicius, Darius, E-mail: darius.abramavicius@ff.vu.lt [Department of Theoretical Physics, Faculty of Physics, Vilnius University, Sauletekio 9-III, 10222 Vilnius (Lithuania)

    2016-12-20

    Highlights: • The Davydov ansatze can be used for finite temperature simulations with an extension. • The accuracy is high if the system is strongly coupled to the environmental phonons. • The approach can simulate time-resolved fluorescence spectra. - Abstract: Time dependent variational approach is a convenient method to characterize the excitation dynamics in molecular aggregates for different strengths of system-bath interaction a, which does not require any additional perturbative schemes. Until recently, however, this method was only applicable in zero temperature case. It has become possible to extend this method for finite temperatures with the introduction of stochastic time dependent variational approach. Here we present a comparison between this approach and the exact hierarchical equations of motion approach for describing excitation dynamics in a broad range of temperatures. We calculate electronic population evolution, absorption and auxiliary time resolved fluorescence spectra in different regimes and find that the stochastic approach shows excellent agreement with the exact approach when the system-bath coupling is sufficiently large and temperatures are high. The differences between the two methods are larger, when temperatures are lower or the system-bath coupling is small.

  6. Local Times of Galactic Cosmic Ray Intensity Maximum and Minimum in the Diurnal Variation

    Directory of Open Access Journals (Sweden)

    Su Yeon Oh

    2006-06-01

    Full Text Available The Diurnal variation of galactic cosmic ray (GCR flux intensity observed by the ground Neutron Monitor (NM shows a sinusoidal pattern with the amplitude of 1sim 2 % of daily mean. We carried out a statistical study on tendencies of the local times of GCR intensity daily maximum and minimum. To test the influences of the solar activity and the location (cut-off rigidity on the distribution in the local times of maximum and minimum GCR intensity, we have examined the data of 1996 (solar minimum and 2000 (solar maximum at the low-latitude Haleakala (latitude: 20.72 N, cut-off rigidity: 12.91 GeV and the high-latitude Oulu (latitude: 65.05 N, cut-off rigidity: 0.81 GeV NM stations. The most frequent local times of the GCR intensity daily maximum and minimum come later about 2sim3 hours in the solar activity maximum year 2000 than in the solar activity minimum year 1996. Oulu NM station whose cut-off rigidity is smaller has the most frequent local times of the GCR intensity maximum and minimum later by 2sim3 hours from those of Haleakala station. This feature is more evident at the solar maximum. The phase of the daily variation in GCR is dependent upon the interplanetary magnetic field varying with the solar activity and the cut-off rigidity varying with the geographic latitude.

  7. Variation in computer time with geometry prescription in monte carlo code KENO-IV

    International Nuclear Information System (INIS)

    Gopalakrishnan, C.R.

    1988-01-01

    In most studies, the Monte Carlo criticality code KENO-IV has been compared with other Monte Carlo codes, but evaluation of its performance with different box descriptions has not been done so far. In Monte Carlo computations, any fractional savings of computing time is highly desirable. Variation in computation time with box description in KENO for two different fast reactor fuel subassemblies of FBTR and PFBR is studied. The K eff of an infinite array of fuel subassemblies is calculated by modelling the subassemblies in two different ways (i) multi-region, (ii) multi-box. In addition to these two cases, excess reactivity calculations of FBTR are also performed in two ways to study this effect in a complex geometry. It is observed that the K eff values calculated by multi-region and multi-box models agree very well. However the increase in computation time from the multi-box to the multi-region is considerable, while the difference in computer storage requirements for the two models is negligible. This variation in computing time arises from the way the neutron is tracked in the two cases. (author)

  8. Variations with time and age of the excess cancer risk among A-bomb survivors

    International Nuclear Information System (INIS)

    Pierce, D.A.; Vaeth, M.; Preston, D.L.

    1990-08-01

    This report has two aims: 1) to describe and analyze the age/time patterns of excess cancer risk in the atomic bomb survivor cohort followed up by RERF, and 2) to describe statistical methods which are used in RERF's analyses of data on mortality and morbidity in the cohort. In contrast to previous analyses of the cohort cancer mortality data, substantial use is made of Japanese national cancer rates for the purpose of investigation of the age/time variations in excess risk. This analysis considers mortality from all cancers except leukemia as a group. Primary attention is given to description in terms of the age-specific excess relative risk, but the importance of appropriate descriptions of the absolute excess risk is also emphasized. When models for the excess risk allow variation with age and time, both constant relative and absolute excess risk models provide very similar fits to the data. Previous reports have indicated that for a given age-at-exposure and sex, the excess age-specific relative risk is remarkably constant throughout the current follow-up period. Statistical analysis here indicates that for those less than about 35 years of age at exposure there is no departure from this pattern, beyond ordinary sampling variation. For those over about 35 years of age-at-exposure, there is modest evidence of an increasing trend in the excess relative risk, which could be plausibly attributed to effects related to minimal latent period. Some brief consideration is given to modeling the absolute excess risk as the product of an age-at-exposure and time-since-exposure effect. Interpretation of these results, particularly in regard to projections beyond the current follow-up, is discussed. (author)

  9. Storm-time variation of radiative cooling by Nitric Oxide as observed by TIMED-SABER and GUVI

    Science.gov (United States)

    Sunil Krishna, M. V.; Bharti, G.; Bag, T.

    2017-12-01

    The variation of O/N2 and nitric oxide radiative emission flux exiting thermosphere have been studied over northern hemisphere during the super-storm event of November 7-12, 2004. The data have been obtained from GUVI and SABER onboard the NASA's TIMED satellite. The NO radiative flux is observed to show an anti-correlation with O/N2 on a global scale. Both NO radiative flux and O/N2 ratio show equatorward motion with maximum penetration in western longitude sectors. A local variation of O, O2 and N2 densities have been calculated by using NRLMSISE-00 model over a mid-latitude location (55oN,180oE). On a local scale, model calculated O/O2 and O/N2 ratios are found to follow the observations made by GUVI. The SABER retrieved NO cooling rate (CR) at a local site suggests an enhancement during the storm period with the peak emission rate closely correlated to the progression of the storm. The peak emission altitude of NO CR moves upward during the main phase of the storm. The NO abundance has been calculated by using cooling rate and NOEM model. Both these suggest huge increase in NO density during the storm which is required to account the changes in NO radiative flux.

  10. Individual variation in habituation: behaviour over time toward different stimuli in threespine sticklebacks (Gasterosteus aculeatus)

    Science.gov (United States)

    Bell, Alison M.; Peeke, Harman V.S.

    2014-01-01

    Habituation, or the relatively permanent waning of a response as a result of repeated stimulation, is a form of behavioural plasticity that allows animals to filter out irrelevant stimuli and to focus selectively on important stimuli. Individuals that fail to habituate might be at a disadvantage if they continue to respond to irrelevant stimuli; therefore, habituation can have adaptive significance. In this study we compared rates of behaviour over time toward three different ecologically-relevant stimuli (food, a male intruder and a gravid female) in threespine sticklebacks (Gasterosteus aculeatus). We detected evidence for habituation to the stimuli, and males in this study were especially aggressive toward both male and female conspecifics. Although there were some clear temporal patterns that could be detected by looking at average behaviour, not all individuals behaved in the same ‘average’ way. We detected substantial inter-individual variation in behaviour toward all three stimuli, inter-individual variation in rates of habituation to both male and female conspecifics, but no evidence for correlations between behaviours across stimuli (behavioural syndromes). These results suggest that individual animals vary in rates of habituation, and prompt hypotheses about the causes and consequences of variation in rates of habituation. PMID:25678715

  11. Temperature variation in metal ceramic technology analyzed using time domain optical coherence tomography

    Science.gov (United States)

    Sinescu, Cosmin; Topala, Florin I.; Negrutiu, Meda Lavinia; Duma, Virgil-Florin; Podoleanu, Adrian G.

    2014-01-01

    The quality of dental prostheses is essential in providing good quality medical services. The metal ceramic technology applied in dentistry implies ceramic sintering inside the dental oven. Every ceramic material requires a special sintering chart which is recommended by the producer. For a regular dental technician it is very difficult to evaluate if the temperature inside the oven remains the same as it is programmed on the sintering chart. Also, maintaining the calibration in time is an issue for the practitioners. Metal ceramic crowns develop a very accurate pattern for the ceramic layers depending on the temperature variation inside the oven where they are processed. Different patterns were identified in the present study for the samples processed with a variation in temperature of +30 °C to +50 °C, respectively - 30 0°C to -50 °C. The OCT imagistic evaluations performed for the normal samples present a uniform spread of the ceramic granulation inside the ceramic materials. For the samples sintered at a higher temperature an alternation between white and darker areas between the enamel and opaque layers appear. For the samples sintered at a lower temperature a decrease in the ceramic granulation from the enamel towards the opaque layer is concluded. The TD-OCT methods can therefore be used efficiently for the detection of the temperature variation due to the ceramic sintering inside the ceramic oven.

  12. Case studies of the storm time variation of the polar cusp

    International Nuclear Information System (INIS)

    Meng, C.

    1983-01-01

    The latitudinal variations of the polar cusp region were examined during three intense geomagnetic storms. The variations were compared with the intensity of storm time ring current inferred from the Dst index, with the magnitude of the north-south component B/sub z/ of the interplanetary magnetic field and with substorm activity. The common feature is that the rapid equatorward shift occurred during the increase of the ring current growth and during the southward turning of the interplanetary magnetic field orientation. The equatorwardmost latitude of the cusp was reached before the peak of the ring current intensity, by a few to several hours, coinciding with the occurrence of the largest magnitude of the southward interplanetary magnetic field component. However, details of the polar cusp latitudinal movement differ from storm to storm. During the three storms studied, the poleward recovery commenced at the peak magnitude of the negative IMF B/sub z/ component, but the recovery proceeded without a clear relation to variations of the interplanetary B/sub z/ component, to the ring current intensity, or to the substorm activity. The lowest cusp latitude observed was at approx.61.7 0 , and the magnitude of this shift seems to be related to the magnitudes of -B/sub z/. It is further observed that the approximate rates of the cusp macroscopic equatorward and poleward movements are about 3 0 and 1.5 0 per hour, respectively

  13. Time resolved FTIR study of the catalytic CO oxidation under periodic variation of the reactant concentration

    Energy Technology Data Exchange (ETDEWEB)

    Kritzenberger, J; Wokaun, A [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    Oxidation of CO over palladium/zirconia catalyst obtained from an amorphous Pd{sub 25}Zr{sub 75} precursor was investigated by time resolved FTIR spectroscopy. Sine wave shaped modulation of the reactant concentration, i.e. variation of CO or O{sub 2} partial pressure, was used to induce variations of the IR signals of product (CO{sub 2}) and unconverted reactant (CO), which were detected in a multi-pass absorption cell. The phase shift {phi} between external perturbation and variation of the CO{sub 2} signal was examined in dependence on temperature (100{sup o}C{<=}T{<=}350{sup o}C) and modulation frequency (1.39x10{sup -4}Hz{<=}{omega}{<=}6.67x10{sup -2}Hz). From the phase shift values, a simple Eley-Rideal mechanism is excluded, and the rate limiting step of the Langmuir-Hinshelwood mechanism for the CO oxidation may be identified. Adsorption and possible surface movement of CO to the actual reaction site determine the rate of the CO oxidation on the palladium/zirconia catalyst used in our study. The introduction of an external perturbation is a first step towards the application of two-dimensional infrared spectroscopy to heterogeneous catalyzed reactions. (author) 3 figs., 4 refs.

  14. Establishing a Set of Macroeconomic Factors Explaining Variation Over Time of Performance in Business Sectors

    Directory of Open Access Journals (Sweden)

    Audrius Dzikevičius

    2016-06-01

    Full Text Available With increasing competitiveness of companies and business sectors in the domestic markets of Lithuania, economic units are frequently confronted with the lack of methods for more detailed analysis of external factors explaining the variation over time of corporate financial indicators. The analysis or forecasting of financial indicators is usually linked with the development of a stock market or undertaken to estimate the probability of bankruptcy. However, there is a lack of studies aimed at identifying links between macroeconomic factors and financial performance indicators and explaining their variation over time. To serve that purpose, the factors of the macroeconomic environment that are most significant for certain economic activities have been identified and analysed to enable explaining the variation over time patterns of corporate financial indicators. The analysis covers economic performance, i.e. financial performance indicators and their links with macroeconomic factors, in 89 business sectors of Lithuania at a three-digit level of NACE 2 ed. The findings of the research indicate that the unemployment level in the country, the volume of export and import and the GDP are the most important macroeconomic factors that can be used to forecast different profitability, financial leverage, liquidity and other financial performance indicators of individual business sectors or companies. The research has not unfolded any significant differences between business sectors therefore the above factors are considered generic macroeconomic factors enabling to explain financial performance indicators of the 89 business sectors. Hence, special attention has to be paid to identifying and analysing specific factors and assessing the causal link. When established, the set of such factors provides a framework for building of a model to forecast business sector financial indicators.

  15. Time variations of fields in superconducting magnets and their effects on accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Herrup, D.A.; Syphers, M.J.; Johnson, D.E.; Johnson, R.P.; Tollestrup, A.V.; Hanft, R.W.; Brown, B.C.; Lamm, M.J.; Kuchnir, M.; McInturff, A.D.

    1988-08-22

    A report on the time dependence of magnetic fields in the superconducting magnets of the Fermilab Tevatron has been published. A field variation of order 1 gauss at the aperture radius is observed. Studies on both full sized Tevatron, dipoles and prototype magnets have been used to elucidate these effects. Explanations based on eddy currents in the coil matrix or on flux creep in the superconducting filaments are explored with these tests. Measurement results and techniques for controlling the effect based on new laboratory tests and the latest accelerator operation are presented. 9 refs., 4 figs.

  16. Time variations of fields in superconducting magnets and their effects on accelerators

    International Nuclear Information System (INIS)

    Herrup, D.A.; Syphers, M.J.; Johnson, D.E.

    1988-01-01

    A report on the time dependence of magnetic fields in the superconducting magnets of the Fermilab Tevatron has been published. A field variation of order 1 gauss at the aperture radius is observed. Studies on both full sized Tevatron, dipoles and prototype magnets have been used to elucidate these effects. Explanations based on eddy currents in the coil matrix or on flux creep in the superconducting filaments are explored with these tests. Measurement results and techniques for controlling the effect based on new laboratory tests and the latest accelerator operation are presented. 9 refs., 4 figs

  17. Interpretation of engine cycle-to-cycle variation by chaotic time series analysis

    Energy Technology Data Exchange (ETDEWEB)

    Daw, C.S.; Kahl, W.K.

    1990-01-01

    In this paper we summarize preliminary results from applying a new mathematical technique -- chaotic time series analysis (CTSA) -- to cylinder pressure data from a spark-ignition (SI) four-stroke engine fueled with both methanol and iso-octane. Our objective is to look for the presence of deterministic chaos'' dynamics in peak pressure variations and to investigate the potential usefulness of CTSA as a diagnostic tool. Our results suggest that sequential peak cylinder pressures exhibit some characteristic features of deterministic chaos and that CTSA can extract previously unrecognized information from such data. 18 refs., 11 figs., 2 tabs.

  18. Time variation of the cosmological redshift in Dicke-Brans-Jordan cosmologies

    International Nuclear Information System (INIS)

    Ruediger, R.

    1982-01-01

    In this paper the time variation z of the cosmological redshift z is discussed for Dicke-Brans-Jordan (DBJ) cosmologies. We determine the general z-z relation in the functional form zH -1 0 = F(z; q 0 , sigma 0 ,xi 0 , ω) for small values of z, where all the symbols have their conventional meanings. For certain combinations of cosmological parameters, which are within the present observational limitations, the DBJ terms in the function F can dominate the general relativistic terms. Furthermore, zH -1 0 can be positive in DBJ cosmologies in contrast to general relativistic cosmologies with q 0 >0

  19. Fast solution of Cahn–Hilliard variational inequalities using implicit time discretization and finite elements

    KAUST Repository

    Bosch, Jessica

    2014-04-01

    We consider the efficient solution of the Cahn-Hilliard variational inequality using an implicit time discretization, which is formulated as an optimal control problem with pointwise constraints on the control. By applying a semi-smooth Newton method combined with a Moreau-Yosida regularization technique for handling the control constraints we show superlinear convergence in function space. At the heart of this method lies the solution of large and sparse linear systems for which we propose the use of preconditioned Krylov subspace solvers using an effective Schur complement approximation. Numerical results illustrate the competitiveness of this approach. © 2014 Elsevier Inc.

  20. Time Resolved Digital PIV Measurements of Flow Field Cyclic Variation in an Optical IC Engine

    Energy Technology Data Exchange (ETDEWEB)

    Jarvis, S; Justham, T; Clarke, A; Garner, C P; Hargrave, G K; Halliwell, N A [Wolfson School of Mechanical and Manufacturing Engineering, Loughborough University, Loughborough, Leicestershire, LE11 3TU (United Kingdom)

    2006-07-15

    Time resolved digital particle image velocimetry (DPIV) experimental data is presented for the in-cylinder flow field development of a motored four stroke spark ignition (SI) optical internal combustion (IC) engine. A high speed DPIV system was employed to quantify the velocity field development during the intake and compression stroke at an engine speed of 1500 rpm. The results map the spatial and temporal development of the in-cylinder flow field structure allowing comparison between traditional ensemble average and cycle average flow field structures. Conclusions are drawn with respect to engine flow field cyclic variations.

  1. Time Resolved Digital PIV Measurements of Flow Field Cyclic Variation in an Optical IC Engine

    International Nuclear Information System (INIS)

    Jarvis, S; Justham, T; Clarke, A; Garner, C P; Hargrave, G K; Halliwell, N A

    2006-01-01

    Time resolved digital particle image velocimetry (DPIV) experimental data is presented for the in-cylinder flow field development of a motored four stroke spark ignition (SI) optical internal combustion (IC) engine. A high speed DPIV system was employed to quantify the velocity field development during the intake and compression stroke at an engine speed of 1500 rpm. The results map the spatial and temporal development of the in-cylinder flow field structure allowing comparison between traditional ensemble average and cycle average flow field structures. Conclusions are drawn with respect to engine flow field cyclic variations

  2. Time Resolved Digital PIV Measurements of Flow Field Cyclic Variation in an Optical IC Engine

    Science.gov (United States)

    Jarvis, S.; Justham, T.; Clarke, A.; Garner, C. P.; Hargrave, G. K.; Halliwell, N. A.

    2006-07-01

    Time resolved digital particle image velocimetry (DPIV) experimental data is presented for the in-cylinder flow field development of a motored four stroke spark ignition (SI) optical internal combustion (IC) engine. A high speed DPIV system was employed to quantify the velocity field development during the intake and compression stroke at an engine speed of 1500 rpm. The results map the spatial and temporal development of the in-cylinder flow field structure allowing comparison between traditional ensemble average and cycle average flow field structures. Conclusions are drawn with respect to engine flow field cyclic variations.

  3. Storm Time Variation of Radiative Cooling by Nitric Oxide as Observed by TIMED-SABER and GUVI

    Science.gov (United States)

    Bharti, Gaurav; Sunil Krishna, M. V.; Bag, T.; Jain, Puneet

    2018-02-01

    The variation of O/N2 (reference to N2 column density 1017 cm-2) and nitric oxide radiative emission flux exiting the thermosphere have been studied over the Northern Hemisphere during the superstorm event of 7-12 November 2004. The data have been obtained from Global Ultraviolet Imager (GUVI) and Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) on board the National Aeronautics and Space Administration (NASA)'s Thermosphere, Ionosphere, Mesosphere Energetics and Dynamics (TIMED) satellite. The NO radiative flux is observed to show an anti-correlation with O/N2 on a global scale. Both NO radiative flux and O/N2 ratio show equatorward motion with maximum penetration in western longitude sectors. A local variation of O, O2, and N2 densities have been calculated using NRLMSISE-00 model over a midlatitude location (55°N,180°E). On a local scale, model calculated O/O2 and O/N2 ratios are found to follow the observations made by GUVI. The collisional excitation of NO with atomic oxygen is the most dominant process for the total cooling rate. The SABER-retrieved NO cooling rate (CR) at a local site suggests an enhancement during the storm period with the peak emission rate closely correlated to the progression of the storm. The peak emission altitude of NO CR moves upward during the main phase of the storm. The NO abundance has been calculated by using cooling rate and Nitric Oxide Empirical Model (NOEM) model. Both these suggest a vary large (3-15 times) increase in NO density during the storm, which is required to account the changes in NO radiative flux. A similar kind of enhancement in NO abundance is also noticed in Student Nitric Oxide Explorer observations during intense geomagnetic storms.

  4. Menstrual variation of breast volume and T2 relaxation times in cyclical mastalgia

    International Nuclear Information System (INIS)

    Hussain, Zainab; Brooks, Jonathan; Percy, Dave

    2008-01-01

    Purpose: Hormonal activity causes breast volume to change during the menstrual cycle. One possible cause of this volume change is thought to be due to water retention or oedema within the tissues. We used magnetic resonance imaging (MRI) to study the variation in breast volume and 1 H Magnetic Resonance Spectroscopy (MRS) to measure T 2 relaxation times which are known to increase with increasing tissue water content. We hypothesised that an increase in breast volume will elevate T 2 relaxation due to the presence of an increased water content within the breast. T 2 Relaxation time and volume were studied in fifteen control subjects and in a cohort of eight patients with cyclical mastalgia in order to determine whether changes in breast volume and T 2 relaxation times differed in controls and patients during menses, ovulation and premenses. Method: Breast volume was determined by the Cavalieri method in combination with point counting techniques on MR images and T 2 relaxation times of the water and fat in a voxel of breast tissue were obtained using 1 H Magnetic Resonance Spectroscopy (MRS). Results: Statistical analysis (ANOVA) demonstrated highly significant differences in breast volume between the three stages of the cycle (p 2 of fat or water did not depend on stage of cycle. T-tests demonstrated no significant differences in T 2 of water or fat between patient and control groups. The average T 2 relaxation time of water was lowest in the patient and control groups during ovulation and highest in the patient group during premenses. Conclusion: We have performed the first combined volumetric and spectroscopic study of women with cyclical mastalgia and demonstrated that the global changes in volumes and T 2 were not significantly different from normal menstrual variations

  5. Frequency variations of gravity waves interacting with a time-varying tide

    Energy Technology Data Exchange (ETDEWEB)

    Huang, C.M.; Zhang, S.D.; Yi, F.; Huang, K.M.; Gan, Q.; Gong, Y. [Wuhan Univ., Hubei (China). School of Electronic Information; Ministry of Education, Wuhan, Hubei (China). Key Lab. of Geospace Environment and Geodesy; State Observatory for Atmospheric Remote Sensing, Wuhan, Hubei (China); Zhang, Y.H. [Nanjing Univ. of Information Science and Technology (China). College of Hydrometeorolgy

    2013-11-01

    Using a nonlinear, 2-D time-dependent numerical model, we simulate the propagation of gravity waves (GWs) in a time-varying tide. Our simulations show that when aGW packet propagates in a time-varying tidal-wind environment, not only its intrinsic frequency but also its ground-based frequency would change significantly. The tidal horizontal-wind acceleration dominates the GW frequency variation. Positive (negative) accelerations induce frequency increases (decreases) with time. More interestingly, tidal-wind acceleration near the critical layers always causes the GW frequency to increase, which may partially explain the observations that high-frequency GW components are more dominant in the middle and upper atmosphere than in the lower atmosphere. The combination of the increased ground-based frequency of propagating GWs in a time-varying tidal-wind field and the transient nature of the critical layer induced by a time-varying tidal zonal wind creates favorable conditions for GWs to penetrate their originally expected critical layers. Consequently, GWs have an impact on the background atmosphere at much higher altitudes than expected, which indicates that the dynamical effects of tidal-GW interactions are more complicated than usually taken into account by GW parameterizations in global models.

  6. Characterization of indoor aerosol temporal variations for the real-time management of indoor air quality

    Science.gov (United States)

    Ciuzas, Darius; Prasauskas, Tadas; Krugly, Edvinas; Sidaraviciute, Ruta; Jurelionis, Andrius; Seduikyte, Lina; Kauneliene, Violeta; Wierzbicka, Aneta; Martuzevicius, Dainius

    2015-10-01

    The study presents the characterization of dynamic patterns of indoor particulate matter (PM) during various pollution episodes for real-time IAQ management. The variation of PM concentrations was assessed for 20 indoor activities, including cooking related sources, other thermal sources, personal care and household products. The pollution episodes were modelled in full-scale test chamber representing a standard usual living room with the forced ventilation of 0.5 h-1. In most of the pollution episodes, the maximum concentration of particles in exhaust air was reached within a few minutes. The most rapid increase in particle concentration was during thermal source episodes such as candle, cigarette, incense stick burning and cooking related sources, while the slowest decay of concentrations was associated with sources, emitting ultrafine particle precursors, such as furniture polisher spraying, floor wet mopping with detergent etc. Placement of the particle sensors in the ventilation exhaust vs. in the centre of the ceiling yielded comparable results for both measured maximum concentrations and temporal variations, indicating that both locations were suitable for the placement of sensors for the management of IAQ. The obtained data provides information that may be utilized considering measurements of aerosol particles as indicators for the real-time management of IAQ.

  7. Study on the Variation of Groundwater Level under Time-varying Recharge

    Science.gov (United States)

    Wu, Ming-Chang; Hsieh, Ping-Cheng

    2017-04-01

    The slopes of the suburbs come to important areas by focusing on the work of soil and water conservation in recent years. The water table inside the aquifer is affected by rainfall, geology and topography, which will result in the change of groundwater discharge and water level. Currently, the way to obtain water table information is to set up the observation wells; however, owing to that the cost of equipment and the wells excavated is too expensive, we develop a mathematical model instead, which might help us to simulate the groundwater level variation. In this study, we will discuss the groundwater level change in a sloping unconfined aquifer with impermeable bottom under time-varying rainfall events. Referring to Child (1971), we employ the Boussinesq equation as the governing equation, and apply the General Integral Transforms Method (GITM) to analyzing the groundwater level after linearizing the Boussinesq equation. After comparing the solution with Verhoest & Troch (2000) and Bansal & Das (2010), we get satisfactory results. To sum up, we have presented an alternative approach to solve the linearized Boussinesq equation for the response of groundwater level in a sloping unconfined aquifer. The present analytical results combine the effect of bottom slope and the time-varying recharge pattern on the water table fluctuations. Owing to the limitation and difficulty of measuring the groundwater level directly, we develop such a mathematical model that we can predict or simulate the variation of groundwater level affected by any rainfall events in advance.

  8. Nonlinear forecasts of ƒoF2: variation of model predictive accuracy over time

    Directory of Open Access Journals (Sweden)

    P. S. Cannon

    Full Text Available Space weather effects can strongly influence high-frequency (HF communications by changing the ionospheric environment through which the radio waves propagate. Since many systems utilize HF communications, the ability to make real-time assessments of propagation conditions is an important part of space weather monitoring systems. In this paper, we present new techniques for measuring high-latitude HF communications link parameters using data from SuperDARN radars. These techniques use ground-scatter returns to define the variation in skip distance with frequency. From these data, the maximum usable frequency (MUF as a function of range is determined and ionospheric critical frequencies are estimated. These calculations are made in near-real-time and the results are made available on the World Wide Web. F-region critical frequencies calculated using this method show good agreement with ionosonde data.Key words. Ionosphere (active experiments; instruments and techniques – Radio science (ionospheric propagation

  9. Nonlinear forecasts of ƒoF2: variation of model predictive accuracy over time

    Directory of Open Access Journals (Sweden)

    A. H. Y. Chan

    2002-07-01

    Full Text Available Space weather effects can strongly influence high-frequency (HF communications by changing the ionospheric environment through which the radio waves propagate. Since many systems utilize HF communications, the ability to make real-time assessments of propagation conditions is an important part of space weather monitoring systems. In this paper, we present new techniques for measuring high-latitude HF communications link parameters using data from SuperDARN radars. These techniques use ground-scatter returns to define the variation in skip distance with frequency. From these data, the maximum usable frequency (MUF as a function of range is determined and ionospheric critical frequencies are estimated. These calculations are made in near-real-time and the results are made available on the World Wide Web. F-region critical frequencies calculated using this method show good agreement with ionosonde data.Key words. Ionosphere (active experiments; instruments and techniques – Radio science (ionospheric propagation

  10. Relaxation time of normal breast tissues. Changes with age and variations during the menstrual cycle

    International Nuclear Information System (INIS)

    Dean, K.I.; Majurin, M.L.; Komu, M.

    1994-01-01

    The influence of age on the relaxation times of normal breast parenchyma and its surrounding fatty tissue were evaluated, and the variations during a normal menstrual cycle were analyzed using an ultra low field 0.02 T imager. Thirty-nine healthy volunteers aged 21 to 59 years were examined to determine T1 and T2 relaxation times, and 8 of these volunteers were studied once weekly during one menstrual cycle. The only significant trend was an increase in the T2 of breast parenchyma with increasing age. During the menstrual cycle there was a slight but insignificant (p=0.10) increase in T1 of the breast parenchyma values during the latter half of the menstrual cycle, and a corresponding increase in T2 values between the 2nd and 3rd weeks of the menstrual cycle, which was significant. (orig.)

  11. Relaxation time of normal breast tissues. Changes with age and variations during the menstrual cycle

    Energy Technology Data Exchange (ETDEWEB)

    Dean, K.I. (University Central Hospital, Turku (Finland). Dept. of Diagnostic Radiology); Majurin, M.L. (University Central Hospital, Turku (Finland). Dept. of Diagnostic Radiology); Komu, M. (University Central Hospital, Turku (Finland). Dept. of Diagnostic Radiology)

    1994-05-01

    The influence of age on the relaxation times of normal breast parenchyma and its surrounding fatty tissue were evaluated, and the variations during a normal menstrual cycle were analyzed using an ultra low field 0.02 T imager. Thirty-nine healthy volunteers aged 21 to 59 years were examined to determine T1 and T2 relaxation times, and 8 of these volunteers were studied once weekly during one menstrual cycle. The only significant trend was an increase in the T2 of breast parenchyma with increasing age. During the menstrual cycle there was a slight but insignificant (p=0.10) increase in T1 of the breast parenchyma values during the latter half of the menstrual cycle, and a corresponding increase in T2 values between the 2nd and 3rd weeks of the menstrual cycle, which was significant. (orig.).

  12. Dynamic linear modeling of monthly electricity demand in Japan: Time variation of electricity conservation effect.

    Science.gov (United States)

    Honjo, Keita; Shiraki, Hiroto; Ashina, Shuichi

    2018-01-01

    After the severe nuclear disaster in Fukushima, which was triggered by the Great East Japan earthquake in March 2011, nuclear power plants in Japan were temporarily shut down for mandatory inspections. To prevent large-scale blackouts, the Japanese government requested companies and households to reduce electricity consumption in summer and winter. It is reported that the domestic electricity demand had a structural decrease because of the electricity conservation effect (ECE). However, quantitative analysis of the ECE is not sufficient, and especially time variation of the ECE remains unclear. Understanding the ECE is important because Japan's NDC (nationally determined contribution) assumes the reduction of CO2 emissions through aggressive energy conservation. In this study, we develop a time series model of monthly electricity demand in Japan and estimate time variation of the ECE. Moreover, we evaluate the impact of electricity conservation on CO2 emissions from power plants. The dynamic linear model is used to separate the ECE from the effects of other irrelevant factors (e.g. air temperature, economic production, and electricity price). Our result clearly shows that consumers' electricity conservation behavior after the earthquake was not temporary but became established as a habit. Between March 2011 and March 2016, the ECE on industrial electricity demand ranged from 3.9% to 5.4%, and the ECE on residential electricity demand ranged from 1.6% to 7.6%. The ECE on the total electricity demand was estimated at 3.2%-6.0%. We found a seasonal pattern that the residential ECE in summer is higher than that in winter. The emissions increase from the shutdown of nuclear power plants was mitigated by electricity conservation. The emissions reduction effect was estimated at 0.82 MtCO2-2.26 MtCO2 (-4.5% on average compared to the zero-ECE case). The time-varying ECE is necessary for predicting Japan's electricity demand and CO2 emissions after the earthquake.

  13. Time-Dependent Variations in Structure of Sheep Wool Irradiated by Electron Beam

    Directory of Open Access Journals (Sweden)

    Zuzana Hanzlíková

    2017-01-01

    Full Text Available Wool scoured in tap water with no special degreasing and containing a balanced humidity responding to usual laboratory conditions was irradiated by accelerated electron beam in the range of 0–350 kGy dose. Time variations of the wool structure were measured using FTIR, Raman, and EPR spectroscopy. The aim was to determine whether preexposure treatment of the wool, as well as postexposure time, affects the properties of the irradiated wool. Reactive products such as S-sulfonate, cystine monoxide, cystine dioxide, cysteic acid, disulphides, and carboxylates displayed a considerable fluctuation in quantity depending on both the absorbed dose and time. Mutual transformations of S-oxidized products into cysteic acid appeared to be faster than those in dry and degreased wool assuming that the present humidity inside the fibres is decisive as an oxygen source. EPR results indicated a longer lifetime for free radicals induced by lower doses compared with the radicals generated by higher ones. The pattern of the conformational composition of the secondary structure (α-helix, β-sheet, random, and residual conformations also showed a large variability depending on absorbed dose as well as postexposure time. The most stable secondary structure was observed in nonirradiated wool but even this showed a small but observable change after a longer time, too.

  14. Measuring Chemotherapy Appointment Duration and Variation Using Real-Time Location Systems.

    Science.gov (United States)

    Barysauskas, Constance M; Hudgins, Gina; Gill, Katie Kupferberg; Camuso, Kristen M; Bagley, Janet; Rozanski, Sheila; Kadish, Sarah

    Clinical schedules drive resource utilization, cost, and patient wait time. Accurate appointment duration allocation ensures appropriate staffing ratios to daily caseloads and maximizes scarce resources. Dana-Farber Cancer Institute (DFCI) infusion appointment duration is adjusted by regimen using a consensus method of experts including pharmacists, nurses, and administrators. Using real-time location system (RTLS), we examined the accuracy of observed appointment duration compared with the scheduled duration. Appointment duration was calculated using RTLS at DFCI between August 1, 2013, and September 30, 2013. Duration was defined as the total time a patient occupied an infusion chair. The top 10 administered infusion regimens were investigated (n = 805). Median observed appointment durations were statistically different than the scheduled durations. Appointment durations were shorter than scheduled 98% (C), 95% (I), and 75% (F) of the time and longer than scheduled 77% (A) and 76% (G) of the time. Fifty-six percent of the longer than scheduled (A) appointments were at least 30 minute longer. RTLS provides reliable and unbiased data to improve schedule accuracy. Replacing consensus with system-based data may improve clinic flow, relieve staff stress, and increase patient satisfaction. Further investigation is warranted to elucidate factors that impact variation in appointment duration.

  15. Long-time observation of annual variation of Taiwan Strait upwelling in summer season

    Science.gov (United States)

    Tang, D. L.; Kawamura, H.; Guan, L.

    The Taiwan Strait is between Taiwan Island and Mainland China, where several upwelling zones are well known for good fishing grounds. Earlier studies in the strait have been conducted on detecting upwelling by ship measurements with short-term cruises, but long-term variations of upwelling in this region are not understood. The present paper examines satellite images for a long-time observation of two major upwelling zones in the Taiwan Strait: Taiwan Bank Upwelling (TBU) and Dongshan Upwelling (DSU). Sea surface temperature (SST) and chlorophyll a (Chl-a) images have been analyzed for summer months (June, July, and August) from 1980 to 2002. Results reveal annual variation of two upwelling zones. These two upwelling zones occur every year characterized with distinct low water temperature and high Chl-a concentrations. During the period from 1989 to 1998, SST is found to be 1.15 °C lower in TBU, and 1.42 °C lower in the DSU than the Taiwan Strait. The size of DSU has been found to be larger during summer of 1989, 1990, 1993 and 1995; TBU has been found to be weak during summer of 1994 and 1997. Ocean color images obtained from CZCS, OCI, and SeaWiFS also show high Chl-a concentrations (0.8-2.5 mg m-3) in two upwelling zones, which coincide with low SST in terms of location, shape, and time. These high Chl-a concentrations in TBU and DSU may be related to upwelling waters that bring nutrients from bottom to surface. The present results also show the potential of using satellite data for monitoring of ocean environment for long time period.

  16. A Discrete-Time Model for Daily S&P500 Returns and Realized Variations: Jumps and Leverage Effects

    DEFF Research Database (Denmark)

    Bollerslev, Tim; Kretschmer, Uta; Pigorsch, Christian

    We develop an empirically highly accurate discrete-time daily stochastic volatility model that explicitly distinguishes between the jump and continuoustime components of price movements using nonparametric realized variation and Bipower variation measures constructed from high-frequency intraday...... dependencies inherent in the high-frequency intraday data....

  17. Variation in timing of ossification affects inferred heterochrony of cranial bones in Lissamphibia.

    Science.gov (United States)

    Sheil, Christopher A; Jorgensen, Michael; Tulenko, Frank; Harrington, Sean

    2014-09-01

    The evolutionary origin of Lissamphibia likely involved heterochrony, as demonstrated by the biphasic lifestyles of most extant orders, differences between Anura (with tadpole-to-froglet metamorphosis) and Urodela (which lack strongly defined metamorphosis), and the appearance of direct development among separate lineages of frogs. Patterns in the timing of appearance of skeletal elements (i.e., ossification sequence data) represent a possible source of information for understanding the origin of Lissamphibia, and with the advent of analytical methods to directly optimize these data onto known phylogenies, there has been a renewed interest in assessing the role of changes in these developmental events. However, little attention has been given to the potential impact of variation in ossification sequence data--this is particularly surprising given that different criteria for collecting these data have been employed. Herein, new and previously published ossification data are compiled and all pairs of data for same-species comparisons are selected. Analyses are run to assess the impact of using data that were collected by different methodologies: (1) wild- versus lab-raised animals; (2) different criteria for recognizing timing of ossification; and (3) randomly selecting ossification sequences for species from which multiple studies have been published, but for which the data were collected by different criteria. Parsimov-based genetic inference is utilized to map ossification sequence data onto an existing phylogeny to reconstruct ancestral sequences of ossification and infer instances of heterochrony. All analyses succeeded in optimizing sequence data on internal nodes and instances of heterochrony were identified. However, among all analyses little congruence was found in reconstructed ancestral sequences or among inferred instances of heterochrony. These results indicate a high degree of variation in timing of ossification, and suggest a cautionary note about use

  18. Time variation in European carbon pass-through rates in electricity futures prices

    International Nuclear Information System (INIS)

    Huisman, Ronald; Kiliç, Mehtap

    2015-01-01

    The European Union Emissions Trading Scheme is a means to price emission allowances. Electricity market prices should reflect these market prices of emission allowances as they are a cost factor for power producers. The pass-through rate is the fraction of the emission allowance price that is passed through to electricity market prices. It is often measured and presented as an average or a fixed estimate over some time period. However, we expect that the pass-through rates should actually vary over time as electricity supply curves reflect the marginal costs of different producers that differ in emission intensity. We apply a Kalman Filter approach to observe pass-through rates in Germany and U.K. and find strong support for time varying instead of fixed pass-through rates. Although policy makers are interested in the impact of a policy on average, our results indicate that one needs to be careful with the time-frame over which pass-through rates are measured for policy evaluation, as an incorrect chosen evaluation period could cause an under- or overestimation of the pass-through rate. In addition, our model helps to provide policy makers with insight in the development of pass-through rates when market circumstances change with respect to power production. - Highlights: • We analyse the time-variation of the emission pass-through rate in power prices. • We examine historical futures prices for Germany and the U.K. • We test the hypothesis by using the Kalman Filter methodology. • Strong support is found that pass-through rates vary over time. • The chosen time-frame for pass-through rates is important for policy evaluation.

  19. The Influence of Variation in Time and HCl Concentration to the Glucose Produced from Kepok Banana

    Science.gov (United States)

    Widodo M, Rohman; Noviyanto, Denny; RM, Faisal

    2016-01-01

    Kepok banana (Musa paradisiaca) is a plant that has many advantagesfrom its fruit, stems, leaves, flowers and cob. However, we just tend to take benefit from the fruit. We grow and harvest the fruit without taking advantages from other parts. So they would be a waste or detrimental to animal nest if not used. The idea to take the benefit from the banana crop yields, especially cob is rarely explored. This study is an introduction to the use of banana weevil especially from the glucose it contains. This study uses current methods of hydrolysis using HCl as a catalyst with the concentration variation of 0.4 N, 0.6 N and 0.8 N and hydrolysis times variation of 20 minutes, 25 minutes and 30 minutes. The stages in the hydrolysis include preparation of materials, the process of hydrolysis and analysis of test results using Fehling and titrate with standard glucose solution. HCl is used as a catalyst because it is cheaper than the enzyme that has the same function. NaOH 60% is used for neutralizing the pH of the filtrate result of hydrolysis. From the results of analysis, known thatthe biggest yield of glucose is at concentration 0.8 N and at 30 minutes reaction, it contains 6.25 gram glucose / 20 gram dry sampel, and the convertion is 27.22% at 20 gram dry sampel.

  20. Polyglutamine variation in a flowering time protein correlates with island age in a Hawaiian plant radiation

    Directory of Open Access Journals (Sweden)

    Laakkonen Liisa

    2007-07-01

    Full Text Available Abstract Background A controversial topic in evolutionary developmental biology is whether morphological diversification in natural populations can be driven by expansions and contractions of amino acid repeats in proteins. To promote adaptation, selection on protein length variation must overcome deleterious effects of multiple correlated traits (pleiotropy. Thus far, systems that demonstrate this capacity include only ancient or artificial morphological diversifications. The Hawaiian Islands, with their linear geological sequence, present a unique environment to study recent, natural radiations. We have focused our research on the Hawaiian endemic mints (Lamiaceae, a large and diverse lineage with paradoxically low genetic variation, in order to test whether a direct relationship between coding-sequence repeat diversity and morphological change can be observed in an actively evolving system. Results Here we show that in the Hawaiian mints, extensive polyglutamine (CAG codon repeat polymorphism within a homolog of the pleiotropic flowering time protein and abscisic acid receptor FCA tracks the natural environmental cline of the island chain, consequent with island age, across a period of 5 million years. CAG expansions, perhaps following their natural tendency to elongate, are more frequent in colonists of recently-formed, nutrient-rich islands than in their forebears on older, nutrient-poor islands. Values for several quantitative morphological variables related to reproductive investment, known from Arabidopsis fca mutant studies, weakly though positively correlate with increasing glutamine tract length. Together with protein modeling of FCA, which indicates that longer polyglutamine tracts could induce suboptimally mobile functional domains, we suggest that CAG expansions may form slightly deleterious alleles (with respect to protein function that become fixed in founder populations. Conclusion In the Hawaiian mint FCA system, we infer that

  1. Variation in Patients' Travel Times among Imaging Examination Types at a Large Academic Health System.

    Science.gov (United States)

    Rosenkrantz, Andrew B; Liang, Yu; Duszak, Richard; Recht, Michael P

    2017-08-01

    Patients' willingness to travel farther distances for certain imaging services may reflect their perceptions of the degree of differentiation of such services. We compare patients' travel times for a range of imaging examinations performed across a large academic health system. We searched the NYU Langone Medical Center Enterprise Data Warehouse to identify 442,990 adult outpatient imaging examinations performed over a recent 3.5-year period. Geocoding software was used to estimate typical driving times from patients' residences to imaging facilities. Variation in travel times was assessed among examination types. The mean expected travel time was 29.2 ± 20.6 minutes, but this varied significantly (p travel times were shortest for ultrasound (26.8 ± 18.9) and longest for positron emission tomography-computed tomography (31.9 ± 21.5). For magnetic resonance imaging, travel times were shortest for musculoskeletal extremity (26.4 ± 19.2) and spine (28.6 ± 21.0) examinations and longest for prostate (35.9 ± 25.6) and breast (32.4 ± 22.3) examinations. For computed tomography, travel times were shortest for a range of screening examinations [colonography (25.5 ± 20.8), coronary artery calcium scoring (26.1 ± 19.2), and lung cancer screening (26.4 ± 14.9)] and longest for angiography (32.0 ± 22.6). For ultrasound, travel times were shortest for aortic aneurysm screening (22.3 ± 18.4) and longest for breast (30.1 ± 19.2) examinations. Overall, men (29.9 ± 21.6) had longer (p travel times than women (27.8 ± 20.3); this difference persisted for each modality individually (p ≤ 0.006). Patients' willingness to travel longer times for certain imaging examination types (particularly breast and prostate imaging) supports the role of specialized services in combating potential commoditization of imaging services. Disparities in travel times by gender warrant further investigation. Copyright

  2. Time Variations of Observed H α Line Profiles and Precipitation Depths of Nonthermal Electrons in a Solar Flare

    Energy Technology Data Exchange (ETDEWEB)

    Falewicz, Robert; Radziszewski, Krzysztof; Rudawy, Paweł; Berlicki, Arkadiusz, E-mail: falewicz@astro.uni.wroc.pl, E-mail: radziszewski@astro.uni.wroc.pl, E-mail: rudawy@astro.uni.wroc.pl, E-mail: berlicki@astro.uni.wroc.pl [Astronomical Institute, University of Wrocław, 51-622 Wrocław, ul. Kopernika 11 (Poland)

    2017-10-01

    We compare time variations of the H α and X-ray emissions observed during the pre-impulsive and impulsive phases of the C1.1-class solar flare on 2013 June 21 with those of plasma parameters and synthesized X-ray emission from a 1D hydrodynamic numerical model of the flare. The numerical model was calculated assuming that the external energy is delivered to the flaring loop by nonthermal electrons (NTEs). The H α spectra and images were obtained using the Multi-channel Subtractive Double Pass spectrograph with a time resolution of 50 ms. The X-ray fluxes and spectra were recorded by RHESSI . Pre-flare geometric and thermodynamic parameters of the model and the delivered energy were estimated using RHESSI data. The time variations of the X-ray light curves in various energy bands and those of the H α intensities and line profiles were well correlated. The timescales of the observed variations agree with the calculated variations of the plasma parameters in the flaring loop footpoints, reflecting the time variations of the vertical extent of the energy deposition layer. Our result shows that the fast time variations of the H α emission of the flaring kernels can be explained by momentary changes of the deposited energy flux and the variations of the penetration depths of the NTEs.

  3. Revisiting the returns-volume relationship: Time variation, alternative measures and the financial crisis

    Science.gov (United States)

    Cook, Steve; Watson, Duncan

    2017-03-01

    Following its introduction in the seminal study of Osborne (1959), a voluminous literature has emerged examining the returns-volume relationship for financial assets. The present paper revisits this relationship in an examination of the FTSE100 which extends the existing literature in two ways. First, alternative daily measures of the FTSE100 index are used to create differing returns and absolute returns series to employ in an examination of returns-volume causality. Second, rolling regression analysis is utilised to explore potential time variation in the returns-volume relationship. The findings obtained depict a hitherto unconsidered complexity in this relationship with the type of returns series considered and financial crisis found to be significant underlying factors. The implications of the newly derived results for both the understanding of the nature of the returns-volume relationship and the development of theories in connection to it are discussed.

  4. Deep CNNs Along the Time Axis With Intermap Pooling for Robustness to Spectral Variations

    Science.gov (United States)

    Lee, Hwaran; Kim, Geonmin; Kim, Ho-Gyeong; Oh, Sang-Hoon; Lee, Soo-Young

    2016-10-01

    Convolutional neural networks (CNNs) with convolutional and pooling operations along the frequency axis have been proposed to attain invariance to frequency shifts of features. However, this is inappropriate with regard to the fact that acoustic features vary in frequency. In this paper, we contend that convolution along the time axis is more effective. We also propose the addition of an intermap pooling (IMP) layer to deep CNNs. In this layer, filters in each group extract common but spectrally variant features, then the layer pools the feature maps of each group. As a result, the proposed IMP CNN can achieve insensitivity to spectral variations characteristic of different speakers and utterances. The effectiveness of the IMP CNN architecture is demonstrated on several LVCSR tasks. Even without speaker adaptation techniques, the architecture achieved a WER of 12.7% on the SWB part of the Hub5'2000 evaluation test set, which is competitive with other state-of-the-art methods.

  5. Variation in the Time of Colonization of Broiler Carcasses by Carrion Flies in Nakhonsawan Province, Thailand.

    Science.gov (United States)

    Moophayak, Kittikhun; Sukontason, Kabkaew L; Ruankham, Watcharapong; Tomberlin, Jeffery K; Bunchu, Nophawan

    2017-09-01

    Carrion flies are the primary insects colonizing vertebrate carrion; however, limited information is available on the variation in the time of colonization (TOC) as related to time of placement (TOP) and time of death (TOD), particularly in Thailand. Three seasonal sets of nine broiler carcasses (euthanized and placed in field within 0.5 h after death) were placed in mesh enclosures within a disturbed deciduous dipterocarp forest at Nakhonsawan Province, upper-central Thailand, for 3 d to determine the colonization time by carrion flies. In total, 21,536 arthropods were collected using traps placed over each carcass. Carrion flies of the family Calliphoridae, Muscidae, and Sarcophagidae predominated (93.42%). Of these, Chrysomya megacephala (F.) (Diptera: Calliphoridae) and Chrysomya rufifacies (Macquart) (Diptera: Calliphoridae) were the dominant species being 36.18% and 35.36%, respectively, across season. These species arrived immediately (5 min) after placement of the carrion in the field during the rainy season, while they were delayed 1-2 h during the dry season. Chrysomya megacephala, C. rufifacies, and Parasarcophaga dux (Thomson) colonized the remains. Time of colonization by C. megacephala and C. rufifacies occurred mostly at ∼1600-1700 hours (10-11 h after placement) for all seasons. In contrast, TOC by P. dux was delayed for 1 d during rainy and dry season. These results mark the first record of carrion fly colonization in this area and also may deserve important information for the further study as they demonstrate time of colonization differs from TOP and most importantly TOD. © Crown copyright 2017.

  6. Menstrual variation of breast volume and T{sub 2} relaxation times in cyclical mastalgia

    Energy Technology Data Exchange (ETDEWEB)

    Hussain, Zainab [Department of Medical Imaging, University of Liverpool, Johnstone Building, Brownlow Hill, P.O. Box 147, Liverpool, Merseyside L69 3GB (United Kingdom); Magnetic Resonance and Image Analysis Research Centre, University of Liverpool, Johnstone Building, Brownlow Hill, P.O. Box 147, Liverpool, Merseyside L69 3GB (United Kingdom)], E-mail: zay@liverpool.ac.uk; Brooks, Jonathan [Magnetic Resonance and Image Analysis Research Centre, University of Liverpool, Johnstone Building, Brownlow Hill, P.O. Box 147, Liverpool, Merseyside L69 3GB (United Kingdom); Department of Human Anatomy and Genetics, University of Oxford, Oxford (United Kingdom); Percy, Dave [Centre for Operational Research and Applied Statistics, University of Salford, Salford, Greater Manchester M5 4WT (United Kingdom)

    2008-02-15

    Purpose: Hormonal activity causes breast volume to change during the menstrual cycle. One possible cause of this volume change is thought to be due to water retention or oedema within the tissues. We used magnetic resonance imaging (MRI) to study the variation in breast volume and {sup 1}H Magnetic Resonance Spectroscopy (MRS) to measure T{sub 2} relaxation times which are known to increase with increasing tissue water content. We hypothesised that an increase in breast volume will elevate T{sub 2} relaxation due to the presence of an increased water content within the breast. T{sub 2} Relaxation time and volume were studied in fifteen control subjects and in a cohort of eight patients with cyclical mastalgia in order to determine whether changes in breast volume and T{sub 2} relaxation times differed in controls and patients during menses, ovulation and premenses. Method: Breast volume was determined by the Cavalieri method in combination with point counting techniques on MR images and T{sub 2} relaxation times of the water and fat in a voxel of breast tissue were obtained using {sup 1}H Magnetic Resonance Spectroscopy (MRS). Results: Statistical analysis (ANOVA) demonstrated highly significant differences in breast volume between the three stages of the cycle (p < 0.0005) with breast volume being greatest premenstrually. Patients did not exhibit an increase in volume premenstrually, significantly above controls. T{sub 2} of fat or water did not depend on stage of cycle. T-tests demonstrated no significant differences in T{sub 2} of water or fat between patient and control groups. The average T{sub 2} relaxation time of water was lowest in the patient and control groups during ovulation and highest in the patient group during premenses. Conclusion: We have performed the first combined volumetric and spectroscopic study of women with cyclical mastalgia and demonstrated that the global changes in volumes and T{sub 2} were not significantly different from normal

  7. Parallel algorithm of real-time infrared image restoration based on total variation theory

    Science.gov (United States)

    Zhu, Ran; Li, Miao; Long, Yunli; Zeng, Yaoyuan; An, Wei

    2015-10-01

    Image restoration is a necessary preprocessing step for infrared remote sensing applications. Traditional methods allow us to remove the noise but penalize too much the gradients corresponding to edges. Image restoration techniques based on variational approaches can solve this over-smoothing problem for the merits of their well-defined mathematical modeling of the restore procedure. The total variation (TV) of infrared image is introduced as a L1 regularization term added to the objective energy functional. It converts the restoration process to an optimization problem of functional involving a fidelity term to the image data plus a regularization term. Infrared image restoration technology with TV-L1 model exploits the remote sensing data obtained sufficiently and preserves information at edges caused by clouds. Numerical implementation algorithm is presented in detail. Analysis indicates that the structure of this algorithm can be easily implemented in parallelization. Therefore a parallel implementation of the TV-L1 filter based on multicore architecture with shared memory is proposed for infrared real-time remote sensing systems. Massive computation of image data is performed in parallel by cooperating threads running simultaneously on multiple cores. Several groups of synthetic infrared image data are used to validate the feasibility and effectiveness of the proposed parallel algorithm. Quantitative analysis of measuring the restored image quality compared to input image is presented. Experiment results show that the TV-L1 filter can restore the varying background image reasonably, and that its performance can achieve the requirement of real-time image processing.

  8. Prezygotic barriers to hybridization in marine broadcast spawners: reproductive timing and mating system variation.

    Directory of Open Access Journals (Sweden)

    Carla A Monteiro

    Full Text Available Sympatric assemblages of congeners with incomplete reproductive barriers offer the opportunity to study the roles that ecological and non-ecological factors play in reproductive isolation. While interspecific asynchrony in gamete release and gametic incompatibility are known prezygotic barriers to hybridization, the role of mating system variation has been emphasized in plants. Reproductive isolation between the sibling brown algal species Fucus spiralis, Fucus guiryi (selfing hermaphrodite and Fucus vesiculosus (dioecious was studied because they form hybrids in parapatry in the rocky intertidal zone, maintain species integrity over a broad geographic range, and have contrasting mating systems. We compared reproductive synchrony (spawning overlap between the three species at several temporal scales (yearly/seasonal, semilunar/tidal, and hourly during single tides. Interspecific patterns of egg release were coincident at seasonal (single peak in spring to early summer to semilunar timescales. Synthesis of available data indicated that spawning is controlled by semidiurnal tidal and daily light-dark cues, and not directly by semilunar cycles. Importantly, interspecific shifts in timing detected at the hourly scale during single tides were consistent with a partial ecological prezygotic hybridization barrier. The species displayed patterns of gamete release consistent with a power law distribution, indicating a high degree of reproductive synchrony, while the hypothesis of weaker selective constraints for synchrony in selfing versus outcrossing species was supported by observed spawning in hermaphrodites over a broader range of tidal phase than in outcrossers. Synchronous gamete release is critical to the success of external fertilization, while high-energy intertidal environments may offer only limited windows of reproductive opportunity. Within these windows, however, subtle variations in reproductive timing have evolved with the potential to

  9. Batch leachate treatment using stirred electrocoagulation reactor with variation of residence time and stirring rate

    Science.gov (United States)

    Sitorus, I. S.; Astono, W.; Iswanto, B.

    2018-01-01

    This study aims to reduce pollutant levels of the leachate by electrocoagulation method using a stirred electrocoagulation reactor as the electrochemical water treatment. The release of active coagulants as metallic ions took place in the anode, while in the cathode, the electrolysis reaction in the form of hydrogen gas dischargeoccurred. The source of wastewater is Waste Water Treatment Plant inlet III of Bantar Gebang, Bekasi. Some parameters were analyzed in this research, i.e., Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD), NH3, NO3 -, NO2 -, N-total, and organic substances as well as the microorganism growth before and after electrocoagulation, with variations of detention time (seconds) of 10, 20, 120, 600 and rapid mixing conditions (rpm) of 60, 100 and 200. The results show that the greater the rapid mixing speed and the detention time of electrolysis, the higher the removal of contaminants in liquid waste. The optimum condition of electrocoagulation was encountered at 200 rpm rapid mixing with 600 seconds of processing time. The removal efficiencies of electrocoagulation method for each parameter are TSS of 46.80%, BOD5 of 71.33%, COD of 73.77%, Pb of 62.5%,and NH3-N of 57.92%,whereas the pH value has been increased from 8.03 to 8.95. The electrocoagulation method can reduce levels of pollutants, complying with the environmental standards.

  10. Time-temperature dependent variations in beta-carotene contents in carrot using different spectrophotometric techniques

    Science.gov (United States)

    Ullah, Rahat; Khan, Saranjam; Shah, Attaullah; Ali, Hina; Bilal, Muhammad

    2018-05-01

    The current study presents time dependent variations in the concentration of beta-carotene in carrot under different storage-temperature conditions using UV–VIS and Raman spectrophotometric techniques. The UV–VIS absorption spectra of beta-carotene extracted from carrot shows three distinct absorption peaks at 442, 467, and 500 nm with maximum absorption at 467 nm. These absorption peaks are very much reproducible and are assigned to β-carotene. Similarly, Raman spectra of carrot samples also confirmed the three main Raman peaks of beta-carotene at shift positions 1003, 1150, and 1515 cm‑1. An overall decrease in beta-carotene content has been observed for time-temperature conditions. These results depict a decrease of about 40% in the content of beta-carotene when carrot samples were stored in a refrigerator (4 °C) for the first 20 d, whereas a decrease of about 25% was observed when carrot samples were stored in a freezer (‑16 °C) for the same period. The objective of this study is to investigate the possible use of Raman spectroscopy and UV–VIS spectroscopy for quick and detailed analysis of changes (degradation) in beta-carotene content associated with time and temperature in storage (frozen foods) in order to promote quality foods for consumers. Future study with a greater focus on the concentration/content of beta-carotene in other fruits/vegetables is also desirable.

  11. Patterns of activity and use of time in rural Bangladesh: class, gender, and seasonal variations.

    Science.gov (United States)

    Zaman, H

    1995-04-01

    Tarapur is a village in the district of Rajshahi, Bangladesh, covering an area of 821.05 acres. 342 households with a total population of 1981 were identified in the village by the 1985 census. The author investigated the use of time during 1984 and 1985 in busy, intermediate, and slack seasons among the village population to examine the variation in time use by gender and social class. Activity patterns were found to vary from one season to another, and also across social classes. The study highlights the need to refine some of the conceptual and methodological issues in the collection of data on women and work. The study also presents useful data on home-based production and market-oriented work. It could be useful to adopt an anthropological approach in order to understand the allocation of time by men and women from the perspective of household production and the local economy and culture. Study findings focus upon the following policy issues: the need for a better understanding and recognition of the significant role of women in field agriculture and postharvest processing, creation of further nontraditional employment and business opportunities for poor women in rural areas, and consciousness-raising and the challenge of cultural barriers affecting women. Rural women, especially those in need of employment and involved in market-oriented production, should be the target of mainstream development activities in future planning.

  12. A search for transit timing variations and orbital decay in WASP-46b

    Science.gov (United States)

    Petrucci, R.; Jofré, E.; Ferrero, L. V.; Cúneo, V.; Saker, L.; Lovos, F.; Gómez, M.; Mauas, P.

    2018-02-01

    We present 12 new transit observations of the exoplanet WASP-46b obtained with the 1.54-m telescope at Estación Astrofísica de Bosque Alegre (EABA, Argentina) and the 0.40-m Horacio Ghielmetti and 2.15-m Jorge Sahade telescopes at Complejo Astronómico El Leoncito (CASLEO, Argentina). We analyse them together with 37 light curves from the literature to re-determine the physical parameters and search for additional planets via transit timing variations (TTVs). We consider the 31 transits with uncertainties in their mid-transit times (e_T0) activity could be affecting the measured mid-transit times. This value of dispersion allows us to rule out the presence of additional bodies with masses larger than 2.3, 4.6, 7 and 9.3 M_{\\oplus} at the first-order mean-motion resonances 2:1, 3:2, 4:3 and 5:4 with the transiting planet, respectively. Despite the 6 yr baseline and a typical light-curve precision of 2 × 10-3, we find that we cannot significantly demonstrate a slow decrease of the orbital period of WASP-46b. We place a lower limit of Q⋆ > 7 × 103 on the tidal quality factor and determine that an additional 6 yr baseline is required to rule out Q⋆ < 105.

  13. NO TIMING VARIATIONS OBSERVED IN THIRD TRANSIT OF SNOW-LINE EXOPLANET KEPLER-421b

    International Nuclear Information System (INIS)

    Dalba, Paul A.; Muirhead, Philip S.

    2016-01-01

    We observed Kepler-421 during the anticipated third transit of the snow-line exoplanet Kepler-421b in order to constrain the existence and extent of transit timing variations (TTVs). Previously, the Kepler spacecraft only observed two transits of Kepler-421b, leaving the planet’s transit ephemeris unconstrained. Our visible light, time-series observations from the 4.3 m Discovery Channel Telescope were designed to capture pre-transit baseline and the partial transit of Kepler-421b, barring significant TTVs. We use the light curves to assess the probabilities of various transit models using both the posterior odds ratio and the Bayesian Information Criterion, and find that a transit model with no TTVs is favored to 3.6 σ confidence. These observations suggest that Kepler-421b is either alone in its system or is only experiencing minor dynamic interactions with an unseen companion. With the Kepler-421b ephemeris constrained, we calculate future transit times and discuss the opportunity to characterize the atmosphere of this cold, long-period exoplanet via transmission spectroscopy. Our investigation emphasizes the difficulties associated with observing long-period exoplanet transits and the consequences that arise from failing to refine transit ephemerides.

  14. Temporal variation of optimal UV exposure time over Korea: risks and benefits of surface UV radiation

    Science.gov (United States)

    Lee, Y. G.; Koo, J. H.

    2015-12-01

    Solar UV radiation in a wavelength range between 280 to 400 nm has both positive and negative influences on human body. Surface UV radiation is the main natural source of vitamin D, providing the promotion of bone and musculoskeletal health and reducing the risk of a number of cancers and other medical conditions. However, overexposure to surface UV radiation is significantly related with the majority of skin cancer, in addition other negative health effects such as sunburn, skin aging, and some forms of eye cataracts. Therefore, it is important to estimate the optimal UV exposure time, representing a balance between reducing negative health effects and maximizing sufficient vitamin D production. Previous studies calculated erythemal UV and vitamin-D UV from the measured and modelled spectral irradiances, respectively, by weighting CIE Erythema and Vitamin D3 generation functions (Kazantzidis et al., 2009; Fioletov et al., 2010). In particular, McKenzie et al. (2009) suggested the algorithm to estimate vitamin-D production UV from erythemal UV (or UV index) and determined the optimum conditions of UV exposure based on skin type Ⅱ according to the Fitzpatrick (1988). Recently, there are various demands for risks and benefits of surface UV radiation on public health over Korea, thus it is necessary to estimate optimal UV exposure time suitable to skin type of East Asians. This study examined the relationship between erythemally weighted UV (UVEry) and vitamin D weighted UV (UVVitD) over Korea during 2004-2012. The temporal variations of the ratio (UVVitD/UVEry) were also analyzed and the ratio as a function of UV index was applied in estimating the optimal UV exposure time. In summer with high surface UV radiation, short exposure time leaded to sufficient vitamin D and erythema and vice versa in winter. Thus, the balancing time in winter was enough to maximize UV benefits and minimize UV risks.

  15. Dynamic linear modeling of monthly electricity demand in Japan: Time variation of electricity conservation effect.

    Directory of Open Access Journals (Sweden)

    Keita Honjo

    Full Text Available After the severe nuclear disaster in Fukushima, which was triggered by the Great East Japan earthquake in March 2011, nuclear power plants in Japan were temporarily shut down for mandatory inspections. To prevent large-scale blackouts, the Japanese government requested companies and households to reduce electricity consumption in summer and winter. It is reported that the domestic electricity demand had a structural decrease because of the electricity conservation effect (ECE. However, quantitative analysis of the ECE is not sufficient, and especially time variation of the ECE remains unclear. Understanding the ECE is important because Japan's NDC (nationally determined contribution assumes the reduction of CO2 emissions through aggressive energy conservation. In this study, we develop a time series model of monthly electricity demand in Japan and estimate time variation of the ECE. Moreover, we evaluate the impact of electricity conservation on CO2 emissions from power plants. The dynamic linear model is used to separate the ECE from the effects of other irrelevant factors (e.g. air temperature, economic production, and electricity price. Our result clearly shows that consumers' electricity conservation behavior after the earthquake was not temporary but became established as a habit. Between March 2011 and March 2016, the ECE on industrial electricity demand ranged from 3.9% to 5.4%, and the ECE on residential electricity demand ranged from 1.6% to 7.6%. The ECE on the total electricity demand was estimated at 3.2%-6.0%. We found a seasonal pattern that the residential ECE in summer is higher than that in winter. The emissions increase from the shutdown of nuclear power plants was mitigated by electricity conservation. The emissions reduction effect was estimated at 0.82 MtCO2-2.26 MtCO2 (-4.5% on average compared to the zero-ECE case. The time-varying ECE is necessary for predicting Japan's electricity demand and CO2 emissions after the

  16. Dynamic linear modeling of monthly electricity demand in Japan: Time variation of electricity conservation effect

    Science.gov (United States)

    Shiraki, Hiroto; Ashina, Shuichi

    2018-01-01

    After the severe nuclear disaster in Fukushima, which was triggered by the Great East Japan earthquake in March 2011, nuclear power plants in Japan were temporarily shut down for mandatory inspections. To prevent large-scale blackouts, the Japanese government requested companies and households to reduce electricity consumption in summer and winter. It is reported that the domestic electricity demand had a structural decrease because of the electricity conservation effect (ECE). However, quantitative analysis of the ECE is not sufficient, and especially time variation of the ECE remains unclear. Understanding the ECE is important because Japan’s NDC (nationally determined contribution) assumes the reduction of CO2 emissions through aggressive energy conservation. In this study, we develop a time series model of monthly electricity demand in Japan and estimate time variation of the ECE. Moreover, we evaluate the impact of electricity conservation on CO2 emissions from power plants. The dynamic linear model is used to separate the ECE from the effects of other irrelevant factors (e.g. air temperature, economic production, and electricity price). Our result clearly shows that consumers’ electricity conservation behavior after the earthquake was not temporary but became established as a habit. Between March 2011 and March 2016, the ECE on industrial electricity demand ranged from 3.9% to 5.4%, and the ECE on residential electricity demand ranged from 1.6% to 7.6%. The ECE on the total electricity demand was estimated at 3.2%–6.0%. We found a seasonal pattern that the residential ECE in summer is higher than that in winter. The emissions increase from the shutdown of nuclear power plants was mitigated by electricity conservation. The emissions reduction effect was estimated at 0.82 MtCO2–2.26 MtCO2 (−4.5% on average compared to the zero-ECE case). The time-varying ECE is necessary for predicting Japan’s electricity demand and CO2 emissions after the

  17. Seasonal variations of aerosol residence time in the lower atmospheric boundary layer

    International Nuclear Information System (INIS)

    Ahmed, A.A.; Mohamed, A.; Ali, A.E.; Barakat, A.; Abd El-Hady, M.; El-Hussein, A.

    2004-01-01

    During a one year period, from Jan. 2002 up to Dec. 2002, approximately 130 air samples were analyzed to determine the atmospheric air activity concentrations of short- and long-lived ( 222 Rn) decay products 214 Pb and 210 Pb. The samples were taken by using a single-filter technique and γ-spectrometry was applied to determine the activity concentrations. A seasonal fluctuation in the concentration of 214 Pb and 210 Pb in surface air was observed. The activity concentrations of both radionuclides were observed to be relatively higher during the winter/autumn season than in spring/summer season. The mean activity concentration of 214 Pb and 210 Pb within the whole year was found to be 1.4±0.27 Bq m -3 and 1.2±0.15 mBq m -3 , respectively. Different 210 Pb: 214 Pb activity ratios during the year varied between 1.78x10 -4 and 1.6x10 -3 with a mean value of 8.9x10 -4 ±7.6x10 -5 . From the ratio between the activity concentrations of the radon decay products 214 Pb and 210 Pb a mean residence time (MRT) of aerosol particles in the atmosphere of about 10.5±0.91 d could be estimated. The seasonal variation pattern shows relatively higher values of MRT in spring/summer season than in winter/autumn season. The MRT data together with relative humidity (RH), air temperature (T) and wind speed (WS), were used for a comprehensive regression analysis of its seasonal variation in the atmospheric air

  18. Phylogenetic heritability of geographic range size in haematophagous ectoparasites: time of divergence and variation among continents.

    Science.gov (United States)

    Krasnov, Boris R; Shenbrot, Georgy I; van der Mescht, Luther; Warburton, Elizabeth M; Khokhlova, Irina S

    2018-04-12

    To understand existence, patterns and mechanisms behind phylogenetic heritability in the geographic range size (GRS) of parasites, we measured phylogenetic signal (PS) in the sizes of both regional (within a region) and continental (within a continent) geographic ranges of fleas in five regions. We asked whether (a) GRS is phylogenetically heritable and (b) the manifestation of PS varies between regions. We also asked whether geographic variation in PS reflects the effects of the environment's spatiotemporal stability (e.g. glaciation disrupting geographic ranges) or is associated with time since divergence (accumulation differences among species over time). Support for the former hypothesis would be indicated by stronger PS in southern than in northern regions, whereas support for the latter hypothesis would be shown by stronger PS in regions with a large proportion of species belonging to the derived lineages than in regions with a large proportion of species belonging to the basal lineages. We detected significant PS in both regional and continental GRSs of fleas from Canada and in continental GRS of fleas from Mongolia. No PS was found in the GRS of fleas from Australia and Southern Africa. Venezuelan fleas demonstrated significant PS in regional GRS only. Local Indicators of Phylogenetic Association detected significant local positive autocorrelations of GRS in some clades even in regions in which PS has not been detected across the entire phylogeny. This was mainly characteristic of younger taxa.

  19. Space-Time Variations in Water Vapor as Observed by the UARS Microwave Limb Sounder

    Science.gov (United States)

    Elson, Lee S.; Read, William G.; Waters, Joe W.; Mote, Philip W.; Kinnersley, Jonathan S.; Harwood, Robert S.

    1996-01-01

    Water vapor in the upper troposphere has a significant impact on the climate system. Difficulties in making accurate global measurements have led to uncertainty in understanding water vapor's coupling to the hydrologic cycle in the lower troposphere and its role in radiative energy balance. The Microwave Limb Sounder (MLS) on the Upper Atmosphere Research Satellite is able to retrieve water vapor concentration in the upper troposphere with good sensitivity and nearly global coverage. An analysis of these preliminary retrievals based on 3 years of observations shows the water vapor distribution to be similar to that measured by other techniques and to model results. The primary MLS water vapor measurements were made in the stratosphere, where this species acts as a conserved tracer under certain conditions. As is the case for the upper troposphere, most of the stratospheric discussion focuses on the time evolution of the zonal mean and zonally varying water vapor. Stratospheric results span a 19-month period and tropospheric results a 36-month period, both beginning in October of 1991. Comparisons with stratospheric model calculations show general agreement, with some differences in the amplitude and phase of long-term variations. At certain times and places, the evolution of water vapor distributions in the lower stratosphere suggests the presence of meridional transport.

  20. Excitation of Earth Rotation Variations "Observed" by Time-Variable Gravity

    Science.gov (United States)

    Chao, Ben F.; Cox, C. M.

    2005-01-01

    Time variable gravity measurements have been made over the past two decades using the space geodetic technique of satellite laser ranging, and more recently by the GRACE satellite mission with improved spatial resolutions. The degree-2 harmonic components of the time-variable gravity contain important information about the Earth s length-of-day and polar motion excitation functions, in a way independent to the traditional "direct" Earth rotation measurements made by, for example, the very-long-baseline interferometry and GPS. In particular, the (degree=2, order= 1) components give the mass term of the polar motion excitation; the (2,O) component, under certain mass conservation conditions, gives the mass term of the length-of-day excitation. Combining these with yet another independent source of angular momentum estimation calculated from global geophysical fluid models (for example the atmospheric angular momentum, in both mass and motion terms), in principle can lead to new insights into the dynamics, particularly the role or the lack thereof of the cores, in the excitation processes of the Earth rotation variations.

  1. Total variation regularization for a backward time-fractional diffusion problem

    International Nuclear Information System (INIS)

    Wang, Liyan; Liu, Jijun

    2013-01-01

    Consider a two-dimensional backward problem for a time-fractional diffusion process, which can be considered as image de-blurring where the blurring process is assumed to be slow diffusion. In order to avoid the over-smoothing effect for object image with edges and to construct a fast reconstruction scheme, the total variation regularizing term and the data residual error in the frequency domain are coupled to construct the cost functional. The well posedness of this optimization problem is studied. The minimizer is sought approximately using the iteration process for a series of optimization problems with Bregman distance as a penalty term. This iteration reconstruction scheme is essentially a new regularizing scheme with coupling parameter in the cost functional and the iteration stopping times as two regularizing parameters. We give the choice strategy for the regularizing parameters in terms of the noise level of measurement data, which yields the optimal error estimate on the iterative solution. The series optimization problems are solved by alternative iteration with explicit exact solution and therefore the amount of computation is much weakened. Numerical implementations are given to support our theoretical analysis on the convergence rate and to show the significant reconstruction improvements. (paper)

  2. Clasp/SJ Observation of Time Variations of Lyman-Alpha Emissions in a Solar Active Region

    Science.gov (United States)

    Ishikawa, S.; Kubo, M.; Katsukawa, Y.; Kano, R.; Narukage, N.; Ishikawa, R.; Bando, T.; Winebarger, A.; Kobayashi, K.; Trujillo Bueno, J.; hide

    2016-01-01

    The Chromospheric Lyman-alpha SpectroPolarimeter (CLASP) is a sounding rocket experiment launched on September 3, 2015 to investigate the solar chromosphere, and the slit-jaw (SJ) optical system took Lya images with the high time cadence of 0.6 s. By the CLASP/SJ observation, many time variations in the solar chromosphere with the time scale of region and investigated the short (regions. As the result, we found the regions. On the other hand, the <30 s time variations had no dependency on the temperature of the loop.

  3. Incorporating Spatio-temporal Phenological Variation in Detecting Exotic Saltcedar Using Landsat Time Series

    Science.gov (United States)

    Diao, C.; Wang, L.

    2017-12-01

    The invasion of exotic species compromises ecosystem functions and causes substantial economic losses at the global scale. Over the past century, non-native saltcedar has expanded into most riparian zones in southwestern United States and posed significant threats to the native biotic communities. Repeated monitoring of saltcedar distribution is essential for conservation agencies to locate highly susceptible areas and develop corresponding control strategies. Throughout the phenological cycle, the leaf senescence stage has been found to be the most crucial in spectrally detecting saltcedar. However, due to climate variability and anthropogenic forcing, the timing of saltcedar leaf senescence may vary over space and time. This spatial and inter-annual variation need to be accommodated to pinpoint the appropriate remotely sensed imagery for saltcedar mapping. The objective of this study was to develop a Landsat-based Multiyear Spectral Angle Clustering (MSAC) model to monitor the inter-annual leaf senescence of exotic saltcedar. At the Landsat scale, the time series analysis of vegetation phenology is usually limited by the temporal resolution of images. The MSAC model can overcome this limit and take advantage of the Landsat images from multiple years to compensate the lack of images in a single year. Results indicated the MSAC model provided a Landsat-based solution to capture the inter-annual leaf senescence of saltcedar. Compared to traditional NDVI-based phenological approaches, the proposed model achieved a more accurate classification results of saltcedar across years. The MSAC model provides unique opportunities to guide the selection of appropriate remotely sensed image for repetitive saltcedar mapping.

  4. The variation of particle gas-borne concentration with time in a gas cooled reactor

    Energy Technology Data Exchange (ETDEWEB)

    Reed, J; Hall, D; Reeks, M W [Central Electricity Generating Board, Berkeley Nuclear Laboratories (United Kingdom)

    1985-07-01

    If volatile fission products are released from fuel during a reactor fault, a significant fraction could become attached to small particles also present in the coolant. In such circumstances the retention of those particles by the reactor circuit will limit the level of gas-borne particle concentration and hence be important in reducing the potential release of fission product activity to the atmosphere. Clearly the retention of particles will be influenced by both the deposition and resuspension of particles from surfaces exposed to the coolant flow. In this paper we consider deposition and resuspension but pay particular attention to the role of resuspension, which in the past has been given little consideration. A recently developed model for the resuspension of small particles by a turbulent flow is outlined. Traditionally, resuspension has been interpreted as a force balance between the aerodynamic removal forces and the surface adhesive forces. In contrast, this new approach embodies an energy balance criterion for particle resuspension. Furthermore, the stochastic nature of this new model has shown that resuspension can be sub-divided into two regimes: (i) initial resuspension (resuspension occurring in times less than a second) which reduces the net deposition of particles to a surface; and (ii) longer term resuspension (resuspension after 1 second) which determines the asymptotic decay of particle gas-borne concentration. It is seen that the asymptotic decay varies almost inversely as the decay time. Force balance models are unsuccessful in accounting for the experimentally observed longer term resuspension. We show that a Volterra integro-differential equation best describes the variation of particle gas-borne concentration with time in a recirculating gas flow such as a gas cooled reactor. It is seen that the longer term resuspension has a major influence in the final decay of particle concentration. (author)

  5. The variation of particle gas-borne concentration with time in a gas cooled reactor

    International Nuclear Information System (INIS)

    Reed, J.; Hall, D.; Reeks, M.W.

    1985-01-01

    If volatile fission products are released from fuel during a reactor fault, a significant fraction could become attached to small particles also present in the coolant. In such circumstances the retention of those particles by the reactor circuit will limit the level of gas-borne particle concentration and hence be important in reducing the potential release of fission product activity to the atmosphere. Clearly the retention of particles will be influenced by both the deposition and resuspension of particles from surfaces exposed to the coolant flow. In this paper we consider deposition and resuspension but pay particular attention to the role of resuspension, which in the past has been given little consideration. A recently developed model for the resuspension of small particles by a turbulent flow is outlined. Traditionally, resuspension has been interpreted as a force balance between the aerodynamic removal forces and the surface adhesive forces. In contrast, this new approach embodies an energy balance criterion for particle resuspension. Furthermore, the stochastic nature of this new model has shown that resuspension can be sub-divided into two regimes: (i) initial resuspension (resuspension occurring in times less than a second) which reduces the net deposition of particles to a surface; and (ii) longer term resuspension (resuspension after 1 second) which determines the asymptotic decay of particle gas-borne concentration. It is seen that the asymptotic decay varies almost inversely as the decay time. Force balance models are unsuccessful in accounting for the experimentally observed longer term resuspension. We show that a Volterra integro-differential equation best describes the variation of particle gas-borne concentration with time in a recirculating gas flow such as a gas cooled reactor. It is seen that the longer term resuspension has a major influence in the final decay of particle concentration. (author)

  6. Gender-related difference, geographical variation and time trend in dietary cadmium intake in Japan

    International Nuclear Information System (INIS)

    Watanabe, T.; Shimbo, S.; Nakatsuka, H.; Koizumi, A.; Higashikawa, K.; Matsuda-Inoguchi, N.; Ikeda, M.

    2004-01-01

    Objectives: The present analysis was initiated to examine possible gender-dependency, geographic variation, and time-dependent changes in dietary intake of cadmium (Cd-F) among general populations in Cd-non-polluted areas in Japan. The role of rice as Cd-F source was also within the scope. Methods: Two databases on Cd and nutritional analyses were re-visited. Both databases were established through collection of 24-h food duplicate portion samples from residents in areas with no known Cd pollution, and contained information on Cd and energy contents in the duplicate portion, together with daily rice consumption, the gender, the age and the location of the residence of each sample donor. The first and the second databases were established through surveys in the years around 1980 on 564 cases and around 1995 on 702 cases, respectively. The two databases were combined for evaluation by multiple regression (MRA) and other analyses. Results: The analyses showed that men tended to take more Cd than women, more clearly so in the 1980 survey than in the 1995 survey. When Cd-F in the 1995 survey was compared with that in the 1980 survey, a substantial decrease was observed, e.g. by 30% (from 37.5 to 26.2 μg/day) in case of women. Cd-F values varied subject to the survey sites in a wide range (e.g. from 20 to 86 μg/day among women in the 1980 survey). In MRA with Cd-F as a dependent variable and survey sites and food intake factors (e.g. rice and energy intakes) as independent variables, the survey sites could explain more than 53% and 35% of total variation in Cd-F in the 1980 and 1995 surveys, respectively. Rice consumption was also influential to Cd-F in both surveys with partial correlation coefficients of 0.36 and 0.21, respectively, the influence being stronger in the 1980 survey than in the 1995 survey. A significant correlation was detected between the 1980 and 1995 survey results both in Cd-F and in rice consumption. Conclusion: Geographic and gender

  7. Effects of detector–source distance and detector bias voltage variations on time resolution of general purpose plastic scintillation detectors

    International Nuclear Information System (INIS)

    Ermis, E.E.; Celiktas, C.

    2012-01-01

    Effects of source-detector distance and the detector bias voltage variations on time resolution of a general purpose plastic scintillation detector such as BC400 were investigated. 133 Ba and 207 Bi calibration sources with and without collimator were used in the present work. Optimum source-detector distance and bias voltage values were determined for the best time resolution by using leading edge timing method. Effect of the collimator usage on time resolution was also investigated. - Highlights: ► Effect of the source-detector distance on time spectra was investigated. ► Effect of the detector bias voltage variations on time spectra was examined. ► Optimum detector–source distance was determined for the best time resolution. ► Optimum detector bias voltage was determined for the best time resolution. ► 133 Ba and 207 Bi radioisotopes were used.

  8. Differences in genetic and environmental variation in adult BMI by sex, age, time period, and region

    DEFF Research Database (Denmark)

    Silventoinen, Karri; Jelenkovic, Aline; Sund, Reijo

    2017-01-01

    Background: Genes and the environment contribute to variation in adult body mass index [BMI (in kg/m(2))], but factors modifying these variance components are poorly understood.Objective: We analyzed genetic and environmental variation in BMI between men and women from young adulthood to old age...

  9. Differences in genetic and environmental variation in adult BMI by sex, age, time period, and region

    DEFF Research Database (Denmark)

    Silventoinen, Karri; Jelenkovic, Aline; Sund, Reijo

    2017-01-01

    Background: Genes and the environment contribute to variation in adult body mass index [BMI (in kg/m(2))], but factors modifying these variance components are poorly understood. Objective: We analyzed genetic and environmental variation in BMI between men and women from young adulthood to old age...

  10. Time evolution of coupled-bunch modes from beta function variation in storage rings

    Directory of Open Access Journals (Sweden)

    Kai Meng Hock

    2007-08-01

    Full Text Available We present an analytical and numerical study of the equations of motion for bunches coupled by transverse wakefields. We base our study on a recent lattice design for the damping rings in the baseline configuration of the International Linear Collider. Using the macroparticle model, and assuming resistive wall wakefield coupling, we present numerical results on the time evolution of the multibunch modes. Decay modes display growth after initial decay, and mode amplitudes exhibit high-frequency oscillations. These phenomena are not expected if the beta function is assumed to have a constant, averaged value. We show analytically that they can come from coupling between modes caused by variation of the beta function in a real lattice. The effect is shown to be comparable to the effect of a nonuniform fill pattern and significantly larger than that of the higher-order mode wakefield localized in the rf cavities. Turning to the case of constant beta function, we develop a more complete treatment of the equations of motion. We derive general formulas for the bunch trajectories, and show that such formulas can only be valid in the limit of small wakefield coupling.

  11. Incidence, time trends and regional variation of childhood leukaemia in Germany and Europe

    International Nuclear Information System (INIS)

    Kaatsch, P.; Mergenthaler, A.

    2008-01-01

    This paper presents data on the German and Europe-wide incidence, time trends and regional variations of childhood leukaemia. Data were provided by the German Childhood Cancer Registry (GCCR), a population-based cancer registry recording all cases of malignant diseases in children under 15 y of age residing in Germany and by the Automated Childhood Cancer Information System (ACCIS) co-ordinated at International Agency for Research on Cancer, Lyon, that combines and evaluates data from several European population-based cancer registries. The incidence of leukaemia (44.0 per million) has increased in Europe as well as in Germany in the last decades (0.6% annually on average). Germany shows no systematic aggregation of regions with low or high cancer incidence in terms of regional clustering. Incidence rates differ between European regions with the highest rates in Northern Europe (48.0 per million) and the lowest rates in Eastern Europe (39.1). Altogether, the results from ACCIS and the GCCR show good agreement. (authors)

  12. Monitoring crop leaf area index time variation from higher resolution remotely sensed data

    International Nuclear Information System (INIS)

    Jiao, Sihong

    2014-01-01

    The leaf area index (LAI) is significant for research on global climate change and ecological environment. China HJ-1 satellite has a revisit cycle of four days, providing CCD data (HJ-1 CCD) with a resolution of 30 m. However, the HJ-1 CCD is incapable of obtaining observations at multiple angles. This is problematic because single angle observations provide insufficient data for determining the LAI. This article proposes a new method for determining LAI using HJ-1 CCD data. The proposed method uses background knowledge of dynamic land surface processes that are extracted from MODerate resolution Imaging Spectroradiometer (MODIS) LAI 1-km resolution data. To process the uncertainties that arise from using two data sources with different spatial resolutions, the proposed method is implemented in a dynamitic Bayesian network scheme by integrating a LAI dynamic process model and a canopy reflectance model with remotely sensed data. Validation results showed that the determination coefficient between estimated and measured LAI was 0.791, and the RMSE was 0.61. This method can enhance the accuracy of the retrieval results while retaining the time series variation characteristics of the vegetation LAI. The results suggest that this algorithm can be widely applied to determining high-resolution leaf area indices using data from China HJ-1 satellite even if information from single angle observations are insufficient for quantitative application

  13. IQ variations across time, race, and nationality: an artifact of differences in literacy skills.

    Science.gov (United States)

    Marks, David F

    2010-06-01

    A body of data on IQ collected over 50 years has revealed that average population IQ varies across time, race, and nationality. An explanation for these differences may be that intelligence test performance requires literacy skills not present in all people to the same extent. In eight analyses, population mean full scale IQ and literacy scores yielded correlations ranging from .79 to .99. In cohort studies, significantly larger improvements in IQ occurred in the lower half of the IQ distribution, affecting the distribution variance and skewness in the predicted manner. In addition, three Verbal subscales on the WAIS show the largest Flynn effect sizes and all four Verbal subscales are among those showing the highest racial IQ differences. This pattern of findings supports the hypothesis that both secular and racial differences in intelligence test scores have an environmental explanation: secular and racial differences in IQ are an artifact of variation in literacy skills. These findings suggest that racial IQ distributions will converge if opportunities are equalized for different population groups to achieve the same high level of literacy skills. Social justice requires more effective implementation of policies and programs designed to eliminate inequities in IQ and literacy.

  14. Time variations of oxygen emission lines and solar wind dynamic parameters in low latitude region

    Science.gov (United States)

    Jamlongkul, P.; Wannawichian, S.; Mkrtichian, D.; Sawangwit, U.; A-thano, N.

    2017-09-01

    Aurora phenomenon is an effect of collision between precipitating particles with gyromotion along Earth’s magnetic field and Earth’s ionospheric atoms or molecules. The particles’ precipitation occurs normally around polar regions. However, some auroral particles can reach lower latitude regions when they are highly energetic. A clear emission from Earth’s aurora is mostly from atomic oxygen. Moreover, the sun’s activities can influence the occurrence of the aurora as well. This work studies time variations of oxygen emission lines and solar wind parameters, simultaneously. The emission’s spectral lines were observed by Medium Resolution Echelle Spectrograph (MRES) along with 2.4 meters diameter telescope at Thai National Observatory, Intanon Mountain, Chiang Mai, Thailand. Oxygen (OI) emission lines were calibrated by Dech-Fits spectra processing program and Dech95 2D image processing program. The correlations between oxygen emission lines and solar wind dynamics will be analyzed. This result could be an evidence of the aurora in low latitude region.

  15. The Sidereal Time Variations of the Lorentz Force and Maximum Attainable Speed of Electrons

    Science.gov (United States)

    Nowak, Gabriel; Wojtsekhowski, Bogdan; Roblin, Yves; Schmookler, Barak

    2016-09-01

    The Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab produces electrons that orbit through a known magnetic system. The electron beam's momentum can be determined through the radius of the beam's orbit. This project compares the beam orbit's radius while travelling in a transverse magnetic field with theoretical predictions from special relativity, which predict a constant beam orbit radius. Variations in the beam orbit's radius are found by comparing the beam's momentum entering and exiting a magnetic arc. Beam position monitors (BPMs) provide the information needed to calculate the beam momentum. Multiple BPM's are included in the analysis and fitted using the method of least squares to decrease statistical uncertainty. Preliminary results from data collected over a 24 hour period show that the relative momentum change was less than 10-4. Further study will be conducted including larger time spans and stricter cuts applied to the BPM data. The data from this analysis will be used in a larger experiment attempting to verify special relativity. While the project is not traditionally nuclear physics, it involves the same technology (the CEBAF accelerator) and the same methods (ROOT) as a nuclear physics experiment. DOE SULI Program.

  16. Novel approach for evaluation of air change rate in naturally ventilated occupied spaces based on metabolic CO2 time variation

    DEFF Research Database (Denmark)

    Melikov, Arsen Krikor; Markov, Detelin G.

    2014-01-01

    IAQ in many residential buildings relies on non-organized natural ventilation. Accurate evaluation of air change rate (ACR) in this situation is difficult due to the nature of the phenomenon - intermittent infiltration-exfiltration periods of mass exchange between the room air and the outdoor air...... at low rate. This paper describes a new approach for ACR evaluation in naturally ventilated occupied spaces. Actual metabolic CO2 time variation record in an interval of time is compared with the computed variation of metabolic CO2 for the same time interval under reference conditions: sleeping occupants...

  17. Alongshore Variation in the Depth of Activation: Implications of Oil Residence Time

    Science.gov (United States)

    Flores, P.; Houser, C.

    2016-12-01

    In 2010 the Deepwater Horizon Oil Spill released approximately 5 million barrels of oil into the Gulf of Mexico just as the nearshore and beach profile were recovering from winter storms. As a consequence, oil mats and tar balls were trapped at depth within the beach and nearshore profile. Excavation of this buried oil during subsequent storms creates the potential for the contamination of adjacent beaches and the degradation of marine ecosystems, which can in turn negatively impact local economies that depend on fisheries and tourism. The potential for oil burial and persistence is dependent on four things: the physio-chemical nature of the oil as it reaches the nearshore environment, the pre-existing morphology of the beach and nearshore, and the evolution of that morphology after the oil is deposited. The depth at which the oil is buried is also dependent on the beach profile during the time of the spill. The purpose of this study is to characterize the alongshore variation in depth of activation on a Deepwater Horizon impacted section of Pensacola Beach, Florida with regards to the implications of oil residence time. Ground- Penetrating Radar (GPR) surveys were conducted along two parallel 1-km transects adjacent to the swash zone and the dune. Additional cross- shore transects were completed every 150 m from the base of the dune to the top of the swash zone. Sediments cores were taken at the crossing points of the alongshore and cross-shore transects, to calibrate the GPR surveys and complete an elemental analysis for the identification of storm layers. The cores were also analyzed for the presence of buried oil.

  18. Timing is everything: international variations in historical sexual partnership concurrency and HIV prevalence.

    Directory of Open Access Journals (Sweden)

    Martina Morris

    Full Text Available BACKGROUND: Higher prevalence of concurrent partnerships is one hypothesis for the severity of the HIV epidemic in the countries of Southern Africa. But measures of the prevalence of concurrency alone do not adequately capture the impact concurrency will have on transmission dynamics. The importance of overlap duration and coital exposure are examined here. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a comparison of data from three studies of sexual behavior carried out in the early 1990s in Uganda, Thailand and the US. Using cumulative concurrency measures, the three countries appeared somewhat similar. Over 50% of both Thai and Ugandan men reported a concurrency within the last three partnerships and over 20% reported a concurrency in the last year, the corresponding rates among US men were nearly 20% for Blacks and Hispanics, and about 10% for other racial/ethnic groups. Concurrency measures that were more sensitive to overlap duration, however, showed large differences. The point prevalence of concurrency on the day of interview was over 10% among Ugandan men compared to 1% for Thai men. Ugandan concurrencies were much longer duration - a median of about two years - than either the Thai (1 day or US concurrencies (4-9 months across all groups, and involved 5-10 times more coital risk exposure with the less frequent partner. In the US, Blacks and Hispanics reported higher prevalence, longer duration and greater coital exposure than Whites, but were lower than Ugandans on nearly every measure. Together, the differences in the prevalence, duration and coital exposure of concurrent partnerships observed align with the HIV prevalence differentials seen in these populations at the time the data were collected. CONCLUSIONS/SIGNIFICANCE: There were substantial variations in the patterns of concurrent partnerships within and between populations. More long-term overlapping partnerships, with regular coital exposure, were found in populations with

  19. Variational data assimilation for the optimized ozone initial state and the short-time forecasting

    Directory of Open Access Journals (Sweden)

    S.-Y. Park

    2016-03-01

    Full Text Available In this study, we apply the four-dimensional variational (4D-Var data assimilation to optimize initial ozone state and to improve the predictability of air quality. The numerical modeling systems used for simulations of atmospheric condition and chemical formation are the Weather Research and Forecasting (WRF model and the Community Multiscale Air Quality (CMAQ model. The study area covers the capital region of South Korea, where the surface measurement sites are relatively evenly distributed. The 4D-Var code previously developed for the CMAQ model is modified to consider background error in matrix form, and various numerical tests are conducted. The results are evaluated with an idealized covariance function for the appropriateness of the modified codes. The background error is then constructed using the NMC method with long-term modeling results, and the characteristics of the spatial correlation scale related to local circulation are analyzed. The background error is applied in the 4D-Var research, and a surface observational assimilation is conducted to optimize the initial concentration of ozone. The statistical results for the 12 h assimilation periods and the 120 observatory sites show a 49.4 % decrease in the root mean squared error (RMSE, and a 59.9 % increase in the index of agreement (IOA. The temporal variation of spatial distribution of the analysis increments indicates that the optimized initial state of ozone concentration is transported to inland areas by the clockwise-rotating local circulation during the assimilation windows. To investigate the predictability of ozone concentration after the assimilation window, a short-time forecasting is carried out. The ratios of the RMSE (root mean squared error with assimilation versus that without assimilation are 8 and 13 % for the +24 and +12 h, respectively. Such a significant improvement in the forecast accuracy is obtained solely by using the optimized initial state. The potential

  20. Compositional variation through time and space in Quaternary magmas of the Chyulu Hills Volcanic Province, Kenya

    Science.gov (United States)

    Widom, E.; Kuentz, D. C.

    2017-12-01

    The Chyulu Hills Volcanic Province, located in southern Kenya >100 km east of the Kenya Rift Valley, has produced mafic, monogenetic eruptions throughout the Quaternary. The volcanic field is considered to be an off-rift manifestation of the East African Rift System, and is known for the significant compositional variability of its eruptive products, which range from nephelinites to basanites, alkali basalts, hawaiites, and orthopyroxene-normative subalkaline basalts [1]. Notably, erupted compositions vary systematically in time and space: Pleistocene volcanism, occurring in the northern Chyulu Hills, was characterized by highly silica-undersaturated magmas, whereas Holocene volcanism, restricted to the southern Chyulu Hills, is less silica-understaturated, consistent with a progressive decrease in depth and increase in degree of melting with time, from north to south [1]. Pronounced negative K anomalies, and enriched trace element and Sr-Nd-Pb isotope signatures have been attributed to a metasomatized, amphibole-bearing, sub-continental lithospheric mantle (SCLM) source [2]. Seismic evidence for a partially molten zone in the SCLM beneath this region [3] may be consistent with such an interpretation. We have analyzed Chyulu Hills samples for Os, Hf and high precision Pb isotopes to further evaluate the magma sources and petrogenetic processes leading to systematic compositional variation in time and space. Sr-Nd-Pb-Hf isotope systematics and strong negative correlations of 206Pb/204Pb and highly incompatible trace element ratios with SiO2 are consistent with the progression from a deeper, HIMU-type source to a shallower, EM-type source. Os isotope systematics, however, suggest a more complex relationship; although all samples are more radiogenic than primitive mantle, the least radiogenic values (similar to primitive OIB) are found in magmas with intermediate SiO2, and those with lower or higher SiO2 are more radiogenic. This may be explained by interaction

  1. Time series of low-degree geopotential coefficients from SLR data: estimation of Earth's figure axis and LOD variations

    Science.gov (United States)

    Luceri, V.; Sciarretta, C.; Bianco, G.

    2012-12-01

    The redistribution of the mass within the earth system induces changes in the Earth's gravity field. In particular, the second-degree geopotential coefficients reflect the behaviour of the Earth's inertia tensor of order 2, describing the main mass variations of our planet impacting the EOPs. Thanks to the long record of accurate and continuous laser ranging observations to Lageos and other geodetic satellites, SLR is the only current space technique capable to monitor the long time variability of the Earth's gravity field with adequate accuracy. Time series of low-degree geopotential coefficients are estimated with our analysis of SLR data (spanning more than 25 years) from several geodetic satellites in order to detect trends and periodic variations related to tidal effects and atmospheric/oceanic mass variations. This study is focused on the variations of the second-degree Stokes coefficients related to the Earth's principal figure axis and oblateness: C21, S21 and C20. On the other hand, surface mass load variations induce excitations in the EOPs that are proportional to the same second-degree coefficients. The time series of direct estimates of low degree geopotential and those derived from the EOP excitation functions are compared and presented together with their time and frequency analysis.

  2. Reconstruction of temporal variations of evapotranspiration using instantaneous estimates at the time of satellite overpass

    Directory of Open Access Journals (Sweden)

    E. Delogu

    2012-08-01

    Full Text Available Evapotranspiration estimates can be derived from remote sensing data and ancillary, mostly meterorological, information. For this purpose, two types of methods are classically used: the first type estimates a potential evapotranspiration rate from vegetation indices, and adjusts this rate according to water availability derived from either a surface temperature index or a first guess obtained from a rough estimate of the water budget, while the second family of methods relies on the link between the surface temperature and the latent heat flux through the surface energy budget. The latter provides an instantaneous estimate at the time of satellite overpass. In order to compute daily evapotranspiration, one needs an extrapolation algorithm. Since no image is acquired during cloudy conditions, these methods can only be applied during clear sky days. In order to derive seasonal evapotranspiration, one needs an interpolation method. Two combined interpolation/extrapolation methods based on the self preservation of evaporative fraction and the stress factor are compared to reconstruct seasonal evapotranspiration from instantaneous measurements acquired in clear sky conditions. Those measurements are taken from instantaneous latent heat flux from 11 datasets in Southern France and Morocco. Results show that both methods have comparable performances with a clear advantage for the evaporative fraction for datasets with several water stress events. Both interpolation algorithms tend to underestimate evapotranspiration due to the energy limiting conditions that prevail during cloudy days. Taking into account the diurnal variations of the evaporative fraction according to an empirical relationship derived from a previous study improved the performance of the extrapolation algorithm and therefore the retrieval of the seasonal evapotranspiration for all but one datasets.

  3. Variations in energy, flux, and brightness of pulsating aurora measured at high time resolution

    Directory of Open Access Journals (Sweden)

    H. Dahlgren

    2017-03-01

    Full Text Available High-resolution multispectral optical and incoherent scatter radar data are used to study the variability of pulsating aurora. Two events have been analysed, and the data combined with electron transport and ion chemistry modelling provide estimates of the energy and energy flux during both the ON and OFF periods of the pulsations. Both the energy and energy flux are found to be reduced during each OFF period compared with the ON period, and the estimates indicate that it is the number flux of foremost higher-energy electrons that is reduced. The energies are found never to drop below a few kilo-electronvolts during the OFF periods for these events. The high-resolution optical data show the occurrence of dips in brightness below the diffuse background level immediately after the ON period has ended. Each dip lasts for about a second, with a reduction in brightness of up to 70 % before the intensity increases to a steady background level again. A different kind of variation is also detected in the OFF period emissions during the second event, where a slower decrease in the background diffuse emission is seen with its brightness minimum just before the ON period, for a series of pulsations. Since the dips in the emission level during OFF are dependent on the switching between ON and OFF, this could indicate a common mechanism for the precipitation during the ON and OFF phases. A statistical analysis of brightness rise, fall, and ON times for the pulsations is also performed. It is found that the pulsations are often asymmetric, with either a slower increase of brightness or a slower fall.

  4. GOM Deepwater Horizon Oil Spill: A Time Series Analysis of Variations in Spilled Hydrocarbons

    Science.gov (United States)

    Palomo, C. M.; Yan, B.

    2013-12-01

    An estimated amount of 210 million gallons of crude oil was released into the Gulf of Mexico (GOM) from April 20th to July 15th 2010 during the Deepwater Horizon oil rig explosion. The spill caused a tremendous financial, ecological, environmental and health impact and continues to affect the GOM today. Variations in hydrocarbons including alkanes, hopanes and poly-cyclic aromatic hydrocarbons (PAHs) can be analyzed to better understand the oil spill and assist in oil source identification. Twenty-one sediment samples*, two tar ball samples and one surface water oil sample were obtained from distinct locations in the GOM and within varying time frames from May to December 2010. Each sample was extracted through the ASE 200 solvent extractor, concentrated down under nitrogen gas, purified through an alumina column, concentrated down again with nitrogen gas and analyzed via GC X GC-TOF MS. Forty-one different hydrocarbons were quantified in each sample. Various hydrocarbon 'fingerprints,' such as parental :alkylate PAH ratios, high molecular weight PAHs: low molecular weight alkane ratios, and carbon preference index were calculated. The initial objective of this project was to identify the relative hydrocarbon contributions of petrogenic sources and combustion sources. Based on the calculated ratios, it is evident that the sediment core taken in October of 2010 was greatly affected by combustion sources. Following the first month of the spill, oil in the gulf was burned in attempts to contain the spill. Combustion related sources have quicker sedimentation rates, and hydrocarbons from a combustion source essentially move into deeper depths quicker than those from a petrogenic source, as was observed in analyses of the October 2010 sediment. *Of the twenty-one sediment samples prepared, nine were quantified for this project.

  5. Time-related variation of volatile contents of Western Ghats volcanic formations, Deccan, India

    Science.gov (United States)

    Marzoli, Andrea; Callegaro, Sara; Baker, Don R.; De Min, Angelo; Renne, Paul R.

    2016-04-01

    Deccan volcanism in India covered more than 1 million square km and reached a maximum thickness of about 3 km, as presently preserved in the Western Ghats volcanic lava piles. Volcanic activity started at about 66.4 Ma (Jawhar formation) and ended at about 65.5 Ma (Mahabaleshwar unit; Renne et al., 2015). Deccan volcanism straddled the Cretaceous-Paleogene boundary (ca. 66.0 Ma) and possibly contributed to the end-Cretaceous mass extinction event through emission of gases such as SO2, CO2, Cl, F that may have triggered global climate changes. Severe pollution by volcanic gases is supported by the high S and Cl contents (up to 1400 and up to 900 ppm, respectively; Self et al., 2008) measured in a few olivine- and plagioclase-hosted melt inclusions from the Jawhar, Neral, and Thakurvadi Formations (early lava flows, ca. 66.3-66.4 ± 0.1 Ma; Renne et al., 2015) and by magmatic S contents (up to 1800 ppm; Callegaro et al., 2014) calculated from S measurements in clinopyroxenes from the Mahabaleshwar unit (ca. 65.5 ± 0.1; Schoene et al., 2015). Here, we present new analyses of S, Cl, and F, obtained by ion-probe and synchrotron light micro-fluorescence analyses on clinopyroxenes and plagioclase phenocrysts from ?al? lava flow units of the Western Ghats. The volatile contents of the host magmas have been calculated from recently published clinopyroxene/basalt partition coefficients. These new data will describe the time-related variation of volatile elements hosted and eventually emitted by Deccan lavas and shed light on their environmental impact. References: Callegaro S. et al. (2014). Geology 42, 895-898. Renne P.R. et al. (2015). Science 350, 76-78. Schoene B. et al. (2015). Science 347, 192-184. Self S. et al. (2008). Science 319, 1654-1657.

  6. Solvent effects in time-dependent self-consistent field methods. II. Variational formulations and analytical gradients

    International Nuclear Information System (INIS)

    Bjorgaard, J. A.; Velizhanin, K. A.; Tretiak, S.

    2015-01-01

    This study describes variational energy expressions and analytical excited state energy gradients for time-dependent self-consistent field methods with polarizable solvent effects. Linear response, vertical excitation, and state-specific solventmodels are examined. Enforcing a variational ground stateenergy expression in the state-specific model is found to reduce it to the vertical excitation model. Variational excited state energy expressions are then provided for the linear response and vertical excitation models and analytical gradients are formulated. Using semiempiricalmodel chemistry, the variational expressions are verified by numerical and analytical differentiation with respect to a static external electric field. Lastly, analytical gradients are further tested by performing microcanonical excited state molecular dynamics with p-nitroaniline

  7. Factors affecting variations in time of the remote effects of depression in the surroundings of Thorez opencast mine

    Energy Technology Data Exchange (ETDEWEB)

    Szilagyi, G.

    1976-01-01

    Dewatering operations have been carried out in Thorez opencast coal mine since 1960 in order to increase the stability of water-bearing strata and to create safe working conditions. Since that time some 0.1 billion cu.m of water have been drained from underground reservoirs, resulting in the formation of a zone of depression 10 to 15 km in radius. Hydrogeological and technical factors affecting the variations in time of the remote effects of depression are analysed. It is found that the decisive influence is the variation in the volume of accumulated water, and to a lesser extent, the effect of the positioning of the drainage system.

  8. Local time variations of the middle atmosphere of Venus: Solar-related structures

    Science.gov (United States)

    Zasova, L.; Khatountsev, I. V.; Ignatiev, N. I.; Moroz, V. I.

    Three-dimensional fields (latitude — altitude — local time) of temperature and aerosol in the upper clouds, obtained from the Venera-15 IR spectrometry data, were studied to search for the solar-related structures. The temperature variation at the isobaric levels vs. solar longitude was presented as a superposition of the cosines with periods of 1, 1/2, 1/3 and 1/4 Venusian days. At low latitudes the diurnal tidal component reaches a maximum above 0.2 mb (92km) level. At high latitudes it dominates at P> 50 mb (68 km) in the cold collar, being roughly twice as much as the semidiurnal one and passing through the maximum of 13 K at 400 mb (57 km). The semidiurnal tidal amplitude exceeds the diurnal one below 90 km (where its maximum locates near 83 km), and also in the upper clouds, above 58 km. At low latitudes the 1/3 days component predominates at 10 - 50 mb (68-76 km). In the upper clouds, where most of the solar energy, absorbed in the middle atmosphere, deposits, all four tidal components, including wavenumbers 3 and 4, have significant amplitudes. A position of the upper boundary of the clouds depends on local time in such a way that the lowest height of the clouds is observed in the morning at all selected latitude ranges. At low latitudes the highest position of the upper boundary of the clouds (at 1218 cm -1) is found at 8 - 9 PM, whereas the lowest one is near the morning terminator. At high latitudes the lowest position of the upper boundary of the clouds shifts towards the dayside being at 10:30 AM at 75° in the cold collar and the highest one shifts to 4 PM. The zonal mean altitude of the upper boundary of the clouds decreases from 69 km at 15° to 59 km at 75°. The diurnal tidal component has the highest amplitude in the cold collar (1.5 km). At low latitudes both amplitudes, diurnal and semidiurnal, reach the values 0.8 - 1 km.

  9. Towards Uniform Accelerometry Analysis: A Standardization Methodology to Minimize Measurement Bias Due to Systematic Accelerometer Wear-Time Variation

    Directory of Open Access Journals (Sweden)

    Tarun R. Katapally, Nazeem Muhajarine

    2014-06-01

    Full Text Available Accelerometers are predominantly used to objectively measure the entire range of activity intensities – sedentary behaviour (SED, light physical activity (LPA and moderate to vigorous physical activity (MVPA. However, studies consistently report results without accounting for systematic accelerometer wear-time variation (within and between participants, jeopardizing the validity of these results. This study describes the development of a standardization methodology to understand and minimize measurement bias due to wear-time variation. Accelerometry is generally conducted over seven consecutive days, with participants' data being commonly considered 'valid' only if wear-time is at least 10 hours/day. However, even within ‘valid’ data, there could be systematic wear-time variation. To explore this variation, accelerometer data of Smart Cities, Healthy Kids study (www.smartcitieshealthykids.com were analyzed descriptively and with repeated measures multivariate analysis of variance (MANOVA. Subsequently, a standardization method was developed, where case-specific observed wear-time is controlled to an analyst specified time period. Next, case-specific accelerometer data are interpolated to this controlled wear-time to produce standardized variables. To understand discrepancies owing to wear-time variation, all analyses were conducted pre- and post-standardization. Descriptive analyses revealed systematic wear-time variation, both between and within participants. Pre- and post-standardized descriptive analyses of SED, LPA and MVPA revealed a persistent and often significant trend of wear-time’s influence on activity. SED was consistently higher on weekdays before standardization; however, this trend was reversed post-standardization. Even though MVPA was significantly higher on weekdays both pre- and post-standardization, the magnitude of this difference decreased post-standardization. Multivariable analyses with standardized SED, LPA and

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

    International Nuclear Information System (INIS)

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

    1978-01-01

    We show that valuable information about both accretion flows and neutron star structure can be obtained from X-ray timing observations of period variations in pulsating sources. Such variations can result from variations in the accretion flow, or from internal torque variations, associated with oscillations of the fluid core or the unpinning of vortices in the inner crust. We develop a statistical description of torque variations in terms of noise processes, indicate how the applicability of such a description may be tested observationally, and show how it may be used to determine from observation both the properties of accretion flows and the internal structure of neutron stars, including the relative inertial moments of the crust and superfluid neutron core, the crust-core coupling time, and the frequencies of any low-frequency internal collective modes. Particular attention is paid to the physical origin of spin-down episodes; it is shown that usyc episodes may result either from external torque reversals or from internal torque variations.With the aid of the statistical description, the response of the star to torque fluctuations is calculated for three stellar models: (i) a completely rigid star; (ii) a two-component star; and (iii) a two-component star with a finite-frequency internal mode, such as the Tkachenko mode of a rotating neutron superfluid. Our calculations show that fluctuating torques could account for the period the period variations and spin-down episodes observed in Her X-1 and Cen X-3, including the large spin-down event observed in the latter source during 1972 September-October. The torque noise strengths inferred from current timing observations using the simple two-component models are shown to be consistent with those to be expected from fluctuations in accretion flows onto magnetic neutron stars

  11. Characterization of Ground Displacement Sources from Variational Bayesian Independent Component Analysis of Space Geodetic Time Series

    Science.gov (United States)

    Gualandi, Adriano; Serpelloni, Enrico; Elina Belardinelli, Maria; Bonafede, Maurizio; Pezzo, Giuseppe; Tolomei, Cristiano

    2015-04-01

    A critical point in the analysis of ground displacement time series, as those measured by modern space geodetic techniques (primarly continuous GPS/GNSS and InSAR) is the development of data driven methods that allow to discern and characterize the different sources that generate the observed displacements. A widely used multivariate statistical technique is the Principal Component Analysis (PCA), which allows to reduce the dimensionality of the data space maintaining most of the variance of the dataset explained. It reproduces the original data using a limited number of Principal Components, but it also shows some deficiencies, since PCA does not perform well in finding the solution to the so-called Blind Source Separation (BSS) problem. The recovering and separation of the different sources that generate the observed ground deformation is a fundamental task in order to provide a physical meaning to the possible different sources. PCA fails in the BSS problem since it looks for a new Euclidean space where the projected data are uncorrelated. Usually, the uncorrelation condition is not strong enough and it has been proven that the BSS problem can be tackled imposing on the components to be independent. The Independent Component Analysis (ICA) is, in fact, another popular technique adopted to approach this problem, and it can be used in all those fields where PCA is also applied. An ICA approach enables us to explain the displacement time series imposing a fewer number of constraints on the model, and to reveal anomalies in the data such as transient deformation signals. However, the independence condition is not easy to impose, and it is often necessary to introduce some approximations. To work around this problem, we use a variational bayesian ICA (vbICA) method, which models the probability density function (pdf) of each source signal using a mix of Gaussian distributions. This technique allows for more flexibility in the description of the pdf of the sources

  12. RADON IN GROUNDWATERS IN THE BAIKAL REGION AND TRANSBAIKALIA: VARIATIONS IN SPACE AND TIME

    Directory of Open Access Journals (Sweden)

    K. Zh. Seminsky

    2016-01-01

    Full Text Available This study aimed to provide a systematic overview of water sources in the Baikal region and Transbaikalia by the content of radon (Q and establish regularities in variations of Q values in space and time.We collected and analyzed our evaluations of Q and the available published Q values for many dozens of water sources in the study area (Fig. 1, and reviewed the monitoring data of eight water sources that belong to the Angarsky fault impact zone in Southern Priangarie (Fig. 5. Radon content in water samples was measured in accordance with the standard procedure using a RRA-01M-03 radiometer (sensitivity of at least 1.4∙10–4 s–1∙Bq–1∙m3; maximum allowable relative error of 30 %.Based on the frequency patterns of Q values measured in the Baikal region and Transbaikalia (Fig. 2 and the analysis of the known classifications of the water sources by radioactivity, we propose a uniform regional classification of groundwaters with respect to 222Rn content (Table 1. In seismically active Baikal region, wherein water sources with Q>185 Bq/l are practically lacking, we distinguish the first three groups with the following Q ranges: Group I – Q≤15 Bq/l, Group II – 16≤Q≤99 Bq/l, and Group III – 100≤Q≤184 Bq/l. Most of the water sources sampled in the Baikal region and Transbaikalia belong to Groups I and II, which allows us to recommend an objectively existing value of 100 Bq/l as the level of intervention in the preparation of drinking water in this region, instead of the limit of 60 Bq/l that is now approved in Russia.In order to identify the special patterns of groundwater sources in the Baikal region and Transbaikalia, which belong to different radioactivity groups, we sampled these sources along the transect from Bayanday to Muhorshibir, across the Baikal rift and other large regional tectonic structures (Fig. 4. On a larger scale, we analysed the radon content variability in the groundwater sources within the zones

  13. Measurement of time series variation of thermal diffusivity of magnetic fluid under magnetic field by forced Rayleigh scattering method

    Energy Technology Data Exchange (ETDEWEB)

    Motozawa, Masaaki, E-mail: motozawa.masaaki@shizuoka.ac.jp [Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu-shi, Shizuoka 432-8561 (Japan); Muraoka, Takashi [Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu-shi, Shizuoka 432-8561 (Japan); Motosuke, Masahiro, E-mail: mot@rs.tus.ac.jp [Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-8585 (Japan); Fukuta, Mitsuhiro, E-mail: fukuta.mitsuhiro@shizuoka.ac.jp [Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu-shi, Shizuoka 432-8561 (Japan)

    2017-04-15

    It can be expected that the thermal diffusivity of a magnetic fluid varies from time to time after applying a magnetic field because of the growth of the inner structure of a magnetic fluid such as chain-like clusters. In this study, time series variation of the thermal diffusivity of a magnetic fluid caused by applying a magnetic field was investigated experimentally. For the measurement of time series variation of thermal diffusivity, we attempted to apply the forced Rayleigh scattering method (FRSM), which has high temporal and high spatial resolution. We set up an optical system for the FRSM and measured the thermal diffusivity. A magnetic field was applied to a magnetic fluid in parallel and perpendicular to the heat flux direction, and the magnetic field intensity was 70 mT. The FRSM was successfully applied to measurement of the time series variation of the magnetic fluid from applying a magnetic field. The results show that a characteristic configuration in the time series variation of the thermal diffusivity of magnetic fluid was obtained in the case of applying a magnetic field parallel to the heat flux direction. In contrast, in the case of applying a magnetic field perpendicular to the heat flux, the thermal diffusivity of the magnetic fluid hardly changed during measurement. - Highlights: • Thermal diffusivity was measured by forced Rayleigh scattering method (FRSM). • FRSM has high temporal and high spatial resolutions for measurement. • We attempted to apply FRSM to magnetic fluid (MF). • Time series variation of thermal diffusivity of MF was successfully measured by FRSM. • Anisotropic thermal diffusivity of magnetic fluid was also successfully confirmed.

  14. Two levels ARIMAX and regression models for forecasting time series data with calendar variation effects

    Science.gov (United States)

    Suhartono, Lee, Muhammad Hisyam; Prastyo, Dedy Dwi

    2015-12-01

    The aim of this research is to develop a calendar variation model for forecasting retail sales data with the Eid ul-Fitr effect. The proposed model is based on two methods, namely two levels ARIMAX and regression methods. Two levels ARIMAX and regression models are built by using ARIMAX for the first level and regression for the second level. Monthly men's jeans and women's trousers sales in a retail company for the period January 2002 to September 2009 are used as case study. In general, two levels of calendar variation model yields two models, namely the first model to reconstruct the sales pattern that already occurred, and the second model to forecast the effect of increasing sales due to Eid ul-Fitr that affected sales at the same and the previous months. The results show that the proposed two level calendar variation model based on ARIMAX and regression methods yields better forecast compared to the seasonal ARIMA model and Neural Networks.

  15. Handheld mechanical nociceptive threshold testing in dairy cows – intra-individual variation, inter-observer agreement and variation over time

    Science.gov (United States)

    Raundal, Peter M; Andersen, Pia H; Toft, Nils; Forkman, Björn; Munksgaard, Lene; Herskin, Mette S

    2014-01-01

    Objective To examine the use of handheld methodology to assess mechanical nociceptive threshold (MNT) on cows kept loose-housed. Study design Prospective randomized partial cross-over experimental study. A one-factor (test day) design was used to evaluate MNT over time. Animals One hundred and fifteen healthy, loose-housed Danish Holstein cattle. Methods We evaluated intra-individual variation, inter-observer agreement and variation over time of MNT using two handheld devices and two stimulation sites. Mechanical, ramped stimulations were performed with an algometer (6.5 mm diameter steel probe, 0–10.0 kgf) or an electronic von Frey device (plastic tip with diameter 0.8 mm, 0–1000 gf). Each cow received 5–6 consecutive stimulations within a 2 × 5 cm skin area on the dorsal or lateral aspect of the left third metatarsus until an avoidance reaction occurred. We investigated the difference in precision [expressed as coefficient of variation (CV)] between the combinations of devices and stimulation sites. The inter-observer agreement and the difference in MNT between test day 1, 3, 7, 10 and 24 were investigated for selected combinations. Data were analysed in mixed models and Bland-Altman as relevant. Results The CVs did not differ [range 0.34–0.52 (p = 0.1)]. Difference between observers (95% limits) was 0.2 kgf (2.8) and 4 gf (369) for the algometer and von Frey device, respectively. Mechanical nociceptive threshold increased from 361 on test day one to 495 gf on test day 24 (p < 0.01). Conclusion and clinical relevance All methods showed a high degree of intra-individual variation, and no combination of device and stimulation site showed superior precision. Mean difference between observers was low, and MNT was not consistent over time. Further development of the methods is required before they can be used in research to investigate possible relations between claw lesions and hyperalgesia. PMID:24734991

  16. Dealing with Variations over Space and Time in Urban Vegetation-Air Quality Assessment

    Science.gov (United States)

    Tan, P. Y.

    2017-12-01

    Studies on role of urban vegetation ameliorate poor air quality frequently encountered in urban areas should aim to answer a pertinent question: what is the net impact of urban vegetation in improving public health directly or indirectly through removal of air pollutants? Answers to this question need to consider that role of urban vegetation in air quality improvement is not just dependent on physical and physiological processes mediated by plants, it is also highly dependent on atmospheric processes. The roles of these two components thus need to be separated. This uncertainty is further complicated by heterogeneity of air quality over spatial scales and fluctuations in air quality over time. Singapore is used to illustrate these complexities. Between seasons, the main external source of atmospheric pollutants is aerosols from biomass burning in plantations in surrounding SE Asian countries, and air quality is highly dependent on wind directions dictated by monsoon systems. When air quality does deteriorate from transboundary pollution, there are also spatial differences within the city, as air pollutant levels differ in different regions. Rainfall from monsoons and other rain-bearing weather systems over Singapore also dictate the relative amounts of wet and dry deposition and the persistence of particulate matter deposited on vegetation surfaces. For locally generated air pollutants, diurnal fluctuations of anthropogenic activities, such as vehicular emissions between peak and non-peak hours, should also lead to fluctuations over the day. Not only does air quality vary from region to region, air quality within a vertical transect in the urban canopy layer also differs due to urban morphology and urban elements. A pedestrian along a treed street may experience poorer air quality than one living on highrise building, despite proximity to vegetation. There are thus interactions between climate, weather and urban context, which lead to spatial heterogeneity over

  17. Is there a time trend in medical practice variations?: a review of the literature and an critical analysis of theoretical approaches.

    NARCIS (Netherlands)

    Groenewegen, P.P.; Westert, G.P.

    2004-01-01

    The aim of this study was to review the research evidence for a decreasing time trend in medical practice variation and to contribute to our theoretical understanding of trends in medical practice variations. We searched Pubmed for articles reporting on time trends in medical practice variations.

  18. Developmental plasticity in Tenebrio molitor (Coleoptera: Tenebrionidae): Analysis of Instar Variation in Number and Development Time under Different Diets

    Science.gov (United States)

    The variation in instar number and the pattern of sequential instar development time of Tenebrio molitor L. (Coleoptera: Tenebrionidae) was studied under 4 different diet regimes. Addition of dietary supplements consisting of dry potato or a mix of dry potato and dry egg whites significantly reduced...

  19. Temperature and time variations during osteotomies performed with different piezosurgical devices: an in vitro study.

    Science.gov (United States)

    Delgado-Ruiz, R A; Sacks, D; Palermo, A; Calvo-Guirado, J L; Perez-Albacete, C; Romanos, G E

    2016-09-01

    The aim of this experimental in vitro study was to evaluate the effects of the piezoelectric device in temperature and time variations in standardized osteotomies performed with similar tip inserts in bovine bone blocks. Two different piezosurgical devices were used the OE-F15(®) (Osada Inc., Los Angeles, California, USA) and the Surgybone(®) (Silfradent Inc., Sofia, Forli Cesena, Italy). Serrated inserts with similar geometry were coupled with each device (ST94 insert/test A and P0700 insert/test B). Osteotomies 10 mm long and 3 mm deep were performed in bone blocks resembling type II (dense) and type IV (soft) bone densities with and without irrigation. Thermal changes and time variations were recorded. The effects of bone density, irrigation, and device on temperature changes and time necessary to accomplish the osteotomies were analyzed. Thermal analysis showed significant higher temperatures during piezosurgery osteotomies in hard bone without irrigation (P  0.05). Time analysis showed that the mean time values necessary to perform osteotomies were shorter in soft bone than in dense bone (P piezosurgery osteotomies in dense bone without irrigation; the time to perform the osteotomy with piezosurgery is shorter in soft bone compared to hard bone; and the piezosurgical device have a minimal influence in the temperature and time variations when a similar tip design is used during piezosurgery osteotomies. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Fast-time Variations of Supernova Neutrino Fluxes and Detection Perspectives

    NARCIS (Netherlands)

    Tamborra, I.; Hanke, F.; Müller, B.; Janka, H.T.; Raffelt, G.G.

    2015-01-01

    In the delayed explosion scenario of a core-collapse supernova, the accretion phase shows pronounced convective over-turns and a low-multipole hydrodynamic instability, the so-called standing accretion shock instability (SASI). Neutrino signal variations from the first full-scale three-dimensional

  1. Creating historical range of variation (HRV) time series using landscape modeling: Overview and issues [Chapter 8

    Science.gov (United States)

    Robert E. Keane

    2012-01-01

    Simulation modeling can be a powerful tool for generating information about historical range of variation (HRV) in landscape conditions. In this chapter, I will discuss several aspects of the use of simulation modeling to generate landscape HRV data, including (1) the advantages and disadvantages of using simulation, (2) a brief review of possible landscape models. and...

  2. Comparative analysis of long-time variations of multicomponent ion ring current according to data of geostationary Gorizont satellite

    International Nuclear Information System (INIS)

    Kovtyukh, A.S.; Panasyuk, M.I.; Vlasova, N.A.; Sosnovets, Eh.N.

    1990-01-01

    Long-time variations of the fluxes of the H + , [N,O] 2+ and [C,N,O] 6 6 + ions with energy E/Q∼60-120 keV/e measured by the GORIZONT (1985-07A) satellite in the geostationary orbit at noon time are analyzed. The results are dsicussed and are compared with current models of the formation of the Earth's ion ring current

  3. Effects of detector-source distance and detector bias voltage variations on time resolution of general purpose plastic scintillation detectors.

    Science.gov (United States)

    Ermis, E E; Celiktas, C

    2012-12-01

    Effects of source-detector distance and the detector bias voltage variations on time resolution of a general purpose plastic scintillation detector such as BC400 were investigated. (133)Ba and (207)Bi calibration sources with and without collimator were used in the present work. Optimum source-detector distance and bias voltage values were determined for the best time resolution by using leading edge timing method. Effect of the collimator usage on time resolution was also investigated. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. CLASP/SJ Observations of Rapid Time Variations in the Ly α Emission in a Solar Active Region

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, Shin-nosuke [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252–5210 (Japan); Kubo, Masahito; Katsukawa, Yukio; Kano, Ryouhei; Narukage, Noriyuki; Ishikawa, Ryohko; Bando, Takamasa [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Winebarger, Amy; Kobayashi, Ken [NASA Marshall Space Flight Center, Huntsville, AL 35812 (United States); Trujillo Bueno, Javier [Instituto de Astrofísica de Canarias, E-38205 La Laguna, Tenerife (Spain); Auchère, Frédéric, E-mail: s.ishikawa@solar.isas.jaxa.jp [Institut d’Astrophysique Spatiale, CNRS/Univ. Paris-Sud 11, Bätiment 121, F-91405 Orsay (France)

    2017-09-10

    The Chromospheric Ly α SpectroPolarimeter (CLASP) is a sounding rocket experiment launched on 2015 September 3 to investigate the solar chromosphere and transition region. The slit-jaw (SJ) optical system captured Ly α images with a high time cadence of 0.6 s. From the CLASP/SJ observations, many variations in the solar chromosphere and transition region emission with a timescale of <1 minute were discovered. In this paper, we focus on the active region within the SJ field of view and investigate the relationship between short (<30 s) temporal variations in the Ly α emission and the coronal structures observed by Solar Dynamics Observatory/Atmospheric Imaging Assembly (AIA). We compare the Ly α temporal variations at the coronal loop footpoints observed in the AIA 211 Å (≈2 MK) and AIA 171 Å (≈0.6 MK) channels with those in the regions with bright Ly α features without a clear association with the coronal loop footpoints. We find more short (<30 s) temporal variations in the Ly α intensity in the footpoint regions. Those variations did not depend on the temperature of the coronal loops. Therefore, the temporal variations in the Ly α intensity at this timescale range could be related to the heating of the coronal structures up to temperatures around the sensitivity peak of 171 Å. No signature was found to support the scenario that these Ly α intensity variations were related to the nanoflares. Waves or jets from the lower layers (lower chromosphere or photosphere) are possible causes for this phenomenon.

  5. Time and space variations of monsoonal upwelling along the west and east coasts of India

    Digital Repository Service at National Institute of Oceanography (India)

    Naidu, P.D.; RameshKumar, M.R.; RameshBabu, V.

    Seasonal variation in the heating of the southern Asian continent produces a semi- annual reversal in the wind direction over the Indian Ocean. During northern hemisphere summer, strong south—west winds blow across the northwest Indian Ocean, producing... distinct planktonic foraminifer assemblages, which eventually deposit in the sediments and forms a geological record. The quantitative and qualitat- ive analyses of planktonic foraminifer assemblages in the sediments have been used successfully...

  6. On the Time Variation of Dust Extinction and Gas Absorption for Type Ia Supernovae Observed through a Nonuniform Interstellar Medium

    Science.gov (United States)

    Huang, X.; Aldering, G.; Biederman, M.; Herger, B.

    2017-11-01

    For Type Ia supernovae (SNe Ia) observed through a nonuniform interstellar medium (ISM) in its host galaxy, we investigate whether the nonuniformity can cause observable time variations in dust extinction and in gas absorption due to the expansion of the SN photosphere with time. We show that, owing to the steep spectral index of the ISM density power spectrum, sizable density fluctuation amplitudes at the length scale of typical ISM structures (≳ 10 {pc}) will translate to much smaller fluctuations on the scales of an SN photosphere. Therefore, the typical amplitude of time variation due to a nonuniform ISM, of absorption equivalent widths, and of extinction, would be small. As a result, we conclude that nonuniform ISM density should not impact cosmology measurements based on SNe Ia. We apply our predictions based on the ISM density power-law power spectrum to the observations of two highly reddened SNe Ia, SN 2012cu and SN 2014J.

  7. Surface Temperature Variation Prediction Model Using Real-Time Weather Forecasts

    Science.gov (United States)

    Karimi, M.; Vant-Hull, B.; Nazari, R.; Khanbilvardi, R.

    2015-12-01

    Combination of climate change and urbanization are heating up cities and putting the lives of millions of people in danger. More than half of the world's total population resides in cities and urban centers. Cities are experiencing urban Heat Island (UHI) effect. Hotter days are associated with serious health impacts, heart attaches and respiratory and cardiovascular diseases. Densely populated cities like Manhattan, New York can be affected by UHI impact much more than less populated cities. Even though many studies have been focused on the impact of UHI and temperature changes between urban and rural air temperature, not many look at the temperature variations within a city. These studies mostly use remote sensing data or typical measurements collected by local meteorological station networks. Local meteorological measurements only have local coverage and cannot be used to study the impact of UHI in a city and remote sensing data such as MODIS, LANDSAT and ASTER have with very low resolution which cannot be used for the purpose of this study. Therefore, predicting surface temperature in urban cities using weather data can be useful.Three months of Field campaign in Manhattan were used to measure spatial and temporal temperature variations within an urban setting by placing 10 fixed sensors deployed to measure temperature, relative humidity and sunlight. Fixed instrument shelters containing relative humidity, temperature and illumination sensors were mounted on lampposts in ten different locations in Manhattan (Vant-Hull et al, 2014). The shelters were fixed 3-4 meters above the ground for the period of three months from June 23 to September 20th of 2013 making measurements with the interval of 3 minutes. These high resolution temperature measurements and three months of weather data were used to predict temperature variability from weather forecasts. This study shows that the amplitude of spatial and temporal variation in temperature for each day can be predicted

  8. Natural time analysis on the ultra-low frequency magnetic field variations prior to the 2016 Kumamoto (Japan) earthquakes

    Science.gov (United States)

    Potirakis, Stelios M.; Schekotov, Alexander; Asano, Tomokazu; Hayakawa, Masashi

    2018-04-01

    On 15 April 2016 a very strong and shallow earthquake (EQ) (MW = 7.0 , depth ∼ 10 km) occurred in Southwest Japan under the city of Kumamoto, while two very strong foreshocks (MW = 6.2 and MW = 6.0) preceded by about one day. The Kumamoto EQs being very catastrophic, have already attracted much attention among the scientific community in a quest for understanding the generation mechanism, as well as for reporting any preseismic anomalies in various observables and assessing the effectivity of the current early warning systems. In the present article we report precursory behavior of the ground-based observed ultra-low frequency (ULF) magnetic field variations before the Kumamoto EQs. By analyzing specific ULF magnetic field characteristics in terms of the recently introduced natural time (NT) analysis method, we identified that ULF magnetic field variations presented critical features from 2 weeks up to 1 month before the Kumamoto EQs. Specifically, the ULF magnetic field characteristics Fh , Fz , Dh and δDep were analyzed. The first two represent variations of the horizontal and vertical components of the geomagnetic field. The third and fourth characteristics correspond to the depression (decrease) and a relative depression of the horizontal magnetic field variations, respectively. The latter depends on the degree of ionospheric disturbance. All of them were found to reach criticality before the Kumamoto EQs; however, in different time periods for each characteristic.

  9. Time Variations of the Radial Velocity of H2O Masers in the Semi-Regular Variable R Crt

    Science.gov (United States)

    Sudou, Hiroshi; Shiga, Motoki; Omodaka, Toshihiro; Nakai, Chihiro; Ueda, Kazuki; Takaba, Hiroshi

    2017-12-01

    H2O maser emission {at 22 GHz} in the circumstellar envelope is one of the good tracers of detailed physics and inematics in the mass loss process of asymptotic giant branch stars. Long-term monitoring of an H2O maser spectrum with high time resolution enables us to clarify acceleration processes of the expanding shell in the stellar atmosphere. We monitored the H2O maser emission of the semi-regular variable R Crt with the Kagoshima 6-m telescope, and obtained a large data set of over 180 maser spectra over a period of 1.3 years with an observational span of a few days. Using an automatic peak detection method based on least-squares fitting, we exhaustively detected peaks as significant velocity components with the radial velocity on a 0.1 km s^{-1} scale. This analysis result shows that the radial velocity of red-shifted and blue-shifted components exhibits a change between acceleration and deceleration on the time scale of a few hundred days. These velocity variations are likely to correlate with intensity variations, in particular during flaring state of H2O masers. It seems reasonable to consider that the velocity variation of the maser source is caused by shock propagation in the envelope due to stellar pulsation.However, it is difficult to explain the relationship between the velocity variation and the intensity variation only from shock propagation effects. We found that a time delay of the integrated maser intensity with respect to the optical light curve is about 150 days.

  10. Short-time-scale Doppler and intensity variations in the spectrum of SS 433

    International Nuclear Information System (INIS)

    Wagner, R.M.; Newsom, G.H.; Foltz, C.B.; Byard, P.L.

    1981-01-01

    Spectroscopic observations of SS 433 were obtained on ten consecutive nights in 1981 May. Measurements of the equivalent widths of the spectral lines and Doppler shifts of the moving lines are presented. Not only does the 6-day period in the wavelengths of the moving lines appear quite clearly, but the data strongly suggest that this period is decreasing at a rate of (3.0 +- 1.1) x 10 -5 days/day. In addition, large equivalent width variations of the stationary lines are observed

  11. Time-dependent variation of the neutron multiplication factor in spent fuel storage

    Energy Technology Data Exchange (ETDEWEB)

    Leotlela, M.J. [Univ. of the Witwatersrand, Johannesburg (South Africa). School of Physics; Eskom, Johannesburg (South Africa). Regulations and Licensing, Koeberg Operating Unit; Olifant, T. [Cape Town Univ. (South Africa). Dept. of Electrical Engineering and Nuclear Power Studies; Koeberg Nuclear Power Station, Cape Town (South Africa). Operating Dept.; Petr, I. [Univ. of the Witwatersrand, Johannesburg (South Africa). School of Physics

    2017-12-15

    After spent fuel assemblies have been discharged from the reactor, reactivity will fluctuate as the cooling period progresses because of changes in the number density of fissile nuclides and neutron absorber nuclides. The purpose of this project was (1) to quantify the contribution of each individual nuclide to the reactivity of the fissile system, (2) to identify nuclides that are responsible for the fluctuation in reactivity, and (3) to determine the effect of the number of nuclides on reactivity. This paper will present the results of the study of the behaviour of the k{sub eff} with respect to variation in the duration of the cooling period during storage.

  12. Nongenetic causes of childhood cancers: evidence from international variation, time trends, and risk factor studies

    International Nuclear Information System (INIS)

    Bunin, Greta R.

    2004-01-01

    Ionizing radiation and a variety of genetic conditions are thought to explain 5-10% of childhood cancers. Infection with Epstein-Barr virus (EBV) in parts of Africa and human immunodeficiency virus (HIV) increase the risk of Burkitt's lymphoma and Kaposi's sarcoma, respectively. Other risk factors have not been conclusively identified. A review of the data on international variation in incidence, recent changes in incidence, and risk factors suggests that many childhood cancers are likely to have nongenetic causes. The pattern of international variation and associations with surrogates of infection suggest an infectious etiology for acute lymphoblastic leukemia, although no agent has been identified. The biologic plausibility is strong that maternal consumption of food containing DNA topoisomerase II inhibitors may increase the risk of acute myeloid leukemia, although the data are limited now. For brain tumors, cured meats, polyomaviruses, and farm exposures may have etiologic roles. Changes in the incidence and characteristics of children with hepatoblastoma as well as risk factor studies suggest a role for an exposure of very low birth weight babies. High birth weight, tea or coffee consumption, and certain paternal occupations have shown some consistency in their association with Wilms' tumor. For most of the other cancers, very few epidemiologic studies have been conducted, so it is not surprising that nongenetic risk factors have not been detected. The most important difference between the cancers for which there are good etiologic clues and those for which there are not may be the number of relevant studies

  13. Time-dependent post-imperative negative variation indicates adaptation and problem solving in migraine patients.

    Science.gov (United States)

    Kropp, Peter; Brecht, Ines-Beatrice; Niederberger, Uwe; Kowalski, Jens; Schröder, Dietmar; Thome, Johannes; Meyer, Wolfgang; Wallasch, Thomas-Martin; Hilgendorf, Inken; Gerber, Wolf-Dieter

    2012-10-01

    According to the Seligman theory of learned helplessness, depression is caused by a repetitive experience of loss of control resulting in internal, stable and global attributional styles for negative events. In depressed patients and healthy controls experiencing such events, an increased amplitude of the post-imperative negative variation (PINV) has been described. The aim of the study was to investigate a possible correlation between migraine, depression, learned helplessness and PINV. 24 patients suffering from migraine without aura and 24 healthy controls were exposed to a situation of loss of control whilst the contingent negative variation (CNV) from C3, C4 and Cz were recorded. Before conducting the experiment, the subjects were asked to answer the Beck Depression Inventory (BDI) and the German attributional style questionnaire (GASQ). Amplitudes of total CNV, early and late component and PINV were calculated in eight blocks of four recordings each. The results confirm findings of a pronounced PINV in situations of loss of control, though high amplitudes were not correlated with low values in the GASQ and therefore with learned helplessness. High PINV in migraine patients correlated with high scores in the BDI and the list of the complaints questionnaire. However, this was not the case in healthy controls. In this experimental situation, PINV in migraine patients can be interpreted as an expectancy potential in order to avoid failure and helplessness.

  14. Seasonal variation and solar activity dependence of the quiet-time ionospheric trough

    Science.gov (United States)

    Ishida, T.; Ogawa, Y.; Kadokura, A.; Hiraki, Y.; Häggström, I.

    2014-08-01

    We have conducted a statistical analysis of the ionospheric F region trough, focusing on its seasonal variation and solar activity dependence under geomagnetically quiet and moderate conditions, using plasma parameter data obtained via Common Program 3 observations performed by the European Incoherent Scatter (EISCAT) radar between 1982 and 2011. We have confirmed that there is a major difference in frictional heating between the high- and low-latitude sides of the EISCAT field of view (FOV) at ~73°0'N-60°5'N (geomagnetic latitude) at an altitude of 325 km, which is associated with trough formation. Our statistical results show that the high-latitude and midlatitude troughs occur on the high- and low-latitude sides of the FOV, respectively. Seasonal variations indicate that dissociative recombination accompanied by frictional heating is a main cause of trough formation in sunlit regions. During summer, therefore, the occurrence rate is maintained at 80-90% in the postmidnight high-latitude region owing to frictional heating by eastward return flow. Solar activity dependence on trough formation indicates that field-aligned currents modulate the occurrence rate of the trough during the winter and equinox seasons. In addition, the trough becomes deeper via dissociative recombination caused by an increased ion temperature with F10.7, at least in the equinox and summer seasons but not in winter.

  15. The variation of the density functions on chaotic spheres in chaotic space-like Minkowski space time

    International Nuclear Information System (INIS)

    El-Ahmady, A.E.

    2007-01-01

    In this article we introduce types of chaotic spheres in chaotic space-like Minkowski space time M n+1 . The variations of the density functions under the folding of these chaotic spheres are defined. The foldings restriction imposed on the density function are also discussed. The relations between the folding of geometry and pure chaotic manifolds are deduced. Some theorems concerning these relations are presented

  16. Explaining the Cross-National Time Series Variation in Life Expectancy: Income, Women’s Education, Shifts, and What Else?

    OpenAIRE

    Lant Pritchett; Martina Viarengo

    2010-01-01

    This paper examines the variation across countries and evolution over time of life expectancy. Using historical data going back to the beginning of the 20th century several basic facts about the relationship between national income and life expectancy are established. The paper shows that even by examining the augmented Preston curve there is no indication that the Preston curve is “breaking down” and no indication from over 100 years of data that a very strong relationship between national i...

  17. Age-related differences in the neural correlates of trial-to-trial variations of reaction time

    Directory of Open Access Journals (Sweden)

    Nancy E. Adleman

    2016-06-01

    Full Text Available Intra-subject variation in reaction time (ISVRT is a developmentally-important phenomenon that decreases from childhood through young adulthood in parallel with the development of executive functions and networks. Prior work has shown a significant association between trial-by-trial variations in reaction time (RT and trial-by-trial variations in brain activity as measured by the blood-oxygenated level-dependent (BOLD response in functional magnetic resonance imaging (fMRI studies. It remains unclear, however, whether such “RT-BOLD” relationships vary with age. Here, we determined whether such trial-by-trial relationships vary with age in a cross-sectional design. We observed an association between age and RT-BOLD relationships in 11 clusters located in visual/occipital regions, frontal and parietal association cortex, precentral/postcentral gyrus, and thalamus. Some of these relationships were negative, reflecting increased BOLD associated with decreased RT, manifesting around the time of stimulus presentation and positive several seconds later. Critically for present purposes, all RT-BOLD relationships increased with age. Thus, RT-BOLD relationships may reflect robust, measurable changes in the brain-behavior relationship across development.

  18. Real-time Monitoring on the Tunnel Wall Movement and Temperature Variation of KURT Facility

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyung Su; Bae, Dae Seok; Koh, Young Kwon; Choi, Jong Won

    2010-04-15

    The optical fiber cable acting as a sensor was embedded in the underground research tunnel and portal area in order to monitor their stability and the spatial temperature variation. This system includes two types of sensing function to monitor the distributed strain and temperature along the line, where sensor cable is installed, not a point sensing. The measurement resolution for rock mass displacement is 1 mm per 1 m and it covers 30 km length with every 1 m interval in minimum. In temperature, the cable measures the range of -160{approx}600 .deg. C with 0.01 .deg. C resolution according to the cable types. This means that it would be applicable to monitoring system for the safe operation of various kinds of facilities having static and/or dynamic characteristics, such as chemical plant, pipeline, rail, huge building, long and slim structures, bridge, subway and marine vessel. etc

  19. Assessing the mean strength and variations of the time-to-time fluctuations of resting-state brain activity.

    Science.gov (United States)

    Li, Zhengjun; Zang, Yu-Feng; Ding, Jianping; Wang, Ze

    2017-04-01

    The time-to-time fluctuations (TTFs) of resting-state brain activity as captured by resting-state fMRI (rsfMRI) have been repeatedly shown to be informative of functional brain structures and disease-related alterations. TTFs can be characterized by the mean and the range of successive difference. The former can be measured with the mean squared successive difference (MSSD), which is mathematically similar to standard deviation; the latter can be calculated by the variability of the successive difference (VSD). The purpose of this study was to evaluate both the resting state-MSSD and VSD of rsfMRI regarding their test-retest stability, sensitivity to brain state change, as well as their biological meanings. We hypothesized that MSSD and VSD are reliable in resting brain; both measures are sensitive to brain state changes such as eyes-open compared to eyes-closed condition; both are predictive of age. These hypotheses were tested with three rsfMRI datasets and proven true, suggesting both MSSD and VSD as reliable and useful tools for resting-state studies.

  20. Study of Track Irregularity Time Series Calibration and Variation Pattern at Unit Section

    Directory of Open Access Journals (Sweden)

    Chaolong Jia

    2014-01-01

    Full Text Available Focusing on problems existing in track irregularity time series data quality, this paper first presents abnormal data identification, data offset correction algorithm, local outlier data identification, and noise cancellation algorithms. And then proposes track irregularity time series decomposition and reconstruction through the wavelet decomposition and reconstruction approach. Finally, the patterns and features of track irregularity standard deviation data sequence in unit sections are studied, and the changing trend of track irregularity time series is discovered and described.

  1. Consequences of variations in spatial turbulence characteristics for fatigue life time of wind turbines

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, G.C.

    1998-09-01

    The fatigue loading of turbines situated in complex terrain is investigated in order to determine the crucial parameters in the spatial structure of the turbulence in such situations. The parameter study is performed by means of numerical calculations, and it embraces three different wind turbine types, representing a pitch controlled concept, a stall controlled concept, and a stall controlled concept with an extremely flexible tower. For each of the turbine concepts, the fatigue load sensibility to the selected turbulence characteristics are investigated for three different mean wind speeds at hub height. The selected mean wind speeds represent the linear-, the stall-, and the post stall aerodynamic region for the stall controlled turbines and analogously the unregulated-, the partly regulated-, and the fully regulated regime for the pitch controlled turbine. Denoting the turbulence component in the mean wind direction by u, the lateral turbulence component by v, and the vertical turbulence component by w, the selected turbulence characteristics comprise the u-turbulence length scale, the ratio between the v- and w-turbulence intensities and the u-turbulence intensity, the uu-coherence decay factor, and finally the u-v and u-w cross-correlations. The turbulence length scale in the mean wind direction gives rise to significant modification of the fatigue loading on all the investigated wind turbine concepts, but for the other selected parameter variations, large individual differences exists between the turbines. With respect to sensitivity to the performed parameter variations, the Vestas V39 wind turbine is the most robust of the investigated turbines. The Nordtank 500/37 turbine, equipped with the (artificial) soft tower, is by far the most sensitive of the investigated turbine concepts - also much more sensitive than the conventional Nordtank 500/37 turbine equipped with a traditional tower. (au) 2 tabs., 43 ills., 7 refs.

  2. Dry-wet variations and cause analysis in Northeast China at multi-time scales

    Science.gov (United States)

    Hu, Qi; Pan, Feifei; Pan, Xuebiao; Hu, Liting; Wang, Xiaoxiao; Yang, Pengyu; Wei, Pei; Pan, Zhihua

    2017-07-01

    Global warming has caused unevenly distributed changes in precipitation and evapotranspiration, which has and will certainly impact on the wet-dry variations. Based on daily meteorological data collected at 91 weather stations in Northeast China (NEC), the spatiotemporal characteristics of dry and wet climatic variables (precipitation, crop reference evapotranspiration (ET0), and humid index (HI)) are analyzed, and the probable reasons causing the changes in these variables are discussed during the period of 1961-2014. Precipitation showed non-significant trend over the period of 1961-2014, while ET0 showed a significant decreasing trend, which led to climate wetting in NEC. The period of 2001-2012 exhibited smaller semiarid area and larger humid area compared to the period of 1961-1980, indicating NEC has experienced wetting process at decadal scale. ET0 was most sensitive to relative humidity, and wind speed was the second most sensitive variable. Sunshine hours and temperature were found to be less influential to ET0 in the study area. The changes in wind speed in the recent 54 years have caused the greatest influence on ET0, followed by temperature. For each month, wind speed was the most significant variable causing ET0 reduction in all months except July. Temperature, as a dominant factor, made a positive contribution to ET0 in February and March, as well as sunshine hours in June and July, and relative humidity in August and September. In summary, NEC has experienced noticeable climate wetting due to the significantly decreasing ET0, and the decrease in wind speed was the biggest contributor for the ET0 reduction. Although agricultural drought crisis is expected to be partly alleviated, regional water resources management and planning in Northeast China should consider the potential water shortage and water conflict in the future because of spatiotemporal dry-wet variations in NEC.

  3. Local time, seasonal, and solar cycle dependency of longitudinal variations of TEC along the crest of EIA over India

    Science.gov (United States)

    Sunda, Surendra; Vyas, B. M.

    2013-10-01

    global wave number 4 structure in the Indian longitudinal region spanning from ~70 to 95°E forming the upward slope of the peak in the total electron content (TEC) are reported along the crest of equatorial ionization anomaly (EIA). The continuous and simultaneous measurements from five GPS stations of GPS Aided Geo Augmented Navigation (GAGAN) network are used in this study. The long-term database (2004-2012) is utilized for examining the local time, seasonal, and solar cycle dependency on the longitudinal variations of TEC. Our results confirm the existence of longitudinal variations of TEC in accordance with wave number 4 longitudinal structure including its strength. The results suggest that these variations, in general, start to develop at ~09 LT, achieve maximum strength at 12-15 LT, and decay thereafter, the decay rate depending on the season. They are more pronounced in equinoctial season followed by summer and winter. The longitudinal variations persist beyond midnight in equinox seasons, whereas in winter, they are conspicuously absent. Interestingly, they also exhibit significant solar cycle dependence in the solstices, whereas in the equinoxes, they are independent of solar activity. The comparison of crest-to-trough ratio (CTR) in the eastern (92°E) and western (72°E) extreme longitudes reveals higher CTR on the eastern side than over the western extreme, suggesting the role of nonmigrating tides in modulating the ExB vertical drift and the consequential EIA crest formation.

  4. Variation in allocation of time, water and energy in Hoopoe Larks from the Arabian Desert

    NARCIS (Netherlands)

    Tieleman, BI; Williams, JB; Visser, GH

    2003-01-01

    1. Patterns of resource allocation in different times of the year can provide insights into the effects of simultaneous environmental constraints on reproduction and survival of desert birds. Field metabolic rate (FMR), water influx rate (WIR) and patterns of time allocation of Hoopoe Larks (Alaemon

  5. Time Spent Outdoors, Depressive Symptoms, and Variation by Race and Ethnicity.

    Science.gov (United States)

    Beyer, Kirsten M M; Szabo, Aniko; Nattinger, Ann B

    2016-09-01

    Numerous studies have explored neighborhood environmental correlates of mental illnesses, presuming that the time individuals spend in their environment can confer benefit or harm based on environmental characteristics. However, few population-based studies have directly examined the relationship between time spent outdoors and mental health, and little work has been done to explore how experiences differ by race and ethnicity. Though some have proposed "doses of outdoor time" to improve health, the absence of information about the benefits conferred by particular "doses," and expected baseline levels of outdoor time, are needed to inform the development of recommendations and interventions. This study examined the relationship between time spent outdoors and depression among a population-based sample of American adults, characterized current levels of time spent outdoors by race and ethnicity, and examined how the relationship between time spent outdoors and depression varies by race and ethnicity. Descriptive statistics and survey regression models were used to examine data from the National Health and Nutrition Examination Survey for 2009-2012. Findings provide evidence that time spent outdoors is associated with fewer depressive symptoms, but this benefit may not be equally distributed by race and ethnicity. Descriptive analyses also reveal differences in time spent outdoors among different racial and ethnic groups. Study findings support the notion that increasing time spent outdoors may result in mental health benefits. However, this study questions whether that benefit is experienced equally among different groups, particularly given differences in occupational experiences and environmental characteristics of neighborhoods. Copyright © 2016 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

  6. Using a "time machine" to test for local adaptation of aquatic microbes to temporal and spatial environmental variation.

    Science.gov (United States)

    Fox, Jeremy W; Harder, Lawrence D

    2015-01-01

    Local adaptation occurs when different environments are dominated by different specialist genotypes, each of which is relatively fit in its local conditions and relatively unfit under other conditions. Analogously, ecological species sorting occurs when different environments are dominated by different competing species, each of which is relatively fit in its local conditions. The simplest theory predicts that spatial, but not temporal, environmental variation selects for local adaptation (or generates species sorting), but this prediction is difficult to test. Although organisms can be reciprocally transplanted among sites, doing so among times seems implausible. Here, we describe a reciprocal transplant experiment testing for local adaptation or species sorting of lake bacteria in response to both temporal and spatial variation in water chemistry. The experiment used a -80°C freezer as a "time machine." Bacterial isolates and water samples were frozen for later use, allowing transplantation of older isolates "forward in time" and newer isolates "backward in time." Surprisingly, local maladaptation predominated over local adaptation in both space and time. Such local maladaptation may indicate that adaptation, or the analogous species sorting process, fails to keep pace with temporal fluctuations in water chemistry. This hypothesis could be tested with more finely resolved temporal data. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

  7. Enamel hypoplasia in the deciduous teeth of great apes: variation in prevalence and timing of defects.

    Science.gov (United States)

    Lukacs, J R

    2001-11-01

    . Results from all three study collections reveal that among the great apes, gorillas (87-92%) and orangutans (91%) have a significantly higher prevalence of canine enamel defects than chimpanzees (22-48%). Sex differences in canine enamel hypoplasia are small and not statistically significant in any great ape. Factors influencing intergroup variation in prevalence of enamel defects and their distribution on the canine crown, including physiological stress and interspecific dento-gnathic morphological variation, are evaluated. Copyright 2001 Wiley-Liss, Inc.

  8. Time trends and occupational variation in the incidence of testicular cancer in the Nordic countries.

    Science.gov (United States)

    Ylönen, Outi; Jyrkkiö, Sirkku; Pukkala, Eero; Syvänen, Kari; Boström, Peter J

    2018-02-20

    To describe the trends and occupational variation in the incidence of testicular cancer in the Nordic countries utilising national cancer registries, NORDCAN (NORDCAN project/database presents the incidence, mortality, prevalence and survival from >50 cancers in the Nordic countries) and NOCCA (Nordic Occupational Cancer) databases. We obtained the incidence data of testicular cancer for 5-year periods from 1960-1964 to 2000-2014 and for 5-year age-groups from the NORDCAN database. Morphological data on incident cases of seminoma and non-seminoma were obtained from national cancer registries. Age-standardised incidence rates (ASR) were calculated per 100 000 person-years (World Standard). Regression analysis was used to evaluate the annual change in the incidence of testicular cancer in each of the Nordic countries. The risk of testicular cancer in different professions was described based on NOCCA information and expressed as standardised incidence ratios (SIRs). During 2010-2014 the ASR for testicular cancer varied from 11.3 in Norway to 5.8 in Finland. Until 1998, the incidence was highest in Denmark. There has not been an increase in Denmark and Iceland since the 1990s, whilst the incidence is still strongly increasing in Norway, Sweden, and Finland. There were no remarkable changes in the ratio of seminoma and non-seminoma incidences during the past 50 years. There was no increase in the incidences in children and those of pension age. The highest significant excess risks of testicular seminoma were found in physicians (SIR 1.48, 95% confidence interval [CI] 1.07-1.99), artistic workers (SIR 1.47, 95% CI 1.06-1.99) and religious workers etc. (SIR 1.33, 95% CI 1.14-1.56). The lowest SIRs of testicular seminoma were seen amongst cooks and stewards (SIR 0.56, 95% CI 0.29-0.98), and forestry workers (SIR 0.64, 95% CI 0.47-0.86). The occupational category of administrators was the only one with a significantly elevated SIR for testicular non-seminoma (SIR 1.21, 95

  9. Consideration of the accuracy by variation of respiration in real-time position management respiratory gating system

    International Nuclear Information System (INIS)

    Na, Jun Young; Kang, Tae Young; Beak, Geum Mun; Kwon, Gyeong Tae

    2013-01-01

    Respiratory Gated Radiation Therapy (RGRT) has been carried out using RPM (Real-time Position Management) Respiratory Gating System (version 1.7.5, varian, USA) in Asan Medical Center. This study was to analyze and evaluate the accuracy of Respiratory Gated Radiation Therapy (RGRT) according to variation of respiration. Making variation of respiration using Motion Phantom:QUASAR Programmable Respiratory Motion Phantom (Moudus Medical Device Inc. CANADA) able to adjust respiration pattern randomly was varying period, amplitude and baseline by analyze 50 patient's respiration of lung and liver cancer. One of the variations of respiration is baseline shift gradually downward per 0.01 cm, 0.03 cm, 0.05 cm. The other variation of respiration is baseline shift accidently downward per 0.2 cm, 0.4 cm, 0.6 cm, 0.8 cm. Experiments were performed in the same way that is used RPM Respiratory Gating System (phase gating, usually 30-70% gating) in Asan Medical Center. It was all exposed radiation under one of the conditions of baseline shift gradually downward per 0.01 cm, 0.03 cm, 0.05 cm. Under the other condition of baseline shift accidently downward per 0.2 cm, 0.4 cm, 0.6 cm, 0.8 cm equally radiation was exposed. The variations of baseline shifts didn't accurately reflect on phase gating in RPM Respiratory Gating System. This inexactitude makes serious uncertainty in Respiratory Gated Radiation Therapy. So, Must be stabilized breathing of patient before conducting Respiratory Gated Radiation Therapy. also must be monitored breathing of patient in the middle of treatment. If you observe considerable changes of breathing when conducting Respiratory Gated Radiation Therapy. Stopping treatment immediately and then must be need to recheck treatment site using fluoroscopy. If patient's respiration rechecked using fluoroscopy restabilize, it is possible to restart Respiratory Gated Radiation Therapy

  10. Crystallite size variation of TiO_2 samples depending time heat treatment

    International Nuclear Information System (INIS)

    Galante, A.G.M.; Paula, F.R. de; Montanhera, M.A.; Pereira, E.A.; Spada, E.R.

    2016-01-01

    Titanium dioxide (TiO_2) is an oxide semiconductor that may be found in mixed phase or in distinct phases: brookite, anatase and rutile. In this work was carried out the study of the residence time influence at a given temperature in the TiO_2 powder physical properties. After the powder synthesis, the samples were divided and heat treated at 650 °C with a ramp up to 3 °C/min and a residence time ranging from 0 to 20 hours and subsequently characterized by x-ray diffraction. Analyzing the obtained diffraction patterns, it was observed that, from 5-hour residence time, began the two-distinct phase coexistence: anatase and rutile. It also calculated the average crystallite size of each sample. The results showed an increase in average crystallite size with increasing residence time of the heat treatment. (author)

  11. Apollo 14 regolith breccias - Different glass populations and their potential for charting space time variations

    Science.gov (United States)

    Delano, John W.

    1988-01-01

    Apollo 14 regolith breccias (14313, 14307, 14301, 14049, 14047) have been found to have different populations of nonagglutinitic, mare-derived glasses. These variations appear to not only reflect different source regoliths but also different closure ages for these breccias. Based upon these different glass populations, 14301 is inferred to have a closure age sometime during the epoch of mare volcanism. All of the other four breccias were formed after the termination of mare volcanism with a possible age sequence from old to young of the following: 14307, 14313, 14049, 14047. Due to the relative simplicity of acquiring high-quality chemical data on large numbers of glasses by electron microprobe, mare glass populations allow: (1) classification of regolith breccias with respect to provenance and (2) estimation of their relative and absolute closure ages. The determination of (Ar-40)-(Ar-39) ages on individual glass spherules within breccias using the laser probe should in the future prove to be a promising extension of the present study.

  12. Volcanic signatures in time gravity variations during the volcanic unrest on El Hierro (Canary Islands)

    Science.gov (United States)

    Sainz-Maza Aparicio, S.; Arnoso Sampedro, J.; Gonzalez Montesinos, F.; Martí Molist, J.

    2014-06-01

    Gravity changes occurring during the initial stage of the 2011-2012 El Hierro submarine eruption are interpreted in terms of the preeruptive signatures during the episode of unrest. Continuous gravity measurements were made at two sites on the island using the relative spring gravimeter LaCoste and Romberg gPhone-054. On 15 September 2011, an observed gravity decrease of 45 μGal, associated with the southward migration of seismic epicenters, is consistent with a lateral magma migration that occurred beneath the volcanic edifice, an apparently clear precursor of the eruption that took place 25 days later on 10 October 2011. High-frequency gravity signals also appeared on 6-11 October 2011, pointing to an occurring interaction between a magmatic intrusion and the ocean floor. These important gravity changes, with amplitudes varying from 10 to -90 μGal, during the first 3 days following the onset of the eruption are consistent with the northward migration of the eruptive focus along an active eruptive fissure. An apparent correlation of gravity variations with body tide vertical strain was also noted, which could indicate that concurrent tidal triggering occurred during the initial stage of the eruption.

  13. Variation in LOV Photoreceptor Activation Dynamics Probed by Time Resolved Infrared Spectroscopy

    KAUST Repository

    Iuliano, James N.

    2017-12-14

    The light, oxygen, voltage (LOV) domain proteins are blue light photoreceptors that utilize a non-covalently bound flavin mononucleotide (FMN) cofactor as the chromophore. The modular nature of these proteins has led to their wide adoption in the emerging fields of optogenetics and optobiology, where the LOV domain has been fused to a variety of output domains leading to novel light-controlled applications. In the present work, we extend our studies of the sub-picosecond to several hundred microsecond transient infrared spectroscopy of the isolated LOV domain AsLOV2 to three full-length photoreceptors in which the LOV domain is fused to an output domain: the LOV-STAS protein, YtvA, the LOV-HTH transcription factor, EL222, and the LOV-histidine kinase, LovK. Despite differences in tertiary structure, the overall pathway leading to cysteine adduct formation from the FMN triplet state is highly conserved, although there are slight variations in rate. However significant differences are observed in the vibrational spectra and kinetics after adduct formation, which are directly linked to the specific output function of the LOV domain. While the rate of adduct formation varies by only 3.6-fold amongst the proteins, the subsequent large-scale structural changes in the full-length LOV photoreceptors occur over the micro- to sub-millisecond timescales and vary by orders of magnitude depending on the different output function of each LOV domain.

  14. Variation in LOV Photoreceptor Activation Dynamics Probed by Time Resolved Infrared Spectroscopy

    KAUST Repository

    Iuliano, James N.; Gil, Agnieszka A.; Laptenok, Sergey P.; Hall, Christopher R.; Tolentino Collado, Jinnette; Lukacs, Andras; Hag Ahmed, Safaa A; Abyad, Jenna; Daryaee, Taraneh; Greetham, Gregory M.; Sazanovich, Igor V.; Illarionov, Boris; Bacher, Adelbert; Fischer, Markus; Towrie, Michael; French, Jarrod B.; Meech, Stephen R.; Tonge, Peter J

    2017-01-01

    The light, oxygen, voltage (LOV) domain proteins are blue light photoreceptors that utilize a non-covalently bound flavin mononucleotide (FMN) cofactor as the chromophore. The modular nature of these proteins has led to their wide adoption in the emerging fields of optogenetics and optobiology, where the LOV domain has been fused to a variety of output domains leading to novel light-controlled applications. In the present work, we extend our studies of the sub-picosecond to several hundred microsecond transient infrared spectroscopy of the isolated LOV domain AsLOV2 to three full-length photoreceptors in which the LOV domain is fused to an output domain: the LOV-STAS protein, YtvA, the LOV-HTH transcription factor, EL222, and the LOV-histidine kinase, LovK. Despite differences in tertiary structure, the overall pathway leading to cysteine adduct formation from the FMN triplet state is highly conserved, although there are slight variations in rate. However significant differences are observed in the vibrational spectra and kinetics after adduct formation, which are directly linked to the specific output function of the LOV domain. While the rate of adduct formation varies by only 3.6-fold amongst the proteins, the subsequent large-scale structural changes in the full-length LOV photoreceptors occur over the micro- to sub-millisecond timescales and vary by orders of magnitude depending on the different output function of each LOV domain.

  15. Structure of carbon monoxide time variations in the atmospheric thickness over Central Eurasia (Issyk Kul Monitoring Station)

    Science.gov (United States)

    Aref'ev, V. N.; Kashin, F. V.; Orozaliev, M. D.; Sizov, N. I.; Sinyakov, V. P.; Sorokina, L. I.

    2013-03-01

    The results of measurements of the CO content in the atmospheric thickness by the method of solar molecular-absorption spectroscopy are presented. Over 87 months of observations, the annual mean CO content decreased by ˜19% at a mean rate of changes equal to -(0.14 ± 0.02) atm cm per year. Maxima and minima of seasonal variations most often fall on February and September, respectively. The mean overall amplitude of changes in the CO content during the annual cycle is about 50% of the mean value. The Fourier analysis revealed variations in the CO composition with periods from 3 to 84 months. A simple statistical model satisfactorily describes time changes in the CO content in the atmospheric thickness. The results of measurements of the CO content in the atmospheric thickness are compared with the data of CO measurements in samples of surface air at stations of the Global Atmospheric Watch.

  16. Chinese L1 children's English L2 verb morphology over time: individual variation in long-term outcomes.

    Science.gov (United States)

    Paradis, Johanne; Tulpar, Yasemin; Arppe, Antti

    2016-05-01

    This study examined accuracy in production and grammaticality judgements of verb morphology by eighteen Chinese-speaking children learning English as a second language (L2) followed longitudinally from four to six years of exposure to English, and who began to learn English at age 4;2. Children's growth in accuracy with verb morphology reached a plateau by six years, where 11/18 children did not display native-speaker levels of accuracy for one or more morphemes. Variation in children's accuracy with verb morphology was predicted by their English vocabulary size and verbal short-term memories primarily, and quality and quantity of English input at home secondarily. This study shows that even very young L2 learners might not all catch up to native speakers in this time frame and that non-age factors play a role in determining individual variation in child L2 learners' long-term outcomes with English morphology.

  17. Estimation of time-dependent Hurst exponents with variational smoothing and application to forecasting foreign exchange rates

    Science.gov (United States)

    Garcin, Matthieu

    2017-10-01

    Hurst exponents depict the long memory of a time series. For human-dependent phenomena, as in finance, this feature may vary in the time. It justifies modelling dynamics by multifractional Brownian motions, which are consistent with time-dependent Hurst exponents. We improve the existing literature on estimating time-dependent Hurst exponents by proposing a smooth estimate obtained by variational calculus. This method is very general and not restricted to the sole Hurst framework. It is globally more accurate and easier than other existing non-parametric estimation techniques. Besides, in the field of Hurst exponents, it makes it possible to make forecasts based on the estimated multifractional Brownian motion. The application to high-frequency foreign exchange markets (GBP, CHF, SEK, USD, CAD, AUD, JPY, CNY and SGD, all against EUR) shows significantly good forecasts. When the Hurst exponent is higher than 0.5, what depicts a long-memory feature, the accuracy is higher.

  18. The search for possible time variations in Davis' measurements of the argon production rate in the solar neutrino experiment

    International Nuclear Information System (INIS)

    Haubold, H.J.; Gerth, E.

    1985-01-01

    With the gradual accumulation of experimental data in the solar neutrino experiment of Davis and collaborators (runs 18-74 for 1970-1982), the question, whether there are time variations of the solar neutrino flux, is of renewed interest. We discuss the mathematical-numerical methods applied to the statistical analysis of Davis' argon-37 production rate up till now known in the literature. These methods are characterized by the arbitrary arrangement of the Davis data in a time series. We perform a certain Fourier transformation for unequally-spaced time series of the measuring data of the argon-37 production rate, discuss the discovered periods and give significance criteria with respect to each period. We find that all periods discussed in the literature are contained in our series of periods. Pointing out the more mathematical character of the time series analysis we emphasize the predominant significance of the detected periods. (author)

  19. Seasonal variation of residence time in spring and groundwater evaluated by CFCs and numerical simulation in mountainous headwater catchment

    Science.gov (United States)

    Tsujimura, Maki; Watanabe, Yasuto; Ikeda, Koichi; Yano, Shinjiro; Abe, Yutaka

    2016-04-01

    Headwater catchments in mountainous region are the most important recharge area for surface and subsurface waters, additionally time information of the water is principal to understand hydrological processes in the catchments. However, there have been few researches to evaluate variation of residence time of subsurface water in time and space at the mountainous headwaters especially with steep slope. We investigated the temporal variation of the residence time of the spring and groundwater with tracing of hydrological flow processes in mountainous catchments underlain by granite, Yamanashi Prefecture, central Japan. We conducted intensive hydrological monitoring and water sampling of spring, stream and ground waters in high-flow and low-flow seasons from 2008 through 2013 in River Jingu Watershed underlain by granite, with an area of approximately 15 km2 and elevation ranging from 950 m to 2000 m. The CFCs, stable isotopic ratios of oxygen-18 and deuterium, inorganic solute constituent concentrations were determined on all water samples. Also, a numerical simulation was conducted to reproduce of the average residence times of the spring and groundwater. The residence time of the spring water estimated by the CFCs concentration ranged from 10 years to 60 years in space within the watershed, and it was higher (older) during the low flow season and lower (younger) during the high flow season. We tried to reproduce the seasonal change of the residence time in the spring water by numerical simulation, and the calculated residence time of the spring water and discharge of the stream agreed well with the observed values. The groundwater level was higher during the high flow season and the groundwater dominantly flowed through the weathered granite with higher permeability, whereas that was lower during the low flow season and that flowed dominantly through the fresh granite with lower permeability. This caused the seasonal variation of the residence time of the spring

  20. Uncertainty in Earthquake Source Imaging Due to Variations in Source Time Function and Earth Structure

    KAUST Repository

    Razafindrakoto, H. N. T.

    2014-03-25

    One way to improve the accuracy and reliability of kinematic earthquake source imaging is to investigate the origin of uncertainty and to minimize their effects. The difficulties in kinematic source inversion arise from the nonlinearity of the problem, nonunique choices in the parameterization, and observational errors. We analyze particularly the uncertainty related to the choice of the source time function (STF) and the variability in Earth structure. We consider a synthetic data set generated from a spontaneous dynamic rupture calculation. Using Bayesian inference, we map the solution space of peak slip rate, rupture time, and rise time to characterize the kinematic rupture in terms of posterior density functions. Our test to investigate the effect of the choice of STF reveals that all three tested STFs (isosceles triangle, regularized Yoffe with acceleration time of 0.1 and 0.3 s) retrieve the patch of high slip and slip rate around the hypocenter. However, the use of an isosceles triangle as STF artificially accelerates the rupture to propagate faster than the target solution. It additionally generates an artificial linear correlation between rupture onset time and rise time. These appear to compensate for the dynamic source effects that are not included in the symmetric triangular STF. The exact rise time for the tested STFs is difficult to resolve due to the small amount of radiated seismic moment in the tail of STF. To highlight the effect of Earth structure variability, we perform inversions including the uncertainty in the wavespeed only, and variability in both wavespeed and layer depth. We find that little difference is noticeable between the resulting rupture model uncertainties from these two parameterizations. Both significantly broaden the posterior densities and cause faster rupture propagation particularly near the hypocenter due to the major velocity change at the depth where the fault is located.

  1. Uncertainty in Earthquake Source Imaging Due to Variations in Source Time Function and Earth Structure

    KAUST Repository

    Razafindrakoto, H. N. T.; Mai, Paul Martin

    2014-01-01

    One way to improve the accuracy and reliability of kinematic earthquake source imaging is to investigate the origin of uncertainty and to minimize their effects. The difficulties in kinematic source inversion arise from the nonlinearity of the problem, nonunique choices in the parameterization, and observational errors. We analyze particularly the uncertainty related to the choice of the source time function (STF) and the variability in Earth structure. We consider a synthetic data set generated from a spontaneous dynamic rupture calculation. Using Bayesian inference, we map the solution space of peak slip rate, rupture time, and rise time to characterize the kinematic rupture in terms of posterior density functions. Our test to investigate the effect of the choice of STF reveals that all three tested STFs (isosceles triangle, regularized Yoffe with acceleration time of 0.1 and 0.3 s) retrieve the patch of high slip and slip rate around the hypocenter. However, the use of an isosceles triangle as STF artificially accelerates the rupture to propagate faster than the target solution. It additionally generates an artificial linear correlation between rupture onset time and rise time. These appear to compensate for the dynamic source effects that are not included in the symmetric triangular STF. The exact rise time for the tested STFs is difficult to resolve due to the small amount of radiated seismic moment in the tail of STF. To highlight the effect of Earth structure variability, we perform inversions including the uncertainty in the wavespeed only, and variability in both wavespeed and layer depth. We find that little difference is noticeable between the resulting rupture model uncertainties from these two parameterizations. Both significantly broaden the posterior densities and cause faster rupture propagation particularly near the hypocenter due to the major velocity change at the depth where the fault is located.

  2. Control of nanoparticle agglomeration through variation of the time-temperature profile in chemical vapor synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Djenadic, Ruzica; Winterer, Markus, E-mail: markus.winterer@uni-due.de [Universität Duisburg-Essen, Nanoparticle Process Technology, Faculty of Engineering and CENIDE (Germany)

    2017-02-15

    The influence of the time-temperature history on the characteristics of nanoparticles such as size, degree of agglomeration, or crystallinity is investigated for chemical vapor synthesis (CVS). A simple reaction-coagulation-sintering model is used to describe the CVS process, and the results of the model are compared to experimental data. Nanocrystalline titania is used as model material. Titania nanoparticles are generated from titanium-tetraisopropoxide (TTIP) in a hot-wall reactor. Pure anatase particles and mixtures of anatase, rutile (up to 11 vol.%), and brookite (up to 29 vol.%) with primary particle sizes from 1.7 nm to 10.5 nm and agglomerate particle sizes from 24.3 nm to 55.6 nm are formed depending on the particle time-temperature history. An inductively heated furnace with variable inductor geometry is used as a novel system to control the time-temperature profile in the reactor externally covering a large wall temperature range from 873 K to 2023 K. An appropriate choice of inductor geometry, i.e. time-temperature profile, can significantly reduce the degree of agglomeration. Other particle characteristics such as crystallinity are also substantially influenced by the time-temperature profile.

  3. Variations in Cooking time with Some physico-chemical properties of stored pea dry seeds

    International Nuclear Information System (INIS)

    Ahmed, H. S.

    2006-01-01

    Cooking time is one of the most important aspects of food quality. Correlation of cooking time with certain quality attributes of stored pea dry seeds were investigated to verify previous findings in faba bean concerning the relationship between cooking time and these characters. Moreover, the study aimed at finding out indices for selection of early cooking pea types. Accordingly, the time when 50% of pea dry seeds considered cooked was determined for six pea genotypes grown at shambat in the season 1999/2000. This parameter revealed significant variance and wide range of variability (84.33-115.33 min) indicating various degrees of seed hardness. Similarly, marked differences in 100-seed weight, test a, cotyledon, moisture, ash and potassium content were recorded due to genotypes. Cooking time showed significant positive correlations (r = 0.892,<0.0001 and r = 0.504, P< 0.0310) with seed weight and cotyledon percentage, respectively, and significant negative correlations (r = - 0.907, P< 0.0001 and r = - 0.505, P=0.0313) with ash and test a percentages, respectively. (Author)

  4. Development of a Photovoltaic Array Emulator System in Real Time Considering Climatic Conditions Variations

    Directory of Open Access Journals (Sweden)

    Camilo E. Ardila-Franco

    2013-11-01

    Full Text Available This paper presents the development of an emulator that has the ability to replicate, in real time, the behavior of photovoltaic panels (PV arrays considering different conditions of irradiation and temperature for each one. The emulator consists of a data acquisition card, a programmable source and a computer. It is based on the bypass diode model that provides a better approximation to real operating conditions. The solution is computed by a simplified equation that uses the Lambert W function, which reduces the computation time. After that, it generates a solution table of values of current as a function of voltage on terminals, temperature and irradiation. Real-time emulation is performed by means of a search algorithm in the solutions table of the closest value to the voltage imposed on the terminals.

  5. Real T1 relaxation time measurement and diurnal variation analysis of intervertebral discs in a healthy population of 50 volunteers

    International Nuclear Information System (INIS)

    Galley, J.; Maestretti, G.; Koch, G.; Hoogewoud, H-M.

    2017-01-01

    Purpose: To measure the real T1 relaxation time of the lumbar intervertebral discs in a young and healthy population, using different inversion recovery times, and assess diurnal variation. Material and methods: Intervertebral discs from D12 to S1 of 50 healthy volunteers from 18 to 25 years old were evaluated twice the same day, in the morning and in the late afternoon. Dedicated MRI sequences with different inversion recovery times (from 100 to 2500 ms) were used to calculate the real T1 relaxation time. Three regions of interest (ROIs) were defined in each disc, the middle representing the nucleus pulposus (NP) and the outer parts the annulus fibrosus (AF) anterior and posterior. Diurnal variation and differences between each disc level were analyzed. Results: T1 mean values in the NP were 1142 ± 12 ms in the morning and 1085 ± 13 ms in the afternoon, showing a highly significant decrease of 57 ms (p < 0.001). A highly significant difference between the levels of the spine was found. The mean T1 of the anterior part of the AF was 577 ± 9 ms in the morning and 554 ± 8 ms in the afternoon. For the posterior part, the mean values were 633 ± 8 ms in the morning and 581 ± 7 ms in the evening. It shows a highly significant decrease of 23 ms for the anterior part and 51 ms for the posterior part (all p < 0.001). Conclusion: T1 mapping is a promising method of intervertebral disc evaluation. Significant diurnal variation and difference between levels of the lumbar spine were demonstrated. A potential use for longitudinal study in post-operative follow up or sport medicine needs to be evaluated.

  6. Real T1 relaxation time measurement and diurnal variation analysis of intervertebral discs in a healthy population of 50 volunteers

    Energy Technology Data Exchange (ETDEWEB)

    Galley, J., E-mail: galleyjulien@gmail.com [Department of Radiology, HFR Fribourg, Hôpital Cantonal (Switzerland); Maestretti, G. [Department of Orthopedic Surgery, HFR Fribourg, Hôpital Cantonal (Switzerland); Koch, G.; Hoogewoud, H-M. [Department of Radiology, HFR Fribourg, Hôpital Cantonal (Switzerland)

    2017-02-15

    Purpose: To measure the real T1 relaxation time of the lumbar intervertebral discs in a young and healthy population, using different inversion recovery times, and assess diurnal variation. Material and methods: Intervertebral discs from D12 to S1 of 50 healthy volunteers from 18 to 25 years old were evaluated twice the same day, in the morning and in the late afternoon. Dedicated MRI sequences with different inversion recovery times (from 100 to 2500 ms) were used to calculate the real T1 relaxation time. Three regions of interest (ROIs) were defined in each disc, the middle representing the nucleus pulposus (NP) and the outer parts the annulus fibrosus (AF) anterior and posterior. Diurnal variation and differences between each disc level were analyzed. Results: T1 mean values in the NP were 1142 ± 12 ms in the morning and 1085 ± 13 ms in the afternoon, showing a highly significant decrease of 57 ms (p < 0.001). A highly significant difference between the levels of the spine was found. The mean T1 of the anterior part of the AF was 577 ± 9 ms in the morning and 554 ± 8 ms in the afternoon. For the posterior part, the mean values were 633 ± 8 ms in the morning and 581 ± 7 ms in the evening. It shows a highly significant decrease of 23 ms for the anterior part and 51 ms for the posterior part (all p < 0.001). Conclusion: T1 mapping is a promising method of intervertebral disc evaluation. Significant diurnal variation and difference between levels of the lumbar spine were demonstrated. A potential use for longitudinal study in post-operative follow up or sport medicine needs to be evaluated.

  7. Millennial-scale climate variations recorded in Early Pliocene colour reflectance time series from the lacustrine Ptolemais Basin (NW Greece)

    Science.gov (United States)

    Steenbrink, J.; Kloosterboer-van Hoeve, M. L.; Hilgen, F. J.

    2003-03-01

    Quaternary climate proxy records show compelling evidence for climate variability on time scales of a few thousand years. The causes for these millennial-scale or sub-Milankovitch cycles are still poorly understood, not least due to the complex feedback mechanisms of large ice sheets during the Quaternary. We present evidence of millennial-scale climate variability in Early Pliocene lacustrine sediments from the intramontane Ptolemais Basin in northwestern Greece. The sediments are well exposed in a series of open-pit lignite mines and exhibit a distinct millennial-scale sedimentary cyclicity of alternating lignites and lacustrine marl beds that resulted from precession-induced variations in climate. The higher-frequency, millennial-scale cyclicity is particularly prominent within the grey-coloured marl segment of individual cycles. A stratigraphic interval of ˜115 ka, covering five precession-induced sedimentary cycles, was studied in nine parallel sections from two open-pit lignite mines located several km apart. High-resolution colour reflectance records were used to quantify the within-cycle variability and to determine its lateral continuity. Much of the within-cycle variability could be correlated between the parallel sections, even in fine detail, which suggests that these changes reflect basin-wide variations in environmental conditions related to (regional) climate fluctuations. Interbedded volcanic ash beds demonstrate the synchronicity of these fluctuations and spectral analysis of the reflectance time series shows a significant concentration of within-cycle variability at periods of ˜11, ˜5.5 and ˜2 ka. The occurrence of variability at such time scales at times before the intensification of the Northern Hemisphere glaciation suggests that they cannot solely have resulted from internal ice-sheet dynamics. Possible candidates include harmonics or combination tones of the main orbital cycles, variations in solar output or periodic motions of the Earth

  8. Variations in soil-to-red pepper transfer factors of radionuclides with time of their application and fruit harvest

    International Nuclear Information System (INIS)

    Choi, Yong Ho; Lee, Won Yun; Lim, Kwang Muk; Park, Soo Won; Lee, Myung Ho; Lee, Chang Woo; Lee, Hyun Duk; Lee, Jeong Ho

    1997-01-01

    A mixed solution of 54 Mn, 60 Co, 85 Sr and 137 Cs was applied to the soil of culture boxes in a greenhouse 2 days before transplanting red pepper and at 3 different times during its growth for investigating transfer factors (m 2 /kg-dry) for its green and red fruits. Transfer factors varied with radionuclide, application time and harvest time by factors of about 20-100. They decreased mostly radionuclide, application time and harvest time by factors of about 20-100. They decreased mostly in the order of 85 Sr> 54 Mn> 60 Co> 137 Cs while 54 Mn and 60 Co was higher than 85 Sr when time lapse between application and harvest was short. Transfer factors of 85 Sr and 137 Cs at the last application were lower than those at the previous one by factors of 3-20 depending on harvest time. Variations in 54 Mn and 60 Co transfer factors with application time after transplanting were comparatively low. Transfer factors of 54 Mn, 60 Co and 85 Sr mixed with topsoil before transplanting were up to 3-9 times higher than those for the application onto soil surface 2 days after transplanting root-uptake concentrations of the radionuclides in red pepper fruit and taking proper measures for its harvest and consumption at the event of an accidental release during the growing season of red pepper

  9. International variations in primary care physician consultation time: a systematic review of 67 countries.

    Science.gov (United States)

    Irving, Greg; Neves, Ana Luisa; Dambha-Miller, Hajira; Oishi, Ai; Tagashira, Hiroko; Verho, Anistasiya; Holden, John

    2017-11-08

    To describe the average primary care physician consultation length in economically developed and low-income/middle-income countries, and to examine the relationship between consultation length and organisational-level economic, and health outcomes. This is a systematic review of published and grey literature in English, Chinese, Japanese, Spanish, Portuguese and Russian languages from 1946 to 2016, for articles reporting on primary care physician consultation lengths. Data were extracted and analysed for quality, and linear regression models were constructed to examine the relationship between consultation length and health service outcomes. One hundred and seventy nine studies were identified from 111 publications covering 28 570 712 consultations in 67 countries. Average consultation length differed across the world, ranging from 48 s in Bangladesh to 22.5 min in Sweden. We found that 18 countries representing about 50% of the global population spend 5 min or less with their primary care physicians. We also found significant associations between consultation length and healthcare spending per capita, admissions to hospital with ambulatory sensitive conditions such as diabetes, primary care physician density, physician efficiency and physician satisfaction. There are international variations in consultation length, and it is concerning that a large proportion of the global population have only a few minutes with their primary care physicians. Such a short consultation length is likely to adversely affect patient healthcare and physician workload and stress. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  10. Variations in time and space of trace metal aerosol concentrations in urban areas and their surroundings

    Science.gov (United States)

    Moreno, T.; Querol, X.; Alastuey, A.; Reche, C.; Cusack, M.; Amato, F.; Pandolfi, M.; Pey, J.; Richard, A.; Prévôt, A. S. H.; Furger, M.; Gibbons, W.

    2011-09-01

    Using an unprecedentedly large geochemical database, we compare temporal and spatial variations in inhalable trace metal background concentrations in a major city (Barcelona, Spain) and at a nearby mountainous site (Montseny) affected by the urban plume. Both sites are contaminated by technogenic metals, with V, Pb, Cu, Zn, Mn, Sn, Bi, Sb and Cd all showing upper continental crust (UCC) normalised values >1 in broadly increasing order. The highest metal concentrations usually occur during winter at Barcelona and summer in Montseny. This seasonal difference was especially marked at the remote mountain site in several elements such as Ti and Rare Earth Elements, which recorded campaign maxima, exceeding PM10 concentrations seen in Barcelona. The most common metals were Zn, Ti, Cu, Mn, Pb and V. Both V and Ni show highest concentrations in summer, and preferentially fractionate into the finest PM sizes (PM1/PM10 > 0.5) especially in Barcelona, this being attributed to regionally dispersed contamination from fuel oil combustion point sources. Within the city, hourly metal concentrations are controlled either by traffic (rush hour double peak for Cu, Sb, Sn, Ba) or industrial plumes (morning peak of Ni, Mn, Cr generated outside the city overnight), whereas at Montseny metal concentrations rise during the morning to a single, prolonged afternoon peak as contaminated air transported by the sea breeze moves into the mountains. Our exceptional database, which includes hourly measurements of chemical concentrations, demonstrates in more detail than previous studies the spatial and temporal variability of urban pollution by trace metals in a given city. Technogenic metalliferous aerosols are commonly fine in size and therefore potentially bioavailable, emphasising the case for basing urban background PM characterisation not only on physical parameters such as mass but also on sample chemistry and with special emphasis on trace metal content.

  11. Recent studies of time variations of natural electromagnetic fields in Scotland

    Science.gov (United States)

    Hutton, V. R. S.; Dawes, G.; Ingham, M.; Kirkwood, S.; Mbipom, E. W.; Sik, J.

    1981-01-01

    A series of geomagnetic induction studies has been undertaken in Scotland since 1973. It includes the operation of two geomagnetic arrays, one over northern Scotland and the other over southern Scotland, subsequent individual station and small-scale geomagnetic array studies, and three sets of magnetotelluric soundings which traverse Scotland from the Lewisian Foreland to the English border. The problems associated with the interpretation of induction data from an island located in the subauroral region are discussed qualitatively and the manner in which both coast and source field effects can be accounted for, is described. The geomagnetic deep sounding data (GDS) from all the observation sites have been collated, and examples of hypothetical event contour maps and traverses across the Great Glen and of individual events from the northern array are presented. They indicate that significant lateral variations in electrical conductivity structure within the crust and upper mantle are associated with the major geological faults in the region. Examples of the results of the magnetotelluric soundings are also presented, together with an outline of the procedure used for one- and two-dimensional modelling. Models of the geo-electric structure in both northern and southern Scotland have been obtained. These show distinctive features which are compatible with the qualitative interpretation of the magnetovariational data. For example, the major granitic blocks are highly resistive while regions of relatively low resistivity exist at upper crustal depths near the Great Glen, Highland boundary and Southern Uplands faults. A zone of low resistivity exists at lower crust-uppermost mantle depths throughout much of the region, the lowest value occurring under the Southern Uplands.

  12. Time variation in the reaction-zone structure of two-phase spray detonations.

    Science.gov (United States)

    Pierce, T. H.; Nicholls, J. A.

    1973-01-01

    A detailed theoretical analysis of the time-varying detonation structure in a monodisperse spray is presented. The theory identifies experimentally observed reaction-zone overpressures as deriving from blast waves formed therein by the explosive ignition of the spray droplets, and follows in time the motion, change in strength, and interactions of these blast waves with one another, and with the leading shock. The results are compared with experimental data by modeling the motion of a finite-size circular pressure transducer through the theoretical data field in an x-t space.

  13. Influence of time of concentration on variation of runoff from a small urbanized watershed

    Science.gov (United States)

    Devendra Amatya; Agnieszka Cupak; Andrzej Walega

    2015-01-01

    The main objective of the paper is to estimate the influence of time of concentration (TC) on maximum flow in an urbanized watershed. The calculations of maximum flow have been carried out using the Rational method, Technical Release 55 (TR55) procedure based on NRCS (National Resources Conservation Services) guidelines, and NRCS-UH rainfall-runoff model. Similarly,...

  14. Compactibility of Al/Al2O3 Isotropic Composite with Variation of Holding Time Sintering.

    Directory of Open Access Journals (Sweden)

    Eddy S Siradj

    2008-11-01

    Full Text Available The requirement of component with structural ability, light weight and also strength is increasing base on Metal Matrix Composites (MMCs by aluminum as matrix (AMCs. A structural ability is connected to composites compactibility which is depend on quality of interfacial bounding. Powder metallurgy is one of method to produce composite with powder mixing, compacting and sintering. Volume fractions reinforced and sintering time can influence composites compactibility. Volume fractions reinforced variable can produce different reinforcement effect. Beside that, on sintering enables the formation of new phase during sintering time. In this research, Al/Al2O3 isotropic composites are made with aluminum as matrix and alumina (Al2O3 as reinforced. Volume fraction reinforced used 10%. 20%. 30% and 40%. Sintering temperature and compaction pressure are each 600oC and 15 kN. The tests that applied are compression and metallographic test. The result that obtained is optimum compactibility of Al/Al2O3 composite reached at holding time 2 hour. During sintering, new phase can occur that is aluminum oxides (alumina, with unstable properties. The best volume fraction reinforced and holding time sintering are 40% and 2 hours.

  15. Socio-demographic and behavioral variation in barriers to leisure-time physical activity.

    Science.gov (United States)

    Borodulin, Katja; Sipilä, Noora; Rahkonen, Ossi; Leino-Arjas, Päivi; Kestilä, Laura; Jousilahti, Pekka; Prättälä, Ritva

    2016-02-01

    We examined the socio-demographic and behavioral determinants of perceived barriers to leisure-time physical activity (LTPA) in a population-based sample of working-aged adults. Data comprised the National FINRISK 2002 Study, a population-based health examination study. Analyses were restricted to those aged 25-64 years and who perceived that their amount of LTPA did not reach sufficient levels. They reported barriers to LTPA, defined as a lack of time, motivation and lack of companionship to be active with, as well as high expenses. Age, education, household income, employment status, family type, physical activity, smoking and body mass index (BMI) were included as explanatory variables. Lack of time was the most frequent barrier. Each barrier was explained by a different set of factors that also varied between genders. The strongest and most systematic associations with the barriers were found for age, employment status and family type. Lack of time was less often reported as a barrier among the unemployed, singles without children and older people. Lacking motivation as a barrier was most common among singles without children. High expenses as a barrier was more often reported by the unemployed, and less often reported in the highest income group. When considering actions to promote LTPA, there is not one single solution, because the perceived barriers vary by population subgroups. © 2015 the Nordic Societies of Public Health.

  16. Transmission of government spending shocks in the Euro area: time variation and driving forces

    NARCIS (Netherlands)

    Kirchner, M.; Cimadomo, J.; Hauptmeier, S.

    2010-01-01

    This paper provides new evidence on the effects of government spending shocks and the fiscal transmission mechanism in the euro area for the period 1980-2008. Our contribution is two-fold. First, we investigate changes in the macroeconomic impact of government spending shocks using time-varying

  17. Transmission of government spending shocks in the Euro area: time variation and driving forces

    NARCIS (Netherlands)

    Kirchner, M.; Cimadomo, J.; Hauptmeier, S.

    This paper applies structural vector autoregressions with time-varying parameters in order to investigate changes in the effects of government spending shocks in the euro area, and the driving forces of those changes. Our contribution is two-fold. First, we present evidence that the short-run impact

  18. Minimal variation in anti-A and -B titers among healthy volunteers over time

    DEFF Research Database (Denmark)

    Sprogøe, Ulrik; Yazer, Mark; Rasmussen, Mads Hvidkjær

    2017-01-01

    BACKGROUND: Using potentially out-of-group blood components, like low titer A plasma and O whole blood, in the resuscitation of trauma patients is becoming increasingly popular. However, very little is known whether the donors’ anti-A and/or -B titers change over time and whether repeated titer m...

  19. Process of advective diffusive enrichment using differential gradients and the effects of variations in relaxation times

    International Nuclear Information System (INIS)

    Suarez Antola R.; Bernasconi, G.; Bertolotti, Angel

    1995-01-01

    A multicomponent solution is considered in advective diffusion chambers between two half-permeable barriers. A mathematical model is developed to calculate the concentration fields in the chamber. A new enrichment process is proposed and assessed using a digital simulation of space-time dynamics, based on the analytical solution of the model

  20. Variations in the Characteristics of Part-Time Faculty by General Fields of Instruction and Research.

    Science.gov (United States)

    Benjamin, Ernst

    1998-01-01

    Data from the 1993 National Study of Postsecondary Faculty are analyzed for patterns in part-time faculty characteristics in vocationally oriented and liberal arts-oriented two- and four-year colleges, by discipline group. Characteristics examined include qualifications, job satisfaction, economic condition (income, additional employment), reasons…

  1. The Effect of Fatherhood on Employment Hours: Variation by Birth Timing, Marriage and Coresidence.

    Science.gov (United States)

    Weinshenker, Matthew

    2015-01-01

    Drawing on the life course paradigm, I assess how the effect of fatherhood on employment hours varies by age of becoming a parent and time elapsed since the birth. Using the National Longitudinal Survey of Youth - 1979 Cohort from 1979 to 2002 (N = 28,514 observations), separate effects are estimated based on fathers' marital status and co-residence with own children. Only unmarried men who became fathers before 24 work longer hours immediately after a first birth, but in the long run, most early fathers work fewer hours as a result of parenthood. Over time, unmarried but coresident men who became fathers between 24 and 29 increase their hours, as do married, coresident men who delayed fatherhood until 30 or older. However, the latter increase is moderated by support for egalitarian gender roles. The findings shed light on the contemporary transition to adulthood and on men's work-family balance.

  2. Space Shuttle Redesigned Solid Rocket Motor nozzle natural frequency variations with burn time

    Science.gov (United States)

    Lui, C. Y.; Mason, D. R.

    1991-01-01

    The effects of erosion and thermal degradation on the Space Shuttle Redesigned Solid Rocket Motor (RSRM) nozzle's structural dynamic characteristics were analytically evaluated. Also considered was stiffening of the structure due to internal pressurization. A detailed NASTRAN finite element model of the nozzle was developed and used to evaluate the influence of these effects at several discrete times during motor burn. Methods were developed for treating erosion and thermal degradation, and a procedure was developed to account for internal pressure stiffening using differential stiffness matrix techniques. Results were verified using static firing test accelerometer data. Fast Fourier Transform and Maximum Entropy Method techniques were applied to the data to generate waterfall plots which track modal frequencies with burn time. Results indicate that the lower frequency nozzle 'vectoring' modes are only slightly affected by erosion, thermal effects and internal pressurization. The higher frequency shell modes of the nozzle are, however, significantly reduced.

  3. Real-time intravital imaging of pH variation associated with osteoclast activity.

    Science.gov (United States)

    Maeda, Hiroki; Kowada, Toshiyuki; Kikuta, Junichi; Furuya, Masayuki; Shirazaki, Mai; Mizukami, Shin; Ishii, Masaru; Kikuchi, Kazuya

    2016-08-01

    Intravital imaging by two-photon excitation microscopy (TPEM) has been widely used to visualize cell functions. However, small molecular probes (SMPs), commonly used for cell imaging, cannot be simply applied to intravital imaging because of the challenge of delivering them into target tissues, as well as their undesirable physicochemical properties for TPEM imaging. Here, we designed and developed a functional SMP with an active-targeting moiety, higher photostability, and a fluorescence switch and then imaged target cell activity by injecting the SMP into living mice. The combination of the rationally designed SMP with a fluorescent protein as a reporter of cell localization enabled quantitation of osteoclast activity and time-lapse imaging of its in vivo function associated with changes in cell deformation and membrane fluctuations. Real-time imaging revealed heterogenic behaviors of osteoclasts in vivo and provided insights into the mechanism of bone resorption.

  4. The influence of time-of-day variation and loading on the aponeurosis plantaris pedis

    DEFF Research Database (Denmark)

    Skou, S T; Rathleff, M S; Moelgaard, C M

    2012-01-01

    aponeurosis plantaris pedis thickness was assessed with a 13-MHz linear-array transducer. In sub-study 1, ten participants (ten aponeurosis') were measured five times during 24 hours. In sub-study 2, ten participants (ten aponeurosis') were measured just before, immediately after and again three hours after 3......AIM: The aim of this paper was to investigate the effect of time-of-day on the thickness of the the aponeurosis plantaris pedis, and to examine the acute effects of high-load strength training and long distance running on the thickness of the aponeurosis plantaris pedis. METHODS: Proximal......x12 unilateral heel-rises. In sub-study 3, 11 healthy experienced runners (11 aponeurosis') were measured just before, immediately after and two hours after a 15km run. The average thickness of three scans of each foot was used in the analysis. The data was analysed using repeated measures one...

  5. Variations with time and age in the relative risks of solid cancer incidence after radiation exposure

    International Nuclear Information System (INIS)

    Little, M.P.; Muirhead, C.R.; de Vathaire, F.; Charles, M.W.

    1997-01-01

    The Japanese atomic bomb survivor cancer incidence dataset and data on five groups exposed to radiation for medical reasons in childhood are analysed and evidence found for a reduction in the radiation-induced relative risk of cancers other than leukaemia with increasing time since exposure and age at exposure. The rate of the reductions in relative risk with time since exposure are not significantly different for those exposed in childhood and for those exposed in adulthood, if adjustment is made for the effects on the relative risk of age at exposure. For those irradiated in childhood, there is a statistically significant annual reduction of 5.8% (95% Cl 2.8, 8.9) in excess relative risk, and there are no strong indications of inter-cohort heterogeniety in the speed of reduction of relative risk. After adjustment for the effects of age at exposure, there is a significant annual reduction of 3.6% (95% Cl 1.6, 5.6) in excess relative risk in all age-at-exposure groups. There are significant reductions of 5.2% (95% Cl 3.7, 6.8) in excess relative risk per year of age at exposure. There are statistically significant (P = 0.04) interactions between the exponential adjustments to the excess relative risk for age at exposure and time since exposure in the Japanese data, but no indications (P = 0.38) of such interactions when powers of time since exposure and attained age are used to adjust the excess relative risk, so that the fit of the model with power adjustments is to be preferred to that of the model with exponential adjustments. (author)

  6. Mechanical & morphological properties of attapulgite/NR composites: Effect of mixing time variation

    Energy Technology Data Exchange (ETDEWEB)

    Nor, Nor Aina Mohd, E-mail: ayena90@yahoo.com; Othman, Nadras, E-mail: srnadras@usm.my; Ismail, Hanafi, E-mail: ihanafi@usm.my [School of Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia, Seri Ampangan, 14300 Nibong Tebal, Pulau Pinang (Malaysia)

    2015-07-22

    The development of composite material based on attapulgite clay (ATP) as a filler and natural rubber (NR) matrices were prepared by combination of melt mixing and latex compounding methods. Sonication technique was chosen in this work to disperse the attapulgite suspension. 6 phr of attapulgite loading was fabricated using different time of mixing ranging from 30 minutes until 2 hours and sonication time was kept constant at 15 minutes. Then, co-coagulating HA latex with attapulgite clay suspension through latex compounding method produced the masterbatch. The masterbatch was compounded with natural rubber by melt mixing method. The mechanical and morphological characteristics were investigated in this work. From mechanical testing, M1 showed the highest value of tensile and tear strength. By comparing with M30 and M2, M1 shows high 300% tensile modulus and lower crosslink density. However, when the time of mixing was prolonged to 2 hours, the results for tensile strength, elongation at break and tear strength were decreased. This is due to flocculation of attapulgite particles. Sonication techniques also proved that the tensile strength and elongation at break of these three samples were higher compared to gum NR (NR) and attapulgite compounded with NR using a conventional method (in-situ 6). From field emission scanning electron microscope (FESEM) results, it revealed that M1 had good dispersion in the NR system. It is proved that the higher tensile strength was due to good dispersion of attapulgite clay in the NR matrix. It was also supported from crosslink density, which is lower than NR and in-situ 6 results. It showed that the penetration of toluene solvent into rubber compound was restricted. The optimum time, M1 give the best results, which can be compared to control the sample.

  7. Time-Dependent Behavior of Shrinkage Strain for Early Age Concrete Affected by Temperature Variation

    OpenAIRE

    Qin, Yu; Yi, Zhijian; Wang, Weina; Wang, Di

    2017-01-01

    Shrinkage has been proven to be an important property of early age concrete. The shrinkage strain leads to inherent engineering problems, such as cracking and loss of prestress. Atmospheric temperature is an important factor in shrinkage strain. However, current research does not provide much attention to the effect of atmospheric temperature on shrinkage of early age concrete. In this paper, a laboratory study was undertaken to present the time-dependent shrinkage of early age concrete under...

  8. The study of coastal groundwater depth and salinity variation using time-series analysis

    International Nuclear Information System (INIS)

    Tularam, G.A.; Keeler, H.P.

    2006-01-01

    A time-series approach is applied to study and model tidal intrusion into coastal aquifers. The authors examine the effect of tidal behaviour on groundwater level and salinity intrusion for the coastal Brisbane region using auto-correlation and spectral analyses. The results show a close relationship between tidal behaviour, groundwater depth and salinity levels for the Brisbane coast. The known effect can be quantified and incorporated into new models in order to more accurately map salinity intrusion into coastal groundwater table

  9. Mechanical & morphological properties of attapulgite/NR composites: Effect of mixing time variation

    International Nuclear Information System (INIS)

    Nor, Nor Aina Mohd; Othman, Nadras; Ismail, Hanafi

    2015-01-01

    The development of composite material based on attapulgite clay (ATP) as a filler and natural rubber (NR) matrices were prepared by combination of melt mixing and latex compounding methods. Sonication technique was chosen in this work to disperse the attapulgite suspension. 6 phr of attapulgite loading was fabricated using different time of mixing ranging from 30 minutes until 2 hours and sonication time was kept constant at 15 minutes. Then, co-coagulating HA latex with attapulgite clay suspension through latex compounding method produced the masterbatch. The masterbatch was compounded with natural rubber by melt mixing method. The mechanical and morphological characteristics were investigated in this work. From mechanical testing, M1 showed the highest value of tensile and tear strength. By comparing with M30 and M2, M1 shows high 300% tensile modulus and lower crosslink density. However, when the time of mixing was prolonged to 2 hours, the results for tensile strength, elongation at break and tear strength were decreased. This is due to flocculation of attapulgite particles. Sonication techniques also proved that the tensile strength and elongation at break of these three samples were higher compared to gum NR (NR) and attapulgite compounded with NR using a conventional method (in-situ 6). From field emission scanning electron microscope (FESEM) results, it revealed that M1 had good dispersion in the NR system. It is proved that the higher tensile strength was due to good dispersion of attapulgite clay in the NR matrix. It was also supported from crosslink density, which is lower than NR and in-situ 6 results. It showed that the penetration of toluene solvent into rubber compound was restricted. The optimum time, M1 give the best results, which can be compared to control the sample

  10. Incorporating temporal variation in seabird telemetry data: time variant kernel density models

    Science.gov (United States)

    Gilbert, Andrew; Adams, Evan M.; Anderson, Carl; Berlin, Alicia; Bowman, Timothy D.; Connelly, Emily; Gilliland, Scott; Gray, Carrie E.; Lepage, Christine; Meattey, Dustin; Montevecchi, William; Osenkowski, Jason; Savoy, Lucas; Stenhouse, Iain; Williams, Kathryn

    2015-01-01

    A key component of the Mid-Atlantic Baseline Studies project was tracking the individual movements of focal marine bird species (Red-throated Loon [Gavia stellata], Northern Gannet [Morus bassanus], and Surf Scoter [Melanitta perspicillata]) through the use of satellite telemetry. This element of the project was a collaborative effort with the Department of Energy (DOE), Bureau of Ocean Energy Management (BOEM), the U.S. Fish and Wildlife Service (USFWS), and Sea Duck Joint Venture (SDJV), among other organizations. Satellite telemetry is an effective and informative tool for understanding individual animal movement patterns, allowing researchers to mark an individual once, and thereafter follow the movements of the animal in space and time. Aggregating telemetry data from multiple individuals can provide information about the spatial use and temporal movements of populations. Tracking data is three dimensional, with the first two dimensions, X and Y, ordered along the third dimension, time. GIS software has many capabilities to store, analyze and visualize the location information, but little or no support for visualizing the temporal data, and tools for processing temporal data are lacking. We explored several ways of analyzing the movement patterns using the spatiotemporal data provided by satellite tags. Here, we present the results of one promising method: time-variant kernel density analysis (Keating and Cherry, 2009). The goal of this chapter is to demonstrate new methods in spatial analysis to visualize and interpret tracking data for a large number of individual birds across time in the mid-Atlantic study area and beyond. In this chapter, we placed greater emphasis on analytical methods than on the behavior and ecology of the animals tracked. For more detailed examinations of the ecology and wintering habitat use of the focal species in the midAtlantic, see Chapters 20-22.

  11. Variation of Time Domain Failure Probabilities of Jack-up with Wave Return Periods

    Science.gov (United States)

    Idris, Ahmad; Harahap, Indra S. H.; Ali, Montassir Osman Ahmed

    2018-04-01

    This study evaluated failure probabilities of jack up units on the framework of time dependent reliability analysis using uncertainty from different sea states representing different return period of the design wave. Surface elevation for each sea state was represented by Karhunen-Loeve expansion method using the eigenfunctions of prolate spheroidal wave functions in order to obtain the wave load. The stochastic wave load was propagated on a simplified jack up model developed in commercial software to obtain the structural response due to the wave loading. Analysis of the stochastic response to determine the failure probability in excessive deck displacement in the framework of time dependent reliability analysis was performed by developing Matlab codes in a personal computer. Results from the study indicated that the failure probability increases with increase in the severity of the sea state representing a longer return period. Although the results obtained are in agreement with the results of a study of similar jack up model using time independent method at higher values of maximum allowable deck displacement, it is in contrast at lower values of the criteria where the study reported that failure probability decreases with increase in the severity of the sea state.

  12. Modelling regional variation of first-time births in Denmark 1980-1994 by an age-period-cohort model

    DEFF Research Database (Denmark)

    Thygesen, Lau Caspar; Knudsen, Lisbeth B.; Keiding, Niels

    2005-01-01

    Despite the small size of Denmark, there have traditionally been rather consistent regional differences in fertility rates. We apply the statistical age-period-cohort model to include the effect of these three time-related factors thereby concisely illuminating the regional differences of first......-time births in Denmark. From the Fertility of Women and Couples Dataset we obtain data on number of births by nulliparous women by year (1980-1994), age (15-45) and county of residence. We show that the APC-model describes the fertility rates of nulliparous women satisfactorily. To catch the regional...... variation an interaction parameter between age and county is necessary, which provides a surprisingly good description suggesting that the county-specific age-distributions of first-time fertility rates differ. Our results are in general agreement with the 'moral geography' concepts of Tonboe (2001)....

  13. Modelling regional variation of first-time births in Denmark 1980-1994 by an age-period-cohort model

    Directory of Open Access Journals (Sweden)

    Lisbeth B. Knudsen

    2005-12-01

    Full Text Available Despite the small size of Denmark, there have traditionally been rather consistent regional differences in fertility rates. We apply the statistical age-period-cohort model to include the effect of these three time-related factors thereby concisely illuminating the regional differences of first-time births in Denmark. From the Fertility of Women and Couples Dataset we obtain data on number of births by nulliparous women by year (1980-1994, age (15-45 and county of residence. We show that the APC-model describes the fertility rates of nulliparous women satisfactorily. To catch the regional variation an interaction parameter between age and county is necessary, which provides a surprisingly good description suggesting that the county-specific age-distributions of first-time fertility rates differ. Our results are in general agreement with the 'moral geography' concepts of Tonboe (2001.

  14. A statistical model for measurement error that incorporates variation over time in the target measure, with application to nutritional epidemiology.

    Science.gov (United States)

    Freedman, Laurence S; Midthune, Douglas; Dodd, Kevin W; Carroll, Raymond J; Kipnis, Victor

    2015-11-30

    Most statistical methods that adjust analyses for measurement error assume that the target exposure T is a fixed quantity for each individual. However, in many applications, the value of T for an individual varies with time. We develop a model that accounts for such variation, describing the model within the framework of a meta-analysis of validation studies of dietary self-report instruments, where the reference instruments are biomarkers. We demonstrate that in this application, the estimates of the attenuation factor and correlation with true intake, key parameters quantifying the accuracy of the self-report instrument, are sometimes substantially modified under the time-varying exposure model compared with estimates obtained under a traditional fixed-exposure model. We conclude that accounting for the time element in measurement error problems is potentially important. Copyright © 2015 John Wiley & Sons, Ltd.

  15. A Wireless Sensor Network Framework for Real-Time Monitoring of Height and Volume Variations on Sandy Beaches and Dunes

    Directory of Open Access Journals (Sweden)

    Alessandro Pozzebon

    2018-04-01

    Full Text Available In this paper, the authors describe the realization and testing of a Wireless Sensor Network (WSN framework aiming at measuring, remotely and in real time, the level variations of the sand layer of sandy beaches or dunes. The proposed framework is based on an innovative low cost sensing structure, able to measure the level variations with a 5-cm degree of precision and to locally transfer the acquired data through the ZigBee protocol. The described sensor is integrated in a wider ZigBee wireless sensor network architecture composed of an array of sensors that, arranged according to a grid layout, can acquire the same data at different points, allowing the definition of a dynamic map of the area under study. The WSN is connected to a local Global System for Mobile Communications (GSM gateway that is in charge of data processing and transmission to a cloud infrastructure through a General Packet Radio Service (GPRS connection. Data are then stored in a MySQL database and made available any time and anywhere through the Internet. The proposed architecture has been tested in a laboratory, to analyze data acquisition, processing timing and power consumption and then in situ to prove the effectiveness of the system. The described infrastructure is expected to be integrated in a wider IoT architecture including different typologies of sensors, in order to create a multi-purpose tool for the study of coastal erosive processes.

  16. Time-Depending Parametric Variational Approach for an Economic General Equilibrium Problem of Pure Exchange with Application

    International Nuclear Information System (INIS)

    Scaramuzzino, F.

    2009-01-01

    This paper considers a qualitative analysis of the solution of a pure exchange general economic equilibrium problem according to two independent parameters. Some recently results obtained by the author in the static and the dynamic case have been collected. Such results have been applied in a particular parametric case: it has been focused the attention on a numerical application for which the existence of the solution of time-depending parametric variational inequality that describes the equilibrium conditions has been proved by means of the direct method. By using MatLab computation after a linear interpolation, the curves of equilibrium have been visualized.

  17. Fetal short time variation during labor: a non-invasive alternative to fetal scalp pH measurements?

    OpenAIRE

    Schiermeier, Sven; Reinhard, Joscha; Hatzmann, Hendrike; Zimmermann, Ralf C.; Westhof, Gregor

    2009-01-01

    Objective: To determine whether short time variation (STV) of fetal heart beat correlates with scalp pH measurements during labor. Patients and methods: From 1279 deliveries, 197 women had at least one fetal scalp pH measurement. Using the CTG-Player®, STVs were calculated from the electronically saved cardiotocography (CTG) traces and related to the fetal scalp pH measurements. Results: There was no correlation between STV and fetal scalp pH measurements (r=−0.0592). Conclusions: Fetal ST...

  18. Natural variation of the RICE FLOWERING LOCUS T 1 contributes to flowering time divergence in rice.

    Directory of Open Access Journals (Sweden)

    Eri Ogiso-Tanaka

    Full Text Available In rice (Oryza sativa L., there is a diversity in flowering time that is strictly genetically regulated. Some indica cultivars show extremely late flowering under long-day conditions, but little is known about the gene(s involved. Here, we demonstrate that functional defects in the florigen gene RFT1 are the main cause of late flowering in an indica cultivar, Nona Bokra. Mapping and complementation studies revealed that sequence polymorphisms in the RFT1 regulatory and coding regions are likely to cause late flowering under long-day conditions. We detected polymorphisms in the promoter region that lead to reduced expression levels of RFT1. We also identified an amino acid substitution (E105K that leads to a functional defect in Nona Bokra RFT1. Sequencing of the RFT1 region in rice accessions from a global collection showed that the E105K mutation is found only in indica, and indicated a strong association between the RFT1 haplotype and extremely late flowering in a functional Hd1 background. Furthermore, SNPs in the regulatory region of RFT1 and the E105K substitution in 1,397 accessions show strong linkage disequilibrium with a flowering time-associated SNP. Although the defective E105K allele of RFT1 (but not of another florigen gene, Hd3a is found in many cultivars, relative rate tests revealed no evidence for differential rate of evolution of these genes. The ratios of nonsynonymous to synonymous substitutions suggest that the E105K mutation resulting in the defect in RFT1 occurred relatively recently. These findings indicate that natural mutations in RFT1 provide flowering time divergence under long-day conditions.

  19. A Bayesian framework to estimate diversification rates and their variation through time and space

    Directory of Open Access Journals (Sweden)

    Silvestro Daniele

    2011-10-01

    Full Text Available Abstract Background Patterns of species diversity are the result of speciation and extinction processes, and molecular phylogenetic data can provide valuable information to derive their variability through time and across clades. Bayesian Markov chain Monte Carlo methods offer a promising framework to incorporate phylogenetic uncertainty when estimating rates of diversification. Results We introduce a new approach to estimate diversification rates in a Bayesian framework over a distribution of trees under various constant and variable rate birth-death and pure-birth models, and test it on simulated phylogenies. Furthermore, speciation and extinction rates and their posterior credibility intervals can be estimated while accounting for non-random taxon sampling. The framework is particularly suitable for hypothesis testing using Bayes factors, as we demonstrate analyzing dated phylogenies of Chondrostoma (Cyprinidae and Lupinus (Fabaceae. In addition, we develop a model that extends the rate estimation to a meta-analysis framework in which different data sets are combined in a single analysis to detect general temporal and spatial trends in diversification. Conclusions Our approach provides a flexible framework for the estimation of diversification parameters and hypothesis testing while simultaneously accounting for uncertainties in the divergence times and incomplete taxon sampling.

  20. Time calibration of AMANDA three variations of a theme of T$_{0}$

    CERN Document Server

    Hanson, K

    2002-01-01

    The AMANDA-II neutrino telescope currently operating at the South Pole is an array of 677 optical modules (OMs) deployed in the ice at depths between 1200 m and 2300 m beneath the surface. Calibration of the timing offsets of each OM is effected primarily by means of in- ice light pulses transmitted via optical fibers from a surface YAG laser. Discriminator walk, which is significant due to the transmission of electrical signals over 2 km distances, is also calibrated using the YAG laser. Another way to calibrate the timing offsets is to use downgoing cosmic ray muons. This method has the advantages of fuller coverage and year-round availability, i.e., it can be done anytime the detector is taking data. Finally, preliminary results of a technique used to calibrate, with nanosecond precision, the local clocks in "digital optical modules" (DOMs), which digitize and timestamp PMT signals in situ, are presented using DOMs in operation in AMANDA-II. The DOM is part of the baseline design for the planned IceCube de...

  1. Transit Timing Observations from Kepler: II. Confirmation of Two Multiplanet Systems via a Non-parametric Correlation Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ford, Eric B.; /Florida U.; Fabrycky, Daniel C.; /Lick Observ.; Steffen, Jason H.; /Fermilab; Carter, Joshua A.; /Harvard-Smithsonian Ctr. Astrophys.; Fressin, Francois; /Harvard-Smithsonian Ctr. Astrophys.; Holman, Matthew J.; /Harvard-Smithsonian Ctr. Astrophys.; Lissauer, Jack J.; /NASA, Ames; Moorhead, Althea V.; /Florida U.; Morehead, Robert C.; /Florida U.; Ragozzine, Darin; /Harvard-Smithsonian Ctr. Astrophys.; Rowe, Jason F.; /NASA, Ames /SETI Inst., Mtn. View /San Diego State U., Astron. Dept.

    2012-01-01

    We present a new method for confirming transiting planets based on the combination of transit timing variations (TTVs) and dynamical stability. Correlated TTVs provide evidence that the pair of bodies are in the same physical system. Orbital stability provides upper limits for the masses of the transiting companions that are in the planetary regime. This paper describes a non-parametric technique for quantifying the statistical significance of TTVs based on the correlation of two TTV data sets. We apply this method to an analysis of the transit timing variations of two stars with multiple transiting planet candidates identified by Kepler. We confirm four transiting planets in two multiple planet systems based on their TTVs and the constraints imposed by dynamical stability. An additional three candidates in these same systems are not confirmed as planets, but are likely to be validated as real planets once further observations and analyses are possible. If all were confirmed, these systems would be near 4:6:9 and 2:4:6:9 period commensurabilities. Our results demonstrate that TTVs provide a powerful tool for confirming transiting planets, including low-mass planets and planets around faint stars for which Doppler follow-up is not practical with existing facilities. Continued Kepler observations will dramatically improve the constraints on the planet masses and orbits and provide sensitivity for detecting additional non-transiting planets. If Kepler observations were extended to eight years, then a similar analysis could likely confirm systems with multiple closely spaced, small transiting planets in or near the habitable zone of solar-type stars.

  2. Simulation of time variation of Uranium, Plutonium and fission product hold up in mixer settler contactors

    International Nuclear Information System (INIS)

    Dionisi, M.; D'Agostino, F.; Remetti, R.

    1990-01-01

    A simulation model of PUREX process extraction phase for a contactors (mixer-settlers) battery has been developed. This model has been implemented in a FORTRAN code tailored both for mainframe and PC. The main goal of the code is to determine Uranium and Plutonium hold-ups vs.time within contactors in order to implement a NRTA project for a reprocessing plant. These results are extremely important for a complete analysis of NRTA system perfomance particularly to overcome the difficulty of executing physical inventory within liquid-liquid contactors of extraction lines. The chemical process simulation has been carried out conventional theoretical models with the exeption of hydrodynamic simulation which has been developed utilizing a model based on experimental results

  3. Experimental study of the variation of spectrum line profiles with time (1962)

    International Nuclear Information System (INIS)

    Laval, G.; Pellat, R.

    1962-01-01

    This study relates to a device conceived by C. BRETON, M. CAPET and F. WAELBROECK and submitted at the Fifth International Conference on Ionization Phenomena in Gases (Munich 1961). To calibrate the device and to know its accurate possibilities, noise in photomultipliers had to be investigated. For weak light signals this investigation has shown that the Schottky effect explains this noise and that there is a strict relation between the time resolution and the accuracy of the results. These results are applied to measurements of Stark Effect broadening of the Dβ line emitted by the plasma of an electrode-less-gun. The densities calculated from the experimental profiles are in good agreement with the densities calculated from magnetic measurements. (authors) [fr

  4. Sociodemographic and socioeconomic variations in leisure time physical activity in a sample of Hungarian youth.

    Science.gov (United States)

    Piko, Bettina F; Keresztes, Noémi

    2008-01-01

    The main goal of the present study is to detect the relationship between youth's leisure time physical activity and a set of sociodemographic (age, gender, family stucture) and socioeconomic variables (SES and parental schooling). Data were collected among Hungarian youth (middle and high school students, N = 1662) aged between 10-20 years using a self-administered questionnaire. Our findings did not indicate gender differences during the years of middle school, whereas gender differences became significant during the years of high school. In multivariate analyses, parental schooling played a decisive role in youth's physical activity, wheres SES self-assessment did not remain significant. These findings provide some useful information on characteristics of the target groups for health education programs.

  5. Dynamic effective properties of heterogeneous geological formations with spherical inclusions under periodic time variations

    Science.gov (United States)

    Rabinovich, A.; Dagan, G.; Miloh, T.

    2013-04-01

    In unsteady groundwater flow (or similar processes of heat/electrical conduction), the heterogeneous medium structure is characterized by two random properties, the conductivity K and the specific storativity S. The average head field ⟨H ⟩and the associated effective properties Kef, Sef are determined for a layer with a periodic head drop between boundaries, such that H is periodic in time, and a medium made up of a matrix with a dilute concentration of spherical inclusions. In the common quasi-steady approximation, Kef is equal to the classical steady solution while Sef = SA, the arithmetic mean. We derive expressions for the frequency dependent Kef, Sef, which are generally complex, i.e., dynamic. The main result is the delineation of the ranges of the parameters: dimensionless frequency (ω) and contrasts of conductivity (κ) and storativity (s) between the matrix and the inclusions, for which dynamic effects are significant.

  6. Time-varying cycle average and daily variation in ambient air pollution and fecundability.

    Science.gov (United States)

    Nobles, Carrie J; Schisterman, Enrique F; Ha, Sandie; Buck Louis, Germaine M; Sherman, Seth; Mendola, Pauline

    2018-01-01

    Does ambient air pollution affect fecundability? While cycle-average air pollution exposure was not associated with fecundability, we observed some associations for acute exposure around ovulation and implantation with fecundability. Ambient air pollution exposure has been associated with adverse pregnancy outcomes and decrements in semen quality. The LIFE study (2005-2009), a prospective time-to-pregnancy study, enrolled 501 couples who were followed for up to one year of attempting pregnancy. Average air pollutant exposure was assessed for the menstrual cycle before and during the proliferative phase of each observed cycle (n = 500 couples; n = 2360 cycles) and daily acute exposure was assessed for sensitive windows of each observed cycle (n = 440 couples; n = 1897 cycles). Discrete-time survival analysis modeled the association between fecundability and an interquartile range increase in each pollutant, adjusting for co-pollutants, site, age, race/ethnicity, parity, body mass index, smoking, income and education. Cycle-average air pollutant exposure was not associated with fecundability. In acute models, fecundability was diminished with exposure to ozone the day before ovulation and nitrogen oxides 8 days post ovulation (fecundability odds ratio [FOR] 0.83, 95% confidence interval [CI]: 0.72, 0.96 and FOR 0.84, 95% CI: 0.71, 0.99, respectively). However, particulate matter ≤10 microns 6 days post ovulation was associated with greater fecundability (FOR 1.25, 95% CI: 1.01, 1.54). Although our study was unlikely to be biased due to confounding, misclassification of air pollution exposure and the moderate study size may have limited our ability to detect an association between ambient air pollution and fecundability. While no associations were observed for cycle-average ambient air pollution exposure, consistent with past research in the United States, exposure during critical windows of hormonal variability was associated with prospectively measured couple

  7. Dosing-time-dependent variation in biliary excretion of flomoxef in rats.

    Science.gov (United States)

    Hishikawa, Shuji; Sugimoto, Koh-ichi; Kobayashi, Eiji; Kumagai, Yuji; Fujimura, Akio

    2003-05-01

    We previously reported that the biliary excretion of flomoxef, an oxacephem antibiotic, was greater after dosing at 21:00 than at 09:00 h in diurnally active human subjects. The present study was undertaken to examine whether the biliary excretion of flomoxef is also dependent on its dosing time in rats. Adult male Wistar rats were housed under light on at 07:00 h and off at 19:00 h. Bile fluid was completely drained through a polyethylene catheter from conscious animals. Flomoxef (20 mg/kg) was injected into the tail vein at 09:00 or 21:00 h by a cross-over design, and drained bile fluid was collected for 8 h after each dosing. The maximum concentration of biliary flomoxef was significantly greater and its total excretion tended to be greater after dosing at 09:00 than 21:00 h. These results suggest the biliary excretion of flomoxef is enhanced after dosing at the beginning of the rest period in rats, as it is in humans.

  8. Airborne gamma anomalies in the Elbe Valley near Koenigstein, Germany - Origin and variation with time

    International Nuclear Information System (INIS)

    Ruhrmann, G.; Schmeling, B.; Schauer, M.; Gatzweiler, R.

    1997-01-01

    In 1982, an airborne gamma spectrometer survey was undertaken by SDAG WISMUT which was directed at the detection of further uranium mineralization in Saxony and Thuringia. Anomalies outlined along the Elbe river near the existing Koenigstein uranium mine were attributed to one or a combination of the following causes: radioactive residues from uranium processing facilities located upstream, temporary accumulation of Rn-decay products attached to dust particles in the atmosphere at the time of the survey, and radioactive waters emerging from uraniferous rocks along tectonic structures. In 1994, WISMUT GmbH re-evaluated the survey to determine the need for implementing cleanup measures. Subsequent to the verification of the original airborne data, ground surveys were undertaken that included gamma spectrometry, percussion probing and river sediment sampling. The new results did not confirm the magnitude of most of the 1982 airborne anomalies. The general decline of the radioactivity pointed out by the 1994 ground measurements is interpreted to be a result of the partial erosion and dilution of radionuclides in fluvial sediments as well as burial by additional river sediments since. Additional anomalous copper and zinc concentrations are attributed to sources other than mining. The ground follow-up delineated a new anomalous zone that is caused by radionuclides discharged with treated process and mine water. It is the only area, which may require further investigations and possible remedial action. (author)

  9. Unitary Dynamics of Strongly Interacting Bose Gases with the Time-Dependent Variational Monte Carlo Method in Continuous Space

    Science.gov (United States)

    Carleo, Giuseppe; Cevolani, Lorenzo; Sanchez-Palencia, Laurent; Holzmann, Markus

    2017-07-01

    We introduce the time-dependent variational Monte Carlo method for continuous-space Bose gases. Our approach is based on the systematic expansion of the many-body wave function in terms of multibody correlations and is essentially exact up to adaptive truncation. The method is benchmarked by comparison to an exact Bethe ansatz or existing numerical results for the integrable Lieb-Liniger model. We first show that the many-body wave function achieves high precision for ground-state properties, including energy and first-order as well as second-order correlation functions. Then, we study the out-of-equilibrium, unitary dynamics induced by a quantum quench in the interaction strength. Our time-dependent variational Monte Carlo results are benchmarked by comparison to exact Bethe ansatz results available for a small number of particles, and are also compared to quench action results available for noninteracting initial states. Moreover, our approach allows us to study large particle numbers and general quench protocols, previously inaccessible beyond the mean-field level. Our results suggest that it is possible to find correlated initial states for which the long-term dynamics of local density fluctuations is close to the predictions of a simple Boltzmann ensemble.

  10. Real-time electrical impedimetric monitoring of blood coagulation process under temperature and hematocrit variations conducted in a microfluidic chip.

    Directory of Open Access Journals (Sweden)

    Kin Fong Lei

    Full Text Available Blood coagulation is an extremely complicated and dynamic physiological process. Monitoring of blood coagulation is essential to predict the risk of hemorrhage and thrombosis during cardiac surgical procedures. In this study, a high throughput microfluidic chip has been developed for the investigation of the blood coagulation process under temperature and hematocrit variations. Electrical impedance of the whole blood was continuously recorded by on-chip electrodes in contact with the blood sample during coagulation. Analysis of the impedance change of the blood was conducted to investigate the characteristics of blood coagulation process and the starting time of blood coagulation was defined. The study of blood coagulation time under temperature and hematocrit variations was shown a good agreement with results in the previous clinical reports. The electrical impedance measurement for the definition of blood coagulation process provides a fast and easy measurement technique. The microfluidic chip was shown to be a sensitive and promising device for monitoring blood coagulation process even in a variety of conditions. It is found valuable for the development of point-of-care coagulation testing devices that utilizes whole blood sample in microliter quantity.

  11. IN TIME VARIATION OF PATHERGY PHENOMENON IN BEHCET'S DISEASE

    Directory of Open Access Journals (Sweden)

    C. Chams F. Davatchi

    1996-07-01

    Full Text Available The pathergy phenomenon (PP is one of the hallmarks of Behcet's Disease (BD. It has been reported to be positive from 17.5% to 83% of cases in different studies. PP is used as a diagnosis criterion in the Dilsen criteria, the Japan criteria, the International criteria, and the Iran criteria. It is therefore important to know wether PP is a fix manifestation of the disease or a cyclic manifestation like mucocutaneous disorders. To evaluate the charaterist'tc of P'P over a period of time, 77 patients were selected randomly (rcgaardless of their disease activity or their disease manifestations, to have a second pathergy test, lite pathcrgy test was performed by needle puncture on the skin of the forearm. Three methods were used: 1- needle prick with a 21 - gauge needle. 2- needle prick with a 25  gauge needle. 3- needle prick with a 25-guage needle and the injection of I drop of a sterile normal saline solution. Tlie result was evaluated 24 hours Liter. Tlie shortest interval between two tests-was one month and the longest 13 years. Die mean interval was 35.4 months, the standard deviation was 36.6 Tlurty-nine patients had a negative PI' at their first evaluation. At the second evaluation, 27 remained negative while 12 changed to positive. Thirty-eight patients had a positive PP at their first evaluation. At the second evaluation, 19 remained positive while 19 changed to negative. Although there is a difference between the two groups, it is not statistically significant (x=3.813 , p=0.05. Our data demonstrates that the pathergy phenomenon is waxing and waning, like the majority of other manifestations of Behcet's Disease. TJierefore, it may be repeated for diagnosis purposes.

  12. Pulsatility index variations using two different transit-time flowmeters in coronary artery bypass surgery.

    Science.gov (United States)

    Nordgaard, Håvard B; Vitale, Nicola; Astudillo, Rafael; Renzulli, Attilio; Romundstad, Pål; Haaverstad, Rune

    2010-05-01

    Transit-time flow measurement is widely accepted as an intra-operative assessment in coronary artery bypass grafting (CABG). However, the two most commonly applied flowmeters, manufactured by MediStim ASA and Transonic Inc., have different default filter settings of 20 and 10 Hz, respectively. This may cause different flow measurements, which will influence the reported results. The aim was to compare pulsatility index (PI) values recorded by the MediStim and Transonic flowmeters in two different clinical settings: (1) analysis of the flow patterns recorded simultaneously by both flowmeters in the same CABGs; and (2) evaluation of flow patterns under different levels of filter settings in the same grafts. Graft flow and PI were measured using the two different flowmeters simultaneously in 19 bypass grafts. Finally, eight grafts were assessed under different digital filter settings at 5, 10, 20, 30, 50 and 100 Hz. The Transonic flowmeter provided substantially lower PI as compared with the MediStim flowmeter. By increasing the filter setting in the flowmeter, PI increased considerably. The Transonic flowmeter displayed a lower PI than the MediStim, due to a lower filter setting. In the Transonic,flow signals are filtered at a lower level, rendering a 'smoother' pattern of flow curves. Because different filter settings determine different PIs, caution must be taken when flow values and flowmeters are compared. The type of flowmeter should be indicated whenever graft flow measurements and derived indexes are provided [corrected]. Copyright 2009 European Association for Cardio-Thoracic Surgery. All rights reserved.

  13. Estimation of water transit time in soils under Amazon forest cover using variations in delta18O values

    International Nuclear Information System (INIS)

    Leopoldo, P.R.; Matsui, E.; Salati, E.

    1984-01-01

    The work was carried out at the forest reserve of the Instituto Nacional de Pesquisas da Amazonia, located at km 45 of Manaus, in an area characterized by Amazon vegetation of the 'terra-firme' type. To extract the soil water, four soil-water collecting stations were installed, and in each the porous cups were placed at 15, 25, 50, 80 and 120 cm depth from the soil surface. The rain-water and soil-water samples were collected only weekly for analysis of the 18 O content. In an attempt to estimate the soil-water transit time using the variation in 18 O values, a statistical model was used. This model is based on linear regression analysis applied to the values observed for soil water and rain water. From this analysis, regression coefficients are obtained which vary according to time. The values of the coefficients obtained can be adjusted generally, according to a quadratic regression, with the maximum value of the function representing the time in which the best statistical correlation between the observed delta 18 O values occurs. The time obtained from these correlations represents the mean time necessary for the water to run from one collecting point to the next. (author)

  14. Spatial and time variations of radon-222 concentration in the atmosphere of a dead-end horizontal tunnel

    International Nuclear Information System (INIS)

    Richon, Patrick; Perrier, Frederic; Sabroux, Jean-Christophe; Trique, Michaeel; Ferry, Cecile; Voisin, Vincent; Pili, Eric

    2004-01-01

    The concentration of radon-222 has been monitored since 1995 in the atmosphere of a 2 m transverse dimension, 128 m long, dead-end horizontal tunnel located in the French Alps, at an altitude of 1600 m. Most of the time, the radon concentration is stable, with an average value ranging from 200 Bq m -3 near the entrance to about 1000 Bq m -3 in the most confined section, with an equilibrium factor between radon and its short-lived decay products varying from 0.61 to 0.78. However, radon bursts are repeatedly observed, with amplitudes reaching up to 36 x 10 3 Bq m -3 and durations varying from one to several weeks, with similar spatial variations along the tunnel as the background concentration. These spatial variations are qualitatively interpreted in terms of natural ventilation. Comparing the radon background concentration with the measured radon exhalation flux at the wall yields an estimate of 8 ± 2 x 10 -6 s -1 (0.03 ± 0.007 h -1 ) for the ventilation rate. The hypothesis that the bursts could be due to transient changes in ventilation can be ruled out. Thus, the bursts are the results of transient increased radon exhalation at the walls, that could be due to meteorological effects or possibly combined hydrological and mechanical forcing associated with the water level variations of the nearby Roselend reservoir lake. Such studies are of interest for radiation protection in poorly ventilated underground settings, and, ultimately, for a better understanding of radon exhalation associated with tectonic or volcanic processes

  15. A New Look at the Eclipse Timing Variation Diagram Analysis of Selected 3-body W UMa Systems

    Science.gov (United States)

    Christopoulou, P.-E.; Papageorgiou, A.

    2015-07-01

    The light travel effect produced by the presence of tertiary components can reveal much about the origin and evolution of over-contact binaries. Monitoring of W UMa systems over the last decade and/or the use of publicly available photometric surveys (NSVS, ASAS, etc.) has uncovered or suggested the presence of many unseen companions, which calls for an in-depth investigation of the parameters derived from cyclic period variations in order to confirm or reject the assumption of hidden companion(s). Progress in the analysis of eclipse timing variations is summarized here both from the empirical and the theoretical points of view, and a more extensive investigation of the proposed orbital parameters of third bodies is proposed. The code we have developed for this, implemented in Python, is set up to handle heuristic scanning with parameter perturbation in parameter space, and to establish realistic uncertainties from the least squares fitting. A computational example is given for TZ Boo, a W UMa system with a spectroscopically detected third component. Future options to be implemented include MCMC and bootstrapping.

  16. Time series analyses of hydrological parameter variations and their correlations at a coastal area in Busan, South Korea

    Science.gov (United States)

    Chung, Sang Yong; Senapathi, Venkatramanan; Sekar, Selvam; Kim, Tae Hyung

    2018-02-01

    Monitoring and time-series analysis of the hydrological parameters electrical conductivity (EC), water pressure, precipitation and tide were carried out, to understand the characteristics of the parameter variations and their correlations at a coastal area in Busan, South Korea. The monitoring data were collected at a sharp interface between freshwater and saline water at the depth of 25 m below ground. Two well-logging profiles showed that seawater intrusion has largely expanded (progressed inland), and has greatly affected the groundwater quality in a coastal aquifer of tuffaceous sedimentary rock over a 9-year period. According to the time series analyses, the periodograms of the hydrological parameters present very similar trends to the power spectral densities (PSD) of the hydrological parameters. Autocorrelation functions (ACF) and partial autocorrelation functions (PACF) of the hydrological parameters were produced to evaluate their self-correlations. The ACFs of all hydrologic parameters showed very good correlation over the entire time lag, but the PACF revealed that the correlations were good only at time lag 1. Crosscorrelation functions (CCF) were used to evaluate the correlations between the hydrological parameters and the characteristics of seawater intrusion in the coastal aquifer system. The CCFs showed that EC had a close relationship with water pressure and precipitation rather than tide. The CCFs of water pressure with tide and precipitation were in inverse proportion, and the CCF of water pressure with precipitation was larger than that with tide.

  17. Short-time variations of the solar neutrino luminosity (Fourier analysis of the argon-37 production rate data)

    International Nuclear Information System (INIS)

    Haubold, H.J.; Gerth, E.

    1985-01-01

    We continue the Fourier analysis of the argon-37 production rate for runs 18--80 observed in Davis' well known solar neutrino experiment. The method of Fourier analysis with the unequally-spaced data of Davis and associates is described and the discovered periods we compare with our recently published results for the analysis of runs 18--69 (Haubold and Gerth, 1983). The harmonic analysis of the data of runs 18--80 shows time variations of the solar neutrino flux with periods π = 8.33; 5.26; 2.13; 1.56; 0.83; 0.64; 0.54; and 0.50 years, respectively, which confirms our earlier computations

  18. A Finite-Time Thermal Cycle Variational Optimization with a Stefan–Boltzmann Law for Three Different Criteria

    Directory of Open Access Journals (Sweden)

    Juan C. Chimal-Eguía

    2012-12-01

    Full Text Available This work shows the power of the variational approach for studying the efficiency of thermal engines in the context of the Finite Time Thermodynamics (FTT. Using an endoreversible Curzon–Ahlborn (CA heat engine as a model for actual thermal engines, three different criteria for thermal efficiency were analyzed: maximum power output, ecological function, and maximum power density. By means of this procedure, the performance of the CA heat engine with a nonlinear heat transfer law (the Stefan–Boltzmann law was studied to describe the heat exchanges between the working substance and its thermal reservoirs. The specific case of the Müser engine for all the criteria was analyzed. The results confirmed some previous findings using other procedures and additionally new results for the Müser engine performance were obtained.

  19. Fetal short time variation during labor: a non-invasive alternative to fetal scalp pH measurements?

    Science.gov (United States)

    Schiermeier, Sven; Reinhard, Joscha; Hatzmann, Hendrike; Zimmermann, Ralf C; Westhof, Gregor

    2009-01-01

    To determine whether short time variation (STV) of fetal heart beat correlates with scalp pH measurements during labor. From 1279 deliveries, 197 women had at least one fetal scalp pH measurement. Using the CTG-Player, STVs were calculated from the electronically saved cardiotocography (CTG) traces and related to the fetal scalp pH measurements. There was no correlation between STV and fetal scalp pH measurements (r=-0.0592). Fetal STV is an important parameter with high sensitivity for antenatal fetal acidosis. This study shows that STV calculations do not correlate with fetal scalp pH measurements during labor, hence are not helpful in identifying fetal acidosis.

  20. Genetic variation in IL-16 miRNA target site and time to prostate cancer diagnosis in African American men

    Science.gov (United States)

    Hughes, Lucinda; Ruth, Karen; Rebbeck, Timothy R.; Giri, Veda N.

    2013-01-01

    Background Men with a family history of prostate cancer and African American men are at high risk for prostate cancer and in need of personalized risk estimates to inform screening decisions. This study evaluated genetic variants in genes encoding microRNA (miRNA) binding sites for informing of time to prostate cancer diagnosis among ethnically-diverse, high-risk men undergoing prostate cancer screening. Methods The Prostate Cancer Risk Assessment Program (PRAP) is a longitudinal screening program for high-risk men. Eligibility includes men ages 35-69 with a family history of prostate cancer or African descent. Participants with ≥ 1 follow-up visit were included in the analyses (n=477). Genetic variants in regions encoding miRNA binding sites in four target genes (ALOX15, IL-16, IL-18, and RAF1) previously implicated in prostate cancer development were evaluated. Genotyping methods included Taqman® SNP Genotyping Assay (Applied Biosystems) or pyrosequencing. Cox models were used to assess time to prostate cancer diagnosis by risk genotype. Results Among 256 African Americans with ≥ one follow-up visit, the TT genotype at rs1131445 in IL-16 was significantly associated with earlier time to prostate cancer diagnosis vs. the CC/CT genotypes (p=0.013), with a suggestive association after correction for false-discovery (p=0.065). Hazard ratio after controlling for age and PSA for TT vs. CC/CT among African Americans was 3.0 (95% CI 1.26-7.12). No association to time to diagnosis was detected among Caucasians by IL-16 genotype. No association to time to prostate cancer diagnosis was found for the other miRNA target genotypes. Conclusions Genetic variation in IL-16 encoding miRNA target site may be informative of time to prostate cancer diagnosis among African American men enrolled in prostate cancer risk assessment, which may inform individualized prostate cancer screening strategies in the future. PMID:24061634

  1. Racial and Ethnic Variation in Time to Prostate Biopsy After an Elevated Screening Level of Serum Prostate-specific Antigen.

    Science.gov (United States)

    Reading, Stephanie R; Porter, Kimberly R; Hsu, Jin-Wen Y; Wallner, Lauren P; Loo, Ronald K; Jacobsen, Steven J

    2016-10-01

    To examine the racial and ethnic variation in time to prostate biopsy after an elevated screening level of serum prostate-specific antigen (PSA). Male members of the Kaiser Permanente of Southern California health plan, 45 years of age or older, with no history of prostate cancer or a prostate biopsy, and at least 1 elevated screening level of serum PSA between January 1, 1998 and December 31, 2007 were retrospectively identified (n = 59,506). All participants were passively followed via electronic health records until their time of prostate biopsy, death, membership disenrollment, or study conclusion (December 31, 2014), whichever was the initial event. Proportional hazard regression analyses were used to estimate the association between time from an elevated screening level of serum PSA to prostate biopsy, adjusting for age, benign prostatic hyperplasia, prostatitis, type 2 diabetes mellitus, hypertension, and Charlson Comorbidity Index score. Median time until biopsy was 0.6 years (214 days), with approximately 41% of participants receiving a prostate biopsy within the study period. Results from the fully adjusted analysis indicated that the non-Hispanic Asian or Pacific Islanders (hazard ratio: 1.10, 95% confidence interval: [1.04, 1.15]) and the non-Hispanic blacks (hazard ratio: 1.04, 95% confidence interval: [1.00, 1.08]) had a slightly shorter time to prostate biopsy after an elevated screening level of serum PSA compared to the non-Hispanic whites. These data suggest that, within an integrated healthcare organization, minimal differences exist between racial and ethnic subgroups in their time to prostate biopsy after an elevated screening level of serum PSA. Copyright © 2016. Published by Elsevier Inc.

  2. Variations in VLT/UVES-based OH rotational temperatures for time scales from hours to 15 years

    Science.gov (United States)

    Noll, Stefan; Kimeswenger, Stefan; Proxauf, Bastian; Kausch, Wolfgang; Unterguggenberger, Stefanie; Jones, Amy M.

    2017-04-01

    Hydroxyl (OH) emission is an important tracer of the climate, chemistry, and dynamics of the Earth's mesopause region. However, the relation of intensity variations in different OH lines is not well understood yet. This is critical for the most popular use of OH lines: the estimate of ambient temperatures based on transitions at low rotational levels of the same band. It is possible that the measured variability of the derived rotational temperature does not coincide with changes in the ambient temperature. Such differences can be caused by varying deviations from the local thermodynamic equilibrium (LTE) for the population distribution over the considered rotational levels. The non-LTE effects depend on the ratio of the thermalising collisions (mostly related to molecular oxygen) and competing radiative transitions or collisions without thermalisation of the rotational level distribution. Therefore, significant changes in the vertical structure of excited OH and its main quenchers can affect the temperature measurements. We have investigated the variability of OH rotational temperatures and the corresponding contributions of non-LTE effects for different OH bands and time scales up to 15 years based on data of the high-resolution echelle spectrograph UVES at the Very Large Telescope at Cerro Paranal in Chile. In order to link the measured rotational temperatures with the structure of the OH emission layer, we have also studied OH emission and kinetic temperature profiles from the multi-channel radiometer SABER on the TIMED satellite taken between 2002 and 2015. The results show that non-LTE contributions can significantly affect the OH rotational temperatures. Their variations can be especially strong during the night and for high upper vibrational levels of the transitions, where amplitudes of several Kelvins can be measured. They appear to be weak if long-term variations such as those caused by the solar cycle are investigated. These differences in the response

  3. Detecting Inter-Annual Variations in the Phenology of Evergreen Conifers Using Long-Term MODIS Vegetation Index Time Series

    Directory of Open Access Journals (Sweden)

    Laura Ulsig

    2017-01-01

    Full Text Available Long-term observations of vegetation phenology can be used to monitor the response of terrestrial ecosystems to climate change. Satellite remote sensing provides the most efficient means to observe phenological events through time series analysis of vegetation indices such as the Normalized Difference Vegetation Index (NDVI. This study investigates the potential of a Photochemical Reflectance Index (PRI, which has been linked to vegetation light use efficiency, to improve the accuracy of MODIS-based estimates of phenology in an evergreen conifer forest. Timings of the start and end of the growing season (SGS and EGS were derived from a 13-year-long time series of PRI and NDVI based on a MAIAC (multi-angle implementation of atmospheric correction processed MODIS dataset and standard MODIS NDVI product data. The derived dates were validated with phenology estimates from ground-based flux tower measurements of ecosystem productivity. Significant correlations were found between the MAIAC time series and ground-estimated SGS (R2 = 0.36–0.8, which is remarkable since previous studies have found it difficult to observe inter-annual phenological variations in evergreen vegetation from satellite data. The considerably noisier NDVI product could not accurately predict SGS, and EGS could not be derived successfully from any of the time series. While the strongest relationship overall was found between SGS derived from the ground data and PRI, MAIAC NDVI exhibited high correlations with SGS more consistently (R2 > 0.6 in all cases. The results suggest that PRI can serve as an effective indicator of spring seasonal transitions, however, additional work is necessary to confirm the relationships observed and to further explore the usefulness of MODIS PRI for detecting phenology.

  4. Community variations in population exposure to near-field tsunami hazards as a function of pedestrian travel time to safety

    Science.gov (United States)

    Wood, Nathan J.; Schmidtlein, Mathew C.

    2013-01-01

    Efforts to characterize population exposure to near-field tsunami threats typically focus on quantifying the number and type of people in tsunami-hazard zones. To develop and prioritize effective risk-reduction strategies, emergency managers also need information on the potential for successful evacuations and how this evacuation potential varies among communities. To improve efforts to properly characterize and differentiate near-field tsunami threats among multiple communities, we assess community variations in population exposure to tsunamis as a function of pedestrian travel time to safety. We focus our efforts on the multiple coastal communities in Grays Harbor and Pacific Counties (State of Washington, USA), where a substantial resident and visitor population is threatened by near-field tsunamis related to a potential Cascadia subduction zone earthquake. Anisotropic, path-distance modeling is conducted to estimate travel times to safety and results are merged with various population data, including residents, employees, public venues, and dependent-care facilities. Results suggest that there is substantial variability among communities in the number of people that may have insufficient time to evacuate. Successful evacuations may be possible in some communities assuming slow-walking speeds, are plausible in others if travel speeds are increased, and are unlikely in another set of communities given the large distances and short time horizon. Emergency managers can use these results to prioritize the location and determine the most appropriate type of tsunami risk-reduction strategies, such as education and training in areas where evacuations are plausible and vertical-evacuation structures in areas where they are not.

  5. Tectono-metamorphic evolution of the Jomolhari massif: Variations in timing of syn-collisional metamorphism across western Bhutan

    Science.gov (United States)

    Regis, Daniele; Warren, Clare J.; Young, David; Roberts, Nick M. W.

    2014-03-01

    Our current understanding of the rates and timescales of mountain-building processes is largely based on information recorded in U-bearing accessory minerals such as monazite, which is found in low abundance but which hosts the majority of the trace element budget. Monazite petrochronology was used to investigate the timing of crustal melting in migmatitic metasedimentary rocks from the Jomolhari massif (NW Bhutan). The samples were metamorphosed at upper amphibolite to granulite facies conditions (~ 0.85 GPa, ~ 800 °C), after an earlier High-Pressure stage (P > 1.4 GPa), and underwent partial melting through dehydration melting reactions involving muscovite and biotite. In order to link the timing of monazite growth/dissolution to the pressure-temperature (P-T) evolution of the samples, we identified 'chemical fingerprints' in major and accessory phases that were used to back-trace specific metamorphic reactions. Variations in Eu anomaly and Ti in garnet were linked to the growth and dissolution of major phases (e.g. growth of K-feldspar and dehydration melting of muscovite/biotite). Differences in M/HREE and Y from garnet core to rim were instead related to apatite breakdown and monazite-forming reactions. Chemically zoned monazite crystals reacted multiple times during the metamorphic evolution suggesting that the Jomolhari massif experienced a prolonged high-temperature metamorphic evolution from 36 Ma to 18 Ma, significantly different from the P-T-time path recorded in other portions of the Greater Himalayan Sequence (GHS) in Bhutan. Our data demonstrate unequivocally that the GHS in Bhutan consists of units that experienced independent high-grade histories and that were juxtaposed across different tectonic structures during exhumation. The GHS may have been exhumed in response to (pulsed) mid-crustal flow but cannot be considered a coherent block.

  6. TRANSIT TIMING VARIATION MEASUREMENTS OF WASP-12b AND QATAR-1b: NO EVIDENCE OF ADDITIONAL PLANETS

    Energy Technology Data Exchange (ETDEWEB)

    Collins, Karen A.; Stassun, Keivan G. [Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235 (United States); Kielkopf, John F. [Department of Physics and Astronomy, University of Louisville, Louisville, KY 40292 (United States)

    2017-02-01

    WASP-12b and Qatar-1b are transiting hot Jupiters for which previous works have suggested the presence of transit timing variations (TTVs) indicative of additional bodies in these systems—an Earth-mass planet in WASP-12 and a brown-dwarf mass object in Qatar-1. Here, we present 23 new WASP-12b and 18 new Qatar-1b complete (or nearly complete) transit observations. We perform global system fits to all of our light curves for each system, as well as RV and stellar spectroscopic parameters from the literature. The global fits provide refined system parameters and uncertainties for each system, including precise transit center times for each transit. The transit model residuals of the combined and five minute binned light curves have an rms of 183 and 255 parts per million (ppm) for WASP-12b and Qatar-1b, respectively. Most of the WASP-12b system parameter values from this work are consistent with values from previous studies, but have ∼40%–50% smaller uncertainties. Most of the Qatar-1b system parameter values and uncertainties from this work are consistent with values recently reported in the literature. We find no convincing evidence for sinusoidal TTVs with a semi-amplitude of more than ∼35 and ∼25 s in the WASP-12b and Qatar-1b systems, respectively.

  7. On the problem of the flux value of cosmic origin radioisotopes on the Earth and their time variations

    International Nuclear Information System (INIS)

    Styro, B.I.; Luyanas, V.Yu.; Zinkyavichyus, P.K.

    1977-01-01

    Cosmogenic radioisotopes flows on the Earth's surface are investigated. Nuclear reactions by the action of slow neutrons (cosmic rays) are analysed. It has been testified that the role of Ne, Kr, Ze and nuclei of the volcanic substance in production of cosmogenic nuclids is insignificant. Radioisotopes can provide by meteorites while passing through the atmosphere as a result of ablation. The evaluations of the meteoritic sustance falling out to the Earth can be used as a base to calculate flows of a number of radioactive isotopes. The flow density of most isotopes which come with the meteoric substance are quite insignificant. However the 26 Al flows can be of the same value as that of the rate of their production in the atmosphere. Changes of the rate of the production of cosmogenic isotopes both due to the flow variations meteoric and as a result of the cosmic ray intensity oscillations first of all effect the stratospheral reservoir. Time oscillations of cosmogenic radioisotope flows to the Earth's surface will occur with some delay because the life time of isotopes in the stratosphere lasts several years. The evaluation is given of the difference of phases between oscillations of the stratospheral rate of the formation of long-living isotopes and the flow density to the Earth's surface. It can approximate to 1-2 years

  8. Rolling Element Bearing Performance Degradation Assessment Using Variational Mode Decomposition and Gath-Geva Clustering Time Series Segmentation

    Directory of Open Access Journals (Sweden)

    Yaolong Li

    2017-01-01

    Full Text Available By focusing on the issue of rolling element bearing (REB performance degradation assessment (PDA, a solution based on variational mode decomposition (VMD and Gath-Geva clustering time series segmentation (GGCTSS has been proposed. VMD is a new decomposition method. Since it is different from the recursive decomposition method, for example, empirical mode decomposition (EMD, local mean decomposition (LMD, and local characteristic-scale decomposition (LCD, VMD needs a priori parameters. In this paper, we will propose a method to optimize the parameters in VMD, namely, the number of decomposition modes and moderate bandwidth constraint, based on genetic algorithm. Executing VMD with the acquired parameters, the BLIMFs are obtained. By taking the envelope of the BLIMFs, the sensitive BLIMFs are selected. And then we take the amplitude of the defect frequency (ADF as a degradative feature. To get the performance degradation assessment, we are going to use the method called Gath-Geva clustering time series segmentation. Afterwards, the method is carried out by two pieces of run-to-failure data. The results indicate that the extracted feature could depict the process of degradation precisely.

  9. Detection of different-time-scale signals in the length of day variation based on EEMD analysis technique

    Directory of Open Access Journals (Sweden)

    Wenbin Shen

    2016-05-01

    Full Text Available Scientists pay great attention to different-time-scale signals in the length of day (LOD variations ΔLOD, which provide signatures of the Earth's interior structure, couplings among different layers, and potential excitations of ocean and atmosphere. In this study, based on the ensemble empirical mode decomposition (EEMD, we analyzed the latest time series of ΔLOD data spanning from January 1962 to March 2015. We observed the signals with periods and amplitudes of about 0.5 month and 0.19 ms, 1.0 month and 0.19 ms, 0.5 yr and 0.22 ms, 1.0 yr and 0.18 ms, 2.28 yr and 0.03 ms, 5.48 yr and 0.05 ms, respectively, in coincidence with the results of predecessors. In addition, some signals that were previously not definitely observed by predecessors were detected in this study, with periods and amplitudes of 9.13 d and 0.12 ms, 13.69 yr and 0.10 ms, respectively. The mechanisms of the LOD fluctuations of these two signals are still open.

  10. Investigation into the Mpemba Effect: Variation in the Freezing Time of Water Dependent on Initial Temperature and Purity

    Science.gov (United States)

    Thvedt, Ingrid; Roseberry, Martha; Lehman, Susan

    2009-03-01

    The observation that hot water sometimes appears to freeze more quickly than cold water, known as the Mpemba effect, has generated vigorous debate. Prior research [1] into the Mpemba effect has resulted in conflicting results, due to a variety of observation techniques, multiple definitions of freezing, and different water treatments. To clarify the previous results, we have tested multiple types of water and improved the sample monitoring. During cooling and freezing, each 50 g water sample is continually monitored by three thermistors at different depths. Samples of tap, distilled, and nanopure water were heated, heated and cooled, or boiled before being frozen. We monitor the time to reach freezing, the duration of freezing, and the total time to reach -7^oC. We observe the Mpemba effect most consistently in the length of the freezing transition in tap water. Observations of temperature variation during freezing will also be presented. [1] See the review by M. Jeng, Am.J.Phys. 74 514 (2006).

  11. Time-of-night variations in the story-like organization of dream experience developed during rapid eye movement sleep.

    Science.gov (United States)

    Cipolli, Carlo; Guazzelli, Mario; Bellucci, Claudia; Mazzetti, Michela; Palagini, Laura; Rosenlicht, Nicholas; Feinberg, Irwin

    2015-04-01

    This study aimed to investigate the cycles (2nd/4th) and duration-related (5/10 min) variations in the story-like organization of dream experience elaborated during rapid eye movement (REM) sleep. Dream reports were analysed using story grammar rules. Reports were provided by those subjects (14 of 22) capable of reporting a dream after each of the four awakenings provoked in 2 consecutive nights during REM sleep of the 2nd and 4th cycles, after periods of either 5 or 10 min, counterbalanced across the nights. Two researchers who were blind as to the sleep condition scored the dream reports independently. The values of the indicators of report length (measured as value of total word count) and of story-like organization of dream reports were matched taking time-of-night (2nd and 4th cycles) and REM duration (5 versus 10 min) as factors. Two-way analyses of variance showed that report length increased significantly in 4th-cycle REM sleep and nearly significantly for longer REM duration, whereas the number of dream-stories per report did not vary. The indices of sequential (number of statements describing the event structure developed in the story) and hierarchical (number of episodes per story) organization increased significantly only in dream-stories reported after 10 min of 4th-cycle REM sleep. These findings indicate that the characteristics of structural organization of dream-stories vary along with time of night, and suggest that the elaboration of a long and complex dream-story requires a fairly long time and the availability of a great amount of cognitive resources to maintain its continuity and coherence. © 2014 European Sleep Research Society.

  12. Life time fatality risk assessment due to variation of indoor radon concentration in dwellings in western Haryana, India

    International Nuclear Information System (INIS)

    Kansal, Sandeep; Mehra, Rohit; Singh, N.P.

    2012-01-01

    Indoor radon measurements in 60 dwellings belonging to 12 villages of Sirsa, Fatehbad and Hisar districts of western Haryana, India, have been carried out, using LR-115 type II cellulose nitrate films in the bare mode. The annual average indoor radon value in the studied area varies from 76.00 to 115.46 Bq m −3 , which is well within the recommended action level 200–300 Bq m −3 (). The winter/summer ratio of indoor radon ranges from 0.78 to 2.99 with an average of 1.52. The values of annual average dose received by the residents and Life time fatality risk assessment due to variation of indoor radon concentration in dwellings of studied area suggests that there is no significance threat to the human beings due to the presence of natural radon in the dwellings. - Highlights: ► The radon concentration values in the dwellings are 2–3 times more than the world average of 40 Bq m −3 . ► These values are lower than the recommended action level of 200–300 Bq m −3 (). ► The annual effective dose is less than the recommended action level of 3–10 mSv per year (). ► The values of life time fatality risk determined for the studied area are within safe standards. ► There is no significant threat to the human beings due to the presence of natural radon in the dwellings.

  13. SYSTEMATIC CENTER-TO-LIMB VARIATION IN MEASURED HELIOSEISMIC TRAVEL TIMES AND ITS EFFECT ON INFERENCES OF SOLAR INTERIOR MERIDIONAL FLOWS

    International Nuclear Information System (INIS)

    Zhao Junwei; Nagashima, Kaori; Bogart, R. S.; Kosovichev, A. G.; Duvall, T. L. Jr.

    2012-01-01

    We report on a systematic center-to-limb variation in measured helioseismic travel times, which must be taken into account for an accurate determination of solar interior meridional flows. The systematic variation, found in time-distance helioseismology analysis using SDO/HMI and SDO/AIA observations, is different in both travel-time magnitude and variation trend for different observables. It is not clear what causes this systematic effect. Subtracting the longitude-dependent east-west travel times, obtained along the equatorial area, from the latitude-dependent north-south travel times, obtained along the central meridian area, gives remarkably similar results for different observables. We suggest this as an effective procedure for removing the systematic center-to-limb variation. The subsurface meridional flows obtained from inversion of the corrected travel times are approximately 10 m s –1 slower than those obtained without removing the systematic effect. The detected center-to-limb variation may have important implications in the derivation of meridional flows in the deep interior and needs to be better understood.

  14. SYSTEMATIC CENTER-TO-LIMB VARIATION IN MEASURED HELIOSEISMIC TRAVEL TIMES AND ITS EFFECT ON INFERENCES OF SOLAR INTERIOR MERIDIONAL FLOWS

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Junwei; Nagashima, Kaori; Bogart, R. S.; Kosovichev, A. G. [W. W. Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305-4085 (United States); Duvall, T. L. Jr. [Solar Physics Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2012-04-10

    We report on a systematic center-to-limb variation in measured helioseismic travel times, which must be taken into account for an accurate determination of solar interior meridional flows. The systematic variation, found in time-distance helioseismology analysis using SDO/HMI and SDO/AIA observations, is different in both travel-time magnitude and variation trend for different observables. It is not clear what causes this systematic effect. Subtracting the longitude-dependent east-west travel times, obtained along the equatorial area, from the latitude-dependent north-south travel times, obtained along the central meridian area, gives remarkably similar results for different observables. We suggest this as an effective procedure for removing the systematic center-to-limb variation. The subsurface meridional flows obtained from inversion of the corrected travel times are approximately 10 m s{sup -1} slower than those obtained without removing the systematic effect. The detected center-to-limb variation may have important implications in the derivation of meridional flows in the deep interior and needs to be better understood.

  15. Systematic Center-To-Limb Variation in Measured Helioseismic Travel Times and Its Effect on Inferences of Solar Interior Meridional Flows

    Science.gov (United States)

    Zhao, Junwei; Nagashima, Kaori; Bogart, R. S.; Kosovichev, Alexander; Duvall, T. L., Jr.

    2012-01-01

    We report on a systematic center-to-limb variation in measured helioseismic travel times, which must be taken into account for an accurate determination of solar interior meridional flows. The systematic variation, found in time-distance helioseismology analysis using SDO/HMI and SDO/AIA observations, is different in both travel-time magnitude and variation trend for different observables. It is not clear what causes this systematic effect. Subtracting the longitude-dependent east-west travel times, obtained along the equatorial area, from the latitude-dependent north-south travel times, obtained along the central meridian area, gives remarkably similar results for different observables. We suggest this as an effective procedure for removing the systematic center-to-limb variation. The subsurface meridional flows obtained from inversion of the corrected travel times are approximately 10 m s-1 slower than those obtained without removing the systematic effect. The detected center-to-limb variation may have important implications in the derivation of meridional flows in the deep interior and needs to be better understood.

  16. Process-variation aware mapping of best-effort and real-time streaming applications to MPSoCs

    NARCIS (Netherlands)

    Mirzoyan, D.; Akesson, K.B.; Goossens, K.G.W.

    2014-01-01

    As technology scales, the impact of process variation on the maximum supported frequency (FMAX) of individual cores in a multiprocessor system-on-chip (MPSoC) becomes more pronounced. Task allocation without variation-aware performance analysis can greatly compromise performance and lead to a

  17. The Space-Time Variation of Global Crop Yields, Detecting Simultaneous Outliers and Identifying the Teleconnections with Climatic Patterns

    Science.gov (United States)

    Najafi, E.; Devineni, N.; Pal, I.; Khanbilvardi, R.

    2017-12-01

    An understanding of the climate factors that influence the space-time variability of crop yields is important for food security purposes and can help us predict global food availability. In this study, we address how the crop yield trends of countries globally were related to each other during the last several decades and the main climatic variables that triggered high/low crop yields simultaneously across the world. Robust Principal Component Analysis (rPCA) is used to identify the primary modes of variation in wheat, maize, sorghum, rice, soybeans, and barley yields. Relations between these modes of variability and important climatic variables, especially anomalous sea surface temperature (SSTa), are examined from 1964 to 2010. rPCA is also used to identify simultaneous outliers in each year, i.e. systematic high/low crop yields across the globe. The results demonstrated spatiotemporal patterns of these crop yields and the climate-related events that caused them as well as the connection of outliers with weather extremes. We find that among climatic variables, SST has had the most impact on creating simultaneous crop yields variability and yield outliers in many countries. An understanding of this phenomenon can benefit global crop trade networks.

  18. Configuring calendar variation based on time series regression method for forecasting of monthly currency inflow and outflow in Central Java

    Science.gov (United States)

    Setiawan, Suhartono, Ahmad, Imam Safawi; Rahmawati, Noorgam Ika

    2015-12-01

    Bank Indonesia (BI) as the central bank of Republic Indonesiahas a single overarching objective to establish and maintain rupiah stability. This objective could be achieved by monitoring traffic of inflow and outflow money currency. Inflow and outflow are related to stock and distribution of money currency around Indonesia territory. It will effect of economic activities. Economic activities of Indonesia,as one of Moslem country, absolutely related to Islamic Calendar (lunar calendar), that different with Gregorian calendar. This research aims to forecast the inflow and outflow money currency of Representative Office (RO) of BI Semarang Central Java region. The results of the analysis shows that the characteristics of inflow and outflow money currency influenced by the effects of the calendar variations, that is the day of Eid al-Fitr (moslem holyday) as well as seasonal patterns. In addition, the period of a certain week during Eid al-Fitr also affect the increase of inflow and outflow money currency. The best model based on the value of the smallestRoot Mean Square Error (RMSE) for inflow data is ARIMA model. While the best model for predicting the outflow data in RO of BI Semarang is ARIMAX model or Time Series Regression, because both of them have the same model. The results forecast in a period of 2015 shows an increase of inflow money currency happened in August, while the increase in outflow money currency happened in July.

  19. Variational Symplectic Integrator for Long-Time Simulations of the Guiding-Center Motion of Charged Particles in General Magnetic Fields

    International Nuclear Information System (INIS)

    Qin Hong; Guan Xiaoyin

    2008-01-01

    A variational symplectic integrator for the guiding-center motion of charged particles in general magnetic fields is developed for long-time simulation studies of magnetized plasmas. Instead of discretizing the differential equations of the guiding-center motion, the action of the guiding-center motion is discretized and minimized to obtain the iteration rules for advancing the dynamics. The variational symplectic integrator conserves exactly a discrete Lagrangian symplectic structure, and has better numerical properties over long integration time, compared with standard integrators, such as the standard and variable time-step fourth order Runge-Kutta methods

  20. Variational Symplectic Integrator for Long-Time Simulations of the Guiding-Center Motion of Charged Particles in General Magnetic Fields

    International Nuclear Information System (INIS)

    Qin, H.; Guan, X.

    2008-01-01

    A variational symplectic integrator for the guiding-center motion of charged particles in general magnetic fields is developed for long-time simulation studies of magnetized plasmas. Instead of discretizing the differential equations of the guiding-center motion, the action of the guiding-center motion is discretized and minimized to obtain the iteration rules for advancing the dynamics. The variational symplectic integrator conserves exactly a discrete Lagrangian symplectic structure, and has better numerical properties over long integration time, compared with standard integrators, such as the standard and variable time-step fourth order Runge-Kutta methods.

  1. How does the predicted geomagnetic main field variation alter the thermosphere-ionosphere storm-time response?

    Science.gov (United States)

    Maute, A. I.; Lu, G.; Richmond, A. D.

    2017-12-01

    Earth's magnetic main field plays an important role in the thermosphere-ionosphere (TI) system, as well as its coupling to Earth's magnetosphere. The ionosphere consists of a weakly ionized plasma strongly influenced by the main field and embedded in the thermosphere. Therefore, ion-neutral coupling and ionospheric electrodynamics can influence the plasma distribution and neutral dynamics. There are strong longitude variations of the TI storm response. At high latitude magnetosphere-ionosphere coupling is organized by the geomagnetic main field, leading in general to stronger northern middle latitude storm time response in the American sector due to the geomagnetic dipole location. In addition, the weak geomagnetic main field in the American sector leads to larger local ExB drift and can alter the plasma densities. During geomagnetic storms the intense energy input into the high latitude region is redistributed globally, leading to thermospheric heating, wind circulation changes and alterations of the ionospheric electrodynamics. The storm time changes are measurable in the plasma density, ion drift, temperature, neutral composition, and other parameters. All these changes depend, to some degree, on the geomagnetic main field which changes on decadal time scales. In this study, we employ a forecast model of the geomagnetic main field based on data assimilation and geodynamo modeling [Aubert et al., 2015]. The main field model predicts that in 50 years the South Atlantic Anomaly is further weakened by 2 mT and drifts westward by approximately 10o. The dipole axis moves northward and westward by 2o and 6o, respectively. Simulating the March 2015 geomagnetic storm with the Thermosphere-Ionosphere Electrodynamics General Circulation Model (TIE-GCM) driven by the Assimilative Mapping of Ionospheric Electrodynamics (AMIE), we evaluate the thermosphere-ionosphere response using the geomagnetic main field of 2015, 2065, and 2115. We compare the TI response for 2015 with

  2. TRANSIT TIMING OBSERVATIONS FROM KEPLER. II. CONFIRMATION OF TWO MULTIPLANET SYSTEMS VIA A NON-PARAMETRIC CORRELATION ANALYSIS

    International Nuclear Information System (INIS)

    Ford, Eric B.; Moorhead, Althea V.; Morehead, Robert C.; Fabrycky, Daniel C.; Steffen, Jason H.; Carter, Joshua A.; Fressin, Francois; Holman, Matthew J.; Ragozzine, Darin; Charbonneau, David; Lissauer, Jack J.; Rowe, Jason F.; Borucki, William J.; Bryson, Stephen T.; Burke, Christopher J.; Caldwell, Douglas A.; Welsh, William F.; Allen, Christopher; Batalha, Natalie M.; Buchhave, Lars A.

    2012-01-01

    We present a new method for confirming transiting planets based on the combination of transit timing variations (TTVs) and dynamical stability. Correlated TTVs provide evidence that the pair of bodies is in the same physical system. Orbital stability provides upper limits for the masses of the transiting companions that are in the planetary regime. This paper describes a non-parametric technique for quantifying the statistical significance of TTVs based on the correlation of two TTV data sets. We apply this method to an analysis of the TTVs of two stars with multiple transiting planet candidates identified by Kepler. We confirm four transiting planets in two multiple-planet systems based on their TTVs and the constraints imposed by dynamical stability. An additional three candidates in these same systems are not confirmed as planets, but are likely to be validated as real planets once further observations and analyses are possible. If all were confirmed, these systems would be near 4:6:9 and 2:4:6:9 period commensurabilities. Our results demonstrate that TTVs provide a powerful tool for confirming transiting planets, including low-mass planets and planets around faint stars for which Doppler follow-up is not practical with existing facilities. Continued Kepler observations will dramatically improve the constraints on the planet masses and orbits and provide sensitivity for detecting additional non-transiting planets. If Kepler observations were extended to eight years, then a similar analysis could likely confirm systems with multiple closely spaced, small transiting planets in or near the habitable zone of solar-type stars.

  3. Transiting Exoplanet Monitoring Project (TEMP). II. Refined System Parameters and Transit Timing Analysis of HAT-P-33b

    Science.gov (United States)

    Wang, Yong-Hao; Wang, Songhu; Liu, Hui-Gen; Hinse, Tobias C.; Laughlin, Gregory; Wu, Dong-Hong; Zhang, Xiaojia; Zhou, Xu; Wu, Zhenyu; Zhou, Ji-Lin; Wittenmyer, R. A.; Eastman, Jason; Zhang, Hui; Hori, Yasunori; Narita, Norio; Chen, Yuanyuan; Ma, Jun; Peng, Xiyan; Zhang, Tian-Meng; Zou, Hu; Nie, Jun-Dan; Zhou, Zhi-Min

    2017-08-01

    We present 10 R-band photometric observations of eight different transits of the hot Jupiter HAT-P-33b, which has been targeted by our Transiting Exoplanet Monitoring Project. The data were obtained by two telescopes at the Xinglong Station of National Astronomical Observatories of China (NAOC) from 2013 December through 2016 January, and exhibit photometric scatter of 1.6{--}3.0 {mmag}. After jointly analyzing the previously published photometric data, radial-velocity (RV) measurements, and our new light curves, we revisit the system parameters and orbital ephemeris for the HAT-P-33b system. Our results are consistent with the published values except for the planet to star radius ratio ({R}{{P}}/{R}* ), the ingress/egress duration (τ) and the total duration (T 14), which together indicate a slightly shallower and shorter transit shape. Our results are based on more complete light curves, whereas the previously published work had only one complete transit light curve. No significant anomalies in Transit Timing Variations (TTVs) are found, and we place upper mass limits on potential perturbers, largely supplanting the loose constraints provided by the extant RV data. The TTV limits are stronger near mean-motion resonances, especially for the low-order commensurabilities. We can exclude the existence of a perturber with mass larger than 0.6, 0.3, 0.5, 0.5, and 0.3 {M}\\oplus near the 1:3, 1:2, 2:3, 3:2, and 2:1 resonances, respectively.

  4. TRANSIT TIMING OBSERVATIONS FROM KEPLER. II. CONFIRMATION OF TWO MULTIPLANET SYSTEMS VIA A NON-PARAMETRIC CORRELATION ANALYSIS

    Energy Technology Data Exchange (ETDEWEB)

    Ford, Eric B.; Moorhead, Althea V.; Morehead, Robert C. [Astronomy Department, University of Florida, 211 Bryant Space Sciences Center, Gainesville, FL 32611 (United States); Fabrycky, Daniel C. [UCO/Lick Observatory, University of California, Santa Cruz, CA 95064 (United States); Steffen, Jason H. [Fermilab Center for Particle Astrophysics, P.O. Box 500, MS 127, Batavia, IL 60510 (United States); Carter, Joshua A.; Fressin, Francois; Holman, Matthew J.; Ragozzine, Darin; Charbonneau, David [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Lissauer, Jack J.; Rowe, Jason F.; Borucki, William J.; Bryson, Stephen T.; Burke, Christopher J.; Caldwell, Douglas A. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Welsh, William F. [Astronomy Department, San Diego State University, San Diego, CA 92182-1221 (United States); Allen, Christopher [Orbital Sciences Corporation/NASA Ames Research Center, Moffett Field, CA 94035 (United States); Batalha, Natalie M. [Department of Physics and Astronomy, San Jose State University, San Jose, CA 95192 (United States); Buchhave, Lars A., E-mail: eford@astro.ufl.edu [Niels Bohr Institute, Copenhagen University, DK-2100 Copenhagen (Denmark); Collaboration: Kepler Science Team; and others

    2012-05-10

    We present a new method for confirming transiting planets based on the combination of transit timing variations (TTVs) and dynamical stability. Correlated TTVs provide evidence that the pair of bodies is in the same physical system. Orbital stability provides upper limits for the masses of the transiting companions that are in the planetary regime. This paper describes a non-parametric technique for quantifying the statistical significance of TTVs based on the correlation of two TTV data sets. We apply this method to an analysis of the TTVs of two stars with multiple transiting planet candidates identified by Kepler. We confirm four transiting planets in two multiple-planet systems based on their TTVs and the constraints imposed by dynamical stability. An additional three candidates in these same systems are not confirmed as planets, but are likely to be validated as real planets once further observations and analyses are possible. If all were confirmed, these systems would be near 4:6:9 and 2:4:6:9 period commensurabilities. Our results demonstrate that TTVs provide a powerful tool for confirming transiting planets, including low-mass planets and planets around faint stars for which Doppler follow-up is not practical with existing facilities. Continued Kepler observations will dramatically improve the constraints on the planet masses and orbits and provide sensitivity for detecting additional non-transiting planets. If Kepler observations were extended to eight years, then a similar analysis could likely confirm systems with multiple closely spaced, small transiting planets in or near the habitable zone of solar-type stars.

  5. SU-E-T-326: The Oxygen Saturation (SO2) and Breath-Holding Time Variation Applied Active Breathing Control (ABC)

    Energy Technology Data Exchange (ETDEWEB)

    Gong, G; Yin, Y [Shandong Cancer Hospital, Jinan, Shandong (China)

    2014-06-01

    Purpose: To study the oxygen saturation (SO2) and breath-holding time variation applied active breathing control (ABC) in radiotherapy of tumor. Methods: 24 volunteers were involved in our trials, and they all did breath-holding motion assisted by ELEKTA Active Breathing Coordinator 2.0 for 10 times respectively. And the patient monitor was used to observe the oxygen saturation (SO2) variation. The variation of SO2, and length of breath-holding time and the time for recovering to the initial value of SO2 were recorded and analyzed. Results: (1) The volunteers were divided into two groups according to the SO2 variation in breath-holding: A group, 14 cases whose SO2 reduction were more than 2% (initial value was 97% to 99%, while termination value was 91% to 96%); B group, 10 cases were less than 2% in breath-holding without inhaling oxygen. (2) The interfraction breath holding time varied from 8 to 20s for A group compared to the first breath-holding time, and for B group varied from 4 to 14s. (3) The breathing holding time of B group prolonged mean 8s, compared to A group. (4) The time for restoring to the initial value of SO2 was from 10s to 30s. And the breath-holding time shortened obviously for patients whose SO2 did not recover to normal. Conclusion: It is very obvious that the SO2 reduction in breath-holding associated with ABC for partial people. It is necessary to check the SO2 variation in breath training, and enough time should be given to recover SO2.

  6. Detection and Characterization of Ground Displacement Sources from Variational Bayesian Independent Component Analysis of GPS Time Series

    Science.gov (United States)

    Gualandi, A.; Serpelloni, E.; Belardinelli, M. E.

    2014-12-01

    A critical point in the analysis of ground displacements time series is the development of data driven methods that allow to discern and characterize the different sources that generate the observed displacements. A widely used multivariate statistical technique is the Principal Component Analysis (PCA), which allows to reduce the dimensionality of the data space maintaining most of the variance of the dataset explained. It reproduces the original data using a limited number of Principal Components, but it also shows some deficiencies. Indeed, PCA does not perform well in finding the solution to the so-called Blind Source Separation (BSS) problem, i.e. in recovering and separating the original sources that generated the observed data. This is mainly due to the assumptions on which PCA relies: it looks for a new Euclidean space where the projected data are uncorrelated. Usually, the uncorrelation condition is not strong enough and it has been proven that the BSS problem can be tackled imposing on the components to be independent. The Independent Component Analysis (ICA) is, in fact, another popular technique adopted to approach this problem, and it can be used in all those fields where PCA is also applied. An ICA approach enables us to explain the time series imposing a fewer number of constraints on the model, and to reveal anomalies in the data such as transient signals. However, the independence condition is not easy to impose, and it is often necessary to introduce some approximations. To work around this problem, we use a variational bayesian ICA (vbICA) method, which models the probability density function (pdf) of each source signal using a mix of Gaussian distributions. This technique allows for more flexibility in the description of the pdf of the sources, giving a more reliable estimate of them. Here we present the application of the vbICA technique to GPS position time series. First, we use vbICA on synthetic data that simulate a seismic cycle

  7. The "Nursing Home Compare" measure of urinary/fecal incontinence: cross-sectional variation, stability over time, and the impact of case mix.

    Science.gov (United States)

    Li, Yue; Schnelle, John; Spector, William D; Glance, Laurent G; Mukamel, Dana B

    2010-02-01

    To assess the impact of facility case mix on cross-sectional variations and short-term stability of the "Nursing Home Compare" incontinence quality measure (QM) and to determine whether multivariate risk adjustment can minimize such impacts. Retrospective analyses of the 2005 national minimum data set (MDS) that included approximately 600,000 long-term care residents in over 10,000 facilities in each quarterly sample. Mixed logistic regression was used to construct the risk-adjusted QM (nonshrinkage estimator). Facility-level ordinary least-squares models and adjusted R(2) were used to estimate the impact of case mix on cross-sectional and short-term longitudinal variations of currently published and risk-adjusted QMs. At least 50 percent of the cross-sectional variation and 25 percent of the short-term longitudinal variation of the published QM are explained by facility case mix. In contrast, the cross-sectional and short-term longitudinal variations of the risk-adjusted QM are much less susceptible to case-mix variations (adjusted R(2)case-mix variations across facilities and over time, and therefore it may be biased. This issue can be largely addressed by multivariate risk adjustment using risk factors available in the MDS.

  8. The time series variations of tritium concentration in precipitation and its relationships to the rainfall-inducing air mass

    International Nuclear Information System (INIS)

    Shimada, Jun

    1978-01-01

    The author measured the tritium concentration in precipitation of Tokyo for every ten-day period from August 1972 to May 1974. Judging from the daily synoptic weather chart, the rainfall-inducing air masses in Japan were classified into five types; polar maritime air mass (Pm), polar continental air mass (Pc), tropical maritime air mass (Tm), tropical continental air mass (Tc), and equatorial maritime air mass (Em). And the precipitation for every ten-day period sampled for tritium measurement were classified into these five types. Based on this classification, it is confirmed that there exist clear difference in the tritium concentration between the rainfall from the continental air mass and ones from the maritime air mass. It is characteristic that the tritium concentration in rainfall induced by equatorial maritime air mass such as typhoon in summer and early fall season is very low whereas the tritium concentration in rainfall and snowfall induced directly by the polar continental air mass in late winter season is very high. The regional difference of the tritium concentration in intermonthly precipitation could considerably be explained by this synoptic meteological classification of rainfall-inducing air mass. In spite of these regional difference of tritium concentration in precipitation, use of the tritium concentration of Tokyo as a representative value of Japan may be allowed because of the similarities of the changing pattern and annual mean tritium concentration. The time series variations of tritium concentration in precipitation of Tokyo from August 1972 to December 1977, Tsukuba from December 1976 to April 1978, and Nagaoka from April 1977 to March 1978 are listed. (author)

  9. Cross-Sectional Distribution of GARCH Coefficients across S&P 500 Constituents: Time-Variation over the Period 2000-2012

    OpenAIRE

    David Ardia; Lennart F. Hoogerheide

    2013-01-01

    We investigate the time-variation of the cross-sectional distribution of asymmetric GARCH model parameters over the S&P 500 constituents for the period 2000-2012. We find the following results. First, the unconditional variances in the GARCH model obviously show major time-variation, with a high level after the dot-com bubble and the highest peak in the latest financial crisis. Second, in these more volatile periods it is especially the persistence of deviations of volatility from is uncondit...

  10. Haplotype Variation of Flowering Time Genes of Sugar Beet and Its Wild Relatives and the Impact on Life Cycle Regimes

    Directory of Open Access Journals (Sweden)

    Nadine Höft

    2018-01-01

    Full Text Available The species Beta vulgaris encompasses wild and cultivated members with a broad range of phenological development. The annual life cycle is commonly found in sea beets (ssp. maritima from Mediterranean environments which germinate, bolt, and flower within one season under long day conditions. Biennials such as the cultivated sugar beet (B. vulgaris ssp. vulgaris as well as sea beets from northern latitudes require prolonged exposure to cold temperature over winter to acquire floral competence. Sugar beet is mainly cultivated for sugar production in Europe and is likely to have originated from sea beet. Flowering time strongly affects seed yield and yield potential and is thus a trait of high agronomic relevance. Besides environmental cues, there are complex genetic networks known to impact life cycle switch in flowering plants. In sugar beet, BTC1, BvBBX19, BvFT1, and BvFT2 are major flowering time regulators. In this study, we phenotyped plants from a diversity Beta panel encompassing cultivated and wild species from different geographical origin. Plants were grown under different day length regimes with and without vernalization. Haplotype analysis of BTC1, BvBBX19, BvFT1, and BvFT2 was performed to identify natural diversity of these genes and their impact on flowering. We found that accessions from northern latitudes flowered significantly later than those from southern latitudes. Some plants did not flower at all, indicating a strong impact of latitude of origin on life cycle. Haplotype analysis revealed a high conservation of the CCT-, REC-, BBX-, and PEBP-domains with regard to SNP occurrence. We identified sequence variation which may impact life cycle adaptation in beet. Our data endorse the importance of BTC1 in the domestication process of cultivated beets and contribute to the understanding of distribution and adaption of Beta species to different life cycle regimes in response to different environments. Moreover, our data provide a

  11. Variation in mode of physical activity by ethnicity and time since immigration: a cross-sectional analysis

    Directory of Open Access Journals (Sweden)

    Ardern Chris I

    2010-10-01

    Full Text Available Abstract Background Physical activity (PA levels are known to be significantly lower in ethnic minority and immigrant groups living in North America and Europe compared to the general population. While there has been an increase in the number of interventions targeting these groups, little is known about their preferred modes of PA. Methods Using three cycles of the Canadian Community Health Survey (cycles 1.1, 2.1, 3.1; 2000-2005, n = 400,055 this investigation determined PA preferences by self-ascribed ethnicity (White, South Asian, South-East Asian, Blacks, Latin American, West Asian, Aboriginal persons and Other and explored variation in PA preference across time since immigration categories (non-immigrant, established immigrant [> 10 years], and recent immigrant [≤ 10 years]. PA preferences over the past three months were collapsed into eight categories: walking, endurance, recreation, sports, conventional exercise, active commuting, and no PA. Logistic regression models were used to estimate the odds of participating in each PA across ethnicity and time since immigration compared to Whites and non-immigrants, respectively. Results Compared to Whites, all other ethnic groups were more likely to report no PA and were less likely to engage in walking, with the exception of Aboriginal persons (OR: 1.25, CI: 1.16-1.34. Further, all ethnic groups including Aboriginal persons were less likely to engage in endurance, recreation, and sport activities, but more likely to have an active commute compared to Whites. Recent and established immigrants were more likely to have an active commute and no PA, but a lower likelihood of walking, sports, endurance, and recreation activities than non-immigrants. Conclusion Ethnic minority groups and immigrants in Canada tend to participate in conventional forms of exercise compared to Whites and non-immigrants and are less likely to engage in endurance exercise, recreation activities, and sports. Health

  12. DISCOVERY OF TIME VARIATION OF THE INTENSITY OF MOLECULAR LINES IN IRC+10216 IN THE SUBMILLIMETER AND FAR-INFRARED DOMAINS

    Energy Technology Data Exchange (ETDEWEB)

    Cernicharo, J.; Quintana-Lacaci, G.; Agúndez, M.; Velilla-Prieto, L. [Group of Molecular Astrophysics, ICMM, CSIC, C/Sor Juana Inés de La Cruz N3, E-28049 Madrid (Spain); Teyssier, D.; García-Lario, P. [ESA, ESAC, P.O. Box 78, Villanueva de la Cañada, E-28691 Madrid (Spain); Daniel, F. [Univ. Grenoble Alpes, IPAG, F-38000 Grenoble (France); Decin, L. [Instituut voor Sterrenkunde, Katholieke Universiteit Leuven, Celestijnenlaan 200D, B-3001 Leuven (Belgium); Guélin, M. [Institut de Radioastronomie Millimétrique, 300 rue de la Piscine, F-38406 St-Martin d' Hères (France); Encrenaz, P. [LERMA, Observatoire de Paris, 61 Av. de l' Observatoire, F-75014 Paris (France); De Beck, E. [Department of Earth and Space Sciences, Chalmers University of Technology, Onsala Space Observatory, SE 439 92 Onsala (Sweden); Barlow, M. J. [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Groenewegen, M. A. T. [Koninklijke Sterrenwacht van België, Ringlaan 3, B-1180 Brussels (Belgium); Neufeld, D. [Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Pearson, J. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

    2014-11-20

    We report on the discovery of strong intensity variations in the high rotational lines of abundant molecular species toward the archetypical circumstellar envelope of IRC+10216. The observations have been carried out with the Heterodyne Instrument for the Far-Infrared (HIFI) instrument on board Herschel and with the IRAM30 m telescope. They cover several observing periods spreading over three years. The line intensity variations for molecules produced in the external layers of the envelope most likely result from time variations in the infrared pumping rates. We analyze the main implications this discovery has on the interpretation of molecular line emission in the envelopes of Mira-type stars. Radiative transfer calculations must take into account both the time variability of infrared pumping and the possible variation of the dust and gas temperatures with stellar phase in order to reproduce the observation of molecular lines at different epochs. The effect of gas temperature variations with stellar phase could be particularly important for lines produced in the innermost regions of the envelope. Each layer of the circumstellar envelope sees the stellar light radiation with a different lag time (phase). Our results show that this effect must be included in the models. The submillimeter and far infrared lines of asymptotic giant branch stars can no longer be considered as safe intensity calibrators.

  13. Toward constructing a time-series of geomagnetic field variations from thermal remanence in slowly cooled igneous rocks

    Science.gov (United States)

    Burns, Z.; Gee, J. S.

    2017-12-01

    Analysis of paleomagnetic data can not only help us to understand the behavior of the ancient magnetic field but may also further our understanding of the current field, as well as of the mechanisms and constraints of the geodynamo and geomagnetic reversals. A question of particular interest is the possible relationship between reversal frequency and geomagnetic field intensity. Some research appears to indicate a correlation between low intensity and high reversal frequency, seeming to support the theory that low field intensity is what makes reversals possible. In order to study this correlation, we obtained several hundred samples from the 182 Ma Dufek Massif, in Antarctica. This intrusion was cooled slowly, at depth, during the high reversal frequency era of the early Jurassic, and most of our samples record multiple polarity intervals. This, combined with their particularly homogeneous magnetic characteristics, makes them ideally suited for recovering a record of geomagnetic field variations. On approximately 300 samples from the lower portion of the intrusion, we performed step-wise thermal demagnetization of the natural remanent magnetization (NRM), followed by thermal demagnetization of a laboratory thermoremance (TRM), imparted as partial TRMs in three orthogonal directions to assess the reliability of the remanence. These two sets of measurements can tell us about the amount and direction of magnetization acquired at each temperature step and the sample's capacity to acquire a remanence. Corrected for anisotropy, the ratio of the NRM/TRM values at each step multiplied by the value of the lab field can give us an estimate of the paleofield intensity. When convolved with a thermal cooling model for the intrusion, this yields a model of the time-varying ancient field during the intrusion's cooling period. Initial analysis of our data shows average field values of around 20 µT and a minimum of four reversals. The average at this high-latitude site is lower

  14. A passive heat tracer experiment to determine the seasonal variation in residence times in a managed aquifer recharge system with DTS

    NARCIS (Netherlands)

    des Tombe, B.F.; Bakker, M.; Schaars, F; van der Made, KJ; Calje, R; Borst, L.

    2016-01-01

    Targeted provisional session N°8.01 The seasonal variation in residence times is determined in a managed aquifer recharge system using a passive heat tracer test. The managed aquifer recharge system consists of a sequence of alternating elongated recharge basins and rows of recovery wells. The

  15. A moving boundary problem for the Stokes equations involving osmosis : Variational modelling and short-time well-posedness

    NARCIS (Netherlands)

    Lippoth, F.; Peletier, M.A.; Prokert, G.

    2016-01-01

    Within the framework of variational modelling we derive a one-phase moving boundary problem describing the motion of a semipermeable membrane enclosing a viscous liquid, driven by osmotic pressure and surface tension of the membrane. For this problem we prove the existence of classical solutions for

  16. A HIGH ORDER SOLUTION OF THREE DIMENSIONAL TIME DEPENDENT NONLINEAR CONVECTIVE-DIFFUSIVE PROBLEM USING MODIFIED VARIATIONAL ITERATION METHOD

    Directory of Open Access Journals (Sweden)

    Pratibha Joshi

    2014-12-01

    Full Text Available In this paper, we have achieved high order solution of a three dimensional nonlinear diffusive-convective problem using modified variational iteration method. The efficiency of this approach has been shown by solving two examples. All computational work has been performed in MATHEMATICA.

  17. Short-term variations of Icelandic ice cap mass inferred from cGPS coordinate time series

    DEFF Research Database (Denmark)

    Compton, Kathleen; Bennett, Richard A.; Hreinsdóttir, Sigrún

    2017-01-01

    As the global climate changes, understanding short-term variations in water storage is increasingly important. Continuously operating Global Positioning System (cGPS) stations in Iceland record annual periodic motion—the elastic response to winter accumulation and spring melt seasons—with peak-to...

  18. Preanalytical and analytical variation of surface-enhanced laser desorption-ionization time-of-flight mass spectrometry of human serum

    DEFF Research Database (Denmark)

    Albrethsen, Jakob; Bøgebo, Rikke; Olsen, Jesper

    2006-01-01

    BACKGROUND: Surface-enhanced laser desorption-ionization time-of-flight (SELDI-TOF) mass spectrometry of human serum is a potential diagnostic tool in human diseases. In the present study, the preanalytical and analytical variation of SELDI-TOF mass spectrometry of serum was assessed in healthy...... was 18% (6%-34%, n=4) for 16 peaks, and inter-individual CV was 38% (16%-56%, n=16) for 20 peaks. CONCLUSIONS: The pre-analytical and analytical conditions of SELDI-TOF mass spectrometry of serum have a significant impact on the protein peaks, with the number of peaks low and the assay variation high...

  19. Annual and inter-annual variations of 6.5-day-planetary-waves in MLT observed by TIMED/SABER

    Science.gov (United States)

    Huang, Yingying; Li, Huijun; Li, Chongyin; Zhang, Shaodong

    2017-04-01

    Annual and inter-annual variations of 6.5DWs in 20-110 km, 52°S-52°N, 2002-2016 are studied by using v2.0 TIMED/SABER kinetic temperature data. Firstly, global annual variations of 6.5DW's spectral power and amplitudes are obtained. Strong wave amplitudes emerge in 30°S/N-50°S/N, and peaks in altitude separate in stratosphere (40-50 km), mesosphere (80-90 km) and the lower thermosphere (100-110 km), respectively. Their annual variations are similar in both hemispheres, but different in altitude. In 40-50 km, the annual maximums emerge mostly in winters: Dec.-Jan. in the NH and Jul.-Aug. in the SH. In MLT, annual peaks arise twice in each half of year. In 80-90 km, they're mainly in equinoctial seasons and winters: May, Aug.-Sep. and Jan. in the NH and Feb., Nov. and May in the SH. In 100-110 km, they emerge mainly in equinoctial seasons: Apr.-May and Aug.-Sep. in the NH and Feb.-Mar. and Oct.-Nov. in the SH. Then, inter-annual variations of 6.5DW amplitudes during the 14-year period are studied. Frequency spectra of monthly-mean amplitudes show that, main dynamics in long-term variations of 6.5DWs are AO and SAO in both hemispheres. Besides, QBO are visible in both hemispheres and 4-month period signals are noticed in the NH in MLT. Amplitudes of SAO, AO and QBO are obtained by bandpass filter. Their amplitudes are comparable in stratosphere and mesosphere, and QBO signals are weaker than the others in the LT. Vertical variations both of SAO and AO amplitudes are very stable. AO structures have little inter-annual changes, while inter-annual variations of SAO are significant and are related with 6.5DW. It means that annual and inter-annual variations of 6.5DW are mainly controlled by AO and SAO, respectively. Although QBO signals are weaker and their variations are less regular than AO and SAO, their phases seems to relate with inter-annual variations of 6.5DW as well.

  20. Short-term variations of Icelandic ice cap mass inferred from cGPS coordinate time series

    DEFF Research Database (Denmark)

    Compton, Kathleen; Bennett, Richard A.; Hreinsdóttir, Sigrún

    2017-01-01

    As the global climate changes, understanding short-term variations in water storage is increasingly important. Continuously operating Global Positioning System (cGPS) stations in Iceland record annual periodic motion—the elastic response to winter accumulation and spring melt seasons—with peak-to...... insulation in response to tephra deposition following volcanic eruptions, processes that are not resolved with once or twice-yearly stake measurements....

  1. On the Time Variation of Dust Extinction and Gas Absorption for Type Ia Supernovae Observed Through Non-uniform Interstellar Medium

    Science.gov (United States)

    Huang, Xiaosheng; Aldering, Gregory; Biederman, Moriah; Herger, Brendan

    2018-01-01

    For Type Ia supernovae (SNe Ia) observed through a non-uniform interstellar medium (ISM) in its host galaxy, we investigate whether the non-uniformity can cause observable time variations in dust extinction and in gas absorption due to the expansion of the SN photosphere with time. We show that, owing to the steep spectral index of the ISM density power spectrum, sizable density fluctuation amplitudes at the length scale of typical ISM structures (>~ 10 pc) will translate to much smaller fluctuations on the scales of a SN photosphere. Therefore the typical amplitude of time variation due to non-uniform ISM, of absorption equivalent widths and of extinction, would be small. As a result, we conclude that non-uniform ISM density should not impact cosmology measurements based on SNe Ia. We apply our predictions based on the ISM density power law power spectrum to the observations of two highly reddened SNe Ia, SN 2012cu and SN 2014J.

  2. Assessment of the Variation Associated with Repeated Measurement of Gastrointestinal Transit Times and Assessment of the Effect of Oral Ranitidine on Gastrointestinal Transit Times Using a Wireless Motility Capsule System in Dogs

    Directory of Open Access Journals (Sweden)

    Jonathan A. Lidbury

    2012-01-01

    Full Text Available This study aimed to evaluate the variation associated with repeated measurement of gastrointestinal (GI transit times and the effect of oral ranitidine on GI transit times in healthy dogs using a wireless motility capsule (WMC system. Eight privately owned healthy adult dogs were enrolled, and one developed diarrhea and was removed from the study. For the first 3 repetitions, each dog was fed a standard meal followed by oral administration of a WMC. For the 4th repetition, each dog was given ranitidine hydrochloride (75 mg PO every 12 hours prior to and during assessment of GI transit times. Mean between-subject coefficients of variation for gastric emptying time (GET, small and large bowel transit time (SLBTT, and total transit time (TTT were 26.9%, 32.3%, and 19.6%, respectively. Mean within-subject coefficients of variation for GET, SLBTT, and TTT were 9.3%, 19.6%, and 15.9%, respectively. Median GET, SLBTT, and TTT without ranitidine were 719, 1,636, and 2,735 minutes, respectively. Median GET, SLBTT, and TTT with ranitidine were 757, 1,227, and 2,083 minutes, respectively. No significant differences in GI transit times were found between any of the 4 repetitions. Under these experimental conditions, no significant effects of oral ranitidine on GI transit times were observed.

  3. Application of Synthetic Storm Technique for Diurnal and Seasonal Variation of Slant Path Ka-Band Rain Attenuation Time Series over a Subtropical Location in South Africa

    Directory of Open Access Journals (Sweden)

    J. S. Ojo

    2015-01-01

    Full Text Available As technology advances and more demands are on satellite services, rain-induced attenuation still creates one of the most damaging effects of the atmosphere on the quality of radio communication signals, especially those operating above 10 GHz. System designers therefore require statistical information on rain-induced attenuation over the coverage area in order to determine the appropriate transmitter and receiver characteristics to be adopted. This paper presents results on the time-varying rain characterization and diurnal variation of slant path rain attenuation in the Ka-band frequency simulated with synthetic storm techniques over a subtropical location in South Africa using 10-year rain rate time-series data. The analysis is based on the CDF of one-minute rain rate; time-series seasonal variation of rain rate observed over four time intervals: 00:00–06:00, 06:00–12:00, 12:00–18:00, and 18:00–24:00; diurnal fades margin; and diurnal variation of rain attenuation. Comparison was also made between the synthesized values and measured attenuation data. The predicted statistics are in good agreement with those obtained from the propagation beacon measurement in the area. The overall results will be needed for an acceptable planning that can effectively reduce the fade margin to a very low value for an optimum data communication over this area.

  4. Annual and interannual variations in global 6.5DWs from 20 to 110 km during 2002-2016 observed by TIMED/SABER

    Science.gov (United States)

    Huang, Y. Y.; Zhang, S. D.; Li, C. Y.; Li, H. J.; Huang, K. M.; Huang, C. M.

    2017-08-01

    Using version 2.0 of the TIMED/SABER kinetic temperature data, we have conducted a study on the annual and interannual variations of 6.5DWs at 20-110 km, from 52°S to 52°N for 2002-2016. First, we obtained global annual variations in the spectral power and amplitudes of 6.5DWs. We found that strong wave amplitudes emerged from 25°S/N to 52°S/N and peaked in the altitudes of the stratosphere, mesosphere, and the lower thermosphere. The annual variations in the 6.5DWs are similar in both hemispheres but different at various altitudes. At 40-50 km, the annual maxima emerge mostly in winters. In the MLT, annual peaks occurred twice every half year. At 80-90 km, 6.5DWs appeared mainly in equinoctial seasons and winters. At 100-110 km, 6.5DWs emerged mainly in equinoctial seasons. Second, we continued the study of the interannual variations in 6.5DW amplitudes from 2002 to 2016. Frequency spectra of the monthly mean amplitudes showed that main dynamics in the long-term variations of 6.5DWs were AO and SAO in both hemispheres. In addition, 4 month period signals were noticed in the MLT of the NH. The amplitudes of SAO and AO were obtained using a band-pass filter and were found to increase with altitude, as do the 6.5DW amplitudes. In both hemispheres, the relative importance of SAO and AO changes with altitude. At 40-50 and 100-110 km, AO play a dominant role, while at 80-90 km, they are weaker than SAO. Our results show that both the annual and interannual variations in 6.5DWs are mainly caused by the combined action of SAO and AO.

  5. Developmental Change and Time-Specific Variation in Global and Specific Aspects of Self-Concept in Adolescence and Association with Depressive Symptoms

    Science.gov (United States)

    Kuzucu, Yasar; Bontempo, Daniel E.; Hofer, Scott M.; Stallings, Michael C.; Piccinin, Andrea M.

    2014-01-01

    Previous research has demonstrated that adolescents make differential self-evaluations in multiple domains that include physical appearance, academic competence, and peer acceptance. We report growth curve analyses over a seven year period from age 9 to age 16 on the six domains of the Harter Self-Perception Profile for Children. In general, we find little change in self-concept, on average, but do find substantial individual differences in level, rate of change, and time-specific variation in these self- evaluations. The results suggest that sex differences and adoptive status were related to only certain aspects of the participants’ self-concept. Depressive symptoms were found to have significant effects on individual differences in rate of change and on time-specific variation in general self-concept, as well as on some of the specific domains of self-concept. PMID:25143664

  6. Wide variation of prostate-specific antigen doubling time of untreated, clinically localized, low-to-intermediate grade, prostate carcinoma.

    Science.gov (United States)

    Choo, Richard; Klotz, Laurence; Deboer, Gerrit; Danjoux, Cyril; Morton, Gerard C

    2004-08-01

    To assess the prostate specific antigen (PSA) doubling time of untreated, clinically localized, low-to-intermediate grade prostate carcinoma. A prospective single-arm cohort study has been in progress since November 1995 to assess the feasibility of a watchful-observation protocol with selective delayed intervention for clinically localized, low-to-intermediate grade prostate adenocarcinoma. The PSA doubling time was estimated from a linear regression of ln(PSA) against time, assuming a simple exponential growth model. As of March 2003, 231 patients had at least 6 months of follow-up (median 45) and at least three PSA measurements (median 8, range 3-21). The distribution of the doubling time was: 50 years, 56. The median doubling time was 7.0 years; 42% of men had a doubling time of >10 years. The doubling time of untreated clinically localized, low-to-intermediate grade prostate cancer varies widely.

  7. Inter-fraction bladder filling variations and time trends for cervical cancer patients assessed with a portable 3-dimensional ultrasound bladder scanner

    International Nuclear Information System (INIS)

    Ahmad, Rozilawati; Hoogeman, Mischa S.; Quint, Sandra; Mens, Jan Willem; Pree, Ilse de; Heijmen, Ben J.M.

    2008-01-01

    Background and Purpose: For cervical cancer patients, bladder filling variations may result in inadequate EBRT target coverage, unless large safety margins are used. For a group of patients who received full bladder instructions, inter-fraction variations and time trends in bladder volume were quantified, and a 3D ultrasound (US) scanner was tested for on-line bladder volume measurements. Methods and materials: For 24 patients, the bladder volume was measured with US at the time of the planning CT scan, and twice weekly during the course of RT. Comparisons of US with planning CT were used to assess the bladder scanner accuracy. Patients were treated in prone on a belly board, EPID images were acquired to correlate set-up errors with bladder filling variations. Results: Measured US and CT bladder volumes were strongly correlated (R = 0.97, slope 1.1 ± 0.1). The population mean bladder volume at planning of 378 ± 209 ml (1 SD) reduced to 109 ± 88 ml (1 SD) in week 6, a reduction by 71% (average reduction 46 ml/week), revealing a large inter-fraction time trend. Intra-patient variation in bladder volume during RT was 168 ml (1 SD) (range 70-266 ml). Rotation around the LR axis was significantly correlated with bladder volume changes. Conclusions: Despite a full bladder instruction, bladder volumes reduced dramatically during treatment, implying large time trends in target position of these patients. The portable US scanner provides a quick and reliable measurement of the bladder volume, which might assist future online treatment adaptation

  8. Global variations and time trends in the prevalence of childhood myopia, a systematic review and quantitative meta-analysis:implications for aetiology and early prevention

    OpenAIRE

    Rudnicka, Alicja R.; Kapetanakis, Venediktos V.; Wathern, Andrea K.; Logan, Nicola S.; Gilmartin, Bernard; Whincup, Peter H.; Cook, Derek G.; Owen, Christopher G.

    2016-01-01

    The aim of this review was to quantify the global variation in childhood myopia prevalence over time taking account of demographic and study design factors. A systematic review identified population-based surveys with estimates of childhood myopia prevalence published by February 2015. Multilevel binomial logistic regression of log odds of myopia was used to examine the association with age, gender, urban versus rural setting and survey year, among populations of different ethnic origins, adj...

  9. Spectroscopic and DFT studies of calix[4]arene: time-dependent DFT calculations for elucidating the variation in the excitation energies with geometry

    Energy Technology Data Exchange (ETDEWEB)

    Boo, Bong Hyun; Kwak, Hae Ran; Hong, Seung Ki [Chungnam National University, Daejeon (Korea, Republic of); Park, Chan Jo [Korea Research Institute of Chemical Technology, Daejeon (Korea, Republic of); No, Kwang Hyun [Sookmyung Womens University, Seoul (Korea, Republic of)

    2010-08-15

    We have searched low-lying conformers of calix[4]arene and found one global minimum having a cone shape, together with three conformers such as partial cone-shape conformers. We then elucidated the thermodynamics for the conformational changes by performing density-functional theory (DFT) calculations. The time-dependent DFT calculation enabled us to assign the absorption spectrum and to reveal a variation of the excitation energies with geometry.

  10. Time variation of meteorological elements as controlled by the quasi-biennial periodicity in the solar phenomena

    International Nuclear Information System (INIS)

    Inoue, Michiharu; Sakurai, Kunitomo

    1981-01-01

    It is shown that the quasi-biennial oscillation observed on some meteorological elements as the ozone content at middle latitudes, both north and south, the zonal wind velocity at the equator and the ground-level temperature at middle latitudes, is produced by the variation of the ultraviolet flux emitted from the sun, which is varying with the solar activity with the period of about 26 months. The ozone content is varying in phase with the ultraviolet flux and the solar activity, whereas the other two elements mentioned above are changing out of phase with these phenomena. There is a possibility that both these meteorological elements and the solar activity are varying quasi-biennially while being modulated by the 26 month periodicity in the efficiency of thermonuclear fusions at the central core of the sun. (author)

  11. The timing of flowering in Douglas-fir is determined by cool-season temperatures and genetic variation

    Science.gov (United States)

    Janet S. Prevey; Constance A. Harrington; J. Bradley St. Clair

    2018-01-01

    Trees have evolved to time flowering to maximize outcrossing, minimize exposure to damaging frosts, and synchronize development with soil moisture and nutrient availability. Understanding the environmental cues that influence the timing of reproductive budburst will be important for predicting how flowering phenology of trees will change with a changing climate, and...

  12. Modal Identification of a Time-Invariant 6-Storey Model Test RC-Frame from Free Decay Tests using Multi-Variate Models

    DEFF Research Database (Denmark)

    Skjærbæk, P. S.; Nielsen, Søren R. K.; Kirkegaard, Poul Henning

    1997-01-01

    in the comparison. The data investigated are sampled from a laboratory model of a plane 6-storey, 2-bay RC-frame. The laboratory model is excited at the top storey where two different types of excitation where considered. In the first case the structure was excited in the first mode and in the second case......The scope of the paper is to apply multi-variate time-domain models for identification of eginfrequencies and mode shapes of a time- invariant model test Reinforced Concrete (RC) frame from measured decays. The frequencies and mode shapes of interest are the two lowest ones since they are normally...

  13. Modal Identification of a Time-Invariant 6-Storey Model Test RC-Frame from Free Decay Tests using Multi-Variate Models

    DEFF Research Database (Denmark)

    Skjærbæk, P. S.; Nielsen, Søren R. K.; Kirkegaard, Poul Henning

    in the comparison. The data investigated are sampled from a laboratory model of a plane 6-storey, 2-bay RC-frame. The laboratory model is excited at the top storey where two different types of excitation where considered. In the first case the structure was excited in the first mode and in the second case......The scope of the paper is to apply multi-variate time-domain models for identification of eginfrequencies and mode shapes of a time- invariant model test Reinforced Concrete (RC) frame from measured decays. The frequencies and mode shapes of interest are the two lowest ones since they are normally...

  14. Method of determining the variation of concentration of the potential alpha energy of radon daughters with time without changing the filter

    International Nuclear Information System (INIS)

    Feddersen, C.

    1979-01-01

    Considering the drawbacks of sample measurement of radon daughter concentration or potential alpha energy concentration, a method is described allowing to determine the variation with time of the measuring quantities mentioned. For this purpose, the same filter is exposed in defined time intervals and the decay curve is evaluated using Markov's method. Residual activity of preceding measurements is estimated as a function of the density of measuring points. A practicable technique is given for taking into account residual activity together with the background. An apparatus consisting of commercial devices and special accessories of own manufacture is described. The results obtained with this apparatus are illustrated and discussed using two examples. (author)

  15. Explaining variation in life history timing across a species range: Effects of climate on spawning time in an exploited marine fish

    DEFF Research Database (Denmark)

    Neuheimer, Anna; MacKenzie, Brian

    . Combined, these results shed light on the adaptive capacity of the species in the face of changing climate. We use our results to estimate expected spawning time under future climate regimes, and discuss the implications for codecology and management across the species’ range, and in the greater ecosystem......The capacity of a species to tolerate and/or adapt to environmental conditions will shape its response to future climate change including climate extremes. Of the many life-history processes affected by climate change, timing of reproduction greatly influences offspring success and resulting...... population production. Here we explore temporal and spatial changes in spawning time for Atlantic cod (Gadus morhua) across the species’ range (4 to 80°N). We estimate spawning time using a physiologically relevant metric that includes information on fish thermal history (degree days, DD). First, we estimate...

  16. Finite time exergy analysis and multi-objective ecological optimization of a regenerative Brayton cycle considering the impact of flow rate variations

    International Nuclear Information System (INIS)

    Naserian, Mohammad Mahdi; Farahat, Said; Sarhaddi, Faramarz

    2015-01-01

    Highlights: • Defining a dimensionless parameter includes the finite-time and size concepts. • Inserting the concept of exergy of fluid streams into finite-time thermodynamics. • Defining, drawing and modifying of maximum ecological function curve. • Suggesting the appropriate performance zone, according to maximum ecological curve. - Abstract: In this study, the optimal performance of a regenerative Brayton cycle is sought through power and then ecological function maximization using finite-time thermodynamic concept and finite-size components. Multi-objective optimization is used for maximizing the ecological function. Optimizations are performed using genetic algorithm. In order to take into account the finite-time and finite-size concepts in current problem, a dimensionless mass-flow parameter is introduced deploying time variations. The variations of output power, total exergy destruction of the system, and decision variables for the optimum state (maximum ecological function state) are compared to the maximum power state using the dimensionless parameter. The modified ecological function in optimum state is obtained and plotted relating to the dimensionless mass-flow parameter. One can see that the modified ecological function study results in a better performance than that obtained with the maximum power state. Finally, the appropriate performance zone of the heat engine will be obtained

  17. 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.

  18. Dating of streamwater using tritium in a post nuclear bomb pulse world: continuous variation of mean transit time with streamflow

    Directory of Open Access Journals (Sweden)

    U. Morgenstern

    2010-11-01

    Full Text Available Tritium measurements of streamwater draining the Toenepi catchment, a small dairy farming area in Waikato, New Zealand, have shown that the mean transit time of the water varies with the flow rate of the stream. Mean transit times through the catchment are 2–5 years during high baseflow conditions in winter, increasing to 30–40 years as baseflow decreases in summer, and then dramatically older water during drought conditions with mean transit time of more than 100 years. Older water is gained in the lower reaches of the stream, compared to younger water in the headwater catchment. The groundwater store supplying baseflow was estimated from the mean transit time and average baseflow to be 15.4 × 106 m3 of water, about 1 m water equivalent over the catchment and 2.3 times total annual streamflow. Nitrate is relatively high at higher flow rates in winter, but is low at times of low flow with old water. This reflects both lower nitrate loading in the catchment several decades ago as compared to current intensive dairy farming, and denitrification processes occurring in the older groundwater. Silica, leached from the aquifer material and accumulating in the water in proportion to contact time, is high at times of low streamflow with old water. There was a good correlation between silica concentration and streamwater age, which potentially allows silica concentrations to be used as a proxy for age when calibrated by tritium measurements. This study shows that tritium dating of stream water is possible with single tritium measurements now that bomb-test tritium has effectively disappeared from hydrological systems in New Zealand, without the need for time-series data.

  19. Variation in the human lymphocyte sister chromatid exchange frequency as a function of time: results of daily and twice-weekly sampling

    Energy Technology Data Exchange (ETDEWEB)

    Tucker, J.D.; Christensen, M.L.; Strout, C.L.; McGee, K.A.; Carrano, A.V.

    1987-01-01

    The variation in lymphocyte sister chromatid exchange (SCE) frequency was investigated in healthy nonsmokers who were not taking any medication. Two separate studies were undertaken. In the first, blood was drawn from four women twice a week for 8 weeks. These donors recorded the onset and termination of menstruation and times of illness. In the second study, blood was obtained from two women and two men for 5 consecutive days on two separate occasions initiated 14 days apart. Analysis of the mean SCE frequencies in each study indicated that significant temporal variation occurred in each donor, and that more variation occurred in the longer study. Some of the variation was found to be associated with the menstrual cycle. In the daily study, most of the variation appeared to be random, but occasional day-to-day changes occurred that were greater than those expected by chance. To determine how well a single SCE sample estimated the pooled mean for each donor in each study, the authors calculated the number of samples that encompassed that donor's pooled mean within 1 or more standard errors. For both studies, about 75% of the samples encompassed the pooled mean within 2 standard errors. An analysis of high-frequency cells (HFCs) was also undertaken. The results for each study indicate that the proportion of HFCs, compared with the use of Fisher's Exact test, is significantly more constant than the means, which were compared by using the t-test. These results coupled with our previous work suggest that HFC analysis may be the method of choice when analyzing data from human population studies.

  20. Ethnic variations in overweight and obesity among children over time: findings from analyses of the Health Surveys for England 1998-2009.

    Science.gov (United States)

    Karlsen, S; Morris, S; Kinra, S; Vallejo-Torres, L; Viner, R M

    2014-06-01

    The increase in the prevalence of obesity among children and adolescents in England since the mid-1990s has been dramatic. Cross-sectional evidence suggests ethnic variations in childhood obesity prevalence. The objective of the study was to examine whether and how ethnic variations in childhood overweight/obesity have changed over time, and are affected by socioeconomic factors. This study uses logistic regression to analyse ethnic differences in the relative likelihood of being at or above the age- and gender-specific thresholds for overweight and obesity developed by the International Obesity Task Force among children aged between 2 and 15 from 11 ethnic groups included in the Health Surveys for England between 1998 and 2009, adjusting for age, gender, year of data collection and equivalized household income. We separately analyse the likelihood of being at or above the thresholds for overweight (but below those for obesity) and obesity. Trends in overweight/obesity over time among ethnic minority groups do not follow those of white English children. Black African children had higher rates of overweight and obesity, which appear to have peaked, and black Caribbean children had higher rates of obesity than other groups examined, which appear to continue rising. These differences were not explained by socioeconomic variations between groups. Policies are required that encourage healthy lifestyles among ethnic minority young people, while engaging with the complexities associated with these choices during childhood and adolescence. © 2013 The Authors. Pediatric Obesity © 2013 International Association for the Study of Obesity.

  1. Drift time variations in CdZnTe detectors measured with alpha-particles: Their correlation with the detector’s responses

    Energy Technology Data Exchange (ETDEWEB)

    Bolotnikov A. E.; Butcher, J.; Hamade, M.; Petryk, M.; Bolotnikov, A.; Camarda, G.; Cui, Y.; Hossain, A.; Kim, K.; Yang, G.; and James, R.

    2012-05-14

    Homogeneity of properties related to material crystallinity is a critical parameter for achieving high-performance CdZnTe (CZT) radiation detectors. Unfortunately, this requirement is not always satisfied in today's commercial CZT material due to high concentrations of extended defects, in particular subgrain boundaries, which are believed to be part of the causes hampering the energy resolution and efficiency of CZT detectors. In the past, the effects of subgrain boundaries have been studied in Si, Ge and other semiconductors. It was demonstrated that subgrain boundaries tend to accumulate secondary phases and impurities causing inhomogeneous distributions of trapping centers. It was also demonstrated that subgrain boundaries result in local perturbations of the electric field, which affect the carrier transport and other properties of semiconductor devices. The subgrain boundaries in CZT material likely behave in a similar way, which makes them responsible for variations in the electron drift time and carrier trapping in CZT detectors. In this work, we employed the transient current technique to measure variations in the electron drift time and related the variations to the device performances and subgrain boundaries, whose presence in the crystals were confirmed with white beam X-ray diffraction topography and infrared transmission microscopy.

  2. Variation in content of macronutrients of guava tree leaves, in function of type and time of storage

    Directory of Open Access Journals (Sweden)

    Henrique Antunes de Souza

    2010-10-01

    Full Text Available Leaf analysis for perennial crops such as the guava tree is an important tool. It was used to evaluate the influence of the type of packaging (with or without refrigerator and storage time after collection on the macronutrient composition of guava tree leaves. The leaf sampling was carried out on a commercial guava tree (cv. Paluma, collecting the third pair of recently matured leaves in full bloom. The experimental design was in randomized blocks, subdivided according to the type of packaging (with or without refrigerator and further subdivided into eight storage times before washing (zero, 6, 12, 24, 48, 72, 96 and 168h after sampling, with four replications. The storage time significantly affected the concentration of leaf nitrogen, calcium and sulfur. Moreover, the type and time of conditioning (with or without refrigerator affected only the magnesium. In general, storage fot up to 12h before washing produced no significant changes in the levels of macronutrients.

  3. Variation in content of macronutrients of guava tree leaves, in function of type and time of storage

    Directory of Open Access Journals (Sweden)

    Henrique Antunes de Souza

    2010-09-01

    Full Text Available Leaf analysis for perennial crops such as the guava tree is an important tool. It was used to evaluate the influence of the type of packaging (with or without refrigerator and storage time after collection on the macronutrient composition of guava tree leaves. The leaf sampling was carried out on a commercial guava tree (cv. Paluma, collecting the third pair of recently matured leaves in full bloom. The experimental design was in randomized blocks, subdivided according to the type of packaging (with or without refrigerator and further subdivided into eight storage times before washing (zero, 6, 12, 24, 48, 72, 96 and 168h after sampling, with four replications. The storage time significantly affected the concentration of leaf nitrogen, calcium and sulfur. Moreover, the type and time of conditioning (with or without refrigerator affected only the magnesium. In general, storage fot up to 12h before washing produced no significant changes in the levels of macronutrients.

  4. A direct solution procedure for calculating time-varying stresses in structural systems by the principles of variational calculus

    International Nuclear Information System (INIS)

    Stefanou, G.D.

    1975-01-01

    The calculation of time-dependent stresses in structural systems operating at elevated temperatures with temperature gradients is discussed. The proposed method described in this report is of a direct formulation technique and

  5. Investigating the temporal variations of the time-clustering behavior of the Koyna-Warna (India) reservoir-triggered seismicity

    International Nuclear Information System (INIS)

    Telesca, Luciano

    2011-01-01

    Research highlights: → Time-clustering behaviour in seismicity can be detected by applying the Allan Factor. → The reservoir-induced seismicity at Koyna-Warna (India) is time-clusterized. → Pre- and co-seismic increases of the time-clustering degree are revealed. - Abstract: The time-clustering behavior of the 1996-2005 seismicity of Koyna-Warna region (India), a unique site where reservoir-triggered earthquakes have been continuously occurring over the last about 50 year, has been analyzed. The scaling exponent α, estimated by using the Allan Factor method, a powerful tool to investigate clusterization in point processes, shows co-seismic and pre-seismic enhancements associated with the occurrence of the major events.

  6. Time of day variation in polyp detection rate for colonoscopies performed on a 3-hour shift schedule.

    LENUS (Irish Health Repository)

    Munson, Gregory W

    2011-03-01

    Recent research suggests that the colonoscopy polyp detection rate (PDR) varies by time of day, possibly because of endoscopist fatigue. Mayo Clinic Rochester (MCR) schedules colonoscopies on 3-hour shifts, which should minimize fatigue.

  7. Near real-time automated dose restoration in IMPT to compensate for daily tissue density variations in prostate cancer

    Science.gov (United States)

    Jagt, Thyrza; Breedveld, Sebastiaan; van de Water, Steven; Heijmen, Ben; Hoogeman, Mischa

    2017-06-01

    Proton therapy is very sensitive to daily density changes along the pencil beam paths. The purpose of this study is to develop and evaluate an automated method for adaptation of IMPT plans to compensate for these daily tissue density variations. A two-step restoration method for ‘densities-of-the-day’ was created: (1) restoration of spot positions (Bragg peaks) by adapting the energy of each pencil beam to the new water equivalent path length; and (2) re-optimization of pencil beam weights by minimizing the dosimetric difference with the planned dose distribution, using a fast and exact quadratic solver. The method was developed and evaluated using 8-10 repeat CT scans of 10 prostate cancer patients. Experiments demonstrated that giving a high weight to the PTV in the re-optimization resulted in clinically acceptable restorations. For all scans we obtained V 95%  ⩾  98% and V 107%  ⩽  2%. For the bladder, the differences between the restored and the intended treatment plan were below  +2 Gy and  +2%-point. The rectum differences were below  +2 Gy and  +2%-point for 90% of the scans. In the remaining scans the rectum was filled with air, which partly overlapped with the PTV. The air cavity distorted the Bragg peak resulting in less favorable rectum doses.

  8. Spatial and temporal variations of thaw layer thickness and its controlling factors identified using time-lapse electrical resistivity tomography and hydro-thermal modeling

    Science.gov (United States)

    Tran, Anh Phuong; Dafflon, Baptiste; Bisht, Gautam; Hubbard, Susan S.

    2018-06-01

    Quantitative understanding of controls on thaw layer thickness (TLT) dynamics in the Arctic peninsula is essential for predictive understanding of permafrost degradation feedbacks to global warming and hydrobiochemical processes. This study jointly interprets electrical resistivity tomography (ERT) measurements and hydro-thermal numerical simulation results to assess spatiotemporal variations of TLT and to determine its controlling factors in Barrow, Alaska. Time-lapse ERT measurements along a 35-m transect were autonomously collected from 2013 to 2015 and inverted to obtain soil electrical resistivity. Based on several probe-based TLT measurements and co-located soil electrical resistivity, we estimated the electrical resistivity thresholds associated with the boundary between the thaw layer and permafrost using a grid search optimization algorithm. Then, we used the obtained thresholds to derive the TLT from all soil electrical resistivity images. The spatiotemporal analysis of the ERT-derived TLT shows that the TLT at high-centered polygons (HCPs) is smaller than that at low-centered polygons (LCPs), and that both thawing and freezing occur earlier at the HCPs compared to the LCPs. In order to provide a physical explanation for dynamics in the thaw layer, we performed 1-D hydro-thermal simulations using the community land model (CLM). Simulation results showed that air temperature and precipitation jointly govern the temporal variations of TLT, while the topsoil organic content (SOC) and polygon morphology are responsible for its spatial variations. When the topsoil SOC and its thickness increase, TLT decreases. Meanwhile, at LCPs, a thicker snow layer and saturated soil contribute to a thicker TLT and extend the time needed for TLT to freeze and thaw. This research highlights the importance of combination of measurements and numerical modeling to improve our understanding spatiotemporal variations and key controls of TLT in cold regions.

  9. Latitudinal cogradient variation of development time and growth rate and a negative latitudinal body weight cline in a widely distributed cabbage beetle.

    Directory of Open Access Journals (Sweden)

    Jianjun Tang

    Full Text Available The evolutionary and phenotypic responses to environmental gradients are often assumed to be the same, a phenomenon known as "cogradient variation". However, only a few insect species display cogradient variation in physiological traits along a latitudinal gradient. We found evidence for such a response in the examination of the life history traits of the cabbage beetle Colaphellus bowringi from 6 different geographical populations at 16, 19, 22, 24, 26 and 28°C. Our results showed that larval and pupal development times significantly decreased as rearing temperature increased, and that growth rates were positively correlated with temperature. Body weight tended to decrease with increasing temperature, consistent with the general pattern in ectothermic animals. Larval development time was positively correlated with latitude, whereas the growth rate decreased as latitude increased, showing an example of latitudinal cogradient variation. Body weight significantly decreased with increasing latitude in a stepwise manner, showing a negative latitudinal body weight cline. Females were significantly larger than males, consistent with the female biased sex dimorphism in insects. Body weight tended to decrease with increasing rearing temperature, whereas the differences in sexual size dimorphism (SSD tended to decrease with increasing body weight, which biased our results toward acceptance of Rensch's rule. We found that weight loss was an important regulator of SSD, and because male pupae lost significantly more weight at metamorphosis than female pupae, SSD was greater in adults than in pupae. Overall, our data provide a new example that a latitudinal cogradient variation in physiological traits is associated with a negative latitudinal body weight cline.

  10. Transit Timing Observations from Kepler: III. Confirmation of 4 Multiple Planet Systems by a Fourier-Domain Study of Anti-correlated Transit Timing Variations

    Energy Technology Data Exchange (ETDEWEB)

    Steffen, Jason H.; /Fermilab; Fabrycky, Daniel C.; /Lick Observ.; Ford, Eric B.; /Florida U.; Carter, Joshua A.; /Harvard-Smithsonian Ctr. Astrophys.; Fressin, Francois; /Harvard-Smithsonian Ctr. Astrophys.; Holman, Matthew J.; /Harvard-Smithsonian Ctr. Astrophys.; Lissauer, Jack J.; /NASA, Ames; Rowe, Jason F.; /SETI Inst., Mtn. View /NASA, Ames; Ragozzine, Darin; /Harvard-Smithsonian Ctr. Astrophys.; Welsh, William F.; /Caltech; Borucki, William J.; /NASA, Ames /UC, Santa Barbara

    2012-01-01

    We present a method to confirm the planetary nature of objects in systems with multiple transiting exoplanet candidates. This method involves a Fourier-domain analysis of the deviations in the transit times from a constant period that result from dynamical interactions within the system. The combination of observed anticorrelations in the transit times and mass constraints from dynamical stability allow us to claim the discovery of four planetary systems, Kepler-25, Kepler-26, Kepler-27 and Kepler-28, containing eight planets and one additional planet candidate.

  11. Sex-related time-dependent variations in post-stroke survival-evidence of a female stroke survival advantage

    DEFF Research Database (Denmark)

    Olsen, Tom Skyhøj; Dehlendorff, Christian; Andersen, Klaus Kaae

    2007-01-01

    the influence of gender on post-stroke mortality, from the time of admission through the subsequent years until death or censoring ( mean follow-up time: 538 days). All patients underwent an evaluation including stroke severity, computed tomography and cardiovascular risk factors. Independent predictors......Background: Women live longer than men, yet most studies show that gender has no influence on survival after stroke. Methods: A registry was started in 2001, with the aim of registering all hospitalized stroke patients in Denmark, and it now holds 39,484 patients of which 48% are female. We studied...... of death were identified by means of a survival model based on 22,222 individuals with a complete data set. Results: Females were older and had severer stroke. Interestingly, the risk of death between genders was time dependent. The female/male stroke mortality rate favoured women from the first day...

  12. Study on time-based variation of blood circulation index, pulse wave energy, and RAI of healthy adult men after different eating times

    Directory of Open Access Journals (Sweden)

    Gyeong-Cheol Kim

    2013-12-01

    Conclusions: Different eating times can bring about changes on blood circulation index, E, and RAI. These changes show a certain tendency and coincide with the physiological factors that eating causes a rise of HR, an increase of systolic cardiac pump performance, and a reduction of peripheral vascular resistance.

  13. Effects of temperature variation between neighbouring days on daily hospital visits for childhood asthma: a time-series analysis.

    Science.gov (United States)

    Li, K; Ni, H; Yang, Z; Wang, Y; Ding, S; Wen, L; Yang, H; Cheng, J; Su, H

    2016-07-01

    To identify the relationship between temperature variation between neighbouring days (TVN) and hospital visits for childhood asthma in age- and sex-specific groups. An ecological design was used to explore the effect of TVN on hospital visits for childhood asthma. A Poisson generalised linear regression model combined with a distributed lag non-linear model was used to analyse the association between TVN and hospital visits for childhood asthma. All hospital visits for childhood asthma from June 2010 to July 2013 were included (n = 17,022). Daily climate data were obtained from Hefei Meteorological Bureau. A significant correlation was found between TVN and hospital visits for childhood asthma in age- and sex-specific groups. For different gender groups, the effect of TVN on childhood asthma was the greatest at 3 and 5 days lag for males and females. For different age groups, the effect of TVN on childhood asthma was the greatest at 1 and 5 days lag for 0-4 years and 5-14 years children, respectively. A 1 °C increase in TVN was associated with a 4.2% (95% confidence interval 0.9-7.6%) increase in hospital visits for childhood asthma. TVN is associated with hospital visits for childhood asthma. Once the temperature change rapidly, guardians will be urged to pay more attention to their children's health, which may reduce the morbidity of childhood asthma. Copyright © 2016 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

  14. Prolonged activated prothromboplastin time and breed specific variation in haemostatic analytes in healthy adult Bernese Mountain dogs

    DEFF Research Database (Denmark)

    Nielsen, Lise; Wiinberg, Bo; Kjelgaard-Hansen, Mads

    2011-01-01

    Coagulation tests are often performed in dogs suspected of haemostatic dysfunction and are interpreted according to validated laboratory reference intervals (RIs). Breed specific RIs for haematological and biochemical analytes have previously been identified in Bernese Mountain dogs, but it remains...... to be determined if breed specific RIs are necessary for haemostasis tests. Activated prothromboplastin time (aPTT), prothrombin time (PT), selected coagulation factors, D-dimers, fibrinogen, von Willebrand factor and thromboelastography (TEG) were analyzed in healthy Bernese Mountain dogs using the CLSI model...

  15. Using mean duration and variation of procedure times to plan a list of surgical operations to fit into the scheduled list time.

    Science.gov (United States)

    Pandit, Jaideep J; Tavare, Aniket

    2011-07-01

    It is important that a surgical list is planned to utilise as much of the scheduled time as possible while not over-running, because this can lead to cancellation of operations. We wished to assess whether, theoretically, the known duration of individual operations could be used quantitatively to predict the likely duration of the operating list. In a university hospital setting, we first assessed the extent to which the current ad-hoc method of operating list planning was able to match the scheduled operating list times for 153 consecutive historical lists. Using receiver operating curve analysis, we assessed the ability of an alternative method to predict operating list duration for the same operating lists. This method uses a simple formula: the sum of individual operation times and a pooled standard deviation of these times. We used the operating list duration estimated from this formula to generate a probability that the operating list would finish within its scheduled time. Finally, we applied the simple formula prospectively to 150 operating lists, 'shadowing' the current ad-hoc method, to confirm the predictive ability of the formula. The ad-hoc method was very poor at planning: 50% of historical operating lists were under-booked and 37% over-booked. In contrast, the simple formula predicted the correct outcome (under-run or over-run) for 76% of these operating lists. The calculated probability that a planned series of operations will over-run or under-run was found useful in developing an algorithm to adjust the planned cases optimally. In the prospective series, 65% of operating lists were over-booked and 10% were under-booked. The formula predicted the correct outcome for 84% of operating lists. A simple quantitative method of estimating operating list duration for a series of operations leads to an algorithm (readily created on an Excel spreadsheet, http://links.lww.com/EJA/A19) that can potentially improve operating list planning.

  16. Combination of real-time PCR and sequencing to detect multiple clinically relevant genetic variations in the lactase gene

    DEFF Research Database (Denmark)

    Brasen, Claus Lohman; Frischknecht, Lone; Ørnskov, Dorthe

    2017-01-01

    in the probe-binding site may cause errors in analysis. The aim of this study was to determine the prevalence of the variants in a Danish cohort examined for lactose intolerance as well as to improve the real-time PCR analysis for detection of the different variants. METHODS: We genotyped 3395 routine samples...

  17. Heritable heading time variation in wheat lines with the same number of Ppd-B1 gene copies.

    Science.gov (United States)

    Ivaničová, Zuzana; Valárik, Miroslav; Pánková, Kateřina; Trávníčková, Martina; Doležel, Jaroslav; Šafář, Jan; Milec, Zbyněk

    2017-01-01

    The ability of plants to identify an optimal flowering time is critical for ensuring the production of viable seeds. The main environmental factors that influence the flowering time include the ambient temperature and day length. In wheat, the ability to assess the day length is controlled by photoperiod (Ppd) genes. Due to its allohexaploid nature, bread wheat carries the following three Ppd-1 genes: Ppd-A1, Ppd-B1 and Ppd-D1. While photoperiod (in)sensitivity controlled by Ppd-A1 and Ppd-D1 is mainly determined by sequence changes in the promoter region, the impact of the Ppd-B1 alleles on the heading time has been linked to changes in the copy numbers (and possibly their methylation status) and sequence changes in the promoter region. Here, we report that plants with the same number of Ppd-B1 copies may have different heading times. Differences were observed among F7 lines derived from crossing two spring hexaploid wheat varieties. Several lines carrying three copies of Ppd-B1 headed 16 days later than other plants in the population with the same number of gene copies. This effect was associated with changes in the gene expression level and methylation of the Ppd-B1 gene.

  18. Time-Qualified Patterns of Variation of PPARγ, DNMT1, and DNMT3B Expression in Pancreatic Cancer Cell Lines

    Directory of Open Access Journals (Sweden)

    Valerio Pazienza

    2012-01-01

    Full Text Available Carcinogenesis is related to the loss of homeostatic control of cellular processes regulated by transcriptional circuits and epigenetic mechanisms. Among these, the activities of peroxisome proliferator-activated receptors (PPARs and DNA methyltransferases (DNMTs are crucial and intertwined. PPARγ is a key regulator of cell fate, linking nutrient sensing to transcription processes, and its expression oscillates with circadian rhythmicity. Aim of our study was to assess the periodicity of PPARγ and DNMTs in pancreatic cancer (PC. We investigated the time-related patterns of PPARG, DNMT1, and DNMT3B expression monitoring their mRNA levels by qRT-PCR at different time points over a 28-hour span in BxPC-3, CFPAC-1, PANC-1, and MIAPaCa-2 PC cells after synchronization with serum shock. PPARG and DNMT1 expression in PANC-1 cells and PPARG expression in MIAPaCa-2 cells were characterized by a 24 h period oscillation, and a borderline significant rhythm was observed for the PPARG, DNMT1, and DNMT3B expression profiles in the other cell lines. The time-qualified profiles of gene expression showed different shapes and phase relationships in the PC cell lines examined. In conclusion, PPARG and DNMTs expression is characterized by different time-qualified patterns in cell lines derived from human PC, and this heterogeneity could influence cell phenotype and human disease behaviour.

  19. Time-Dependent Variations in the Arctic’s Surface Albedo Feedback and the Link to Seasonality in Sea Ice

    NARCIS (Netherlands)

    Andry, Olivier; Bintanja, Richard; Hazeleger, Wilco

    2017-01-01

    The Arctic is warming 2 to 3 times faster than the global average. Arctic sea ice cover is very sensitive to this warming and has reached historic minima in late summer in recent years (e.g., 2007 and 2012). Considering that the Arctic Ocean is mainly ice covered and that the albedo of sea ice is

  20. A real time measurement of junction temperature variation in high power IGBT modules for wind power converter application

    DEFF Research Database (Denmark)

    Ghimire, Pramod; Pedersen, Kristian Bonderup; de Vega, Angel Ruiz

    2014-01-01

    This paper presents a real time measurement of on-state forward voltage and estimating the junction temperature for a high power IGBT module during a power converter operation. The power converter is realized as it can be used for a wind turbine system. The peak of the junction temperature is dec...

  1. Heritable heading time variation in wheat lines with the same number of Ppd-B1 gene copies.

    Directory of Open Access Journals (Sweden)

    Zuzana Ivaničová

    Full Text Available The ability of plants to identify an optimal flowering time is critical for ensuring the production of viable seeds. The main environmental factors that influence the flowering time include the ambient temperature and day length. In wheat, the ability to assess the day length is controlled by photoperiod (Ppd genes. Due to its allohexaploid nature, bread wheat carries the following three Ppd-1 genes: Ppd-A1, Ppd-B1 and Ppd-D1. While photoperiod (insensitivity controlled by Ppd-A1 and Ppd-D1 is mainly determined by sequence changes in the promoter region, the impact of the Ppd-B1 alleles on the heading time has been linked to changes in the copy numbers (and possibly their methylation status and sequence changes in the promoter region. Here, we report that plants with the same number of Ppd-B1 copies may have different heading times. Differences were observed among F7 lines derived from crossing two spring hexaploid wheat varieties. Several lines carrying three copies of Ppd-B1 headed 16 days later than other plants in the population with the same number of gene copies. This effect was associated with changes in the gene expression level and methylation of the Ppd-B1 gene.

  2. Artificial Neural Network classification of operator workload with an assessment of time variation and noise-enhancement to increase performance

    Directory of Open Access Journals (Sweden)

    Alexander James Casson

    2014-12-01

    Full Text Available Workload classification---the determination of whether a human operator is in a high or low workload state to allow their working environment to be optimized---is an emerging application of passive Brain-Computer Interface (BCI systems. Practical systems must not only accurately detect the current workload state, but also have good temporal performance: requiring little time to set up and train the classifier, and ensuring that the reported performance level is consistent and predictable over time. This paper investigates the temporal performance of an Artificial Neural Network based classification system. For networks trained on little EEG data good classification accuracies (86% are achieved over very short time frames, but substantial decreases in accuracy are found as the time gap between the network training and the actual use is increased. Noise-enhanced processing, where artificially generated noise is deliberately added to the testing signals, is investigated as a potential technique to mitigate this degradation without requiring the network to be re-trained using more data. Small stochastic resonance effects are demonstrated whereby the classification process gets better in the presence of more noise. The effect is small and does not eliminate the need for re-training, but it is consistent, and this is the first demonstration of such effects for non-evoked/free-running EEG signals suitable for passive BCI.

  3. An integrated, indicator framework for assessing large-scale variations and change in seasonal timing and phenology (Invited)

    Science.gov (United States)

    Betancourt, J. L.; Weltzin, J. F.

    2013-12-01

    As part of an effort to develop an Indicator System for the National Climate Assessment (NCA), the Seasonality and Phenology Indicators Technical Team (SPITT) proposed an integrated, continental-scale framework for understanding and tracking seasonal timing in physical and biological systems. The framework shares several metrics with the EPA's National Climate Change Indicators. The SPITT framework includes a comprehensive suite of national indicators to track conditions, anticipate vulnerabilities, and facilitate intervention or adaptation to the extent possible. Observed, modeled, and forecasted seasonal timing metrics can inform a wide spectrum of decisions on federal, state, and private lands in the U.S., and will be pivotal for international efforts to mitigation and adaptation. Humans use calendars both to understand the natural world and to plan their lives. Although the seasons are familiar concepts, we lack a comprehensive understanding of how variability arises in the timing of seasonal transitions in the atmosphere, and how variability and change translate and propagate through hydrological, ecological and human systems. For example, the contributions of greenhouse warming and natural variability to secular trends in seasonal timing are difficult to disentangle, including earlier spring transitions from winter (strong westerlies) to summer (weak easterlies) patterns of atmospheric circulation; shifts in annual phasing of daily temperature means and extremes; advanced timing of snow and ice melt and soil thaw at higher latitudes and elevations; and earlier start and longer duration of the growing and fire seasons. The SPITT framework aims to relate spatiotemporal variability in surface climate to (1) large-scale modes of natural climate variability and greenhouse gas-driven climatic change, and (2) spatiotemporal variability in hydrological, ecological and human responses and impacts. The hierarchical framework relies on ground and satellite observations

  4. Geostatistical Characteristic of Space -Time Variation in Underground Water Selected Quality Parameters in Klodzko Water Intake Area (SW Part of Poland)

    Science.gov (United States)

    Namysłowska-Wilczyńska, Barbara

    2016-04-01

    This paper presents selected results of research connected with the development of a (3D) geostatistical hydrogeochemical model of the Klodzko Drainage Basin, dedicated to the spatial and time variation in the selected quality parameters of underground water in the Klodzko water intake area (SW part of Poland). The research covers the period 2011÷2012. Spatial analyses of the variation in various quality parameters, i.e, contents of: ammonium ion [gNH4+/m3], NO3- (nitrate ion) [gNO3/m3], PO4-3 (phosphate ion) [gPO4-3/m3], total organic carbon C (TOC) [gC/m3], pH redox potential and temperature C [degrees], were carried out on the basis of the chemical determinations of the quality parameters of underground water samples taken from the wells in the water intake area. Spatial and time variation in the quality parameters was analyzed on the basis of archival data (period 1977÷1999) for 22 (pump and siphon) wells with a depth ranging from 9.5 to 38.0 m b.g.l., later data obtained (November 2011) from tests of water taken from 14 existing wells. The wells were built in the years 1954÷1998. The water abstraction depth (difference between the terrain elevation and the dynamic water table level) is ranged from 276÷286 m a.s.l., with an average of 282.05 m a.s.l. Dynamic water table level is contained between 6.22 m÷16.44 m b.g.l., with a mean value of 9.64 m b.g.l. The latest data (January 2012) acquired from 3 new piezometers, with a depth of 9÷10m, which were made in other locations in the relevant area. Thematic databases, containing original data on coordinates X, Y (latitude, longitude) and Z (terrain elevation and time - years) and on regionalized variables, i.e. the underground water quality parameters in the Klodzko water intake area determined for different analytical configurations (22 wells, 14 wells, 14 wells + 3 piezometers), were created. Both archival data (acquired in the years 1977÷1999) and the latest data (collected in 2011÷2012) were analyzed

  5. Detecting Inter-Annual Variations in the Phenology of Evergreen Conifers Using Long-Term MODIS Vegetation Index Time Series

    OpenAIRE

    Ulsig, Laura; Nichol, Caroline J.; Huemmrich, Karl F.; Landis, David R.; Middleton, Elizabeth M.; Lyapustin, Alexei I.; Mammarella, Ivan; Levula, Janne; Porcar-Castell, Albert

    2017-01-01

    Long-term observations of vegetation phenology can be used to monitor the response of terrestrial ecosystems to climate change. Satellite remote sensing provides the most efficient means to observe phenological events through time series analysis of vegetation indices such as the Normalized Difference Vegetation Index (NDVI). This study investigates the potential of a Photochemical Reflectance Index (PRI), which has been linked to vegetation light use efficiency, to improve the accuracy of MO...

  6. Detecting inter-annual variations in the phenology of evergreen conifers using long-term MODIS vegetation index time series.

    OpenAIRE

    Ulsig, Laura

    2016-01-01

    Long-term observations of vegetation phenology can be used to monitor the response of terrestrial ecosystems to climate change. Satellite remote sensing provides the most efficient means to observe phenological events through time series analysis of vegetation indices such as the Normalised Difference Vegetation Index (NDVI). This study investigates the potential of the Photochemical Reflectance Index (PRI), which has been linked to vegetation light use efficiency, to improve the accuracy of ...

  7. Phase-Pure of BiFeO3 Ceramic Based on Citric Acid - Assisted Gel by Sintering Time Variation

    Science.gov (United States)

    Suastiyanti, Dwita; Ismojo

    2017-07-01

    Bismuth ferrite powder (BiFeO3/BFO) with high purity was synthesized by sol-gel process. It was used Bi5O(OH)9(NO3)4 and Fe(NO3)3.9H2O as main compound sources. Citric acid (C6H8O7) was used as fuell. As multiferroic material, BFO promises important technological applications in several devices like data strorage, spinotronics, sensor, actuator devices etc. This research would know the optimum process condition of sol-gel process to produce BFO powder by varying of sintering time. The novelty of this research is how to produce BFO in single phase by simple method. It was used calcination condition at 160°C for 4 hours and sintering condition at 600°C with varying of sintering time of 4, 6 and 8 hours. Thermogravimetric Analysis/Differential Thermal Analysis (TGA/DTA), X Ray Diffraction (XRD) and Scanning Electron Microscope (SEM) were used to characterize the powder. Loss of mass and heat flow were seen at TGA/DTA test at 160°C approximately (used as reference of calcination temperature). BFO powder sintered at for 8 hours has no secondary phase, meanwhile for another sintering time (4 and 6 hours) it has Bi2O3 as secondary phase. It is also show at SEM observation result that powder with sintering time of 8 hours has finer grain than of 4 and 6 hours sintering at the same temperature. The grains of BFO powder has heterogenous in size, shape and still agglomerated.

  8. Volumetric humidity timely variation, at different depths, in soils of a toposequence of the Reconcavo Baiano - Brazil

    International Nuclear Information System (INIS)

    Ribeiro, Antonio Carlos; Costa, Liovando Marciano da; Paiva, Arlicelio de Queiroz; Souza, Luciano da Silva; Santana, Marlete Bastos

    1997-01-01

    Aiming the time basis volumetric humidity evaluation, at different depths, the present work has been developed in a Reconcavo Baiano toposequence consisting of three different soils, in accordance with the distances from the toposequence begin. A neutron probe has been used for determination of the soil water contents. The relative counting of the neutron probe has been converted to gravimetric humidity by using regression equation for each type of soil

  9. Heritable heading time variation in wheat lines with the same number of Ppd-B1 gene copies

    Czech Academy of Sciences Publication Activity Database

    Ivaničová, Zuzana; Valárik, Miroslav; Pánková, K.; Trávníčková, M.; Doležel, Jaroslav; Šafář, Jan; Milec, Zbyněk

    2017-01-01

    Roč. 12, č. 8 (2017), č. článku e0183745. E-ISSN 1932-6203 R&D Projects: GA MŠk(CZ) LO1204; GA ČR GBP501/12/G090 Institutional support: RVO:61389030 Keywords : triticum-aestivum l. * dna methylation * copy number * flowering time * human genome * se gene * vernalization * earliness * barley * region Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Plant sciences, botany Impact factor: 2.806, year: 2016

  10. Variation in the use of advanced imaging at the time of breast cancer diagnosis in a statewide registry.

    Science.gov (United States)

    Henry, N Lynn; Braun, Thomas M; Breslin, Tara M; Gorski, David H; Silver, Samuel M; Griggs, Jennifer J

    2017-08-01

    Although national guidelines do not recommend extent of disease imaging for patients with newly diagnosed early stage breast cancer given that the harm outweighs the benefits, high rates of testing have been documented. The 2012 Choosing Wisely guidelines specifically addressed this issue. We examined the change over time in imaging use across a statewide collaborative, as well as the reasons for performing imaging and the impact on cost of care. Clinicopathologic data and use of advanced imaging tests (positron emission tomography, computed tomography, and bone scan) were abstracted from the medical records of patients treated at 25 participating sites in the Michigan Breast Oncology Quality Initiative (MiBOQI). For patients diagnosed in 2014 and 2015, reasons for testing were abstracted from the medical record. Of the 34,078 patients diagnosed with stage 0-II breast cancer between 2008 and 2015 in MiBOQI, 6853 (20.1%) underwent testing with at least 1 imaging modality in the 90 days after diagnosis. There was considerable variability in rates of testing across the 25 sites for all stages of disease. Between 2008 and 2015, testing decreased over time for patients with stage 0-IIA disease (all P diagnosis decreased over time in a large statewide collaborative. Additional interventions are warranted to further reduce rates of unnecessary imaging to improve quality of care for patients with breast cancer. Cancer 2017;123:2975-83. © 2017 American Cancer Society. © 2017 American Cancer Society.

  11. Detection of Variations in Air Temperature at Different Time Scales During the Period 1889-1998 at Firenze, Italy

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, P.V. [Central Research Institute for Dryland Agriculture, Santoshnagar, Saidabad, Hyderabad, 500059, Andhra Pradesh (India); Bindi, M. [DISAT-UNIFI, P.le delle Cascine 18, 50144, Firenze (Italy); Crisci, A. [LaMMA-Laboratorio per la Meteorologia, Climatologia e la Modellistica Ambientale, Campi Bisenzio (Italy); Maracchi, G. [IATA-CNR, P.le delle Cascine 18, 50144 Firenze (Italy)

    2005-09-01

    In an attempt to contribute to studies on global climatic change, 110 years of temperature data for Firenze, Italy, were analysed. Means and trends of annual and monthly temperatures (minimum, maximum and average) were analysed at three different time scales: short (20 years), medium (36-38 years) and long (55 years). Comparative changes in extreme events viz. frosts in the first and second parts of the 20th century were also analysed. At short time scales, climatic change was found in minimum and average temperatures but not in maximum temperatures. At all three time scales, the annual means of minimum, maximum and average temperatures were significantly warmer in the last part than in the early part of the 20th century. The monthly mean temperatures showed significant warming of winter months. Over the last four decades, minimum, maximum and average temperatures had warmed by 0.4, 0.43 and 0.4C per decade, respectively, and if this trend continues, they will be warmer by 4C by the end of the 21st century. The significant decline in days with subzero temperatures and frosts in the last half of the 20th century, further substantiated the occurrence of climate change at this site.

  12. Microstructure and phase analysis of Zirconia-ODS (Oxide Dispersion Strengthen) alloy sintered by APS with milling time variation

    Science.gov (United States)

    Sugeng, Bambang; Bandriyana, B.; Sugeng, Bambang; Salam, Rohmad; Sumariyo; Sujatno, Agus; Dimyati, Arbi

    2018-03-01

    Investigation on the relationship between the process conditions of milling time and the microstructure on the synthesis of the zirconia-ODS steel alloy has been performed. The elemental composition of the alloy was determined on 20 wt% Cr and zirconia dispersoid of 0.50 wt%. The synthesis was carried out by powder metallurgy method with milling time of 3, 5 and 7 hours, static compression of 20 Ton and sintering process for 4 minutes using the APS (Arc Plasma Sintering) equipment. SEM-EDX and XRD test was carried out to characterize the phase and morphology of the alloy and the effect to the mechanical properties was evaluated by the Vickers Hardness testing. The synthesis produced sample of ODS steel with good dense and very little porous with the Fe-Cr phase that clearly observed in the XRD peak pattern. In addition milling time increased the homogeneously of Fe-Cr phase formulation, enhanced the grain refinement of the structure and increase the hardness of the alloy.

  13. Worldwide variation in atmospheric noise intensities with sunspot number: an in-depth look at the 20 to 24 hour seasonal time block

    International Nuclear Information System (INIS)

    Joglekar, P.J.; Sathiamurthy, T.S.

    1975-01-01

    Comparisons of the variation of atmospheric radio noise intensities for 20 to 24 hr to sunspot numbers have been completed. Statistical dependence between the noise intensities and sunspot numbers was found for different seasons at a number of frequencies for many locations in the global network of ARN-2 noise recorders. The noise intensities generally tended to decrease with sunspot number in the range from 50 kHz to 5 MHz, which is presumed to be due to increases in residual ionospheric absorption during nighttime. At frequencies greater than 5 MHz, noise intensities increased with sunspot number in many cases, which would be expected from our present knowledge of ionospheric behavior in the HF range. By convention, CCIR treats year-to-year variation in the noise intensities as random and includes them in the prediction uncertainty sigma /sub Fam/ (for which one value is given at a frequency for a seasonal time block for all locations) in system performance evaluation. An error analysis on a global basis shows that a large portion of the year-to-year variability is due to sunspot variation. This suggests the possibility of improved noise estimates. (auth)

  14. Variability of OH rotational temperatures on time scales from hours to 15 years by kinetic temperature variations, emission layer changes, and non-LTE effects

    Science.gov (United States)

    Noll, Stefan

    2016-07-01

    Rotational temperatures derived from hydroxyl (OH) line emission are frequently used to study atmospheric temperatures at altitudes of about 87 km. While the measurement only requires intensities of a few bright lines of an OH band, the interpretation can be complicated. Ground-based temperatures are averages for the entire, typically 8 km wide emission layer. Variations in the rotational temperature are then caused by changes of the kinetic temperature and the OH emission profile. The latter can also be accompanied by differences in the layer-averaged efficiency of the thermalisation of the OH rotational level populations. Since this especially depends on the frequency of collisions with O_2, which is low at high altitudes, the non-local thermodynamic equilibrium (non-LTE) contribution to the measured temperatures can be significant and variable. In order to understand the impact of the different sources of OH rotational temperature variations from time scales of hours to a solar cycle, we have studied spectra from the astronomical echelle spectrographs X-shooter and UVES located at Cerro Paranal in Chile. While the X-shooter data spanning 3.5 years allowed us to measure temperatures for 25 OH and two O_2 bands, the UVES spectra cover no more than 10 OH bands simultaneously but a period of about 15 years. These data have been complemented by kinetic temperature and OH and O_2 emission profiles from the multi-channel radiometer SABER on the TIMED satellite. Taking the O_2 and SABER kinetic temperatures as reference and considering the different band-dependent emission profiles, we could evaluate the contribution of non-LTE effects to the measured OH rotational temperatures depending on line set, band, and time. Non-LTE contributions are significant for most bands and can exceed 10 K. The amplitudes of their average nocturnal and seasonal variation are of the order of 1 to 2 K.

  15. The Kepler-19 System: A Thick-envelope Super-Earth with Two Neptune-mass Companions Characterized Using Radial Velocities and Transit Timing Variations

    Energy Technology Data Exchange (ETDEWEB)

    Malavolta, Luca; Borsato, Luca; Granata, Valentina; Piotto, Giampaolo; Nascimbeni, Valerio [Dipartimento di Fisica e Astronomia “Galileo Galilei”, Universita’di Padova, Vicolo dell’Osservatorio 3, I-35122 Padova (Italy); Lopez, Eric [SUPA, Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh, EH93HJ (United Kingdom); Vanderburg, Andrew; Charbonneau, David [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138 (United States); Figueira, Pedro [Instituto de Astrofísica e Ciências do Espaço, Universidade do Porto, CAUP, Rua das Estrelas, PT4150-762 Porto (Portugal); Mortier, Annelies; Cameron, Andrew Collier [Centre for Exoplanet Science, SUPA, School of Physics and Astronomy, University of St. Andrews, St. Andrews KY16 9SS (United Kingdom); Affer, Laura [INAF—Osservatorio Astronomico di Palermo, Piazza del Parlamento 1, I-90124 Palermo (Italy); Bonomo, Aldo S. [INAF—Osservatorio Astrofisico di Torino, via Osservatorio 20, I-10025 Pino Torinese (Italy); Bouchy, Francois [Observatoire Astronomique de l’Université de Genève, 51 ch. des Maillettes, 1290 Versoix (Switzerland); Buchhave, Lars A. [Centre for Star and Planet Formation, Natural History Museum of Denmark and Niels Bohr Institute, University of Copenhagen, Øster Voldgade 5-7, DK-1350 Copenhagen K (Denmark); Cosentino, Rosario, E-mail: luca.malavolta@unipd.it [INAF—Fundación Galileo Galilei, Rambla José Ana Fernandez Pérez 7, E-38712 Breña Baja (Spain); and others

    2017-05-01

    We report a detailed characterization of the Kepler-19 system. This star was previously known to host a transiting planet with a period of 9.29 days, a radius of 2.2 R {sub ⊕}, and an upper limit on the mass of 20 M {sub ⊕}. The presence of a second, non-transiting planet was inferred from the transit time variations (TTVs) of Kepler-19b over eight quarters of Kepler photometry, although neither the mass nor period could be determined. By combining new TTVs measurements from all the Kepler quarters and 91 high-precision radial velocities obtained with the HARPS-N spectrograph, using dynamical simulations we obtained a mass of 8.4 ± 1.6 M {sub ⊕} for Kepler-19b. From the same data, assuming system coplanarity, we determined an orbital period of 28.7 days and a mass of 13.1 ± 2.7 M {sub ⊕} for Kepler-19c and discovered a Neptune-like planet with a mass of 20.3 ± 3.4 M {sub ⊕} on a 63-day orbit. By comparing dynamical simulations with non-interacting Keplerian orbits, we concluded that neglecting interactions between planets may lead to systematic errors that can hamper the precision in the orbital parameters when the data set spans several years. With a density of 4.32 ± 0.87 g cm{sup −3} (0.78 ± 0.16 ρ {sub ⊕}) Kepler-19b belongs to the group of planets with a rocky core and a significant fraction of volatiles, in opposition to low-density planets characterized only by transit time variations and an increasing number of rocky planets with Earth-like density. Kepler-19 joins the small number of systems that reconcile transit timing variation and radial velocity measurements.

  16. SU-E-T-16: A Comparison of Expected Dwell Times and Dose Variations for NAMD Patients Treated with An Episcleral Brachytherapy Device

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton, R [Univ Arizona, Tucson, AZ (United States); Patel, P; Balaggan, K; Restori, M; Ilginis, T [Moorfields Eye Hospital, London (United Kingdom); Drew, M; McGovern, M; Vitali, J; Marsteller, L [Salutaris Medical Devices, Inc., Tucson, AZ (United States)

    2015-06-15

    Purpose: To evaluate the variations in dwell times and doses expected when using an episcleral brachytherapy device for treatment of neovascular agerelated macular degeneration (n-AMD) based on accurate imaging modalities Methods: Data from 40 eyes from 40 subjects with known n- AMD acquired through the Distance of Choroid Study (DOCS) conducted at Moorfields Eye Hospital was used to determine the target depth; the distance from the outer scleral surface of the eye, through the choroid, to the apex of the choroidal neovascularization (CNV). Each subject underwent, in triplicate, enhanced-depth Spectral Domain Optical Coherence Tomography (SD-OCT), Swept Source Optical Coherence Tomography, (SS-OCT) and Ocular Ultrasound (O-US). These data are the most comprehensive and accurate measurements of the dimensions of the CNV and adjacent layers of the eye for this cohort of patients. During treatment of n-AMD, patients receive a dose of 24Gy to the apex at the target depth. Using the percentage depth dose for a Sr-90 episcleral brachytherapy device, dwell times and doses to the apex were computed to determine the expected variations. Results: The mean target depth and the 95% confidence interval (CI) determined by combining O-US with SD-OCT were 1326 (956,1696)µm and with SS-OCT were 1332 (970,1693)µm. The calculated corresponding mean dwell times and 95% (CI) were 334 (223,445)s and 335 (226,445)s for SD-OCT and SS-OCT determined depths, respectively. The corresponding mean apex dose and 95% (CI) were 24 (35.9,18.0)Gy (SD-OCT) and 24 (35.6,18.1)Gy (SS-OCT). Conclusion: For episcleral brachytherapy treatment of n-AMD, using a patient population average target depth for treatment planning is inadequate, resulting in dose variations of a factor of approximately two over the 95% CI and larger variations for a nontrivial segment of the population. Each patient should have individualized imaging studies to determine the target depth for use in the dwell time calculation

  17. SU-E-T-16: A Comparison of Expected Dwell Times and Dose Variations for NAMD Patients Treated with An Episcleral Brachytherapy Device

    International Nuclear Information System (INIS)

    Hamilton, R; Patel, P; Balaggan, K; Restori, M; Ilginis, T; Drew, M; McGovern, M; Vitali, J; Marsteller, L

    2015-01-01

    Purpose: To evaluate the variations in dwell times and doses expected when using an episcleral brachytherapy device for treatment of neovascular agerelated macular degeneration (n-AMD) based on accurate imaging modalities Methods: Data from 40 eyes from 40 subjects with known n- AMD acquired through the Distance of Choroid Study (DOCS) conducted at Moorfields Eye Hospital was used to determine the target depth; the distance from the outer scleral surface of the eye, through the choroid, to the apex of the choroidal neovascularization (CNV). Each subject underwent, in triplicate, enhanced-depth Spectral Domain Optical Coherence Tomography (SD-OCT), Swept Source Optical Coherence Tomography, (SS-OCT) and Ocular Ultrasound (O-US). These data are the most comprehensive and accurate measurements of the dimensions of the CNV and adjacent layers of the eye for this cohort of patients. During treatment of n-AMD, patients receive a dose of 24Gy to the apex at the target depth. Using the percentage depth dose for a Sr-90 episcleral brachytherapy device, dwell times and doses to the apex were computed to determine the expected variations. Results: The mean target depth and the 95% confidence interval (CI) determined by combining O-US with SD-OCT were 1326 (956,1696)µm and with SS-OCT were 1332 (970,1693)µm. The calculated corresponding mean dwell times and 95% (CI) were 334 (223,445)s and 335 (226,445)s for SD-OCT and SS-OCT determined depths, respectively. The corresponding mean apex dose and 95% (CI) were 24 (35.9,18.0)Gy (SD-OCT) and 24 (35.6,18.1)Gy (SS-OCT). Conclusion: For episcleral brachytherapy treatment of n-AMD, using a patient population average target depth for treatment planning is inadequate, resulting in dose variations of a factor of approximately two over the 95% CI and larger variations for a nontrivial segment of the population. Each patient should have individualized imaging studies to determine the target depth for use in the dwell time calculation

  18. Allelic Variations at Four Major Maturity E Genes and Transcriptional Abundance of the E1 Gene Are Associated with Flowering Time and Maturity of Soybean Cultivars

    Science.gov (United States)

    Wang, Yueqiang; Chen, Xin; Ren, Haixiang; Yang, Jiayin; Cheng, Wen; Zong, Chunmei; Gu, Heping; Qiu, Hongmei; Wu, Hongyan; Zhang, Xingzheng; Cui, Tingting; Xia, Zhengjun

    2014-01-01

    The time to flowering and maturity are ecologically and agronomically important traits for soybean landrace and cultivar adaptation. As a typical short-day crop, long day conditions in the high-latitude regions require soybean cultivars with photoperiod insensitivity that can mature before frost. Although the molecular basis of four major E loci (E1 to E4) have been deciphered, it is not quite clear whether, or to what degree, genetic variation and the expression level of the four E genes are associated with the time to flowering and maturity of soybean cultivars. In this study, we genotyped 180 cultivars at E1 to E4 genes, meanwhile, the time to flowering and maturity of those cultivars were investigated at six geographic locations in China from 2011 to 2012 and further confirmed in 2013. The percentages of recessive alleles at E1, E2, E3 and E4 loci were 38.34%, 84.45%, 36.33%, and 7.20%, respectively. Statistical analysis showed that allelic variations at each of four loci had a significant effect on flowering time as well as maturity. We classified the 180 cultivars into eight genotypic groups based on allelic variations of the four major E loci. The genetic group of e1-nf representing dysfunctional alleles at the E1 locus flowered earliest in all the geographic locations. In contrast, cultivars in the E1E2E3E4 group originated from the southern areas flowered very late or did not flower before frost at high latitude locations. The transcriptional abundance of functional E1 gene was significantly associated with flowering time. However, the ranges of time to flowering and maturity were quite large within some genotypic groups, implying the presence of some other unknown genetic factors that are involved in control of flowering time or maturity. Known genes (e.g. E3 and E4) and other unknown factors may function, at least partially, through regulation of the expression of the E1 gene. PMID:24830458

  19. The rhesus macaque is three times as diverse but more closely equivalent in damaging coding variation as compared to the human

    Directory of Open Access Journals (Sweden)

    Yuan Qiaoping

    2012-06-01

    Full Text Available Abstract Background As a model organism in biomedicine, the rhesus macaque (Macaca mulatta is the most widely used nonhuman primate. Although a draft genome sequence was completed in 2007, there has been no systematic genome-wide comparison of genetic variation of this species to humans. Comparative analysis of functional and nonfunctional diversity in this highly abundant and adaptable non-human primate could inform its use as a model for human biology, and could reveal how variation in population history and size alters patterns and levels of sequence variation in primates. Results We sequenced the mRNA transcriptome and H3K4me3-marked DNA regions in hippocampus from 14 humans and 14 rhesus macaques. Using equivalent methodology and sampling spaces, we identified 462,802 macaque SNPs, most of which were novel and disproportionately located in the functionally important genomic regions we had targeted in the sequencing. At least one SNP was identified in each of 16,797 annotated macaque genes. Accuracy of macaque SNP identification was conservatively estimated to be >90%. Comparative analyses using SNPs equivalently identified in the two species revealed that rhesus macaque has approximately three times higher SNP density and average nucleotide diversity as compared to the human. Based on this level of diversity, the effective population size of the rhesus macaque is approximately 80,000 which contrasts with an effective population size of less than 10,000 for humans. Across five categories of genomic regions, intergenic regions had the highest SNP density and average nucleotide diversity and CDS (coding sequences the lowest, in both humans and macaques. Although there are more coding SNPs (cSNPs per individual in macaques than in humans, the ratio of dN/dS is significantly lower in the macaque. Furthermore, the number of damaging nonsynonymous cSNPs (have damaging effects on protein functions from PolyPhen-2 prediction in the macaque is more

  20. Parametric control of structural vibrations and sound radiation by fast time-space variation of distributed stiffness parameters

    International Nuclear Information System (INIS)

    Krylov, V.I.; Sorokin, S.V.

    1998-01-01

    The dynamics of a Euler-Bernoulli beam with a time-and-space dependent bending stiffness is studied. The , problem is considered in connection with the application of noise control using smart structures. It is shown that a control for the vibrations of the beam can be achieved by varying the bending stiffness. The technique of direct separation of fast and slow motion coupled with a Green's function method is used to analyze the dynamics of the beam with high-frequency modulation of the stiffness

  1. The timing of bud break in warming conditions: variation among seven sympatric conifer species from Eastern Canada

    Science.gov (United States)

    Rossi, Sergio; Isabel, Nathalie

    2017-11-01

    Phenological changes are expected with the ongoing global warming, which could create mismatches in the growth patterns among sympatric species or create synchrony with insect herbivores. In this study, we performed a comparative assessment of the timings of bud break among seven conifer species of Eastern Canada by evaluating seedling development in growth chambers under different temperatures (16, 20 and 24 °C). Bud break occurred earliest in Larix laricina, while Pinus strobus and Pinus resinosa had the latest. Warmer conditions advanced bud break, with the greatest effects being observed at the lower temperatures. Mixed models estimated that one additional degree of temperature produced advancements of 5.3 and 2.1 days at 16 and 20 °C, respectively. The hypothesis of an asynchronous change between species under warming was demonstrated only for the last phenological phases (split buds and exposed shoots), and principally in pines. Abies balsamea showed changes in bud break comparable with the other species analysed, rejecting the hypothesis of mismatches under warmer conditions. The observed non-linear responses of the timings of bud break to warming suggest that the major changes in bud phenology should be expected at the lowest temperatures.

  2. A new set of qualitative reliability criteria to aid inferences on palaeomagnetic dipole moment variations through geological time

    Directory of Open Access Journals (Sweden)

    Andrew John Biggin

    2014-10-01

    Full Text Available Records of reversal frequency support forcing of the geodynamo over geological timescales but obtaining these for earlier times (e.g. the Precambrian is a major challenge. Changes in the measured virtual (axial dipole moment of the Earth, averaged over several millions of years or longer, also have the potential to constrain core and mantle evolution through deep time. There have been a wealth of recent innovations in palaeointensity methods, but there is, as yet, no comprehensive means for assessing the reliability of new and existing dipole moment data. Here we present a new set of largely qualitative reliability criteria for palaeointensity results at the site mean level, which we term QPI in reference to the long-standing Q criteria used for assessing palaeomagnetic poles. These represent the first attempt to capture the range of biasing agents applicable to palaeointensity measurements and to recognise the various approaches employed to obviate them. A total of 8 criteria are proposed and applied to 312 dipole moment estimates recently incorporated into the PINT global database. The number of these criteria fulfilled by a single dipole moment estimate (the QPI value varies between 1 and 6 in the examined dataset and has a median of 3. Success rates for each of the criteria are highly variable, but each criterion was met by at least a few results. The new criteria will be useful for future studies as a means of gauging the reliability of new and published dipole moment estimates.

  3. Solar wind variations and geomagnetic storms - A study of individual storms based on high time resolution ISEE 3 data

    Science.gov (United States)

    Akasofu, S.-I.; Olmsted, C.; Smith, E. J.; Tsurutani, B.; Okida, R.; Baker, D. N.

    1985-01-01

    Two independent methods are employed to determine the relationship between the parameter epsilon and total energy dissipation rate of the magnetosphere U sub T by selecting disturbed periods from the same data d set used by Baker et al. (1983). Specifically, four storms are examined in detail, since the accuracy of estimating U sub T is significantly improved during disturbed periods. The first method assumes that U sub T = M sub A exp.2- alpha(epsilon) where M sub A is the Alfven Mach number and alpha varies with time. The second method considers a linear, time-invariant dynamic system with epsilon as input and U sub T as output. This means that U sub T = W(asterisk)epsilon where asterisk is the convolution and W is a transfer function characteristic of the system. It is found that alpha values fluctuate mainly between 0 and -0.25. The transfer function analysis indicates that W often resembles a delta-function or a narrow rectangular impulse. Both results give the same implication (namely that U sub T is approximately equal to epsilon) and thus are consistent with the view that the magnetosphere is primarily a directly driven system during disturbed periods.

  4. Changes in the flagellar bundling time account for variations in swimming behavior of flagellated bacteria in viscous media

    Science.gov (United States)

    Qu, Zijie; Temel, Fatma; Henderikx, Rene; Breuer, Kenneth

    2017-11-01

    The motility of bacteria E.coli in viscous fluids has been widely studied, although conflicting results on the effect of viscosity on swimming speed abound. The swimming mode of wild-type E.coli is idealized as a run-and-tumble sequence in which periods of straight swimming at a constant speed are randomly interrupted by a tumble, defined as a sudden change of direction with a very low speed. Using a tracking microscope, we follow cells for extended time and find that the swimming behavior of a single cell can exhibit a variety of behaviors including run-and-tumble and ``slow-random-walk'' in which the cells move at relatively low speed without the characteristic run. Although the characteristic swimming speed varies between individuals and in different polymer solutions, we find that the skewness of the speed distribution is solely a function of viscosity, and uniquely determines the ratio of the average speed to the characteristic run speed. Using Resistive Force Theory and the cell-specific measured characteristic run speed, we show that differences in the swimming behavior observed in solutions of different viscosity are due to changes in the flagellar bundling time, which increases as the viscosity rises, due to lower rotation rate of the flagellar motor. National Science Foundation.

  5. The influence of storage time and pH variation on water sorption by different composite resins.

    Science.gov (United States)

    Gusmão, George Mário de Araújo Silva; De Queiroz, Thiago Vinicius Veras; Pompeu, Guilherme Ferrer; Menezes Filho, Paulo Fonseca; da Silva, Cláudio Heliomar Vicente

    2013-01-01

    The objective of this work was to assess the influence of storage time and pH cycling on water sorption by different composite resins. Nine resin brands were selected and divided into groups: G1-ROK (SDI), G2-ICE (SDI), G3-GLACIER (SDI), G4-Z350 (3M/ESPE), G5-Z250 (3M/ESPE), G6-TPH 3 (DENTSPLY), G7-ESTHET X (DENTSPLY), G8-SUPRAFILL (SSWHITE), and G9-MASTERFILL (BIODINΒMICS). Ninety specimens, ten per group, were obtained using an aluminum matrix. Specimens measured 10 mm diameter × 2 mm width. The groups were divided into subgroups according to the immersion solution: A - control (n = 05) stored in artificial saliva pH = 7.0 and B-test (n = 05) submitted to seven consecutive days of pH cycling (cariogenic challenger) that consisted of immersion in a pH° = 4.3 solution for 6 h followed by immersion in a pH¹ =7.0 solution for 18 h and stored in artificial saliva pH = 7.0 until the end of the experiment. The specimens were weighed on six occasions: T 0 (after fabrication), T 1 (24 h), T 2 (7 days), T 3 (15 days), T 4 (30 days), T 5 (60 days), and then analyzed. The water sorption was determined by the weight difference between the specimens at the time intervals. The mean weight gain was exactly the same for both the subgroups within group G4. The highest means for the control subgroup were found in groups: G1, G5, G7, G8, and G9. For the pH cycling subgroup, the highest means were found in G2, G3, and G6; however, significant differences between the subgroups compared to the mean-weight gain were found for G1, G5, and G7. The water sorption of composite resins is dependent upon their storage time. The pH cycling created a significant impact on resins G1, G5, and G7. The sorption and solubility of composite resins vary according to their chemical composition.

  6. No Escaping the Rat Race: Simulated Night Shift Work Alters the Time-of-Day Variation in BMAL1 Translational Activity in the Prefrontal Cortex.

    Science.gov (United States)

    Marti, Andrea R; Patil, Sudarshan; Mrdalj, Jelena; Meerlo, Peter; Skrede, Silje; Pallesen, Ståle; Pedersen, Torhild T; Bramham, Clive R; Grønli, Janne

    2017-01-01

    Millions of people worldwide work during the night, resulting in disturbed circadian rhythms and sleep loss. This may cause deficits in cognitive functions, impaired alertness and increased risk of errors and accidents. Disturbed circadian rhythmicity resulting from night shift work could impair brain function and cognition through disrupted synthesis of proteins involved in synaptic plasticity and neuronal function. Recently, the circadian transcription factor brain-and-muscle arnt-like protein 1 (BMAL1) has been identified as a promoter of mRNA translation initiation, the most highly regulated step in protein synthesis, through binding to the mRNA "cap". In this study we investigated the effects of simulated shift work on protein synthesis markers. Male rats ( n = 40) were exposed to forced activity, either in their rest phase (simulated night shift work) or in their active phase (simulated day shift work) for 3 days. Following the third work shift, experimental animals and time-matched undisturbed controls were euthanized (rest work at ZT12; active work at ZT0). Tissue lysates from two brain regions (prefrontal cortex, PFC and hippocampus) implicated in cognition and sleep loss, were analyzed with m 7 GTP (cap) pull-down to examine time-of-day variation and effects of simulated shift work on cap-bound protein translation. The results show time-of-day variation of protein synthesis markers in PFC, with increased protein synthesis at ZT12. In the hippocampus there was little difference between ZT0 and ZT12. Active phase work did not induce statistically significant changes in protein synthesis markers at ZT0 compared to time-matched undisturbed controls. Rest work, however, resulted in distinct brain-region specific changes of protein synthesis markers compared to time-matched controls at ZT12. While no changes were observed in the hippocampus, phosphorylation of cap-bound BMAL1 and its regulator S6 kinase beta-1 (S6K1) was significantly reduced in the PFC

  7. No Escaping the Rat Race: Simulated Night Shift Work Alters the Time-of-Day Variation in BMAL1 Translational Activity in the Prefrontal Cortex

    Directory of Open Access Journals (Sweden)

    Andrea R. Marti

    2017-10-01

    Full Text Available Millions of people worldwide work during the night, resulting in disturbed circadian rhythms and sleep loss. This may cause deficits in cognitive functions, impaired alertness and increased risk of errors and accidents. Disturbed circadian rhythmicity resulting from night shift work could impair brain function and cognition through disrupted synthesis of proteins involved in synaptic plasticity and neuronal function. Recently, the circadian transcription factor brain-and-muscle arnt-like protein 1 (BMAL1 has been identified as a promoter of mRNA translation initiation, the most highly regulated step in protein synthesis, through binding to the mRNA “cap”. In this study we investigated the effects of simulated shift work on protein synthesis markers. Male rats (n = 40 were exposed to forced activity, either in their rest phase (simulated night shift work or in their active phase (simulated day shift work for 3 days. Following the third work shift, experimental animals and time-matched undisturbed controls were euthanized (rest work at ZT12; active work at ZT0. Tissue lysates from two brain regions (prefrontal cortex, PFC and hippocampus implicated in cognition and sleep loss, were analyzed with m7GTP (cap pull-down to examine time-of-day variation and effects of simulated shift work on cap-bound protein translation. The results show time-of-day variation of protein synthesis markers in PFC, with increased protein synthesis at ZT12. In the hippocampus there was little difference between ZT0 and ZT12. Active phase work did not induce statistically significant changes in protein synthesis markers at ZT0 compared to time-matched undisturbed controls. Rest work, however, resulted in distinct brain-region specific changes of protein synthesis markers compared to time-matched controls at ZT12. While no changes were observed in the hippocampus, phosphorylation of cap-bound BMAL1 and its regulator S6 kinase beta-1 (S6K1 was significantly reduced in

  8. Spatial and temporal variation of residence time and storage volume of subsurface water evaluated by multi-tracers approach in mountainous headwater catchments

    Science.gov (United States)

    Tsujimura, Maki; Yano, Shinjiro; Abe, Yutaka; Matsumoto, Takehiro; Yoshizawa, Ayumi; Watanabe, Ysuhito; Ikeda, Koichi

    2015-04-01

    Headwater catchments in mountainous region are the most important recharge area for surface and subsurface waters, additionally time and stock information of the water is principal to understand hydrological processes in the catchments. However, there have been few researches to evaluate variation of residence time and storage volume of subsurface water in time and space at the mountainous headwaters especially with steep slope. We performed an investigation on age dating and estimation of storage volume using simple water budget model in subsurface water with tracing of hydrological flow processes in mountainous catchments underlain by granite, Paleozoic and Tertiary, Yamanashi and Tsukuba, central Japan. We conducted hydrometric measurements and sampling of spring, stream and ground waters in high-flow and low-flow seasons from 2008 through 2012 in the catchments, and CFCs, stable isotopic ratios of oxygen-18 and deuterium, inorganic solute constituent concentrations were determined on all water samples. Residence time of subsurface water ranged from 11 to 60 years in the granite catchments, from 17 to 32 years in the Paleozoic catchments, from 13 to 26 years in the Tertiary catchments, and showed a younger age during the high-flow season, whereas it showed an older age in the low-flow season. Storage volume of subsurface water was estimated to be ranging from 10 ^ 4 to 10 ^ 6 m3 in the granite catchments, from 10 ^ 5 to 10 ^ 7 m3 in the Paleozoic catchments, from 10 ^ 4 to 10 ^ 6 m3 in the Tertiary catchments. In addition, seasonal change of storage volume in the granite catchments was the highest as compared with those of the Paleozoic and the Tertiary catchments. The results suggest that dynamic change of hydrological process seems to cause a larger variation of the residence time and storage volume of subsurface water in time and space in the granite catchments, whereas higher groundwater recharge rate due to frequent fissures or cracks seems to cause larger

  9. Use of intraspecific variation in thermal responses for estimating an elevational cline in the timing of cold hardening in a sub-boreal conifer.

    Science.gov (United States)

    Ishizuka, W; Ono, K; Hara, T; Goto, S

    2015-01-01

    To avoid winter frost damage, evergreen coniferous species develop cold hardiness with suitable phenology for the local climate regime. Along the elevational gradient, a genetic cline in autumn phenology is often recognised among coniferous populations, but further quantification of evolutionary adaptation related to the local environment and its responsible signals generating the phenological variation are poorly understood. We evaluated the timing of cold hardening among populations of Abies sachalinensis, based on time series freezing tests using trees derived from four seed source populations × three planting sites. Furthermore, we constructed a model to estimate the development of hardening from field temperatures and the intraspecific variations occurring during this process. An elevational cline was detected such that high-elevation populations developed cold hardiness earlier than low-elevation populations, representing significant genetic control. Because development occurred earlier at high-elevation planting sites, the genetic trend across elevation overlapped with the environmental trend. Based on the trade-off between later hardening to lengthen the active growth period and earlier hardening to avoid frost damage, this genetic cline would be adaptive to the local climate. Our modelling approach estimated intraspecific variation in two model components: the threshold temperature, which was the criterion for determining whether the trees accumulated the thermal value, and the chilling requirement for trees to achieve adequate cold hardiness. A higher threshold temperature and a lower chilling requirement could be responsible for the earlier phenology of the high-elevation population. These thermal responses may be one of the important factors driving the elevation-dependent adaptation of A. sachalinensis. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

  10. Using areas of known occupancy to identify sources of variation in detection probability of raptors: taking time lowers replication effort for surveys.

    Science.gov (United States)

    Murn, Campbell; Holloway, Graham J

    2016-10-01

    Species occurring at low density can be difficult to detect and if not properly accounted for, imperfect detection will lead to inaccurate estimates of occupancy. Understanding sources of variation in detection probability and how they can be managed is a key part of monitoring. We used sightings data of a low-density and elusive raptor (white-headed vulture Trigonoceps occipitalis ) in areas of known occupancy (breeding territories) in a likelihood-based modelling approach to calculate detection probability and the factors affecting it. Because occupancy was known a priori to be 100%, we fixed the model occupancy parameter to 1.0 and focused on identifying sources of variation in detection probability. Using detection histories from 359 territory visits, we assessed nine covariates in 29 candidate models. The model with the highest support indicated that observer speed during a survey, combined with temporal covariates such as time of year and length of time within a territory, had the highest influence on the detection probability. Averaged detection probability was 0.207 (s.e. 0.033) and based on this the mean number of visits required to determine within 95% confidence that white-headed vultures are absent from a breeding area is 13 (95% CI: 9-20). Topographical and habitat covariates contributed little to the best models and had little effect on detection probability. We highlight that low detection probabilities of some species means that emphasizing habitat covariates could lead to spurious results in occupancy models that do not also incorporate temporal components. While variation in detection probability is complex and influenced by effects at both temporal and spatial scales, temporal covariates can and should be controlled as part of robust survey methods. Our results emphasize the importance of accounting for detection probability in occupancy studies, particularly during presence/absence studies for species such as raptors that are widespread and

  11. Evaluation of quantitative imaging methods for organ activity and residence time estimation using a population of phantoms having realistic variations in anatomy and uptake

    International Nuclear Information System (INIS)

    He Bin; Du Yong; Segars, W. Paul; Wahl, Richard L.; Sgouros, George; Jacene, Heather; Frey, Eric C.

    2009-01-01

    Estimating organ residence times is an essential part of patient-specific dosimetry for radioimmunotherapy (RIT). Quantitative imaging methods for RIT are often evaluated using a single physical or simulated phantom but are intended to be applied clinically where there is variability in patient anatomy, biodistribution, and biokinetics. To provide a more relevant evaluation, the authors have thus developed a population of phantoms with realistic variations in these factors and applied it to the evaluation of quantitative imaging methods both to find the best method and to demonstrate the effects of these variations. Using whole body scans and SPECT/CT images, organ shapes and time-activity curves of 111In ibritumomab tiuxetan were measured in dosimetrically important organs in seven patients undergoing a high dose therapy regimen. Based on these measurements, we created a 3D NURBS-based cardiac-torso (NCAT)-based phantom population. SPECT and planar data at realistic count levels were then simulated using previously validated Monte Carlo simulation tools. The projections from the population were used to evaluate the accuracy and variation in accuracy of residence time estimation methods that used a time series of SPECT and planar scans. Quantitative SPECT (QSPECT) reconstruction methods were used that compensated for attenuation, scatter, and the collimator-detector response. Planar images were processed with a conventional (CPlanar) method that used geometric mean attenuation and triple-energy window scatter compensation and a quantitative planar (QPlanar) processing method that used model-based compensation for image degrading effects. Residence times were estimated from activity estimates made at each of five time points. The authors also evaluated hybrid methods that used CPlanar or QPlanar time-activity curves rescaled to the activity estimated from a single QSPECT image. The methods were evaluated in terms of mean relative error and standard deviation of the

  12. A variational model for propagation time, volumetric and synchronicity optimization in the spinal cord axon network, and a method for testing it

    Science.gov (United States)

    Mota, Bruno

    2014-03-01

    Most information in the central nervous system in general and the (simpler) spinal cord in particular, is transmitted along bundles of parallel axons. Each axon's transmission time increases linearly with length and decreases as a power law of caliber. Therefore, evolution must find a distribution of axonal numbers, lengths and calibers that balances the various tradeoffs between gains in propagation time, signal throughput and synchronicity, against volumetric and metabolic costs. Here I apply a variational method to calculate the distribution of axonal caliber in the spinal cord as a function of axonal length, that minimizes the average axonal signal propagation time, subject to the constraints of white matter total volume and the variance of propagation times, and allowing for arbitrary fiber priorities and end-points. The Lagrange multipliers obtained thereof can be naturally interpreted as 'exchange rates', e.g., how much evolution is willing to pay, in white matter added volume, per unit time decrease of propagation time. This is, to my knowledge, the first model that quantifies explicitly these evolutionary tradeoffs, and can obtain them empirically by measuring the distribution of axonal calibers. We are in the process of doing so using the isotropic fractionator method. I thank FAPERJ for financial support.

  13. Analyzing Seasonal Variations in Suicide With Fourier Poisson Time-Series Regression: A Registry-Based Study From Norway, 1969-2007.

    Science.gov (United States)

    Bramness, Jørgen G; Walby, Fredrik A; Morken, Gunnar; Røislien, Jo

    2015-08-01

    Seasonal variation in the number of suicides has long been acknowledged. It has been suggested that this seasonality has declined in recent years, but studies have generally used statistical methods incapable of confirming this. We examined all suicides occurring in Norway during 1969-2007 (more than 20,000 suicides in total) to establish whether seasonality decreased over time. Fitting of additive Fourier Poisson time-series regression models allowed for formal testing of a possible linear decrease in seasonality, or a reduction at a specific point in time, while adjusting for a possible smooth nonlinear long-term change without having to categorize time into discrete yearly units. The models were compared using Akaike's Information Criterion and analysis of variance. A model with a seasonal pattern was significantly superior to a model without one. There was a reduction in seasonality during the period. Both the model assuming a linear decrease in seasonality and the model assuming a change at a specific point in time were both superior to a model assuming constant seasonality, thus confirming by formal statistical testing that the magnitude of the seasonality in suicides has diminished. The additive Fourier Poisson time-series regression model would also be useful for studying other temporal phenomena with seasonal components. © The Author 2015. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  14. Considerable Variation of Antibacterial Activity of Cu Nanoparticles Suspensions Depending on the Storage Time, Dispersive Medium, and Particle Sizes

    Directory of Open Access Journals (Sweden)

    Olga V. Zakharova

    2015-01-01

    Full Text Available Suspensions of Cu nanoparticles are promising for creating the new class of alternative antimicrobial products. In this study we examined copper nanoparticles of various sizes obtained by the method of wire electric explosion: nanopowder average size 50 nm (Cu 50 and 100 nm (Cu 100. The paper presents the complex study of the influence of physicochemical properties such as particle size and concentration of the freshly prepared and 24-hour suspensions of Cu nanoparticles in distilled water and physiological solution upon their toxicity to bacteria E. coli M-17. Ionic solution of Cu2+ and sodium dichloroisocyanurate was used for comparison study. It has been shown that decrease in the nanoparticle size leads to changes in the correlation between toxicity and concentration as toxicity peaks are observed at low concentrations (0.0001⋯0.01 mg/L. It has been observed that antibacterial properties of Cu 50 nanoparticle suspensions are ceased after 24-hour storage, while for Cu 100 suspensions no correlation between antibacterial properties and storage time has been noted. Cu 100 nanoparticle suspensions at 10 mg/L concentration display higher toxicity at substituting physiological solution for water than Cu 50 suspensions. Dependence of the toxicity on the mean particle aggregates size in suspension was not revealed.

  15. Real-time simulation of response to load variation for a ship reactor based on point-reactor double regions and lumped parameter model

    Energy Technology Data Exchange (ETDEWEB)

    Wang Qiao; Zhang De [Department of Nuclear Energy Science and Engineering, Naval University of Engineering, Wuhan 430033 (China); Chen Wenzhen, E-mail: Cwz2@21cn.com [Department of Nuclear Energy Science and Engineering, Naval University of Engineering, Wuhan 430033 (China); Chen Zhiyun [Department of Nuclear Energy Science and Engineering, Naval University of Engineering, Wuhan 430033 (China)

    2011-05-15

    Research highlights: > We calculate the variation of main parameters of the reactor core by the Simulink. > The Simulink calculation software (SCS) can deal well with the stiff problem. > The high calculation precision is reached with less time, and the results can be easily displayed. > The quick calculation of ship reactor transient can be achieved by this method. - Abstract: Based on the point-reactor double regions and lumped parameter model, while the nuclear power plant second loop load is increased or decreased quickly, the Simulink calculation software (SCS) is adopted to calculate the variation of main physical and thermal-hydraulic parameters of the reactor core. The calculation results are compared with those of three-dimensional simulation program. It is indicated that the SCS can deal well with the stiff problem of the point-reactor kinetics equations and the coupled problem of neutronics and thermal-hydraulics. The high calculation precision can be reached with less time, and the quick calculation of parameters of response to load disturbance for the ship reactor can be achieved. The clear image of the calculation results can also be displayed quickly by the SCS, which is very significant and important to guarantee the reactor safety operation.

  16. Cone-Beam Computed Tomography–Guided Positioning of Laryngeal Cancer Patients with Large Interfraction Time Trends in Setup and Nonrigid Anatomy Variations

    International Nuclear Information System (INIS)

    Gangsaas, Anne; Astreinidou, Eleftheria; Quint, Sandra; Levendag, Peter C.; Heijmen, Ben

    2013-01-01

    Purpose: To investigate interfraction setup variations of the primary tumor, elective nodes, and vertebrae in laryngeal cancer patients and to validate protocols for cone beam computed tomography (CBCT)-guided correction. Methods and Materials: For 30 patients, CBCT-measured displacements in fractionated treatments were used to investigate population setup errors and to simulate residual setup errors for the no action level (NAL) offline protocol, the extended NAL (eNAL) protocol, and daily CBCT acquisition with online analysis and repositioning. Results: Without corrections, 12 of 26 patients treated with radical radiation therapy would have experienced a gradual change (time trend) in primary tumor setup ≥4 mm in the craniocaudal (CC) direction during the fractionated treatment (11/12 in caudal direction, maximum 11 mm). Due to these trends, correction of primary tumor displacements with NAL resulted in large residual CC errors (required margin 6.7 mm). With the weekly correction vector adjustments in eNAL, the trends could be largely compensated (CC margin 3.5 mm). Correlation between movements of the primary and nodal clinical target volumes (CTVs) in the CC direction was poor (r 2 =0.15). Therefore, even with online setup corrections of the primary CTV, the required CC margin for the nodal CTV was as large as 6.8 mm. Also for the vertebrae, large time trends were observed for some patients. Because of poor CC correlation (r 2 =0.19) between displacements of the primary CTV and the vertebrae, even with daily online repositioning of the vertebrae, the required CC margin around the primary CTV was 6.9 mm. Conclusions: Laryngeal cancer patients showed substantial interfraction setup variations, including large time trends, and poor CC correlation between primary tumor displacements and motion of the nodes and vertebrae (internal tumor motion). These trends and nonrigid anatomy variations have to be considered in the choice of setup verification protocol and

  17. Microbial communities of the Lemon Creek Glacier show subtle structural variation yet stable phylogenetic composition over space and time

    Directory of Open Access Journals (Sweden)

    Cody Springer Sheik

    2015-05-01

    Full Text Available Glaciers are geologically important yet transient ecosystems that support diverse, biogeochemically significant microbial communities. During the melt season glaciers undergo dramatic physical, geochemical and biological changes that exert great influence on downstream biogeochemical cycles. Thus, we sought to understand the temporal melt-season dynamics of microbial communities and associated geochemistry at the terminus of Lemon Creek Glacier (LCG in coastal southern Alaska. Due to late season snowfall, sampling of LCG occurred in three interconnected areas: proglacial Lake Thomas, the lower glacial outflow stream and the glacier’s terminus. LCG associated microbial communities were phylogenetically diverse and varied by sampling location. However, Betaproteobacteria, Alphaproteobacteria and Bacteroidetes dominated communities at all sampling locations. Strict anaerobic groups such as methanogens, SR1, and OP11 were also recovered from glacier outflows, indicating anoxic conditions in at least some portions of the LCG subglacial environment. Microbial community structure was significantly correlated with sampling location and sodium concentrations. Microbial communities sampled from terminus outflow waters exhibited day-to-day fluctuation in taxonomy and phylogenetic similarity. However, these communities were not significantly different from randomly constructed communities from all three sites. These results indicate that glacial outflows share a large proportion of phylogenetic overlap with downstream environments and that the observed significant shifts in community structure are driven by changes in relative abundance of different taxa, and not complete restructuring of communities. We conclude that LCG glacial discharge hosts a diverse and relatively stable microbiome that shifts at fine taxonomic scales in response to geochemistry and likely water residence time.

  18. Meta-analysis of congenitally missing teeth in the permanent dentition: Prevalence, variations across ethnicities, regions and time.

    Science.gov (United States)

    Rakhshan, Vahid; Rakhshan, Hamid

    2015-09-01

    Congenitally missing teeth (CMT) are of concern to many fields of dentistry. Only a few reviews have been published in this regard. The aim was to analyze the literature on CMT in the permanent dentition, excluding the third molars, and to identify potential links with ethnicity, geographical regions, and time. A total of 118 reports on CMT were collected by two authors by interrogating databases. Sample homogeneity, publication bias, publication year (in Caucasian and Mongoloid samples, and in general), ethnicities, and geography of CMT prevalence were statistically analyzed using a Q-test, Egger regression, linear regression, a Spearman coefficient, Kruskal-Wallis, a Dunn post-hoc (α = 0.05), and a Mann-Whitney U test (α = 0.0125, α = 0.0071). The mean CMT prevalence was 6.53% ± 3.33%. There were significant geographic differences in CMT rates (P = 0.0001, Kruskal-Wallis) and between ethnicities (P = 0.0002, Kruskal-Wallis). According to the Mann-Whitney U test (α = 0.0071), eastern Asians (P = 0.0008) and Europeans (marginally significant, P = 0.0128) showed an elevated prevalence, while Western Asians (P = 0.0001) and Americans (marginally significant, P = 0.0292) had lower prevalence rates. Compared with other ethnicities, Mongoloids showed higher prevalence (P = 0.0009) while Asian Caucasians showed lower rates (P = 0.0005, Mann-Whitney U, α = 0.0125). The year of publication was not significantly correlated with any of the subsamples studied (P > 0.3, linear regression). Clinicians should be vigilant in the assessment of CMT in Mongoloids. No increase of this condition was detected during the last century. Copyright © 2015 CEO. Published by Elsevier Masson SAS. All rights reserved.

  19. Variation in honey yield per hive of Africanized bees depending on the introducing time of young queens

    Directory of Open Access Journals (Sweden)

    Vladson Carbonari

    2016-05-01

    Full Text Available ABSTRACT: The objective of this research was to evaluate the honey production per hive and the egg laying rates of queens produced in 2007, 2008 and 2010. Thirty colonies initiated with a queen per colony at each climatic season were used during the three years. The years, started on January (summer, April (autumn, July (winter and October (spring and ended 12 months later, at the same periods related to each season of the later years. Honey supply were weighed before and after centrifugation to evaluate the quantity of the stored honey. Colonies with queens introduced during autumn and winter in the three years produced 57.2±6.0kg and 60.7±7.5kg of honey, respectively. In the first year of production activity, after the introduction of queens in the initial colonies, values were significantly higher than those obtained in colonies with queens introduced in the summer (39.3±7.6kg and spring (41.8±3.7kg. Egg laying rates of queens were higher in spring (98.2±3.9% and summer (88.4±7%, indicating greater food flow (flowerings in these seasons compared to the averages in autumn (30.3±8.1% and winter (24.5±7.2%. Produce and introduce queens of Africanized Apis mellifera in colonies initiated during autumn and winter was found to be economically feasible. Honey production of colonies initiated in these periods were higher and they had greater population stability in times of scarcity of flowerings.

  20. Bioaugmentation of anaerobic sludge digestion with iron-reducing bacteria: process and microbial responses to variations in hydraulic retention time.

    Science.gov (United States)

    Baek, Gahyun; Kim, Jaai; Shin, Seung Gu; Lee, Changsoo

    2016-01-01

    Although anaerobic digestion (AD) is a widely used option to manage waste activated sludge (WAS), there are some drawbacks related to its slow reaction rate and low energy productivity. This study examined an anaerobic WAS digester, augmented with an iron-reducing microbial consortium, relative to changes in microbial community structure and process performance at decreasing hydraulic retention times (HRTs) of 20 to 10 days. The enhanced methanation performance (approximately 40 % increase in methane yield) by the bioaugmentation was sustained until the HRT was decreased to 12.5 days, under Fe(3+)-rich conditions (ferric oxyhydroxide, 20 mM Fe). Enhanced iron-reducing activity was evidenced by the increased Fe(2+) to total Fe ratio maintained above 50 % during the stable operational phases. A further decrease in HRT to 10 days resulted in a significant performance deterioration, along with a drop in the Fe(2+) to total Fe ratio to bacteria (IRBs) was identified by denaturing gradient gel electrophoresis (DGGE), with Spirochaetaceae- and Thauera-related organisms being dominant members, and clear dominance shifts among them with respect to decrease in HRT were observed. Lowering HRT led to evident shifts in bacterial community structure likely associated with washout of IRBs, leading to decreases in iron respiration activity and AD performance at a lower HRT. The bacterial community structure shifted dynamically over phases, and the community transitions correlated well with the changes in process performance. Overall, the combined biostimulation and bioaugmentation investigated in this study proved effective for enhanced methane recovery from anaerobic WAS digestion, which suggests an interesting potential for high-rate AD.

  1. VARIATIONS IN CLINICAL AND IMAGING FINDINGS BY TIME OF DIAGNOSIS IN FEMALES WITH HYPOPITUITARISM ATTRIBUTED TO LYMPHOCYTIC HYPOPHYSITIS.

    Science.gov (United States)

    Tirosh, Amit; Hirsch, Dania; Robenshtok, Eyal; Masri-Iraqi, Hiba; Yoel, Uri; Toledano, Yoel; Twito, Orit; Tsvetov, Gloria; Shimon, Ilan

    2016-04-01

    To describe the various patterns of presentation, including assisting analyses, associated with the timing of diagnosis of females with hypopituitarism and suspected clinical diagnosis of lymphocytic hypophysitis. A retrospective study of 9 consecutive females with pituitary dysfunction developed during or after pregnancy. All subjects were treated in our clinics between 2008 and 2014. Data were collected on clinical characteristics, pituitary hormone levels, and imaging findings. The study group included 9 patients with a mean age 33.7 ± 7.8 years at delivery. The probable cause of disease was lymphocytic hypophysitis. Headache or specific symptoms/signs of hypopituitarism appeared within 1 year of delivery. Five patients had headache, and 8 had difficulty breastfeeding or amenorrhea. Laboratory findings included central hypocortisolism (8/9 patients), hypogonadotropic hypogonadism (8/9), and central hypothyroidism (6/7). Insulin-like growth factor-1 (IGF-1) levels were low in 8/8 patients. Prolactin levels were low in 3/9 patients, and 1 patient had diabetes insipidus. Seven patients were diagnosed less than 1 year from symptom onset; 4 (57%) complained of headaches, and 5 (71%) had panhypopituitarism. Two patients were diagnosed later. Both had difficulty breastfeeding and amenorrhea, and one also had headaches. Both had panhypopituitarism and reduced pituitary volume. None of the patients fully recovered pituitary function. Normalization of the thyrotroph axis occurred in 3 patients, gonadotroph function in 3, the corticotroph axis in 2, and IGF-1 normalized in 1 subject. Hypopituitarism attributed to lymphocytic hypophysitis may present during pregnancy or early postpartum period with a clear clinical picture, or later, with indolent and nonspecific symptoms and signs.

  2. Seasonal Changes in Estuarine Dissolved Organic Matter Due to Variations in Discharge, Flushing Times and Wind-driven Mixing Events

    Science.gov (United States)

    Dixon, Jennifer Louise

    isotopes (Bauer, 2002) and lignin (e.g., Benner and Opsahl, 2001; Harvey and Mannino, 2001). Marine DOM derived from phytoplankton typically has carbon stable isotope (delta13C) values that range from --20 to --22‰, while terrestrial DOM derived from C3 land plants typically have delta13C values that range from --26 to --28‰ (Bauer, 2002). Lignin is an important component of vascular plants, thus making it a unique geochemical biomarker, which can be used to trace the fate of terrestrial DOM in coastal seawater (e.g., Hernes and Benner, 2003; Walker et al. 2009; Osburn and Stedmon, 2011). Further, the ratios of the different phenolic compounds derived from the oxidation of lignin can be used to distinguish between plant sources (e.g. angiosperm vs. gymnosperm, or woody vs. non-woody tissue) and the extent of exposure to degradation (Hedges et al. 1988). The highly productive, eutrophic waters of the Neuse River Estuary (NRE), in eastern North Carolina, USA, serve as a transition zone for terrigenous DOM between the head of the Neuse River and Pamlico Sound. Previous studies have determined that the NRE is dominated by inputs from riverine discharge, yet very clear shifts in DOM quality are apparent as discharge varied (Paerl et al. 1998; Osburn et al. 2012). Furthermore, flushing times within the NRE will aid in determining whether DOM is primarily autochthonous or allochthonous and if it is processed internally or transported downstream to the Pamlico Sound (Paerl et al. 1998; Mari et al. 2007, Peierls et al. 2012). Therefore, the main sources of DOM and its composition can change throughout an estuary depending on the hydrodynamic conditions. For example, increases in flushing time may allow for the accumulation of autochthonous DOM because of (1) planktonic communities within the water column having more time to utilize nutrients within the system, resulting in phytoplankton blooms and (2) lower inputs of allochthonous OM from the NRE's watershed (Dixon et al

  3. Variation Trend Analysis of Runoff and Sediment Time Series Based on the R/S Analysis of Simulated Loess Tilled Slopes in the Loess Plateau, China

    Directory of Open Access Journals (Sweden)

    Ju Zhang

    2017-12-01

    Full Text Available The objective of this study was to illustrate the temporal variation of runoff and sediment of loess tilled slopes under successive rainfall conditions. Loess tilled slopes with four microtopography types (straight cultivated slope, artificial backhoe, artificial digging, and contour tillage under five slope gradients (5°, 10°, 15°, 20°, 25° were simulated and a rainfall intensity of 60 mm/h was adopted. The temporal trends of runoff and sediment yield were predicted based on the Rescaled Range (R/S analysis method. The results indicate that the Hurst indices of runoff time series and sediment time series are higher than 0.5, and a long-term positive correlation exists between the future and the past. This means that runoff and sediment of loess tilled slopes in the future will have the same trends as in the past. The results obtained by the classical R/S analysis method were the same as those of the modified R/S analysis method. The rationality and reliability of the R/S analysis method were further identified and the method can be used for predicting the trend of runoff and sediment yield. The correlation between the microtopography and the Hurst indices of the runoff and sediment yield time series, as well as between the slopes and the Hurst indices, were tested, and the result was that there was no significant correlation between them. The microtopography and slopes cannot affect the correlation and continuity of runoff and sediment yield time series. This study provides an effective method for predicting variations in the trends of runoff and sediment yield on loess tilled slopes.

  4. Multi variate regression model of the water level and production rate time series of the geothermal reservoir Waiwera (New Zealand)

    Science.gov (United States)

    Kühn, Michael; Schöne, Tim

    2017-04-01

    Water management tools are essential to ensure the conservation of natural resources. The geothermal hot water reservoir below the village of Waiwera, on the Northern Island of New Zealand is used commercially since 1863. The continuous production of 50 °C hot geothermal water, to supply hotels and spas, has a negative impact on the reservoir. Until the year 1969 from all wells drilled the warm water flow was artesian. Due to overproduction the water needs to be pumped up nowadays. Further, within the years 1975 to 1976 the warm water seeps on the beach of Waiwera ran dry. In order to protect the reservoir and the historical and tourist site in the early 1980s a water management plan was deployed. The "Auckland Council" established guidelines to enable a sustainable management of the resource [1]. The management plan demands that the water level in the official and appropriate observation well of the council is 0.5 m above sea level throughout the year in average. Almost four decades of data (since 1978 until today) are now available [2]. For a sustainable water management, it is necessary to be able to forecast the water level as a function of the production rates in the production wells. The best predictions are provided by a multivariate regression model of the water level and production rate time series, which takes into account the production rates of individual wells. It is based on the inversely proportional relationship between the independent variable (production rate) and the dependent variable (measured water level). In production scenarios, a maximum total production rate of approx. 1,100 m3 / day is determined in order to comply with the guidelines of the "Auckland Council". [1] Kühn M., Stöfen H. (2005) A reactive flow model of the geothermal reservoir Waiwera, New Zealand. Hydrogeology Journal 13, 606-626, doi: 10.1007/s10040-004-0377-6 [2] Kühn M., Altmannsberger C. (2016) Assessment of data driven and process based water management tools for

  5. Variation in type and frequency of diagnostic imaging during trauma care across multiple time points by patient insurance type

    International Nuclear Information System (INIS)

    Bell, Nathaniel; Repáraz, Laura; Fry, William R.; Smith, R. Stephen; Luis, Alejandro

    2016-01-01

    Research has shown that uninsured patients receive fewer radiographic studies during trauma care, but less is known as to whether differences in care are present among other insurance groups or across different time points during hospitalization. Our objective was to examine the number of radiographic studies administered to a cohort of trauma patients over the entire hospital stay as well as during the first 24-hours of care. Patient data were obtained from an American College of Surgeons (ACS) verified Level I Trauma Center between January 1, 2011 and December 31, 2012. We used negative binomial regression to construct relative risk (RR) ratios for type and frequency of radiographic imaging received among persons with Medicare, Medicaid, no insurance, or government insurance plans in reference to those with commercial indemnity plans. The analysis was adjusted for patient age, sex, race/ethnicity, injury severity score, injury mechanism, comorbidities, complications, hospital length of stay, and Intensive Care Unit (ICU) admission. A total of 3621 records from surviving patients age > =18 years were assessed. After adjustment for potential confounders, the expected number of radiographic studies decreased by 15 % among Medicare recipients (RR 0.85, 95 % CI 0.78–0.93), 11 % among Medicaid recipients (0.89, 0.81–0.99), 10 % among the uninsured (0.90, 0.85–0.96) and 19 % among government insurance groups (0.81, 0.72–0.90), compared with the reference group. This disparity was observed during the first 24-hours of care among patients with Medicare (0.78, 0.71–0.86) and government insurance plans (0.83, 0.74–0.94). Overall, there were no differences in the number of radiographic studies among the uninsured or among Medicaid patients during the first 24-hours of care compared with the reference group, but differences were observed among the uninsured in a sub-analysis of severely injured patients (ISS > 15). Both uninsured and insured patients treated at a

  6. Growth of anatase and rutile phase TiO{sub 2} nanoparticles using pulsed laser ablation in liquid: Influence of surfactant addition and ablation time variation

    Energy Technology Data Exchange (ETDEWEB)

    Chaturvedi, Amita, E-mail: amita-chaturvedi@rrcat.gov.in [Laser Material Processing Division, Raja Ramanna Centre for Advanced Technology, Indore 452013, MP (India); Joshi, M.P. [Laser Material Processing Division, Raja Ramanna Centre for Advanced Technology, Indore 452013, MP (India); Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai – 400094 (India); Mondal, P.; Sinha, A.K.; Srivastava, A.K. [Indus Synchrotron Utilization Division, Raja Ramanna Centre for Advanced Technology, Indore 452013, MP (India)

    2017-02-28

    Highlights: • Ablations of Ti metal target were carried out in DI water and in 0.001 M SDS solution for different times using PLAL process. • Different characterization studies have been carried out to confirm the growth of TiO{sub 2} nanoparticles in both the liquid mediums. • Anatase phase TiO{sub 2} nanoparticles were obtained in DI water and rutile phase in 0.001 M SDS aqueous solution. • In surfactant solution, longer time ablation leads depletion of SDS molecules causes growth of anatase phase for 90 min. • Our studies confirmed the role of liquid ambience conditions variation over the different phase formations of nanoparticles. - Abstract: Titanium dioxide (TiO{sub 2}) nanoparticles were grown using nanosecond pulsed laser ablation of Ti target in DI water and in 0.001 M sodium dodecyl sulfate (SDS) surfactant aqueous solution. Growth was carried out with varying ablation times i. e. 30 min, 60 min and 90 min. The objective of our study was to investigate the influence of variations in liquid ambience conditions on the growth of the nanoparticles in a pulsed laser ablation in liquid (PLAL) process. Size, composition and optical properties of the grown TiO{sub 2} nanoparticles were investigated using transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), optical absorption, photoluminescence (PL) spectroscopy and X-ray diffraction (XRD) studies. The obtained nanoparticles of TiO{sub 2} were found almost spherical in shape and polycrystalline in nature in both the liquid mediums i.e. DI water and aqueous solution of surfactant. Nanoparticles number density was also found to increase with increasing ablation time in both the liquid mediums. However crystalline phase of the grown TiO{sub 2} nanoparticles differs with the change in liquid ambience conditions. Selected area electron diffraction (SAED), PL and XRD studies suggest that DI water ambience is favorable for the growth of anatase phase TiO{sub 2} nanoparticles for all

  7. Seasonal variations in high time-resolved chemical compositions, sources, and evolution of atmospheric submicron aerosols in the megacity Beijing

    Directory of Open Access Journals (Sweden)

    W. Hu

    2017-08-01

    Full Text Available A severe regional haze problem in the megacity Beijing and surrounding areas, caused by fast formation and growth of fine particles, has attracted much attention in recent years. In order to investigate the secondary formation and aging process of urban aerosols, four intensive campaigns were conducted in four seasons between March 2012 and March 2013 at an urban site in Beijing (116.31° E, 37.99° N. An Aerodyne high-resolution time-of-flight aerosol mass spectrometry (HR-ToF-AMS was deployed to measure non-refractory chemical components of submicron particulate matter (NR-PM1. The average mass concentrations of PM1 (NR-PM1+black carbon were 45.1 ± 45.8, 37.5 ± 31.0, 41.3 ± 42.7, and 81.7 ± 72.4 µg m−3 in spring, summer, autumn, and winter, respectively. Organic aerosol (OA was the most abundant component in PM1, accounting for 31, 33, 44, and 36 % seasonally, and secondary inorganic aerosol (SNA, sum of sulfate, nitrate, and ammonium accounted for 59, 57, 43, and 55 % of PM1 correspondingly. Based on the application of positive matrix factorization (PMF, the sources of OA were obtained, including the primary ones of hydrocarbon-like (HOA, cooking (COA, biomass burning OA (BBOA and coal combustion OA (CCOA, and secondary component oxygenated OA (OOA. OOA, which can be split into more-oxidized (MO-OOA and less-oxidized OOA (LO-OOA, accounted for 49, 69, 47, and 50 % in four seasons, respectively. Totally, the fraction of secondary components (OOA+SNA contributed about 60–80 % to PM1, suggesting that secondary formation played an important role in the PM pollution in Beijing, and primary sources were also non-negligible. The evolution process of OA in different seasons was investigated with multiple metrics and tools. The average carbon oxidation states and other metrics show that the oxidation state of OA was the highest in summer, probably due to both strong photochemical and aqueous-phase oxidations

  8. Seasonal variations in high time-resolved chemical compositions, sources, and evolution of atmospheric submicron aerosols in the megacity Beijing

    Science.gov (United States)

    Hu, Wei; Hu, Min; Hu, Wei-Wei; Zheng, Jing; Chen, Chen; Wu, Yusheng; Guo, Song

    2017-08-01

    A severe regional haze problem in the megacity Beijing and surrounding areas, caused by fast formation and growth of fine particles, has attracted much attention in recent years. In order to investigate the secondary formation and aging process of urban aerosols, four intensive campaigns were conducted in four seasons between March 2012 and March 2013 at an urban site in Beijing (116.31° E, 37.99° N). An Aerodyne high-resolution time-of-flight aerosol mass spectrometry (HR-ToF-AMS) was deployed to measure non-refractory chemical components of submicron particulate matter (NR-PM1). The average mass concentrations of PM1 (NR-PM1+black carbon) were 45.1 ± 45.8, 37.5 ± 31.0, 41.3 ± 42.7, and 81.7 ± 72.4 µg m-3 in spring, summer, autumn, and winter, respectively. Organic aerosol (OA) was the most abundant component in PM1, accounting for 31, 33, 44, and 36 % seasonally, and secondary inorganic aerosol (SNA, sum of sulfate, nitrate, and ammonium) accounted for 59, 57, 43, and 55 % of PM1 correspondingly. Based on the application of positive matrix factorization (PMF), the sources of OA were obtained, including the primary ones of hydrocarbon-like (HOA), cooking (COA), biomass burning OA (BBOA) and coal combustion OA (CCOA), and secondary component oxygenated OA (OOA). OOA, which can be split into more-oxidized (MO-OOA) and less-oxidized OOA (LO-OOA), accounted for 49, 69, 47, and 50 % in four seasons, respectively. Totally, the fraction of secondary components (OOA+SNA) contributed about 60-80 % to PM1, suggesting that secondary formation played an important role in the PM pollution in Beijing, and primary sources were also non-negligible. The evolution process of OA in different seasons was investigated with multiple metrics and tools. The average carbon oxidation states and other metrics show that the oxidation state of OA was the highest in summer, probably due to both strong photochemical and aqueous-phase oxidations. It was indicated by the good correlations

  9. Analysis of holding time variations to Ni and Fe content and morphology in nickel laterite limonitic reduction process by using coal-dolomite bed

    Science.gov (United States)

    Abdul, Fakhreza; Pintowantoro, Sungging; Yuwandono, Ridwan Bagus

    2018-04-01

    With the depletion of nickel sulfide ore resources, the nickel laterit processing become an attention to fulfill nickel world demans. Reducing laterite nickel by using a low cost carbonaceous reductan has proved produces high grade ferronickel alloy. In this research, reduction was carried out to low grade laterite nickel (limonite) with 1.25% nikel content by using CO gas reductant formed by reaction between coal and dolomite. Reduction process preceded by forming brickets mixture from limonit ore, coal, and Na2SO4, then the brickets placed inside crucible bed together with dolomit and reduced at temperature 1400 °C with holding time variations 4, 6, and 8 hours. EDX, XRD, and SEM test were carried out to find out the Ni and nickel grade after reduced, the phases that formed, and the morphology brickets after reduced. The reduction results shows that the highest increase on nickel grade was obtained by 8 hours holding time increasing 5.84 % from initial grade, and the highest recovery was obtained by 6 hours holding time with recovery 88.51 %. While the higest increase on Fe grade was obtained by 4 hours holding time, and the highest recovery Fe was obtained by 4 hours holding time with recovery 85.41%.

  10. General practice variation in spirometry testing among patients receiving first-time prescriptions for medication targeting obstructive lung disease in Denmark: a population-based observational study.

    Science.gov (United States)

    Koefoed, Mette M; Søndergaard, Jens; Christensen, René dePont; Jarbøl, Dorte E

    2013-08-07

    Spirometry testing is essential to confirm an obstructive lung disease, but studies have reported that a large proportion of patients diagnosed with COPD or asthma have no history of spirometry testing. Also, it has been shown that many patients are prescribed medication for obstructive lung disease without a relevant diagnosis or spirometry test registered. General practice characteristics have been reported to influence diagnosis and management of several chronic diseases. However, these findings are inconsistent, and it is uncertain whether practice characteristics influence spirometry testing among patients receiving medication for obstructive lung disease. The aim of this study was therefore to examine if practice characteristics are associated with spirometry testing among patients receiving first-time prescriptions for medication targeting obstructive lung disease. A national register-based cohort study was performed. All patients over 18 years receiving first-time prescriptions for medication targeting obstructive lung disease in 2008 were identified and detailed patient-specific data on sociodemographic status and spirometry tests were extracted. Information on practice characteristics like number of doctors, number of patients per doctor, training practice status, as well as age and gender of the general practitioners was linked to each medication user. Partnership practices had a higher odds ratio (OR) of performing spirometry compared with single-handed practices (OR 1.24, CI 1.09-1.40). We found a significant association between increasing general practitioner age and decreasing spirometry testing. This tendency was most pronounced among partnership practices, where doctors over 65 years had the lowest odds of spirometry testing (OR 0.25, CI 0.10-0.61). Training practice status was significantly associated with spirometry testing among single-handed practices (OR 1.40, CI 1.10-1.79). Some of the variation in spirometry testing among patients receiving

  11. Variation in highbush blueberry floral volatile profiles as a function of pollination status, cultivar, time of day and flower part: implications for flower visitation by bees

    Science.gov (United States)

    Rodriguez-Saona, Cesar; Parra, Leonardo; Quiroz, Andrés; Isaacs, Rufus

    2011-01-01

    Background and Aims Studies of the effects of pollination on floral scent and bee visitation remain rare, particularly in agricultural crops. To fill this gap, the hypothesis that bee visitation to flowers decreases after pollination through reduced floral volatile emissions in highbush blueberries, Vaccinium corymbosum, was tested. Other sources of variation in floral emissions and the role of floral volatiles in bee attraction were also examined. Methods Pollinator visitation to blueberry flowers was manipulated by bagging all flowers within a bush (pollinator excluded) or leaving them unbagged (open pollinated), and then the effect on floral volatile emissions and future bee visitation were measured. Floral volatiles were also measured from different blueberry cultivars, times of the day and flower parts, and a study was conducted to test the attraction of bees to floral volatiles. Key Results Open-pollinated blueberry flowers had 32 % lower volatile emissions than pollinator-excluded flowers. In particular, cinnamyl alcohol, a major component of the floral blend that is emitted exclusively from petals, was emitted in lower quantities from open-pollinated flowers. Although, no differences in cinnamyl alcohol emissions were detected among three blueberry cultivars or at different times of day, some components of the blueberry floral blend were emitted in higher amounts from certain cultivars and at mid-day. Field observations showed that more bees visited bushes with pollinator-excluded flowers. Also, more honey bees were caught in traps baited with a synthetic blueberry floral blend than in unbaited traps. Conclusions Greater volatile emissions may help guide bees to unpollinated flowers, and thus increase plant fitness and bee energetic return when foraging in blueberries. Furthermore, the variation in volatile emissions from blueberry flowers depending on pollination status, plant cultivar and time of day suggests an adaptive role of floral signals in

  12. Topographical Variation of Human Femoral Articular Cartilage Thickness, T1rho and T2 Relaxation Times Is Related to Local Loading during Walking.

    Science.gov (United States)

    Van Rossom, Sam; Wesseling, Mariska; Van Assche, Dieter; Jonkers, Ilse

    2018-01-01

    Objective Early detection of degenerative changes in the cartilage matrix composition is essential for evaluating early interventions that slow down osteoarthritis (OA) initiation. T1rho and T2 relaxation times were found to be effective for detecting early changes in proteoglycan and collagen content. To use these magnetic resonance imaging (MRI) methods, it is important to document the topographical variation in cartilage thickness, T1rho and T2 relaxation times in a healthy population. As OA is partially mechanically driven, the relation between these MRI-based parameters and localized mechanical loading during walking was investigated. Design MR images were acquired in 14 healthy adults and cartilage thickness and T1rho and T2 relaxation times were determined. Experimental gait data was collected and processed using musculoskeletal modeling to identify weight-bearing zones and estimate the contact force impulse during gait. Variation of the cartilage properties (i.e., thickness, T1rho, and T2) over the femoral cartilage was analyzed and compared between the weight-bearing and non-weight-bearing zone of the medial and lateral condyle as well as the trochlea. Results Medial condyle cartilage thickness was correlated to the contact force impulse ( r = 0.78). Lower T1rho, indicating increased proteoglycan content, was found in the medial weight-bearing zone. T2 was higher in all weight-bearing zones compared with the non-weight-bearing zones, indicating lower relative collagen content. Conclusions The current results suggest that medial condyle cartilage is adapted as a long-term protective response to localized loading during a frequently performed task and that the weight-bearing zone of the medial condyle has superior weight bearing capacities compared with the non-weight-bearing zones.

  13. Variation in highbush blueberry floral volatile profiles as a function of pollination status, cultivar, time of day and flower part: implications for flower visitation by bees.

    Science.gov (United States)

    Rodriguez-Saona, Cesar; Parra, Leonardo; Quiroz, Andrés; Isaacs, Rufus

    2011-06-01

    Studies of the effects of pollination on floral scent and bee visitation remain rare, particularly in agricultural crops. To fill this gap, the hypothesis that bee visitation to flowers decreases after pollination through reduced floral volatile emissions in highbush blueberries, Vaccinium corymbosum, was tested. Other sources of variation in floral emissions and the role of floral volatiles in bee attraction were also examined. Pollinator visitation to blueberry flowers was manipulated by bagging all flowers within a bush (pollinator excluded) or leaving them unbagged (open pollinated), and then the effect on floral volatile emissions and future bee visitation were measured. Floral volatiles were also measured from different blueberry cultivars, times of the day and flower parts, and a study was conducted to test the attraction of bees to floral volatiles. Open-pollinated blueberry flowers had 32 % lower volatile emissions than pollinator-excluded flowers. In particular, cinnamyl alcohol, a major component of the floral blend that is emitted exclusively from petals, was emitted in lower quantities from open-pollinated flowers. Although, no differences in cinnamyl alcohol emissions were detected among three blueberry cultivars or at different times of day, some components of the blueberry floral blend were emitted in higher amounts from certain cultivars and at mid-day. Field observations showed that more bees visited bushes with pollinator-excluded flowers. Also, more honey bees were caught in traps baited with a synthetic blueberry floral blend than in unbaited traps. Greater volatile emissions may help guide bees to unpollinated flowers, and thus increase plant fitness and bee energetic return when foraging in blueberries. Furthermore, the variation in volatile emissions from blueberry flowers depending on pollination status, plant cultivar and time of day suggests an adaptive role of floral signals in increasing pollination of flowers.

  14. Interacting effects of genetic variation for seed dormancy and flowering time on phenology, life history, and fitness of experimental Arabidopsis thaliana populations over multiple generations in the field.

    Science.gov (United States)

    Taylor, Mark A; Cooper, Martha D; Sellamuthu, Reena; Braun, Peter; Migneault, Andrew; Browning, Alyssa; Perry, Emily; Schmitt, Johanna

    2017-10-01

    Major alleles for seed dormancy and flowering time are well studied, and can interact to influence seasonal timing and fitness within generations. However, little is known about how this interaction controls phenology, life history, and population fitness across multiple generations in natural seasonal environments. To examine how seed dormancy and flowering time shape annual plant life cycles over multiple generations, we established naturally dispersing populations of recombinant inbred lines of Arabidopsis thaliana segregating early and late alleles for seed dormancy and flowering time in a field experiment. We recorded seasonal phenology and fitness of each genotype over 2 yr and several generations. Strong seed dormancy suppressed mid-summer germination in both early- and late-flowering genetic backgrounds. Strong dormancy and late-flowering genotypes were both necessary to confer a winter annual life history; other genotypes were rapid-cycling. Strong dormancy increased within-season fecundity in an early-flowering background, but decreased it in a late-flowering background. However, there were no detectable differences among genotypes in population growth rates. Seasonal phenology, life history, and cohort fitness over multiple generations depend strongly upon interacting genetic variation for dormancy and flowering. However, similar population growth rates across generations suggest that different life cycle genotypes can coexist in natural populations. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  15. Seasonal Variation in Meteor Decay Time Profiles Measured by a Meteor Radar at King Sejong Station (62°S, 58°W), Antarctica

    Science.gov (United States)

    Kim, Y.; Kim, J.; Lee, C.; Jee, G.

    2008-12-01

    A VHF meteor radar at King Sejong Station (62°S, 58°W), Antarctica has been detecting echoes from more than 20,000 meteors per day since March 2007. Meteor echoes are decayed typically within seconds as meteor trail plasma spread away or are neutralized. Assuming that diffusion is the only process for decay of meteor echo signals, the atmospheric temperatures and pressures have been inferred from the measured meteor decay times at the peak meteor altitudes around 90 km. In this study, we analyze altitude profiles of meteor decay times in each month, which clearly show a maximum at 80 ~ 85 km. The maximum appears at higher altitude during austral summer than winter. The fast decay of meteor signals below the maximum cannot be explained by atmospheric diffusion which decreases with increasing atmospheric densities. We find that the measured meteor decay time profiles can be fitted with a loss rate profile, in addition to diffusion, with a peak altitude of 55 ~ 73 km and a peak rate of 4 ~ 15 sec- 1. The additional loss of meteor plasma may be due to electron absorption by icy particles in the mesosphere, but the estimated peak altitudes are much lower than the layers of NLC or PME. The estimated peak loss rates seem to be too large to be accounted by absorption by icy or dust particles. We will discuss other processes to explain the fast meteor times and their variation over season.

  16. Elements of Dynamics of a One-Dimensional Trapped Bose-Einstein Condensate Excited by a Time-Dependent Dimple: A Lagrangian Variational Approach

    Science.gov (United States)

    Sakhel, Asaad R.; Sakhel, Roger R.

    2018-02-01

    We examine the dynamics of a one-dimensional harmonically trapped Bose-Einstein condensate (BEC), induced by the addition of a dimple trap whose depth oscillates with time. For this purpose, the Lagrangian variational method (LVM) is applied to provide the required analytical equations. The goal is to provide an analytical explanation for the quasiperiodic oscillations of the BEC size at resonance, that is additional to the one given by Adhikari (J Phys B At Mol Opt Phys 36:1109, 2003). It is shown that LVM is able to reproduce instabilities in the dynamics along the same lines outlined by Lellouch et al. (Phys Rev X 7:021015, 2017). Moreover, it is found that at resonance the energy dynamics display ordered oscillations, whereas at off-resonance they tend to be chaotic. Further, by using the Poincare-Lindstedt method to solve the LVM equation of motion, the resulting solution is able to reproduce the quasiperiodic oscillations of the BEC.

  17. Near Real-Time Assessment of Anatomic and Dosimetric Variations for Head and Neck Radiation Therapy via Graphics Processing Unit–based Dose Deformation Framework

    Energy Technology Data Exchange (ETDEWEB)

    Qi, X. Sharon, E-mail: xqi@mednet.ucla.edu [Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California (United States); Santhanam, Anand; Neylon, John; Min, Yugang; Armstrong, Tess; Sheng, Ke [Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California (United States); Staton, Robert J.; Pukala, Jason [Department of Radiation Oncology, UF Health Cancer Center - Orlando Health, Orlando, Florida (United States); Pham, Andrew; Low, Daniel A.; Lee, Steve P. [Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California (United States); Steinberg, Michael; Manon, Rafael [Department of Radiation Oncology, UF Health Cancer Center - Orlando Health, Orlando, Florida (United States); Chen, Allen M.; Kupelian, Patrick [Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California (United States)

    2015-06-01

    Purpose: The purpose of this study was to systematically monitor anatomic variations and their dosimetric consequences during intensity modulated radiation therapy (IMRT) for head and neck (H&N) cancer by using a graphics processing unit (GPU)-based deformable image registration (DIR) framework. Methods and Materials: Eleven IMRT H&N patients undergoing IMRT with daily megavoltage computed tomography (CT) and weekly kilovoltage CT (kVCT) scans were included in this analysis. Pretreatment kVCTs were automatically registered with their corresponding planning CTs through a GPU-based DIR framework. The deformation of each contoured structure in the H&N region was computed to account for nonrigid change in the patient setup. The Jacobian determinant of the planning target volumes and the surrounding critical structures were used to quantify anatomical volume changes. The actual delivered dose was calculated accounting for the organ deformation. The dose distribution uncertainties due to registration errors were estimated using a landmark-based gamma evaluation. Results: Dramatic interfractional anatomic changes were observed. During the treatment course of 6 to 7 weeks, the parotid gland volumes changed up to 34.7%, and the center-of-mass displacement of the 2 parotid glands varied in the range of 0.9 to 8.8 mm. For the primary treatment volume, the cumulative minimum and mean and equivalent uniform doses assessed by the weekly kVCTs were lower than the planned doses by up to 14.9% (P=.14), 2% (P=.39), and 7.3% (P=.05), respectively. The cumulative mean doses were significantly higher than the planned dose for the left parotid (P=.03) and right parotid glands (P=.006). The computation including DIR and dose accumulation was ultrafast (∼45 seconds) with registration accuracy at the subvoxel level. Conclusions: A systematic analysis of anatomic variations in the H&N region and their dosimetric consequences is critical in improving treatment efficacy. Nearly real-time

  18. The Influence of Spatial Variation in Chromatin Density Determined by X-Ray Tomograms on the Time to Find DNA Binding Sites

    Science.gov (United States)

    Larabell, Carolyn A.; Le Gros, Mark A.; McQueen, David M.; Peskin, Charles S.

    2014-01-01

    In this work, we examine how volume exclusion caused by regions of high chromatin density might influence the time required for proteins to find specific DNA binding sites. The spatial variation of chromatin density within mouse olfactory sensory neurons is determined from soft X-ray tomography reconstructions of five nuclei. We show that there is a division of the nuclear space into regions of low-density euchromatin and high-density heterochromatin. Volume exclusion experienced by a diffusing protein caused by this varying density of chromatin is modeled by a repulsive potential. The value of the potential at a given point in space is chosen to be proportional to the density of chromatin at that location. The constant of proportionality, called the volume exclusivity, provides a model parameter that determines the strength of volume exclusion. Numerical simulations demonstrate that the mean time for a protein to locate a binding site localized in euchromatin is minimized for a finite, nonzero volume exclusivity. For binding sites in heterochromatin, the mean time is minimized when the volume exclusivity is zero (the protein experiences no volume exclusion). An analytical theory is developed to explain these results. The theory suggests that for binding sites in euchromatin there is an optimal level of volume exclusivity that balances a reduction in the volume searched in finding the binding site, with the height of effective potential barriers the protein must cross during the search process. PMID:23955281

  19. Joint inversion of shear wave travel time residuals and geoid and depth anomalies for long-wavelength variations in upper mantle temperature and composition along the Mid-Atlantic Ridge

    Science.gov (United States)

    Sheehan, Anne F.; Solomon, Sean C.

    1991-01-01

    Measurements were carried out for SS-S differential travel time residuals for nearly 500 paths crossing the northern Mid-Atlantic Ridge, assuming that the residuals are dominated by contributions from the upper mantle near the surface bounce point of the reflected phase SS. Results indicate that the SS-S travel time residuals decrease linearly with square root of age, to an age of 80-100 Ma, in general agreement with the plate cooling model. A joint inversion was formulated of travel time residuals and geoid and bathymetric anomalies for lateral variation in the upper mantle temperature and composition. The preferred inversion solutions were found to have variations in upper mantle temperature along the Mid-Atlantic Ridge of about 100 K. It was calculated that, for a constant bulk composition, such a temperature variation would produce about a 7-km variation in crustal thickness, larger than is generally observed.

  20. High time-resolved elemental components in fine and coarse particles in the Pearl River Delta region of Southern China: Dynamic variations and effects of meteorology.

    Science.gov (United States)

    Zhou, Shengzhen; Davy, Perry K; Wang, Xuemei; Cohen, Jason Blake; Liang, Jiaquan; Huang, Minjuan; Fan, Qi; Chen, Weihua; Chang, Ming; Ancelet, Travis; Trompetter, William J

    2016-12-01

    Hourly-resolved PM 2.5 and PM 10-2.5 samples were collected in the industrial city Foshan in the Pearl River Delta region, China. The samples were subsequently analyzed for elemental components and black carbon (BC). A key purpose of the study was to understand the composition of particulate matter (PM) at high-time resolution in a polluted urban atmosphere to identify key components contributing to extreme PM concentration events and examine the diurnal chemical concentration patterns for air quality management purposes. It was found that BC and S concentrations dominated in the fine mode, while elements with mostly crustal and oceanic origins such as Si, Ca, Al and Cl were found in the coarse size fraction. Most of the elements showed strong diurnal variations. S did not show clear diurnal variations, suggesting regional rather than local origin. Based on empirical orthogonal functions (EOF) method, 3 forcing factors were identified contributing to the extreme events of PM 2.5 and selected elements, i.e., urban direct emissions, wet deposition and a combination of coarse mode sources. Conditional probability functions (CPF) were performed using wind profiles and elemental concentrations. The CPF results showed that BC and elemental Cl, K, Fe, Cu and Zn in the fine mode were mostly from the northwest, indicating that industrial emissions and combustion were the main sources. For elements in the coarse mode, Si, Al, K, Ca, Fe and Ti showed similar patterns, suggesting same sources such as local soil dust/construction activities. Coarse elemental Cl was mostly from the south and southeast, implying the influence of marine aerosol sources. For other trace elements, we found vanadium (V) in fine PM was mainly from the sources located to the southeast of the measuring site. Combined with CPF results of S and V in fine PM, we concluded shipping emissions were likely an important elemental emission source. Copyright © 2016. Published by Elsevier B.V.

  1. Global variations and time trends in the prevalence of childhood myopia, a systematic review and quantitative meta-analysis: implications for aetiology and early prevention.

    Science.gov (United States)

    Rudnicka, Alicja R; Kapetanakis, Venediktos V; Wathern, Andrea K; Logan, Nicola S; Gilmartin, Bernard; Whincup, Peter H; Cook, Derek G; Owen, Christopher G

    2016-07-01

    The aim of this review was to quantify the global variation in childhood myopia prevalence over time taking account of demographic and study design factors. A systematic review identified population-based surveys with estimates of childhood myopia prevalence published by February 2015. Multilevel binomial logistic regression of log odds of myopia was used to examine the association with age, gender, urban versus rural setting and survey year, among populations of different ethnic origins, adjusting for study design factors. 143 published articles (42 countries, 374 349 subjects aged 1-18 years, 74 847 myopia cases) were included. Increase in myopia prevalence with age varied by ethnicity. East Asians showed the highest prevalence, reaching 69% (95% credible intervals (CrI) 61% to 77%) at 15 years of age (86% among Singaporean-Chinese). Blacks in Africa had the lowest prevalence; 5.5% at 15 years (95% CrI 3% to 9%). Time trends in myopia prevalence over the last decade were small in whites, increased by 23% in East Asians, with a weaker increase among South Asians. Children from urban environments have 2.6 times the odds of myopia compared with those from rural environments. In whites and East Asians sex differences emerge at about 9 years of age; by late adolescence girls are twice as likely as boys to be myopic. Marked ethnic differences in age-specific prevalence of myopia exist. Rapid increases in myopia prevalence over time, particularly in East Asians, combined with a universally higher risk of myopia in urban settings, suggest that environmental factors play an important role in myopia development, which may offer scope for prevention. 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/.

  2. Variations in DNA synthesis and mitotic indices in hepatocytes and sinusoid litoral cells of adult intact male mouse along a circadian time span.

    Science.gov (United States)

    Surur, J M; Moreno, F R; Badrán, A F; Llanos, J M

    1985-01-01

    Variations of DNA synthesis (DNAS) and mitotic indices along a circadian time span are described in the hepatocyte and sinusoid litoral cell populations of adult intact male mouse liver. Standardized (light from 0600 to 1800) mice were killed in groups of six to nine animals, every 2-4 hr along a circadian time span. Hepatocytes show significant peaks in the synthesis of DNA and the mitotic activity at 0200 and 1400, respectively. These results correspond to those previously described by us in young immature liver, regenerating liver and hepatomas. The phase differences between these peaks and the differences between their absolute values are discussed. Also considered are the practical consequences of our findings for experimental design. The curve of DNA synthesis of sinusoid litoral cells show a peak at 0200. The mitotic index show a bimodal waveform with peaks at 0800 and 2000. The existence of four different cell populations composing the so called sinusoid litoral cells and also the migration into and out of the liver of some macrophages considered as litoral (Kupffer) cells in our counts, makes interpretation of the curves somewhat complicated and deserves further analysis.

  3. A self-similar solution of a curved shock wave and its time-dependent force variation for a starting flat plate airfoil in supersonic flow

    Directory of Open Access Journals (Sweden)

    Zijun CHEN

    2018-02-01

    Full Text Available The problem of aeroelasticity and maneuvering of command surface and gust wing interaction involves a starting flow period which can be seen as the flow of an airfoil attaining suddenly an angle of attack. In the linear or nonlinear case, compressive Mach or shock waves are generated on the windward side and expansive Mach or rarefaction waves are generated on the leeward side. On each side, these waves are composed of an oblique steady state wave, a vertically-moving one-dimensional unsteady wave, and a secondary wave resulting from the interaction between the steady and unsteady ones. An analytical solution in the secondary wave has been obtained by Heaslet and Lomax in the linear case, and this linear solution has been borrowed to give an approximate solution by Bai and Wu for the nonlinear case. The structure of the secondary shock wave and the appearance of various force stages are two issues not yet considered in previous studies and has been studied in the present paper. A self-similar solution is obtained for the secondary shock wave, and the reason to have an initial force plateau as observed numerically is identified. Moreover, six theoretical characteristic time scales for pressure load variation are determined which explain the slope changes of the time-dependent force curve. Keywords: Force, Self-similar solution, Shock-shock interaction, Shock waves, Unsteady flow

  4. Studying Basin Water Balance Variations at Inter- and Intra-annual Time Scales Based On the Budyko Hypothesis and GRACE Gravimetry Satellite Observations

    Science.gov (United States)

    Shen, H.

    2017-12-01

    Increasing intensity in global warming and anthropogenic activities has triggered significant changes over regional climates and landscapes, which, in turn, drive the basin water cycle and hydrological balance into a complex and unstable state. Budyko hypothesis is a powerful tool to characterize basin water balance and hydrological variations at long-term average scale. However, due to the absence of basin water storage change, applications of Budyko theory to the inter-annual and intra-annual time scales has been prohibited. The launch of GRACE gavimetry satellites provides a great opportunity to quantify terrestrial water storage change, which can be further introduced into the Budyko hypothesis to reveal the inter- and intra-annual response of basin water components under impacts of climate variability and/or human activities. This research targeted Hai River Basin (in China) and Murray-Darling Basin (in Australia), which have been identified with a continuous groundwater depletion trend as well as impacts by extreme climates in the past decade. This can help us to explore how annual or seasonal precipitation were redistributed to evapotranspiration and runoff via changing basin water storage. Moreover, the impacts of vegetation on annual basin water balance will be re-examined. Our results are expected to provide deep insights about the water cycle and hydrological behaviors for the targeted basins, as well as a proof for a consideration of basin water storage change into the Budyko model at inter- or intra-annual time steps.

  5. Actinide collisions for QED and superheavy elements with the time-dependent Hartree-Fock theory and the Balian-Vénéroni variational principle

    Directory of Open Access Journals (Sweden)

    Kedziora David J.

    2011-10-01

    Full Text Available Collisions of actinide nuclei form, during very short times of few zs (10−21 s, the heaviest ensembles of interacting nucleons available on Earth. Such collisions are used to produce super-strong electric fields by the huge number of interacting protons to test spontaneous positron-electron pair emission (vacuum decay predicted by the quantum electrodynamics (QED theory. Multi-nucleon transfer in actinide collisions could also be used as an alternative way to fusion in order to produce neutron-rich heavy and superheavy elements thanks to inverse quasifission mechanisms. Actinide collisions are studied in a dynamical quantum microscopic approach. The three-dimensional time-dependent Hartree-Fock (TDHF code tdhf3d is used with a full Skyrme energy density functional to investigate the time evolution of expectation values of one-body operators, such as fragment position and particle number. This code is also used to compute the dispersion of the particle numbers (e.g., widths of fragment mass and charge distributions from TDHF transfer probabilities, on the one hand, and using the BalianVeneroni variational principle, on the other hand. A first application to test QED is discussed. Collision times in 238U+238U are computed to determine the optimum energy for the observation of the vacuum decay. It is shown that the initial orientation strongly affects the collision times and reaction mechanism. The highest collision times predicted by TDHF in this reaction are of the order of ~ 4 zs at a center of mass energy of 1200 MeV. According to modern calculations based on the Dirac equation, the collision times at Ecm > 1 GeV are sufficient to allow spontaneous electron-positron pair emission from QED vacuum decay, in case of bare uranium ion collision. A second application of actinide collisions to produce neutron-rich transfermiums is discussed. A new inverse quasifission mechanism associated to a specific orientation of the nuclei is proposed to

  6. Precision Timing of PSR J0437-4715: An Accurate Pulsar Distance, a High Pulsar Mass, and a Limit on the Variation of Newton's Gravitational Constant

    Science.gov (United States)

    Verbiest, J. P. W.; Bailes, M.; van Straten, W.; Hobbs, G. B.; Edwards, R. T.; Manchester, R. N.; Bhat, N. D. R.; Sarkissian, J. M.; Jacoby, B. A.; Kulkarni, S. R.

    2008-05-01

    Analysis of 10 years of high-precision timing data on the millisecond pulsar PSR J0437-4715 has resulted in a model-independent kinematic distance based on an apparent orbital period derivative, dot Pb , determined at the 1.5% level of precision (Dk = 157.0 +/- 2.4 pc), making it one of the most accurate stellar distance estimates published to date. The discrepancy between this measurement and a previously published parallax distance estimate is attributed to errors in the DE200 solar system ephemerides. The precise measurement of dot Pb allows a limit on the variation of Newton's gravitational constant, |Ġ/G| <= 23 × 10-12 yr-1. We also constrain any anomalous acceleration along the line of sight to the pulsar to |a⊙/c| <= 1.5 × 10-18 s-1 at 95% confidence, and derive a pulsar mass, mpsr = 1.76 +/- 0.20 M⊙, one of the highest estimates so far obtained.

  7. Measurement of arterial transit time and renal blood flow using pseudocontinuous ASL MRI with multiple post-labeling delays: Feasibility, reproducibility, and variation.

    Science.gov (United States)

    Kim, Dong Won; Shim, Woo Hyun; Yoon, Seong Kuk; Oh, Jong Yeong; Kim, Jeong Kon; Jung, Hoesu; Matsuda, Tsuyoshi; Kim, Dongeun

    2017-09-01

    To evaluate the feasibility, reproducibility, and variation of renal perfusion and arterial transit time (ATT) using pseudocontinuous arterial spin labeling magnetic resonance imaging (PCASL MRI) in healthy volunteers. PCASL MRI at 3T was performed in 25 healthy volunteers on two different occasions. The ATT and ATT-corrected renal blood flow (ATT-cRBF) were calculated at four different post-labeling delay points (0.5, 1.0, 1.5, and 2.0 s) and evaluated for each kidney and subject. The intraclass correlation (ICC) and Bland-Altman plot were used to assess the reproducibility of the PCASL MRI technique. The within-subject coefficient of variance was determined. Results were obtained for 46 kidneys of 23 subjects with a mean age of 38.6 ± 9.8 years and estimated glomerular filtration rate (eGFR) of 89.1 ± 21.2 ml/min/1.73 m 2 . Two subjects failed in the ASL MRI examination. The mean cortical and medullary ATT-cRBF for the subjects were 215 ± 65 and 81 ± 21 ml/min/100 g, respectively, and the mean cortical and medullary ATT were 1141 ± 262 and 1123 ± 245 msec, correspondingly. The ICC for the cortical ATT-cRBF was 0.927 and the within-subject coefficient of variance was 14.4%. The ICCs for the medullary ATT-cRBF and the cortical and medullary ATT were poor. The Bland-Altman plot for cortical RBF showed good agreement between the two measurements. PCASL MRI is a feasible and reproducible method for measuring renal cortical perfusion. In contrast, ATT for the renal cortex and medulla has poor reproducibility and high variation. 2 Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;46:813-819. © 2017 International Society for Magnetic Resonance in Medicine.

  8. Expression conservation within the circadian clock of a monocot: natural variation at barley Ppd-H1 affects circadian expression of flowering time genes, but not clock orthologs.

    Science.gov (United States)

    Campoli, Chiara; Shtaya, Munqez; Davis, Seth J; von Korff, Maria

    2012-06-21

    The circadian clock is an endogenous mechanism that coordinates biological processes with daily changes in the environment. In plants, circadian rhythms contribute to both agricultural productivity and evolutionary fitness. In barley, the photoperiod response regulator and flowering-time gene Ppd-H1 is orthologous to the Arabidopsis core-clock gene PRR7. However, relatively little is known about the role of Ppd-H1 and other components of the circadian clock in temperate crop species. In this study, we identified barley clock orthologs and tested the effects of natural genetic variation at Ppd-H1 on diurnal and circadian expression of clock and output genes from the photoperiod-response pathway. Barley clock orthologs HvCCA1, HvGI, HvPRR1, HvPRR37 (Ppd-H1), HvPRR73, HvPRR59 and HvPRR95 showed a high level of sequence similarity and conservation of diurnal and circadian expression patterns, when compared to Arabidopsis. The natural mutation at Ppd-H1 did not affect diurnal or circadian cycling of barley clock genes. However, the Ppd-H1 mutant was found to be arrhythmic under free-running conditions for the photoperiod-response genes HvCO1, HvCO2, and the MADS-box transcription factor and vernalization responsive gene Vrn-H1. We suggest that the described eudicot clock is largely conserved in the monocot barley. However, genetic differentiation within gene families and differences in the function of Ppd-H1 suggest evolutionary modification in the angiosperm clock. Our data indicates that natural variation at Ppd-H1 does not affect the expression level of clock genes, but controls photoperiodic output genes. Circadian control of Vrn-H1 in barley suggests that this vernalization responsive gene is also controlled by the photoperiod-response pathway. Structural and functional characterization of the barley circadian clock will set the basis for future studies of the adaptive significance of the circadian clock in Triticeae species.

  9. Long-term variations of the UV-B radiation over Central Europe as derived from the reconstructed UV time series

    Directory of Open Access Journals (Sweden)

    J. W. Krzyscin

    2004-04-01

    Full Text Available The daily doses of the erythemally weighted UV radiation are reconstructed for three sites in Central Europe: Belsk-Poland (1966–2001, Hradec Kralove-Czech Republic (1964–2001, and Tõravere-Estonia (1967–2001 to discuss the UV climatology and the long-term changes of the UV-B radiation since the mid 1960s. Various reconstruction models are examined: a purely statistical model based on the Multivariate Adaptive Regression Splines (MARS methodology, and a hybrid model combining radiative transfer model calculations with empirical estimates of the cloud effects on the UV radiation. Modeled long-term variations of the surface UV doses appear to be in a reasonable agreement with the observed ones. A simple quality control procedure is proposed to check the homogeneity of the biometer and pyranometer data. The models are verified using the results of UV observations carried out at Belsk since 1976. MARS provides the best estimates of the UV doses, giving a mean difference between the modeled and observed monthly means equal to 0.6±2.5%. The basic findings are: similar climatological forcing by clouds for all considered stations (~30% reduction in the surface UV, long-term variations in UV monthly doses having the same temporal pattern for all stations with extreme low monthly values (~5% below overall mean level at the end of the 1970s and extreme high monthly values (~5% above overall mean level in the mid 1990s, regional peculiarities in the cloud long-term forcing sometimes leading to extended periods with elevated UV doses, recent stabilization of the ozone induced UV long-term changes being a response to a trendless tendency of total ozone since the mid 1990s. In the case of the slowdown of the total ozone trend over Northern Hemisphere mid-latitudes it seems that clouds will appear as the most important modulator of the UV radiation both in long- and short-time scales over next decades. Key words. Atmospheric composition and structure

  10. Long-term variations of the UV-B radiation over Central Europe as derived from the reconstructed UV time series

    Directory of Open Access Journals (Sweden)

    J. W. Krzyscin

    2004-04-01

    Full Text Available The daily doses of the erythemally weighted UV radiation are reconstructed for three sites in Central Europe: Belsk-Poland (1966–2001, Hradec Kralove-Czech Republic (1964–2001, and Tõravere-Estonia (1967–2001 to discuss the UV climatology and the long-term changes of the UV-B radiation since the mid 1960s. Various reconstruction models are examined: a purely statistical model based on the Multivariate Adaptive Regression Splines (MARS methodology, and a hybrid model combining radiative transfer model calculations with empirical estimates of the cloud effects on the UV radiation. Modeled long-term variations of the surface UV doses appear to be in a reasonable agreement with the observed ones. A simple quality control procedure is proposed to check the homogeneity of the biometer and pyranometer data. The models are verified using the results of UV observations carried out at Belsk since 1976. MARS provides the best estimates of the UV doses, giving a mean difference between the modeled and observed monthly means equal to 0.6±2.5%. The basic findings are: similar climatological forcing by clouds for all considered stations (~30% reduction in the surface UV, long-term variations in UV monthly doses having the same temporal pattern for all stations with extreme low monthly values (~5% below overall mean level at the end of the 1970s and extreme high monthly values (~5% above overall mean level in the mid 1990s, regional peculiarities in the cloud long-term forcing sometimes leading to extended periods with elevated UV doses, recent stabilization of the ozone induced UV long-term changes being a response to a trendless tendency of total ozone since the mid 1990s. In the case of the slowdown of the total ozone trend over Northern Hemisphere mid-latitudes it seems that clouds will appear as the most important modulator of the UV radiation both in long- and short-time scales over next decades.

    Key words. Atmospheric composition and

  11. High Throughput qPCR Expression Profiling of Circulating MicroRNAs Reveals Minimal Sex- and Sample Timing-Related Variation in Plasma of Healthy Volunteers.

    Directory of Open Access Journals (Sweden)

    Catherine Mooney

    Full Text Available MicroRNAs are a class of small non-coding RNA that regulate gene expression at a post-transcriptional level. MicroRNAs have been identified in various body fluids under normal conditions and their stability as well as their dysregulation in disease opens up a new field for biomarker study. However, diurnal and day-to-day variation in plasma microRNA levels, and differential regulation between males and females, may affect biomarker stability. A QuantStudio 12K Flex Real-Time PCR System was used to profile plasma microRNA levels using OpenArray in male and female healthy volunteers, in the morning and afternoon, and at four time points over a one month period. Using this system we were able to run four OpenArray plates in a single run, the equivalent of 32 traditional 384-well qPCR plates or 12,000 data points. Up to 754 microRNAs can be identified in a single plasma sample in under two hours. 108 individual microRNAs were identified in at least 80% of all our samples which compares favourably with other reports of microRNA profiles in serum or plasma in healthy adults. Many of these microRNAs, including miR-16-5p, miR-17-5p, miR-19a-3p, miR-24-3p, miR-30c-5p, miR-191-5p, miR-223-3p and miR-451a are highly expressed and consistent with previous studies using other platforms. Overall, microRNA levels were very consistent between individuals, males and females, and time points and we did not detect significant differences in levels of microRNAs. These results suggest the suitability of this platform for microRNA profiling and biomarker discovery and suggest minimal confounding influence of sex or sample timing. However, the platform has not been subjected to rigorous validation which must be demonstrated in future biomarker studies where large differences may exist between disease and control samples.

  12. Study of a sample of faint Be stars in the exofield of CoRoT. II. Pulsation and outburst events: Time series analysis of photometric variations

    Science.gov (United States)

    Semaan, T.; Hubert, A. M.; Zorec, J.; Gutiérrez-Soto, J.; Frémat, Y.; Martayan, C.; Fabregat, J.; Eggenberger, P.

    2018-06-01

    Context. The class of Be stars are the epitome of rapid rotators in the main sequence. These stars are privileged candidates for studying the incidence of rotation on the stellar internal structure and on non-radial pulsations. Pulsations are considered possible mechanisms to trigger mass-ejection phenomena required to build up the circumstellar disks of Be stars. Aims: Time series analyses of the light curves of 15 faint Be stars observed with the CoRoT satellite were performed to obtain the distribution of non-radial pulsation (NRP) frequencies in their power spectra at epochs with and without light outbursts and to discriminate pulsations from rotation-related photometric variations. Methods: Standard Fourier techniques were employed to analyze the CoRoT light curves. Fundamental parameters corrected for rapid-rotation effects were used to study the power spectrum as a function of the stellar location in the instability domains of the Hertzsprung-Russell (H-R) diagram. Results: Frequencies are concentrated in separate groups as predicted for g-modes in rapid B-type rotators, except for the two stars that are outside the H-R instability domain. In five objects the variations in the power spectrum are correlated with the time-dependent outbursts characteristics. Time-frequency analysis showed that during the outbursts the amplitudes of stable main frequencies within 0.03 c d-1 intervals strongly change, while transients and/or frequencies of low amplitude appear separated or not separated from the stellar frequencies. The frequency patterns and activities depend on evolution phases: (i) the average separations between groups of frequencies are larger in the zero-age main sequence (ZAMS) than in the terminal age main sequence (TAMS) and are the largest in the middle of the MS phase; (ii) a poor frequency spectrum with f ≲ 1 cd-1 of low amplitude characterizes the stars beyond the TAMS; and (iii) outbursts are seen in stars hotter than B4 spectral type and in the

  13. The Terminator Time in subionospheric VLF/LF diurnal variation as recorded by the Romanian VLF/LF radio monitoring system related to earthquake occurrence and volcano erruptions

    Science.gov (United States)

    Moldovan, I. A.; Moldovan, A. S.; Biagi, P. F.; Ionescu, C.; Schwingenschuh, K.; Boudjada, M. Y.

    2012-04-01

    The Romanian VLF/LF monitoring system consisting in a radio receiver and the infrastructure that is necessary to record and transmit the collected data is part of the European international network named INFREP. Information on electromagnetic fields' intensities created by transmitters at a receiving site are indicating the quality of the propagation along the paths between the receivers and transmitters. Studying the ionosphere's influences on the electromagnetic waves' propagation along a certain path is a method to put into evidence possible modifications of its lower structure and composition as earthquakes' precursors. The VLF/LF receiver installed in Romania was put into operation in February 2009 and has already 3 years of testing, functioning and proving its utility in the forecast of some earthquakes or volcanic eruptions. Simultaneously we monitor, in the same site with the VLF/LF receiver, the vertical atmospheric electric field and different other meteorological parameters as: temperature, pressure or rainfall. The global magnetic conditions are emphasized with the help of Daily Geomagnetic Index Kp. At a basic level, the adopted analysis consists in a simple statistical evaluation of the signals by comparing the instantaneous values to the trend of the signal. In this paper we pay attention to the terminator times in subionospheric VLF/LF diurnal variation, which are defined as the times of minimum in amplitude (or phase) around sunrise and sunset. These terminator times are found to shift significantly just around the earthquake. In the case of Kobe earthquake, there were found significant shifts in both morning and evening terminator times and these authors interpreted the shift in terminator time in terms of the lowering of lower ionosphere by using the full-wave mode theory. A LabVIEW application which accesses the VLF/LF receiver through internet was developed. This program opens the receiver's web-page and automatically retrieves the list of data

  14. Enhanced sensitivity to the time variation of the fine-structure constant and mp/me in diatomic molecules: A closer examination of silicon monobromide

    International Nuclear Information System (INIS)

    Beloy, K.; Borschevsky, A.; Schwerdtfeger, P.; Flambaum, V. V.

    2010-01-01

    Recently it was pointed out that transition frequencies in certain diatomic molecules have an enhanced sensitivity to variations in the fine-structure constant α and the proton-to-electron mass ratio m p /m e due to a near cancellation between the fine structure and vibrational interval in a ground electronic multiplet [V. V. Flambaum and M. G. Kozlov, Phys. Rev. Lett. 99, 150801 (2007)]. One such molecule possessing this favorable quality is silicon monobromide. Here we take a closer examination of SiBr as a candidate for detecting variations in α and m p /m e . We analyze the rovibronic spectrum by employing the most accurate experimental data available in the literature and perform ab initio calculations to determine the precise dependence of the spectrum on variations in α. Furthermore, we calculate the natural linewidths of the rovibronic levels, which place a fundamental limit on the accuracy to which variations may be determined.

  15. Illustration of compositional variations over time of Chinese porcelain glazes combining micro-X-ray Fluorescence spectrometry, multivariate data analysis and Seger formulas

    International Nuclear Information System (INIS)

    Van Pevenage, J.; Verhaeven, E.; Vekemans, B.; Lauwers, D.; Herremans, D.; De Clercq, W.; Vincze, L.; Moens, L.; Vandenabeele, P.

    2015-01-01

    In this research, the transparent glaze layers of Chinese porcelain samples were investigated. Depending on the production period, these samples can be divided into two groups: the samples of group A dating from the Kangxi period (1661–1722), and the samples of group B produced under emperor Qianlong (1735–1795). Due to the specific sample preparation method and the small spot size of the X-ray beam, investigation of the transparent glaze layers is enabled. Despite the many existing research papers about glaze investigations of ceramics and/or porcelain ware, this research reveals new insights into the glaze composition and structure of Chinese porcelain samples. In this paper it is demonstrated, using micro-X-ray Fluorescence (μ-XRF) spectrometry, multivariate data analysis and statistical analysis (Hotelling's T-Square test) that the transparent glaze layers of the samples of groups A and B are significantly different (95% confidence level). Calculation of the Seger formulas, enabled classification of the glazes. Combining all the information, the difference in composition of the Chinese porcelain glazes of the Kangxi period and the Qianlong period can be demonstrated. - Highlights: • Fully described methodology for the analysis of silicate glazes of Chinese porcelain samples • The combination of a semi-quantitative analysis of silicate glazes, multi-variate data and statistical analysis. • The use of Seger formula to understand better the composition of the glazes. • New insights into the glaze composition and structure of Chinese porcelain glazes of different time periods

  16. Illustration of compositional variations over time of Chinese porcelain glazes combining micro-X-ray Fluorescence spectrometry, multivariate data analysis and Seger formulas

    Energy Technology Data Exchange (ETDEWEB)

    Van Pevenage, J., E-mail: Raman@UGent.be [Department of Analytical Chemistry, Raman Spectroscopy Research Group, Ghent University, Krijgslaan 281, S12, B-9000 Ghent (Belgium); Verhaeven, E. [Department of Conservation and Restoration, University College Antwerp, Blindestraat 9, B-2000 Antwerp (Belgium); Vekemans, B. [Department of Analytical Chemistry, Ghent University, Krijgslaan 281, S12, B-9000 Ghent (Belgium); Lauwers, D., E-mail: Raman@UGent.be [Department of Analytical Chemistry, Raman Spectroscopy Research Group, Ghent University, Krijgslaan 281, S12, B-9000 Ghent (Belgium); Herremans, D.; De Clercq, W. [Department of Archaeology, Ghent University, Sint-Pietersnieuwstraat 35, B-9000 Ghent (Belgium); Vincze, L. [Department of Analytical Chemistry, Ghent University, Krijgslaan 281, S12, B-9000 Ghent (Belgium); Moens, L., E-mail: Raman@UGent.be [Department of Analytical Chemistry, Raman Spectroscopy Research Group, Ghent University, Krijgslaan 281, S12, B-9000 Ghent (Belgium); Vandenabeele, P. [Department of Archaeology, Ghent University, Sint-Pietersnieuwstraat 35, B-9000 Ghent (Belgium)

    2015-01-01

    In this research, the transparent glaze layers of Chinese porcelain samples were investigated. Depending on the production period, these samples can be divided into two groups: the samples of group A dating from the Kangxi period (1661–1722), and the samples of group B produced under emperor Qianlong (1735–1795). Due to the specific sample preparation method and the small spot size of the X-ray beam, investigation of the transparent glaze layers is enabled. Despite the many existing research papers about glaze investigations of ceramics and/or porcelain ware, this research reveals new insights into the glaze composition and structure of Chinese porcelain samples. In this paper it is demonstrated, using micro-X-ray Fluorescence (μ-XRF) spectrometry, multivariate data analysis and statistical analysis (Hotelling's T-Square test) that the transparent glaze layers of the samples of groups A and B are significantly different (95% confidence level). Calculation of the Seger formulas, enabled classification of the glazes. Combining all the information, the difference in composition of the Chinese porcelain glazes of the Kangxi period and the Qianlong period can be demonstrated. - Highlights: • Fully described methodology for the analysis of silicate glazes of Chinese porcelain samples • The combination of a semi-quantitative analysis of silicate glazes, multi-variate data and statistical analysis. • The use of Seger formula to understand better the composition of the glazes. • New insights into the glaze composition and structure of Chinese porcelain glazes of different time periods.

  17. Contrast variation by dynamic nuclear polarization and time-of-flight small-angle neutron scattering. I. Application to industrial multi-component nanocomposites1

    Science.gov (United States)

    Noda, Yohei; Koizumi, Satoshi; Masui, Tomomi; Mashita, Ryo; Kishimoto, Hiroyuki; Yamaguchi, Daisuke; Kumada, Takayuki; Takata, Shin-ichi; Ohishi, Kazuki; Suzuki, Jun-ichi

    2016-01-01

    Dynamic nuclear polarization (DNP) at low temperature (1.2 K) and high magnetic field (3.3 T) was applied to a contrast variation study in small-angle neutron scattering (SANS) focusing on industrial rubber materials. By varying the scattering contrast by DNP, time-of-flight SANS profiles were obtained at the pulsed neutron source of the Japan Proton Accelerator Research Complex (J-PARC). The concentration of a small organic