Science.gov

Sample records for 1-d coda methodology

  1. An Application of the Coda Methodology for Moment-Rate Spectra Using Broadband Stations in Turkey

    SciTech Connect

    Eken Tuna, Kevin Mayeda, Abraham Hofstetter, Rengin Gok, Gonca Orgulu, Niyazi Turkelli

    2004-07-11

    A recently developed coda magnitude methodology was applied to selected broadband stations in Turkey for the purpose of testing the coda method in a large, laterally complex region. As found in other, albeit smaller regions, coda envelope amplitude measurements are significantly less variable than distance-corrected direct wave measurements (i.e., L{sub g} and surface waves) by roughly a factor 3-to-4. Despite strong lateral crustal heterogeneity in Turkey, they found that the region could be adequately modeled assuming a simple 1-D, radially symmetric path correction. After calibrating the stations ISP, ISKB and MALT for local and regional distances, single-station moment-magnitude estimates (M{sub W}) derived from the coda spectra were in excellent agreement with those determined from multistation waveform modeling inversions, exhibiting a data standard deviation of 0.17. Though the calibration was validated using large events, the results of the calibration will extend M{sub W} estimates to significantly smaller events which could not otherwise be waveform modeled. The successful application of the method is remarkable considering the significant lateral complexity in Turkey and the simple assumptions used in the coda method.

  2. Identification of surface wave higher modes using a methodology based on seismic noise and coda waves

    NASA Astrophysics Data System (ADS)

    Rivet, Diane; Campillo, Michel; Sanchez-Sesma, Francisco; Shapiro, Nikolaï M.; Singh, Shri Krishna

    2015-11-01

    Dispersion analysis of Rayleigh waves is performed to assess the velocity of complex structures such as sedimentary basins. At short periods several modes of the Rayleigh waves are often exited. To perform a reliable inversion of the velocity structure an identification of these modes is thus required. We propose a novel method to identify the modes of surface waves. We use the spectral ratio of the ground velocity for the horizontal components over the vertical component (H/V) measured on seismic coda. We then compare the observed values with the theoretical H/V ratio for velocity models deduced from surface wave dispersion when assuming a particular mode. We first invert the Rayleigh wave measurements retrieved from ambient noise cross-correlation with the assumptions that (1) the fundamental mode and (2) the first overtone are excited. Then we use these different velocity models to predict theoretical spectral ratios of the ground velocity for the horizontal components over the vertical component (H/V). These H/V ratios are computed under the hypothesis of equipartition of a diffuse field in a layered medium. Finally we discriminate between fundamental and higher modes by comparing the theoretical H/V ratio with the H/V ratio measured on seismic coda. In an application, we reconstruct Rayleigh waves from cross-correlations of ambient seismic noise recorded at seven broad-band stations in the Valley of Mexico. For paths within the soft quaternary sediments basin, the maximum energy is observed at velocities higher than expected for the fundamental mode. We identify that the dominant mode is the first higher mode, which suggests the importance of higher modes as the main vectors of energy in such complex structures.

  3. 2-D Path Corrections for Local and Regional Coda Waves: A Test of Transportability

    SciTech Connect

    Mayeda, K M; Malagnini, L; Phillips, W S; Walter, W R; Dreger, D S; Morasca, P

    2005-07-13

    Reliable estimates of the seismic source spectrum are necessary for accurate magnitude, yield, and energy estimation. In particular, how seismic radiated energy scales with increasing earthquake size has been the focus of recent debate within the community and has direct implications on earthquake source physics studies as well as hazard mitigation. The 1-D coda methodology of Mayeda et al. [2003] has provided the lowest variance estimate of the source spectrum when compared against traditional approaches that use direct S-waves, thus making it ideal for networks that have sparse station distribution. The 1-D coda methodology has been mostly confined to regions of approximately uniform complexity. For larger, more geophysically complicated regions, 2-D path corrections may be required. We will compare performance of 1-D versus 2-D path corrections in a variety of regions. First, the complicated tectonics of the northern California region coupled with high quality broadband seismic data provides for an ideal ''apples-to-apples'' test of 1-D and 2-D path assumptions on direct waves and their coda. Next, we will compare results for the Italian Alps using high frequency data from the University of Genoa. For Northern California, we used the same station and event distribution and compared 1-D and 2-D path corrections and observed the following results: (1) 1-D coda results reduced the amplitude variance relative to direct S-waves by roughly a factor of 8 (800%); (2) Applying a 2-D correction to the coda resulted in up to 40% variance reduction from the 1-D coda results; (3) 2-D direct S-wave results, though better than 1-D direct waves, were significantly worse than the 1-D coda. We found that coda-based moment-rate source spectra derived from the 2-D approach were essentially identical to those from the 1-D approach for frequencies less than {approx}0.7-Hz, however for the high frequencies (0.7 {le} f {le} 8.0-Hz), the 2-D approach resulted in inter-station scatter

  4. 2-D Coda and Direct Wave Attenuation Tomography in Northern Italy

    SciTech Connect

    Morasca, P; Mayeda, K; Gok, R; Phillips, W S; Malagnini, L

    2007-10-17

    A 1-D coda method was proposed by Mayeda et al. (2003) in order to obtain stable seismic source moment-rate spectra using narrowband coda envelope measurements. That study took advantage of the averaging nature of coda waves to derive stable amplitude measurements taking into account all propagation, site, and Sto-coda transfer function effects. Recently this methodology was applied to micro earthquake data sets from three sub-regions of northern Italy (i.e., western Alps, northern Apennines and eastern Alps). Since the study regions were small, ranging between local-to-near-regional distances, the simple 1-D path assumptions used in the coda method worked very well. The lateral complexity of this region would suggest, however, that a 2-D path correction might provide even better results if the datasets were combined, especially when paths traverse larger distances and complicated regions. The structural heterogeneity of northern Italy makes the region ideal to test the extent to which coda variance can be reduced further by using a 2-D Q tomography technique. The approach we use has been developed by Phillips et al. (2005) and is an extension of previous amplitude ratio techniques to remove source effects from the inversion. The method requires some assumptions such as isotropic source radiation which is generally true for coda waves. Our results are compared against direct Swave inversions for 1/Q and results from both share very similar attenuation features that coincide with known geologic structures. We compare our results with those derived from direct waves as well as some recent results from northern California obtained by Mayeda et al. (2005) which tested the same tomographic methodology applied in this study to invert for 1/Q. We find that 2-D coda path corrections for this region significantly improve upon the 1-D corrections, in contrast to California where only a marginal improvement was observed. We attribute this difference to stronger lateral

  5. Monitoring with Coda Wave Interferometry

    NASA Astrophysics Data System (ADS)

    Gret, A.; Snieder, R.

    2004-12-01

    Aki has been a pioneer in monitoring the subsurface with coda waves and with guided waves. His analysis of temporal and spatial variations in coda Q has proven to be a powerful tool for monitoring purposes. We have extended his technique in new method called coda wave interferometry where changes in the full waveforms of coda waves are used to monitor changes in the subsurface. We have developed and implemented the theory to use this technique to monitor the following changes: a change in the seismic velocity, a change in scatterer locations, and a change in the location of earthquakes. As shown by Aki, the seismic coda is dominated by shear waves. Therefore our technique is primarily sensitive to changes in the S-velocity. Aki also worked on wave propagation in volcanoes. We have used coda wave interferometry to monitor two active volcanoes, Arenal (Costa Rica) and Mt. Erebus (Antarctica). I will give several examples to illustrate how coda waves can be used for monitoring purposes.

  6. Phase statistics of seismic coda waves.

    PubMed

    Anache-Ménier, D; van Tiggelen, B A; Margerin, L

    2009-06-19

    We report the analysis of the statistics of the phase fluctuations in the coda of earthquakes recorded during a temporary experiment deployed at Pinyon Flats Observatory, California. The observed distributions of the spatial derivatives of the phase in the seismic coda exhibit universal power-law decays whose exponents agree accurately with circular Gaussian statistics. The correlation function of the phase derivative is measured and used to estimate the mean free path of Rayleigh waves.

  7. Spectral analysis and inversion of experimental codas

    SciTech Connect

    Jannaud, L.R.; Jacquin, C.G. ); Adler, P.M. . Lab. d'Aerothermique)

    1993-03-01

    A method developed for the determination of the characteristic lengths of an heterogeneous medium from the spectral analysis of codas is based on an extension of Aki's theory to anisotropic elastic media. An equivalent Gaussian model is obtained and seems to be in good agreement with the two experimental data sets that illustrate the method. The first set was obtained in a laboratory experiment with an isotropic marble sample. This sample is characterized by a submillimetric length scale that can be directly observed on a thin section. The spectral analysis of codas and their inversion yields an equivalent correlation length that is in good agreement with the observed one. The second data set is obtained in a crosshole experiment at the usual scale of a seismic survey. The codas are recorded, analyzed, and inverted. The analysis yields a vertical characteristic length for the studied subsurface that compares well with the characteristic length measured by seismic and stratigraphic logs.

  8. Attenuation Tomography of Northern California and the Yellow Sea / Korean Peninsula from Coda-source Normalized and Direct Lg Amplitudes

    SciTech Connect

    Ford, S R; Dreger, D S; Phillips, W S; Walter, W R; Mayeda, K; Malagnini, L

    2008-07-16

    Inversions for regional attenuation (1/Q) of Lg are performed in two different regions. The path attenuation component of the Lg spectrum is isolated using the coda-source normalization method, which corrects the Lg spectral amplitude for the source using the stable, coda-derived source spectra. Tomographic images of Northern California agree well with one-dimensional (1-D) Lg Q estimated from five different methods. We note there is some tendency for tomographic smoothing to increase Q relative to targeted 1-D methods. For example in the San Francisco Bay Area, which contains high attenuation relative to the rest of it's region, Q is over-estimated by {approx}30. Coda-source normalized attenuation tomography is also carried out for the Yellow Sea/Korean Peninsula (YSKP) where output parameters (site, source, and path terms) are compared with those from the amplitude tomography method of Phillips et al. (2005) as well as a new method that ties the source term to the MDAC formulation (Walter and Taylor, 2001). The source terms show similar scatter between coda-source corrected and MDAC source perturbation methods, whereas the amplitude method has the greatest correlation with estimated true source magnitude. The coda-source better represents the source spectra compared to the estimated magnitude and could be the cause of the scatter. The similarity in the source terms between the coda-source and MDAC-linked methods shows that the latter method may approximate the effect of the former, and therefore could be useful in regions without coda-derived sources. The site terms from the MDAC-linked method correlate slightly with global Vs30 measurements. While the coda-source and amplitude ratio methods do not correlate with Vs30 measurements, they do correlate with one another, which provides confidence that the two methods are consistent. The path Q{sup -1} values are very similar between the coda-source and amplitude ratio methods except for small differences in the Da

  9. Coda-derived source spectra, moment magnitudes, and energy-moment scaling in the western Alps

    NASA Astrophysics Data System (ADS)

    Morasca, P.; Mayeda, K.; Malagnini, L.

    2003-04-01

    the obtained source spectra validate our path and site corrections and also shows that the coda is effectively averaging over any source radiation pattern as well as any lateral crustal heterogeneity. These source spectra were then used to estimate stable MW for the entire dataset. Furthermore, we tied our coda-derived source amplitude at 2-3 Hz with the RSNI averaged ML. As expected, plotting our MW versus our ML, we show that the coda-moment magnitude scales with 2/3 slope for small events (less than ML ~3) and scales 1-to-1 for the intermediate magnitude events. The coda methodology can extend the network's capability in measuring stable MW and ML. In addition to magnitude, we studied the effect of dynamic stress drop scaling by computing the radiated S-wave energy from the source spectra. We first extrapolated the observed spectra to both high and low frequency limits, converted to velocity, squared the spectra and then integrated to obtain the radiated S-wave energy. Using these estimates, we show that the dynamic stress-drop has a non-constant trend in this region, and increases with increasing seismic moment, in good agreement with results from the western United States (e.g., Abercrombie, 1995; Mayeda &Walter, 1996).

  10. An Optimality-Theoretic Analysis of Codas in Brazilian Portuguese

    ERIC Educational Resources Information Center

    Goodin-Mayeda, C. Elizabeth

    2015-01-01

    Brazilian Portuguese allows only /s, N, l, r/ syllable finally, and of these, only /s/ is realized faithfully (as well as /r/ for some speakers). In order to avoid unacceptable codas, dialects of Brazilian Portuguese employ such strategies as epenthesis, nasal absorption, debucalization, and gliding. The current analysis argues that codas in…

  11. The Learnability of Phonotactic Patterns in Onset and Coda Positions

    ERIC Educational Resources Information Center

    Wang, Yuanyuan; Seidl, Amanda

    2015-01-01

    Cross-linguistically, languages allow a wider variety of phonotactic patterns in onsets than in codas. However, the variability of phonotactic patterns in coda position in different languages suggests these patterns must, at least in part, be learned. Two experiments were conducted to explore whether there is an asymmetry in English-learning…

  12. Seismic codas on the earth and the moon - A comparison

    NASA Technical Reports Server (NTRS)

    Dainty, A. M.; Toksoz, M. N.

    1981-01-01

    The seismic codas, representing that part of the seismogram following the arrival of the surface waves or the direct S waves, characteristic of the earth and moon are compared with regard to the implications of coda characteristics for scattering and attenuation. Scattering models based on single S-S scatter theory, in which seismic energy in the coda is assumed to be S waves that have undergone only one scattering without conversion, and on diffusion theory, which assumed that energy in the coda has been scattered many times, are examined, and situations where the single-scattering and multiple-scattering theories are applicable are distinguished by the ratio of attenuation distance to the scattering mean free path. Values of the attenuation distance and the mean free path derived from coda studies for the earth and moon are compared, and it is found that for the frequency range 0.5-10 Hz, diffusion scattering is important in lunar codas, while at frequencies from 1 to 25 Hz single scattering is important in terrestrial codas. It is pointed out that attenuation acts to eliminate scattering paths much longer than the attenuation length. The observed differences between terrestrial and lunar codas are thus attributed to lesser attenuation and greater scattering on the moon.

  13. Regional Body-Wave Attenuation Using a Coda Source Normalization Method: Application to MEDNET Records of Earthquakes in Italy

    SciTech Connect

    Walter, W R; Mayeda, K; Malagnini, L; Scognamiglio, L

    2007-02-01

    We develop a new methodology to determine apparent attenuation for the regional seismic phases Pn, Pg, Sn, and Lg using coda-derived source spectra. The local-to-regional coda methodology (Mayeda, 1993; Mayeda and Walter, 1996; Mayeda et al., 2003) is a very stable way to obtain source spectra from sparse networks using as few as one station, even if direct waves are clipped. We develop a two-step process to isolate the frequency-dependent Q. First, we correct the observed direct wave amplitudes for an assumed geometrical spreading. Next, an apparent Q, combining path and site attenuation, is determined from the difference between the spreading-corrected amplitude and the independently determined source spectra derived from the coda methodology. We apply the technique to 50 earthquakes with magnitudes greater than 4.0 in central Italy as recorded by MEDNET broadband stations around the Mediterranean at local-to-regional distances. This is an ideal test region due to its high attenuation, complex propagation, and availability of many moderate sized earthquakes. We find that a power law attenuation of the form Q(f) = Q{sub 0}f{sup Y} fit all the phases quite well over the 0.5 to 8 Hz band. At most stations, the measured apparent Q values are quite repeatable from event to event. Finding the attenuation function in this manner guarantees a close match between inferred source spectra from direct waves and coda techniques. This is important if coda and direct wave amplitudes are to produce consistent seismic results.

  14. CODA: Coordinated Observations of Dynamics in Aurora

    NASA Technical Reports Server (NTRS)

    Larsen, M. F.

    2003-01-01

    The grant funds were provided to carry out chemical tracer wind and turbulence measurements in the mesosphere and lower thermosphere as part of the Coordinated Observations of Dynamics in Aurora (CODA) experiment for which Dr. Andy Christensen of the Aerospace Corp. was the Principal Investigator. Clemson University was a co-investigator institution on the project and was tasked with designing, building, and testing a total of four chemical tracer release payloads which were used to release trimethyl aluminum (TMA) to measure the winds and turbulent diffusion. All four payloads were flown from the rocket range at Poker Flat, Alaska, in support of instrumented payloads flown from the same location. The CODA experiment was designed to investigate the changes in the chemical composition in the lower thermosphere during an auroral substorm event. In particular, the objective was to determine the relative importance of two competing mechanisms. The first mechanism is associated with the advection of air from the polar cap into the auroral oval. A flow in that direction is typical in the postmidnight sector of the oval. As the air moves from the region of negligible forcing in the polar cap to the region of strong forcing and heating in the oval, changes in the composition are expected to occur. Alternatively, enhanced local mixing will also cause such changes. Since the auroral forcing accelerates the neutral winds in the lower E region, but not at lower altitudes, the forcing results in large shears that can be large enough to be unstable in the Richardson number sense. The unstable shears are expected to generate turbulence and therefore enhanced mixing. Such mixing will also create composition changes similar to what is observed. In the CODA experiment an instrumented payload designed and built by the Aerospace Corporation was used to measure the composition and plasma parameters needed to define the auroral forcing. In addition, three chemical tracer payloads were

  15. Stacking coda waves to resolve the scattering and attenuation structure of Southern California

    NASA Astrophysics Data System (ADS)

    Wang, W.; Shearer, P. M.

    2015-12-01

    Seismic attenuation is caused by two factors, scattering and intrinsic absorption. Charactering the scattering and attenuation properties and the power spectrum of crustal heterogeneity is a fundamental problem for informing strong ground motion estimates at high frequencies, where scattering and attenuation effects are critical. Determining the relative amount of attenuation caused by scattering and intrinsic absorption has been a long-standing interest of seismologists. The wavetrain following the direct body-wave phases is called the coda and is caused by scattered energy. Many studies have analyzed local-event coda to infer crustal and upper-mantle scattering strength and intrinsic attenuation. Here we describe a comprehensive study of coda behavior in Southern California to resolve scattering and intrinsic attenuation structure. First, we apply an envelope-function stacking method to 287,410 seismograms from 6928 geographically dispersed events of M ≥ 1.8 from 1981-2005. The results are presented as spatial averages as a function of distance, source depth, and frequency. Second, we use a Monte Carlo seismic phonon algorithm to simulate the effects of depth-dependent scattering and intrinsic attenuation, which computes scattering probabilities and scattering angles based on theoretical results for random heterogeneity models. This method has the advantage of including both P- and S-wave scattering and is energy conserving even for multiple scattering models. The input 1-D velocity model can be layered to incorporate reflected phases, such as PmP and SmS, to better fit the observations. We will summarize our results for the average scattering and attenuation properties of the southern California crust and the implications for strong ground motion predictions.

  16. Coda Spectral Peaking for Nevada Nuclear Test Site Explosions

    SciTech Connect

    Murphy, K R; Mayeda, K; Walter, W R

    2007-09-10

    We have applied the regional S-wave coda calibration technique of Mayeda et al. (2003) to earthquake data in and around the Nevada Test Site (NTS) using 4 regional broadband stations from the LLNL seismic network. We applied the same path and site corrections to tamped nuclear explosion data and averaged the source spectra over the four stations. Narrowband coda amplitudes from the spectra were then regressed against inferred yield based on the regional m{sub b}(Pn) magnitude of Denny et al. (1987), along with the yield formulation of Vergino and Mensing (1990). We find the following: (1) The coda-derived spectra show a peak which is dependent upon emplacement depth, not event size; (2) Source size estimates are stable for the coda and show a dependence upon the near-source strength and gas porosity; (3) For explosions with the same m{sub b}(Pn) or inferred yield, those in weaker material have lower coda amplitudes at 1-3 Hz.

  17. Perception Mirrors Production in 14- and 18-Month-Olds: The Case of Coda Consonants

    ERIC Educational Resources Information Center

    Levelt, Clara C.

    2012-01-01

    In a word learning experiment, 14- and 18-month-old infants are tested on their perceptual sensitivity to coda-consonant omissions. The results indicate that 14-month-olds are not sensitive to coda consonant omissions, showing a parallel with the omission of target coda consonants in early child language productions. At 18 months, infants are…

  18. Linguistic Constraints on the Acquisition of English Syllable Codas by Native Speakers of Mandarin Chinese.

    ERIC Educational Resources Information Center

    Hansen, Jette G.

    2001-01-01

    Investigated the acquisition of English syllable codas by speakers of Mandarin Chinese. Three participants' naturalistic production of syllable codas were studied and analyzed through VARBRUL and descriptive statistics to determine accuracy orders and production modifications of codas by length at two data collection times with a time span of 6…

  19. Long-range correlations in the diffuse seismic coda.

    PubMed

    Campillo, Michel; Paul, Anne

    2003-01-24

    The late seismic coda may contain coherent information about the elastic response of Earth. We computed the correlations of the seismic codas of 101 distant earthquakes recorded at stations that were tens of kilometers apart. By stacking cross-correlation functions of codas, we found a low-frequency coherent part in the diffuse field. The extracted pulses have the polarization characteristics and group velocities expected for Rayleigh and Love waves. The set of cross-correlations has the symmetries of the surface-wave part of the Green tensor. This seismological example shows that diffuse waves produced by distant sources are sufficient to retrieve direct waves between two perfectly located points of observation. Because it relies on general properties of diffuse waves, this result has potential applications in other fields.

  20. Scattered surface wave energy in the seismic coda

    USGS Publications Warehouse

    Zeng, Y.

    2006-01-01

    One of the many important contributions that Aki has made to seismology pertains to the origin of coda waves (Aki, 1969; Aki and Chouet, 1975). In this paper, I revisit Aki's original idea of the role of scattered surface waves in the seismic coda. Based on the radiative transfer theory, I developed a new set of scattered wave energy equations by including scattered surface waves and body wave to surface wave scattering conversions. The work is an extended study of Zeng et al. (1991), Zeng (1993) and Sato (1994a) on multiple isotropic-scattering, and may shed new insight into the seismic coda wave interpretation. The scattering equations are solved numerically by first discretizing the model at regular grids and then solving the linear integral equations iteratively. The results show that scattered wave energy can be well approximated by body-wave to body wave scattering at earlier arrival times and short distances. At long distances from the source, scattered surface waves dominate scattered body waves at surface stations. Since surface waves are 2-D propagating waves, their scattered energies should in theory follow a common decay curve. The observed common decay trends on seismic coda of local earthquake recordings particular at long lapse times suggest that perhaps later seismic codas are dominated by scattered surface waves. When efficient body wave to surface wave conversion mechanisms are present in the shallow crustal layers, such as soft sediment layers, the scattered surface waves dominate the seismic coda at even early arrival times for shallow sources and at later arrival times for deeper events.

  1. A model of seismic coda arrivals to suppress spurious events.

    NASA Astrophysics Data System (ADS)

    Arora, N.; Russell, S.

    2012-04-01

    We describe a model of coda arrivals which has been added to NET-VISA (Network processing Vertically Integrated Seismic Analysis) our probabilistic generative model of seismic events, their transmission, and detection on a global seismic network. The scattered energy that follows a seismic phase arrival tends to deceive typical STA/LTA based arrival picking software into believing that a real seismic phase has been detected. These coda arrivals which tend to follow all seismic phases cause most network processing software including NET-VISA to believe that multiple events have taken place. It is not a simple matter of ignoring closely spaced arrivals since arrivals from multiple events can indeed overlap. The current practice in NET-VISA of pruning events within a small space-time neighborhood of a larger event works reasonably well, but it may mask real events produced in an after-shock sequence. Our new model allows any seismic arrival, even coda arrivals, to trigger a subsequent coda arrival. The probability of such a triggered arrival depends on the amplitude of the triggering arrival. Although real seismic phases are more likely to generate such coda arrivals. Real seismic phases also tend to generate coda arrivals with more strongly correlated parameters, for example azimuth and slowness. However, the SNR (Signal to Noise Ratio) of a coda arrival immediately following a phase arrival tends to be lower because of the nature of the SNR calculation. We have calibrated our model on historical statistics of such triggered arrivals and our inference accounts for them while searching for the best explanation of seismic events their association to the arrivals and the coda arrivals. We have tested our new model on one week of global seismic data spanning March 22, 2009 to March 29, 2009. Our model was trained on two and half months of data from April 5, 2009 to June 20, 2009. We use the LEB bulletin produced by the IDC (International Data Center) as the ground truth

  2. Extracting changes in air temperature using acoustic coda phase delays.

    PubMed

    Marcillo, Omar; Arrowsmith, Stephen; Whitaker, Rod; Morton, Emily; Scott Phillips, W

    2014-10-01

    Blast waves produced by 60 high-explosive detonations were recorded at short distances (few hundreds of meters); the corresponding waveforms show charge-configuration independent coda-like features (i.e., similar shapes, amplitudes, and phases) lasting several seconds. These features are modeled as reflected and/or scattered waves by acoustic reflectors/scatters surrounding the explosions. Using explosion pairs, relative coda phase delays are extracted and modeled as changes in sound speed due to changes in air temperature. Measurements from nearby weather towers are used for validation. PMID:25324115

  3. Regional P-Coda for Stable Estimates of Body Wave Magnitude: Extending the Ms:mb Discriminant to Smaller Events

    NASA Astrophysics Data System (ADS)

    Mayeda, K.; Bonner, J.

    2007-12-01

    The most successful teleseismic discriminant is Ms:mb, and many studies are underway to try and extend surface wave magnitude (Ms) estimation to regional distances. A problem that is encountered at regional distances and small magnitudes is how to estimate mb so that the Ms:mb discriminant is meaningful and consistent with teleseismic measures. Over the past several years, a regional S-coda wave methodology has been developed that provides for the lowest variance estimate of the seismic source spectrum. Thus, regional MW and mb estimates derived from Sn and Lg coda are very stable, even when only a single station is used. However, these mb's&p are inherently biased for earthquakes because they are an S-based measurement, and explosions are relatively depleted in S-waves. Previous research projects have used region-specific mb scales based on direct measurements of Pn and Pg to improve the Ms:mb discrimination, even though the mb estimates often had a large variance. In our preliminary research, we have found that P-coda envelopes for both explosions and earthquakes can be obtained for events from both the NTS and NZ regions without bias. Our next step at NTS will be to derive path corrections, similar to the approach of Mayeda et al. (2003) for Lg-coda. We will compare inter-station scatter of distance-corrected amplitudes as a function of window length. This will provide an empirical measure of error based on window length for each frequency band. For each frequency band, we will regress our coda envelope amplitudes against regional and teleseismic estimates of mb (e.g., mb(Pn), mb(P)) to determine which band provides the lowest variance. This will yield slope and intercept values for each frequency band. We will then derive mb(Pn) and mb(P) (following Denny et al., 1989) to compare against mb(P-coda) to assess performance at the network and single-station level. Most of the nuclear explosions already have an mb(Pn) compiled by Vergino and Mensing (1989). Patton

  4. Children's Acquisition of English Onset and Coda /l/: Articulatory Evidence

    ERIC Educational Resources Information Center

    Lin, Susan; Demuth, Katherine

    2015-01-01

    Purpose: The goal of this study was to better understand how and when onset /l/ ("leap") and coda /l/ ("peel") are acquired by children by examining both the articulations involved and adults' perceptions of the produced segments. Method: Twenty-five typically developing Australian English-speaking children aged 3;0…

  5. Perception of English palatal codas by Korean speakers of English

    NASA Astrophysics Data System (ADS)

    Yeon, Sang-Hee

    2003-04-01

    This study aimed at looking at perception of English palatal codas by Korean speakers of English to determine if perception problems are the source of production problems. In particular, first, this study looked at the possible first language effect on the perception of English palatal codas. Second, a possible perceptual source of vowel epenthesis after English palatal codas was investigated. In addition, individual factors, such as length of residence, TOEFL score, gender and academic status, were compared to determine if those affected the varying degree of the perception accuracy. Eleven adult Korean speakers of English as well as three native speakers of English participated in the study. Three sets of a perception test including identification of minimally different English pseudo- or real words were carried out. The results showed that, first, the Korean speakers perceived the English codas significantly worse than the Americans. Second, the study supported the idea that Koreans perceived an extra /i/ after the final affricates due to final release. Finally, none of the individual factors explained the varying degree of the perceptional accuracy. In particular, TOEFL scores and the perception test scores did not have any statistically significant association.

  6. Children's Acquisition of English Onset and Coda /l/: Articulatory Evidence

    PubMed Central

    Demuth, Katherine

    2015-01-01

    Purpose The goal of this study was to better understand how and when onset /l/ (leap) and coda /l/ (peel) are acquired by children by examining both the articulations involved and adults' perceptions of the produced segments. Method Twenty-five typically developing Australian English–speaking children aged 3;0 (years;months) to 7;11 participated in an elicited imitation task, during which audio, video, and lingual ultrasound images were collected. Transcribers perceptually rated audio, whereas video and ultrasound images were visually examined for the presence of adult-like articulations. Results Data from this study establish that for Australian English–learning children, coda /l/s are acquired later than onset /l/s, and older children produce greater proportions of adultlike /l/s in both onset and coda positions, roughly following established norms for American English–speaking children. However, although perceptibility of coda /l/s was correlated with their articulations, onset /l/s were nearly uniformly perceived as adultlike despite substantial variation in the articulations used to produce them. Conclusions The disparity in the production and perception of children's singleton onset /l/s is linked to both physiological and phonological development. Suggestions are made for future research to tease these factors apart. PMID:25321384

  7. Sperm whale codas may encode individuality as well as clan identity.

    PubMed

    Oliveira, Cláudia; Wahlberg, Magnus; Silva, Mónica A; Johnson, Mark; Antunes, Ricardo; Wisniewska, Danuta M; Fais, Andrea; Gonçalves, João; Madsen, Peter T

    2016-05-01

    Sperm whales produce codas for communication that can be grouped into different types according to their temporal patterns. Codas have led researchers to propose that sperm whales belong to distinct cultural clans, but it is presently unclear if they also convey individual information. Coda clicks comprise a series of pulses and the delay between pulses is a function of organ size, and therefore body size, and so is one potential source of individual information. Another potential individual-specific parameter could be the inter-click intervals within codas. To test whether these parameters provide reliable individual cues, stereo-hydrophone acoustic tags (Dtags) were attached to five sperm whales of the Azores, recording a total of 802 codas. A discriminant function analysis was used to distinguish 288 5 Regular codas from four of the sperm whales and 183 3 Regular codas from two sperm whales. The results suggest that codas have consistent individual features in their inter-click intervals and inter-pulse intervals which may contribute to individual identification. Additionally, two whales produced different coda types in distinct foraging dive phases. Codas may therefore be used by sperm whales to convey information of identity as well as activity within a social group to a larger extent than previously assumed. PMID:27250178

  8. Sperm whale codas may encode individuality as well as clan identity.

    PubMed

    Oliveira, Cláudia; Wahlberg, Magnus; Silva, Mónica A; Johnson, Mark; Antunes, Ricardo; Wisniewska, Danuta M; Fais, Andrea; Gonçalves, João; Madsen, Peter T

    2016-05-01

    Sperm whales produce codas for communication that can be grouped into different types according to their temporal patterns. Codas have led researchers to propose that sperm whales belong to distinct cultural clans, but it is presently unclear if they also convey individual information. Coda clicks comprise a series of pulses and the delay between pulses is a function of organ size, and therefore body size, and so is one potential source of individual information. Another potential individual-specific parameter could be the inter-click intervals within codas. To test whether these parameters provide reliable individual cues, stereo-hydrophone acoustic tags (Dtags) were attached to five sperm whales of the Azores, recording a total of 802 codas. A discriminant function analysis was used to distinguish 288 5 Regular codas from four of the sperm whales and 183 3 Regular codas from two sperm whales. The results suggest that codas have consistent individual features in their inter-click intervals and inter-pulse intervals which may contribute to individual identification. Additionally, two whales produced different coda types in distinct foraging dive phases. Codas may therefore be used by sperm whales to convey information of identity as well as activity within a social group to a larger extent than previously assumed.

  9. 1-D and 2-D Probabilistic Inversions of Fault Zone Guided Waves

    NASA Astrophysics Data System (ADS)

    Gulley, A.; Eccles, J. D.; Kaipio, J. P.; Malin, P. E.

    2015-12-01

    Fault Zone Guided Waves (FZGWs) are seismic coda that are trapped by the low velocity damage zone of faults. Inversions of these phases can be carried out using their measured dispersion and a Bayesian probability approach. This method utilises a Markov chain Monte Carlo which allows uncertainties and trade-offs to be quantified. Accordingly we have developed a scheme that estimates the dispersion curve and amplitude response variability from a FZGW record. This method allows the computation of both the point estimates and the covariance of the dispersion curve. The subsequent estimation of fault zone parameters is then based on a Gaussian model for the dispersion curve. We then show that inversions using FZGW dispersion data can only resolve fault zone velocity contrast and fault zone width - it leaves densities, absolute country rock velocities and the earthquake location unresolved. We show that they do however significantly affect the estimated fault zone velocities and widths. As these parameters cannot be resolved, we allow for their effects on the estimates of fault zone width and velocity contrast by using the Bayesian approximation error method. We show that using this method reduces computational time from days to minutes and the associated loss of accuracy is insignificant compared to carrying out the inversion on all parameters. We have extended our scheme to 2-D using 1-D slices. The Bayesian approximation error methodology is further employed to provide a 'correction term' with uncertainty for the 1-D slice approximation. We investigate these features with both synthetic data and FZGW data from the Alpine Fault of New Zealand.

  10. Coda wave interferometry for estimating nonlinear behavior in seismic velocity.

    PubMed

    Snieder, Roel; Grêt, Alexandre; Douma, Huub; Scales, John

    2002-03-22

    In coda wave interferometry, one records multiply scattered waves at a limited number of receivers to infer changes in the medium over time. With this technique, we have determined the nonlinear dependence of the seismic velocity in granite on temperature and the associated acoustic emissions. This technique can be used in warning mode, to detect the presence of temporal changes in the medium, or in diagnostic mode, where the temporal change in the medium is quantified.

  11. Individual, unit and vocal clan level identity cues in sperm whale codas.

    PubMed

    Gero, Shane; Whitehead, Hal; Rendell, Luke

    2016-01-01

    The 'social complexity hypothesis' suggests that complex social structure is a driver of diversity in animal communication systems. Sperm whales have a hierarchically structured society in which the largest affiliative structures, the vocal clans, are marked on ocean-basin scales by culturally transmitted dialects of acoustic signals known as 'codas'. We examined variation in coda repertoires among both individual whales and social units-the basic element of sperm whale society-using data from nine Caribbean social units across six years. Codas were assigned to individuals using photo-identification and acoustic size measurement, and we calculated similarity between repertoires using both continuous and categorical methods. We identified 21 coda types. Two of those ('1+1+3' and '5R1') made up 65% of the codas recorded, were shared across all units and have dominated repertoires in this population for at least 30 years. Individuals appear to differ in the way they produce '5R1' but not '1+1+3' coda. Units use distinct 4-click coda types which contribute to making unit repertoires distinctive. Our results support the social complexity hypothesis in a marine species as different patterns of variation between coda types suggest divergent functions, perhaps representing selection for identity signals at several levels of social structure.

  12. Individual, unit and vocal clan level identity cues in sperm whale codas.

    PubMed

    Gero, Shane; Whitehead, Hal; Rendell, Luke

    2016-01-01

    The 'social complexity hypothesis' suggests that complex social structure is a driver of diversity in animal communication systems. Sperm whales have a hierarchically structured society in which the largest affiliative structures, the vocal clans, are marked on ocean-basin scales by culturally transmitted dialects of acoustic signals known as 'codas'. We examined variation in coda repertoires among both individual whales and social units-the basic element of sperm whale society-using data from nine Caribbean social units across six years. Codas were assigned to individuals using photo-identification and acoustic size measurement, and we calculated similarity between repertoires using both continuous and categorical methods. We identified 21 coda types. Two of those ('1+1+3' and '5R1') made up 65% of the codas recorded, were shared across all units and have dominated repertoires in this population for at least 30 years. Individuals appear to differ in the way they produce '5R1' but not '1+1+3' coda. Units use distinct 4-click coda types which contribute to making unit repertoires distinctive. Our results support the social complexity hypothesis in a marine species as different patterns of variation between coda types suggest divergent functions, perhaps representing selection for identity signals at several levels of social structure. PMID:26909165

  13. Individual, unit and vocal clan level identity cues in sperm whale codas

    PubMed Central

    Gero, Shane; Whitehead, Hal; Rendell, Luke

    2016-01-01

    The ‘social complexity hypothesis’ suggests that complex social structure is a driver of diversity in animal communication systems. Sperm whales have a hierarchically structured society in which the largest affiliative structures, the vocal clans, are marked on ocean-basin scales by culturally transmitted dialects of acoustic signals known as ‘codas’. We examined variation in coda repertoires among both individual whales and social units—the basic element of sperm whale society—using data from nine Caribbean social units across six years. Codas were assigned to individuals using photo-identification and acoustic size measurement, and we calculated similarity between repertoires using both continuous and categorical methods. We identified 21 coda types. Two of those (‘1+1+3’ and ‘5R1’) made up 65% of the codas recorded, were shared across all units and have dominated repertoires in this population for at least 30 years. Individuals appear to differ in the way they produce ‘5R1’ but not ‘1+1+3’ coda. Units use distinct 4-click coda types which contribute to making unit repertoires distinctive. Our results support the social complexity hypothesis in a marine species as different patterns of variation between coda types suggest divergent functions, perhaps representing selection for identity signals at several levels of social structure. PMID:26909165

  14. Spatial variation of coda wave attenuation in northwestern Colombia

    NASA Astrophysics Data System (ADS)

    Vargas, Carlos A.; Ugalde, Arantza; Pujades, Lluís G.; Canas, José A.

    2004-08-01

    One thousand seven hundred and eighty-six vertical-component, short-period observations of microearthquake codas from regional earthquakes recorded by 17 stations belonging to the National Seismological Network of Colombia were used to estimate seismic wave attenuation in Colombia. Local magnitudes range from 2.9 to 6.0 and only events occurring at hypocentral distances up to 255 km were considered for the analysis. The frequencies of interest lay between 1 and 19 Hz and the analysis was performed for each seismic station separately. Coda-wave attenuation (Q-1c) was estimated by means of a single-scattering method whereas the separation of intrinsic absorption (Q-1i) and scattering attenuation (Q-1s) from total attenuation (Q-1t) was performed using a multiple lapse time-window analysis based on the hypothesis of multiple isotropic scattering and uniform distribution of scatterers. A regionalization of the estimated Q0 (Qc at 1 Hz) values was performed and a contour map of seismic coda attenuation in Colombia is presented, where four zones with significant variations of attenuation related to different geological and tectonic characteristics can be observed. The highest attenuation is linked to the central and western regions (Q0 around 50 and 56) whereas a lower attenuation (Q0 around 69 and 67) is assigned to the northern and eastern regions. Results show that the Q-1 values are frequency dependent in the considered frequency range, and are approximated by a least-square fit to the power law Q-1(f) =Q-10(f/f0)-η. The exponents of the frequency dependence law ranged from η= 0.65 to 1.01 for Q-1c, η= 0.62 to 1.78 for Q-1i, η= 0.28 to 1.49 for Q-1s, and η= 0.53 to 1.67 for Q-1t. On the other hand, intrinsic absorption is found to dominate over scattering in the attenuation process for most of the stations and frequency bands analysed. Some discrepancies have been observed between the theoretical model and the observations for some frequency bands which indicate

  15. Long codas of coupled wave systems in seismic basins

    NASA Astrophysics Data System (ADS)

    Seligman, Thomas H.

    2002-11-01

    Quite some time ago it was pointed out that the damage patterns and Fourier spectra of the 1985 earthquake in Mexico City are only compatible with a resonant effect of horizontal waves with the approximate speed of sound waves in water [see Flores et al., Nature 326, 783 (1987)]. In a more recent paper it was pointed out that this indeed will occur with a very specific frequency selection for a coupled system of Raleigh waves at the interface of the bottom of the ancient lakebed with the more solid deposits, and an evanescent sound wave in the mud above [see J. Flores et al., Bull. Seismol. Soc. Am. 89, 14-21 (1999)]. In the present talk we shall go over these arguments again and show that strong reflection at the edges of the lake must occur to account for the strong magnification entailing necessarily a long coda, and that the mecanism can be understood in the same terms.

  16. The Last Months of Andreas Vesalius: a Coda.

    PubMed

    Biesbrouck, Maurits; Goddeeris, Theodoor; Steeno, Omer

    2012-12-01

    Since the publication in this journal of our two articles on the end of Andreas Vesalius' life, some very old sources have recently become available that we were unable to consult at the time of writing and that now prompt us to add a coda. These sources give an even better picture of both the circumstances of the disaster that led to Vesalius' death and the correct site of his burial. Firstly, there is a text by Reinerus Solenander that casts a completely different light on the circumstances in which his ship was at sea and the way in which it reached land; in addition, there is a new early eye-witness report of his burial-place by Christoph Fürer von Haimendorf, dating from 6 August 1565. PMID:26255386

  17. The Last Months of Andreas Vesalius: a Coda.

    PubMed

    Biesbrouck, Maurits; Goddeeris, Theodoor; Steeno, Omer

    2012-12-01

    Since the publication in this journal of our two articles on the end of Andreas Vesalius' life, some very old sources have recently become available that we were unable to consult at the time of writing and that now prompt us to add a coda. These sources give an even better picture of both the circumstances of the disaster that led to Vesalius' death and the correct site of his burial. Firstly, there is a text by Reinerus Solenander that casts a completely different light on the circumstances in which his ship was at sea and the way in which it reached land; in addition, there is a new early eye-witness report of his burial-place by Christoph Fürer von Haimendorf, dating from 6 August 1565.

  18. Upstream Design and 1D-CAE

    NASA Astrophysics Data System (ADS)

    Sawada, Hiroyuki

    Recently, engineering design environment of Japan is changing variously. Manufacturing companies are being challenged to design and bring out products that meet the diverse demands of customers and are competitive against those produced by rising countries(1). In order to keep and strengthen the competitiveness of Japanese companies, it is necessary to create new added values as well as conventional ones. It is well known that design at the early stages has a great influence on the final design solution. Therefore, design support tools for the upstream design is necessary for creating new added values. We have established a research society for 1D-CAE (1 Dimensional Computer Aided Engineering)(2), which is a general term for idea, methodology and tools applicable for the upstream design support, and discuss the concept and definition of 1D-CAE. This paper reports our discussion about 1D-CAE.

  19. The development of acoustic cues to coda contrasts in young children learning American Englisha

    PubMed Central

    Song, Jae Yung; Demuth, Katherine; Shattuck-Hufnagel, Stefanie

    2012-01-01

    Research on children’s speech perception and production suggests that consonant voicing and place contrasts may be acquired early in life, at least in word-onset position. However, little is known about the development of the acoustic correlates of later-acquired, word-final coda contrasts. This is of particular interest in languages like English where many grammatical morphemes are realized as codas. This study therefore examined how various non-spectral acoustic cues vary as a function of stop coda voicing (voiced vs. voiceless) and place (alveolar vs. velar) in the spontaneous speech of 6 American-English-speaking mother-child dyads. The results indicate that children as young as 1;6 exhibited many adult-like acoustic cues to voicing and place contrasts, including longer vowels and more frequent use of voice bar with voiced codas, and a greater number of bursts and longer post-release noise for velar codas. However, 1;6-year-olds overall exhibited longer durations and more frequent occurrence of these cues compared to mothers, with decreasing values by 2;6. Thus, English-speaking 1;6-year-olds already exhibit adult-like use of some of the cues to coda voicing and place, though implementation is not yet fully adult-like. Physiological and contextual correlates of these findings are discussed. PMID:22501078

  20. Monitoring volcano precursory activity with the materials failure approach, using rates of cumulative seismic coda length

    SciTech Connect

    Cornelius, R.R.; Voight, B. . Dept. of Geosciences)

    1992-01-01

    The proportionality between the energy, E, of an elastic wave and the square of its amplitude led to the usage of Benioff diagrams'' for purposes of volcano monitoring. These diagrams show the time-integrated amplitude as [radical]E versus time. The authors propose to use accelerating cumulative coda length directly in volcano monitoring. This surrogate measure of energy'' is used for practical reasons, as it eliminates the intermediate step required for energy calculations with regional and instrument-specific constants. Rates of cumulative coda (s/day) may be used for the materials failure approach'' to eruption prediction, which fits data according to an empirical rate-acceleration relationship. The method allows numerical or graphical rate extrapolation towards the expected failure rate; eruption windows may be established. Rate series derived from either cumulative amplitude, cumulative coda, or calculated [radical]E can be analyzed by the materials failure approach equally well; neither series is favored by this method because of similar characteristics. They suggest rate interpolation from the time-integrated data over constant coda-increments instead of over constant time-increments. This results in an increasingly higher frequency of rate data towards the end of an accelerating time series. The end-weighted rate calculation emphasizes the latest precursory developments while it smooths noise at lower rates. Adjusting the applied constant coda-increment for rate calculations as a function of total encountered coda, is a technique for an automated and sequential update of the extrapolated failure time.

  1. Attenuation of seismic waves obtained by coda waves analysis in the West Bohemia earthquake swarm region

    NASA Astrophysics Data System (ADS)

    Bachura, Martin; Fischer, Tomas

    2014-05-01

    Seismic waves are attenuated by number of factors, including geometrical spreading, scattering on heterogeneities and intrinsic loss due the anelasticity of medium. Contribution of the latter two processes can be derived from the tail part of the seismogram - coda (strictly speaking S-wave coda), as these factors influence the shape and amplitudes of coda. Numerous methods have been developed for estimation of attenuation properties from the decay rate of coda amplitudes. Most of them work with the S-wave coda, some are designed for the P-wave coda (only on teleseismic distances) or for the whole waveforms. We used methods to estimate the 1/Qc - attenuation of coda waves, methods to separate scattering and intrinsic loss - 1/Qsc, Qi and methods to estimate attenuation of direct P and S wave - 1/Qp, 1/Qs. In this study, we analyzed the S-wave coda of local earthquake data recorded in the West Bohemia/Vogtland area. This region is well known thanks to the repeated occurrence of earthquake swarms. We worked with data from the 2011 earthquake swarm, which started late August and lasted with decreasing intensity for another 4 months. During the first week of swarm thousands of events were detected with maximum magnitudes ML = 3.6. Amount of high quality data (including continuous datasets and catalogues with an abundance of well-located events) is available due to installation of WEBNET seismic network (13 permanent and 9 temporary stations) monitoring seismic activity in the area. Results of the single-scattering model show seismic attenuations decreasing with frequency, what is in agreement with observations worldwide. We also found decrease of attenuation with increasing hypocentral distance and increasing lapse time, which was interpreted as a decrease of attenuation with depth (coda waves on later lapse times are generated in bigger depths - in our case in upper lithosphere, where attenuations are small). We also noticed a decrease of frequency dependence of 1/Qc

  2. Evidence For Departure in Self-Similarity: A New Spectral Ratio Method Using Narrowband Coda Envelopes

    SciTech Connect

    Mayeda, K; Malagnini, L; Walter, W R

    2007-03-16

    This study is motivated by renewed interest within the seismic source community to resolve the long-standing question on energy scaling of earthquakes, specifically, 'Do earthquakes scale self-similarly or are large earthquakes dynamically different than small ones?' This question is important from a seismic hazard prediction point of view, as well as for understanding basic rupture dynamics for earthquakes. Estimating the total radiated energy (ER) from earthquakes requires significant broadband corrections for path and site effects. Moreover, source radiation pattern and directivity corrections can be equally significant and also must be accounted for. Regional studies have used a number of different methods, each with their own advantages and disadvantages. These methods include: integration of squared shear wave moment-rate spectra, direct integration of broadband velocity-squared waveforms, empirical Green's function deconvolution, and spectral ratio techniques. The later two approaches have gained popularity because adjacent or co-located events recorded at common stations have shared path and site effects, which therefore cancel. In spite of this, a number of such studies find very large amplitude variance across a network of stations. In this paper we test the extent to which narrowband coda envelopes can improve upon the traditional spectral ratio using direct phases, allowing a better comparison with theoretical models to investigate similarity. The motivation for using the coda is its stability relative to direct waves and its unique property of spatially homogenizing its energy. The local and regional coda is virtually insensitive to lateral crustal heterogeneity and source radiation pattern, and the use of the coda might allow for more stable amplitude ratios to better constrain source differences between event pairs. We first compared amplitude ratio performance between local and near-regional S and coda waves in the San Francisco Bay region for

  3. Predicting Lg Coda Using Synthetic Seismograms and Media With Stochastic Heterogeneity

    NASA Astrophysics Data System (ADS)

    Tibuleac, I. M.; Stroujkova, A.; Bonner, J. L.; Mayeda, K.

    2005-12-01

    Recent examinations of the characteristics of coda-derived Sn and Lg spectra for yield estimation have shown that the spectral peak of Nevada Test Site (NTS) explosion spectra is depth-of-burial dependent, and that this peak is shifted to higher frequencies for Lop Nor explosions at the same depths. To confidently use coda-based yield formulas, we need to understand and predict coda spectral shape variations with depth, source media, velocity structure, topography, and geological heterogeneity. We present results of a coda modeling study to predict Lg coda. During the initial stages of this research, we have acquired and parameterized a deterministic 6 deg. x 6 deg. velocity and attenuation model centered on the Nevada Test Site. Near-source data are used to constrain density and attenuation profiles for the upper five km. The upper crust velocity profiles are quilted into a background velocity profile at depths greater than five km. The model is parameterized for use in a modified version of the Generalized Fourier Method in two dimensions (GFM2D). We modify this model to include stochastic heterogeneities of varying correlation lengths within the crust. Correlation length, Hurst number and fractional velocity perturbation of the heterogeneities are used to construct different realizations of the random media. We use nuclear explosion and earthquake cluster waveform analysis, as well as well log and geological information to constrain the stochastic parameters for a path between the NTS and the seismic stations near Mina, Nevada. Using multiple runs, we quantify the effects of variations in the stochastic parameters, of heterogeneity location in the crust and attenuation on coda amplitude and spectral characteristics. We calibrate these parameters by matching synthetic earthquake Lg coda envelopes to coda envelopes of local earthquakes with well-defined moments and mechanisms. We generate explosion synthetics for these calibrated deterministic and stochastic

  4. Calibration for Coda Derived Moment Magnitude Using Berkeley Complete Waveform Moment-Tensor Solutions

    NASA Astrophysics Data System (ADS)

    Tajima, F.; Mayeda, K. M.; Dreger, D. S.; Wurman, G.

    2002-12-01

    The method of seismic moment-tensor determination using complete waveforms (Dreger and Helmberger, 1993; Pasyanos et al., 1996) provides stable solutions for local and regional events if the data propagation paths are well-calibrated to calculate Green's functions. However, this waveform modeling approach has a limitation to apply to smaller events with the cut-off magnitude of approximately 3.5 due to reduction of S/N ratios in the passband employed. We carried out an experiment to extend the moment magnitude scale to smaller events (M<3.5) in northern California using an empirical method of coda derived moment magnitude (Mw(coda)) calibration (Mayeda et al., 2002). The basic assumption of this approach is that the coda spectra are the results of scatters from randomly distributed inhomogeneities in the crust and represent seismic energy propagation, independent of the source radiation pattern, as a function of propagation distance with a specific attenuation rule. In practice we found that when the data propagation paths cross a wide range of different structural areas, the standard deviation of the parameters is large and the parameter estimation is less coherent. Thus, in the course of calibration the entire northern California is divided into several tectonic subregions, in each of which the calibration parameters are relatively coherent. The present study suggests a conservative application of the coda envelope calibration method to estimate Mw(coda) that avoids ambiguities.

  5. On the practical convergence of coda-based correlations: a window optimization approach

    NASA Astrophysics Data System (ADS)

    Chaput, J.; Clerc, V.; Campillo, M.; Roux, P.; Knox, H.

    2016-02-01

    We present a novel optimization approach to improve the convergence of interstation coda correlation functions towards the medium's empirical Green's function. For two stations recording a series of impulsive events in a multiply scattering medium, we explore the impact of coda window selection through a Markov Chain Monte Carlo scheme, with the aim of generating a gather of correlation functions that is the most coherent and symmetric over events, thus recovering intuitive elements of the interstation Green's function without any nonlinear post-processing techniques. This approach is tested here for a 2-D acoustic finite difference model, where a much improved correlation function is obtained, as well as for a database of small impulsive icequakes recorded on Erebus Volcano, Antarctica, where similar robust results are shown. The average coda solutions, as deduced from the posterior probability distributions of the optimization, are further representative of the scattering strength of the medium, with stronger scattering resulting in a slightly delayed overall coda sampling. The recovery of singly scattered arrivals in the coda of correlation functions are also shown to be possible through this approach, and surface wave reflections from outer craters on Erebus volcano were mapped in this fashion. We also note that, due to the improvement of correlation functions over subsequent events, this approach can further be used to improve the resolution of passive temporal monitoring.

  6. Nonlinear coda wave analysis of hysteretic elastic behavior in strongly scattering media

    NASA Astrophysics Data System (ADS)

    Ouarabi, M. Ait; Boubenider, F.; Gliozzi, A. S.; Scalerandi, M.

    2016-10-01

    Strongly scattering elastic media, such as consolidated granular materials, respond to ultrasonic pulse excitations with a long response signal with peculiar properties. The portion of the signal at late times, termed coda, is due to multiple scattering. It contains information about the elastic properties of the material, and it has been proven to be very sensitive to small variations in the modulus. Here we propose a technique based on a nonlinear analysis of the coda of a signal, which might be applied to quantify the nonlinear elastic response in consolidated granular media exhibiting a hysteretic elastic behavior. The method proposed allows for an intrinsic definition of the reference signal which is normally needed for applying coda-based methods.

  7. Characteristics of PKP-Cdiff coda observed with small-aperture seismic arrays

    NASA Astrophysics Data System (ADS)

    Tanaka, S.

    2004-12-01

    PKP-Cdiff is a compressional wave diffracted around the inner core boundary (ICB), which may contain much information on the structure of the ICB. Here I have determined slowness of PKP-Cdiff and its coda with small-aperture arrays as large as several kilometers in size to approach the unsettled issues on the origin of the PKP-Cdiff coda (Morita, 1987; Umetsu, 1989; Nakanishi, 1990). The short-period seismic array data is collected from the Prototype International Data Center (pIDC) of the International Monitoring System (IMS) as Koper et al. (2004) did. The criteria of data selection (focal depths greater than 100 km, mb greater than 5.5, epicentral distances from 153 to 160 degrees, the period since Jan. 1995 through Feb. 2000) yielded twenty-nine event-array pairs, the band-pass filters comprising sixteen frequency bands from 0.25 to 4 Hz with 0.5 Hz bandwidths were operated to the array seismograms. Then the beam-forming as functions of slowness and incident azimuth were applied to each band-pass filtered array record. The difference of array response functions were adjusted by using the phase weighted stack with variation of the power index of the phase stack. The stacked powers for the PKP-Cdiff coda were investigated on the vespagram for all the frequency bands and the slownesses were distributed around two peaks of 1-3 s/deg and 4-5 s/deg, corresponding to the slowness of PKP-Cdiff and PKP-AB, respectively. The incident azimuths concentrated around the great-circle directions connecting the events and arrays. The specific stacked powers with slowness of 1-3 s/deg observed at distance 153-155 degrees tended to occur just after the PKP-Cdiff first arrivals whereas those at 156-160 degrees scattered uniformly in the time window between PKP-Cdiff and PKP-AB and are a few around the PKP-Cdiff first arrivals. Such characteristics of the slowness filtered PKP-Cdiff coda imply that the PKP-Cdiff coda is affected with the ICB structure. Because the small first

  8. Internal stress determination in a polymer composite by Coda wave interferometry

    NASA Astrophysics Data System (ADS)

    Zhu, Q.; Binetruy, C.; Burtin, C.

    2016-07-01

    Coda wave interferometry (CWI) is largely employed in geotechnical applications to monitor changes due to cracks in materials but it is still not used for composite materials. In this paper, the technique is proposed to study internal stresses in a composite laminate [0°/90°]63 and was compared with the traditional acoustic technique. It is shown that the Coda wave interferometry has better precision and sensibility than the method based on the first arriving time of flight (TOF) measurement, especially when the fiber orientation is normal to the wave propagation. This method is found to be promising for residual stress evaluation in composite materials.

  9. Twenty-Four-Month-Olds' Perception of Word-Medial Onsets and Codas

    ERIC Educational Resources Information Center

    Wang, Yuanyuan; Seidl, Amanda

    2016-01-01

    Recent work has shown that children have detailed phonological representations of consonants at both word-initial and word-final edges. Nonetheless, it remains unclear whether onsets and codas are equally represented by young learners since word edges are isomorphic with syllable edges in this work. The current study sought to explore toddler's…

  10. Segmental and Positional Effects on Children's Coda Production: Comparing Evidence from Perceptual Judgments and Acoustic Analysis

    ERIC Educational Resources Information Center

    Theodore, Rachel M.; Demuth, Katherine; Shattuck-Hufnagel, Stephanie

    2012-01-01

    Children's early productions are highly variable. Findings from children's early productions of grammatical morphemes indicate that some of the variability is systematically related to segmental and phonological factors. Here, we extend these findings by assessing 2-year-olds' production of non-morphemic codas using both listener decisions and…

  11. Syllable Splitting in Literate and Preliterate Hebrew Speakers: Onsets and Rimes or Bodies and Codas?

    ERIC Educational Resources Information Center

    Share, David L.; Blum, Peri

    2005-01-01

    This study examined consonant-vowel-consonant (CVC) syllable splitting among literate (Grade 2) and preliterate (kindergarten) Hebrew speakers. Consideration of both the architecture of Hebrew orthography and phonology led to the prediction that a body-coda rather than an onset-rime subdivision would predominate. Structured and unstructured tasks…

  12. Application of the Telegraph Model to Coda Q Variations in Southern California

    NASA Astrophysics Data System (ADS)

    Davis, P. M.; Clayton, R. W.

    2006-12-01

    We examine data used to construct coda magnitude in southern California to estimate the spatial variation of coda Q and its dependence on frequency. Our analysis combined with independent borehole data (Abercrombie, 1995) suggests coda is mainly generated by multiple scattering in the upper few km of the crust where large impedance contrasts occur due to surface layering or fracturing. The ubiquitous observation that coda Q increases with frequency is explained as arising from multiple reverberations in the upper crust. We suggest that the telegraph model that has been successfully used to describe reflection seismogram multiples in the exploration industry may also apply to earthquakes. Under this model the apparent increase of Q with frequency is due to trapping of high frequency energy in the upper crust. This behavior is expected if the associated reflector series has an exponential autocorrelation function, a feature of the telegraph model. At lower frequencies trapping is less efficient. The combined effects give rise to an apparent absorption band that we suppose is superimposed on frequency-independent intrinsic attenuation. Maximum apparent attenuation occurs at wavelengths equal to the dimensions of the regions of upper crust that contain the scattering layers. At lower frequencies trapping is less effective and attenuation decreases as the longer wavelength waves sample the deeper crust and upper mantle where, due to over-burden pressures, acoustic impedance contrasts are less extreme.

  13. The Prosodic Licensing of Coda Consonants in Early Speech: Interactions with Vowel Length

    ERIC Educational Resources Information Center

    Miles, Kelly; Yuen, Ivan; Cox, Felicity; Demuth, Katherine

    2016-01-01

    English has a word-minimality requirement that all open-class lexical items must contain at least two moras of structure, forming a bimoraic foot (Hayes, 1995).Thus, a word with either a long vowel, or a short vowel and a coda consonant, satisfies this requirement. This raises the question of when and how young children might learn this…

  14. Mapping stripe rust resistance genes in a Brundage x Coda winter wheat recombinant inbred line population

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A recombinant inbred line (RIL) mapping population developed from a cross between winter wheat (Triticum aestivum L.) cultivars Coda and Brundage was evaluated for reaction to stripe rust (caused by Puccinia striiformis f. sp. tritici). Two hundred and sixty eight RIL from the population were evalua...

  15. The Coda of the Transient Response in a Sensitive Cochlea: A Computational Modeling Study.

    PubMed

    Li, Yizeng; Grosh, Karl

    2016-07-01

    In a sensitive cochlea, the basilar membrane response to transient excitation of any kind-normal acoustic or artificial intracochlear excitation-consists of not only a primary impulse but also a coda of delayed secondary responses with varying amplitudes but similar spectral content around the characteristic frequency of the measurement location. The coda, sometimes referred to as echoes or ringing, has been described as a form of local, short term memory which may influence the ability of the auditory system to detect gaps in an acoustic stimulus such as speech. Depending on the individual cochlea, the temporal gap between the primary impulse and the following coda ranges from once to thrice the group delay of the primary impulse (the group delay of the primary impulse is on the order of a few hundred microseconds). The coda is physiologically vulnerable, disappearing when the cochlea is compromised even slightly. The multicomponent sensitive response is not yet completely understood. We use a physiologically-based, mathematical model to investigate (i) the generation of the primary impulse response and the dependence of the group delay on the various stimulation methods, (ii) the effect of spatial perturbations in the properties of mechanically sensitive ion channels on the generation and separation of delayed secondary responses. The model suggests that the presence of the secondary responses depends on the wavenumber content of a perturbation and the activity level of the cochlea. In addition, the model shows that the varying temporal gaps between adjacent coda seen in experiments depend on the individual profiles of perturbations. Implications for non-invasive cochlear diagnosis are also discussed. PMID:27380177

  16. Effect of anelastic and scattering structures of the lithosphere on the shape of local earthquake coda

    USGS Publications Warehouse

    Chouet, B.

    1990-01-01

    A simple model of single acoustic scattering is used to study the dependence of the shape of local earthquake coda on the anelastic and scattering structures of the lithosphere. The model is applied to the coda of earthquakes located near Stone Canyon, central California, and provides an explanation for the features observed in the data, which include an interesting temporal variation in the coda shape. A surficial layer with a Q of 50 and thickness of 10 or 25 km underlain by a zone with a Q of 1000 extending to the bottom of the lithosphere, together with a scattering scale length, a, that varies with depth z according to the relation a=0.3 exp[-(z/45)2] are found to constitute the simplest structure of the medium compatible with the coda data and with body and surface wave attenuation data. The profile of heterogeneity sizes implies that the scattering strength increases strongly with depth, a constraint required by the necessity to boost the energy of the later coda without forcing the intrinsic Q to be excessively high in the uppermost mantle. This constraint is viewed as an artifact of the single scattering model which overstimates the scattering coefficient due to the neglect of multiple scattering. The observed temporal variation of the signal is difficult to explain by a simple change of the intrinsic Q at some depth. Rather, it is suggested that the scattering properties at depth changed with time through a variation of the fractional rms velocity fluctuation on the order of one percent. ?? 1990 Birkha??user Verlag.

  17. The Coda of the Transient Response in a Sensitive Cochlea: A Computational Modeling Study

    PubMed Central

    Li, Yizeng; Grosh, Karl

    2016-01-01

    In a sensitive cochlea, the basilar membrane response to transient excitation of any kind–normal acoustic or artificial intracochlear excitation–consists of not only a primary impulse but also a coda of delayed secondary responses with varying amplitudes but similar spectral content around the characteristic frequency of the measurement location. The coda, sometimes referred to as echoes or ringing, has been described as a form of local, short term memory which may influence the ability of the auditory system to detect gaps in an acoustic stimulus such as speech. Depending on the individual cochlea, the temporal gap between the primary impulse and the following coda ranges from once to thrice the group delay of the primary impulse (the group delay of the primary impulse is on the order of a few hundred microseconds). The coda is physiologically vulnerable, disappearing when the cochlea is compromised even slightly. The multicomponent sensitive response is not yet completely understood. We use a physiologically-based, mathematical model to investigate (i) the generation of the primary impulse response and the dependence of the group delay on the various stimulation methods, (ii) the effect of spatial perturbations in the properties of mechanically sensitive ion channels on the generation and separation of delayed secondary responses. The model suggests that the presence of the secondary responses depends on the wavenumber content of a perturbation and the activity level of the cochlea. In addition, the model shows that the varying temporal gaps between adjacent coda seen in experiments depend on the individual profiles of perturbations. Implications for non-invasive cochlear diagnosis are also discussed. PMID:27380177

  18. Markov Chain Monte Carlo Sampling Methods for 1D Seismic and EM Data Inversion

    2008-09-22

    This software provides several Markov chain Monte Carlo sampling methods for the Bayesian model developed for inverting 1D marine seismic and controlled source electromagnetic (CSEM) data. The current software can be used for individual inversion of seismic AVO and CSEM data and for joint inversion of both seismic and EM data sets. The structure of the software is very general and flexible, and it allows users to incorporate their own forward simulation codes and rockmore » physics model codes easily into this software. Although the softwae was developed using C and C++ computer languages, the user-supplied codes can be written in C, C++, or various versions of Fortran languages. The software provides clear interfaces for users to plug in their own codes. The output of this software is in the format that the R free software CODA can directly read to build MCMC objects.« less

  19. Comparison of techniques that use the single scattering model to compute the quality factor Q from coda waves

    USGS Publications Warehouse

    Novelo-Casanova, D. A.; Lee, W.H.K.

    1991-01-01

    Using simulated coda waves, the resolution of the single-scattering model to extract coda Q (Qc) and its power law frequency dependence was tested. The back-scattering model of Aki and Chouet (1975) and the single isotropic-scattering model of Sato (1977) were examined. The results indicate that: (1) The input Qc models are reasonably well approximated by the two methods; (2) almost equal Qc values are recovered when the techniques sample the same coda windows; (3) low Qc models are well estimated in the frequency domain from the early and late part of the coda; and (4) models with high Qc values are more accurately extracted from late code measurements. ?? 1991 Birkha??user Verlag.

  20. CODAS syndrome is associated with mutations of LONP1, encoding mitochondrial AAA+ Lon protease.

    PubMed

    Strauss, Kevin A; Jinks, Robert N; Puffenberger, Erik G; Venkatesh, Sundararajan; Singh, Kamalendra; Cheng, Iteen; Mikita, Natalie; Thilagavathi, Jayapalraja; Lee, Jae; Sarafianos, Stefan; Benkert, Abigail; Koehler, Alanna; Zhu, Anni; Trovillion, Victoria; McGlincy, Madeleine; Morlet, Thierry; Deardorff, Matthew; Innes, A Micheil; Prasad, Chitra; Chudley, Albert E; Lee, Irene Nga Wing; Suzuki, Carolyn K

    2015-01-01

    CODAS syndrome is a multi-system developmental disorder characterized by cerebral, ocular, dental, auricular, and skeletal anomalies. Using whole-exome and Sanger sequencing, we identified four LONP1 mutations inherited as homozygous or compound-heterozygous combinations among ten individuals with CODAS syndrome. The individuals come from three different ancestral backgrounds (Amish-Swiss from United States, n = 8; Mennonite-German from Canada, n = 1; mixed European from Canada, n = 1). LONP1 encodes Lon protease, a homohexameric enzyme that mediates protein quality control, respiratory-complex assembly, gene expression, and stress responses in mitochondria. All four pathogenic amino acid substitutions cluster within the AAA(+) domain at residues near the ATP-binding pocket. In biochemical assays, pathogenic Lon proteins show substrate-specific defects in ATP-dependent proteolysis. When expressed recombinantly in cells, all altered Lon proteins localize to mitochondria. The Old Order Amish Lon variant (LONP1 c.2161C>G[p.Arg721Gly]) homo-oligomerizes poorly in vitro. Lymphoblastoid cell lines generated from affected children have (1) swollen mitochondria with electron-dense inclusions and abnormal inner-membrane morphology; (2) aggregated MT-CO2, the mtDNA-encoded subunit II of cytochrome c oxidase; and (3) reduced spare respiratory capacity, leading to impaired mitochondrial proteostasis and function. CODAS syndrome is a distinct, autosomal-recessive, developmental disorder associated with dysfunction of the mitochondrial Lon protease.

  1. Detonation charge size versus coda magnitude relations in California and Nevada

    USGS Publications Warehouse

    Brocher, T.M.

    2003-01-01

    Magnitude-charge size relations have important uses in forensic seismology and are used in Comprehensive Nuclear-Test-Ban Treaty monitoring. I derive empirical magnitude versus detonation-charge-size relationships for 322 detonations located by permanent seismic networks in California and Nevada. These detonations, used in 41 different seismic refraction or network calibration experiments, ranged in yield (charge size) between 25 and 106 kg; coda magnitudes reported for them ranged from 0.5 to 3.9. Almost all represent simultaneous (single-fired) detonations of one or more boreholes. Repeated detonations at the same shotpoint suggest that the reported coda magnitudes are repeatable, on average, to within 0.1 magnitude unit. An empirical linear regression for these 322 detonations yields M = 0.31 + 0.50 log10(weight [kg]). The detonations compiled here demonstrate that the Khalturin et al. (1998) relationship, developed mainly for data from large chemical explosions but which fits data from nuclear blasts, can be used to estimate the minimum charge size for coda magnitudes between 0.5 and 3.9. Drilling, loading, and shooting logs indicate that the explosive specification, loading method, and effectiveness of tamp are the primary factors determining the efficiency of a detonation. These records indicate that locating a detonation within the water table is neither a necessary nor sufficient condition for an efficient shot.

  2. Onsets and codas in 1.5-year-olds’ word recognition

    PubMed Central

    Swingley, Daniel

    2009-01-01

    Previous tests of toddlers’ phonological knowledge of familiar words using word recognition tasks have examined syllable onsets but not word-final consonants (codas). However, there are good reasons to suppose that children’s knowledge of coda consonants might be less complete than their knowledge of onset consonants. To test this hypothesis, the present study examined 14- to 21-month-old children’s knowledge of the phonological forms of familiar words by measuring their comprehension of correctly-pronounced and mispronounced instances of those words using a visual fixation task. Mispronunciations substituted onset or coda consonants. Adults were tested in the same task for comparison with children. Children and adults fixated named targets more upon hearing correct pronunciations than upon hearing mispronunciations, whether those mispronunciations involved the word’s initial or final consonant. In addition, detailed analysis of the timing of adults’ and children’s eye movements provided clear evidence for incremental interpretation of the speech signal. Children’s responses were slower and less accurate overall, but children and adults showed nearly identical temporal effects of the placement of phonological substitutions. The results demonstrate accurate encoding of consonants even in words children cannot yet say. PMID:20126290

  3. CODAS Syndrome Is Associated with Mutations of LONP1, Encoding Mitochondrial AAA+ Lon Protease

    PubMed Central

    Strauss, Kevin A.; Jinks, Robert N.; Puffenberger, Erik G.; Venkatesh, Sundararajan; Singh, Kamalendra; Cheng, Iteen; Mikita, Natalie; Thilagavathi, Jayapalraja; Lee, Jae; Sarafianos, Stefan; Benkert, Abigail; Koehler, Alanna; Zhu, Anni; Trovillion, Victoria; McGlincy, Madeleine; Morlet, Thierry; Deardorff, Matthew; Innes, A. Micheil; Prasad, Chitra; Chudley, Albert E.; Lee, Irene Nga Wing; Suzuki, Carolyn K.

    2015-01-01

    CODAS syndrome is a multi-system developmental disorder characterized by cerebral, ocular, dental, auricular, and skeletal anomalies. Using whole-exome and Sanger sequencing, we identified four LONP1 mutations inherited as homozygous or compound-heterozygous combinations among ten individuals with CODAS syndrome. The individuals come from three different ancestral backgrounds (Amish-Swiss from United States, n = 8; Mennonite-German from Canada, n = 1; mixed European from Canada, n = 1). LONP1 encodes Lon protease, a homohexameric enzyme that mediates protein quality control, respiratory-complex assembly, gene expression, and stress responses in mitochondria. All four pathogenic amino acid substitutions cluster within the AAA+ domain at residues near the ATP-binding pocket. In biochemical assays, pathogenic Lon proteins show substrate-specific defects in ATP-dependent proteolysis. When expressed recombinantly in cells, all altered Lon proteins localize to mitochondria. The Old Order Amish Lon variant (LONP1 c.2161C>G[p.Arg721Gly]) homo-oligomerizes poorly in vitro. Lymphoblastoid cell lines generated from affected children have (1) swollen mitochondria with electron-dense inclusions and abnormal inner-membrane morphology; (2) aggregated MT-CO2, the mtDNA-encoded subunit II of cytochrome c oxidase; and (3) reduced spare respiratory capacity, leading to impaired mitochondrial proteostasis and function. CODAS syndrome is a distinct, autosomal-recessive, developmental disorder associated with dysfunction of the mitochondrial Lon protease. PMID:25574826

  4. Variation of Seismic Coda Wave Attenuation in the Garhwal Region, Northwestern Himalaya

    NASA Astrophysics Data System (ADS)

    Tripathi, Jayant N.; Singh, Priyamvada; Sharma, Mukat L.

    2012-01-01

    Seismic coda wave attenuation ( Q_{text{c}}^{ - 1} ) characteristics in the Garhwal region, northwestern Himalaya is studied using 113 short-period, vertical component seismic observations from local events with hypocentral distance less than 250 km and magnitude range between 1.0 to 4.0. They are located mainly in the vicinity of the Main Boundary Thrust (MBT) and the Main Central Thrust (MCT), which are well-defined tectonic discontinuities in the Himalayas. Coda wave attenuation ( Q_{text{c}}^{ - 1} ) is estimated using the single isotropic scattering method at central frequencies 1.5, 3, 5, 7, 9, 12, 16, 20, 24 and 28 Hz using several starting lapse times and coda window lengths for the analysis. Results show that the ( Q_{text{c}}^{ - 1} ) values are frequency dependent in the considered frequency range, and they fit the frequency power law ( Q_{text{c}}^{ - 1} left( f right) = Q0^{ - 1} f^{ - n} ). The Q 0 ( Q c at 1 Hz) estimates vary from about 50 for a 10 s lapse time and 10 s window length, to about 350 for a 60 s lapse time and 60 s window length combination. The exponent of the frequency dependence law, n ranges from 1.2 to 0.7; however, it is greater than 0.8, in general, which correlates well with the values obtained in other seismically and tectonically active and highly heterogeneous regions. The attenuation in the Garhwal region is found to be lower than the Q {c/-1} values obtained for other seismically active regions of the world; however, it is comparable to other regions of India. The spatial variation of coda attenuation indicates that the level of heterogeneity decreases with increasing depth. The variation of coda attenuation has been estimated for different lapse time and window length combinations to observe the effect with depth and it indicates that the upper lithosphere is more active seismically as compared to the lower lithosphere and the heterogeneity decreases with increasing depth.

  5. Frequency dependent attenuation characteristics of coda waves in the Northwestern Himalayan (India) region

    NASA Astrophysics Data System (ADS)

    Kumar, Sushil; Singh, Priyamvada; Singh, Pitam; Biswal, Shubhasmita; Parija, Mahesh Prasad

    2016-03-01

    Digital seismogram data of 82 earthquakes from the Northwestern Himalayan (India) region recorded at different stations during 2004-2006 were analyzed to study the seismic coda wave attenuation characteristics in this region. We used 132 seismic observations from local earthquakes with a hypocentral distance <240 km and a magnitude range of 1.2-4.9 to study the coda QC using the single isotropic scattering model. These earthquakes were recorded at 20 temporary seismic stations installed in the Northwestern Himalayas (India) by the Wadia institute of Himalayan Geology, Dehradun. The QC values were estimated at 10 central frequencies: 1.5, 3, 5, 7, 9, 12, 16, 20, 24, and 28 Hz using starting lapse-times of 10, 20, 30, 40, 50, and 60 s and coda window-lengths of 10, 20, 30, 40, and 50 s. The QC fits the frequency dependent power-law, QC =Q0fn . For a 10 s lapse time with a 10-s coda window length QC = 47.42f1.012 and for a 50 s lapse time with a 50 s coda window length, QC = 204.1f0.934 . Q0 (QC at 1 Hz) varied from ∼47 for a 10 s lapse time and a 10 s window length, to ∼204 for a 50 s lapse time and a 50 s window length. An average frequency dependent power law fit for the study region may be given as QC = 116.716f0.9943 . The exponent of the frequency dependence law n ranged from 1.08 to 0.9, which correlates well with values obtained in other seismically and tectonically active and heterogeneous regions of the world. In our study region, QC increases both with respect to lapse time and frequency, i.e., the attenuation decreases as the quality factor is inversely proportional to attenuation. The low QC values or high attenuation at lower frequencies and high QC values or low attenuation at higher frequencies suggest that the heterogeneity decreases with increasing depth in our study region.

  6. On PKiKP Recorded at Short Distance on the Warramunga Array and the High Frequency PKiKP Coda

    NASA Astrophysics Data System (ADS)

    Poupinet, G.; Kennett, B. L.

    2003-12-01

    PKiKP is the P-wave reflected on the inner core boundary (ICB). PKiKP is frequently observed on the Warramunga seismic array in Australia for events of magnitude larger than 6 in the distance range 15-45 degrees. In the frame of the Comprehensive Test Ban Treaty, the Warramunga array has been upgraded with a high dynamic range (24 bits) recording system and broadband sensors. This improvement permits to detect PKiKP on single traces, without stacking. PKiKP is a sharp arrival in the frequency band 2 Hz to 5 Hz. Its waveform is sometimes showing some complexity: it can be preceded by a small onset or can exhibit double or triple pulses, not observed on PcP. In this frequency band, the amplitude of PKiKP is larger than the event's coda. The coda of PKiKP is quickly decreasing within the first 20 seconds. We do not observe the slow (60 s.) building up of amplitude in the PKiKP coda observed by Vidale et Earle (2000) on LASA data which lead them to infer strong kilometer-scale heterogeneites beneath the ICB. We filter the signal in 5 different bandpasses. In each bandpass, we compute the average of the maxima of the 24 traces in successive 2 seconds moving windows. This simple processing exhibits the decay of the coda as a function of time and frequency along the entire seismogram. For reflected phases like PcP or ScP, usually the coda decreases rapidly after the phase arrival time and returns to its level before the arrival of the phase. For the S phase, the amplitude of the coda remains higher after the S arrival time than before: a coda offset is generated at the time of S. The same occurs for PKiKP. PKiKP is followed by a coda with an amplitude about half that of PKiKP, predominantly in the frequency range 3 Hz -6 Hz. This high frequency PKiKP coda seems to ring for a very long duration. Unfortunately, for the events of magnitude 6-7 available, the sensitivity level of the recording system is reached near 1200-1300 s and the coda amplitude becomes smaller than the

  7. Temporal change in coda wave attenuation observed during an eruption of Mount St. Helens

    SciTech Connect

    Fehler, M.; Roberts, P.; Fairbanks, T.

    1988-05-10

    During the past few years there have been numerous reports of changes in coda wave attenuation occurring before major earthquakes. These observations are important because they may provide insight into stress-related structural changes taking place in the focal region prior to the occurrence of large earthquakes. The results of these studies led us to suspect that temporal changes in coda wave attenuation might also accompany volcanic eruptions. By measuring power decay envelopes for earthquakes at Mount St. Helens recorded before, during, and after an eruption that took place during September 3--6, 1981, we found that coda Q/sup -1/ for frequencies between 6 and 30 Hz was 20--30% higher before the eruption than after. The change is attributed to an increase in the density of open microcracks in the rock associated with inflation of the volcano prior to the eruption. Q/sup -1/ was found to be only weakly dependent on frequency and displayed a slight peak near 10 Hz. The weak frequency dependence is attributed to the dominance of intrinsic attenuation over scattering attenuation, since it is generally accepted that intrinsic attenuation is constant with frequency, whereas scattering attenuation decreases strongly at higher frequencies. The weak frequency dependence of Q/sup -1/ at Mount St. Helens contrasts with results reported for studies in nonvolcanic regions. The peak in Q/sup -1/ near 10 Hz at Mount St. Helens is attributed to the scale length of heterogeneity responsible for generating backscattered waves. Results for nonvolcanic regions have shown this peak to occur near 0.5 Hz. Thus a smaller scale length of heterogeneity is required to explain the 10-Hz peak at Mount St. Helens. copyright American Geophysical Union 1988

  8. Lateral and depth variations of coda Q in the Zagros region of Iran

    NASA Astrophysics Data System (ADS)

    Irandoust, Mohsen Ahmadzadeh; Sobouti, Farhad; Rahimi, Habib

    2016-01-01

    We have analyzed more than 2800 local earthquakes recorded by the Iranian National Seismic Network (INSN) and the Iranian Seismological Center (IRSC) to estimate coda wave quality factor, Q c , in the Zagros fold and thrust belt and the Sanandaj-Sirjan metamorphic zone in Iran. We used the single backscattering model to investigate lateral and depth variations of Q c in the study region. In the interior of Zagros, no strong lateral variation in attenuation parameters is observed. In SE Zagros (the Bandar-Abbas region) where transition to the Makran subduction setting begins, the medium shows lower attenuation. The average frequency relations for the SSZ, the Bandar-Abbas region, and the Zagros are Q c = (124 ± 11) f 0.82 ± 0.04, Q c = (109 ± 2) f 0.99 ± 0.01, and Q c = (85 ± 5) f 1.06 ± 0.03, respectively. To investigate the depth variation of Q c , 18 time windows between 5 and 90 s and at two epicentral distance ranges of R < 100 km and 100 < R < 200 km were considered. It was observed that with increasing coda lapse time, Q 0 ( Q c at 1 Hz) and n (frequency dependence factor) show increasing and decreasing trends, respectively. Beneath the SSZ and at depths of about 50 to 80 km, there is a correlation between the reported low velocity medium and the observed sharp change in the trend of Q 0 and n curves. In comparison with results obtained in other regions of the Iranian plateau, the Zagros along with the Alborz Mountains in the north show highest attenuation of coda wave and strongest frequency dependence, an observation that reflects the intense seismicity and active faulting in these mountain ranges. We also observe a stronger depth dependence of attenuation in the Zagros and SSZ compared to central Iran, indicating a thicker lithosphere in the Zagros region than in central Iran.

  9. Broadband bearing-time records of three-component seismic array data and their application to the study of local earthquake coda

    NASA Astrophysics Data System (ADS)

    Wagner, Gregory S.; Owens, Thomas J.

    1993-09-01

    High-frequency three-component array d, are used to study the P and S coda produced by* cal earthquakes. The data are displayed as broadba bearing-time records which allow us to examine a compl, time history of the propagation directions and arrival tin of direct and scattered phases crossing the array. This ~ sualization technique is used to examine the wavefield ~ two scale lengths using two sub-arrays~of sensors. Resu suggest that P coda is dominated by P energy propag, ing sub-parallel to the direct P arrival. The S coda pro agates in all directions and appears to be composed p~ dominantly of S and/or surface wave energy. Significant more 0e coda appears on the smaller scale length sub-art relative to the larger scale array suggesting that much, the ~, coda remains coherent for only very short distanc

  10. Coda-wave interferometry analysis of time-lapse VSP data for monitoring geological carbon sequestration

    SciTech Connect

    Zhou, R.; Huang, L.; Rutledge, J.T.; Fehler, M.; Daley, T.M.; Majer, E.L.

    2009-11-01

    Injection and movement/saturation of carbon dioxide (CO2) in a geological formation will cause changes in seismic velocities. We investigate the capability of coda-wave interferometry technique for estimating CO2-induced seismic velocity changes using time-lapse synthetic vertical seismic profiling (VSP) data and the field VSP datasets acquired for monitoring injected CO2 in a brine aquifer in Texas, USA. Synthetic VSP data are calculated using a finite-difference elastic-wave equation scheme and a layered model based on the elastic Marmousi model. A possible leakage scenario is simulated by introducing seismic velocity changes in a layer above the CO2 injection layer. We find that the leakage can be detected by the detection of a difference in seismograms recorded after the injection compared to those recorded before the injection at an earlier time in the seismogram than would be expected if there was no leakage. The absolute values of estimated mean velocity changes, from both synthetic and field VSP data, increase significantly for receiver positions approaching the top of a CO2 reservoir. Our results from field data suggest that the velocity changes caused by CO2 injection could be more than 10% and are consistent with results from a crosswell tomogram study. This study demonstrates that time-lapse VSP with coda-wave interferometry analysis can reliably and effectively monitor geological carbon sequestration.

  11. Coda wave interferometry for the measurement of thermally induced ultrasonic velocity variations in CFRP laminates

    NASA Astrophysics Data System (ADS)

    Livings, Richard; Dayal, Vinay; Barnard, Dan

    2016-02-01

    Ultrasonic velocity measurement is a well-established method to measure properties and estimate strength as well as detect and locate damage. Determination of accurate and repeatable ultrasonic wave velocities can be difficult due to the influence of environmental and experimental factors. Diffuse fields created by a multiple scattering environment have been shown to be sensitive to homogeneous strain fields such as those caused by temperature variations, and Coda Wave Interferometry has been used to measure the thermally induced ultrasonic velocity variation in concrete, aluminum, and the Earth's crust. In this work, we analyzed the influence of several parameters of the experimental configuration on the measurement of thermally induced ultrasonic velocity variations in a carbon-fiber reinforced polymer plate. Coda Wave Interferometry was used to determine the relative velocity change between a baseline signal taken at room temperature and the signal taken at various temperatures. The influence of several parameters of the experimental configuration, such as the material type, the receiver aperture size, and fiber orientation on the results of the processing algorithm was evaluated in order to determine the optimal experimental configuration.---This work is supported by the NSF Industry/University Cooperative Research Program of the Center for Nondestructive Evaluation at Iowa State University.

  12. The role of coda consonants in triggering speech errors: An ultrasound study

    NASA Astrophysics Data System (ADS)

    Pouplier, Marianne

    2001-05-01

    Recent speech-error research using articulatory data has shown that errors can often result in a phonologically illegal structure. These findings have been interpreted to mean that speech production is a fundamentally coordinative process. In speech errors, gestures can fall into grammatically illegal, albeit dynamically stable coordination modes. Shared gestural structures, such as identical consonants in the vicinity of the gestures affected by error, set up the conditions under which dynamically stable coordination modes can come to dominate over grammatical coordination patterns (e.g., Pouplier, 2003). This approach finds support in the often-observed phenomenon that a shared final consonant between two words will increase the likelihood of the initial consonants interacting. The present study uses ultrasound data of speech errors to investigate in what domains other than the coda shared gestural structure can trigger errors. Stimuli without coda consonants are employed to investigate whether errors on the initial consonants can be triggered by a shared vowel only. It is further examined whether the shared structure triggering errors can reside within the initial consonants themselves, e.g., when the initial consonants are complex, multigestural constellations that overlap in some aspects of their gestural composition. [Work supported by NIH RO1-DC01758.

  13. Transgenic poplar expressing codA exhibits enhanced growth and abiotic stress tolerance.

    PubMed

    Ke, Qingbo; Wang, Zhi; Ji, Chang Yoon; Jeong, Jae Cheol; Lee, Haeng-Soon; Li, Hongbing; Xu, Bingcheng; Deng, Xiping; Kwak, Sang-Soo

    2016-03-01

    Glycine betaine (GB), a compatible solute, effectively stabilizes the structure and function of macromolecules and enhances abiotic stress tolerance in plants. We generated transgenic poplar plants (Populus alba × Populus glandulosa) expressing a bacterial choline oxidase (codA) gene under the control of the oxidative stress-inducible SWPA2 promoter (referred to as SC plants). Among the 13 SC plants generated, three lines (SC4, SC14 and SC21) were established based on codA transcript levels, tolerance to methyl viologen-mediated oxidative stress and Southern blot analysis. Growth was better in SC plants than in non-transgenic (NT) plants, which was related to elevated transcript levels of auxin-response genes. SC plants accumulated higher levels of GB under oxidative stress compared to the NT plants. In addition, SC plants exhibited increased tolerance to drought and salt stress, which was associated with increased efficiency of photosystem II activity. Finally, SC plants maintained lower levels of ion leakage and reactive oxygen species under cold stress compared to the NT plants. These observations suggest that SC plants might be useful for reforestation on global marginal lands, including desertification and reclaimed areas. PMID:26795732

  14. Estimation of the intrinsic absorption and scattering attenuation in Northeastern Venezuela (Southeastern Caribbean) using coda waves

    USGS Publications Warehouse

    Ugalde, A.; Pujades, L.G.; Canas, J.A.; Villasenor, A.

    1998-01-01

    Northeastern Venezuela has been studied in terms of coda wave attenuation using seismograms from local earthquakes recorded by a temporary short-period seismic network. The studied area has been separated into two subregions in order to investigate lateral variations in the attenuation parameters. Coda-Q-1 (Q(c)-1) has been obtained using the single-scattering theory. The contribution of the intrinsic absorption (Q(i)-1) and scattering (Q(s)-1) to total attenuation (Q(t)-1) has been estimated by means of a multiple lapse time window method, based on the hypothesis of multiple isotropic scattering with uniform distribution of scatterers. Results show significant spatial variations of attenuation: the estimates for intermediate depth events and for shallow events present major differences. This fact may be related to different tectonic characteristics that may be due to the presence of the Lesser Antilles subduction zone, because the intermediate depth seismic zone may be coincident with the southern continuation of the subducting slab under the arc.

  15. Attenuation Characteristics of the Armutlu Peninsula (NW Turkey) Using Coda Q

    NASA Astrophysics Data System (ADS)

    Yavuz, Evrim; Çaka, Deniz; Tunç, Berna; Woith, Heiko; Gottfried Lühr, Birger; Barış, Şerif

    2016-04-01

    Attenuation characteristic of seismic waves was determined using coda Q in the frame of MARsite (MARsite has received funding from the European Union's Seventh Programme for research, technological development and demonstration under grant agreement No 308417). Data from 82 earthquakes recorded in 2013-2014 in the Armutlu Peninsula and its vicinity by 9 ARNET seismic stations were used for processing. The earthquake magnitudes (Ml) and depths vary from 1.5 to 3.7 and 1.2-16.9 km, respectively. Epicentral distances closer than 90 km were selected to ensure better signal-to-noise ratios. Lapse times between 20 seconds and 40 seconds at intervals of 5 seconds were used for the calculation of the coda wave quality factor. The coda windows were filtered at central frequencies of 1.5, 3, 6, 9 and 12 Hz bandpass filter. To obtain reliable results, only data with signal-to-noise ratios greater than 5 and correlation coefficents higher than 0.7 were used. The SEISAN software and one of its subroutines (CODAQ) were used for data processing and analyses. In the whole study area, Qc=(51±4)f^(0.91±0.04) for 20 seconds, Qc=(77±7)f^(0.80±0.04) for 30 seconds and Qc=(112±13)f^(0.72±0.06) for 40 seconds lapse times are obtained for coda wave quality factor. The observed quality factor is dependent on frequency and lapse time. The results indicate that the upper lithosphere is more heterogeneous and seismically more active than the lower lithosphere as expected in the region which is tectonically complex refering to the effects of the North Anatolian Fault Zone. By considering earthquake clusters and recorded stations, the scattering area was drawn. The intersection of the scattered areas for 20 seconds lapse time is covering all stations. Quality factor in 1 Hz and frequency dependent values were calculated separately and for the intersection of all scattered areas. Calculated Qo and n values of the intersection area are 50 and 0.89, respectively. Hence, the Qo and n values

  16. Are Onsets and Codas Important in Processing Letter Position? A Comparison of TL Effects in English and Korean

    ERIC Educational Resources Information Center

    Lee, Chang H.; Taft, Marcus

    2009-01-01

    When two consonants within an English word were transposed to create a nonword, difficulty in lexical decision responses to that nonword was revealed, most strongly when the coda of the first syllable was exchanged with the onset of the second (e.g., "nakpin" derived from "napkin"), but also when onsets were exchanged between syllables (e.g.,…

  17. 77 FR 65886 - Century Metal Recycling PVT. LTD v. Dacon Logistics, LLC dba CODA Forwarding, Great American...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-31

    ... From the Federal Register Online via the Government Publishing Office FEDERAL MARITIME COMMISSION Century Metal Recycling PVT. LTD v. Dacon Logistics, LLC dba CODA Forwarding, Great American Alliance... Commission (Commission) by Century Metal Recycling Pvt. Ltd d/ b/a/CMR American, LLC (Century...

  18. Compensatory Vowel Lengthening for Omitted Coda Consonants: A Phonetic Investigation of Children's Early Representations of Prosodic Words

    ERIC Educational Resources Information Center

    Song, Jae Yung; Demuth, Katherine

    2008-01-01

    Children's early word productions often differ from the target form, sometimes exhibiting vowel lengthening when word-final coda consonants are omitted (e.g., "dog" /d[open o]g/ [arrow right] [d[open o]:]). It has typically been assumed that such lengthening compensates for a missing prosodic unit (a mora). However, this study raises the…

  19. Estimation of coda wave attenuation for NW Himalayan region using local earthquakes

    NASA Astrophysics Data System (ADS)

    Kumar, Naresh; Parvez, Imtiyaz A.; Virk, H. S.

    2005-08-01

    The attenuation of seismic wave energy in NW Himalayas has been estimated using local earthquakes. Most of the analyzed events are from the vicinity of the Main Boundary Thrust (MBT) and the Main Central Thrust (MCT), which are well-defined tectonic discontinuities in the Himalayas. The time-domain coda-decay method of a single back-scattering model is employed to calculate frequency dependent values of Coda Q (Qc). A total of 36 local earthquakes of magnitude range 2.1-4.8 have been used for Qc estimation at central frequencies 1.5, 3.0, 6.0, 9.0, 12.0 and 18.0 Hz through eight lapse time windows from 25 to 60 s starting at double the time of the primary S-wave from the origin time. The estimated average frequency dependence quality factor gives the relation, Qc = 158 f1.05, while the average Qc values vary from 210 at 1.5 Hz to 2861 at 18 Hz central frequencies. The observed coda quality factor is strongly dependent on frequency, which indicates that the region is seismic and tectonically active with high heterogeneities. The variation of the quality factor Qc has been estimated at different lapse times to observe its effect with depth. The estimated average frequency dependent relations of Qc vary from 85 f1.16 to 216 f0.91 at 25 to 60 s lapse window length respectively. For 25 s lapse time window, the average Qc value of the region varies from 131 ± 36 at 1.5 Hz to 2298 ± 397 at 18 Hz, while for 60 s lapse time window its variation is from 285 ± 95 at 1.5 Hz to 2868 ± 336 at 18 Hz of central frequency. The variation of Qc with frequency and lapse time shows that the upper crustal layers are seismically more active compared to the lower lithosphere. The decreasing value of the frequency parameter with increasing lapse time shows that the lithosphere acquires homogeneity with depth.

  20. Creep of sound paths in consolidated granular material detected through coda wave interferometry.

    PubMed

    Espíndola, David; Galaz, Belfor; Melo, Francisco

    2016-07-01

    The time evolution of the contact force structure of a consolidated granular material subjected to a constant stress is monitored using the coda wave interferometry method. In addition, the nature of the aging and rejuvenation processes are investigated. These processes are interpreted in terms of affine and nonaffine structural path deformations. During the later stages of creep, the rearrangements of subgrains are so small that they only produce affine deformations in the contact paths, without any significant changes in the structural configuration. As a result, the strain path distribution follows the macroscopic strain. Conversely, in the presence of ultrasonic perturbations, the nonaffine grain buckling mechanism dominates, producing relatively drastic changes in the structural configuration accompanied by path deformations of the order of the grain size. This plastic mechanism induces material rejuvenation that is observed macroscopically as an ultrasonically accelerated creep. PMID:27575200

  1. Creep of sound paths in consolidated granular material detected through coda wave interferometry

    NASA Astrophysics Data System (ADS)

    Espíndola, David; Galaz, Belfor; Melo, Francisco

    2016-07-01

    The time evolution of the contact force structure of a consolidated granular material subjected to a constant stress is monitored using the coda wave interferometry method. In addition, the nature of the aging and rejuvenation processes are investigated. These processes are interpreted in terms of affine and nonaffine structural path deformations. During the later stages of creep, the rearrangements of subgrains are so small that they only produce affine deformations in the contact paths, without any significant changes in the structural configuration. As a result, the strain path distribution follows the macroscopic strain. Conversely, in the presence of ultrasonic perturbations, the nonaffine grain buckling mechanism dominates, producing relatively drastic changes in the structural configuration accompanied by path deformations of the order of the grain size. This plastic mechanism induces material rejuvenation that is observed macroscopically as an ultrasonically accelerated creep.

  2. Monitoring stress changes in a concrete bridge with coda wave interferometry.

    PubMed

    Stähler, Simon Christian; Sens-Schönfelder, Christoph; Niederleithinger, Ernst

    2011-04-01

    Coda wave interferometry is a recent analysis method now widely used in seismology. It uses the increased sensitivity of multiply scattered elastic waves with long travel-times for monitoring weak changes in a medium. While its application for structural monitoring has been shown to work under laboratory conditions, the usability on a real structure with known material changes had yet to be proven. This article presents experiments on a concrete bridge during construction. The results show that small velocity perturbations induced by a changing stress state in the structure can be determined even under adverse conditions. Theoretical estimations based on the stress calculations by the structural engineers are in good agreement with the measured velocity variations. PMID:21476650

  3. Coda Q Attenuation and Source Parameters Analysis in North East India Using Local Earthquakes

    NASA Astrophysics Data System (ADS)

    Mohapatra, A. K.; Mohanty, W. K.; Earthquake Seismology

    2010-12-01

    Alok Kumar Mohapatra1* and William Kumar Mohanty1 *Corresponding author: alokgpiitkgp@gmail.com 1Department of Geology and Geophysics, Indian Institute of Technology, Kharagpur, West Bengal, India. Pin-721302 ABSTRACT In the present study, the quality factor of coda waves (Qc) and the source parameters has been estimated for the Northeastern India, using the digital data of ten local earthquakes from April 2001 to November 2002. Earthquakes with magnitude range from 3.8 to 4.9 have been taken into account. The time domain coda decay method of a single back scattering model is used to calculate frequency dependent values of Coda Q (Qc) where as, the source parameters like seismic moment(Mo), stress drop, source radius(r), radiant energy(Wo),and strain drop are estimated using displacement amplitude spectrum of body wave using Brune's model. The earthquakes with magnitude range 3.8 to 4.9 have been used for estimation Qc at six central frequencies 1.5 Hz, 3.0 Hz, 6.0 Hz, 9.0 Hz, 12.0 Hz, and 18.0 Hz. In the present work, the Qc value of local earthquakes are estimated to understand the attenuation characteristic, source parameters and tectonic activity of the region. Based on a criteria of homogeneity in the geological characteristics and the constrains imposed by the distribution of available events the study region has been classified into three zones such as the Tibetan Plateau Zone (TPZ), Bengal Alluvium and Arakan-Yuma Zone (BAZ), Shillong Plateau Zone (SPZ). It follows the power law Qc= Qo (f/fo)n where, Qo is the quality factor at the reference frequency (1Hz) fo and n is the frequency parameter which varies from region to region. The mean values of Qc reveals a dependence on frequency, varying from 292.9 at 1.5 Hz to 4880.1 at 18 Hz. Average frequency dependent relationship Qc values obtained of the Northeastern India is 198 f 1.035, while this relationship varies from the region to region such as, Tibetan Plateau Zone (TPZ): Qc= 226 f 1.11, Bengal Alluvium

  4. Creep of sound paths in consolidated granular material detected through coda wave interferometry.

    PubMed

    Espíndola, David; Galaz, Belfor; Melo, Francisco

    2016-07-01

    The time evolution of the contact force structure of a consolidated granular material subjected to a constant stress is monitored using the coda wave interferometry method. In addition, the nature of the aging and rejuvenation processes are investigated. These processes are interpreted in terms of affine and nonaffine structural path deformations. During the later stages of creep, the rearrangements of subgrains are so small that they only produce affine deformations in the contact paths, without any significant changes in the structural configuration. As a result, the strain path distribution follows the macroscopic strain. Conversely, in the presence of ultrasonic perturbations, the nonaffine grain buckling mechanism dominates, producing relatively drastic changes in the structural configuration accompanied by path deformations of the order of the grain size. This plastic mechanism induces material rejuvenation that is observed macroscopically as an ultrasonically accelerated creep.

  5. Study of concrete's behavior under 4-point bending load using Coda Wave Interferometry (CWI) analysis

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Abraham, O.; Chapeleau, X.; Cottineau, L.-M.; Tournat, V.; Le Duff, A.; Lascoup, B.; Durand, O.

    2013-01-01

    Coda Wave Interferometry (CWI) is an ultrasonic NDT method suitable for complex material such as concrete that can precisely measure small propagation velocity variation (10-2%). By measuring variation of propagation velocity in concrete caused by acoustoelasticity phenomena, CWI analysis can be used to monitor concrete's internal stress level. For the first time, CWI is used to measure propagation velocity variations due to a stress field in a concrete beam under four-points bending test, which contains simultaneously compressive and tensile stress. Embedded optical-fiber sensors, strain gauges are used in the experiment, in order to confirm and validate the CWI analysis result. Thermocouples are also embedded into concrete beams for monitoring internal temperature fluctuations.

  6. Monitoring stress changes in a concrete bridge with coda wave interferometry.

    PubMed

    Stähler, Simon Christian; Sens-Schönfelder, Christoph; Niederleithinger, Ernst

    2011-04-01

    Coda wave interferometry is a recent analysis method now widely used in seismology. It uses the increased sensitivity of multiply scattered elastic waves with long travel-times for monitoring weak changes in a medium. While its application for structural monitoring has been shown to work under laboratory conditions, the usability on a real structure with known material changes had yet to be proven. This article presents experiments on a concrete bridge during construction. The results show that small velocity perturbations induced by a changing stress state in the structure can be determined even under adverse conditions. Theoretical estimations based on the stress calculations by the structural engineers are in good agreement with the measured velocity variations.

  7. Regional estimation of Q from seismic coda observations by the Gauribidanur seismic array (southern India)

    NASA Astrophysics Data System (ADS)

    Tripathi, J. N.; Ugalde, A.

    2003-04-01

    1143 vertical-component, short period observations of microearthquake codas from shallow earthquakes recorded by the Gauribidanur seismic array were used to estimate seismic wave attenuation in southern India. The magnitudes of the earthquakes range from 0.7 to 3.7 and only the events occurred at hypocentral distances up to 200 km were considered for the analysis. Coda-wave attenuation (1/Qc) was estimated by means of a single-isotropic-scattering method whereas the separation of intrinsic absorption (1/Qi) and scattering attenuation (1/Qs) from total attenuation (1/Qt) was performed using a multiple lapse time window analysis based on the hypothesis of multiple isotropic scattering and uniform distribution of scatterers. Results show that the Q values are frequency dependent in the range 1 to 10 Hz and are approximated by a least-squares fit to the power law 1/Qc(f)=(1/Qo)(f/fo)**n. Results show some differences in 1/Qo and n for short and long hypocentral distances, ranging from 1/Qo=0.027 to 1/Qo=0.014 and n=-1.57 to n=-1.21. On the other hand, scattering attenuation is found to be greater than intrinsic absorption for all the frequency bands. A high value of the seismic albedo is found at short and long hypocentral distances, which indicates very strong scattering. Moreover, the observed energy at 0 to 15 seconds from the S wave arrival time bends significantly downward with decreasing distance. In order to clarify this phenomenon, there is a need to take into account the vertical varying velocity structure in the theoretical model.

  8. Regional estimation of Q from seismic coda observations by the Gauribidanur seismic array (southern India)

    NASA Astrophysics Data System (ADS)

    Tripathi, Jayant Nath; Ugalde, Arantza

    2004-07-01

    Attenuation properties of the lithosphere in southern India are estimated from 1219 vertical-component, short-period observations of microearthquake codas recorded by the Gauribidanur seismic array. The magnitudes of the earthquakes range from 0.3 to 3.7 and have focal depths less than 10 km. Coda-wave attenuation ( Qc-1) is estimated by means of a single isotropic scattering method and a multiple lapse time window analysis based on the hypothesis of multiple isotropic scattering and uniform distribution of scatterers is used to estimate the contribution of intrinsic absorption ( Qi-1) and scattering ( Qs-1) to total attenuation ( Qt-1). All the attenuation parameters are estimated, as a function of frequency for hypocentral distances up to 255 km. Results show a frequency dependent relation of the Qc-1 values in the range 1-10 Hz that fit the power law Q -1(f)=Q 0-1(f/f 0) ηA Q 0-1 value of 0.014 and a decrease of f-1.2 have been found using data from the whole region. On the other hand, scattering attenuation is found to be greater than intrinsic absorption for all the frequency bands. A high value of the seismic albedo (which ranges from 0.68 to 1) is found which indicates that scattering is the dominant effect in the study region. Nevertheless, the attenuation parameters estimated are much lower than the obtained for other regions in the world. On the other hand, the observed energy at 0-15 s from the S-wave arrival time bends significantly downward with decreasing distance. In order to clarify this phenomenon, there is a need to take into account the vertical varying velocity structure in the theoretical model.

  9. Introducing CoDa (Cosmic Dawn): Radiation-Hydrodynamics of Galaxy Formation in the Early Universe

    NASA Astrophysics Data System (ADS)

    Ocvirk, Pierre; Gillet, Nicolas; Shapiro, Paul; Aubert, Dominique; Iliev, Ilian; Romain, Teyssier; Yepes, Gustavo; Choi, Jun-hwan; Sullivan, David; Knebe, Alexander; Gottloeber, Stefan; D'Aloisio, Anson; Park, Hyunbae; Hoffman, Yehuda

    2015-08-01

    CoDa (Cosmic Dawn) is the largest fully coupled radiation hydrodynamics simulation of the reionization of the local Universe to date. It was performed using RAMSES-CUDATON running on 8192 nodes (i.e. 8192 GPUs) on the titan supercomputer at Oak Ridge National Laboratory to simulate a 64 h-1Mpc side box down to z=4.23. In this simulation, reionization proceeds self-consistently, driven by stellar radiation. We compare the simulation's reionization history, ionizing flux density, the cosmic star formation history and the CMB Thompson scattering optical depth with their observational values. Luminosity functions are also in rather good agreement with high redshift observations, although very bright objects (MAB1600 < -21) are overabundant in CoDa. We investigate the evolution of the intergalactic medium, and find that gas filaments present a sheathed structure, with a hot envelope surrounding a cooler core. They are however not able to self-shield, while regions denser than 10^-4.5 H atoms per comoving h^-3cm^3 are. Haloes below M ˜ 3.10^9 M⊙ are severely affected by the expanding, rising UV background: their ISM is quickly photo-heated to temperatures above our star formation threshold and therefore stop forming stars after local reionization has occured. Overall, the haloes between 10^(10-11) M⊙ dominate the star formation budget of the box for most of the Epoch of Reionization. Several additional studies will follow, looking for instance at environmental effects on galaxy properties, and the regimes of accretion.

  10. Regional Attenuation in Northern California: A Comparison of Five 1-D Q Methods

    SciTech Connect

    Ford, S R; Dreger, D S; Mayeda, K; Walter, W R; Malagnini, L; Phillips, W S

    2007-08-03

    The determination of regional attenuation Q{sup -1} can depend upon the analysis method employed. The discrepancies between methods are due to differing parameterizations (e.g., geometrical spreading rates), employed datasets (e.g., choice of path lengths and sources), and the methodologies themselves (e.g., measurement in the frequency or time domain). Here we apply five different attenuation methodologies to a Northern California dataset. The methods are: (1) coda normalization (CN), (2) two-station (TS), (3) reverse two-station (RTS), (4) source-pair/receiver-pair (SPRP), and (5) coda-source normalization (CS). The methods are used to measure Q of the regional phase, Lg (Q{sub Lg}), and its power-law dependence on frequency of the form Q{sub 0}f{sup {eta}} with controlled parameterization in the well-studied region of Northern California using a high-quality dataset from the Berkeley Digital Seismic Network. We investigate the difference in power-law Q calculated among the methods by focusing on the San Francisco Bay Area, where knowledge of attenuation is an important part of seismic hazard mitigation. This approximately homogeneous subset of our data lies in a small region along the Franciscan block. All methods return similar power-law parameters, though the range of the joint 95% confidence regions is large (Q{sub 0} = 85 {+-} 40; {eta} = 0.65 {+-} 0.35). The RTS and TS methods differ the most from the other methods and from each other. This may be due to the removal of the site term in the RTS method, which is shown to be significant in the San Francisco Bay Area. In order to completely understand the range of power-law Q in a region, it is advisable to use several methods to calculate the model. We also test the sensitivity of each method to changes in geometrical spreading, Lg frequency bandwidth, the distance range of data, and the Lg measurement window. For a given method, there are significant differences in the power-law parameters, Q{sub 0} and {eta

  11. DESIGN PACKAGE 1D SYSTEM SAFETY ANALYSIS

    SciTech Connect

    L.R. Eisler

    1995-02-02

    The purpose of this analysis is to systematically identify and evaluate hazards related to the Yucca Mountain Project Exploratory Studies Facility (ESF) Design Package 1D, Surface Facilities, (for a list of design items included in the package 1D system safety analysis see section 3). This process is an integral part of the systems engineering process; whereby safety is considered during planning, design, testing, and construction. A largely qualitative approach was used since a radiological System Safety analysis is not required. The risk assessment in this analysis characterizes the accident scenarios associated with the Design Package 1D structures/systems/components in terms of relative risk and includes recommendations for mitigating all identified risks. The priority for recommending and implementing mitigation control features is: (1) Incorporate measures to reduce risks and hazards into the structure/system/component (S/S/C) design, (2) add safety devices and capabilities to the designs that reduce risk, (3) provide devices that detect and warn personnel of hazardous conditions, and (4) develop procedures and conduct training to increase worker awareness of potential hazards, on methods to reduce exposure to hazards, and on the actions required to avoid accidents or correct hazardous conditions. The scope of this analysis is limited to the Design Package 1D structures/systems/components (S/S/Cs) during normal operations excluding hazards occurring during maintenance and ''off normal'' operations.

  12. Phonetic Encoding of Coda Voicing Contrast under Different Focus Conditions in L1 vs. L2 English

    PubMed Central

    Choi, Jiyoun; Kim, Sahayng; Cho, Taehong

    2016-01-01

    This study investigated how coda voicing contrast in English would be phonetically encoded in the temporal vs. spectral dimension of the preceding vowel (in vowel duration vs. F1/F2) by Korean L2 speakers of English, and how their L2 phonetic encoding pattern would be compared to that of native English speakers. Crucially, these questions were explored by taking into account the phonetics-prosody interface, testing effects of prominence by comparing target segments in three focus conditions (phonological focus, lexical focus, and no focus). Results showed that Korean speakers utilized the temporal dimension (vowel duration) to encode coda voicing contrast, but failed to use the spectral dimension (F1/F2), reflecting their native language experience—i.e., with a more sparsely populated vowel space in Korean, they are less sensitive to small changes in the spectral dimension, and hence fine-grained spectral cues in English are not readily accessible. Results also showed that along the temporal dimension, both the L1 and L2 speakers hyperarticulated coda voicing contrast under prominence (when phonologically or lexically focused), but hypoarticulated it in the non-prominent condition. This indicates that low-level phonetic realization and high-order information structure interact in a communicatively efficient way, regardless of the speakers’ native language background. The Korean speakers, however, used the temporal phonetic space differently from the way the native speakers did, especially showing less reduction in the no focus condition. This was also attributable to their native language experience—i.e., the Korean speakers’ use of temporal dimension is constrained in a way that is not detrimental to the preservation of coda voicing contrast, given that they failed to add additional cues along the spectral dimension. The results imply that the L2 phonetic system can be more fully illuminated through an investigation of the phonetics-prosody interface in

  13. Phonetic Encoding of Coda Voicing Contrast under Different Focus Conditions in L1 vs. L2 English.

    PubMed

    Choi, Jiyoun; Kim, Sahayng; Cho, Taehong

    2016-01-01

    This study investigated how coda voicing contrast in English would be phonetically encoded in the temporal vs. spectral dimension of the preceding vowel (in vowel duration vs. F1/F2) by Korean L2 speakers of English, and how their L2 phonetic encoding pattern would be compared to that of native English speakers. Crucially, these questions were explored by taking into account the phonetics-prosody interface, testing effects of prominence by comparing target segments in three focus conditions (phonological focus, lexical focus, and no focus). Results showed that Korean speakers utilized the temporal dimension (vowel duration) to encode coda voicing contrast, but failed to use the spectral dimension (F1/F2), reflecting their native language experience-i.e., with a more sparsely populated vowel space in Korean, they are less sensitive to small changes in the spectral dimension, and hence fine-grained spectral cues in English are not readily accessible. Results also showed that along the temporal dimension, both the L1 and L2 speakers hyperarticulated coda voicing contrast under prominence (when phonologically or lexically focused), but hypoarticulated it in the non-prominent condition. This indicates that low-level phonetic realization and high-order information structure interact in a communicatively efficient way, regardless of the speakers' native language background. The Korean speakers, however, used the temporal phonetic space differently from the way the native speakers did, especially showing less reduction in the no focus condition. This was also attributable to their native language experience-i.e., the Korean speakers' use of temporal dimension is constrained in a way that is not detrimental to the preservation of coda voicing contrast, given that they failed to add additional cues along the spectral dimension. The results imply that the L2 phonetic system can be more fully illuminated through an investigation of the phonetics-prosody interface in connection

  14. Phonetic Encoding of Coda Voicing Contrast under Different Focus Conditions in L1 vs. L2 English.

    PubMed

    Choi, Jiyoun; Kim, Sahayng; Cho, Taehong

    2016-01-01

    This study investigated how coda voicing contrast in English would be phonetically encoded in the temporal vs. spectral dimension of the preceding vowel (in vowel duration vs. F1/F2) by Korean L2 speakers of English, and how their L2 phonetic encoding pattern would be compared to that of native English speakers. Crucially, these questions were explored by taking into account the phonetics-prosody interface, testing effects of prominence by comparing target segments in three focus conditions (phonological focus, lexical focus, and no focus). Results showed that Korean speakers utilized the temporal dimension (vowel duration) to encode coda voicing contrast, but failed to use the spectral dimension (F1/F2), reflecting their native language experience-i.e., with a more sparsely populated vowel space in Korean, they are less sensitive to small changes in the spectral dimension, and hence fine-grained spectral cues in English are not readily accessible. Results also showed that along the temporal dimension, both the L1 and L2 speakers hyperarticulated coda voicing contrast under prominence (when phonologically or lexically focused), but hypoarticulated it in the non-prominent condition. This indicates that low-level phonetic realization and high-order information structure interact in a communicatively efficient way, regardless of the speakers' native language background. The Korean speakers, however, used the temporal phonetic space differently from the way the native speakers did, especially showing less reduction in the no focus condition. This was also attributable to their native language experience-i.e., the Korean speakers' use of temporal dimension is constrained in a way that is not detrimental to the preservation of coda voicing contrast, given that they failed to add additional cues along the spectral dimension. The results imply that the L2 phonetic system can be more fully illuminated through an investigation of the phonetics-prosody interface in connection

  15. Site amplification at five locations in San Francisco, California: A comparison of S waves, codas, and microtremors

    USGS Publications Warehouse

    Seekins, L.C.; Wennerberg, L.; Margheriti, L.; Liu, Huaibao P.

    1996-01-01

    We compare microtremor data to weak-motion 5-wave and coda recordings at sites in San Francisco in order to clarify the range of applicability of microtremor data to ground-motion prediction. We also compare 5-wave results to coda results. For each type of data, we compute spectral ratios of motions from two soil/rock station pairs and from an uphole/downhole pair in the Marina district. We compute horizontal/vertical ratios (Nakamura's method) at a soil site, a rock site, and the surface and borehole instruments. In the station-pair analyses, microtremor data show amplifications at the same fundamental frequency as S waves, but the frequencies of other peaks do not agree. The amplification at frequencies higher than 2 Hz is greater in the microtremor data. Station-pair ratios of coda data generally show spectral peaks occurring at the same frequencies, but with levels varying from one to four times the amplification from S-wave ratios. Nakamura's method of analyzing microtremors agrees better with S-wave station-pair results than the microtremor station-pair method over a limited frequency band that varies from station to station.

  16. 3-D Shear Wave Velocity Model of Mexico and South US: Bridging Seismic Networks with Ambient Noise Cross-Correlations (C1) and Correlation of Coda of Correlations (C3).

    NASA Astrophysics Data System (ADS)

    Spica, Zack; Perton, Mathieu; Calò, Marco; Legrand, Denis; Córdoba Montiel, Francisco; Iglesias, Arturo

    2016-07-01

    This work presents an innovative strategy to enhance the resolution of surface wave tomography obtained from ambient noise cross-correlation (C1) by bridging asynchronous seismic networks through the correlation of coda of correlations (C3). Rayleigh wave group dispersion curves show consistent results between synchronous and asynchronous stations. Rayleigh wave group travel times are inverted to construct velocity-period maps with unprecedented resolution for a region covering Mexico and the southern United States. The resulting period maps are then used to regionalize dispersion curves in order to obtain local 1-D shear velocity models (VS) of the crust and uppermost mantle in every cell of a grid of 0.4°. The 1-D structures are obtained by iteratively adding layers until reaching a given misfit, and a global tomography model is considered as an input for depths below 150 km. Finally, a high-resolution 3-D VS model is obtained from these inversions. The major structures observed in the 3-D model are in agreement with the tectonic-geodynamic features and with previous regional and local studies. It also offers new insights to understand the present and past tectonic evolution of the region.

  17. 3-D shear wave velocity model of Mexico and South US: bridging seismic networks with ambient noise cross-correlations (C1) and correlation of coda of correlations (C3)

    NASA Astrophysics Data System (ADS)

    Spica, Zack; Perton, Mathieu; Calò, Marco; Legrand, Denis; Córdoba-Montiel, Francisco; Iglesias, Arturo

    2016-09-01

    This work presents an innovative strategy to enhance the resolution of surface wave tomography obtained from ambient noise cross-correlation (C1) by bridging asynchronous seismic networks through the correlation of coda of correlations (C3). Rayleigh wave group dispersion curves show consistent results between synchronous and asynchronous stations. Rayleigh wave group traveltimes are inverted to construct velocity-period maps with unprecedented resolution for a region covering Mexico and the southern United States. The resulting period maps are then used to regionalize dispersion curves in order to obtain local 1-D shear velocity models (VS) of the crust and uppermost mantle in every cell of a grid of 0.4°. The 1-D structures are obtained by iteratively adding layers until reaching a given misfit, and a global tomography model is considered as an input for depths below 150 km. Finally, a high-resolution 3-D VS model is obtained from these inversions. The major structures observed in the 3-D model are in agreement with the tectonic-geodynamic features and with previous regional and local studies. It also offers new insights to understand the present and past tectonic evolution of the region.

  18. Centrosome Positioning in 1D Cell Migration

    NASA Astrophysics Data System (ADS)

    Adlerz, Katrina; Aranda-Espinoza, Helim

    During cell migration, the positioning of the centrosome and nucleus define a cell's polarity. For a cell migrating on a two-dimensional substrate the centrosome is positioned in front of the nucleus. Under one-dimensional confinement, however, the centrosome is positioned behind the nucleus in 60% of cells. It is known that the centrosome is positioned by CDC42 and dynein for cells moving on a 2D substrate in a wound-healing assay. It is currently unknown, however, if this is also true for cells moving under 1D confinement, where the centrosome position is often reversed. Therefore, centrosome positioning was studied in cells migrating under 1D confinement, which mimics cells migrating through 3D matrices. 3 to 5 μm fibronectin lines were stamped onto a glass substrate and cells with fluorescently labeled nuclei and centrosomes migrated on the lines. Our results show that when a cell changes directions the centrosome position is maintained. That is, when the centrosome is between the nucleus and the cell's trailing edge and the cell changes direction, the centrosome will be translocated across the nucleus to the back of the cell again. A dynein inhibitor did have an influence on centrosome positioning in 1D migration and change of directions.

  19. Laboratory coda wave interferometry for the monitoring of rock property variations

    NASA Astrophysics Data System (ADS)

    Schmittbuhl, Jean; Chaintreuil, Marie; Lengliné, Olivier; Griffiths, Luke; Heap, Mike; Baud, Patrick

    2016-04-01

    A significant effort is on-going in the community to continuously monitor deep geothermal reservoirs using ambient seismic noise tomography (e.g. Calo et al, 2013; Lehujeur et al, 2015). It is a method that determines the Green's function between a pair of receivers by correlating sufficiently long seismic noise records. Very small changes of the medium are accessible using this new monitoring technique (significantly smaller than those deduced from direct arrivals). In particular, very small variations of seismic velocities are shown to appear both in time and space during the stimulation of the reservoir. A central question is how to interpret these transient or lateral variations of the seismic velocities for a precise 4D tomography of the reservoir properties. In this study, we address the direct problem of monitoring small variations in seismic velocities when small variations in stress or temperature are slowly applied to the sample. We use a network of piezo-electric sensors on laboratory samples (sandstone and granite from Soultz-sous-Forêts core samples) to perform coda wave interferometry from the multiple scattering of well-controlled seismic pulses (Grêt et al, 2006). The data collected are estimates of the relative variation of travel time. We combine acoustic measurements and strain gauges to differentiate between travel time variations due to seismic velocity changes and those due to deformation effects. We expect this approach to provide useful information for large scale seismic tomography despite the significant difference of considered wavelengths.

  20. Evidence for inner-core rotation from possible changes with time in PKP coda

    NASA Astrophysics Data System (ADS)

    Vidale, John E.; Earle, Paul S.

    2005-01-01

    Inner-core-grazing PKP waves from seven French nuclear tests on Mururoa Island recorded at NORSAR appear to change over a decade. We compared filtered and stacked signals from the explosions, which took place from 1977 to 1987 and were separated by less than 10 km. The PKP energy 3 to 10 s after the first arrivals differs greatly between the NORSAR subarrays, and evolves over time. The small time shifts of coda arrivals, a few tenths of a second, are qualitatively consistent with shifts predicted for point scatterers in an inner core that rotates in the range 0.05° to 0.10° per year. There are also visible changes in the envelope of the PKP energy. Although the alternative of systematic shifts in source location cannot be ruled out, the apparent time evolution of PKP supports claims of slow inner core rotation [Song and Richards, 1996; Creager, 1997; Laske and Masters, 1999; Vidale et al., 2000] and offers a powerful new tool for its assessment.

  1. Imaging the Alpine Fault, South Island, New Zealand, using local earthquake coda

    NASA Astrophysics Data System (ADS)

    Bannister, S.; Louie, J.; Henrys, S.

    2004-12-01

    The major strike-slip Alpine fault marks the boundary between the obliquely converging Pacific and Australian plates in South Island, New Zealand. Previous studies have inferred a total strike-slip displacement of c. 450 km along this transpressional section of the plate boundary, and an estimated c. 100 km of shortening, which has resulted in the uplift of the Southern Alps mountain range. Active-source seismic reflection imaging suggests that the Alpine fault dips southeast at c. 40 degrees, to a depth of around 22 km (Davey et al., 1998). Here, we attempt to directly image the Alpine fault zone using back-projection migration of local-earthquake coda. We specifically use records from aftershocks of the Mw 6.7 Arthur's Pass earthquake, the largest earthquake in the region for 65 years, which occurred about 25 km southeast of the Alpine fault. The aftershocks of this earthquake were well recorded by a 6-station portable array (Abercrombie et al., 2000). Pre-processing involved relocation of these aftershocks with the double difference technique, utilising cross-correlation differences between the waveforms. This relocation substantially improved relative event locations, and highlighted the Bruce fault and other secondary faults in the region. Subsequent back-projection imaging, using station gathers of the seismograms of the relocated events, results in reflectivity images of the mid-crust near the Alpine fault and beneath the aftershock sequence.

  2. Monitoring the self-healing process of biomimetic mortar using coda wave interferometry method

    NASA Astrophysics Data System (ADS)

    Liu, Shukui; Basaran, Zeynep; Zhu, Jinying; Ferron, Raissa

    2014-02-01

    Internal stresses might induce microscopic cracks in concrete, which can provide pathways for ingress of harmful chemicals and can lead to loss of strength. Recent research in concrete materials suggests that it might be possible to develop a smart cement-based material that is capable of self-healing by leveraging the metabolic activity of microorganisms to provide biomineralization. Limited research on biomineralization in cement-based systems has shown promising results that healing of cracks can occur on the surface of concrete and reduce permeability. This paper presents the results from an investigation regarding the potential for a cement-based material to repair itself internally through biomineralization. Compressive strength test and coda wave interferometry (CWI) analyses were conducted on mortar samples that were loaded to 70% of their compressive strength and cured in different conditions. Experimental results indicate that the damaged mortar samples with microorganisms showed significantly higher strength development and higher increase of ultrasonic wave velocity compared to samples without microorganisms at 7 and 28 days.

  3. Coda quality factors of P and S Waves in West Bohemia/Vogtland

    NASA Astrophysics Data System (ADS)

    Bachura, Martin; Fischer, Tomas

    2016-04-01

    We used coda normalization method to analyze the attenuation properties (quality factors) of the fault zone of the West Bohemian/Vogtland earthquakes. Three mainshock-aftershock series of 2014 with more than 3000 located events and maximum magnitude of 4.4 were analyzed. The method itself was slightly improved - we tried to use only the events with similar seismograms (events with high cross-correlation coefficient) in order to derive the real relative amplitudes and to avoid the biasing influence of the differences in the focal mechanisms and radiation patterns. We also focused on the temporal stability of the quality factors within the focal area and studied eventual temporal variations, since the area itself exhibits strong temporal changes of rheological properties during the seismic activity (Vp/Vs, Poisson ratio) as a result of dynamic fluid activity in the focal depths. The first tests and trials show promising results and suggest the successful applicability of the method in its modified version. With proper dataset and careful data processing it should be able to analyze the quality factors with improved spatial resolution and allow to analyze the temporal changes and Q anisotropy as well.

  4. A 1-D dusty plasma photonic crystal

    SciTech Connect

    Mitu, M. L.; Ticoş, C. M.; Toader, D.; Banu, N.; Scurtu, A.

    2013-09-21

    It is demonstrated numerically that a 1-D plasma crystal made of micron size cylindrical dust particles can, in principle, work as a photonic crystal for terahertz waves. The dust rods are parallel to each other and arranged in a linear string forming a periodic structure of dielectric-plasma regions. The dispersion equation is found by solving the waves equation with the boundary conditions at the dust-plasma interface and taking into account the dielectric permittivity of the dust material and plasma. The wavelength of the electromagnetic waves is in the range of a few hundred microns, close to the interparticle separation distance. The band gaps of the 1-D plasma crystal are numerically found for different types of dust materials, separation distances between the dust rods and rod diameters. The distance between levitated dust rods forming a string in rf plasma is shown experimentally to vary over a relatively wide range, from 650 μm to about 1350 μm, depending on the rf power fed into the discharge.

  5. A continuous record of intereruption velocity change at Mount St. Helens from coda wave interferometry

    USGS Publications Warehouse

    Hotovec-Ellis, Alicia J.; Gomberg, Joan S.; Vidale, John; Creager, Ken C.

    2014-01-01

    In September 2004, Mount St. Helens volcano erupted after nearly 18 years of quiescence. However, it is unclear from the limited geophysical observations when or if the magma chamber replenished following the 1980–1986 eruptions in the years before the 2004–2008 extrusive eruption. We use coda wave interferometry with repeating earthquakes to measure small changes in the velocity structure of Mount St. Helens volcano that might indicate magmatic intrusion. By combining observations of relative velocity changes from many closely located earthquake sources, we solve for a continuous function of velocity changes with time. We find that seasonal effects dominate the relative velocity changes. Seismicity rates and repeating earthquake occurrence also vary seasonally; therefore, velocity changes and seismicity are likely modulated by snow loading, fluid saturation, and/or changes in groundwater level. We estimate hydrologic effects impart stress changes on the order of tens of kilopascals within the upper 4 km, resulting in annual velocity variations of 0.5 to 1%. The largest nonseasonal change is a decrease in velocity at the time of the deep Mw = 6.8 Nisqually earthquake. We find no systematic velocity changes during the most likely times of intrusions, consistent with a lack of observable surface deformation. We conclude that if replenishing intrusions occurred, they did not alter seismic velocities where this technique is sensitive due to either their small size or the finite compressibility of the magma chamber. We interpret the observed velocity changes and shallow seasonal seismicity as a response to small stress changes in a shallow, pressurized system.

  6. Equatorial anisotropy of the Earth's inner inner core from autocorrelations of earthquake coda

    NASA Astrophysics Data System (ADS)

    Wang, T.; Song, X.; Xia, H.

    2014-12-01

    The anisotropic structure of the inner core seems complex with significant depth and lateral variations. An innermost inner core has been suggested with a distinct form of anisotropy, but it has considerable uncertainties in its form, size, or even existence. All the previous inner-core anisotropy models have assumed a cylindrical anisotropy with the symmetry axis parallel (or nearly parallel) to the Earth's spin axis. In this study, we obtain inner-core phases, PKIIKP2 and PKIKP2 (the round-trip phases between the station and its antipode that passes straight through the center of the Earth and that is reflected from the inner-core boundary, respectively), from stackings of autocorrelations of earthquake coda at seismic station clusters around the world. The differential travel times PKIIKP2 - PKIKP2, which are sensitive to inner-core structure, show fast arrivals at high latitudes. However, we also observed large variations of up to 10 s along equatorial paths. These observations can be explained by a cylindrical anisotropy in the inner inner core (IIC) (with a radius of slightly less than half the inner core radius) that has a fast axis aligned near the equator and a cylindrical anisotropy in the outer inner core (OIC) that has a fast axis along the north-south direction. The equatorial fast axis of the IIC is near the Central America and the Southeast Asia. The form of the anisotropy in the IIC is distinctly different from that in the OIC and the anisotropy amplitude in the IIC is about 70% stronger than in the OIC. The different forms of anisotropy may be explained by a two-phase system of iron in the inner core (hcp in the OIC and bcc in the IIC). These results may suggest a major shift of the tectonics of the inner core during its formation and growth.

  7. 1D fast coded aperture camera.

    PubMed

    Haw, Magnus; Bellan, Paul

    2015-04-01

    A fast (100 MHz) 1D coded aperture visible light camera has been developed as a prototype for imaging plasma experiments in the EUV/X-ray bands. The system uses printed patterns on transparency sheets as the masked aperture and an 80 channel photodiode array (9 V reverse bias) as the detector. In the low signal limit, the system has demonstrated 40-fold increase in throughput and a signal-to-noise gain of ≈7 over that of a pinhole camera of equivalent parameters. In its present iteration, the camera can only image visible light; however, the only modifications needed to make the system EUV/X-ray sensitive are to acquire appropriate EUV/X-ray photodiodes and to machine a metal masked aperture. PMID:25933861

  8. 1D fast coded aperture camera.

    PubMed

    Haw, Magnus; Bellan, Paul

    2015-04-01

    A fast (100 MHz) 1D coded aperture visible light camera has been developed as a prototype for imaging plasma experiments in the EUV/X-ray bands. The system uses printed patterns on transparency sheets as the masked aperture and an 80 channel photodiode array (9 V reverse bias) as the detector. In the low signal limit, the system has demonstrated 40-fold increase in throughput and a signal-to-noise gain of ≈7 over that of a pinhole camera of equivalent parameters. In its present iteration, the camera can only image visible light; however, the only modifications needed to make the system EUV/X-ray sensitive are to acquire appropriate EUV/X-ray photodiodes and to machine a metal masked aperture.

  9. 1D-VAR Retrieval Using Superchannels

    NASA Technical Reports Server (NTRS)

    Liu, Xu; Zhou, Daniel; Larar, Allen; Smith, William L.; Schluessel, Peter; Mango, Stephen; SaintGermain, Karen

    2008-01-01

    Since modern ultra-spectral remote sensors have thousands of channels, it is difficult to include all of them in a 1D-var retrieval system. We will describe a physical inversion algorithm, which includes all available channels for the atmospheric temperature, moisture, cloud, and surface parameter retrievals. Both the forward model and the inversion algorithm compress the channel radiances into super channels. These super channels are obtained by projecting the radiance spectra onto a set of pre-calculated eigenvectors. The forward model provides both super channel properties and jacobian in EOF space directly. For ultra-spectral sensors such as Infrared Atmospheric Sounding Interferometer (IASI) and the NPOESS Airborne Sounder Testbed Interferometer (NAST), a compression ratio of more than 80 can be achieved, leading to a significant reduction in computations involved in an inversion process. Results will be shown applying the algorithm to real IASI and NAST data.

  10. Comparison of Source Time Functions Retrieved from Various Regional Waves and Coda Using Moderate Earthquakes in East and Central Asia

    NASA Astrophysics Data System (ADS)

    Xie, J.; Torpey, M. E.

    2015-12-01

    Source time functions may vary with various P and S wave types. Regional Lg waves have been used to estimate radiated energy and apparent stress. In nuclear explosion seismology, the practice of discriminating Earthquake and explosions using regional wave spectra and spectral ratios relies on a fundamental assumption that Earthquakes and explosions excite various regional waves in a systematically-different manner. We have been carrying out a systematic study to retrieve source time functions (STFs) from seismic sources using the empirical Green's function (EGF) approach. In phase 1 of the study, we focus on retrieving STFs from moderate earthquakes in east and central Asia using regional Lg, Pg, Lg coda, and Sn and Pn waves to see whether or not the shape of the STFs varies with the wave type. We explored various methods to reduce the noise in the deconvolved STFs which tend to be higher for the relatively weaker Pg, Sn, Pn and coda waves. For example, an array-stacking method is used to enhance source pulses and reduce the level of side-lobes. Preliminary results suggest that Lg and Lg coda STFs may be similar, as generally believed. Pg STF is less similar to Lg STF. For example, when a stacked Lg STF is clearly asymmetric with a sharp-rise time, the stack Pg STF seems to be fairly symmetric. In general, our confidence on this kind of dissimilarity is still limited by the non-diminishing deconvolution noise in the retrieved Pg STFs, and by the small number of events studied. We are trying to further reduce the deconvolution noise for each regional wave, and find and analyze more moderate events. We will present newly-retrieved STFs from each of the various regional waves and coda, and compare the pulse widths and shapes of the STFs from different waves. We will also present estimates of source-radiated energy and apparent stresses using the estimated Lg STFs without using various simplified source models and Q corrections.

  11. Lapse time and frequency-dependent attenuation of coda waves in the Zagros continental collision zone in Southwestern Iran

    NASA Astrophysics Data System (ADS)

    Rahimi, H.; Hamzehloo, H.

    2008-06-01

    The coda Q, Qc, were estimated for the Zagros continental collision zone in southwestern Iran by analyzing the coda waves of 51 local earthquakes recorded on the three stations of the Iranian National Seismic Network (INSN) with magnitudes of between 3.1 and 4.9 recorded in the region during March and April 2006. Most of the analyzed events are foreshocks and aftershocks of the Darb-e-Astane earthquake which occurred on 31 March 2006 with a magnitude of 6.1 (IIEES). The earthquakes had an epicentral distance of between 120 and 200 km and a focal depth of about 18 km. The Qc values were computed at nine central frequencies of 1.5, 2.0, 3.0, 4.0, 6.0, 8.0, 12.0, 16.0 and 20.0 Hz through eight lapse time windows from 25 to 60 s starting at double the time of the primary S-wave from the origin time using the time-domain coda-decay method of a single backscattering model. In this study the collected data were compared between the events that occurred before and after the main event (foreshocks and aftershocks). The analysis showed a significant variation in the value of coda, Q, for the study region in different lapse times and frequencies. The variation of the quality factor, Qc, before and after the main event was estimated at different lapse time windows to observe its effect with depth. The estimated average frequency-dependent relation of Qc for foreshocks varies from Qc = (144 ± 24)f(0.42 ± 0.23) at 25 s to Qc = (85 ± 10)f(0.92 ± 0.11) at 60 s lapse window time length, respectively. For aftershocks, it varies from Qc = (121 ± 55)f(0.97 ± 0.26) at 25 s to Qc = (212 ± 59)f(0.82 ± 0.15) at 60 s. The averages of Qc in all stations and lapse times window are obtained as Qc = 99f0.84 and Qc = 178f0.86 for foreshocks and aftershocks, respectively. The Q frequency relationship for foreshocks is similar to that for the South Carolina, Koyna, western Anatolia and Aleutian earthquakes, whereas for aftershocks it is similar to the Kumaun, NW Himalaya and Parkfield

  12. Seismic ambient noise H/V spectral ratio using the ACA (autocorrelations of coda of autocorrelations) approach

    NASA Astrophysics Data System (ADS)

    Sanchez-Sesma, F. J.; Piña, J.; Campillo, M.; Luzón, F.; García-Jerez, A.; Albarello, D.; Lunedei, E.

    2012-12-01

    The seismic ambient noise horizontal-to-vertical spectral ratios (NHVSR) are valuable for microzonation, and seismic prospecting. This is particularly true for low-cost dense spatial sampling projects. Arai and Tokimatsu (2004) proposed to use average energy densities to compose the ratios. It means that H/V comes from the square root of the ratio of averages. On the other hand, a popular approach makes the average of spectral ratios. For ergodic processes peak values are usually the same using these two approaches. Sometimes however, the observations are insufficient and computed values for low frequencies display large variability and the corresponding H/V estimates may be inaccurate. The bias caused by localized sources may be the source of errors in the estimates. In this work we propose to compute the NHVSR using the Autocorrelations of Coda of Autocorrelations. This ACA approach is inspired in the work by Stehly et al. (2008). They used the Correlations of Coda of Correlations (C3) to isotropize the field. In our ACA approach the whole time series, say of 30 minutes, for each component is autocorrelated and the averages of the spectral density of selected windows (late coda windows are eliminated) are then improved estimates of directional energy densities. The computation of NHVSR using ACA appears more stable and free of transient effects. It remains to establish how this may be accounted for in forward calculation of H/V spectral ratios for models like a layered medium (e.g. Sánchez-Sesma et al., 2011; Albarello and Lunedei, 2011). This will require further scrutiny. References. Albarello, D. & E. Lunedei (2011). Structure of ambient vibration wavefield in the frequency range of engineering interest ([0.5, 20] Hz): insights from numerical modelling. Near Surface Geophysics 9, 543-559. Arai, H. & K. Tokimatsu (2004). S-wave velocity profiling by inversion of microtremor H/V spectrum, Bull. Seismol. Soc. Am. 94, 53-63. Sánchez-Sesma, F. J., M. Rodr

  13. Lapse-time dependent coda-wave depth sensitivity to local velocity perturbations in 3-D heterogeneous elastic media

    NASA Astrophysics Data System (ADS)

    Obermann, Anne; Planès, Thomas; Hadziioannou, Céline; Campillo, Michel

    2016-07-01

    In the context of seismic monitoring, recent studies made successful use of seismic coda waves to locate medium changes on the horizontal plane. Locating the depth of the changes, however, remains a challenge. In this paper, we use 3-D wavefield simulations to address two problems: firstly, we evaluate the contribution of surface and body wave sensitivity to a change at depth. We introduce a thin layer with a perturbed velocity at different depths and measure the apparent relative velocity changes due to this layer at different times in the coda and for different degrees of heterogeneity of the model. We show that the depth sensitivity can be modelled as a linear combination of body- and surface-wave sensitivity. The lapse-time dependent sensitivity ratio of body waves and surface waves can be used to build 3-D sensitivity kernels for imaging purposes. Secondly, we compare the lapse-time behavior in the presence of a perturbation in horizontal and vertical slabs to address, for instance, the origin of the velocity changes detected after large earthquakes.

  14. Lapse-time-dependent coda-wave depth sensitivity to local velocity perturbations in 3-D heterogeneous elastic media

    NASA Astrophysics Data System (ADS)

    Obermann, Anne; Planès, Thomas; Hadziioannou, Céline; Campillo, Michel

    2016-10-01

    In the context of seismic monitoring, recent studies made successful use of seismic coda waves to locate medium changes on the horizontal plane. Locating the depth of the changes, however, remains a challenge. In this paper, we use 3-D wavefield simulations to address two problems: first, we evaluate the contribution of surface- and body-wave sensitivity to a change at depth. We introduce a thin layer with a perturbed velocity at different depths and measure the apparent relative velocity changes due to this layer at different times in the coda and for different degrees of heterogeneity of the model. We show that the depth sensitivity can be modelled as a linear combination of body- and surface-wave sensitivity. The lapse-time-dependent sensitivity ratio of body waves and surface waves can be used to build 3-D sensitivity kernels for imaging purposes. Second, we compare the lapse-time behaviour in the presence of a perturbation in horizontal and vertical slabs to address, for instance, the origin of the velocity changes detected after large earthquakes.

  15. Nonlinear mixing of ultrasonic coda waves with lower frequency-swept pump waves for a global detection of defects in multiple scattering media

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Tournat, V.; Abraham, O.; Durand, O.; Letourneur, S.; Le Duff, A.; Lascoup, B.

    2013-02-01

    An ultrasonic method providing for an efficient global detection of defects in complex media (multiple scattering or reverberating media) is reported herein; this method is based on the nonlinear acoustic mixing of coda waves (stemming from multiple scattering) with lower frequency-swept pump waves. Such a nonlinear mixing step is made possible by the presence of nonlinear scatterers, such as cracks and delamination, yet remains absent when the waves are scattered only by linear scatterers, as is the case in a complex but defect-free medium. A global inspection is achieved thanks to the use of wide-band coda and pump signals, which ensure the excitation of many resonances along with a homogeneous acoustic energy distribution in the medium. We introduce the existing sensitivity tools developed for Coda Wave Interferometry in extracting the pump amplitude-dependent parameters of the coda waves associated with effective nonlinear parameters of the medium. By comparing results at two damage levels, these effective nonlinear parameters are shown to be correlated with crack presence in glass samples. The mechanisms potentially responsible for the observed amplitude dependence on the tested elastic parameters and waveform modification are discussed.

  16. The Concept of Coda in Carson McCullers's sic "The Ballad of the Sad Cafe," and August Strindberg's "The Ghost Sonata."

    ERIC Educational Resources Information Center

    Sandberg, Elisabeth; Shadko, Jacqueline A.

    1996-01-01

    Discovers that Carson McCullers and August Strindberg both made extensive use of musical structure in their literature. Specifically discusses the use of the coda, a last section of music that creates a sense of finality by reiterating the principal theme. Briefly discusses literary uses of the ballad and sonata. (MJP)

  17. 1D-1D Coulomb drag in a 6 Million Mobility Bi-layer Heterostructure

    NASA Astrophysics Data System (ADS)

    Bilodeau, Simon; Laroche, Dominique; Xia, Jian-Sheng; Lilly, Mike; Reno, John; Pfeiffer, Loren; West, Ken; Gervais, Guillaume

    We report Coulomb drag measurements in vertically-coupled quantum wires. The wires are fabricated in GaAs/AlGaAs bilayer heterostructures grown from two different MBE chambers: one at Sandia National Laboratories (1.2M mobility), and the other at Princeton University (6M mobility). The previously observed positive and negative drag signals are seen in both types of devices, demonstrating the robustness of the result. However, attempts to determine the temperature dependence of the drag signal in the 1D regime proved challenging in the higher mobility heterostructure (Princeton), in part because of difficulties in aligning the wires within the same transverse subband configuration. Nevertheless, this work, performed at the Microkelvin laboratory of the University of Florida, is an important proof-of-concept for future investigations of the temperature dependence of the 1D-1D drag signal down to a few mK. Such an experiment could confirm the Luttinger charge density wave interlocking predicted to occur in the wires. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under Contract DE-AC04-94AL8500.

  18. An experiment to locate cavities as strong scatterers using S-coda waves -the Cooke4 mine in South Africa-

    NASA Astrophysics Data System (ADS)

    Imagawa, S.; Kawakata, H.; Doi, I.; Yoshimitsu, N.; Murakami, O.; Nakatani, M.; Naoi, M.; Philipp, J.; Ward, A.; Visser, V.; Masakale, T.; Milev, A. M.; Durrheim, R. J.; Ribeiro, L.; Ward, M.; Ogasawara, H.

    2013-12-01

    To investigate short-wavelength heterogeneity of the crust, scattered waves contained in coda waves are useful. In general, locations of the scatterers are estimated from the travel times of scattered waves with a stochastic back-projection method, so that artifacts may emerge if seismic stations and sources are inadequately distributed. In this study, using coda waves, we try to locate well-mapped cavities such as tunnels, shafts and stopes in the Cooke4 Gold Mine in South Africa. At this mine, we have developed a dense seismic network in the vicinity of a region with high seismicity. The seismic network is narrow and the source distribution is far from being uniform, which can cause artifacts. We use 3-component accelerograms recorded at 6 stations about 1 km below surface in the shaft pillar area. The data are recorded for 6.6 ms at the sampling frequency of 500 kHz. Considering the size (2-4 m) of tunnels and shafts, a band-pass filter of 800-1600 Hz is applied. Considering the distribution of seismic sources and stations, and also the data length, an analysis volume of 300×300×260 m3 is set and divided into blocks of 4×4×4 m3. In general, the exponential decays of the coda wave amplitude from an event tend to be the same regardless of the distance from seismic source to station (Aki, 1980). If strong scatterers exist, a phase with relatively large amplitude would appear at the corresponding time. We identify such phases by looking for phases where the amplitude significantly exceeds the overall envelope of S-coda. Using the travel time of thus picked 'scattering phase', we locate the corresponding scatterer. Since our target structures are highly localized strong scatterers, we assume single scattering in the present analysis, as, for example, Matsumoto et al. (2006). The block containing the estimated scatterer location receives votes according to the amplitude of the scattering phase. By adding votes from all the traces, we have obtained a three

  19. Human serotonin 1D receptor is encoded by a subfamily of two distinct genes: 5-HT1D alpha and 5-HT1D beta.

    PubMed Central

    Weinshank, R L; Zgombick, J M; Macchi, M J; Branchek, T A; Hartig, P R

    1992-01-01

    The serotonin 1D (5-HT1D) receptor is a pharmacologically defined binding site and functional receptor site. Observed variations in the properties of 5-HT1D receptors in different tissues have led to the speculation that multiple receptor proteins with slightly different properties may exist. We report here the cloning, deduced amino acid sequences, pharmacological properties, and second-messenger coupling of a pair of human 5-HT1D receptor genes, which we have designated 5-HT1D alpha and 5-HT1D beta due to their strong similarities in sequence, pharmacological properties, and second-messenger coupling. Both genes are free of introns in their coding regions, are expressed in the human cerebral cortex, and can couple to inhibition of adenylate cyclase activity. The pharmacological binding properties of these two human receptors are very similar, and match closely the pharmacological properties of human, bovine, and guinea pig 5-HT1D sites. Both receptors exhibit high-affinity binding of sumatriptan, a new anti-migraine medication, and thus are candidates for the pharmacological site of action of this drug. Images PMID:1565658

  20. A continent-wide map of 1-Hz Lg coda Q variation across Eurasia and its relation to lithospheric evolution

    NASA Astrophysics Data System (ADS)

    Mitchell, Brian J.; Cong, Lianli; EkströM, Goran

    2008-04-01

    We present new maps of Lg coda Q (Qo and its frequency dependence) at 1-Hz that cover virtually all of Eurasia. Qo is relatively high, up to 650 or more, in the east European, Siberian, Indian, and Kazakh platforms but is surprisingly low (300-500) in the Arabian platform and western portion of the Siberian platform as well as in Great Britain and the northwestern portion of mainland Europe. It is generally low throughout the Tethysides orogenic belt, but there too it displays substantial regional variations (150-400). Most Qo anomalies appear to be related to the tectonic history of the Eurasian crust. The four regions with lowest values coincide with four of Eurasia's most active concentrations of earthquake activity. Observed Eurasian Qo values are consistent with a previously determined empirical plot of global values in which Qo in any region is proportional to the time elapsed since the most recent episode of tectonic or orogenic activity there. Comparisons of the new Qo map with maps of Rayleigh wave velocity, temperature, subducted lithosphere, and seismicity lead us to infer that Lg coda wave attenuation is most easily explained by energy lost in moving fluids through permeable rock or in being scattered from fluid-enhanced zones. The fluids are likely to have originated by hydrothermal release from subducting lithosphere or other upper mantle heat sources. Anomalies in Qo and other lithospheric properties in some cases extend well outside the Tethysides belt and other regions where upper mantle heat sources are known to occur. Possible explanations include earlier episodes of subduction activity, crustal deformation due to collision of the Afro-Arabian and Indian plates, or broader than expected back-arc activity beneath Eurasia.

  1. Cosmic Dawn (CoDa): the First Radiation-Hydrodynamics Simulation of Reionization and Galaxy Formation in the Local Universe

    NASA Astrophysics Data System (ADS)

    Ocvirk, Pierre; Gillet, Nicolas; Shapiro, Paul R.; Aubert, Dominique; Iliev, Ilian T.; Teyssier, Romain; Yepes, Gustavo; Choi, Jun-Hwan; Sullivan, David; Knebe, Alexander; Gottlöber, Stefan; D'Aloisio, Anson; Park, Hyunbae; Hoffman, Yehuda; Stranex, Timothy

    2016-08-01

    Cosmic reionization by starlight from early galaxies affected their evolution, thereby impacting reionization, itself. Star formation suppression, for example, may explain the observed underabundance of Local Group dwarfs relative to N-body predictions for Cold Dark Matter. Reionization modelling requires simulating volumes large enough [ ˜ (100 Mpc)3] to sample reionization "patchiness", while resolving millions of galaxy sources above ˜108 M⊙ , combining gravitational and gas dynamics with radiative transfer. Modelling the Local Group requires initial cosmological density fluctuations pre-selected to form the well-known structures of the local universe today. Cosmic Dawn ("CoDa") is the first such fully-coupled, radiation-hydrodynamics simulation of reionization of the local universe. Our new hybrid CPU-GPU code, RAMSES-CUDATON, performs hundreds of radiative transfer and ionization rate-solver timesteps on the GPUs for each hydro-gravity timestep on the CPUs. CoDa simulated (91Mpc)3 with 40963 particles and cells, to redshift 4.23, on ORNL supercomputer Titan, utilizing 8192 cores and 8192 GPUs. Global reionization ended slightly later than observed. However, a simple temporal rescaling which brings the evolution of ionized fraction into agreement with observations also reconciles ionizing flux density, cosmic star formation history, CMB electron scattering optical depth and galaxy UV luminosity function with their observed values. Photoionization heating suppressed the star formation of haloes below ˜2 × 109 M⊙ , For most of reionization, star formation was dominated by haloes between 1010 - 1011 M⊙ , so low-mass halo suppression was not reflected by a distinct feature in the global star formation history. Intergalactic filaments display sheathed structures, with hot envelopes surrounding cooler cores, but do not self-shield, unlike regions denser than 100 <ρ>.

  2. Regional Analysis of Lg Attenuation: Comparison of 1D Methods in Northern California and Application to the Yellow Sea / Korean Peninsula

    SciTech Connect

    Ford, S R; Dreger, D S; Mayeda, K M; Walter, W R; Malagnini, L; Phillips, W S

    2007-07-06

    The measurement of regional attenuation Q{sup -1} can produce method dependent results. The discrepancies among methods are due to differing parameterizations (e.g., geometrical spreading rates), employed datasets (e.g., choice of path lengths and sources), and methodologies themselves (e.g., measurement in the frequency or time domain). We apply the coda normalization (CN), two-station (TS), reverse two-station (RTS), source-pair/receiver-pair (SPRP), and the new coda-source normalization (CS) methods to measure Q of the regional phase, Lg (Q{sub Lg}), and its power-law dependence on frequency of the form Q{sub 0}f{sup {eta}} with controlled parameterization in the well-studied region of northern California using a high-quality dataset from the Berkeley Digital Seismic Network. We test the sensitivity of each method to changes in geometrical spreading, Lg frequency bandwidth, the distance range of data, and the Lg measurement window. For a given method, there are significant differences in the power-law parameters, Q{sub 0} and {eta}, due to perturbations in the parameterization when evaluated using a conservative pairwise comparison. The CN method is affected most by changes in the distance range, which is most probably due to its fixed coda measurement window. Since, the CS method is best used to calculate the total path attenuation, it is very sensitive to the geometrical spreading assumption. The TS method is most sensitive to the frequency bandwidth, which may be due to its incomplete extraction of the site term. The RTS method is insensitive to parameterization choice, whereas the SPRP method as implemented here in the time-domain for a single path has great error in the power-law model parameters and {eta} is greatly affected by changes in the method parameterization. When presenting results for a given method it is best to calculate Q{sub 0}f{sup {eta}} for multiple parameterizations using some a priori distribution. We also investigate the difference in

  3. VES/TEM 1D joint inversion by using Controlled Random Search (CRS) algorithm

    NASA Astrophysics Data System (ADS)

    Bortolozo, Cassiano Antonio; Porsani, Jorge Luís; Santos, Fernando Acácio Monteiro dos; Almeida, Emerson Rodrigo

    2015-01-01

    Electrical (DC) and Transient Electromagnetic (TEM) soundings are used in a great number of environmental, hydrological, and mining exploration studies. Usually, data interpretation is accomplished by individual 1D models resulting often in ambiguous models. This fact can be explained by the way as the two different methodologies sample the medium beneath surface. Vertical Electrical Sounding (VES) is good in marking resistive structures, while Transient Electromagnetic sounding (TEM) is very sensitive to conductive structures. Another difference is VES is better to detect shallow structures, while TEM soundings can reach deeper layers. A Matlab program for 1D joint inversion of VES and TEM soundings was developed aiming at exploring the best of both methods. The program uses CRS - Controlled Random Search - algorithm for both single and 1D joint inversions. Usually inversion programs use Marquadt type algorithms but for electrical and electromagnetic methods, these algorithms may find a local minimum or not converge. Initially, the algorithm was tested with synthetic data, and then it was used to invert experimental data from two places in Paraná sedimentary basin (Bebedouro and Pirassununga cities), both located in São Paulo State, Brazil. Geoelectric model obtained from VES and TEM data 1D joint inversion is similar to the real geological condition, and ambiguities were minimized. Results with synthetic and real data show that 1D VES/TEM joint inversion better recovers simulated models and shows a great potential in geological studies, especially in hydrogeological studies.

  4. Determination of the source time function of seismic event by blind deconvolution of regional coda wavefield: application to December 22, 2009 explosion at Kambarata, Kyrgyzstan

    NASA Astrophysics Data System (ADS)

    Sebe, O. G.; Guilbert, J.; Bard, P.

    2011-12-01

    At regional distance, recovering the source time function of a seismic event is a rather difficult task as the Green function is unknown due to large scattering of the waves by crust heterogeneities. Contrary to classical methods based on deterministic assessment of the Green function, this work proposes to exploit the stochastic nature of regional coda wavefield in order to extract the seismic source time function of a regional event. Since the work of Aki and Chouet 1975, it is well recognized that regional coda waves can provide stable and robust information on the source of seismic events. Unfortunately, all the proposed techniques are limited to the power spectral density of the seismic source function. A modified version of our two step spectral factorization algorithm [Sèbe et al. 2005] of coda waves has been proposed in order to include higher order statistic (HOS) blind deconvolution techniques. Assuming that the coda excitation time series is a non-Gaussian independent and identically distributed random signal, the higher order statistics, especially the tricorrelation, is able to remove the randomness of coda excitation and extract source properties. In addition, unlike classical second order approach which only provides the power spectral density, the tricorrelation keeps the information on the phase spectrum of the source, allowing the estimation of the source time function. This original blind deconvolution algorithm of coda waves has been applied on the regional records of the December 22, 2009 explosion in Kambara, Kyrgyzstan. Based on statistic analyses of the higher order cumulants, this method has been able to recover the main properties of the source time function of this detonation: two successive explosions have been identified with a time delay of about 1.7 sec and an amplitude ratio of about 2 in favour of second explosion. This successful blind recovering of high resolution source properties is an encouraging result toward the development

  5. A local earthquake coda magnitude and its relation to duration, moment M sub O, and local Richter magnitude M sub L

    NASA Technical Reports Server (NTRS)

    Suteau, A. M.; Whitcomb, J. H.

    1977-01-01

    A relationship was found between the seismic moment, M sub O, of shallow local earthquakes and the total duration of the signal, t, in seconds, measured from the earthquakes origin time, assuming that the end of the coda is composed of backscattering surface waves due to lateral heterogenity in the shallow crust following Aki. Using the linear relationship between the logarithm of M sub O and the local Richter magnitude M sub L, a relationship between M sub L and t, was found. This relationship was used to calculate a coda magnitude M sub C which was compared to M sub L for Southern California earthquakes which occurred during the period from 1972 to 1975.

  6. Brady 1D seismic velocity model ambient noise prelim

    DOE Data Explorer

    Mellors, Robert J.

    2013-10-25

    Preliminary 1D seismic velocity model derived from ambient noise correlation. 28 Green's functions filtered between 4-10 Hz for Vp, Vs, and Qs were calculated. 1D model estimated for each path. The final model is a median of the individual models. Resolution is best for the top 1 km. Poorly constrained with increasing depth.

  7. Frequency dependent Qα and Qβ in the Umbria-Marche (Italy) region using a quadratic approximation of the coda-normalization method

    NASA Astrophysics Data System (ADS)

    de Lorenzo, Salvatore; Bianco, Francesca; Del Pezzo, Edoardo

    2013-06-01

    The coda normalization method is one of the most used methods in the inference of attenuation parameters Qα and Qβ. Since, in this method, the geometrical spreading exponent γ is an unknown model parameter, the most part of studies assumes a fixed γ, generally equal to 1. However γ and Q could be also jointly inferred from the non-linear inversion of coda-normalized logarithms of amplitudes, but the trade-off between γ and Q could give rise to unreasonable values of these parameters. To minimize the trade-off between γ and Q, an inversion method based on a parabolic expression of the coda-normalization equation has been developed. The method has been applied to the waveforms recorded during the 1997 Umbria-Marche seismic crisis. The Akaike criterion has been used to compare results of the parabolic model with those of the linear model, corresponding to γ = 1. A small deviation from the spherical geometrical spreading has been inferred, but this is accompanied by a significant variation of Qα and Qβ values. For almost all the considered stations, Qα smaller than Qβ has been inferred, confirming that seismic attenuation, in the Umbria-Marche region, is controlled by crustal pore fluids.

  8. Deriving Sensitivity Kernels of Coda-Wave Travel Times to Velocity Changes Based on the Three-Dimensional Single Isotropic Scattering Model

    NASA Astrophysics Data System (ADS)

    Nakahara, Hisashi; Emoto, Kentaro

    2016-08-01

    Recently, coda-wave interferometry has been used to monitor temporal changes in subsurface structures. Seismic velocity changes have been detected by coda-wave interferometry in association with large earthquakes and volcanic eruptions. To constrain the spatial extent of the velocity changes, spatial homogeneity is often assumed. However, it is important to locate the region of the velocity changes correctly to understand physical mechanisms causing them. In this paper, we are concerned with the sensitivity kernels relating travel times of coda waves to velocity changes. In previous studies, sensitivity kernels have been formulated for two-dimensional single scattering and multiple scattering, three-dimensional multiple scattering, and diffusion. In this paper, we formulate and derive analytical expressions of the sensitivity kernels for three-dimensional single-scattering case. These sensitivity kernels show two peaks at both source and receiver locations, which is similar to the previous studies using different scattering models. The two peaks are more pronounced for later lapse time. We validate our formulation by comparing it with finite-difference simulations of acoustic wave propagation. Our formulation enables us to evaluate the sensitivity kernels analytically, which is particularly useful for the analysis of body waves from deeper earthquakes.

  9. Endoplasmic Reticulum Glycoprotein Quality Control Regulates CD1d Assembly and CD1d-mediated Antigen Presentation*

    PubMed Central

    Kunte, Amit; Zhang, Wei; Paduraru, Crina; Veerapen, Natacha; Cox, Liam R.; Besra, Gurdyal S.; Cresswell, Peter

    2013-01-01

    The non-classical major histocompatibility complex (MHC) homologue CD1d presents lipid antigens to innate-like lymphocytes called natural-killer T (NKT) cells. These cells, by virtue of their broad cytokine repertoire, shape innate and adaptive immune responses. Here, we have assessed the role of endoplasmic reticulum glycoprotein quality control in CD1d assembly and function, specifically the role of a key component of the quality control machinery, the enzyme UDP glucose glycoprotein glucosyltransferase (UGT1). We observe that in UGT1-deficient cells, CD1d associates prematurely with β2-microglobulin (β2m) and is able to rapidly exit the endoplasmic reticulum. At least some of these CD1d-β2m heterodimers are shorter-lived and can be rescued by provision of a defined exogenous antigen, α-galactosylceramide. Importantly, we show that in UGT1-deficient cells the CD1d-β2m heterodimers have altered antigenicity despite the fact that their cell surface levels are unchanged. We propose that UGT1 serves as a quality control checkpoint during CD1d assembly and further suggest that UGT1-mediated quality control can shape the lipid repertoire of newly synthesized CD1d. The quality control process may play a role in ensuring stability of exported CD1d-β2m complexes, in facilitating presentation of low abundance high affinity antigens, or in preventing deleterious responses to self lipids. PMID:23615906

  10. Continuous fabrication of scalable 2-dimensional (2D) micro- and nanostructures by sequential 1D mechanical patterning processes.

    PubMed

    Ok, Jong G; Panday, Ashwin; Lee, Taehwa; Jay Guo, L

    2014-12-21

    We present a versatile and simple methodology for continuous and scalable 2D micro/nano-structure fabrication via sequential 1D patterning strokes enabled by dynamic nano-inscribing (DNI) and vibrational indentation patterning (VIP) as well as a 'single-stroke' 2D patterning using a DNI tool in VIP. PMID:25363145

  11. Interaction of environmental contaminants with zebrafish organic anion transporting polypeptide, Oatp1d1 (Slco1d1)

    SciTech Connect

    Popovic, Marta; Zaja, Roko; Fent, Karl; Smital, Tvrtko

    2014-10-01

    Polyspecific transporters from the organic anion transporting polypeptide (OATP/Oatp) superfamily mediate the uptake of a wide range of compounds. In zebrafish, Oatp1d1 transports conjugated steroid hormones and cortisol. It is predominantly expressed in the liver, brain and testes. In this study we have characterized the transport of xenobiotics by the zebrafish Oatp1d1 transporter. We developed a novel assay for assessing Oatp1d1 interactors using the fluorescent probe Lucifer yellow and transient transfection in HEK293 cells. Our data showed that numerous environmental contaminants interact with zebrafish Oatp1d1. Oatp1d1 mediated the transport of diclofenac with very high affinity, followed by high affinity towards perfluorooctanesulfonic acid (PFOS), nonylphenol, gemfibrozil and 17α-ethinylestradiol; moderate affinity towards carbaryl, diazinon and caffeine; and low affinity towards metolachlor. Importantly, many environmental chemicals acted as strong inhibitors of Oatp1d1. A strong inhibition of Oatp1d1 transport activity was found by perfluorooctanoic acid (PFOA), chlorpyrifos-methyl, estrone (E1) and 17β-estradiol (E2), followed by moderate to low inhibition by diethyl phthalate, bisphenol A, 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4 tetrahydronapthalene and clofibrate. In this study we identified Oatp1d1 as a first Solute Carrier (SLC) transporter involved in the transport of a wide range of xenobiotics in fish. Considering that Oatps in zebrafish have not been characterized before, our work on zebrafish Oatp1d1 offers important new insights on the understanding of uptake processes of environmental contaminants, and contributes to the better characterization of zebrafish as a model species. - Highlights: • We optimized a novel assay for determination of Oatp1d1 interactors • Oatp1d1 is the first SLC characterized fish xenobiotic transporter • PFOS, nonylphenol, diclofenac, EE2, caffeine are high affinity Oatp1d1substrates • PFOA, chlorpyrifos

  12. Using P-Wave Coda to Understand the Evolution of Fault Zone Elastic Properties During the Seismic Cycle

    NASA Astrophysics Data System (ADS)

    Tinti, E.; Scuderi, M. M.; Scognamiglio, L.; Di Stefano, G.; Collettini, C.; Marone, C.

    2015-12-01

    Fault slip can occur not only seismically, or aseismically but also through quasi-dynamic processes such as slow-slip, which represent slow but self-propagating acceleration of slip along fault zones. However, the underlying physics is still poorly understood. To investigate these quasi-dynamic processes, we performed laboratory experiments on simulated fault gouge in the double direct shear configuration, under boundary conditions where the loading system (k) approaches the critical rheologic stiffness of the fault gouge (kc). We varied k and measured acoustic properties for the full spectrum of slip behaviors as a function of the ratio k/kc. When k≈kc, we observe slow-slip events emerging from steady frictional sliding. Stick-slip stress drop varied inversely with k'=k/kc, ranging from 0.1 to 0.6 MPa over the range of k' from 1.0 to 0.7. The duration of failure events varied from 10-3 to a few seconds and peak slip velocities ranged from 0.1 to 0.15 mm/s. To shed light on the micro-physical mechanisms governing slow-slip we analyzed variations in fault zone elastic properties including P-wave velocity (Vp) and amplitude. Although the first arrival of the P-wave is not always clearly detectable, we are able to find clear, systematic changes in elastic properties by carefully evaluating the P-wave coda. To quantify variations in flight time we cross-correlate different sections of the P-wave coda. We use a simplified ray-propagation scheme to account for the sample geometry and derive an equation to describe the expected flight time of reflected and transmitted waves within the fault zone and loading blocks. We study the peak-to-peak amplitude variation of the P-arrival in order to investigate acoustic transmissivity and its variation during failure. We find that precursory changes in Vp scale inversely with stick-slip failure velocity. Our results provide significant insight into the mechanics of slow stick-slip and transient fault slip.

  13. Coda Q and its Frequency Dependence in the Eastern Himalayan and Indo-Burman Plate Boundary Systems

    NASA Astrophysics Data System (ADS)

    Mitra, S.; Kumar, A.

    2015-12-01

    We use broadband waveform data for 305 local earthquakes from the Eastern Himalayan and Indo-Burman plate boundary systems, to model the seismic attenuation in NE India. We measure the decay in amplitude of coda waves at discreet frequencies (between 1 and 12Hz) to evaluate the quality factor (Qc) as a function of frequency. We combine these measurements to evaluate the frequency dependence of Qc of the form Qc(f)=Qof η, where Qo is the quality factor at 1Hz and η is the frequency dependence. Computed Qo values range from 80-360 and η ranges from 0.85-1.45. To study the lateral variation in Qo and η, we regionalise the Qc by combining all source-receiver measurements using a back-projection algorithm. For a single back scatter model, the coda waves sample an elliptical area with the epicenter and receiver at the two foci. We parameterize the region using square grids. The algorithm calculates the overlap in area and distributes Qc in the sampled grids using the average Qc as the boundary value. This is done in an iterative manner, by minimising the misfit between the observed and computed Qc within each grid. This process is repeated for all frequencies and η is computed for each grid by combining Qc for all frequencies. Our results reveal strong variation in Qo and η across NE India. The highest Qo are in the Bengal Basin (210-280) and the Indo-Burman subduction zone (300-360). The Shillong Plateau and Mikir Hills have intermediate Qo (~160) and the lowest Qo (~80) is observed in the Naga fold thrust belt. This variation in Qo demarcates the boundary between the continental crust beneath the Shillong Plateau and Mikir Hills and the transitional to oceanic crust beneath the Bengal Basin and Indo-Burman subduction zone. Thick pile of sedimentary strata in the Naga fold thrust belt results in the low Qo. Frequency dependence (η) of Qc across NE India is observed to be very high, with regions of high Qo being associated with relatively higher η.

  14. Methodological Gravitism

    ERIC Educational Resources Information Center

    Zaman, Muhammad

    2011-01-01

    In this paper the author presents the case of the exchange marriage system to delineate a model of methodological gravitism. Such a model is not a deviation from or alteration to the existing qualitative research approaches. I have adopted culturally specific methodology to investigate spouse selection in line with the Grounded Theory Method. This…

  15. D1/D5 dopamine receptors modulate spatial memory formation.

    PubMed

    da Silva, Weber C N; Köhler, Cristiano C; Radiske, Andressa; Cammarota, Martín

    2012-02-01

    We investigated the effect of the intra-CA1 administration of the D1/D5 receptor antagonist SCH23390 and the D1/D5 receptor agonist SKF38393 on spatial memory in the water maze. When given immediately, but not 3h after training, SCH23390 hindered long-term spatial memory formation without affecting non-spatial memory or the normal functionality of the hippocampus. On the contrary, post-training infusion of SKF38393 enhanced retention and facilitated the spontaneous recovery of the original spatial preference after reversal learning. Our findings demonstrate that hippocampal D1/D5 receptors play an essential role in spatial memory processing.

  16. A human serotonin 1D receptor variant (5HT1D beta) encoded by an intronless gene on chromosome 6.

    PubMed Central

    Demchyshyn, L; Sunahara, R K; Miller, K; Teitler, M; Hoffman, B J; Kennedy, J L; Seeman, P; Van Tol, H H; Niznik, H B

    1992-01-01

    An intronless gene encoding a serotonin receptor (5HT1D beta) has been cloned and functionally expressed in mammalian fibroblast cultures. Based on the deduced amino acid sequence, the gene encodes a 390-amino acid protein displaying considerable homology, within putative transmembrane domains (approximately 75% identity) to the canine and human 5HT1D receptors. Membranes prepared from CHO cells stably expressing the receptor bound [3H]serotonin with high affinity (Kd 4 nM) and displayed a pharmacological profile consistent, but not identical, with that of the characterized serotonin 5HT1D receptor. Most notably, metergoline and serotonergic piperazine derivatives, as a group, display 3- to 8-fold lower affinity for the 5HT1D beta receptor than for the 5HT1D receptor, whereas both receptors display similar affinities for tryptamine derivatives, including the antimigraine drug sumatriptan. Northern blot analysis revealed an mRNA of approximately 5.5 kilobases expressed in human and monkey frontal cortex, medulla, striatum, hippocampus and amygdala but not in cerebellum, olfactory tubercle, and pituitary. The 5HT1D beta gene maps to human chromosome 6. The existence of multiple neuronal 5HT1D-like receptors may help account for some of the complexities associated with [3H]serotonin binding patterns in native membranes. Images PMID:1351684

  17. 60. BOILER CHAMBER No. 1, D LOOP STEAM GENERATOR AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    60. BOILER CHAMBER No. 1, D LOOP STEAM GENERATOR AND MAIN COOLANT PUMP LOOKING NORTHEAST (LOCATION OOO) - Shippingport Atomic Power Station, On Ohio River, 25 miles Northwest of Pittsburgh, Shippingport, Beaver County, PA

  18. Severe Hypertriglyceridemia in Glut1D on Ketogenic Diet.

    PubMed

    Klepper, Joerg; Leiendecker, Baerbel; Heussinger, Nicole; Lausch, Ekkehart; Bosch, Friedrich

    2016-04-01

    High-fat ketogenic diets are the only treatment available for Glut1 deficiency (Glut1D). Here, we describe an 8-year-old girl with classical Glut1D responsive to a 3:1 ketogenic diet and ethosuximide. After 3 years on the diet a gradual increase of blood lipids was followed by rapid, severe asymptomatic hypertriglyceridemia (1,910 mg/dL). Serum lipid apheresis was required to determine liver, renal, and pancreatic function. A combination of medium chain triglyceride-oil and a reduction of the ketogenic diet to 1:1 ratio normalized triglyceride levels within days but triggered severe myoclonic seizures requiring comedication with sultiam. Severe hypertriglyceridemia in children with Glut1D on ketogenic diets may be underdiagnosed and harmful. In contrast to congenital hypertriglyceridemias, children with Glut1D may be treated effectively by dietary adjustments alone. PMID:26902182

  19. 1D Nanostructures: Controlled Fabrication and Energy Applications

    SciTech Connect

    Hu, Michael Z.

    2013-01-01

    Jian Wei, Xuchun Song, Chunli Yang, and Michael Z. Hu, 1D Nanostructures: Controlled Fabrication and Energy Applications, Journal of Nanomaterials, published special issue (http://www.hindawi.com/journals/jnm/si/197254/) (2013).

  20. Anisotropy of the Earth's inner inner core from autocorrelations of earthquake coda in China Regional Seismic Networks

    NASA Astrophysics Data System (ADS)

    Xia, H.; Song, X.; Wang, T.

    2014-12-01

    The Earth's inner core possesses strong cylindrical anisotropy with the fast symmetry axis parallel to the rotation axis. However, recent study has suggested that the inner part of the inner core has a fast symmetry axis near the equator with a different form of anisotropy from the outer part (Wang et al., this session). To confirm the observation, we use data from dense seismic arrays of the China Regional Seismic Networks. We perform autocorrelation (ACC) of the coda after major earthquakes (Mw>=7.0) at each station and then stack the ACCs at each cluster of stations. The PKIKP2 and PKIIKP2 phases (round-trip phase from the Earth's surface reflections) can be clearly extracted from the stacked empirical Green's functions. We observe systematic variation of the differential times between PKIKP2 and PKIIKP2 phases, which are sensitive to the bulk anisotropy of the inner core. The differential times show large variations with both latitudes and longitudes, even though our ray paths are not polar (with our stations at mid-range latitudes of about 20 to 45 degrees). The observations cannot be explained by an averaged anisotropy model with the fast axis along the rotation axis. The pattern appears consistent with an inner inner core that has a fast axis near the equator.

  1. TBC1D24 genotype–phenotype correlation

    PubMed Central

    Balestrini, Simona; Milh, Mathieu; Castiglioni, Claudia; Lüthy, Kevin; Finelli, Mattea J.; Verstreken, Patrik; Cardon, Aaron; Stražišar, Barbara Gnidovec; Holder, J. Lloyd; Lesca, Gaetan; Mancardi, Maria M.; Poulat, Anne L.; Repetto, Gabriela M.; Banka, Siddharth; Bilo, Leonilda; Birkeland, Laura E.; Bosch, Friedrich; Brockmann, Knut; Cross, J. Helen; Doummar, Diane; Félix, Temis M.; Giuliano, Fabienne; Hori, Mutsuki; Hüning, Irina; Kayserili, Hulia; Kini, Usha; Lees, Melissa M.; Meenakshi, Girish; Mewasingh, Leena; Pagnamenta, Alistair T.; Peluso, Silvio; Mey, Antje; Rice, Gregory M.; Rosenfeld, Jill A.; Taylor, Jenny C.; Troester, Matthew M.; Stanley, Christine M.; Ville, Dorothee; Walkiewicz, Magdalena; Falace, Antonio; Fassio, Anna; Lemke, Johannes R.; Biskup, Saskia; Tardif, Jessica; Ajeawung, Norbert F.; Tolun, Aslihan; Corbett, Mark; Gecz, Jozef; Afawi, Zaid; Howell, Katherine B.; Oliver, Karen L.; Berkovic, Samuel F.; Scheffer, Ingrid E.; de Falco, Fabrizio A.; Oliver, Peter L.; Striano, Pasquale; Zara, Federico

    2016-01-01

    Objective: To evaluate the phenotypic spectrum associated with mutations in TBC1D24. Methods: We acquired new clinical, EEG, and neuroimaging data of 11 previously unreported and 37 published patients. TBC1D24 mutations, identified through various sequencing methods, can be found online (http://lovd.nl/TBC1D24). Results: Forty-eight patients were included (28 men, 20 women, average age 21 years) from 30 independent families. Eighteen patients (38%) had myoclonic epilepsies. The other patients carried diagnoses of focal (25%), multifocal (2%), generalized (4%), and unclassified epilepsy (6%), and early-onset epileptic encephalopathy (25%). Most patients had drug-resistant epilepsy. We detail EEG, neuroimaging, developmental, and cognitive features, treatment responsiveness, and physical examination. In silico evaluation revealed 7 different highly conserved motifs, with the most common pathogenic mutation located in the first. Neuronal outgrowth assays showed that some TBC1D24 mutations, associated with the most severe TBC1D24-associated disorders, are not necessarily the most disruptive to this gene function. Conclusions: TBC1D24-related epilepsy syndromes show marked phenotypic pleiotropy, with multisystem involvement and severity spectrum ranging from isolated deafness (not studied here), benign myoclonic epilepsy restricted to childhood with complete seizure control and normal intellect, to early-onset epileptic encephalopathy with severe developmental delay and early death. There is no distinct correlation with mutation type or location yet, but patterns are emerging. Given the phenotypic breadth observed, TBC1D24 mutation screening is indicated in a wide variety of epilepsies. A TBC1D24 consortium was formed to develop further research on this gene and its associated phenotypes. PMID:27281533

  2. 1D nanocrystals with precisely controlled dimensions, compositions, and architectures

    NASA Astrophysics Data System (ADS)

    Pang, Xinchang; He, Yanjie; Jung, Jaehan; Lin, Zhiqun

    2016-09-01

    The ability to synthesize a diverse spectrum of one-dimensional (1D) nanocrystals presents an enticing prospect for exploring nanoscale size- and shape-dependent properties. Here we report a general strategy to craft a variety of plain nanorods, core-shell nanorods, and nanotubes with precisely controlled dimensions and compositions by capitalizing on functional bottlebrush-like block copolymers with well-defined structures and narrow molecular weight distributions as nanoreactors. These cylindrical unimolecular nanoreactors enable a high degree of control over the size, shape, architecture, surface chemistry, and properties of 1D nanocrystals. We demonstrate the synthesis of metallic, ferroelectric, upconversion, semiconducting, and thermoelectric 1D nanocrystals, among others, as well as combinations thereof.

  3. The GIRAFFE Archive: 1D and 3D Spectra

    NASA Astrophysics Data System (ADS)

    Royer, F.; Jégouzo, I.; Tajahmady, F.; Normand, J.; Chilingarian, I.

    2013-10-01

    The GIRAFFE Archive (http://giraffe-archive.obspm.fr) contains the reduced spectra observed with the intermediate and high resolution multi-fiber spectrograph installed at VLT/UT2 (ESO). In its multi-object configuration and the different integral field unit configurations, GIRAFFE produces 1D spectra and 3D spectra. We present here the status of the archive and the different functionalities to select and download both 1D and 3D data products, as well as the present content. The two collections are available in the VO: the 1D spectra (summed in the case of integral field observations) and the 3D field observations. These latter products can be explored using the VO Paris Euro3D Client (http://voplus.obspm.fr/ chil/Euro3D).

  4. PC-1D installation manual and user's guide

    SciTech Connect

    Basore, P.A.

    1991-05-01

    PC-1D is a software package for personal computers that uses finite-element analysis to solve the fully-coupled two-carrier semiconductor transport equations in one dimension. This program is particularly useful for analyzing the performance of optoelectronic devices such as solar cells, but can be applied to any bipolar device whose carrier flows are primarily one-dimensional. This User's Guide provides the information necessary to install PC-1D, define a problem for solution, solve the problem, and examine the results. Example problems are presented which illustrate these steps. The physical models and numerical methods utilized are presented in detail. This document supports version 3.1 of PC-1D, which incorporates faster numerical algorithms with better convergence properties than previous versions of the program. 51 refs., 17 figs., 5 tabs.

  5. Pitch-based pattern splitting for 1D layout

    NASA Astrophysics Data System (ADS)

    Nakayama, Ryo; Ishii, Hiroyuki; Mikami, Koji; Tsujita, Koichiro; Yaegashi, Hidetami; Oyama, Kenichi; Smayling, Michael C.; Axelrad, Valery

    2015-07-01

    The pattern splitting algorithm for 1D Gridded-Design-Rules layout (1D layout) for sub-10 nm node logic devices is shown. It is performed with integer linear programming (ILP) based on the conflict graph created from a grid map for each designated pitch. The relation between the number of times for patterning and the minimum pitch is shown systematically with a sample pattern of contact layer for each node. From the result, the number of times for patterning for 1D layout is fewer than that for conventional 2D layout. Moreover, an experimental result including SMO and total integrated process with hole repair technique is presented with the sample pattern of contact layer whose pattern density is relatively high among critical layers (fin, gate, local interconnect, contact, and metal).

  6. 1D nanocrystals with precisely controlled dimensions, compositions, and architectures.

    PubMed

    Pang, Xinchang; He, Yanjie; Jung, Jaehan; Lin, Zhiqun

    2016-09-16

    The ability to synthesize a diverse spectrum of one-dimensional (1D) nanocrystals presents an enticing prospect for exploring nanoscale size- and shape-dependent properties. Here we report a general strategy to craft a variety of plain nanorods, core-shell nanorods, and nanotubes with precisely controlled dimensions and compositions by capitalizing on functional bottlebrush-like block copolymers with well-defined structures and narrow molecular weight distributions as nanoreactors. These cylindrical unimolecular nanoreactors enable a high degree of control over the size, shape, architecture, surface chemistry, and properties of 1D nanocrystals. We demonstrate the synthesis of metallic, ferroelectric, upconversion, semiconducting, and thermoelectric 1D nanocrystals, among others, as well as combinations thereof. PMID:27634531

  7. Flexible Photodetectors Based on 1D Inorganic Nanostructures

    PubMed Central

    Lou, Zheng

    2015-01-01

    Flexible photodetectors with excellent flexibility, high mechanical stability and good detectivity, have attracted great research interest in recent years. 1D inorganic nanostructures provide a number of opportunities and capabilities for use in flexible photodetectors as they have unique geometry, good transparency, outstanding mechanical flexibility, and excellent electronic/optoelectronic properties. This article offers a comprehensive review of several types of flexible photodetectors based on 1D nanostructures from the past ten years, including flexible ultraviolet, visible, and infrared photodetectors. High‐performance organic‐inorganic hybrid photodetectors, as well as devices with 1D nanowire (NW) arrays, are also reviewed. Finally, new concepts of flexible photodetectors including piezophototronic, stretchable and self‐powered photodetectors are examined to showcase the future research in this exciting field. PMID:27774404

  8. Scaling relationship between corner frequencies and seismic moments of ultra micro earthquakes estimated with coda-wave spectral ratio -the Mponeng mine in South Africa

    NASA Astrophysics Data System (ADS)

    Wada, N.; Kawakata, H.; Murakami, O.; Doi, I.; Yoshimitsu, N.; Nakatani, M.; Yabe, Y.; Naoi, M. M.; Miyakawa, K.; Miyake, H.; Ide, S.; Igarashi, T.; Morema, G.; Pinder, E.; Ogasawara, H.

    2011-12-01

    Scaling relationship between corner frequencies, fc, and seismic moments, Mo is an important clue to understand the seismic source characteristics. Aki (1967) showed that Mo is proportional to fc-3 for large earthquakes (cubic law). Iio (1986) claimed breakdown of the cubic law between fc and Mo for smaller earthquakes (Mw < 2), and Gibowicz et al. (1991) also showed the breakdown for the ultra micro and small earthquakes (Mw < -2). However, it has been reported that the cubic law holds even for micro earthquakes (-1 < Mw > 4) by using high quality data observed at a deep borehole (Abercrombie, 1995; Ogasawara et al., 2001; Hiramatsu et al., 2002; Yamada et al., 2007). In order to clarify the scaling relationship for smaller earthquakes (Mw < -1), we analyzed ultra micro earthquakes using very high sampling records (48 kHz) of borehole seismometers installed within a hard rock at the Mponeng mine in South Africa. We used 4 tri-axial accelerometers of three-component that have a flat response up to 25 kHz. They were installed to be 10 to 30 meters apart from each other at 3,300 meters deep. During the period from 2008/10/14 to 2008/10/30 (17 days), 8,927 events were recorded. We estimated fc and Mo for 60 events (-3 < Mw < -1) within 200 meters from the seismometers. Assuming the Brune's source model, we estimated fc and Mo from spectral ratios. Common practice is using direct waves from adjacent events. However, there were only 5 event pairs with the distance between them less than 20 meters and Mw difference over one. In addition, the observation array is very small (radius less than 30 m), which means that effects of directivity and radiation pattern on direct waves are similar at all stations. Hence, we used spectral ratio of coda waves, since these effects are averaged and will be effectively reduced (Mayeda et al., 2007; Somei et al., 2010). Coda analysis was attempted only for relatively large 20 events (we call "coda events" hereafter) that have coda energy

  9. Estimation of the frequency-dependent site amplification factors of Japan based on the coda normalization method

    NASA Astrophysics Data System (ADS)

    Takemoto, T.; Furumura, T.; Saito, T.; Maeda, T.; Noguchi, S.

    2011-12-01

    We estimated the frequency dependent properties of the site amplification factors at each station of the K-NET and KiK-net strong motion network across Japan based on the coda normalization method. Using a large number of waveform data of 3,004 acceleration record from 48 earthquakes and waveform record from 1800 strong motion stations, we estimated the site amplification factors at each frequency band from f=0.5-1 Hz, 1-2 Hz, 2-4 Hz, to 4-8 Hz. In this study we assumed a rock-site station (Tashiro at Kyushu) as a reference of the site amplification estimates. The estimated site amplification factors show strong variations in the low frequency band (0.5-1 Hz) as compare with that of the high frequency band (4-8 Hz). Large site amplification factor in the low-frequency band is found in major populated cities such as Tokyo, Osaka, and Nagoya with varying amplification factors between 10 to 20 dB relative to the reference rock-site station. Such distribution of the site amplification factors in the low-frequency (0.5-1 Hz) band is in good corresponding to the depth distribution of a basement rocks with S-wave speed greater than 2.9 km/s. On the other hand the site-amplification factors in high-frequency (4-8 Hz) band are rather small (5 to 10 dB) as compared with that of the low-frequency band and spatial distribution is almost randomly distributed irrespective to surface geology. In order to examine the reliability of our estimates of the site amplification factors based on the coda-normalization method and to examine how the site amplification modify the distribution of seismic intensity distributions for large earthquakes, we reproduced intensity distributions of recent Japanese M7 earthquakes such as the 2004 Niigata Chuetsu (M6.8), the 2005 Western Fukuoka (M7.0), and the 2008 Coast of Iwate (M6.8) earthquakes by removing the site amplification factors of each frequency band from the acceleration waveform record at each K-NET and the KiK-net station. The site

  10. Pyrimidine, purine and nitrogen control of cytosine deaminase synthesis in Escherichia coli K 12. Involvement of the glnLG and purR genes in the regulation of codA expression.

    PubMed

    Andersen, L; Kilstrup, M; Neuhard, J

    1989-01-01

    Cytosine deaminase, encoded by the codA gene in Escherichia coli catalyzes the deamination of cytosine to uracil and ammonia. Regulation of codA expression was studied by determining the level of cytosine deaminase in E. coli K12 grown in various defined media. Addition of either pyrimidine or purine nucleobases to the growth medium caused repressed enzyme levels, whereas growth on a poor nitrogen source such as proline resulted in derepression of cytosine deaminase synthesis. Derepression of codA expression was induced by starvation for either uracil or cytosine nucleotides. Nitrogen control was found to be mediated by the glnLG gene products, and purine repression required a functional purR gene product. Studies with strains harbouring multiple mutations affecting both pyrimidine, purine and nitrogen control revealed that the overall regulation of cytosine deaminase synthesis by the different metabolites is cumulative.

  11. Bodies and codas or core syllables plus appendices? Evidence for a developmental theory of subsyllabic division preference.

    PubMed

    Chen, Aleck Shih-Wei

    2011-12-01

    Two experiments examining the subsyllabic division behaviors of Chinese-speaking children learning English as a foreign language (EFL) are reported. In Experiment 1, target phonemes of monosyllabic English nonwords were varied in phonotactic context (e.g., (C)VC vs. (C)CVC), marginality (e.g., (C)CVC vs. C(C)VC), and/or position (e.g., (C)VC vs. CV(C)) in phoneme deletion and isolation tasks, with confounds such as global similarity, vowel length, and targets' sonority controlled. The fourth graders found the initial obstruent more difficult to isolate when it constituted the onset itself, i.e., (C)VC, than when it was part of a clustered onset, i.e., (C)CVC; no such difference was observed (non)word-finally, however. The results thus failed to support a subsyllabic preference for either onsets and rimes or bodies and codas. In Experiment 2, 49 second graders were tested on two other sets of phoneme awareness tasks and similar results were obtained. Items of one task were adapted from Hulme et al. (2002), in which the English-speaking first graders found the initial phoneme of a clustered onset, i.e., (C)CVC, more difficult to delete than the cluster as a whole, i.e., (CC)VC. The opposite patterns were observed with the Chinese EFL learners in Experiment 2, who found instead the initial consonant easier to remove. Taken together, the results suggested that Chinese-speaking EFL children process an English syllable as a linear combination of an intact core syllable (i.e., CV) plus its appendices. In both experiments, moreover, only performance in segmenting core syllable, but not that of segmenting appendices from the core syllable, predicted decoding success, a pattern again opposite to that of Hulme et al. (2002). The seemingly conflicting results were nevertheless consistent with a general developmental account of intra-syllabic division preference. PMID:21924411

  12. GIS-BASED 1-D DIFFUSIVE WAVE OVERLAND FLOW MODEL

    SciTech Connect

    KALYANAPU, ALFRED; MCPHERSON, TIMOTHY N.; BURIAN, STEVEN J.

    2007-01-17

    This paper presents a GIS-based 1-d distributed overland flow model and summarizes an application to simulate a flood event. The model estimates infiltration using the Green-Ampt approach and routes excess rainfall using the 1-d diffusive wave approximation. The model was designed to use readily available topographic, soils, and land use/land cover data and rainfall predictions from a meteorological model. An assessment of model performance was performed for a small catchment and a large watershed, both in urban environments. Simulated runoff hydrographs were compared to observations for a selected set of validation events. Results confirmed the model provides reasonable predictions in a short period of time.

  13. Observation of Dynamical Fermionization in 1D Bose Gases

    NASA Astrophysics Data System (ADS)

    Malvania, Neel; Xia, Lin; Xu, Wei; Wilson, Joshua M.; Zundel, Laura A.; Rigol, Marcos; Weiss, David S.

    2016-05-01

    The momentum distribution of a harmonically trapped 1D Bose gases in the Tonks-Girardeau limit is expected to undergo dynamical fermionization. That is, after the harmonic trap is suddenly turned off, the momentum distribution steadily transforms into that of an ideal Fermi gas in the same initial trap. We measure 1D momentum distributions at variable times after such a quench, and observe the predicted dynamical fermionization. In addition to working in the strong coupling limit, we also perform the experiment with intermediate coupling, where theoretical calculations are more challenging.

  14. Auto Correlation Analysis of Coda Waves from Local Earthquakes for Detecting Temporal Changes in Shallow Subsurface Structures: the 2011 Tohoku-Oki, Japan Earthquake

    NASA Astrophysics Data System (ADS)

    Nakahara, Hisashi

    2015-02-01

    For monitoring temporal changes in subsurface structures I propose to use auto correlation functions of coda waves from local earthquakes recorded at surface receivers, which probably contain more body waves than surface waves. Use of coda waves requires earthquakes resulting in decreased time resolution for monitoring. Nonetheless, it may be possible to monitor subsurface structures in sufficient time resolutions in regions with high seismicity. In studying the 2011 Tohoku-Oki, Japan earthquake (Mw 9.0), for which velocity changes have been previously reported, I try to validate the method. KiK-net stations in northern Honshu are used in this analysis. For each moderate earthquake normalized auto correlation functions of surface records are stacked with respect to time windows in the S-wave coda. Aligning the stacked, normalized auto correlation functions with time, I search for changes in phases arrival times. The phases at lag times of <1 s are studied because changes at shallow depths are focused. Temporal variations in the arrival times are measured at the stations based on the stretching method. Clear phase delays are found to be associated with the mainshock and to gradually recover with time. The amounts of the phase delays are 10 % on average with the maximum of about 50 % at some stations. The deconvolution analysis using surface and subsurface records at the same stations is conducted for validation. The results show the phase delays from the deconvolution analysis are slightly smaller than those from the auto correlation analysis, which implies that the phases on the auto correlations are caused by larger velocity changes at shallower depths. The auto correlation analysis seems to have an accuracy of about several percent, which is much larger than methods using earthquake doublets and borehole array data. So this analysis might be applicable in detecting larger changes. In spite of these disadvantages, this analysis is still attractive because it can

  15. Non-cooperative Brownian donkeys: A solvable 1D model

    NASA Astrophysics Data System (ADS)

    Jiménez de Cisneros, B.; Reimann, P.; Parrondo, J. M. R.

    2003-12-01

    A paradigmatic 1D model for Brownian motion in a spatially symmetric, periodic system is tackled analytically. Upon application of an external static force F the system's response is an average current which is positive for F < 0 and negative for F > 0 (absolute negative mobility). Under suitable conditions, the system approaches 100% efficiency when working against the external force F.

  16. 1D design style implications for mask making and CEBL

    NASA Astrophysics Data System (ADS)

    Smayling, Michael C.

    2013-09-01

    At advanced nodes, CMOS logic is being designed in a highly regular design style because of the resolution limitations of optical lithography equipment. Logic and memory layouts using 1D Gridded Design Rules (GDR) have been demonstrated to nodes beyond 12nm.[1-4] Smaller nodes will require the same regular layout style but with multiple patterning for critical layers. One of the significant advantages of 1D GDR is the ease of splitting layouts into lines and cuts. A lines and cuts approach has been used to achieve good pattern fidelity and process margin to below 12nm.[4] Line scaling with excellent line-edge roughness (LER) has been demonstrated with self-aligned spacer processing.[5] This change in design style has important implications for mask making: • The complexity of the masks will be greatly reduced from what would be required for 2D designs with very complex OPC or inverse lithography corrections. • The number of masks will initially increase, as for conventional multiple patterning. But in the case of 1D design, there are future options for mask count reduction. • The line masks will remain simple, with little or no OPC, at pitches (1x) above 80nm. This provides an excellent opportunity for continual improvement of line CD and LER. The line pattern will be processed through a self-aligned pitch division sequence to divide pitch by 2 or by 4. • The cut masks can be done with "simple OPC" as demonstrated to beyond 12nm.[6] Multiple simple cut masks may be required at advanced nodes. "Coloring" has been demonstrated to below 12nm for two colors and to 8nm for three colors. • Cut/hole masks will eventually be replaced by e-beam direct write using complementary e-beam lithography (CEBL).[7-11] This transition is gated by the availability of multiple column e-beam systems with throughput adequate for high- volume manufacturing. A brief description of 1D and 2D design styles will be presented, followed by examples of 1D layouts. Mask complexity for 1

  17. Numerical simulations of heavily polluted fine-grained sediment remobilization using 1D, 1D+, and 2D channel schematization.

    PubMed

    Kaiglová, Jana; Langhammer, Jakub; Jiřinec, Petr; Janský, Bohumír; Chalupová, Dagmar

    2015-03-01

    This article used various hydrodynamic and sediment transport models to analyze the potential and the limits of different channel schematizations. The main aim was to select and evaluate the most suitable simulation method for fine-grained sediment remobilization assessment. Three types of channel schematization were selected to study the flow potential for remobilizing fine-grained sediment in artificially modified channels. Schematization with a 1D cross-sectional horizontal plan, a 1D+ approach, splitting the riverbed into different functional zones, and full 2D mesh, adopted in MIKE by the DHI modeling suite, was applied to the study. For the case study, a 55-km stretch of the Bílina River, in the Czech Republic, Central Europe, which has been heavily polluted by the chemical and coal mining industry since the mid-twentieth century, was selected. Long-term exposure to direct emissions of toxic pollutants including heavy metals and persistent organic pollutants (POPs) resulted in deposits of pollutants in fine-grained sediments in the riverbed. Simulations, based on three hydrodynamic model schematizations, proved that for events not exceeding the extent of the riverbed profile, the 1D schematization can provide comparable results to a 2D model. The 1D+ schematization can improve accuracy while keeping the benefits of high-speed simulation and low requirements of input DEM data, but the method's suitability is limited by the channel properties. PMID:25687259

  18. Recording of anomalous shear energy in the teleseismic P-wave coda at Long Valley Caldera, California, on a small aperture array

    SciTech Connect

    Zucca, J.J.; Zandt, G. ); Steck, L.K.; Prothero, W.A. . Dept. of Geology)

    1990-03-01

    Anomalous energy in the coda of teleseismic P-waves at Long Valley caldera has been suggested to be a P to S converted arrival, perhaps with the conversion occurring at the boundaries of magma bodies beneath the caldera. We have collected new data with a small-aperture, three-component array located in the northwestern quadrant of the caldera with the purpose of testing this hypothesis. An examination of three teleseismic events using array and particle motion techniques shows that converted P- to S-waves comprise a significant fraction of the early arriving anomalous energy. In volcanic areas such as Long Valley, the scattered energy could originate at a high velocity contrast feature such as magma body interface. In addition, later arriving energy was detected with slow phase velocity and is tentatively identified as body wave to surface wave scattering. Our interpretation is illustrated with waveforms of two earthquakes from the Kuril Islands and one in northern Peru. Our results show that a small-aperture, three-component array can be used to perform detailed analysis of the coda. 12 refs., 8 figs., 1 tab.

  19. 1-D Numerical Analysis of ABCC Engine Performance

    NASA Technical Reports Server (NTRS)

    Holden, Richard

    1999-01-01

    ABCC engine combines air breathing and rocket engine into a single engine to increase the specific impulse over an entire flight trajectory. Except for the heat source, the basic operation of the ABCC is similar to the basic operation of the RBCC engine. The ABCC is intended to have a higher specific impulse than the RBCC for single stage Earth to orbit vehicle. Computational fluid dynamics (CFD) is a useful tool for the analysis of complex transport processes in various components in ABCC propulsion system. The objective of the present research was to develop a transient 1-D numerical model using conservation of mass, linear momentum, and energy equations that could be used to predict flow behavior throughout a generic ABCC engine following a flight path. At specific points during the development of the 1-D numerical model a myriad of tests were performed to prove the program produced consistent, realistic numbers that follow compressible flow theory for various inlet conditions.

  20. Phase diagram of a bulk 1d lattice Coulomb gas

    NASA Astrophysics Data System (ADS)

    Démery, V.; Monsarrat, R.; Dean, D. S.; Podgornik, R.

    2016-01-01

    The exact solution, via transfer matrix, of the simple one-dimensional lattice Coulomb gas (1d LCG) model can reproduce peculiar features of ionic liquid capacitors, such as overscreening, layering, and camel- and bell-shaped capacitance curves. Using the same transfer matrix method, we now compute the bulk properties of the 1d LCG in the constant voltage ensemble. We unveil a phase diagram with rich structure exhibiting low-density disordered and high-density ordered phases, separated by a first-order phase transition at low temperature; the solid state at full packing can be ordered or not, depending on the temperature. This phase diagram, which is strikingly similar to its three-dimensional counterpart, also sheds light on the behaviour of the confined system.

  1. 1D Josephson quantum interference grids: diffraction patterns and dynamics

    NASA Astrophysics Data System (ADS)

    Lucci, M.; Badoni, D.; Corato, V.; Merlo, V.; Ottaviani, I.; Salina, G.; Cirillo, M.; Ustinov, A. V.; Winkler, D.

    2016-02-01

    We investigate the magnetic response of transmission lines with embedded Josephson junctions and thus generating a 1D underdamped array. The measured multi-junction interference patterns are compared with the theoretical predictions for Josephson supercurrent modulations when an external magnetic field couples both to the inter-junction loops and to the junctions themselves. The results provide a striking example of the analogy between Josephson phase modulation and 1D optical diffraction grid. The Fiske resonances in the current-voltage characteristics with voltage spacing {Φ0}≤ft(\\frac{{\\bar{c}}}{2L}\\right) , where L is the total physical length of the array, {Φ0} the magnetic flux quantum and \\bar{c} the speed of light in the transmission line, demonstrate that the discrete line supports stable dynamic patterns generated by the ac Josephson effect interacting with the cavity modes of the line.

  2. Morphodynamics and sediment tracers in 1-D (MAST-1D): 1-D sediment transport that includes exchange with an off-channel sediment reservoir

    NASA Astrophysics Data System (ADS)

    Lauer, J. Wesley; Viparelli, Enrica; Piégay, Hervé

    2016-07-01

    Bed material transported in geomorphically active gravel bed rivers often has a local source at nearby eroding banks and ends up sequestered in bars not far downstream. However, most 1-D numerical models for gravel transport assume that gravel originates from and deposits on the channel bed. In this paper, we present a 1-D framework for simulating morphodynamic evolution of bed elevation and size distribution in a gravel-bed river that actively exchanges sediment with its floodplain, which is represented as an off-channel sediment reservoir. The model is based on the idea that sediment enters the channel at eroding banks whose elevation depends on total floodplain sediment storage and on the average elevation of the floodplain relative to the channel bed. Lateral erosion of these banks occurs at a specified rate that can represent either net channel migration or channel widening. Transfer of material out of the channel depends on a typical bar thickness and a specified lateral exchange rate due either to net channel migration or narrowing. The model is implemented using an object oriented framework that allows users to explore relationships between bank supply, bed structure, and lateral change rates. It is applied to a ∼50-km reach of the Ain River, France, that experienced significant reduction in sediment supply due to dam construction during the 20th century. Results are strongly sensitive to lateral exchange rates, showing that in this reach, the supply of sand and gravel at eroding banks and the sequestration of gravel in point bars can have strong influence on overall reach-scale sediment budgets.

  3. Spatial changes of seismic attenuation and multiscale geological heterogeneity in the Baikal rift and surroundings from analysis of coda waves

    NASA Astrophysics Data System (ADS)

    Dobrynina, Anna A.; Sankov, Vladimir A.; Chechelnitsky, Vladimir V.; Déverchère, Jacques

    2016-04-01

    The Baikal rift system is undergoing an active tectonic deformation expressed by a high level of seismic activity. This deformation leads to physical and mechanical changes of crustal properties which can be investigated by the seismic quality factor and its frequency dependence. Using a single backscattering model, a seismic quality-factor (QC), a frequency parameter (n) and an attenuation coefficient (δ) have been estimated by analyzing coda waves of 274 local earthquakes of the Baikal rift system for nineteen lapse time windows (W) from 10 to 100 s every 5 s and for six central frequencies (0.3, 0.75, 1.5, 3, 6 and 12 Hz). The average QC value increases with the frequency and lapse time window from 46 ± 52 (at 0.75 Hz) to 502 ± 109 (at 12 Hz) for W = 10 s and from 114 ± 49 (at 0.3 Hz) to 1865 ± 679 (at 12 Hz) for W = 100 s. The values of QC(f) and δ were estimated for the whole Baikal rift system and for separate tectonic blocks: the stable Siberian Platform, main rift basins, spurs and uplifts. Along the rift system, the Q0-value (QC-factor at the frequency f = 1 Hz) varies within 72-109 and the frequency parameter n ranges from 0.87 to 1.22, whereas Q0 is 134 and n is 0.48 for the stable Siberian Platform. Vertical variations of attenuation reveal that sharp changes of δ and n are confined to the velocity discontinuities. The comparison of lateral variations of seismic wave attenuation and geological and geophysical characteristics of the Baikal rift system shows that attenuation is correlated with both seismic activity and heat flow and in a lesser degree with the surface fault density and the age of the crust. Seismic wave attenuation found across the main shear zones of the south-western Baikal rift (Main Sayan strike-slip fault zone and Tunka, Obruchev and Primorsky normal faults) is increased by more than 25-60% compared to the neighboring areas.

  4. Enhancing Solar Cell Efficiencies through 1-D Nanostructures

    PubMed Central

    2009-01-01

    The current global energy problem can be attributed to insufficient fossil fuel supplies and excessive greenhouse gas emissions resulting from increasing fossil fuel consumption. The huge demand for clean energy potentially can be met by solar-to-electricity conversions. The large-scale use of solar energy is not occurring due to the high cost and inadequate efficiencies of existing solar cells. Nanostructured materials have offered new opportunities to design more efficient solar cells, particularly one-dimensional (1-D) nanomaterials for enhancing solar cell efficiencies. These 1-D nanostructures, including nanotubes, nanowires, and nanorods, offer significant opportunities to improve efficiencies of solar cells by facilitating photon absorption, electron transport, and electron collection; however, tremendous challenges must be conquered before the large-scale commercialization of such cells. This review specifically focuses on the use of 1-D nanostructures for enhancing solar cell efficiencies. Other nanostructured solar cells or solar cells based on bulk materials are not covered in this review. Major topics addressed include dye-sensitized solar cells, quantum-dot-sensitized solar cells, and p-n junction solar cells.

  5. Constructing 3D interaction maps from 1D epigenomes

    PubMed Central

    Zhu, Yun; Chen, Zhao; Zhang, Kai; Wang, Mengchi; Medovoy, David; Whitaker, John W.; Ding, Bo; Li, Nan; Zheng, Lina; Wang, Wei

    2016-01-01

    The human genome is tightly packaged into chromatin whose functional output depends on both one-dimensional (1D) local chromatin states and three-dimensional (3D) genome organization. Currently, chromatin modifications and 3D genome organization are measured by distinct assays. An emerging question is whether it is possible to deduce 3D interactions by integrative analysis of 1D epigenomic data and associate 3D contacts to functionality of the interacting loci. Here we present EpiTensor, an algorithm to identify 3D spatial associations within topologically associating domains (TADs) from 1D maps of histone modifications, chromatin accessibility and RNA-seq. We demonstrate that active promoter–promoter, promoter–enhancer and enhancer–enhancer associations identified by EpiTensor are highly concordant with those detected by Hi-C, ChIA-PET and eQTL analyses at 200 bp resolution. Moreover, EpiTensor has identified a set of interaction hotspots, characterized by higher chromatin and transcriptional activity as well as enriched TF and ncRNA binding across diverse cell types, which may be critical for stabilizing the local 3D interactions. PMID:26960733

  6. Constructing 3D interaction maps from 1D epigenomes.

    PubMed

    Zhu, Yun; Chen, Zhao; Zhang, Kai; Wang, Mengchi; Medovoy, David; Whitaker, John W; Ding, Bo; Li, Nan; Zheng, Lina; Wang, Wei

    2016-01-01

    The human genome is tightly packaged into chromatin whose functional output depends on both one-dimensional (1D) local chromatin states and three-dimensional (3D) genome organization. Currently, chromatin modifications and 3D genome organization are measured by distinct assays. An emerging question is whether it is possible to deduce 3D interactions by integrative analysis of 1D epigenomic data and associate 3D contacts to functionality of the interacting loci. Here we present EpiTensor, an algorithm to identify 3D spatial associations within topologically associating domains (TADs) from 1D maps of histone modifications, chromatin accessibility and RNA-seq. We demonstrate that active promoter-promoter, promoter-enhancer and enhancer-enhancer associations identified by EpiTensor are highly concordant with those detected by Hi-C, ChIA-PET and eQTL analyses at 200 bp resolution. Moreover, EpiTensor has identified a set of interaction hotspots, characterized by higher chromatin and transcriptional activity as well as enriched TF and ncRNA binding across diverse cell types, which may be critical for stabilizing the local 3D interactions. PMID:26960733

  7. Development of 1D Liner Compression Code for IDL

    NASA Astrophysics Data System (ADS)

    Shimazu, Akihisa; Slough, John; Pancotti, Anthony

    2015-11-01

    A 1D liner compression code is developed to model liner implosion dynamics in the Inductively Driven Liner Experiment (IDL) where FRC plasmoid is compressed via inductively-driven metal liners. The driver circuit, magnetic field, joule heating, and liner dynamics calculations are performed at each time step in sequence to couple these effects in the code. To obtain more realistic magnetic field results for a given drive coil geometry, 2D and 3D effects are incorporated into the 1D field calculation through use of correction factor table lookup approach. Commercial low-frequency electromagnetic fields solver, ANSYS Maxwell 3D, is used to solve the magnetic field profile for static liner condition at various liner radius in order to derive correction factors for the 1D field calculation in the code. The liner dynamics results from the code is verified to be in good agreement with the results from commercial explicit dynamics solver, ANSYS Explicit Dynamics, and previous liner experiment. The developed code is used to optimize the capacitor bank and driver coil design for better energy transfer and coupling. FRC gain calculations are also performed using the liner compression data from the code for the conceptual design of the reactor sized system for fusion energy gains.

  8. Molecular characterization of zebrafish Oatp1d1 (Slco1d1), a novel organic anion-transporting polypeptide.

    PubMed

    Popovic, Marta; Zaja, Roko; Fent, Karl; Smital, Tvrtko

    2013-11-22

    The organic anion-transporting polypeptide (OATP/Oatp) superfamily includes a group of polyspecific transporters that mediate transport of large amphipathic, mostly anionic molecules across cell membranes of eukaryotes. OATPs/Oatps are involved in the disposition and elimination of numerous physiological and foreign compounds. However, in non-mammalian species, the functional properties of Oatps remain unknown. We aimed to elucidate the role of Oatp1d1 in zebrafish to gain insights into the functional and structural evolution of the OATP1/Oatp1 superfamily. We show that diversification of the OATP1/Oatp1 family occurs after the emergence of jawed fish and that the OATP1A/Oatp1a and OATP1B/Oatp1b subfamilies appeared at the root of tetrapods. The Oatp1d subfamily emerged in teleosts and is absent in tetrapods. The zebrafish Oatp1d1 is similar to mammalian OATP1A/Oatp1a and OATP1B/Oatp1b members, with the main physiological role in transport and balance of steroid hormones. Oatp1d1 activity is dependent upon pH gradient, which could indicate bicarbonate exchange as a mode of transport. Our analysis of evolutionary conservation and structural properties revealed that (i) His-79 in intracellular loop 3 is conserved within OATP1/Oatp1 family and is crucial for the transport activity; (ii) N-glycosylation impacts membrane targeting and is conserved within the OATP1/Oatp1 family with Asn-122, Asn-133, Asn-499, and Asn-512 residues involved; (iii) the evolutionarily conserved cholesterol recognition interaction amino acid consensus motif is important for membrane localization; and (iv) Oatp1d1 is present in dimeric and possibly oligomeric form in the cell membrane. In conclusion, we describe the first detailed characterization of a new Oatp transporter in zebrafish, offering important insights into the functional evolution of the OATP1/Oatp1 family and the physiological role of Oatp1d1.

  9. Mycotoxin methodology.

    PubMed

    Scott, P M

    1995-01-01

    Sensitive, specific, accurate and precise methods of analysis are needed for enforcement of mycotoxin regulations, other monitoring programmes, and research studies. Rapid screening tests are useful for control at all stages of food and feed production. There is a wide choice of both quantitative and qualitative methods for the more well known mycotoxins. Those at present covered by method standardization organizations such as AOAC International are aflatoxins (including M1), Alternaria toxins, citrinin, cyclopiazonic acid, ergot alkaloids, fumonisins, ochratoxins, patulin, trichothecenes, and zearalenone. Methodology for mycotoxins is selectively reviewed in this paper with emphasis on the procedures comprising the analytical method--sampling, extraction of naturally contaminated samples, clean-up, detection and determination, and confirmation. Also covered are automation, method comparison, and method assessment.

  10. Extended-Range Ultrarefractive 1D Photonic Crystal Prisms

    NASA Technical Reports Server (NTRS)

    Ting, David Z.

    2007-01-01

    A proposal has been made to exploit the special wavelength-dispersive characteristics of devices of the type described in One-Dimensional Photonic Crystal Superprisms (NPO-30232) NASA Tech Briefs, Vol. 29, No. 4 (April 2005), page 10a. A photonic crystal is an optical component that has a periodic structure comprising two dielectric materials with high dielectric contrast (e.g., a semiconductor and air), with geometrical feature sizes comparable to or smaller than light wavelengths of interest. Experimental superprisms have been realized as photonic crystals having three-dimensional (3D) structures comprising regions of amorphous Si alternating with regions of SiO2, fabricated in a complex process that included sputtering. A photonic crystal of the type to be exploited according to the present proposal is said to be one-dimensional (1D) because its contrasting dielectric materials would be stacked in parallel planar layers; in other words, there would be spatial periodicity in one dimension only. The processes of designing and fabricating 1D photonic crystal superprisms would be simpler and, hence, would cost less than do those for 3D photonic crystal superprisms. As in 3D structures, 1D photonic crystals may be used in applications such as wavelength-division multiplexing. In the extended-range configuration, it is also suitable for spectrometry applications. As an engineered structure or artificially engineered material, a photonic crystal can exhibit optical properties not commonly found in natural substances. Prior research had revealed several classes of photonic crystal structures for which the propagation of electromagnetic radiation is forbidden in certain frequency ranges, denoted photonic bandgaps. It had also been found that in narrow frequency bands just outside the photonic bandgaps, the angular wavelength dispersion of electromagnetic waves propagating in photonic crystal superprisms is much stronger than is the angular wavelength dispersion obtained

  11. Non-linearity in Bayesian 1-D magnetotelluric inversion

    NASA Astrophysics Data System (ADS)

    Guo, Rongwen; Dosso, Stan E.; Liu, Jianxin; Dettmer, Jan; Tong, Xiaozhong

    2011-05-01

    This paper applies a Bayesian approach to examine non-linearity for the 1-D magnetotelluric (MT) inverse problem. In a Bayesian formulation the posterior probability density (PPD), which combines data and prior information, is interpreted in terms of parameter estimates and uncertainties, which requires optimizing and integrating the PPD. Much work on 1-D MT inversion has been based on (approximate) linearized solutions, but more recently fully non-linear (numerical) approaches have been applied. This paper directly compares results of linearized and non-linear uncertainty estimation for 1-D MT inversion; to do so, advanced methods for both approaches are applied. In the non-linear formulation used here, numerical optimization is carried out using an adaptive-hybrid algorithm. Numerical integration applies Metropolis-Hastings sampling, rotated to a principal-component parameter space for efficient sampling of correlated parameters, and employing non-unity sampling temperatures to ensure global sampling. Since appropriate model parametrizations are generally not known a priori, both under- and overparametrized approaches are considered. For underparametrization, the Bayesian information criterion is applied to determine the number of layers consistent with the resolving power of the data. For overparametrization, prior information is included which favours simple structure in a manner similar to regularized inversion. The data variance and/or trade-off parameter regulating data and prior information are treated in several ways, including applying fixed optimal estimates (an empirical Bayesian approach) or including them as hyperparameters in the sampling (hierarchical Bayesian). The latter approach has the benefit of accounting for the uncertainty in the hyperparameters in estimating model parameter uncertainties. Non-linear and linearized inversion results are compared for synthetic test cases and for the measured COPROD1 MT data by considering marginal probability

  12. A facile route for 3D aerogels from nanostructured 1D and 2D materials

    PubMed Central

    Jung, Sung Mi; Jung, Hyun Young; Dresselhaus, Mildred S.; Jung, Yung Joon; Kong, Jing

    2012-01-01

    Aerogels have numerous applications due to their high surface area and low densities. However, creating aerogels from a large variety of materials has remained an outstanding challenge. Here, we report a new methodology to enable aerogel production with a wide range of materials. The method is based on the assembly of anisotropic nano-objects (one-dimensional (1D) nanotubes, nanowires, or two-dimensional (2D) nanosheets) into a cross-linking network from their colloidal suspensions at the transition from the semi-dilute to the isotropic concentrated regime. The resultant aerogels have highly porous and ultrafine three-dimensional (3D) networks consisting of 1D (Ag, Si, MnO2, single-walled carbon nanotubes (SWNTs)) and 2D materials (MoS2, graphene, h-BN) with high surface areas, low densities, and high electrical conductivities. This method opens up a facile route for aerogel production with a wide variety of materials and tremendous opportunities for bio-scaffold, energy storage, thermoelectric, catalysis, and hydrogen storage applications. PMID:23152940

  13. A facile route for 3D aerogels from nanostructured 1D and 2D materials.

    PubMed

    Jung, Sung Mi; Jung, Hyun Young; Dresselhaus, Mildred S; Jung, Yung Joon; Kong, Jing

    2012-01-01

    Aerogels have numerous applications due to their high surface area and low densities. However, creating aerogels from a large variety of materials has remained an outstanding challenge. Here, we report a new methodology to enable aerogel production with a wide range of materials. The method is based on the assembly of anisotropic nano-objects (one-dimensional (1D) nanotubes, nanowires, or two-dimensional (2D) nanosheets) into a cross-linking network from their colloidal suspensions at the transition from the semi-dilute to the isotropic concentrated regime. The resultant aerogels have highly porous and ultrafine three-dimensional (3D) networks consisting of 1D (Ag, Si, MnO(2), single-walled carbon nanotubes (SWNTs)) and 2D materials (MoS(2), graphene, h-BN) with high surface areas, low densities, and high electrical conductivities. This method opens up a facile route for aerogel production with a wide variety of materials and tremendous opportunities for bio-scaffold, energy storage, thermoelectric, catalysis, and hydrogen storage applications.

  14. Viscous behavior in a quasi-1D fractal cluster glass.

    PubMed

    Etzkorn, S J; Hibbs, Wendy; Miller, Joel S; Epstein, A J

    2002-11-11

    The spin glass transition of a quasi-1D organic-based magnet ([MnTPP][TCNE]) is explored using both ac and dc measurements. A scaling analysis of the ac susceptibility shows a spin glass transition near 4 K, with a viscous decay of the thermoremanent magnetization recorded above 4 K. We propose an extension to a fractal cluster model of spin glasses that determines the dimension of the spin clusters (D) ranging from approximately 0.8 to over 1.5 as the glass transition is approached. Long-range dipolar interactions are suggested as the origin of this low value for the apparent lower critical dimension.

  15. Practical variational tomography for critical 1D systems

    NASA Astrophysics Data System (ADS)

    Lee, Jong Yeon; Landon-Cardinal, Olivier

    2015-03-01

    We further investigate a recently introduced efficient quantum state reconstruction procedure targeted to states well-approximated by the multi-scale entanglement renormalization ansatz (MERA). First, we introduce an improved optimization scheme that can be easily generalized for MERA states with larger bond dimension. Second, we provide a detailed analysis of the error propagation and quantify how it affects the distance between the experimental state and the reconstructed state. Third, we explain how to bound this distance using local data, providing an efficient scalable certification method. Fourth, we examine the performance of MERA tomography on the ground states of several 1D critical models.

  16. Structural stability of a 1D compressible viscoelastic fluid model

    NASA Astrophysics Data System (ADS)

    Huo, Xiaokai; Yong, Wen-An

    2016-07-01

    This paper is concerned with a compressible viscoelastic fluid model proposed by Öttinger. Although the model has a convex entropy, the Hessian matrix of the entropy does not symmetrize the system of first-order partial differential equations due to the non-conservative terms in the constitutive equation. We show that the corresponding 1D model is symmetrizable hyperbolic and dissipative and satisfies the Kawashima condition. Based on these, we prove the global existence of smooth solutions near equilibrium and justify the compatibility of the model with the Navier-Stokes equations.

  17. Nonlocal Order Parameters for the 1D Hubbard Model

    NASA Astrophysics Data System (ADS)

    Montorsi, Arianna; Roncaglia, Marco

    2012-12-01

    We characterize the Mott-insulator and Luther-Emery phases of the 1D Hubbard model through correlators that measure the parity of spin and charge strings along the chain. These nonlocal quantities order in the corresponding gapped phases and vanish at the critical point Uc=0, thus configuring as hidden order parameters. The Mott insulator consists of bound doublon-holon pairs, which in the Luther-Emery phase turn into electron pairs with opposite spins, both unbinding at Uc. The behavior of the parity correlators is captured by an effective free spinless fermion model.

  18. Deconvolution/identification techniques for 1-D transient signals

    SciTech Connect

    Goodman, D.M.

    1990-10-01

    This paper discusses a variety of nonparametric deconvolution and identification techniques that we have developed for application to 1-D transient signal problems. These methods are time-domain techniques that use direct methods for matrix inversion. Therefore, they are not appropriate for large data'' problems. These techniques involve various regularization methods and permit the use of certain kinds of a priori information in estimating the unknown. These techniques have been implemented in a package using standard FORTRAN that should make the package readily transportable to most computers. This paper is also meant to be an instruction manual for the package. 25 refs., 17 figs., 1 tab.

  19. Coherent thermal conductance of 1-D photonic crystals

    NASA Astrophysics Data System (ADS)

    Tschikin, Maria; Ben-Abdallah, Philippe; Biehs, Svend-Age

    2012-10-01

    We present an exact calculation of coherent thermal conductance in 1-D multilayer photonic crystals using the S-matrix method. In particular, we study the thermal conductance in a bilayer structure of Si/vacuum or Al2O3/vacuum slabs by means of the exact radiative heat flux expression. Based on the results obtained for the Al2O3/vacuum structure we show by comparison with previous works that the material losses and (localized) surface modes supported by the inner layers play a fundamental role and cannot be omitted in the definition of thermal conductance. Our results could have significant implications in the conception of efficient thermal barriers.

  20. A simple quasi-1D model of Fibonacci anyons

    NASA Astrophysics Data System (ADS)

    Aasen, David; Mong, Roger; Clarke, David; Alicea, Jason; Fendley, Paul

    2015-03-01

    There exists various ways of understanding the topological properties of Ising anyons--from simple free-fermion toy models to formal topological quantum field theory. For other types of anyons simple toy models rarely exist; their properties have to be obtained using formal self-consistency relations. We explore a family of gapped 1D local bosonic models that in a certain limit become trivial to solve and provide an intuitive picture for Fibonacci anyons. One can interpret this model as a quasi-1D wire that forms the building block of a 2D topological phase with Fibonacci anyons. With this interpretation all topological properties of the Fibonacci anyons become manifest including ground state degeneracy and braid relations. We conjecture that the structure of the model is protected by an emergent symmetry analogous to fermion parity. 1) NSF Grant DMR-1341822 2) Institute for Quantum Information and Matter, an NSF physics frontier center with support from the Moore Foundation. 3) NSERC-PGSD.

  1. A 1D analysis of two high order MOC methods

    SciTech Connect

    Everson, M. S.; Forget, B.

    2012-07-01

    The work presented here provides two different methods for evaluating angular fluxes along long characteristics. One is based off a projection of the 1D transport equation onto a complete set of Legendre polynomials, while the other uses the 1D integral transport equation to evaluate the angular flux values at specific points along each track passing through a cell. The Moment Long Characteristic (M-LC) method is shown to provide 2(P+1) spatial convergence and significant gains in accuracy with the addition of only a few spatial degrees of freedom. The M-LC method, though, is shown to be ill-conditioned at very high order and for optically thin geometries. The Point Long Characteristic (P-LC) method, while less accurate, significantly improves stability to problems with optically thin cells. The P-LC method is also more flexible, allowing for extra angular flux evaluations along a given track to give a more accurate representation of the shape along each track. This is at the expense of increasing the degrees of freedom of the system, though, and requires an increase in memory storage. This work concludes that both may be used simultaneously within the same geometry to provide the best mix of accuracy and stability possible. (authors)

  2. Engineered atom-light interactions in 1D photonic crystals

    NASA Astrophysics Data System (ADS)

    Martin, Michael J.; Hung, Chen-Lung; Yu, Su-Peng; Goban, Akihisa; Muniz, Juan A.; Hood, Jonathan D.; Norte, Richard; McClung, Andrew C.; Meenehan, Sean M.; Cohen, Justin D.; Lee, Jae Hoon; Peng, Lucas; Painter, Oskar; Kimble, H. Jeff

    2014-05-01

    Nano- and microscale optical systems offer efficient and scalable quantum interfaces through enhanced atom-field coupling in both resonators and continuous waveguides. Beyond these conventional topologies, new opportunities emerge from the integration of ultracold atomic systems with nanoscale photonic crystals. One-dimensional photonic crystal waveguides can be engineered for both stable trapping configurations and strong atom-photon interactions, enabling novel cavity QED and quantum many-body systems, as well as distributed quantum networks. We present the experimental realization of such a nanophotonic quantum interface based on a nanoscale photonic crystal waveguide, demonstrating a fractional waveguide coupling of Γ1 D /Γ' of 0 . 32 +/- 0 . 08 , where Γ1 D (Γ') is the atomic emission rate into the guided (all other) mode(s). We also discuss progress towards intra-waveguide trapping of ultracold Cs. This work was supported by the IQIM, an NSF Physics Frontiers Center with support from the Moore Foundation, the DARPA ORCHID program, the AFOSR QuMPASS MURI, the DoD NSSEFF program, NSF, and the Kavli Nanoscience Institute (KNI) at Caltech.

  3. Testing methodologies

    SciTech Connect

    Bender, M.A.

    1990-01-01

    Several methodologies are available for screening human populations for exposure to ionizing radiation. Of these, aberration frequency determined in peripheral blood lymphocytes is the best developed. Individual exposures to large doses can easily be quantitated, and population exposures to occupational levels can be detected. However, determination of exposures to the very low doses anticipated from a low-level radioactive waste disposal site is more problematical. Aberrations occur spontaneously, without known cause. Exposure to radiation induces no new or novel types, but only increases their frequency. The limitations of chromosomal aberration dosimetry for detecting low level radiation exposures lie mainly in the statistical signal to noise'' problem, the distribution of aberrations among cells and among individuals, and the possible induction of aberrations by other environmental occupational or medical exposures. However, certain features of the human peripheral lymphocyte-chromosomal aberration system make it useful in screening for certain types of exposures. Future technical developments may make chromosomal aberration dosimetry more useful for low-level radiation exposures. Other methods, measuring gene mutations or even minute changes on the DNA level, while presently less will developed techniques, may eventually become even more practical and sensitive assays for human radiation exposure. 15 refs.

  4. LOCA hydroloads calculations with multidimensional nonlinear fluid/structure interaction. Volume 1: STEALTH 1D single-phase fluid studies. Final report. [PWR

    SciTech Connect

    Santee, G.E. Jr.; Mortensen, G.A.; Caraher, D.L.

    1980-04-01

    This report, which is the first in a series of reports for RP-1065, describes the first step in the stepwise approach for developing the methodology to assess the hydroloads on a large PWR during the subcooled portions of a hypothetical LOCA. The first step in the methodology considers enhancements and special modifications to the 1D STEALTH computer code in order that acoustic phenomena in piping and vessel networks may be simulated. The resulting code is termed 1D STEALTH-HYDRO. The 1D STEALTH-HYDRO enhancements consist of three control volume models to simulate area changes, orifices, and tees in piping networks. The theory of the control volume models is described.

  5. Crustal-scale interferometric imaging in the Malargüe region, Argentina, with P-wave coda and multidimensional deconvolution

    NASA Astrophysics Data System (ADS)

    Nishitsuji, Yohei; Minato, Shohei; Hartstra, Iris; Boullenger, Boris; Wapenaar, Kees; Gomez, Martín; Draganov, Deyan

    2016-04-01

    Several seismic investigations - using receiver-function methods as well as tomographic approaches - have been carried out in the Malargüe region (Argentina) for various purposes over a few decades. We use a body-wave seismic interferometry (SI) approach to retrieve reflections later used for the consecutive imaging of the subsurface. We investigate the applicability of the body-wave SI using P-wave coda from local earthquakes with the aim to retrieve reflection responses from a part of the Andean crust below the seismic array we use. We called our technique local-earthquake P-wave coda (LEPC) SI. In this presentation, we show three different LEPC SI results based on three different SI theories: crosscorrelation, crosscoherence, and multidimensional deconvolution. We find that, from a structural-interpretation point of view, multidimensional deconvolution based on the truncated singular-value decomposition scheme provides us with a better structural imaging than the other SI approaches. We interpret deep thrust faults in the imaging results from LEPC SI, whose presence in this region has previously been indicated from interpretation of active seismic-survey data and exploration-well data. We also interpret dimmed-amplitude parts in the reflection image as possible melting zones that have been previously indicated by magnetotelluric methods. The LEPC SI method we propose could be used as a low-cost alternative to active-source seismic surveys for imaging and monitoring purposes of deeper geothermal reservoirs, e.g. in enhanced geothermal systems where the target structures are down to 10 km depth.

  6. Axion string dynamics I: 2+1D

    NASA Astrophysics Data System (ADS)

    Fleury, Leesa M.; Moore, Guy D.

    2016-05-01

    If the axion exists and if the initial axion field value is uncorrelated at causally disconnected points, then it should be possible to predict the efficiency of cosmological axion production, relating the axionic dark matter density to the axion mass. The main obstacle to making this prediction is correctly treating the axion string cores. We develop a new algorithm for treating the axionic string cores correctly in 2+1 dimensions. When the axionic string cores are given their full physical string tension, axion production is about twice as efficient as in previous simulations. We argue that the string network in 2+1 dimensions should behave very differently than in 3+1 dimensions, so this result cannot be simply carried over to the physical case. We outline how to extend our method to 3+1D axion string dynamics.

  7. 1D-transport properties of single superconducting lead nanowires

    NASA Astrophysics Data System (ADS)

    Michotte, S.; Mátéfi-Tempfli, S.; Piraux, L.

    2003-09-01

    We report on the transport properties of single superconducting lead nanowires grown by an electrodeposition technique, embedded in a nanoporous track-etched polymer membrane. The nanowires are granular, have uniform diameter of ∼40 nm and a very large aspect ratio (∼500). The diameter of the nanowire is small enough to ensure a 1D superconducting regime in a wide temperature range below Tc. The non-zero resistance in the superconducting state and its variation caused by fluctuations of the superconducting order parameter were measured versus temperature, magnetic field, and applied DC current (or voltage). The current induced breakdowns in the V- I characteristics may be explained by the formation of phase slip centers. Moreover, DC voltage driven measurements reveal the existence of a new S-shape behavior near the formation of these phase slip centers.

  8. Microlens Masses from 1-D Parallaxes and Heliocentric Proper Motions

    NASA Astrophysics Data System (ADS)

    Gould, Andrew

    2014-12-01

    One-dimensional (1-D) microlens parallaxes can be combined with heliocentric lens-source relative proper motion measurements to derive the lens mass and distance, as suggested by Ghosh et al. (2004). Here I present the first mathematical anlysis of this procedure, which I show can be represented as a quadratic equation. Hence, it is formally subject to a two-fold degeneracy. I show that this degeneracy can be broken in many cases using the relatively crude 2-D parallax information that is often available for microlensing events. I also develop an explicit formula for the region of parameter space where it is more difficult to break this degeneracy. Although no mass/distance measurements have yet been made using this technique, it is likely to become quite common over the next decade.

  9. Quadratic Finite Element Method for 1D Deterministic Transport

    SciTech Connect

    Tolar, Jr., D R; Ferguson, J M

    2004-01-06

    In the discrete ordinates, or SN, numerical solution of the transport equation, both the spatial ({und r}) and angular ({und {Omega}}) dependences on the angular flux {psi}{und r},{und {Omega}}are modeled discretely. While significant effort has been devoted toward improving the spatial discretization of the angular flux, we focus on improving the angular discretization of {psi}{und r},{und {Omega}}. Specifically, we employ a Petrov-Galerkin quadratic finite element approximation for the differencing of the angular variable ({mu}) in developing the one-dimensional (1D) spherical geometry S{sub N} equations. We develop an algorithm that shows faster convergence with angular resolution than conventional S{sub N} algorithms.

  10. Effective theory of black holes in the 1/D expansion

    NASA Astrophysics Data System (ADS)

    Emparan, Roberto; Shiromizu, Tetsuya; Suzuki, Ryotaku; Tanabe, Kentaro; Tanaka, Takahiro

    2015-06-01

    The gravitational field of a black hole is strongly localized near its horizon when the number of dimensions D is very large. In this limit, we can effectively replace the black hole with a surface in a background geometry (e.g. Minkowski or Anti-deSitter space). The Einstein equations determine the effective equations that this `black hole surface' (or membrane) must satisfy. We obtain them up to next-to-leading order in 1/ D for static black holes of the Einstein-(A)dS theory. To leading order, and also to next order in Minkowski backgrounds, the equations of the effective theory are the same as soap-film equations, possibly up to a redshift factor. In particular, the Schwarzschild black hole is recovered as a spherical soap bubble. Less trivially, we find solutions for `black droplets', i.e. black holes localized at the boundary of AdS, and for non-uniform black strings.

  11. Connected components of irreducible maps and 1D quantum phases

    NASA Astrophysics Data System (ADS)

    Szehr, Oleg; Wolf, Michael M.

    2016-08-01

    We investigate elementary topological properties of sets of completely positive (CP) maps that arise in quantum Perron-Frobenius theory. We prove that the set of primitive CP maps of fixed Kraus rank is path-connected and we provide a complete classification of the connected components of irreducible CP maps at given Kraus rank and fixed peripheral spectrum in terms of a multiplicity index. These findings are then applied to analyse 1D quantum phases by studying equivalence classes of translational invariant matrix product states that correspond to the connected components of the respective CP maps. Our results extend the previously obtained picture in that they do not require blocking of physical sites, they lead to analytic paths, and they allow us to decompose into ergodic components and to study the breaking of translational symmetry.

  12. Glycolipid antigen processing for presentation by CD1d molecules.

    PubMed

    Prigozy, T I; Naidenko, O; Qasba, P; Elewaut, D; Brossay, L; Khurana, A; Natori, T; Koezuka, Y; Kulkarni, A; Kronenberg, M

    2001-01-26

    The requirement for processing glycolipid antigens in T cell recognition was examined with mouse CD1d-mediated responses to glycosphingolipids (GSLs). Although some disaccharide GSL antigens can be recognized without processing, the responses to three other antigens, including the disaccharide GSL Gal(alpha1-->2)GalCer (Gal, galactose; GalCer, galactosylceramide), required removal of the terminal sugars to permit interaction with the T cell receptor. A lysosomal enzyme, alpha-galactosidase A, was responsible for the processing of Gal(alpha1-->2)GalCer to generate the antigenic monosaccharide epitope. These data demonstrate a carbohydrate antigen processing system analogous to that used for peptides and an ability of T cells to recognize processed fragments of complex glycolipids.

  13. 2-D or not 2-D, that is the question: A Northern California test

    SciTech Connect

    Mayeda, K; Malagnini, L; Phillips, W S; Walter, W R; Dreger, D

    2005-06-06

    Reliable estimates of the seismic source spectrum are necessary for accurate magnitude, yield, and energy estimation. In particular, how seismic radiated energy scales with increasing earthquake size has been the focus of recent debate within the community and has direct implications on earthquake source physics studies as well as hazard mitigation. The 1-D coda methodology of Mayeda et al. has provided the lowest variance estimate of the source spectrum when compared against traditional approaches that use direct S-waves, thus making it ideal for networks that have sparse station distribution. The 1-D coda methodology has been mostly confined to regions of approximately uniform complexity. For larger, more geophysically complicated regions, 2-D path corrections may be required. The complicated tectonics of the northern California region coupled with high quality broadband seismic data provides for an ideal ''apples-to-apples'' test of 1-D and 2-D path assumptions on direct waves and their coda. Using the same station and event distribution, we compared 1-D and 2-D path corrections and observed the following results: (1) 1-D coda results reduced the amplitude variance relative to direct S-waves by roughly a factor of 8 (800%); (2) Applying a 2-D correction to the coda resulted in up to 40% variance reduction from the 1-D coda results; (3) 2-D direct S-wave results, though better than 1-D direct waves, were significantly worse than the 1-D coda. We found that coda-based moment-rate source spectra derived from the 2-D approach were essentially identical to those from the 1-D approach for frequencies less than {approx}0.7-Hz, however for the high frequencies (0.7{le} f {le} 8.0-Hz), the 2-D approach resulted in inter-station scatter that was generally 10-30% smaller. For complex regions where data are plentiful, a 2-D approach can significantly improve upon the simple 1-D assumption. In regions where only 1-D coda correction is available it is still preferable over 2

  14. Roles of TBC1D1 and TBC1D4 in insulin- and exercise-stimulated glucose transport of skeletal muscle

    PubMed Central

    Cartee, Gregory D.

    2014-01-01

    This review focuses on two paralogue Rab GTPase activating proteins known as TBC1D1 Tre-2/BUB2/cdc 1 domain family (TBC1D) 1 and TBC1D4 (also called Akt Substrate of 160 kDa, AS160) and their roles in controlling skeletal muscle glucose transport in response to the independent and combined effects of insulin and exercise. Convincing evidence implicates Akt2-dependent TBC1D4 phosphorylation on T642 as a key part of the mechanism for insulin-stimulated glucose uptake by skeletal muscle. TBC1D1 phosphorylation on several insulin-responsive sites (including T596, a site corresponding to T642 in TBC1D4) does not appear to be essential for in vivo insulin-stimulated glucose uptake by skeletal muscle. In vivo exercise or ex vivo contraction of muscle result in greater TBC1D1 phosphorylation on S237 that is likely to be secondary to increased AMP-activated protein kinase activity and potentially important for contraction-stimulated glucose uptake. Several studies that evaluated both normal and insulin-resistant skeletal muscle stimulated with a physiological insulin concentration after a single exercise session found that greater post-exercise insulin-stimulated glucose uptake was accompanied by greater TBC1D4 phosphorylation on several sites. In contrast, enhanced post-exercise insulin sensitivity was not accompanied by greater insulin-stimulated TBC1D1 phosphorylation. The mechanism for greater TBC1D4 phosphorylation in insulin-stimulated muscles after acute exercise is uncertain, and a causal link between enhanced TBC1D4 phosphorylation and increased post-exercise insulin sensitivity has yet to be established. In summary, TBC1D1 and TBC1D4 have important, but distinct roles in regulating muscle glucose transport in response to insulin and exercise. PMID:25280670

  15. 1D X-ray Beam Compressing Monochromators

    SciTech Connect

    Korytar, D.; Dobrocka, E.; Konopka, P.; Zaprazny, Z.; Ferrari, C.; Mikulik, P.; Vagovic, P.; Ac, V.; Erko, A.; Abrosimov, N.

    2010-04-06

    A total beam compression of 5 and 10 corresponding to the asymmetry angles of 9 deg. and 12 deg. is achieved with V-5 and V-10 monochromators, respectively, in standard single crystal pure germanium (220) X-ray beam compressing (V-shaped) monochromators for CuKalpha{sub 1} radiation. A higher 1D compression of X-ray beam is possible using larger angles of asymmetry, however it is achieved at the expense of the total intensity, which is decreased due to the refraction effect. To increase the monochromator intensity, several ways are considered both theoretically and experimentally. Linearly graded germanium rich Ge{sub x}Si{sub (1-x)} single crystal was used to prepare a V-21 single crystal monochromator with 15 deg. asymmetry angles (compression factor of 21). Its temperature gradient version is discussed for CuKalpha{sub 1} radiation. X-ray diffraction measurements on the graded GeSi monochromator showed more than 3-times higher intensity at the output compared with that of a pure Ge monochromator.

  16. 1-D Numerical Analysis of RBCC Engine Performance

    NASA Technical Reports Server (NTRS)

    Han, Samuel S.

    1998-01-01

    An RBCC engine combines air breathing and rocket engines into a single engine to increase the specific impulse over an entire flight trajectory. Considerable research pertaining to RBCC propulsion was performed during the 1960's and these engines were revisited recently as a candidate propulsion system for either a single-stage-to-orbit (SSTO) or two-stage-to-orbit (TSTO) launch vehicle. There are a variety of RBCC configurations that had been evaluated and new designs are currently under development. However, the basic configuration of all RBCC systems is built around the ejector scramjet engine originally developed for the hypersonic airplane. In this configuration, a rocket engine plays as an ejector in the air-augmented initial acceleration mode, as a fuel injector in scramjet mode and the rocket in all rocket mode for orbital insertion. Computational fluid dynamics (CFD) is a useful tool for the analysis of complex transport processes in various components in RBCC propulsion systems. The objective of the present research was to develop a transient 1-D numerical model that could be used to predict flow behavior throughout a generic RBCC engine following a flight path.

  17. Dynamic decoupling in the presence of 1D random walk

    NASA Astrophysics Data System (ADS)

    Chakrabarti, Arnab; Chakraborty, Ipsita; Bhattacharyya, Rangeet

    2016-05-01

    In the recent past, many dynamic decoupling sequences have been proposed for the suppression of decoherence of spins connected to thermal baths of various natures. Dynamic decoupling schemes for suppressing decoherence due to Gaussian diffusion have also been developed. In this work, we study the relative performances of dynamic decoupling schemes in the presence of a non-stationary Gaussian noise such as a 1D random walk. Frequency domain analysis is not suitable to determine the performances of various dynamic decoupling schemes in suppressing decoherence due to such a process. Thus, in this work, we follow a time domain calculation to arrive at the following conclusions: in the presence of such a noise, we show that (i) the traditional Carr–Purcell–Meiboom–Gill (CPMG) sequence outperforms Uhrig’s dynamic decoupling scheme, (ii) CPMG remains the optimal sequence for suppression of decoherence due to random walk in the presence of an external field gradient. Later, the theoretical predictions are experimentally verified by using nuclear magnetic resonance spectroscopy on spin 1/2 particles diffusing in a liquid medium.

  18. Control and imaging of O(1D2) precession

    NASA Astrophysics Data System (ADS)

    Wu, Shiou-Min; Radenovic, Dragana Č.; van der Zande, Wim J.; Groenenboom, Gerrit C.; Parker, David H.; Vallance, Claire; Zare, Richard N.

    2011-01-01

    Larmor precession of a quantum mechanical angular momentum vector about an applied magnetic field forms the basis for a range of magnetic resonance techniques, including nuclear magnetic resonance spectroscopy and magnetic resonance imaging. We have used a polarized laser pump-probe scheme with velocity-map imaging detection to visualize, for the first time, the precessional motion of a quantum mechanical angular momentum vector. Photodissociation of O2 at 157 nm provides a clean source of fast-moving O(1D2) atoms, with their electronic angular momentum vector strongly aligned perpendicular to the recoil direction. In the presence of an external magnetic field, the distribution of atomic angular momenta precesses about the field direction, and polarization-sensitive images of the atomic scattering distribution recorded as a function of field strength yield ‘time-lapse-photography’ style movies of the precessional motion. We present movies recorded in various experimental geometries, and discuss potential consequences and applications in atmospheric chemistry and reaction dynamics.

  19. Optimal modeling of 1D azimuth correlations in the context of Bayesian inference

    NASA Astrophysics Data System (ADS)

    De Kock, Michiel B.; Eggers, Hans C.; Trainor, Thomas A.

    2015-09-01

    Analysis and interpretation of spectrum and correlation data from high-energy nuclear collisions is currently controversial because two opposing physics narratives derive contradictory implications from the same data, one narrative claiming collision dynamics is dominated by dijet production and projectile-nucleon fragmentation, the other claiming collision dynamics is dominated by a dense, flowing QCD medium. Opposing interpretations seem to be supported by alternative data models, and current model-comparison schemes are unable to distinguish between them. There is clearly need for a convincing new methodology to break the deadlock. In this study we introduce Bayesian inference (BI) methods applied to angular correlation data as a basis to evaluate competing data models. For simplicity the data considered are projections of two-dimensional (2D) angular correlations onto a 1D azimuth from three centrality classes of 200-GeV Au-Au collisions. We consider several data models typical of current model choices, including Fourier series (FS) and a Gaussian plus various combinations of individual cosine components. We evaluate model performance with BI methods and with power-spectrum analysis. We find that FS-only models are rejected in all cases by Bayesian analysis, which always prefers a Gaussian. A cylindrical quadrupole cos(2 ϕ ) is required in some cases but rejected for 0%-5%-central Au-Au collisions. Given a Gaussian centered at the azimuth origin, "higher harmonics" cos(m ϕ ) for m >2 are rejected. A model consisting of Gaussian +dipole cos(ϕ )+quadrupole cos(2 ϕ ) provides good 1D data descriptions in all cases.

  20. Absolute rate constant determinations for the deactivation of O/1D/ by time resolved decay of O/1D/ yields O/3P/ emission

    NASA Technical Reports Server (NTRS)

    Davidson, J. A.; Sadowski, C. M.; Schiff, H. I.; Howard, C. J.; Schmeltekopf, A. L.; Jennings, D. A.; Streit, G. E.

    1976-01-01

    Absolute rate constants for the deactivation of O(1D) atoms by some atmospheric gases have been determined by observing the time-resolved emission of O(1D) at 630 nm. O(1D) atoms were produced by the dissociation of ozone via repetitive laser pulses at 266 nm. Absolute rate constants for the relaxation of O(1D) at 298 K are reported for N2, O2, CO2, O3, H2, D2, CH4, HCl, NH3, H2O, N2O, and Ne. The results obtained are compared with previous relative and absolute measurements reported in the literature.

  1. Assessing the impact of different sources of topographic data on 1-D hydraulic modelling of floods

    NASA Astrophysics Data System (ADS)

    Ali, A. Md; Solomatine, D. P.; Di Baldassarre, G.

    2015-01-01

    to the use of low-cost DEM that have not only a lower resolution, but also a lower quality. Lastly, to better explore the sensitivity of the 1-D hydraulic models to different DEMs, we performed an uncertainty analysis based on the GLUE methodology.

  2. Physical synthesis methodology and enhanced gas sensing and photoelectrochemical performance of 1D serrated zinc oxide-zinc ferrite nanocomposites.

    PubMed

    Liang, Yuan-Chang; Liu, Shang-Luen; Hsia, Hao-Yuan

    2015-12-01

    We successfully prepared one-dimensional ZnO-ZnFe2O4 (ZFO) heterostructures for acetone gas-sensing and photoelectrochemical applications, by using sputter deposition of ZFO crystallites on ZnO nanostructure templates. The nanoscale ZFO crystallites were homogeneously coated on the surfaces of the ZnO nanostructures. Electron microscope images revealed that the ZnO-ZFO heterostructures exhibited a serrated surface morphology. Coating the ZnO nanostructures with a ZFO aggregated layer appreciably enhanced their acetone gas-sensing capability at 250 °C in comparison with pure ZnO nanostructures. The presence of many depleted nanoscale ZFO crystallites, the rugged surface of the heterostructures, and electron depletion at the ZnO/ZFO interface might contribute to the enhanced acetone gas-sensing response. Furthermore, the larger surface area and higher light absorption of ZnO-ZFO relative to the surface area and light absorption of ZnO were correlated with a substantial enhancement of the photocurrent value of ZnO-ZFO in photoelectrochemical tests produced by the simulated solar light irradiation.

  3. Evidence against dopamine D1/D2 receptor heteromers

    PubMed Central

    Frederick, Aliya L.; Yano, Hideaki; Trifilieff, Pierre; Vishwasrao, Harshad D.; Biezonski, Dominik; Mészáros, József; Sibley, David R.; Kellendonk, Christoph; Sonntag, Kai C.; Graham, Devon L.; Colbran, Roger J.; Stanwood, Gregg D.; Javitch, Jonathan A.

    2014-01-01

    Hetero-oligomers of G-protein-coupled receptors have become the subject of intense investigation because their purported potential to manifest signaling and pharmacological properties that differ from the component receptors makes them highly attractive for the development of more selective pharmacological treatments. In particular, dopamine D1 and D2 receptors have been proposed to form hetero-oligomers that couple to Gαq proteins, and SKF83959 has been proposed to act as a biased agonist that selectively engages these receptor complexes to activate Gαq and thus phospholipase C. D1/D2 heteromers have been proposed as relevant to the pathophysiology and treatment of depression and schizophrenia. We used in vitro bioluminescence resonance energy transfer (BRET), ex vivo analyses of receptor localization and proximity in brain slices, and behavioral assays in mice to characterize signaling from these putative dimers/oligomers. We were unable to detect Gαq or Gα11 protein coupling to homomers or heteromers of D1 or D2 receptors using a variety of biosensors. SKF83959-induced locomotor and grooming behaviors were eliminated in D1 receptor knockout mice, verifying a key role for D1-like receptor activation. In contrast, SKF83959-induced motor responses were intact in D2 receptor and Gαq knockout mice, as well as in knock-in mice expressing a mutant Ala286-CaMKIIα, that cannot autophosphorylate to become active. Moreover, we found that in the shell of the nucleus accumbens, even in neurons in which D1 and D2 receptor promoters are both active, the receptor proteins are segregated and do not form complexes. These data are not compatible with SKF83959 signaling through Gαq or through a D1–D2 heteromer and challenge the existence of such a signaling complex in the adult animals that we used for our studies. PMID:25560761

  4. Dynamical functions of a 1D correlated quantum liquid

    NASA Astrophysics Data System (ADS)

    Carmelo, J. M. P.; Bozi, D.; Penc, K.

    2008-10-01

    The dynamical correlation functions in one-dimensional electronic systems show power-law behaviour at low energies and momenta close to integer multiples of the charge and spin Fermi momenta. These systems are usually referred to as Tomonaga-Luttinger liquids. However, near well defined lines of the (k,ω) plane the power-law behaviour extends beyond the low-energy cases mentioned above, and also appears at higher energies, leading to singular features in the photoemission spectra and other dynamical correlation functions. The general spectral-function expressions derived in this paper were used in recent theoretical studies of the finite-energy singular features in photoemission of the organic compound tetrathiafulvalene-tetracyanoquinodimethane (TTF-TCNQ) metallic phase. They are based on a so-called pseudofermion dynamical theory (PDT), which allows us to systematically enumerate and describe the excitations in the Hubbard model starting from the Bethe ansatz, as well as to calculate the charge and spin object phase shifts appearing as exponents of the power laws. In particular, we concentrate on the spin-density m\\rightarrow 0 limit and on effects in the vicinity of the singular border lines, as well as close to half filling. Our studies take into account spectral contributions from types of microscopic processes that do not occur for finite values of the spin density. In addition, the specific processes involved in the spectral features of TTF-TCNQ are studied. Our results are useful for the further understanding of the unusual spectral properties observed in low-dimensional organic metals and also provide expressions for the one- and two-atom spectral functions of a correlated quantum system of ultracold fermionic atoms in a 1D optical lattice with on-site two-atom repulsion.

  5. Synthesis, characterization, and physical properties of 1D nanostructures

    NASA Astrophysics Data System (ADS)

    Marley, Peter Mchael

    The roster of materials exhibiting metal---insulator transitions with sharply discontinuous switching of electrical conductivity close to room temperature remains rather sparse despite the fundamental interest in the electronic instabilities manifested in such materials and the plethora of potential technological applications, ranging from frequency-agile metamaterials to electrochromic coatings and Mott field-effect transistors. Vanadium oxide bronzes with the general formula MxV2O 5, provide a wealth of compositions and frameworks where strong electron correlation can be systematically (albeit thus far only empirically) tuned. Charge fluctuations along the quasi-1D frameworks of MxV 2O5 bronzes have evinced much recent interest owing to the manifestation of colossal metal---insulator transitions and superconductivity. We start with a general review on the phase transitions, both electronic and structural, of vanadium oxide bronzes in Chapter 1. In Chapter 2, we demonstrate an unprecedented reversible transformation between double-layered (delta) and tunnel (beta) quasi-1D geometries for nanowires of a divalent vanadium bronze CaxV2O5 (x ˜0.23) upon annealing-induced dehydration and hydrothermally-induced hydration. Such a facile hydration/dehydration-induced interconversion between two prominent quasi-1D structures (accompanied by a change in charge ordering motifs) has not been observed in the bulk and is posited to result from the ease of propagation of crystallographic slip processes across the confined nanowire widths for the delta→beta conversion and the facile diffusion of water molecules within the tunnel geometries for the beta→delta reversion. We demonstrate in Chapter 3 unprecedented pronounced metal-insulator transitions induced by application of a voltage for nanowires of a vanadium oxide bronze with intercalated divalent cations, beta-PbxV 2O5 (x ˜0.33). The induction of the phase transition through application of an electric field at room

  6. Synthesis, characterization, and physical properties of 1D nanostructures

    NASA Astrophysics Data System (ADS)

    Marley, Peter Mchael

    The roster of materials exhibiting metal---insulator transitions with sharply discontinuous switching of electrical conductivity close to room temperature remains rather sparse despite the fundamental interest in the electronic instabilities manifested in such materials and the plethora of potential technological applications, ranging from frequency-agile metamaterials to electrochromic coatings and Mott field-effect transistors. Vanadium oxide bronzes with the general formula MxV2O 5, provide a wealth of compositions and frameworks where strong electron correlation can be systematically (albeit thus far only empirically) tuned. Charge fluctuations along the quasi-1D frameworks of MxV 2O5 bronzes have evinced much recent interest owing to the manifestation of colossal metal---insulator transitions and superconductivity. We start with a general review on the phase transitions, both electronic and structural, of vanadium oxide bronzes in Chapter 1. In Chapter 2, we demonstrate an unprecedented reversible transformation between double-layered (delta) and tunnel (beta) quasi-1D geometries for nanowires of a divalent vanadium bronze CaxV2O5 (x ˜0.23) upon annealing-induced dehydration and hydrothermally-induced hydration. Such a facile hydration/dehydration-induced interconversion between two prominent quasi-1D structures (accompanied by a change in charge ordering motifs) has not been observed in the bulk and is posited to result from the ease of propagation of crystallographic slip processes across the confined nanowire widths for the delta→beta conversion and the facile diffusion of water molecules within the tunnel geometries for the beta→delta reversion. We demonstrate in Chapter 3 unprecedented pronounced metal-insulator transitions induced by application of a voltage for nanowires of a vanadium oxide bronze with intercalated divalent cations, beta-PbxV 2O5 (x ˜0.33). The induction of the phase transition through application of an electric field at room

  7. SCCRO3 (DCUN1D3) Antagonizes the Neddylation and Oncogenic Activity of SCCRO (DCUN1D1)*

    PubMed Central

    Huang, Guochang; Stock, Cameron; Bommeljé, Claire C.; Weeda, Víola B.; Shah, Kushyup; Bains, Sarina; Buss, Elizabeth; Shaha, Manish; Rechler, Willi; Ramanathan, Suresh Y.; Singh, Bhuvanesh

    2014-01-01

    The activity of cullin-RING type ubiquitination E3 ligases is regulated by neddylation, a process analogous to ubiquitination that culminates in covalent attachment of the ubiquitin-like protein Nedd8 to cullins. As a component of the E3 for neddylation, SCCRO/DCUN1D1 plays a key regulatory role in neddylation and, consequently, cullin-RING ligase activity. The essential contribution of SCCRO to neddylation is to promote nuclear translocation of the cullin-ROC1 complex. The presence of a myristoyl sequence in SCCRO3, one of four SCCRO paralogues present in humans that localizes to the membrane, raises questions about its function in neddylation. We found that although SCCRO3 binds to CAND1, cullins, and ROC1, it does not efficiently bind to Ubc12, promote cullin neddylation, or conform to the reaction processivity paradigms, suggesting that SCCRO3 does not have E3 activity. Expression of SCCRO3 inhibits SCCRO-promoted neddylation by sequestering cullins to the membrane, thereby blocking its nuclear translocation. Moreover, SCCRO3 inhibits SCCRO transforming activity. The inhibitory effects of SCCRO3 on SCCRO-promoted neddylation and transformation require both an intact myristoyl sequence and PONY domain, confirming that membrane localization and binding to cullins are required for in vivo functions. Taken together, our findings suggest that SCCRO3 functions as a tumor suppressor by antagonizing the neddylation activity of SCCRO. PMID:25349211

  8. 1-D Radiative-Convective Model for Terrestrial Exoplanet Atmospheres

    NASA Astrophysics Data System (ADS)

    Leung, Cecilia W. S.; Robinson, Tyler D.

    2016-10-01

    We present a one dimensional radiative-convective model to study the thermal structure of terrestrial exoplanetary atmospheres. The radiative transfer and equilibrium chemistry in our model is based on similar methodologies in models used for studying Extrasolar Giant Planets (Fortney et al. 2005b.) We validated our model in the optically thin and thick limits, and compared our pressure-temperature profiles against the analytical solutions of Robinson & Catling (2012). For extrasolar terrestrial planets with pure hydrogen atmospheres, we evaluated the effects of H2-H2 collision induced absorption and identified the purely roto-translational band in our modeled spectra. We also examined how enhanced atmospheric metallicities affect the temperature structure, chemistry, and spectra of terrestrial exoplanets. For a terrestrial extrasolar planet whose atmospheric compostion is 100 times solar orbiting a sun-like star at 2 AU, our model resulted in a reducing atmosphere with H2O, CH4, and NH3 as the dominant greenhouse gases.

  9. 1-D Tremor Streaks: Implications for a Streak Source Model

    NASA Astrophysics Data System (ADS)

    Houston, H.; Ghosh, A.; Vidale, J. E.

    2009-12-01

    Recent observations of non-volcanic tremor in Cascadia and Japan show “streaks” of tremor moving up and down dip in a convergence-parallel direction at “driving velocities” (i.e., 30 to 120 km/hr). Streak lengths of 30 to 40 km are occasionally observed. We explore the implications of these observations for a source model and spectrum of tremor. Key elements involve the extreme geometry and slow “rupture velocity” implied by the streaks. The source spectrum of tremor and other ETS seismic radiation exhibits a spectral falloff roughly as the inverse of frequency (1/f) in contrast to that of earthquakes, which follow a spectral falloff of 1/f squared above a corner frequency. Nevertheless, several observations suggest that the deformation that generates tremor is shear slip in the plate convergence direction. A fundamental question, then, has been what slip source could produce such an observed 1/f falloff over a wide frequency range. We propose a kinematic model, consistent with the 1-D geometry of the tremor streaks, in which fault displacement and width are strongly limited and rupture growth occurs only along fault length, which is oriented in a convergence-parallel direction (up or down dip). This is a version of the well-known Haskell model in which the durations of the two boxcars are very different. A 1/f spectral falloff holds between the corner frequencies associated with the two durations. Thus, the frequency range of the observed 1/f spectral falloff of tremor provides constraints on the durations of the boxcars. Further constraints involve the maximum likely displacement in an ETS event, the rupture velocities of the streaks, and the moment release rate. The narrow streak geometry implies fairly high strain and stress drops, in contrast to the low overall stress drops inferred from tidal modulation of tremor and the low strain across the entire ETS region. The observation of tremor streaks migrating at 10's of km/hour, in conjunction with the

  10. Human CD1d knock-in mouse model demonstrates potent antitumor potential of human CD1d-restricted invariant natural killer T cells

    PubMed Central

    Wen, Xiangshu; Rao, Ping; Carreño, Leandro J.; Kim, Seil; Lawrenczyk, Agnieszka; Porcelli, Steven A.; Cresswell, Peter; Yuan, Weiming

    2013-01-01

    Despite a high degree of conservation, subtle but important differences exist between the CD1d antigen presentation pathways of humans and mice. These differences may account for the minimal success of natural killer T (NKT) cell-based antitumor therapies in human clinical trials, which contrast strongly with the powerful antitumor effects in conventional mouse models. To develop an accurate model for in vivo human CD1d (hCD1d) antigen presentation, we have generated a hCD1d knock-in (hCD1d-KI) mouse. In these mice, hCD1d is expressed in a native tissue distribution pattern and supports NKT cell development. Reduced numbers of invariant NKT (iNKT) cells were observed, but at an abundance comparable to that in most normal humans. These iNKT cells predominantly expressed mouse Vβ8, the homolog of human Vβ11, and phenotypically resembled human iNKT cells in their reduced expression of CD4. Importantly, iNKT cells in hCD1d knock-in mice exert a potent antitumor function in a melanoma challenge model. Our results show that replacement of mCD1d by hCD1d can select a population of functional iNKT cells closely resembling human iNKT cells. These hCD1d knock-in mice will allow more accurate in vivo modeling of human iNKT cell responses and will facilitate the preclinical assessment of iNKT cell-targeted antitumor therapies. PMID:23382238

  11. Photonic clays: a new family of functional 1D photonic crystals.

    PubMed

    Lotsch, Bettina V; Ozin, Geoffrey A

    2008-10-28

    Clays have shown potential as intelligent optical sensing platforms when integrated into a one-dimensional photonic crystal (PC) environment. The clay component imparts intrinsic functionality to the multilayer system by combining the signature ion exchange with the tunable structural color of photonic crystals, giving rise to environmentally sensitive photonic clay architectures. We have fabricated different Laponite-based 1D PCs and clay defect PCs by simple bottom-up self-assembly methodologies and elaborate their working principles and chemically encoded optical response. Accessibility of the multilayer system to analytes is studied on the background of the barrier properties of clays and diffusion control by the mesoporous oxide layers. The time dependence of analyte uptake and the extent and driving force for analyte release are pointed out and discussed in the context of different interactions between the clay layers and analytes. We demonstrate the possibility of optical cycling associated with repeated analyte uptake and removal processes, rendering photonic clays recyclable and low cost sensing platforms with simple optical read-out.

  12. Study of aging in oil paintings by 1D and 2D NMR spectroscopy.

    PubMed

    Spyros, Apostolos; Anglos, Demetrios

    2004-09-01

    Nuclear magnetic resonance spectroscopy is proposed as an efficient analytical tool in the study of painted artworks. The binding medium from two original oil paintings, dated from the early 20th and the late 17th century, was studied via high-resolution 1D and 2D NMR, establishing the advanced state of hydrolysis and oxidation of the oil paint. Studies of the solvent-extractable component from model samples of various drying oils, raw oil paints, and aged oil paints allowed the definition of several markers based on the integral ratios of various chemical species present in the 1H and 13C NMR spectra. These markers are sensitive to hydrolytic and oxidative processes that reflect the extent of aging in oil paintings. The rapidity, simplicity, and nondestructive nature of the proposed analytical NMR methodology represents a great advantage, since the usually minute sample quantities available from original artwork can be subsequently analyzed further by other analytical techniques, if necessary. PMID:15373425

  13. Proteasome-mediated degradation antagonizes critical levels of the apoptosis-inducing C1D protein

    PubMed Central

    Rothbarth, Karsten; Stammer, Hermann; Werner, Dieter

    2002-01-01

    The C1D gene is expressed in a broad spectrum of mammalian cells and tissues but its product induces apoptotic cell death when exceeding a critical level. Critical levels are achieved in a fraction of cells by transient transfection with EGFP-tagged C1D expression constructs. However, transfected cells expressing sub-critical levels of C1D(EGFP) escape apoptotic cell death by activation of a proteasome-mediated rescue mechanism. Inhibition of the proteasome-dependent degradation of the C1D(EGFP) protein results in a parallel increase of the intracellular C1D level and in the fraction of apoptotic cells. PMID:12379155

  14. Control Region Variability of Haplogroup C1d and the Tempo of the Peopling of the Americas

    PubMed Central

    Figueiro, Gonzalo; Hidalgo, Pedro C.; Sans, Mónica

    2011-01-01

    Background Among the founding mitochondrial haplogroups involved in the peopling of the Americas, haplogroup C1d has been viewed as problematic because of its phylogeny and because of the estimates of its antiquity, apparently being much younger than other founding haplogroups. Several recent analyses, based on data from the entire mitochondrial genome, have contributed to an advance in the resolution of these problems. The aim of our analysis is to compare the conclusions drawn from the available HVR-I and HVR-II data for haplogroup C1d with the ones based on whole mitochondrial genomes. Methodology/Principal Findings HVR-I and HVR-II sequences defined as belonging to haplogroup C1d by standard criteria were gathered from the literature as well as from population studies carried out in Uruguay. Sequence phylogeny was reconstructed using median-joining networks, geographic distribution of lineages was analyzed and the age of the most recent common ancestor estimated using the ρ-statistic and two different mutation rates. The putative ancestral forms of the haplogroup were found to be more widespread than the derived lineages, and the lineages defined by np 194 were found to be widely distributed and of equivalent age. Conclusions/Significance The analysis of control region sequences is found to still harbor great potential in tracing microevolutionary phenomena, especially those found to have occurred in more recent times. Based on the geographic distributions of the alleles of np 7697 and np 194, both discussed as possible basal mutations of the C1d phylogeny, we suggest that both alleles were part of the variability of the haplogroup at the time of its entrance. Moreover, based on the mutation rates of the different sites stated to be diagnostic, it is possible that the anomalies found when analyzing the haplogroup are due to paraphyly. PMID:21695136

  15. Enhanced Rayleigh waves tomography of Mexico using ambient noise cross-correlations (C1) and correlations of coda of correlations (C3)

    NASA Astrophysics Data System (ADS)

    Spica, Z. J.; Perton, M.; Calo, M.; Cordoba-Montiel, F.; Legrand, D.; Iglesias, A.

    2015-12-01

    Standard application of the seismic ambient noise tomography considers the existence of synchronous records at stations for green's functions retrieval. More recent theoretical and experimental observations showed the possibility to apply correlation of coda of noise correlation (C3) to obtain green's functions between stations of asynchronous seismic networks making possible to dramatically increase databases for imagining the Earth's interior. However, this possibility has not been fully exploited yet, and right now the data C3 are not included into tomographic inversions to refine seismic structures. Here we show for the first time how to incorporate the data of C1 and C3 to calculate dispersion maps of Rayleigh waves in the range period of 10-120s, and how the merging of these datasets improves the resolution of the structures imaged. Tomographic images are obtained for an area covering Mexico, the Gulf of Mexico and the southern U.S. We show dispersion maps calculated using both data of C1 and the complete dataset (C1+C3). The latter provide new details of the seismic structure of the region allowing a better understanding of their role on the geodynamics of the study area. The resolving power obtained in our study is several times higher than in previous studies based on ambient noise. This demonstrates the new possibilities for imaging the Earth's crust and upper mantle using this enlarged database.

  16. Grid Cell Responses in 1D Environments Assessed as Slices through a 2D Lattice.

    PubMed

    Yoon, KiJung; Lewallen, Sam; Kinkhabwala, Amina A; Tank, David W; Fiete, Ila R

    2016-03-01

    Grid cells, defined by their striking periodic spatial responses in open 2D arenas, appear to respond differently on 1D tracks: the multiple response fields are not periodically arranged, peak amplitudes vary across fields, and the mean spacing between fields is larger than in 2D environments. We ask whether such 1D responses are consistent with the system's 2D dynamics. Combining analytical and numerical methods, we show that the 1D responses of grid cells with stable 1D fields are consistent with a linear slice through a 2D triangular lattice. Further, the 1D responses of comodular cells are well described by parallel slices, and the offsets in the starting points of the 1D slices can predict the measured 2D relative spatial phase between the cells. From these results, we conclude that the 2D dynamics of these cells is preserved in 1D, suggesting a common computation during both types of navigation behavior. PMID:26898777

  17. External fixator configurations in tibia fractures: 1D optimization and 3D analysis comparison.

    PubMed

    Roseiro, Luis M; Neto, M Augusta; Amaro, Ana; Leal, Rogerio P; Samarra, Miguel C

    2014-01-01

    The use of external fixation devices in orthopedic surgery is very common in open tibial fractures. A properly applied fixator may improve the healing process while one improperly applied might delay the healing process. The several external fixator systems used in clinical today, can be categorized into uniplanar-unilateral, uniplanar-bilateral, biplanar and multiplanar. The stability on the fracture focus and, therefore, the fracture healing process, is related with the type of external fixator configuration that is selected. The aim of this study is to discuss the principles for the successful application of unilateral-uniplanar external fixation, the assembly of its components, for the case of a transverse fractures using computational models. In this context, the fixation stiffness characteristics are evaluated using a simplified 1D finite element model for the tibia and external fixator. The beams are modeled with realistic cross-sectional geometry and material properties instead of a simplified model. The VABS (the Variational Asymptotic Beam Section analysis) methodology is used to compute the cross-sectional model for the generalized Timoshenko model, which was embedded in the finite element solver FEAP. The use of Timoshenko beam theory allows accounting for several kinds of loads, including torsion moments. Optimal design is performed with respect to the assembly of fixator components using a genetic algorithm. The optimization procedure is based on the evaluation of an objective function, which is dependent on the displacement at the fracture focus. The initial and optimal results are compared by performing a 3D analysis, for which different three-dimensional finite element models are created. The geometrical model of a tibia is created on the basis of data acquired by CAT scan, made for a healthy tibia of a 22 year old male. The 3D comparison of the 1D optimal results show a clear improvement on the objective function for the several load cases and

  18. Payload training methodology study

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The results of the Payload Training Methodology Study (PTMS) are documented. Methods and procedures are defined for the development of payload training programs to be conducted at the Marshall Space Flight Center Payload Training Complex (PCT) for the Space Station Freedom program. The study outlines the overall training program concept as well as the six methodologies associated with the program implementation. The program concept outlines the entire payload training program from initial identification of training requirements to the development of detailed design specifications for simulators and instructional material. The following six methodologies are defined: (1) The Training and Simulation Needs Assessment Methodology; (2) The Simulation Approach Methodology; (3) The Simulation Definition Analysis Methodology; (4) The Simulator Requirements Standardization Methodology; (5) The Simulator Development Verification Methodology; and (6) The Simulator Validation Methodology.

  19. Expression of CD1d protein in human testis showing normal and abnormal spermatogenesis.

    PubMed

    Adly, Mohamed A; Abdelwahed Hussein, Mahmoud-Rezk

    2011-05-01

    CD1d is a member of CD1 family of transmembrane glycoproteins, which represent antigen-presenting molecules. Immunofluorescent staining methods were utilized to examine expression pattern of CD1d in human testicular specimens. In testis showing normal spermatogenesis, a strong CD1d cytoplasmic expression was seen the Sertoli cells, spermatogonia, and Leydig cells. A moderate expression was observed in the spermatocytes. In testes showing maturation arrest, CD1d expression was strong in the Sertoli cells and weak in spermatogonia and spermatocytes compared to testis with normal spermatogenesis. In Sertoli cell only syndrome, CD1d expression was strong in the Sertoli and Leydig cells. This preliminary study displayed testicular infertility-related changes in CD1d expression. The ultrastructural changes associated with with normal and abnormal spermatogenesis are open for further investigations.

  20. Examination of 1D Solar Cell Model Limitations Using 3D SPICE Modeling: Preprint

    SciTech Connect

    McMahon, W. E.; Olson, J. M.; Geisz, J. F.; Friedman, D. J.

    2012-06-01

    To examine the limitations of one-dimensional (1D) solar cell modeling, 3D SPICE-based modeling is used to examine in detail the validity of the 1D assumptions as a function of sheet resistance for a model cell. The internal voltages and current densities produced by this modeling give additional insight into the differences between the 1D and 3D models.

  1. Tunable Design of Structural Colors Produced by Pseudo-1D Photonic Crystals of Graphene Oxide.

    PubMed

    Tong, Liping; Qi, Wei; Wang, Mengfan; Huang, Renliang; Su, Rongxin; He, Zhimin

    2016-07-01

    It is broadly observed that graphene oxide (GO) films appear transparent with a thickness of about several nanometers, whereas they appear dark brown or almost black with thickness of more than 1 μm. The basic color mechanism of GO film on a sub-micrometer scale, however, is not well understood. This study reports on GO pseudo-1D photonic crystals (p1D-PhCs) exhibiting tunable structural colors in the visible wavelength range owing to its 1D Bragg nanostructures. Striking structural colors of GO p1D-PhCs could be tuned by simply changing either the volume or concentration of the aqueous GO dispersion during vacuum filtration. Moreover, the quantitative relationship between thickness and reflection wavelength of GO p1D-PhCs has been revealed, thereby providing a theoretical basis to rationally design structural colors of GO p1D-PhCs. The spectral response of GO p1D-PhCs to humidity is also obtained clearly showing the wavelength shift of GO p1D-PhCs at differently relative humidity values and thus encouraging the integration of structural color printing and the humidity-responsive property of GO p1D-PhCs to develop a visible and fast-responsive anti-counterfeiting label. The results pave the way for a variety of potential applications of GO in optics, structural color printing, sensing, and anti-counterfeiting.

  2. Exercise increases TBC1D1 phosphorylation in human skeletal muscle

    PubMed Central

    Jessen, Niels; An, Ding; Lihn, Aina S.; Nygren, Jonas; Hirshman, Michael F.; Thorell, Anders

    2011-01-01

    Exercise and weight loss are cornerstones in the treatment and prevention of type 2 diabetes, and both interventions function to increase insulin sensitivity and glucose uptake into skeletal muscle. Studies in rodents demonstrate that the underlying mechanism for glucose uptake in muscle involves site-specific phosphorylation of the Rab-GTPase-activating proteins AS160 (TBC1D4) and TBC1D1. Multiple kinases, including Akt and AMPK, phosphorylate TBC1D1 and AS160 on distinct residues, regulating their activity and allowing for GLUT4 translocation. In contrast to extensive rodent-based studies, the regulation of AS160 and TBC1D1 in human skeletal muscle is not well understood. In this study, we determined the effects of dietary intervention and a single bout of exercise on TBC1D1 and AS160 site-specific phosphorylation in human skeletal muscle. Ten obese (BMI 33.4 ± 2.4, M-value 4.3 ± 0.5) subjects were studied at baseline and after a 2-wk dietary intervention. Muscle biopsies were obtained from the subjects in the resting (basal) state and immediately following a 30-min exercise bout (70% V̇o2 max). Muscle lysates were analyzed for AMPK activity and Akt phosphorylation and for TBC1D1 and AS160 phosphorylation on known or putative AMPK and Akt sites as follows: AS160 Ser711 (AMPK), TBC1D1 Ser231 (AMPK), TBC1D1 Ser660 (AMPK), TBC1D1 Ser700 (AMPK), and TBC1D1 Thr590 (Akt). The diet intervention that consisted of a major shift in the macronutrient composition resulted in a 4.2 ± 0.4 kg weight loss (P < 0.001) and a significant increase in insulin sensitivity (M value 5.6 ± 0.6), but surprisingly, there was no effect on expression or phosphorylation of any of the muscle-signaling proteins. Exercise increased muscle AMPKα2 activity but did not increase Akt phosphorylation. Exercise increased phosphorylation on AS160 Ser711, TBC1D1 Ser231, and TBC1D1 Ser660 but had no effect on TBC1D1 Ser700. Exercise did not increase TBC1D1 Thr590 phosphorylation or TBC1D1/AS160 PAS

  3. Language Policy and Methodology

    ERIC Educational Resources Information Center

    Liddicoat, Antony J.

    2004-01-01

    The implementation of a language policy is crucially associated with questions of methodology. This paper explores approaches to language policy, approaches to methodology and the impact that these have on language teaching practice. Language policies can influence decisions about teaching methodologies either directly, by making explicit…

  4. Potent neutralizing anti-CD1d antibody reduces lung cytokine release in primate asthma model.

    PubMed

    Nambiar, Jonathan; Clarke, Adam W; Shim, Doris; Mabon, David; Tian, Chen; Windloch, Karolina; Buhmann, Chris; Corazon, Beau; Lindgren, Matilda; Pollard, Matthew; Domagala, Teresa; Poulton, Lynn; Doyle, Anthony G

    2015-01-01

    CD1d is a receptor on antigen-presenting cells involved in triggering cell populations, particularly natural killer T (NKT) cells, to release high levels of cytokines. NKT cells are implicated in asthma pathology and blockade of the CD1d/NKT cell pathway may have therapeutic potential. We developed a potent anti-human CD1d antibody (NIB.2) that possesses high affinity for human and cynomolgus macaque CD1d (KD ∼100 pM) and strong neutralizing activity in human primary cell-based assays (IC50 typically <100 pM). By epitope mapping experiments, we showed that NIB.2 binds to CD1d in close proximity to the interface of CD1d and the Type 1 NKT cell receptor β-chain. Together with data showing that NIB.2 inhibited stimulation via CD1d loaded with different glycolipids, this supports a mechanism whereby NIB.2 inhibits NKT cell activation by inhibiting Type 1 NKT cell receptor β-chain interactions with CD1d, independent of the lipid antigen in the CD1d antigen-binding cleft. The strong in vitro potency of NIB.2 was reflected in vivo in an Ascaris suum cynomolgus macaque asthma model. Compared with vehicle control, NIB.2 treatment significantly reduced bronchoalveolar lavage (BAL) levels of Ascaris-induced cytokines IL-5, IL-8 and IL-1 receptor antagonist, and significantly reduced baseline levels of GM-CSF, IL-6, IL-15, IL-12/23p40, MIP-1α, MIP-1β, and VEGF. At a cellular population level NIB.2 also reduced numbers of BAL lymphocytes and macrophages, and blood eosinophils and basophils. We demonstrate that anti-CD1d antibody blockade of the CD1d/NKT pathway modulates inflammatory parameters in vivo in a primate inflammation model, with therapeutic potential for diseases where the local cytokine milieu is critical.

  5. Potent neutralizing anti-CD1d antibody reduces lung cytokine release in primate asthma model

    PubMed Central

    Nambiar, Jonathan; Clarke, Adam W; Shim, Doris; Mabon, David; Tian, Chen; Windloch, Karolina; Buhmann, Chris; Corazon, Beau; Lindgren, Matilda; Pollard, Matthew; Domagala, Teresa; Poulton, Lynn; Doyle, Anthony G

    2015-01-01

    CD1d is a receptor on antigen-presenting cells involved in triggering cell populations, particularly natural killer T (NKT) cells, to release high levels of cytokines. NKT cells are implicated in asthma pathology and blockade of the CD1d/NKT cell pathway may have therapeutic potential. We developed a potent anti-human CD1d antibody (NIB.2) that possesses high affinity for human and cynomolgus macaque CD1d (KD ∼100 pM) and strong neutralizing activity in human primary cell-based assays (IC50 typically <100 pM). By epitope mapping experiments, we showed that NIB.2 binds to CD1d in close proximity to the interface of CD1d and the Type 1 NKT cell receptor β-chain. Together with data showing that NIB.2 inhibited stimulation via CD1d loaded with different glycolipids, this supports a mechanism whereby NIB.2 inhibits NKT cell activation by inhibiting Type 1 NKT cell receptor β-chain interactions with CD1d, independent of the lipid antigen in the CD1d antigen-binding cleft. The strong in vitro potency of NIB.2 was reflected in vivo in an Ascaris suum cynomolgus macaque asthma model. Compared with vehicle control, NIB.2 treatment significantly reduced bronchoalveolar lavage (BAL) levels of Ascaris-induced cytokines IL-5, IL-8 and IL-1 receptor antagonist, and significantly reduced baseline levels of GM-CSF, IL-6, IL-15, IL-12/23p40, MIP-1α, MIP-1β, and VEGF. At a cellular population level NIB.2 also reduced numbers of BAL lymphocytes and macrophages, and blood eosinophils and basophils. We demonstrate that anti-CD1d antibody blockade of the CD1d/NKT pathway modulates inflammatory parameters in vivo in a primate inflammation model, with therapeutic potential for diseases where the local cytokine milieu is critical. PMID:25751125

  6. Electronic-to-vibrational energy transfer efficiency in the O/1 D/-N2 and O/1 D/-CO systems

    NASA Technical Reports Server (NTRS)

    Slanger, T. G.; Black, G.

    1974-01-01

    With the aid of a molecular resonance fluorescence technique, which utilizes optical pumping from the v = 1 level of the ground state of CO by A 1 Pi-X 1 Sigma radiation, a study is made of the efficiency of E-V transfer from O(1 D) to CO. O(1 D) is generated at a known rate by O2 photodissociation at 1470 A in an intermittent mode, and the small modulation of the fluorescent signal associated with CO (v = 1) above the normal thermal background is interpreted in terms of E-V transfer efficiency. The CO (v = 1) lifetime in this system is determined mainly by resonance trapping of the IR fundamental band, and is found to be up to ten times longer than the natural radiative lifetime. For CO, (40 plus or minus 8)% of the O(1 D) energy is converted into vibrational energy. By observing the effect of N2 on the CO (v = 1) fluorescent intensity and lifetime, it is possible to obtain the E-V transfer efficiency for the system O(1 D)-N2 relative to that for O(1 D)-CO. The results indicate that the efficiency for N2 is (83 plus or minus 10)% of that for CO.

  7. Mapping of the serotonin 5-HT{sub 1D{alpha}} autoreceptor gene (HTR1D) on chromosome 1 using a silent polymorphism in the coding region

    SciTech Connect

    Ozaki, N.; Lappalainen, J.; Linnoila, M.

    1995-04-24

    Serotonin (5-HT){sub ID} receptors are 5-HT release-regulating autoreceptors in the human brain. Abnormalities in brain 5-HT function have been hypothesized in the pathophysiology of various psychiatric disorders, including obsessive-compulsive disorder, autism, mood disorders, eating disorders, impulsive violent behavior, and alcoholism. Thus, mutations occurring in 5-HT autoreceptors may cause or increase the vulnerability to any of these conditions. 5-HT{sub 1D{alpha}} and 5-HT{sub 1D{Beta}} subtypes have been previously localized to chromosomes 1p36.3-p34.3 and 6q13, respectively, using rodent-human hybrids and in situ localization. In this communication, we report the detection of a 5-HT{sub 1D{alpha}} receptor gene polymorphism by single strand conformation polymorphism (SSCP) analysis of the coding sequence. The polymorphism was used for fine scale linkage mapping of 5-HT{sub 1D{alpha}} on chromosome 1. This polymorphism should also be useful for linkage studies in populations and in families. Our analysis also demonstrates that functionally significant coding sequence variants of the 5-HT{sub 1D{alpha}} are probably not abundant either among alcoholics or in the general population. 14 refs., 1 fig., 1 tab.

  8. 1-D transient numerical model of a regenerator in a novel sub Kelvin Active Magnetic Regenerative Refrigerator

    NASA Astrophysics Data System (ADS)

    Jahromi, Amir E.; Miller, Franklin K.

    2016-03-01

    A sub Kelvin Active Magnetic Regenerative Refrigerator (AMRR) is being developed at the University of Wisconsin - Madison. This AMRR consists of two circulators, two regenerators, one superleak, one cold heat exchanger, and two warm heat exchangers. The circulators are novel non-moving part pumps that reciprocate a superfluid mixture of 4He-3He in the system. Heat from the mixture is removed within the two regenerators of this tandem system. An accurate model of the regenerators in this AMRR is necessary in order to predict the performance of these components, which in turn helps predicting the overall performance of the AMRR system. This work presents modeling methodology along with results from a 1-D transient numerical model of the regenerators of an AMRR capable of removing 2.5 mW at 850 mK at cyclic steady state.

  9. Neodymium 1D systems: targeting new sources for field-induced slow magnetization relaxation.

    PubMed

    Jassal, Amanpreet Kaur; Aliaga-Alcalde, Núria; Corbella, Montserrat; Aravena, Daniel; Ruiz, Eliseo; Hundal, Geeta

    2015-09-28

    Two non-isostructural homometallic 1D neodymium species displaying field-induced slow magnetization relaxations are presented together with theoretical studies. It is established that both systems are better described as organized 1D single molecule magnets (SMMs). Studies show great potential of Nd(III) ions to provide homometallic chains with slow magnetic relaxation.

  10. Characterization of the fraction components using 1D TOCSY and 1D ROESY experiments. Four new spirostane saponins from Agave brittoniana Trel. spp. Brachypus.

    PubMed

    Macías, Francisco A; Guerra, José O; Simonet, Ana M; Nogueiras, Clara M

    2007-07-01

    A careful NMR analysis, especially 1D TOCSY and 1D ROESY, of two refined saponin fractions allowed us to determine the structures of four new saponins from a polar extract of the Agave brittoniana Trel. spp. Brachypus leaves. A full assignment of the 1H and 13C spectral data for these new saponins, agabrittonosides A-D (1-4), and one previously known saponin, karatavioside A (5) is reported. Their structures were established using a combination of 1D and 2D (1H, 1H-COSY, TOCSY, ROESY, g-HSQC, g-HMBC and g-HSQC-TOCSY) NMR techniques and ESI-MS. Moreover, the work represents a new approach to structural elucidation of saponins in refined fractions by NMR investigations.

  11. Decays B(s)→a1(b1)D(s), a1(b1)D(s)* in the perturbative QCD approach

    NASA Astrophysics Data System (ADS)

    Zhang, Zhi-Qing

    2013-04-01

    Within the framework of the perturbative QCD approach, we study the branching ratios of the two-body charmed decays B(s)→a1(b1)D(s), a1(b1)D(s)*, which, including Cabibbo-Kobayashi-Maskawa, allowed and suppressed decays. Our calculations are consistent with the currently available data and the experimental upper limits. Certainly, many of these predicted channels have not been measured by experiments and can be confronted with the future experimental data. We also discuss the polarization factions of the decays B(s)→a1(b1)D(s)*, some of which are sensitive to the distinct Gegenbauer moments of the wave functions and the decay constants of mesons a1 and b1.

  12. TBC1D1 reduces palmitate oxidation by inhibiting β-HAD activity in skeletal muscle.

    PubMed

    Maher, A C; McFarlan, J; Lally, J; Snook, L A; Bonen, A

    2014-11-01

    In skeletal muscle the Rab-GTPase-activating protein TBC1D1 has been implicated in the regulation of fatty acid oxidation by an unknown mechanism. We determined whether TBC1D1 altered fatty acid utilization via changes in protein-mediated fatty acid transport and/or selected enzymes regulating mitochondrial fatty acid oxidation. We also determined the effects of TBC1D1 on glucose transport and oxidation. Electrotransfection of mouse soleus muscles with TBC1D1 cDNA increased TBC1D1 protein after 2 wk (P<0.05), without altering its paralog AS160. TBC1D1 overexpression decreased basal palmitate oxidation (-22%) while blunting 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR)-stimulated palmitate oxidation (-18%). There was a tendency to increase fatty acid esterification (+10 nmol·g(-1)·60 min(-1), P=0.07), which reflected the reduction in fatty acid oxidation (-12 nmol·g(-1)·60 min(-1)). Concomitantly, basal (+21%) and AICAR-stimulated glucose oxidation (+8%) were increased in TBC1D1-transfected muscles relative to their respective controls (P<0.05), independent of changes in GLUT4 and glucose transport. The reductions in TBC1D1-mediated fatty acid oxidation could not be attributed to changes in the transporter FAT/CD36, muscle mitochondrial content, CPT1 expression or the expression and phosphorylation of AS160, acetyl-CoA carboxylase, or AMPK. However, TBC1D1 overexpression reduced β-HAD enzyme activity (-18%, P<0.05). In conclusion, TBC1D1-mediated reduction of muscle fatty acid oxidation appears to occur via inhibition of β-HAD activity.

  13. Reliability Centered Maintenance - Methodologies

    NASA Technical Reports Server (NTRS)

    Kammerer, Catherine C.

    2009-01-01

    Journal article about Reliability Centered Maintenance (RCM) methodologies used by United Space Alliance, LLC (USA) in support of the Space Shuttle Program at Kennedy Space Center. The USA Reliability Centered Maintenance program differs from traditional RCM programs because various methodologies are utilized to take advantage of their respective strengths for each application. Based on operational experience, USA has customized the traditional RCM methodology into a streamlined lean logic path and has implemented the use of statistical tools to drive the process. USA RCM has integrated many of the L6S tools into both RCM methodologies. The tools utilized in the Measure, Analyze, and Improve phases of a Lean Six Sigma project lend themselves to application in the RCM process. All USA RCM methodologies meet the requirements defined in SAE JA 1011, Evaluation Criteria for Reliability-Centered Maintenance (RCM) Processes. The proposed article explores these methodologies.

  14. Mycobacterial phosphatidylinositol mannoside is a natural antigen for CD1d-restricted T cells

    PubMed Central

    Fischer, Karsten; Scotet, Emmanuel; Niemeyer, Marcus; Koebernick, Heidrun; Zerrahn, Jens; Maillet, Sophie; Hurwitz, Robert; Kursar, Mischo; Bonneville, Marc; Kaufmann, Stefan H. E.; Schaible, Ulrich E.

    2004-01-01

    A group of T cells recognizes glycolipids presented by molecules of the CD1 family. The CD1d-restricted natural killer T cells (NKT cells) are primarily considered to be self-reactive. By employing CD1d-binding and T cell assays, the following structural parameters for presentation by CD1d were defined for a number of mycobacterial and mammalian lipids: two acyl chains facilitated binding, and a polar head group was essential for T cell recognition. Of the mycobacterial lipids tested, only a phosphatidylinositol mannoside (PIM) fulfilled the requirements for CD1d binding and NKT cell stimulation. This PIM activated human and murine NKT cells via CD1d, thereby triggering antigen-specific IFN-γ production and cell-mediated cytotoxicity, and PIM-loaded CD1d tetramers identified a subpopulation of murine and human NKT cells. This phospholipid, therefore, represents a mycobacterial antigen recognized by T cells in the context of CD1d. PMID:15243159

  15. Structure and Catalytic Mechanism of Human Steroid 5-Reductase (AKR1D1)

    SciTech Connect

    Costanzo, L.; Drury, J; Christianson, D; Penning, T

    2009-01-01

    Human steroid 5{beta}-reductase (aldo-keto reductase (AKR) 1D1) catalyzes reduction of {Delta}{sup 4}-ene double bonds in steroid hormones and bile acid precursors. We have reported the structures of an AKR1D1-NADP{sup +} binary complex, and AKR1D1-NADP{sup +}-cortisone, AKR1D1-NADP{sup +}-progesterone and AKR1D1-NADP{sup +}-testosterone ternary complexes at high resolutions. Recently, structures of AKR1D1-NADP{sup +}-5{beta}-dihydroprogesterone complexes showed that the product is bound unproductively. Two quite different mechanisms of steroid double bond reduction have since been proposed. However, site-directed mutagenesis supports only one mechanism. In this mechanism, the 4-pro-R hydride is transferred from the re-face of the nicotinamide ring to C5 of the steroid substrate. E120, a unique substitution in the AKR catalytic tetrad, permits a deeper penetration of the steroid substrate into the active site to promote optimal reactant positioning. It participates with Y58 to create a 'superacidic' oxyanion hole for polarization of the C3 ketone. A role for K87 in the proton relay proposed using the AKR1D1-NADP{sup +}-5{beta}-dihydroprogesterone structure is not supported.

  16. TBC1D14 regulates autophagy via the TRAPP complex and ATG9 traffic.

    PubMed

    Lamb, Christopher A; Nühlen, Stefanie; Judith, Delphine; Frith, David; Snijders, Ambrosius P; Behrends, Christian; Tooze, Sharon A

    2016-02-01

    Macroautophagy requires membrane trafficking and remodelling to form the autophagosome and deliver its contents to lysosomes for degradation. We have previously identified the TBC domain-containing protein, TBC1D14, as a negative regulator of autophagy that controls delivery of membranes from RAB11-positive recycling endosomes to forming autophagosomes. In this study, we identify the TRAPP complex, a multi-subunit tethering complex and GEF for RAB1, as an interactor of TBC1D14. TBC1D14 binds to the TRAPP complex via an N-terminal 103 amino acid region, and overexpression of this region inhibits both autophagy and secretory traffic. TRAPPC8, the mammalian orthologue of a yeast autophagy-specific TRAPP subunit, forms part of a mammalian TRAPPIII-like complex and both this complex and TBC1D14 are needed for RAB1 activation. TRAPPC8 modulates autophagy and secretory trafficking and is required for TBC1D14 to bind TRAPPIII. Importantly, TBC1D14 and TRAPPIII regulate ATG9 trafficking independently of ULK1. We propose a model whereby TBC1D14 and TRAPPIII regulate a constitutive trafficking step from peripheral recycling endosomes to the early Golgi, maintaining the cycling pool of ATG9 required for initiation of autophagy. PMID:26711178

  17. Role and regulation of CD1d in normal and pathological B cells

    PubMed Central

    Chaudhry, Mohammed S.; Karadimitris, Anastasios

    2015-01-01

    CD1d is a non-polymorphic, MHC class I-like molecule, which presents phosphoand glycosphingo-lipid antigens to a subset of CD1d-restricted T cells called invariant NKT (iNKT) cells. This CD1d-iNKT cell axis regulates nearly all aspects of both the innate and adaptive immune response. Expression of CD1d on B cells is suggestive of the ability of these cells to present antigen to and form cognate interactions with iNKT cells. Herein we summarise key evidence regarding the role and regulation of CD1d in normal B cells and in humoral immunity. We then extend the discussion to B cell disorders, with emphasis on autoimmune disease, viral infection and neoplastic transformation of B lineage cells, where CD1d expression can be altered as a mechanism of immune evasion, and can have both diagnostic and prognostic importance. Finally we highlight current and future therapeutic strategies that aim to target the CD1d-iNKT axis in B cells. PMID:25381357

  18. Calreticulin Controls the Rate of Assembly of CD1d Molecules in the Endoplasmic Reticulum*

    PubMed Central

    Zhu, Yajuan; Zhang, Wei; Veerapen, Natacha; Besra, Gurdyal; Cresswell, Peter

    2010-01-01

    CD1d is an MHC class I-like molecule comprised of a transmembrane glycoprotein (heavy chain) associated with β2-microglobulin (β2m) that presents lipid antigens to NKT cells. Initial folding of the heavy chain involves its glycan-dependent association with calreticulin (CRT), calnexin (CNX), and the thiol oxidoreductase ERp57, and is followed by assembly with β2m to form the heterodimer. Here we show that in CRT-deficient cells CD1d heavy chains convert to β2m-associated dimers at an accelerated rate, indicating faster folding of the heavy chain, while the rate of intracellular transport after assembly is unaffected. Unlike the situation with MHC class I molecules, antigen presentation by CD1d is not impaired in the absence of CRT. Instead, there are elevated levels of stable and functional CD1d on the surface of CRT-deficient cells. Association of the heavy chains with the ER chaperones Grp94 and Bip is observed in the absence of CRT, and these may replace CRT in mediating CD1d folding and assembly. ER retention of free CD1d heavy chains is impaired in CRT-deficient cells, allowing their escape and subsequent expression on the plasma membrane. However, these free heavy chains are rapidly internalized and degraded in lysosomes, indicating that β2m association is required for the exceptional resistance of CD1d to lysosomal degradation that is normally observed. PMID:20861015

  19. The FC-1D: The profitable alternative Flying Circus Commercial Aviation Group

    NASA Technical Reports Server (NTRS)

    Meza, Victor J.; Alvarez, Jaime; Harrington, Brook; Lujan, Michael A.; Mitlyng, David; Saroughian, Andy; Silva, Alex; Teale, Tim

    1994-01-01

    The FC-1D was designed as an advanced solution for a low cost commercial transport meeting or exceeding all of the 1993/1994 AIAA/Lockheed request for proposal requirements. The driving philosophy behind the design of the FC-1D was the reduction of airline direct operating costs. Every effort was made during the design process to have the customer in mind. The Flying Circus Commercial Aviation Group targeted reductions in drag, fuel consumption, manufacturing costs, and maintenance costs. Flying Circus emphasized cost reduction throughout the entire design program. Drag reduction was achieved by implementation of the aft nacelle wing configuration to reduce cruise drag and increase cruise speeds. To reduce induced drag, rather than increasing the wing span of the FC-1D, spiroids were included in the efficient wing design. Profile and friction drag are reduced by using riblets in place of paint around the fuselage and empennage of the FC-1D. Choosing a single aisle configuration enabled the Flying Circus to optimize the fuselage diameter. Thus, reducing fuselage drag while gaining high structural efficiency. To further reduce fuel consumption a weight reduction program was conducted through the use of composite materials. An additional quality of the FC-1D is its design for low cost manufacturing and assembly. As a result of this design attribute, the FC-1D will have fewer parts which reduces weight as well as maintenance and assembly costs. The FC-1D is affordable and effective, the apex of commercial transport design.

  20. On the current drive capability of low dimensional semiconductors: 1D versus 2D

    DOE PAGES

    Zhu, Y.; Appenzeller, J.

    2015-10-29

    Low-dimensional electronic systems are at the heart of many scaling approaches currently pursuit for electronic applications. Here, we present a comparative study between an array of one-dimensional (1D) channels and its two-dimensional (2D) counterpart in terms of current drive capability. Lastly, our findings from analytical expressions derived in this article reveal that under certain conditions an array of 1D channels can outperform a 2D field-effect transistor because of the added degree of freedom to adjust the threshold voltage in an array of 1D devices.

  1. TCTEX1D2 mutations underlie Jeune asphyxiating thoracic dystrophy with impaired retrograde intraflagellar transport.

    PubMed

    Schmidts, Miriam; Hou, Yuqing; Cortés, Claudio R; Mans, Dorus A; Huber, Celine; Boldt, Karsten; Patel, Mitali; van Reeuwijk, Jeroen; Plaza, Jean-Marc; van Beersum, Sylvia E C; Yap, Zhi Min; Letteboer, Stef J F; Taylor, S Paige; Herridge, Warren; Johnson, Colin A; Scambler, Peter J; Ueffing, Marius; Kayserili, Hulya; Krakow, Deborah; King, Stephen M; Beales, Philip L; Al-Gazali, Lihadh; Wicking, Carol; Cormier-Daire, Valerie; Roepman, Ronald; Mitchison, Hannah M; Witman, George B

    2015-01-01

    The analysis of individuals with ciliary chondrodysplasias can shed light on sensitive mechanisms controlling ciliogenesis and cell signalling that are essential to embryonic development and survival. Here we identify TCTEX1D2 mutations causing Jeune asphyxiating thoracic dystrophy with partially penetrant inheritance. Loss of TCTEX1D2 impairs retrograde intraflagellar transport (IFT) in humans and the protist Chlamydomonas, accompanied by destabilization of the retrograde IFT dynein motor. We thus define TCTEX1D2 as an integral component of the evolutionarily conserved retrograde IFT machinery. In complex with several IFT dynein light chains, it is required for correct vertebrate skeletal formation but may be functionally redundant under certain conditions. PMID:26044572

  2. TCTEX1D2 mutations underlie Jeune asphyxiating thoracic dystrophy with impaired retrograde intraflagellar transport

    PubMed Central

    Schmidts, Miriam; Hou, Yuqing; Cortés, Claudio R.; Mans, Dorus A.; Huber, Celine; Boldt, Karsten; Patel, Mitali; van Reeuwijk, Jeroen; Plaza, Jean-Marc; van Beersum, Sylvia E. C.; Yap, Zhi Min; Letteboer, Stef J. F.; Taylor, S. Paige; Herridge, Warren; Johnson, Colin A.; Scambler, Peter J.; Ueffing, Marius; Kayserili, Hulya; Krakow, Deborah; King, Stephen M.; Beales, Philip L.; Al-Gazali, Lihadh; Wicking, Carol; Cormier-Daire, Valerie; Roepman, Ronald; Mitchison, Hannah M.; Witman, George B.; Al-Turki, Saeed; Anderson, Carl; Anney, Richard; Antony, Dinu; Asimit, Jennifer; Ayub, Mohammad; Barrett, Jeff; Barroso, Inês; Bentham, Jamie; Bhattacharya, Shoumo; Blackwood, Douglas; Bobrow, Martin; Bochukova, Elena; Bolton, Patrick; Boustred, Chris; Breen, Gerome; Brion, Marie-Jo; Brown, Andrew; Calissano, Mattia; Carss, Keren; Chatterjee, Krishna; Chen, Lu; Cirak, Sebhattin; Clapham, Peter; Clement, Gail; Coates, Guy; Collier, David; Cosgrove, Catherine; Cox, Tony; Craddock, Nick; Crooks, Lucy; Curran, Sarah; Daly, Allan; Danecek, Petr; Smith, George Davey; Day-Williams, Aaron; Day, Ian; Durbin, Richard; Edkins, Sarah; Ellis, Peter; Evans, David; Farooqi, I. Sadaf; Fatemifar, Ghazaleh; Fitzpatrick, David; Flicek, Paul; Floyd, Jamie; Foley, A. Reghan; Franklin, Chris; Futema, Marta; Gallagher, Louise; Gaunt, Tom; Geschwind, Daniel; Greenwood, Celia; Grozeva, Detelina; Guo, Xiaosen; Gurling, Hugh; Hart, Deborah; Hendricks, Audrey; Holmans, Peter; Huang, Jie; Humphries, Steve E.; Hurles, Matt; Hysi, Pirro; Jackson, David; Jamshidi, Yalda; Jewell, David; Chris, Joyce; Kaye, Jane; Keane, Thomas; Kemp, John; Kennedy, Karen; Kent, Alastair; Kolb-Kokocinski, Anja; Lachance, Genevieve; Langford, Cordelia; Lee, Irene; Li, Rui; Li, Yingrui; Ryan, Liu; Lönnqvist, Jouko; Lopes, Margarida; MacArthur, Daniel G.; Massimo, Mangino; Marchini, Jonathan; Maslen, John; McCarthy, Shane; McGuffin, Peter; McIntosh, Andrew; McKechanie, Andrew; McQuillin, Andrew; Memari, Yasin; Metrustry, Sarah; Min, Josine; Moayyeri, Alireza; Morris, James; Muddyman, Dawn; Muntoni, Francesco; Northstone, Kate; O'Donovan, Michael; O'Rahilly, Stephen; Onoufriadis, Alexandros; Oualkacha, Karim; Owen, Michael; Palotie, Aarno; Panoutsopoulou, Kalliope; Parker, Victoria; Parr, Jeremy; Paternoster, Lavinia; Paunio, Tiina; Payne, Felicity; Perry, John; Pietilainen, Olli; Plagnol, Vincent; Quail, Michael A.; Quaye, Lydia; Raymond, Lucy; Rehnström, Karola; Brent Richards, J.; Ring, Sue; Ritchie, Graham R S; Savage, David B.; Schoenmakers, Nadia; Semple, Robert K.; Serra, Eva; Shihab, Hashem; Shin, So-Youn; Skuse, David; Small, Kerrin; Smee, Carol; Soler, Artigas María; Soranzo, Nicole; Southam, Lorraine; Spector, Tim; St Pourcain, Beate; St. Clair, David; Stalker, Jim; Surdulescu, Gabriela; Suvisaari, Jaana; Tachmazidou, Ioanna; Tian, Jing; Timpson, Nic; Tobin, Martin; Valdes, Ana; van Kogelenberg, Margriet; Vijayarangakannan, Parthiban; Wain, Louise; Walter, Klaudia; Wang, Jun; Ward, Kirsten; Wheeler, Ellie; Whittall, Ros; Williams, Hywel; Williamson, Kathy; Wilson, Scott G.; Wong, Kim; Whyte, Tamieka; ChangJiang, Xu; Zeggini, Eleftheria; Zhang, Feng; Zheng, Hou-Feng

    2015-01-01

    The analysis of individuals with ciliary chondrodysplasias can shed light on sensitive mechanisms controlling ciliogenesis and cell signalling that are essential to embryonic development and survival. Here we identify TCTEX1D2 mutations causing Jeune asphyxiating thoracic dystrophy with partially penetrant inheritance. Loss of TCTEX1D2 impairs retrograde intraflagellar transport (IFT) in humans and the protist Chlamydomonas, accompanied by destabilization of the retrograde IFT dynein motor. We thus define TCTEX1D2 as an integral component of the evolutionarily conserved retrograde IFT machinery. In complex with several IFT dynein light chains, it is required for correct vertebrate skeletal formation but may be functionally redundant under certain conditions. PMID:26044572

  3. Comet Halley O(1D) and H2O production rates

    NASA Technical Reports Server (NTRS)

    Magee-Sauer, K.; Scherb, F.; Roesler, F. L.; Harlander, J.

    1990-01-01

    Ground-based dual-etalon Fabry-Perot spectrometer observations have been made of Comet Halley's forbidden O I 6300 A emission. The 0.2 A resolution of the spectral scans was sufficient to resolve the O I forbidden line emissions from both nearby cometary NH2 and telluric emissions. On the basis of these measurements, the production rate Q of O(1D) was determined; it is then found, by taking into account the photodissociation of H2O and OH as sources of O(1D), that the ratio of H2O/O(1D) production rates is of the order of 6.

  4. On the Current Drive Capability of Low Dimensional Semiconductors: 1D versus 2D.

    PubMed

    Zhu, Y; Appenzeller, J

    2015-12-01

    Low-dimensional electronic systems are at the heart of many scaling approaches currently pursuit for electronic applications. Here, we present a comparative study between an array of one-dimensional (1D) channels and its two-dimensional (2D) counterpart in terms of current drive capability. Our findings from analytical expressions derived in this article reveal that under certain conditions an array of 1D channels can outperform a 2D field-effect transistor because of the added degree of freedom to adjust the threshold voltage in an array of 1D devices.

  5. Ubiquitination and degradation of the hominoid-specific oncoprotein TBC1D3 is regulated by protein palmitoylation

    SciTech Connect

    Kong, Chen; Lange, Jeffrey J.; Samovski, Dmitri; Su, Xiong; Liu, Jialiu; Sundaresan, Sinju; Stahl, Philip D.

    2013-05-03

    Highlights: •Hominoid-specific oncogene TBC1D3 is targeted to plasma membrane by palmitoylation. •TBC1D3 is palmitoylated on two cysteine residues: 318 and 325. •TBC1D3 palmitoylation governs growth factors-induced TBC1D3 degradation. •Post-translational modifications may regulate oncogenic properties of TBC1D3. -- Abstract: Expression of the hominoid-specific oncoprotein TBC1D3 promotes enhanced cell growth and proliferation by increased activation of signal transduction through several growth factors. Recently we documented the role of CUL7 E3 ligase in growth factors-induced ubiquitination and degradation of TBC1D3. Here we expanded our study to discover additional molecular mechanisms that control TBC1D3 protein turnover. We report that TBC1D3 is palmitoylated on two cysteine residues: 318 and 325. The expression of double palmitoylation mutant TBC1D3:C318/325S resulted in protein mislocalization and enhanced growth factors-induced TBC1D3 degradation. Moreover, ubiquitination of TBC1D3 via CUL7 E3 ligase complex was increased by mutating the palmitoylation sites, suggesting that depalmitoylation of TBC1D3 makes the protein more available for ubiquitination and degradation. The results reported here provide novel insights into the molecular mechanisms that govern TBC1D3 protein degradation. Dysregulation of these mechanisms in vivo could potentially result in aberrant TBC1D3 expression and promote oncogenesis.

  6. Pseudo 1-D Micro/Nanofluidic Device for Exact Electrokinetic Responses.

    PubMed

    Kim, Junsuk; Kim, Ho-Young; Lee, Hyomin; Kim, Sung Jae

    2016-06-28

    Conventionally, a 1-D micro/nanofluidic device, whose nanochannel bridged two microchannels, was widely chosen in the fundamental electrokinetic studies; however, the configuration had intrinsic limitations of the time-consuming and labor intensive tasks of filling and flushing the microchannel due to the high fluidic resistance of the nanochannel bridge. In this work, a pseudo 1-D micro/nanofluidic device incorporating air valves at each microchannel was proposed for mitigating these limitations. High Laplace pressure formed at liquid/air interface inside the microchannels played as a virtual valve only when the electrokinetic operations were conducted. The identical electrokinetic behaviors of the propagation of ion concentration polarization layer and current-voltage responses were obtained in comparison with the conventional 1-D micro/nanofluidic device by both experiments and numerical simulations. Therefore, the suggested pseudo 1-D micro/nanofluidic device owned not only experimental conveniences but also exact electrokinetic responses. PMID:27248856

  7. Quantum and semi-classical transport in RTDs using NEMO 1-D

    NASA Technical Reports Server (NTRS)

    Klimeck, G.; Stout, P.; Bowen, R. C.

    2003-01-01

    NEMO 1-D has been developed primarily for the simulation of resonant tunneling diodes, and quantitative and predictive agreements with experimental high performance, high current density devices have been achieved in the past.

  8. The Methodology of Magpies

    ERIC Educational Resources Information Center

    Carter, Susan

    2014-01-01

    Arts/Humanities researchers frequently do not explain methodology overtly; instead, they "perform" it through their use of language, textual and historic cross-reference, and theory. Here, methodologies from literary studies are shown to add to Higher Education (HE) an exegetical and critically pluralist approach. This includes…

  9. Menopause and Methodological Doubt

    ERIC Educational Resources Information Center

    Spence, Sheila

    2005-01-01

    Menopause and methodological doubt begins by making a tongue-in-cheek comparison between Descartes' methodological doubt and the self-doubt that can arise around menopause. A hermeneutic approach is taken in which Cartesian dualism and its implications for the way women are viewed in society are examined, both through the experiences of women…

  10. Data Centric Development Methodology

    ERIC Educational Resources Information Center

    Khoury, Fadi E.

    2012-01-01

    Data centric applications, an important effort of software development in large organizations, have been mostly adopting a software methodology, such as a waterfall or Rational Unified Process, as the framework for its development. These methodologies could work on structural, procedural, or object oriented based applications, but fails to capture…

  11. Novel electronic structures of self-organized 1D surface nanostructures

    NASA Astrophysics Data System (ADS)

    Yeom, Han Woong

    2002-03-01

    Recently we have searched for the exotic physical properties of the nanostructures formed on semiconductor surfaces by STM and photoelectron spectroscopy [1]. The major objects have been the 1D chains of metal adsorbates on Si or SiC surfaces. It now seems obvious that such (sub)nanometer-scale atomic chains possess significant technological implications for the future device technology. Furthermore those systems provide very attractive and unprecedented opportunity to study exotic physical properties of 1D electronic systems in detail, such as Peierls instability, charge density wave (CDW), electron correlation, non-Fermi liquid behavior, and interplay of defects with 1D excitations (1D solitons, 1D domain walls and etc). The present talk focuses on the recent experimental and theoretical studies for the novel electronic properties of the 1D atomic chain systems on the Si(111) surface such as Si(111)4x1-In [2], Si(111)5x2-Au [3], Si(557)5x2-Au [4], and Si(111)3x2-Ba(or Ca) [5]. These systems have well defined one dimensional electronic bands, which exhibit intriguing properties challenging our present understanding. The major points of debates right now are the origin of the periodicity-doubling phase transition of Si(111)4x1-In in relation to 1D CDW [2], the nature of the band gap (or pseudo gap) of Si(111)5x2-Au (also related to 1D CDW idea) [3], the Si(111)3x2-Ba (or Ca) surface (1D Mott-Hubbard system ?) [5], and the nature of the band dispersion of the Si(557)5x2-Au surface (any Luttinger liquid behavior ?) [4]. Some new aspects of these systems are introduced such as the doping dependence of the 1D CDW system and the transport measurements across the 1D CDW transition. References [1] For a recent review, see H. W. Yeom, J. Electron Spectro. and Rel. Phenom., 114-116, 283 (2001). [2] H.W. Yeom et al., Phys. Rev. Lett. 82, 4898 (1999); C. Kumpf et al, Phys. Rev. Lett. 85, 4916 (2001); H.W. Yeom et al., submitted; G. Le Lay et al., submitted; J.-H. Cho et al

  12. Design, Synthesis, and Functional Activity of Labeled CD1d Glycolipid Agonists

    PubMed Central

    2013-01-01

    Invariant natural killer T cells (iNKT cells) are restricted by CD1d molecules and activated upon CD1d-mediated presentation of glycolipids to T cell receptors (TCRs) located on the surface of the cell. Because the cytokine response profile is governed by the structure of the glycolipid, we sought a method for labeling various glycolipids to study their in vivo behavior. The prototypical CD1d agonist, α-galactosyl ceramide (α-GalCer) 1, instigates a powerful immune response and the generation of a wide range of cytokines when it is presented to iNKT cell TCRs by CD1d molecules. Analysis of crystal structures of the TCR−α-GalCer–CD1d ternary complex identified the α-methylene unit in the fatty acid side chain, and more specifically the pro-S hydrogen at this position, as a site for incorporating a label. We postulated that modifying the glycolipid in this way would exert a minimal impact on the TCR–glycolipid–CD1d ternary complex, allowing the labeled molecule to function as a good mimic for the CD1d agonist under investigation. To test this hypothesis, the synthesis of a biotinylated version of the CD1d agonist threitol ceramide (ThrCer) was targeted. Both diastereoisomers, epimeric at the label tethering site, were prepared, and functional experiments confirmed the importance of substituting the pro-S, and not the pro-R, hydrogen with the label for optimal activity. Significantly, functional experiments revealed that biotinylated ThrCer (S)-10 displayed behavior comparable to that of ThrCer 5 itself and also confirmed that the biotin residue is available for streptavidin and antibiotin antibody recognition. A second CD1d agonist, namely α-GalCer C20:2 4, was modified in a similar way, this time with a fluorescent label. The labeled α-GalCer C20:2 analogue (11) again displayed functional behavior comparable to that of its unlabeled substrate, supporting the notion that the α-methylene unit in the fatty acid amide chain should be a suitable site for

  13. Actinometric measurement of j(O3-O(1D)) using a luminol detector

    NASA Technical Reports Server (NTRS)

    Bairai, Solomon T.; Stedman, Donald H.

    1992-01-01

    The photolysis frequency of ozone to singlet D oxygen atoms has been measured by means of a chemical actinometer using a luminol based detector. The instrument measures j(O3-O(1D)) with a precision of 10 percent. The data collected in winter and spring of 1991 is in agreement with model predictions and previously measured values. Data from a global solar radiometer can be used to estimate the effects of local cloudiness on j(O3-O(1D)).

  14. Structural resistance of chemically modified 1-D nanostructured titanates in inorganic acid environment

    SciTech Connect

    Marinkovic, Bojan A.; Fredholm, Yann C.; Morgado, Edisson

    2010-10-15

    Sodium containing one-dimensional nanostructured layered titanates (1-D NSLT) were produced both from commercial anatase powder and Brazilian natural rutile mineral sands by alkali hydrothermal process. The 1-D NSLT were chemically modified with proton, cobalt or iron via ionic exchange and all products were additionally submitted to intensive inorganic acid aging (pH = 0.5) for 28 days. The morphology and crystal structure transformations of chemically modified 1-D NSLT were followed by transmission electron microscopy, powder X-ray diffraction, selected area electron diffraction and energy dispersive spectroscopy. It was found that the original sodium rich 1-D NSLT and cobalt substituted 1-D NSLT were completely converted to rutile nanoparticles, while the protonated form was transformed in a 70%-30% (by weight) anatase-rutile nanoparticles mixture, very similar to that of the well-known TiO{sub 2}-photocatalyst P25 (Degussa). The iron substituted 1-D NSLT presented better acid resistance as 13% of the original structure and morphology remained, the rest being converted in rutile. A significant amount of remaining 1-D NSLT was also observed after the acid treatment of the product obtained from rutile sand. The results showed that phase transformation of NSLT into titanium dioxide polymorph in inorganic acid conditions were controllable by varying the exchanged cations. Finally, the possibility to transform, through acid aging, 1-D NSLT obtained from Brazilian natural rutile sand into TiO{sub 2}-polymorphs was demonstrated for the first time to the best of authors' knowledge, opening path for producing TiO{sub 2}-nanoproducts with different morphologies through a simple process and from a low cost precursor.

  15. Coherent Synchrotron Radiation and Space Charge for a 1-D Bunch on an Arbitrary Planar Orbit

    SciTech Connect

    Warnock, R.L.; /SLAC

    2008-01-08

    Realistic modeling of coherent synchrotron radiation (CSR) and the space charge force in single-pass systems and rings usually requires at least a two-dimensional (2-D) description of the charge/current density of the bunch. Since that leads to costly computations, one often resorts to a 1-D model of the bunch for first explorations. This paper provides several improvements to previous 1-D theories, eliminating unnecessary approximations and physical restrictions.

  16. NR1D1 ameliorates Mycobacterium tuberculosis clearance through regulation of autophagy

    PubMed Central

    Chandra, Vemika; Bhagyaraj, Ella; Nanduri, Ravikanth; Ahuja, Nancy; Gupta, Pawan

    2015-01-01

    NR1D1 (nuclear receptor subfamily 1, group D, member 1), an adopted orphan nuclear receptor, is widely known to orchestrate the expression of genes involved in various biological processes such as adipogenesis, skeletal muscle differentiation, and lipid and glucose metabolism. Emerging evidence suggests that various members of the nuclear receptor superfamily perform a decisive role in the modulation of autophagy. Recently, NR1D1 has been implicated in augmenting the antimycobacterial properties of macrophages and providing protection against Mycobacterium tuberculosis infection by downregulating the expression of the IL10 gene in human macrophages. This antiinfective property of NR1D1 suggests the need for an improved understanding of its role in other host-associated antimycobacterial pathways. The results presented here demonstrate that in human macrophages either ectopic expression of NR1D1 or treatment with its agonist, GSK4112, enhanced the number of acidic vacuoles as well as the level of MAP1LC3-II, a signature molecule for determination of autophagy progression, in a concentration- and time-dependent manner. Conversely, a decrease in NR1D1 in knockdown cells resulted in the reduced expression of lysosomal-associated membrane protein 1, LAMP1, commensurate with a decrease in the level of transcription factor EB, TFEB. This is indicative of that NR1D1 may have a regulatory role in lysosome biogenesis. NR1D1 being a repressor, its positive regulation on LAMP1 and TFEB is suggestive of an indirect byzantine mechanism of action. Its role in the modulation of autophagy and lysosome biogenesis together with its ability to repress IL10 gene expression supports the theory that NR1D1 has a pivotal antimycobacterial function in human macrophages. PMID:26390081

  17. PPM1D controls nucleolar formation by up-regulating phosphorylation of nucleophosmin.

    PubMed

    Kozakai, Yuuki; Kamada, Rui; Furuta, Junya; Kiyota, Yuhei; Chuman, Yoshiro; Sakaguchi, Kazuyasu

    2016-01-01

    An increase of nucleolar number and size has made nucleoli essential markers for cytology and tumour development. However, the underlying basis for their structural integrity and abundance remains unclear. Protein phosphatase PPM1D was found to be up-regulated in different carcinomas including breast cancers. Here, we demonstrate for the first time that PPM1D regulates nucleolar formation via inducing an increased phosphorylation of the nucleolar protein NPM. We show that PPM1D overexpression induces an increase in the nucleolar number regardless of p53 status. We also demonstrated that specific sequential phosphorylation of NPM is important for nucleolar formation and that PPM1D is a novel upstream regulator of this phosphorylation pathway. These results enhance our understanding of the molecular mechanisms that govern nucleoli formation by demonstrating that PPM1D regulates nucleolar formation by regulating NPM phosphorylation status through a novel signalling pathway, PPM1D-CDC25C-CDK1-PLK1. PMID:27619510

  18. Epigenetic activation of a cryptic TBC1D16 transcript enhances melanoma progression by targeting EGFR

    PubMed Central

    Vizoso, Miguel; Ferreira, Humberto J; Lopez-Serra, Paula; Javier Carmona, F; Martínez-Cardús, Anna; Girotti, Maria Romina; Villanueva, Alberto; Guil, Sonia; Moutinho, Catia; Liz, Julia; Portela, Anna; Heyn, Holger; Moran, Sebastian; Vidal, August; Martinez-Iniesta, Maria; Manzano, Jose L; Fernandez-Figueras, Maria Teresa; Elez, Elena; Muñoz-Couselo, Eva; Botella-Estrada, Rafael; Berrocal, Alfonso; Pontén, Fredrik; van den Oord, Joost; Gallagher, William M; Frederick, Dennie T; Flaherty, Keith T; McDermott, Ultan; Lorigan, Paul; Marais, Richard; Esteller, Manel

    2016-01-01

    Metastasis is responsible for most cancer-related deaths, and, among common tumor types, melanoma is one with great potential to metastasize. Here we study the contribution of epigenetic changes to the dissemination process by analyzing the changes that occur at the DNA methylation level between primary cancer cells and metastases. We found a hypomethylation event that reactivates a cryptic transcript of the Rab GTPase activating protein TBC1D16 (TBC1D16-47 kDa; referred to hereafter as TBC1D16-47KD) to be a characteristic feature of the metastatic cascade. This short isoform of TBC1D16 exacerbates melanoma growth and metastasis both in vitro and in vivo. By combining immunoprecipitation and mass spectrometry, we identified RAB5C as a new TBC1D16 target and showed that it regulates EGFR in melanoma cells. We also found that epigenetic reactivation of TBC1D16-47KD is associated with poor clinical outcome in melanoma, while conferring greater sensitivity to BRAF and MEK inhibitors. PMID:26030178

  19. PPM1D controls nucleolar formation by up-regulating phosphorylation of nucleophosmin

    PubMed Central

    Kozakai, Yuuki; Kamada, Rui; Furuta, Junya; Kiyota, Yuhei; Chuman, Yoshiro; Sakaguchi, Kazuyasu

    2016-01-01

    An increase of nucleolar number and size has made nucleoli essential markers for cytology and tumour development. However, the underlying basis for their structural integrity and abundance remains unclear. Protein phosphatase PPM1D was found to be up-regulated in different carcinomas including breast cancers. Here, we demonstrate for the first time that PPM1D regulates nucleolar formation via inducing an increased phosphorylation of the nucleolar protein NPM. We show that PPM1D overexpression induces an increase in the nucleolar number regardless of p53 status. We also demonstrated that specific sequential phosphorylation of NPM is important for nucleolar formation and that PPM1D is a novel upstream regulator of this phosphorylation pathway. These results enhance our understanding of the molecular mechanisms that govern nucleoli formation by demonstrating that PPM1D regulates nucleolar formation by regulating NPM phosphorylation status through a novel signalling pathway, PPM1D-CDC25C-CDK1-PLK1. PMID:27619510

  20. The Role of O(1D) in the Oxidation of Si(100)

    SciTech Connect

    Kaspar, Tiffany C. ); Tuan, Allan C. ); Tonkyn, Russell G. ); Hess, Wayne P. ); Rogers, Jr., J. W.; Ono, Yoshi

    2003-03-20

    Oxidation of silicon with neutral atomic oxygen species generated in a rare gas plasma has recently been shown to produce high-quality thin oxides. It has been speculated that atomic oxygen in the first excited state, O(1D), is a dominant reactive species in the oxidation mechanism. In this study, we investigate the role of O(1D) in silicon oxidation in the absence of other oxidizing species. The O(1D) is generated by laser-induced photodissociation of N2O at 193 nm. We find that, at 400?C, O(1D) is effective in the initial stages of oxidation, but the oxide growth rate falls dramatically past 1.5 nm. Oxide films thicker than 2 nm were unachievable regardless of oxidation time or N2O partial pressure (0.5-90 mTorr), indicating O(1D) cannot be a dominant reactive species in thicker oxidation mechanisms. We suggest that quenching of O(1D) to O(3P) (ground state) during diffusion through thicker oxides results in drastically slower oxidation kinetics. In contrast, oxidation with a vacuum ultraviolet (VUV) excimer lamp operating at 172 nm resulted in oxide thicknesses up to 4 nm. Thus, other species produced in plasmas and excimer lamps, such as molecular and atomic ions, photons, and free and conduction band electrons, play a dominant role in the rapid oxidation mechanism of thicker oxides (> 2 nm).

  1. Epigenetic activation of a cryptic TBC1D16 transcript enhances melanoma progression by targeting EGFR.

    PubMed

    Vizoso, Miguel; Ferreira, Humberto J; Lopez-Serra, Paula; Carmona, F Javier; Martínez-Cardús, Anna; Girotti, Maria Romina; Villanueva, Alberto; Guil, Sonia; Moutinho, Catia; Liz, Julia; Portela, Anna; Heyn, Holger; Moran, Sebastian; Vidal, August; Martinez-Iniesta, Maria; Manzano, Jose L; Fernandez-Figueras, Maria Teresa; Elez, Elena; Muñoz-Couselo, Eva; Botella-Estrada, Rafael; Berrocal, Alfonso; Pontén, Fredrik; Oord, Joost van den; Gallagher, William M; Frederick, Dennie T; Flaherty, Keith T; McDermott, Ultan; Lorigan, Paul; Marais, Richard; Esteller, Manel

    2015-07-01

    Metastasis is responsible for most cancer-related deaths, and, among common tumor types, melanoma is one with great potential to metastasize. Here we study the contribution of epigenetic changes to the dissemination process by analyzing the changes that occur at the DNA methylation level between primary cancer cells and metastases. We found a hypomethylation event that reactivates a cryptic transcript of the Rab GTPase activating protein TBC1D16 (TBC1D16-47 kDa; referred to hereafter as TBC1D16-47KD) to be a characteristic feature of the metastatic cascade. This short isoform of TBC1D16 exacerbates melanoma growth and metastasis both in vitro and in vivo. By combining immunoprecipitation and mass spectrometry, we identified RAB5C as a new TBC1D16 target and showed that it regulates EGFR in melanoma cells. We also found that epigenetic reactivation of TBC1D16-47KD is associated with poor clinical outcome in melanoma, while conferring greater sensitivity to BRAF and MEK inhibitors.

  2. Cell wall glycosphingolipids of Sphingomonas paucimobilis are CD1d-specific ligands for NKT cells.

    PubMed

    Sriram, Venkataraman; Du, Wenjun; Gervay-Hague, Jacquelyn; Brutkiewicz, Randy R

    2005-06-01

    The current consensus on characterization of NKT cells is based on their reactivity to the synthetic glycolipid, alpha-galactosylceramide (alpha-GalCer) in a CD1d-dependent manner. Because of the limited availability of alpha-GalCer, there is a constant search for CD1d-presented ligands that activate NKT cells. The alpha-anomericity of the carbohydrate is considered to be an important requisite for the CD1d-specific activation of NKT cells. The gram-negative, lipopolysaccharide-free bacterium Sphingomonas paucimobilis is known to contain glycosphingolipids (GSL) with alpha-anomeric sugars attached to the lipid chain. Here, we report that GSL extracted from this bacterium are able to stimulate NKT cells in a CD1d-specific manner. In addition, soluble CD1d-Ig dimers loaded with this lipid extract specifically bind to NKT cells (but not conventional T cells). Further studies on the S. paucimobilis GSL could potentially lead to other natural sources of CD1d-specific ligands useful for NKT cell analyses and aimed at identifying novel therapies for a variety of disease states.

  3. Assessing 1D Atmospheric Solar Radiative Transfer Models: Interpretation and Handling of Unresolved Clouds.

    NASA Astrophysics Data System (ADS)

    Barker, H. W.; Stephens, G. L.; Partain, P. T.; Bergman, J. W.; Bonnel, B.; Campana, K.; Clothiaux, E. E.; Clough, S.; Cusack, S.; Delamere, J.; Edwards, J.; Evans, K. F.; Fouquart, Y.; Freidenreich, S.; Galin, V.; Hou, Y.; Kato, S.; Li, J.;  Mlawer, E.;  Morcrette, J.-J.;  O'Hirok, W.;  Räisänen, P.;  Ramaswamy, V.;  Ritter, B.;  Rozanov, E.;  Schlesinger, M.;  Shibata, K.;  Sporyshev, P.;  Sun, Z.;  Wendisch, M.;  Wood, N.;  Yang, F.

    2003-08-01

    The primary purpose of this study is to assess the performance of 1D solar radiative transfer codes that are used currently both for research and in weather and climate models. Emphasis is on interpretation and handling of unresolved clouds. Answers are sought to the following questions: (i) How well do 1D solar codes interpret and handle columns of information pertaining to partly cloudy atmospheres? (ii) Regardless of the adequacy of their assumptions about unresolved clouds, do 1D solar codes perform as intended?One clear-sky and two plane-parallel, homogeneous (PPH) overcast cloud cases serve to elucidate 1D model differences due to varying treatments of gaseous transmittances, cloud optical properties, and basic radiative transfer. The remaining four cases involve 3D distributions of cloud water and water vapor as simulated by cloud-resolving models. Results for 25 1D codes, which included two line-by-line (LBL) models (clear and overcast only) and four 3D Monte Carlo (MC) photon transport algorithms, were submitted by 22 groups. Benchmark, domain-averaged irradiance profiles were computed by the MC codes. For the clear and overcast cases, all MC estimates of top-of-atmosphere albedo, atmospheric absorptance, and surface absorptance agree with one of the LBL codes to within ±2%. Most 1D codes underestimate atmospheric absorptance by typically 15-25 W m-2 at overhead sun for the standard tropical atmosphere regardless of clouds.Depending on assumptions about unresolved clouds, the 1D codes were partitioned into four genres: (i) horizontal variability, (ii) exact overlap of PPH clouds, (iii) maximum/random overlap of PPH clouds, and (iv) random overlap of PPH clouds. A single MC code was used to establish conditional benchmarks applicable to each genre, and all MC codes were used to establish the full 3D benchmarks. There is a tendency for 1D codes to cluster near their respective conditional benchmarks, though intragenre variances typically exceed those for

  4. Benchmarks and models for 1-D radiation transport in stochastic participating media

    SciTech Connect

    Miller, D S

    2000-08-21

    Benchmark calculations for radiation transport coupled to a material temperature equation in a 1-D slab and 1-D spherical geometry binary random media are presented. The mixing statistics are taken to be homogeneous Markov statistics in the 1-D slab but only approximately Markov statistics in the 1-D sphere. The material chunk sizes are described by Poisson distribution functions. The material opacities are first taken to be constant and then allowed to vary as a strong function of material temperature. Benchmark values and variances for time evolution of the ensemble average of material temperature energy density and radiation transmission are computed via a Monte Carlo type method. These benchmarks are used as a basis for comparison with three other approximate methods of solution. One of these approximate methods is simple atomic mix. The second approximate model is an adaptation of what is commonly called the Levermore-Pomraning model and which is referred to here as the standard model. It is shown that recasting the temperature coupling as a type of effective scattering can be useful in formulating the third approximate model, an adaptation of a model due to Su and Pomraning which attempts to account for the effects of scattering in a stochastic context. This last adaptation shows consistent improvement over both the atomic mix and standard models when used in the 1-D slab geometry but shows limited improvement in the 1-D spherical geometry. Benchmark values are also computed for radiation transmission from the 1-D sphere without material heating present. This is to evaluate the performance of the standard model on this geometry--something which has never been done before. All of the various tests demonstrate the importance of stochastic structure on the solution. Also demonstrated are the range of usefulness and limitations of a simple atomic mix formulation.

  5. Turned on by danger: activation of CD1d-restricted invariant natural killer T cells.

    PubMed

    Lawson, Victoria

    2012-09-01

    CD1d-restricted invariant natural killer T (iNKT) cells bear characteristics of innate and adaptive lymphocytes, which allow them to bridge the two halves of the immune response and play roles in many disease settings. Recent work has characterized precisely how their activation is initiated and regulated. Novel antigens from important pathogens have been identified, as has an abundant self-antigen, β-glucopyranosylcaramide, capable of mediating an iNKT-cell response. Studies of the iNKT T-cell receptor (TCR)-antigen-CD1d complex show how docking between CD1d-antigen and iNKT TCR is highly conserved, and how small sequence differences in the TCR establish intrinsic variation in iNKT TCR affinity. The sequence of the TCR CDR3β loop determines iNKT TCR affinity for ligand-CD1d, independent of ligand identity. CD1d ligands can promote T helper type 1 (Th1) or Th2 biased cytokine responses, depending on the composition of their lipid tails. Ligands loaded into CD1d on the cell surface promote Th2 responses, whereas ligands with long hydrophobic tails are loaded endosomally and promote Th1 responses. This information is informing the design of synthetic iNKT-cell antigens. The iNKT cells may be activated by exogenous antigen, or by a combination of dendritic cell-derived interleukin-12 and iNKT TCR-self-antigen-CD1d engagement. The iNKT-cell activation is further modulated by recent foreign or self-antigen encounter. Activation of dendritic cells through pattern recognition receptors alters their antigen presentation and cytokine production, strongly influencing iNKT-cell activation. In a range of bacterial infections, dendritic cell-dependent innate activation of iNKT cells through interleukin-12 is the dominant influence on their activity.

  6. GPS system simulation methodology

    NASA Technical Reports Server (NTRS)

    Ewing, Thomas F.

    1993-01-01

    The following topics are presented: background; Global Positioning System (GPS) methodology overview; the graphical user interface (GUI); current models; application to space nuclear power/propulsion; and interfacing requirements. The discussion is presented in vugraph form.

  7. Designing Heterogeneous 1D Nanostructure Arrays Based on AAO Templates for Energy Applications.

    PubMed

    Wen, Liaoyong; Wang, Zhijie; Mi, Yan; Xu, Rui; Yu, Shu-Hong; Lei, Yong

    2015-07-01

    In order to fulfill the multiple requirements for energy production, storage, and utilization in the future, the conventional planar configuration of current energy conversion/storage devices has to be reformed, since technological evolution has promoted the efficiency of the corresponding devices to be close to the theoretical values. One promising strategy is to construct multifunctional 1D nanostructure arrays to replace their planar counterparts for device fabrication, ascribing to the significant superiorities of such 1D nanostructure arrays. In the last three decades, technologies based on anodic aluminium oxide (AAO) templates have turned out to be valuable meaning for the realization of 1D nanostructures and have attracted tremendous interest. In this review, recent progress in energy-related devices equipped with heterogeneous 1D nanostructure arrays that fabricated through the assistance of AAO templates is highlighted. Particular emphasis is given on how to develop efficient devices via optimizing the componential and morphological parameters of the 1D nanostructure arrays. Finally, aspects relevant to the further improvement of device performance are discussed.

  8. Crystal orbital studies on the 1D silic-diyne nanoribbons and nanotubes.

    PubMed

    Zhu, Ying; Bai, Hongcun; Huang, Yuanhe

    2016-02-01

    This work presents crystal orbital studies on novel one-dimensional (1D) nanoscale materials derived from a Si-diyne sheet, based on the density functional theory. The two-dimensional (2D) Si-diyne layer is observed to be carbo-merized silicene, with a similar structure to graphdiyne. The 2D Si-diyne and its 1D ribbons and tubes, of different size and chirality, have been addressed systematically. The low dimensional Si-diyne materials studied exhibit relatively high stability, according to phonon-frequency calculations and molecular dynamics simulations. With comparable diameters, the Si-diyne tubes have lower strain energies than silicene and silicon carbide nanotubes. The Si-diyne layer and its 1D derivatives are all semiconductors, regardless of the size and chirality of the strips and tubes. In addition, the band gaps of the 1D Si-diyne nanoribbons and nanotubes with different chirality, always monotonically decrease as their sizes increases. A quantitative relationship between the band gap and the size of the ribbons and tubes was obtained. The mobility of charge carriers for the 1D Si-diyne structures was also investigated. It was found that both hole and electron mobility of the ribbons and tubes exhibit linear increase with increasing size. The electrons have greater mobility than the holes for each strip and tube. In addition, the mechanical properties of the Si-diyne nanostructures were also investigated by calculation of the Young's modulus and the Poisson's ratio. PMID:26744378

  9. A Mathematical Model of T1D Acceleration and Delay by Viral Infection.

    PubMed

    Moore, James R; Adler, Fred

    2016-03-01

    Type 1 diabetes (T1D) is often triggered by a viral infection, but the T1D prevalence is rising among populations that have a lower exposure to viral infection. In an animal model of T1D, the NOD mouse, viral infection at different ages may either accelerate or delay disease depending on the age of infection and the type of virus. Viral infection may affect the progression of T1D via multiple mechanisms: triggering inflammation, bystander activation of self-reactive T-cells, inducing a competitive immune response, or inducing a regulatory immune response. In this paper, we create mathematical models of the interaction of viral infection with T1D progression, incorporating each of these four mechanisms. Our goal is to understand how each viral mechanism interacts with the age of infection. The model predicts that each viral mechanism has a unique pattern of interaction with disease progression. Viral inflammation always accelerates disease, but the effect decreases with age of infection. Bystander activation has little effect at younger ages and actually decreases incidence at later ages while accelerating disease in mice that do get the disease. A competitive immune response to infection can decrease incidence at young ages and increase it at older ages, with the effect decreasing over time. Finally, an induced Treg response decreases incidence at any age of infection, but the effect decreases with age. Some of these patterns resemble those seen experimentally. PMID:27030351

  10. Fabrication and characterization of hexagonally patterned quasi-1D ZnO nanowire arrays

    PubMed Central

    2014-01-01

    Quasi-one-dimensional (quasi-1D) ZnO nanowire arrays with hexagonal pattern have been successfully synthesized via the vapor transport process without any metal catalyst. By utilizing polystyrene microsphere self-assembled monolayer, sol–gel-derived ZnO thin films were used as the periodic nucleation sites for the growth of ZnO nanowires. High-quality quasi-1D ZnO nanowires were grown from nucleation sites, and the original hexagonal periodicity is well-preserved. According to the experimental results, the vapor transport solid condensation mechanism was proposed, in which the sol–gel-derived ZnO film acting as a seed layer for nucleation. This simple method provides a favorable way to form quasi-1D ZnO nanostructures applicable to diverse fields such as two-dimensional photonic crystal, nanolaser, sensor arrays, and other optoelectronic devices. PMID:24521308

  11. Measurement of tropospheric 300 nm solar ultraviolet flux for determination of O/1D/ photoproduction rate

    NASA Technical Reports Server (NTRS)

    Sellers, B.; Hanser, F. A.

    1978-01-01

    The tropospheric importance of the OH radical, and the reaction scheme that leads to its formation, are now being widely investigated. Ozone photolysis at wavelengths no greater than 318 nm produces O(1D), a small fraction of which then reacts with water vapor to yield OH. Although experimental data are available for the O(1D) quantum yield, as well as the O3 absorption cross section, all previous tropospheric photochemical models have had to use theoretical calculations to determine the UV flux. Discussed in this paper are aircraft spectral measurements of the solar UV flux at two altitudes - 2 and 6 km. These results have been compared with three theoretical approaches. The measured experimental fluxes have been combined here with recent quantum yield data to calculate the O(1D) photoproduction rate for various albedo values. This rate is larger than that used in models by about a factor of 2 for reasonable values of assumed albedo.

  12. A comparison of 1D and 2D LSTM architectures for the recognition of handwritten Arabic

    NASA Astrophysics Data System (ADS)

    Yousefi, Mohammad Reza; Soheili, Mohammad Reza; Breuel, Thomas M.; Stricker, Didier

    2015-01-01

    In this paper, we present an Arabic handwriting recognition method based on recurrent neural network. We use the Long Short Term Memory (LSTM) architecture, that have proven successful in different printed and handwritten OCR tasks. Applications of LSTM for handwriting recognition employ the two-dimensional architecture to deal with the variations in both vertical and horizontal axis. However, we show that using a simple pre-processing step that normalizes the position and baseline of letters, we can make use of 1D LSTM, which is faster in learning and convergence, and yet achieve superior performance. In a series of experiments on IFN/ENIT database for Arabic handwriting recognition, we demonstrate that our proposed pipeline can outperform 2D LSTM networks. Furthermore, we provide comparisons with 1D LSTM networks trained with manually crafted features to show that the automatically learned features in a globally trained 1D LSTM network with our normalization step can even outperform such systems.

  13. Collective mode damping and viscosity in a 1D unitary Fermi gas

    NASA Astrophysics Data System (ADS)

    Punk, M.; Zwerger, W.

    2006-08-01

    We calculate the damping of the Bogoliubov Anderson mode in a one-dimensional (1D) two-component attractive Fermi gas for arbitrary coupling strength within a quantum hydrodynamic approach. Using the Bethe-ansatz solution of the 1D BCS-BEC crossover problem, we derive analytic results for the viscosity covering the full range from a Luther Emery liquid of weakly bound pairs to a Lieb Liniger gas of strongly bound bosonic dimers. At the unitarity point, the system is a Tonks Girardeau gas with a universal constant αζ = 0.38 in the viscosity ζ = αζplanck n for T = 0. For the trapped case, we calculate the Q-factor of the breathing mode and show that the damping provides a sensitive measure of temperature in 1D Fermi gases.

  14. Fabrication and characterization of hexagonally patterned quasi-1D ZnO nanowire arrays

    NASA Astrophysics Data System (ADS)

    Kuo, Shou-Yi; Lin, Hsin-I.

    2014-02-01

    Quasi-one-dimensional (quasi-1D) ZnO nanowire arrays with hexagonal pattern have been successfully synthesized via the vapor transport process without any metal catalyst. By utilizing polystyrene microsphere self-assembled monolayer, sol-gel-derived ZnO thin films were used as the periodic nucleation sites for the growth of ZnO nanowires. High-quality quasi-1D ZnO nanowires were grown from nucleation sites, and the original hexagonal periodicity is well-preserved. According to the experimental results, the vapor transport solid condensation mechanism was proposed, in which the sol-gel-derived ZnO film acting as a seed layer for nucleation. This simple method provides a favorable way to form quasi-1D ZnO nanostructures applicable to diverse fields such as two-dimensional photonic crystal, nanolaser, sensor arrays, and other optoelectronic devices.

  15. Fabrication and characterization of hexagonally patterned quasi-1D ZnO nanowire arrays.

    PubMed

    Kuo, Shou-Yi; Lin, Hsin-I

    2014-01-01

    Quasi-one-dimensional (quasi-1D) ZnO nanowire arrays with hexagonal pattern have been successfully synthesized via the vapor transport process without any metal catalyst. By utilizing polystyrene microsphere self-assembled monolayer, sol-gel-derived ZnO thin films were used as the periodic nucleation sites for the growth of ZnO nanowires. High-quality quasi-1D ZnO nanowires were grown from nucleation sites, and the original hexagonal periodicity is well-preserved. According to the experimental results, the vapor transport solid condensation mechanism was proposed, in which the sol-gel-derived ZnO film acting as a seed layer for nucleation. This simple method provides a favorable way to form quasi-1D ZnO nanostructures applicable to diverse fields such as two-dimensional photonic crystal, nanolaser, sensor arrays, and other optoelectronic devices. PMID:24521308

  16. TBC1D24 mutation causes autosomal-dominant nonsyndromic hearing loss.

    PubMed

    Azaiez, Hela; Booth, Kevin T; Bu, Fengxiao; Huygen, Patrick; Shibata, Seiji B; Shearer, A Eliot; Kolbe, Diana; Meyer, Nicole; Black-Ziegelbein, E Ann; Smith, Richard J H

    2014-07-01

    Hereditary hearing loss is extremely heterogeneous. Over 70 genes have been identified to date, and with the advent of massively parallel sequencing, the pace of novel gene discovery has accelerated. In a family segregating progressive autosomal-dominant nonsyndromic hearing loss (NSHL), we used OtoSCOPE® to exclude mutations in known deafness genes and then performed segregation mapping and whole-exome sequencing to identify a unique variant, p.Ser178Leu, in TBC1D24 that segregates with the hearing loss phenotype. TBC1D24 encodes a GTPase-activating protein expressed in the cochlea. Ser178 is highly conserved across vertebrates and its change is predicted to be damaging. Other variants in TBC1D24 have been associated with a panoply of clinical symptoms including autosomal recessive NSHL, syndromic hearing impairment associated with onychodystrophy, osteodystrophy, mental retardation, and seizures (DOORS syndrome), and a wide range of epileptic disorders. PMID:24729539

  17. ISUAL side-way observations of the OI(1D) night airglows

    NASA Astrophysics Data System (ADS)

    Chiang, C.; Chang, T.; Lin, C.; Rajesh, P.; Liu, J.; Chen, A. B.; Su, H.; Hsu, R.

    2008-12-01

    Recently, ISUAL/FORMOSAT-2 Satellite has devoted more observation time to investigate the OI(1D) nightglow from the sideway, which provides the first comprehensive survey of 630.0nm emission in the pre- midnight sector at F layer. It is found that the OI(1D) nightglow enhancement exhibited remarkable seasonal variations. In this study, we want to highlight the following three points. First, semiannual anomaly and winter anomaly existed in the form of the brightening emission in the region of equatorial anomaly. Second, the data indicates that the tidally enhanced regions show significant longitudinal variability. Third, the latitudinal variability of OI(1D) nightglow can be contributed to both the Equatorial Ionization Anomaly (EIA) effect and the upward propagation tides.

  18. S-duality constraints on 1D patterns associated with fractional quantum Hall states.

    PubMed

    Seidel, Alexander

    2010-07-01

    Using the modular invariance of the torus, constraints on the 1D patterns are derived that are associated with various fractional quantum Hall ground states, e.g., through the thin torus limit. In the simplest case, these constraints enforce the well-known odd-denominator rule, which is seen to be a necessary property of all 1D patterns associated to quantum Hall states with minimum torus degeneracy. However, the same constraints also have implications for the non-Abelian states possible within this framework. In simple cases, including the ν=1 Moore-Read state and the ν=3/2 level 3 Read-Rezayi state, the filling factor and the torus degeneracy uniquely specify the possible patterns, and thus all physical properties that are encoded in them. It is also shown that some states, such as the "strong p-wave pairing state," cannot in principle be described through 1D patterns.

  19. Targeted disruption of CD1d prevents NKT cell development in pigs

    PubMed Central

    Yang, Guan; Artiaga, Bianca L.; Hackmann, Timothy J.; Samuel, Melissa S.; Walters, Eric M; Salek-Ardakani, Shahram; Driver, John P.

    2016-01-01

    Studies in mice genetically lacking natural killer T (NKT) cells show that these lymphocytes make important contributions to both innate and adaptive immune responses. However, the usefulness of murine models to study human NKT cells is limited by the many differences between mice and humans, including that their NKT cell frequencies, subsets and distribution are dissimilar. A more suitable model may be swine that share many metabolic, physiological and growth characteristics with humans and are also similar for NKT cells. Thus, we analyzed genetically modified pigs made deficient for CD1d that is required for the development of Type I invariant NKT (iNKT) cells that express a semi-invariant T cell receptor (TCR) and Type II NKT cells that use variable TCRs. Peripheral blood analyzed by flow cytometry and interferon-γ (IFNγ) enzyme-linked immuno spot (ELISPOT) assays demonstrated that CD1d-knockout pigs completely lack iNKT cells while other leukocyte populations remain intact. CD1d and NKT cells have been shown to be involved in shaping the composition of the commensal microbiota in mice. Therefore, we also compared the fecal microbiota profile between pigs expressing and lacking NKT cells. However, no differences were found between pigs lacking or expressing CD1d. Our results are the first to show that knocking-out CD1d prevents the development of iNKT cells in a non-rodent species. CD1d-deficient pigs should offer a useful model to more accurately determine the contribution of NKT cells for human immune responses. They also have potential for understanding how NKT cells impact the health of commercial swine. PMID:25930071

  20. Characterisation and improvement of j(O1D) filter radiometers

    NASA Astrophysics Data System (ADS)

    Bohn, Birger; Heard, Dwayne E.; Mihalopoulos, Nikolaos; Plass-Dülmer, Christian; Schmitt, Rainer; Whalley, Lisa K.

    2016-07-01

    Atmospheric O3 → O(1D) photolysis frequencies j(O1D) are crucial parameters for atmospheric photochemistry because of their importance for primary OH formation. Filter radiometers have been used for many years for in situ field measurements of j(O1D). Typically the relationship between the output of the instruments and j(O1D) is non-linear because of changes in the shape of the solar spectrum dependent on solar zenith angles and total ozone columns. These non-linearities can be compensated for by a correction method based on laboratory measurements of the spectral sensitivity of the filter radiometer and simulated solar actinic flux density spectra. Although this correction is routinely applied, the results of a previous field comparison study of several filter radiometers revealed that some corrections were inadequate. In this work the spectral characterisations of seven instruments were revised, and the correction procedures were updated and harmonised considering recent recommendations of absorption cross sections and quantum yields of the photolysis process O3 → O(1D). Previous inconsistencies were largely removed using these procedures. In addition, optical interference filters were replaced to improve the spectral properties of the instruments. Successive determinations of spectral sensitivities and field comparisons of the modified instruments with a spectroradiometer reference confirmed the improved performance. Overall, filter radiometers remain a low-maintenance alternative of spectroradiometers for accurate measurements of j(O1D) provided their spectral properties are known and potential drifts in sensitivities are monitored by regular calibrations with standard lamps or reference instruments.

  1. Synthesis and characterization of 1D iron(II) spin crossover coordination polymers with hysteresis.

    PubMed

    Bauer, Wolfgang; Lochenie, Charles; Weber, Birgit

    2014-02-01

    Purposeful ligand design was used for the synthesis of eight new 1D iron(II) spin crossover coordination polymers aiming for cooperative spin transitions with hysteresis. The results from magnetic measurements and X-ray structure analysis show that the combination of rigid linkers and a hydrogen bond network between the 1D chains is a promising tool to reach this goal. Five of the eight new samples show a cooperative spin transition with hysteresis with up to 43 K wide hysteresis loops.

  2. Quench dynamics of 1D spin-imbalanced Fermi-Hubbard model

    NASA Astrophysics Data System (ADS)

    Yin, Xiao; Radzihovsky, Leo

    We study a non-equilibrium dynamics of a 1D spin-imbalanced Fermi-Hubbard model following a quantum quench of on-site interaction, using bosonization and exact analysis. By focusing on the evolution of singlet-, triplet-, density and magnetization correlation functions, we find that the evolution and the final state display a strong dependence on the initial state. Thus, we demonstrate that such quantum quench may be used as a new approach to identify and probe the 1D gapless analogue of the elusive FFLO state. Supported by NSF through DMR-1001240 and by Simons Investigator award from Simons.

  3. Opto-digital image encryption by using Baker mapping and 1-D fractional Fourier transform

    NASA Astrophysics Data System (ADS)

    Liu, Zhengjun; Li, She; Liu, Wei; Liu, Shutian

    2013-03-01

    We present an optical encryption method based on the Baker mapping in one-dimensional fractional Fourier transform (1D FrFT) domains. A thin cylinder lens is controlled by computer for implementing 1D FrFT at horizontal direction or vertical direction. The Baker mapping is introduced to scramble the amplitude distribution of complex function. The amplitude and phase of the output of encryption system are regarded as encrypted image and key. Numerical simulation has been performed for testing the validity of this encryption scheme.

  4. 50 CFR Table 1d to Part 660... - At-Sea Whiting Fishery Annual Set-Asides, 2013

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false At-Sea Whiting Fishery Annual Set-Asides, 2013 1d Table 1d to Part 660, Subpart C Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OFF WEST COAST STATES Pt. 660, Subpt. C, Table 1d...

  5. 50 CFR Table 1d to Part 660... - At-Sea Whiting Fishery Annual Set-Asides, 2013

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false At-Sea Whiting Fishery Annual Set-Asides, 2013 1d Table 1d to Part 660, Subpart C Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OFF WEST COAST STATES Pt. 660, Subpt. C, Table 1d...

  6. Regional Shelter Analysis Methodology

    SciTech Connect

    Dillon, Michael B.; Dennison, Deborah; Kane, Jave; Walker, Hoyt; Miller, Paul

    2015-08-01

    The fallout from a nuclear explosion has the potential to injure or kill 100,000 or more people through exposure to external gamma (fallout) radiation. Existing buildings can reduce radiation exposure by placing material between fallout particles and exposed people. Lawrence Livermore National Laboratory was tasked with developing an operationally feasible methodology that could improve fallout casualty estimates. The methodology, called a Regional Shelter Analysis, combines the fallout protection that existing buildings provide civilian populations with the distribution of people in various locations. The Regional Shelter Analysis method allows the consideration of (a) multiple building types and locations within buildings, (b) country specific estimates, (c) population posture (e.g., unwarned vs. minimally warned), and (d) the time of day (e.g., night vs. day). The protection estimates can be combined with fallout predictions (or measurements) to (a) provide a more accurate assessment of exposure and injury and (b) evaluate the effectiveness of various casualty mitigation strategies. This report describes the Regional Shelter Analysis methodology, highlights key operational aspects (including demonstrating that the methodology is compatible with current tools), illustrates how to implement the methodology, and provides suggestions for future work.

  7. Epitaxial 1D electron transport layers for high-performance perovskite solar cells

    NASA Astrophysics Data System (ADS)

    Han, Gill Sang; Chung, Hyun Suk; Kim, Dong Hoe; Kim, Byeong Jo; Lee, Jin-Wook; Park, Nam-Gyu; Cho, In Sun; Lee, Jung-Kun; Lee, Sangwook; Jung, Hyun Suk

    2015-09-01

    We demonstrate high-performance perovskite solar cells with excellent electron transport properties using a one-dimensional (1D) electron transport layer (ETL). The 1D array-based ETL is comprised of 1D SnO2 nanowires (NWs) array grown on a F:SnO2 transparent conducting oxide substrate and rutile TiO2 nanoshells epitaxially grown on the surface of the 1D SnO2 NWs. The optimized devices show more than 95% internal quantum yield at 750 nm, and a power conversion efficiency (PCE) of 14.2%. The high quantum yield is attributed to dramatically enhanced electron transport in the epitaxial TiO2 layer, compared to that in conventional nanoparticle-based mesoporous TiO2 (mp-TiO2) layers. In addition, the open space in the 1D array-based ETL increases the prevalence of uniform TiO2/perovskite junctions, leading to reproducible device performance with a high fill factor. This work offers a method to achieve reproducible, high-efficiency perovskite solar cells with high-speed electron transport.We demonstrate high-performance perovskite solar cells with excellent electron transport properties using a one-dimensional (1D) electron transport layer (ETL). The 1D array-based ETL is comprised of 1D SnO2 nanowires (NWs) array grown on a F:SnO2 transparent conducting oxide substrate and rutile TiO2 nanoshells epitaxially grown on the surface of the 1D SnO2 NWs. The optimized devices show more than 95% internal quantum yield at 750 nm, and a power conversion efficiency (PCE) of 14.2%. The high quantum yield is attributed to dramatically enhanced electron transport in the epitaxial TiO2 layer, compared to that in conventional nanoparticle-based mesoporous TiO2 (mp-TiO2) layers. In addition, the open space in the 1D array-based ETL increases the prevalence of uniform TiO2/perovskite junctions, leading to reproducible device performance with a high fill factor. This work offers a method to achieve reproducible, high-efficiency perovskite solar cells with high-speed electron transport

  8. Methodology for research I

    PubMed Central

    Garg, Rakesh

    2016-01-01

    The conduct of research requires a systematic approach involving diligent planning and its execution as planned. It comprises various essential predefined components such as aims, population, conduct/technique, outcome and statistical considerations. These need to be objective, reliable and in a repeatable format. Hence, the understanding of the basic aspects of methodology is essential for any researcher. This is a narrative review and focuses on various aspects of the methodology for conduct of a clinical research. The relevant keywords were used for literature search from various databases and from bibliographies of the articles. PMID:27729690

  9. Scale up tools in reactive extrusion and compounding processes. Could 1D-computer modeling be helpful?

    NASA Astrophysics Data System (ADS)

    Pradel, J.-L.; David, C.; Quinebèche, S.; Blondel, P.

    2014-05-01

    Industrial scale-up (or scale down) in Compounding and Reactive Extrusion processes is one of the most critical R&D challenges. Indeed, most of High Performances Polymers are obtained within a reactive compounding involving chemistry: free radical grafting, in situ compatibilization, rheology control... but also side reactions: oxidation, branching, chain scission... As described by basic Arrhenius and kinetics laws, the competition between all chemical reactions depends on residence time distribution and temperature. Then, to ensure the best possible scale up methodology, we need tools to match thermal history of the formulation along the screws from a lab scale twin screw extruder to an industrial one. This paper proposes a comparison between standard scale-up laws and the use of Computer modeling Software such as Ludovic® applied and compared to experimental data. Scaling data from a compounding line to another one, applying general rules (for example at constant specific mechanical energy), shows differences between experimental and computed data, and error depends on the screw speed range. For more accurate prediction, 1D-Computer Modeling could be used to optimize the process conditions to ensure the best scale-up product, especially in temperature sensitive reactive extrusion processes. When the product temperature along the screws is the key, Ludovic® software could help to compute the temperature profile along the screws and extrapolate conditions, even screw profile, on industrial extruders.

  10. Thermal characterization of large size lithium-ion pouch cell based on 1d electro-thermal model

    NASA Astrophysics Data System (ADS)

    Vertiz, G.; Oyarbide, M.; Macicior, H.; Miguel, O.; Cantero, I.; Fernandez de Arroiabe, P.; Ulacia, I.

    2014-12-01

    Thermal management is one of the key factors to keep lithium-ion cells in optimum electrical performance, under safe working conditions and into a reasonably low ageing process. This issue is becoming particularly relevant due to the heterogeneous heat generation along the cell. Cell working temperature is determined by ambient temperature, heat generation and evacuation capacity. Therefore, thermal management is established by: i) the intrinsic thermal properties (heat capacity & thermal conductivity) and ii) the heat generation electro-thermal parameters (internal resistance, open circuit voltage & entropic factor). In this research, different methods - calculated and experimental - are used to characterize the main heat properties of a 14Ah -LiFePO4/graphite-commercial large sizes pouch cell. In order to evaluate the accuracy of methods, two comparisons were performed. First, Newman heat generation estimations were compared with experimental heat measurements. Secondly, empirical thermal cell behaviour was match with 1D electro-thermal model response. Finally, considering the results, the most adequate methodology to evaluate the key thermal parameters of a large size Lithium-ion pouch cell are proposed to be: i) pulse method for internal resistance, ii)heat loss method for entropic factor; and iii)experimental measurement (ARC calorimeter and C-177-97 standard method) for heat capacity and thermal conductivity.

  11. Extending the Nonlinear-Beam-Dynamics Concept of 1D Fixed Points to 2D Fixed Lines.

    PubMed

    Franchetti, G; Schmidt, F

    2015-06-12

    The origin of nonlinear dynamics traces back to the study of the dynamics of planets with the seminal work of Poincaré at the end of the nineteenth century: Les Méthodes Nouvelles de la Mécanique Céleste, Vols. 1-3 (Gauthier Villars, Paris, 1899). In his work he introduced a methodology fruitful for investigating the dynamical properties of complex systems, which led to the so-called "Poincaré surface of section," which allows one to capture the global dynamical properties of a system, characterized by fixed points and separatrices with respect to regular and chaotic motion. For two-dimensional phase space (one degree of freedom) this approach has been extremely useful and applied to particle accelerators for controlling their beam dynamics as of the second half of the twentieth century. We describe here an extension of the concept of 1D fixed points to fixed lines in two dimensions. These structures become the fundamental entities for characterizing the nonlinear motion in the four-dimensional phase space (two degrees of freedom).

  12. Extending the Nonlinear-Beam-Dynamics Concept of 1D Fixed Points to 2D Fixed Lines

    NASA Astrophysics Data System (ADS)

    Franchetti, G.; Schmidt, F.

    2015-06-01

    The origin of nonlinear dynamics traces back to the study of the dynamics of planets with the seminal work of Poincaré at the end of the nineteenth century: Les Méthodes Nouvelles de la Mécanique Céleste, Vols. 1-3 (Gauthier Villars, Paris, 1899). In his work he introduced a methodology fruitful for investigating the dynamical properties of complex systems, which led to the so-called "Poincaré surface of section," which allows one to capture the global dynamical properties of a system, characterized by fixed points and separatrices with respect to regular and chaotic motion. For two-dimensional phase space (one degree of freedom) this approach has been extremely useful and applied to particle accelerators for controlling their beam dynamics as of the second half of the twentieth century. We describe here an extension of the concept of 1D fixed points to fixed lines in two dimensions. These structures become the fundamental entities for characterizing the nonlinear motion in the four-dimensional phase space (two degrees of freedom).

  13. Extending the Nonlinear-Beam-Dynamics Concept of 1D Fixed Points to 2D Fixed Lines.

    PubMed

    Franchetti, G; Schmidt, F

    2015-06-12

    The origin of nonlinear dynamics traces back to the study of the dynamics of planets with the seminal work of Poincaré at the end of the nineteenth century: Les Méthodes Nouvelles de la Mécanique Céleste, Vols. 1-3 (Gauthier Villars, Paris, 1899). In his work he introduced a methodology fruitful for investigating the dynamical properties of complex systems, which led to the so-called "Poincaré surface of section," which allows one to capture the global dynamical properties of a system, characterized by fixed points and separatrices with respect to regular and chaotic motion. For two-dimensional phase space (one degree of freedom) this approach has been extremely useful and applied to particle accelerators for controlling their beam dynamics as of the second half of the twentieth century. We describe here an extension of the concept of 1D fixed points to fixed lines in two dimensions. These structures become the fundamental entities for characterizing the nonlinear motion in the four-dimensional phase space (two degrees of freedom). PMID:26196806

  14. 1D-TlInSe2: Band Structure, Dielectric Function and Nanorods

    NASA Astrophysics Data System (ADS)

    Mamedov, Nazim; Wakita, Kazuki; Akita, Seiji; Nakayama, Yoshikazu

    2005-01-01

    Linear combination of atomic orbitals (LCAO) analysis of the electronic band states has been completed for one-dimensional (1D) TlInSe2 having rod-like ground state shape of bulky crystal. The total scenario of the occurrence of the band states from the atomic states has been established. According to this scenario, in dipole approximation the optical transitions at band gap (point T of Brillouin zone) are either entirely forbidden or allowed for T2-T10 transitions in e\\perpc configuration provided that either initial or terminate state has T2 symmetry and both are Se-like. As a whole, the obtained results on the electronic spectrum, including dielectric function, are applicable to all obtained 1D-TlInSe2 nanorods which were as thin as 30--50 nm in cross-section, and apparently preserved tetragonal crystal structure of bulky material. The thermal instabilities developing already in bulky samples of 1D-TlInSe2 are considered to be an ultimate source of the nanoparticles emerging in plenty during nanorods preparation. The nanoplates of a chemically similar but 2D material, TlInS2, are demonstrated for comparison to show the absence of nanoparticles in that case. A possibility of nanoparticle preparation using laser excited coherent phonon trains in the nanorods of 1D-TlInSe2 is figured out.

  15. A South American Prehistoric Mitogenome: Context, Continuity, and the Origin of Haplogroup C1d

    PubMed Central

    Sans, Mónica; Figueiro, Gonzalo; Hughes, Cris E.; Lindo, John; Hidalgo, Pedro C.; Malhi, Ripan S.

    2015-01-01

    Based on mitochondrial DNA (mtDNA), it has been estimated that at least 15 founder haplogroups peopled the Americas. Subhaplogroup C1d3 was defined based on the mitogenome of a living individual from Uruguay that carried a lineage previously identified in hypervariable region I sequences from ancient and modern Uruguayan individuals. When complete mitogenomes were studied, additional substitutions were found in the coding region of the mitochondrial genome. Using a complete ancient mitogenome and three modern mitogenomes, we aim to clarify the ancestral state of subhaplogroup C1d3 and to better understand the peopling of the region of the Río de la Plata basin, as well as of the builders of the mounds from which the ancient individuals were recovered. The ancient mitogenome, belonging to a female dated to 1,610±46 years before present, was identical to the mitogenome of one of the modern individuals. All individuals share the mutations defining subhaplogroup C1d3. We estimated an age of 8,974 (5,748–12,261) years for the most recent common ancestor of C1d3, in agreement with the initial peopling of the geographic region. No individuals belonging to the defined lineage were found outside of Uruguay, which raises questions regarding the mobility of the prehistoric inhabitants of the country. Moreover, the present study shows the continuity of Native lineages over at least 6,000 years. PMID:26509686

  16. Combustion synthesis as a novel method for production of 1-D SiC nanostructures.

    PubMed

    Huczko, Andrzej; Bystrzejewski, Michał; Lange, Hubert; Fabianowska, Agnieszka; Cudziło, Stanisław; Panas, Andrzej; Szala, Mateusz

    2005-09-01

    1-D nanostructures of cubic phase silicon carbide (beta-SiC) were efficiently produced by combustion synthesis of mixtures containing Si-containing compounds and halocarbons in a calorimetric bomb. The influence of the operating parameters on 1-D SiC formation yield was studied. The heat release, the heating rate, and the chamber pressure increase were monitored during the process. The composition and structural features of the products were characterized by elemental analysis, X-ray diffraction, differential thermal analysis/ thermogravimetric technique, Raman spectroscopy, scanning and transmission electron microscopy, and energy-dispersive X-ray spectrometry. This self-induced growth process can produce SiC nanofibers and nanotubes ca. 20-100 nm in diameter with the aspect ratio higher than 1000. Bulk scale Raman studies showed the product to be comprised of mostly cubic polytype of SiC and that finite size effects are present. We believe that the nucleation mechanism involving radical gaseous species is responsible for 1-D nanostructures growth. The present study has enlarged the family of nanofibers and nanotubes available and offers a possible, new general route to 1-D crystalline materials. PMID:16853065

  17. Toward Structural Correctness: Aquatolide and the Importance of 1D Proton NMR FID Archiving.

    PubMed

    Pauli, Guido F; Niemitz, Matthias; Bisson, Jonathan; Lodewyk, Michael W; Soldi, Cristian; Shaw, Jared T; Tantillo, Dean J; Saya, Jordy M; Vos, Klaas; Kleinnijenhuis, Roel A; Hiemstra, Henk; Chen, Shao-Nong; McAlpine, James B; Lankin, David C; Friesen, J Brent

    2016-02-01

    The revision of the structure of the sesquiterpene aquatolide from a bicyclo[2.2.0]hexane to a bicyclo[2.1.1]hexane structure using compelling NMR data, X-ray crystallography, and the recent confirmation via full synthesis exemplify that the achievement of "structural correctness" depends on the completeness of the experimental evidence. Archived FIDs and newly acquired aquatolide spectra demonstrate that archiving and rigorous interpretation of 1D (1)H NMR data may enhance the reproducibility of (bio)chemical research and curb the growing trend of structural misassignments. Despite being the most accessible NMR experiment, 1D (1)H spectra encode a wealth of information about bonds and molecular geometry that may be fully mined by (1)H iterative full spin analysis (HiFSA). Fully characterized 1D (1)H spectra are unideterminant for a given structure. The corresponding FIDs may be readily submitted with publications and collected in databases. Proton NMR spectra are indispensable for structural characterization even in conjunction with 2D data. Quantum interaction and linkage tables (QuILTs) are introduced for a more intuitive visualization of 1D J-coupling relationships, NOESY correlations, and heteronuclear experiments. Overall, this study represents a significant contribution to best practices in NMR-based structural analysis and dereplication. PMID:26812443

  18. Energy transformation of plasmonic photocatalytic oxidation on 1D quantum well of platinum thin film

    NASA Astrophysics Data System (ADS)

    Huang, Hung Ji; Liu, Bo-Heng

    2015-12-01

    The energy transformation of vertical incident light into energy for a chemical reaction is demonstrated in the endothermic oxidation of ammonium ions in a spinning disk reactor. The plasmonic enhancement on photocatalytic reaction demonstrated the generation of quantum hot charge on 1D quantum well of platinum thin film.

  19. α(1D)-Adrenergic receptors constitutive activity and reduced expression at the plasma membrane.

    PubMed

    García-Sáinz, J Adolfo; Romero-Ávila, M Teresa; Medina, Luz Del Carmen

    2010-01-01

    Adrenergic receptors are a heterogeneous family of the G protein-coupled receptors that mediate the actions of adrenaline and noradrenaline. Adrenergic receptors comprise three subfamilies (α(1), α(2), and β, with three members each) and the α(1D)-adrenergic receptor is one of the members of the α(1) subfamily with some interesting traits. The α(1D)-adrenergic receptor is difficult to express, seems predominantly located intracellularly, and exhibits constitutive activity. In this chapter, we will describe in detail the conditions and procedures used to determine changes in intracellular free calcium concentration which has been instrumental to define the constitutive activity of these receptors. Taking advantage of the fact that truncation of the first 79 amino acids of α(1D)-adrenergic receptors markedly increased their membrane expression, we were able to show that constitutive activity is present in receptors truncated at the amino and carboxyl termini, which indicates that such domains are dispensable for this action. Constitutive activity could be observed in cells expressing either the rat or human α(1D)-adrenergic receptor orthologs. Such constitutive activity has been observed in native rat arteries and we will discuss the possible functional implications that it might have in the regulation of blood pressure.

  20. Quasi 1-D Study of Pulse Detonation Rocket Engine Blowdown Gasdynamics and Performance

    NASA Technical Reports Server (NTRS)

    Morris, Christopher I.

    2002-01-01

    Pulse detonation rocket engines (PDREs) offer potential performance improvements over conventional designs, but represent a challenging modeling task. A quasi 1-D, finite-rate chemistry CFD model for a PDRE is described and implemented. A parametric study of the effect of blowdown pressure ratio on the performance of several different PDRE nozzle configurations is reported.

  1. Recent developments in testing techniques for elastic mechanical properties of 1-D nanomaterials.

    PubMed

    Wang, Weidong; Li, Shuai; Zhang, Hongti; Lu, Yang

    2015-01-01

    One-dimensional (1-D) nanomaterials exhibit great potentials in their applications to functional materials, nano-devices and systems owing to their excellent properties. In the past decade, considerable studies have been done, with new patents being developed, on these 1-D building blocks for for their mechanical properties, especially elastic properties, which provide a solid foundation for the design of nanoelectromechanical systems (NEMS) and predictions of reliability and longevity for their devices. This paper reviews some of the recent investigations on techniques as well as patents available for the quantitative characterization of the elastic behaviors of various 1-D nanomaterials, with particular focus on on-chip testing system. The review begins with an overview of major testing methods for 1-D nanostructures' elastic properties, including nanoindentation testing, AFM (atomic force microscopy) testing, in situ SEM (scanning electron microscopy) testing, in situ TEM (transmission electron microscopy) testing and the testing system on the basis of MEMS (micro-electro-mechanical systems) technology, followed by advantages and challenges of each testing approach. This review also focuses on the MEMS-based testing apparatus, which can be actuated and measured inside SEM and TEM with ease, allowing users to highly magnify the continuous images of the specimen while measuring load electronically and independently. The combination of on-chip technologies and the in situ electron microscopy is expected to be a potential testing technique for nanomechanics. Finally, details are presented on the key challenges and possible solutions in the implementation of the testing techniques referred above.

  2. Millimeter and Submillimeter Studies of O(^1D) Insertion Reactions to Form Molecules of Astrophysical Interest

    NASA Astrophysics Data System (ADS)

    Hays, Brian; Wehres, Nadine; Deprince, Bridget Alligood; Roy, Althea A. M.; Laas, Jacob; Widicus Weaver, Susanna L.

    2015-06-01

    While both the number of detected interstellar molecules and their chemical complexity continue to increase, understanding of the processes leading to their formation is lacking. Our research group combines laboratory spectroscopy, observational astronomy, and astrochemical modeling for an interdisciplinary examination of the chemistry of star and planet formation. This talk will focus on our laboratory studies of O(^1D) insertion reactions with organic molecules to produce molecules of astrophysical interest. By employing these reactions in a supersonic expansion, we are able to produce interstellar organic reaction intermediates that are unstable under terrestrial conditions; we then probe the products using millimeter and submillimeter spectroscopy. We benchmarked this setup using the well-studied O(^1D) + methane reaction to form methanol. After optimizing methanol production, we moved on to study the O(^1D) + ethylene reaction to form vinyl alcohol (CH_2CHOH), and the O(^1D) + methyl amine reaction to form aminomethanol (NH_2CH_2OH). Vinyl alcohol measurements have now been extended up to 450 GHz, and the associated spectral analysis is complete. A possible detection of aminomethanol has also been made, and continued spectral studies and analysis are underway. We will present the results from these experiments and discuss future applications of these molecular and spectroscopic techniques.

  3. Build up An Operational Flood Simulation from Existing 1D Channel Flow Works

    NASA Astrophysics Data System (ADS)

    Chang, Che-Hao; Hsu, Chih-Tsung; Wu, Shiang-Jen; Lien, Ho-Cheng; Shen, Jhih-Cyuan; Chung, Ming-Ko

    2016-04-01

    Several 2D flood simulations will be developed for urban area in recent years in Taiwan. Original ideas focus on the static flood maps produced by the 2D flood simulation with respect to design events, which could be useful no matter for planning or disaster awareness. However, an extra bonus is expected to see if we can reuse the 2D flood simulation framework for operational use or not. Such a project goal inspire us to setup a standard operation procedure before any progress from existing 1D channel flow works. 3 key issues are taken into account in the SOP: 1. High Resolution Terrain: A 1m resolution digital terrain model (DTM) is considered as a reference. The Channels and structures should be setup in 1D channel flow works if we can identify under such high resolution. One should examine the existing 1D channel flow works consistent with the DTM or not. 2. Meteo Stations Referenced: Real time precipitation would be send to referenced location in RR models during an operational forecast. Existing 1D channels flow works are usually specifically for design events which are not necessarily equipped with such references. 3. Time Consuming: A full scale 2D flood simulation needs a lot of computation resources. A solution should be derived within practical time limits. Under the above consideration, some impacts and procedures will be analyzed and developed to setup the SOP for further model modification.

  4. Plasma as a tool for growth of 1D and 2D nanomaterials and their conversions

    NASA Astrophysics Data System (ADS)

    Cvelbar, Uros

    2015-09-01

    The growth of 1D and 2D nanostructures in low pressure oxygen plasma is presented with the special stress on metal-oxide nanowires and their deterministic growth mechanisms. Since the resulting nanostructures not always have required properties for applications their modifications are required. Therefore their conversions into different oxides or sulphites/nitrides are required with either molecules, atoms, electrons or photons.

  5. Observing the 1D-3D Crossover in a Spin-Imbalanced Fermi Gas

    NASA Astrophysics Data System (ADS)

    Revelle, Melissa C.; Fry, Jacob A.; Olsen, Ben A.; Hulet, Randall G.

    2016-05-01

    Trapped two-component Fermi gases phase separate into superfluid and normal phases when their spin populations are imbalanced. In 3D, a balanced superfluid core is surrounded by shells of partially polarized and normal phases, while in 1D, the balanced superfluid occupies the low density wings. We explored the crossover from 3D to 1D using a two-spin component ultracold atomic gas of 6 Li prepared in the lowest two hyperfine sublevels, where the interactions are tuned by a Feshbach resonance. The atoms are confined to 1D tubes where the tunneling rate t between tubes is varied by changing the depth of a 2D optical lattice. We observe the transition from 1D to 3D-like phase separation by varying t and interaction strength which changes the pair binding energy ɛB. We find a universal scaling of the dimensional crossover with t /ɛB , in agreement with previous theory. The crossover region is believed to be the most promising to find the exotic FFLO superfluid phase. Supported by the NSF and the Welch Foundation.

  6. Behavioral Responses in Animal Model of Congenital Muscular Dystrophy 1D.

    PubMed

    Comim, Clarissa M; Schactae, Aryadnne L; Soares, Jaime A; Ventura, Letícia; Freiberger, Viviane; Mina, Francielle; Dominguini, Diogo; Vainzof, Mariz; Quevedo, João

    2016-01-01

    Congenital muscular dystrophies 1D (CMD1D) present a mutation on the LARGE gene and are characterized by an abnormal glycosylation of α-dystroglycan (α-DG), strongly implicated as having a causative role in the development of central nervous system abnormalities such as cognitive impairment seen in patients. However, in the animal model of CMD1D, the brain involvement remains unclear. Therefore, the objective of this study is to evaluate the cognitive involvement in the Large(myd) mice. To this aim, we used adult homozygous, heterozygous, and wild-type mice. The mice underwent six behavioral tasks: habituation to an open field, step-down inhibitory avoidance, continuous multiple trials step-down inhibitory avoidance task, object recognition, elevated plus-maze, and forced swimming test. It was observed that Large(myd) individuals presented deficits on the habituation to the open field, step down inhibitory avoidance, continuous multiple-trials step-down inhibitory avoidance, object recognition, and forced swimming. This study shows the first evidence that abnormal glycosylation of α-DG may be affecting memory storage and restoring process in an animal model of CMD1D.

  7. Formation of 1D adsorbed water structures on CaO(001)

    NASA Astrophysics Data System (ADS)

    Zhao, Xunhua; Bhattacharya, Saswata; Ghiringhelli, Luca M.; Levchenko, Sergey V.; Scheffler, Matthias

    2015-03-01

    Understanding the interaction of water with oxide surfaces is of fundamental importance for basic and engineering sciences. Recently, a spontaneous formation of one-dimensional (1D) adsorbed water structures have been observed on CaO(001). Interestingly, at other alkaline earth metal oxides, in particular MgO(001) and SrO(001), such structures have not been found experimentally. We calculate the relative stability of adsorbed water structures on the three oxides using density-functional theory combined with the ab initio atomistic thermodynamics. Low-energy structures at different coverages are obtained with a first-principles genetic algorithm. Finite-temperature vibrational spectra are calculated using ab initio molecular dynamics. We find a range of (T, p) conditions where 1D structures are thermodynamically stable on CaO(001). The orientation and vibrational spectra of the 1D structures are in agreement with the experiments. The formation of the 1D structures is found to be actuated by a symmetry breaking in the adsorbed water tetramer, as well as by a balance between water-water and water-substrate interactions, determined by the lattice constant of the oxide.

  8. CD1d-restricted peripheral T cell lymphoma in mice and humans.

    PubMed

    Bachy, Emmanuel; Urb, Mirjam; Chandra, Shilpi; Robinot, Rémy; Bricard, Gabriel; de Bernard, Simon; Traverse-Glehen, Alexandra; Gazzo, Sophie; Blond, Olivier; Khurana, Archana; Baseggio, Lucile; Heavican, Tayla; Ffrench, Martine; Crispatzu, Giuliano; Mondière, Paul; Schrader, Alexandra; Taillardet, Morgan; Thaunat, Olivier; Martin, Nadine; Dalle, Stéphane; Le Garff-Tavernier, Magali; Salles, Gilles; Lachuer, Joel; Hermine, Olivier; Asnafi, Vahid; Roussel, Mikael; Lamy, Thierry; Herling, Marco; Iqbal, Javeed; Buffat, Laurent; Marche, Patrice N; Gaulard, Philippe; Kronenberg, Mitchell; Defrance, Thierry; Genestier, Laurent

    2016-05-01

    Peripheral T cell lymphomas (PTCLs) are a heterogeneous entity of neoplasms with poor prognosis, lack of effective therapies, and a largely unknown pathophysiology. Identifying the mechanism of lymphomagenesis and cell-of-origin from which PTCLs arise is crucial for the development of efficient treatment strategies. In addition to the well-described thymic lymphomas, we found that p53-deficient mice also developed mature PTCLs that did not originate from conventional T cells but from CD1d-restricted NKT cells. PTCLs showed phenotypic features of activated NKT cells, such as PD-1 up-regulation and loss of NK1.1 expression. Injections of heat-killed Streptococcus pneumonia, known to express glycolipid antigens activating NKT cells, increased the incidence of these PTCLs, whereas Escherichia coli injection did not. Gene expression profile analyses indicated a significant down-regulation of genes in the TCR signaling pathway in PTCL, a common feature of chronically activated T cells. Targeting TCR signaling pathway in lymphoma cells, either with cyclosporine A or anti-CD1d blocking antibody, prolonged mice survival. Importantly, we identified human CD1d-restricted lymphoma cells within Vδ1 TCR-expressing PTCL. These results define a new subtype of PTCL and pave the way for the development of blocking anti-CD1d antibody for therapeutic purposes in humans. PMID:27069116

  9. Toward Structural Correctness: Aquatolide and the Importance of 1D Proton NMR FID Archiving

    PubMed Central

    2016-01-01

    The revision of the structure of the sesquiterpene aquatolide from a bicyclo[2.2.0]hexane to a bicyclo[2.1.1]hexane structure using compelling NMR data, X-ray crystallography, and the recent confirmation via full synthesis exemplify that the achievement of “structural correctness” depends on the completeness of the experimental evidence. Archived FIDs and newly acquired aquatolide spectra demonstrate that archiving and rigorous interpretation of 1D 1H NMR data may enhance the reproducibility of (bio)chemical research and curb the growing trend of structural misassignments. Despite being the most accessible NMR experiment, 1D 1H spectra encode a wealth of information about bonds and molecular geometry that may be fully mined by 1H iterative full spin analysis (HiFSA). Fully characterized 1D 1H spectra are unideterminant for a given structure. The corresponding FIDs may be readily submitted with publications and collected in databases. Proton NMR spectra are indispensable for structural characterization even in conjunction with 2D data. Quantum interaction and linkage tables (QuILTs) are introduced for a more intuitive visualization of 1D J-coupling relationships, NOESY correlations, and heteronuclear experiments. Overall, this study represents a significant contribution to best practices in NMR-based structural analysis and dereplication. PMID:26812443

  10. A South American Prehistoric Mitogenome: Context, Continuity, and the Origin of Haplogroup C1d.

    PubMed

    Sans, Mónica; Figueiro, Gonzalo; Hughes, Cris E; Lindo, John; Hidalgo, Pedro C; Malhi, Ripan S

    2015-01-01

    Based on mitochondrial DNA (mtDNA), it has been estimated that at least 15 founder haplogroups peopled the Americas. Subhaplogroup C1d3 was defined based on the mitogenome of a living individual from Uruguay that carried a lineage previously identified in hypervariable region I sequences from ancient and modern Uruguayan individuals. When complete mitogenomes were studied, additional substitutions were found in the coding region of the mitochondrial genome. Using a complete ancient mitogenome and three modern mitogenomes, we aim to clarify the ancestral state of subhaplogroup C1d3 and to better understand the peopling of the region of the Río de la Plata basin, as well as of the builders of the mounds from which the ancient individuals were recovered. The ancient mitogenome, belonging to a female dated to 1,610±46 years before present, was identical to the mitogenome of one of the modern individuals. All individuals share the mutations defining subhaplogroup C1d3. We estimated an age of 8,974 (5,748-12,261) years for the most recent common ancestor of C1d3, in agreement with the initial peopling of the geographic region. No individuals belonging to the defined lineage were found outside of Uruguay, which raises questions regarding the mobility of the prehistoric inhabitants of the country. Moreover, the present study shows the continuity of Native lineages over at least 6,000 years. PMID:26509686

  11. A new EEG measure using the 1D cluster variation method

    NASA Astrophysics Data System (ADS)

    Maren, Alianna J.; Szu, Harold H.

    2015-05-01

    A new information measure, drawing on the 1-D Cluster Variation Method (CVM), describes local pattern distributions (nearest-neighbor and next-nearest neighbor) in a binary 1-D vector in terms of a single interaction enthalpy parameter h for the specific case where the fractions of elements in each of two states are the same (x1=x2=0.5). An example application of this method would be for EEG interpretation in Brain-Computer Interfaces (BCIs), especially in the frontier of invariant biometrics based on distinctive and invariant individual responses to stimuli containing an image of a person with whom there is a strong affiliative response (e.g., to a person's grandmother). This measure is obtained by mapping EEG observed configuration variables (z1, z2, z3 for next-nearest neighbor triplets) to h using the analytic function giving h in terms of these variables at equilibrium. This mapping results in a small phase space region of resulting h values, which characterizes local pattern distributions in the source data. The 1-D vector with equal fractions of units in each of the two states can be obtained using the method for transforming natural images into a binarized equi-probability ensemble (Saremi & Sejnowski, 2014; Stephens et al., 2013). An intrinsically 2-D data configuration can be mapped to 1-D using the 1-D Peano-Hilbert space-filling curve, which has demonstrated a 20 dB lower baseline using the method compared with other approaches (cf. SPIE ICA etc. by Hsu & Szu, 2014). This CVM-based method has multiple potential applications; one near-term one is optimizing classification of the EEG signals from a COTS 1-D BCI baseball hat. This can result in a convenient 3-D lab-tethered EEG, configured in a 1-D CVM equiprobable binary vector, and potentially useful for Smartphone wireless display. Longer-range applications include interpreting neural assembly activations via high-density implanted soft, cellular-scale electrodes.

  12. Experimental use of TRMM precipitation radar observations in 1D+4D-Var assimilation

    NASA Astrophysics Data System (ADS)

    Benedetti, Angela; Lopez, Philippe; Bauer, Peter; Moreau, Emmanuel

    2005-07-01

    This paper presents a new application of the Tropical Rainfall Measuring Mission (TRMM) precipitation radar (PR) observations for indirect assimilation into the European Centre for Medium-Range Weather Forecasts (ECMWF) model. The PR reflectivities are first processed using a one-dimensional variational (1D-Var) method to adjust model temperature and specific humidity. The retrieved Total Column Water Vapour (TCWV) is then assimilated into the operational four-dimensional variational (4D-Var) system. The applicability of the 1D+4D-Var approach to the radar observations is discussed in detail.Several case studies were run to assess the feasibility and the effectiveness of assimilating PR reflectivities with a 1D-Var approach. Results show good behaviour of the 1D-Var system in terms of convergence and stability. Its performance in terms of retrieved TCWV is comparable to that of other 1D-Vars which make use of TRMM Microwave Imager (TMI) observations. When the 1D-Var TCWV pseudo-observations are input into the 4D-Var system, a positive impact is shown in the analysis and the subsequent forecasts, both on moisture-related fields and also on winds and surface pressure. The quality of the forecast is verified using track observations for the tropical cyclones. The track forecasts from the experiments which include 1D-Var TCWV are generally closer to the observed track than a control run. Despite their much smaller spatial coverage than TMI observations, it is found that the PR data have a comparable impact, provided the satellite samples a meaningful portion of the storm, possibly its centre. This is possibly due to the fact that TCWV increments from PR and from TMI brightness temperature have similar magnitudes.These results show that active sensor data can provide indirect yet useful information on the moisture field and that this information can effectively be assimilated to improve the analysis and the forecast of tropical disturbances. Although this is a sub

  13. Ascites Specific Inhibition of CD1d-Mediated Activation of NKT cells

    PubMed Central

    Webb, Tonya J.; Giuntoli, Robert L.; Rogers, Ophelia; Schneck, Jonathan; Oelke, Mathias

    2009-01-01

    Purpose Natural killer T (NKT) cells recognize lipid antigen presented by CD1 molecules. NKT cells can both directly, through cytotoxicity, and indirectly, through activation of other effector cells, mediate anti-tumor immunity. However, it has been shown that tumor associated lipids are frequently shed into the tumor microenvironment, which can mediate immunosuppressive activity. Given that ovarian cancer associated ascites has been reported to have increased levels of gangliosides, we examined the effect of tumor associated and other ascites on CD1d-mediated antigen presentation to NKT cells. Experimental Design To investigate the effects of ascites on NKT cell activation, we pretreated CD1d-expressing cells with the ascites and measured their ability to stimulate cytokine production in NKT cells. To determine whether antigen processing or editing was necessary, CD1d-Ig-based artificial Antigen Presenting Cells (aAPC) were also incubated with ascites. In addition, to examine specificity, we analyzed whether ascites fluid could influence the activation of classical CD8+ T cells. Results Pretreatment of CD1d-expressing cells with ascites from the majority of patients inhibited the cells’ ability to stimulate/activate NKT cells in a dose-dependent manner. Ascites treatment also partially blocked the ability of α-GalCer loaded CD1d-Ig-based artificial Antigen Presenting Cells (aAPC) to activate NKT cells. In addition, our data demonstrate that treatment with ascites does not inhibit HLA-A2 mediated activation of classical CD8+ T cells. Conclusions Together, these data suggest that ovarian and other cancers may have developed immune evasion mechanisms specifically targeting the CD1/NKT cell system. PMID:19047090

  14. The D1-D2 region of the large subunit ribosomal DNA as barcode for ciliates.

    PubMed

    Stoeck, T; Przybos, E; Dunthorn, M

    2014-05-01

    Ciliates are a major evolutionary lineage within the alveolates, which are distributed in nearly all habitats on our planet and are an essential component for ecosystem function, processes and stability. Accurate identification of these unicellular eukaryotes through, for example, microscopy or mating type reactions is reserved to few specialists. To satisfy the demand for a DNA barcode for ciliates, which meets the standard criteria for DNA barcodes defined by the Consortium for the Barcode of Life (CBOL), we here evaluated the D1-D2 region of the ribosomal DNA large subunit (LSU-rDNA). Primer universality for the phylum Ciliophora was tested in silico with available database sequences as well as in the laboratory with 73 ciliate species, which represented nine of 12 ciliate classes. Primers tested in this study were successful for all tested classes. To test the ability of the D1-D2 region to resolve conspecific and congeneric sequence divergence, 63 Paramecium strains were sampled from 24 mating species. The average conspecific D1-D2 variation was 0.18%, whereas congeneric sequence divergence averaged 4.83%. In pairwise genetic distance analyses, we identified a D1-D2 sequence divergence of <0.6% as an ideal threshold to discriminate Paramecium species. Using this definition, only 3.8% of all conspecific and 3.9% of all congeneric sequence comparisons had the potential of false assignments. Neighbour-joining analyses inferred monophyly for all taxa but for two Paramecium octaurelia strains. Here, we present a protocol for easy DNA amplification of single cells and voucher deposition. In conclusion, the presented data pinpoint the D1-D2 region as an excellent candidate for an official CBOL barcode for ciliated protists.

  15. What causes the large extensions of red supergiant atmospheres?. Comparisons of interferometric observations with 1D hydrostatic, 3D convection, and 1D pulsating model atmospheres

    NASA Astrophysics Data System (ADS)

    Arroyo-Torres, B.; Wittkowski, M.; Chiavassa, A.; Scholz, M.; Freytag, B.; Marcaide, J. M.; Hauschildt, P. H.; Wood, P. R.; Abellan, F. J.

    2015-03-01

    Aims: This research has two main goals. First, we present the atmospheric structure and the fundamental parameters of three red supergiants (RSGs), increasing the sample of RSGs observed by near-infrared spectro-interferometry. Additionally, we test possible mechanisms that may explain the large observed atmospheric extensions of RSGs. Methods: We carried out spectro-interferometric observations of the RSGs V602 Car, HD 95687, and HD 183589 in the near-infrared K-band (1.92-2.47 μm) with the VLTI/AMBER instrument at medium spectral resolution (R ~ 1500). To categorize and comprehend the extended atmospheres, we compared our observational results to predictions by available hydrostatic PHOENIX, available 3D convection, and new 1D self-excited pulsation models of RSGs. Results: Our near-infrared flux spectra of V602 Car, HD 95687, and HD 183589 are well reproduced by the PHOENIX model atmospheres. The continuum visibility values are consistent with a limb-darkened disk as predicted by the PHOENIX models, allowing us to determine the angular diameter and the fundamental parameters of our sources. Nonetheless, in the case of V602 Car and HD 95686, the PHOENIX model visibilities do not predict the large observed extensions of molecular layers, most remarkably in the CO bands. Likewise, the 3D convection models and the 1D pulsation models with typical parameters of RSGs lead to compact atmospheric structures as well, which are similar to the structure of the hydrostatic PHOENIX models. They can also not explain the observed decreases in the visibilities and thus the large atmospheric molecular extensions. The full sample of our RSGs indicates increasing observed atmospheric extensions with increasing luminosity and decreasing surface gravity, and no correlation with effective temperature or variability amplitude. Conclusions: The location of our RSG sources in the Hertzsprung-Russell diagram is confirmed to be consistent with the red limits of recent evolutionary tracks

  16. Polychalcogenophosphate flux synthesis of 1D-KInP 2Se 6 and 1D and 3D-NaCrP 2S 6

    NASA Astrophysics Data System (ADS)

    Coste, Servane; Kopnin, Evgeni; Evain, Michel; Jobic, Stéphane; Brec, Raymond; Chondroudis, Konstantinos; Kanatzidis, Mercouri G.

    2002-04-01

    Three new chalcogenophosphates, 1D-KInP 2Se 6 ( I), 1D-NaCrP 2S 6 ( II) and 3D-NaCrP 2S 6 ( III), have been synthesized and their structure determined from single crystal diffraction analysis. ( I) and ( II) crystallize in the monoclinic system (space group P2 1/n, No. 14) with cell parameters a=7.5112(11), b=6.4861(5), c=22.789(2) Å and β=98.912(16)° ( V=1096.9(2) Å 3), Z=4 and R/ Rw( F2)=0.0234/0.0387 (for 900 observed reflections and 92 refined parameters) for ( I) and a=7.0279(5), b=5.8797(2), c=21.2578(14) Å and β=92.110(3)° ( V=877.82(9) Å 3), Z=4 and R/ Rw( F2)=0.0572/0.1151 (for 1455 observed reflections and 92 refined parameters) for ( II). Both materials exhibit 1/ ∞[MP 2Q 6] - chains built upon [MQ 6] octahedra (M=In, Cr; Q=Se, S) sharing edges to define 1/ ∞[MQ 4] 5- zigzag fibers which are capped by tetradentate ethane-like [P 2Q 6] groups. ( III) crystallizes in the orthorhombic system (space group Fdd2, No. 43) with cell parameters a=10.9742(7), b=7.9828(6), c=20.8590(19) Å ( V=1827.3(4) Å 3), Z=8 and R/ Rw=0.0184/0.0378 (for 967 observed reflections and 47 refined parameters), and displays a three-dimensional framework arrangement. Its structure is similar to that of TiP 2S 6 where titanium atoms are substituted for the chromium, the sodium atoms being inserted in the empty tunnels to ensure the charge balance. The exfoliation properties of 1D-NaCrP 2S 6 in polar solvents are reported.

  17. Courseware Engineering Methodology.

    ERIC Educational Resources Information Center

    Uden, Lorna

    2002-01-01

    Describes development of the Courseware Engineering Methodology (CEM), created to guide novices in designing effective courseware. Discusses CEM's four models: pedagogical (concerned with the courseware's pedagogical aspects), conceptual (dealing with software engineering), interface (relating to human-computer interaction), and hypermedia…

  18. Complicating Methodological Transparency

    ERIC Educational Resources Information Center

    Bridges-Rhoads, Sarah; Van Cleave, Jessica; Hughes, Hilary E.

    2016-01-01

    A historical indicator of the quality, validity, and rigor of qualitative research has been the documentation and disclosure of the behind-the-scenes work of the researcher. In this paper, we use what we call "methodological data" as a tool to complicate the possibility and desirability of such transparency. Specifically, we draw on our…

  19. Video: Modalities and Methodologies

    ERIC Educational Resources Information Center

    Hadfield, Mark; Haw, Kaye

    2012-01-01

    In this article, we set out to explore what we describe as the use of video in various modalities. For us, modality is a synthesizing construct that draws together and differentiates between the notion of "video" both as a method and as a methodology. It encompasses the use of the term video as both product and process, and as a data collection…

  20. Deletion of the Rab GAP Tbc1d1 modifies glucose, lipid, and energy homeostasis in mice.

    PubMed

    Hargett, Stefan R; Walker, Natalie N; Hussain, Syed S; Hoehn, Kyle L; Keller, Susanna R

    2015-08-01

    Tbc1d1 is a Rab GTPase-activating protein (GAP) implicated in regulating intracellular retention and cell surface localization of the glucose transporter GLUT4 and thus glucose uptake in a phosphorylation-dependent manner. Tbc1d1 is most abundant in skeletal muscle but is expressed at varying levels among different skeletal muscles. Previous studies with male Tbc1d1-deficient (Tbc1d1(-/-)) mice on standard and high-fat diets established a role for Tbc1d1 in glucose, lipid, and energy homeostasis. Here we describe similar, but also additional abnormalities in male and female Tbc1d1(-/-) mice. We corroborate that Tbc1d1 loss leads to skeletal muscle-specific and skeletal muscle type-dependent abnormalities in GLUT4 expression and glucose uptake in female and male mice. Using subcellular fractionation, we show that Tbc1d1 controls basal intracellular GLUT4 retention in large skeletal muscles. However, cell surface labeling of extensor digitorum longus muscle indicates that Tbc1d1 does not regulate basal GLUT4 cell surface exposure as previously suggested. Consistent with earlier observations, female and male Tbc1d1(-/-) mice demonstrate increased energy expenditure and skeletal muscle fatty acid oxidation. Interestingly, we observe sex-dependent differences in in vivo phenotypes. Female, but not male, Tbc1d1(-/-) mice have decreased body weight and impaired glucose and insulin tolerance, but only male Tbc1d1(-/-) mice show increased lipid clearance after oil gavage. We surmise that similar changes at the tissue level cause differences in whole-body metabolism between male and female Tbc1d1(-/-) mice and between male Tbc1d1(-/-) mice in different studies due to variations in body composition and nutrient handling.

  1. Deletion of the Rab GAP Tbc1d1 modifies glucose, lipid, and energy homeostasis in mice.

    PubMed

    Hargett, Stefan R; Walker, Natalie N; Hussain, Syed S; Hoehn, Kyle L; Keller, Susanna R

    2015-08-01

    Tbc1d1 is a Rab GTPase-activating protein (GAP) implicated in regulating intracellular retention and cell surface localization of the glucose transporter GLUT4 and thus glucose uptake in a phosphorylation-dependent manner. Tbc1d1 is most abundant in skeletal muscle but is expressed at varying levels among different skeletal muscles. Previous studies with male Tbc1d1-deficient (Tbc1d1(-/-)) mice on standard and high-fat diets established a role for Tbc1d1 in glucose, lipid, and energy homeostasis. Here we describe similar, but also additional abnormalities in male and female Tbc1d1(-/-) mice. We corroborate that Tbc1d1 loss leads to skeletal muscle-specific and skeletal muscle type-dependent abnormalities in GLUT4 expression and glucose uptake in female and male mice. Using subcellular fractionation, we show that Tbc1d1 controls basal intracellular GLUT4 retention in large skeletal muscles. However, cell surface labeling of extensor digitorum longus muscle indicates that Tbc1d1 does not regulate basal GLUT4 cell surface exposure as previously suggested. Consistent with earlier observations, female and male Tbc1d1(-/-) mice demonstrate increased energy expenditure and skeletal muscle fatty acid oxidation. Interestingly, we observe sex-dependent differences in in vivo phenotypes. Female, but not male, Tbc1d1(-/-) mice have decreased body weight and impaired glucose and insulin tolerance, but only male Tbc1d1(-/-) mice show increased lipid clearance after oil gavage. We surmise that similar changes at the tissue level cause differences in whole-body metabolism between male and female Tbc1d1(-/-) mice and between male Tbc1d1(-/-) mice in different studies due to variations in body composition and nutrient handling. PMID:26015432

  2. Modeling of impurity spectroscopy in the divertor and SOL of DIII-D using the 1D multifluid model NEWT1D

    SciTech Connect

    West, W.P.; Evans, T.E.; Brooks, N.H.

    1996-10-01

    NEWT1D, a one dimensional multifluid model of the scrape-off layer and divertor plasma, has been used to model the plasma including the distribution of carbon ionization states in the SOL and divertor of ELMing H-mode at two injected power levels in DIII-D. Comparison of the code predictions to the measured divertor and scrape-off layer (SOL) plasma density and temperature shows good agreement. Comparison of the predicted line emissions to the spectroscopic data suggests that physically sputtered carbon from the strike point is not transported up the flux tube; a distributed source of carbon a few centimeters up the flux tube is required to achieve reasonable agreement.

  3. O(1D) kinetic study of key ozone depleting substances and greenhouse gases.

    PubMed

    Baasandorj, Munkhbayar; Fleming, Eric L; Jackman, Charles H; Burkholder, James B

    2013-03-28

    A key stratospheric loss process for ozone depleting substances (ODSs) and greenhouse gases (GHGs) is reaction with the O((1)D) atom. In this study, rate coefficients, k, for the O((1)D) atom reaction were measured for the following key halocarbons: chlorofluorocarbons (CFCs) CFCl3 (CFC-11), CF2Cl2 (CFC-12), CFCl2CF2Cl (CFC-113), CF2ClCF2Cl (CFC-114), CF3CF2Cl (CFC-115); hydrochlorofluorocarbons (HCFCs) CHF2Cl (HCFC-22), CH3CClF2 (HCFC-142b); and hydrofluorocarbons (HFCs) CHF3 (HFC-23), CHF2CF3 (HFC-125), CH3CF3 (HFC-143a), and CF3CHFCF3 (HFC-227ea). Total rate coefficients, kT, corresponding to the loss of the O((1)D) atom, were measured over the temperature range 217-373 K using a competitive reactive technique. kT values for the CFC and HCFC reactions were >1 × 10(-10) cm(3) molecule(-1) s(-1), except for CFC-115, and the rate coefficients for the HFCs were in the range (0.095-0.72) × 10(-10) cm(3) molecule(-1) s(-1). Rate coefficients for the CFC-12, CFC-114, CFC-115, HFC-23, HFC-125, HFC-143a, and HFC-227ea reactions were observed to have a weak negative temperature dependence, E/R ≈ -25 K. Reactive rate coefficients, kR, corresponding to the loss of the halocarbon, were measured for CFC-11, CFC-115, HCFC-22, HCFC-142b, HFC-23, HFC-125, HFC-143a, and HFC-227ea using a relative rate technique. The reactive branching ratio obtained was dependent on the composition of the halocarbon and the trend in O((1)D) reactivity with the extent of hydrogen and chlorine substitution is discussed. The present results are critically compared with previously reported kinetic data and the discrepancies are discussed. 2D atmospheric model calculations were used to evaluate the local and global annually averaged atmospheric lifetimes of the halocarbons and the contribution of O((1)D) chemistry to their atmospheric loss. The O((1)D) reaction was found to be a major global loss process for CFC-114 and CFC-115 and a secondary global loss process for the other molecules included

  4. TCTEX1D4 Interactome in Human Testis: Unraveling the Function of Dynein Light Chain in Spermatozoa

    PubMed Central

    Freitas, Maria João; Korrodi-Gregório, Luís; Morais-Santos, Filipa; da Cruz e Silva, Edgar

    2014-01-01

    Abstract Studies were designed to identify the TCTEX1D4 interactome in human testis, with the purpose of unraveling putative protein complexes essential to male reproduction and thus novel TCTEX1D4 functions. TCTEX1D4 is a dynein light chain that belongs to the DYNT1/TCTEX1 family. In spermatozoa, it appears to be important to sperm motility, intraflagellar transport, and acrosome reaction. To contribute to the knowledge on TCTEX1D4 function in testis and spermatozoa, a yeast two-hybrid assay was performed in testis, which allowed the identification of 40 novel TCTEX1D4 interactors. Curiously, another dynein light chain, TCTEX1D2, was identified and its existence demonstrated for the first time in human spermatozoa. Immunofluorescence studies proved that TCTEX1D2 is an intra-acrosomal protein also present in the midpiece, suggesting a role in cargo movement in human spermatozoa. Further, an in silico profile of TCTEX1D4 revealed that most TCTEX1D4 interacting proteins were not previously characterized and the ones described present a very broad nature. This reinforces TCTEX1D4 as a dynein light chain that is capable of interacting with a variety of functionally different proteins. These observations collectively contribute to a deeper molecular understanding of the human spermatozoa function. PMID:24606217

  5. TCTEX1D4 interactome in human testis: unraveling the function of dynein light chain in spermatozoa.

    PubMed

    Freitas, Maria João; Korrodi-Gregório, Luís; Morais-Santos, Filipa; Cruz e Silva, Edgar da; Fardilha, Margarida

    2014-04-01

    Studies were designed to identify the TCTEX1D4 interactome in human testis, with the purpose of unraveling putative protein complexes essential to male reproduction and thus novel TCTEX1D4 functions. TCTEX1D4 is a dynein light chain that belongs to the DYNT1/TCTEX1 family. In spermatozoa, it appears to be important to sperm motility, intraflagellar transport, and acrosome reaction. To contribute to the knowledge on TCTEX1D4 function in testis and spermatozoa, a yeast two-hybrid assay was performed in testis, which allowed the identification of 40 novel TCTEX1D4 interactors. Curiously, another dynein light chain, TCTEX1D2, was identified and its existence demonstrated for the first time in human spermatozoa. Immunofluorescence studies proved that TCTEX1D2 is an intra-acrosomal protein also present in the midpiece, suggesting a role in cargo movement in human spermatozoa. Further, an in silico profile of TCTEX1D4 revealed that most TCTEX1D4 interacting proteins were not previously characterized and the ones described present a very broad nature. This reinforces TCTEX1D4 as a dynein light chain that is capable of interacting with a variety of functionally different proteins. These observations collectively contribute to a deeper molecular understanding of the human spermatozoa function.

  6. Tobacco documents research methodology.

    PubMed

    Anderson, Stacey J; McCandless, Phyra M; Klausner, Kim; Taketa, Rachel; Yerger, Valerie B

    2011-05-01

    Tobacco documents research has developed into a thriving academic enterprise since its inception in 1995. The technology supporting tobacco documents archiving, searching and retrieval has improved greatly since that time, and consequently tobacco documents researchers have considerably more access to resources than was the case when researchers had to travel to physical archives and/or electronically search poorly and incompletely indexed documents. The authors of the papers presented in this supplement all followed the same basic research methodology. Rather than leave the reader of the supplement to read the same discussion of methods in each individual paper, presented here is an overview of the methods all authors followed. In the individual articles that follow in this supplement, the authors present the additional methodological information specific to their topics. This brief discussion also highlights technological capabilities in the Legacy Tobacco Documents Library and updates methods for organising internal tobacco documents data and findings.

  7. Soft Systems Methodology

    NASA Astrophysics Data System (ADS)

    Checkland, Peter; Poulter, John

    Soft systems methodology (SSM) is an approach for tackling problematical, messy situations of all kinds. It is an action-oriented process of inquiry into problematic situations in which users learn their way from finding out about the situation, to taking action to improve it. The learning emerges via an organised process in which the situation is explored using a set of models of purposeful action (each built to encapsulate a single worldview) as intellectual devices, or tools, to inform and structure discussion about a situation and how it might be improved. This paper, written by the original developer Peter Checkland and practitioner John Poulter, gives a clear and concise account of the approach that covers SSM's specific techniques, the learning cycle process of the methodology and the craft skills which practitioners develop. This concise but theoretically robust account nevertheless includes the fundamental concepts, techniques, core tenets described through a wide range of settings.

  8. Acoustic methodology review

    NASA Technical Reports Server (NTRS)

    Schlegel, R. G.

    1982-01-01

    It is important for industry and NASA to assess the status of acoustic design technology for predicting and controlling helicopter external noise in order for a meaningful research program to be formulated which will address this problem. The prediction methodologies available to the designer and the acoustic engineer are three-fold. First is what has been described as a first principle analysis. This analysis approach attempts to remove any empiricism from the analysis process and deals with a theoretical mechanism approach to predicting the noise. The second approach attempts to combine first principle methodology (when available) with empirical data to formulate source predictors which can be combined to predict vehicle levels. The third is an empirical analysis, which attempts to generalize measured trends into a vehicle noise prediction method. This paper will briefly address each.

  9. Hyperbranched quasi-1D TiO2 nanostructure for hybrid organic-inorganic solar cells.

    PubMed

    Ghadirzadeh, Ali; Passoni, Luca; Grancini, Giulia; Terraneo, Giancarlo; Li Bassi, Andrea; Petrozza, Annamaria; Di Fonzo, Fabio

    2015-04-15

    The performance of hybrid solar cells is strongly affected by the device morphology. In this work, we demonstrate a poly(3-hexylthiophene-2,5-diyl)/TiO2 hybrid solar cell where the TiO2 photoanode comprises an array of tree-like hyperbranched quasi-1D nanostructures self-assembled from the gas phase. This advanced architecture enables us to increase the power conversion efficiency to over 1%, doubling the efficiency with respect to state of the art devices employing standard mesoporous titania photoanodes. This improvement is attributed to several peculiar features of this array of nanostructures: high interfacial area; increased optical density thanks to the enhanced light scattering; and enhanced crystallization of poly(3-hexylthiophene-2,5-diyl) inside the quasi-1D nanostructure. PMID:25822757

  10. A 1D model for the description of mixing-controlled reacting diesel sprays

    SciTech Connect

    Desantesa, J.M.; Pastor, J.V.; Garcia-Oliver, J.M.; Pastor, J.M.

    2009-01-15

    The paper reports an investigation on the transient evolution of diesel flames in terms of fuel-air mixing, spray penetration and combustion rate. A one-dimensional (1D) spray model, which was previously validated for inert diesel sprays, is extended to reacting conditions. The main assumptions of the model are the mixing-controlled hypothesis and the validity of self-similarity for conservative properties. Validation is achieved by comparing model predictions with both CFD gas jet simulations and experimental diesel spray measurements. The 1D model provides valuable insight into the evolution of the flow within the spray (momentum and mass fluxes, tip penetration, etc.) when shifting from inert to reacting conditions. Results show that the transient diesel flame evolution is mainly governed by two combustion-induced effects, namely the reduction in local density and the increase in flame radial width. (author)

  11. Static sign language recognition using 1D descriptors and neural networks

    NASA Astrophysics Data System (ADS)

    Solís, José F.; Toxqui, Carina; Padilla, Alfonso; Santiago, César

    2012-10-01

    A frame work for static sign language recognition using descriptors which represents 2D images in 1D data and artificial neural networks is presented in this work. The 1D descriptors were computed by two methods, first one consists in a correlation rotational operator.1 and second is based on contour analysis of hand shape. One of the main problems in sign language recognition is segmentation; most of papers report a special color in gloves or background for hand shape analysis. In order to avoid the use of gloves or special clothing, a thermal imaging camera was used to capture images. Static signs were picked up from 1 to 9 digits of American Sign Language, a multilayer perceptron reached 100% recognition with cross-validation.

  12. Lipid and glycolipid antigens of CD1d-restricted natural killer T cells

    PubMed Central

    Venkataswamy, Manjunatha M.; Porcelli, Steven A.

    2009-01-01

    In spite of their relatively limited antigen receptor repertoire, CD1d-restricted NKT cells recognize a surprisingly diverse range of lipid and glycolipid antigens. Recent studies of natural and synthetic CD1d presented antigens provide an increasingly detailed picture of how the specific structural features of these lipids and glycolipids influence their ability to be presented to NKT cells and stimulate their diverse immunologic functions. Particularly for synthetic analogues of α-galactosylceramides which have been the focus of intense recent investigation, it is becoming clear that the design of glycolipid antigens with the ability to precisely control the specific immunologic activities of NKT cells is likely to be feasible. The emerging details of the mechanisms underlying the structure-activity relationship of NKT cell antigens will assist greatly in the design and production of immunomodulatory agents for the precise manipulation of NKT cells and the many other components of the immune system that they influence. PMID:19945296

  13. 1D Scaling with Ablation for K-Shell Radiation from Stainless Steel Wire Arrays

    SciTech Connect

    Giuliani, J. L.; Thornhill, J. W.; Dasgupta, A.; Davis, J.; Clark, R. W.; Jones, B.; Cuneo, M.; Coverdale, C. A.; Deeney, C.

    2009-01-21

    A 1D Lagrangian magnetohydrodynamic z-pinch simulation code is extended to include wire ablation. The plasma transport coefficients are calibrated to reproduce the K-shell yields measured on the Z generator for three stainless steel arrays of diameter 55 mm and masses ranging from 1.8 to 2.7 mg. The resulting 1D scaling model is applied to a larger SS array (65 mm and 2.5 mg) on the refurbished Z machine. Simulation results predict a maximum K-shell yield of 77 kJ for an 82 kV charging voltage. This maximum drops to 42 kJ at 75 kV charging. Neglecting the ablation precursor leads to a {approx}10% change in the calculated yield.

  14. Slice imaging of nitric acid photodissociation: The O({sup 1}D) + HONO channel

    SciTech Connect

    Herath, Nuradhika; Everhart, Stephanie C.; Suits, Arthur G.; Vasyuntinskii, Oleg S.

    2011-01-21

    We report an imaging study of nitric acid (HNO{sub 3}) photodissociation near 204 nm with detection of O({sup 1}D), one of the major decomposition products in this region. The images show structure reflecting the vibrational distribution of the HONO coproduct and significant angular anisotropy that varies with recoil speed. The images also show substantial alignment of the O({sup 1}D) orbital, which is analyzed using an approximate treatment that reveals that the polarization is dominated by incoherent, high order contributions. The results offer additional insight into the dynamics of the dissociation of nitric acid through the S{sub 3} (2 {sup 1}A{sup '}) excited state, resolving an inconsistency in previously reported angular distributions, and pointing the way to future studies of the angular momentum polarization.

  15. Evaluated rate constants for selected HCFC's and HFC's with OH and O((sup)1D)

    NASA Technical Reports Server (NTRS)

    Hampson, Robert F.; Kurylo, Michael J.; Sander, Stanley P.

    1990-01-01

    The chemistry of HCFC's and HFC's in the troposphere is controlled by reactions with OH in which a hydrogen atom is abstracted from the halocarbon to form water and a halo-alkyl radical. The halo-alkyl radical subsequently reacts with molecular oxygen to form a peroxy radical. The reactions of HCFC's and HFC's with O(exp1D) atoms are unimportant in the troposphere, but may be important in producing active chlorine of OH in the stratosphere. Here, the rate constants for the reactions of OH and O(exp1D) with many HFC's and HCFC's are evaluated. Recommendations are given for the five HCFC's and three HFC's specified by AFEAS as primary alternatives as well as for all other isomers of C1 and C2 HCFC's and HFC's where rate data exist. In addition, recommendations are included for CH3CCl3, CH2Cl2, and CH4.

  16. Analytical investigations of the magnetotelluric directionality estimation in 1-D anisotropic layered media

    NASA Astrophysics Data System (ADS)

    Okazaki, T.; Oshiman, N.; Yoshimura, R.

    2016-11-01

    Inferring geoelectric dimensionality (1D, 2D or 3D) and directionality (strike directions) from the impedance tensor is a basic procedure in magnetotelluric data processing. Given that electrical anisotropy is increasingly recognized in observations, it is valuable to understand the imprint of anisotropy in these analyses. In this paper, we analytically investigate the estimation of strike directions based on rotational invariants in 1D anisotropic layered media. We first show that if anisotropy axes are identical in all anisotropic layers, the estimated strike coincides with that direction. We then derive an analytical formula of the strike angle at long periods for general anisotropic layers with an isotropic basement. This formula shows a clear physical interpretation that the strike angle points where the conductance integrated along depth takes a maximum value.

  17. Bifurcations of families of 1D-tori in 4D symplectic maps.

    PubMed

    Onken, Franziska; Lange, Steffen; Ketzmerick, Roland; Bäcker, Arnd

    2016-06-01

    The regular structures of a generic 4d symplectic map with a mixed phase space are organized by one-parameter families of elliptic 1d-tori. Such families show prominent bends, gaps, and new branches. We explain these features in terms of bifurcations of the families when crossing a resonance. For these bifurcations, no external parameter has to be varied. Instead, the longitudinal frequency, which varies along the family, plays the role of the bifurcation parameter. As an example, we study two coupled standard maps by visualizing the elliptic and hyperbolic 1d-tori in a 3d phase-space slice, local 2d projections, and frequency space. The observed bifurcations are consistent with the analytical predictions previously obtained for quasi-periodically forced oscillators. Moreover, the new families emerging from such a bifurcation form the skeleton of the corresponding resonance channel.

  18. Localized self-heating in large arrays of 1D nanostructures

    NASA Astrophysics Data System (ADS)

    Monereo, O.; Illera, S.; Varea, A.; Schmidt, M.; Sauerwald, T.; Schütze, A.; Cirera, A.; Prades, J. D.

    2016-02-01

    One dimensional (1D) nanostructures offer a promising path towards highly efficient heating and temperature control in integrated microsystems. The so called self-heating effect can be used to modulate the response of solid state gas sensor devices. In this work, efficient self-heating was found to occur at random networks of nanostructured systems with similar power requirements to highly ordered systems (e.g. individual nanowires, where their thermal efficiency was attributed to the small dimensions of the objects). Infrared thermography and Raman spectroscopy were used to map the temperature profiles of films based on random arrangements of carbon nanofibers during self-heating. Both the techniques demonstrate consistently that heating concentrates in small regions, the here-called ``hot-spots''. On correlating dynamic temperature mapping with electrical measurements, we also observed that these minute hot-spots rule the resistance values observed macroscopically. A physical model of a random network of 1D resistors helped us to explain this observation. The model shows that, for a given random arrangement of 1D nanowires, current spreading through the network ends up defining a set of spots that dominate both the electrical resistance and power dissipation. Such highly localized heating explains the high power savings observed in larger nanostructured systems. This understanding opens a path to design highly efficient self-heating systems, based on random or pseudo-random distributions of 1D nanostructures.One dimensional (1D) nanostructures offer a promising path towards highly efficient heating and temperature control in integrated microsystems. The so called self-heating effect can be used to modulate the response of solid state gas sensor devices. In this work, efficient self-heating was found to occur at random networks of nanostructured systems with similar power requirements to highly ordered systems (e.g. individual nanowires, where their thermal

  19. Channel specific rate constants for reactions of O(1D) with HCl and HBr

    NASA Technical Reports Server (NTRS)

    Wine, P. H.; Wells, J. R.; Ravishankara, A. R.

    1986-01-01

    The absolute rate coefficients and product yields for reactions of O(1D) with HCl(1) and HBr(2) at 287 K are presently determined by means of the time-resolved resonance fluorescence detection of O(3P) and H(2S) in conjunction with pulsed laser photolysis of O3/HX/He mixtures. Total rate coefficients for O(1D) removal are found to be, in units of 10 to the -10th cu cm/molecule per sec, k(1) = 1.50 + or - 0.18 and k(2) 1.48 + or - 0.16; the absolute accuracy of these rate coefficients is estimated to be + or - 20 percent.

  20. Formation of Water Chains on CaO(001): What Drives the 1D Growth?

    PubMed

    Zhao, Xunhua; Shao, Xiang; Fujimori, Yuichi; Bhattacharya, Saswata; Ghiringhelli, Luca M; Freund, Hans-Joachim; Sterrer, Martin; Nilius, Niklas; Levchenko, Sergey V

    2015-04-01

    Formation of partly dissociated water chains is observed on CaO(001) films upon water exposure at 300 K. While morphology and orientation of the 1D assemblies are revealed from scanning tunneling microscopy, their atomic structure is identified with infrared absorption spectroscopy combined with density functional theory calculations. The latter exploit an ab initio genetic algorithm linked to atomistic thermodynamics to determine low-energy H2O configurations on the oxide surface. The development of 1D structures on the C4v symmetric CaO(001) is triggered by symmetry-broken water tetramers and a favorable balance between adsorbate-adsorbate versus adsorbate-surface interactions at the constraint of the CaO lattice parameter.

  1. Measuring Spin-Charge Separation in a 1D Fermi Gas

    NASA Astrophysics Data System (ADS)

    Fry, Jacob A.; Revelle, Melissa C.; Hulet, Randall G.

    2016-05-01

    We present progress on measurement of spin-charge separation in a two-component, strongly interacting, 1D gas of fermionic lithium. A characteristic feature of interacting 1D Fermi gases is that the velocity of a charge excitation propagates faster than a spin excitation. We create an excitation by applying a dipole force at the center of the cloud using a sheet of light. Depending on the detuning of this beam, we can either excite both spin species equally (charge excitation) or preferentially (spin excitation). Once this beam is turned off, the excitations propagate to the edges of the atomic cloud at a velocity determined by coupling strength. A magnetically tuned Feshbach resonance enables us to vary this coupling and map out the velocities of spin and charge excitations. Supported by an ARO MURI Grant, NSF, and The Welch Foundation

  2. The Dmca1D channel mediates Ca(2+) inward currents in Drosophila embryonic muscles.

    PubMed

    Hara, Yusuke; Koganezawa, Masayuki; Yamamoto, Daisuke

    2015-01-01

    We studied, in a genetic model organism, Drosophila melanogaster, the channel mechanisms underlying membrane excitation in the embryonic body wall muscle whose biophysical properties have been poorly characterized. The inward current underlying the action potential was solely mediated by a high-threshold class of voltage-gated Ca(2+) channels, which exhibited slow inactivation, Ca(2+) permeability with saturation at high [Ca(2+)]OUT, and sensitivity to a Ca(2+) channel blocker, Cd(2+). The Ca(2+) current in the embryonic muscle was completely eliminated in Dmca1D mutants, indicating that the Dmca1D-encoded Ca(2+) channel is the major mediator of inward currents in the body wall muscles throughout the embryonic and larval stages. PMID:26004544

  3. Bifurcations of families of 1D-tori in 4D symplectic maps

    NASA Astrophysics Data System (ADS)

    Onken, Franziska; Lange, Steffen; Ketzmerick, Roland; Bäcker, Arnd

    2016-06-01

    The regular structures of a generic 4d symplectic map with a mixed phase space are organized by one-parameter families of elliptic 1d-tori. Such families show prominent bends, gaps, and new branches. We explain these features in terms of bifurcations of the families when crossing a resonance. For these bifurcations, no external parameter has to be varied. Instead, the longitudinal frequency, which varies along the family, plays the role of the bifurcation parameter. As an example, we study two coupled standard maps by visualizing the elliptic and hyperbolic 1d-tori in a 3d phase-space slice, local 2d projections, and frequency space. The observed bifurcations are consistent with the analytical predictions previously obtained for quasi-periodically forced oscillators. Moreover, the new families emerging from such a bifurcation form the skeleton of the corresponding resonance channel.

  4. Membranes having aligned 1-D nanoparticles in a matrix layer for improved fluid separation

    DOEpatents

    Revanur, Ravindra; Lulevich, Valentin; Roh, Il Juhn; Klare, Jennifer E.; Kim, Sangil; Noy, Aleksandr; Bakajin, Olgica

    2015-12-22

    Membranes for fluid separation are disclosed. These membranes have a matrix layer sandwiched between an active layer and a porous support layer. The matrix layer includes 1-D nanoparticles that are vertically aligned in a porous polymer matrix, and which substantially extend through the matrix layer. The active layer provides species-specific transport, while the support layer provides mechanical support. A matrix layer of this type has favorable surface morphology for forming the active layer. Furthermore, the pores that form in the matrix layer tend to be smaller and more evenly distributed as a result of the presence of aligned 1-D nanoparticles. Improved performance of separation membranes of this type is attributed to these effects.

  5. The structure and electronic properties of copper iodide 1D nanocrystals within single walled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Kiselev, N. A.; Kumskov, A. S.; Zhigalina, V. G.; Verbitskiy, N. I.; Yashina, L. V.; Chuvilin, A. L.; Vasiliev, A. L.; Eliseev, A. A.

    2013-11-01

    Copper iodide one-dimensional nanocrystals within single walled carbon nanotubes (1D CuI@SWCNTs), i.e. meta-nanotubes [1], were investigated by high resolution electron microscopy (HRTEM). In meta-nanotubes of diameter Dm = 1.3-1.4 nm produced by arc-discharge (AD) method close-packed hexagonal or deformed cubic 1D crystal anion sublattices were observed with cations in octahedral or tetrahedral positions. These two sublattices reversibly transform to one another. In catalysed chemical vapour deposition (CCVD) meta-nanotubes of diameters Dm = 1.5-2.0 nm cubic anion sublattices are formed. For diameters >=2.0 nm three-dimensional (3D) crystallization is observed.

  6. 1-D seismic velocity model and hypocenter relocation using double difference method around West Papua region

    SciTech Connect

    Sabtaji, Agung E-mail: agung.sabtaji@bmkg.go.id; Nugraha, Andri Dian

    2015-04-24

    West Papua region has fairly high of seismicity activities due to tectonic setting and many inland faults. In addition, the region has a unique and complex tectonic conditions and this situation lead to high potency of seismic hazard in the region. The precise earthquake hypocenter location is very important, which could provide high quality of earthquake parameter information and the subsurface structure in this region to the society. We conducted 1-D P-wave velocity using earthquake data catalog from BMKG for April, 2009 up to March, 2014 around West Papua region. The obtained 1-D seismic velocity then was used as input for improving hypocenter location using double-difference method. The relocated hypocenter location shows fairly clearly the pattern of intraslab earthquake beneath New Guinea Trench (NGT). The relocated hypocenters related to the inland fault are also observed more focus in location around the fault.

  7. A 1D (radial) Plasma Jet Propagation Study for the Plasma Liner Experiment (PLX)

    NASA Astrophysics Data System (ADS)

    Thompson, J. R.; Bogatu, I. N.; Galkin, S. A.; Kim, J. S.; Welch, D. R.; Thoma, C.; Golovkin, I.; Macfarlane, J. J.; Case, A.; Messer, S. J.; Witherspoon, F. D.; Cassibry, J. T.; Awe, T. J.; Hsu, S. C.

    2011-10-01

    The Plasma Liner Experiment will explore the formation of imploding spherical ``plasma liners'' that reach peak pressures of 0.1 Mbar upon stagnation. The liners will be formed through the merging of dense, high velocity plasma jets (n ~1017 cm-3, T ~3 eV, v ~50 km/s) in a spherically convergent geometry. The focus of this 1D (radial) study is argon plasma jet evolution during propagation from the rail gun source to the jet merging radius. The study utilizes the Large Scale Plasma (LSP) PIC code with atomic physics included through the use of a non-Local Thermal Equilibrium (NLTE) Equation of State (EOS) table. We will present scenarios for expected 1D (radial) plasma jet evolution, from upon exiting the PLX rail gun to reaching the jet merging radius. The importance of radiation cooling early in the simulation is highlighted. Work supported by US DOE grant DE-FG02-05ER54835.

  8. Methodology for research II

    PubMed Central

    Bhaskar, S Bala; Manjuladevi, M

    2016-01-01

    Research is a systematic process, which uses scientific methods to generate new knowledge that can be used to solve a query or improve on the existing system. Any research on human subjects is associated with varying degree of risk to the participating individual and it is important to safeguard the welfare and rights of the participants. This review focuses on various steps involved in methodology (in continuation with the previous section) before the data are submitted for publication. PMID:27729691

  9. Fast track evaluation methodology.

    PubMed

    Duke, J R

    1991-06-01

    Evaluating hospital information systems has taken a variety of forms since the initial development and use of automation. The process itself has moved from a hardware-based orientation controlled by data processing professionals to systems solutions and a user-driven process overseen by management. At Harbor Hospital Center in Baltimore, a fast track methodology has been introduced to shorten system evaluation time to meet the rapid changes that constantly affect the healthcare industry.

  10. Darwin's Methodological Evolution.

    PubMed

    Lennox, James G

    2005-01-01

    A necessary condition for having a revolution named after you is that you are an innovator in your field. I argue that if Charles Darwin meets this condition, it is as a philosopher and methodologist. In 1991, I made the case for Darwin's innovative use of "thought experiment" in the Origin. Here I place this innovative practice in the context of Darwin's methodological commitments, trace its origins back into Darwin's notebooks, and pursue Darwin's suggestion that it owes its inspiration to Charles Lyell.

  11. Mosaic PPM1D mutations are associated with predisposition to breast and ovarian cancer.

    PubMed

    Ruark, Elise; Snape, Katie; Humburg, Peter; Loveday, Chey; Bajrami, Ilirjana; Brough, Rachel; Rodrigues, Daniel Nava; Renwick, Anthony; Seal, Sheila; Ramsay, Emma; Duarte, Silvana Del Vecchio; Rivas, Manuel A; Warren-Perry, Margaret; Zachariou, Anna; Campion-Flora, Adriana; Hanks, Sandra; Murray, Anne; Ansari Pour, Naser; Douglas, Jenny; Gregory, Lorna; Rimmer, Andrew; Walker, Neil M; Yang, Tsun-Po; Adlard, Julian W; Barwell, Julian; Berg, Jonathan; Brady, Angela F; Brewer, Carole; Brice, Glen; Chapman, Cyril; Cook, Jackie; Davidson, Rosemarie; Donaldson, Alan; Douglas, Fiona; Eccles, Diana; Evans, D Gareth; Greenhalgh, Lynn; Henderson, Alex; Izatt, Louise; Kumar, Ajith; Lalloo, Fiona; Miedzybrodzka, Zosia; Morrison, Patrick J; Paterson, Joan; Porteous, Mary; Rogers, Mark T; Shanley, Susan; Walker, Lisa; Gore, Martin; Houlston, Richard; Brown, Matthew A; Caufield, Mark J; Deloukas, Panagiotis; McCarthy, Mark I; Todd, John A; Turnbull, Clare; Reis-Filho, Jorge S; Ashworth, Alan; Antoniou, Antonis C; Lord, Christopher J; Donnelly, Peter; Rahman, Nazneen

    2013-01-17

    Improved sequencing technologies offer unprecedented opportunities for investigating the role of rare genetic variation in common disease. However, there are considerable challenges with respect to study design, data analysis and replication. Using pooled next-generation sequencing of 507 genes implicated in the repair of DNA in 1,150 samples, an analytical strategy focused on protein-truncating variants (PTVs) and a large-scale sequencing case-control replication experiment in 13,642 individuals, here we show that rare PTVs in the p53-inducible protein phosphatase PPM1D are associated with predisposition to breast cancer and ovarian cancer. PPM1D PTV mutations were present in 25 out of 7,781 cases versus 1 out of 5,861 controls (P = 1.12 × 10(-5)), including 18 mutations in 6,912 individuals with breast cancer (P = 2.42 × 10(-4)) and 12 mutations in 1,121 individuals with ovarian cancer (P = 3.10 × 10(-9)). Notably, all of the identified PPM1D PTVs were mosaic in lymphocyte DNA and clustered within a 370-base-pair region in the final exon of the gene, carboxy-terminal to the phosphatase catalytic domain. Functional studies demonstrate that the mutations result in enhanced suppression of p53 in response to ionizing radiation exposure, suggesting that the mutant alleles encode hyperactive PPM1D isoforms. Thus, although the mutations cause premature protein truncation, they do not result in the simple loss-of-function effect typically associated with this class of variant, but instead probably have a gain-of-function effect. Our results have implications for the detection and management of breast and ovarian cancer risk. More generally, these data provide new insights into the role of rare and of mosaic genetic variants in common conditions, and the use of sequencing in their identification. PMID:23242139

  12. INFIL1D: a quasi-analytical model for simulating one-dimensional, constant flux infiltration

    SciTech Connect

    Simmons, C.S.; McKeon, T.J.

    1984-04-01

    The program INFIL1D is designed to calculate approximate wetting-front advance into an unsaturated, uniformly moist, homogeneous soil profile, under constant surface-flux conditions. The code is based on a quasi-analytical method, which utilizes an assumed invariant functional relationship between reduced (normalized) flux and water content. The code uses general hydraulic property data in tabular form to simulate constant surface-flux infiltration. 10 references, 4 figures.

  13. Mosaic PPM1D mutations are associated with predisposition to breast and ovarian cancer.

    PubMed

    Ruark, Elise; Snape, Katie; Humburg, Peter; Loveday, Chey; Bajrami, Ilirjana; Brough, Rachel; Rodrigues, Daniel Nava; Renwick, Anthony; Seal, Sheila; Ramsay, Emma; Duarte, Silvana Del Vecchio; Rivas, Manuel A; Warren-Perry, Margaret; Zachariou, Anna; Campion-Flora, Adriana; Hanks, Sandra; Murray, Anne; Ansari Pour, Naser; Douglas, Jenny; Gregory, Lorna; Rimmer, Andrew; Walker, Neil M; Yang, Tsun-Po; Adlard, Julian W; Barwell, Julian; Berg, Jonathan; Brady, Angela F; Brewer, Carole; Brice, Glen; Chapman, Cyril; Cook, Jackie; Davidson, Rosemarie; Donaldson, Alan; Douglas, Fiona; Eccles, Diana; Evans, D Gareth; Greenhalgh, Lynn; Henderson, Alex; Izatt, Louise; Kumar, Ajith; Lalloo, Fiona; Miedzybrodzka, Zosia; Morrison, Patrick J; Paterson, Joan; Porteous, Mary; Rogers, Mark T; Shanley, Susan; Walker, Lisa; Gore, Martin; Houlston, Richard; Brown, Matthew A; Caufield, Mark J; Deloukas, Panagiotis; McCarthy, Mark I; Todd, John A; Turnbull, Clare; Reis-Filho, Jorge S; Ashworth, Alan; Antoniou, Antonis C; Lord, Christopher J; Donnelly, Peter; Rahman, Nazneen

    2013-01-17

    Improved sequencing technologies offer unprecedented opportunities for investigating the role of rare genetic variation in common disease. However, there are considerable challenges with respect to study design, data analysis and replication. Using pooled next-generation sequencing of 507 genes implicated in the repair of DNA in 1,150 samples, an analytical strategy focused on protein-truncating variants (PTVs) and a large-scale sequencing case-control replication experiment in 13,642 individuals, here we show that rare PTVs in the p53-inducible protein phosphatase PPM1D are associated with predisposition to breast cancer and ovarian cancer. PPM1D PTV mutations were present in 25 out of 7,781 cases versus 1 out of 5,861 controls (P = 1.12 × 10(-5)), including 18 mutations in 6,912 individuals with breast cancer (P = 2.42 × 10(-4)) and 12 mutations in 1,121 individuals with ovarian cancer (P = 3.10 × 10(-9)). Notably, all of the identified PPM1D PTVs were mosaic in lymphocyte DNA and clustered within a 370-base-pair region in the final exon of the gene, carboxy-terminal to the phosphatase catalytic domain. Functional studies demonstrate that the mutations result in enhanced suppression of p53 in response to ionizing radiation exposure, suggesting that the mutant alleles encode hyperactive PPM1D isoforms. Thus, although the mutations cause premature protein truncation, they do not result in the simple loss-of-function effect typically associated with this class of variant, but instead probably have a gain-of-function effect. Our results have implications for the detection and management of breast and ovarian cancer risk. More generally, these data provide new insights into the role of rare and of mosaic genetic variants in common conditions, and the use of sequencing in their identification.

  14. Development of a hybrid deterministic/stochastic method for 1D nuclear reactor kinetics

    SciTech Connect

    Terlizzi, Stefano; Dulla, Sandra; Ravetto, Piero; Rahnema, Farzad; Zhang, Dingkang

    2015-12-31

    A new method has been implemented for solving the time-dependent neutron transport equation efficiently and accurately. This is accomplished by coupling the hybrid stochastic-deterministic steady-state coarse-mesh radiation transport (COMET) method [1,2] with the new predictor-corrector quasi-static method (PCQM) developed at Politecnico di Torino [3]. In this paper, the coupled method is implemented and tested in 1D slab geometry.

  15. Transfer Matrix Approach to 1d Random Band Matrices: Density of States

    NASA Astrophysics Data System (ADS)

    Shcherbina, Mariya; Shcherbina, Tatyana

    2016-08-01

    We study the special case of n× n 1D Gaussian Hermitian random band matrices, when the covariance of the elements is determined by the matrix J=(-W^2triangle +1)^{-1} . Assuming that n≥ CW log W≫ 1 , we prove that the averaged density of states coincides with the Wigner semicircle law up to the correction of order W^{-1}.

  16. Mosaic PPM1D mutations are associated with predisposition to breast and ovarian cancer

    PubMed Central

    Ruark, Elise; Snape, Katie; Humburg, Peter; Loveday, Chey; Bajrami, Ilirjana; Brough, Rachel; Rodrigues, Daniel Nava; Renwick, Anthony; Seal, Sheila; Ramsay, Emma; Duarte, Silvana Del Vecchio; Rivas, Manuel A.; Warren-Perry, Margaret; Zachariou, Anna; Campion-Flora, Adriana; Hanks, Sandra; Murray, Anne; Pour, Naser Ansari; Douglas, Jenny; Gregory, Lorna; Rimmer, Andrew; Walker, Neil M.; Yang, Tsun-Po; Adlard, Julian W.; Barwell, Julian; Berg, Jonathan; Brady, Angela F.; Brewer, Carole; Brice, Glen; Chapman, Cyril; Cook, Jackie; Davidson, Rosemarie; Donaldson, Alan; Douglas, Fiona; Eccles, Diana; Evans, D. Gareth; Greenhalgh, Lynn; Henderson, Alex; Izatt, Louise; Kumar, Ajith; Lalloo, Fiona; Miedzybrodzka, Zosia; Morrison, Patrick J.; Paterson, Joan; Porteous, Mary; Rogers, Mark T.; Shanley, Susan; Walker, Lisa; Gore, Martin; Houlston, Richard; Brown, Matthew A.; Caufield, Mark J.; Deloukas, Panagiotis; McCarthy, Mark I.; Todd, John A.; Turnbull, Clare; Reis-Filho, Jorge S.; Ashworth, Alan; Antoniou, Antonis C.; Lord, Christopher J.; Donnelly, Peter; Rahman, Nazneen

    2013-01-01

    Improved sequencing technologies offer unprecedented opportunities for investigating the role of rare genetic variation in common disease. However, there are considerable challenges with respect to study design, data analysis and replication1. Here, using pooled next-generation sequencing of 507 genes implicated in the repair of DNA in 1,150 samples, an analytical strategy focussed on protein truncating variants (PTVs) and a large-scale sequencing case-control replication experiment in 13,642 individuals, we show that rare PTVs in the p53 inducible protein phosphatase PPM1D are associated with predisposition to breast cancer and to ovarian cancer. PPM1D PTV mutations were present in 25/7781 cases vs 1/5861 controls; P=1.12×10−5, which included 18 mutations in 6,912 individuals with breast cancer; P = 2.42×10−4 and 12 mutations in 1,121 individuals with ovarian cancer; P = 3.10×10−9. Notably, all the identified PPM1D PTVs were mosaic in lymphocyte DNA and clustered within a 370 bp region in the final exon of the gene, C-terminal to the phosphatase catalytic domain. Functional studies demonstrated that the mutations result in enhanced suppression of p53 in response to ionising radiation exposure, suggesting the mutant alleles encode hyperactive PPM1D isoforms. Thus, although the mutations cause premature protein truncation, they do not result in the simple loss-of-function typically associated with this class of variant, but instead likely have a gain-of-function effect. Our results have implications for the detection and management of breast and ovarian cancer risk. More generally, these data provide new insights into the role of rare and of mosaic genetic variants in common conditions, and the utility of sequencing in their identification. PMID:23242139

  17. Discontinuous Galerkin finite element method applied to the 1-D spherical neutron transport equation

    SciTech Connect

    Machorro, Eric . E-mail: machorro@amath.washington.edu

    2007-04-10

    Discontinuous Galerkin finite element methods are used to estimate solutions to the non-scattering 1-D spherical neutron transport equation. Various trial and test spaces are compared in the context of a few sample problems whose exact solution is known. Certain trial spaces avoid unphysical behaviors that seem to plague other methods. Comparisons with diamond differencing and simple corner-balancing are presented to highlight these improvements.

  18. Subscale study of engine bellmouth inlet vortices in test cell R1D

    NASA Astrophysics Data System (ADS)

    Reed, James A.; Hiers, Robert S., Jr.

    1995-05-01

    A technology program was conducted in Test Cell R1D concerning bellmouth flow quality. Flow visualization was used to determine the presence of inlet vortices. It was shown that these vortices can be eliminated using a 45-deg conical extension attached to the bellmouth inlet. Design guidelines were developed to assist in determining acceptable cone angles and axial and radial gaps between the conical extension and the bellmouth inlet.

  19. Scattering coefficients and gray-body factor for 1D BEC acoustic black holes: Exact results

    NASA Astrophysics Data System (ADS)

    Fabbri, Alessandro; Balbinot, Roberto; Anderson, Paul R.

    2016-03-01

    A complete set of exact analytic solutions to the mode equation is found in the region exterior to the acoustic horizon for a class of 1D Bose-Einstein condensate acoustic black holes. From these, analytic expressions for the scattering coefficients and gray-body factor are obtained. The results are used to verify previous predictions regarding the behaviors of the scattering coefficients and gray-body factor in the low-frequency limit.

  20. Regulation of anthocyanin biosynthesis in Arabidopsis thaliana red pap1-D cells metabolically programmed by auxins.

    PubMed

    Liu, Zhong; Shi, Ming-Zhu; Xie, De-Yu

    2014-04-01

    Red pap1-D cells of Arabidopsis thaliana have been cloned from production of anthocyanin pigmentation 1-Dominant (pap1-D) plants. The red cells are metabolically programmed to produce high levels of anthocyanins by a WD40-bHLH-MYB complex that is composed of the TTG1, TT8/GL3 and PAP1 transcription factors. Here, we report that indole 3-acetic acid (IAA), naphthaleneacetic acid (NAA) and 2,4-dichlorophenoxyacetic acid (2,4-D) regulate anthocyanin biosynthesis in these red cells. Seven concentrations (0, 0.2, 0.4, 2.2, 9, 18 and 27 μM) were tested for the three auxins. IAA and 2,4-D at 2.2-27 μM reduced anthocyanin levels. NAA at 0-0.2 μM or above 9 μM also decreased anthocyanin levels, but from 0.4 to 9 μM, it increased them. HPLC-ESI-MS analysis identified seven cyanin molecules that were produced in red pap1-D cells, and their levels were affected by auxins. The expression levels of ten genes, including six transcription factors (TTG1, EGL3, MYBL2, TT8, GL3 and PAP1) and four pathway genes (PAL1, CHS, DFR and ANS) involved in anthocyanin biosynthesis were analyzed upon various auxin treatments. The resulting data showed that 2,4-D, NAA and IAA control anthocyanin biosynthesis by regulating the expression of TT8, GL3 and PAP1 as well as genes in the anthocyanin biosynthetic pathway, such as DFR and ANS. In addition, the expression of MYBL2, PAL1 and CHS in red pap1-D and wild-type cells differentially respond to the three auxins. Our data demonstrate that the three auxins regulate anthocyanin biosynthesis in metabolically programmed red cells via altering the expression of transcription factor genes and pathway genes. PMID:24370633

  1. Development of a hybrid deterministic/stochastic method for 1D nuclear reactor kinetics

    NASA Astrophysics Data System (ADS)

    Terlizzi, Stefano; Rahnema, Farzad; Zhang, Dingkang; Dulla, Sandra; Ravetto, Piero

    2015-12-01

    A new method has been implemented for solving the time-dependent neutron transport equation efficiently and accurately. This is accomplished by coupling the hybrid stochastic-deterministic steady-state coarse-mesh radiation transport (COMET) method [1,2] with the new predictor-corrector quasi-static method (PCQM) developed at Politecnico di Torino [3]. In this paper, the coupled method is implemented and tested in 1D slab geometry.

  2. A 1D exact treatment of shock waves within spectral methods in plane geometry

    NASA Astrophysics Data System (ADS)

    Bonazzola, Silvano; Marck, Jean-Alain

    1991-12-01

    A high-accuracy numerical technique is presented which employs two moving grids, respectively before and after the shock formation, to solve 1D Euler equations that are coupled with the transport equations for the entropy and the chemical abundances in cases with and without shock formation. Chebychev polynomial series are used to expand quantities on both sides of the matching point, and Rankine-Hugoniot conditions are used to ascertain the shock velocity after shock formation. Illustrative results are presented.

  3. Uranium(VI) coordination polymers with pyromellitate ligand: Unique 1D channel structures and diverse fluorescence

    SciTech Connect

    Zhang, Yingjie; Bhadbhade, Mohan; Karatchevtseva, Inna; Price, Jason R.; Liu, Hao; Zhang, Zhaoming; Kong, Linggen; Čejka, Jiří; Lu, Kim; Lumpkin, Gregory R.

    2015-03-15

    Three new coordination polymers of uranium(VI) with pyromellitic acid (H{sub 4}btca) have been synthesized and structurally characterized. (ED)[(UO{sub 2})(btca)]·(DMSO)·3H{sub 2}O (1) (ED=ethylenediammonium; DMSO=dimethylsulfoxide) has a lamellar structure with intercalation of ED and DMSO. (NH{sub 4}){sub 2}[(UO{sub 2}){sub 6}O{sub 2}(OH){sub 6}(btca)]·~6H{sub 2}O (2) has a 3D framework built from 7-fold coordinated uranyl trinuclear units and btca ligands with 1D diamond-shaped channels (~8.5 Å×~8.6 Å). [(UO{sub 2}){sub 2}(H{sub 2}O)(btca)]·4H{sub 2}O (3) has a 3D network constructed by two types of 7-fold coordinated uranium polyhedron. The unique μ{sub 5}-coordination mode of btca in 3 enables the formation of 1D olive-shaped large channels (~4.5 Å×~19 Å). Vibrational modes, thermal stabilities and fluorescence properties have been investigated. - Graphical abstract: Table of content: three new uranium(VI) coordination polymers with pyromellitic acid (H{sub 4}btca) have been synthesized via room temperature and hydrothermal synthesis methods, and structurally characterized. Two to three dimensional (3D) frameworks are revealed. All 3D frameworks have unique 1D large channels. Their vibrational modes, thermal stabilities and photoluminescence properties have been investigated. - Highlights: • Three new coordination polymers of U(VI) with pyromellitic acid (H{sub 4}btca). • Structures from a 2D layer to 3D frameworks with unique 1D channels. • Unusual µ{sub 5}-(η{sub 1}:η{sub 2}:η{sub 1}:η{sub 2:}η{sub 1}) coordination mode of btca ligand. • Vibrational modes, thermal stabilities and luminescent properties reported.

  4. EXTENSION OF THE 1D FOUR-GROUP ANALYTIC NODAL METHOD TO FULL MULTIGROUP

    SciTech Connect

    B. D. Ganapol; D. W. Nigg

    2008-09-01

    In the mid 80’s, a four-group/two-region, entirely analytical 1D nodal benchmark appeared. It was readily acknowledged that this special case was as far as one could go in terms of group number and still achieve an analytical solution. In this work, we show that by decomposing the solution to the multigroup diffusion equation into homogeneous and particular solutions, extension to any number of groups is a relatively straightforward exercise using the mathematics of linear algebra.

  5. Zero finite-temperature charge stiffness within the half-filled 1D Hubbard model

    SciTech Connect

    Carmelo, J.M.P.; Gu, Shi-Jian; Sacramento, P.D.

    2013-12-15

    Even though the one-dimensional (1D) Hubbard model is solvable by the Bethe ansatz, at half-filling its finite-temperature T>0 transport properties remain poorly understood. In this paper we combine that solution with symmetry to show that within that prominent T=0 1D insulator the charge stiffness D(T) vanishes for T>0 and finite values of the on-site repulsion U in the thermodynamic limit. This result is exact and clarifies a long-standing open problem. It rules out that at half-filling the model is an ideal conductor in the thermodynamic limit. Whether at finite T and U>0 it is an ideal insulator or a normal resistor remains an open question. That at half-filling the charge stiffness is finite at U=0 and vanishes for U>0 is found to result from a general transition from a conductor to an insulator or resistor occurring at U=U{sub c}=0 for all finite temperatures T>0. (At T=0 such a transition is the quantum metal to Mott–Hubbard-insulator transition.) The interplay of the η-spin SU(2) symmetry with the hidden U(1) symmetry beyond SO(4) is found to play a central role in the unusual finite-temperature charge transport properties of the 1D half-filled Hubbard model. -- Highlights: •The charge stiffness of the half-filled 1D Hubbard model is evaluated. •Its value is controlled by the model symmetry operator algebras. •We find that there is no charge ballistic transport at finite temperatures T>0. •The hidden U(1) symmetry controls the U=0 phase transition for T>0.

  6. Piezo-semiconductive quasi-1D nanodevices with or without anti-symmetry.

    PubMed

    Araneo, Rodolfo; Lovat, Giampiero; Burghignoli, Paolo; Falconi, Christian

    2012-09-01

    The piezopotential in floating, homogeneous, quasi-1D piezo-semiconductive nanostructures under axial stress is an anti-symmetric (i.e., odd) function of force. Here, after introducing piezo-nano-devices with floating electrodes for maximum piezo-potential, we show that breaking the anti-symmetric nature of the piezopotential-force relation, for instance by using conical nanowires, can lead to better nanogenerators, piezotronic and piezophototronic devices.

  7. Transfer Matrix Approach to 1d Random Band Matrices: Density of States

    NASA Astrophysics Data System (ADS)

    Shcherbina, Mariya; Shcherbina, Tatyana

    2016-09-01

    We study the special case of n× n 1D Gaussian Hermitian random band matrices, when the covariance of the elements is determined by the matrix J=(-W^2triangle +1)^{-1}. Assuming that n≥ CW log W≫ 1, we prove that the averaged density of states coincides with the Wigner semicircle law up to the correction of order W^{-1}.

  8. Construction and Functions of Cyclodextrin-Based 1D Supramolecular Strands and their Secondary Assemblies.

    PubMed

    Chen, Yong; Liu, Yu

    2015-09-23

    Cyclodextrins (CDs), a class of cyclic oligosaccharides, are water-soluble, nontoxic, and commercial available with a low price, and their well-defined hydrophobic cavity can bind various organic/biological substrates. Through their molecular assembly mediated by organic, inorganic, or polymeric molecules as templates, CDs and their functional derivatives can be assembled to 1D supramolecular strands, wherein the functional groups of the CDs are closely located in a highly ordered manner. This structural feature greatly favors the cooperative effect of numerous functional groups in the supramolecular strand, as well as the interactions of the supramolecular strands with the multiple binding sites of substrates, especially biological substrates. Therefore, CD-based 1D supramolecular strands exhibit many material, biological, and catalytic functions, and these properties can be further improved through their secondary assembly. An overview of recent advances in the development of the construction and functions of CD-based 1D supramolecular strands and their secondary assemblies is given here. It is expected that the representative contributions described can inspire future investigations and lead to discoveries that promote the research of CD-based functional materials. PMID:26270410

  9. Numerical Modeling of Imploding Plasma liners Using the 1D Radiation-Hydrodynamics Code HELIOS

    NASA Astrophysics Data System (ADS)

    Davis, J. S.; Hanna, D. S.; Awe, T. J.; Hsu, S. C.; Stanic, M.; Cassibry, J. T.; Macfarlane, J. J.

    2010-11-01

    The Plasma Liner Experiment (PLX) is attempting to form imploding plasma liners to reach 0.1 Mbar upon stagnation, via 30--60 spherically convergent plasma jets. PLX is partly motivated by the desire to develop a standoff driver for magneto-inertial fusion. The liner density, atomic makeup, and implosion velocity will help determine the maximum pressure that can be achieved. This work focuses on exploring the effects of atomic physics and radiation on the 1D liner implosion and stagnation dynamics. For this reason, we are using Prism Computational Science's 1D Lagrangian rad-hydro code HELIOS, which has both equation of state (EOS) table-lookup and detailed configuration accounting (DCA) atomic physics modeling. By comparing a series of PLX-relevant cases proceeding from ideal gas, to EOS tables, to DCA treatments, we aim to identify how and when atomic physics effects are important for determining the peak achievable stagnation pressures. In addition, we present verification test results as well as brief comparisons to results obtained with RAVEN (1D radiation-MHD) and SPHC (smoothed particle hydrodynamics).

  10. Resonance Raman Spectroscopy of Extreme Nanowires and Other 1D Systems.

    PubMed

    Smith, David C; Spencer, Joseph H; Sloan, Jeremy; McDonnell, Liam P; Trewhitt, Harrison; Kashtiban, Reza J; Faulques, Eric

    2016-01-01

    This paper briefly describes how nanowires with diameters corresponding to 1 to 5 atoms can be produced by melting a range of inorganic solids in the presence of carbon nanotubes. These nanowires are extreme in the sense that they are the limit of miniaturization of nanowires and their behavior is not always a simple extrapolation of the behavior of larger nanowires as their diameter decreases. The paper then describes the methods required to obtain Raman spectra from extreme nanowires and the fact that due to the van Hove singularities that 1D systems exhibit in their optical density of states, that determining the correct choice of photon excitation energy is critical. It describes the techniques required to determine the photon energy dependence of the resonances observed in Raman spectroscopy of 1D systems and in particular how to obtain measurements of Raman cross-sections with better than 8% noise and measure the variation in the resonance as a function of sample temperature. The paper describes the importance of ensuring that the Raman scattering is linearly proportional to the intensity of the laser excitation intensity. It also describes how to use the polarization dependence of the Raman scattering to separate Raman scattering of the encapsulated 1D systems from those of other extraneous components in any sample. PMID:27168195

  11. Dynamics of the reactions of O(1D) with HCl, DCl, and Cl2

    NASA Astrophysics Data System (ADS)

    Matsumi, Yutaka; Tonokura, Kenichi; Kawasaki, Masahiro; Tsuji, Kazuhide; Obi, Kinichi

    1993-05-01

    The reactions O(1D)+HCl→OH+Cl (1a) and OCl+H (1b), O(1D)+DCl→OD+Cl (2a) and OCl+D (2b), and O(1D)+Cl2→OCl+Cl (3) are studied at an average collision energy of 7.6, 7.7, and 8.8 kcal/mol for (1), (2), and (3), respectively. H, D, and Cl atoms are detected by the resonance-enhanced multiphoton ionization technique. The average kinetic energies released to the products are estimated from Doppler profile measurements of the product atoms. The relative yields [OCl+H]/[OH+Cl] and [OCl+D]/[OD+Cl] are directly measured, and a strong isotope effect (H/D) on the relative yields is found. The fine-structure branding ratios [Cl(2P1/2]/[Cl(2P3/2)] of the reaction products are also measured. The results suggest that nonadiabatic couplings take place at the exit channels of the reactions (1a) and (2a), while the reaction (3) is totally adiabatic.

  12. Resonance Raman Spectroscopy of Extreme Nanowires and Other 1D Systems

    PubMed Central

    Smith, David C.; Spencer, Joseph H.; Sloan, Jeremy; McDonnell, Liam P.; Trewhitt, Harrison; Kashtiban, Reza J.; Faulques, Eric

    2016-01-01

    This paper briefly describes how nanowires with diameters corresponding to 1 to 5 atoms can be produced by melting a range of inorganic solids in the presence of carbon nanotubes. These nanowires are extreme in the sense that they are the limit of miniaturization of nanowires and their behavior is not always a simple extrapolation of the behavior of larger nanowires as their diameter decreases. The paper then describes the methods required to obtain Raman spectra from extreme nanowires and the fact that due to the van Hove singularities that 1D systems exhibit in their optical density of states, that determining the correct choice of photon excitation energy is critical. It describes the techniques required to determine the photon energy dependence of the resonances observed in Raman spectroscopy of 1D systems and in particular how to obtain measurements of Raman cross-sections with better than 8% noise and measure the variation in the resonance as a function of sample temperature. The paper describes the importance of ensuring that the Raman scattering is linearly proportional to the intensity of the laser excitation intensity. It also describes how to use the polarization dependence of the Raman scattering to separate Raman scattering of the encapsulated 1D systems from those of other extraneous components in any sample. PMID:27168195

  13. Secure information embedding into 1D biomedical signals based on SPIHT.

    PubMed

    Rubio, Oscar J; Alesanco, Alvaro; García, José

    2013-08-01

    This paper proposes an encoding system for 1D biomedical signals that allows embedding metadata and provides security and privacy. The design is based on the analysis of requirements for secure and efficient storage, transmission and access to medical tests in e-health environment. This approach uses the 1D SPIHT algorithm to compress 1D biomedical signals with clinical quality, metadata embedding in the compressed domain to avoid extra distortion, digital signature to implement security and attribute-level encryption to support Role-Based Access Control. The implementation has been extensively tested using standard electrocardiogram and electroencephalogram databases (MIT-BIH Arrhythmia, MIT-BIH Compression and SCCN-EEG), demonstrating high embedding capacity (e.g. 3 KB in resting ECGs, 200 KB in stress tests, 30 MB in ambulatory ECGs), short delays (2-3.3s in real-time transmission) and compression of the signal (by ≃3 in real-time transmission, by ≃5 in offline operation) despite of the embedding of security elements and metadata to enable e-health services.

  14. E-beam to complement optical lithography for 1D layouts

    NASA Astrophysics Data System (ADS)

    Lam, David K.; Liu, Enden D.; Smayling, Michael C.; Prescop, Ted

    2011-04-01

    The semiconductor industry is moving to highly regular designs, or 1D gridded layouts, to enable scaling to advanced nodes, as well as improve process latitude, chip size and chip energy consumption. The fabrication of highly regular ICs is straightforward. Poly and metal layers are arranged into 1D layouts. These 1D layouts facilitate a two-step patterning approach: a line-creation step, followed by a line-cutting step, to form the desired IC pattern (See Figure 1). The first step, line creation, can be accomplished with a variety of lithography techniques including 193nm immersion (193i) and Self-Aligned Double Patterning (SADP). It appears feasible to create unidirectional parallel lines to at least 11 nm half-pitch, with two applications of SADP for pitch division by four. Potentially, this step can also be accomplished with interference lithography or directed self assembly in the future. The second step, line cutting, requires an extremely high-resolution lithography technique. At advanced nodes, the only options appear to be the costly quadruple patterning with 193i, or EUV or E-Beam Lithography (EBL). This paper focuses on the requirements for a lithography system for "line cutting", using EBL to complement Optical. EBL is the most cost-effective option for line cutting at advanced nodes for HVM.

  15. NMR 1D-imaging of water infiltration into mesoporous matrices.

    PubMed

    Le Feunteun, Steven; Diat, Olivier; Guillermo, Armel; Poulesquen, Arnaud; Podor, Renaud

    2011-04-01

    It is shown that coupling nuclear magnetic resonance (NMR) 1D-imaging with the measure of NMR relaxation times and self-diffusion coefficients can be a very powerful approach to investigate fluid infiltration into porous media. Such an experimental design was used to study the very slow seeping of pure water into hydrophobic materials. We consider here three model samples of nuclear waste conditioning matrices which consist in a dispersion of NaNO(3) (highly soluble) and/or BaSO(4) (poorly soluble) salt grains embedded in a bitumen matrix. Beyond studying the moisture progression according to the sample depth, we analyze the water NMR relaxation times and self-diffusion coefficients along its 1D-concentration profile to obtain spatially resolved information on the solution properties and on the porous structure at different scales. It is also shown that, when the relaxation or self-diffusion properties are multimodal, the 1D-profile of each water population is recovered. Three main levels of information were disclosed along the depth-profiles. They concern (i) the water uptake kinetics, (ii) the salinity and the molecular dynamics of the infiltrated solutions and (iii) the microstructure of the water-filled porosities: open networks coexisting with closed pores. All these findings were fully validated and enriched by NMR cryoporometry experiments and by performing environmental scanning electronic microscopy observations. Surprisingly, results clearly show that insoluble salts enhance the water progression and thereby increase the capability of the material to uptake water.

  16. Neutronic analysis of the 1D and 1E banks reflux detection system

    SciTech Connect

    Blanchard, A.

    1999-12-21

    Two H Canyon neutron monitoring systems for early detection of postulated abnormal reflux conditions in the Second Uranium Cycle 1E and 1D Mixer-Settle Banks have been designed and built. Monte Carlo neutron transport simulations using the general purpose, general geometry, n-particle MCNP code have been performed to model expected response of the monitoring systems to varying conditions.The confirmatory studies documented herein conclude that the 1E and 1D neutron monitoring systems are able to achieve adequate neutron count rates for various neutron source and detector configurations, thereby eliminating excessive integration count time. Neutron count rate sensitivity studies are also performed. Conversely, the transport studies concluded that the neutron count rates are statistically insensitive to nitric acid content in the aqueous region and to the transition region length. These studies conclude that the 1E and 1D neutron monitoring systems are able to predict the postulated reflux conditions for all examined perturbations in the neutron source and detector configurations. In the cases examined, the relative change in the neutron count rates due to postulated transitions from normal {sup 235}U concentration levels to reflux levels remain satisfactory detectable.

  17. Measuring the Speed of Sound in a 1D Fermi Gas

    NASA Astrophysics Data System (ADS)

    Fry, Jacob; Revelle, Melissa; Hulet, Randall

    2016-05-01

    We report measurements of the speed of sound in a two-spin component, 1D gas of fermionic lithium. The 1D system is an array of one-dimensional tubes created by a 2D optical lattice. By increasing the lattice depth, the tunneling between tubes is sufficiently small to make each an independent 1D system. To measure the speed of sound, we create a density notch at the center of the atom cloud using a sheet of light tuned far from resonance. The dipole force felt by both spin states will be equivalent, so this notch can be thought of as a charge excitation. Once this beam is turned off, the notch propagates to the edge of the atomic cloud with a velocity that depends on the strength of interatomic interactions. We control interactions using a magnetically tuned Feshbach resonance, allowing us to measure the speed of sound over a wide range of interaction. This method may be used to extract the Luttinger parameter vs. interaction strength. Supported by an ARO MURI Grant, NSF, and The Welch Foundation.

  18. Mechanisms of action of the 5-HT1B/1D receptor agonists.

    PubMed

    Tepper, Stewart J; Rapoport, Alan M; Sheftell, Fred D

    2002-07-01

    Recent studies of the pathophysiology of migraine provide evidence that the headache phase is associated with multiple physiologic actions. These actions include the release of vasoactive neuropeptides by the trigeminovascular system, vasodilation of intracranial extracerebral vessels, and increased nociceptive neurotransmission within the central trigeminocervical complex. The 5-HT(1B/1D) receptor agonists, collectively known as triptans, are a major advance in the treatment of migraine. The beneficial effects of the triptans in patients with migraine are related to their multiple mechanisms of action at sites implicated in the pathophysiology of migraine. These mechanisms are mediated by 5-HT(1B/1D) receptors and include vasoconstriction of painfully dilated cerebral blood vessels, inhibition of the release of vasoactive neuropeptides by trigeminal nerves, and inhibition of nociceptive neurotransmission. The high affinity of the triptans for 5-HT(1B/1D) receptors and their favorable pharmacologic properties contribute to the beneficial effects of these drugs, including rapid onset of action, effective relief of headache and associated symptoms, and low incidence of adverse effects. PMID:12117355

  19. Reversible interconversion of a divalent vanadium bronze between δ and β quasi-1D structures.

    PubMed

    Marley, Peter M; Banerjee, Sarbajit

    2012-05-01

    Charge fluctuations along the quasi-1D frameworks of M(x)V(2)O(5) bronzes have evinced much recent interest owing to the manifestation of colossal metal-insulator transitions and superconductivity. Depending upon the nature of the intercalating cation (M), distinctive geometries of the V(2)O(5) framework are accessible. Herein, we demonstrate an unprecedented reversible transformation between double-layered (δ) and tunnel (β) quasi-1D geometries for nanowires of a divalent vanadium bronze, Ca(x)V(2)O(5) (x ≈ 0.23), upon annealing-induced dehydration and hydrothermally induced hydration. Such a facile hydration/dehydration-induced interconversion between two prominent quasi-1D structures (accompanied by a change in charge-ordering motifs) has not been observed in the bulk and is posited to result from the ease of propagation of crystallographic slip processes across the confined nanowire widths for the δ → β conversion and the facile diffusion of water molecules within the tunnel geometries for the β → δ reversion.

  20. Realizing 1-D conducting channel between oppositely gated regions in bilayer graphene

    NASA Astrophysics Data System (ADS)

    Lee, Janghee; Watanabe, Kenji; Taniguchi, Takashi; Lee, Hu-Jong

    The band gap of bilayer graphene (BLG) can be tuned by applying an external electric field perpendicular to the plane of a BLG sheet. If direction of the electric fields in two adjacent regions in BLG are opposite, one-dimensional (1-D) conducting channel emerges at the boundary between two regions with chiral nature. In this presentation, we introduce a method for fabricating two pairs of split-gates attached to BLG, which is sandwiched between two atomically clean hexagonal boron nitride (h-BN) single crystals and thus allows ballistic transport of carriers at least within the device size. Current-voltage characteristics show a large transport gap, which is comparable to the results obtained from optical measurements and numerical calculations. Opening the band gap in two adjacent regions of the BLG flake by oppositely gated electric fields, we observed metallic behavior in transport characteristics along the boundary between the two regions although the resistance of two gapped regions are a few hundreds of k Ω. These results indicate that a 1-D conducting channel formed between the two regions where the induced band gaps were inverted to each other. The formation of this 1-D conducting channel mimics the topological edge conducting channels emerging at the boundary of a two-dimensional topological insulator and may be utilized for applying BLG to valleytronics

  1. Study of phase transformation and crystal structure for 1D carbon-modified titania ribbons

    SciTech Connect

    Zhou, Lihui Zhang, Fang; Li, Jinxia

    2014-02-15

    One-dimensional hydrogen titanate ribbons were successfully prepared with hydrothermal reaction in a highly basic solution. A series of one-dimensional carbon-modified TiO{sub 2} ribbons were prepared via calcination of the mixture of hydrogen titanate ribbons and sucrose solution under N{sub 2} flow at different temperatures. The phase transformation process of hydrogen titanate ribbons was investigated by in-situ X-ray diffraction at various temperatures. Besides, one-dimensional carbon-modified TiO{sub 2} ribbons calcined at different temperatures were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, nitrogen adsorption isotherms, diffuse reflectance ultraviolet–visible spectroscopy, and so on. Carbon-modified TiO{sub 2} ribbons showed one-dimensional ribbon crystal structure and various crystal phases of TiO{sub 2}. After being modified with carbon, a layer of uniform carbon film was coated on the surface of TiO{sub 2} ribbons, which improved their adsorption capacity for methyl orange as a model organic pollutant. One-dimensional carbon-modified TiO{sub 2} ribbons also exhibited enhanced visible-light absorbance with the increase of calcination temperatures. - Highlights: • The synthesis of 1D carbon-modified TiO{sub 2} ribbons. • The phase transformation of 1D carbon-modified TiO{sub 2} ribbons. • 1D carbon-modified TiO{sub 2} exhibites enhanced visible-light absorbance.

  2. Toward a consistent use of overshooting parametrizations in 1D stellar evolution codes

    NASA Astrophysics Data System (ADS)

    Viallet, M.; Meakin, C.; Prat, V.; Arnett, D.

    2015-08-01

    Several parametrizations for overshooting in 1D stellar evolution calculations coexist in the literature. These parametrizations are used somewhat arbitrarily in stellar evolution codes, based on what works best for a given problem or even for the historical reasons related to the development of each code. We point out that these different parametrizations correspond to different physical regimes of overshooting, depending on whether the effects of radiation are dominant, marginal, or negligible. Our analysis is based on previously published theoretical results, as well as on multidimensional hydrodynamical simulations of stellar convection where the interaction between the convective region and a stably stratified region is observed. Although the underlying hydrodynamical processes are the same, the outcome of the overshooting process is profoundly affected by radiative effects. Using a simple picture of the scales involved in the overshooting process, we show how three regimes are obtained, depending on the importance of radiative effects. These three regimes correspond to the different behaviors observed in hydrodynamical simulations so far and to the three types of parametrizations used in 1D codes. We suggest that the existing parametrizations for overshooting should coexist in 1D stellar evolution codes and should be applied consistently at convective boundaries depending on the local physical conditions.

  3. Altered expression profile of renal α(1D)-adrenergic receptor in diabetes and its modulation by PPAR agonists.

    PubMed

    Zhao, Xueying; Zhang, Yuanyuan; Leander, Michelle; Li, Lingyun; Wang, Guoshen; Emmett, Nerimiah

    2014-01-01

    Alpha(1D)-adrenergic receptor (α(1D)-AR) plays important roles in regulating physiological and pathological responses mediated by catecholamines, particularly in the cardiovascular and urinary systems. The present study was designed to investigate the expression profile of α(1D)-AR in the diabetic kidneys and its modulation by activation of peroxisome proliferator-activated receptors (PPARs). 12-week-old Zucker lean (ZL) and Zucker diabetic fatty (ZD) rats were treated with fenofibrate or rosiglitazone for 8-10 weeks. Gene microarray, real-time PCR, and confocal immunofluorescence microscopy were performed to assess mRNA and protein expression of α(1D)-AR in rat kidney tissue. Using microarray, we found that α(1D)-AR gene was dramatically upregulated in 22-week-old ZD rats compared to ZL controls. Quantitative PCR analysis verified a 16-fold increase in α(1D)-AR mRNA in renal cortex from ZD animals compared to normal controls. Chronic treatment with fenofibrate or rosiglitazone reduced renal cortical α(1D)-AR gene. Immunofluorescence staining confirmed that α(1D)-AR protein was induced in the glomeruli and tubules of diabetic rats. Moreover, dual immunostaining for α(1D)-AR and kidney injury molecule-1 indicated that α(1D)-AR was expressed in dedifferentiated proximal tubules of diabetic Zucker rats. Taken together, our results show that α(1D)-AR expression is upregulated in the diabetic kidneys. PPAR activation suppressed renal expression of α(1D)-AR in diabetic nephropathy.

  4. Hydrothermally processed 1D hydroxyapatite: Mechanism of formation and biocompatibility studies.

    PubMed

    Stojanović, Zoran S; Ignjatović, Nenad; Wu, Victoria; Žunič, Vojka; Veselinović, Ljiljana; Škapin, Srečo; Miljković, Miroslav; Uskoković, Vuk; Uskoković, Dragan

    2016-11-01

    Recent developments in bone tissue engineering have led to an increased interest in one-dimensional (1D) hydroxyapatite (HA) nano- and micro-structures such as wires, ribbons and tubes. They have been proposed for use as cell substrates, reinforcing phases in composites and carriers for biologically active substances. Here we demonstrate the synthesis of 1D HA structures using an optimized, urea-assisted, high-yield hydrothermal batch process. The one-pot process, yielding HA structures composed of bundles of ribbons and wires, was typified by the simultaneous occurrence of a multitude of intermediate reactions, failing to meet the uniformity criteria over particle morphology and size. To overcome these issues, the preparation procedure was divided to two stages: dicalcium phosphate platelets synthesized in the first step were used as a precursor for the synthesis of 1D HA in the second stage. Despite the elongated particle morphologies, both the precursor and the final product exhibited excellent biocompatibility and caused no reduction of viability when tested against osteoblastic MC3T3-E1 cells in 2D culture up to the concentration of 2.6mg/cm(2). X-ray powder diffraction combined with a range of electron microscopies and laser diffraction analyses was used to elucidate the formation mechanism and the microstructure of the final particles. The two-step synthesis involved a more direct transformation of DCP to 1D HA with the average diameter of 37nm and the aspect ratio exceeding 100:1. The comparison of crystalline domain sizes along different crystallographic directions showed no signs of significant anisotropy, while indicating that individual nanowires are ordered in bundles in the b crystallographic direction of the P63/m space group of HA. Intermediate processes, e.g., dehydration of dicalcium phosphate, are critical for the formation of 1D HA alongside other key aspects of this phase transformation, it must be investigated in more detail in the continuous

  5. Hydrothermally processed 1D hydroxyapatite: Mechanism of formation and biocompatibility studies.

    PubMed

    Stojanović, Zoran S; Ignjatović, Nenad; Wu, Victoria; Žunič, Vojka; Veselinović, Ljiljana; Škapin, Srečo; Miljković, Miroslav; Uskoković, Vuk; Uskoković, Dragan

    2016-11-01

    Recent developments in bone tissue engineering have led to an increased interest in one-dimensional (1D) hydroxyapatite (HA) nano- and micro-structures such as wires, ribbons and tubes. They have been proposed for use as cell substrates, reinforcing phases in composites and carriers for biologically active substances. Here we demonstrate the synthesis of 1D HA structures using an optimized, urea-assisted, high-yield hydrothermal batch process. The one-pot process, yielding HA structures composed of bundles of ribbons and wires, was typified by the simultaneous occurrence of a multitude of intermediate reactions, failing to meet the uniformity criteria over particle morphology and size. To overcome these issues, the preparation procedure was divided to two stages: dicalcium phosphate platelets synthesized in the first step were used as a precursor for the synthesis of 1D HA in the second stage. Despite the elongated particle morphologies, both the precursor and the final product exhibited excellent biocompatibility and caused no reduction of viability when tested against osteoblastic MC3T3-E1 cells in 2D culture up to the concentration of 2.6mg/cm(2). X-ray powder diffraction combined with a range of electron microscopies and laser diffraction analyses was used to elucidate the formation mechanism and the microstructure of the final particles. The two-step synthesis involved a more direct transformation of DCP to 1D HA with the average diameter of 37nm and the aspect ratio exceeding 100:1. The comparison of crystalline domain sizes along different crystallographic directions showed no signs of significant anisotropy, while indicating that individual nanowires are ordered in bundles in the b crystallographic direction of the P63/m space group of HA. Intermediate processes, e.g., dehydration of dicalcium phosphate, are critical for the formation of 1D HA alongside other key aspects of this phase transformation, it must be investigated in more detail in the continuous

  6. HLA class II susceptibility pattern for type 1 diabetes (T1D) in an Iranian population.

    PubMed

    Kiani, J; Hajilooi, M; Furst, D; Rezaei, H; Shahryari-Hesami, S; Kowsarifard, S; Zamani, A; Solgi, G

    2015-08-01

    This study aimed to determine the HLA-DRB1/HLA-DQB1 susceptibility and protection pattern for type 1 diabetes (T1D) in a population from Hamadan, north-west of Iran. A total of 133 patients with T1D were tested for HLA-DRB1 and HLA-DQB1 alleles using PCR-SSP compared to 100 ethnic-matched healthy controls. Alleles and haplotypes frequencies were compared between both groups. The most susceptible alleles for disease were HLA-DRB1*03:01, DRB1*04:02, DQB1*02:01 and DQB1*03:02, and protective alleles were HLA-DRB1*07:01, *11:01, *13:01, *14:01 and DRB1*15 and HLA-DQB1*06:01, *06:02 and *06:03. Haplotype analysis revealed that patients with T1D had higher frequencies of DRB1*03:01-DQB1*02:01 (OR = 4.86, P < 10(-7) ) and DRB1*04:02-DQB1*03:02 (OR = 9.93, P < 10(-7) ) and lower frequencies of DRB1*07:01-DQB1*02:01 (P = 0.0005), DRB1*11:01-DQB1*03:01 (P = 0.001), DRB1*13:01-DQB1*06:03 (P = 0.002) and DRB1*15-DQB1*06:01 (P = 0.001) haplotypes compared to healthy controls. Heterozygote combination of both susceptible haplotypes (DR3/DR4) confers the highest risk for T1D (RR = 18.80, P = 4 × 10(-5) ). Additionally, patients with homozygote diplotype, DR3/DR3 and DR4/DR4, showed a similar risk with less extent to heterozygote combination (P = 0.0004 and P = 0.01, respectively). Our findings not only confirm earlier reports from Iranians but also are in line with Caucasians and partly with Asians and some African patients with T1D. Remarkable differences were the identification of DRB1*04:01-DQB1*03:02, DRB1*07:01-DQB1*03:03 and DRB1*16-DQB1*05:02 as neutral and DRB1*13:01-DQB1*06:03 as the most protective haplotypes in this study.

  7. Regulation of inflorescence branch development in rice through a novel pathway involving the pentatricopeptide repeat protein sped1-D.

    PubMed

    Jiang, Guanghuai; Xiang, Yanghai; Zhao, Jiying; Yin, Dedong; Zhao, Xianfeng; Zhu, Lihuang; Zhai, Wenxue

    2014-08-01

    Panicle type has a direct bearing on rice yield. Here, we characterized a rice clustered-spikelet mutant, sped1-D, with shortened pedicels and/or secondary branches, which exhibits decreased pollen fertility. We cloned sped1-D and found that it encodes a pentatricopeptide repeat protein. We investigated the global expression profiles of wild-type, 9311, and sped1-D plants using Illumina RNA sequencing. The expression of several GID1L2 family members was downregulated in the sped1-D mutant, suggesting that the gibberellin (GA) pathway is involved in the elongation of pedicels and/or secondary branches. When we overexpressed one GID1L2, AK070299, in sped1-D plants, the panicle phenotype was restored to varying degrees. In addition, we analyzed the expression of genes that function in floral meristems and found that RFL and WOX3 were severely downregulated in sped1-D. These results suggest that sped1-D may prompt the shortening of pedicels and secondary branches by blocking the action of GID1L2, RFL, and Wox3. Moreover, overexpression of sped1-D in Arabidopsis resulted in the shortening of pedicels and clusters of siliques, which indicates that the function of sped1-D is highly conserved in monocotyledonous and dicotyledonous plants. Sequence data from this article have been deposited with the miRBase Data Libraries under accession no. MI0003201.

  8. Computational Study and Analysis of Structural Imperfections in 1D and 2D Photonic Crystals

    SciTech Connect

    Maskaly, Karlene Rosera

    2005-06-01

    Dielectric reflectors that are periodic in one or two dimensions, also known as 1D and 2D photonic crystals, have been widely studied for many potential applications due to the presence of wavelength-tunable photonic bandgaps. However, the unique optical behavior of photonic crystals is based on theoretical models of perfect analogues. Little is known about the practical effects of dielectric imperfections on their technologically useful optical properties. In order to address this issue, a finite-difference time-domain (FDTD) code is employed to study the effect of three specific dielectric imperfections in 1D and 2D photonic crystals. The first imperfection investigated is dielectric interfacial roughness in quarter-wave tuned 1D photonic crystals at normal incidence. This study reveals that the reflectivity of some roughened photonic crystal configurations can change up to 50% at the center of the bandgap for RMS roughness values around 20% of the characteristic periodicity of the crystal. However, this reflectivity change can be mitigated by increasing the index contrast and/or the number of bilayers in the crystal. In order to explain these results, the homogenization approximation, which is usually applied to single rough surfaces, is applied to the quarter-wave stacks. The results of the homogenization approximation match the FDTD results extremely well, suggesting that the main role of the roughness features is to grade the refractive index profile of the interfaces in the photonic crystal rather than diffusely scatter the incoming light. This result also implies that the amount of incoherent reflection from the roughened quarterwave stacks is extremely small. This is confirmed through direct extraction of the amount of incoherent power from the FDTD calculations. Further FDTD studies are done on the entire normal incidence bandgap of roughened 1D photonic crystals. These results reveal a narrowing and red-shifting of the normal incidence bandgap with

  9. Architectural Methodology Report

    NASA Technical Reports Server (NTRS)

    Dhas, Chris

    2000-01-01

    The establishment of conventions between two communicating entities in the end systems is essential for communications. Examples of the kind of decisions that need to be made in establishing a protocol convention include the nature of the data representation, the for-mat and the speed of the date representation over the communications path, and the sequence of control messages (if any) which are sent. One of the main functions of a protocol is to establish a standard path between the communicating entities. This is necessary to create a virtual communications medium with certain desirable characteristics. In essence, it is the function of the protocol to transform the characteristics of the physical communications environment into a more useful virtual communications model. The final function of a protocol is to establish standard data elements for communications over the path; that is, the protocol serves to create a virtual data element for exchange. Other systems may be constructed in which the transferred element is a program or a job. Finally, there are special purpose applications in which the element to be transferred may be a complex structure such as all or part of a graphic display. NASA's Glenn Research Center (GRC) defines and develops advanced technology for high priority national needs in communications technologies for application to aeronautics and space. GRC tasked Computer Networks and Software Inc. (CNS) to describe the methodologies used in developing a protocol architecture for an in-space Internet node. The node would support NASA:s four mission areas: Earth Science; Space Science; Human Exploration and Development of Space (HEDS); Aerospace Technology. This report presents the methodology for developing the protocol architecture. The methodology addresses the architecture for a computer communications environment. It does not address an analog voice architecture.

  10. Probabilistic river forecast methodology

    NASA Astrophysics Data System (ADS)

    Kelly, Karen Suzanne

    1997-09-01

    The National Weather Service (NWS) operates deterministic conceptual models to predict the hydrologic response of a river basin to precipitation. The output from these models are forecasted hydrographs (time series of the future river stage) at certain locations along a river. In order for the forecasts to be useful for optimal decision making, the uncertainty associated with them must be quantified. A methodology is developed for this purpose that (i) can be implemented with any deterministic hydrologic model, (ii) receives a probabilistic forecast of precipitation as input, (iii) quantifies all sources of uncertainty, (iv) operates in real-time and within computing constraints, and (v) produces probability distributions of future river stages. The Bayesian theory which supports the methodology involves transformation of a distribution of future precipitation into one of future river stage, and statistical characterization of the uncertainty in the hydrologic model. This is accomplished by decomposing total uncertainty into that associated with future precipitation and that associated with the hydrologic transformations. These are processed independently and then integrated into a predictive distribution which constitutes a probabilistic river stage forecast. A variety of models are presented for implementation of the methodology. In the most general model, a probability of exceedance associated with a given future hydrograph specified. In the simplest model, a probability of exceedance associated with a given future river stage is specified. In conjunction with the Ohio River Forecast Center of the NWS, the simplest model is used to demonstrate the feasibility of producing probabilistic river stage forecasts for a river basin located in headwaters. Previous efforts to quantify uncertainty in river forecasting have only considered selected sources of uncertainty, been specific to a particular hydrologic model, or have not obtained an entire probability

  11. Injector element characterization methodology

    NASA Technical Reports Server (NTRS)

    Cox, George B., Jr.

    1988-01-01

    Characterization of liquid rocket engine injector elements is an important part of the development process for rocket engine combustion devices. Modern nonintrusive instrumentation for flow velocity and spray droplet size measurement, and automated, computer-controlled test facilities allow rapid, low-cost evaluation of injector element performance and behavior. Application of these methods in rocket engine development, paralleling their use in gas turbine engine development, will reduce rocket engine development cost and risk. The Alternate Turbopump (ATP) Hot Gas Systems (HGS) preburner injector elements were characterized using such methods, and the methodology and some of the results obtained will be shown.

  12. SHRS RRCL selection methodology

    SciTech Connect

    Trainer, J E; Delaney, H M

    1980-05-01

    The CRBRP Safety Related Reliability Program requires a listing of those design items whose failure would impact the ability of the plant for a safe shutdown or shutdown heat removal mission. This listing is referred to as the Reliability Related Components List (RRCL) and heretofore, has been based on sound engineering judgement. As a check for completeness and as a means of providing a probabilistic-based rationale for component selection, this report presents a methodology by which this selection can be made for each of the decay heat removal loops comprising the Shutdown Heat Removal System (SHRS) using existing EG and G fault tree models.

  13. Emergency exercise methodology

    SciTech Connect

    Klimczak, C.A.

    1993-01-01

    Competence for proper response to hazardous materials emergencies is enhanced and effectively measured by exercises which test plans and procedures and validate training. Emergency exercises are most effective when realistic criteria is used and a sequence of events is followed. The scenario is developed from pre-determined exercise objectives based on hazard analyses, actual plans and procedures. The scenario should address findings from previous exercises and actual emergencies. Exercise rules establish the extent of play and address contingencies during the exercise. All exercise personnel are assigned roles as players, controllers or evaluators. These participants should receive specialized training in advance. A methodology for writing an emergency exercise plan will be detailed.

  14. Methodology of stereotactic biopsy.

    PubMed

    Carapella, C M; Mastrostefano, R; Raus, L; Riccio, A

    1989-01-01

    The great technological improvement in the neurosurgical tools and in the neuroradiological imaging has brought about the diffusion of the stereotactic techniques. They are crucial for the diagnosis and treatment of intracranial expanding lesions of small dimensions or located in sites inaccessible to conventional techniques. The Authors describe the most common systems and methodologies for the stereotactic biopsy. They stress the importance of performing serial explorations which can provide evidence of the heterogeneity of the neoplastic lesion and of the infiltration of the brain adjacent to the tumor.

  15. RHIC DATA CORRELATION METHODOLOGY.

    SciTech Connect

    MICHNOFF,R.; D'OTTAVIO,T.; HOFF,L.; MACKAY,W.; SATOGATA,T.

    1999-03-29

    A requirement for RHIC data plotting software and physics analysis is the correlation of data from all accelerator data gathering systems. Data correlation provides the capability for a user to request a plot of multiple data channels vs. time, and to make meaningful time-correlated data comparisons. The task of data correlation for RHIC requires careful consideration because data acquisition triggers are generated from various asynchronous sources including events from the RHIC Event Link, events from the two Beam Sync Links, and other unrelated clocks. In order to correlate data from asynchronous acquisition systems a common time reference is required. The RHIC data correlation methodology will allow all RHIC data to be converted to a common wall clock time, while still preserving native acquisition trigger information. A data correlation task force team, composed of the authors of this paper, has been formed to develop data correlation design details and provide guidelines for software developers. The overall data correlation methodology will be presented in this paper.

  16. Relative Hazard Calculation Methodology

    SciTech Connect

    DL Strenge; MK White; RD Stenner; WB Andrews

    1999-09-07

    The methodology presented in this document was developed to provide a means of calculating the RH ratios to use in developing useful graphic illustrations. The RH equation, as presented in this methodology, is primarily a collection of key factors relevant to understanding the hazards and risks associated with projected risk management activities. The RH equation has the potential for much broader application than generating risk profiles. For example, it can be used to compare one risk management activity with another, instead of just comparing it to a fixed baseline as was done for the risk profiles. If the appropriate source term data are available, it could be used in its non-ratio form to estimate absolute values of the associated hazards. These estimated values of hazard could then be examined to help understand which risk management activities are addressing the higher hazard conditions at a site. Graphics could be generated from these absolute hazard values to compare high-hazard conditions. If the RH equation is used in this manner, care must be taken to specifically define and qualify the estimated absolute hazard values (e.g., identify which factors were considered and which ones tended to drive the hazard estimation).

  17. Comparison of Analysis Results Between 2D/1D Synthesis and RAPTOR-M3G in the Korea Standard Nuclear Plant (KSNP)

    NASA Astrophysics Data System (ADS)

    Joung Lim, Mi; Maeng, Young Jae; Fero, Arnold H.; Anderson, Stanwood L.

    2016-02-01

    The 2D/1D synthesis methodology has been used to calculate the fast neutron (E > 1.0 MeV) exposure to the beltline region of the reactor pressure vessel. This method uses the DORT 3.1 discrete ordinates code and the BUGLE-96 cross-section library based on ENDF/B-VI. RAPTOR-M3G (RApid Parallel Transport Of Radiation-Multiple 3D Geometries) which performs full 3D calculations was developed and is based on domain decomposition algorithms, where the spatial and angular domains are allocated and processed on multi-processor computer architecture. As compared to traditional single-processor applications, this approach reduces the computational load as well as the memory requirement per processor. Both methods are applied to surveillance test results for the Korea Standard Nuclear Plant (KSNP)-OPR (Optimized Power Reactor) 1000 MW. The objective of this paper is to compare the results of the KSNP surveillance program between 2D/1D synthesis and RAPTOR-M3G. Each operating KSNP has a reactor vessel surveillance program consisting of six surveillance capsules located between the core and the reactor vessel in the downcomer region near the reactor vessel wall. In addition to the In-Vessel surveillance program, an Ex-Vessel Neutron Dosimetry (EVND) program has been implemented. In order to estimate surveillance test results, cycle-specific forward transport calculations were performed by 2D/1D synthesis and by RAPTOR-M3G. The ratio between measured and calculated (M/C) reaction rates will be discussed. The current plan is to install an EVND system in all of the Korea PWRs including the new reactor type, APR (Advanced Power Reactor) 1400 MW. This work will play an important role in establishing a KSNP-specific database of surveillance test results and will employ RAPTOR-M3G for surveillance dosimetry location as well as positions in the KSNP reactor vessel.

  18. Nested 1D-2D approach for urban surface flood modeling

    NASA Astrophysics Data System (ADS)

    Murla, Damian; Willems, Patrick

    2015-04-01

    Floods in urban areas as a consequence of sewer capacity exceedance receive increased attention because of trends in urbanization (increased population density and impermeability of the surface) and climate change. Despite the strong recent developments in numerical modeling of water systems, urban surface flood modeling is still a major challenge. Whereas very advanced and accurate flood modeling systems are in place and operation by many river authorities in support of flood management along rivers, this is not yet the case in urban water management. Reasons include the small scale of the urban inundation processes, the need to have very high resolution topographical information available, and the huge computational demands. Urban drainage related inundation modeling requires a 1D full hydrodynamic model of the sewer network to be coupled with a 2D surface flood model. To reduce the computational times, 0D (flood cones), 1D/quasi-2D surface flood modeling approaches have been developed and applied in some case studies. In this research, a nested 1D/2D hydraulic model has been developed for an urban catchment at the city of Gent (Belgium), linking the underground sewer (minor system) with the overland surface (major system). For the overland surface flood modelling, comparison was made of 0D, 1D/quasi-2D and full 2D approaches. The approaches are advanced by considering nested 1D-2D approaches, including infiltration in the green city areas, and allowing the effects of surface storm water storage to be simulated. An optimal nested combination of three different mesh resolutions was identified; based on a compromise between precision and simulation time for further real-time flood forecasting, warning and control applications. Main streets as mesh zones together with buildings as void regions constitute one of these mesh resolution (3.75m2 - 15m2); they have been included since they channel most of the flood water from the manholes and they improve the accuracy of

  19. 1D-3D registration for intra-operative nuclear imaging in radio-guided surgery.

    PubMed

    Vetter, Christoph; Lasser, Tobias; Okur, Asli; Navab, Nassir

    2015-02-01

    3D functional nuclear imaging modalities like SPECT or PET provide valuable information, as small structures can be marked with radioactive tracers to be localized before surgery. This positional information is valuable during surgery as well, for example when locating potentially cancerous lymph nodes in the case of breast cancer. However, the volumetric information provided by pre-operative SPECT scans loses validity quickly due to posture changes and manipulation of the soft tissue during surgery. During the intervention, the surgeon has to rely on the acoustic feedback provided by handheld gamma-detectors in order to localize the marked structures. In this paper, we present a method that allows updating the pre-operative image with a very limited number of tracked readings. A previously acquired 3D functional volume serves as prior knowledge and a limited number of new 1D detector readings is used in order to update the prior knowledge. This update is performed by a 1D-3D registration algorithm that registers the volume to the detector readings. This enables the rapid update of the visual guidance provided to the surgeon during a radio-guided surgery without slowing down the surgical workflow. We evaluate the performance of this approach using Monte-Carlo simulations, phantom experiments and patient data, resulting in a positional error of less than 8 mm which is acceptable for surgery. The 1D-3D registration is also compared to a volumetric reconstruction using the tracked detector measurements without taking prior information into account, and achieves a comparable accuracy with significantly less measurements.

  20. Universal low-energy physics in 1D strongly repulsive multi-component Fermi gases

    NASA Astrophysics Data System (ADS)

    Jiang, Yuzhu; He, Peng; Guan, Xi-Wen

    2016-04-01

    It has been shown (Yang and You 2011 Chin. Phys. Lett. 28 020503) that at zero temperature the ground state of the one-dimensional (1D) w-component Fermi gas coincides with that of the spinless Bose gas in the limit ω \\to ∞ . This behavior was experimentally evidenced through quasi-1D tightly trapping ultracold 173Yb atoms in a recent paper (Pagano et al 2014 Nat. Phys. 10 198). However, understanding of low-temperature behavior of Fermi gases with a repulsive interaction requires spin-charge separated conformal field theories of an effective Tomonaga-Luttinger liquid and an antiferromagnetic SU(w) Heisenberg spin chain. Here we analytically derive universal thermodynamics of 1D strongly repulsive fermionic gases with SU(w) symmetry via the Yang-Yang thermodynamic Bethe ansatz method. The analytical free energy and magnetic properties of the systems at low temperature in a weak magnetic field are obtained through the Wiener-Hopf method. In particular, the free energy essentially manifests the spin-charge separated conformal field theories for high-symmetry systems with arbitrary repulsive interaction strength. We also find that the sound velocity of the Fermi gases in the large w limit coincides with that for the spinless Bose gas, whereas the spin velocity vanishes quickly as w becomes large. This indicates strong suppression of the Fermi exclusion statistics by the commutativity feature among the w-component fermions with different spin states in the Tomonaga-Luttinger liquid phase. Moreover, the equations of state and critical behavior of physical quantities at finite temperature are analytically derived in terms of the polylogarithm functions in the quantum critical region.

  1. Supersymmetric configurations in the rotating D1-D5 system andpp-waves

    NASA Astrophysics Data System (ADS)

    Maoz, Liat

    Two families of supersymmetric configurations are considered. One is the 1/4 supersymmetric D1--D5 system with angular momentum, and the other is a family of pp-waves of type IIB string theory with some supersymmetry. In the first part of the thesis some configurations of the D1--D5 system are examined which give conical singularities in AdS 3 as their near horizon limit. It is shown that they can be made non-singular by adding angular momentum to the brane system. The smooth asymptotically flat solutions constructed this way are used to obtain global AdS 3 as the near horizon geometry. Using the relation of the D1--D5 system to the oscillating string, a large family of supergravity solutions is constructed which describe BPS excitations on AdS3 x S 3 with angular momentum on S3. These solutions take into account the full back reaction on the metric, and can be viewed as Kaluza-Klein monopole "supertubes", which are completely non-singular geometries. The different chiral primaries of the dual CFT are identified with these different supergravity solutions. This part is adapted from the papers [1], [2]. In its second part, a general class of supersymmetric pp-wave solutions of type IIB string theory is constructed, such that the superstring worldsheet action in light cone gauge is that of an interacting massive field theory. It is shown that when the light cone Lagrangian has (2.2) supersymmetry, one can find backgrounds that lead to arbitrary superpotentials on the worldsheet. Both flat and curved transverse spaces are considered. In particular, the background giving rise to the N = 2 sine Gordon theory on the worldsheet is analyzed. Massive mirror symmetry relates it to the deformed CP1 model (or sausage model) which seems to elude a purely supergravity target space interpretation. These are results which appeared in the paper [3].

  2. Assessment and improvement of the 2D/1D method stability in DeCART

    SciTech Connect

    Stimpson, S.; Young, M.; Collins, B.; Kelley, B.; Downar, T.

    2013-07-01

    As part of ongoing work with Consortium for Advanced Simulation of Light Water Reactors (CASL), the 2D/1D code, DeCART, has demonstrated some of the advantages of the 2D/1D method with respect to realistic, full-core analysis, particularly over explicit 3D transport methods, which generally have higher memory and computation requirements. The 2D/1D method performs 2D-radial transport sweeps coupled with ID-axial diffusion calculations to provide a full 3D simulation. DeCART employs the 2D method of characteristics for the radial sweeps and ID one-node nodal diffusion for the axial sweeps, coupling the two methods with transverse leakages to ensure a more consistent representation of the transport equation. It has been observed that refinement of the axial plane thickness leads to instabilities in the calculation scheme. This work assesses the sources of these instabilities and the approaches to improve them, especially with respect to negative scattering cross sections and the tightness of the 2D-radial/ID-axial coupling schemes. Fourier analyses show that the existing iteration scheme is not unconditionally stable, suggesting a tighter coupling scheme is required. For this reason 3D-CMFD has been implemented, among other developments, to ensure more stable calculation. A matrix of test cases has been used to assess the convergence, with the primary parameter being the axial plane thickness, which has been refined down to 1 cm. These cases demonstrate the issues observed and how the modification improve the stability. However, it is apparent that more work is necessary to ensure unconditional stability. (authors)

  3. Bed-load transport modelling by coupling an empirical routing scheme and a hydrological-1-D-hydrodynamic model - case study application for a large alpine valley

    NASA Astrophysics Data System (ADS)

    Gems, B.; Achleitner, S.; Plörer, M.; Schöberl, F.; Huttenlau, M.; Aufleger, M.

    2012-12-01

    Sediment transport in mountain rivers and torrents is a substantial process within the assessment of flood related hazard potential and vulnerability in alpine catchments. Focusing on fluvial transport processes, river bed erosion and deposition considerably affects the extent of inundation. The present work deals with scenario-specific bed-load transport modelling in a large alpine valley in the Austrian Alps. A routing scheme founding on empirical equations for the calculation of transport capacities, incipient motion conditions and drag forces is set up and applied to the case study area for two historic flood events. The required hydraulic data result from a distributed hydrological-1-D-hydraulic model. Hydraulics and bed-load transport are simulated sequentially providing a technically well-founded and feasible methodology for the estimation of bed-load transport rates during flood events.

  4. Review of Zero-D and 1-D Models of Blood Flow in the Cardiovascular System

    PubMed Central

    2011-01-01

    Background Zero-dimensional (lumped parameter) and one dimensional models, based on simplified representations of the components of the cardiovascular system, can contribute strongly to our understanding of circulatory physiology. Zero-D models provide a concise way to evaluate the haemodynamic interactions among the cardiovascular organs, whilst one-D (distributed parameter) models add the facility to represent efficiently the effects of pulse wave transmission in the arterial network at greatly reduced computational expense compared to higher dimensional computational fluid dynamics studies. There is extensive literature on both types of models. Method and Results The purpose of this review article is to summarise published 0D and 1D models of the cardiovascular system, to explore their limitations and range of application, and to provide an indication of the physiological phenomena that can be included in these representations. The review on 0D models collects together in one place a description of the range of models that have been used to describe the various characteristics of cardiovascular response, together with the factors that influence it. Such models generally feature the major components of the system, such as the heart, the heart valves and the vasculature. The models are categorised in terms of the features of the system that they are able to represent, their complexity and range of application: representations of effects including pressure-dependent vessel properties, interaction between the heart chambers, neuro-regulation and auto-regulation are explored. The examination on 1D models covers various methods for the assembly, discretisation and solution of the governing equations, in conjunction with a report of the definition and treatment of boundary conditions. Increasingly, 0D and 1D models are used in multi-scale models, in which their primary role is to provide boundary conditions for sophisticate, and often patient-specific, 2D and 3D models

  5. Synthesis, Characterization, and Application of 1-D Cerium Oxide Nanomaterials: A Review

    PubMed Central

    Lin, Kuen-Song; Chowdhury, Sujan

    2010-01-01

    The present work provides a comprehensive overview of the recent progress of research work toward developing new one dimensional (1-D) ceria (CeO2) nanomaterials. The review has been classified into three parts: the preparation procedures with identification of the existing different dimensional ceria nanomaterials, the formation mechanisms, and an analysis of their applications. From literature survey, it is inaugurated that the fundamental structures of the ceria nanomaterials constructively dominate their properties and applications. In addition, this work will also provide a perspective on the future technical trends for the development of different dimensional CeO2 nanomaterials. PMID:20957090

  6. Formation of Molecules near a Feshbach Resonance in a 1D Optical Lattice

    SciTech Connect

    Orso, G.; Pitaevskii, L.P.; Stringari, S.; Wouters, M.

    2005-08-05

    We study the molecular behavior of two atoms interacting near a Feshbach resonance in the presence of a 1D periodic potential. The critical value of the scattering length needed to produce a molecule and the binding energy at resonance are calculated as a function of the intensity of the periodic potential. Because of the nonseparability of the center of mass and relative motion, the binding energy depends on the quasimomentum of the molecule. This has dramatic consequences on the molecular tunneling properties, which become strongly dependent on the scattering length.

  7. Thermodynamic nature of vitrification in a 1D model of a structural glass former

    SciTech Connect

    Semenov, A. N.

    2015-07-28

    We propose a new spin-glass model with no positional quenched disorder which is regarded as a coarse-grained model of a structural glass-former. The model is analyzed in the 1D case when the number N of states of a primary cell is large. For N → ∞, the model exhibits a sharp freezing transition of the thermodynamic origin. It is shown both analytically and numerically that the glass transition is accompanied by a significant growth of a static length scale ξ pointing to the structural (equilibrium) nature of dynamical slowdown effects in supercooled liquids.

  8. Hair on non-extremal D1-D5 bound states

    NASA Astrophysics Data System (ADS)

    Roy, Pratik; Srivastava, Yogesh K.; Virmani, Amitabh

    2016-09-01

    We consider a truncation of type IIB supergravity on four-torus where in addition to the Ramond-Ramond 2-form field, the Ramond-Ramond axion ( w) and the NS-NS 2-form field ( B) are also retained. In the ( w, B) sector we construct a linearised perturbation carrying only left moving momentum on two-charge non-extremal D1-D5 geometries of Jejjala, Madden, Ross and Titchener. The perturbation is found to be smooth everywhere and normalisable. It is constructed by matching to leading order solutions of the perturbation equations in the inner and outer regions of the geometry.

  9. Delocalization of Weakly Interacting Bosons in a 1D Quasiperiodic Potential

    NASA Astrophysics Data System (ADS)

    Michal, V. P.; Altshuler, B. L.; Shlyapnikov, G. V.

    2014-07-01

    We consider weakly interacting bosons in a 1D quasiperiodic potential (Aubry-Azbel-Harper model) in the regime where all single-particle states are localized. We show that the interparticle interaction may lead to the many-body delocalization and we obtain the finite-temperature phase diagram. Counterintuitively, in a wide range of parameters the delocalization requires stronger coupling as the temperature increases. This means that the system of bosons can undergo a transition from a fluid to insulator (glass) state under heating.

  10. Analytic solutions for the approximated 1-D Monge-Kantorovich mass transfer problems

    NASA Astrophysics Data System (ADS)

    Lu, Xiaojun; Lv, Xiaofen

    2016-10-01

    This paper mainly investigates the approximation of a global maximizer of the 1-D Monge-Kantorovich mass transfer problem through the approach of nonlinear differential equations with Dirichlet boundary. Using an approximation mechanism, the primal maximization problem can be transformed into a sequence of minimization problems. By applying the canonical duality theory, one is able to derive a sequence of analytic solutions for the minimization problems. In the final analysis, the convergence of the sequence to a global maximizer of the primal Monge-Kantorovich problem will be demonstrated.

  11. Thermodynamic nature of vitrification in a 1D model of a structural glass former.

    PubMed

    Semenov, A N

    2015-07-28

    We propose a new spin-glass model with no positional quenched disorder which is regarded as a coarse-grained model of a structural glass-former. The model is analyzed in the 1D case when the number N of states of a primary cell is large. For N → ∞, the model exhibits a sharp freezing transition of the thermodynamic origin. It is shown both analytically and numerically that the glass transition is accompanied by a significant growth of a static length scale ξ pointing to the structural (equilibrium) nature of dynamical slowdown effects in supercooled liquids. PMID:26233148

  12. Monochromatic Neutron Tomography Using 1-D PSD Detector at Low Flux Research Reactor

    SciTech Connect

    Ashari, N. Abidin; Saleh, J. Mohamad; Abdullah, M. Zaid; Mohamed, A. Aziz; Azman, A.; Jamro, R.

    2008-03-17

    This paper describes the monochromatic neutron tomography experiment using the 1-D Position Sensitive Neutron Detector (PSD) located at Nuclear Malaysia TRIGA MARK II Research reactor. Experimental work was performed using monochromatic neutron source from beryllium filter and HOPG crystal monochromator. The principal main aim of this experiment was to test the detector efficiency, image reconstruction algorithm and the usage of 0.5 nm monochromatic neutrons for the neutron tomography setup. Other objective includes gathering important parameters and features to characterize the system.

  13. The 1D Kardar-Parisi-Zhang equation: Height distribution and universality

    NASA Astrophysics Data System (ADS)

    Sasamoto, Tomohiro

    2016-02-01

    The Kardar-Parisi-Zhang (KPZ) equation, which was introduced in 1986 as a model equation to describe the dynamics of an interface motion, has been attracting renewed interest in recent years. In particular, the height distribution of its 1D version was determined exactly for a few special initial conditions. Its relevance in experiments was demonstrated and our understanding of the mathematical structures behind its tractability has deepened considerably. There are also new developments in the applicability of the KPZ universality in wider contexts. This paper is a short introductory review on the basics of the equation and on a few recent topics.

  14. Structural and magnetic properties of Fe1+dTe single crystals

    NASA Astrophysics Data System (ADS)

    Mizuguchi, Yoshikazu; Hamada, Kentaro; Miura, Osuke

    We have grown single crystals of Fe1+dTe by a conventional self-flux method. We obtained plate-like single crystals with dnom ≥ 0.1. The value of the magnetization increased with increasing excess Fe concentration, and a broadening of the antiferromagnetic transition was observed for dnom >1.15. Further, we noted that the antiferromagnetic transition of Fe1.134Te (dnom = 0.15) was clearly suppressed to a lower temperature, which would indicate a possibility of controllability of magnetism by excess Fe concentration.

  15. Scratched-XY Universality and Phase Diagram of Disordered 1D Bosons in Optical Lattice

    NASA Astrophysics Data System (ADS)

    Yao, Zhiyuan; Pollet, Lode; Prokof'ev, Nikolay; Svistunov, Boris

    The superfluid-insulator quantum phase transition in a 1D system with weak links belongs to the so-called scratched-XY universality class, provided the irrenormalizable exponent ζ characterizing the distribution of weak links is smaller than 2 / 3 . With a combination of worm-algorithm Monte Carlo simulations and asymptotically exact analytics, we accurately trace the position of the scratched-XY critical line on the ground-state phase diagram of bosonic Hubbard model at unity filling. In particular, we reveal the location of the tricritical point separating the scratched-XY criticality from the Giamarchi-Schulz one.

  16. Effect of low transverse magnetic field on the confinement strength in a quasi-1D wire

    SciTech Connect

    Kumar, Sanjeev; Thomas, K. J.; Smith, L. W.; Farrer, I.; Ritchie, D. A.; Jones, G. A. C.; Griffiths, J.; Pepper, M.

    2013-12-04

    Transport measurements in a quasi-one dimensional (1D) quantum wire are reported in the presence of low transverse magnetic field. Differential conductance shows weak quantised plateaus when the 2D electrons are squeezed electrostatically. Application of a small transverse magnetic field (0.2T) enhances the overall degree of quantisation due to the formation of magneto-electric subbands. The results show the role of magnetic field to fine tune the confinement strength in low density wires when interaction gives rise to double row formation.

  17. Phase-Sensitive Detection of Bragg Scattering at 1D Optical Lattices

    SciTech Connect

    Slama, S.; Cube, C. von; Deh, B.; Ludewig, A.; Zimmermann, C.; Courteille, Ph.W.

    2005-05-20

    We report on the observation of Bragg scattering at 1D atomic lattices. Cold atoms are confined by optical dipole forces at the antinodes of a standing wave generated by the two counterpropagating modes of a laser-driven high-finesse ring cavity. By heterodyning the Bragg-scattered light with a reference beam, we obtain detailed information on phase shifts imparted by the Bragg scattering process. Being deep in the Lamb-Dicke regime, the scattered light is not broadened by the motion of individual atoms.

  18. Simulations of Edge Effect in 1D Spin Crossover Compounds by Atom-Phonon Coupling Model

    NASA Astrophysics Data System (ADS)

    Linares, J.; Chiruta, D.; Jureschi, C. M.; Alayli, Y.; Turcu, C. O.; Dahoo, P. R.

    2016-08-01

    We used the atom-phonon coupling model to explain and illustrate the behaviour of a linear nano-chain of molecules. The analysis of the system's behaviour was performed using Free Energy method, and by applying Monte Carlo Metropolis (MCM) method which take into account the phonon contribution. In particular we tested both the MCM algorithm and the dynamic-matrix method and we expose how the thermal behaviour of a 1D spin crossover system varies as a function of different factors. Furthermore we blocked the edge atoms of the chain in its high spin state to study the effect on the system's behaviour.

  19. Injectable composites via functionalization of 1D nanoclays and biodegradable coupling with a polysaccharide hydrogel.

    PubMed

    Del Buffa, Stefano; Rinaldi, Elia; Carretti, Emiliano; Ridi, Francesca; Bonini, Massimo; Baglioni, Piero

    2016-09-01

    The use of injectable materials in minimally invasive surgical procedures could help in facing the bone diseases connected to the ageing of world population. To this aim, materials integrating the rheological properties of biocompatible polymers with the mechanical properties of 1D inorganic nanostructures represent promising scaffolds. Here we describe the preparation of hydrogel composites made of carboxymethyl cellulose (CMC) and halloysite nanotubes (HNT) as injectable materials for the local treatment of bone defects. The rheology and injectability of the materials reflects their structural properties, showing the possibility of successfully injecting the prepared composites over a large range of operative conditions.

  20. Almost ideal 1D water diffusion in imogolite nanotubes evidenced by NMR relaxometry.

    PubMed

    Belorizky, Elie; Fries, Pascal H; Guillermo, Armel; Poncelet, Olivier

    2010-06-21

    The longitudinal proton relaxation rates R(1) of water diffusing inside synthetic aluminium silicate imogolite nanotubes are measured by fast field-cycling NMR for frequencies between 0.02 and 35 MHz at 25, 37 and 50 degrees C. We give analytical expressions of the dominant intermolecular dipolar spin-spin contribution to R(1) and to the transverse relaxation rate R(2). A remarkable variation of R(1) by more than two orders of magnitude is observed and shown to be close to the theoretical law, inversely proportional to the square root of the resonance frequency, which is characteristic of perfect molecular 1D diffusion. The physics of diffusion is discussed.

  1. Pharmacological evidence that 5-HT1D activation induces renal vasodilation by NO pathway in rats.

    PubMed

    García-Pedraza, José-Ángel; García, Mónica; Martín, María-Luisa; Morán, Asunción

    2015-06-01

    5-HT is a powerful vasoconstrictor substance in renal vasculature (mainly by 5-HT₂ activation). Nevertheless, 5-HT is notable for its dual cardiovascular effects, producing both vasodilator and vasoconstrictor actions. This study aimed to investigate whether, behind the predominant serotonergic vasoconstrictor action, THE 5-HT system may exert renal vasodilator actions, and, if so, characterize the 5-HT receptors and possible indirect pathways. Renal perfusion pressure (PP), systemic blood pressure (SBP) and heart rate (HR) measurement in in situ autoperfused rat kidney was determined in phenylephrine infused rats. Intra arterial (i.a.) bolus administration of 5-HT (0.00000125-0.1 μg/kg) decreased renal PP in the presence of a phenylephrine continuous infusion (phenylephrine-infusion group), without modifying SBP or HR. These vasodilator responses were potentiated by 5-HT₂ antagonism (ritanserin, 1 mg/kg i.v.), whereas the responses were abolished by 5-HT₁ /₇ antagonist (methiothepin, 100 μg/kg i.v.) or 5-HT1D antagonist (LY310762, 1 mg/kg i.v.). The i.a. administration (0.00000125 to 0.1 μg/kg) of 5-CT or L-694,247 (5-HT1D agonist) mimicked 5-HT vasodilator effect, while other agonists (1-PBG, α-methyl-5-HT, AS-19 (5-HT₇), 8-OH-DPAT (5-HT1A) or CGS-12066B (5-HT1B)) did not alter baseline haemodynamic variables. L-694,247 vasodilation was abolished by i.v. bolus of antagonists LY310762 (5-HT1D, 1 mg/kg) or L-NAME (nitric oxide, 10 mg/kg), but not by i.v. bolus of indomethacin (cyclooxygenase, 2 mg/kg) or glibenclamide (ATP-dependent K(+) channel, 20 mg/kg). These outcomes suggest that 5-HT1D activation produces a vasodilator effect in the in situ autoperfused kidney of phenylephrine-infusion rats mediated by the NO pathway. PMID:25854421

  2. 2D ESR image reconstruction from 1D projections using the modulated field gradient method

    NASA Astrophysics Data System (ADS)

    Páli, T.; Sass, L.; Horvat, L. I.; Ebert, B.

    A method for the reconstruction of 2D ESR images from 1 D projections which is based on the modulated field gradient method has been explored. The 2D distribution of spin-labeled stearic acid in oriented and unoriented dimyristoyl phosphatidylcholine multilayers on a flat quartz support was determined. Such samples are potentially useful for the determination of lipid lateral diffusion in oriented multilayers by monitoring the spreading of a sharp concentration profile in one or two dimensions. The limitations of the method are discussed and the improvements which are needed for dynamic measurements are outlined.

  3. Exponentially-convergent Monte Carlo for the 1-D transport equation

    SciTech Connect

    Peterson, J. R.; Morel, J. E.; Ragusa, J. C.

    2013-07-01

    We define a new exponentially-convergent Monte Carlo method for solving the one-speed 1-D slab-geometry transport equation. This method is based upon the use of a linear discontinuous finite-element trial space in space and direction to represent the transport solution. A space-direction h-adaptive algorithm is employed to restore exponential convergence after stagnation occurs due to inadequate trial-space resolution. This methods uses jumps in the solution at cell interfaces as an error indicator. Computational results are presented demonstrating the efficacy of the new approach. (authors)

  4. Prediction of car cabin environment by means of 1D and 3D cabin model

    NASA Astrophysics Data System (ADS)

    Fišer, J.; Pokorný, J.; Jícha, M.

    2012-04-01

    Thermal comfort and also reduction of energy requirements of air-conditioning system in vehicle cabins are currently very intensively investigated and up-to-date issues. The article deals with two approaches of modelling of car cabin environment; the first model was created in simulation language Modelica (typical 1D approach without cabin geometry) and the second one was created in specialized software Theseus-FE (3D approach with cabin geometry). Performance and capabilities of this tools are demonstrated on the example of the car cabin and the results from simulations are compared with the results from the real car cabin climate chamber measurements.

  5. KAM Tori for 1D Nonlinear Wave Equationswith Periodic Boundary Conditions

    NASA Astrophysics Data System (ADS)

    Chierchia, Luigi; You, Jiangong

    In this paper, one-dimensional (1D) nonlinear wave equations with periodic boundary conditions are considered; V is a periodic smooth or analytic function and the nonlinearity f is an analytic function vanishing together with its derivative at u≡0. It is proved that for ``most'' potentials V(x), the above equation admits small-amplitude periodic or quasi-periodic solutions corresponding to finite dimensional invariant tori for an associated infinite dimensional dynamical system. The proof is based on an infinite dimensional KAM theorem which allows for multiple normal frequencies.

  6. Monochromatic Neutron Tomography Using 1-D PSD Detector at Low Flux Research Reactor

    NASA Astrophysics Data System (ADS)

    Ashari, N. Abidin; Saleh, J. Mohamad; Abdullah, M. Zaid; Mohamed, A. Aziz; Azman, A.; Jamro, R.

    2008-03-01

    This paper describes the monochromatic neutron tomography experiment using the 1-D Position Sensitive Neutron Detector (PSD) located at Nuclear Malaysia TRIGA MARK II Research reactor. Experimental work was performed using monochromatic neutron source from beryllium filter and HOPG crystal monochromator. The principal main aim of this experiment was to test the detector efficiency, image reconstruction algorithm and the usage of 0.5 nm monochromatic neutrons for the neutron tomography setup. Other objective includes gathering important parameters and features to characterize the system.

  7. 75 FR 3159 - Corporate Reorganizations; Distributions Under Sections 368(a)(1)(D) and 354(b)(1)(B); Correction

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-20

    ... Sections 368(a)(1)(D) and 354(b)(1)(B); Correction AGENCY: Internal Revenue Service (IRS), Treasury...) that were published in the Federal Register on Friday, December 18, 2009 (74 FR 67053) providing...)(1)(D) where no stock and/or securities of the acquiring corporation is issued and distributed in...

  8. 50 CFR Table 1d to Part 660... - At-Sea Whiting Fishery Annual Set-Asides, 2011 and 2012.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false At-Sea Whiting Fishery Annual Set-Asides, 2011 and 2012. 1d Table 1d to Part 660, Subpart C Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OFF WEST COAST STATES Pt. 660, Subpt. C,...

  9. Severe hypoglycemia and diabetic ketoacidosis among youth with type 1 diabetes in the T1D Exchange clinic registry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Severe hypoglycemia (SH) and diabetic ketoacidosis (DKA) are common serious acute complications of type 1 diabetes (T1D). The aim of this study was to determine the frequency of SH and DKA and identify factors related to their occurrence in the T1D Exchange pediatric and young adult cohort. The anal...

  10. Recombinant Phage Coated 1D Al2O3 Nanostructures for Controlling the Adhesion and Proliferation of Endothelial Cells

    PubMed Central

    Lee, Juseok; Jeon, Hojeong; Haidar, Ayman; Abdul-Khaliq, Hashim; Veith, Michael; Kim, Youngjun

    2015-01-01

    A novel synthesis of a nanostructured cell adhesive surface is investigated for future stent developments. One-dimensional (1D) Al2O3 nanostructures were prepared by chemical vapor deposition of a single source precursor. Afterwards, recombinant filamentous bacteriophages which display a short binding motif with a cell adhesive peptide (RGD) on p3 and p8 proteins were immobilized on these 1D Al2O3 nanostructures by a simple dip-coating process to study the cellular response of human endothelial EA hy.926. While the cell density decreased on as-deposited 1D Al2O3 nanostructures, we observed enhanced cell proliferation and cell-cell interaction on recombinant phage overcoated 1D Al2O3 nanostructures. The recombinant phage overcoating also supports an isotropic cell spreading rather than elongated cell morphology as we observed on as-deposited Al2O3 1D nanostructures. PMID:26090458

  11. CD1d- and MR1-Restricted T Cells in Sepsis

    PubMed Central

    Szabo, Peter A.; Anantha, Ram V.; Shaler, Christopher R.; McCormick, John K.; Haeryfar, S.M. Mansour

    2015-01-01

    Dysregulated immune responses to infection, such as those encountered in sepsis, can be catastrophic. Sepsis is typically triggered by an overwhelming systemic response to an infectious agent(s) and is associated with high morbidity and mortality even under optimal critical care. Recent studies have implicated unconventional, innate-like T lymphocytes, including CD1d- and MR1-restricted T cells as effectors and/or regulators of inflammatory responses during sepsis. These cell types are typified by invariant natural killer T (iNKT) cells, variant NKT (vNKT) cells, and mucosa-associated invariant T (MAIT) cells. iNKT and vNKT cells are CD1d-restricted, lipid-reactive cells with remarkable immunoregulatory properties. MAIT cells participate in antimicrobial defense, and are restricted by major histocompatibility complex-related protein 1 (MR1), which displays microbe-derived vitamin B metabolites. Importantly, NKT and MAIT cells are rapid and potent producers of immunomodulatory cytokines. Therefore, they may be considered attractive targets during the early hyperinflammatory phase of sepsis when immediate interventions are urgently needed, and also in later phases when adjuvant immunotherapies could potentially reverse the dangerous state of immunosuppression. We will highlight recent findings that point to the significance or the therapeutic potentials of NKT and MAIT cells in sepsis and will also discuss what lies ahead in research in this area. PMID:26322041

  12. Assessment of a fast electro-optical shutter for 1D spontaneous Raman scattering in flames

    NASA Astrophysics Data System (ADS)

    Ajrouche, Hassan; Lo, Amath; Vervisch, Pierre; Cessou, Armelle

    2015-07-01

    A critical aspect of 1D single-shot spontaneous Raman scattering (SRS) experiments in turbulent flames is the need to ensure highly efficient detection associated with fast temporal gating to remove flame emission. Back-illuminated CCD cameras are remarkable for their high quantum efficiency, large dynamic range, good spatial resolution and low readout noise. However, their full-frame architecture makes these detectors difficult to use for SRS measurements in flame and requires the development of a high-speed shutter. The present work proposes a fast electro-optical shutter composed of a large aperture Pockels cell placed between two crossed polarizers, providing high-speed gating up to 500 ns. The throughput of the shutter and its spatial homogeneity are measured. The angular tolerance of the Pockels cell is determined and its suitability for 1D probing is assessed. Spectra acquired in a premixed methane-air flame show the capacity of the shutter to remove flame emission and increase the signal-to-noise ratio for major Raman species.

  13. Gap opening in graphene by 1D and 2D periodic corrugations

    NASA Astrophysics Data System (ADS)

    Naumov, Ivan; Bratkovsky, Alexander

    2012-02-01

    Using first-principles methods and symmetry arguments, we show that a graphene monolayer, which is periodically corrugated in one or two direction(s), can be either semimetal or semiconductor, depending on how strong corrugation is or how the initial symmetry is broken. In the case of 1D periodic ripples, a gap at the Dirac points opens up only due to (i) breaking of the inversion symmetry or equivalence between A and B sublattices and/or (ii) merging of two inequivalent Dirac points, D and -D. Since breaking the inversion symmetry has only relatively modest effect, a tangible gap can be mainly induced by mutual annihilation of the Dirac points, which requires large corrugations, close to mechanical breaking point. In contrast to 1D, the 2D ripples can additionally induce a semiconducting gap via mixing of electronic states belonging to two different K, K' valleys. In this case, a gap on the order of 0.5 eV can be opened up at strains safely lower than the graphene failure strain [1]. [4pt] [1] I.I. Naumov, A.M. Bratkovsky, arXiv:1104.0314v1.

  14. Superdescendants of the D1D5 CFT and their dual 3-charge geometries

    NASA Astrophysics Data System (ADS)

    Giusto, Stefano; Russo, Rodolfo

    2014-03-01

    We describe how to obtain the gravity duals of semiclassical states in the D1-D5 CFT that are superdescendants of a class of RR ground states. On the gravity side, the configurations we construct are regular and asymptotically reproduce the 3-charge D1-D5-P black hole compactified on S 1 × T 4. The geometries depend trivially on the T 4 directions but non-trivially on the remaining 6D space. In the decoupling limit, they reduce to asymptotically AdS3 × S 3 × T 4 spaces that are dual to CFT states obtained by acting with (exponentials of) the operators of the superconformal algebra. As explicit examples, we generalise the solution first constructed in arXiv:1306.1745 and discuss another class of states that have a more complicated dual geometry. By using the free orbifold description of the CFT we calculate the average values for momentum and the angular momenta of these configurations. Finally we compare the CFT results with those obtained in the bulk from the asymptotically M 1,4 × S 1 × T 4 region.

  15. Photodetachment of O^- Yielding O(1D_2, {}^3P) Atoms, Viewed with Velocity Map Imaging

    NASA Astrophysics Data System (ADS)

    Gibson, Stephen T.; Laws, Benjamin A.; Lewis, Brenton R.; Duong, Ly

    2016-06-01

    lectron photodetachment of O^-(2P3/2,1/2) is measured using velocity-map imaging at wavelengths near 350 nm, where detachment yields both O(^1D_2) and O(^3P2,1,0) atoms, simultaneously, producing slow (˜ 0.1 eV) and fast electrons (˜ 2 eV). The photoelectron spectrum resolves the fine-structure transitions, which together with the well known atomic fine-structure splittings, and intensity ratios, provide an excellent test of the spectral quality of the velocity-map imaging technique. Although the photoelectron angular distribution for the two atomic limits have the same negative anisotropy sign, the energy dependence differs. The variation is qualitatively in accordance with R-matrix cross section calculations, that indicate a more gradual d-wave onset for the ^1D limit. However, more exact evaluation is only possible with information about the matrix element phases. Research supported by the Australian Research Council Discovery Project GrantDP160102585. physics.nist.gov/cgi-bin/ASD/energy1.pl O. Scharf and M. R. Godefried, arXiv:0808.3529v1 O. Zatsarinny and K. Bartschat, Phys. Rev. A, 73, 022714 (2006). doi:10.1103/PhysRevA.73.022714

  16. Diffusive Public Goods and Coexistence of Cooperators and Cheaters on a 1D Lattice

    PubMed Central

    Scheuring, István

    2014-01-01

    Many populations of cells cooperate through the production of extracellular materials. These materials (enzymes, siderophores) spread by diffusion and can be applied by both the cooperator and cheater (non-producer) cells. In this paper the problem of coexistence of cooperator and cheater cells is studied on a 1D lattice where cooperator cells produce a diffusive material which is beneficial to the individuals according to the local concentration of this public good. The reproduction success of a cell increases linearly with the benefit in the first model version and increases non-linearly (saturates) in the second version. Two types of update rules are considered; either the cooperative cell stops producing material before death (death-production-birth, DpB) or it produces the common material before it is selected to die (production-death-birth, pDB). The empty space is occupied by its neighbors according to their replication rates. By using analytical and numerical methods I have shown that coexistence of the cooperator and cheater cells is possible although atypical in the linear version of this 1D model if either DpB or pDB update rule is assumed. While coexistence is impossible in the non-linear model with pDB update rule, it is one of the typical behaviors in case of the non-linear model with DpB update rule. PMID:25025985

  17. Calibration of Axisymmetric and Quasi-1D Solvers for High Enthalpy Nozzles

    NASA Technical Reports Server (NTRS)

    Papadopoulos, P. E.; Gochberg, L. A.; Tokarcik-Polsky, S.; Venkatapathy, E.; Deiwert, G. S.; Edwards, Thomas A. (Technical Monitor)

    1994-01-01

    The proposed paper will present a numerical investigation of the flow characteristics and boundary layer development in the nozzles of high enthalpy shock tunnel facilities used for hypersonic propulsion testing. The computed flow will be validated against existing experimental data. Pitot pressure data obtained at the entrance of the test cabin will be used to validate the numerical simulations. It is necessary to accurately model the facility nozzles in order to characterize the test article flow conditions. Initially the axisymmetric nozzle flow will be computed using a Navier Stokes solver for a range of reservoir conditions. The calculated solutions will be compared and calibrated against available experimental data from the DLR HEG piston-driven shock tunnel and the 16-inch shock tunnel at NASA Ames Research Center. The Reynolds number is assumed to be high enough at the throat that the boundary layer flow is assumed turbulent at this point downstream. The real gas affects will be examined. In high Mach number facilities the boundary layer is thick. Attempts will be made to correlate the boundary layer displacement thickness. The displacement thickness correlation will be used to calibrate the quasi-1D codes NENZF and LSENS in order to provide fast and efficient tools of characterizing the facility nozzles. The calibrated quasi-1D codes will be implemented to study the effects of chemistry and the flow condition variations at the test section due to small variations in the driver gas conditions.

  18. Assessment of improved root growth representation in a 1-D, field scale crop model

    NASA Astrophysics Data System (ADS)

    Miltin Mboh, Cho; Gaiser, Thomas; Ewert, Frank

    2015-04-01

    Many 1-D, field scale crop models over-simplify root growth. The over-simplification of this "hidden half" of the crop may have significant consequences on simulated root water and nutrient uptake with a corresponding reflection on the simulated crop yields. Poor representation of root growth in crop models may therefore constitute a major source of uncertainty propagation. In this study we assess the effect of an improved representation of root growth in a model solution of the model framework SIMPLACE (Scientific Impact assessment and Modeling PLatform for Advanced Crop and Ecosystem management) compared to conventional 1-D approaches. The LINTUL5 crop growth model is coupled to the Hillflow soil water balance model within the SIMPLACE modeling framework (Gaiser et al, 2013). Root water uptake scenarios in the soil hydrological simulator Hillflow (Bronstert, 1995) together with an improved representation of root growth is compared to scenarios for which root growth is simplified. The improvement of root growth is achieved by integrating root growth solutions from R-SWMS (Javaux et al., 2008) into the SIMPLACE model solution. R-SWMS is a three dimensional model for simultaneous modeling of root growth, soil water fluxes and solute transport and uptake. These scenarios are tested by comparing how well the simulated water contents match with the observed soil water dynamics. The impacts of the scenarios on above ground biomass and wheat grain are assessed

  19. Testing a 1-D Analytical Salt Intrusion Model and the Predictive Equation in Malaysian Estuaries

    NASA Astrophysics Data System (ADS)

    Gisen, Jacqueline Isabella; Savenije, Hubert H. G.

    2013-04-01

    Little is known about the salt intrusion behaviour in Malaysian estuaries. Study on this topic sometimes requires large amounts of data especially if a 2-D or 3-D numerical models are used for analysis. In poor data environments, 1-D analytical models are more appropriate. For this reason, a fully analytical 1-D salt intrusion model, based on the theory of Savenije in 2005, was tested in three Malaysian estuaries (Bernam, Selangor and Muar) because it is simple and requires minimal data. In order to achieve that, site surveys were conducted in these estuaries during the dry season (June-August) at spring tide by moving boat technique. Data of cross-sections, water levels and salinity were collected, and then analysed with the salt intrusion model. This paper demonstrates a good fit between the simulated and observed salinity distribution for all three estuaries. Additionally, the calibrated Van der Burgh's coefficient K, Dispersion coefficient D0, and salt intrusion length L, for the estuaries also displayed a reasonable correlations with those calculated from the predictive equations. This indicates that not only is the salt intrusion model valid for the case studies in Malaysia but also the predictive model. Furthermore, the results from this study describe the current state of the estuaries with which the Malaysian water authority in Malaysia can make decisions on limiting water abstraction or dredging. Keywords: salt intrusion, Malaysian estuaries, discharge, predictive model, dispersion

  20. Dimensional phase transition from 1D behavior to a 3D Bose-Einstein condensate

    NASA Astrophysics Data System (ADS)

    Pelster, Axel; Morath, Denis; Straßel, Dominik; Eggert, Sebastian

    The emergence of new properties from low-dimensional building blocks is a universal theme in different areas in physics. The investigation of transitions between isolated and coupled low-dimensional systems promises to reveal new phenomena and exotic phases. Interacting 1D bosons, which are coupled in a two-dimensional array, are maybe the most fundamental example of a system which illustrates the concept of a dimensional phase transition. However, recent experiments using ultracold gases have shown a surprising discrepancy between theory and experiment and it is far from obvious if the power laws from the underlying 1D theory can predict the transition temperature and order parameter correctly for all interaction strengths. Using a combination of large-scale Quantum Monte-Carlo simulations and chain mean-field calculations, we show that the behavior of the ordering temperature as a function of inter-chain coupling strength does not follow a universal powerlaw, but also depends strongly on the filling

  1. Diffusive public goods and coexistence of cooperators and cheaters on a 1D lattice.

    PubMed

    Scheuring, István

    2014-01-01

    Many populations of cells cooperate through the production of extracellular materials. These materials (enzymes, siderophores) spread by diffusion and can be applied by both the cooperator and cheater (non-producer) cells. In this paper the problem of coexistence of cooperator and cheater cells is studied on a 1D lattice where cooperator cells produce a diffusive material which is beneficial to the individuals according to the local concentration of this public good. The reproduction success of a cell increases linearly with the benefit in the first model version and increases non-linearly (saturates) in the second version. Two types of update rules are considered; either the cooperative cell stops producing material before death (death-production-birth, DpB) or it produces the common material before it is selected to die (production-death-birth, pDB). The empty space is occupied by its neighbors according to their replication rates. By using analytical and numerical methods I have shown that coexistence of the cooperator and cheater cells is possible although atypical in the linear version of this 1D model if either DpB or pDB update rule is assumed. While coexistence is impossible in the non-linear model with pDB update rule, it is one of the typical behaviors in case of the non-linear model with DpB update rule.

  2. DISCOLORATION OF THE WETTED SURFACE IN THE 6.1D DISSOLVER

    SciTech Connect

    Rudisill, T.; Mickalonis, J.; Crapse, K.

    2013-12-18

    During a camera inspection of a failed coil in the 6.1D dissolver, an orange discoloration was observed on a portion of the dissolver wall and coils. At the request of H-Canyon Engineering, the inspection video of the dissolver was reviewed by SRNL to assess if the observed condition (a non-uniform, orange-colored substance on internal surfaces) was a result of corrosion. Although the dissolver vessel and coil corrode during dissolution operations, the high acid conditions are not consistent with the formation of ferrous oxides (i.e., orange/rust-colored corrosion products). In a subsequent investigation, SRNL performed dissolution experiments to determine if residues from the nylon bags used for Pu containment could have generated the orange discoloration following dissolution. When small pieces of a nylon bag were placed in boiling 8 M nitric acid solutions containing other components representative of the H-Canyon process, complete dissolution occurred almost immediately. No residues were obtained even when a nylon mass to volume ratio greater than 100 times the 6.1D dissolver value was used. Degradation products from the dissolution of nylon bags are not responsible for the discoloration observed in the dissolver.

  3. CoPc 2D and 1D Arrangement on a Ferromagnetic Surface.

    PubMed

    Annese, Emilia; ViolBarbosa, Carlos E; Rossi, Giorgio; Fujii, Jun

    2016-05-31

    We investigated the growth and electronic properties of Co-phthalocyanine (CoPc) molecule deposited on iron film with different structures (pseudomorph-fcc and bcc) and on iron nanowires by scanning tunnelling microscopy and X-ray absorption spectroscopy (XAS). CoPc molecules self-assemble in a two-dimensional (2D) arrangement with the molecular plane parallel to the iron surfaces, and the local order is lost after the first layer. The molecule-ferromagnet interaction causes the broadening of Co and N unoccupied molecular states as well as different electronic distribution of N states as a function of the atomic structure of iron surface. The ferromagnetic coupling between the molecule and the iron film is dominated by the electronic interaction between Co and the first Fe layer. CoPc 2D arrangement turns into 1D by using as a template the iron nanowire grown on a facet surface of oxidized Cu(332) surface. CoPc molecules interact weakly with the iron nanowires manifesting a substantial Co 3dz spectral feature in XAS spectrum and the possibility of a magnetic interaction between Co moment and iron nanowires. Both CoPc 2D and 1D arrangements can open up new interesting scenarios to tune the magnetic properties of hybrid interfaces involving metallorganic molecules. PMID:27191039

  4. Rhythm-Induced Spike-Timing Patterns Characterized by 1D Firing Map

    NASA Astrophysics Data System (ADS)

    Engelbrecht, Jan; Mirollo, Rennie

    2012-02-01

    A basic problem in neuroscience is to understand how the dynamic mechanisms that govern the responses of nerve cells to stimuli, which are both non-linear and noisy, still produce reliable collective activity. We study patterning in the responses of neurons subjected to periodic rhythms. These patterns are governed by simple, low-dimensional mathematical structures independent of modeling detail. We show both theoretically and in whole-cell recordings that the 1D map generated from successive spike times is such a construct. As expected, the stable periodic points of this 1D map cause a neuron's entrainment or phase-locking to a periodic rhythm. But our work has also revealed a complementary and unexpected patterning in the spike-timing of un-entrained neurons in the form of repeated sequences of reliable spike-phase advances, which cannot be characterized simply as a noisy perturbation near the stable periodic points of the noise-free return map. This new patterning appears to require both noise and a sufficiently steep return map.

  5. Atomic layer deposition on phase-shift lithography generated photoresist patterns for 1D nanochannel fabrication.

    PubMed

    Güder, Firat; Yang, Yang; Krüger, Michael; Stevens, Gregory B; Zacharias, Margit

    2010-12-01

    A versatile, low-cost, and flexible approach is presented for the fabrication of millimeter-long, sub-100 nm wide 1D nanochannels with tunable wall properties (wall thickness and material) over wafer-scale areas on glass, alumina, and silicon surfaces. This approach includes three fabrication steps. First, sub-100 nm photoresist line patterns were generated by near-field contact phase-shift lithography (NFC-PSL) using an inexpensive homemade borosilicate mask (NFC-PSM). Second, various metal oxides were directly coated on the resist patterns with low-temperature atomic layer deposition (ALD). Finally, the remaining photoresist was removed via an acetone dip, and then planar nanochannel arrays were formed on the substrate. In contrast to all the previous fabrication routes, the sub-100 nm photoresist line patterns produced by NFC-PSL are directly employed as a sacrificial layer for the creation of nanochannels. Because both the NFC-PSL and the ALD deposition are highly reproducible processes, the strategy proposed here can be regarded as a general route for nanochannel fabrication in a simplified and reliable manner. In addition, the fabricated nanochannels were used as templates to synthesize various organic and inorganic 1D nanostructures on the substrate surface. PMID:21047101

  6. Atomic layer deposition on phase-shift lithography generated photoresist patterns for 1D nanochannel fabrication.

    PubMed

    Güder, Firat; Yang, Yang; Krüger, Michael; Stevens, Gregory B; Zacharias, Margit

    2010-12-01

    A versatile, low-cost, and flexible approach is presented for the fabrication of millimeter-long, sub-100 nm wide 1D nanochannels with tunable wall properties (wall thickness and material) over wafer-scale areas on glass, alumina, and silicon surfaces. This approach includes three fabrication steps. First, sub-100 nm photoresist line patterns were generated by near-field contact phase-shift lithography (NFC-PSL) using an inexpensive homemade borosilicate mask (NFC-PSM). Second, various metal oxides were directly coated on the resist patterns with low-temperature atomic layer deposition (ALD). Finally, the remaining photoresist was removed via an acetone dip, and then planar nanochannel arrays were formed on the substrate. In contrast to all the previous fabrication routes, the sub-100 nm photoresist line patterns produced by NFC-PSL are directly employed as a sacrificial layer for the creation of nanochannels. Because both the NFC-PSL and the ALD deposition are highly reproducible processes, the strategy proposed here can be regarded as a general route for nanochannel fabrication in a simplified and reliable manner. In addition, the fabricated nanochannels were used as templates to synthesize various organic and inorganic 1D nanostructures on the substrate surface.

  7. Structure, electrochemical properties and capacitance performance of polypyrrole electrodeposited onto 1-D crystals of iridium complex

    NASA Astrophysics Data System (ADS)

    Wysocka-Żołopa, Monika; Winkler, Krzysztof

    2015-12-01

    Composites of polypyrrole and one-dimensional iridium complex crystals [(C2H5)4N]0.55[IrCl2(CO)2] were prepared by in situ two-step electrodeposition. Initially, iridium complex crystals were formed during [IrCl2(CO)2]- complex oxidation. Next, pyrrole was electropolymerized on the surface of the iridium needles. The morphology of the composite was investigated by scanning and transmission electron microscopy. At positive potentials, the iridium complex crystals and the polypyrrole were oxidized. In aprotic solvents, oxidation of the iridium complex crystals resulted in their dissolution. In water containing tetra(n-butyl)ammonium chlorides, the 1-D iridium complex crystals were reversibly oxidized. The product of the iridium complex oxidation remained on the electrode surface in crystalline form. The iridium complex needles significantly influenced the redox properties of the polymer. The polypyrrole involved electrode processes become more reversible in presence of crystals of iridium complex. The current of polypyrrole oxidation was higher compared to that of pure polypyrrole and the capacitance properties of the polymer were significantly enhanced. A specific capacitance as high as 590 F g-1 was obtained for a composite of polypyrrole and 1-D crystals of the iridium complex in water containing tetra(n-butyl)ammonium chloride. This value is approximately twice as high as the capacitance of the pure polymer deposited onto the electrode surface.

  8. NOKIN1D: one-dimensional neutron kinetics based on a nodal collocation method

    NASA Astrophysics Data System (ADS)

    Verdú, G.; Ginestar, D.; Miró, R.; Jambrina, A.; Barrachina, T.; Soler, Amparo; Concejal, Alberto

    2014-06-01

    The TRAC-BF1 one-dimensional kinetic model is a formulation of the neutron diffusion equation in the two energy groups' approximation, based on the analytical nodal method (ANM). The advantage compared with a zero-dimensional kinetic model is that the axial power profile may vary with time due to thermal-hydraulic parameter changes and/or actions of the control systems but at has the disadvantages that in unusual situations it fails to converge. The nodal collocation method developed for the neutron diffusion equation and applied to the kinetics resolution of TRAC-BF1 thermal-hydraulics, is an adaptation of the traditional collocation methods for the discretization of partial differential equations, based on the development of the solution as a linear combination of analytical functions. It has chosen to use a nodal collocation method based on a development of Legendre polynomials of neutron fluxes in each cell. The qualification is carried out by the analysis of the turbine trip transient from the NEA benchmark in Peach Bottom NPP using both the original 1D kinetics implemented in TRAC-BF1 and the 1D nodal collocation method.

  9. Nonparametric 1-D temperature restoration in lossy media using Tikhonov regularization on sparse radiometry data.

    PubMed

    Jacobsen, Svein; Stauffer, Paul R

    2003-02-01

    Microwave thermometry has the potential to characterize thermal gradients in lossy materials down to a few centimeters depth. The problem of retrieving temperature profiles from sets of brightness temperatures is studied using Galerkin expansion of one-dimensional (1-D) temperature profiles combined with Tikhonov regularization and predefined boundary conditions. From a priori knowledge of the temperature field shape, smooth Chebyshev polynomials are used as basis functions in the series expansion. The proposed estimator does not require iterative calculations that are normally performed using conventional numerical methods for signal parameter estimation and is, thus, very fast. Noise effects versus bandwidth limitations (smoothness of solutions) are studied in terms of four performance indexes defined in the text. In general, statistical spread of the temperature estimator increases with increasing number of Chebyshev polynomials. Systematic deviation from true values (bias) decreases as the number of Chebyshev polynomials increases. Results show that smooth temperature profiles can be reproduced using 6-7 Chebyshev polynomials. With additional constraints such as boundary conditions and maxima localization, a three-frequency-band radiometric scan is sufficient to produce acceptable results in regions with low thermal gradients. As the spatial variability of the 1-D temperature profile increases, more radiometric bands (5-6) are required to provide nonbiased estimates.

  10. Transient 1D transport equation simulated by a mixed Green element formulation

    NASA Astrophysics Data System (ADS)

    Taigbenu, Akpofure Efemena; Onyejekwe, Okey Oseloka

    1997-08-01

    New discrete element equations or coefficients are derived for the transient 1D diffusion-advection or transport equation based on the Green element replication of the differential equation using linear elements. The Green element method (GEM), which solves the singular boundary integral theory (a Fredholm integral equation of the second kind) on a typical element, gives rise to a banded global coefficient matrix which is amenable to efficient matrix solvers. It is herein derived for the transient 1D transport equation with uniform and non-uniform ambient flow conditions and in which first-order decay of the containment is allowed to take place. Because the GEM implements the singular boundary integral theory within each element at a time, the integrations are carried out in exact fashion, thereby making the application of the boundary integral theory more utilitarian. This system of discrete equations, presented herein for the first time, using linear interpolating functions in the spatial dimensions shows promising stable characteristics for advection-dominant transport. Three numerical examples are used to demonstrate the capabilities of the method. The second-order-correct Crank-Nicolson scheme and the modified fully implicit scheme with a difference weighting value of two give superior solutions in all simulated examples.

  11. Thermodynamics of large N gauge theories with chemical potentials in a 1/ D expansion

    NASA Astrophysics Data System (ADS)

    Morita, Takeshi

    2010-08-01

    In order to understand thermodynamical properties of N D-branes with chemical potentials associated with R-symmetry charges, we study a one dimensional large N gauge theory (bosonic BFSS type model) as a first step. This model is obtained through a dimensional reduction of a 1 + D dimensional SU( N) Yang-Mills theory and we use a 1 /D expansion to investigate the phase structure. We find three phases in the μ - T plane. We also show that all the adjoint scalars condense at large D and obtain a mass dynamically. This dynamical mass protects our model from the usual perturbative instability of massless scalars in a non-zero chemical potential. We find that the system is at least meta-stable for arbitrary large values of the chemical potentials in D → ∞ limit. We also explore the existence of similar condensation in higher dimensional gauge theories in a high temperature limit. In 2 and 3 dimensions, the condensation always happens as in one dimensional case. On the other hand, if the dimension is higher than 4, there is a critical chemical potential and the condensation happens only if the chemical potentials are below it.

  12. A world-line framework for 1D topological conformal σ-models

    NASA Astrophysics Data System (ADS)

    Baulieu, L.; Holanda, N. L.; Toppan, F.

    2015-11-01

    We use world-line methods for pseudo-supersymmetry to construct sl(2|1)-invariant actions for the (2, 2, 0) chiral and (1, 2, 1) real supermultiplets of the twisted D-module representations of the sl(2|1) superalgebra. The derived one-dimensional topological conformal σ-models are invariant under nilpotent operators. The actions are constructed for both parabolic and hyperbolic/trigonometric realizations (with extra potential terms in the latter case). The scaling dimension λ of the supermultiplets defines a coupling constant, 2λ + 1, the free theories being recovered at λ = - /1 2 . We also present, generalizing previous works, the D-module representations of one-dimensional superconformal algebras induced by N = ( p , q ) pseudo-supersymmetry acting on (k, n, n - k) supermultiplets. Besides sl(2|1), we obtain the superalgebras A(1, 1), D(2, 1; α), D(3, 1), D(4, 1), A(2, 1) from (p, q) = (1, 1), (2, 2), (3, 3), (4, 4), (5, 1), at given k, n and critical values of λ.

  13. 1D and 2D Assembly of Plant Viruses for Materials Development

    SciTech Connect

    Qian Wang

    2013-01-11

    The research focused on the development of novel bionanoparticle (BNP)-based materials, especially the assembly of chemically and genetically-tailored BNP at the interface between immiscible fluids. The chemical, physical, dynamical and mechanistic aspects have been studied in this research. In particular, rod-like tobacco mosaic virus (TMV) based anisotropic nanorods were synthesized via RNA or polymer assisted assembling process. Such kind of TMV-rods offers an ideal model system for the mechanistic study of orienting and packing anisotropic nanoparticles, which may have great potential in the applications of photovoltaic and field emission devices. Specific objectives include: 1) Synthesize BNPs with controlled functionality at defined positions; 2) synthesize 1D nanorods with defined length via polymer or RNA assisted assembly of TMV or TMV coat proteins; 3) self-assemble and crosslink BNPs and TMV-nanorods at liquid-liquid interfaces; 4) quantitatively characterize the structural organization of the 1D and 2D BNP-assemblies using both small angle neutron scattering and synchrotron small angle X-ray scattering; and 5) develop methods to apply grazing incidence small angle X-ray/neutron scattering to investigate the assemblies of BNPs.

  14. Quasi-1D physics in metal-organic frameworks: MIL-47(V) from first principles

    PubMed Central

    Jaeken, Jan W; De Baerdemacker, Stijn; Lejaeghere, Kurt; Van Speybroeck, Veronique

    2014-01-01

    Summary The geometric and electronic structure of the MIL-47(V) metal-organic framework (MOF) is investigated by using ab initio density functional theory (DFT) calculations. Special focus is placed on the relation between the spin configuration and the properties of the MOF. The ground state is found to be antiferromagnetic, with an equilibrium volume of 1554.70 Å3. The transition pressure of the pressure-induced large-pore-to-narrow-pore phase transition is calculated to be 82 MPa and 124 MPa for systems with ferromagnetic and antiferromagnetic chains, respectively. For a mixed system, the transition pressure is found to be a weighted average of the ferromagnetic and antiferromagnetic transition pressures. Mapping DFT energies onto a simple-spin Hamiltonian shows both the intra- and inter-chain coupling to be antiferromagnetic, with the latter coupling constant being two orders of magnitude smaller than the former, suggesting the MIL-47(V) to present quasi-1D behavior. The electronic structure of the different spin configurations is investigated and it shows that the band gap position varies strongly with the spin configuration. The valence and conduction bands show a clear V d-character. In addition, these bands are flat in directions orthogonal to VO6 chains, while showing dispersion along the the direction of the VO6 chains, similar as for other quasi-1D materials. PMID:25383285

  15. Optimisation of A 1d-ecosystem Model To Observations In The North Atlantic Ocean

    NASA Astrophysics Data System (ADS)

    Schartau, M.; Oschlies, A.

    An optimisation experiment is performed with a vertically resolved, nitrogen based ecosystem model, comprising four state variables (1D-NPZD model): dissolved inor- ganic nitrogen (N), phytoplankton (P), herbivorous zooplankton (Z) and detritus (D). Parameter values of the NPZD-model are optimised while regarding observational data from three locations in the North Atlantic simultaneously: Bermuda Atlantic Time-series Study (BATS), data of the North Atlantic Bloom Experiment (NABE) and observations from Ocean Weather Ship-India (OWS-INDIA). The simultaneous opti- misation yields a best parameter set which can be utilized for basin wide simulations in coupled physical-biological (general circulation) models of the North Atlantic. After optimisation of the 1D-NPZD model, systematic discrepancies between 14C-fixation rates and modelled primary production are emphasized. Using the optimal parame- ter estimates for coupled 3D-simulations, the biogeochemical fluxes show substantial differences in contrast to previous model results. For instance, rapid recycling of or- ganic matter enhances primary production rates. This becomes most evident within the oligotrophic regions of the subtropical gyre.

  16. Quasinormal modes of (anti-)de Sitter black holes in the 1 /D expansion

    NASA Astrophysics Data System (ADS)

    Emparan, Roberto; Suzuki, Ryotaku; Tanabe, Kentaro

    2015-04-01

    We use the inverse-dimensional expansion to compute analytically the frequencies of a set of quasinormal modes of static black holes of Einstein-(Anti-)de Sitter gravity, including the cases of spherical, planar or hyperbolic horizons. The modes we study are decoupled modes localized in the near-horizon region, which are the ones that capture physics peculiar to each black hole (such as their instabilities), and which in large black holes contain hydrodynamic behavior. Our results also give the unstable Gregory-Laflamme frequencies of Ricci-flat black branes to two orders higher in 1 /D than previous calculations. We discuss the limits on the accuracy of these results due to the asymptotic but not convergent character of the 1 /D expansion, which is due to the violation of the decoupling condition at finite D. Finally, we compare the frequencies for AdS black branes to calculations in the hydrodynamic expansion in powers of the momentum k. Our results extend up to k 9 for the sound mode and to k 8 for the shear mode.

  17. What is the smallest physically acceptable scale for 1D turbulence schemes ?

    NASA Astrophysics Data System (ADS)

    Honnert, Rachel; Masson, Valéry

    2014-10-01

    In numerical weather prediction (NWP) models, at mesoscale, the subgrid convective boundary-layer turbulence is dominated by the uni-directional (1D) vertical thermal production. In Large-Eddy Simulations (LES), the thermal plumes are resolved and the residual subgrid turbulent motions are homogeneous and isotropic, thus three-dimensional (3D), resulting from the dynamical production. This article sets the critical horizontal resolution for which the usually 1D turbulence schemes of NWP models must be replaced by 3D turbulence schemes. LES from five dry and cumulus-topped free convective boundary layers and one forced convective boundary layer are performed. From these LES data, the thermal production and vertical and horizontal dynamical productions are calculated at several resolutions from LES to mesoscale. It appears that the production terms of both dry and cumulus-topped free convective boundary layers have the same behavior. A pattern emerges whenever data are ranked by the resolution scaled by the size of thermal plumes, (h + hc , where h is the boundary-layer height and hc is the depth of the cloud layer). In free onvective boundary layers, the critical horizontal resolution for which the horizontal motions must be represented is 0.5(h + hc ). However, the critical horizontal resolution in the forced convective boundary layer case is 3(h + hc ).

  18. Measurements of O(1 D) quenching rates in the F-region

    NASA Technical Reports Server (NTRS)

    Sipler, D. P.; Biondi, M. A.

    1972-01-01

    In-situ determinations of the quenching of O(1 D) atoms by N2 and O2 molecules were made from observations of 6300 A nightglow intensity enhancements produced by the Platteville 1.6 MW transmitter. The heating of F-region electrons near the point of reflection of the RF wave leads to electron impact excitation of oxygen atoms to the O(1 D) state. It is shown that the resulting region of enhance 6300 A emission is localized to the region of electron energy absorption for heating at the lower altitudes. At 225 km the measured time constants for intensity buildup following transmitter turn-on and for intensity decay following turn-off are identical and equal to (13 plus or minus 1) sec. Time constants varying from 30 to 80 sec are found for the altitude range 260 to 300 km. The inferred quenching coefficient for the whole altitude range, 225 to 300 km, is 4.4 + 2 or - 1 x 10 to the minus 11th power cu cm/sec at 950 K, in good agreement with laboratory data. The quenching frequency obtained at 225 km, when referred to the altitude 120 km, is equal to (21 plus or minus 2)/sec, in agreement with less direct ionospheric determinations.

  19. Tunable Splitting of the Ground-State Degeneracy in 1D Parafermionic Wires

    NASA Astrophysics Data System (ADS)

    Chen, Chun; Burnell, Fiona

    Systems with topologically protected ground-state degeneracies are currently of great interest due to their potential applications in quantum computing. In practise this degeneracy is never exact, and the magnitude of the ground-state degeneracy splitting imposes constraints on the timescales over which information is topologically protected. In this Letter we use an instanton approach to evaluate the splitting of topological ground-state degeneracy in quasi-1D systems with parafermion zero modes, in the specific case where parafermions are realized by inducing a superconducting gap in pairs of fractional quantum Hall (FQH) edges. We show that, like 1D topological superconducting wires, this splitting has an oscillatory dependence on the chemical potential, which arises from an intrinsic Berry phase that produces interference between distinct instanton tunneling events. These Berry phases can be mapped to chiral phases in a (dual) quantum clock model using a Fradkin-Kadanoff transformation. Comparing our low-energy spectrum to that of phenomenological parafermion models allows us to evaluate the real and imaginary parts of the hopping integral between adjacent parafermionic zero modes as functions of the chemical potential.

  20. CD1d Expression and Invariant NKT Cell Responses in Herpesvirus Infections

    PubMed Central

    Chung, Brian K.; Priatel, John J.; Tan, Rusung

    2015-01-01

    Invariant natural killer T (iNKT) cells are a highly conserved subset of unconventional T lymphocytes that express a canonical, semi-invariant T cell receptor and surface markers shared with the natural killer cell lineage. iNKT cells recognize exogenous and endogenous glycolipid antigens restricted by non-polymorphic CD1d molecules, and are highly responsive to the prototypical agonist, α-galactosylceramide. Upon activation, iNKT cells rapidly coordinate signaling between innate and adaptive immune cells through the secretion of proinflammatory cytokines, leading to the maturation of antigen-presenting cells, and expansion of antigen-specific CD4+ and CD8+ T cells. Because of their potent immunoregulatory properties, iNKT cells have been extensively studied and are known to play a pivotal role in mediating immune responses against microbial pathogens including viruses. Here, we review evidence that herpesviruses manipulate CD1d expression to escape iNKT cell surveillance and establish lifelong latency in humans. Collectively, published findings suggest that iNKT cells play critical roles in anti-herpesvirus immune responses and could be harnessed therapeutically to limit viral infection and viral-associated disease. PMID:26161082

  1. 1D self-assembly of chemisorbed thymine on Cu(110) driven by dispersion forces

    NASA Astrophysics Data System (ADS)

    Temprano, I.; Thomas, G.; Haq, S.; Dyer, M. S.; Latter, E. G.; Darling, G. R.; Uvdal, P.; Raval, R.

    2015-03-01

    Adsorption of thymine on a defined Cu(110) surface was studied using reflection-absorption infrared spectroscopy (RAIRS), temperature programmed desorption (TPD), and scanning tunnelling microscopy (STM). In addition, density functional theory (DFT) calculations were undertaken in order to further understand the energetics of adsorption and self-assembly. The combination of RAIRS, TPD, and DFT results indicates that an upright, three-point-bonded adsorption configuration is adopted by the deprotonated thymine at room temperature. DFT calculations show that the upright configuration adopted by individual molecules arises as a direct result of strong O-Cu and N-Cu bonds between the molecule and the surface. STM data reveal that this upright thymine motif self-assembles into 1D chains, which are surprisingly oriented along the open-packed [001] direction of the metal surface and orthogonal to the alignment of the functional groups that are normally implicated in H-bonding interactions. DFT modelling of this system reveals that the molecular organisation is actually driven by dispersion interactions, which cause a slight tilt of the molecule and provide the major driving force for assembly into dimers and 1D chains. The relative orientations and distances of neighbouring molecules are amenable for π-π stacking, suggesting that this is an important contributor in the self-assembly process.

  2. Reduced synaptic vesicle protein degradation at lysosomes curbs TBC1D24/sky-induced neurodegeneration

    PubMed Central

    Fernandes, Ana Clara; Uytterhoeven, Valerie; Kuenen, Sabine; Wang, Yu-Chun; Slabbaert, Jan R.; Swerts, Jef; Kasprowicz, Jaroslaw; Aerts, Stein

    2014-01-01

    Synaptic demise and accumulation of dysfunctional proteins are thought of as common features in neurodegeneration. However, the mechanisms by which synaptic proteins turn over remain elusive. In this paper, we study Drosophila melanogaster lacking active TBC1D24/Skywalker (Sky), a protein that in humans causes severe neurodegeneration, epilepsy, and DOOR (deafness, onychdystrophy, osteodystrophy, and mental retardation) syndrome, and identify endosome-to-lysosome trafficking as a mechanism for degradation of synaptic vesicle-associated proteins. In fly sky mutants, synaptic vesicles traveled excessively to endosomes. Using chimeric fluorescent timers, we show that synaptic vesicle-associated proteins were younger on average, suggesting that older proteins are more efficiently degraded. Using a genetic screen, we find that reducing endosomal-to-lysosomal trafficking, controlled by the homotypic fusion and vacuole protein sorting (HOPS) complex, rescued the neurotransmission and neurodegeneration defects in sky mutants. Consistently, synaptic vesicle proteins were older in HOPS complex mutants, and these mutants also showed reduced neurotransmission. Our findings define a mechanism in which synaptic transmission is facilitated by efficient protein turnover at lysosomes and identify a potential strategy to suppress defects arising from TBC1D24 mutations in humans. PMID:25422373

  3. Situating methodology within qualitative research.

    PubMed

    Kramer-Kile, Marnie L

    2012-01-01

    Qualitative nurse researchers are required to make deliberate and sometimes complex methodological decisions about their work. Methodology in qualitative research is a comprehensive approach in which theory (ideas) and method (doing) are brought into close alignment. It can be difficult, at times, to understand the concept of methodology. The purpose of this research column is to: (1) define qualitative methodology; (2) illuminate the relationship between epistemology, ontology and methodology; (3) explicate the connection between theory and method in qualitative research design; and 4) highlight relevant examples of methodological decisions made within cardiovascular nursing research. Although there is no "one set way" to do qualitative research, all qualitative researchers should account for the choices they make throughout the research process and articulate their methodological decision-making along the way.

  4. Crystal Structures of Human TBC1D1 and TBC1D4 (AS160) RabGTPase-activating Protein (RabGAP) Domains Reveal Critical Elements for GLUT4 Translocation

    SciTech Connect

    S Park; W Jin; S Shoelson

    2011-12-31

    We have solved the x-ray crystal structures of the RabGAP domains of human TBC1D1 and human TBC1D4 (AS160), at 2.2 and 3.5 {angstrom} resolution, respectively. Like the yeast Gyp1p RabGAP domain, whose structure was solved previously in complex with mouse Rab33B, the human TBC1D1 and TBC1D4 domains both have 16 {alpha}-helices and no {beta}-sheet elements. We expected the yeast Gyp1p RabGAP/mouse Rab33B structure to predict the corresponding interfaces between cognate mammalian RabGAPs and Rabs, but found that residues were poorly conserved. We further tested the relevance of this model by Ala-scanning mutagenesis, but only one of five substitutions within the inferred binding site of the TBC1D1 RabGAP significantly perturbed catalytic efficiency. In addition, substitution of TBC1D1 residues with corresponding residues from Gyp1p did not enhance catalytic efficiency. We hypothesized that biologically relevant RabGAP/Rab partners utilize additional contacts not described in the yeast Gyp1p/mouse Rab33B structure, which we predicted using our two new human TBC1D1 and TBC1D4 structures. Ala substitution of TBC1D1 Met{sup 930}, corresponding to a residue outside of the Gyp1p/Rab33B contact, substantially reduced catalytic activity. GLUT4 translocation assays confirmed the biological relevance of our findings. Substitutions with lowest RabGAP activity, including catalytically dead RK and Met{sup 930} and Leu{sup 1019} predicted to perturb Rab binding, confirmed that biological activity requires contacts between cognate RabGAPs and Rabs beyond those in the yeast Gyp1p RabGAP/mouse Rab33B structure.

  5. Analog Ensemble Methodology: Expansion and Optimization for Renewable Energy Applications

    NASA Astrophysics Data System (ADS)

    Harding, L.; Cervone, G.; Delle Monache, L.

    2015-12-01

    Renewable energy is fundamental for sustaining and developing society. Solar and wind energy are promising sources because of their decreased environmental impact relative to conventional energy sources, improved efficiency, and increased use. A key challenge with renewable energy production is the generation of accurate renewable energy forecasts at varying spatial and temporal scales to assist utility companies in effective energy management. Specifically, this research applies the Analog Ensemble (AnEn) methodology to short-term (0-48 hour) wind speed forecasting for power generation and short-term (0-72) hour solar power measured (PM) output predictions. AnEn uses a set of past observations corresponding to the best analogs of a deterministic numerical weather prediction model to generate a probability distribution of future atmospheric states: an ensemble of analogs. Currently the AnEn methodology equally weights predictors and only handles 1D(time). We determine an optimal distribution of predictor weights based upon parameter characteristics, investigate spatial variations in the application of the methodology and develop a theory expanding the methodology into 2D. The AnEn methodology improves short-term prediction accuracy, decreases computational costs and provides uncertainty quantification allowing utility companies to manage over- or under power generation for renewable energy sources.

  6. Data Assimilation of Lightning using 1D+3D/4D WRF Var Assimilation Schemes with Non-Linear Observation Operators

    NASA Astrophysics Data System (ADS)

    Navon, M. I.; Stefanescu, R.; Fuelberg, H. E.; Marchand, M.

    2012-12-01

    between inner and outer loops of the incremental 3-D/4-D VAR minimization. The first part of this paper will describe the methodology and performance analysis of the 1D-Var retrieval scheme that adjusts the WRF temperature profiles closer to an observed value as in Mahfouf et al. (2005). The second part will show the positive impact of these 1D-Var pseudo - temperature observations on both model 3D/4D-Var WRF analyses and short-range forecasts for three cases - the Tuscaloosa tornado outbreak (April 27, 2011) with intense but localized lightning, a second severe storm outbreak with more widespread but less intense lightning (June 27, 2011), and a northeaster containing much less lightning.

  7. Adipocyte-specific CD1d-deficiency mitigates diet-induced obesity and insulin resistance in mice

    PubMed Central

    Satoh, Masashi; Hoshino, Miyuki; Fujita, Koki; Iizuka, Misao; Fujii, Satoshi; Clingan, Christopher S.; Van Kaer, Luc; Iwabuchi, Kazuya

    2016-01-01

    It has been shown that CD1d expression and glycolipid-reactive, CD1d-restricted NKT cells exacerbate the development of obesity and insulin resistance in mice. However, the relevant CD1d-expressing cells that influence the effects of NKT cells on the progression of obesity remain incompletely defined. In this study, we have demonstrated that 3T3-L1 adipocytes can present endogenous ligands to NKT cells, leading to IFN-γ production, which in turn, stimulated 3T3-L1 adipocytes to enhance expression of CD1d and CCL2, and decrease expression of adiponectin. Furthermore, adipocyte-specific CD1d deletion decreased the size of the visceral adipose tissue mass and enhanced insulin sensitivity in mice fed a high-fat diet (HFD). Accordingly, NKT cells were less activated, IFN-γ production was significantly reduced, and levels of adiponectin were increased in these animals as compared with control mice on HFD. Importantly, macrophage recruitment into the adipose tissue of adipocyte-specific CD1d-deficient mice was significantly blunted. These findings indicate that interactions between NKT cells and CD1d-expressing adipocytes producing endogenous NKT cell ligands play a critical role in the induction of inflammation and functional modulation of adipose tissue that leads to obesity. PMID:27329323

  8. Syntrophin isoforms play specific functional roles in the α1D-adrenergic receptor/DAPC signalosome

    PubMed Central

    Lyssand, John S.; Lee, Kyung-Soon; DeFino, Mia; Adams, Marvin E.; Hague, Chris

    2014-01-01

    α1D-Adrenergic receptors, key regulators of cardiovascular system function, are organized as a multi-protein complex in the plasma membrane. Using a Type-I PDZ-binding motif in their distal C-terminal domain, α1D-ARs associate with syntrophins and dystrophin-associated protein complex (DAPC) members utrophin, dystrobrevin and α-catulin. Three of the five syntrophin isoforms (α, β1 and β2) interact with α1D-ARs and our previous studies suggest multiple isoforms are required for proper α1D-AR function in vivo. This study determined the contribution of each specific syntrophin isoform to α1D-AR function. Radioligand binding experiments reveal α-syntrophin enhances α1D-AR binding site density, while phosphoinositol and ERK1/2 signaling assays indicate β2-syntrophin augments full and partial agonist efficacy for coupling to downstream signaling mechanisms. The results of this study provide clear evidence that the cytosolic components within the α1D-AR/DAPC signalosome significantly alter the pharmacological properties of α1-AR ligands in vitro. PMID:21846462

  9. Lysophospholipid presentation by CD1d and recognition by a human Natural Killer T-cell receptor

    SciTech Connect

    López-Sagaseta, Jacinto; Sibener, Leah V.; Kung, Jennifer E.; Gumperz, Jenny; Adams, Erin J.

    2014-10-02

    Invariant Natural Killer T (iNKT) cells use highly restricted {alpha}{beta} T cell receptors (TCRs) to probe the repertoire of lipids presented by CD1d molecules. Here, we describe our studies of lysophosphatidylcholine (LPC) presentation by human CD1d and its recognition by a native, LPC-specific iNKT TCR. Human CD1d presenting LPC adopts an altered conformation from that of CD1d presenting glycolipid antigens, with a shifted {alpha}1 helix resulting in an open A pocket. Binding of the iNKT TCR requires a 7-{angstrom} displacement of the LPC headgroup but stabilizes the CD1d-LPC complex in a closed conformation. The iNKT TCR CDR loop footprint on CD1d-LPC is anchored by the conserved positioning of the CDR3{alpha} loop, whereas the remaining CDR loops are shifted, due in part to amino-acid differences in the CDR3{beta} and J{beta} segment used by this iNKT TCR. These findings provide insight into how lysophospholipids are presented by human CD1d molecules and how this complex is recognized by some, but not all, human iNKT cells.

  10. Evaluation of static pressure drops and PM10 and TSP emissions for modified 1D-3D cyclones

    SciTech Connect

    Holt, G.A.; Baker, R.V.; Hughs, S.E.

    1999-12-01

    Five modifications of a standard 1D3D cyclone were tested and compared against the standard 1D3D design in the areas of particulate emissions and static pressure drop across the cyclone. The modifications to the 1D3D design included a 2D2D inlet, a 2D2D air outlet, a D/3 trash exit, an expansion chamber with a D/3 trash exit, and a tapered air outlet duct. The 1D3D modifications that exhibited a significant improvement in reducing both PM10 and total suspended particulate (TSP) emissions were the designs with the 2D2D inlet and air exhaust combined with either the conical D/3 tail cone or the expansion chamber. In reference to the standard 1D3D cyclone, the average reduction in PM10 emissions was 24 to 29% with a 29 to 35% reduction observed in TSP emissions. The modifications with the tapered air outlets did not show any significant improvements in controlling PM10 emissions. However, the modification with the tapered air outlet/expansion chamber combination exhibited statistical significance in reducing TSP emissions by 18% compared to the 1D3D cyclone. All modifications tested exhibited lower static pressure drops than the standard 1D3D.

  11. Effects of vanadium- and iron-doping on crystal morphology and electrochemical properties of 1D nanostructured manganese oxides

    NASA Astrophysics Data System (ADS)

    Yoo, Ha Na; Park, Dae Hoon; Hwang, Seong-Ju

    One-dimensional (1D) nanostructures of vanadium- and iron-doped manganese oxides, Mn 1- xM xO 2 (M = V and Fe), are synthesized via one-pot hydrothermal reactions. The results of X-ray diffraction studies and electron microscopic analyses demonstrate that all the present 1D nanostructured materials possess α-MnO 2-type structure. While the vanadium dopants produce 1D nanorods with a smaller aspect ratio of ∼3-5, iron dopants produce 1D nanowires with a high aspect ratio of >20. X-ray absorption spectroscopy clearly shows that the dopant vanadium ions are stabilized in tetravalent oxidation state with distorted octahedral symmetry, while the iron ions are stabilized in trivalent oxidation state with regular octahedral symmetry. Significant local structural distortion and size mismatch of dopant vanadium ions are responsible for the low aspect ratio of the vanadium-doped nanorods through the less effective growth of a 1D nanostructure. According to electrochemical measurements, doping with Fe and V can improve the electrode performance of 1D nanostructured manganate and such a positive effect is much more prominent for the iron dopant. The present study clearly indicates that doping with Fe and V provides an effective way of tailoring the crystal dimension and electrochemical properties of 1D nanostructured manganese oxides.

  12. Structure and binding kinetics of three different human CD1d-alpha-galactosylceramide-specific T cell receptors.

    PubMed

    Gadola, Stephan D; Koch, Michael; Marles-Wright, Jon; Lissin, Nikolai M; Shepherd, Dawn; Matulis, Gediminas; Harlos, Karl; Villiger, Peter M; Stuart, David I; Jakobsen, Bent K; Cerundolo, Vincenzo; Jones, E Yvonne

    2006-03-20

    Invariant human TCR Valpha24-Jalpha18+/Vbeta11+ NKT cells (iNKT) are restricted by CD1d-alpha-glycosylceramides. We analyzed crystal structures and binding characteristics for an iNKT TCR plus two CD1d-alpha-GalCer-specific Vbeta11+ TCRs that use different TCR Valpha chains. The results were similar to those previously reported for MHC-peptide-specific TCRs, illustrating the versatility of the TCR platform. Docking TCR and CD1d-alpha-GalCer structures provided plausible insights into their interaction. The model supports a diagonal orientation of TCR on CD1d and suggests that complementarity determining region (CDR)3alpha, CDR3beta, and CDR1beta interact with ligands presented by CD1d, whereas CDR2beta binds to the CD1d alpha1 helix. This docking provides an explanation for the dominant usage of Vbeta11 and Vbeta8.2 chains by human and mouse iNKT cells, respectively, for recognition of CD1d-alpha-GalCer.

  13. Retinoic acid regulates CD1d gene expression at the transcriptional level in human and rodent monocytic cells.

    PubMed

    Chen, Qiuyan; Ross, A Catharine

    2007-04-01

    CD1d belongs to a group of nonclassical antigen-presenting molecules that present glycolipid antigens and thereby activate natural killer T (NKT) cells, a subset of bifunctional T cells. Little is known so far regarding the expression and physiologic regulation of CD1d. Here we show that all-trans-retinoic acid (RA), the active metabolite of vitamin A, rapidly (1 hr after treatment) increases CD1d mRNA in human and rodent monocytic cells at a physiologic dose (10 nM). The induction is RA specific and RA receptor (RAR) dependent-RA and an RARalpha agonist, Am580, both had a pronounced positive effect, whereas the addition of RARalpha antagonist partially blocked the increase in CD1d mRNA induced by RA and Am580. The induction was also completely blocked by the presence of actinomycin D. A putative RA-response element was identified in the distal 5' flanking region of the CD1d gene, which binds nuclear retinoid receptors and was responsive to RA in both gel mobility shift assay and transient transfection assay in THP-1 cells. These results further confirmed the transcriptional regulation of RA in CD1d gene expression. Moreover, RA significantly increased alpha-galactosylceramide-induced spleen cell proliferation. These studies together provide evidence for a previously unknown mechanism of CD1d gene expression regulation by RA and suggest that RA is a significant modulator of NKT cell activation.

  14. Role for lysosomal phospholipase A2 in iNKT cell-mediated CD1d recognition

    PubMed Central

    Paduraru, Crina; Bezbradica, Jelena S.; Kunte, Amit; Kelly, Robert; Shayman, James A.; Veerapen, Natacha; Cox, Liam R.; Besra, Gurdyal S.; Cresswell, Peter

    2013-01-01

    Invariant natural killer T (iNKT) cells recognize self lipid antigens presented by CD1d molecules. The nature of the self-antigens involved in the development and maturation of iNKT cells is poorly defined. Lysophospholipids are self-antigens presented by CD1d that are generated through the action of phospholipases A1 and A2. Lysosomal phospholipase A2 (LPLA2, group XV phospholipase A2) resides in the endocytic system, the main site where CD1d antigen acquisition occurs, suggesting that it could be particularly important in CD1d function. We find that Lpla2−/− mice show a decrease in iNKT cell numbers that is neither the result of a general effect on the development of lymphocyte populations nor of effects on CD1d expression. However, endogenous lipid antigen presentation by CD1d is reduced in the absence of LPLA2. Our data suggest that LPLA2 plays a role in the generation of CD1d complexes with thymic lipids required for the normal selection and maturation of iNKT cells. PMID:23493550

  15. Dynamics of the gas-liquid interfacial reaction of O(1D) with a liquid hydrocarbon.

    PubMed

    Waring, Carla; King, Kerry L; Costen, Matthew L; McKendrick, Kenneth G

    2011-06-30

    The dynamics of the gas-liquid interfacial reaction of the first electronically excited state of the oxygen atom, O((1)D), with the surface of a liquid hydrocarbon, squalane (C(30)H(62); 2,6,10,15,19,23-hexamethyltetracosane) has been studied experimentally. Translationally hot O((1)D) atoms were generated by 193 nm photolysis of a low pressure (nominally 1 mTorr) of N(2)O a short distance (mean = 6 mm) above a continually refreshed liquid squalane surface. Nascent OH (X(2)Π, v' = 0) reaction products were detected by laser-induced fluorescence (LIF) on the OH A(2)Σ(+)-X(2)Π (1,0) band at the same distance above the surface. The speed distribution of the recoiling OH was characterized by measuring the appearance profiles as a function of photolysis-probe delay for selected rotational levels, N'. The rotational (and, partially, fine-structure) state distributions were also measured by recording LIF excitation spectra at selected photolysis-probe delays. The OH v' = 0 rotational distribution is bimodal and can be empirically decomposed into near thermal (~300 K) and much hotter (~6000 K) Boltzmann-temperature components. There is a strong positive correlation between rotational excitation and translation energy. However, the colder rotational component still represents a significant fraction (~30%) of the fastest products, which have substantially superthermal speeds. We estimate an approximate upper limit of 3% for the quantum yield of OH per O((1)D) atom that collides with the surface. By comparison with established mechanisms for the corresponding reactions in the gas phase, we conclude that the rotationally and translationally hot products are formed via a nonstatistical insertion mechanism. The rotationally cold but translationally hot component is most likely produced by direct abstraction. Secondary collisions at the liquid surface of products of either of the previous two mechanisms are most likely responsible for the rotationally and translationally cold

  16. 1D coordination polymers with polychalcogenides as linkers between metal atoms

    SciTech Connect

    Kysliak, Oleksandr; Beck, Johannes

    2013-07-15

    The reactions of zinc metal with elemental selenium and selenium/sulfur mixtures in liquid ammonia or methylamine under solvothermal conditions in closed glass ampoules at 50 °C lead within some days specifically to [Zn(NH{sub 3}){sub 2}Se{sub 4}]{sub n} (1), [Zn(MeNH{sub 2}){sub 2}Se{sub 4}]{sub n} (2), [Zn(NH{sub 3}){sub 2}Se{sub 2.23}S{sub 1.77}]{sub n} (3). From MnCl{sub 2}, Rb{sub 2}Se and excess Se in n-butylamine [Mn({sup n}BuNH{sub 2}){sub 4}Se{sub 6}]{sub n} (4) is obtained after prolonged reaction time at ambient temperature. The compounds are sensitive towards air and loss of NH{sub 3} or the amine ligands. The crystal structures were determined by single crystal diffraction at low temperatures. As a common structural feature, all compounds represent 1D coordination polymers with polychalcogenide chains as linkers between the metal atoms and consist of infinite [M–Ch{sub m}–]{sub n} chains (M=Zn, Mn; Ch{sub m}=Se{sub 4}, (S/Se){sub 4}, Se{sub 6}). The Zn central atoms in 1–3 have tetrahedral coordination with two amine ligands, the Mn atoms in 4 have octahedral coordination with four amine ligands and cis position of the two Se atoms. Raman spectra of 1–3 show the stretching mode vibrations of the Ch{sub 4} groups. The observation of S–S, S–Se, and Se–Se vibration bands in the spectrum of 3 indicates the presence of mixed S/Se polyanions. An optical band gap of 1.86(5) eV was determined for 2 by diffuse reflectance spectroscopy. - Graphical abstract: The reaction of Zn and Se in liquid methylamine yields dark red [Zn(NH{sub 2}CH{sub 3})Se{sub 4}], a 1D coordination polymer consisting of helical Zn–Se{sub 4}–Zn– chains. - Highlights: • A series of 1D coordination polymers consisting of metal amine complexes concatenated by polychalcogenide ions is presented. • Syntheses were performed as solvothermal reactions in liquid ammonia, liquid methylamine and n-butylamine. • Crystal structures are dominated by helices [M–Ch{sub m

  17. Higher-order local and non-local correlations for 1D strongly interacting Bose gas

    NASA Astrophysics Data System (ADS)

    Nandani, EJKP; Römer, Rudolf A.; Tan, Shina; Guan, Xi-Wen

    2016-05-01

    The correlation function is an important quantity in the physics of ultracold quantum gases because it provides information about the quantum many-body wave function beyond the simple density profile. In this paper we first study the M-body local correlation functions, g M , of the one-dimensional (1D) strongly repulsive Bose gas within the Lieb-Liniger model using the analytical method proposed by Gangardt and Shlyapnikov (2003 Phys. Rev. Lett. 90 010401; 2003 New J. Phys. 5 79). In the strong repulsion regime the 1D Bose gas at low temperatures is equivalent to a gas of ideal particles obeying the non-mutual generalized exclusion statistics with a statistical parameter α =1-2/γ , i.e. the quasimomenta of N strongly interacting bosons map to the momenta of N free fermions via {k}i≈ α {k}iF with i=1,\\ldots ,N. Here γ is the dimensionless interaction strength within the Lieb-Liniger model. We rigorously prove that such a statistical parameter α solely determines the sub-leading order contribution to the M-body local correlation function of the gas at strong but finite interaction strengths. We explicitly calculate the correlation functions g M in terms of γ and α at zero, low, and intermediate temperatures. For M = 2 and 3 our results reproduce the known expressions for g 2 and g 3 with sub-leading terms (see for instance (Vadim et al 2006 Phys. Rev. A 73 051604(R); Kormos et al 2009 Phys. Rev. Lett. 103 210404; Wang et al 2013 Phys. Rev. A 87 043634). We also express the leading order of the short distance non-local correlation functions < {{{\\Psi }}}\\dagger ({x}1)\\cdots {{{\\Psi }}}\\dagger ({x}M){{\\Psi }}({y}M)\\cdots {{\\Psi }}({y}1)> of the strongly repulsive Bose gas in terms of the wave function of M bosons at zero collision energy and zero total momentum. Here {{\\Psi }}(x) is the boson annihilation operator. These general formulas of the higher-order local and non-local correlation functions of the 1D Bose gas provide new insights into the

  18. Optineurin mediates a negative regulation of Rab8 by the GTPase-activating protein TBC1D17.

    PubMed

    Vaibhava, Vipul; Nagabhushana, Ananthamurthy; Chalasani, Madhavi Latha Somaraju; Sudhakar, Cherukuri; Kumari, Asha; Swarup, Ghanshyam

    2012-11-01

    Rab GTPases regulate various membrane trafficking pathways but the mechanisms by which GTPase-activating proteins recognise specific Rabs are not clear. Rab8 is involved in controlling several trafficking processes, including the trafficking of transferrin receptor from the early endosome to the recycling endosome. Here, we provide evidence to show that TBC1D17, a Rab GTPase-activating protein, through its catalytic activity, regulates Rab8-mediated endocytic trafficking of transferrin receptor. Optineurin, a Rab8-binding effector protein, mediates the interaction and colocalisation of TBC1D17 with Rab8. A non-catalytic region of TBC1D17 is required for direct interaction with optineurin. Co-expression of Rab8, but not other Rabs tested, rescues the inhibition of transferrin receptor trafficking by TBC1D17. The activated GTP-bound form of Rab8 is localised to the tubules emanating from the endocytic recycling compartment. Through its catalytic activity, TBC1D17 inhibits recruitment of Rab8 to the tubules and reduces colocalisation of transferrin receptor and Rab8. Knockdown of optineurin or TBC1D17 results in enhanced recruitment of Rab8 to the tubules. A glaucoma-associated mutant of optineurin, E50K, causes enhanced inhibition of Rab8 by TBC1D17, resulting in defective endocytic recycling of transferrin receptor. Our results show that TBC1D17, through its interaction with optineurin, regulates Rab8-mediated endocytic recycling of transferrin receptor and recruitment of Rab8 to the endocytic recycling tubules. We describe a mechanism of regulating a Rab GTPase by an effector protein (optineurin) that acts as an adaptor to bring together a Rab (Rab8) and its GTPase-activating protein (TBC1D17).

  19. Glycaemic index methodology.

    PubMed

    Brouns, F; Bjorck, I; Frayn, K N; Gibbs, A L; Lang, V; Slama, G; Wolever, T M S

    2005-06-01

    The glycaemic index (GI) concept was originally introduced to classify different sources of carbohydrate (CHO)-rich foods, usually having an energy content of >80 % from CHO, to their effect on post-meal glycaemia. It was assumed to apply to foods that primarily deliver available CHO, causing hyperglycaemia. Low-GI foods were classified as being digested and absorbed slowly and high-GI foods as being rapidly digested and absorbed, resulting in different glycaemic responses. Low-GI foods were found to induce benefits on certain risk factors for CVD and diabetes. Accordingly it has been proposed that GI classification of foods and drinks could be useful to help consumers make 'healthy food choices' within specific food groups. Classification of foods according to their impact on blood glucose responses requires a standardised way of measuring such responses. The present review discusses the most relevant methodological considerations and highlights specific recommendations regarding number of subjects, sex, subject status, inclusion and exclusion criteria, pre-test conditions, CHO test dose, blood sampling procedures, sampling times, test randomisation and calculation of glycaemic response area under the curve. All together, these technical recommendations will help to implement or reinforce measurement of GI in laboratories and help to ensure quality of results. Since there is current international interest in alternative ways of expressing glycaemic responses to foods, some of these methods are discussed.

  20. Engineering radioecology: Methodological considerations

    SciTech Connect

    Nechaev, A.F.; Projaev, V.V.; Sobolev, I.A.; Dmitriev, S.A.

    1995-12-31

    The term ``radioecology`` has been widely recognized in scientific and technical societies. At the same time, this scientific school (radioecology) does not have a precise/generally acknowledged structure, unified methodical basis, fixed subjects of investigation, etc. In other words, radioecology is a vast, important but rather amorphous conglomerate of various ideas, amalgamated mostly by their involvement in biospheric effects of ionizing radiation and some conceptual stereotypes. This paradox was acceptable up to a certain time. However, with the termination of the Cold War and because of remarkable political changes in the world, it has become possible to convert the problem of environmental restoration from the scientific sphere in particularly practical terms. Already the first steps clearly showed an imperfection of existing technologies, managerial and regulatory schemes; lack of qualified specialists, relevant methods and techniques; uncertainties in methodology of decision-making, etc. Thus, building up (or maybe, structuring) of special scientific and technological basis, which the authors call ``engineering radioecology``, seems to be an important task. In this paper they endeavored to substantiate the last thesis and to suggest some preliminary ideas concerning the subject matter of engineering radioecology.

  1. Cancer Cytogenetics: Methodology Revisited

    PubMed Central

    2014-01-01

    The Philadelphia chromosome was the first genetic abnormality discovered in cancer (in 1960), and it was found to be consistently associated with CML. The description of the Philadelphia chromosome ushered in a new era in the field of cancer cytogenetics. Accumulating genetic data have been shown to be intimately associated with the diagnosis and prognosis of neoplasms; thus, karyotyping is now considered a mandatory investigation for all newly diagnosed leukemias. The development of FISH in the 1980s overcame many of the drawbacks of assessing the genetic alterations in cancer cells by karyotyping. Karyotyping of cancer cells remains the gold standard since it provides a global analysis of the abnormalities in the entire genome of a single cell. However, subsequent methodological advances in molecular cytogenetics based on the principle of FISH that were initiated in the early 1990s have greatly enhanced the efficiency and accuracy of karyotype analysis by marrying conventional cytogenetics with molecular technologies. In this review, the development, current utilization, and technical pitfalls of both the conventional and molecular cytogenetics approaches used for cancer diagnosis over the past five decades will be discussed. PMID:25368816

  2. Profiles of 5-HT 1B/1D agonists in acute migraine with special reference to second generation agents.

    PubMed

    Deleu, D; Hanssens, Y

    1999-06-01

    The efficacy of 5-hydroxytryptamine 1B/1D (5-HT 1B/1D) agonists is related to their inhibitory effects on neurogenic inflammation, mediated through serotoninergic control mechanisms. Recently, a series of oral second generation 5-HT 1B/1D agonists (eletriptan, naratriptan, rizatriptan and zolmitriptan) have been developed and are reviewed in this paper. Their in vitro and in vivo pharmacological properties, clinical efficacy, drug interactions, and adverse effects are evaluated and compared to the gold standard in the treatment of acute migraine, sumatriptan. PMID:10427351

  3. Wavelength modulated SERS hot spot distribution in 1D nanostructures on metal film

    NASA Astrophysics Data System (ADS)

    Wang, Lili; Zeng, Xiping; Liu, Ting; Zhang, Xuemei; Wei, Hua; Huang, Yingzhou; Liu, Anping; Wang, Shuxia; Wen, Weijia

    2016-10-01

    Surface plasmons confining strong electromagnetic fields near metal surfaces, well-known as hot spots, provide an extremely efficient platform for surface-enhanced Raman scattering (SERS). In this work, SERS spectra of probing molecules in a silver particle-wire 1D nanostructure on a thin gold film are investigated. The Raman features of SERS spectra collected at the particle-wire joints exhibit an obvious wavelength dependence phenomenon. This result is confirmed electromagnetic field simulation, revealing that hot spot distribution is sensitively influenced by the wavelength of incident light at the joints. Further studies indicate this wavelength dependence of hot spot distribution is immune to influence from the geometric shape of the particle or the angle between wire and particle, which improves fabrication tolerance. This technology may have promising applications in surface plasmon related fields, such as ultrasensors, solar energy and selective surface catalysis.

  4. Fep1d: a script for the analysis of reaction coordinates.

    PubMed

    Banushkina, Polina V; Krivov, Sergei V

    2015-05-01

    The dynamics of complex systems with many degrees of freedom can be analyzed by projecting it onto one or few coordinates (collective variables). The dynamics is often described then as diffusion on a free energy landscape associated with the coordinates. Fep1d is a script for the analysis of such one-dimensional coordinates. The script allows one to construct conventional and cut-based free energy profiles, to assess the optimality of a reaction coordinate, to inspect whether the dynamics projected on the coordinate is diffusive, to transform (rescale) the reaction coordinate to more convenient ones, and to compute such quantities as the mean first passage time, the transition path times, the coordinate dependent diffusion coefficient, and so forth. Here, we describe the implemented functionality together with the underlying theoretical framework.

  5. Fluid friction and wall viscosity of the 1D blood flow model.

    PubMed

    Wang, Xiao-Fei; Nishi, Shohei; Matsukawa, Mami; Ghigo, Arthur; Lagrée, Pierre-Yves; Fullana, Jose-Maria

    2016-02-29

    We study the behavior of the pulse waves of water into a flexible tube for application to blood flow simulations. In pulse waves both fluid friction and wall viscosity are damping factors, and difficult to evaluate separately. In this paper, the coefficients of fluid friction and wall viscosity are estimated by fitting a nonlinear 1D flow model to experimental data. In the experimental setup, a distensible tube is connected to a piston pump at one end and closed at another end. The pressure and wall displacements are measured simultaneously. A good agreement between model predictions and experiments was achieved. For amplitude decrease, the effect of wall viscosity on the pulse wave has been shown as important as that of fluid viscosity. PMID:26862041

  6. Metal-dielectric photonic crystal superlattice: 1D and 2D models and empty lattice approximation

    NASA Astrophysics Data System (ADS)

    Kichin, G.; Weiss, T.; Gao, H.; Henzie, J.; Odom, T. W.; Tikhodeev, S. G.; Giessen, H.

    2012-10-01

    Periodic nanostructures are one of the main building blocks in modern nanooptics. They are used for constructing photonic crystals and metamaterials and provide optical properties that can be changed by adjusting the geometrical parameters of the structures. In this paper the optical properties of a photonic crystal slab with a 2D superlattice are discussed. The structure consists of a gold layer with a finite periodic pattern of air holes that is itself repeated periodically with a larger superperiod. We propose simplified 1D and 2D models to understand the physical nature of Wood's anomalies in the optical spectra of the investigated structure. The latter are attributed to the Rayleigh anomalies, surface plasmon Bragg resonances and the hole-localized plasmons.

  7. Mt Response of a 1d Earth Model Employing the Born Approximation with Variable Background Conductivities

    NASA Astrophysics Data System (ADS)

    Tejero, A.; Chavez, R. E.

    2001-12-01

    The Born approximation method has been commonly employed to study the electromagnetic field response. Other interpretative techniques have benn employed based upon the Born Approximation, like the extended Born approximation (EBA). This method employs the total field, instead of the primary field. Also, the Quasi Linear Approximation method (QLA) is an extension of EVA. In the present work, we propose an alternative technique, which employs the Born Approximation using variable background conductivities (BAVBC). The Green function is represented as a Born perturbation of zero order. Such that, the reference medium conductivity is a parameter selected according the working frequency. A similar procedure has been reported for stratified 1D-earth seismic models. This technique (BAVBC) has been applied to model computational models with reasonable results, as compared with available computational packages in the market. This method permits variations in the conductivity contrast of up to 80%, which provides solutions with 30% error, with respect of the analytical solution.

  8. Smooth non-extremal D1-D5-P solutions as charged gravitational instantons

    NASA Astrophysics Data System (ADS)

    Chakrabarty, Bidisha; Rocha, Jorge V.; Virmani, Amitabh

    2016-08-01

    We present an alternative and more direct construction of the non-super-symmetric D1-D5-P supergravity solutions found by Jejjala, Madden, Ross and Titchener. We show that these solutions — with all three charges and both rotations turned on — can be viewed as a charged version of the Myers-Perry instanton. We present an inverse scattering construction of the Myers-Perry instanton metric in Euclidean five-dimensional gravity. The angular momentum bounds in this construction turn out to be precisely the ones necessary for the smooth microstate geometries. We add charges on the Myers-Perry instanton using appropriate SO(4, 4) hidden symmetry transformations. The full construc-tion can be viewed as an extension and simplification of a previous work by Katsimpouri, Kleinschmidt and Virmani.

  9. 1D GAS-DYNAMIC SIMULATION OF SHOCK-WAVE PROCESSES VIA INTERNET

    SciTech Connect

    Khishchenko, K. V.; Levashov, P. R.; Povarnitsyn, M. E.; Zakharenkov, A. S.

    2009-12-28

    We present a Web-interface for 1D simulation of different shock-wave experiments. The choosing of initial parameters, the modeling itself and output data treatment can be made directly via the Internet. The interface is based upon the expert system on shock-wave data and equations of state and contains both the Eulerian and Lagrangian Godunov hydrocodes. The availability of equations of state for a broad set of substances makes this system a useful tool for planning and interpretation of shock-wave experiments. As an example of simulation with the system, results of modeling of multistep shock loading of potassium between polytetrafluoroethylene and stainless steel plates are presented in comparison with experimental data from Shakhray et al.(2005).

  10. A novel CMOS digital pixel sensor for 1D barcode scanning

    NASA Astrophysics Data System (ADS)

    Yan, Mei; DeGeronimo, Gianluigi; O'Connor, Paul; Carlson, Bradley S.

    2004-06-01

    A 1-D CMOS digital pixel image sensor system architecture is presented. Each pixel contains a photodiode, a low-power charge-sensitive amplifier, low noise sample/hold circuit, an 8-bit single-slope ADC, a 12-bit shift register and timing & control logic. The pixel is laid out on a 4μm pitch to enable a cost efficient implementation of high-resolution pixel arrays. Fixed pattern noise (FPN) is reduced by a charge-sensitive feedback amplifier, and the reset noise is cancelled by correlated double sampling read out. A prototype chip containing 512 pixels has been fabricated in the TSMC .25um logic process. A 40μV/e- conversion gain is measured with 100 e- rms read noise.

  11. Statistics of scattered photons from a driven three-level emitter in 1D open space

    SciTech Connect

    Roy, Dibyendu; Bondyopadhaya, Nilanjan

    2014-01-07

    We derive the statistics of scattered photons from a Λ- or ladder-type three-level emitter (3LE) embedded in a 1D open waveguide. The weak probe photons in the waveguide are coupled to one of the two allowed transitions of the 3LE, and the other transition is driven by a control beam. This system shows electromagnetically induced transparency (EIT) which is accompanied with the Autler-Townes splitting (ATS) at a strong driving by the control beam, and some of these effects have been observed recently. We show that the nature of second-order coherence of the transmitted probe photons near two-photon resonance changes from bunching to antibunching to constant as strength of the control beam is ramped up from zero to a higher value where the ATS appears.

  12. Quantum Diffusion on Molecular Tubes: Universal Scaling of the 1D to 2D Transition

    NASA Astrophysics Data System (ADS)

    Chuang, Chern; Lee, Chee Kong; Moix, Jeremy M.; Knoester, Jasper; Cao, Jianshu

    2016-05-01

    The transport properties of disordered systems are known to depend critically on dimensionality. We study the diffusion coefficient of a quantum particle confined to a lattice on the surface of a tube, where it scales between the 1D and 2D limits. It is found that the scaling relation is universal and independent of the temperature, disorder, and noise parameters, and the essential order parameter is the ratio between the localization length in 2D and the circumference of the tube. Phenomenological and quantitative expressions for transport properties as functions of disorder and noise are obtained and applied to real systems: In the natural chlorosomes found in light-harvesting bacteria the exciton transfer dynamics is predicted to be in the 2D limit, whereas a family of synthetic molecular aggregates is found to be in the homogeneous limit and is independent of dimensionality.

  13. Quantum Diffusion on Molecular Tubes: Universal Scaling of the 1D to 2D Transition.

    PubMed

    Chuang, Chern; Lee, Chee Kong; Moix, Jeremy M; Knoester, Jasper; Cao, Jianshu

    2016-05-13

    The transport properties of disordered systems are known to depend critically on dimensionality. We study the diffusion coefficient of a quantum particle confined to a lattice on the surface of a tube, where it scales between the 1D and 2D limits. It is found that the scaling relation is universal and independent of the temperature, disorder, and noise parameters, and the essential order parameter is the ratio between the localization length in 2D and the circumference of the tube. Phenomenological and quantitative expressions for transport properties as functions of disorder and noise are obtained and applied to real systems: In the natural chlorosomes found in light-harvesting bacteria the exciton transfer dynamics is predicted to be in the 2D limit, whereas a family of synthetic molecular aggregates is found to be in the homogeneous limit and is independent of dimensionality. PMID:27232033

  14. A low power, area efficient fpga based beamforming technique for 1-D CMUT arrays.

    PubMed

    Joseph, Bastin; Joseph, Jose; Vanjari, Siva Rama Krishna

    2015-08-01

    A low power area efficient digital beamformer targeting low frequency (2MHz) 1-D linear Capacitive Micromachined Ultrasonic Transducer (CMUT) array is developed. While designing the beamforming logic, the symmetry of the CMUT array is well exploited to reduce the area and power consumption. The proposed method is verified in Matlab by clocking an Arbitrary Waveform Generator(AWG). The architecture is successfully implemented in Xilinx Spartan 3E FPGA kit to check its functionality. The beamforming logic is implemented for 8, 16, 32, and 64 element CMUTs targeting Application Specific Integrated Circuit (ASIC) platform at Vdd 1.62V for UMC 90nm technology. It is observed that the proposed architecture consumes significantly lesser power and area (1.2895 mW power and 47134.4 μm(2) area for a 64 element digital beamforming circuit) compared to the conventional square root based algorithm.

  15. Quasi 1-D Analysis of a Circular, Compressible, Turbulent Jet Laden with Water Droplets. Appendix C

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Recent experimental studies indicate that presence of small amount of liquid droplets reduces the Overall Sound Pressure Level (OASPL) of a jet. Present study is aimed at numerically investigating the effect of liquid particles on the overall flow quantities of a heated, compressible round jet. The jet is assumed perfectly expanded. A quasi-1D model was developed for this purpose which uses area-averaged quantities that satisfy integral conservation equations. Special attention is given to represent the early development region since it is acoustically important. Approximate velocity and temperature profiles were assumed in this region to evaluate entrainment rate. Experimental correlations were used to obtain spreading rate of shear layer. The base flow thus obtained is then laden with water droplets at the exit of the nozzle. Mass, momentum and energy coupling between the two phases is represented using empirical relations. Droplet size and mass loading are varied to observe their effect on flow variables.

  16. A low power, area efficient fpga based beamforming technique for 1-D CMUT arrays.

    PubMed

    Joseph, Bastin; Joseph, Jose; Vanjari, Siva Rama Krishna

    2015-08-01

    A low power area efficient digital beamformer targeting low frequency (2MHz) 1-D linear Capacitive Micromachined Ultrasonic Transducer (CMUT) array is developed. While designing the beamforming logic, the symmetry of the CMUT array is well exploited to reduce the area and power consumption. The proposed method is verified in Matlab by clocking an Arbitrary Waveform Generator(AWG). The architecture is successfully implemented in Xilinx Spartan 3E FPGA kit to check its functionality. The beamforming logic is implemented for 8, 16, 32, and 64 element CMUTs targeting Application Specific Integrated Circuit (ASIC) platform at Vdd 1.62V for UMC 90nm technology. It is observed that the proposed architecture consumes significantly lesser power and area (1.2895 mW power and 47134.4 μm(2) area for a 64 element digital beamforming circuit) compared to the conventional square root based algorithm. PMID:26737263

  17. Survey of Multi-Material Closure Models in 1D Lagrangian Hydrodynamics

    SciTech Connect

    Maeng, Jungyeoul Brad; Hyde, David Andrew Bulloch

    2015-07-28

    Accurately treating the coupled sub-cell thermodynamics of computational cells containing multiple materials is an inevitable problem in hydrodynamics simulations, whether due to initial configurations or evolutions of the materials and computational mesh. When solving the hydrodynamics equations within a multi-material cell, we make the assumption of a single velocity field for the entire computational domain, which necessitates the addition of a closure model to attempt to resolve the behavior of the multi-material cells’ constituents. In conjunction with a 1D Lagrangian hydrodynamics code, we present a variety of both the popular as well as more recently proposed multi-material closure models and survey their performances across a spectrum of examples. We consider standard verification tests as well as practical examples using combinations of fluid, solid, and composite constituents within multi-material mixtures. Our survey provides insights into the advantages and disadvantages of various multi-material closure models in different problem configurations.

  18. Statistical investigation and thermal properties for a 1-D impact system with dissipation

    NASA Astrophysics Data System (ADS)

    Díaz I., Gabriel; Livorati, André L. P.; Leonel, Edson D.

    2016-05-01

    The behavior of the average velocity, its deviation and average squared velocity are characterized using three techniques for a 1-D dissipative impact system. The system - a particle, or an ensemble of non-interacting particles, moving in a constant gravitation field and colliding with a varying platform - is described by a nonlinear mapping. The average squared velocity allows to describe the temperature for an ensemble of particles as a function of the parameters using: (i) straightforward numerical simulations; (ii) analytically from the dynamical equations; (iii) using the probability distribution function. Comparing analytical and numerical results for the three techniques, one can check the robustness of the developed formalism, where we are able to estimate numerical values for the statistical variables, without doing extensive numerical simulations. Also, extension to other dynamical systems is immediate, including time dependent billiards.

  19. 1D accretion discs around eccentric planets: observable near-infrared variability

    NASA Astrophysics Data System (ADS)

    Dunhill, A. C.

    2015-03-01

    I present the results of 1D models of circumplanetary discs around planets on eccentric orbits. I use a classical viscous heating model to calculate emission fluxes at the wavelengths targeted by the NIRCam instrument on JWST, and compare the variability of this signal with the published NIRCam sensitivity specifications. This variability is theoretically detectable by JWST for a sufficiently viscous disc (α ˜ 10-2) around a sufficiently eccentric planet (e ˜ 0.1-0.2) and if the circumplanetary disc accretes material from its parent disc at a rate dot{M} ≳ 10^{-7} M_{⊙} yr-1. I discuss the limitations of the models used, and the implications of the result for probing the effectiveness of disc interactions for growing a planet's orbital eccentricity.

  20. Continuous 1D-Metallic Microfibers Web for Flexible Organic Solar Cells.

    PubMed

    Hong, Kihyon; Ham, Juyoung; Kim, Byoung-Joon; Park, Jae Yong; Lim, Dong Chan; Lee, Joo Yul; Lee, Jong-Lam

    2015-12-16

    We report the use of a continuous 1D-metallic microfibers web (MFW) as transparent electrode for organic solar cells (OSCs). The MFW electrode can be produced with a process that involves simple electrospinning and wet etching of metal thin film. Au MFW exhibits a maximum optical transmittance of 90.8% (at 15 Ω/sq of the sheet resistance) and excellent mechanical flexibility. The MFW structure has an average width in the range from 4 to 6 μm and a junction-free structure, resulting in very smooth surface roughness. The OSCs with Au MFW electrode exhibited a higher power conversion efficiency (PCE) of 3.50% than the device with an indium tin oxide electrode (PCE = 3.20%). The optical modeling calculation showed that the Au MFW electrode induced light scattering and improved the light absorption in the active layer, resulting in an improved PCE in the OSCs.