Radioisotope thermophotovoltaic system design and its application to an illustrative space mission

NASA Astrophysics Data System (ADS)

Schock, A.; Kumar, V.

1995-01-01

The paper describes the results of a DOE-sponsored design study of a radioisotope thermophotovoltaic generator (RTPV), to complement similar studies of Radioisotope Thermoelectric Generators (RTGs) and Stirling Generators (RSGs) previously published by the author. Instead of conducting a generic study, it was decided to focus the design effort by directing it at a specific illustrative space mission, Pluto Fast Flyby (PFF). That mission, under study by JPL, envisages a direct eight-year flight to Pluto (the only unexplored planet in the solar system), followed by comprehensive mapping, surface composition, and atmospheric structure measurements during a brief flyby of the planet and its moon Charon, and transmission of the recorded science data to Earth during a post-encounter cruise lasting up to one year. Because of Pluto's long distance from the sun (30-50 A.U.) and the mission's large energy demand, JPL has baselined the use of a radioisotope power system for the PFF spacecraft. TRGs have been tentatively selected, because they have been successfully flown on many space missions, and have demonstrated exceptional reliability and durability. The only reason for exploring the applicability of the far less mature RTPV systems is their potential for much higher conversion efficiencies, which would greatly reduce the mass and cost of the required radioisotope heat source. Those attributes are particularly important for the PFF mission, which—like all NASA missions under current consideration—is severely mass- and cost-limited. The paper describes the design of the radioisotope heat source, the thermophotovoltaic converter, and the heat rejection system; and depicts its integration with the PFF spacecraft. A companion paper presented at this conference presents the results of the thermal, electrical, and structural analysis and the design optimization of the integrated RTPV system. It also discusses the programmatic implications of the analytical results, which suggest that the RTPV generator, when developed by DOE and/or NASA, would be quite valuable not only for the PFF mission but also for other future missions requiring small, long-lived, low-mass generators.

On the influence of manufacturing practices on the SCC behavior of Alloy 690 steam generator tubing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Doherty, P.E.; Doyle, D.M.; Sarver, J.M.

1996-12-31

Thermally treated (TT) Alloy 690 is the tubing materials of choice for replacement steam generators (RSGs) throughout the world. It is manufactured using a variety of processing methods with regards to melt practice and thermomechanical forming. Studies assessing the IGSCC resistance of Alloy 690 TT SG tubing have identified a variability in the corrosion performance of nominally identical alloys. While tubing of comparable bulk chemistry may exhibit variations in microchemistry as a result of different melt practice, the correlation between melt practice and SCC resistance is difficult to assess due to other contributing factors. The other contributing factors are identifiedmore » in this investigation as microstructural features whose generation is dependent on features of particular strain-anneal forming methods by which SG tubes are fabricated. In this study the microstructural characteristics which appear to affect inservice corrosion performance of Alloy 690 TT SG tubes were evaluated. The studies included extensive microstructural examinations in addition to CERT tests performed on actual Alloy 690 TT nuclear SG tubing. The CERT test results indicate that Alloy 690 TT tubing processed at higher mill anneal temperatures display the highest degree of stress corrosion cracking (SCC) resistance. This observation is discussed with reference to carbide distributions, textural aspects and grain boundary orientation character.« less

VLTI/AMBER spectro-interferometry of the late-type supergiants V766 Cen (=HR 5171 A), σ Oph, BM Sco, and HD 206859

NASA Astrophysics Data System (ADS)

Wittkowski, M.; Arroyo-Torres, B.; Marcaide, J. M.; Abellan, F. J.; Chiavassa, A.; Guirado, J. C.

2017-01-01

Aims: We add four warmer late-type supergiants to our previous spectro-interferometric studies of red giants and supergiants. Methods: We measure the near-continuum angular diameter, derive fundamental parameters, discuss the evolutionary stage, and study extended atmospheric atomic and molecular layers. Results: V766 Cen (=HR 5171 A) is found to be a high-luminosity (log L/L⊙ = 5.8 ± 0.4) source of effective temperature 4290 ± 760 K and radius 1490 ± 540 R⊙, located in the Hertzsprung-Russell (HR) diagram close to both the Hayashi limit and Eddington limit; this source is consistent with a 40 M⊙ evolutionary track without rotation and current mass 27-36 M⊙. V766 Cen exhibits Na I in emission arising from a shell of radius 1.5 RPhot and a photocenter displacement of about 0.1 RPhot. It shows strong extended molecular (CO) layers and a dusty circumstellar background component. The other three sources are found to have lower luminosities of about log L/L⊙ = 3.4-3.5, corresponding to 5-9 M⊙ evolutionary tracks. They cover effective temperatures of 3900 K to 5300 K and radii of 60-120 R⊙. They do not show extended molecular layers as observed for higher luminosity RSGs of our sample. BM Sco shows an unusually strong contribution by an over-resolved circumstellar dust component. Conclusions: V766 Cen is a red supergiant located close to the Hayashi limit instead of a yellow hypergiant already evolving back toward warmer effective temperatures as discussed in the literature. Our observations of the Na I line and the extended molecular layers suggest an optically thick pseudo-photosphere at about 1.5 RPhot at the onset of the wind. The stars σ Oph, BM Sco, and HD 206859 are more likely high-mass red giants instead of RSGs as implied by their luminosity class Ib. This leaves us with an unsampled locus in the HR diagram corresponding to luminosities log L/L⊙ 3.8-4.8 or masses 10-13 M⊙, possibly corresponding to the mass region where stars explode as (type II-P) supernovae during the red supergiant stage. With V766 Cen, we now confirm that our previously found relation of increasing strength of extended molecular layers with increasing luminosities extends to double our previous luminosities and up to the Eddington limit. This might further point to steadily increasing radiative winds with increasing luminosity. Based on observations made with the VLT Interferometer (VLTI) at Paranal Observatory under program ID 093.D-0014.

Evaluation of automated global mapping of Reference Soil Groups of WRB2015

NASA Astrophysics Data System (ADS)

Mantel, Stephan; Caspari, Thomas; Kempen, Bas; Schad, Peter; Eberhardt, Einar; Ruiperez Gonzalez, Maria

2017-04-01

SoilGrids is an automated system that provides global predictions for standard numeric soil properties at seven standard depths down to 200 cm, currently at spatial resolutions of 1km and 250m. In addition, the system provides predictions of depth to bedrock and distribution of soil classes based on WRB and USDA Soil Taxonomy (ST). In SoilGrids250m(1), soil classes (WRB, version 2006) consist of the RSG and the first prefix qualifier, whereas in SoilGrids1km(2), the soil class was assessed at RSG level. Automated mapping of World Reference Base (WRB) Reference Soil Groups (RSGs) at a global level has great advantages. Maps can be updated in a short time span with relatively little effort when new data become available. To translate soil names of older versions of FAO/WRB and national classification systems of the source data into names according to WRB 2006, correlation tables are used in SoilGrids. Soil properties and classes are predicted independently from each other. This means that the combinations of soil properties for the same cells or soil property-soil class combinations do not necessarily yield logical combinations when the map layers are studied jointly. The model prediction procedure is robust and probably has a low source of error in the prediction of RSGs. It seems that the quality of the original soil classification in the data and the use of correlation tables are the largest sources of error in mapping the RSG distribution patterns. Predicted patterns of dominant RSGs were evaluated in selected areas and sources of error were identified. Suggestions are made for improvement of WRB2015 RSG distribution predictions in SoilGrids. Keywords: Automated global mapping; World Reference Base for Soil Resources; Data evaluation; Data quality assurance References 1 Hengl T, de Jesus JM, Heuvelink GBM, Ruiperez Gonzalez M, Kilibarda M, et al. (2016) SoilGrids250m: global gridded soil information based on Machine Learning. Earth System Science Data (ESSD), in review. 2 Hengl T, de Jesus JM, MacMillan RA, Batjes NH, Heuvelink GBM, et al. (2014) SoilGrids1km — Global Soil Information Based on Automated Mapping. PLoS ONE 9(8): e105992. doi:10.1371/journal.pone.0105992

Quantitative spectroscopic J-band study of red supergiants in Perseus OB-1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gazak, J. Zachary; Kudritzki, Rolf; Davies, Ben

2014-06-10

We demonstrate how the metallicities of red supergiant (RSG) stars can be measured from quantitative spectroscopy down to resolutions of ≈3000 in the J-band. We have obtained high resolution spectra on a sample of the RSG population of h and χ Persei, a double cluster in the solar neighborhood. We show that careful application of the MARCS model atmospheres returns measurements of Z consistent with solar metallicity. Using two grids of synthetic spectra–one in pure LTE and one with non-LTE (NLTE) calculations for the most important diagnostic lines–we measure Z = +0.04 ± 0.10 (LTE) and Z = –0.04 ±more » 0.08 (NLTE) for the sample of eleven RSGs in the cluster. We degrade the spectral resolution of our observations and find that those values remain consistent down to resolutions of less than λ/δλ of 3000. Using measurements of effective temperatures we compare our results with stellar evolution theory and find good agreement. We construct a synthetic cluster spectrum and find that analyzing this composite spectrum with single-star RSG models returns an accurate metallicity. We conclude that the RSGs make ideal targets in the near infrared for measuring the metallicities of star forming galaxies out to 7-10 Mpc and up to 10 times farther by observing the integrated light of unresolved super star clusters.« less

Evidence for the pulsational origin of the Long Secondary Periods: The red supergiant star V424 Lac (HD 216946)

NASA Astrophysics Data System (ADS)

Messina, Sergio

2007-10-01

The results of a long-term UBV photometric monitoring of the red supergiant (RSG) star V424 Lac are presented. V424 Lac shows multiperiodic brightness variations which can be attributed to pulsational oscillations. A much longer period ( P = 1601 d), that allows us to classify this star as a long secondary period variable star (LSPV) has been also detected. The B - V and U - B color variations related to the long secondary period (LSP) are similar to those related to the shorter periods, supporting the pulsational nature of LSP. The long period brightness variation of V424 Lac is accompanied by a near-UV (NUV) excess, which was spectroscopically detected in a previous study [Massey, P., Plez, B., Levesque, E.M., et al., 2005. ApJ 634, 1286] and which is now found to be variable from photometry. On the basis of the results found for V424 Lac, the NUV excess recently found in a number of RSGs may be due not solely to circumstellar dust but may also have a contribution from a still undetected LSP variability.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neugent, Kathryn F.; Massey, Philip; Skiff, Brian

Due to their transitionary nature, yellow supergiants (YSGs) provide a critical challenge for evolutionary modeling. Previous studies within M31 and the Small Magellanic Cloud show that the Geneva evolutionary models do a poor job at predicting the lifetimes of these short-lived stars. Here, we extend this study to the Large Magellanic Cloud (LMC) while also investigating the galaxy's red supergiant (RSG) content. This task is complicated by contamination by Galactic foreground stars that color and magnitude criteria alone cannot weed out. Therefore, we use proper-motions and the LMC's large systemic radial velocity ({approx}278 km s{sup -1}) to separate out thesemore » foreground dwarfs. After observing nearly 2000 stars, we identified 317 probable YSGs, 6 possible YSGs, and 505 probable RSGs. Foreground contamination of our YSG sample was {approx}80%, while that of the RSG sample was only 3%. By placing the YSGs on the Hertzsprung-Russell diagram and comparing them against the evolutionary tracks, we find that new Geneva evolutionary models do an exemplary job at predicting both the locations and the lifetimes of these transitory objects.« less

LUMINOUS AND VARIABLE STARS IN M31 AND M33. III. THE YELLOW AND RED SUPERGIANTS AND POST-RED SUPERGIANT EVOLUTION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gordon, Michael S.; Humphreys, Roberta M.; Jones, Terry J., E-mail: gordon@astro.umn.edu, E-mail: roberta@umn.edu, E-mail: tjj@astro.umn.edu

Recent supernova (SN) and transient surveys have revealed an increasing number of non-terminal stellar eruptions. Though the progenitor class of these eruptions includes the most luminous stars, little is known of the pre-SN mechanics of massive stars in their most evolved state, thus motivating a census of possible progenitors. From surveys of evolved and unstable luminous star populations in nearby galaxies, we select a sample of yellow and red supergiant (RSG) candidates in M31 and M33 for review of their spectral characteristics and spectral energy distributions (SEDs). Since the position of intermediate- and late-type supergiants on the color–magnitude diagram canmore » be heavily contaminated by foreground dwarfs, we employ spectral classification and multi-band photometry from optical and near-infrared surveys to confirm membership. Based on spectroscopic evidence for mass loss and the presence of circumstellar (CS) dust in their SEDs, we find that 30%–40% of the yellow supergiants are likely in a post-RSG state. Comparison with evolutionary tracks shows that these mass-losing, post-RSGs have initial masses between 20 and 40 M {sub ⊙}. More than half of the observed RSGs in M31 and M33 are producing dusty CS ejecta. We also identify two new warm hypergiants in M31, J004621.05+421308.06 and J004051.59+403303.00, both of which are likely in a post-RSG state.« less

IRC -10414: a bow-shock-producing red supergiant star

NASA Astrophysics Data System (ADS)

Gvaramadze, V. V.; Menten, K. M.; Kniazev, A. Y.; Langer, N.; Mackey, J.; Kraus, A.; Meyer, D. M.-A.; Kamiński, T.

2014-01-01

Most runaway OB stars, like the majority of massive stars residing in their parent clusters, go through the red supergiant (RSG) phase during their lifetimes. Nonetheless, although many dozens of massive runaways were found to be associated with bow shocks, only two RSG bow-shock-producing stars, Betelgeuse and μ Cep, are known to date. In this paper, we report the discovery of an arc-like nebula around the late M-type star IRC -10414 using the SuperCOSMOS H-alpha Survey. Our spectroscopic follow-up of IRC -10414 with the Southern African Large Telescope (SALT) showed that it is a M7 supergiant, which supports previous claims on the RSG nature of this star based on observations of its maser emission. This was reinforced by our new radio- and (sub)millimetre-wavelength molecular line observations made with the Atacama Pathfinder Experiment 12-m telescope and the Effelsberg 100-m radio telescope, respectively. The SALT spectrum of the nebula indicates that its emission is the result of shock excitation. This finding along with the arc-like shape of the nebula and an estimate of the space velocity of IRC -10414 (≈70 ± 20 km s-1) imply the bow shock interpretation for the nebula. Thus, IRC -10414 represents the third case of a bow-shock-producing RSG and the first one with a bow shock visible at optical wavelengths. We discuss the smooth appearance of the bow shocks around IRC -10414 and Betelgeuse and propose that one of the necessary conditions for stability of bow shocks generated by RSGs is the ionization of the stellar wind. Possible ionization sources of the wind of IRC -10414 are proposed and discussed.

Evolutionary Models of Red Supergiants: Evidence for A Metallicity-dependent Mixing Length and Implications for Type IIP Supernova Progenitors

NASA Astrophysics Data System (ADS)

Chun, Sang-Hyun; Yoon, Sung-Chul; Jung, Moo-Keon; Kim, Dong Uk; Kim, Jihoon

2018-01-01

Recent studies on the temperatures of red supergiants (RSGs) in the local universe provide us with an excellent observational constraint on RSG models. We calibrate the mixing length parameter by comparing model predictions with the empirical RSG temperatures in Small and Large Magellanic Clouds, Milky Way, and M31, which are inferred from the TiO band and the spectral energy distribution (SED). Although our RSG models are computed with the MESA code, our result may be applied to other stellar evolution codes, including the BEC and TWIN codes. We find evidence that the mixing length increases with increasing metallicity for both cases where the TiO and SED temperatures of RSGs are used for the calibration. Together with the recent finding of a similar correlation in low-mass red giants by Tayar et al., this implies that the metallicity dependence of the mixing length is a universal feature in post-main sequence stars of both low and high masses. Our result implies that typical Type IIP supernova (SN IIP) progenitors with initial masses of ∼ 10{--}16 {M}ȯ have a radius range of 400 {R}ȯ ≲ R≲ 800 {R}ȯ regardless of metallicity. As an auxiliary result of this study, we find that the hydrogen-rich envelope mass of SN IIP progenitors for a given initial mass is predicted to be largely independent of metallicity if the Ledoux criterion with slow semiconvection is adopted, while the Schwarzschild models predict systematically more massive hydrogen-rich envelopes for lower metallicity.

On the stability of bow shocks generated by red supergiants: the case of IRC -10414

NASA Astrophysics Data System (ADS)

Meyer, D. M.-A.; Gvaramadze, V. V.; Langer, N.; Mackey, J.; Boumis, P.; Mohamed, S.

2014-03-01

In this Letter, we explore the hypothesis that the smooth appearance of bow shocks around some red supergiants (RSGs) might be caused by the ionization of their winds by external sources of radiation. Our numerical simulations of the bow shock generated by IRC -10414 (the first-ever RSG with an optically detected bow shock) show that the ionization of the wind results in its acceleration by a factor of 2, which reduces the difference between the wind and space velocities of the star and makes the contact discontinuity of the bow shock stable for a range of stellar space velocities and mass-loss rates. Our best-fitting model reproduces the overall shape and surface brightness of the observed bow shock and suggests that the space velocity and mass-loss rate of IRC -10414 are ≈50 km s-1 and ≈10-6 M⊙ yr-1, respectively, and that the number density of the local interstellar medium is ≈3 cm-3. It also shows that the bow shock emission comes mainly from the shocked stellar wind. This naturally explains the enhanced nitrogen abundance in the line-emitting material, derived from the spectroscopy of the bow shock. We found that photoionized bow shocks are ≈15-50 times brighter in optical line emission than their neutral counterparts, from which we conclude that the bow shock of IRC -10414 must be photoionized.

High-Resolution Infrared Imaging and Polarimetry plus Spectroscopy of Evolved Red and Yellow Supergiants

NASA Astrophysics Data System (ADS)

Gordon, Michael Scott; Humphreys, Roberta; Jones, Terry J.; Gehrz, Robert D.

2018-01-01

To what extent mass loss and periods of enhanced stellar outflow can influence the terminal state of the most massive stars remains an outstanding question in the fields of stellar physics, chemical enrichment of the Local Universe, andsupernova research. For my dissertation, I focus on characterizing the stellar ejecta around supergiants through a combination of observing techniques. Using the LBT, MMT, IRTF, VLT, and SOFIA observatories, I have performed high-resolution imaging, spectroscopy, and polarimetry—methods that provide us with keen insight on mass-loss histories and 3D morphology of the Local Group's most fascinating stars.Based on spectroscopic evidence for mass loss in the optical and the presence ofcircumstellar (CS) dust in infrared SEDs, we find that 30%–40% of observed yellow supergiants in M31 and M33 are likely in a post-RSG state. We also presentnear-IR spectra from IRTF/SPeX of optically-obscured RSGs in M33. These IR-bright sources likely have some of the highest mass-loss rates and are self-obscured in the optical by their own CS ejecta. For Galactic red supergiants (RSGs), we are able to observe the gas and CS dust ejecta both close in to the central star and at larger distances. The resulting radial profiles are valuable probes on timescale for the ejecta when combined with radiative-transfer models. We find evidence for both variable/high mass-loss events and constant mass loss over the last few thousand years. Finally, we discuss the use of high-resolution imaging polarimetry with VLT/NACO of two co-eval RSG clusters toward the Galactic center. The resulting polarized intensity images in the near-infrared provide unprecedented spatial and contrast resolution of the scattered light from extended nebular material.

A Spitzer Space Telescope Far-infrared Spectral Atlas of Compact Sources in the Magellanic Clouds. II. The Small Magellanic Cloud

NASA Astrophysics Data System (ADS)

van Loon, Jacco Th.; Oliveira, Joana M.; Gordon, Karl D.; Sloan, G. C.; Engelbracht, C. W.

2010-04-01

We present far-infrared spectra, λ = 52-93 μm, obtained with the Spitzer Space Telescope in the spectral energy distribution mode of its Multiband Imaging Photometer for Spitzer instrument, of a selection of luminous compact far-infrared sources in the Small Magellanic Cloud (SMC). These comprise nine young stellar objects (YSOs), the compact H II region N 81 and a similar object within N 84, and two red supergiants (RSGs). We use the spectra to constrain the presence and temperature of cool dust and the excitation conditions within the neutral and ionized gas, in the circumstellar environments and interfaces with the surrounding interstellar medium. We compare these results with those obtained in the Large Magellanic Cloud (LMC). The spectra of the sources in N 81 (of which we also show the Infrared Space Observatory-Long-wavelength Spectrograph spectrum between 50 and 170 μm) and N 84 both display strong [O I] λ63 μm and [O III] λ88 μm fine-structure line emission. We attribute these lines to strong shocks and photo-ionized gas, respectively, in a "champagne flow" scenario. The nitrogen content of these two H II regions is very low, definitely N(N)/N(O) < 0.04 but possibly as low as N(N)/N(O) < 0.01. Overall, the oxygen lines and dust continuum are weaker in star-forming objects in the SMC than in the LMC. We attribute this to the lower metallicity of the SMC compared to that of the LMC. While the dust mass differs in proportion to metallicity, the oxygen mass differs less; both observations can be reconciled with higher densities inside star-forming cloud cores in the SMC than in the LMC. The dust in the YSOs in the SMC is warmer (37-51 K) than in comparable objects in the LMC (32-44 K). We attribute this to the reduced shielding and reduced cooling at the low metallicity of the SMC. On the other hand, the efficiency of the photo-electric effect to heat the gas is found to be indistinguishable to that measured in the same manner in the LMC, ≈0.1%-0.3%. This may result from higher cloud-core densities, or smaller grains, in the SMC. The dust associated with the two RSGs in our SMC sample is cool, and we argue that it is swept-up interstellar dust, or formed (or grew) within the bow-shock, rather than dust produced in these metal-poor RSGs themselves. Strong emission from crystalline water-ice is detected in at least one YSO. The spectra constitute a valuable resource for the planning and interpretation of observations with the Herschel Space Observatory and the Stratospheric Observatory For Infrared Astronomy.

Reconstruction of in-plane strain maps using hybrid dense sensor network composed of sensing skin

NASA Astrophysics Data System (ADS)

Downey, Austin; Laflamme, Simon; Ubertini, Filippo

2016-12-01

The authors have recently developed a soft-elastomeric capacitive (SEC)-based thin film sensor for monitoring strain on mesosurfaces. Arranged in a network configuration, the sensing system is analogous to a biological skin, where local strain can be monitored over a global area. Under plane stress conditions, the sensor output contains the additive measurement of the two principal strain components over the monitored surface. In applications where the evaluation of strain maps is useful, in structural health monitoring for instance, such signal must be decomposed into linear strain components along orthogonal directions. Previous work has led to an algorithm that enabled such decomposition by leveraging a dense sensor network configuration with the addition of assumed boundary conditions. Here, we significantly improve the algorithm’s accuracy by leveraging mature off-the-shelf solutions to create a hybrid dense sensor network (HDSN) to improve on the boundary condition assumptions. The system’s boundary conditions are enforced using unidirectional RSGs and assumed virtual sensors. Results from an extensive experimental investigation demonstrate the good performance of the proposed algorithm and its robustness with respect to sensors’ layout. Overall, the proposed algorithm is seen to effectively leverage the advantages of a hybrid dense network for application of the thin film sensor to reconstruct surface strain fields over large surfaces.

Luminous and Variable Stars in M31 and M33. III. The Yellow and Red Supergiants and Post-red Supergiant Evolution

NASA Astrophysics Data System (ADS)

Gordon, Michael S.; Humphreys, Roberta M.; Jones, Terry J.

2016-07-01

Recent supernova (SN) and transient surveys have revealed an increasing number of non-terminal stellar eruptions. Though the progenitor class of these eruptions includes the most luminous stars, little is known of the pre-SN mechanics of massive stars in their most evolved state, thus motivating a census of possible progenitors. From surveys of evolved and unstable luminous star populations in nearby galaxies, we select a sample of yellow and red supergiant (RSG) candidates in M31 and M33 for review of their spectral characteristics and spectral energy distributions (SEDs). Since the position of intermediate- and late-type supergiants on the color-magnitude diagram can be heavily contaminated by foreground dwarfs, we employ spectral classification and multi-band photometry from optical and near-infrared surveys to confirm membership. Based on spectroscopic evidence for mass loss and the presence of circumstellar (CS) dust in their SEDs, we find that 30%-40% of the yellow supergiants are likely in a post-RSG state. Comparison with evolutionary tracks shows that these mass-losing, post-RSGs have initial masses between 20 and 40 M ⊙. More than half of the observed RSGs in M31 and M33 are producing dusty CS ejecta. We also identify two new warm hypergiants in M31, J004621.05+421308.06 and J004051.59+403303.00, both of which are likely in a post-RSG state. Based on observations obtained with the Large Binocular Telescope (LBT), an international collaboration among institutions in the United States, Italy, and Germany. LBT Corporation partners are: The University of Arizona on behalf of the Arizona university system; Istituto Nazionale di Astrofisica, Italy; LBT Beteiligungsgesellschaft, Germany, representing the Max-Planck Society, the Astrophysical Institute Potsdam, and Heidelberg University; The Ohio State University, and The Research Corporation, on behalf of The University of Notre Dame, University of Minnesota, and University of Virginia.

A Star on the Run

NASA Astrophysics Data System (ADS)

Kohler, Susanna

2015-10-01

Usually stars that are born together tend to move together but sometimes stars can go rogue and run away from their original birthplace. A pair of astronomers have now discovered the first runaway red supergiant (RSG) ever identified in another galaxy. With a radial velocity discrepancy of 300 km/s, its also the fastest runaway massive star known. Discrepant Speeds: When massive stars form in giant molecular clouds, they create what are known as OB associations: groups of hot, massive, short-lived stars that have similar velocities because theyre moving through space together. But sometimes stars that appear to be part of an OB association dont have the same velocity as the rest of the group. These stars are called runaways.What causes an OB star to run away is still debated, but we know that a fairly significant fraction of OB stars are runaways. In spite of this, surprisingly few runaways have been found that are evolved massive stars i.e., the post-main-sequence state of OB stars. This is presumably because these evolved stars have had more time to move away from their birthplace, and its more difficult to identify a runaway without the context of its original group. An Evolved Runaway: Difference between observed velocity and expected velocity, plotted as a function of expected velocity. The black points are foreground stars. The red points are expected RSGs, clustered around a velocity difference of zero. The green pentagon is the runaway RSG J004330.06+405258.4. [Evans Massey 2015]Despite this challenge, a recent survey of RSGs in the galaxy M31 has led to the detection of a massive star on the run! Kate Evans (Lowell Observatory and California Institute of Technology) and Philip Massey (Lowell Observatory and Northern Arizona University) discovered that RSG J004330.06+405258.4 is moving through the Andromeda Galaxy with a radial velocity thats off by about 300 km/s from the radial velocity expected for its location.Evans and Massey discovered this rogue star via a photometric survey of RSGs in M31, followed up by spectroscopy with the Multiple Mirror Telescope. They determined that the star is also separated from other massive stars in the disk of the galaxy by about 4.6 kpc which is roughly the distance it would be expected to travel, given its discrepant motion, in an assumed age of about 10 Myr.The authors suggest that this star may be a high-mass analog of hypervelocity stars stars within the Milky Way that are moving fast enough to escape the galaxy. The authors demonstrate that the total discrepant speed of RSG J004330.06+405258.4 is probably comparable to the escape velocity of M31s disk.But whether or not this star is moving fast enough to escape turns out to be moot: it will only live another million years, which means it wont have enough time to leave the galaxy before ending its life in a spectacular supernova. Citation: Kate Anne Evans and Philip Massey 2015 AJ 150 149. doi:10.1088/0004-6256/150/5/149

Luminous Infrared Sources in the Local Group: Identifying the Missing Links in Massive Star Evolution

NASA Astrophysics Data System (ADS)

Britavskiy, N.; Bonanos, A. Z.; Mehner, A.

2015-01-01

We present the first systematic survey of dusty massive stars (RSGs, LBVs, sgB[e]) in nearby galaxies, with the goal of understanding their importance in massive star evolution. Using the fact that these stars are bright in mid-infrared colors due to dust, we provide a technique for selecting and identifying dusty evolved stars based on the results of Bonanos et al. (2009, 2010), Britavskiy et al. (2014), and archival Spitzer/IRAC photometry. We present the results of our spectroscopic follow-up of luminous infrared sources in the Local Group dwarf irregular galaxies: Pegasus, Phoenix, Sextans A and WLM. The survey aims to complete the census of dusty massive stars in the Local Group.

Strong magnetic field generated by the extreme oxygen-rich red supergiant VY Canis Majoris

NASA Astrophysics Data System (ADS)

Shinnaga, Hiroko; Claussen, Mark J.; Yamamoto, Satoshi; Shimojo, Masumi

2017-12-01

Evolved stars experience high mass-loss rates forming thick circumstellar envelopes (CSEs). The circumstellar material is made of the result of stellar nucleosynthesis and, as such, plays a crucial role in the chemical evolution of galaxies and the universe. Since asymmetric geometries of CSEs are common, and with very complex structures for some cases, radiative pressure from the stars can explain only a small portion of the mass-loss processes; thus the essential driving mechanism is still unknown, particularly for high-mass stars. Here we report on magnetic field measurements associated with the well-known extreme red supergiant (RSG) VY Canis Majoris (VY CMa). We measured the linear polarization and the Zeeman splitting of the SiO v = 0, J = 1-0 transition using a sensitive radio interferometer. The measured magnetic field strengths are surprisingly high; their upper limits range between 150 and 650 G within 530 au (˜80 R*) of the star. The lower limit of the field strength is expected to be at least ˜10 G based on the high degree of linear polarization. Since the field strengths are very high, the magnetic field must be a key element in understanding the stellar evolution of VY CMa, as well as the dynamical and chemical evolution of the complex CSE of the star. M-type RSGs, with large stellar surface, were thought to be very slow rotators. This would seem to make a dynamo in operation difficult, and would also dilute any fossil magnetic field. At least for VY CMa, we expect that powerful dynamo processes must still be active to generate the intense magnetic field.

How well does the Friends-of-Friends algorithm recover group properties from galaxy catalogues limited in both distance and luminosity?

NASA Astrophysics Data System (ADS)

Duarte, Manuel; Mamon, Gary A.

2014-05-01

The specific star formation rates of galaxies are influenced both by their mass and by their environment. Moreover, the mass function of groups and clusters serves as a powerful cosmological tool. It is thus important to quantify the accuracy to which group properties are extracted from redshift surveys. We test here the Friends-of-Friends (FoF) grouping algorithm, which depends on two linking lengths (LLs), plane-of-sky and line-of-sight (LOS), normalized to the mean nearest neighbour separation of field galaxies. We argue, on theoretical grounds, that LLs should be b⊥ ≃ 0.11, and b∥ ≈ 1.3 to recover 95 per cent of all galaxies with projected radii within the virial radius r200 and 95 per cent of the galaxies along the LOS. We then predict that 80 to 90 per cent of the galaxies in FoF groups should lie within their parent real-space groups (RSGs), defined within their virial spheres. We test the FoF extraction for 16 × 16 pairs of LLs, using subsamples of galaxies, doubly complete in distance and luminosity, of a flux-limited mock Sloan Digital Sky Survey (SDSS) galaxy catalogue. We find that massive RSGs are more prone to fragmentation, while the fragments typically have low estimated mass, with typically 30 per cent of groups of low and intermediate estimated mass being fragments. Group merging rises drastically with estimated mass. For groups of three or more galaxies, galaxy completeness and reliability are both typically better than 80 per cent (after discarding the fragments). Estimated masses of extracted groups are biased low, by up to a factor 4 at low richness, while the inefficiency of mass estimation improves from 0.85 dex to 0.2 dex when moving from low to high multiplicity groups. The optimal LLs depend on the scientific goal for the group catalogue. We propose b⊥ ≃ 0.07, with b∥ ≃ 1.1 for studies of environmental effects, b∥ ≃ 2.5 for cosmographic studies and b∥ ≃ 5 for followups of individual groups.

GHOSTS IN THE ATTIC: MAPPING THE STELLAR CONTENT OF THE S0 GALAXY NGC 5102

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davidge, T. J.

2010-02-15

The spatial distribution of stars in the nearby S0 galaxy NGC 5102 is investigated using images obtained with WIRCam and MegaCam on the Canada-France-Hawaii Telescope. With the exception of gaps between detector elements, the entire galaxy is surveyed in r' and i', while the J and Ks data extend out to R {sub GC} {approx} 6 kpc, which corresponds to almost 7 disk scale lengths. A modest population of main-sequence stars with M{sub V} < -3.5 and ages {approx}70 Myr are detected throughout the disk, with the majority located in the southern half of the galaxy. The stellar disk inmore » the northern half of the galaxy is warped, following structure that is also seen in H I. Objects with photometric properties that are consistent with those of bright asymptotic giant branch (AGB) stars are seen throughout the disk, and the ratio of C stars to bright M giants is consistent with an overall increase in the star formation rate within the past 1 Gyr. Star-forming activity during the interval 0.1-2 Gyr was more centrally concentrated than during the past {approx}100 Myr. The structure of the disk changes near R {sub GC} {approx} 5 kpc (5.5 disk scale lengths), in the sense that the radial surface density profile defined by red supergiants (RSGs) and bright AGB stars levels off at larger radii. RSGs and bright AGB stars are traced out to a radius of 14 kpc (15.6 scale lengths) along the southern portion of the major axis, while a tentative detection is also made of bright AGB stars at a projected distance of {approx}16 kpc along the southeast minor axis. A large clump of AGB stars that subtends {approx}1 arcmin is identified to the west of the galaxy center. It is argued that this is the remnant of a companion galaxy that triggered past episodes of elevated star-forming activity.« less

The nature of the ionised nebula surrounding the red supergiant W26

NASA Astrophysics Data System (ADS)

Wesson, Roger

2015-08-01

The red supergiant W26 in the massive star cluster Westerlund 1 is surrounded by a compact ionised nebula. This is unique among RSGs, and the excitation mechanism of the nebula is not yet known - it may be ionised by an unseen compact companion, or by a nearby blue supergiant. We present new observations of the nebula: high resolution spatially resolved spectra taken with FLAMES at the VLT show that the nebula is a ring, with velocities consistent with that expected for red supergiant ejecta, and ruling out the possibility of a Luminous Blue Variable-type eruption preceding the RSG phase as the origin of the nebula. A triangular patch of nebulosity outside the ring appears to be associated with W26, and may be material stripped from the expanding ring by the cumulative cluster wind and radiation field.

The initial masses of the red supergiant progenitors to Type II supernovae

NASA Astrophysics Data System (ADS)

Davies, Ben; Beasor, Emma R.

2018-02-01

There are a growing number of nearby supernovae (SNe) for which the progenitor star is detected in archival pre-explosion imaging. From these images it is possible to measure the progenitor's brightness a few years before explosion, and ultimately estimate its initial mass. Previous work has shown that II-P and II-L SNe have red supergiant (RSG) progenitors, and that the range of initial masses for these progenitors seems to be limited to ≲ 17 M⊙. This is in contrast with the cut-off of 25-30 M⊙ predicted by evolutionary models, a result that is termed the `red supergiant problem'. Here we investigate one particular source of systematic error present in converting pre-explosion photometry into an initial mass, which of the bolometric correction (BC) used to convert a single-band flux into a bolometric luminosity. We show, using star clusters, that RSGs evolve to later spectral types as they approach SN, which in turn causes the BC to become larger. Failure to account for this results in a systematic underestimate of a star's luminosity, and hence its initial mass. Using our empirically motivated BCs we reappraise the II-P and II-L SNe that have their progenitors detected in pre-explosion imaging. Fitting an initial mass function to these updated masses results in an increased upper mass cut-off of Mhi = 19.0^{+2.5}_{-1.3} M⊙, with a 95 per cent upper confidence limit of <27 M⊙. Accounting for finite sample size effects and systematic uncertainties in the mass-luminosity relationship raises the cut-off to Mhi = 25 M⊙ (<33 M⊙, 95 per cent confidence). We therefore conclude that there is currently no strong evidence for `missing' high-mass progenitors to core-collapse SNe.

The prognostic value of reactive stroma on prostate needle biopsy: a population-based study.

PubMed

Saeter, Thorstein; Vlatkovic, Ljiljana; Waaler, Gudmund; Servoll, Einar; Nesland, Jahn M; Axcrona, Karol; Axcrona, Ulrika

2015-05-01

Reactive tumor stroma has been shown to play an active role in prostatic carcinogenesis. A grading system for reactive stroma in prostate cancer (PC) has recently been established and found to predict biochemical recurrence and prostate cancer-specific mortality (PCSM) in prostatectomized patients. To the best of our knowledge, there has been no study investigating the prognostic value of reactive stromal grading (RSG) with regard to PCSM when evaluated in diagnostic prostate needle biopsies. A population-based study on 318 patients, encompassing all cases of PC diagnosed by needle biopsies and without evidence of systemic metastasis at the time of diagnosis in Aust-Agder County in the period 1991-1999. Patients were identified by cross-referencing the Cancer Registry of Norway. Clinical data were obtained by review of medical charts. The endpoint was PCSM. RSG was evaluated on haematoxylin and eosin stained sections according to previously described criteria; grade 0, 0-5% reactive stroma; grade 1, 6-15%; grade 2, 16-50%; grade 3, 51-100%. RSG could be evaluated in 278 patients. The median follow- up time was 110 months (interquartile range: 51-171). The 10-year PC - specific survival rate for RSGs of 0, 1, 2, and 3 was 96%, 81%, 69%, and 63%, respectively (P < 0.005). RSG remained independently associated with PCSM in a multivariate Cox regression analysis adjusting for prostate-specific antigen level, clinical stage, Gleason score, and mode of treatment. The concordance index of the multivariate model was 0.814 CONCLUSIONS: Our study demonstrates that RSG in diagnostic prostate needle biopsies predicts PCSM independently of other evaluable prognostic factors. Hence, RSG could be used in addition to traditional prognostic factors for prognostication and treatment stratification of PC patients. © 2015 Wiley Periodicals, Inc.

Seeing Red in NGC 1978, NGC 55, and NGC 3109

NASA Astrophysics Data System (ADS)

Davidge, T. J.

2018-04-01

Spectra of the intermediate-age star cluster NGC 1978 and the dwarf irregular galaxies NGC 55 and NGC 3109 are discussed. The spectra were recorded with the Gemini Multi-object Spectrograph on Gemini South and span the 0.7–1.1 μm wavelength interval. Five slit pointings were observed in NGC 1978, and these are used to examine stochastic effects on the integrated red light from an intermediate-age cluster. The removal of either the brightest M giant or the brightest C star from the co-added spectrum has minor effects on the equivalent withs of the Ca triplet. The most robust signature of C stars in the integrated cluster spectrum at these wavelengths is the CN band head near 7900 Å. The equivalent widths of Ca triplet lines in the NGC 1978 spectrum and in the spectra of individual cluster stars are larger than expected for a scaled-solar abundance system. It is suggested that these stars have a lower than expected surface gravity, which might occur if the stars in NGC 1978 have been subject to extra mixing processes, as suggested by Lederer et al. The near-infrared color profile of NGC 1978 is shown to contain a prominent red cusp in the central 10 arcsec, and the suppression of light from this cusp does not affect the depth of the Ca lines in the integrated spectrum. The NGC 55 spectra run parallel to the major axis, and a gradient is found in the strength of the Ca lines, in the sense that the Ca lines weaken with increasing distance from the disk plane. Comparisons with models suggest that the disk light is dominated by stars with ages 1–2 Gyr, in agreement with star-forming histories (SFHs) obtained from the analysis of color–magnitude diagrams (CMDs). The NGC 55 spectra also sample a large star-forming complex. The age of this complex inferred from comparisons with models is broadly consistent with that estimated from a near-infrared CMD of the same region. The CN band head at 7900 Å in this part of NGC 55 is detected, but this is likely a signature of red supergiants (RSGs) rather than C stars. The NGC 3109 observations sample three different parts of that galaxy but have a low signal-to-noise ratio. Comparisons with models suggest that the light from the NGC 3109 disk at red wavelengths is dominated by RSGs with ages of at most a few tens of Myr, in qualitative agreement with SFHs that are based on photometric measurements.

The Upside of Failure: How Regional Student Groups Learn from Their Mistakes

PubMed Central

Mishra, Tarun; Parra, R. Gonzalo; Abeel, Thomas

2014-01-01

Success is the result of planning, hard work, determination, foresight, and a little bit of luck. Unfortunately, nobody has thought to pave the road to success. Although failure can be discouraging and time-consuming, it presents incredible learning opportunities—the biggest difference between those who succeed and those who abandon their projects lies in their response to adversity. This article reviews events undertaken by the Regional Student Groups (RSGs) in India and Argentina, the problems they encountered, and what can be learned from them. RSG-India attempted to organize an online scientific meeting (also known as a virtual conference) with geographically dispersed stakeholders, a totally new concept for them. RSG-Argentina tackled the challenge of organizing a two-day symposium, their first event ever. Some of the complications they faced were easy to fix, others led to the cancellation of activities, and all of them resulted in valuable lessons. The main goal of this article is to highlight, through their experiences, the universal importance of a healthy panel of contingency plans. PMID:25101799

RED SUPERGIANT STARS AS COSMIC ABUNDANCE PROBES: NLTE EFFECTS IN J-BAND IRON AND TITANIUM LINES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bergemann, Maria; Kudritzki, Rolf-Peter; Lind, Karin

2012-06-01

Detailed non-LTE (NLTE) calculations for red supergiant (RSG) stars are presented to investigate the influence of NLTE on the formation of atomic iron and titanium lines in the J band. With their enormous brightness at J band RSG stars are ideal probes of cosmic abundances. Recent LTE studies have found that metallicities accurate to 0.15 dex can be determined from medium-resolution spectroscopy of individual RSGs in galaxies as distant as 10 Mpc. The NLTE results obtained in this investigation support these findings. NLTE abundance corrections for iron are smaller than 0.05 dex for effective temperatures between 3400 K and 4200more » K and 0.1 dex at 4400 K. For titanium the NLTE abundance corrections vary smoothly between -0.4 dex and +0.2 dex as a function of effective temperature. For both elements, the corrections also depend on stellar gravity and metallicity. The physical reasons behind the NLTE corrections and the consequences for extragalactic J-band abundance studies are discussed.« less

The Italian contribution to the World Soils Book Series: The Soils of Italy

NASA Astrophysics Data System (ADS)

Costantini, Edoardo; Dazzi, Carmelo

2015-04-01

Passing to the age of "Anthropocene", man has forgotten the ancient bond that ties him to the soil, and turning from "homo sapiens" to "homo technologicus" he has stopped considering how much his well-being and the quality of life on Earth are fundamentally linked to the quality of soils. Yet today, as never before, maintaining the quality of soils is of paramount relevance for the sustainable development of humanity. Unfortunately, as soils are a crypto-resource, not many lay-people recognize its importance in the biosphere equilibrium and, unfortunately, seldom consider it among the environmental resources that must be protected! To fill such a gap in knowledge, the Springer editor, under the leading of professor Alfred Hartemink, has published the World Soils Book Series, whose aim is to spread the knowledge on the soils in a particular country in a concise and highly reader-friendly way. The volume "The Soils of Italy" belongs to this international series of books. Its ambitious goals are to establish a broad base for the knowledge of the soils of Italy, and to give useful information on i) their characteristics, diffusion and fertility, ii) the main threats they are subjected, and iii) the future scenarios of relationships between soil sciences and the disciplines, which are not traditionally linked to the world of agriculture, such as urban development, medicine, economics, sociology, archaeology. In Italy there is about 75% of the global pedodiversity. A vast majority of the WRB reference soil groups (25 out of 32), as well as soil orders of Soil Taxonomy (10 out of 12) are represented in the main Italian soil typological units (STUs). More than a fourth of STUs belongs to Cambisols, more than a half to only four reference soil groups (Cambisols, Luvisols, Regosols, Phaeozems), and 88% to nine RSGs (the former plus Calcisols, Vertisols, Fluvisols, Leptosols, and Andosols), while the remaining 16 RSGs are represented in 12% of STUs. The clear skewness and lognormal distribution of STUs demonstrate the utmost endemic nature of most of Italian soils, which make many of them threatened with extinction. The writing of this book was attended by numerous experts from several Italian universities and research centres, which have taken on the responsibility of editing the various chapters. A specific characteristic of the book is that it collects scripts of both mature and young soil scientists, who contributed in a decisive way to render the text up-to-date and, hopefully, attractive. It is a common aspiration of the authors that this book could provide interesting information to soil experts and students, so that they can enhance the attention of the public on the Italian soils: a very limited but very economically and environmentally important resource of Italy.

Luminous and Variable Stars in M31 and M33. V. The Upper HR Diagram

NASA Astrophysics Data System (ADS)

Humphreys, Roberta M.; Davidson, Kris; Hahn, David; Martin, John C.; Weis, Kerstin

2017-07-01

We present HR diagrams for the massive star populations in M31 and M33, including several different types of emission-line stars: the confirmed luminous blue variables (LBVs), candidate LBVs, B[e] supergiants, and the warm hypergiants. We estimate their apparent temperatures and luminosities for comparison with their respective massive star populations and evaluate the possible relationships of these different classes of evolved, massive stars, and their evolutionary state. Several of the LBV candidates lie near the LBV/S Dor instability strip that supports their classification. Most of the B[e] supergiants, however, are less luminous than the LBVs. Many are very dusty with the infrared flux contributing one-third or more to their total flux. They are also relatively isolated from other luminous OB stars. Overall, their spatial distribution suggests a more evolved state. Some may be post-RSGs (red supergiants) like the warm hypergiants, and there may be more than one path to becoming a B[e] star. There are sufficient differences in the spectra, luminosities, spatial distribution, and the presence or lack of dust between the LBVs and B[e] supergiants to conclude that one group does not evolve into the other.

Luminous and Variable Stars in M31 and M33. V. The Upper HR Diagram

DOE Office of Scientific and Technical Information (OSTI.GOV)

Humphreys, Roberta M.; Davidson, Kris; Hahn, David

We present HR diagrams for the massive star populations in M31 and M33, including several different types of emission-line stars: the confirmed luminous blue variables (LBVs), candidate LBVs, B[e] supergiants, and the warm hypergiants. We estimate their apparent temperatures and luminosities for comparison with their respective massive star populations and evaluate the possible relationships of these different classes of evolved, massive stars, and their evolutionary state. Several of the LBV candidates lie near the LBV/S Dor instability strip that supports their classification. Most of the B[e] supergiants, however, are less luminous than the LBVs. Many are very dusty with themore » infrared flux contributing one-third or more to their total flux. They are also relatively isolated from other luminous OB stars. Overall, their spatial distribution suggests a more evolved state. Some may be post-RSGs (red supergiants) like the warm hypergiants, and there may be more than one path to becoming a B[e] star. There are sufficient differences in the spectra, luminosities, spatial distribution, and the presence or lack of dust between the LBVs and B[e] supergiants to conclude that one group does not evolve into the other.« less

A Study of Hypergiant Mass Loss in the Near-To-Mid Infrared: VY CMa, IRC +10420, mu Cep and rho Cas

NASA Astrophysics Data System (ADS)

Shenoy, Dinesh Prabhakar

2016-01-01

Stars of initial mass greater than 9 M_sun become red supergiants (RSGs), a short-lived stage during which they experience mass-loss that strongly influences their post-RSG evolution and end state. The highest luminosity RSGs, referred to here as hypergiants, experience episodic mass-loss whose mechanism remains poorly understood and motivates observations to help constrain it. This thesis studies mass loss from hypergiant stars with near-to-mid infrared imaging over a range of angular scales. The recent mass-loss history of the extreme red supergiant VY Canis Majoris and the warm hypergiant star IRC +10420 are studied at the sub-arcsecond scale with adaptive optics imaging and imaging polarimetry from 1 - 5 micron using LMIRCam on the Large Binocular Telescope (LBT) and MMT-Pol at the MMT Observatory. The nebular features of VY CMa are found to be highly polarized at 1.3 and 3.1 micron, with optically thick scattering required to reproduce the observed surface brightness. The flux of VY CMa's peculiar ``Southwest Clump'' is demonstrated to be due almost entirely to optically thick scattering, with little thermal emission, and with a lower limit mass of 5E-03 M_sun in this single feature. The imaging polarimetry of IRC +10420 at 2.2 micron resolves nebular emission with intrinsic polarization of 30%, with a high surface brightness indicating optically thick scattering largely in the plane of the sky. Using the polarimetry to constrain the scattered light emission, it is shown that the nebula's the emission is mostly thermal with a color temperature well above that for typical astrophysical dust. To probe further into hypergiants' history of mass-loss, mid-IR imaging with MMT/ MIRAC and SOFIA/FORCAST is used to study VY CMa, IRC +10420 and two additional hypergiants: the RSG mu Cep and the warm hypergiant rho Cas. Using DUSTY 1-D radiative transfer models, mu Cep's mass-loss rate is found to have declined by about a factor of 5 over a 13,000 history, ranging from 5E-06 down to ~1E-06 M_sun / yr. The mo rphology of VY CMa indicates a cooler dust component coincident with the highly asymmetric reflection nebulae seen in the visual and near-IR. The lack of cold dust at greater distances around VY CMa indicates its mass-loss history is limited to the last ~1200 years, with an average rate of 6E-04 M_sun / yr. Two distinct periods are found in the mass-loss history of IRC +10420, with a high rate of 2E-03 M_sun / yr until approximately 2000 yr ago, followed by an order of magnitude decrease in the recent past, with the change indicating its evolution beyond the RSG stage. The new infrared photometry of rho Cas is consistent with emission from the expanding dust shell ejected in its 1946 eruption, with no evidence of newer dust formation from its more recent events.

Effect of Environmental Factors on Sulfur Gas Emissions from Drywall

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maddalena, Randy

2011-08-20

Problem drywall installed in U.S. homes is suspected of being a source of odorous and potentially corrosive indoor pollutants. The U.S. Consumer Product Safety Commission's (CPSC) investigation of problem drywall incorporates three parallel tracks: (1) evaluating the relationship between the drywall and reported health symptoms; (2) evaluating the relationship between the drywall and electrical and fire safety issues in affected homes; and (3) tracing the origin and the distribution of the drywall. To assess the potential impact on human health and to support testing for electrical and fire safety, the CPSC has initiated a series of laboratory tests that providemore » elemental characterization of drywall, characterization of chemical emissions, and in-home air sampling. The chemical emission testing was conducted at Lawrence Berkeley National Laboratory (LBNL). The LBNL study consisted of two phases. In Phase 1 of this study, LBNL tested thirty drywall samples provided by CPSC and reported standard emission factors for volatile organic compounds (VOCs), aldehydes, reactive sulfur gases (RSGs) and volatile sulfur compounds (VSCs). The standard emission factors were determined using small (10.75 liter) dynamic test chambers housed in a constant temperature environmental chamber. The tests were all run at 25 C, 50% relative humidity (RH) and with an area-specific ventilation rate of {approx}1.5 cubic meters per square meter of emitting surface per hour [m{sup 3}/m{sup 2}/h]. The thirty samples that were tested in Phase 1 included seventeen that were manufactured in China in 2005, 2006 and 2009, and thirteen that were manufactured in North America in 2009. The measured emission factors for VOCs and aldehydes were generally low and did not differ significantly between the Chinese and North American drywall. Eight of the samples tested had elevated emissions of volatile sulfur-containing compounds with total RSG emission factors between 32 and 258 micrograms per square meter per hour [{micro}g/m{sup 2}/h]. The dominant sulfur containing compounds in the RSG emission stream were hydrogen sulfide with emission factors between 17-201 {micro}g/m{sup 2}/h, and sulfur dioxide with emission factors between 8-64 {micro}g/m{sup 2}/h. The four highest emitting samples also had a unique signature of VSC emissions including > 40 higher molecular weight sulfur-containing compounds although the emission rate for the VSCs was several orders of magnitude lower than that of the RSGs. All of the high emitting drywall samples were manufactured in China in 2005-2006. Results from Phase 1 provided baseline emission factors for drywall samples manufactured in China and in North America but the results exclude variations in environmental conditions that may exist in homes or other built structures, including various combinations of temperature, RH, ventilation rate and the influence of coatings such as texture and paints. The objective of Phase 2 was to quantify the effect of temperature and RH on the RSG emission factors for uncoated drywall, and to measure the effect of plaster and paint coatings on RSG emission factors from drywall. Additional experiments were also performed to assess the influence of ventilation rate on measured emission factors for drywall.« less

Discovery of a Thorne-Żytkow object candidate in the Small Magellanic Cloud

NASA Astrophysics Data System (ADS)

Levesque, Emily M.; Massey, Philip; Żytkow, Anna N.; Morrell, Nidia

2015-01-01

Thorne-Żytkow objects (TŻOs) are a theoretical class of star in which a compact neutron star is surrounded by a large, diffuse envelope. Supergiant TŻOs are predicted to be almost identical in appearance to red supergiants (RSGs), with their very red colors and cool temperatures placing them at the Hayashi limit on the H-R diagram. The only features that can be used at present to distinguish TŻOs from the general RSG population are the unusually strong heavy-element and lithium lines present in their spectra. These elements are the unique products of the stars fully convective envelope linking the photosphere with the extraordinarily hot burning region in the vicinity of the neutron star core. We have recently discovered a TŻO candidate in the Small Magellanic Cloud. It is the first star to display the distinctive chemical profile of anomalous element enhancements thought to be characteristic of TŻOs however, up-to-date models and additional observable predictions (including potential asteroseismological signatures) are required to solidify this discovery. The definitive detection of a TŻO would provide the first direct evidence for a completely new model of stellar interiors, a theoretically predicted fate for massive binary systems, and never-before-seen nucleosynthesis processes that would offer a new channel for heavy-element and lithium production in our universe.

Digital exploration via Skype: connecting your classroom with the experts

NASA Astrophysics Data System (ADS)

Hay, Rachel

2014-05-01

This presentation describes experiences of using Skype in the classroom to connect learners with scientists and explorers all over the world in order to deepen learners' knowledge and understanding of course material, develop their enquiry skills, and broaden their perspectives on life beyond the classroom walls. In a session organised by the Royal Scottish Geographical Society (RSGS) in partnership with Digital Explorer, twenty-five Perth High School students who were studying coral reefs took part in an exciting live Skype chat with researchers on Australia's Great Barrier Reef. Students spoke to a marine biologist and a geographer who were on-board their research vessel some 15,000km away. They learned about the Catlin Survey's cutting-edge research, which was set up to study conditions on the reef, take 50,000 images, and create a baseline for future comparisons. In addition, the scientists aimed to develop an underwater equivalent of Google Streetview, called Seaview, which will allow people everywhere to engage with this incredible ecosystem. We heard about the divers' encounter with Tiger sharks earlier that same day, and had a tour of the research vessel, as well as asking the experts questions about their research findings and career paths. Feedback from the students was extremely positive, and it was clear that the experience had greatly enhanced their studies. For myself and the other teachers involved, it was an exciting (and surreal!) experience, and helped to update our knowledge of our subjects. Between July and December 2013 I volunteered as Community Manager for Digital Explorer in their partnership with Skype in the classroom. Digital Explorer is an educational social enterprise dedicated to engaging young people in global issues, and preparing them to tackle environmental and technological changes in the 21st century. We offered seventeen lessons as part of Skype in the classroom's Exploring Oceans event in October and November, which aimed to educate and enthuse young people about the world's oceans. It was fascinating to connect with other teachers and with the guest speakers, and there is huge potential for future events on different themes. This presentation will outline what I think are the main benefits of, and challenges to, embedding the use of Skype in more classrooms, and offer some tips for successful Skype lessons. Value is added when Skype lessons are incorporated into a well-planned scheme of work that utilises high-quality, innovative resources, such as those produced by Digital Explorer. The use of this technology in schools increases student engagement in course material, as well as in local and global issues, thus facilitating the development of successful learners and informed global citizens. In addition, it provides opportunities for learners to take responsibility for, and direct, their own learning and skill development. I hope that more teachers will develop their confidence in using Skype with their students, as it offers exciting opportunities for creating interactive lessons and bringing the world into your classroom. Acknowledgements: Jamie Buchanan-Dunlop - Director, Digital Explorer http://digitalexplorer.com @de_updates Charlotte Moore - Made By Many/Skype in the Classroom https://education.skype.com/ @SkypeClassroom Dr Joyce Gilbert - Education Officer, Royal Scottish Geographical Society http://www.rsgs.org/ @RoyalScotGeoSoc

Modeling of the Inner Coma of Comet 67P/Churyumov-Gerasimenko Constrained by VIRTIS and ROSINA Observations

NASA Astrophysics Data System (ADS)

Fougere, N.; Combi, M. R.; Tenishev, V.; Bieler, A. M.; Migliorini, A.; Bockelée-Morvan, D.; Toth, G.; Huang, Z.; Gombosi, T. I.; Hansen, K. C.; Capaccioni, F.; Filacchione, G.; Piccioni, G.; Debout, V.; Erard, S.; Leyrat, C.; Fink, U.; Rubin, M.; Altwegg, K.; Tzou, C. Y.; Le Roy, L.; Calmonte, U.; Berthelier, J. J.; Rème, H.; Hässig, M.; Fuselier, S. A.; Fiethe, B.; De Keyser, J.

2015-12-01

As it orbits around comet 67P/Churyumov-Gerasimenko (CG), the Rosetta spacecraft acquires more information about its main target. The numerous observations made at various geometries and at different times enable a good spatial and temporal coverage of the evolution of CG's cometary coma. However, the question regarding the link between the coma measurements and the nucleus activity remains relatively open notably due to gas expansion and strong kinetic effects in the comet's rarefied atmosphere. In this work, we use coma observations made by the ROSINA-DFMS instrument to constrain the activity at the surface of the nucleus. The distribution of the H2O and CO2 outgassing is described with the use of spherical harmonics. The coordinates in the orthogonal system represented by the spherical harmonics are computed using a least squared method, minimizing the sum of the square residuals between an analytical coma model and the DFMS data. Then, the previously deduced activity distributions are used in a Direct Simulation Monte Carlo (DSMC) model to compute a full description of the H2O and CO2 coma of comet CG from the nucleus' surface up to several hundreds of kilometers. The DSMC outputs are used to create synthetic images, which can be directly compared with VIRTIS measurements. The good agreement between the VIRTIS observations and the DSMC model, itself constrained with ROSINA data, provides a compelling juxtaposition of the measurements from these two instruments. Acknowledgements Work at UofM was supported by contracts JPL#1266313, JPL#1266314 and NASA grant NNX09AB59G. Work at UoB was funded by the State of Bern, the Swiss National Science Foundation and by the ESA PRODEX Program. Work at Southwest Research institute was supported by subcontract #1496541 from the JPL. Work at BIRA-IASB was supported by the Belgian Science Policy Office via PRODEX/ROSINA PEA 90020. The authors would like to thank ASI, CNES, DLR, NASA for supporting this research. VIRTIS was built by a consortium formed by Italy, France and Germany, under the scientific responsibility of the IAPS of INAF, which guides also the scientific operations. The consortium includes also the LESIA of the Observatoire de Paris, and the Institut für Planetenforschung of DLR. The authors wish to thank the RSGS and the RMOC for their continuous support.

The Vast Population of Wolf-Rayet and Red Supergiant Stars in M101. I. Motivation and First Results

NASA Astrophysics Data System (ADS)

Shara, Michael M.; Bibby, Joanne L.; Zurek, David; Crowther, Paul A.; Moffat, Anthony F. J.; Drissen, Laurent

2013-12-01

Assembling a catalog of at least 10,000 Wolf-Rayet (W-R) stars is an essential step in proving (or disproving) that these stars are the progenitors of Type Ib and Type Ic supernovae. To this end, we have used the Hubble Space Telescope (HST) to carry out a deep, He II optical narrowband imaging survey of the ScI spiral galaxy M101. Almost the entire galaxy was imaged with the unprecedented depth and resolution that only the HST affords. Differenced with archival broadband images, the narrowband images allow us to detect much of the W-R star population of M101. We describe the extent of the survey and our images, as well as our data reduction procedures. A detailed broadband-narrowband imaging study of a field east of the center of M101, containing the giant star-forming region NGC 5462, demonstrates our completeness limits, how we find W-R candidates, their properties and spatial distribution, and how we rule out most contaminants. We use the broadband images to locate luminous red supergiant (RSG) candidates. The spatial distributions of the W-R and RSG stars near NGC 5462 are strikingly different. W-R stars dominate the complex core, while RSGs dominate the complex halo. Future papers in this series will describe and catalog more than a thousand W-R and RSG candidates that are detectable in our images, as well as spectra of many of those candidates.

The vast population of Wolf-Rayet and red supergiant stars in M101. I. Motivation and first results

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shara, Michael M.; Bibby, Joanne L.; Zurek, David

Assembling a catalog of at least 10,000 Wolf-Rayet (W-R) stars is an essential step in proving (or disproving) that these stars are the progenitors of Type Ib and Type Ic supernovae. To this end, we have used the Hubble Space Telescope (HST) to carry out a deep, He II optical narrowband imaging survey of the ScI spiral galaxy M101. Almost the entire galaxy was imaged with the unprecedented depth and resolution that only the HST affords. Differenced with archival broadband images, the narrowband images allow us to detect much of the W-R star population of M101. We describe the extentmore » of the survey and our images, as well as our data reduction procedures. A detailed broadband-narrowband imaging study of a field east of the center of M101, containing the giant star-forming region NGC 5462, demonstrates our completeness limits, how we find W-R candidates, their properties and spatial distribution, and how we rule out most contaminants. We use the broadband images to locate luminous red supergiant (RSG) candidates. The spatial distributions of the W-R and RSG stars near NGC 5462 are strikingly different. W-R stars dominate the complex core, while RSGs dominate the complex halo. Future papers in this series will describe and catalog more than a thousand W-R and RSG candidates that are detectable in our images, as well as spectra of many of those candidates.« less

Red Supergiants as Potential Type IIn Supernova Progenitors: Spatially Resolved 4.6 μm CO Emission Around VY CMa and Betelgeuse

NASA Astrophysics Data System (ADS)

Smith, Nathan; Hinkle, Kenneth H.; Ryde, Nils

2009-03-01

We present high-resolution 4.6 μm CO spectra of the circumstellar environments of two red supergiants (RSGs) that are potential supernova (SN) progenitors: Betelgeuse and VY Canis Majoris (VY CMa). Around Betelgeuse, 12CO emission within ±3'' (±12 km s-1) follows a mildly clumpy but otherwise spherical shell, smaller than its ~55'' shell in K I λ7699. In stark contrast, 4.6 μm CO emission around VY CMa is coincident with bright K I in its clumpy asymmetric reflection nebula, within ±5'' (±40 km s-1) of the star. Our CO data reveal redshifted features not seen in K I spectra of VY CMa, indicating a more isotropic distribution of gas punctuated by randomly distributed asymmetric clumps. The relative CO and K I distribution in Betelgeuse arises from ionization effects within a steady wind, whereas in VY CMa, K I is emitted from skins of CO cloudlets resulting from episodic mass ejections 500-1000 yr ago. In both cases, CO and K I trace potential pre-SN circumstellar matter: we conclude that an extreme RSG like VY CMa might produce a Type IIn event like SN 1988Z if it were to explode in its current state, but Betelgeuse will not. VY CMa demonstrates that luminous blue variables are not necessarily the only progenitors of SNe IIn, but it underscores the requirement that SNe IIn suffer enhanced episodic mass loss shortly before exploding. Based on observations obtained at the Gemini Observatory.

A dearth of OH/IR stars in the Small Magellanic Cloud

NASA Astrophysics Data System (ADS)

Goldman, Steven R.; van Loon, Jacco Th.; Gómez, José F.; Green, James A.; Zijlstra, Albert A.; Nanni, Ambra; Imai, Hiroshi; Whitelock, Patricia A.; Groenewegen, Martin A. T.; Oliveira, Joana M.

2018-01-01

We present the results of targeted observations and a survey of 1612-, 1665- and 1667-MHz circumstellar OH maser emission from asymptotic giant branch (AGB) stars and red supergiants (RSGs) in the Small Magellanic Cloud (SMC), using the Parkes and Australia Telescope Compact Array (ATCA) radio telescopes. No clear OH maser emission has been detected in any of our observations targeting luminous, long-period, large-amplitude variable stars, which have been confirmed spectroscopically and photometrically to be mid- to late-M spectral type. These observations have probed 3-4 times deeper than any OH maser survey in the SMC. Using a bootstrapping method with Large Magellanic Cloud (LMC) and Galactic OH/IR star samples and our SMC observation upper limits, we have calculated the likelihood of not detecting maser emission in any of the two sources considered to be the top maser candidates to be less than 0.05 per cent, assuming a similar pumping mechanism as the LMC and Galactic OH/IR sources. We have performed a population comparison of the Magellanic Clouds and used Spitzer IRAC and MIPS photometry to confirm that we have observed all high luminosity SMC sources that are expected to exhibit maser emission. We suspect that, compared to the OH/IR stars in the Galaxy and LMC, the reduction in metallicity may curtail the dusty wind phase at the end of the evolution of the most massive cool stars. We also suspect that the conditions in the circumstellar envelope change beyond a simple scaling of abundances and wind speed with metallicity.

"Life without nuclear power": A nuclear plant retirement formulation model and guide based on economics. San Onofre Nuclear Generating Station case: Economic impacts and reliability considerations leading to plant retirement

NASA Astrophysics Data System (ADS)

Wasko, Frank

Traditionally, electric utilities have been slow to change and very bureaucratic in nature. This culture, in and of itself, has now contributed to a high percentage of United States electric utilities operating uneconomical nuclear plants (Crooks, 2014). The economic picture behind owning and operating United States nuclear plants is less than favorable for many reasons including rising fuel, capital and operating costs (EUCG, 2012). This doctoral dissertation is specifically focused on life without nuclear power. The purpose of this dissertation is to create a model and guide that will provide electric utilities who currently operate or will operate uneconomical nuclear plants the opportunity to economically assess whether or not their nuclear plant should be retired. This economic assessment and stakeholder analysis will provide local government, academia and communities the opportunity to understand how Southern California Edison (SCE) embraced system upgrade import and "voltage support" opportunities to replace "base load" generation from San Onofre Nuclear Generating Station (SONGS) versus building new replacement generation facilities. This model and guide will help eliminate the need to build large replacement generation units as demonstrated in the SONGS case analysis. The application of The Nuclear Power Retirement Model and Guide will provide electric utilities with economic assessment parameters and an evaluation assessment progression needed to better evaluate when an uneconomical nuclear plant should be retired. It will provide electric utilities the opportunity to utilize sound policy, planning and development skill sets when making this difficult decision. There are currently 62 nuclear power plants (with 100 nuclear reactors) operating in the United States (EIA, 2014). From this group, 38 are at risk of early retirement based on the work of Cooper (2013). As demonstrated in my model, 35 of the 38 nuclear power plants qualify to move to the economic assessment review and then on to the stakeholder cost benefit analysis (if model qualifications are met) leading to a final plant retirement decision. This application via the model and guide, in turn, will lead electric utilities to explore system upgrade import opportunities and mitigation measures versus building new replacement generation facilities. United States nuclear reactors are licensed for 40 years with a 20 year extension available prior to the expiration date (EIA, 2013). Since late 2012, electric power companies have announced the early retirement of four uneconomical nuclear power plants while other studies have indicated that as many as 70 percent of United States nuclear power plants are potentially at risk for early retirement (Crooks, 2014 and Cooper, 2013). A high percentage of these aforementioned nuclear plants have operating licenses that will not expire until 2030 and beyond. Thus, for the most part, replacement power contingency planning has not been initiated for these plants or is still in preliminary stages. The recent nuclear plant retirements are the first since 1998 (EIA, 2013). Decisions to retire the plants involved concerns over maintenance and repair costs as well as declining profitability (EIA, 2013). In addition, the Energy Information Administration (2010-2012) released data that demonstrated that the worst 25 percent of United States nuclear plants are far more expensive to operate and generate electricity than new gas plants. It is equally important to understand and explain the economic and power replacement implications to both ratepayers and end-users. A SONGS case study analysis will review the economic, operational and political challenges that SCE faced leading to the retirement decision of SONGS. As preface to the case study, replacement steam generators (RSGs) were installed in Unit 2 in 2009 and in Unit 3 in 2010. In January 2012, while Unit 2 was down for routine maintenance, a small leak was discovered inside a steam generator in Unit 3. Because of the situation, both units remained shut down to evaluate the cause of the leakage and to make repairs. SCE submitted plans to the Nuclear Regulatory Commission (NRC) to re-start Unit 2 at reduced power. However, concerns over the length of the review process and the high costs associated with steam generator repairs led SCE to retire both reactors (SCE SONGS Fact Sheets, 2012-2013). Finally, collaborative resource power replacement planning is needed more than ever as nuclear facilities in the United States are now being retired for economic related reasons (Crooks, 2014). This collaborative power replacement process and implementation must encompass all relevant stakeholders including state grid operators, ratepayers, shareholders and the electric utility company.

Heavy quark radiation in NLO+PS POWHEG generators

NASA Astrophysics Data System (ADS)

Buonocore, Luca; Nason, Paolo; Tramontano, Francesco

2018-02-01

In this paper we deal with radiation from heavy quarks in the context of next-to-leading order calculations matched to parton shower generators. A new algorithm for radiation from massive quarks is presented that has considerable advantages over the one previously employed. We implement the algorithm in the framework of the POWHEG-BOX, and compare it with the previous one in the case of the hvq generator for bottom production in hadronic collisions, and in the case of the bb4l generator for top production and decay.

Generational forecasting in academic medicine: a unique method of planning for success in the next two decades.

PubMed

Howell, Lydia Pleotis; Joad, Jesse P; Callahan, Edward; Servis, Gregg; Bonham, Ann C

2009-08-01

Multigenerational teams are essential to the missions of academic health centers (AHCs). Generational forecasting using Strauss and Howe's predictive model, "the generational diagonal," can be useful for anticipating and addressing issues so that each generation is effective. Forecasts are based on the observation that cyclical historical events are experienced by all generations, but the response of each generation differs according to its phase of life and previous defining experiences. This article relates Strauss and Howe's generational forecasts to AHCs. Predicted issues such as work-life balance, indebtedness, and succession planning have existed previously, but they now have different causes or consequences because of the unique experiences and life stages of current generations. Efforts to address these issues at the authors' AHC include a work-life balance workgroup, expanded leave, and intramural grants.

A New Lagrangian Relaxation Method Considering Previous Hour Scheduling for Unit Commitment Problem

NASA Astrophysics Data System (ADS)

Khorasani, H.; Rashidinejad, M.; Purakbari-Kasmaie, M.; Abdollahi, A.

2009-08-01

Generation scheduling is a crucial challenge in power systems especially under new environment of liberalization of electricity industry. A new Lagrangian relaxation method for unit commitment (UC) has been presented for solving generation scheduling problem. This paper focuses on the economical aspect of UC problem, while the previous hour scheduling as a very important issue is studied. In this paper generation scheduling of present hour has been conducted by considering the previous hour scheduling. The impacts of hot/cold start-up cost have been taken in to account in this paper. Case studies and numerical analysis presents significant outcomes while it demonstrates the effectiveness of the proposed method.

2nd Generation Reusable Launch Vehicle Potential Commercial Development Scenarios

NASA Technical Reports Server (NTRS)

Creech, Stephen D.; Rogacki, John R. (Technical Monitor)

2001-01-01

The presentation will discuss potential commercial development scenarios for a Second Generation Reusable Launch Vehicle. The analysis of potential scenarios will include commercial rates of return, government return on investment, and market considerations. The presentation will include policy considerations in addition to analysis of Second Generation Reusable Launch Vehicle economics. The data discussed is being developed as a part of NASA's Second Generation Reusable Launch Vehicle Program, for consideration as potential scenarios for enabling a next generation system. Material will include potential scenarios not previously considered by NASA or presented at other conferences. Candidate paper has not been presented at a previous meeting, and conference attendance of the author has been approved by NASA.

The Detection Rate of Early UV Emission from Supernovae: A Dedicated Galex/PTF Survey and Calibrated Theoretical Estimates

NASA Astrophysics Data System (ADS)

Ganot, Noam; Gal-Yam, Avishay; Ofek, Eran. O.; Sagiv, Ilan; Waxman, Eli; Lapid, Ofer; Kulkarni, Shrinivas R.; Ben-Ami, Sagi; Kasliwal, Mansi M.; The ULTRASAT Science Team; Chelouche, Doron; Rafter, Stephen; Behar, Ehud; Laor, Ari; Poznanski, Dovi; Nakar, Ehud; Maoz, Dan; Trakhtenbrot, Benny; WTTH Consortium, The; Neill, James D.; Barlow, Thomas A.; Martin, Christofer D.; Gezari, Suvi; the GALEX Science Team; Arcavi, Iair; Bloom, Joshua S.; Nugent, Peter E.; Sullivan, Mark; Palomar Transient Factory, The

2016-03-01

The radius and surface composition of an exploding massive star, as well as the explosion energy per unit mass, can be measured using early UV observations of core-collapse supernovae (SNe). We present the first results from a simultaneous GALEX/PTF search for early ultraviolet (UV) emission from SNe. Six SNe II and one Type II superluminous SN (SLSN-II) are clearly detected in the GALEX near-UV (NUV) data. We compare our detection rate with theoretical estimates based on early, shock-cooling UV light curves calculated from models that fit existing Swift and GALEX observations well, combined with volumetric SN rates. We find that our observations are in good agreement with calculated rates assuming that red supergiants (RSGs) explode with fiducial radii of 500 R ⊙, explosion energies of 1051 erg, and ejecta masses of 10 M ⊙. Exploding blue supergiants and Wolf-Rayet stars are poorly constrained. We describe how such observations can be used to derive the progenitor radius, surface composition, and explosion energy per unit mass of such SN events, and we demonstrate why UV observations are critical for such measurements. We use the fiducial RSG parameters to estimate the detection rate of SNe during the shock-cooling phase (<1 day after explosion) for several ground-based surveys (PTF, ZTF, and LSST). We show that the proposed wide-field UV explorer ULTRASAT mission is expected to find >85 SNe per year (˜0.5 SN per deg2), independent of host galaxy extinction, down to an NUV detection limit of 21.5 mag AB. Our pilot GALEX/PTF project thus convincingly demonstrates that a dedicated, systematic SN survey at the NUV band is a compelling method to study how massive stars end their life.

Progenitors of low-luminosity Type II-Plateau supernovae

NASA Astrophysics Data System (ADS)

Lisakov, Sergey M.; Dessart, Luc; Hillier, D. John; Waldman, Roni; Livne, Eli

2018-01-01

The progenitors of low-luminosity Type II-Plateau supernovae (SNe II-P) are believed to be red supergiant (RSG) stars, but there is much disparity in the literature concerning their mass at core collapse and therefore on the main sequence. Here, we model the SN radiation arising from the low-energy explosion of RSG stars of 12, 25 and 27 M⊙ on the main sequence and formed through single star evolution. Despite the narrow range in ejecta kinetic energy (2.5-4.2 × 1050 erg) in our model set, the SN observables from our three models are significantly distinct, reflecting the differences in progenitor structure (e.g. surface radius, H-rich envelope mass and He-core mass). Our higher mass RSG stars give rise to Type II SNe that tend to have bluer colours at early times, a shorter photospheric phase, and a faster declining V-band light curve (LC) more typical of Type II-linear SNe, in conflict with the LC plateau observed for low-luminosity SNe II. The complete fallback of the CO core in the low-energy explosions of our high-mass RSG stars prevents the ejection of any 56Ni (nor any core O or Si), in contrast to low-luminosity SNe II-P, which eject at least 0.001 M⊙ of 56Ni. In contrast to observations, Type II SN models from higher mass RSGs tend to show an H α absorption that remains broad at late times (due to a larger velocity at the base of the H-rich envelope). In agreement with the analyses of pre-explosion photometry, we conclude that low-luminosity SNe II-P likely arise from low-mass rather than high-mass RSG stars.

Doing better by getting worse: posthypnotic amnesia improves random number generation.

PubMed

Terhune, Devin Blair; Brugger, Peter

2011-01-01

Although forgetting is often regarded as a deficit that we need to control to optimize cognitive functioning, it can have beneficial effects in a number of contexts. We examined whether disrupting memory for previous numerical responses would attenuate repetition avoidance (the tendency to avoid repeating the same number) during random number generation and thereby improve the randomness of responses. Low suggestible and low dissociative and high dissociative highly suggestible individuals completed a random number generation task in a control condition, following a posthypnotic amnesia suggestion to forget previous numerical responses, and in a second control condition following the cancellation of the suggestion. High dissociative highly suggestible participants displayed a selective increase in repetitions during posthypnotic amnesia, with equivalent repetition frequency to a random system, whereas the other two groups exhibited repetition avoidance across conditions. Our results demonstrate that temporarily disrupting memory for previous numerical responses improves random number generation.

Doing Better by Getting Worse: Posthypnotic Amnesia Improves Random Number Generation

PubMed Central

Terhune, Devin Blair; Brugger, Peter

2011-01-01

Although forgetting is often regarded as a deficit that we need to control to optimize cognitive functioning, it can have beneficial effects in a number of contexts. We examined whether disrupting memory for previous numerical responses would attenuate repetition avoidance (the tendency to avoid repeating the same number) during random number generation and thereby improve the randomness of responses. Low suggestible and low dissociative and high dissociative highly suggestible individuals completed a random number generation task in a control condition, following a posthypnotic amnesia suggestion to forget previous numerical responses, and in a second control condition following the cancellation of the suggestion. High dissociative highly suggestible participants displayed a selective increase in repetitions during posthypnotic amnesia, with equivalent repetition frequency to a random system, whereas the other two groups exhibited repetition avoidance across conditions. Our results demonstrate that temporarily disrupting memory for previous numerical responses improves random number generation. PMID:22195022

The Role of Domain Knowledge in Creative Generation

ERIC Educational Resources Information Center

Ward, Thomas B.

2008-01-01

Previous studies have shown that a predominant tendency in creative generation tasks is to base new ideas on well-known, specific instances of previous ideas (e.g., basing ideas for imaginary aliens on dogs, cats or bears). However, a substantial minority of individuals has been shown to adopt more abstract approaches to the task and to develop…

Is Social Mobility Spatial? Characteristics of Immigrant Metros and Second Generation Outcomes: 1940–1970 and 1970–2000

PubMed Central

Goodwin-White, Jamie

2016-01-01

Research on immigrant and second generation outcomes has often examined their locations, following ideas that geographic dispersion facilitates social mobility, and that characteristics of the ethnic environment enable or constrain progress. I contend that second generation socioeconomic outcomes depend in part on the location choices and characteristics of a previous immigrant generation. Further, I suggest that this relationship reflects the changing geography of immigrants and labour markets, rather than geographically unfolding assimilation. Using the 1940, 1970, and 2000 Integrated Public Use Microdata Series files from the US Census, I regress second and 1.5 generation wage and educational outcomes in 1970 and 2000 on metro-area characteristics of a previous generation (1940 and 1970, respectively). Current labour market and second generation characteristics are included as controls and to facilitate interpretation. Characteristics of a previous immigrant generation’s location were more important for second generation outcomes in the 1940–1970 period, while current place characteristics become more significant by 2000. There is evidence of selection operating through the positive intergenerational effects of places where immigrants’ educational levels were high a generation ago. Metro-level immigrant concentration and manufacturing employment also have generally positive effects, although variations across generations and by nationality suggest their significance for social mobility is inadequately understood. The historical immigrant geographies of the US, and the ways in which metro labour market conditions intersect with immigrants’ locational choices, both within and between generations, are thus a critical piece of the economic and spatial assimilation puzzle. PMID:28280452

Simulation-Based Rule Generation Considering Readability

PubMed Central

Yahagi, H.; Shimizu, S.; Ogata, T.; Hara, T.; Ota, J.

2015-01-01

Rule generation method is proposed for an aircraft control problem in an airport. Designing appropriate rules for motion coordination of taxiing aircraft in the airport is important, which is conducted by ground control. However, previous studies did not consider readability of rules, which is important because it should be operated and maintained by humans. Therefore, in this study, using the indicator of readability, we propose a method of rule generation based on parallel algorithm discovery and orchestration (PADO). By applying our proposed method to the aircraft control problem, the proposed algorithm can generate more readable and more robust rules and is found to be superior to previous methods. PMID:27347501

Simulating the Effects of Cross-Generational Cultural Transmission on Language Change

NASA Astrophysics Data System (ADS)

Gong, Tao; Shuai, Lan

Language evolves in a socio-cultural environment. Apart from biological evolution and individual learning, cultural transmission also casts important influence on many aspects of language evolution. In this paper, based on the lexicon-syntax coevolution model, we extend the acquisition framework in our previous work to examine the roles of three forms of cultural transmission spanning the offspring, parent, and grandparent generations in language change. These transmissions are: those between the parent and offspring generations (PO), those within the offspring generation (OO), and those between the grandparent and offspring generations (GO). The simulation results of the considered model and relevant analyses illustrate not only the necessity of PO and OO transmissions for language change, thus echoing our previous findings, but also the importance of GO transmission, a form of cross-generational cultural transmission, on preserving the mutual understandability of the communal language across generations of individuals.

NREL Triples Previous Estimates of U.S. Wind Power Potential (Fact Sheet)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

The National Renewable Energy Laboratory (NREL) recently released new estimates of the U.S. potential for wind-generated electricity, using advanced wind mapping and validation techniques to triple previous estimates of the size of the nation's wind resources. The new study, conducted by NREL and AWS TruePower, finds that the contiguous 48 states have the potential to generate up to 37 million gigawatt-hours annually. In comparison, the total U.S. electricity generation from all sources was roughly 4 million gigawatt-hours in 2009.

Long-life electromechanical sine-cosine generator

NASA Technical Reports Server (NTRS)

Flagge, B.

1971-01-01

Sine-cosine generator with no sliding parts is capable of withstanding a 20 Hz oscillation for more than 14 hours. Tests show that generator is electrically equal to potentiometer and that it has excellent dynamic characteristics. Generator shows promise of higher-speed applications than was previously possible.

Alternative Constraint Handling Technique for Four-Bar Linkage Path Generation

NASA Astrophysics Data System (ADS)

Sleesongsom, S.; Bureerat, S.

2018-03-01

This paper proposes an extension of a new concept for path generation from our previous work by adding a new constraint handling technique. The propose technique was initially designed for problems without prescribed timing by avoiding the timing constraint, while remain constraints are solving with a new constraint handling technique. The technique is one kind of penalty technique. The comparative study is optimisation of path generation problems are solved using self-adaptive population size teaching-learning based optimization (SAP-TLBO) and original TLBO. In this study, two traditional path generation test problem are used to test the proposed technique. The results show that the new technique can be applied with the path generation problem without prescribed timing and gives better results than the previous technique. Furthermore, SAP-TLBO outperforms the original one.

Digital gate pulse generator for cycloconverter control

DOEpatents

Klein, Frederick F.; Mutone, Gioacchino A.

1989-01-01

The present invention provides a digital gate pulse generator which controls the output of a cycloconverter used for electrical power conversion applications by determining the timing and delivery of the firing pulses to the switching devices in the cycloconverter. Previous gate pulse generators have been built with largely analog or discrete digital circuitry which require many precision components and periodic adjustment. The gate pulse generator of the present invention utilizes digital techniques and a predetermined series of values to develop the necessary timing signals for firing the switching device. Each timing signal is compared with a reference signal to determine the exact firing time. The present invention is significantly more compact than previous gate pulse generators, responds quickly to changes in the output demand and requires only one precision component and no adjustments.

Get Ready for Generation Next.

ERIC Educational Resources Information Center

Wellner, Alison

1999-01-01

"Generation Next" are the 68 million people born between 1977 and 1994. They are the first generation that has grown up with such technologies as computers, the Internet, compact disks, and microwaves and they have more education than previous generations. They will have an effect on trainers and training methods in the workplace. (JOW)

Why Do First-Generation Students Fail?

ERIC Educational Resources Information Center

Mehta, Sanjay S.; Newbold, John J.; O'Rourke, Matthew A.

2011-01-01

Previous studies have determined factors contributing to first-generation student success. This study finds that first-generation students are less involved, have less social and financial support, and do not show a preference for active coping strategies. First-generation students report less social and academic satisfaction as well as lower…

Essential Elements for Recruitment and Retention: Generation Y

ERIC Educational Resources Information Center

Luscombe, Jenna; Lewis, Ioni; Biggs, Herbert C.

2013-01-01

Purpose: Generation Y (Gen Y) is the newest and largest generation entering the workforce. Gen Y may differ from previous generations in work-related characteristics which may have recruitment and retention repercussions. Currently, limited theoretically-based research exists regarding Gen Y's work expectations and goals in relation to…

A Probabilistic Account of Exemplar and Category Generation

ERIC Educational Resources Information Center

Jern, Alan; Kemp, Charles

2013-01-01

People are capable of imagining and generating new category exemplars and categories. This ability has not been addressed by previous models of categorization, most of which focus on classifying category exemplars rather than generating them. We develop a formal account of exemplar and category generation which proposes that category knowledge is…

No evidence of age-related increases in unconscious plagiarism during free recall.

PubMed

Perfect, Timothy John; Defeldre, Anne-Catherine; Elliman, Rachel; Dehon, Hedwige

2011-07-01

In three experiments younger and older participants took part in a group generation task prior to a delayed recall task. In each, participants were required to recall the items that they had generated, avoiding plagiarism errors. All studies showed the same pattern: older adults did not plagiarise their partners any more than younger adults did. However, older adults were more likely than younger adults to intrude with entirely novel items not previously generated by anyone. These findings stand in opposition to the single previous demonstration of age-related increases in plagiarism during recall.

Rewired: Understanding the iGeneration and the Way They Learn

ERIC Educational Resources Information Center

Rosen, Larry D.

2010-01-01

The iGeneration is radically different from any previous generation of students and a variety of existing technologies can be used to engage and excite them in the learning process. The iGeneration is a creative, multimedia generation. They think of the world as a canvas to paint with words, sights, sounds, video, music, web pages, and anything…

75 FR 28506 - Airworthiness Directives; Hawker Beechcraft Corporation (Type Certificate No. A00010WI Previously...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-21

... installation of certain serial number (S/N) starter generators and replacing the starter generator if one with an affected serial number is found. This proposed AD results from reports that starter generators... proposing this AD to detect and replace starter generators with defective armature insulating materials...

75 FR 52235 - Airworthiness Directives; Hawker Beechcraft Corporation (Type Certificate No. A00010WI Previously...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-25

... certain serial number (S/N) starter generators and replace the starter generator if one with an affected serial number is found. This AD results from reports that starter generators with deficient armature... replace starter generators with defective armature insulating materials. This condition could result in...

Intake of key chronic disease-related nutrients among baby boomers.

PubMed

King, Dana E; Xiang, Jun; Brown, Alexander

2014-06-01

The dietary habits of baby boomers (people born between 1946 and 1964) undoubtedly will have a substantial impact on their future health; however, dietary information regarding the intake of key chronic disease-related nutrients is lacking for this generation. The objective of this study was to compare the dietary intake of key chronic disease-related nutrients of the baby boomer generation with the previous generation of middle-aged adults. National cross-sectional study comparison analyzing data from the National Health and Nutrition Examination Survey (NHANES) including NHANES III (1988-1994) and the NHANES for 2007-2010, focused on adult respondents ages 46 to 64 years who were not institutionalized at the time of each survey. The two cohorts were compared with regard to dietary intake of key nutritional components. The main outcome measures were intake of total calories, sodium, cholesterol, fat, fruits, vegetables, vitamin C, water, and fiber. The baby boomers' average daily intake of nutrients exceeded that of the previous generation of middle-aged adults for total calories (2118/1999), total fat (82/76 g), sodium (3513/3291 mg), and cholesterol (294/262 g; all P < 0.001). The intake of vitamin C (105/89 g), water (1208/1001 g), and vegetables (199/229 g) was less than that of the previous generation (P < 0.001), and the dietary intake of fruit and fiber was unchanged. In regression analyses, dietary changes remained significant after controlling for age, race, sex, and socioeconomic status (all P < 0.01). The study findings document higher dietary intake of key chronic disease-related nutrients along with reduced vegetable intake among baby boomers compared with the previous generation of middle-aged adults. These findings are indicative of a diet that may contribute to increased rates of chronic disease among individuals in this age group.

76 FR 30206 - Southern Nuclear Operating Company, Inc., Vogtle Electric Generating Plant, Unit 1 and 2; Notice...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-24

... High-High, Nominal Trip Setpoint (NTSP) and Allowable Value. The Steam Generator Water Level High-High... previously evaluated is not increased. The Steam Generator Water Level High-High function revised values..., Steam Generator Water Level High-High, Nominal Trip Setpoint (NTSP) and Allowable Value. Function 5c...

Generating human-like movements on an anthropomorphic robot using an interior point method

NASA Astrophysics Data System (ADS)

Costa e Silva, E.; Araújo, J. P.; Machado, D.; Costa, M. F.; Erlhagen, W.; Bicho, E.

2013-10-01

In previous work we have presented a model for generating human-like arm and hand movements on an anthropomorphic robot involved in human-robot collaboration tasks. This model was inspired by the Posture-Based Motion-Planning Model of human movements. Numerical results and simulations for reach-to-grasp movements with two different grip types have been presented previously. In this paper we extend our model in order to address the generation of more complex movement sequences which are challenged by scenarios cluttered with obstacles. The numerical results were obtained using the IPOPT solver, which was integrated in our MATLAB simulator of an anthropomorphic robot.

Improving Generation Y Volunteerism in Extension Programs

ERIC Educational Resources Information Center

Andrews, Kevin B.; Lockett, Landry L.

2013-01-01

Members of Generation Y have many positive attributes that make them attractive to Extension volunteer administrators as a potential source of labor. However, they think differently, have unique needs, require new management styles, and have less tolerance for unpleasant working conditions than previous generations. Additionally, they are engaged…

Consistent Yokoya-Chen Approximation to Beamstrahlung(LCC-0010)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peskin, M

2004-04-22

I reconsider the Yokoya-Chen approximate evolution equation for beamstrahlung and modify it slightly to generate simple, consistent analytical approximations for the electron and photon energy spectra. I compare these approximations to previous ones, and to simulation data.I reconsider the Yokoya-Chen approximate evolution equation for beamstrahlung and modify it slightly to generate simple, consistent analytical approximations for the electron and photon energy spectra. I compare these approximations to previous ones, and to simulation data.

A Miniature Electromechanical Generator Design Utilizing Human Motion

DTIC Science & Technology

2010-09-01

Inductance Operating Range In the previous chapter, it was mentioned that the EMF induced from the generator was related to a time-changing magnetic...ELECTROMECHANICAL GENERATOR DESIGN UTILIZING HUMAN MOTION by Nicholas G. Hoffman September 2010 Thesis Co-Advisors: Alexander L. Julian...AND DATES COVERED Master’s Thesis 4. TITLE AND SUBTITLE A Miniature Electromechanical Generator Design Utilizing Human Motion 5. FUNDING NUMBERS

The Duality of Individualism: Attitudes toward Women, Generation Me, and the Method of Cross-Temporal Meta-Analysis

ERIC Educational Resources Information Center

Twenge, Jean M.

2011-01-01

This author became intrigued by the idea that her generation, who had grown up reaping the benefits of second-wave feminism, might differ from previous generations in their attitudes toward women. What was unclear was how this period of progress might have combined with feminist backlash in affecting subsequent generations' responses to typical…

Helping Teenagers into Adulthood: A Guide for the Next Generation.

ERIC Educational Resources Information Center

Holmes, George R.

Noting that the current generation of adolescents is experiencing more stressful and negative experiences at an earlier age than previous generations, and that the consequences include drug abuse, delinquency, and mental illness, this book provides caregivers and parents with specific tactics to move teenagers successfully through adolescence. The…

Engaging the Millennial Generation in Class Discussions

ERIC Educational Resources Information Center

Roehling, Patricia Vincent; Vander Kooi, Thomas Lee; Dykema, Stephanie; Quisenberry, Brooke; Vandlen, Chelsea

2011-01-01

Students in the Millennial Generation (late 20s and younger) have been raised in an environment in which individuality is highly valued and information, entertainment, and social interactions are unlimited and at their fingertips. As a result, these students may have different educational expectations and needs than previous generations. Class…

Dynamic Courseware Generation on the WWW.

ERIC Educational Resources Information Center

Vassileva, Julita; Deters, Ralph

1998-01-01

The Dynamic Courseware Generator (DCG), which runs on a Web server, was developed for the authoring of adaptive computer-assisted learning courses. It generates an individual course according to the learner's goals and previous knowledge, and dynamically adapts the course according to the learner's success in knowledge acquisition. The tool may be…

Rethinking "Generation Me": A Study of Cohort Effects From 1976-2006.

PubMed

Trzesniewski, Kali H; Donnellan, M Brent

2010-01-01

Social commentators have argued that changes over the last decades have coalesced to create a relatively unique generation of young people. However, using large samples of U.S. high-school seniors from 1976 to 2006 (Total N = 477,380), we found little evidence of meaningful change in egotism, self-enhancement, individualism, self-esteem, locus of control, hopelessness, happiness, life satisfaction, loneliness, antisocial behavior, time spent working or watching television, political activity, the importance of religion, and the importance of social status over the last 30 years. Today's youth are less fearful of social problems than previous generations and they are also more cynical and less trusting. In addition, today's youth have higher educational expectations than previous generations. However, an inspection of effect sizes provided little evidence for strong or widespread cohort-linked changes. © The Author(s) 2010.

Programmatic Re-Evaluation of Ion Exchange as a 1st Generation ITP Replacement

DOE Office of Scientific and Technical Information (OSTI.GOV)

Scott, A.B.

This re-evaluation differs from previous work in that (1) the Ion Exchange option was evaluated from a standpoint assuming that ITP would never start up, thus Ion Exchange was the only viable option, (2) the DOE prescribed balanced assumptions were quite different than the WSRC Assumptions used previously, and (3) other Site events and changes within HLWM have tended to reduce the disadvantages of Ion Exchange relative to ITP as the first generation salt decontamination process.

Are LIGO's Black Holes Made from Smaller Black Holes?

NASA Astrophysics Data System (ADS)

Fishbach, Maya; Holz, Daniel; Farr, Ben; LIGO Collaboration

2017-01-01

We consider the hierarchical merger model for the formation of stellar mass black holes (such as the binary black holes observable by LIGO). In the hierarchical merger model, each black hole in a black hole binary is the result of a merger of two lesser black holes from a previous generation, and the previous generation's black holes may themselves be merger products of an even earlier generation. We apply the formulas of Hofmann, Barausse and Rezzolla (2016) to show that if black holes form in this hierarchical merger scenario, their spin magnitudes follow a certain probability distribution. We demonstrate how to compare this spin distribution to LIGO spin measurements in order to constrain the hierarchical merger scenario.

Analysis of disconnected diallel mating designs II: results from a third generation progeny test of the New Zealand radiata pine improvement programme.

Treesearch

J.N. King; M.J. Carson; G.R. Johnson

1998-01-01

Genetic parameters from a second generation (F2) disconnected diallel progeny test of the New Zealand radiata pine improvement programme are presented. Heritability estimates of growth and yield traits of 0.2 are similar to progeny test results of the previous generation (F1) generation tests. A trend of declining dominance...

Popular Music, Television, and Generational Identity.

ERIC Educational Resources Information Center

Burns, Gary

Although previous generations have by no means been disloyal to the popular music of their youth, the tenacious attachment of the Baby Boomers to the music of the 1960s seems unprecedented. Three main reasons account for this constantly widening musical reclamation project. First, the Baby Boomers have a clearer sense of generational identity that…

The Crossover Generation: Baby Boomers and the Role of the Public Library

ERIC Educational Resources Information Center

Williamson, Kirsty; Bannister, Marion; Sullivan, Jen

2010-01-01

The article explores the concept of baby boomers as a "crossover" generation, one that embodies characteristics of previous and later generations. The context is the retirement of the baby boomers and its potential impact on the public library. Ethnographic method within a constructivist framework was used, employing the techniques of…

Expertise-Based Differences in Search and Option-Generation Strategies

ERIC Educational Resources Information Center

Raab, Markus; Johnson, Joseph G.

2007-01-01

The current work builds on option-generation research using experts of various skill levels in a realistic task. We extend previous findings that relate an athlete's performance strategy to generated options and subsequent choices in handball. In a 2-year longitudinal study, we present eye-tracking data to independently verify decision strategies…

Executive Functions in Children with Communications Impairments, in Relation to Autistic Symptomatology. I: Generativity

ERIC Educational Resources Information Center

Bishop, Dorothy V. M.; Norbury, Courtenay Frazier

2005-01-01

Previous research has found that people with autism generate few novel responses in ideational fluency tasks, and it has been suggested this deficit is a specific correlate of stereotyped/repetitive behavior. We assessed generativity in children with pragmatic language impairment (PLI) who showed communicative abnormalities resembling those seen…

Partially ionized plasmas including the third symposium on uranium plasmas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krishnan, M.

1976-09-01

Separate abstracts are included for 28 papers on electrically generated plasmas, fission generated plasmas, nuclear pumped lasers, gaseous fuel reactor research, and applications. Five papers have been previously abstracted and included in ERA.

Maximizing fluid delivered by bubble-free electroosmotic pump with optimum pulse voltage waveform.

PubMed

Tawfik, Mena E; Diez, Francisco J

2017-03-01

In generating high electroosmotic (EO) flows for use in microfluidic pumps, a limiting factor is faradaic reactions that are more pronounced at high electric fields. These reactions lead to bubble generation at the electrodes and pump efficiency reduction. The onset of gas generation for high current density EO pumping depends on many parameters including applied voltage, working fluid, and pulse duration. The onset of gas generation can be delayed and optimized for maximum volume pumped in the minimum time possible. This has been achieved through the use of a novel numerical model that predicts the onset of gas generation during EO pumping using an optimized pulse voltage waveform. This method allows applying current densities higher than previously reported. Optimal pulse voltage waveforms are calculated based on the previous theories for different current densities and electrolyte molarity. The electroosmotic pump performance is investigated by experimentally measuring the fluid volume displaced and flow rate. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Vulnerability of US thermoelectric power generation to climate change when incorporating state-level environmental regulations

NASA Astrophysics Data System (ADS)

Liu, Lu; Hejazi, Mohamad; Li, Hongyi; Forman, Barton; Zhang, Xiao

2017-08-01

Previous modelling studies suggest that thermoelectric power generation is vulnerable to climate change, whereas studies based on historical data suggest the impact will be less severe. Here we explore the vulnerability of thermoelectric power generation in the United States to climate change by coupling an Earth system model with a thermoelectric power generation model, including state-level representation of environmental regulations on thermal effluents. We find that the impact of climate change is lower than in previous modelling estimates due to an inclusion of a spatially disaggregated representation of environmental regulations and provisional variances that temporarily relieve power plants from permit requirements. More specifically, our results indicate that climate change alone may reduce average generating capacity by 2-3% by the 2060s, while reductions of up to 12% are expected if environmental requirements are enforced without waivers for thermal variation. Our work highlights the significance of accounting for legal constructs and underscores the effects of provisional variances in addition to environmental requirements.

Intake of Key Chronic Disease–Related Nutrients among Baby Boomers

PubMed Central

King, Dana E.; Xiang, Jun; Brown, Alexander

2014-01-01

Objectives The dietary habits of baby boomers (people born between 1946 and 1964) undoubtedly will have a substantial impact on their future health; however, dietary information regarding the intake of key chronic disease–related nutrients is lacking for this generation. The objective of this study was to compare the dietary intake of key chronic disease–related nutrients of the baby boomer generation with the previous generation of middle-aged adults. Methods National cross-sectional study comparison analyzing data from the National Health and Nutrition Examination Survey (NHANES) including NHANES III (1988–1994) and the NHANES for 2007–2010, focused on adult respondents ages 46 to 64 years who were not institutionalized at the time of each survey. The two cohorts were compared with regard to dietary intake of key nutritional components. The main outcome measures were intake of total calories, sodium, cholesterol, fat, fruits, vegetables, vitamin C, water, and fiber. Results The baby boomers’ average daily intake of nutrients exceeded that of the previous generation of middle-aged adults for total calories (2118/1999), total fat (82/76 g), sodium (3513/3291 mg), and cholesterol (294/262 g; all P < 0.001). The intake of vitamin C (105/89 g), water (1208/1001 g), and vegetables (199/229 g) was less than that of the previous generation (P < 0.001), and the dietary intake of fruit and fiber was unchanged. In regression analyses, dietary changes remained significant after controlling for age, race, sex, and socioeconomic status (all P < 0.01). Conclusions The study findings document higher dietary intake of key chronic disease–related nutrients along with reduced vegetable intake among baby boomers compared with the previous generation of middle-aged adults. These findings are indicative of a diet that may contribute to increased rates of chronic disease among individuals in this age group. PMID:24945165

Multifunctional pulse generator for high-intensity focused ultrasound system

NASA Astrophysics Data System (ADS)

Tamano, Satoshi; Yoshizawa, Shin; Umemura, Shin-Ichiro

2017-07-01

High-intensity focused ultrasound (HIFU) can achieve high spatial resolution for the treatment of diseases. A major technical challenge in implementing a HIFU therapeutic system is to generate high-voltage high-current signals for effectively exciting a multichannel HIFU transducer at high efficiencies. In this paper, we present the development of a multifunctional multichannel generator/driver. The generator can produce a long burst as well as an extremely high-voltage short pulse of pseudosinusoidal waves (trigger HIFU) and second-harmonic superimposed waves for HIFU transmission. The transmission timing, waveform, and frequency can be controlled using a field-programmable gate array (FPGA) via a universal serial bus (USB) microcontroller. The hardware is implemented in a compact printed circuit board. The test results of trigger HIFU reveal that the power consumption and the temperature rise of metal-oxide semiconductor field-effect transistors were reduced by 19.9% and 38.2 °C, respectively, from the previous design. The highly flexible performance of the novel generator/driver is demonstrated in the generation of second-harmonic superimposed waves, which is useful for cavitation-enhanced HIFU treatment, although the previous design exhibited difficulty in generating it.

THE DETECTION RATE OF EARLY UV EMISSION FROM SUPERNOVAE: A DEDICATED GALEX/PTF SURVEY AND CALIBRATED THEORETICAL ESTIMATES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ganot, Noam; Gal-Yam, Avishay; Ofek, Eran O.

The radius and surface composition of an exploding massive star, as well as the explosion energy per unit mass, can be measured using early UV observations of core-collapse supernovae (SNe). We present the first results from a simultaneous GALEX/PTF search for early ultraviolet (UV) emission from SNe. Six SNe II and one Type II superluminous SN (SLSN-II) are clearly detected in the GALEX near-UV (NUV) data. We compare our detection rate with theoretical estimates based on early, shock-cooling UV light curves calculated from models that fit existing Swift and GALEX observations well, combined with volumetric SN rates. We find thatmore » our observations are in good agreement with calculated rates assuming that red supergiants (RSGs) explode with fiducial radii of 500 R{sub ⊙}, explosion energies of 10{sup 51} erg, and ejecta masses of 10 M{sub ⊙}. Exploding blue supergiants and Wolf–Rayet stars are poorly constrained. We describe how such observations can be used to derive the progenitor radius, surface composition, and explosion energy per unit mass of such SN events, and we demonstrate why UV observations are critical for such measurements. We use the fiducial RSG parameters to estimate the detection rate of SNe during the shock-cooling phase (<1 day after explosion) for several ground-based surveys (PTF, ZTF, and LSST). We show that the proposed wide-field UV explorer ULTRASAT mission is expected to find >85 SNe per year (∼0.5 SN per deg{sup 2}), independent of host galaxy extinction, down to an NUV detection limit of 21.5 mag AB. Our pilot GALEX/PTF project thus convincingly demonstrates that a dedicated, systematic SN survey at the NUV band is a compelling method to study how massive stars end their life.« less

Coma dust environment observed by GIADA during the Perihelion of 67P/Churyumov-Gerasimenko.

NASA Astrophysics Data System (ADS)

Rotundi, A.; Della Corte, V.; Fulle, M.; Ferrari, M.; Ivanovski, S. L.; Sordini, R.; Mazzotta Epifani, E.; Palumbo, P.; Colangeli, L.; Lopez-Moreno, J. J.; Rodriguez, J.; Zakharov, V.; Bussoletti, E.; Crifo, J. F.; Esposito, F.; Green, S.; Gruen, E.; Lamy, P. L.; McDonnell, T.; Mennella, V.; Molina, A.; Moreno, F.; Ortiz, J. L.; Palomba, E.; Perrin, J. M.; Rodrigo, R.; Weissman, P. R.; Zarnecki, J.; Cosi, M.; Giovane, F.; Gustafson, B.; Herranz, M.; Jeronimo, J. M.; Leese, M.; Lopez-Jimenez, A.; Morales, R.

2015-12-01

GIADA (Grain Impact Analyzer and Dust Accumulator) is an in-situ instrument mounted onboard Rosetta monitoring the dust environment of comet 67P/Churyumov-Gerasimenko. GIADA is composed of 3 sub-systems: 1) the Grain Detection System, based on particle detection through light scattering; 2) the Impact Sensor, giving momentum measurement; 3) the Micro-Balances System, constituted of 5 quartz crystal microbalances, giving cumulative deposited dust. The combination of the measurements performed by these 3 subsystems provides: the number, the mass, the momentum and the speed distribution of dust particles emitted from the comet nucleus. We will present the coma dust environment as observed by GIADA during the perihelion phase of the Rosetta space mission. Despite the large distance from the nucleus, more than 200 km, GIADA was able to detect temporal and spatial variation of dust density distribution. Specific high dust spatial density sectors of the coma have been identified and their evolution during the perihelion phase was studied. Acknowledgements. GIADA was built by a consortium led by the Univ. Napoli "Parthenope" & INAF- Oss. Astr. Capodimonte, IT, in collaboration with the Inst. de Astrofisica de Andalucia, ES, Selex-ES s.p.a. and SENER. GIADA is presently managed & operated by Ist. di Astrofisica e Planetologia Spaziali-INAF, IT. GIADA was funded and managed by the Agenzia Spaziale Italiana, IT, with a support of the Spanish Ministry of Education and Science MEC, ES. GIADA was developped from a PI proposal supported by the University of Kent; sci. & tech. contribution given by CISAS, IT, Lab. d'Astr. Spat., FR, and Institutions from UK, IT, FR, DE and USA. We thank the RSGS/ESAC, RMOC/ESOC & Rosetta Project/ESTEC for their outstanding work. Science support provided by NASA through the US Rosetta Project managed by JPL/California Institute of Technology. GIADA calibrated data will be available through the ESA's PSA web site.

Economics of hydrogen production and liquefaction updated to 1980

NASA Technical Reports Server (NTRS)

Baker, C. R.

1979-01-01

Revised costs for generating and liquefying hydrogen in mid-1980 are presented. Plant investments were treated as straight-forward escalations resulting from inflation. Operating costs, however, were derived in terms of the unit cost of coal, fuel gas and electrical energy to permit the determination of the influence of these parameters on the cost of liquid hydrogen. Inflationary influence was recognized by requiring a 15% discounted rate of return on investment for Discounted Cash Flow financing analysis, up from 12% previously. Utility financing was revised to require an 11% interest rate on debt. The scope of operation of the hydrogen plant was revised from previous studies to include only the hydrogen generation and liquefaction facilities. On-site fuel gas and power generation, originally a part of the plant complex, was eliminated. Fuel gas and power are now treated as purchased utilities. Costs for on-site generation of fuel gas however, are included.

Airborne Sensor Thermal Management Solution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ng, K. K.

2015-06-03

The customer wants to outfit aircraft (de Havilland Twin Otter) with optical sensors. In previous product generations the sensor line-of-sight direction was fixed – the sensor’s direction relied on the orientation of the aircraft. The next generation sensor will be packaged in a rotatable turret so that the line-of-sight is reasonably independent of the aircraft’s orientation. This turret will be mounted on a boom protruding from the side of the aircraft. The customer wants to outfit aircraft (de Havilland Twin Otter) with optical sensors. In previous product generations the sensor line-of-sight direction was fixed – the sensor’s direction relied onmore » the orientation of the aircraft. The next generation sensor will be packaged in a rotatable turret so that the line-of-sight is reasonably independent of the aircraft’s orientation. This turret will be mounted on a boom protruding from the side of the aircraft.« less

Data-Driven Hint Generation from Peer Debugging Solutions

ERIC Educational Resources Information Center

Liu, Zhongxiu

2015-01-01

Data-driven methods have been a successful approach to generating hints for programming problems. However, the majority of previous studies are focused on procedural hints that aim at moving students to the next closest state to the solution. In this paper, I propose a data-driven method to generate remedy hints for BOTS, a game that teaches…

Becoming a College Student: An Empirical Phenomenological Analysis of First Generation College Students

ERIC Educational Resources Information Center

Whitehead, Patrick M.; Wright, Robert

2017-01-01

This article is an empirical phenomenological examination of the perceived security that first generation college students have in their identity as college students. First generation college students (FGCS) have been defined as students whose parents or guardians have not completed a 2- or 4-year postsecondary degree. Previous research (Davis,…

Effects of Problem Scope and Creativity Instructions on Idea Generation and Selection

ERIC Educational Resources Information Center

Rietzschel, Eric F.; Nijstad, Bernard A.; Stroebe, Wolfgang

2014-01-01

The basic assumption of brainstorming is that increased quantity of ideas results in increased generation as well as selection of creative ideas. Although previous research suggests that idea quantity correlates strongly with the number of good ideas generated, quantity has been found to be unrelated to the quality of selected ideas. This article…

Using Self-Generated Analogies in Teaching of Thermodynamics

ERIC Educational Resources Information Center

Haglund, Jesper; Jeppsson, Fredrik

2012-01-01

Using self-generated analogies has been proposed as a method in a constructivist tradition for students to learn about a new subject, by use of what they previously know. We report on a group exercise on using self-generated analogies to make sense of two thermodynamic processes, reversible adiabatic expansion and free adiabatic expansion of an…

Uncharted Territory: Growing Up Gifted amid a Culture of Social Media

ERIC Educational Resources Information Center

Cross, Tracy L.

2013-01-01

While it is true that every generation of children grows up with a different confluence of historical influences than the previous generation, the current generation of students with gifts and talents (SWGT) has matured during a unique time during which they have been immersed within an electronic social network. While some factors that influence…

AutoGen Version 5.0

NASA Technical Reports Server (NTRS)

Gladden, Roy E.; Khanampornpan, Teerapat; Fisher, Forest W.

2010-01-01

Version 5.0 of the AutoGen software has been released. Previous versions, variously denoted Autogen and autogen, were reported in two articles: Automated Sequence Generation Process and Software (NPO-30746), Software Tech Briefs (Special Supplement to NASA Tech Briefs), September 2007, page 30, and Autogen Version 2.0 (NPO- 41501), NASA Tech Briefs, Vol. 31, No. 10 (October 2007), page 58. To recapitulate: AutoGen (now signifying automatic sequence generation ) automates the generation of sequences of commands in a standard format for uplink to spacecraft. AutoGen requires fewer workers than are needed for older manual sequence-generation processes, and greatly reduces sequence-generation times. The sequences are embodied in spacecraft activity sequence files (SASFs). AutoGen automates generation of SASFs by use of another previously reported program called APGEN. AutoGen encodes knowledge of different mission phases and of how the resultant commands must differ among the phases. AutoGen also provides means for customizing sequences through use of configuration files. The approach followed in developing AutoGen has involved encoding the behaviors of a system into a model and encoding algorithms for context-sensitive customizations of the modeled behaviors. This version of AutoGen addressed the MRO (Mars Reconnaissance Orbiter) primary science phase (PSP) mission phase. On previous Mars missions this phase has more commonly been referred to as mapping phase. This version addressed the unique aspects of sequencing orbital operations and specifically the mission specific adaptation of orbital operations for MRO. This version also includes capabilities for MRO s role in Mars relay support for UHF relay communications with the MER rovers and the Phoenix lander.

Environmental Heat and Salt Stress Induce Transgenerational Phenotypic Changes in Arabidopsis thaliana

PubMed Central

Suter, Léonie; Widmer, Alex

2013-01-01

Plants that can adapt their phenotype may be more likely to survive changing environmental conditions. Heritable epigenetic variation could provide a way to rapidly adapt to such changes. Here we tested whether environmental stress induces heritable, potentially adaptive phenotypic changes independent of genetic variation over few generations in Arabidopsis thaliana. We grew two accessions (Col-0, Sha-0) of A. thaliana for three generations under salt, heat and control conditions and tested for induced heritable phenotypic changes in the fourth generation (G4) and in reciprocal F1 hybrids generated in generation three. Using these crosses we further tested whether phenotypic changes were maternally or paternally transmitted. In generation five (G5), we assessed whether phenotypic effects persisted over two generations in the absence of stress. We found that exposure to heat stress in previous generations accelerated flowering under G4 control conditions in Sha-0, but heritable effects disappeared in G5 after two generations without stress exposure. Previous exposure to salt stress increased salt tolerance in one of two reciprocal F1 hybrids. Transgenerational effects were maternally and paternally inherited. Lacking genetic variability, maternal and paternal inheritance and reversibility of transgenerational effects together indicate that stress can induce heritable, potentially adaptive phenotypic changes, probably through epigenetic mechanisms. These effects were strongly dependent on plant genotype and may not be a general response to stress in A. thaliana. PMID:23585834

High efficiency IR supercontinuum generation and applications: a review

NASA Astrophysics Data System (ADS)

Yin, Shizhuo; Ruffin, Paul; Brantley, Christina; Edwards, Eugene; Cheng, Jiping; Yao, Jimmy; Luo, Claire

2011-10-01

In this paper, we have reviewed our recent works on IR supercontinuum generation (SCG) and its applications. First, we provide a brief review on the physical mechanism of the supercontinuum generation and our previous works in this field. Second, the transmission characteristics of a new type of IR fibers is presented. Furthermore, the SCG generation in this new type of optical fiber is experimentally demonstrated. Finally, the suggestion for the future effort is discussed.

High efficiency IR supercontinuum generation and applications: a recent review

NASA Astrophysics Data System (ADS)

Yin, Shizhuo; Ruffin, Paul; Brantley, Christina; Edwards, Eugene; Cheng, Jiping; Luo, Claire

2012-10-01

In this paper, we have reviewed our recent works on IR supercontinuum generation (SCG) and its applications. First, we provide a brief review on the physical mechanism of the supercontinuum generation and our previous works in this field. Second, a thinner IR crystal fiber is fabricated. The supercontinuum generation in this thinner fiber is also demonstrated, which shows the enhanced performance. The suggestion for the future effort is also included.

RADON GENERATION AND TRANSPORT IN AGED CONCRETE

EPA Science Inventory

The report gives results of a characterization of radon generation and transport in Florida concretes sampled from 12- to 45-year-old residential slabs. It also compares measurements from old concrete samples to previous measurements on newly poured Florida residential concretes....

Effect of inert cover gas on performance of radioisotope Stirling space power system

NASA Astrophysics Data System (ADS)

Carpenter, R.; Kumar, V.; Or, C.; Schock, A.

2001-02-01

This paper describes an updated Orbital design of a radioisotope Stirling power system and its predicted performance at the beginning and end of a six-year mission to the Jovian moon Europa. The design is based on General Purpose Heat Source (GPHS) modules identical to those previously developed and safety-qualified by the Department of Energy (DOE) which were successfully launched on missions to Jupiter and Saturn by the Jet Propulsion Laboratory (JPL). In each generator, the heat produced by the decay of the Pu-238 isotope is converted to electric power by two free-piston Stirling engines and linear alternators developed by Stirling Technology Company (STC), and their rejected waste heat is transported to radiators by heat pipes. The principal difference between the proposed system design and previous Orbital designs (Or et al., 2000) is the thermal insulation between the heat source and the generator's housing. Previous designs had employed multifoil insulation, whereas the design described here employs Min-K-1800 thermal insulation. Such insulation had been successfully used by Teledyne and GE in earlier RTGs (Radioisotope Thermoelectric Generators). Although Min-K is a much poorer insulator than multifoil in vacuum and requires a substantially greater thickness for equivalent performance, it offers compensating advantages. Specifically it makes it possible to adjust the generator's BOM temperatures by filling its interior volume with inert cover gas. This makes it possible to meet the generator's BOM and EOM performance goals without exceeding its allowable temperature at the beginning of the mission. .

40 CFR 52.226 - Control strategy and regulations: Particulate matter, San Joaquin Valley and Mountain Counties...

Code of Federal Regulations, 2014 CFR

2014-07-01

... previously approved in 40 CFR 52.223 is retained. (iii) The addition of Rule 209, Fossil Fuel-Steam Generator... CFR 52.223 are retained. (ii) Rule 209, Fossil Fuel-Steam Generator Facility, submitted on July 22...) Rule 209, Fossil Fuel-Steam Generator Facility, submitted on February 10, 1977, is disapproved and the...

40 CFR 52.226 - Control strategy and regulations: Particulate matter, San Joaquin Valley and Mountain Counties...

Code of Federal Regulations, 2011 CFR

2011-07-01

... previously approved in 40 CFR 52.223 is retained. (iii) The addition of Rule 209, Fossil Fuel-Steam Generator... CFR 52.223 are retained. (ii) Rule 209, Fossil Fuel-Steam Generator Facility, submitted on July 22...) Rule 209, Fossil Fuel-Steam Generator Facility, submitted on February 10, 1977, is disapproved and the...

40 CFR 52.226 - Control strategy and regulations: Particulate matter, San Joaquin Valley and Mountain Counties...

Code of Federal Regulations, 2013 CFR

2013-07-01

... previously approved in 40 CFR 52.223 is retained. (iii) The addition of Rule 209, Fossil Fuel-Steam Generator... CFR 52.223 are retained. (ii) Rule 209, Fossil Fuel-Steam Generator Facility, submitted on July 22...) Rule 209, Fossil Fuel-Steam Generator Facility, submitted on February 10, 1977, is disapproved and the...

40 CFR 52.226 - Control strategy and regulations: Particulate matter, San Joaquin Valley and Mountain Counties...

Code of Federal Regulations, 2010 CFR

2010-07-01

... previously approved in 40 CFR 52.223 is retained. (iii) The addition of Rule 209, Fossil Fuel-Steam Generator... CFR 52.223 are retained. (ii) Rule 209, Fossil Fuel-Steam Generator Facility, submitted on July 22...) Rule 209, Fossil Fuel-Steam Generator Facility, submitted on February 10, 1977, is disapproved and the...

40 CFR 52.226 - Control strategy and regulations: Particulate matter, San Joaquin Valley and Mountain Counties...

Code of Federal Regulations, 2012 CFR

2012-07-01

... previously approved in 40 CFR 52.223 is retained. (iii) The addition of Rule 209, Fossil Fuel-Steam Generator... CFR 52.223 are retained. (ii) Rule 209, Fossil Fuel-Steam Generator Facility, submitted on July 22...) Rule 209, Fossil Fuel-Steam Generator Facility, submitted on February 10, 1977, is disapproved and the...

On the Use of Extended TAM to Assess Students' Acceptance and Intent to Use Third-Generation Learning Management Systems

ERIC Educational Resources Information Center

Ros, Salvador; Hernández, Roberto; Caminero, Agustín; Robles, Antonio; Barbero, Isabel; Maciá, Araceli; Holgado, Francisco Pablo

2015-01-01

Service-oriented e-learning platforms can be considered as a third generation of learning management systems (LMSs). As opposed to the previous generations, consisting of ad hoc solutions and traditional LMS, this new technology contemplates e-learning systems as services that can be integrated into different learning scenarios. This paper shows…

The Effect of Enrichment on the Utilization of and the Perceived Effectiveness of Millennial Theory-Based Pedagogies: A Comparative Quantitative Study

ERIC Educational Resources Information Center

Wilkerson, Matt

2014-01-01

The Millennial generation, individuals born after 1982, has been thoroughly characterized and shown to be drastically different from previous generations. This characterization has created change in the way the college classroom is organized. Varieties of pedagogies that address the characterization of the Millennial generation exist and are being…

On the generation of magnetohydrodynamic waves in a stratified and magnetized fluid. II - Magnetohydrodynamic energy fluxes for late-type stars

NASA Technical Reports Server (NTRS)

Musielak, Z. E.; Rosner, R.

1988-01-01

Magnetohydrodynamic (MHD) wave energy fluxes for late-type stars are calculated, using previously obtained formulae for the source functions for the generation of MHD waves in a stratified, but otherwise uniform, turbulent atmosphere; the magnetic fields in the wave generation region are assumed to be homogeneous. In contradiction to previous results, it is shown that in this uniform magnetic field case there is no significant increase in the efficiency of MHD wave generation, at least within the theory's limits of applicability. The major results are that the MHD energy fluxes calculated for late-type stars are less than those obtained for compressible modes in the magnetic field-free case, and that these MHD energy fluxes do not vary enough for a given spectral type to explain the observed range of UV and X-ray fluxes from such stars. It is therefore concluded that MHD waves in stellar atmospheres with homogeneous magnetic fields in the wave generation region cannot explain the observed stellar coronal emissions; if such MHD waves are responsible for a significant component of stellar coronal heating, then nonuniform fields within the generation region must be appealed to.

Pirfenidone inhibits p38-mediated generation of procoagulant microparticles by human alveolar epithelial cells.

PubMed

Neri, Tommaso; Lombardi, Stefania; Faìta, Francesca; Petrini, Silvia; Balìa, Cristina; Scalise, Valentina; Pedrinelli, Roberto; Paggiaro, Pierluigi; Celi, Alessandro

2016-08-01

Pirfenidone is a drug recently approved for idiopathic pulmonary fibrosis but its mechanisms of action are partially unknown. We have previously demonstrated that the airways of patients with idiopathic pulmonary fibrosis contain procoagulant microparticles that activate coagulation factor X to its active form, Xa, a proteinase that signals fibroblast growth and differentiation, thus potentially contributing to the pathogenesis of the disease. We also reported that in vitro exposure of human alveolar cells to H2O2 causes microparticle generation. Since p38 activation is involved in microparticle generation in some cell models and p38 inhibition is one of the mechanisms of action of pirfenidone, we investigated the hypothesis that H2O2-induced generation of microparticles by alveolar cells is dependent on p38 phosphorylation and is inhibited by pirfenidone. H2O2 stimulation of alveolar cells caused p38 phosphorylation that was inhibited by pirfenidone. The drug also inhibited H2O2 induced microparticle generation as assessed by two independent methods (solid phase thrombin generation and flow cytometry). The shedding of microparticle-bound tissue factor activity was also inhibited by pirfenidone. Inhibition of p38-mediated generation of procoagulant microparticle is a previously unrecognized mechanism of action of the antifibrotic drug, pirfenidone. Copyright © 2016 Elsevier Ltd. All rights reserved.

GR@PPA 2.8: Initial-state jet matching for weak-boson production processes at hadron collisions

NASA Astrophysics Data System (ADS)

Odaka, Shigeru; Kurihara, Yoshimasa

2012-04-01

The initial-state jet matching method introduced in our previous studies has been applied to the event generation of single W and Z production processes and diboson (WW, WZ and ZZ) production processes at hadron collisions in the framework of the GR@PPA event generator. The generated events reproduce the transverse momentum spectra of weak bosons continuously in the entire kinematical region. The matrix elements (ME) for hard interactions are still at the tree level. As in previous versions, the decays of weak bosons are included in the matrix elements. Therefore, spin correlations and phase-space effects in the decay of weak bosons are exact at the tree level. The program package includes custom-made parton shower programs as well as ME-based hard interaction generators in order to achieve self-consistent jet matching. The generated events can be passed to general-purpose event generators to make the simulation proceed down to the hadron level. Catalogue identifier: ADRH_v3_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADRH_v3_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 112 146 No. of bytes in distributed program, including test data, etc.: 596 667 Distribution format: tar.gz Programming language: Fortran; with some included libraries coded in C and C++ Computer: All Operating system: Any UNIX-like system RAM: 1.6 Mega bytes at minimum Classification: 11.2 Catalogue identifier of previous version: ADRH_v2_0 Journal reference of previous version: Comput. Phys. Comm. 175 (2006) 665 External routines: Bash and Perl for the setup, and CERNLIB, ROOT, LHAPDF, PYTHIA according to the user's choice. Does the new version supersede the previous version?: No, this version supports only a part of the processes included in the previous versions. Nature of problem: We need to combine those processes including 0 jet and 1 jet in the matrix elements using an appropriate matching method, in order to simulate weak-boson production processes in the entire kinematical region. Solution method: The leading logarithmic components to be included in parton distribution functions and parton showers are subtracted from 1-jet matrix elements. Custom-made parton shower programs are provided to ensure satisfactory performance of the matching method. Reasons for new version: An initial-state jet matching method has been implemented. Summary of revisions: Weak-boson production processes associated with 0 jet and 1 jet can be consistently merged using the matching method. Restrictions: The built-in parton showers are not compatible with the PYTHIA new PS and the HERWIG PS. Unusual features: A large number of particles may be produced by the parton showers and passed to general-purpose event generators. Running time: About 10 min for initialization plus 25 s for every 1k-event generation for W production in the LHC condition, on a 3.0-GHz Intel Xeon processor with the default setting.

Microwave-signal generation in a planar Gunn diode with radiation exposure taken into account

DOE Office of Scientific and Technical Information (OSTI.GOV)

Obolenskaya, E. S., E-mail: bess009@mail.ru, E-mail: obolensk@rf.unn.ru; Tarasova, E. A.; Churin, A. Yu.

2016-12-15

Microwave-signal generation in planar Gunn diodes with a two-dimensional electron gas, in which we previously studied steady-state electron transport, is theoretically studied. The applicability of a control electrode similar to a field-effect transistor gate to control the parameters of the output diode microwave signal is considered. The results of physical-topological modeling of semiconductor structures with different diode active-region structures, i.e., without a quantum well, with one and two quantum wells separated by a potential barrier, are compared. The calculated results are compared with our previous experimental data on recording Gunn generation in a Schottky-gate field-effect transistor. It is theoretically andmore » experimentally shown that the power of the signal generated by the planar Gunn diode with a quantum well and a control electrode is sufficient to implement monolithic integrated circuits of different functionalities. It is theoretically and experimentally shown that the use of a control electrode on account of the introduction of corrective feedback allows a significant increase in the radiation resistance of a microwave generator with Schottky-gate field-effect transistors.« less

Production of the antimicrobial peptides Caseicin A and B by Bacillus isolates growing on sodium caseinate.

PubMed

Kent, R M; Guinane, C M; O'Connor, P M; Fitzgerald, G F; Hill, C; Stanton, C; Ross, R P

2012-08-01

The aim of this study was to identify Bacillus isolates capable of degrading sodium caseinate and subsequently to generate bioactive peptides with antimicrobial activity. Sodium caseinate (2.5% w/v) was inoculated separately with 16 Bacillus isolates and allowed to ferment overnight. Protein breakdown in the fermentates was analysed using gel permeation-HPLC (GP-HPLC) and screened for peptides (<3-kDa) with MALDI-TOF mass spectrometry. Caseicin A (IKHQGLPQE) and caseicin B (VLNENLLR), two previously characterized antimicrobial peptides, were identified in the fermentates of both Bacillus cereus and Bacillus thuringiensis isolates. The caseicin peptides were subsequently purified by RP-HPLC and antimicrobial assays indicated that the peptides maintained the previously identified inhibitory activity against the infant formula pathogen Cronobacter sakazakii. We report a new method using Bacillus sp. to generate two previously characterized antimicrobial peptides from casein. This study highlights the potential to exploit Bacillus sp. or the enzymes they produce for the generation of bioactive antimicrobial peptides from bovine casein. © 2012 The Authors. Letters in Applied Microbiology © 2012 The Society for Applied Microbiology.

Ancestral dichlorodiphenyltrichloroethane (DDT) exposure promotes epigenetic transgenerational inheritance of obesity

PubMed Central

2013-01-01

Background Ancestral environmental exposures to a variety of environmental factors and toxicants have been shown to promote the epigenetic transgenerational inheritance of adult onset disease. The present work examined the potential transgenerational actions of the insecticide dichlorodiphenyltrichloroethane (DDT) on obesity and associated disease. Methods Outbred gestating female rats were transiently exposed to a vehicle control or DDT and the F1 generation offspring bred to generate the F2 generation and F2 generation bred to generate the F3 generation. The F1 and F3 generation control and DDT lineage rats were aged and various pathologies investigated. The F3 generation male sperm were collected to investigate methylation between the control and DDT lineage male sperm. Results The F1 generation offspring (directly exposed as a fetus) derived from the F0 generation exposed gestating female rats were not found to develop obesity. The F1 generation DDT lineage animals did develop kidney disease, prostate disease, ovary disease and tumor development as adults. Interestingly, the F3 generation (great grand-offspring) had over 50% of males and females develop obesity. Several transgenerational diseases previously shown to be associated with metabolic syndrome and obesity were observed in the testis, ovary and kidney. The transgenerational transmission of disease was through both female (egg) and male (sperm) germlines. F3 generation sperm epimutations, differential DNA methylation regions (DMR), induced by DDT were identified. A number of the genes associated with the DMR have previously been shown to be associated with obesity. Conclusions Observations indicate ancestral exposure to DDT can promote obesity and associated disease transgenerationally. The etiology of disease such as obesity may be in part due to environmentally induced epigenetic transgenerational inheritance. PMID:24228800

Do upslope impervious surfaces impact the run-on/runoff relationship?

USDA-ARS?s Scientific Manuscript database

Development of watersheds previously managed for agricultural uses for commercial and residential uses results in the replacement of pervious soil surfaces with impervious surfaces. Characteristics of runoff generated on new upslope impervious surfaces may differ from runoff generated on the predeve...

40 CFR 141.707 - Grandfathering previously collected data.

Code of Federal Regulations, 2013 CFR

2013-07-01

... determines that a previously collected data set submitted for grandfathering was generated during source... additional source water monitoring data, as determined by the State, to ensure that the data set used under... data. 141.707 Section 141.707 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED...

40 CFR 141.707 - Grandfathering previously collected data.

Code of Federal Regulations, 2012 CFR

2012-07-01

... determines that a previously collected data set submitted for grandfathering was generated during source... additional source water monitoring data, as determined by the State, to ensure that the data set used under... data. 141.707 Section 141.707 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED...

40 CFR 141.707 - Grandfathering previously collected data.

Code of Federal Regulations, 2014 CFR

2014-07-01

... determines that a previously collected data set submitted for grandfathering was generated during source... additional source water monitoring data, as determined by the State, to ensure that the data set used under... data. 141.707 Section 141.707 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED...

Octave spanning supercontinuum in an As₂S₃ taper using ultralow pump pulse energy.

PubMed

Hudson, Darren D; Dekker, Stephen A; Mägi, Eric C; Judge, Alexander C; Jackson, Stuart D; Li, Enbang; Sanghera, J S; Shaw, L B; Aggarwal, I D; Eggleton, Benjamin J

2011-04-01

An octave spanning spectrum is generated in an As₂S₃ taper via 77 pJ pulses from an ultrafast fiber laser. Using a previously developed tapering method, we construct a 1.3 μm taper that has a zero-dispersion wavelength around 1.4 μm. The low two-photon absorption of sulfide-based chalcogenide fiber allows for higher input powers than previous efforts in selenium-based chalcogenide tapered fibers. This higher power handling capability combined with input pulse chirp compensation allows an octave spanning spectrum to be generated directly from the taper using the unamplified laser output.

Encouraging the next generation into land-based industries.

PubMed

Rowarth, Js

2008-12-01

Members of the Y-Generation (born between approximately 1978 and 1994) have expectations of careers, rewards and 'work-life balance' that are very different from those of previous generations. This paper discusses these differences, how the land-based industries can position in order to offer 'the career path of choice', and how doing so will be of benefit not only to employers but also to New Zealand.

Chemical Characterization and Toxicological Evaluation of Airborne Mixtures; A System for Generating Mixed Aerosols from a Petroleum Based Liquid and a Fine Solid

DTIC Science & Technology

1989-03-01

diesel fuel aerasol generator described previously at the temperatures used with the diese .! fuel was found to be unsatisfactamy. The ecut temperature was...generator input. Leaving the tube in place with fuel flow stopped hat caused blockage of tho delivery tube. This is apparently the result of pyrolysis of

X-Ray Absorption Spectroscopy of Electrochemically Generated Species

DTIC Science & Technology

1993-02-01

that is a modification of our previously reported design (17) with reticulated vitreous carbon (RVC) as the working electrode. A peristaltic pump...and a flowing analyte stream. A packed carbon -bed bulk electrolysis cell generates the desired metal oxidation state. Completa oxidation and...packed carbon -bed bulk electrolysis cell generates the desired metal oxidation state. The system consists of a closed loop of electrolyte solution

Efficient generation of low-energy folded states of a model protein

NASA Astrophysics Data System (ADS)

Gordon, Heather L.; Kwan, Wai Kei; Gong, Chunhang; Larrass, Stefan; Rothstein, Stuart M.

2003-01-01

A number of short simulated annealing runs are performed on a highly-frustrated 46-"residue" off-lattice model protein. We perform, in an iterative fashion, a principal component analysis of the 946 nonbonded interbead distances, followed by two varieties of cluster analyses: hierarchical and k-means clustering. We identify several distinct sets of conformations with reasonably consistent cluster membership. Nonbonded distance constraints are derived for each cluster and are employed within a distance geometry approach to generate many new conformations, previously unidentified by the simulated annealing experiments. Subsequent analyses suggest that these new conformations are members of the parent clusters from which they were generated. Furthermore, several novel, previously unobserved structures with low energy were uncovered, augmenting the ensemble of simulated annealing results, and providing a complete distribution of low-energy states. The computational cost of this approach to generating low-energy conformations is small when compared to the expense of further Monte Carlo simulated annealing runs.

Gas Generation Testing of Spherical Resorcinol-Formaldehyde (sRF) Resin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Colburn, Heather A.; Bryan, Samuel A.; Camaioni, Donald M.

This report describes gas generation testing of the spherical resorcinol-formaldehyde (sRF) resin that was conducted to support the technology maturation of the LAWPS facility. The current safety basis for the LAWPS facility is based primarily on two studies that had limited or inconclusive data sets. The two studies indicated a 40% increase in hydrogen generation rate of water (as predicted by the Hu model) with sRF resin over water alone. However, the previous studies did not test the range of conditions (process fluids and temperatures) that are expected in the LAWPS facility. Additionally, the previous studies did not obtain replicatemore » test results or comparable liquid-only control samples. All of the testing described in this report, conducted with water, 0.45M nitric acid, and waste simulants with and without sRF resin, returned hydrogen generation rates that are within the current safety basis for the facility of 1.4 times the Hu model output for water.« less

Using Iterative Plan-Do-Study-Act Cycles to Improve Teaching Pedagogy.

PubMed

Murray, Elizabeth J

2018-01-15

Most students entering nursing programs today are members of Generation Y or the Millennial generation, and they learn differently than previous generations. Nurse educators must consider implementing innovative teaching strategies that appeal to the newest generation of learners. The Plan-Do-Study-Act cycle is a framework that can be helpful when planning, assessing, and continually improving teaching pedagogy. This article describes the use of iterative Plan-Do-Study-Act cycles to implement a change in teaching pedagogy.

Breastfeeding is positively associated with child intelligence even net of parental IQ.

PubMed

Kanazawa, Satoshi

2015-12-01

Some previous reviews conclude that breastfeeding is not significantly associated with increased intelligence in children once mother's IQ is statistically controlled. The conclusion may potentially have both theoretical and methodological problems. The National Child Development Study allows the examination of the effect of breastfeeding on intelligence in two consecutive generations of British children. The analysis of the first generation shows that the effect of breastfeeding on intelligence increases from Age 7 to 16. The analysis of the second generation shows that each month of breastfeeding, net of parental IQ and other potential confounds, is associated with an increase of .16 IQ points. Further analyses suggest that some previous studies may have failed to uncover the effect of breastfeeding on child intelligence because of their reliance on one IQ test. (c) 2015 APA, all rights reserved).

Temporally consistent segmentation of point clouds

NASA Astrophysics Data System (ADS)

Owens, Jason L.; Osteen, Philip R.; Daniilidis, Kostas

2014-06-01

We consider the problem of generating temporally consistent point cloud segmentations from streaming RGB-D data, where every incoming frame extends existing labels to new points or contributes new labels while maintaining the labels for pre-existing segments. Our approach generates an over-segmentation based on voxel cloud connectivity, where a modified k-means algorithm selects supervoxel seeds and associates similar neighboring voxels to form segments. Given the data stream from a potentially mobile sensor, we solve for the camera transformation between consecutive frames using a joint optimization over point correspondences and image appearance. The aligned point cloud may then be integrated into a consistent model coordinate frame. Previously labeled points are used to mask incoming points from the new frame, while new and previous boundary points extend the existing segmentation. We evaluate the algorithm on newly-generated RGB-D datasets.

Random Number Generation in Autism.

ERIC Educational Resources Information Center

Williams, Mark A.; Moss, Simon A.; Bradshaw, John L.; Rinehart, Nicole J.

2002-01-01

This study explored the ability of 14 individuals with autism to generate a unique series of digits. Individuals with autism were more likely to repeat previous digits than comparison individuals, suggesting they may exhibit a shortfall in response inhibition. Results support the executive dysfunction theory of autism. (Contains references.)…

Improving Undergraduates' Critique via Computer Mediated Communication

ERIC Educational Resources Information Center

Mohamad, Maslawati; Musa, Faridah; Amin, Maryam Mohamed; Mufti, Norlaila; Latiff, Rozmel Abdul; Sallihuddin, Nani Rahayu

2014-01-01

Our current university students, labeled as "Generation Y" or Millennials, are different from previous generations due to wide exposure to media. Being technologically savvy, they are accustomed to Internet for information and social media for socializing. In line with this current trend, teaching through computer mediated communication…

Teaching Generation Me

ERIC Educational Resources Information Center

Twenge, Jean M.

2013-01-01

Today's college students are significantly different from previous generations. On average, they are overconfident, have high expectations, report higher narcissism, are lower in creativity, are less interested in civic issues, and are less inclined to read long passages of text. They are highly confident of their abilities and received…

Climate change impacts on high-elevation hydroelectricity in California

NASA Astrophysics Data System (ADS)

Madani, Kaveh; Guégan, Marion; Uvo, Cintia B.

2014-03-01

While only about 30% of California's usable water storage capacity lies at higher elevations, high-elevation (above 300 m) hydropower units generate, on average, 74% of California's in-state hydroelectricity. In general, high-elevation plants have small man-made reservoirs and rely mainly on snowpack. Their low built-in storage capacity is a concern with regard to climate warming. Snowmelt is expected to shift to earlier in the year, and the system may not be able to store sufficient water for release in high-demand periods. Previous studies have explored the climate warming effects on California's high-elevation hydropower by focusing on the supply side (exploring the effects of hydrological changes on generation and revenues) ignoring the warming effects on hydroelectricity demand and pricing. This study extends the previous work by simultaneous consideration of climate change effects on high-elevation hydropower supply and pricing in California. The California's Energy-Based Hydropower Optimization Model (EBHOM 2.0) is applied to evaluate the adaptability of California's high-elevation hydropower system to climate warming, considering the warming effects on hydroelectricity supply and pricing. The model's results relative to energy generation, energy spills, reservoir energy storage, and average shadow prices of energy generation and storage capacity expansion are examined and discussed. These results are compared with previous studies to emphasize the need to consider climate change effects on hydroelectricity demand and pricing when exploring the effects of climate change on hydropower operations.

Nonlinear viscous higher harmonics generation due to incident and reflecting internal wave beam collision

NASA Astrophysics Data System (ADS)

Aksu, Anil A.

2017-09-01

In this paper, we have considered the non-linear effects arising due to the collision of incident and reflected internal wave beams. It has already been shown analytically [Tabaei et al., "Nonlinear effects in reflecting and colliding internal wave beams," J. Fluid Mech. 526, 217-243 (2005)] and numerically [Rodenborn et al., "Harmonic generation by reflecting internal waves," Phys. Fluids 23, 026601 (2011)] that the internal wave beam collision generates the higher harmonics and mean flow in a linear stratification. In this paper, similar to previous analytical work, small amplitude wave theory is employed; however, it is formulated from energetics perspective which allows considering internal wave beams as the product of slowly varying amplitude and fast complex exponential. As a result, the mean energy propagation equation for the second harmonic wave is obtained. Finally, a similar dependence on the angle of incidence is obtained for the non-linear energy transfer to the second harmonic with previous analyses. A possible physical mechanism for this angle dependence on the second harmonic generation is also discussed here. In addition to previous studies, the viscous effects are also included in the mean energy propagation equation for the incident, the reflecting, and the second harmonic waves. Moreover, even though the mean flow obtained here is only confined to the interaction region, it is also affected by viscosity via the decay in the incident and the reflecting internal wave beams. Furthermore, a framework for the non-linear harmonic generation in non-linear stratification is also proposed here.

Effect of Inert Cover Gas on Performance of Radioisotope Stirling Space Power System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carpenter, Robert; Kumar, V; Ore, C

2001-01-01

This paper describes an updated Orbital design of a radioisotope Stirling power system and its predicted performance at the beginning and end of a six-year mission to the Jovian moon Europa. The design is based on General Purpose Heat Source (GPHS) modules identical to those previously developed and safety-qualified by the Department of Energy (DOE) which were successfully launched to Jupiter and Saturn by the Jet Propulsion Laboratory (JPL). In each generator, the heat produced by the decay of the Pu-238 isotope is converted to electric power by two free-piston Stirling engines and linear alternators developed by Stirling Technology Companymore » (STC), and their rejected waste heat is transported to radiators by heat pipes. The principal difference between the proposed system design and previous Orbital designs (Or et al. 2000) is the thermal insulation between the heat source and the generator's housing. Previous designs had employed multifoil insulation, whereas the design described here employs Min-K-1800 thermal insulation. Such insulation had been successfully used by Teledyne and GE in earlier RTGs (Radioisotope Thermoelectric Generators). Although Min-K is a much poorer insulator than multifoil in vacuum and requires a substantially greater thickness for equivalent performance, it offers compensating advantages. Specifically it makes it possible to adjust the generator's BOM temperatures by filling its interior volume with inert cover gas. This makes it possible to meet the generator's BOM and EOM performance goals without exceeding its allowable temperature at the beginning of the mission.« less

Emission characteristics of volatile organic compounds from coal-, coal gangue-, and biomass-fired power plants in China

NASA Astrophysics Data System (ADS)

Yan, Yulong; Yang, Chao; Peng, Lin; Li, Rumei; Bai, Huiling

2016-10-01

Face the large electricity demand, thermal power generation still derives the main way of electricity supply in China, account for 78.19% of total electricity production in 2013. Three types of thermal power plants, including coal-fired power plant, coal gangue-fired power plant and biomass-fired power plant, were chosen to survey the source profile, chemical reactivity and emission factor of VOCs during the thermal power generation. The most abundant compounds generated during coal- and coal gangue-fired power generation were 1-Butene, Styrene, n-Hexane and Ethylene, while biomass-fired power generation were Propene, 1-Butenen, Ethyne and Ethylene. The ratios of B/T during thermal power generation in this study was 0.8-2.6, which could be consider as the characteristics of coal and biomass burning. The field tested VOCs emission factor from coal-, coal gangue- and biomass-fired power plant was determined to be 0.88, 0.38 and 3.49 g/GJ, or showed as 0.023, 0.005 and 0.057 g/kg, with the amount of VOCs emission was 44.07, 0.08, 0.45 Gg in 2013, respectively. The statistical results of previous emission inventory, which calculated the VOCs emission used previous emission factor, may overestimate the emission amount of VOCs from thermal power generation in China.

Frequency regulator for synchronous generators

DOEpatents

Karlicek, Robert F.

1982-01-01

The present invention is directed to a novel frequency regulator which controls a generator output frequency for variations in both the input power to the generator and the power supplied to an uncontrolled external load. The present invention further includes over current and current balance protection devices which are relatively inexpensive to manufacture, which may be encapsulated to provide protection from the operating environment and which respond more quickly than previously known electromechanical devices.

Talking about Their Generations: Making Sense of a School Environment Made Up of Gen-Xers and Millennials

ERIC Educational Resources Information Center

Strauss, William

2005-01-01

New generations come and go, and people shouldn't be surprised that each thinks differently from the previous, but they do. Boomers haven't quite figured out Generation X. What they think they have figured out, they often don't respect or appreciate for its significance in shaping the future. Right now, significant changes are happening in K-12…

Solar-Driven Liquid-Metal MHD Generator

NASA Technical Reports Server (NTRS)

Hohl, F.; Lee, J. H.

1982-01-01

Liquid-metal magnetohydrodynamic (MHD) power generator with solar oven as its heat source has potential to produce electric power in space and on Earth at high efficiency. Generator focuses radiation from Sun to heat driving gas that pushes liquid metal past magnetic coil. Power is extracted directly from electric currents set up in conducting liquid. Using solar energy as fuel can save considerable costs and payload weight, compared to previous systems.

Analytical redundancy and the design of robust failure detection systems

NASA Technical Reports Server (NTRS)

Chow, E. Y.; Willsky, A. S.

1984-01-01

The Failure Detection and Identification (FDI) process is viewed as consisting of two stages: residual generation and decision making. It is argued that a robust FDI system can be achieved by designing a robust residual generation process. Analytical redundancy, the basis for residual generation, is characterized in terms of a parity space. Using the concept of parity relations, residuals can be generated in a number of ways and the design of a robust residual generation process can be formulated as a minimax optimization problem. An example is included to illustrate this design methodology. Previously announcedd in STAR as N83-20653

Robust generation of isolated attosecond pulse against the variation of carrier envelope phase of driving laser pulses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zou Pu; Zeng Zhinan; Zheng Yinghui

2010-11-15

We propose a scheme for generating isolated attosecond pulse (IAP) via high-order harmonic generation in gases using a chirped two-color laser field of multicycle duration. In contrast to previous techniques where the stable carrier-envelope phase (CEP) of the driving laser pulses is a prerequisite for IAP generation, the proposed scheme is robust against the large variation of CEP. We show the generation of IAP with an intensity fluctuation less than 50% and an intensity contrast ratio higher than 5:1 when the CEP shift is as large as 1.35{pi}.

Behavioral Response Generation and Selection of Rejected-Reactive Aggressive, Rejected-Nonaggressive, and Average Status Children.

ERIC Educational Resources Information Center

Wood, C. Nannette; Gross, Alan M.

2002-01-01

Examines response decision processes of rejected-reactive aggressive, rejected-nonaggressive and average children in terms of the presence or absence of behavioral response alternatives. Congruent with previous research, rejected-reactive aggressive children made significantly more hostile attributions and generated a higher number of aggressive…

Understanding and Teaching Generation Y

ERIC Educational Resources Information Center

Reilly, Peter

2012-01-01

English teaching professionals working with children in primary school, adolescents in secondary school, or adults at university know that learners nowadays think and behave differently than those from previous generations. These students were born into a world of information technology; they prefer to multitask rather than focus on one thing at a…

Interpersonal Stress Generation as a Mechanism Linking Rumination to Internalizing Symptoms in Early Adolescents

ERIC Educational Resources Information Center

McLaughlin, Katie A.; Nolen-Hoeksema, Susan

2012-01-01

Rumination is a risk factor for depressive and anxiety symptoms in adolescents. Previous investigations of the mechanisms linking rumination to internalizing problems have focused primarily on cognitive factors. We investigated whether interpersonal stress generation plays a role in the longitudinal relationship between rumination and…

What affects millennials' mobility? part II : the impact of residential location, individual preferences and lifestyles on young adults' travel behavior in California.

DOT National Transportation Integrated Search

2017-03-01

Young adults (millennials, or members of Generation Y) are increasingly reported to have : different lifestyles and travel behavior from previous generations at the same stage in life. They : postpone the time at which they obtain a drive...

Micro Chemical Oxygen-Iodine Laser (COIL)

DTIC Science & Technology

2007-10-01

required to form a good o-ring seal. Steam generator design A pumping system based on steam ejectors was designed during the course of the previous HEL-JTO...options for the steam generator design . The first is to catalyze the decomposition of hydrogen peroxide through the use of a standard solid

Adolescents and Youth in Developing Countries: Health and Development Issues in Context

ERIC Educational Resources Information Center

Fatusi, Adesegun O.; Hindin, Michelle J.

2010-01-01

Adolescence is a period of transition, marked by physical, psychological, and cognitive changes underpin by biological factors. Today's generation of young people--the largest in history--is approaching adulthood in a world vastly different from previous generations; AIDS, globalisation, urbanisation, electronic communication, migration, and…

Radiation effect on implanted pacemakers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pourhamidi, A.H.

1983-10-01

It was previously thought that diagnostic or therapeutic ionizing radiation did not have an adverse effect on the function of cardiac pacemakers. Recently, however, some authors have reported damaging effect of therapeutic radiation on cardiac pulse generators. An analysis of a recently-extracted pacemaker documented the effect of radiation on the pacemaker pulse generator.

Degrees of Durability and the New World of Credentialing

ERIC Educational Resources Information Center

DiSalvio, Philip

2013-01-01

The erosion of the college credit monopoly, the devaluation of the degree and the rise of new forms of credentialing suggest a generation of students and higher education institutions somewhat different than the previous generation. Consider a higher learning environment where students create their own academic portfolios and shape their…

Will the Real Digital Native Please Stand Up?

ERIC Educational Resources Information Center

Waters, John K.

2011-01-01

A decade has passed since author, game designer, and educational thought leader Marc Prensky heralded the arrival of a new generation of students whose immersion in information technology distinguished them in fundamental ways from previous generations. Because they had spent their entire lives "surrounded by and using computers, videogames,…

Unsupervised MDP Value Selection for Automating ITS Capabilities

ERIC Educational Resources Information Center

Stamper, John; Barnes, Tiffany

2009-01-01

We seek to simplify the creation of intelligent tutors by using student data acquired from standard computer aided instruction (CAI) in conjunction with educational data mining methods to automatically generate adaptive hints. In our previous work, we have automatically generated hints for logic tutoring by constructing a Markov Decision Process…

Experimental investigations on characteristics of stable water electrospray in air without discharge

NASA Astrophysics Data System (ADS)

Park, Inyong; Hong, Won Seok; Kim, Sang Bok; Kim, Sang Soo

2017-06-01

An experimental study was conducted to resolve previous conflicting results on water electrospray in air at atmospheric pressure. Using a small flow rate relative to that used in previous studies and a small nonmetallic nozzle, we observed stable electrospray of water in air without discharge and distinguished three distinct operating regimes for applied voltage and flow rate. The well-known cone-jet mode was observed and the general scaling law of the generated droplet size in the cone-jet mode was confirmed by direct visualization of the meniscus, jet, and generated droplets. We also observed and analyzed whipping motion in the electrified water jet.

Search for an Appropriate Behavior within the Emotional Regulation in Virtual Creatures Using a Learning Classifier System

PubMed Central

Rosales, Jonathan-Hernando; Cervantes, José-Antonio

2017-01-01

Emotion regulation is a process by which human beings control emotional behaviors. From neuroscientific evidence, this mechanism is the product of conscious or unconscious processes. In particular, the mechanism generated by a conscious process needs a priori components to be computed. The behaviors generated by previous experiences are among these components. These behaviors need to be adapted to fulfill the objectives in a specific situation. The problem we address is how to endow virtual creatures with emotion regulation in order to compute an appropriate behavior in a specific emotional situation. This problem is clearly important and we have not identified ways to solve this problem in the current literature. In our proposal, we show a way to generate the appropriate behavior in an emotional situation using a learning classifier system (LCS). We illustrate the function of our proposal in unknown and known situations by means of two case studies. Our results demonstrate that it is possible to converge to the appropriate behavior even in the first case; that is, when the system does not have previous experiences and in situations where some previous information is available our proposal proves to be a very powerful tool. PMID:29209362

ALL-ELECTRONIC DROPLET GENERATION ON-CHIP WITH REAL-TIME FEEDBACK CONTROL FOR EWOD DIGITIAL MICROFLUIDICS

PubMed Central

Gong, Jian; Kim, Chang-Jin “CJ”

2009-01-01

Electrowetting-on-dielectric (EWOD) actuation enables digital (or droplet) microfluidics where small packets of liquids are manipulated on a two-dimensional surface. Due to its mechanical simplicity and low energy consumption, EWOD holds particular promise for portable systems. To improve volume precision of the droplets, which is desired for quantitative applications such as biochemical assays, existing practices would require near-perfect device fabricaion and operation conditions unless the droplets are generated under feedback control by an extra pump setup off of the chip. In this paper, we develop an all-electronic (i.e., no ancillary pumping) real-time feedback control of on-chip droplet generation. A fast voltage modulation, capacitance sensing, and discrete-time PID feedback controller are integrated on the operating electronic board. A significant improvement is obtained in the droplet volume uniformity, compared with an open loop control as well as the previous feedback control employing an external pump. Furthermore, this new capability empowers users to prescribe the droplet volume even below the previously considered minimum, allowing, for example, 1:x (x < 1) mixing, in comparison to the previously considered n:m mixing (i.e., n and m unit droplets). PMID:18497909

All-electronic droplet generation on-chip with real-time feedback control for EWOD digital microfluidics.

PubMed

Gong, Jian; Kim, Chang-Jin C J

2008-06-01

Electrowetting-on-dielectric (EWOD) actuation enables digital (or droplet) microfluidics where small packets of liquids are manipulated on a two-dimensional surface. Due to its mechanical simplicity and low energy consumption, EWOD holds particular promise for portable systems. To improve volume precision of the droplets, which is desired for quantitative applications such as biochemical assays, existing practices would require near-perfect device fabrication and operation conditions unless the droplets are generated under feedback control by an extra pump setup off of the chip. In this paper, we develop an all-electronic (i.e., no ancillary pumping) real-time feedback control of on-chip droplet generation. A fast voltage modulation, capacitance sensing, and discrete-time PID feedback controller are integrated on the operating electronic board. A significant improvement is obtained in the droplet volume uniformity, compared with an open loop control as well as the previous feedback control employing an external pump. Furthermore, this new capability empowers users to prescribe the droplet volume even below the previously considered minimum, allowing, for example, 1 : x (x < 1) mixing, in comparison to the previously considered n : m mixing (i.e., n and m unit droplets).

Fe(III) oxides accelerate microbial nitrate reduction and electricity generation by Klebsiella pneumoniae L17.

PubMed

Liu, Tongxu; Li, Xiaomin; Zhang, Wei; Hu, Min; Li, Fangbai

2014-06-01

Klebsiella pneumoniae L17 is a fermentative bacterium that can reduce iron oxide and generate electricity under anoxic conditions, as previously reported. This study reveals that K. pneumoniae L17 is also capable of dissimilatory nitrate reduction, producing NO2(-), NH4(+), NO and N2O under anoxic conditions. The presence of Fe(III) oxides (i.e., α-FeOOH, γ-FeOOH, α-Fe2O3 and γ-Fe2O3) significantly accelerates the reduction of nitrate and generation of electricity by K. pneumoniae L17, which is similar to a previous report regarding another fermentative bacterium, Bacillus. No significant nitrate reduction was observed upon treatment with Fe(2+) or α-FeOOH+Fe(2+), but a slight facilitation of nitrate reduction and electricity generation was observed upon treatment with L17+Fe(2+). This result suggests that aqueous Fe(II) or mineral-adsorbed Fe(II) cannot reduce nitrate abiotically but that L17 can catalyze the reduction of nitrate and generation of electricity in the presence of Fe(II) (which might exist as cell surface-bound Fe(II)). To rule out the potential effect of Fe(II) produced by L17 during microbial iron reduction, treatments with the addition of TiO2 or Al2O3 instead of Fe(III) oxides also exhibited accelerated microbial nitrate reduction and electricity generation, indicating that cell-mineral sorption did account for the acceleration effect. However, the acceleration caused by Fe(III) oxides is only partially attributed to the cell surface-bound Fe(II) and cell-mineral sorption but may be driven by the iron oxide conduction band-mediated electron transfer from L17 to nitrate or an electrode, as proposed previously. The current study extends the diversity of bacteria of which nitrate reduction and electricity generation can be facilitated by the presence of iron oxides and confirms the positive role of Fe(III) oxides on microbial nitrate reduction and electricity generation by particular fermentative bacteria in anoxic environments. Copyright © 2014 Elsevier Inc. All rights reserved.

Frequency regulator for synchronous generators

DOEpatents

Karlicek, R.F.

1982-08-10

The present invention is directed to a novel frequency regulator which controls a generator output frequency for variations in both the input power to the generator and the power supplied to an uncontrolled external load. The present invention further includes over current and current balance protection devices which are relatively inexpensive to manufacture, which may be encapsulated to provide protection from the operating environment and which respond more quickly than previously known electromechanical devices. 11 figs.

An electronic rationale for observed initiation rates in ruthenium-mediated olefin metathesis: charge donation in phosphine and N-heterocyclic carbene ligands.

PubMed

Getty, Kendra; Delgado-Jaime, Mario Ulises; Kennepohl, Pierre

2007-12-26

Ru K-edge XAS data indicate that second generation ruthenium-based olefin metathesis precatalysts (L = N-heterocyclic carbene) possess a more electron-deficient metal center than in the corresponding first generation species (L = tricyclohexylphosphine). This surprising effect is also observed from DFT calculations and provides a simple rationale for the slow phosphine dissociation kinetics previously noted for second-generation metathesis precatalysts.

Impact of material absorption on supercontinuum generation in liquid core photonic crystal fiber

NASA Astrophysics Data System (ADS)

Nithyanandan, K.; Raja, Vasantha Jayakantha; Uthayakumar, T.; Porsezian, K.

2013-06-01

The impact of material absorption on supercontinuum generation (SCG) in liquid core photonic crystal fiber (LCPCF) is presented. While PCFs with cores made from different glasses are well studied in previous works with saturable nonlinear response (SNL), in this paper, it is planned to investigate the dynamics of nonlinear processes of supercontinuum generation in high-index fiber with material absorption to understand the physical phenomena of pulse propagation.

Dynamical mass generation in unquenched QED using the Dyson-Schwinger equations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kızılersü, Ayse; Sizer, Tom; Pennington, Michael R.

We present a comprehensive numerical study of dynamical mass generation for unquenched QED in four dimensions, in the absence of four-fermion interactions, using the Dyson-Schwinger approach. We begin with an overview of previous investigations of criticality in the quenched approximation. To this we add an analysis using a new fermion-antifermion-boson interaction ansatz, the Kizilersu-Pennington (KP) vertex, developed for an unquenched treatment. After surveying criticality in previous unquenched studies, we investigate the performance of the KP vertex in dynamical mass generation using a renormalized fully unquenched system of equations. This we compare with the results for two hybrid vertices incorporating themore » Curtis-Pennington vertex in the fermion equation. We conclude that the KP vertex is as yet incomplete, and its relative gauge-variance is due to its lack of massive transverse components in its design.« less

Upper Atmosphere Heating From Ocean-Generated Acoustic Wave Energy

DOE PAGES

Bowman, D. C.; Lees, J. M.

2018-04-27

We present that colliding sea surface waves generate the ocean microbarom, an acoustic signal that may transmit significant energy to the upper atmosphere. Previous estimates of acoustic energy flux from the ocean microbarom and mountain-wind interactions are on the order of 0.01 to 1 mW/m 2, heating the thermosphere by tens of Kelvins per day. We captured upgoing ocean microbarom waves with a balloon-borne infrasound microphone; the maximum acoustic energy flux was approximately 0.05 mW/m 2. This is about half the average value reported in previous ground-based microbarom observations spanning 8 years. The acoustic flux from the microbarom episode describedmore » here may have heated the thermosphere by several Kelvins per day while the source persisted. Lastly, we suggest that ocean wave models could be used to parameterize acoustically generated heating of the upper atmosphere based on sea state.« less

Dynamical mass generation in unquenched QED using the Dyson-Schwinger equations

DOE PAGES

Kızılersü, Ayse; Sizer, Tom; Pennington, Michael R.; ...

2015-03-13

We present a comprehensive numerical study of dynamical mass generation for unquenched QED in four dimensions, in the absence of four-fermion interactions, using the Dyson-Schwinger approach. We begin with an overview of previous investigations of criticality in the quenched approximation. To this we add an analysis using a new fermion-antifermion-boson interaction ansatz, the Kizilersu-Pennington (KP) vertex, developed for an unquenched treatment. After surveying criticality in previous unquenched studies, we investigate the performance of the KP vertex in dynamical mass generation using a renormalized fully unquenched system of equations. This we compare with the results for two hybrid vertices incorporating themore » Curtis-Pennington vertex in the fermion equation. We conclude that the KP vertex is as yet incomplete, and its relative gauge-variance is due to its lack of massive transverse components in its design.« less

Upper Atmosphere Heating From Ocean-Generated Acoustic Wave Energy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bowman, D. C.; Lees, J. M.

We present that colliding sea surface waves generate the ocean microbarom, an acoustic signal that may transmit significant energy to the upper atmosphere. Previous estimates of acoustic energy flux from the ocean microbarom and mountain-wind interactions are on the order of 0.01 to 1 mW/m 2, heating the thermosphere by tens of Kelvins per day. We captured upgoing ocean microbarom waves with a balloon-borne infrasound microphone; the maximum acoustic energy flux was approximately 0.05 mW/m 2. This is about half the average value reported in previous ground-based microbarom observations spanning 8 years. The acoustic flux from the microbarom episode describedmore » here may have heated the thermosphere by several Kelvins per day while the source persisted. Lastly, we suggest that ocean wave models could be used to parameterize acoustically generated heating of the upper atmosphere based on sea state.« less

Method of Simulating Flow-Through Area of a Pressure Regulator

NASA Technical Reports Server (NTRS)

Hass, Neal E. (Inventor); Schallhorn, Paul A. (Inventor)

2011-01-01

The flow-through area of a pressure regulator positioned in a branch of a simulated fluid flow network is generated. A target pressure is defined downstream of the pressure regulator. A projected flow-through area is generated as a non-linear function of (i) target pressure, (ii) flow-through area of the pressure regulator for a current time step and a previous time step, and (iii) pressure at the downstream location for the current time step and previous time step. A simulated flow-through area for the next time step is generated as a sum of (i) flow-through area for the current time step, and (ii) a difference between the projected flow-through area and the flow-through area for the current time step multiplied by a user-defined rate control parameter. These steps are repeated for a sequence of time steps until the pressure at the downstream location is approximately equal to the target pressure.

An experimental and numerical approach to understand the effect of the IPMC composition on its sensing and energy harvesting behavior

NASA Astrophysics Data System (ADS)

Akle, Barbar; Khairallah, Reef; Challita, Elio

2014-03-01

Ionic Polymer Metal Composite (IPMC) is an Electo-Active Polymer (EAP) that is well-known for its actuation and sensing behavior. It has been shown that in charge sensing mode an IPMC generates one order of magnitude larger current as compared to piezoelectric materials. However the voltage generated is on the order of couple millivolts, making it less attractive as a sensor and energy harvester. Previous numerical work by the author, demonstrated that increasing the ionic concentration of the ionomer will increase the current and voltage generated by an IPMC. Conversely, the previous study showed that the electrode composition and architecture had minimal effects. This paper will present an experimental investigation of the effect of changing the composition of the ionomer, the membrane thickness, and electrode architecture on the sensing and energy harvesting behavior. The response of all IPMC transducers is analyzed and compared to numerical simulations.

Effect of Forcing Function on Nonlinear Acoustic Standing Waves

NASA Technical Reports Server (NTRS)

Finkheiner, Joshua R.; Li, Xiao-Fan; Raman, Ganesh; Daniels, Chris; Steinetz, Bruce

2003-01-01

Nonlinear acoustic standing waves of high amplitude have been demonstrated by utilizing the effects of resonator shape to prevent the pressure waves from entering saturation. Experimentally, nonlinear acoustic standing waves have been generated by shaking an entire resonating cavity. While this promotes more efficient energy transfer than a piston-driven resonator, it also introduces complicated structural dynamics into the system. Experiments have shown that these dynamics result in resonator forcing functions comprised of a sum of several Fourier modes. However, previous numerical studies of the acoustics generated within the resonator assumed simple sinusoidal waves as the driving force. Using a previously developed numerical code, this paper demonstrates the effects of using a forcing function constructed with a series of harmonic sinusoidal waves on resonating cavities. From these results, a method will be demonstrated which allows the direct numerical analysis of experimentally generated nonlinear acoustic waves in resonators driven by harmonic forcing functions.

Development of multiplex microsatellite PCR panels for the seagrass Thalassia hemprichii (Hydrocharitaceae).

PubMed

van Dijk, Kor-Jent; Mellors, Jane; Waycott, Michelle

2014-11-01

New microsatellites were developed for the seagrass Thalassia hemprichii (Hydrocharitaceae), a long-lived seagrass species that is found throughout the shallow waters of tropical and subtropical Indo-West Pacific. Three multiplex PCR panels were designed utilizing new and previously developed markers, resulting in a toolkit for generating a 16-locus genotype. • Through the use of microsatellite enrichment and next-generation sequencing, 16 new, validated, polymorphic microsatellite markers were isolated. Diversity was between two and four alleles per locus totaling 36 alleles. These markers, plus previously developed microsatellite markers for T. hemprichii and T. testudinum, were tested for suitability in multiplex PCR panels. • The generation of an easily replicated suite of multiplex panels of codominant molecular markers will allow for high-resolution and detailed genetic structure analysis and clonality assessment with minimal genotyping costs. We suggest the establishment of a T. hemprichii primer convention for the unification of future data sets.

Transapical Implantation of a 2nd-Generation JenaValve Device in Patient with Extremely High Surgical Risk

PubMed Central

Mieres, Juan; Menéndez, Marcelo; Fernández-Pereira, Carlos; Rubio, Miguel; Rodríguez, Alfredo E.

2015-01-01

Transcatheter Aortic Valve Replacement (TAVR) is performed in patients who are poor surgical candidates. Many patients have inadequate femoral access, and alternative access sites have been used such as the transapical approach discussed in this paper. We present an elderly and fragile patient not suitable for surgery for unacceptable high risk, including poor ventricular function, previous myocardial infarction with percutaneous coronary intervention, pericardial effusion, and previous cardiac surgery with replacement of mechanical mitral valve. Transapical aortic valve replacement with a second-generation self-expanding JenaValve is performed. The JenaValve is a second-generation transapical TAVR valve consisting of a porcine root valve mounted on a low-profile nitinol stent. The valve is fully retrievable and repositionable. We discuss transapical access, implantation technique, and feasibility of valve implantation in this extremely high surgical risk patient. PMID:26346128

Transapical Implantation of a 2nd-Generation JenaValve Device in Patient with Extremely High Surgical Risk.

PubMed

Mieres, Juan; Menéndez, Marcelo; Fernández-Pereira, Carlos; Rubio, Miguel; Rodríguez, Alfredo E

2015-01-01

Transcatheter Aortic Valve Replacement (TAVR) is performed in patients who are poor surgical candidates. Many patients have inadequate femoral access, and alternative access sites have been used such as the transapical approach discussed in this paper. We present an elderly and fragile patient not suitable for surgery for unacceptable high risk, including poor ventricular function, previous myocardial infarction with percutaneous coronary intervention, pericardial effusion, and previous cardiac surgery with replacement of mechanical mitral valve. Transapical aortic valve replacement with a second-generation self-expanding JenaValve is performed. The JenaValve is a second-generation transapical TAVR valve consisting of a porcine root valve mounted on a low-profile nitinol stent. The valve is fully retrievable and repositionable. We discuss transapical access, implantation technique, and feasibility of valve implantation in this extremely high surgical risk patient.

Influence of air-jet vortex generator diameter on separation region

NASA Astrophysics Data System (ADS)

Szwaba, Ryszard

2013-08-01

Control of shock wave and boundary layer interaction continues to attract a lot of attention. In recent decades several methods of interaction control have been investigated. The research has mostly concerned solid (vane type) vortex generators and transpiration methods of suction and blowing. This investigation concerns interaction control using air-jets to generate streamwise vortices. The effectiveness of air-jet vortex generators in controlling separation has been proved in a previous research. The present paper focuses on the influence of the vortex generator diameter on the separation region. It presents the results of experimental investigations and provides new guidelines for the design of air-jet vortex generators to obtain more effective separation control.

EDUCATIONAL ATTITUDES, SCHOOL PEER CONTEXT, AND THE “IMMIGRANT PARADOX” IN EDUCATION

PubMed Central

Greenman, Emily

2013-01-01

Previous research has been unable to explain declines in educational outcomes across immigrant generations. This study uses data on Mexican and Asian-origin youth from Add Health to test educational attitudes and behaviors as mechanisms linking immigrant generation to four educational outcomes. First, it assesses whether generational changes in attitudes and behaviors correspond to generational differences in educational outcomes. Second, it tests whether generational changes in immigrant children’s attitudes depend on the school peer context in which they acculturate. Findings show that educational attitudes and behaviors do decline across immigrant generations, but that these changes in attitudes account for little of the generational variation in educational outcomes. The relationship between immigrant generation and attitudes is strongest in schools with more negative peer cultures. PMID:23521989

Student Engagement with Computer-Generated Feedback: A Case Study

ERIC Educational Resources Information Center

Zhang, Zhe

2017-01-01

In order to benefit from feedback on their writing, students need to engage effectively with it. This article reports a case study on student engagement with computer-generated feedback, known as automated writing evaluation (AWE) feedback, in an EFL context. Differing from previous studies that explored commercially available AWE programs, this…

Meeting the Needs of the 21st Century Student

ERIC Educational Resources Information Center

Niles, Phyllis

2011-01-01

This paper will examine the learning needs of millennial students, a generation different from any previous generation, so librarians should adjust their teaching methods to accommodate their needs. Should we, as librarians, consider changing our reference services--the way we present instruction and the materials that we order for the library?…

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boyer, W.H.

The last several centuries have led humanity to believe that each succeeding generation can expect to live better than did the previous generation. But this is no longer true, and, to survive, the human species must successfully face four impending crises: overpopulation, the destruction of the biosphere, the end of cheap and available energy, and the threat of thermonuclear holocaust.

Family Capital: How First-Generation Higher Education Students Break the Intergenerational Cycle

ERIC Educational Resources Information Center

Gofen, Anat

2009-01-01

Individuals who attain a higher education, whereas both their parents did not, embody the realization of social mobility. They are referred to as first-generation higher education students. Previous analyses had often portrayed them as succeeding despite their family background. This research suggests that although they face many challenges, their…

Arbitrary grammars generating context-free languages

NASA Technical Reports Server (NTRS)

Baker, B. S.

1972-01-01

If G is a grammar such that in each noncontext-free rule of G, the right side contains a string of terminals longer than any terminal string appearing between two nonterminals in the left side; then the language generated by G is context-free. Six previous results follow as simple corollaries of this theorem.

Epidemiology of 3rd generation cephalosporin-resistant Escherichia coli on dairy farms

USDA-ARS?s Scientific Manuscript database

Dairy cattle have been identified as a reservoir for 3rd generation cephalosporin (3GC)-resistant Escherichia coli. We previously identified 3GC-resistant E. coli from manure composite samples of calves and cows in a survey of 80 farms in Pennsylvania. Resistant strains were most frequently isolated...

Youth and Citizenship in the Digital Age: A View from Egypt

ERIC Educational Resources Information Center

Herrera, Linda

2012-01-01

Youth are coming of age in a digital era and learning and exercising citizenship in fundamentally different ways compared to previous generations. Around the globe, a monumental generational rupture is taking place that is being facilitated--not driven in some inevitable and teleological process--by new media and communication technologies. The…

Heating and flooding: A unified approach for rapid generation of free energy surfaces

NASA Astrophysics Data System (ADS)

Chen, Ming; Cuendet, Michel A.; Tuckerman, Mark E.

2012-07-01

We propose a general framework for the efficient sampling of conformational equilibria in complex systems and the generation of associated free energy hypersurfaces in terms of a set of collective variables. The method is a strategic synthesis of the adiabatic free energy dynamics approach, previously introduced by us and others, and existing schemes using Gaussian-based adaptive bias potentials to disfavor previously visited regions. In addition, we suggest sampling the thermodynamic force instead of the probability density to reconstruct the free energy hypersurface. All these elements are combined into a robust extended phase-space formalism that can be easily incorporated into existing molecular dynamics packages. The unified scheme is shown to outperform both metadynamics and adiabatic free energy dynamics in generating two-dimensional free energy surfaces for several example cases including the alanine dipeptide in the gas and aqueous phases and the met-enkephalin oligopeptide. In addition, the method can efficiently generate higher dimensional free energy landscapes, which we demonstrate by calculating a four-dimensional surface in the Ramachandran angles of the gas-phase alanine tripeptide.

Distribution and diagenesis of microfossils from the lower Proterozoic Duck Creek Dolomite, Western Australia

NASA Technical Reports Server (NTRS)

Knoll, A. H.; Strother, P. K.; Rossi, S.

1988-01-01

Two distinct generations of microfossils occur in silicified carbonates from a previously undescribed locality of the Lower Proterozoic Duck Creek Dolomite, Western Australia. The earlier generation occurs in discrete organic-rich clasts and clots characterized by microquartz anhedra; it contains a variety of filamentous and coccoidal fossils in varying states of preservation. Second generation microfossils consist almost exclusively of well-preserved Gunflintia minuta filaments that drape clasts or appear to float in clear chalcedony. These filaments appear to represent an ecologically distinct assemblage that colonized a substrate containing the partially degraded remains of the first generation community. The two assemblages differ significantly in taxonomic frequency distribution from previously described Duck Creek florules. Taken together, Duck Creek microfossils exhibit a range of assemblage variability comparable to that found in other Lower Proterozoic iron formations and ferruginous carbonates. With increasing severity of post-mortem alteration, Duck Creek microfossils appear to converge morphologically on assemblages of simple microstructures described from early Archean cherts. Two new species are described: Oscillatoriopsis majuscula and O. cuboides; the former is among the largest septate filamentous fossils described from any Proterozoic formation.

Mass and Volume Optimization of Space Flight Medical Kits

NASA Technical Reports Server (NTRS)

Keenan, A. B.; Foy, Millennia Hope; Myers, Jerry

2014-01-01

Resource allocation is a critical aspect of space mission planning. All resources, including medical resources, are subject to a number of mission constraints such a maximum mass and volume. However, unlike many resources, there is often limited understanding in how to optimize medical resources for a mission. The Integrated Medical Model (IMM) is a probabilistic model that estimates medical event occurrences and mission outcomes for different mission profiles. IMM simulates outcomes and describes the impact of medical events in terms of lost crew time, medical resource usage, and the potential for medically required evacuation. Previously published work describes an approach that uses the IMM to generate optimized medical kits that maximize benefit to the crew subject to mass and volume constraints. We improve upon the results obtained previously and extend our approach to minimize mass and volume while meeting some benefit threshold. METHODS We frame the medical kit optimization problem as a modified knapsack problem and implement an algorithm utilizing dynamic programming. Using this algorithm, optimized medical kits were generated for 3 mission scenarios with the goal of minimizing the medical kit mass and volume for a specified likelihood of evacuation or Crew Health Index (CHI) threshold. The algorithm was expanded to generate medical kits that maximize likelihood of evacuation or CHI subject to mass and volume constraints. RESULTS AND CONCLUSIONS In maximizing benefit to crew health subject to certain constraints, our algorithm generates medical kits that more closely resemble the unlimited-resource scenario than previous approaches which leverage medical risk information generated by the IMM. Our work here demonstrates that this algorithm provides an efficient and effective means to objectively allocate medical resources for spaceflight missions and provides an effective means of addressing tradeoffs in medical resource allocations and crew mission success parameters.

Evaluation of two 4th generation point-of-care assays for the detection of Human Immunodeficiency Virus infection.

PubMed

Stafylis, Chrysovalantis; Klausner, Jeffrey D

2017-01-01

Fourth generation assays detect simultaneously antibodies for HIV and the p24 antigen, identifying HIV infection earlier than previous generation tests. Previous studies have shown that the Alere Determine HIV-1/2 Combo has lower than anticipated performance in detecting antibodies for HIV and the p24 antigen. Furthermore, there are currently very few studies evaluating the performance of Standard Diagnostics BIOLINE HIV Ag/Ab Combo. To evaluate the performance of the Alere Determine HIV-1/2 Combo and the Standard Diagnostics BIOLINE HIV Ag/Ab Combo in a panel of frozen serum samples. The testing panel included 133 previously frozen serum specimens from the UCLA Clinical Microbiology & Immunoserology laboratory. Reference testing included testing for HIV antibodies by a 3rd generation enzyme immunoassay followed by HIV RNA detection. Antibody negative and RNA positive sera were also tested by a laboratory 4th generation HIV Ab/Ag enzyme immunoassay. Reference testing yielded 97 positives for HIV infection and 36 negative samples. Sensitivity of the Alere test was 95% (88-98%), while the SD Bioline sensitivity was 91% (83-96%). Both assays showed 100% (90-100%) specificity. No indeterminate or invalid results were recorded. Among 13 samples with acute infection (HIV RNA positive, HIV antibody negative), 12 were found positive by the first assay and 8 by the second. The antigen component of the Alere assay detected 10 acute samples, while the SD Bioline assay detected only one. Both rapid assays showed very good overall performance in detecting HIV infection in frozen serum samples, but further improvements are required to improve the performance in acute infection.

A questionnaire-based study on patients' experiences with rechargeable implanted programmable generators for spinal cord stimulation to treat chronic lumbar spondylosis pain.

PubMed

McAuley, John; Farah, Nima; van Gröningen, Richard; Green, Christopher

2013-01-01

The latest generation of rechargeable implantable programmable generators (IPGs) for spinal cord stimulation may greatly extend IPG lifespan compared with previous nonrechargeable devices. This study explores patients' experiences with these devices. Twenty-five patients attending the Department of Neurostimulation, Royal London Hospital, who were implanted with a rechargeable IPG (SC-1110; Boston Scientific, Minneapolis, MN, USA) to provide pain relief from post-surgical lumbosacral spondylosis were surveyed using a questionnaire. Patients reported a mean (SD) benefit from stimulation of 43.7% (32.6%). On a 1 (worst) to 5 (best) scale, the median score was 5 for ease of recharging. Eight patients who had previously had nonrechargeable IPGs felt the rechargeable system was better (p= 0.0143). A particular issue with nonrechargeable batteries was that, while patients considered 5 years an acceptable interval for battery replacements and the procedure itself not too inconvenient, they felt an acceptable wait for replacement after failure to be only 1 week, much shorter than actual waiting times. Patients found the rechargeable IPG easy to recharge and those who had had previous experience with nonrechargeable devices preferred using the rechargeable device. Its benefits in terms of pain relief fell within the range expected from previous studies using nonrechargeable batteries. The main disadvantage of nonrechargeable devices as reported by the patients in this study was concern over the length of time they would have to wait without pain relief between battery replacements. © 2012 International Neuromodulation Society.

Infection before pregnancy affects immunity and response to social challenge in the next generation.

PubMed

Curno, Olivia; Reader, Tom; McElligott, Alan G; Behnke, Jerzy M; Barnard, Chris J

2011-12-12

Natural selection should favour parents that are able to adjust their offspring's life-history strategy and resource allocation in response to changing environmental and social conditions. Pathogens impose particularly strong and variable selective pressure on host life histories, and parental genes will benefit if offspring are appropriately primed to meet the immunological challenges ahead. Here, we investigated transgenerational immune priming by examining reproductive resource allocation by female mice in response to direct infection with Babesia microti prior to pregnancy. Female mice previously infected with B. microti gained more weight over pregnancy, and spent more time nursing their offspring. These offspring generated an accelerated response to B. microti as adults, clearing the infection sooner and losing less weight as a result of infection. They also showed an altered hormonal response to novel social environments, decreasing instead of increasing testosterone production upon social housing. These results suggest that a dominance-resistance trade-off can be mediated by cues from the previous generation. We suggest that strategic maternal investment in response to an infection leads to increased disease resistance in the following generation. Offspring from previously infected mothers downregulate investment in acquisition of social dominance, which in natural systems would reduce access to mating opportunities. In doing so, however, they avoid the reduced disease resistance associated with increased testosterone and dominance. The benefits of accelerated clearance of infection and reduced weight loss during infection may outweigh costs associated with reduced social dominance in an environment where the risk of disease is high.

Default Mode and Executive Networks Areas: Association with the Serial Order in Divergent Thinking

PubMed Central

Heinonen, Jarmo; Numminen, Jussi; Hlushchuk, Yevhen; Antell, Henrik; Taatila, Vesa; Suomala, Jyrki

2016-01-01

Scientific findings have suggested a two-fold structure of the cognitive process. By using the heuristic thinking mode, people automatically process information that tends to be invariant across days, whereas by using the explicit thinking mode people explicitly process information that tends to be variant compared to typical previously learned information patterns. Previous studies on creativity found an association between creativity and the brain regions in the prefrontal cortex, the anterior cingulate cortex, the default mode network and the executive network. However, which neural networks contribute to the explicit mode of thinking during idea generation remains an open question. We employed an fMRI paradigm to examine which brain regions were activated when participants (n = 16) mentally generated alternative uses for everyday objects. Most previous creativity studies required participants to verbalize responses during idea generation, whereas in this study participants produced mental alternatives without verbalizing. This study found activation in the left anterior insula when contrasting idea generation and object identification. This finding suggests that the insula (part of the brain’s salience network) plays a role in facilitating both the central executive and default mode networks to activate idea generation. We also investigated closely the effect of the serial order of idea being generated on brain responses: The amplitude of fMRI responses correlated positively with the serial order of idea being generated in the anterior cingulate cortex, which is part of the central executive network. Positive correlation with the serial order was also observed in the regions typically assigned to the default mode network: the precuneus/cuneus, inferior parietal lobule and posterior cingulate cortex. These networks support the explicit mode of thinking and help the individual to convert conventional mental models to new ones. The serial order correlated negatively with the BOLD responses in the posterior presupplementary motor area, left premotor cortex, right cerebellum and left inferior frontal gyrus. This finding might imply that idea generation without a verbal processing demand reflecting lack of need for new object identification in idea generation events. The results of the study are consistent with recent creativity studies, which emphasize that the creativity process involves working memory capacity to spontaneously shift between different kinds of thinking modes according to the context. PMID:27627760

Bulk electron spin polarization generated by the spin Hall current

NASA Astrophysics Data System (ADS)

Korenev, V. L.

2006-07-01

It is shown that the spin Hall current generates a nonequilibrium spin polarization in the interior of crystals with reduced symmetry in a way that is drastically different from the previously well-known “equilibrium” polarization during the spin relaxation process. The steady state spin polarization value does not depend on the strength of spin-orbit interaction offering possibility to generate relatively high spin polarization even in the case of weak spin-orbit coupling.

The P3 Power Generation System for Advanced Missile Defense Applications

DTIC Science & Technology

2008-11-01

circuit. This increased the output power to the load resistor . The inductor couples with the piezo element to form an electrical LC tuned circuit and...of RMS power was generated with an efficiency of 40 % when an inductor of 250 mH was connected in series to a 100 ohm resistor . From power density...per cycle for generating electrical energy in a piezo -crystal membrane. Steady-state heat transfer measurements have been made previously with a

Incremental Learning of Context Free Grammars by Parsing-Based Rule Generation and Rule Set Search

NASA Astrophysics Data System (ADS)

Nakamura, Katsuhiko; Hoshina, Akemi

This paper discusses recent improvements and extensions in Synapse system for inductive inference of context free grammars (CFGs) from sample strings. Synapse uses incremental learning, rule generation based on bottom-up parsing, and the search for rule sets. The form of production rules in the previous system is extended from Revised Chomsky Normal Form A→βγ to Extended Chomsky Normal Form, which also includes A→B, where each of β and γ is either a terminal or nonterminal symbol. From the result of bottom-up parsing, a rule generation mechanism synthesizes minimum production rules required for parsing positive samples. Instead of inductive CYK algorithm in the previous version of Synapse, the improved version uses a novel rule generation method, called ``bridging,'' which bridges the lacked part of the derivation tree for the positive string. The improved version also employs a novel search strategy, called serial search in addition to minimum rule set search. The synthesis of grammars by the serial search is faster than the minimum set search in most cases. On the other hand, the size of the generated CFGs is generally larger than that by the minimum set search, and the system can find no appropriate grammar for some CFL by the serial search. The paper shows experimental results of incremental learning of several fundamental CFGs and compares the methods of rule generation and search strategies.

Human infertility: is medical treatment enough? A cross-sectional study of a sample of Italian couples.

PubMed

Sina, Manuela; Ter Meulen, Ruud; Carrasco de Paula, Ignacio

2010-09-01

To explore infertile couples' well-being, needs and drop-out rates considering their previous gynaecological history, treatments and support received. Self-reported questionnaires and a telephone follow-up were used to gather data from a sample of 57 Italian couples undergoing first-step procedures for infertility treatment. The questions concerned socio-demographic and personality factors, global perspective on generation, childbearing motivation, intra-psychic and relational dimensions. The study found a strong need for psychological and ethical counselling and showed that drop-out rates were related to psychological discontent. Among couples who had a longer history of infertility, those who had no previous treatments presented higher dyadic adjustment than those who had an history of previous treatments. Moreover, the study provides evidences of the stronger need for personal support for couples who had undergone previous treatments, and for psychological and ethical support for couples with previous generative failures. It also showed that there were beneficial effects to attending to couples' religious and ethical needs. Professional care for those who are undergoing or have undergone fertility treatment should (i) embrace a broader and more comprehensive perspective to understand infertile couples' experience and should (ii) provide appropriate therapy to cope with these experiences.

Characteristics of a Cognitive Tool That Helps Students Learn Diagnostic Problem Solving

ERIC Educational Resources Information Center

Danielson, Jared A.; Mills, Eric M.; Vermeer, Pamela J.; Preast, Vanessa A.; Young, Karen M.; Christopher, Mary M.; George, Jeanne W.; Wood, R. Darren; Bender, Holly S.

2007-01-01

Three related studies replicated and extended previous work (J.A. Danielson et al. (2003), "Educational Technology Research and Development," 51(3), 63-81) involving the Diagnostic Pathfinder (dP) (previously Problem List Generator [PLG]), a cognitive tool for learning diagnostic problem solving. In studies 1 and 2, groups of 126 and 113…

Prediction and generation of binary Markov processes: Can a finite-state fox catch a Markov mouse?

NASA Astrophysics Data System (ADS)

Ruebeck, Joshua B.; James, Ryan G.; Mahoney, John R.; Crutchfield, James P.

2018-01-01

Understanding the generative mechanism of a natural system is a vital component of the scientific method. Here, we investigate one of the fundamental steps toward this goal by presenting the minimal generator of an arbitrary binary Markov process. This is a class of processes whose predictive model is well known. Surprisingly, the generative model requires three distinct topologies for different regions of parameter space. We show that a previously proposed generator for a particular set of binary Markov processes is, in fact, not minimal. Our results shed the first quantitative light on the relative (minimal) costs of prediction and generation. We find, for instance, that the difference between prediction and generation is maximized when the process is approximately independently, identically distributed.

Automated Item Generation with Recurrent Neural Networks.

PubMed

von Davier, Matthias

2018-03-12

Utilizing technology for automated item generation is not a new idea. However, test items used in commercial testing programs or in research are still predominantly written by humans, in most cases by content experts or professional item writers. Human experts are a limited resource and testing agencies incur high costs in the process of continuous renewal of item banks to sustain testing programs. Using algorithms instead holds the promise of providing unlimited resources for this crucial part of assessment development. The approach presented here deviates in several ways from previous attempts to solve this problem. In the past, automatic item generation relied either on generating clones of narrowly defined item types such as those found in language free intelligence tests (e.g., Raven's progressive matrices) or on an extensive analysis of task components and derivation of schemata to produce items with pre-specified variability that are hoped to have predictable levels of difficulty. It is somewhat unlikely that researchers utilizing these previous approaches would look at the proposed approach with favor; however, recent applications of machine learning show success in solving tasks that seemed impossible for machines not too long ago. The proposed approach uses deep learning to implement probabilistic language models, not unlike what Google brain and Amazon Alexa use for language processing and generation.

Ear-body lift and a novel thrust generating mechanism revealed by the complex wake of brown long-eared bats (Plecotus auritus)

NASA Astrophysics Data System (ADS)

Johansson, L. Christoffer; Håkansson, Jonas; Jakobsen, Lasse; Hedenström, Anders

2016-04-01

Large ears enhance perception of echolocation and prey generated sounds in bats. However, external ears likely impair aerodynamic performance of bats compared to birds. But large ears may generate lift on their own, mitigating the negative effects. We studied flying brown long-eared bats, using high resolution, time resolved particle image velocimetry, to determine the aerodynamics of flying with large ears. We show that the ears and body generate lift at medium to cruising speeds (3-5 m/s), but at the cost of an interaction with the wing root vortices, likely reducing inner wing performance. We also propose that the bats use a novel wing pitch mechanism at the end of the upstroke generating thrust at low speeds, which should provide effective pitch and yaw control. In addition, the wing tip vortices show a distinct spiraling pattern. The tip vortex of the previous wingbeat remains into the next wingbeat and rotates together with a newly formed tip vortex. Several smaller vortices, related to changes in circulation around the wing also spiral the tip vortex. Our results thus show a new level of complexity in bat wakes and suggest large eared bats are less aerodynamically limited than previous wake studies have suggested.

GPU based contouring method on grid DEM data

NASA Astrophysics Data System (ADS)

Tan, Liheng; Wan, Gang; Li, Feng; Chen, Xiaohui; Du, Wenlong

2017-08-01

This paper presents a novel method to generate contour lines from grid DEM data based on the programmable GPU pipeline. The previous contouring approaches often use CPU to construct a finite element mesh from the raw DEM data, and then extract contour segments from the elements. They also need a tracing or sorting strategy to generate the final continuous contours. These approaches can be heavily CPU-costing and time-consuming. Meanwhile the generated contours would be unsmooth if the raw data is sparsely distributed. Unlike the CPU approaches, we employ the GPU's vertex shader to generate a triangular mesh with arbitrary user-defined density, in which the height of each vertex is calculated through a third-order Cardinal spline function. Then in the same frame, segments are extracted from the triangles by the geometry shader, and translated to the CPU-side with an internal order in the GPU's transform feedback stage. Finally we propose a "Grid Sorting" algorithm to achieve the continuous contour lines by travelling the segments only once. Our method makes use of multiple stages of GPU pipeline for computation, which can generate smooth contour lines, and is significantly faster than the previous CPU approaches. The algorithm can be easily implemented with OpenGL 3.3 API or higher on consumer-level PCs.

Think Bubbles and Socrates: Teaching Critical Thinking to Millennials in Public Relations Classes

ERIC Educational Resources Information Center

Tallent, Rebecca J.; Barnes, Justin J.

2015-01-01

Critical thinking skills are crucial in the public relations profession, but teaching these skills to the Millennial Generation is vastly different from previous generations. How can a professor get past No Child Left Behind's dependence on test review guides and "everybody wins" in getting students to think for themselves? Using the…

25 CFR 547.14 - What are the minimum technical standards for electronic random number generation?

Code of Federal Regulations, 2011 CFR

2011-04-01

... CLASS II GAMES § 547.14 What are the minimum technical standards for electronic random number generation... rules of the game. For example, if a bingo game with 75 objects with numbers or other designations has a... serial correlation (outcomes shall be independent from the previous game); and (x) Test on subsequences...

25 CFR 547.14 - What are the minimum technical standards for electronic random number generation?

Code of Federal Regulations, 2012 CFR

2012-04-01

... CLASS II GAMES § 547.14 What are the minimum technical standards for electronic random number generation... rules of the game. For example, if a bingo game with 75 objects with numbers or other designations has a... serial correlation (outcomes shall be independent from the previous game); and (x) Test on subsequences...

25 CFR 547.14 - What are the minimum technical standards for electronic random number generation?

Code of Federal Regulations, 2010 CFR

2010-04-01

... CLASS II GAMES § 547.14 What are the minimum technical standards for electronic random number generation... rules of the game. For example, if a bingo game with 75 objects with numbers or other designations has a... serial correlation (outcomes shall be independent from the previous game); and (x) Test on subsequences...

Discovering Shared Experiences of Second Generation Community College Employees: A Grounded Theory Study

ERIC Educational Resources Information Center

Studebaker, Eric J.

2012-01-01

The second generation community college employee had not been a target population of any previous research in the field of higher education. This study added to a broader understanding of employees, their various characteristics, and the implications of those characteristics. The purpose of this study was to develop a grounded theory defining the…

Pupal abnormalities among laboratory-reared gypsy moths

Treesearch

Richard W. Hansen

1991-01-01

Gypsy moth cohorts from 10 near-wild strains (one to six previous generations in culture), six wild strains (field-collected egg masses), and the standard "New Jersey" lab strain (34th and 35th generation in culture) were reared on Otis wheat germ-based artificial diet, in a constant environment. Rearings were begun with newly-hatched first instars; pupae...

A Study of the Information Search Behaviour of the Millennial Generation

ERIC Educational Resources Information Center

Taylor, Arthur

2012-01-01

Introduction: Members of the millennial generation (born after 1982) have come of age in a society infused with technology and information. It is unclear how they determine the validity of information gathered, or whether or not validity is even a concern. Previous information search models based on mediated searches with different age groups may…

(De)Valuing Higher Education: Educated Youth, Generational Differences and a Changing Educational Landscape in Kathmandu, Nepal

ERIC Educational Resources Information Center

Kölbel, Andrea

2013-01-01

Within a single generation Nepal has seen a tremendous increase in higher education opportunities. This rapid growth has encouraged the participation of many young people from social groups previously unrepresented at university. A more questionable consequence however has been the growing divergence and complexity of the educational landscape…

Using Automatic Item Generation to Meet the Increasing Item Demands of High-Stakes Educational and Occupational Assessment

ERIC Educational Resources Information Center

Arendasy, Martin E.; Sommer, Markus

2012-01-01

The use of new test administration technologies such as computerized adaptive testing in high-stakes educational and occupational assessments demands large item pools. Classic item construction processes and previous approaches to automatic item generation faced the problems of a considerable loss of items after the item calibration phase. In this…

REDUCING FUNGICIDE USAGE FOR POTATO PRODUCTION BY UNRAVELING TUBER AND FOLIAGE DEFENSE MECHANISMS AGAINST THE LATE BLIGHT PATHOGEN PHYTOPHTHORA INFESTANS

EPA Science Inventory

1. More than 215 million RNA sequences from potato tubers infected with P. infestans were generated. This represents a >1,300-fold increase in data generation relative to our previous expectation of 160,000 sequence reads. This increase was achieved by capi...

2. Family Capital: How First-Generation Higher-Education Students Break the Intergenerational Cycle. Discussion Paper No. 1322-07

   ERIC Educational Resources Information Center

   Gofen, Anat

   2007-01-01

   The first children in a family to attain a higher education, referred to as "first-generation students," embody the realization of social mobility. Previous analysis has often portrayed them as succeeding despite their family background. This research suggests that although they face many material challenges, their families are often a…

3. The Challenges to Human Resources Development of Libraries in Times of Radical and Generational Changes.

   ERIC Educational Resources Information Center

   Muller, Uta

   Librarianship has undergone a radical change in recent years, which will be continued in the future. Whereas previously the administration of media was most important, nowadays an ever increasing willingness to provide a service is required. In addition to the essential restructuring of libraries, a generational change is taking place within the…

4. Neomillennial User Experience Design Strategies: Utilizing Social Networking Media to Support "Always On" Learning Styles

   ERIC Educational Resources Information Center

   Baird, Derek E.; Fisher, Mercedes

   2006-01-01

   Raised in the "always on" world of interactive media, the Internet, and digital messaging technologies, today's student has different expectations and learning styles than previous generations. This net-centric generation values their ability to use the Web to create a self-paced, customized, on-demand learning path that includes multiple forms of…

5. Confronting Conceptual Challenges in Thermodynamics by Use of Self-Generated Analogies

   ERIC Educational Resources Information Center

   Haglund, Jesper; Jeppsson, Fredrik

   2014-01-01

   Use of self-generated analogies has been proposed as a method for students to learn about a new subject by reference to what they previously know, in line with a constructivist perspective on learning and a resource perspective on conceptual change. We report on a group exercise on using completion problems in combination with self-generated…

6. Talking Pictures: Exploiting the Potential of Visual Sources to Generate Productive Pupil Talk

   ERIC Educational Resources Information Center

   Card, Jane

   2012-01-01

   Jane Card has long been fascinated by the power of visual sources to stimulate pupil thought and discussion. In previous articles she has shared insights from her own expert practice, fusing deep subject knowledge with careful planning to generate highly skilful questioning. Here she presents another rich example of classroom practice, carefully…

7. Problem Solving as an Encoding Task: A Special Case of the Generation Effect

   ERIC Educational Resources Information Center

   Kizilirmak, Jasmin M.; Wiegmann, Berit; Richardson-Klavehn, Alan

   2016-01-01

   Recent evidence suggests that solving problems through insight can enhance long-term memory for the problem and its solution. Previous findings have shown that generation of the solution as well as experiencing a feeling of Aha! can have a beneficial relationship to later memory. These findings lead to the question of how learning in…

8. Previous tip moth infestation predispose trees to heavier attacks in subsequent generations

   Treesearch

   Anthony R. Coody; Christopher J. Fettig; John T. Nowak; C. Wayne Berisford

   2000-01-01

   The Nantucket pine tip moth, Rhyacionia frustrana (Comstock) (Lepidoptera: Tortricidae), is a common regeneration pest of pine plantations in the southeastern U.S.A. The insect has two to five generations annually depending on climate (Fettig et al. 1999a, USDA For. Serv. Res. Pap., In press). Following oviposition and eclosion, first-instar larvae...

9. Defining Sex and Abstinence: Dialogue Is the Key

   ERIC Educational Resources Information Center

   Hamill, Shelley D.; Chepko, Stevie

   2005-01-01

   When does abstinence end and sexual activity begin? In previous generations, the continuum of sexual activity was well-defined in the old baseball analogy. Teens, parents, and teachers knew what going to first, second, or third base involved. For the current generation of young people, sex and abstinence are not so well-defined. As parents and…

10. Nazarov cyclization initiated by peracid oxidation: the total synthesis of (+/-)-rocaglamide.

    PubMed

    Malona, John A; Cariou, Kevin; Frontier, Alison J

    2009-06-10

    The total syntheses of aglafolin, rocagloic acid, and rocaglamide using Nazarov cyclization are described. Generation of the necessary oxyallyl cation intermediate was accomplished via peracid oxidation of an allenol ether to generate an unusual oxycarbenium ion species that undergoes cyclization. The synthesis is efficient, highly diastereoselective, and strategically distinct from previous syntheses of rocaglamide.

11. The correlation structure of several popular pseudorandom number generators

    NASA Technical Reports Server (NTRS)

    Neuman, F.; Merrick, R.; Martin, C. F.

    1973-01-01

    One of the desirable properties of a pseudorandom number generator is that the sequence of numbers it generates should have very low autocorrelation for all shifts except for zero shift and those that are multiples of its cycle length. Due to the simple methods of constructing random numbers, the ideal is often not quite fulfilled. A simple method of examining any random generator for previously unsuspected regularities is discussed. Once they are discovered it is often easy to derive the mathematical relationships, which describe the mathematical relationships, which describe the regular behavior. As examples, it is shown that high correlation exists in mixed and multiplicative congruential random number generators and prime moduli Lehmer generators for shifts a fraction of their cycle lengths.

12. The quest for blue supergiants : The evolution of the progenitor of SN 1987A

    NASA Astrophysics Data System (ADS)

    Menon, Athira; Heger, Alexander

    2015-08-01

    SN 1987A is historically one of the most remarkable supernova explosions to be seen from Earth. Due to the proximity of its location in the LMC, it remains the most well-studied object outside the solar system. It was also the only supernova whose progenitor was observed prior to its explosion.SN 1987A however, was a unique and enigmatic core collapse supernova. It was the first Type II supernova to have been observed to have exploded while its progenitor was a blue supergiant (BSG). Until then Type II supernovae were expected to originate from explosions of red supergiants (RSGs). A spectacular triple-ring nebula structure, rich in helium and nitrogen, was observed around the remnant, indicating a recent RSG phase before becoming a BSG. Even today it is not entirely understood what the evolutionary history may have been to cause a BSG to explode. The most commonly accepted hypothesis for its origin is the merger of a massive binary star system.An evolutionary scenario for such a binary system, was proposed by Podsiadlowski (1992) (P92). Through SPH simulations of the merger and the stellar evolution of the post-merger remnant, Ivanova & Podsiadlowski (2002) and (2003) (I&M) could successfully obtain the RSG to BSG transition of the progenitor.The aim of the present work is to produce the evolutionary history of the progenitor of SN 1987A and its explosion. We construct our models based on the results of P92 and I&M. Here, the secondary (less massive) star is accreted on the primary, while being simultaneously mixed in its envelope over a period of 100 years. The merged star is evolved until the onset of core collapse. For this work we use the 1-dimensional, implicit, hydrodynamical stellar evolution code, KEPLER. A large parameter space is explored, consisting of primary (16-20 Ms) and secondary masses (5-8 Ms), mixing boundaries, and accreting timescales. Those models whose end states match the observed properties of the progenitor of SN 1987A are exploded. The nuclear yields and light curve of the explosion are then compared with the observed data of SN 1987A.

13. Core collapse supernovae from blue supergiant progenitors : The evolutionary history of SN 1987A

    NASA Astrophysics Data System (ADS)

    Menon, Athira

    2015-08-01

    SN 1987A is historically one of the most remarkable supernova explosions to be seen from Earth. Due to the proximity of its location in the LMC, it remains the most well-studied object outside the solar system. It was also the only supernova whose progenitor was observed prior to its explosion.SN 1987A however, was a unique and enigmatic core collapse supernova. It was the first Type II supernova to have been observed to have exploded while its progenitor was a blue supergiant (BSG). Until then Type II supernovae were expected to originate from explosions of red supergiants (RSGs). A spectacular triple-ring nebula structure, rich in helium and nitrogen, was observed around the remnant, indicating a recent RSG phase before becoming a BSG. Even today it is not entirely understood what the evolutionary history may have been to cause a BSG to explode. The most commonly accepted hypothesis for its origin is the merger of a massive binary star system.An evolutionary scenario for such a binary system, was proposed by Podsiadlowski (1992) (P92). Through SPH simulations of the merger and the stellar evolution of the post-merger remnant, Ivanova & Podsiadlowski (2002) and (2003) (I&M) could successfully obtain the RSG to BSG transition of the progenitor.The aim of the present work is to produce the evolutionary history of the progenitor of SN 1987A and its explosion. We construct our models based on the results of P92 and I&M. Here, the secondary (less massive) star is accreted on the primary, while being simultaneously mixed in its envelope over a period of 100 years. The merged star is evolved until the onset of core collapse. For this work we use the 1-dimensional, implicit, hydrodynamical stellar evolution code, KEPLER. A large parameter space is explored, consisting of primary (16-20 Ms) and secondary masses (5-8 Ms), mixing boundaries, and accreting timescales. Those models whose end states match the observed properties of the progenitor of SN 1987A are exploded. The nuclear yields and light curve of the explosion are then compared with the observed data of SN 1987A.

14. Evolved massive stars in W33 and in GMC 23.3-0.3

    NASA Astrophysics Data System (ADS)

    Messineo, Maria; Clark, J. Simon; Figer, Donald F.; Menten, Karl M.; Kudritzki, Rolf-Peter; Najarro, Francisco; Rich, Michael; Ivanov, Valentin D.; Valenti, Elena; Trombley, Christine; Chen, Rosie; Davies, Ben; MacKenty, John W.

    2015-08-01

    We have conducted an infrared spectroscopic survey for massive evolved stars and/or clusters in the Galactic giant molecular clouds G23.3-0.3 and W33. A large number of extraordinary sub-clumps/clusters of massive stars were detected. The spatial and temporal distribution of these massive stars yields information on the star formation history of the clouds.In G23.3-0.3, we discovered a dozen massive O-type stars, one candidate luminous blue variable, and several red supergiants. The O-type stars have masses from 25 to 50 Msun and ages of 5-8 Myr, while the RSGs belong to a burst that occurred 20-30 Myr ago. Therefore, GMC G23.3-0.3 has had one of the longest known histories of star formation (20-30 Myr). GMC G23.3-0.3 is rich in HII regions and supernova remnants; we detected massive stars in the cores of SNR W41 and of SNR G22.7-0.2.In W33, we detected a few evolved O-type stars and one Wolf-Rayet star, but none of the late-type objects has the luminosity of a red supergiant. W33 is characterized by discrete sources and has had at least 3-5 Myr of star formation history, which is now propagating from west to east. While our detections of massive evolved stars in W33 are made on the west side of the cloud, several dense molecular cores that may harbor proto clusters have recently been detected on the east side of the cloud by Immer et al. (2014).Messineo, Maria; Menten, Karl M.; Figer, Donald F.; Davies, Ben; Clark, J. Simon; Ivanov, Valentin D.Kudritzki, Rolf-Peter; Rich, R. Michael; MacKenty, John W.; Trombley, Christine 2014A&A...569A..20MMessineo, Maria; Clark, J. Simon; Figer, Donald F.; Kudritzki, Rolf-Peter; Francisco, Najarro; Rich, R. Michael; Menten, Karl M.; Ivanov, Valentin D.; Valenti, Elena; Trombley, Christine; Chen, C.H. Rosie; Davies, Ben; submitted to ApJ.

15. A starburst region at the tip of the Galactic bar around l=347-350

    NASA Astrophysics Data System (ADS)

    Marco, Amparo; Negueruela, Ignacio; González-Fernández, Carlos; Maíz-Apellániz, Jesús; Dorda, Ricardo; Clark, J. Simon

    2015-08-01

    In the past few years, several clusters of red supergiants have been discovered in a small region of the Milky Way, close to the base of the Scutum-Crux Arm and the tip of the Long Bar, between l=24º and l=29º. According to the number of observed red supergiants and using population synthesis models, they must contain very large stellar populations to harbour so many RSGs, some of them being candidates to the most massive young clusters in the Galaxy. These massive open clusters are part of a huge structure most likely containing hundreds of red supergiants. These results suggest that the Scutum complex represents a giant star formation region triggered by dynamical excitation by the Galactic bar, whose tip is believed to intersect the Scutum-Crux Arm close to this region. If this scenario is correct, a similar structure would be expected close to the opposite end of the Galactic long bar. We must find in an area between l=347º-350º (these sight lines include the expected location of the far tip of the Galactic bar in the model of González-Fernández et al. (2012)) likely candidates to very massive open clusters.We are carrying out a comprehensive optical and infrared photometric and spectroscopic study of this region containing the open clusters VdBH 222, Teutsch 85 and their surroundings. We have analyzed the population of VdBH 222 and we have found a large population of luminous supergiants and OB stars. The cluster lies behind ~7.5 mag of extinction and has a probable distance of ~ 10 kpc and an age of ~12 Ma. VdBH 222 is a young massive cluster with a likely mass > 20000 Msolar. Now, we are analyzing the population of the open cluster Teutsch 85 and surroundings, finding a numerous population of supergiants.In this work, we will discuss the possible role of the Galactic bar in triggering the formation of starburst clusters.

16. Giada improved calibration of measurement subsystems

    NASA Astrophysics Data System (ADS)

    Della Corte, V.; Rotundi, A.; Sordini, R.; Accolla, M.; Ferrari, M.; Ivanovski, S.; Lucarelli, F.; Mazzotta Epifani, E.; Palumbo, P.

    2014-12-01

    GIADA (Grain Impact Analyzer and Dust Accumulator) is an in-situ instrument devoted to measure the dynamical properties of the dust grains emitted by the comet. An Extended Calibration activity using the GIADA Flight Spare Model has been carried out taking into account the knowledge gained through the analyses of IDPs and cometary samples returned from comet 81P/Wild 2. GIADA consists of three measurement subsystems: Grain Detection System, an optical device measuring the optical cross-section for individual dust; Impact Sensor an aluminum plate connected to 5 piezo-sensors measuring the momentum of impacting single dust grains; Micro Balance System measuring the cumulative deposition in time of dust grains smaller than 10 μm. The results of the analyses on data acquired with the GIADA PFM and the comparison with calibration data acquired during the pre-launch campaign allowed us to improve GIADA performances and capabilities. We will report the results of the following main activities: a) definition of a correlation between the 2 GIADA Models (PFM housed in laboratory and In-Flight Model on-board ROSETTA); b) characterization of the sub-systems performances (signal elaboration, sensitivities, space environment effects); c) new calibration measurements and related curves by means of the PFM model using realistic cometary dust analogues. Acknowledgements: GIADA was built by a consortium led by the Univ. Napoli "Parthenope" & INAF-Oss. Astr. Capodimonte, IT, in collaboration with the Inst. de Astrofisica de Andalucia, ES, Selex-ES s.p.a. and SENER. GIADA is presently managed & operated by Ist. di Astrofisica e Planetologia Spaziali-INAF, IT. GIADA was funded and managed by the Agenzia Spaziale Italiana, IT, with a support of the Spanish Ministry of Education and Science MEC, ES. GIADA was developed from a University of Kent, UK, PI proposal; sci. & tech. contribution given by CISAS, IT, Lab. d'Astr. Spat., FR, and Institutions from UK, IT, FR, DE and USA. We thank the RSGS/ESAC, RMOC/ESOC & Rosetta Project/ESTEC for their outstanding work. Science support provided by NASA through the US Rosetta Project managed by JPL/California Institute of Technology. GIADA calibrated data will be available through the ESA's PSA web site (www.rssd.esa.int/index.php?project=PSA&page=index).

17. The Mass-loss Return from Evolved Stars to the Large Magellanic Cloud. VI. Luminosities and Mass-loss Rates on Population Scales

    NASA Astrophysics Data System (ADS)

    Riebel, D.; Srinivasan, S.; Sargent, B.; Meixner, M.

    2012-07-01

    We present results from the first application of the Grid of Red Supergiant and Asymptotic Giant Branch ModelS (GRAMS) model grid to the entire evolved stellar population of the Large Magellanic Cloud (LMC). GRAMS is a pre-computed grid of 80,843 radiative transfer models of evolved stars and circumstellar dust shells composed of either silicate or carbonaceous dust. We fit GRAMS models to ~30,000 asymptotic giant branch (AGB) and red supergiant (RSG) stars in the LMC, using 12 bands of photometry from the optical to the mid-infrared. Our published data set consists of thousands of evolved stars with individually determined evolutionary parameters such as luminosity and mass-loss rate. The GRAMS grid has a greater than 80% accuracy rate discriminating between oxygen- and carbon-rich chemistry. The global dust injection rate to the interstellar medium (ISM) of the LMC from RSGs and AGB stars is on the order of 2.1 × 10-5 M ⊙ yr-1, equivalent to a total mass injection rate (including the gas) into the ISM of ~6 × 10-3 M ⊙ yr-1. Carbon stars inject two and a half times as much dust into the ISM as do O-rich AGB stars, but the same amount of mass. We determine a bolometric correction factor for C-rich AGB stars in the K s band as a function of J - K s color, BC_{K_{s}} = -0.40(J-K_{s})^2 + 1.83(J-K_{s}) + 1.29. We determine several IR color proxies for the dust mass-loss rate (\\dot{M}_{d}) from C-rich AGB stars, such as log \\dot{M_{d}} = ({-18.90}/({(K_{s}-[8.0])+3.37}))-5.93. We find that a larger fraction of AGB stars exhibiting the "long-secondary period" phenomenon are more O-rich than stars dominated by radial pulsations, and AGB stars without detectable mass loss do not appear on either the first-overtone or fundamental-mode pulsation sequences.

18. Monitoring Comet 67P/C-G Micrometer Dust Flux: GIADA onboard Rosetta.

    NASA Astrophysics Data System (ADS)

    Della Corte, Vincenzo; Rotundi, Alessandra; Ivanovski, Stavro; Accolla, Mario; Ferrari, Marco; Sordini, Roberto; Lucarelli, Francesca; Zakharov, Vladimir; Fulle, Marco; Mazzotta Epifani, Elena; López-Moreno, José J.; Rodríguez, Julio; Colangeli, Luigi; Palumbo, Pasquale; Bussoletti, Ezio; Crifo, Jean-Francois; Esposito, Francesca; Green, Simon F.; Grün, Eberhard; Lamy, Philippe L.

    2015-04-01

    (21)ESA-ESAC, Camino Bajo del Castillo, s/n., Urb. Villafranca del Castillo, 28692 Villanueva de la Cañada, Madrid, Spagna The MicroBalance System (MBS) is one of the three measurement subsystems of GIADA, the Grain Impact Analyzer and Dust Accumulator on board the Rosetta/ESA spacecraft (S/C). It consists of five Quartz Crystal Microbalances (QCMs) in roughly orthogonal directions providing the cumulative dust flux of grains smaller than 10 microns. The MBS is continuously monitoring comet 67P/CG since the beginning of May 2014. During the first 4 months of measurements, before the insertion of the S/C in the bound orbit phase, there were no evidences of dust accumulation on the QCMs. Starting from the beginning of October, three out of five QCMs measured an increase of the deposited dust. The measured fluxes show, as expected, a strong anisotropy. In particular, the dust flux appears to be much higher from the Sun direction with respect to the comet direction. Acknowledgment: GIADA was built by a consortum led by the Univ. Napoli "Parthenope" & INAF- Oss. Astr. Capodimonte, in collaboration with the Inst. de Astrofisica de Andalucia, Selex-ES, FI and SENER. GIADA is presently managed & operated by Ist. di Astrofisica e Planetologia Spaziali-INAF, IT. GIADA was funded and managed by the Agenzia Spaziale Italiana, IT, with the support of the Spanish Ministry of Education and Science MEC, ES. GIADA was developed from a PI proposal from the University of Kent; sci. & tech. contribution were provided by CISAS, IT, Lab. d'Astr. Spat., FR, and Institutions from UK, IT, FR, DE and USA. We thank the RSGS/ESAC, RMOC/ESOC & Rosetta Project/ESTEC for their out-standing work. Science support provided was by NASA through the US Rosetta Project managed by the Jet Propulsion Laboratory/ California Institute of Technology. GIADA calibrated data will be available through ESA's PSA web site (www.rssd.esa.int/index.php? project=PSA&page=in dex). We would like to thank Angioletta Coradini for her contribution as a GIADA Co-I.

19. Automatic HDL firmware generation for FPGA-based reconfigurable measurement and control systems with mezzanines in FMC standard

    NASA Astrophysics Data System (ADS)

    Wojenski, Andrzej; Kasprowicz, Grzegorz; Pozniak, Krzysztof T.; Romaniuk, Ryszard

    2013-10-01

    The paper describes a concept of automatic firmware generation for reconfigurable measurement systems, which uses FPGA devices and measurement cards in FMC standard. Following sections are described in details: automatic HDL code generation for FPGA devices, automatic communication interfaces implementation, HDL drivers for measurement cards, automatic serial connection between multiple measurement backplane boards, automatic build of memory map (address space), automatic generated firmware management. Presented solutions are required in many advanced measurement systems, like Beam Position Monitors or GEM detectors. This work is a part of a wider project for automatic firmware generation and management of reconfigurable systems. Solutions presented in this paper are based on previous publication in SPIE.

Increased thrombin generation after acute versus chronic coronary disease as assessed by the thrombin generation test.

PubMed

Orbe, Josune; Zudaire, Maite; Serrano, Rosario; Coma-Canella, Isabel; Martínez de Sizarrondo, Sara; Rodríguez, Jose A; Páramo, Jose A

2008-02-01

Atherosclerosis is the most common pathophysiologic substrate of coronary artery disease (CAD). Whereas plaque progression and arterial remodeling are critical components in chronic CAD, intracoronary thrombosis over plaque disruption is causally related to acute CAD. It was the objective of this study to investigate the differences between prior acute CAD and chronic CAD by a simple global coagulation assay measuring thrombin generation. A cross-sectional study involving 15 healthy controls, 35 patients with chronic stable CAD, and 60 patients after an episode of acute myocardial infarction (AMI) was performed. Thrombin generation was measured between three and 11 months after the initial diagnosis (mean 6 months) by a commercially available fluorogenic assay (Technothrombin TGA). In each patient the lag phase, velocity index and peak thrombin were obtained from the thrombogram profile. Traditional cardiovascular risk factors were recorded, and the inflammatory markers, fibrinogen and hs-C-reactive protein were determined. Compared with stable CAD patients, showing normal thrombograms, those with previous AMI showed earlier lag phase (p < 0.05) and significant increase of both the velocity index (p < 0.001) and peak thrombin (p < 0.05), indicating faster and higher thrombin generation in the AMI group. Differences in thrombin generation between stable and acute CAD patients remained significant (p < 0.001) after adjusting for conventional CAD risk factors (age, gender, diabetes, hypertension, smoking, and hypercholesterolemia). In conclusion, patients with a previous history of acute CAD showed earlier, faster and higher thrombin generation than stable chronic CAD patients. The thrombin generation test may be of clinical value to monitor hypercoagulable/vulnerable blood and/or guide therapy in CAD.

Augmenting Conceptual Design Trajectory Tradespace Exploration with Graph Theory

NASA Technical Reports Server (NTRS)

Dees, Patrick D.; Zwack, Mathew R.; Steffens, Michael; Edwards, Stephen

2016-01-01

Within conceptual design changes occur rapidly due to a combination of uncertainty and shifting requirements. To stay relevant in this fluid time, trade studies must also be performed rapidly. In order to drive down analysis time while improving the information gained by these studies, surrogate models can be created to represent the complex output of a tool or tools within a specified tradespace. In order to create this model however, a large amount of data must be collected in a short amount of time. By this method, the historical approach of relying on subject matter experts to generate the data required is schedule infeasible. However, by implementing automation and distributed analysis the required data can be generated in a fraction of the time. Previous work focused on setting up a tool called multiPOST capable of orchestrating many simultaneous runs of an analysis tool assessing these automated analyses utilizing heuristics gleaned from the best practices of current subject matter experts. In this update to the previous work, elements of graph theory are included to further drive down analysis time by leveraging data previously gathered. It is shown to outperform the previous method in both time required, and the quantity and quality of data produced.

DNA Barcodes for the FIshes of the Narmada, One of India’s Longest Rivers

PubMed Central

Khedkar, Gulab Dattarao; Jamdade, Rahul; Naik, Suresh; David, Lior; Haymer, David

2014-01-01

This study describes the species diversity of fishes of the Narmada River in India. A total of 820 fish specimens were collected from 17 sampling locations across the whole river basin. Fish were taxonomically classified into one of 90 possible species based on morphological characters, and then DNA barcoding was employed using COI gene sequences as a supplemental identification method. A total of 314 different COI sequences were generated, and specimens were confirmed to belong to 85 species representing 63 genera, 34 families and 10 orders. Findings of this study include the identification of five putative cryptic or sibling species and 43 species not previously known from the Narmada River basin. Five species are endemic to India and three are introduced species that had not been previously reported to occur in the Narmada River. Conversely, 43 species previously reported to occur in the Narmada were not found. Genetic diversity and distance values were generated for all of the species within genera, families and orders using Kimura’s 2 parameter distance model followed by the construction of a Neighbor Joining tree. High resolution clusters generated in NJ trees aided the groupings of species corresponding to their genera and families which are in confirmation to the values generated by Automatic Barcode Gap Discovery bioinformatics platform. This aided to decide a threshold value for the discrimination of species boundary from the Narmada River. This study provides an important validation of the use of DNA barcode sequences for monitoring species diversity and changes within complex ecosystems such as the Narmada River. PMID:24991801

DNA barcodes for the fishes of the Narmada, one of India's longest rivers.

PubMed

Khedkar, Gulab Dattarao; Jamdade, Rahul; Naik, Suresh; David, Lior; Haymer, David

2014-01-01

This study describes the species diversity of fishes of the Narmada River in India. A total of 820 fish specimens were collected from 17 sampling locations across the whole river basin. Fish were taxonomically classified into one of 90 possible species based on morphological characters, and then DNA barcoding was employed using COI gene sequences as a supplemental identification method. A total of 314 different COI sequences were generated, and specimens were confirmed to belong to 85 species representing 63 genera, 34 families and 10 orders. Findings of this study include the identification of five putative cryptic or sibling species and 43 species not previously known from the Narmada River basin. Five species are endemic to India and three are introduced species that had not been previously reported to occur in the Narmada River. Conversely, 43 species previously reported to occur in the Narmada were not found. Genetic diversity and distance values were generated for all of the species within genera, families and orders using Kimura's 2 parameter distance model followed by the construction of a Neighbor Joining tree. High resolution clusters generated in NJ trees aided the groupings of species corresponding to their genera and families which are in confirmation to the values generated by Automatic Barcode Gap Discovery bioinformatics platform. This aided to decide a threshold value for the discrimination of species boundary from the Narmada River. This study provides an important validation of the use of DNA barcode sequences for monitoring species diversity and changes within complex ecosystems such as the Narmada River.

Heading control and the effects of display characteristics

NASA Technical Reports Server (NTRS)

Hinz, Stephanie J.; Bennett, C. Thomas

1989-01-01

The present study evaluates whether type of display (dot or wire frame) and direction of movement have an effect on a person's ability to actively maintain a specific heading angle. The questions addressed were: (1) does the magnitude of the heading angle errors differ in the two displays, (2) are some heading angles more difficult to maintain than others, and (3) does the magnitude of some errors differ as a function of display type and direction of movement. Differences between the results of this study and previous research are explained by methodological differences across the studies. Another factor that may be responsible for the difference between previous findings and those presented here is the type of graphics used to display the simulated motion. The physical characteristics of the display or the graphics engines that generate the scene have varied greatly across the studies. Analyses and diagrams are presented showing results of the study and the differences generated from previous studies on this subject.

Updates to Enhanced Geothermal System Resource Potential Estimate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Augustine, Chad

The deep EGS electricity generation resource potential estimate maintained by the National Renewable Energy Laboratory was updated using the most recent temperature-at-depth maps available from the Southern Methodist University Geothermal Laboratory. The previous study dates back to 2011 and was developed using the original temperature-at-depth maps showcased in the 2006 MIT Future of Geothermal Energy report. The methodology used to update the deep EGS resource potential is the same as in the previous study and is summarized in the paper. The updated deep EGS resource potential estimate was calculated for depths between 3 and 7 km and is binned inmore » 25 degrees C increments. The updated deep EGS electricity generation resource potential estimate is 4,349 GWe. A comparison of the estimates from the previous and updated studies shows a net increase of 117 GWe in the 3-7 km depth range, due mainly to increases in the underlying temperature-at-depth estimates from the updated maps.« less

Update to Enhanced Geothermal System Resource Potential Estimate: Preprint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Augustine, Chad

2016-10-01

The deep EGS electricity generation resource potential estimate maintained by the National Renewable Energy Laboratory was updated using the most recent temperature-at-depth maps available from the Southern Methodist University Geothermal Laboratory. The previous study dates back to 2011 and was developed using the original temperature-at-depth maps showcased in the 2006 MIT Future of Geothermal Energy report. The methodology used to update the deep EGS resource potential is the same as in the previous study and is summarized in the paper. The updated deep EGS resource potential estimate was calculated for depths between 3 and 7 km and is binned inmore » 25 degrees C increments. The updated deep EGS electricity generation resource potential estimate is 4,349 GWe. A comparison of the estimates from the previous and updated studies shows a net increase of 117 GWe in the 3-7 km depth range, due mainly to increases in the underlying temperature-at-depth estimates from the updated maps.« less

Interactive Land-Use Optimization Using Laguerre Voronoi Diagram with Dynamic Generating Point Allocation

NASA Astrophysics Data System (ADS)

Chaidee, S.; Pakawanwong, P.; Suppakitpaisarn, V.; Teerasawat, P.

2017-09-01

In this work, we devise an efficient method for the land-use optimization problem based on Laguerre Voronoi diagram. Previous Voronoi diagram-based methods are more efficient and more suitable for interactive design than discrete optimization-based method, but, in many cases, their outputs do not satisfy area constraints. To cope with the problem, we propose a force-directed graph drawing algorithm, which automatically allocates generating points of Voronoi diagram to appropriate positions. Then, we construct a Laguerre Voronoi diagram based on these generating points, use linear programs to adjust each cell, and reconstruct the diagram based on the adjustment. We adopt the proposed method to the practical case study of Chiang Mai University's allocated land for a mixed-use complex. For this case study, compared to other Voronoi diagram-based method, we decrease the land allocation error by 62.557 %. Although our computation time is larger than the previous Voronoi-diagram-based method, it is still suitable for interactive design.

Development of multiplex microsatellite PCR panels for the seagrass Thalassia hemprichii (Hydrocharitaceae)1

PubMed Central

van Dijk, Kor-jent; Mellors, Jane; Waycott, Michelle

2014-01-01

• Premise of the study: New microsatellites were developed for the seagrass Thalassia hemprichii (Hydrocharitaceae), a long-lived seagrass species that is found throughout the shallow waters of tropical and subtropical Indo-West Pacific. Three multiplex PCR panels were designed utilizing new and previously developed markers, resulting in a toolkit for generating a 16-locus genotype. • Methods and Results: Through the use of microsatellite enrichment and next-generation sequencing, 16 new, validated, polymorphic microsatellite markers were isolated. Diversity was between two and four alleles per locus totaling 36 alleles. These markers, plus previously developed microsatellite markers for T. hemprichii and T. testudinum, were tested for suitability in multiplex PCR panels. • Conclusions: The generation of an easily replicated suite of multiplex panels of codominant molecular markers will allow for high-resolution and detailed genetic structure analysis and clonality assessment with minimal genotyping costs. We suggest the establishment of a T. hemprichii primer convention for the unification of future data sets. PMID:25383269

DOUBLE SHELL TANK (DST) HYDROXIDE DEPLETION MODEL FOR CARBON DIOXIDE ABSORPTION

DOE Office of Scientific and Technical Information (OSTI.GOV)

OGDEN DM; KIRCH NW

2007-10-31

This document generates a supernatant hydroxide ion depletion model based on mechanistic principles. The carbon dioxide absorption mechanistic model is developed in this report. The report also benchmarks the model against historical tank supernatant hydroxide data and vapor space carbon dioxide data. A comparison of the newly generated mechanistic model with previously applied empirical hydroxide depletion equations is also performed.

75 FR 91 - Airworthiness Directives; Bombardier, Inc. (Type Certificate Previously Held by Canadair) Model...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-04

... condition as: Two cases of a crack on a ``dry'' ADG (Air Driven Generator) (Hamilton Sundstrand part number in the 761339 series) in the aft area of the strut and generator housing assembly, have been reported... typically 45 days, which is consistent with the comment period for domestic transport ADs. We will post all...

Do UOC Students Fit in the Net Generation Profile? An Approach to their Habits in ICT Use

ERIC Educational Resources Information Center

Romero, Marc; Guitert, Montse; Sangra, Albert; Bullen, Mark

2013-01-01

Some authors have stated that university students born after 1982 have been profoundly influenced by digital technologies, showing different characteristics when compared to previous generations. However, it is worth asking if that is a current observable phenomenon. Are those students born after the 80s really more familiar with ICT tools than…

Digital Learners: How Are They Expanding the Horizon of Learning?

ERIC Educational Resources Information Center

Jackson, Sherion H.; Crawford, Debi

2008-01-01

Young learners today are not growing up at the foot of the family radio or spending a good portion of their childhood glued to the television while Sesame Street and Mr. Rogers disseminate information in a constant stream as did previous generations. Rather, this generation of young learners continues to spend many out-of-school hours in a digital…

Photochemically assisted fast abiotic oxidation of manganese and formation of δ-MnO 2 nanosheets in nitrate solution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jung, Haesung; Chadha, Tandeep S.; Kim, Doyoon

This study introduces a new and previously unconsidered fast abiotic formation of Mn(IV) oxides. We report photochemically assisted fast abiotic oxidation of Mn 2+ (aq) to Mn(IV) (s) by superoxide radicals generated from nitrate photolysis. This photochemical pathway generates randomly stacked layered birnessite (δ-MnO 2) nanosheets.

Relational Security Moderates the Effect of Serotonin Transporter Gene Polymorphism (5-HTTLPR) on Stress Generation and Depression among Adolescents

ERIC Educational Resources Information Center

Starr, Lisa R.; Hammen, Constance; Brennan, Patricia A.; Najman, Jake M.

2013-01-01

Previous research demonstrates that carriers of the short allele of the serotonin transporter gene (5-HTTLPR) show both greater susceptibility to depression in response to stressful life events and higher rates of generation of stressful events in response to depression. The current study examines relational security (i.e., self-reported beliefs…

Shifting from Implicit to Explicit Knowledge: Different Roles of Early- and Late-Night Sleep

ERIC Educational Resources Information Center

Yordanova, Juliana; Kolev, Vasil; Verleger, Rolf; Bataghva, Zhamak; Born, Jan; Wagner, Ullrich

2008-01-01

Sleep has been shown to promote the generation of explicit knowledge as indicated by the gain of insight into previously unrecognized task regularities. Here, we explored whether this generation of explicit knowledge depends on pre-sleep implicit knowledge, and specified the differential roles of slow-wave sleep (SWS) vs. rapid eye movement (REM)…

The Religious Behavior and Beliefs of Orthodox Young People in the Mogilev Area

ERIC Educational Resources Information Center

Iudin, V. V.

2007-01-01

In the past twenty years a generation has grown up that, unlike previous generations, was not the object of atheistic upbringing. In this article, based on sociological surveys of young people in Mogilev and Mogilev Oblast conducted in 2002 and 2004, the author examines the religious behavior of young believers and analyze the level and degree of…

Optimized Generator Designs for the DTU 10-MW Offshore Wind Turbine using GeneratorSE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sethuraman, Latha; Maness, Michael; Dykes, Katherine

Compared to land-based applications, offshore wind imposes challenges for the development of next generation wind turbine generator technology. Direct-drive generators are believed to offer high availability, efficiency, and reduced operation and maintenance requirements; however, previous research suggests difficulties in scaling to several megawatts or more in size. The resulting designs are excessively large and/or massive, which are major impediments to transportation logistics, especially for offshore applications. At the same time, geared wind turbines continue to sustain offshore market growth through relatively cheaper and lightweight generators. However, reliability issues associated with mechanical components in a geared system create significant operation andmore » maintenance costs, and these costs make up a large portion of overall system costs offshore. Thus, direct-drive turbines are likely to outnumber their gear-driven counterparts for this market, and there is a need to review the costs or opportunities of building machines with different types of generators and examining their competitiveness at the sizes necessary for the next generation of offshore wind turbines. In this paper, we use GeneratorSE, the National Renewable Energy Laboratory's newly developed systems engineering generator sizing tool to estimate mass, efficiency, and the costs of different generator technologies satisfying the electromagnetic, structural, and basic thermal design requirements for application in a very large-scale offshore wind turbine such as the Technical University of Denmark's (DTU) 10-MW reference wind turbine. For the DTU reference wind turbine, we use the previously mentioned criteria to optimize a direct-drive, radial flux, permanent-magnet synchronous generator; a direct-drive electrically excited synchronous generator; a medium-speed permanent-magnet generator; and a high-speed, doubly-fed induction generator. Preliminary analysis of leveled costs of energy indicate that for large turbines, the cost of permanent magnets and reliability issues associated with brushes in electrically excited machines are the biggest deterrents for building direct-drive systems. The advantage of medium-speed permanent-magnet machines over doubly-fed induction generators is evident, yet, variability in magnet prices and solutions to address reliability issues associated with gearing and brushes can change this outlook. This suggests the need to potentially pursue fundamentally new innovations in generator designs that help avoid high capital costs but still have significant reliability related to performance.« less

Optimized Generator Designs for the DTU 10-MW Offshore Wind Turbine using GeneratorSE: Preprint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sethuraman, Latha; Maness, Michael; Dykes, Katherine

Compared to land-based applications, offshore wind imposes challenges for the development of next generation wind turbine generator technology. Direct-drive generators are believed to offer high availability, efficiency, and reduced operation and maintenance requirements; however, previous research suggests difficulties in scaling to several megawatts or more in size. The resulting designs are excessively large and/or massive, which are major impediments to transportation logistics, especially for offshore applications. At the same time, geared wind turbines continue to sustain offshore market growth through relatively cheaper and lightweight generators. However, reliability issues associated with mechanical components in a geared system create significant operation andmore » maintenance costs, and these costs make up a large portion of overall system costs offshore. Thus, direct-drive turbines are likely to outnumber their gear-driven counterparts for this market, and there is a need to review the costs or opportunities of building machines with different types of generators and examining their competitiveness at the sizes necessary for the next generation of offshore wind turbines. In this paper, we use GeneratorSE, the National Renewable Energy Laboratory's newly developed systems engineering generator sizing tool to estimate mass, efficiency, and the costs of different generator technologies satisfying the electromagnetic, structural, and basic thermal design requirements for application in a very large-scale offshore wind turbine such as the Technical University of Denmark's (DTU) 10-MW reference wind turbine. For the DTU reference wind turbine, we use the previously mentioned criteria to optimize a direct-drive, radial flux, permanent-magnet synchronous generator; a direct-drive electrically excited synchronous generator; a medium-speed permanent-magnet generator; and a high-speed, doubly-fed induction generator. Preliminary analysis of leveled costs of energy indicate that for large turbines, the cost of permanent magnets and reliability issues associated with brushes in electrically excited machines are the biggest deterrents for building direct-drive systems. The advantage of medium-speed permanent-magnet machines over doubly-fed induction generators is evident, yet, variability in magnet prices and solutions to address reliability issues associated with gearing and brushes can change this outlook. This suggests the need to potentially pursue fundamentally new innovations in generator designs that help avoid high capital costs but still have significant reliability related to performance.« less

Power combination of a self-coherent high power microwave source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yan, Xiaolu, E-mail: yanxl-dut@163.com; Zhang, Xiaoping; Li, Yangmei

2015-09-15

In our previous work, generating two phase-locked high power microwaves (HPMs) in a single self-coherent HPM device has been demonstrated. In this paper, after optimizing the structure of the previous self-coherent source, we design a power combiner with a folded phase-adjustment waveguide to realize power combination between its two sub-sources. Further particle-in-cell simulation of the combined source shows that when the diode voltage is 687 kV and the axial magnetic field is 0.8 T, a combined output microwave with 3.59 GW and 9.72 GHz is generated. The impedance of the combined device is 36 Ω and the total power conversion efficiency is 28%.

Figure-ground segmentation based on class-independent shape priors

NASA Astrophysics Data System (ADS)

Li, Yang; Liu, Yang; Liu, Guojun; Guo, Maozu

2018-01-01

We propose a method to generate figure-ground segmentation by incorporating shape priors into the graph-cuts algorithm. Given an image, we first obtain a linear representation of an image and then apply directional chamfer matching to generate class-independent, nonparametric shape priors, which provide shape clues for the graph-cuts algorithm. We then enforce shape priors in a graph-cuts energy function to produce object segmentation. In contrast to previous segmentation methods, the proposed method shares shape knowledge for different semantic classes and does not require class-specific model training. Therefore, the approach obtains high-quality segmentation for objects. We experimentally validate that the proposed method outperforms previous approaches using the challenging PASCAL VOC 2010/2012 and Berkeley (BSD300) segmentation datasets.

On sound generation by turbulent convection: A new look at old results

NASA Technical Reports Server (NTRS)

Musielak, Z. E.; Rosner, R.; Stein, R. F.; Ulmschneider, P.

1994-01-01

We have revisited the problem of acoustic wave generation by turbulent convection in stellar atmospheres. The theory of aerodynamically generated sound, originally developed by Lighthill and later modified by Stein to include the effects of stratification, has been used to estimate the acoustic wave energy flux generated in solar and stellar convection zones. We correct the earlier computations by incorporating an improved description of the spatial and temporal spectrum of the turbulent convection. We show the dependence of the resulting wave fluxes on the nature of the turbulence, and compute the wave energy spectra and wave energy fluxes generated in the Sun on the basis of a mixing-length model of the solar convection zone. In contrast to the previous results, we show that the acoustic energy generation does not depend very sensitively on the turbulent energy spectrum. However, typical total acoustic fluxes of order F(sub A) = 5 x 10(exp 7) ergs/sq cm/s with a peak of the acoustic frequency spectrum near omega = 100 mHz are found to be comparable to those previously calculated. The acoustic flux turns out to be strongly dependent on the solar model, scaling with the mixing-length parameter alpha as alpha(exp 3.8). The computed fluxes most likely constitute a lower limit on the acoustic energy produced in the solar convection zone if recent convection simulations suggesting the presence of shocks near the upper layers of the convection zone apply to the Sun.

Insight into Generation and Evolution of Sea-Salt Aerosols from Field Measurements in Diversified Marine and Coastal Atmospheres

PubMed Central

Feng, Limin; Shen, Hengqing; Zhu, Yujiao; Gao, Huiwang; Yao, Xiaohong

2017-01-01

This report focuses on studying generation and/or evolution of sea-salt aerosols (SSA) on basis of measurements in the Northwest Pacific Ocean (NWPO), the marginal seas of China, at sea-beach sites and a semi-urban coastal site in 2012–2015. From measurements in the NWPO, we obtained the smallest generation function of the super-micron SSA mass ([MSSA]) by the local wind comparing to those previously reported. Vessel-caused wave-breaking was found to greatly enhance generation of SSA and increase [MSSA], which was subject to non-natural generation of SSA. However, naturally enhanced generation of SSA was indeed observed in the marginal seas and at the sea-beach site. The two enhancement mechanisms may explain the difference among this and previous studies. Size distributions of super-micron SSA exhibited two modes, i.e., 1–2 μm mode and ~5 μm mode. The 1–2 μm mode of SSA was enhanced more and comparable to the ~5 μm mode under the wind speed >7 m/s. However, the smaller mode SSA was largely reduced from open oceans to sea-beach sites with reducing wind speed. The two super-micron modes were comparable again at a semi-urban coastal site, suggesting that the smaller super-micron mode SSA may play more important roles in atmospheres. PMID:28120906

A revision of the subtract-with-borrow random number generators

NASA Astrophysics Data System (ADS)

Sibidanov, Alexei

2017-12-01

The most popular and widely used subtract-with-borrow generator, also known as RANLUX, is reimplemented as a linear congruential generator using large integer arithmetic with the modulus size of 576 bits. Modern computers, as well as the specific structure of the modulus inferred from RANLUX, allow for the development of a fast modular multiplication - the core of the procedure. This was previously believed to be slow and have too high cost in terms of computing resources. Our tests show a significant gain in generation speed which is comparable with other fast, high quality random number generators. An additional feature is the fast skipping of generator states leading to a seeding scheme which guarantees the uniqueness of random number sequences. Licensing provisions: GPLv3 Programming language: C++, C, Assembler

Fourth-generation plasma immersion ion implantation and deposition facility for hybrid surface modification layer fabrication.

PubMed

Wang, Langping; Huang, Lei; Xie, Zhiwen; Wang, Xiaofeng; Tang, Baoyin

2008-02-01

The fourth-generation plasma immersion ion implantation and deposition (PIIID) facility for hybrid and batch treatment was built in our laboratory recently. Comparing with our previous PIIID facilities, several novel designs are utilized. Two multicathode pulsed cathodic arc plasma sources are fixed on the chamber wall symmetrically, which can increase the steady working time from 6 h (the single cathode source in our previous facilities) to about 18 h. Meanwhile, the inner diameter of the pulsed cathodic arc plasma source is increased from the previous 80 to 209 mm, thus, large area metal plasma can be obtained by the source. Instead of the simple sample holder in our previous facility, a complex revolution-rotation sample holder composed of 24 shafts, which can rotate around its axis and adjust its position through revolving around the center axis of the vacuum chamber, is fixed in the center of the vacuum chamber. In addition, one magnetron sputtering source is set on the chamber wall instead of the top cover in the previous facility. Because of the above characteristic, the PIIID hybrid process involving ion implantation, vacuum arc, and magnetron sputtering deposition can be acquired without breaking vacuum. In addition, the PIIID batch treatment of cylinderlike components can be finished by installing these components on the rotating shafts on the sample holder.

Reduced graphene oxide coated thin aluminum film as an optoacoustic transmitter for high pressure and high frequency ultrasound generation

NASA Astrophysics Data System (ADS)

Hwan Lee, Seok; Park, Mi-ae; Yoh, Jack J.; Song, Hyelynn; Yun Jang, Eui; Hyup Kim, Yong; Kang, Sungchan; Seop Yoon, Yong

2012-12-01

We demonstrate that reduced graphene oxide (rGO) coated thin aluminum film is an effective optoacoustic transmitter for generating high pressure and high frequency ultrasound previously unattainable by other techniques. The rGO layer of different thickness is deposited between a 100 nm-thick aluminum film and a glass substrate. Under a pulsed laser excitation, the transmitter generates enhanced optoacoustic pressure of 64 times the aluminum-alone transmitter. A promising optoacoustic wave generation is possible by optimizing thermoelasticity of metal film and thermal conductivity of rGO in the proposed transmitter for laser-induced ultrasound applications.

Thermal Analysis of Step 2 GPHS for Next Generation Radioisotope Power Source Missions

NASA Astrophysics Data System (ADS)

Pantano, David R.; Hill, Dennis H.

2005-02-01

The Step 2 General Purpose Heat Source (GPHS) is a slightly larger and more robust version of the heritage GPHS modules flown on previous Radioisotope Thermoelectric Generator (RTG) missions like Galileo, Ulysses, and Cassini. The Step 2 GPHS is to be used in future small radioisotope power sources, such as the Stirling Radioisotope Generator (SRG110) and the Multi-Mission Radioisotope Thermoelectric Generator (MMRTG). New features include an additional central web of Fine Weave Pierced Fabric (FWPF) graphite in the aeroshell between the two Graphite Impact Shells (GIS) to improve accidental reentry and impact survivability and an additional 0.1-inch of thickness to the aeroshell broad faces to improve ablation protection. This paper details the creation of the thermal model using Thermal Desktop and AutoCAD interfaces and provides comparisons of the model to results of previous thermal analysis models of the heritage GPHS. The results of the analysis show an anticipated decrease in total thermal gradient from the aeroshell to the iridium clads compared to the heritage results. In addition, the Step 2 thermal model is investigated under typical SRG110 boundary conditions, with cover gas and gravity environments included where applicable, to provide preliminary guidance for design of the generator. Results show that the temperatures of the components inside the GPHS remain within accepted design limits during all envisioned mission phases.

Generation of action potentials in a mathematical model of corticotrophs.

PubMed Central

LeBeau, A P; Robson, A B; McKinnon, A E; Donald, R A; Sneyd, J

1997-01-01

Corticotropin-releasing hormone (CRH) is an important regulator of adrenocorticotropin (ACTH) secretion from pituitary corticotroph cells. The intracellular signaling system that underlies this process involves modulation of voltage-sensitive Ca2+ channel activity, which leads to the generation of Ca2+ action potentials and influx of Ca2+. However, the mechanisms by which Ca2+ channel activity is modulated in corticotrophs are not currently known. We investigated this process in a Hodgkin-Huxley-type mathematical model of corticotroph plasma membrane electrical responses. We found that an increase in the L-type Ca2+ current was sufficient to generate action potentials from a previously resting state of the model. The increase in the L-type current could be elicited by either a shift in the voltage dependence of the current toward more negative potentials, or by an increase in the conductance of the current. Although either of these mechanisms is potentially responsible for the generation of action potentials, previous experimental evidence favors the former mechanism, with the magnitude of the shift required being consistent with the experimental findings. The model also shows that the T-type Ca2+ current plays a role in setting the excitability of the plasma membrane, but does not appear to contribute in a dynamic manner to action potential generation. Inhibition of a K+ conductance that is active at rest also affects the excitability of the plasma membrane. PMID:9284294

Contribution of different generations of the brown shrimp Crangon crangon (L.) in the Dutch Wadden Sea to commercial fisheries: A dynamic energy budget approach

NASA Astrophysics Data System (ADS)

Campos, Joana; Van der Veer, Henk W.; Freitas, Vânia; Kooijman, Sebastiaan A. L. M.

2009-08-01

In this paper a contribution is made to the ongoing debate on which brown shrimp generation mostly sustains the autumn peak in coastal North Sea commercial fisheries: the generation born in summer, or the winter one. Since the two perspectives are based on different considerations on the growth timeframe from settlement till commercial size, the Dynamic Energy Budget (DEB) theory was applied to predict maximum possible growth under natural conditions. First, the parameters of the standard DEB model for Crangon crangon L. were estimated using available data sets. These were insufficient to allow a direct estimation, requiring a special protocol to achieve consistency between parameters. Next, the DEB model was validated by comparing simulations with published experimental data on shrimp growth in relation to water temperatures. Finally, the DEB model was applied to simulate growth under optimal food conditions using the prevailing water temperature conditions in the Wadden Sea. Results show clear differences between males and females whereby the fastest growth rates were observed in females. DEB model simulations of maximum growth in the Wadden Sea suggest that it is not the summer brood from the current year as Boddeke claimed, nor the previous winter generation as Kuipers and Dapper suggested, but more likely the summer generation from the previous year which contributes to the bulk of the fisheries recruits in autumn.

Statistical aspects of evolution under natural selection, with implications for the advantage of sexual reproduction.

PubMed

Crouch, Daniel J M

2017-10-27

The prevalence of sexual reproduction remains mysterious, as it poses clear evolutionary drawbacks compared to reproducing asexually. Several possible explanations exist, with one of the most likely being that finite population size causes linkage disequilibria to randomly generate and impede the progress of natural selection, and that these are eroded by recombination via sexual reproduction. Previous investigations have either analysed this phenomenon in detail for small numbers of loci, or performed population simulations for many loci. Here we present a quantitative genetic model for fitness, based on the Price Equation, in order to examine the theoretical consequences of randomly generated linkage disequilibria when there are many loci. In addition, most previous work has been concerned with the long-term consequences of deleterious linkage disequilibria for population fitness. The expected change in mean fitness between consecutive generations, a measure of short-term evolutionary success, is shown under random environmental influences to be related to the autocovariance in mean fitness between the generations, capturing the effects of stochastic forces such as genetic drift. Interaction between genetic drift and natural selection, due to randomly generated linkage disequilibria, is demonstrated to be one possible source of mean fitness autocovariance. This suggests a possible role for sexual reproduction in reducing the negative effects of genetic drift, thereby improving the short-term efficacy of natural selection. Copyright © 2017 Elsevier Ltd. All rights reserved.

Evaluation of Generation Alternation Models in Evolutionary Robotics

NASA Astrophysics Data System (ADS)

Oiso, Masashi; Matsumura, Yoshiyuki; Yasuda, Toshiyuki; Ohkura, Kazuhiro

For efficient implementation of Evolutionary Algorithms (EA) to a desktop grid computing environment, we propose a new generation alternation model called Grid-Oriented-Deletion (GOD) based on comparison with the conventional techniques. In previous research, generation alternation models are generally evaluated by using test functions. However, their exploration performance on the real problems such as Evolutionary Robotics (ER) has not been made very clear yet. Therefore we investigate the relationship between the exploration performance of EA on an ER problem and its generation alternation model. We applied four generation alternation models to the Evolutionary Multi-Robotics (EMR), which is the package-pushing problem to investigate their exploration performance. The results show that GOD is more effective than the other conventional models.

EFFECTS OF LASER RADIATION ON MATTER. LASER PLASMA: Low-threshold generation of harmonics and hard x radiation in a laser plasma. 2. Multipeak generation

NASA Astrophysics Data System (ADS)

Apollonov, V. V.; Derzhavin, S. I.; Kazakov, K. Kh

1993-02-01

The conditions for the generation of hard x radiation with a multipeak structure in a plasma pumped by a long pulse from a free-running CO2 laser at a low intensity (q≲10 GW/cm2) have been studied. This x-ray generation had been observed in a previous study by the present authors. It is shown that this generation of hard x radiation with a multipeak structure leads to a more than tenfold increase in the yield of hard x radiation per laser pulse, under optimum conditions. This increase results from the additional peaks in the x-ray signal. An explanation of this effect is proposed.

Hydrogen generation at ambient conditions: application in fuel cells.

PubMed

Boddien, Albert; Loges, Björn; Junge, Henrik; Beller, Matthias

2008-01-01

The efficient generation of hydrogen from formic acid/amine adducts at ambient temperature is demonstrated. The highest catalytic activity (TOF up to 3630 h(-1) after 20 min) was observed in the presence of in situ generated ruthenium phosphine catalysts. Compared to the previously known methods to generate hydrogen from liquid feedstocks, the systems presented here can be operated at room temperature without the need for any high-temperature reforming processes, and the hydrogen produced can then be directly used in fuel cells. A variety of Ru precursors and phosphine ligands were investigated for the decomposition of formic acid/amine adducts. These catalytic systems are particularly interesting for the generation of H2 for new applications in portable electric devices.

Presystolic tricuspid valve closure: an alternative mechanism of diastolic sound genesis.

PubMed

Lee, C H; Xiao, H B; Gibson, D G

1990-01-01

We describe a previously unrecognised cause of an added diastolic heart sound. The patient had first-degree heart block and diastolic tricuspid regurgitation, leading to presystolic closure of the tricuspid valve and the production of a loud diastolic sound. Unlike previously described mechanisms for diastolic sounds, this sound was generated by the sudden acceleration of retrograde AV flow in late diastole.

One-way quantum repeaters with quantum Reed-Solomon codes

NASA Astrophysics Data System (ADS)

Muralidharan, Sreraman; Zou, Chang-Ling; Li, Linshu; Jiang, Liang

2018-05-01

We show that quantum Reed-Solomon codes constructed from classical Reed-Solomon codes can approach the capacity on the quantum erasure channel of d -level systems for large dimension d . We study the performance of one-way quantum repeaters with these codes and obtain a significant improvement in key generation rate compared to previously investigated encoding schemes with quantum parity codes and quantum polynomial codes. We also compare the three generations of quantum repeaters using quantum Reed-Solomon codes and identify parameter regimes where each generation performs the best.

Self-consistent determination of the spike-train power spectrum in a neural network with sparse connectivity.

PubMed

Dummer, Benjamin; Wieland, Stefan; Lindner, Benjamin

2014-01-01

A major source of random variability in cortical networks is the quasi-random arrival of presynaptic action potentials from many other cells. In network studies as well as in the study of the response properties of single cells embedded in a network, synaptic background input is often approximated by Poissonian spike trains. However, the output statistics of the cells is in most cases far from being Poisson. This is inconsistent with the assumption of similar spike-train statistics for pre- and postsynaptic cells in a recurrent network. Here we tackle this problem for the popular class of integrate-and-fire neurons and study a self-consistent statistics of input and output spectra of neural spike trains. Instead of actually using a large network, we use an iterative scheme, in which we simulate a single neuron over several generations. In each of these generations, the neuron is stimulated with surrogate stochastic input that has a similar statistics as the output of the previous generation. For the surrogate input, we employ two distinct approximations: (i) a superposition of renewal spike trains with the same interspike interval density as observed in the previous generation and (ii) a Gaussian current with a power spectrum proportional to that observed in the previous generation. For input parameters that correspond to balanced input in the network, both the renewal and the Gaussian iteration procedure converge quickly and yield comparable results for the self-consistent spike-train power spectrum. We compare our results to large-scale simulations of a random sparsely connected network of leaky integrate-and-fire neurons (Brunel, 2000) and show that in the asynchronous regime close to a state of balanced synaptic input from the network, our iterative schemes provide an excellent approximations to the autocorrelation of spike trains in the recurrent network.

This Is Your Future: A Case Study Approach to Foster Health Literacy

ERIC Educational Resources Information Center

Brey, Rebecca A.; Clark, Susan E.; Wantz, Molly S.

2008-01-01

Today's young people seem to live in an even faster fast-paced society than previous generations. As in the past, they are involved in sports, music, school, church, work, and are exposed to many forms of mass media that add to their base of information. However, they also have instant access to computer-generated information such as the Internet,…

Has Democracy Led to the Demise of Racism in South Africa? A Search for the Answer in Gauteng Schools

ERIC Educational Resources Information Center

Pillay, Jace

2014-01-01

The paper interrogates the misplaced belief that at the time of the framing of the South African Constitution a transition to popular democratic representation would miraculously end racism within the country. Would the first post-apartheid generation be free of the prejudices of the previous generations, or would the legacy of the old disposition…

Program Synthesizes UML Sequence Diagrams

NASA Technical Reports Server (NTRS)

Barry, Matthew R.; Osborne, Richard N.

2006-01-01

A computer program called "Rational Sequence" generates Universal Modeling Language (UML) sequence diagrams of a target Java program running on a Java virtual machine (JVM). Rational Sequence thereby performs a reverse engineering function that aids in the design documentation of the target Java program. Whereas previously, the construction of sequence diagrams was a tedious manual process, Rational Sequence generates UML sequence diagrams automatically from the running Java code.

An Investigation of Middle School Science Teachers and Students Use of Technology inside and outside of Classrooms: Considering Whether Digital Natives Are More Technology Savvy than Their Teachers

ERIC Educational Resources Information Center

Wang, Shiang-Kwei; Hsu, Hui-Yin; Campbell, Todd; Coster, Daniel C.; Longhurst, Max

2014-01-01

The purpose of the study is to investigate the popular assumption that the "digital natives" generation surpasses the previous "digital immigrants" generation in terms of their technology experiences, because they grow up with information and communication technology. The assumption presumes that teachers, the digital…

Characterization of Sensory Differences in Mixing and Premium Rums Through the Use of Descriptive Sensory Analysis.

PubMed

Ickes, Chelsea M; Cadwallader, Keith R

2017-11-01

This study identified and quantitated perceived sensory differences between 7 premium rums and 2 mixing rums using a hybrid of the Quantitative Descriptive Analysis and Spectrum methods. In addition, the results of this study validated the previously developed rum flavor wheel created from web-based materials. Results showed that the use of the rum flavor wheel aided in sensory term generation, as 17 additional terms were generated after the wheel was provided to panelists. Thirty-eight sensory terms encompassing aroma, aroma-by-mouth, mouthfeel, taste and aftertaste modalities, were generated and evaluated by the panel. Of the finalized terms, only 5 did not exist previously on the rum flavor wheel. Twenty attributes were found to be significantly different among rums. The majority of rums showed similar aroma profiles with the exception of 2 rums, which were characterized by higher perceived intensities of brown sugar, caramel, vanilla, and chocolate aroma, caramel, maple, and vanilla aroma-by-mouth and caramel aftertaste. These results demonstrate the previously developed rum flavor wheel can be used to adequately describe the flavor profile of rum. Additionally, results of this study document the sensory differences among premium rums and may be used to correlate with analytical data to better understand how changes in chemical composition of the product affect sensory perception. © 2017 Institute of Food Technologists®.

Associated factors and outcomes for OXA-232 Carbapenem-resistant Enterobacteriaceae infections in a tertiary care centre in Mexico City: A case-control-control study.

PubMed

Torres-González, Pedro; Ortiz-Brizuela, Edgar; Cervera-Hernandez, Miguel Enrique; Bobadilla-Del Valle, Miriam; Martínez-Gamboa, Areli; Sifuentes-Osornio, José; Ponce-de-Leon, Alfredo

2016-10-01

We describe the outcomes and factors associated with OXA-232 producing carbapenem-resistant Enterobacteriaceae infections. A case-control-control study was performed; each case of infection by a carbapenem-resistant/OXA-232 (OXA-232-cases, n=27) was matched by isolation site, species, and date, with 2 cases of infection by carbapenem-susceptible/third-generation cephalosporin-susceptible (TGCS-controls, n=54) and 2 cases by carbapenem-susceptible/ESBL producing Enterobacteriaceae (ESBL-controls, n=54); 66% were urinary tract and 18.5% intra-abdominal infections. In the multivariable analysis with ESBL-controls, previous use β-lactam/β-lactamase antibiotics (OR 6.2; 95% CI 1.6-23.8) and, third-generation cephalosporins (OR 0.2; 95% CI 0.05-0.8) were associated with OXA-232 infection; with TGSC-controls previous use of β-lactam/β-lactamase antibiotics (OR 3.7; 95% 1.1-12.0) was associated. Among the OXA-232-cases, 29% received imipenem/cilastatin or meropenem, 11.1% ceftriaxone, 22.2% a carbapenem-based combination and 33.3% other antimicrobials as treatment. Previous β-lactam/β-lactamase antibiotics are associated with OXA-232 infections, and some may be treated with other active carbapenems or, in the absence of ESBL, third-generation cephalosporins. Copyright © 2016 Elsevier Inc. All rights reserved.

Fatigue testing of weldable high strength steels under simulated service conditions

NASA Astrophysics Data System (ADS)

Tantbirojn, Natee

There have been concerns over the effect of Cathodic Protection (CP) on weldable high strength steels employed in Jack-up production platform. The guidance provided by the Department of Energy HSE on higher strength steels, based on previous work, was to avoid overprotection as this could cause hydrogen embrittlement. However, the tests conducted so far at UCL for the SE702 type high strength steels (yields strength around 690 MPa) have shown that the effect of over protection on high strength steels may not be as severe as previously thought. For this thesis, SE702 high strength steels have been investigated in more detail. Thick (85mm) parent and ground welded plates were tested under constant amplitude in air and seawater with CP. Tests were also conducted on Thick (40mm) T-butt welded plates under variable amplitude loading in air and seawater with two CP levels (-800mV and -1050mV). Different backing materials (ceramic and metallic) for the welding process of the T-butt plates were also investigated. The variable amplitude sequences employed were generated using the Jack-up Offshore Standard load History (JOSH). The fatigue results are presented as crack growth and S/N curves. They were compared to the conventional offshore steel (BS 4360 50D). The results suggested that the fatigue life of the high strength steels was comparable to the BS 4360 50D steels. The effect of increasing the CP was found to be detrimental to the fatigue life but the effect was not large. The effect of CP was less noticeable in T-butt welded plates. However, in general, the effect of overprotection is not as detrimental to the Jack-up steels as previously thought. The load histories generated by JOSH were found to have some unfavourable characteristics. The framework is based on Markov Chain method and pseudo-random number generator for selecting sea-states. A study was carried out on the sequence generated by JOSH. The generated sequences were analysed for their validity for fatigue testing. This has resulted in recommendations on the methods for generating standard load histories.

Development of second generation gold-supported palladium material with low-leaching and recyclable characteristics in aromatic amination.

PubMed

Al-Amin, Mohammad; Arai, Satoshi; Hoshiya, Naoyoki; Honma, Tetsuo; Tamenori, Yusuke; Sato, Takatoshi; Yokoyama, Mami; Ishii, Akira; Takeuchi, Masashi; Maruko, Tomohiro; Shuto, Satoshi; Arisawa, Mitsuhiro

2013-08-02

An improved process for the preparation of sulfur-modified gold-supported palladium material [SAPd, second generation] is presented. The developed preparation method is safer and generates less heat (aqueous Na2S2O8 and H2SO4) for sulfur fixation on a gold surface, and it is superior to the previous method of preparing SAPd (first generation), which requires the use of the more heat-generating and dangerous piranha solution (concentrated H2SO4 and 35% H2O2) in the sulfur fixation step. This safer and improved preparation method is particularly important for the mass production of SAPd (second generation) for which the catalytic activity was examined in ligand-free Buchwald-Hartwig cross-coupling reactions. The catalytic activities were the same between the first and second generation SAPds in aromatic aminations, but the lower palladium leaching properties and safer preparative method of second generation SAPd are a significant improvement over the first generation SAPd.

How Visuo-Spatial Mental Imagery Develops: Image Generation and Maintenance

PubMed Central

Wimmer, Marina C.; Maras, Katie L.; Robinson, Elizabeth J; Doherty, Martin J; Pugeault, Nicolas

2015-01-01

Two experiments examined the nature of visuo-spatial mental imagery generation and maintenance in 4-, 6-, 8-, 10-year old children and adults (N = 211). The key questions were how image generation and maintenance develop (Experiment 1) and how accurately children and adults coordinate mental and visually perceived images (Experiment 2). Experiment 1 indicated that basic image generation and maintenance abilities are present at 4 years of age but the precision with which images are generated and maintained improves particularly between 4 and 8 years. In addition to increased precision, Experiment 2 demonstrated that generated and maintained mental images become increasingly similar to visually perceived objects. Altogether, findings suggest that for simple tasks demanding image generation and maintenance, children attain adult-like precision younger than previously reported. This research also sheds new light on the ability to coordinate mental images with visual images in children and adults. PMID:26562296

The Rack-Gear Tool Generation Modelling. Non-Analytical Method Developed in CATIA, Using the Relative Generating Trajectories Method

NASA Astrophysics Data System (ADS)

Teodor, V. G.; Baroiu, N.; Susac, F.; Oancea, N.

2016-11-01

The modelling of a curl of surfaces associated with a pair of rolling centrodes, when it is known the profile of the rack-gear's teeth profile, by direct measuring, as a coordinate matrix, has as goal the determining of the generating quality for an imposed kinematics of the relative motion of tool regarding the blank. In this way, it is possible to determine the generating geometrical error, as a base of the total error. The generation modelling allows highlighting the potential errors of the generating tool, in order to correct its profile, previously to use the tool in machining process. A method developed in CATIA is proposed, based on a new method, namely the method of “relative generating trajectories”. They are presented the analytical foundation, as so as some application for knows models of rack-gear type tools used on Maag teething machines.

GENXICC2.0: An upgraded version of the generator for hadronic production of double heavy baryons Ξ, Ξ and Ξ

NASA Astrophysics Data System (ADS)

Chang, Chao-Hsi; Wang, Jian-Xiong; Wu, Xing-Gang

2010-06-01

An upgraded (second) version of the package GENXICC (A Generator for Hadronic Production of the Double Heavy Baryons Ξ, Ξ and Ξ by C.H. Chang, J.X. Wang and X.G. Wu [its first version in: Comput. Phys. Comm. 177 (2007) 467]) is presented. Users, with this version being implemented in PYTHIA and a GNU C compiler, may simulate full events of these processes in various experimental environments conveniently. In comparison with the previous version, in order to implement it in PYTHIA properly, a subprogram for the fragmentation of the produced double heavy diquark to the relevant baryon is supplied and the interface of the generator to PYTHIA is changed accordingly. In the subprogram, with explanation, certain necessary assumptions (approximations) are made in order to conserve the momenta and the QCD 'color' flow for the fragmentation. Program summaryProgram title: GENXICC2.0 Catalogue identifier: ADZJ_v2_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADZJ_v2_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 102 482 No. of bytes in distributed program, including test data, etc.: 1 469 519 Distribution format: tar.gz Programming language: Fortran 77/90 Computer: Any LINUX based on PC with FORTRAN 77 or FORTRAN 90 and GNU C compiler as well Operating system: Linux RAM: About 2.0 MByte Classification: 11.2 Catalogue identifier of previous version: ADZJ_v1_0 Journal reference of previous version: Comput. Phys. Comm. 177 (2007) 467 Does the new version supersede the previous version?: No Nature of problem: Hadronic production of double heavy baryons Ξ, Ξ and Ξ Solution method: The code is based on NRQCD framework. With proper options, it can generate weighted and un-weighted events of hadronic double heavy baryon production. When the hadronizations of the produced jets and double heavy diquark are taken into account in the production, the upgraded version with proper interface to PYTHIA can generate full events. Reasons for new version: Responding to the feedback from users, we improve the generator mainly by carefully completing the 'final non-perturbative process', i.e. the formulation of the double heavy baryon from relevant intermediate diquark. In the present version, the information for fragmentation about momentum-flow and the color-flow, that is necessary for PYTHIA to generate full events, is retained although reasonable approximations are made. In comparison with the original version, the upgraded one can implement it in PYTHIA properly to do the full event simulation of the double heavy baryon production. Summary of revisions:We try to explain the treatment of the momentum distribution of the process more clearly than the original version, and show how the final baryon is generated through the typical intermediate diquark precisely. We present color flow of the involved processes precisely and the corresponding changes for the program are made. The corresponding changes of the program are explained in the paper. Restrictions: The color flow, particularly, in the piece of code programming of the fragmentation from the produced colorful double heavy diquark into a relevant double heavy baryon, is treated carefully so as to implement it in PYTHIA properly. Running time: It depends on which option is chosen to configure PYTHIA when generating full events and also on which mechanism is chosen to generate the events. Typically, for the most complicated case with gluon-gluon fusion mechanism to generate the mixed events via the intermediate diquark in (cc)[ and (cc)[ states, under the option, IDWTUP=1, to generate 1000 events, takes about 20 hours on a 1.8 GHz Intel P4-processor machine, whereas under the option, IDWTUP=3, even to generate 106 events takes about 40 minutes on the same machine.

Highlights from the previous volumes

NASA Astrophysics Data System (ADS)

-C., Liu K.; al., Kumar N. et; al., Anishchenko V. et; al., Jaeckel J. et; et al.

2009-10-01

The physics of pizza tossing and the next generation of micromotors Is diamagnetism possible classically? Phase dynamics of two coupled oscillators under external periodic force Optical communications through dense matter

Pulse - Accelerator Science in Medicine

Science.gov Websites

intermediate machines. Each generation of particle accelerators build on the accomp-lishments of the previous ones, raising the level of technology ever higher. Security, Privacy Legal

Modeling and Grid Generation of Iced Airfoils

NASA Technical Reports Server (NTRS)

Vickerman, Mary B.; Baez, Marivell; Braun, Donald C.; Hackenberg, Anthony W.; Pennline, James A.; Schilling, Herbert W.

2007-01-01

SmaggIce Version 2.0 is a software toolkit for geometric modeling and grid generation for two-dimensional, singleand multi-element, clean and iced airfoils. A previous version of SmaggIce was described in Preparing and Analyzing Iced Airfoils, NASA Tech Briefs, Vol. 28, No. 8 (August 2004), page 32. To recapitulate: Ice shapes make it difficult to generate quality grids around airfoils, yet these grids are essential for predicting ice-induced complex flow. This software efficiently creates high-quality structured grids with tools that are uniquely tailored for various ice shapes. SmaggIce Version 2.0 significantly enhances the previous version primarily by adding the capability to generate grids for multi-element airfoils. This version of the software is an important step in streamlining the aeronautical analysis of ice airfoils using computational fluid dynamics (CFD) tools. The user may prepare the ice shape, define the flow domain, decompose it into blocks, generate grids, modify/divide/merge blocks, and control grid density and smoothness. All these steps may be performed efficiently even for the difficult glaze and rime ice shapes. Providing the means to generate highly controlled grids near rough ice, the software includes the creation of a wrap-around block (called the "viscous sublayer block"), which is a thin, C-type block around the wake line and iced airfoil. For multi-element airfoils, the software makes use of grids that wrap around and fill in the areas between the viscous sub-layer blocks for all elements that make up the airfoil. A scripting feature records the history of interactive steps, which can be edited and replayed later to produce other grids. Using this version of SmaggIce, ice shape handling and grid generation can become a practical engineering process, rather than a laborious research effort.

An efficient and scalable graph modeling approach for capturing information at different levels in next generation sequencing reads

PubMed Central

2013-01-01

Background Next generation sequencing technologies have greatly advanced many research areas of the biomedical sciences through their capability to generate massive amounts of genetic information at unprecedented rates. The advent of next generation sequencing has led to the development of numerous computational tools to analyze and assemble the millions to billions of short sequencing reads produced by these technologies. While these tools filled an important gap, current approaches for storing, processing, and analyzing short read datasets generally have remained simple and lack the complexity needed to efficiently model the produced reads and assemble them correctly. Results Previously, we presented an overlap graph coarsening scheme for modeling read overlap relationships on multiple levels. Most current read assembly and analysis approaches use a single graph or set of clusters to represent the relationships among a read dataset. Instead, we use a series of graphs to represent the reads and their overlap relationships across a spectrum of information granularity. At each information level our algorithm is capable of generating clusters of reads from the reduced graph, forming an integrated graph modeling and clustering approach for read analysis and assembly. Previously we applied our algorithm to simulated and real 454 datasets to assess its ability to efficiently model and cluster next generation sequencing data. In this paper we extend our algorithm to large simulated and real Illumina datasets to demonstrate that our algorithm is practical for both sequencing technologies. Conclusions Our overlap graph theoretic algorithm is able to model next generation sequencing reads at various levels of granularity through the process of graph coarsening. Additionally, our model allows for efficient representation of the read overlap relationships, is scalable for large datasets, and is practical for both Illumina and 454 sequencing technologies. PMID:24564333

Plastics Derived Endocrine Disruptors (BPA, DEHP and DBP) Induce Epigenetic Transgenerational Inheritance of Obesity, Reproductive Disease and Sperm Epimutations

PubMed Central

Manikkam, Mohan; Tracey, Rebecca; Guerrero-Bosagna, Carlos; Skinner, Michael K.

2013-01-01

Environmental compounds are known to promote epigenetic transgenerational inheritance of adult onset disease in subsequent generations (F1–F3) following ancestral exposure during fetal gonadal sex determination. The current study was designed to determine if a mixture of plastic derived endocrine disruptor compounds bisphenol-A (BPA), bis(2-ethylhexyl)phthalate (DEHP) and dibutyl phthalate (DBP) at two different doses promoted epigenetic transgenerational inheritance of adult onset disease and associated DNA methylation epimutations in sperm. Gestating F0 generation females were exposed to either the “plastics” or “lower dose plastics” mixture during embryonic days 8 to 14 of gonadal sex determination and the incidence of adult onset disease was evaluated in F1 and F3 generation rats. There were significant increases in the incidence of total disease/abnormalities in F1 and F3 generation male and female animals from plastics lineages. Pubertal abnormalities, testis disease, obesity, and ovarian disease (primary ovarian insufficiency and polycystic ovaries) were increased in the F3 generation animals. Kidney and prostate disease were only observed in the direct fetally exposed F1 generation plastic lineage animals. Analysis of the plastics lineage F3 generation sperm epigenome previously identified 197 differential DNA methylation regions (DMR) in gene promoters, termed epimutations. A number of these transgenerational DMR form a unique direct connection gene network and have previously been shown to correlate with the pathologies identified. Observations demonstrate that a mixture of plastic derived compounds, BPA and phthalates, can promote epigenetic transgenerational inheritance of adult onset disease. The sperm DMR provide potential epigenetic biomarkers for transgenerational disease and/or ancestral environmental exposures. PMID:23359474

Point process models for localization and interdependence of punctate cellular structures.

PubMed

Li, Ying; Majarian, Timothy D; Naik, Armaghan W; Johnson, Gregory R; Murphy, Robert F

2016-07-01

Accurate representations of cellular organization for multiple eukaryotic cell types are required for creating predictive models of dynamic cellular function. To this end, we have previously developed the CellOrganizer platform, an open source system for generative modeling of cellular components from microscopy images. CellOrganizer models capture the inherent heterogeneity in the spatial distribution, size, and quantity of different components among a cell population. Furthermore, CellOrganizer can generate quantitatively realistic synthetic images that reflect the underlying cell population. A current focus of the project is to model the complex, interdependent nature of organelle localization. We built upon previous work on developing multiple non-parametric models of organelles or structures that show punctate patterns. The previous models described the relationships between the subcellular localization of puncta and the positions of cell and nuclear membranes and microtubules. We extend these models to consider the relationship to the endoplasmic reticulum (ER), and to consider the relationship between the positions of different puncta of the same type. Our results do not suggest that the punctate patterns we examined are dependent on ER position or inter- and intra-class proximity. With these results, we built classifiers to update previous assignments of proteins to one of 11 patterns in three distinct cell lines. Our generative models demonstrate the ability to construct statistically accurate representations of puncta localization from simple cellular markers in distinct cell types, capturing the complex phenomena of cellular structure interaction with little human input. This protocol represents a novel approach to vesicular protein annotation, a field that is often neglected in high-throughput microscopy. These results suggest that spatial point process models provide useful insight with respect to the spatial dependence between cellular structures. © 2016 International Society for Advancement of Cytometry. © 2016 International Society for Advancement of Cytometry.

Temporal Dynamics of Hypothesis Generation: The Influences of Data Serial Order, Data Consistency, and Elicitation Timing

PubMed Central

Lange, Nicholas D.; Thomas, Rick P.; Davelaar, Eddy J.

2012-01-01

The pre-decisional process of hypothesis generation is a ubiquitous cognitive faculty that we continually employ in an effort to understand our environment and thereby support appropriate judgments and decisions. Although we are beginning to understand the fundamental processes underlying hypothesis generation, little is known about how various temporal dynamics, inherent in real world generation tasks, influence the retrieval of hypotheses from long-term memory. This paper presents two experiments investigating three data acquisition dynamics in a simulated medical diagnosis task. The results indicate that the mere serial order of data, data consistency (with previously generated hypotheses), and mode of responding influence the hypothesis generation process. An extension of the HyGene computational model endowed with dynamic data acquisition processes is forwarded and explored to provide an account of the present data. PMID:22754547

[Reproduction of the trematode Echinostoma caproni parthenites (Digenea: Echinostomatidae)].

PubMed

Ataev, G L; Isakova, N P; Dobrovol'skiĭ, A A

2007-01-01

Dynamics of the reproduction in the trematode Echinostoma caproni parthenites (Echinostomatidae) was observed. Early laying and maturation of the generative cells are for the first time shown to be characteristic for all parthenogenetic generations. Really the process of reproduction had been finishing to the beginning of the generating of new age by parthenites. Mother sporocysts, as well as redia of different generations, in fact stop producing new generative cells with the beginning of the generating of new age, and assume the function of a brood pouch. This feature was considered previously as peculiar mainly to mother sporocysts. Data on the autotomy of the anterior body end in mother sporocysts are verified. In our opinion, these data are an evidence of an early manifestation of the evolutionary trend to the morpho-functional regress and disintegration of the parasitic stage of mother sporocyst.

High-flux soft x-ray harmonic generation from ionization-shaped few-cycle laser pulses

PubMed Central

Brahms, Christian; Gregory, Andrew; Tisch, John W. G.; Marangos, Jon P.

2018-01-01

Laser-driven high-harmonic generation provides the only demonstrated route to generating stable, tabletop attosecond x-ray pulses but has low flux compared to other x-ray technologies. We show that high-harmonic generation can produce higher photon energies and flux by using higher laser intensities than are typical, strongly ionizing the medium and creating plasma that reshapes the driving laser field. We obtain high harmonics capable of supporting attosecond pulses up to photon energies of 600 eV and a photon flux inside the water window (284 to 540 eV) 10 times higher than previous attosecond sources. We demonstrate that operating in this regime is key for attosecond pulse generation in the x-ray range and will become increasingly important as harmonic generation moves to fields that drive even longer wavelengths. PMID:29756033

An Algorithm to Automatically Generate the Combinatorial Orbit Counting Equations

PubMed Central

Melckenbeeck, Ine; Audenaert, Pieter; Michoel, Tom; Colle, Didier; Pickavet, Mario

2016-01-01

Graphlets are small subgraphs, usually containing up to five vertices, that can be found in a larger graph. Identification of the graphlets that a vertex in an explored graph touches can provide useful information about the local structure of the graph around that vertex. Actually finding all graphlets in a large graph can be time-consuming, however. As the graphlets grow in size, more different graphlets emerge and the time needed to find each graphlet also scales up. If it is not needed to find each instance of each graphlet, but knowing the number of graphlets touching each node of the graph suffices, the problem is less hard. Previous research shows a way to simplify counting the graphlets: instead of looking for the graphlets needed, smaller graphlets are searched, as well as the number of common neighbors of vertices. Solving a system of equations then gives the number of times a vertex is part of each graphlet of the desired size. However, until now, equations only exist to count graphlets with 4 or 5 nodes. In this paper, two new techniques are presented. The first allows to generate the equations needed in an automatic way. This eliminates the tedious work needed to do so manually each time an extra node is added to the graphlets. The technique is independent on the number of nodes in the graphlets and can thus be used to count larger graphlets than previously possible. The second technique gives all graphlets a unique ordering which is easily extended to name graphlets of any size. Both techniques were used to generate equations to count graphlets with 4, 5 and 6 vertices, which extends all previous results. Code can be found at https://github.com/IneMelckenbeeck/equation-generator and https://github.com/IneMelckenbeeck/graphlet-naming. PMID:26797021

Mendelism: New Insights from Gregor Mendel's Lectures in Brno.

PubMed

Zhang, Hui; Chen, Wen; Sun, Kun

2017-09-01

Interpretation of Gregor Mendel's work has previously been based on study of his published paper "Experiments in Plant Hybridization." In contrast, the lectures that he gave preceding publication of this work have been largely neglected for more than 150 years. Here, we report on and interpret the content of Mendel's previous two lectures, as they were reported in a local newspaper. We comprehensively reference both the text of his paper and the historical background of his experiments. Our analysis shows that while Mendel had inherited the traditional research program on interspecific hybridization in plants, he introduced the novel method of ratio analysis for representing the variation of unit-characters among offspring of hybrids. His aim was to characterize and explain the developmental features of the distributional pattern of unit-characters in two series of hybrid experiments, using self-crosses and backcrosses with parents. In doing so, he not only answered the question of what the unit-characters were and the nature of their hierarchical classification, but also successfully inferred the numerical principle of unit-character transmission from generation to generation. He also established the nature of the composition and behaviors of reproductive cells from one generation to the next. Here we highlight the evidence from Mendel's lectures, clearly announcing that he had discovered the general law of cross-generation transmission of unit-characters through reproductive cells containing unit-factors. The recovered content of these previous lectures more accurately describes the work he performed with his garden peas than his published paper and shows how he first presented it in Brno. It is thus an invaluable resource for understanding the origin of the science of genetics. Copyright © 2017 by the Genetics Society of America.

Streamlining Traffic Mitigation Fees

DOT National Transportation Integrated Search

1999-01-01

The City of Lacey rewrote the ordinance governing collection of fees to mitigate : development impacts on the transportation system. Previously developers : submitted traffic generation and distribution reports prepared by qualified : traffic enginee...

SFG characterization of a cationic ONLO dye in biological thin films

NASA Astrophysics Data System (ADS)

Johnson, Lewis E.; Casford, Michael T.; Elder, Delwin L.; Davies, Paul B.; Johal, Malkiat S.

2013-10-01

Biopolymer-based thin films, such as those composed of CTMA-DNA, can be used as a host material for NLOactive dyes for applications such as electro-optic (EO) switching and second harmonic generation. Previous work by Heckman et al. (Proc. SPIE 6401, 640108-2) has demonstrated functioning DNA-based EO modulators. Improved performance requires optimization of both the first hyperpolarizabilities (β) and degree of acentric ordering exhibited by the chromophores. The cationic dye DANPY-1 (Proc. SPIE 8464, 846409-D) has a high affinity for DNA and a substantial hyperpolarizability; however, its macroscopic ordering has not been previously characterized. We have characterized the acentric ordering of the dye using sum-frequency generation (SFG) vibrational spectroscopy in surface-immobilized DNA and on planar metal and dielectric surfaces.

Precise algorithm to generate random sequential adsorption of hard polygons at saturation

NASA Astrophysics Data System (ADS)

Zhang, G.

2018-04-01

Random sequential adsorption (RSA) is a time-dependent packing process, in which particles of certain shapes are randomly and sequentially placed into an empty space without overlap. In the infinite-time limit, the density approaches a "saturation" limit. Although this limit has attracted particular research interest, the majority of past studies could only probe this limit by extrapolation. We have previously found an algorithm to reach this limit using finite computational time for spherical particles and could thus determine the saturation density of spheres with high accuracy. In this paper, we generalize this algorithm to generate saturated RSA packings of two-dimensional polygons. We also calculate the saturation density for regular polygons of three to ten sides and obtain results that are consistent with previous, extrapolation-based studies.

Precise algorithm to generate random sequential adsorption of hard polygons at saturation.

PubMed

Zhang, G

2018-04-01

Random sequential adsorption (RSA) is a time-dependent packing process, in which particles of certain shapes are randomly and sequentially placed into an empty space without overlap. In the infinite-time limit, the density approaches a "saturation" limit. Although this limit has attracted particular research interest, the majority of past studies could only probe this limit by extrapolation. We have previously found an algorithm to reach this limit using finite computational time for spherical particles and could thus determine the saturation density of spheres with high accuracy. In this paper, we generalize this algorithm to generate saturated RSA packings of two-dimensional polygons. We also calculate the saturation density for regular polygons of three to ten sides and obtain results that are consistent with previous, extrapolation-based studies.

Optical digital chaos cryptography

NASA Astrophysics Data System (ADS)

Arenas-Pingarrón, Álvaro; González-Marcos, Ana P.; Rivas-Moscoso, José M.; Martín-Pereda, José A.

2007-10-01

In this work we present a new way to mask the data in a one-user communication system when direct sequence - code division multiple access (DS-CDMA) techniques are used. The code is generated by a digital chaotic generator, originally proposed by us and previously reported for a chaos cryptographic system. It is demonstrated that if the user's data signal is encoded with a bipolar phase-shift keying (BPSK) technique, usual in DS-CDMA, it can be easily recovered from a time-frequency domain representation. To avoid this situation, a new system is presented in which a previous dispersive stage is applied to the data signal. A time-frequency domain analysis is performed, and the devices required at the transmitter and receiver end, both user-independent, are presented for the optical domain.

Transoral robotic thyroidectomy: a preclinical feasibility study using the da Vinci Xi platform.

PubMed

Russell, Jonathon O; Noureldine, Salem I; Al Khadem, Mai G; Chaudhary, Hamad A; Day, Andrew T; Kim, Hoon Yub; Tufano, Ralph P; Richmon, Jeremy D

2017-09-01

Transoral thyroid surgery allows the surgeon to conceal incisions within the oral cavity without significantly increasing the amount of required dissection. TORT provides an ideal scarless, midline access to the thyroid gland and bilateral central neck compartments. This approach, however, presents multiple technical challenges. Herein, we present our experience using the latest generation robotic surgical system to accomplish transoral robotic thyroidectomy (TORT). In two human cadavers, the da Vinci Xi surgical system (Intuitive Surgical, Sunnyvale, CA, USA) was used to complete TORT. Total thyroidectomy and bilateral central neck dissection was successfully completed in both cadavers. The da Vinci Xi platform offered several technologic advantages over previous robotic generations including overhead docking, narrower arms, and improved range of motion allowing for improved execution of previously described TORT techniques.

Whose idea was that? Source monitoring for idea ownership following elaboration.

PubMed

Stark, Louisa-Jayne; Perfect, Timothy J

2007-10-01

Unconscious plagiarism (UP) occurs when an individual claims a previously experienced idea as their own. Previous studies have explored the cognitive precursors of such errors by manipulating the ways that ideas are thought about between initial idea exposure and later test. While imagining other's ideas does not increase rates of UP relative to control on either a recall-own or generate-new task, improving others' ideas substantially increases such errors in the recall-own task. This study explored the effects of elaboration on rates of UP when a source-monitoring test replaced the recall-own test. Plagiarism was again observed following idea improvement but not idea imagery even though participants engaged explicit source evaluation. Thus the probability of plagiarising another's idea appears linked to the generative nature of the idea processing performed.

Comparison of the Battery Life of Nonrechargeable Generators for Deep Brain Stimulation.

PubMed

Helmers, Ann-Kristin; Lübbing, Isabel; Deuschl, Günther; Witt, Karsten; Synowitz, Michael; Mehdorn, Hubertus Maximilian; Falk, Daniela

2017-11-03

Nonrechargeable deep brain stimulation (DBS) generators must be replaced when the battery capacity is exhausted. Battery life depends on many factors and differs between generator models. A new nonrechargeable generator model replaced the previous model in 2008. Our clinical impression is that the earlier model had a longer battery life than the new one. We conducted this study to substantiate this. We determined the battery life of every DBS generator that had been implanted between 2005 and 2012 in our department for the treatment of Parkinson's disease, and compared the battery lives of the both devices. We calculated the current used by estimating the total electrical energy delivered (TEED) based on the stimulation parameters in use one year after electrode implantation. One hundred ninety-two patients were included in the study; 105 with the old and 86 with the new model generators. The mean battery life in the older model was significantly longer (5.44 ± 0.20 years) than that in the new model (4.44 ± 0.17 years) (p = 0.023). The mean TEED without impedance was 219.9 ± 121.5 mW * Ω in the older model and 145.1 ± 72.7 mW * Ω in the new one, which indicated significantly lower stimulation parameters in the new model (p = 0.00038). The battery life of the new model was significantly shorter than that of the previous model. A lower battery capacity is the most likely reason, since current consumption was similar in both groups. © 2017 International Neuromodulation Society.

Chief of Naval Air Training Automated Management Information System (CAMIS). User’s Guide.

DTIC Science & Technology

1982-04-01

display. This display allows the user to insert, update, delete , or analyze various data elements, or generate reports. The Flight Schedule Input...instructor, student, and aircraft utiliza- tion. Additionally, it provides a means to delete any erroneous sortie information previously entered. 5...appear: 10 Technical Report 121 VT-## FLIGHT SCHEDULE PROGRAM 1. ADD NEW FLIGHT SCHEDULE DATA 2. DELETE ERRONEOUS SORTIES PREVIOUSLY ENTERED KEY IN

GStream: Improving SNP and CNV Coverage on Genome-Wide Association Studies

PubMed Central

Alonso, Arnald; Marsal, Sara; Tortosa, Raül; Canela-Xandri, Oriol; Julià, Antonio

2013-01-01

We present GStream, a method that combines genome-wide SNP and CNV genotyping in the Illumina microarray platform with unprecedented accuracy. This new method outperforms previous well-established SNP genotyping software. More importantly, the CNV calling algorithm of GStream dramatically improves the results obtained by previous state-of-the-art methods and yields an accuracy that is close to that obtained by purely CNV-oriented technologies like Comparative Genomic Hybridization (CGH). We demonstrate the superior performance of GStream using microarray data generated from HapMap samples. Using the reference CNV calls generated by the 1000 Genomes Project (1KGP) and well-known studies on whole genome CNV characterization based either on CGH or genotyping microarray technologies, we show that GStream can increase the number of reliably detected variants up to 25% compared to previously developed methods. Furthermore, the increased genome coverage provided by GStream allows the discovery of CNVs in close linkage disequilibrium with SNPs, previously associated with disease risk in published Genome-Wide Association Studies (GWAS). These results could provide important insights into the biological mechanism underlying the detected disease risk association. With GStream, large-scale GWAS will not only benefit from the combined genotyping of SNPs and CNVs at an unprecedented accuracy, but will also take advantage of the computational efficiency of the method. PMID:23844243

A retrospective evaluation of traffic forecasting techniques.

DOT National Transportation Integrated Search

2016-08-01

Traffic forecasting techniquessuch as extrapolation of previous years traffic volumes, regional travel demand models, or : local trip generation rateshelp planners determine needed transportation improvements. Thus, knowing the accuracy of t...

Generating electricity while walking with loads.

PubMed

Rome, Lawrence C; Flynn, Louis; Goldman, Evan M; Yoo, Taeseung D

2005-09-09

We have developed the suspended-load backpack, which converts mechanical energy from the vertical movement of carried loads (weighing 20 to 38 kilograms) to electricity during normal walking [generating up to 7.4 watts, or a 300-fold increase over previous shoe devices (20 milliwatts)]. Unexpectedly, little extra metabolic energy (as compared to that expended carrying a rigid backpack) is required during electricity generation. This is probably due to a compensatory change in gait or loading regime, which reduces the metabolic power required for walking. This electricity generation can help give field scientists, explorers, and disaster-relief workers freedom from the heavy weight of replacement batteries and thereby extend their ability to operate in remote areas.

Stirling Convertor Performance Mapping Test Results for Future Radioisotope Power Systems

NASA Astrophysics Data System (ADS)

Qiu, Songgang; Peterson, Allen A.; Faultersack, Franklyn D.; Redinger, Darin L.; Augenblick, John E.

2004-02-01

Long-life radioisotope-fueled generators based on free-piston Stirling convertors are an energy-conversion solution for future space applications. The high efficiency of Stirling machines makes them more attractive than the thermoelectric generators currently used in space. Stirling Technology Company (STC) has been performance-testing its Stirling generators to provide data for potential system integration contractors. This paper describes the most recent test results from the STC RemoteGen™ 55 W-class Stirling generators (RG-55). Comparisons are made between the new data and previous Stirling thermodynamic simulation models. Performance-mapping tests are presented including variations in: internal charge pressure, cold end temperature, hot end temperature, alternator temperature, input power, and variation of control voltage.

Phase Change Material Thermal Power Generator

NASA Technical Reports Server (NTRS)

Jones, Jack A.

2013-01-01

An innovative modification has been made to a previously patented design for the Phase Change Material (PCM) Thermal Generator, which works in water where ocean temperature alternatively melts wax in canisters, or allows the wax to re-solidify, causing high-pressure oil to flow through a hydraulic generator, thus creating electricity to charge a battery that powers the vehicle. In this modification, a similar thermal PCM device has been created that is heated and cooled by the air and solar radiation instead of using ocean temperature differences to change the PCM from solid to liquid. This innovation allows the device to use thermal energy to generate electricity on land, instead of just in the ocean.

Does intergenerational transmission of trauma skip a generation? No meta-analytic evidence for tertiary traumatization with third generation of Holocaust survivors.

PubMed

Sagi-Schwartz, Abraham; van IJzendoorn, Marinus H; Bakermans-Kranenburg, Marian J

2008-06-01

In a series of meta-analyses with the second generation of Holocaust survivors, no evidence for secondary traumatization was found (Van IJzendoorn, Bakermans-Kranenburg, & Sagi-Schwartz, 2003). With regard to third generation traumatization, various reports suggest the presence of intergenerational transmission of trauma. Some scholars argue that intergenerational transmission of trauma might skip a generation. Therefore, we focus in this study on the transmission of trauma to the third generation offspring (the grandchildren) of the first generation's traumatic Holocaust experiences (referred to as "tertiary traumatization"), and we present a narrative review of the pertinent studies. Meta-analytic results of 13 non-clinical samples involving 1012 participants showed no evidence for tertiary traumatization in Holocaust survivor families. Our previous meta-analytic study on secondary traumatization and the present one on third generation's psychological consequences of the Holocaust indicate a remarkable resilience of profoundly traumatized survivors in their (grand-)parental roles.

Cycle Analysis of Two-stage Planar SOFC Power Generation by Series Connection of Low and High Temperature SOFCs

NASA Astrophysics Data System (ADS)

Ohba, Takahiro; Takezawa, Shinya; Araki, Takuto; Onda, Kazuo; Sakaki, Yoshinori

Solid Oxide Fuel Cell (SOFC) can be composed by solid components, and high power generation efficiency of a whole cycle is obtained by using high temperature exhaust heat for fuel reforming and bottoming power generation. Recently, the low temperature SOFC, which runs in the temperature range of around 600°C or above, has been developed with the high efficiency of power generation. On the other hand, multi-stage power generation system has been proposed by the United States DOE. In this study, a power generation system of two-stage SOFC by series connection of low and high temperature SOFCs has been studied. Overpotential data for low-temperature SOFC used in this study are based on recent published data, and those for high temperature SOFC arhaihe based on our previous study. The analytical results show the two-stage SOFC power generation efficiency of 50.3% and the total power generation efficiency of 56.1% under a standard operating condition.

Electricity generation by Rhodopseudomonas palustris DX-1.

PubMed

Xing, Defeng; Zuo, Yi; Cheng, Shaoan; Regan, John M; Logan, Bruce E

2008-06-01

Bacteria able to generate electricity in microbial fuel cells (MFCs) are of great interest, but there are few strains capable of high power production in these systems. Here we report that the phototrophic purple nonsulfur bacterium Rhodopseudomonas palustris DX-1, isolated from an MFC, produced electricity at higher power densities (2720 +/- 60 mW/m2) than mixed cultures in the same device. While Rhodopseudomonas species are known for their ability to generate hydrogen, they have not previously been shown to generate power in an MFC, and current was generated without the need for light or hydrogen production. Strain DX-1 utilizes a wide variety of substrates (volatile acids, yeast extract, and thiosulfate) for power production in different metabolic modes, making it highly useful for studying power generation in MFCs and generating power from a range of simple and complex sources of organic matter. These results demonstrate that a phototrophic purple nonsulfur bacterium can efficiently generate electricity by direct electron transfer in MFCs, providing another model microorganism for MFC investigations.

Intravenous Solutions for Exploration Missions

NASA Technical Reports Server (NTRS)

Miller, Fletcher J.; Niederhaus, Charles; Barlow, Karen; Griffin, DeVon

2007-01-01

This paper describes the intravenous (IV) fluids requirements being developed for medical care during NASA s future exploration class missions. Previous research on IV solution generation and mixing in space is summarized. The current exploration baseline mission profiles are introduced, potential medical conditions described and evaluated for fluidic needs, and operational issues assessed. We briefly introduce potential methods for generating IV fluids in microgravity. Conclusions on the recommended fluid volume requirements are presented.

A leap forward with UTK s Cray XC30

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fahey, Mark R

2014-01-01

This paper shows a significant productivity leap for several science groups and the accomplishments they have made to date on Darter - a Cray XC30 at the University of Tennessee Knoxville. The increased productivity is due to faster processors and interconnect combined in a new generation from Cray, and yet it still has a very similar programming environment as compared to previous generations of Cray machines that makes porting easy.

A Constraint Generation Approach to Learning Stable Linear Dynamical Systems

DTIC Science & Technology

2008-01-01

task of learning dynamic textures from image sequences as well as to modeling biosurveillance drug-sales data. The constraint generation approach...previous methods in our experiments. One application of LDSs in computer vision is learning dynamic textures from video data [8]. An advantage of...over-the-counter (OTC) drug sales for biosurveillance , and sunspot numbers from the UCR archive [9]. Comparison to the best alternative methods [7, 10

Simultaneous suppression of TGF-β and ERK signaling contributes to the highly efficient and reproducible generation of mouse embryonic stem cells from previously considered refractory and non-permissive strains.

PubMed

Hassani, Seyedeh-Nafiseh; Totonchi, Mehdi; Farrokhi, Ali; Taei, Adeleh; Larijani, Mehran Rezaei; Gourabi, Hamid; Baharvand, Hossein

2012-06-01

Mouse embryonic stem cells (ESCs) are pluripotent stem cell lines derived from pre-implantation embryos. The efficiency of mESC generation is affected by genetic variation in mice; that is, some mouse strains are refractory or non-permissive to ESC establishment. Developing an efficient method to derive mESCs from strains of various genetic backgrounds should be valuable for establishment of ESCs in various mammalian species. In the present study, we identified dual inhibition of TGF-β and ERK1/2, by SB431542 and PD0325901, respectively led to the highly efficient and reproducible generation of mESC lines from NMRI, C57BL/6, BALB/c, DBA/2, and FVB/N strains, which previously considered refractory or non-permissive for ESC establishment. These mESCs expressed pluripotency markers and retained the capacity to differentiate into derivatives of all three germ layers. The evaluated lines exhibited high rates of chimerism when reintroduced into blastocysts. To our knowledge, this is the first report of efficient (100%) mESC lines generation from different genetic backgrounds. The application of these two inhibitors will not only solve the problems of mESC derivation but also clarifies new signaling pathways in pluripotent mESCs.

Code Modernization of VPIC

NASA Astrophysics Data System (ADS)

Bird, Robert; Nystrom, David; Albright, Brian

2017-10-01

The ability of scientific simulations to effectively deliver performant computation is increasingly being challenged by successive generations of high-performance computing architectures. Code development to support efficient computation on these modern architectures is both expensive, and highly complex; if it is approached without due care, it may also not be directly transferable between subsequent hardware generations. Previous works have discussed techniques to support the process of adapting a legacy code for modern hardware generations, but despite the breakthroughs in the areas of mini-app development, portable-performance, and cache oblivious algorithms the problem still remains largely unsolved. In this work we demonstrate how a focus on platform agnostic modern code-development can be applied to Particle-in-Cell (PIC) simulations to facilitate effective scientific delivery. This work builds directly on our previous work optimizing VPIC, in which we replaced intrinsic based vectorisation with compile generated auto-vectorization to improve the performance and portability of VPIC. In this work we present the use of a specialized SIMD queue for processing some particle operations, and also preview a GPU capable OpenMP variant of VPIC. Finally we include a lessons learnt. Work performed under the auspices of the U.S. Dept. of Energy by the Los Alamos National Security, LLC Los Alamos National Laboratory under contract DE-AC52-06NA25396 and supported by the LANL LDRD program.

The Trajectory Synthesizer Generalized Profile Interface

NASA Technical Reports Server (NTRS)

Lee, Alan G.; Bouyssounouse, Xavier; Murphy, James R.

2010-01-01

The Trajectory Synthesizer is a software program that generates aircraft predictions for Air Traffic Management decision support tools. The Trajectory Synthesizer being used by researchers at NASA Ames Research Center was restricted in the number of trajectory types that could be generated. This limitation was not sufficient to support the rapidly changing Air Traffic Management research requirements. The Generalized Profile Interface was developed to address this issue. It provides a flexible approach to describe the constraints applied to trajectory generation and may provide a method for interoperability between trajectory generators. It also supports the request and generation of new types of trajectory profiles not possible with the previous interface to the Trajectory Synthesizer. Other enhancements allow the Trajectory Synthesizer to meet the current and future needs of Air Traffic Management research.

Thermoelectric-Driven Autonomous Sensors for a Biomass Power Plant

NASA Astrophysics Data System (ADS)

Rodríguez, A.; Astrain, D.; Martínez, A.; Gubía, E.; Sorbet, F. J.

2013-07-01

This work presents the design and development of a thermoelectric generator intended to harness waste heat in a biomass power plant, and generate electric power to operate sensors and the required electronics for wireless communication. The first objective of the work is to design the optimum thermoelectric generator to harness heat from a hot surface, and generate electric power to operate a flowmeter and a wireless transmitter. The process is conducted by using a computational model, presented in previous papers, to determine the final design that meets the requirements of electric power consumption and number of transmissions per minute. Finally, the thermoelectric generator is simulated to evaluate its performance. The final device transmits information every 5 s. Moreover, it is completely autonomous and can be easily installed, since no electric wires are required.

Are merging black holes born from stellar collapse or previous mergers?

NASA Astrophysics Data System (ADS)

Gerosa, Davide; Berti, Emanuele

2017-06-01

Advanced LIGO detectors at Hanford and Livingston made two confirmed and one marginal detection of binary black holes during their first observing run. The first event, GW150914, was from the merger of two black holes much heavier that those whose masses have been estimated so far, indicating a formation scenario that might differ from "ordinary" stellar evolution. One possibility is that these heavy black holes resulted from a previous merger. When the progenitors of a black hole binary merger result from previous mergers, they should (on average) merge later, be more massive, and have spin magnitudes clustered around a dimensionless spin ˜0.7 . Here we ask the following question: can gravitational-wave observations determine whether merging black holes were born from the collapse of massive stars ("first generation"), rather than being the end product of earlier mergers ("second generation")? We construct simple, observationally motivated populations of black hole binaries, and we use Bayesian model selection to show that measurements of the masses, luminosity distance (or redshift), and "effective spin" of black hole binaries can indeed distinguish between these different formation scenarios.

Arc Jet Facility Test Condition Predictions Using the ADSI Code

NASA Technical Reports Server (NTRS)

Palmer, Grant; Prabhu, Dinesh; Terrazas-Salinas, Imelda

2015-01-01

The Aerothermal Design Space Interpolation (ADSI) tool is used to interpolate databases of previously computed computational fluid dynamic solutions for test articles in a NASA Ames arc jet facility. The arc jet databases are generated using an Navier-Stokes flow solver using previously determined best practices. The arc jet mass flow rates and arc currents used to discretize the database are chosen to span the operating conditions possible in the arc jet, and are based on previous arc jet experimental conditions where possible. The ADSI code is a database interpolation, manipulation, and examination tool that can be used to estimate the stagnation point pressure and heating rate for user-specified values of arc jet mass flow rate and arc current. The interpolation is performed in the other direction (predicting mass flow and current to achieve a desired stagnation point pressure and heating rate). ADSI is also used to generate 2-D response surfaces of stagnation point pressure and heating rate as a function of mass flow rate and arc current (or vice versa). Arc jet test data is used to assess the predictive capability of the ADSI code.

Between-language repetition priming in antonym generation: evidence that translation-equivalent adjectives have shared conceptual representations across languages.

PubMed

Taylor, Randolph S; Francis, Wendy S

2017-03-01

Previous literature has demonstrated conceptual repetition priming across languages in bilinguals. This between-language priming effect is taken as evidence that translation equivalents have shared conceptual representations across languages. However, the vast majority of this research has been conducted using only concrete nouns as stimuli. The present experiment examined conceptual repetition priming within and between languages in adjectives, a part of speech not previously investigated in studies of bilingual conceptual representation. The participants were 100 Spanish-English bilinguals who had regular exposure to both languages. At encoding, participants performed a shallow processing task and a deep-processing task on English and Spanish adjectives. At test, they performed an antonym-generation task in English, in which the target responses were either adjectives presented at encoding or control adjectives not previously presented. The measure of priming was the response time advantage for producing repeated adjectives relative to control adjectives. Significant repetition priming was observed both within and between languages under deep, but not shallow, encoding conditions. The results indicate that the conceptual representations of adjective translation equivalents are shared across languages.

Ideal solar cell equation in the presence of photon recycling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lan, Dongchen, E-mail: d.lan@unsw.edu.au; Green, Martin A., E-mail: m.green@unsw.edu.au

Previous derivations of the ideal solar cell equation based on Shockley's p-n junction diode theory implicitly assume negligible effects of photon recycling. This paper derives the equation in the presence of photon recycling that modifies the values of dark saturation and light-generated currents, using an approach applicable to arbitrary three-dimensional geometries with arbitrary doping profile and variable band gap. The work also corrects an error in previous work and proves the validity of the reciprocity theorem for charge collection in such a more general case with the previously neglected junction depletion region included.

EPA Lean Government Initiative: How to Replicate Lean Successes

EPA Pesticide Factsheets

This Lean Replication Primer describes how EPA Offices and Regions can identify and adapt successful practices from previous Lean projects to “replicate” their successes and generate further improvements.

Hardware multiplier processor

DOEpatents

Pierce, Paul E.

1986-01-01

A hardware processor is disclosed which in the described embodiment is a memory mapped multiplier processor that can operate in parallel with a 16 bit microcomputer. The multiplier processor decodes the address bus to receive specific instructions so that in one access it can write and automatically perform single or double precision multiplication involving a number written to it with or without addition or subtraction with a previously stored number. It can also, on a single read command automatically round and scale a previously stored number. The multiplier processor includes two concatenated 16 bit multiplier registers, two 16 bit concatenated 16 bit multipliers, and four 16 bit product registers connected to an internal 16 bit data bus. A high level address decoder determines when the multiplier processor is being addressed and first and second low level address decoders generate control signals. In addition, certain low order address lines are used to carry uncoded control signals. First and second control circuits coupled to the decoders generate further control signals and generate a plurality of clocking pulse trains in response to the decoded and address control signals.

Comprehensive Virus Detection Using Next Generation Sequencing in Grapevine Vascular Tissues of Plants Obtained from the Wine Regions of Bohemia and Moravia (Czech Republic)

PubMed Central

2016-01-01

Comprehensive next generation sequencing virus detection was used to detect the whole spectrum of viruses and viroids in selected grapevines from the Czech Republic. The novel NGS approach was based on sequencing libraries of small RNA isolated from grapevine vascular tissues. Eight previously partially-characterized grapevines of diverse varieties were selected and subjected to analysis: Chardonnay, Laurot, Guzal Kara, and rootstock Kober 125AA from the Moravia wine-producing region; plus Müller-Thurgau and Pinot Noir from the Bohemia wine-producing region, both in the Czech Republic. Using next generation sequencing of small RNA, the presence of 8 viruses and 2 viroids were detected in a set of eight grapevines; therefore, confirming the high effectiveness of the technique in plant virology and producing results supporting previous data on multiple infected grapevines in Czech vineyards. Among the pathogens detected, the Grapevine rupestris vein feathering virus and Grapevine yellow speckle viroid 1 were recorded in the Czech Republic for the first time. PMID:27959951

Bas-relief generation using adaptive histogram equalization.

PubMed

Sun, Xianfang; Rosin, Paul L; Martin, Ralph R; Langbein, Frank C

2009-01-01

An algorithm is presented to automatically generate bas-reliefs based on adaptive histogram equalization (AHE), starting from an input height field. A mesh model may alternatively be provided, in which case a height field is first created via orthogonal or perspective projection. The height field is regularly gridded and treated as an image, enabling a modified AHE method to be used to generate a bas-relief with a user-chosen height range. We modify the original image-contrast-enhancement AHE method to use gradient weights also to enhance the shape features of the bas-relief. To effectively compress the height field, we limit the height-dependent scaling factors used to compute relative height variations in the output from height variations in the input; this prevents any height differences from having too great effect. Results of AHE over different neighborhood sizes are averaged to preserve information at different scales in the resulting bas-relief. Compared to previous approaches, the proposed algorithm is simple and yet largely preserves original shape features. Experiments show that our results are, in general, comparable to and in some cases better than the best previously published methods.

Generation and characterization of field-emitting surface dielectric barrier discharges in liquids

NASA Astrophysics Data System (ADS)

Kawamura, Tomohisa; Kanno, Moriyuki; Stauss, Sven; Kuribara, Koichi; Pai, David Z.; Ito, Tsuyohito; Terashima, Kazuo

2018-01-01

Field-emitting surface dielectric barrier discharges (FESDBDs), previously generated in CO2 from high pressures up to supercritical conditions using 10 kHz ac excitation, were investigated in non-aqueous liquid CO2 and liquid silicone oil. In both liquids, the maximum amount of negative charge Q-deposited as a function of the applied voltage amplitude was consistent with the Fowler-Nordheim equation, which demonstrated the presence of field emission. Furthermore, purely continuum optical emission spectra attributable to electron-neutral bremsstrahlung were confirmed. The fact that these characteristics were identical to those in high-pressure CO2 reported from previous research shows that FESDBDs can be generated independently of the medium type and that they are low-power (on the order of 10 mW) discharges. To investigate the charging function of FESDBDs, the motion of fine particles suspended above the FESDBDs was studied by high-speed imaging. It revealed that the speed of fine particles affected by the FESDBDs depends on the particle size, the FESDBDs' function being to charge fine particles.

Tsunami hazard assessment in the southern Colombian Pacific basin and a proposal to regenerate a previous barrier island as protection

NASA Astrophysics Data System (ADS)

Otero, L. J.; Restrepo, J. C.; Gonzalez, M.

2014-05-01

In this study, the tsunami hazard posed to 120 000 inhabitants of Tumaco (Colombia) is assessed, and an evaluation and analysis of regenerating the previous El Guano Island for tsunami protection is conducted. El Guano Island was a sandy barrier island in front of the city of Tumaco until its disappearance during the tsunami of 1979; the island is believed to have played a protective role, substantially reducing the scale of the disaster. The analysis is conducted by identifying seismotectonic parameters and focal mechanisms of tsunami generation in the area, determining seven potential generation sources, applying a numerical model for tsunami generation and propagation, and evaluating the effect of tsunamis on Tumaco. The results show that in the current situation, this area is vulnerable to impact and flooding by tsunamis originating nearby. El Guano Island was found to markedly reduce flood levels and the energy flux of tsunami waves in Tumaco during the 1979 tsunami. By reducing the risk of flooding due to tsunamis, the regeneration and morphological modification of El Guano Island would help to protect Tumaco.

Tsunami hazard assessment in the southern Colombian Pacific Basin and a proposal to regenerate a previous barrier island as protection

NASA Astrophysics Data System (ADS)

Otero, L. J.; Restrepo, J. C.; Gonzalez, M.

2013-04-01

In this study, the tsunami hazard posed to 120 000 inhabitants of Tumaco (Colombia) is assessed, and an evaluation and analysis of regenerating the previous El Guano Island for tsunami protection is conducted. El Guano Island was a sandy barrier island in front of the city of Tumaco until its disappearance during the tsunami of 1979; the island is believed to have played a protective role, substantially reducing the scale of the disaster. The analysis is conducted by identifying seismotectonic parameters and focal mechanisms of tsunami generation in the area, determining seven potential generation sources, applying a numerical model for tsunami generation and propagation, and evaluating the effect of tsunamis on Tumaco. The results show that in the current situation, this area is vulnerable to impact and flooding by tsunamis originating nearby. El Guano Island was found to markedly reduce flood levels and the energy flux of tsunami waves in Tumaco during the 1979 tsunami. To reduce the risk of flooding due to tsunamis, the regeneration and morphological modification of El Guano Island would help to protect Tumaco.

Mitigating Hypoxic Stress on Pancreatic Islets via In situ Oxygen Generating Biomaterial

PubMed Central

Coronel, Maria M.; Geusz, Ryan; Stabler, Cherie L.

2017-01-01

A major obstacle in the survival and efficacy of tissue engineered transplants is inadequate oxygenation, whereby unsupportive oxygen tensions result in significant cellular dysfunction and death within the implant. In a previous report, we developed an innovative oxygen generating biomaterial, termed OxySite, to provide supportive in situ oxygenation to cells and prevent hypoxia-induced damage. Herein, we explored the capacity of this biomaterial to mitigate hypoxic stress in both rat and nonhuman primate pancreatic islets by decreasing cell death, supporting metabolic activity, sustaining aerobic metabolism, preserving glucose responsiveness, and decreasing the generation of inflammatory cytokines. Further, the impact of supplemental oxygenation on in vivo cell function was explored by the transplantation of islets previously co-cultured with OxySite into a diabetic rat model. Transplant outcomes revealed significant improvement in graft efficacy for OxySite-treated islets, when transplanted within an extrahepatic site. These results demonstrate the potency of the OxySite material to mitigate activation of detrimental hypoxia-induced pathways in islets during culture and highlights the importance of in situ oxygenation on resulting islet transplant outcomes. PMID:28342320

Comprehensive Virus Detection Using Next Generation Sequencing in Grapevine Vascular Tissues of Plants Obtained from the Wine Regions of Bohemia and Moravia (Czech Republic).

PubMed

Eichmeier, Aleš; Komínková, Marcela; Komínek, Petr; Baránek, Miroslav

2016-01-01

Comprehensive next generation sequencing virus detection was used to detect the whole spectrum of viruses and viroids in selected grapevines from the Czech Republic. The novel NGS approach was based on sequencing libraries of small RNA isolated from grapevine vascular tissues. Eight previously partially-characterized grapevines of diverse varieties were selected and subjected to analysis: Chardonnay, Laurot, Guzal Kara, and rootstock Kober 125AA from the Moravia wine-producing region; plus Müller-Thurgau and Pinot Noir from the Bohemia wine-producing region, both in the Czech Republic. Using next generation sequencing of small RNA, the presence of 8 viruses and 2 viroids were detected in a set of eight grapevines; therefore, confirming the high effectiveness of the technique in plant virology and producing results supporting previous data on multiple infected grapevines in Czech vineyards. Among the pathogens detected, the Grapevine rupestris vein feathering virus and Grapevine yellow speckle viroid 1 were recorded in the Czech Republic for the first time.

Hardware multiplier processor

DOEpatents

Pierce, P.E.

A hardware processor is disclosed which in the described embodiment is a memory mapped multiplier processor that can operate in parallel with a 16 bit microcomputer. The multiplier processor decodes the address bus to receive specific instructions so that in one access it can write and automatically perform single or double precision multiplication involving a number written to it with or without addition or subtraction with a previously stored number. It can also, on a single read command automatically round and scale a previously stored number. The multiplier processor includes two concatenated 16 bit multiplier registers, two 16 bit concatenated 16 bit multipliers, and four 16 bit product registers connected to an internal 16 bit data bus. A high level address decoder determines when the multiplier processor is being addressed and first and second low level address decoders generate control signals. In addition, certain low order address lines are used to carry uncoded control signals. First and second control circuits coupled to the decoders generate further control signals and generate a plurality of clocking pulse trains in response to the decoded and address control signals.

On the fractional Eulerian numbers and equivalence of maps with long term power-law memory (integral Volterra equations of the second kind) to Grünvald-Letnikov fractional difference (differential) equations.

PubMed

Edelman, Mark

2015-07-01

In this paper, we consider a simple general form of a deterministic system with power-law memory whose state can be described by one variable and evolution by a generating function. A new value of the system's variable is a total (a convolution) of the generating functions of all previous values of the variable with weights, which are powers of the time passed. In discrete cases, these systems can be described by difference equations in which a fractional difference on the left hand side is equal to a total (also a convolution) of the generating functions of all previous values of the system's variable with the fractional Eulerian number weights on the right hand side. In the continuous limit, the considered systems can be described by the Grünvald-Letnikov fractional differential equations, which are equivalent to the Volterra integral equations of the second kind. New properties of the fractional Eulerian numbers and possible applications of the results are discussed.

Towards an analytical framework for tailoring supercontinuum generation.

PubMed

Castelló-Lurbe, David; Vermeulen, Nathalie; Silvestre, Enrique

2016-11-14

A fully analytical toolbox for supercontinuum generation relying on scenarios without pulse splitting is presented. Furthermore, starting from the new insights provided by this formalism about the physical nature of direct and cascaded dispersive wave emission, a unified description of this radiation in both normal and anomalous dispersion regimes is derived. Previously unidentified physics of broadband spectra reported in earlier works is successfully explained on this basis. Finally, a foundry-compatible few-millimeters-long silicon waveguide allowing octave-spanning supercontinuum generation pumped at telecom wavelengths in the normal dispersion regime is designed, hence showcasing the potential of this new analytical approach.

Teaching Radiology Trainees From the Perspective of a Millennial.

PubMed

Chen, Po-Hao; Scanlon, Mary H

2018-06-01

The millennial generation consists of today's medical students, radiology residents, fellows, and junior staff. Millennials' comfort with immersive technology, high expectations for success, and desire for constant feedback differentiate them from previous generations. Drawing from an author's experiences through radiology residency and fellowship as a millennial, from published literature, and from the mentorship of a long-time radiology educator, this article explores educational strategies that embrace these characteristics to engage today's youngest generation both in and out of the reading room. Copyright © 2018 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

Interval-level measurement with visual analogue scales in Internet-based research: VAS Generator.

PubMed

Reips, Ulf-Dietrich; Funke, Frederik

2008-08-01

The present article describes VAS Generator (www.vasgenerator.net), a free Web service for creating a wide range of visual analogue scales that can be used as measurement devices in Web surveys and Web experimentation, as well as for local computerized assessment. A step-by-step example for creating and implementing a visual analogue scale with visual feedback is given. VAS Generator and the scales it generates work independently of platforms and use the underlying languages HTML and JavaScript. Results from a validation study with 355 participants are reported and show that the scales generated with VAS Generator approximate an interval-scale level. In light of previous research on visual analogue versus categorical (e.g., radio button) scales in Internet-based research, we conclude that categorical scales only reach ordinal-scale level, and thus visual analogue scales are to be preferred whenever possible.

Identity, prosocial behavior, and generative concern in German and Cameroonian Nso adolescents.

PubMed

Busch, Holger; Hofer, Jan

2011-08-01

Little is known about whether ego identity statuses have the same developmental concomitants in different cultural contexts. Thus, 159 German and 158 Cameroonian Nso adolescents aged 15-18 were recruited to test if associations between identity and generativity (i.e. the desire to create a positive legacy) and prosocial behavior (i.e. helpful and supportive behavior), respectively, are comparable. In both cultural samples, only identity achievement was positively linked with generative concern and prosocial tendencies. Integrating these and previous findings on the association between prosocial behavior and generativity, a partial mediation of the relation between identity achievement and generative concern through prosocial tendencies was hypothesized and confirmed for both cultural groups. Thus, there is an equivalent association between identity achievement, prosocial behavior, and generative concern in adolescents with widely different cultural background. Copyright © 2010 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Neural network based control of Doubly Fed Induction Generator in wind power generation

NASA Astrophysics Data System (ADS)

Barbade, Swati A.; Kasliwal, Prabha

2012-07-01

To complement the other types of pollution-free generation wind energy is a viable option. Previously wind turbines were operated at constant speed. The evolution of technology related to wind systems industry leaded to the development of a generation of variable speed wind turbines that present many advantages compared to the fixed speed wind turbines. In this paper the phasor model of DFIG is used. This paper presents a study of a doubly fed induction generator driven by a wind turbine connected to the grid, and controlled by artificial neural network ANN controller. The behaviour of the system is shown with PI control, and then as controlled by ANN. The effectiveness of the artificial neural network controller is compared to that of a PI controller. The SIMULINK/MATLAB simulation for Doubly Fed Induction Generator and corresponding results and waveforms are displayed.

Precise algorithm to generate random sequential adsorption of hard polygons at saturation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, G.

Random sequential adsorption (RSA) is a time-dependent packing process, in which particles of certain shapes are randomly and sequentially placed into an empty space without overlap. In the infinite-time limit, the density approaches a "saturation'' limit. Although this limit has attracted particular research interest, the majority of past studies could only probe this limit by extrapolation. We have previously found an algorithm to reach this limit using finite computational time for spherical particles, and could thus determine the saturation density of spheres with high accuracy. Here in this paper, we generalize this algorithm to generate saturated RSA packings of two-dimensionalmore » polygons. We also calculate the saturation density for regular polygons of three to ten sides, and obtain results that are consistent with previous, extrapolation-based studies.« less

A cryocooler for applications requiring low magnetic and mechanical interference

NASA Technical Reports Server (NTRS)

Zimmerman, J. E.; Daney, D. E.; Sullivan, D. B.

1983-01-01

A very low-power, low-interference Stirling cryocooler is being developed based on principles and techniques described in several previous publications over the last four years. It differs in several important details from those built previously. It uses a tapered displacer based upon an analytical optimization procedure. The displacer is driven by an auxiliary piston and cylinder (rather than by mechanical linkage) using some of the working fluid itself to provide the driving force. This provides smooth, vibration-free motion, and, more importantly, allows complete mechanical and spatial separation of the cryostat from the pressure-wave generator. Either of two different pressure-wave generators can be used. One is a non-contaminating, unlubricated ceramic piston and cylinder. The other is a compressed-air-operated rubber diaphragm with motor-driven valves to cycle the pressure between appropriate limits.

Effect of Control Blade History, and Axial Coolant Density and Burnup Profiles on BWR Burnup Credit

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marshall, William BJ J

2016-01-01

A technical basis for peak reactivity boiling water reactor (BWR) burnup credit (BUC) methods was recently generated, and the technical basis for extended BWR BUC is now being developed. In this paper, a number of effects related to extended BWR BUC are analyzed, including three major operational effects in BWRs: the coolant density axial distribution, the use of control blades during operation, and the axial burnup profile. Specifically, uniform axial moderator density profiles are analyzed and compared to previous results and an additional temporal fidelity study combing moderator density profiles for three different fuel assemblies is presented. Realistic control blademore » histories and cask criticality results are compared to previously generated constructed control blade histories. Finally, a preliminary study of the axial burnup profile is provided.« less

Precise algorithm to generate random sequential adsorption of hard polygons at saturation

DOE PAGES

Zhang, G.

2018-04-30

Random sequential adsorption (RSA) is a time-dependent packing process, in which particles of certain shapes are randomly and sequentially placed into an empty space without overlap. In the infinite-time limit, the density approaches a "saturation'' limit. Although this limit has attracted particular research interest, the majority of past studies could only probe this limit by extrapolation. We have previously found an algorithm to reach this limit using finite computational time for spherical particles, and could thus determine the saturation density of spheres with high accuracy. Here in this paper, we generalize this algorithm to generate saturated RSA packings of two-dimensionalmore » polygons. We also calculate the saturation density for regular polygons of three to ten sides, and obtain results that are consistent with previous, extrapolation-based studies.« less

Urinary tract infections in hospital pediatrics: many previous antibiotherapy and antibiotics resistance, including fluoroquinolones.

PubMed

Garraffo, A; Marguet, C; Checoury, A; Boyer, S; Gardrat, A; Houivet, E; Caron, F

2014-02-01

We studied antibiotic resistance in pediatric UTIs and we evaluated the impact of antibiotic exposure in the previous 12 months, very little French data being available for this population. We conducted a multicenter prospective study including children consulting for, or admitted in 2 hospitals. Prior antibiotic exposure was documented from their health record. One hundred and ten patients (73 girls), 11 days to 12 years of age, were included in 10 months. Ninety-six percent presented with pyelonephritis, associated to uropathy for 25%. Escherichia coli was predominant (78%), followed by Proteus spp. and Enterococcus spp. The antibiotic resistance rate of E. coli was high and close to that reported for adults with complicated UTIs: amoxicillin 60%, amoxicillin-clavulanate 35%, cefotaxim 5%, trimethoprim-sulfametoxazole 26%, nalidixic acid 9%, ciprofloxacin 7%, gentamycin 1%, nitrofurantoin and fosfomycin 0%. The antibiotic exposure in the previous 12 months involved 62 children (56%) most frequently with β-lactams (89%) for a respiratory tract infection (56%). A clear relationship between exposure and resistance was observed for amoxicillin (71% vs. 46%), first generation (65% vs. 46%) and third generation (9% vs. 3%) cephalosporins, or trimethoprim-sulfamethoxazole (36% vs. 15%). However, antibiotic exposure could not account alone for the results, as suggested by the 7% of ciprofloxacin resistance, observed without any identified previous treatment. Bacterial species and antibiotic resistance level in children are similar to those reported for adults. Antibiotic exposure in the previous 12 months increases the risk of resistance but other factors are involved (previous antibiotic therapies and fecal-oral or mother-to-child transmission). Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Partnership in Innovative Preparation for Educators and Students (PIPES)

DTIC Science & Technology

2013-12-23

it? Sign up for this workshop to find out! You will construct a working wind generator to find out which turbine generates the most electricity...program an advanced robot that will accomplish a greater number of amazing tasks using additional sensors and commands. Requires some previous NXT...tech wireless networks and cell phones to solve a cyber-bullying mystery . Learn ways to stay safe online. 19 Kitchen Chemistry – Science and

A Methodology for Projecting U.S.-Flag Commercial Tanker Capacity

DTIC Science & Technology

1986-03-01

total crude supply for the total US is less than the sum of the total crude supplies of the PADDs . The algorithm generating the output shown in tables...other PADDs . Accordingly, projected receipts for PADD V are zero , and in conjunction with the values for the vari- ables that previously were...SHIPMENTS ALGORITHM This section presents the mathematics of the algorithm that generates the shipments projections for each PADD . The notation

Comparison of second generation open-pollinated, mass control-pollinated, and varietal pine planting stock through 6 years on a North Mississippi site

Treesearch

Randall J. Rousseau; Scott D. Roberts; Billy L. Herrin

2015-01-01

Landowners face a wide array of loblolly pine genetic material to choose from at the time of regeneration. In general, most opt to plant open-pollinated second-generation stock (second-Gen OP) as previously recommended by either consultants or industry personnel. The goal of this study is to evaluate a selected second-Gen OP family, a selected mass control-pollinated...

Center for High-Frequency Microelectronics

DTIC Science & Technology

1992-08-31

34 IEEE Transactions on Electron Devices, 38, No. 6, pp. 1324-1333, June 1991. 185. C. C. Chen, R. K. Mains and G. I. Haddad, " High - Power Generation in...Weiss, J. Hu and W.-P. Hong, "Electronic 0 Properties of Power High Electron Mobility Transistors," Conference on Ballistic Electrons for Transistors...method at higher frequencies than previously believed. - Calculations of high - power generation modes in Si IMPATT devices in the 100-200 GHz range have

In Vivo Demonstration of a Self-Sustaining, Implantable, Stimulated-Muscle-Powered Piezoelectric Generator Prototype

PubMed Central

Lewandowski, B. E.; Kilgore, K. L.; Gustafson, K. J.

2010-01-01

An implantable, stimulated-muscle-powered piezoelectric active energy harvesting generator was previously designed to exploit the fact that the mechanical output power of muscle is substantially greater than the electrical power necessary to stimulate the muscle’s motor nerve. We reduced to practice the concept by building a prototype generator and stimulator. We demonstrated its feasibility in vivo, using rabbit quadriceps to drive the generator. The generated power was sufficient for self-sustaining operation of the stimulator and additional harnessed power was dissipated through a load resistor. The prototype generator was developed and the power generating capabilities were tested with a mechanical muscle analog. In vivo generated power matched the mechanical muscle analog, verifying its usefulness as a test-bed for generator development. Generator output power was dependent on the muscle stimulation parameters. Simulations and in vivo testing demonstrated that for a fixed number of stimuli/minute, two stimuli applied at a high frequency generated greater power than single stimuli or tetanic contractions. Larger muscles and circuitry improvements are expected to increase available power. An implanted, self-replenishing power source has the potential to augment implanted battery or transcutaneously powered electronic medical devices. PMID:19657742

Is your residency program ready for Generation Y?

PubMed

Schlitzkus, Lisa L; Schenarts, Kimberly D; Schenarts, Paul J

2010-01-01

Current residency applicants are members of Generation Y and are significantly different from previous generations of trainees as well as the faculty who attract, recruit, and manage them. Generation Y has been affected by globalization, diversification, terrorism, and international crisis. They are products of the self-esteem movement in child rearing, education, and extracurricular activities where they were all declared winners. Children's activities no longer had winners and losers or first, second, and third place; every child received a participation trophy. Even though they were raised to be a team player, their parents always told them they are special. Technology is ingrained into their daily lives, and they expect its use to be effective and efficient. Generation Y-ers desire to impact the world and give back to their communities and demand immediate access to leadership. This generation poses a challenge to residency programs that will need to attract, recruit, and manage them effectively. This article will provide an overview of Generation Y, contrast Generation Y with Generation X, and discuss how to use generation-specific strategies to attract, recruit, and manage a Generation Y resident. Copyright 2010 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

Why do I always have the best ideas? The role of idea quality in unconscious plagiarism.

PubMed

Perfect, Timothy J; Stark, Louisa-Jayne

2008-05-01

Groups of individuals often work together to generate solutions to a problem. Subsequently, one member of the group can plagiarise another either by recalling that person's idea as their own (recall-own plagiarism), or by generating a novel solution that duplicates a previous idea (generate-new plagiarism). The current study examines the extent to which these forms of plagiarism are influenced by the quality of the ideas. Groups of participants initially generated ideas, prior to an elaboration phase in which idea quality was manipulated in two ways: participants received feedback on the quality of the ideas as rated by independent judges, and they generated improvements to a subset of the ideas. Unconscious plagiarism was measured in recall-own and generate-new tasks. For recall, idea improvement led to increased plagiarism, while for the generate-new task, the independent ratings influenced plagiarism. These data indicate that different source-judgement processes underlie the two forms of plagiarism, neither of which can be reduced simply to memory strength.

Time-series-based hybrid mathematical modelling method adapted to forecast automotive and medical waste generation: Case study of Lithuania.

PubMed

Karpušenkaitė, Aistė; Ruzgas, Tomas; Denafas, Gintaras

2018-05-01

The aim of the study was to create a hybrid forecasting method that could produce higher accuracy forecasts than previously used 'pure' time series methods. Mentioned methods were already tested with total automotive waste, hazardous automotive waste, and total medical waste generation, but demonstrated at least a 6% error rate in different cases and efforts were made to decrease it even more. Newly developed hybrid models used a random start generation method to incorporate different time-series advantages and it helped to increase the accuracy of forecasts by 3%-4% in hazardous automotive waste and total medical waste generation cases; the new model did not increase the accuracy of total automotive waste generation forecasts. Developed models' abilities to forecast short- and mid-term forecasts were tested using prediction horizon.

Generation of physical random numbers by using homodyne detection

NASA Astrophysics Data System (ADS)

Hirakawa, Kodai; Oya, Shota; Oguri, Yusuke; Ichikawa, Tsubasa; Eto, Yujiro; Hirano, Takuya; Tsurumaru, Toyohiro

2016-10-01

Physical random numbers generated by quantum measurements are, in principle, impossible to predict. We have demonstrated the generation of physical random numbers by using a high-speed balanced photodetector to measure the quadrature amplitudes of vacuum states. Using this method, random numbers were generated at 500 Mbps, which is more than one order of magnitude faster than previously [Gabriel et al:, Nature Photonics 4, 711-715 (2010)]. The Crush test battery of the TestU01 suite consists of 31 tests in 144 variations, and we used them to statistically analyze these numbers. The generated random numbers passed 14 of the 31 tests. To improve the randomness, we performed a hash operation, in which each random number was multiplied by a random Toeplitz matrix; the resulting numbers passed all of the tests in the TestU01 Crush battery.

Laser generation of XeCl exciplex molecules in a longitudinal repetitively pulsed discharge in a Xe - CsCl mixture

NASA Astrophysics Data System (ADS)

Boichenko, A. M.; Klenovskii, M. S.

2015-12-01

By using the previously developed kinetic model, we have carried out simulations to study the possibility of laser generation of XeCl exciplex molecules in the working medium based on a mixture of Xe with CsCl vapours, excited by a longitudinal repetitively pulsed discharge. The formation mechanism of exciplex molecules in this mixture is fundamentally different from the formation mechanisms in the traditional mixtures of exciplex lasers. The conditions that make the laser generation possible are discussed. For these conditions, with allowance for available specific experimental conditions of the repetitively pulsed discharge excitation, we have obtained the calculated dependences of the power and efficiency of generation on the reflectivity of mirrors in a laser cavity.

Design and performance of honeycomb structure for nanobubbles generating apparatus having different cell dimensions

NASA Astrophysics Data System (ADS)

Ueda, T.; Zhai, H. F.; Ren, F.; Noda, N.-A.; Sano, Y.; Takase, Yasushi; Yonezawa, Y.; Tanaka, H.

2018-06-01

In recent years, nanobubble technology has drawn great attention due to their wide applications in various fields of science and technology, such as water treatment, biomedical engineering, and nanomaterials. This study focuses on the application to seafood long term storage. The nitrogen nanobubble water circulation may reduce the oxygen in water and slow the progressions of oxidation and spoilage. Our previous study showed the pressure reduction and shear stress are involved in nanobubble generation apparatus with honeycomb cells. In this work, the nanobubble generating performance is studied experimentally for honeycomb structures by varying the cell size and the flow velocity. Computational Fluid Dynamics analysis is also performed to simulate the experiment and find out the efficient nanobubble generation.

A small-signal generator based on a multi-layer graphene/molybdenum disulfide heterojunction

NASA Astrophysics Data System (ADS)

Tan, Zhen; Tian, He; Feng, Tingting; Zhao, Lianfeng; Xie, Dan; Yang, Yi; Xiao, Lei; Wang, Jing; Ren, Tian-Ling; Xu, Jun

2013-12-01

In this work, we fabricate a heterojunction small-signal generator (HSSG) based on a graphene-molybdenum disulfide (MoS2) heterojunction. The HSSG is fundamentally different from any analog device developed previously. The HSSG is composed of two quasi-2D heterojunctions and has three terminals named injector (I), recombinator (R), and generator (G). MoS2 serves as I and G, and graphene works as R in the HSSG. The scale coefficient (β = IG/IR) of the HSSG is 1.14 × 10-4 (VIG, IR = 0.2 V) to 1.95 × 10-4 (VIG, IR = 1 V). The current generated from G could be as low as pA scale, which reveals the good performance of the HSSG.

Investigating the role of future thinking in social problem solving.

PubMed

Noreen, Saima; Whyte, Katherine E; Dritschel, Barbara

2015-03-01

There is well-established evidence that both rumination and depressed mood negatively impact the ability to solve social problems. A preliminary stage of the social problem solving process may be the process of catapulting oneself forward in time to think about the consequences of a problem before attempting to solve it. The aim of the present study was to examine how thinking about the consequences of a social problem being resolved or unresolved prior to solving it influences the solution of the problem as a function of levels of rumination and dysphoric mood. Eighty six participants initially completed the Beck Depression Inventory- II (BDI-II) and the Ruminative Response Scale (RRS). They were then presented with six social problems and generated consequences for half of the problems being resolved and half of the problems remaining unresolved. Participants then solved some of the problems, and following a delay, were asked to recall all of the consequences previously generated. Participants reporting higher levels of depressed mood and rumination were less effective at generating problem solutions. Specifically, those reporting higher levels of rumination produced less effective solutions for social problems that they had previously generated unresolved than resolved consequences. We also found that individuals higher in rumination, irrespective of depressed mood recalled more of the unresolved consequences in a subsequent memory test. As participants did not solve problems for scenarios where no consequences were generated, no baseline measure of problem solving was obtained. Our results suggest thinking about the consequences of a problem remaining unresolved may impair the generation of effective solutions in individuals with higher levels of rumination. Copyright © 2014 Elsevier Ltd. All rights reserved.

Virtual non-contrast dual-energy CT compared to single-energy CT of the urinary tract: a prospective study.

PubMed

Lundin, Margareta; Lidén, Mats; Magnuson, Anders; Mohammed, Ahmed Abdulilah; Geijer, Håkan; Andersson, Torbjörn; Persson, Anders

2012-07-01

Dual-energy computed tomography (DECT) has been shown to be useful for subtracting bone or calcium in CT angiography and gives an opportunity to produce a virtual non-contrast-enhanced (VNC) image from a series where contrast agents have been given intravenously. High noise levels and low resolution have previously limited the diagnostic value of the VNC images created with the first generation of DECT. With the recent introduction of a second generation of DECT, there is a possibility of obtaining VNC images with better image quality at hopefully lower radiation dose compared to the previous generation. To compare the image quality of the single-energy series to a VNC series obtained with a two generations of DECT scanners. CT of the urinary tract was used as a model. Thirty patients referred for evaluation of hematuria were examined with an older system (Somatom Definition) and another 30 patients with a new generation (Somatom Definition Flash). One single-energy series was obtained before and one dual-energy series after administration of intravenous contrast media. We created a VNC series from the contrast-enhanced images. Images were assessed concerning image quality with a visual grading scale evaluation of the VNC series with the single-energy series as gold standard. The image quality of the VNC images was rated inferior to the single-energy variant for both scanners, OR 11.5-67.3 for the Definition and OR 2.1-2.8 for the Definition Flash. Visual noise and overall quality were regarded as better with Flash than Definition. Image quality of VNC images obtained with the new generation of DECT is still slightly inferior compared to native images. However, the difference is smaller with the new compared to the older system.

Accomplishments in free-piston stirling tests at NASA GRC

NASA Astrophysics Data System (ADS)

Schreiber, Jeffrey G.; Skupinski, Robert C.

2002-01-01

A power system based on the Stirling Radioisotope Generator (SRG) has been identified for potential use on deep space missions, as well as for Mars rovers that may benefit from extended operation. The Department of Energy (DOE) has responsibility for developing the generator and the NASA Glenn Research Center (GRC) is supporting DOE in this effort. The generator is based on a free-piston Stirling power convertor that has been developed by the Stirling Technology Company (STC) under contract to DOE. The generator would be used as a high-efficiency alternative to the Radioisotope Thermoelectric Generators (RTGs) that have been used on many previous missions. The increased efficiency leads to a factor of 3 to 4 reduction in the inventory of plutonium required to heat the generator. GRC has been involved in the development of Stirling power conversion technology for over 25 years. The support provided to this project by GRC has many facets and draws upon the lab's scientists and engineers that have gained experience in applying their skills to the previous Stirling projects. This has created a staff with an understanding of the subtleties involved in applying their expertise to Stirling systems. Areas include materials, structures, tribology, controls, electromagnetic interference, permanent magnets, alternator analysis, structural dynamics, and cycle performance. One of the key areas of support to the project is in the performance testing of the free-piston Stirling convertors. Since these power convertors are the smallest, lowest power Stirling machines that have been tested at GRC, a new laboratory was equipped for this project. Procedures and test plans have been created, instrumentation and data systems developed, and Stirling convertors have been tested. This paper will describe the GRC test facility, the test procedures that are used, present some of the test results and outline plans for the future. .

Performance of OSC's initial Amtec generator design, and comparison with JPL's Europa Orbiter goals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schock, A.; Noravian, H.; Or, C.

1998-07-01

The procedure for the analysis (with overpotential correction) of multitube AMTEC (Alkali Metal Thermal-to-Electrical Conversion) cells described in Paper IECEC 98-243 was applied to a wide range of multicell radioisotope space power systems. System design options consisting of one or two generators, each with 2, 3, or 4 stacked GPHS (General Purpose Heat Source) modules, identical to those used on previous NASA missions, were analyzed and performance-mapped. The initial generators analyzed by OSC had 8 AMTEC cells on each end of the heat source stack, with five beta-alumina solid electrolyte (BASE) tubes per cell. The heat source and converters inmore » the Orbital generator designs are embedded in a thermal insulation system consisting of Min-K fibrous insulation surrounded by graded-length molybdenum multifoils. Detailed analyses in previous Orbital studies found that such an insulation system could reduce extraneous heat losses to about 10%. For the above design options, the present paper presents the system mass and performance (i.e., the EOM system efficiency and power output and the BOM evaporator and clad temperatures) for a wide range of heat inputs and load voltages, and compares the results with JPL's preliminary goals for the Europa Orbiter mission to be launched in November 2003. The analytical results showed that the initial 16-cell generator designs resulted in either excessive evaporator and clad temperatures and/or insufficient power outputs to meet the JPL-specified mission goals. The computed performance of modified OSC generators with different numbers of AMTEC cells, cell diameters, cell lengths, cell materials, BASE tube lengths, and number of tubes per cell are described in Paper IECEC.98.245 in these proceedings.« less

Benefits gained, benefits lost: comparing baby boomers to other generations in a longitudinal cohort study of self-rated health.

PubMed

Badley, Elizabeth M; Canizares, Mayilee; Perruccio, Anthony V; Hogg-Johnson, Sheilah; Gignac, Monique A M

2015-03-01

POLICY POINTS: Despite beliefs that baby boomers are healthier than previous generations, we found no evidence that the health of baby boomers is substantially different from that of the previous or succeeding cohorts. The effects of increased education, higher income, and lower smoking rates on improving self-rated health were nearly counterbalanced by the adverse effect of increasing body mass index (BMI). Assumptions that baby boomers will require less health care as they age because of better education, more prosperity, and less propensity to smoke may not be realized because of increases in obesity. Baby boomers are commonly believed to be healthier than the previous generation. Using self-rated health (SRH) as an indicator of health status, this study examines the effects of age, period, and birth cohort on the trajectory of health across 4 generations: World War II (born between 1935 and 1944), older baby boomers (born between 1945 and 1954), younger baby boomers (born between 1955 and 1964), and Generation X (born between 1965 and 1974). We analyzed Canada's longitudinal National Population Health Survey 1994-2010 (n = 8,570 at baseline), using multilevel growth models to estimate the age trajectory of SRH by cohort, accounting for period and incorporating the influence of changes in education, household income, smoking status, and body mass index (BMI) on SRH over time. SRH worsened with increasing age in all cohorts. Cohort differences in SRH were modest (p = 0.034), but there was a significant period effect (p = 0.002). We found marked cohort effects for increasing education, income, and BMI, and decreasing smoking from the youngest to the oldest cohorts, which were much reduced (education and smoking) or removed (income and BMI) once period was taken into account. At the population level, multivariable analysis showed the benefits of increasing education and income and declines in smoking on the trajectory of improving SRH were almost counterbalanced by the effects of increasing BMI (obesity). We found no evidence to support the expectation that baby boomers will age more or less healthily than previous cohorts did. We also found that increasing BMI has likely undermined improvements in health that might have otherwise occurred, with possible implications for the need for health care. Period effects had a more profound effect than birth cohort effects. This suggests that interventions to improve health, such as reducing obesity, can be targeted to the entire, or a major portion of the, population and need not single out particular birth cohorts. © 2015 Milbank Memorial Fund.

Benefits Gained, Benefits Lost: Comparing Baby Boomers to Other Generations in a Longitudinal Cohort Study of Self-Rated Health

PubMed Central

BADLEY, ELIZABETH M; CANIZARES, MAYILEE; PERRUCCIO, ANTHONY V; HOGG-JOHNSON, SHEILAH; GIGNAC, MONIQUE AM

2015-01-01

Policy Points Despite beliefs that baby boomers are healthier than previous generations, we found no evidence that the health of baby boomers is substantially different from that of the previous or succeeding cohorts. The effects of increased education, higher income, and lower smoking rates on improving self-rated health were nearly counterbalanced by the adverse effect of increasing body mass index (BMI). Assumptions that baby boomers will require less health care as they age because of better education, more prosperity, and less propensity to smoke may not be realized because of increases in obesity. Context Baby boomers are commonly believed to be healthier than the previous generation. Using self-rated health (SRH) as an indicator of health status, this study examines the effects of age, period, and birth cohort on the trajectory of health across 4 generations: World War II (born between 1935 and 1944), older baby boomers (born between 1945 and 1954), younger baby boomers (born between 1955 and 1964), and Generation X (born between 1965 and 1974). Methods We analyzed Canada’s longitudinal National Population Health Survey 1994-2010 (n = 8,570 at baseline), using multilevel growth models to estimate the age trajectory of SRH by cohort, accounting for period and incorporating the influence of changes in education, household income, smoking status, and body mass index (BMI) on SRH over time. Findings SRH worsened with increasing age in all cohorts. Cohort differences in SRH were modest (p = 0.034), but there was a significant period effect (p = 0.002). We found marked cohort effects for increasing education, income, and BMI, and decreasing smoking from the youngest to the oldest cohorts, which were much reduced (education and smoking) or removed (income and BMI) once period was taken into account. At the population level, multivariable analysis showed the benefits of increasing education and income and declines in smoking on the trajectory of improving SRH were almost counterbalanced by the effects of increasing BMI (obesity). Conclusions We found no evidence to support the expectation that baby boomers will age more or less healthily than previous cohorts did. We also found that increasing BMI has likely undermined improvements in health that might have otherwise occurred, with possible implications for the need for health care. Period effects had a more profound effect than birth cohort effects. This suggests that interventions to improve health, such as reducing obesity, can be targeted to the entire, or a major portion of the, population and need not single out particular birth cohorts. PMID:25752350

Changes of Cattle Fecal Microbiome Under Field Conditions.

EPA Science Inventory

Next generation sequencing (NGS) has been applied to study the microbiome in wastewater, sewage sludge, and feces. Previous microbial survival studies have shown different fecal-associated microbes have different decay rates and regrowth behaviors.

Changes of Cattle Fecal Microbiome Under Field Conditions

EPA Science Inventory

Next generation sequencing (NGS) has been applied to study the microbiome in wastewater, sewage sludge, and feces. Previous microbial survival studies have shown different fecal-associated microbes have different decay rates and regrowth behaviors.

455 N St Clair St, August 2012, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the spoil materials generated during the drilling process did not exceed the respective threshold values previously stated withthe maximum unshielded gamma reading observed being 5,500 cpm.

Determining the source of strong LF/VLF TIPP events: Implications for association with NPBPs and NNBPs

NASA Astrophysics Data System (ADS)

Zuelsdorf, R. S.; Franz, R. C.; Strangeway, R. J.; Russell, C. T.

2000-08-01

Transionospheric pulse pairs (TIPPs) as detected by the Blackbeard VHF radio instrument onboard the ALEXIS satellite have been shown to correlate with pulses detected by stations in the National Lightning Detection Network (NLDN). The short peak-to-zero time of these NLDN-detected pulses (<10 μs) are indicative of interior cloud processes, as opposed to the longer pulses associated with cloud-to-ground discharges. TIPPs are most probably generated by the same discharge responsible for narrow bipolar pulses (NBPs), which have been detected on the ground but are also believed to be generated entirely inside the cloud. Here we report on five TIPPs detected by Blackbeard that are correlated with cloud-generated pulses detected by multiple stations in the NLDN during powerful storms. Previously, a maximum of two stations at a time showed such a correlation. Given the greater area of detection, these pulses radiate more powerfully in the LF/VLF frequencies than those previously detected as TIPPs by Blackbeard. We are able to place the sources of the TIPPs in Hurricane Fausto off the coast of Mexico, and in a remnant of the same storm eight days later over Texas. The heights of the sources are higher than those previously determined for TIPPs. The higher altitudes and the greater power of the TIPP-correlating signals may be related to the intensity of the storms. Two of these five TIPPs were also correlated with the ground detection of HF signals, and the TIPPs and HF signals were determined to originate from the same source region. These HF signals are similar to those previously recorded with the field change signature of narrow positive bipolar pulses (NPBPs), but we find that both polarities are detected, four out of the five being negative. This indicates that TIPPs correlate with narrow negative bipolar pulses (NNBPs) as well as NPBPs. The detection of NNBPs, which has previously been much rarer than NPBPs, may also be related to the intensity of the storms and the resultant higher-altitude sources.

Development of Optical Crystals for High Power and Tunable Visible and Infrared Light Generation

DTIC Science & Technology

2015-02-11

ultra high chemical purity (5N), 95% isotopically enriched 6Li was purified in a multi-stage vacuum distillation process previously reported by...enriched 6Li was purified in a multi-stage vacuum distillation process previously reported by Stowe et al.[4]. 6LiIn alloy was synthesized in a... quantum mechanics, it has been determined that atoms, molecules, ions have discrete energy levels. Therefore there exists allowed atomic transitions

Advanced High-Power Generator Research Program

DTIC Science & Technology

1986-05-01

lOOx ............. ... 3A-6 3A-3 Carbides in the Inconel are Well Broken Up. No Continuous Networks as in Previous Bonds. Unetched. Magnified 225X.. 3A...7 3A-4 Carbides in the Inconel are Well Broken Uo. No Continuous Networks as in Previous Bonds. Unetched. Magnified 225X.. 3A-7 3A-5 Carbides are Well...3A-9 3A-8 Typical Tensile Rupture. Failure Occurred with Inconel 718 Carbide Precipitation Zone. Magnified 225X

Targeted next-generation sequencing makes new molecular diagnoses and expands genotype-phenotype relationship in Ehlers-Danlos syndrome.

PubMed

Weerakkody, Ruwan A; Vandrovcova, Jana; Kanonidou, Christina; Mueller, Michael; Gampawar, Piyush; Ibrahim, Yousef; Norsworthy, Penny; Biggs, Jennifer; Abdullah, Abdulshakur; Ross, David; Black, Holly A; Ferguson, David; Cheshire, Nicholas J; Kazkaz, Hanadi; Grahame, Rodney; Ghali, Neeti; Vandersteen, Anthony; Pope, F Michael; Aitman, Timothy J

2016-11-01

Ehlers-Danlos syndrome (EDS) comprises a group of overlapping hereditary disorders of connective tissue with significant morbidity and mortality, including major vascular complications. We sought to identify the diagnostic utility of a next-generation sequencing (NGS) panel in a mixed EDS cohort. We developed and applied PCR-based NGS assays for targeted, unbiased sequencing of 12 collagen and aortopathy genes to a cohort of 177 unrelated EDS patients. Variants were scored blind to previous genetic testing and then compared with results of previous Sanger sequencing. Twenty-eight pathogenic variants in COL5A1/2, COL3A1, FBN1, and COL1A1 and four likely pathogenic variants in COL1A1, TGFBR1/2, and SMAD3 were identified by the NGS assays. These included all previously detected single-nucleotide and other short pathogenic variants in these genes, and seven newly detected pathogenic or likely pathogenic variants leading to clinically significant diagnostic revisions. Twenty-two variants of uncertain significance were identified, seven of which were in aortopathy genes and required clinical follow-up. Unbiased NGS-based sequencing made new molecular diagnoses outside the expected EDS genotype-phenotype relationship and identified previously undetected clinically actionable variants in aortopathy susceptibility genes. These data may be of value in guiding future clinical pathways for genetic diagnosis in EDS.Genet Med 18 11, 1119-1127.

Second-Generation Prisoners and the Transmission of Domestic Violence.

PubMed

Will, Joanna L; Loper, Ann B; Jackson, Shelly L

2016-01-01

Adult inmates who experienced the incarceration of a parent, known as "second-generation prisoners," experience unique challenges and are at heightened risk for experiencing other adversities throughout the life span. Our study investigated one specific, and previously unexplored, type of adversity--domestic violence--within a sample of 293 incarcerated adults. We examined the relation between generation status (first- or second-generation prisoners), childhood exposure to domestic violence, and participation in adult relationship violence prior to incarceration. Results indicate that prisoners who had been exposed to domestic violence in childhood were more likely to engage in intimate partner violence resulting in inflicted and received injury. Relative to first-generation prisoners, second-generation prisoners reported more childhood domestic violence exposure and were more likely to have been injured by a relationship partner. However, this relation between second-generation status and injury victimization was mediated by domestic violence exposure. These results support an intergenerational pattern of domestic violence and suggest that second-generation prisoners are a unique population worthy of future investigation and mental health intervention. © The Author(s) 2014.

An improved offset generator developed for Allan deviation measurement of ultra stable frequency standards

NASA Technical Reports Server (NTRS)

Hamell, Robert L.; Kuhnle, Paul F.; Sydnor, Richard L.

1992-01-01

Measuring the performance of ultra stable frequency standards such as the Superconducting Cavity Maser Oscillator (SCMO) necessitates improvement of some test instrumentation. The frequency stability test equipment used at JPL includes a 1 Hz Offset Generator to generate a beat frequency between a pair of 100 MHz signals that are being compared. The noise floor of the measurement system using the current Offset Generator is adequate to characterize stability of hydrogen masers, but it is not adequate for the SCMO. A new Offset Generator with improved stability was designed and tested at JPL. With this Offset Generator and a new Zero Crossing Detector, recently developed at JPL, the measurement flow was reduced by a factor of 5.5 at 1 second tau, 3.0 at 1000 seconds, and 9.4 at 10,000 seconds, compared against the previous design. In addition to the new circuit designs of the Offset Generator and Zero Crossing Detector, tighter control of the measurement equipment environment was required to achieve this improvement. The design of this new Offset Generator are described, along with details of the environment control methods used.

The Effect of a Previously-Generated Hypothesis on Hypothesis Generation Performance.

DTIC Science & Technology

1980-08-05

distinction 17I -’ai S between availability and accessibility has been made by Tulving and Pearlstone (1966). A datum may be present in memory, but may...1977. Thorndyke, P.W. The role of inference in discourse comprehension. Journal of Verbal Learning and Verbal Behavior, 1976, 15, 437-446. Tulving ...E. and Pearlstone , Z. Availability versus accessibility of infor- mation in memory for words. Journal of Verbal Learning and Verbal Behavior, 1966, 5

Discrete retardance second harmonic generation ellipsometry.

PubMed

Dehen, Christopher J; Everly, R Michael; Plocinik, Ryan M; Hedderich, Hartmut G; Simpson, Garth J

2007-01-01

A new instrument was constructed to perform discrete retardance nonlinear optical ellipsometry (DR-NOE). The focus of the design was to perform second harmonic generation NOE while maximizing sample and application flexibility and minimizing data acquisition time. The discrete retardance configuration results in relatively simple computational algorithms for performing nonlinear optical ellipsometric analysis. NOE analysis of a disperse red 19 monolayer yielded results that were consistent with previously reported values for the same surface system, but with significantly reduced acquisition times.

Nonlocal symmetries and Bäcklund transformations for the self-dual Yang-Mills system

NASA Astrophysics Data System (ADS)

Papachristou, C. J.; Harrison, B. Kent

1988-01-01

The observation is made that generalized evolutionary isovectors of the self-dual Yang-Mills equation, obtained by ``verticalization'' of the geometrical isovectors derived in a previous paper [J. Math. Phys. 28, 1261 (1987)], generate Bäcklund transformations for the self-dual system. In particular, new Bäcklund transformations are obtained by ``verticalizing'' the generators of point transformations on the solution manifold. A geometric ansatz for the derivation of such (generally nonlocal) symmetries is proposed.

Glycosyl-Nucleolipids as new bioinspired amphiphiles.

PubMed

Latxague, Laurent; Patwa, Amit; Amigues, Eric; Barthélémy, Philippe

2013-09-30

Four new Glycosyl-NucleoLipid (GNL) analogs featuring either a single fluorocarbon or double hydrocarbon chains were synthesized in good yields from azido thymidine as starting material. Physicochemical studies (surface tension measurements, differential scanning calorimetry) indicate that hydroxybutanamide-based GNLs feature endothermic phase transition temperatures like the previously reported double chain glycerol-based GNLs. The second generation of GNFs featuring a free nucleobase reported here presents a better surface activity (lower glim) compared to the first generation of GNFs.

Profiles of executive function in parents and siblings of individuals with autism spectrum disorders.

PubMed

Wong, D; Maybery, M; Bishop, D V M; Maley, A; Hallmayer, J

2006-11-01

Delineation of a cognitive endophenotype for autism is useful both for exploring the genetic mechanisms underlying the disorder and for identifying which cognitive traits may be primary to it. This study investigated whether first-degree relatives of individuals with autism spectrum disorders (ASDs) demonstrate a specific profile of performance on a range of components of executive function (EF), to determine whether EF deficits represent possible endophenotypes for autism. Parents and siblings of ASD and control probands were tested on EF tasks measuring planning, set-shifting, inhibition and generativity. ASD parents showed poorer performance than control parents on a test of ideational fluency or generativity, and ASD fathers demonstrated a weakness in set-shifting to a previously irrelevant dimension. ASD siblings revealed a mild reduction in ideational fluency and a weakness in non-verbal generativity when compared with control siblings. Neither ASD parents nor siblings displayed significant difficulties with planning or inhibition. These results indicated that the broad autism phenotype may not be characterized primarily by impairments in planning and cognitive flexibility, as had been previously proposed. Weaknesses in generativity emerged as stronger potential endophenotypes in this study, suggesting that this aspect of EF should play a central role in cognitive theories of autism. However, discrepancies in the EF profile demonstrated by parents and siblings suggest that factors related to age or parental responsibility may affect the precise pattern of deficits observed.

Effect of pre-acclimation of granular activated carbon on microbial electrolysis cell startup and performance.

PubMed

LaBarge, Nicole; Yilmazel, Yasemin Dilsad; Hong, Pei-Ying; Logan, Bruce E

2017-02-01

Microbial electrolysis cells (MECs) can generate methane by fixing carbon dioxide without using expensive catalysts, but the impact of acclimation procedures on subsequent performance has not been investigated. Granular activated carbon (GAC) was used to pre-enrich electrotrophic methanogenic communities, as GAC has been shown to stimulate direct transfer of electrons between different microbial species. MEC startup times using pre-acclimated GAC were improved compared to controls (without pre-acclimation or without GAC), and after three fed batch cycles methane generation rates were similar (P>0.4) for GAC acclimated to hydrogen (22±9.3nmolcm -3 d -1 ), methanol (25±9.7nmolcm -3 d -1 ), and a volatile fatty acid (VFA) mix (22±11nmolcm -3 d -1 ). However, MECs started with GAC but no pre-acclimation had lower methane generation rates (13±4.1nmolcm -3 d -1 ), and MECs without GAC had the lowest rates (0.7±0.8nmolcm -3 d -1 after cycle 2). Microbes previously found in methanogenic MECs, or previously shown to be capable of exocellular electron transfer, were enriched on the GAC. Pre-acclimation using GAC is therefore a simple approach to enrich electroactive communities, improve methane generation rates, and decrease startup times in MECs. Copyright © 2016 Elsevier B.V. All rights reserved.

An advancing front Delaunay triangulation algorithm designed for robustness

NASA Technical Reports Server (NTRS)

Mavriplis, D. J.

1992-01-01

A new algorithm is described for generating an unstructured mesh about an arbitrary two-dimensional configuration. Mesh points are generated automatically by the algorithm in a manner which ensures a smooth variation of elements, and the resulting triangulation constitutes the Delaunay triangulation of these points. The algorithm combines the mathematical elegance and efficiency of Delaunay triangulation algorithms with the desirable point placement features, boundary integrity, and robustness traditionally associated with advancing-front-type mesh generation strategies. The method offers increased robustness over previous algorithms in that it cannot fail regardless of the initial boundary point distribution and the prescribed cell size distribution throughout the flow-field.

Direct generation of abruptly focusing vortex beams using a 3/2 radial phase-only pattern.

PubMed

Davis, Jeffrey A; Cottrell, Don M; Zinn, Jonathan M

2013-03-20

Abruptly focusing Airy beams have previously been generated using a radial cubic phase pattern that represents the Fourier transform of the Airy beam. The Fourier transform of this pattern is formed using a system length of 2f, where f is the focal length of the Fourier transform lens. In this work, we directly generate these abruptly focusing Airy beams using a 3/2 radial phase pattern encoded onto a liquid crystal display. The resulting optical system is much shorter. In addition, we can easily produce vortex patterns at the focal point of these beams. Experimental results match theoretical predictions.

MSTB 2 x 6-Inch Low Speed Tunnel Turbulence Generator Grid/Honeycomb PIV Measurements and Analysis

NASA Technical Reports Server (NTRS)

Blackshire, James L.

1997-01-01

An assessment of the turbulence levels present in the Measurement Science and Technology (MSTB) branch's 2 x 6-inch low speed wind tunnel was made using Particle Image Velocimetry (PIV), and a turbulence generator consisting of a grid/honeycomb structure. Approximately 3000 digital PIV images were captured and analyzed covering an approximate 2 x 6-inch area along the centerline of the tunnel just beyond the turbulence generator system. Custom software for analysis and acquisition was developed for semi-automated digital PIV image acquisition and analysis. Comparisons between previously obtained LTA and LV turbulence measurements taken in the tunnel are presented.

On application of kernel PCA for generating stimulus features for fMRI during continuous music listening.

PubMed

Tsatsishvili, Valeri; Burunat, Iballa; Cong, Fengyu; Toiviainen, Petri; Alluri, Vinoo; Ristaniemi, Tapani

2018-06-01

There has been growing interest towards naturalistic neuroimaging experiments, which deepen our understanding of how human brain processes and integrates incoming streams of multifaceted sensory information, as commonly occurs in real world. Music is a good example of such complex continuous phenomenon. In a few recent fMRI studies examining neural correlates of music in continuous listening settings, multiple perceptual attributes of music stimulus were represented by a set of high-level features, produced as the linear combination of the acoustic descriptors computationally extracted from the stimulus audio. NEW METHOD: fMRI data from naturalistic music listening experiment were employed here. Kernel principal component analysis (KPCA) was applied to acoustic descriptors extracted from the stimulus audio to generate a set of nonlinear stimulus features. Subsequently, perceptual and neural correlates of the generated high-level features were examined. The generated features captured musical percepts that were hidden from the linear PCA features, namely Rhythmic Complexity and Event Synchronicity. Neural correlates of the new features revealed activations associated to processing of complex rhythms, including auditory, motor, and frontal areas. Results were compared with the findings in the previously published study, which analyzed the same fMRI data but applied linear PCA for generating stimulus features. To enable comparison of the results, methodology for finding stimulus-driven functional maps was adopted from the previous study. Exploiting nonlinear relationships among acoustic descriptors can lead to the novel high-level stimulus features, which can in turn reveal new brain structures involved in music processing. Copyright © 2018 Elsevier B.V. All rights reserved.

75 FR 9622 - Southern Nuclear Operating Company, Inc.; Vogtle Electric Generating Plant, Units 1 and 2; Exemption

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-03

... requirements similar to those previously imposed by Commission orders issued after the terrorist attacks of... Security Plan, Training and Qualification Plan, Safeguards Contingency Plan, and Cyber Security Plan...

Scalability of a Methodology for Generating Technical Trading Rules with GAPs Based on Risk-Return Adjustment and Incremental Training

NASA Astrophysics Data System (ADS)

de La Cal, E. A.; Fernández, E. M.; Quiroga, R.; Villar, J. R.; Sedano, J.

In previous works a methodology was defined, based on the design of a genetic algorithm GAP and an incremental training technique adapted to the learning of series of stock market values. The GAP technique consists in a fusion of GP and GA. The GAP algorithm implements the automatic search for crisp trading rules taking as objectives of the training both the optimization of the return obtained and the minimization of the assumed risk. Applying the proposed methodology, rules have been obtained for a period of eight years of the S&P500 index. The achieved adjustment of the relation return-risk has generated rules with returns very superior in the testing period to those obtained applying habitual methodologies and even clearly superior to Buy&Hold. This work probes that the proposed methodology is valid for different assets in a different market than previous work.

Preliminary experimental investigation of an X-band Cerenkov-type high power microwave oscillator without guiding magnetic field.

PubMed

Guo, Liming; Shu, Ting; Li, Zhiqiang; Ju, Jinchuan; Fang, Xiaoting

2017-02-01

Among high power microwave (HPM) generators without guiding magnetic field, Cerenkov-type oscillator is expected to achieve a relatively high efficiency, which has already been realized in X-band in our previous simulation work. This paper presents the preliminary experimental investigations into an X-band Cerenkov-type HPM oscillator without guiding magnetic field. Based on the previous simulation structure, some modifications regarding diode structure were made. Different cathode structures and materials were tested in the experiments. By using a ring-shaped graphite cathode, microwave of about one hundred megawatt level was generated with a pure center frequency of 9.14 GHz, and an efficiency of about 1.3%. As analyzed in the paper, some practical issues reduce the efficiency in experiments, such as real features of the electron beam, probable breakdown regions on the cathode surface which can damage the diode, and so forth.

From bosonic topological transition to symmetric fermion mass generation

NASA Astrophysics Data System (ADS)

You, Yi-Zhuang; He, Yin-Chen; Vishwanath, Ashvin; Xu, Cenke

2018-03-01

A bosonic topological transition (BTT) is a quantum critical point between the bosonic symmetry-protected topological phase and the trivial phase. In this work, we investigate such a transition in a (2+1)-dimensional lattice model with the maximal microscopic symmetry: an internal SO (4 ) symmetry. We derive a description for this transition in terms of compact quantum electrodynamics (QED) with four fermion flavors (Nf=4 ). Within a systematic renormalization group analysis, we identify the critical point with the desired O (4 ) emergent symmetry and all expected deformations. By lowering the microscopic symmetry, we recover the previous Nf=2 noncompact QED description of the BTT. Finally, by merging two BTTs we recover a previously discussed theory of symmetric mass generation, as an SU (2 ) quantum chromodynamics-Higgs theory with Nf=4 flavors of SU (2 ) fundamental fermions and one SU (2 ) fundamental Higgs boson. This provides a consistency check on both theories.

[Sexuality of our seniors: happy end or new beginning?].

PubMed

Degauquier, C; Absil, A S; Meuris, S; Psalti, I; Jurysta, F

2012-01-01

Comparing surveys from successive periods demonstrates that elderly people now enjoy a better and more varied sexual life than previous generations. The proportion of older people who remain sexually active has significantly increased, and the practices of masturbation or oral sex have spread considerably. The generation effect has an incidence upon sexual behaviour: older people's repertoire of sexual practices differs from that of younger people, in the sense that it focuses less on sexual intercourse and oral sex. Women and men, beyond the common trends towards sexuality characterised by a more open repertoire of sexual practices, differ in terms of sexual interest and subjective sexual wellbeing. The cessation of sexual activity by individuals who had previously been sexually active is often the result of a cascade of reactions, such as the occurrence of a sexual dysfunction in one or both partners, anticipation of failure, increased anxiety, lack of adaptation of sexuality and/or avoidance behaviour.

Waste streams in a typical crewed space habitat: An update

NASA Technical Reports Server (NTRS)

Golub, M. A.; Wydeven, T.

1992-01-01

A compilation of generation rates and chemical compositions of potential waste streams in a typical crewed space habitat, reported in a prior NASA Technical Memorandum and a related journal article, was updated. This report augments that compilation by the inclusion of the following new data: those data uncovered since completion of the prior report; those obtained from Soviet literature relevant to life support issues; and those for various minor human body wastes not presented previously (saliva, flatus, hair, finger- and toenails, dried skin and skin secretions, tears, and semen), but included here for purposes of completeness. These waste streams complement those discussed previously: toilet waste (urine, feces, etc.), hygiene water (laundry, shower/handwash, dishwasher water and cleansing agents), trash, humidity condensate, perspiration and respiration water, trace contaminants, and dust generation. This report also reproduces the latest information on the environmental control and life support system design parameters for Space Station Freedom.

Subliminal mere exposure: specific, general, and diffuse effects.

PubMed

Monahan, J L; Murphy, S T; Zajonc, R B

2000-11-01

The present research examined the possibility that repeated exposure may simultaneously produce specific and diffuse effects. In Study 1, participants were presented with 5-ms exposures of 25 stimuli each shown once (single-exposure condition) or with five repetitions of 5 stimuli (repeated-exposure condition). Participants in the repeated-exposure condition subsequently rated their own mood more positively than those in the single-exposure condition. Study 2 examined whether affect generated by subliminal repeated exposures transfers to unrelated stimuli. After a subliminal exposure phase, affective reactions to previously exposed stimuli, to new but similar stimuli, and to stimuli from a different category were obtained. Previously exposed stimuli were rated most positively and novel different stimuli least positively. All stimuli were rated more positively in the repeated-exposure condition than in the single-exposure condition. These findings suggest that affect generated by subliminal repeated exposure is sufficiently diffuse to influence ratings of unrelated stimuli and mood.

Separable Processes Before, During, and After the N400 Elicited by Previously Inferred and New Information: Evidence from Time-Frequency Decompositions

PubMed Central

Steele, Vaughn R.; Bernat, Edward M.; van den Broek, Paul; Collins, Paul F.; Patrick, Christopher J.; Marsolek, Chad J.

2012-01-01

Successful comprehension during reading often requires inferring information not explicitly presented. This information is readily accessible when subsequently encountered, and a neural correlate of this is an attenuation of the N400 event-related potential (ERP). We used ERPs and time-frequency (TF) analysis to investigate neural correlates of processing inferred information after a causal coherence inference had been generated during text comprehension. Participants read short texts, some of which promoted inference generation. After each text, they performed lexical decisions to target words that were unrelated or inference-related to the preceding text. Consistent with previous findings, inference-related words elicited an attenuated N400 relative to unrelated words. TF analyses revealed unique contributions to the N400 from activity occurring at 1–6 Hz (theta) and 0–2 Hz (delta), supporting the view that multiple, sequential processes underlie the N400. PMID:23165117

Identification of distinct telencephalic progenitor pools for neuronal diversity in the amygdala.

PubMed

Hirata, Tsutomu; Li, Peijun; Lanuza, Guillermo M; Cocas, Laura A; Huntsman, Molly M; Corbin, Joshua G

2009-02-01

The development of the amygdala, a central structure of the limbic system, remains poorly understood. We found that two spatially distinct and early-specified telencephalic progenitor pools marked by the homeodomain transcription factor Dbx1 are major sources of neuronal cell diversity in the mature mouse amygdala. We found that Dbx1-positive cells of the ventral pallium generate the excitatory neurons of the basolateral complex and cortical amygdala nuclei. Moreover, Dbx1-derived cells comprise a previously unknown migratory stream that emanates from the preoptic area (POA), a ventral telencephalic domain adjacent to the diencephalic border. The Dbx1-positive, POA-derived population migrated specifically to the amygdala and, as defined by both immunochemical and electrophysiological criteria, generated a unique subclass of inhibitory neurons in the medial amygdala nucleus. Thus, this POA-derived population represents a previously unknown progenitor pool dedicated to the limbic system.

Realistic Specific Power Expectations for Advanced Radioisotope Power Systems

NASA Technical Reports Server (NTRS)

Mason, Lee S.

2006-01-01

Radioisotope Power Systems (RPS) are being considered for a wide range of future NASA space science and exploration missions. Generally, RPS offer the advantages of high reliability, long life, and predictable power production regardless of operating environment. Previous RPS, in the form of Radioisotope Thermoelectric Generators (RTG), have been used successfully on many NASA missions including Apollo, Viking, Voyager, and Galileo. NASA is currently evaluating design options for the next generation of RPS. Of particular interest is the use of advanced, higher efficiency power conversion to replace the previous thermoelectric devices. Higher efficiency reduces the quantity of radioisotope fuel and potentially improves the RPS specific power (watts per kilogram). Power conversion options include Segmented Thermoelectric (STE), Stirling, Brayton, and Thermophotovoltaic (TPV). This paper offers an analysis of the advanced 100 watt-class RPS options and provides credible projections for specific power. Based on the analysis presented, RPS specific power values greater than 10 W/kg appear unlikely.

Method and system for efficient video compression with low-complexity encoder

NASA Technical Reports Server (NTRS)

Chen, Jun (Inventor); He, Dake (Inventor); Sheinin, Vadim (Inventor); Jagmohan, Ashish (Inventor); Lu, Ligang (Inventor)

2012-01-01

Disclosed are a method and system for video compression, wherein the video encoder has low computational complexity and high compression efficiency. The disclosed system comprises a video encoder and a video decoder, wherein the method for encoding includes the steps of converting a source frame into a space-frequency representation; estimating conditional statistics of at least one vector of space-frequency coefficients; estimating encoding rates based on the said conditional statistics; and applying Slepian-Wolf codes with the said computed encoding rates. The preferred method for decoding includes the steps of; generating a side-information vector of frequency coefficients based on previously decoded source data, encoder statistics, and previous reconstructions of the source frequency vector; and performing Slepian-Wolf decoding of at least one source frequency vector based on the generated side-information, the Slepian-Wolf code bits and the encoder statistics.

TH-CD-202-07: A Methodology for Generating Numerical Phantoms for Radiation Therapy Using Geometric Attribute Distribution Models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dolly, S; Chen, H; Mutic, S

Purpose: A persistent challenge for the quality assessment of radiation therapy treatments (e.g. contouring accuracy) is the absence of the known, ground truth for patient data. Moreover, assessment results are often patient-dependent. Computer simulation studies utilizing numerical phantoms can be performed for quality assessment with a known ground truth. However, previously reported numerical phantoms do not include the statistical properties of inter-patient variations, as their models are based on only one patient. In addition, these models do not incorporate tumor data. In this study, a methodology was developed for generating numerical phantoms which encapsulate the statistical variations of patients withinmore » radiation therapy, including tumors. Methods: Based on previous work in contouring assessment, geometric attribute distribution (GAD) models were employed to model both the deterministic and stochastic properties of individual organs via principle component analysis. Using pre-existing radiation therapy contour data, the GAD models are trained to model the shape and centroid distributions of each organ. Then, organs with different shapes and positions can be generated by assigning statistically sound weights to the GAD model parameters. Organ contour data from 20 retrospective prostate patient cases were manually extracted and utilized to train the GAD models. As a demonstration, computer-simulated CT images of generated numerical phantoms were calculated and assessed subjectively and objectively for realism. Results: A cohort of numerical phantoms of the male human pelvis was generated. CT images were deemed realistic both subjectively and objectively in terms of image noise power spectrum. Conclusion: A methodology has been developed to generate realistic numerical anthropomorphic phantoms using pre-existing radiation therapy data. The GAD models guarantee that generated organs span the statistical distribution of observed radiation therapy patients, according to the training dataset. The methodology enables radiation therapy treatment assessment with multi-modality imaging and a known ground truth, and without patient-dependent bias.« less

Industrial hazardous waste management in Turkey: current state of the field and primary challenges.

PubMed

Salihoglu, Güray

2010-05-15

A holistic evaluation of a country's hazardous waste management (HWM) practices is useful in identifying the necessary actions to focus on. Based on an analysis of industrial hazardous waste (HW) generation in Turkey, this paper attempts to critically evaluate and report current Turkish HWM practices and discuss the primary challenges to be addressed. The generation of industrial HW for Turkey reported in 2004 was 1.195 million tons, which accounted for 7% of the total industrial solid waste (ISW) generated by the manufacturing industry, and for nearly 4.9% of the total solid waste generated in the country. The HW generated by the top five manufacturing product categories--basic metals, chemicals and chemical products, food and beverages, coke and refined petroleum, motor vehicles and trailers--accounted for 89.0% of total industrial HW. 21% of the HW generated in 2004 was recycled or reused, and 6% was sold or donated, whereas 73% was sent to ultimate disposal. 67% of the HW sent to ultimate disposal was disposed of at municipal landfills. The total capacity of the existing regional HW facilities is 212,500 tons/year, which accounts for about 24% of the HW to be disposed. Turkey has identified the HW problem in the country and enacted legislation, designated a lead agency, and promulgated rules and regulations. Several new initiatives are planned for improving HW management nationally; however, some HWM problems will be persistent due to previous and existing industrial development plans. These development policies led to the concentration of industry in regions marked by precious agricultural fields and high population density. This occurred because the government previously exhibited a default prioritization towards industrial development, leading to insufficient implementation of regulations on HW generators. Some of the problems may also be rooted in other countries that allow illegal trans boundary HW movements despite international regulations. Copyright (c) 2009 Elsevier B.V. All rights reserved.

Subjective randomness as statistical inference.

PubMed

Griffiths, Thomas L; Daniels, Dylan; Austerweil, Joseph L; Tenenbaum, Joshua B

2018-06-01

Some events seem more random than others. For example, when tossing a coin, a sequence of eight heads in a row does not seem very random. Where do these intuitions about randomness come from? We argue that subjective randomness can be understood as the result of a statistical inference assessing the evidence that an event provides for having been produced by a random generating process. We show how this account provides a link to previous work relating randomness to algorithmic complexity, in which random events are those that cannot be described by short computer programs. Algorithmic complexity is both incomputable and too general to capture the regularities that people can recognize, but viewing randomness as statistical inference provides two paths to addressing these problems: considering regularities generated by simpler computing machines, and restricting the set of probability distributions that characterize regularity. Building on previous work exploring these different routes to a more restricted notion of randomness, we define strong quantitative models of human randomness judgments that apply not just to binary sequences - which have been the focus of much of the previous work on subjective randomness - but also to binary matrices and spatial clustering. Copyright © 2018 Elsevier Inc. All rights reserved.

The red supergiant population in the Perseus arm

NASA Astrophysics Data System (ADS)

Dorda, R.; Negueruela, I.; González-Fernández, C.

2018-04-01

We present a new catalogue of cool supergiants in a section of the Perseus arm, most of which had not been previously identified. To generate it, we have used a set of well-defined photometric criteria to select a large number of candidates (637) that were later observed at intermediate resolution in the infrared calcium triplet spectral range, using a long-slit spectrograph. To separate red supergiants from luminous red giants, we used a statistical method, developed in previous works and improved in the present paper. We present a method to assign probabilities of being a red supergiant to a given spectrum and use the properties of a population to generate clean samples, without contamination from lower luminosity stars. We compare our identification with a classification done using classical criteria and discuss their respective efficiencies and contaminations as identification methods. We confirm that our method is as efficient at finding supergiants as the best classical methods, but with a far lower contamination by red giants than any other method. The result is a catalogue with 197 cool supergiants, 191 of which did not appear in previous lists of red supergiants. This is the largest coherent catalogue of cool supergiants in the Galaxy.

Transmission and full-band coherent detection of polarization-multiplexed all-optical Nyquist signals generated by Sinc-shaped Nyquist pulses

PubMed Central

Zhang, Junwen; Yu, Jianjun; Chi, Nan

2015-01-01

All optical method is considered as a promising technique for high symbol rate Nyquist signal generation, which has attracted a lot of research interests for high spectral-efficiency and high-capacity optical communication system. In this paper, we extend our previous work and report the fully experimental demonstration of polarization-division multiplexed (PDM) all-optical Nyquist signal generation based on Sinc-shaped Nyquist pulse with advanced modulation formats, fiber-transmission and single-receiver full-band coherent detection. Using this scheme, we have successfully demonstrated the generation, fiber transmission and single-receiver full-band coherent detection of all-optical Nyquist PDM-QPSK and PDM-16QAM signals up to 125-GBaud. 1-Tb/s single-carrier PDM-16QAM signal generation and full-band coherent detection is realized, which shows the advantage and feasibility of the single-carrier all-optical Nyquist signals. PMID:26323238

Simulation studies of vapor bubble generation by short-pulse lasers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Amendt, P.; London, R.A.; Strauss, M.

1997-10-26

Formation of vapor bubbles is characteristic of many applications of short-pulse lasers in medicine. An understanding of the dynamics of vapor bubble generation is useful for developing and optimizing laser-based medical therapies. To this end, experiments in vapor bubble generation with laser light deposited in an aqueous dye solution near a fiber-optic tip have been performed. Numerical hydrodynamic simulations have been developed to understand and extrapolate results from these experiments. Comparison of two-dimensional simulations with the experiment shows excellent agreement in tracking the bubble evolution. Another regime of vapor bubble generation is short-pulse laser interactions with melanosomes. Strong shock generationmore » and vapor bubble generation are common physical features of this interaction. A novel effect of discrete absorption by melanin granules within a melanosome is studied as a possible role in previously reported high Mach number shocks.« less

Family trauma through generations: incest and domestic violence in rural Sweden in the nineteenth century.

PubMed

Drugge, Ulf

2008-10-01

Two generations of a family who lived in mid-nineteenth rural Sweden are described. Domestic violence was a common feature in the first generation family. The salient feature there was undoubtedly the incestuous father-daughter relationships. The way incest appeared in Sweden about 150 years ago, the role of local authorities, and the serious consequences to those victimized is analyzed with reference to both the cultural context of that time and to modern theories of incest. Seemingly puzzling violence committed by a second generation family member is related to the domestic violence in the previous generation. Due to the extraordinary character of the incest cases and the specific church council sessions in which the incest case was treated, aspects of family life normally hidden behind curtains of conventions were made public. Reaction patterns drawn from this case indicate a patriarchal system of oppression and badly-directed considerations.

Optimisation of Combined Cycle Gas Turbine Power Plant in Intraday Market: Riga CHP-2 Example

NASA Astrophysics Data System (ADS)

Ivanova, P.; Grebesh, E.; Linkevics, O.

2018-02-01

In the research, the influence of optimised combined cycle gas turbine unit - according to the previously developed EM & OM approach with its use in the intraday market - is evaluated on the generation portfolio. It consists of the two combined cycle gas turbine units. The introduced evaluation algorithm saves the power and heat balance before and after the performance of EM & OM approach by making changes in the generation profile of units. The aim of this algorithm is profit maximisation of the generation portfolio. The evaluation algorithm is implemented in multi-paradigm numerical computing environment MATLab on the example of Riga CHP-2. The results show that the use of EM & OM approach in the intraday market can be profitable or unprofitable. It depends on the initial state of generation units in the intraday market and on the content of the generation portfolio.

Pressure generation to 65 GPa in a Kawai-type multi-anvil apparatus with tungsten carbide anvils

NASA Astrophysics Data System (ADS)

Ishii, Takayuki; Yamazaki, Daisuke; Tsujino, Noriyoshi; Xu, Fang; Liu, Zhaodong; Kawazoe, Takaaki; Yamamoto, Takafumi; Druzhbin, Dmitry; Wang, Lin; Higo, Yuji; Tange, Yoshinori; Yoshino, Takashi; Katsura, Tomoo

2017-10-01

We have expanded the pressure ranges at room and high temperatures generated in a Kawai-type multi-anvil apparatus (KMA) using tungsten carbide (WC) anvils with a high hardness of Hv = 2700 and a Young's modulus of 660 GPa. At room temperature, a pressure of 64 GPa, which is the highest pressure generated with KMA using WC anvils in the world, was achieved using 1°-tapered anvils with a 1.5-mm truncation. Pressures of 48-50 GPa were generated at high temperatures of 1600-2000 K, which are also higher than previously achieved. Tapered anvils make wide anvil gaps enabling efficient X-ray diffraction. The present pressure generation technique can be used for studying the upper part of the Earth's lower mantle down to 1200 km depth without sintered diamond anvils.

Theory and computation of hot carriers generated by surface plasmon polaritons in noble metals

PubMed Central

Bernardi, Marco; Mustafa, Jamal; Neaton, Jeffrey B.; Louie, Steven G.

2015-01-01

Hot carriers (HC) generated by surface plasmon polaritons (SPPs) in noble metals are promising for application in optoelectronics, plasmonics and renewable energy. However, existing models fail to explain key quantitative details of SPP-to-HC conversion experiments. Here we develop a quantum mechanical framework and apply first-principles calculations to study the energy distribution and scattering processes of HCs generated by SPPs in Au and Ag. We find that the relative positions of the s and d bands of noble metals regulate the energy distribution and mean free path of the HCs, and that the electron–phonon interaction controls HC energy loss and transport. Our results prescribe optimal conditions for HC generation and extraction, and invalidate previously employed free-electron-like models. Our work combines density functional theory, GW and electron–phonon calculations to provide microscopic insight into HC generation and ultrafast dynamics in noble metals. PMID:26033445

Overpressures in the Uinta Basin, Utah: Analysis using a three-dimensional basin evolution model

NASA Astrophysics Data System (ADS)

McPherson, Brian J. O. L.; Bredehoeft, John D.

2001-04-01

High pore fluid pressures, approaching lithostatic, are observed in the deepest sections of the Uinta basin, Utah. Geologic observations and previous modeling studies suggest that the most likely cause of observed overpressures is hydrocarbon generation. We studied Uinta overpressures by developing and applying a three-dimensional, numerical model of the evolution of the basin. The model was developed from a public domain computer code, with addition of a new mesh generator that builds the basin through time, coupling the structural, thermal, and hydrodynamic evolution. Also included in the model are in situ hydrocarbon generation and multiphase migration. The modeling study affirmed oil generation as an overpressure mechanism, but also elucidated the relative roles of multiphase fluid interaction, oil density and viscosity, and sedimentary compaction. An important result is that overpressures by oil generation create conditions for rock fracturing, and associated fracture permeability may regulate or control the propensity to maintain overpressures.

The energetics of electric organ discharge generation in gymnotiform weakly electric fish.

PubMed

Salazar, Vielka L; Krahe, Rüdiger; Lewis, John E

2013-07-01

Gymnotiform weakly electric fish produce an electric signal to sense their environment and communicate with conspecifics. Although the generation of such relatively large electric signals over an entire lifetime is expected to be energetically costly, supporting evidence to date is equivocal. In this article, we first provide a theoretical analysis of the energy budget underlying signal production. Our analysis suggests that wave-type and pulse-type species invest a similar fraction of metabolic resources into electric signal generation, supporting previous evidence of a trade-off between signal amplitude and frequency. We then consider a comparative and evolutionary framework in which to interpret and guide future studies. We suggest that species differences in signal generation and plasticity, when considered in an energetics context, will not only help to evaluate the role of energetic constraints in the evolution of signal diversity but also lead to important general insights into the energetics of bioelectric signal generation.

A spectral study of a radio-frequency plasma-generated flux of atomic oxygen

NASA Technical Reports Server (NTRS)

Batten, Carmen E.; Brown, Kenneth G.; Lewis, Beverley W.

1994-01-01

The active environment of a radio-frequency (RF) plasma generator, with and without low-pressure oxygen, has been characterized through the identification of emission lines in the spectral region from 250 to 900 nm. The environment is shown to be dependent on the partial pressure of oxygen and the power applied to the RF generator. Atomic oxygen has been found in significant amounts as well as atomic hydrogen and the molecular oxygen species O2((sup 1)Sigma). The only charged species observed was the singly charged molecular ion O2(+). With a polymer specimen in the plasma chamber, carbon monoxide was also observed. The significance of these observations with respect to previous studies using this type of generator to stimulate material degradation in space is discussed. The possibility of using these generators as atomic oxygen sources in the development of oxygen atom fluorescence sensors is explored.

Variable Cultural Acquisition Costs Constrain Cumulative Cultural Evolution

PubMed Central

Mesoudi, Alex

2011-01-01

One of the hallmarks of the human species is our capacity for cumulative culture, in which beneficial knowledge and technology is accumulated over successive generations. Yet previous analyses of cumulative cultural change have failed to consider the possibility that as cultural complexity accumulates, it becomes increasingly costly for each new generation to acquire from the previous generation. In principle this may result in an upper limit on the cultural complexity that can be accumulated, at which point accumulated knowledge is so costly and time-consuming to acquire that further innovation is not possible. In this paper I first review existing empirical analyses of the history of science and technology that support the possibility that cultural acquisition costs may constrain cumulative cultural evolution. I then present macroscopic and individual-based models of cumulative cultural evolution that explore the consequences of this assumption of variable cultural acquisition costs, showing that making acquisition costs vary with cultural complexity causes the latter to reach an upper limit above which no further innovation can occur. These models further explore the consequences of different cultural transmission rules (directly biased, indirectly biased and unbiased transmission), population size, and cultural innovations that themselves reduce innovation or acquisition costs. PMID:21479170

Geometric optimization of an active magnetic regenerative refrigerator via second-law analysis

NASA Astrophysics Data System (ADS)

Li, Peng; Gong, Maoqiong; Wu, Jianfeng

2008-11-01

Previous analyses [Z. Yan and J. Chen, J. Appl. Phys. 72, 1 (1992); J. Chen and Z. Yan, ibid., 84, 1791 (1998); Lin et al., Physica B 344, 147 (2004); Yang et al., ibid., 364, 33 (2005); Xia et al., ibid., 381, 246 (2006).] of irreversibilities in magnetic refrigerators overlooked several important losses that could be dominant in a real active magnetic regenerative refrigerator (AMRR). No quantitative expressions have been provided yet to estimate the corresponding entropy generations in real AMRRs. The important geometric parameters of AMRRs, such as the aspect ratio of the active magnetic regenerator and the refrigerant diameter, are still arbitrarily chosen. Expressions for calculating different types of entropy generations in the AMRR were derived and used to optimize the aspect ratio and the refrigerant diameter. An optimal coefficient of performance (15.54) was achieved at an aspect ratio of 6.39 and a refrigerant diameter of 1.1mm for our current system. Further study showed that the dissipative sources (e.g., the fluid friction and the unbalanced magnetic forces) in AMRRs, which were overlooked by previous investigations, could significantly contribute to entropy generations.

[Protective role of autotypic contacts under cerebellar neural net injury by toxic doses of NO-generative compounds].

PubMed

Samosudova, N V; Reutov, V P; Larionova, N P; Chaĭlakhian, L M

2005-01-01

In the present work, cerebellar neural net injury was induced by toxic doses of NO-generative compound (NaNO2). A protective role of glial cells was revealed in such conditions. The present results were compared with those of the previous work concerning the action of high concentration glutamate on the frog cerebellum (Samosudova et al., 1996). In both cases we observed the appearance of spiral-like structures--"wrappers)"--involving several rows of transformed glial processes with smaller width and bridges connecting the inner sides of row (autotypic contact). A statistic analysis was made according to both previous and present data. We calculated the number and width of rows, and intervals between bridges depending on experimental conditions. As the injury increased (stimulation in the NO-presence), the row number in "wrappers" also increased, while the row width and intervals between bridges decreased. The presence of autotypic contacts in glial "wrappers" enables us to suppose the involvement of adhesive proteins--cadherins in its formation. The obtained data suggested that the formation of spiral structures--"wrappers" may be regarded as a compensative-adaptive reaction on the injury of cerebellar neural net glutamate and NO-generative compounds.

True Randomness from Big Data.

PubMed

Papakonstantinou, Periklis A; Woodruff, David P; Yang, Guang

2016-09-26

Generating random bits is a difficult task, which is important for physical systems simulation, cryptography, and many applications that rely on high-quality random bits. Our contribution is to show how to generate provably random bits from uncertain events whose outcomes are routinely recorded in the form of massive data sets. These include scientific data sets, such as in astronomics, genomics, as well as data produced by individuals, such as internet search logs, sensor networks, and social network feeds. We view the generation of such data as the sampling process from a big source, which is a random variable of size at least a few gigabytes. Our view initiates the study of big sources in the randomness extraction literature. Previous approaches for big sources rely on statistical assumptions about the samples. We introduce a general method that provably extracts almost-uniform random bits from big sources and extensively validate it empirically on real data sets. The experimental findings indicate that our method is efficient enough to handle large enough sources, while previous extractor constructions are not efficient enough to be practical. Quality-wise, our method at least matches quantum randomness expanders and classical world empirical extractors as measured by standardized tests.

Mitigating hypoxic stress on pancreatic islets via in situ oxygen generating biomaterial.

PubMed

Coronel, Maria M; Geusz, Ryan; Stabler, Cherie L

2017-06-01

A major obstacle in the survival and efficacy of tissue engineered transplants is inadequate oxygenation, whereby unsupportive oxygen tensions result in significant cellular dysfunction and death within the implant. In a previous report, we developed an innovative oxygen generating biomaterial, termed OxySite, to provide supportive in situ oxygenation to cells and prevent hypoxia-induced damage. Herein, we explored the capacity of this biomaterial to mitigate hypoxic stress in both rat and nonhuman primate pancreatic islets by decreasing cell death, supporting metabolic activity, sustaining aerobic metabolism, preserving glucose responsiveness, and decreasing the generation of inflammatory cytokines. Further, the impact of supplemental oxygenation on in vivo cell function was explored by the transplantation of islets previously co-cultured with OxySite into a diabetic rat model. Transplant outcomes revealed significant improvement in graft efficacy for OxySite-treated islets, when transplanted within an extrahepatic site. These results demonstrate the potency of the OxySite material to mitigate activation of detrimental hypoxia-induced pathways in islets during culture and highlights the importance of in situ oxygenation on resulting islet transplant outcomes. Copyright © 2017 Elsevier Ltd. All rights reserved.

A separate universe view of the asymmetric sky

NASA Astrophysics Data System (ADS)

Kobayashi, Takeshi; Cortês, Marina; Liddle, Andrew R.

2015-05-01

We provide a unified description of the hemispherical asymmetry in the cosmic microwave background generated by the mechanism proposed by Erickcek, Kamionkowski, and Carroll, using a δ Script N formalism that consistently accounts for the asymmetry-generating mode throughout. We derive a general form for the power spectrum which explicitly exhibits the broken translational invariance. This can be directly compared to cosmic microwave background observables, including the observed quadrupole and fNL values, automatically incorporating the Grishchuk-Zel'dovich effect. Our calculation unifies and extends previous calculations in the literature, in particular giving the full dependence of observables on the phase of our location in the super-horizon mode that generates the asymmetry. We demonstrate how the apparently different results obtained by previous authors arise as different limiting cases. We confirm the existence of non-linear contributions to the microwave background quadrupole from the super-horizon mode identified by Erickcek et al. and further explored by Kanno et al., and show that those contributions are always significant in parameter regimes capable of explaining the observed asymmetry. We indicate example parameter values capable of explaining the observed power asymmetry without violating other observational bounds.

True Randomness from Big Data

NASA Astrophysics Data System (ADS)

Papakonstantinou, Periklis A.; Woodruff, David P.; Yang, Guang

2016-09-01

Generating random bits is a difficult task, which is important for physical systems simulation, cryptography, and many applications that rely on high-quality random bits. Our contribution is to show how to generate provably random bits from uncertain events whose outcomes are routinely recorded in the form of massive data sets. These include scientific data sets, such as in astronomics, genomics, as well as data produced by individuals, such as internet search logs, sensor networks, and social network feeds. We view the generation of such data as the sampling process from a big source, which is a random variable of size at least a few gigabytes. Our view initiates the study of big sources in the randomness extraction literature. Previous approaches for big sources rely on statistical assumptions about the samples. We introduce a general method that provably extracts almost-uniform random bits from big sources and extensively validate it empirically on real data sets. The experimental findings indicate that our method is efficient enough to handle large enough sources, while previous extractor constructions are not efficient enough to be practical. Quality-wise, our method at least matches quantum randomness expanders and classical world empirical extractors as measured by standardized tests.

Comparative factor analysis models for an empirical study of EEG data, II: A data-guided resolution of the rotation indeterminacy.

PubMed

Rogers, L J; Douglas, R R

1984-02-01

In this paper (the second in a series), we consider a (generic) pair of datasets, which have been analyzed by the techniques of the previous paper. Thus, their "stable subspaces" have been established by comparative factor analysis. The pair of datasets must satisfy two confirmable conditions. The first is the "Inclusion Condition," which requires that the stable subspace of one of the datasets is nearly identical to a subspace of the other dataset's stable subspace. On the basis of that, we have assumed the pair to have similar generating signals, with stochastically independent generators. The second verifiable condition is that the (presumed same) generating signals have distinct ratios of variances for the two datasets. Under these conditions a small elaboration of some elementary linear algebra reduces the rotation problem to several eigenvalue-eigenvector problems. Finally, we emphasize that an analysis of each dataset by the method of Douglas and Rogers (1983) is an essential prerequisite for the useful application of the techniques in this paper. Nonempirical methods of estimating the number of factors simply will not suffice, as confirmed by simulations reported in the previous paper.

True Randomness from Big Data

PubMed Central

Papakonstantinou, Periklis A.; Woodruff, David P.; Yang, Guang

2016-01-01

Generating random bits is a difficult task, which is important for physical systems simulation, cryptography, and many applications that rely on high-quality random bits. Our contribution is to show how to generate provably random bits from uncertain events whose outcomes are routinely recorded in the form of massive data sets. These include scientific data sets, such as in astronomics, genomics, as well as data produced by individuals, such as internet search logs, sensor networks, and social network feeds. We view the generation of such data as the sampling process from a big source, which is a random variable of size at least a few gigabytes. Our view initiates the study of big sources in the randomness extraction literature. Previous approaches for big sources rely on statistical assumptions about the samples. We introduce a general method that provably extracts almost-uniform random bits from big sources and extensively validate it empirically on real data sets. The experimental findings indicate that our method is efficient enough to handle large enough sources, while previous extractor constructions are not efficient enough to be practical. Quality-wise, our method at least matches quantum randomness expanders and classical world empirical extractors as measured by standardized tests. PMID:27666514

A possible alternative mechanism of kinin generation in vivo by cathepsin L.

PubMed

Puzer, Luciano; Vercesi, Juliana; Alves, Marcio F M; Barros, Nilana M T; Araujo, Mariana S; Aparecida Juliano, Maria; Reis, Marina L; Juliano, Luiz; Carmona, Adriana K

2005-07-01

We investigated the ability of cathepsin L to induce a hypotensive effect after intravenous injection in rats and correlated this decrease in blood pressure with kinin generation. Simultaneously with blood pressure decrease, we detected plasma kininogen depletion in the treated rats. The effect observed in vivo was abolished by pre-incubation of cathepsin L with the cysteine peptidase-specific inhibitor E-64 (1 microM) or by previous administration of the bradykinin B2 receptor antagonist JE049 (4 mg/kg). A potentiation of the hypotensive effect caused by cathepsin L was observed by previous administration of the angiotensin I-converting enzyme inhibitor captopril (5 mg/kg). In vitro studies indicated that cathepsin L excised bradykinin from the synthetic fluorogenic peptide Abz-MTSVIRRPPGFSPFRAPRV-NH2, based on the Met375-Val393 sequence of rat kininogen (Abz = o-aminobenzoic acid). In conclusion, our data indicate that in vivo cathepsin L releases a kinin-related peptide, and in vitro experiments suggest that the kinin generated is bradykinin. Although it is well known that cysteine proteases are strongly inhibited by kininogen, cathepsin L could represent an alternative pathway for kinin production in pathological processes.

Characterization of monoclonal antibodies to avian Escherichia coli Iss.

PubMed

Lynne, Aaron M; Foley, Steven L; Nolan, Lisa K

2006-09-01

Colibacillosis accounts for annual multimillion dollar losses in the poultry industry, and control of this disease is hampered by limited understanding of the virulence mechanisms used by avian pathogenic Escherichia coli (APEC). Previous work in our laboratory has found that the presence of the increased serum survival gene (iss) is strongly associated with APEC but not commensal E. coli, making iss and the protein it encodes (Iss) candidate targets of colibacillosis-control procedures. Previously, we produced monoclonal antibodies (MAbs) against Iss to be used as a reagent in studies of APEC virulence and colibacillosis pathogenesis. Unfortunately, the utility of these MAbs was limited because these MAbs exhibited nonspecific binding. It was thought that the lack of specificity might be related to the fact that these MAbs were of the immunoglobulin M (IgM) isotype. In the present study, new MAbs were produced using a different immunization strategy in an effort to generate MAbs of a different isotype. Also, because Iss bears strong similarity to Bor, a lambda-derived protein that occurs commonly among E. coli, MAbs were assessed for their ability to distinguish Iss and Bor. For these studies, the bor gene from an APEC isolate was cloned into an expression vector. The fusion protein expressed from this construct was used to assess the potential of the anti-Iss MAbs produced in the past and present studies to distinguish Bor and Iss. The MAbs produced in this study were of the IgG1 isotype, which appeared to bind more specifically to Iss than previously generated antibodies in certain immunologic procedures. These results suggested that the MAbs generated in this study might prove superior to the previous MAbs as a reagent for study of APEC. However, both MAbs recognized recombinant Iss and Bor, suggesting that any results obtained using anti-Iss MAbs would need to be interpreted with this cross-reactivity in mind.

Social Noise: Generating Random Numbers from Twitter Streams

NASA Astrophysics Data System (ADS)

Fernández, Norberto; Quintas, Fernando; Sánchez, Luis; Arias, Jesús

2015-12-01

Due to the multiple applications of random numbers in computer systems (cryptography, online gambling, computer simulation, etc.) it is important to have mechanisms to generate these numbers. True Random Number Generators (TRNGs) are commonly used for this purpose. TRNGs rely on non-deterministic sources to generate randomness. Physical processes (like noise in semiconductors, quantum phenomenon, etc.) play this role in state of the art TRNGs. In this paper, we depart from previous work and explore the possibility of defining social TRNGs using the stream of public messages of the microblogging service Twitter as randomness source. Thus, we define two TRNGs based on Twitter stream information and evaluate them using the National Institute of Standards and Technology (NIST) statistical test suite. The results of the evaluation confirm the feasibility of the proposed approach.

Polarization gating of high harmonic generation in the water window

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Jie; Ren, Xiaoming; Yin, Yanchun

2016-06-06

We implement the polarization gating (PG) technique with a two-cycle, 1.7 μm driving field to generate an attosecond supercontinuum extending to the water window spectral region. The ellipticity dependence of the high harmonic yield over a photon energy range much broader than previous work is measured and compared with a semi-classical model. When PG is applied, the carrier-envelope phase (CEP) is swept to study its influence on the continuum generation. PG with one-cycle (5.7 fs) and two-cycle (11.3 fs) delay are tested, and both give continuous spectra spanning from 50 to 450 eV under certain CEP values, strongly indicating the generation ofmore » isolated attosecond pulses in the water window region.« less

Concurrent generation of multivariate mixed data with variables of dissimilar types.

PubMed

Amatya, Anup; Demirtas, Hakan

2016-01-01

Data sets originating from wide range of research studies are composed of multiple variables that are correlated and of dissimilar types, primarily of count, binary/ordinal and continuous attributes. The present paper builds on the previous works on multivariate data generation and develops a framework for generating multivariate mixed data with a pre-specified correlation matrix. The generated data consist of components that are marginally count, binary, ordinal and continuous, where the count and continuous variables follow the generalized Poisson and normal distributions, respectively. The use of the generalized Poisson distribution provides a flexible mechanism which allows under- and over-dispersed count variables generally encountered in practice. A step-by-step algorithm is provided and its performance is evaluated using simulated and real-data scenarios.

Correlated Template-Switching Events during Minus-Strand DNA Synthesis: a Mechanism for High Negative Interference during Retroviral Recombination

PubMed Central

Anderson, Jeffrey A.; Teufel, Ronald J.; Yin, Philip D.; Hu, Wei-Shau

1998-01-01

Two models for the mechanism of retroviral recombination have been proposed: forced copy choice (minus-strand recombination) and strand displacement-assimilation (plus-strand recombination). Each minus-strand recombination event results in one template switch, whereas each plus-strand recombination event results in two template switches. Recombinant proviruses with one and more than one template switches were previously observed. Recombinants with one template switch were generated by minus-strand recombination, while recombinants containing more than one template switch may have been generated by plus-strand recombination or by correlated minus-strand recombination. We recently observed that retroviral recombination exhibits high negative interference whereby the frequency of recombinants containing multiple template-switching events is higher than expected. To delineate the mechanism that generates recombinants with more than one template switch, we devised a system that permits only minus-strand recombination. Two highly homologous vectors, WH204 and WH221, containing eight different restriction site markers were used. The primer binding site (PBS) of WH221 was deleted; although reverse transcription cannot initiate from WH221 RNA, it can serve as a template for DNA synthesis in heterozygotic virions. After one round of retroviral replication, the structures of the recombinant proviruses were examined. Recombinants containing two, three, four, and five template switches were observed at 1.4-, 10-, 65-, and 50-fold-higher frequencies, respectively, than expected. This indicates that minus-strand recombination events are correlated and can generate proviruses with multiple template switches efficiently. The frequencies of recombinants containing multiple template switches were similar to those observed in the previous system, which allowed both minus- and plus-strand recombination. Thus, the previously reported high negative interference during retroviral recombination can be caused by correlated template switches during minus-strand DNA synthesis. In addition, all examined recombinants contained an intact PBS, indicating that most of the plus-strand DNA transfer occurs after completion of the strong-stop DNA. PMID:9445017

Typing DNA profiles from previously enhanced fingerprints using direct PCR.

PubMed

Templeton, Jennifer E L; Taylor, Duncan; Handt, Oliva; Linacre, Adrian

2017-07-01

Fingermarks are a source of human identification both through the ridge patterns and DNA profiling. Typing nuclear STR DNA markers from previously enhanced fingermarks provides an alternative method of utilising the limited fingermark deposit that can be left behind during a criminal act. Dusting with fingerprint powders is a standard method used in classical fingermark enhancement and can affect DNA data. The ability to generate informative DNA profiles from powdered fingerprints using direct PCR swabs was investigated. Direct PCR was used as the opportunity to generate usable DNA profiles after performing any of the standard DNA extraction processes is minimal. Omitting the extraction step will, for many samples, be the key to success if there is limited sample DNA. DNA profiles were generated by direct PCR from 160 fingermarks after treatment with one of the following dactyloscopic fingerprint powders: white hadonite; silver aluminium; HiFi Volcano silk black; or black magnetic fingerprint powder. This was achieved by a combination of an optimised double-swabbing technique and swab media, omission of the extraction step to minimise loss of critical low-template DNA, and additional AmpliTaq Gold ® DNA polymerase to boost the PCR. Ninety eight out of 160 samples (61%) were considered 'up-loadable' to the Australian National Criminal Investigation DNA Database (NCIDD). The method described required a minimum of working steps, equipment and reagents, and was completed within 4h. Direct PCR allows the generation of DNA profiles from enhanced prints without the need to increase PCR cycle numbers beyond manufacturer's recommendations. Particular emphasis was placed on preventing contamination by applying strict protocols and avoiding the use of previously used fingerprint brushes. Based on this extensive survey, the data provided indicate minimal effects of any of these four powders on the chance of obtaining DNA profiles from enhanced fingermarks. Copyright © 2017 Elsevier B.V. All rights reserved.

MCNP HPGe detector benchmark with previously validated Cyltran model.

PubMed

Hau, I D; Russ, W R; Bronson, F

2009-05-01

An exact copy of the detector model generated for Cyltran was reproduced as an MCNP input file and the detection efficiency was calculated similarly with the methodology used in previous experimental measurements and simulation of a 280 cm(3) HPGe detector. Below 1000 keV the MCNP data correlated to the Cyltran results within 0.5% while above this energy the difference between MCNP and Cyltran increased to about 6% at 4800 keV, depending on the electron cut-off energy.

ABOVE-THE-LOOP-TOP OSCILLATION AND QUASI-PERIODIC CORONAL WAVE GENERATION IN SOLAR FLARES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Takasao, Shinsuke; Shibata, Kazunari, E-mail: takasao@kwasan.kyoto-u.ac.jp

Observations revealed that various kinds of oscillations are excited in solar flare regions. Quasi-periodic pulsations (QPPs) in flare emissions are commonly observed in a wide range of wavelengths. Recent observations have found that fast-mode magnetohydrodynamic (MHD) waves are quasi-periodically emitted from some flaring sites (quasi-periodic propagating fast-mode magnetoacoustic waves; QPFs). Both QPPs and QPFs imply a cyclic disturbance originating from the flaring sites. However, the physical mechanisms remain puzzling. By performing a set of two-dimensional MHD simulations of a solar flare, we discovered the local oscillation above the loops filled with evaporated plasma (above-the-loop-top region) and the generation of QPFsmore » from such oscillating regions. Unlike all previous models for QPFs, our model includes essential physics for solar flares such as magnetic reconnection, heat conduction, and chromospheric evaporation. We revealed that QPFs can be spontaneously excited by the above-the-loop-top oscillation. We found that this oscillation is controlled by the backflow of the reconnection outflow. The new model revealed that flare loops and the above-the-loop-top region are full of shocks and waves, which is different from the previous expectations based on a standard flare model and previous simulations. In this paper, we show the QPF generation process based on our new picture of flare loops and will briefly discuss a possible relationship between QPFs and QPPs. Our findings will change the current view of solar flares to a new view in which they are a very dynamic phenomenon full of shocks and waves.« less

A Facile Method to Establish Human Induced Pluripotent Stem Cells From Adult Blood Cells Under Feeder-Free and Xeno-Free Culture Conditions: A Clinically Compliant Approach

PubMed Central

Chou, Bin-Kuan; Gu, Haihui; Gao, Yongxing; Dowey, Sarah N.; Wang, Ying; Shi, Jun; Li, Yanxin; Ye, Zhaohui; Cheng, Tao

2015-01-01

Reprogramming human adult blood mononuclear cells (MNCs) cells by transient plasmid expression is becoming increasingly popular as an attractive method for generating induced pluripotent stem (iPS) cells without the genomic alteration caused by genome-inserting vectors. However, its efficiency is relatively low with adult MNCs compared with cord blood MNCs and other fetal cells and is highly variable among different adult individuals. We report highly efficient iPS cell derivation under clinically compliant conditions via three major improvements. First, we revised a combination of three EBNA1/OriP episomal vectors expressing five transgenes, which increased reprogramming efficiency by ≥10–50-fold from our previous vectors. Second, human recombinant vitronectin proteins were used as cell culture substrates, alleviating the need for feeder cells or animal-sourced proteins. Finally, we eliminated the previously critical step of manually picking individual iPS cell clones by pooling newly emerged iPS cell colonies. Pooled cultures were then purified based on the presence of the TRA-1-60 pluripotency surface antigen, resulting in the ability to rapidly expand iPS cells for subsequent applications. These new improvements permit a consistent and reliable method to generate human iPS cells with minimal clonal variations from blood MNCs, including previously difficult samples such as those from patients with paroxysmal nocturnal hemoglobinuria. In addition, this method of efficiently generating iPS cells under feeder-free and xeno-free conditions allows for the establishment of clinically compliant iPS cell lines for future therapeutic applications. PMID:25742692

Knowledge of response location alone is not sufficient to generate social inhibition of return.

PubMed

Welsh, Timothy N; Manzone, Joseph; McDougall, Laura

2014-11-01

Previous research has revealed that the inhibition of return (IOR) effect emerges when individuals respond to a target at the same location as their own previous response or the previous response of a co-actor. The latter social IOR effect is thought to occur because the observation of co-actor's response evokes a representation of that action in the observer and that the observation-evoked response code subsequently activates the inhibitory mechanisms underlying IOR. The present study was conducted to determine if knowledge of the co-actor's response alone is sufficient to evoke social IOR. Pairs of participants completed responses to targets that appeared at different button locations. Button contact generated location-contingent auditory stimuli (high and low tones in Experiment 1 and colour words in Experiment 2). In the Full condition, the observer saw the response and heard the auditory stimuli. In the Auditory Only condition, the observer did not see the co-actor's response, but heard the auditory stimuli generated via button contact to indicate response endpoint. It was found that, although significant individual and social IOR effects emerged in the Full conditions, there were no social IOR effects in the Auditory Only conditions. These findings suggest that knowledge of the co-actor's response alone via auditory information is not sufficient to activate the inhibitory processes leading to IOR. The activation of the mechanisms that lead to social IOR seems to be dependent on processing channels that code the spatial characteristics of action. Copyright © 2014 Elsevier B.V. All rights reserved.

Conversion efficiency of skutterudite-based thermoelectric modules.

PubMed

Salvador, James R; Cho, Jung Y; Ye, Zuxin; Moczygemba, Joshua E; Thompson, Alan J; Sharp, Jeffrey W; Koenig, Jan D; Maloney, Ryan; Thompson, Travis; Sakamoto, Jeffrey; Wang, Hsin; Wereszczak, Andrew A

2014-06-28

Presently, the only commercially available power generating thermoelectric (TE) modules are based on bismuth telluride (Bi2Te3) alloys and are limited to a hot side temperature of 250 °C due to the melting point of the solder interconnects and/or generally poor power generation performance above this point. For the purposes of demonstrating a TE generator or TEG with higher temperature capability, we selected skutterudite based materials to carry forward with module fabrication because these materials have adequate TE performance and are mechanically robust. We have previously reported the electrical power output for a 32 couple skutterudite TE module, a module that is type identical to ones used in a high temperature capable TEG prototype. The purpose of this previous work was to establish the expected power output of the modules as a function of varying hot and cold side temperatures. Recent upgrades to the TE module measurement system built at the Fraunhofer Institute for Physical Measurement Techniques allow for the assessment of not only the power output, as previously described, but also the thermal to electrical energy conversion efficiency. Here we report the power output and conversion efficiency of a 32 couple, high temperature skutterudite module at varying applied loading pressures and with different interface materials between the module and the heat source and sink of the test system. We demonstrate a 7% conversion efficiency at the module level when a temperature difference of 460 °C is established. Extrapolated values indicate that 7.5% is achievable when proper thermal interfaces and loading pressures are used.

Beamlike photon pairs entangled by a 2x2 fiber

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lo, Hsin-Pin; Department of Electrophysics, National Chiao-Tung University, Hsinchu, 300, Taiwan; Yabushita, Atsushi

Polarization-entangled photon pairs have been widely used as a light source of quantum communication. The polarization-entangled photon pairs are generally obtained at the crossing points of the light cones that are generated from a type-II nonlinear crystal. However, it is hard to pick up the photon pairs coming out from the crossing points because of their invisible wavelength and low intensity. In our previous work, we succeeded in generating polarization-entangled photon pairs by overlapping two light paths for the photon-pair generation. The photon pairs could be entangled in all of the generated photon pairs without clipping the crossing points, evenmore » with some difficulty in its alignment to overlap the two light paths. In this paper, we have developed an optical system which generates polarization-entangled photon pairs using a beamlike photon pair, without the difficulty in alignment. The measured results show that the photon pairs generated in the system are entangled in their polarizations.« less

A source array for generating higher order acoustic modes in circular ducts

NASA Technical Reports Server (NTRS)

Wyerman, B. R.; Reethof, G.

1976-01-01

A unique source array has been developed for the generation of both spinning and non-spinning higher order modes in a circular duct. The array consists of two concentric rings of sources. Through individual control of the response of each element, the array provided phase and amplitude control in the radial as well as circumferential directions. Radial modes shapes were measured in a 12-inch diameter anechoically-terminated hollow duct. These modes could be generated at their cut-off frequency and throughout a frequency range extending to the cut-off frequency for the next higher order radial mode. Comparisons are given between theory and experiment for the generation of specific modes. The radial dependence of the measured mode shapes was enhanced considerably by the design of this array. The results indicate a significant improvement over previous mode generation mechanisms. The contamination of the generated mode by additional spurious modes is also considered for variations between individual elements within the source array.

Corrugated Textile based Triboelectric Generator for Wearable Energy Harvesting

PubMed Central

Choi, A Young; Lee, Chang Jun; Park, Jiwon; Kim, Dogyun; Kim, Youn Tae

2017-01-01

Triboelectric energy harvesting has been applied to various fields, from large-scale power generation to small electronics. Triboelectric energy is generated when certain materials come into frictional contact, e.g., static electricity from rubbing a shoe on a carpet. In particular, textile-based triboelectric energy-harvesting technologies are one of the most promising approaches because they are not only flexible, light, and comfortable but also wearable. Most previous textile-based triboelectric generators (TEGs) generate energy by vertically pressing and rubbing something. However, we propose a corrugated textile-based triboelectric generator (CT-TEG) that can generate energy by stretching. Moreover, the CT-TEG is sewn into a corrugated structure that contains an effective air gap without additional spacers. The resulting CT-TEG can generate considerable energy from various deformations, not only by pressing and rubbing but also by stretching. The maximum output performances of the CT-TEG can reach up to 28.13 V and 2.71 μA with stretching and releasing motions. Additionally, we demonstrate the generation of sufficient energy from various activities of a human body to power about 54 LEDs. These results demonstrate the potential application of CT-TEGs for self-powered systems. PMID:28349928

Corrugated Textile based Triboelectric Generator for Wearable Energy Harvesting

NASA Astrophysics Data System (ADS)

Choi, A. Young; Lee, Chang Jun; Park, Jiwon; Kim, Dogyun; Kim, Youn Tae

2017-03-01

Triboelectric energy harvesting has been applied to various fields, from large-scale power generation to small electronics. Triboelectric energy is generated when certain materials come into frictional contact, e.g., static electricity from rubbing a shoe on a carpet. In particular, textile-based triboelectric energy-harvesting technologies are one of the most promising approaches because they are not only flexible, light, and comfortable but also wearable. Most previous textile-based triboelectric generators (TEGs) generate energy by vertically pressing and rubbing something. However, we propose a corrugated textile-based triboelectric generator (CT-TEG) that can generate energy by stretching. Moreover, the CT-TEG is sewn into a corrugated structure that contains an effective air gap without additional spacers. The resulting CT-TEG can generate considerable energy from various deformations, not only by pressing and rubbing but also by stretching. The maximum output performances of the CT-TEG can reach up to 28.13 V and 2.71 μA with stretching and releasing motions. Additionally, we demonstrate the generation of sufficient energy from various activities of a human body to power about 54 LEDs. These results demonstrate the potential application of CT-TEGs for self-powered systems.

Modeling of the VIRTIS-M Observations of the Coma of Comet 67P/Churyumov-Gerasimenko

NASA Astrophysics Data System (ADS)

Fougere, Nicolas; Combi, Michael R.; Tenishev, Valeriy; Bieler, Andre; Migliorini, Alessandra; Piccioni, Giuseppe; Capaccioni, Fabrizio; Filacchione, Gianrico; Toth, Gabor; Huang, Zhenguang; Gombosi, Tamas; Hansen, Kenneth; Bockelee-Morvan, Dominique; Debout, Vincent; Erard, Stephane; Leyrat, Cedric; Fink, Uwe; Rubin, Martin; Altwegg, Kathrin; Tzou, Chia-Yu; Le Roy, Lena; Calmonte, Ursina; Berthelier, Jean-Jacques; Reme, Henri; Hassig, Myrtha; Fuselier, Stephen; Fiethe, Bjorn; De Keyser, Johan

2015-11-01

The recent images of the inner coma of 67P/Churyumov-Gerasimenko (CG) made by the infrared channel of the VIRTIS-M instrument on board the Rosetta spacecraft show the gas distribution as it expands in the coma (Migliorini et al. 2015, DPS abstract).Since VIRTIS is a remote sensing instrument, a proper modeling of these observations requires the computation of the full coma of comet CG, which necessitates the use of a kinetic approach due to the rather low gas densities. Hence, we apply a Direct Simulation Monde Carlo (DSMC) method to solve the Boltzmann equation and describe CG’s coma from the nucleus surface up to a few hundreds of kilometers. The model uses the SHAP5 nucleus shape model from the OSIRIS team. The gas flux distribution takes into account solar illumination, including self-shadowing. The local activity at the surface of the nucleus is given by spherical harmonics expansion reproducing best the ROSINA-DFMS data. The densities from the DSMC model outputs are then integrated along the line-of-sight to create synthetic images that are directly comparable with the VIRTIS-M column density measurements.The good agreement between the observations and the model illustrates our continuously improving understanding of the physics of the coma of comet CG.AcknowledgementsWork at UofM was supported by contracts JPL#1266313, JPL#1266314 and NASA grant NNX09AB59G. Work at UoB was funded by the State of Bern, the Swiss National Science Foundation and by the European Space Agency PRODEX Program. Work at Southwest Research institute was supported by subcontract #1496541 from the JPL. Work at BIRA-IASB was supported by the Belgian Science Policy Office via PRODEX/ROSINA PEA 90020. The authors would like to thank ASI, CNES, DLR, NASA for supporting this research. VIRTIS was built by a consortium formed by Italy, France and Germany, under the scientific responsibility of the IAPS of INAF, which guides also the scientific operations. The consortium includes also the LESIA of the Observatoire de Paris, and the Institut für Planetenforschung of DLR. The authors wish to thank the RSGS and the RMOC for their continuous support.

THE MASS-LOSS RETURN FROM EVOLVED STARS TO THE LARGE MAGELLANIC CLOUD. VI. LUMINOSITIES AND MASS-LOSS RATES ON POPULATION SCALES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Riebel, D.; Meixner, M.; Srinivasan, S.

We present results from the first application of the Grid of Red Supergiant and Asymptotic Giant Branch ModelS (GRAMS) model grid to the entire evolved stellar population of the Large Magellanic Cloud (LMC). GRAMS is a pre-computed grid of 80,843 radiative transfer models of evolved stars and circumstellar dust shells composed of either silicate or carbonaceous dust. We fit GRAMS models to {approx}30,000 asymptotic giant branch (AGB) and red supergiant (RSG) stars in the LMC, using 12 bands of photometry from the optical to the mid-infrared. Our published data set consists of thousands of evolved stars with individually determined evolutionarymore » parameters such as luminosity and mass-loss rate. The GRAMS grid has a greater than 80% accuracy rate discriminating between oxygen- and carbon-rich chemistry. The global dust injection rate to the interstellar medium (ISM) of the LMC from RSGs and AGB stars is on the order of 2.1 Multiplication-Sign 10{sup -5} M{sub Sun} yr{sup -1}, equivalent to a total mass injection rate (including the gas) into the ISM of {approx}6 Multiplication-Sign 10{sup -3} M{sub Sun} yr{sup -1}. Carbon stars inject two and a half times as much dust into the ISM as do O-rich AGB stars, but the same amount of mass. We determine a bolometric correction factor for C-rich AGB stars in the K{sub s} band as a function of J - K{sub s} color, BC{sub K{sub s}}= -0.40(J-K{sub s}){sup 2} + 1.83(J-K{sub s}) + 1.29. We determine several IR color proxies for the dust mass-loss rate (M-dot{sub d}) from C-rich AGB stars, such as log M-dot{sub d} = (-18.90/((K{sub s}-[8.0])+3.37) - 5.93. We find that a larger fraction of AGB stars exhibiting the 'long-secondary period' phenomenon are more O-rich than stars dominated by radial pulsations, and AGB stars without detectable mass loss do not appear on either the first-overtone or fundamental-mode pulsation sequences.« less

GIADA onboard Rosetta characterising comet 67/PChuryumov-Gerasimenko dust environment inbound to and outbound from perihelion.

NASA Astrophysics Data System (ADS)

Della Corte, Vincenzo; Rotundi, Alessandra; Fulle, Marco

2016-07-01

GIADA (Grain Impact Analyzer and Dust Accumulator) is an in-situ instrument onboard Rosetta monitoring the dust environment of comet 67P/Churyumov-Gerasimenko. GIADA is composed of 3 sub-systems: 1) the Grain Detection System, based on particle detection through light scattering; 2) the Impact Sensor, measuring particle momentum; 3) the Micro-Balances System, constituted of 5 quartz crystal microbalances, providing cumulated dust from different directions. From the combination of the measurements performed by the three subsystems we retrieve: the number, the mass, the momentum, the speed of individual dust particles and the cumulative dust flux emitted from the comet nucleus. We will present the coma dust environment as observed by GIADA during the pre-landing and escort phases of the Rosetta space mission. GIADA was able to detect temporal and spatial variation of dust density distribution and to disentangle different types of impacting dust particles. Specific high dust spatial density sectors of the coma have been identified and their evolution with respect to the heliocentric distance was studied. From August 2014 to December 2015, i.e. inbound, at and outbound perihelion, Rosetta performed different trajectories around the nucleus and flybys with different close approach distances, different coordinates of the sub-spacecraft point and different observing geometry (phase angle), allowed GIADA to characterize the dust environment within the 67P/C-G coma and its temporal variation. Acknowledgements. GIADA was built by a consortium led by the Univ. Napoli "Parthenope" & INAF- Oss. Astr. Capodimonte, IT, in collaboration with the Inst. de Astrofisica de Andalucia, ES, Selex-ES s.p.a. and SENER. GIADA is presently managed & operated by Ist. di Astrofisica e Planetologia Spaziali-INAF, IT. GIADA was funded and managed by the Agenzia Spaziale Italiana, IT, with a support of the Spanish Ministry of Education and Science MEC, ES. GIADA was developed from a PI proposal supported by the University of Kent; sci. & tech. contribution given by CISAS, IT, Lab. d'Astr. Spat., FR, and Institutions from UK, IT, FR, DE and USA. We thank the RSGS/ESAC, RMOC/ESOC & Rosetta Project/ESTEC for their outstanding work. Science support provided by NASA through the US Rosetta Project managed by JPL/California Institute of Technology. GIADA calibrated data will be available through the ESA's PSA web site.

GIADA On-Board Rosetta: Early Dust Grain Detections and Dust Coma Characterization of Comet 67P/C-G

NASA Astrophysics Data System (ADS)

Rotundi, A.; Della Corte, V.; Accolla, M.; Ferrari, M.; Ivanovski, S.; Lucarelli, F.; Mazzotta Epifani, E.; Sordini, R.; Palumbo, P.; Colangeli, L.; Lopez-Moreno, J. J.; Rodriguez, J.; Fulle, M.; Bussoletti, E.; Crifo, J. F.; Esposito, F.; Green, S.; Grün, E.; Lamy, P. L.; McDonnell, T.; Mennella, V.; Molina, A.; Moreno, F.; Ortiz, J. L.; Palomba, E.; Perrin, J. M.; Rodrigo, R.; Weissman, P. R.; Zakharov, V.; Zarnecki, J.

2014-12-01

GIADA (Grain Impact Analyzer and Dust Accumulator) flying on-board Rosetta is devoted to study the cometary dust environment of 67P/Churiumov-Gerasimenko. GIADA is composed of 3 sub-systems: the GDS (Grain Detection System), based on grain detection through light scattering; an IS (Impact Sensor), giving momentum measurement detecting the impact on a sensed plate connected with 5 piezoelectric sensors; the MBS (MicroBalances System), constituted of 5 Quartz Crystal Microbalances (QCMs), giving cumulative deposited dust mass by measuring the variations of the sensors' frequency. The combination of the measurements performed by these 3 subsystems provides: the number, the mass, the momentum and the velocity distribution of dust grains emitted from the cometary nucleus.No prior in situ dust dynamical measurements at these close distances from the nucleus and starting from such large heliocentric distances are available up to date. We present here the first results obtained from the beginning of the Rosetta scientific phase. We will report dust grains early detection at about 800 km from the nucleus in August 2014 and the following measurements that allowed us characterizing the 67P/C-G dust environment at distances less than 100 km from the nucleus and single grains dynamical properties. Acknowledgements. GIADA was built by a consortium led by the Univ. Napoli "Parthenope" & INAF-Oss. Astr. Capodimonte, IT, in collaboration with the Inst. de Astrofisica de Andalucia, ES, Selex-ES s.p.a. and SENER. GIADA is presently managed & operated by Ist. di Astrofisica e Planetologia Spaziali-INAF, IT. GIADA was funded and managed by the Agenzia Spaziale Italiana, IT, with a support of the Spanish Ministry of Education and Science MEC, ES. GIADA was developped from a PI proposal supported by the University of Kent; sci. & tech. contribution given by CISAS, IT, Lab. d'Astr. Spat., FR, and Institutions from UK, IT, FR, DE and USA. We thank the RSGS/ESAC, RMOC/ESOC & Rosetta Project/ESTEC for their outstanding work. Science support provided by NASA through the US Rosetta Project managed by JPL/California Institute of Technology. GIADA calibrated data will be available through the ESA's PSA web site (www.rssd.esa.int/index.php?project=PSA&page=index). Thanks Angioletta.

TSARINA: A Computer Model for Assessing Conventional and Chemical Attacks on Airbases

DTIC Science & Technology

1990-09-01

IV, and has been updated to FORTRAN 77; it has been adapted to various computer systems, as was the widely used AIDA model and the previous versions of...conventional and chemical attacks on sortie generation. In the first version of TSARINA [1 2], several key additions were made to the AIDA model so that (1...various on-base resources, in addition to the estimates of hits and facility damage that are generated by the original AIDA model . The second version

A Compact 700-KV Erected Pulse Forming Network for HPM Applications (Postprint)

DTIC Science & Technology

2011-04-28

previously investigated for driving rail guns , electric launchers, or other nonlinear loads albeit for much longer pulse lengths [8]. In this version...The output of the generator was connected to a coaxial CuS04 resistor through 100-ft of coaxial high-voltage cable. The current pulse on the cable was...shown in Figure 6. This pulse was delivered to a 50-ohm cable and measured by a coaxial inline CVR at the generator output. Typical pulse

Newly discovered geological features and their potential impact on Darlington and Pickering. Report No. INFO-0342

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wallach, J.L.

1990-01-01

The design basis seismic ground motion for the nuclear generating stations at Darlington and at Pickering were determined solely through the assessment of previous earthquakes with no geological, or any other geophysical, input. Since then geophysical maps, showing a north-northwest oriented linear feature with some possible associated seismic activity, were examined. This report discusses the impact of these new discoveries on the Darlington and Pickering nuclear generating stations and on the already known geophysical features of the area.

Mini- and microgenerators applicable in the MEMS technology

NASA Astrophysics Data System (ADS)

Fiala, P.; Szabo, Z.; Marcon, P.; Roubal, Z.

2017-06-01

The article presents certain general conclusions obtained from an investigation of a vibration-powered milli- or microgenerator functioning as a harvester. In this context, the authors summarize the parameters that are critical in designing optimal generators to retrieve the residual energy contained in an electromechanical system and transferred through the vibrations of an independent structure. The discussion exploits our previous results, which theoretically define the properties characterizing the models of individual basic configurations of a generator based on Faraday's law of induction.

On the Generation of Intermediate Number Squeezed State of the Quantized Radiation Field

NASA Astrophysics Data System (ADS)

Baseia, B.; de Lima, A. F.; Bagnato, V. S.

Recently, a new state of the quantized radiation field — the intermediate number squeezed state (INSS) — has been introduced in the literature: it interpolates between the number state |n> and the squeezed state |z, α>=Ŝ(z)|α>, and exhibits interesting nonclassical properties as antibunching, sub-Poissonian statistics and squeezing. Here we introduce a slight modification in the previous definition allowing us a proposal to generate the INSS. Nonclassical properties using a new set of parameters are also studied.

Harmful Algal Blooms Research

EPA Science Inventory

This project represents the Agency’s first effort to unify harmful algal blooms (HABs) research that had been previously carried out in isolation within various laboratories. A unified program is the most efficient way generate useful results for the Agency’s decision...

Research implementation of the SMART SIGNAL system on Trunk Highway (TH) 13.

DOT National Transportation Integrated Search

2013-02-01

In our previous research, the SMART-SIGNAL (Systematic Monitoring of Arterial Road Traffic and Signals) : system that can collect event-based traffic data and generate comprehensive performance measures has been : successfully developed by the Univer...

300 East Randolph, December 2010, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Field gamma measurements within the excavation and the spoil materials generated during theexcavation process did not exceed the respective threshold values previously stated and generallyranged from 4,050 cpm to 9,690 cpm with the unshielded probe.

Absorption machine with desorber-resorber

DOEpatents

Biermann, Wendell J.

1985-01-01

An absorption refrigeration system utilizing a low temperature desorber and intermediate temperature resorber. The system operates at three temperatures and three pressures to increase the efficiency of the system and is capable of utilizing a lower generator temperature than previously used.

441 E Ontario, August 2010, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gammameasurements within the excavation and the spoil materials generated during the excavation process did notexceed the respective threshold values previously stated and ranged from a minimum of 5,200 cpm to amaximum of 9,200 cpm.

502 N Peshtigo, October 2010, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation andthe spoil materials generated during the excavation process did not exceed the respective thresholdvalues previously stated and ranged from a minimum of 690 cpm to a maximum of 6,950 cpm.

GeneratorSE: A Sizing Tool for Variable-Speed Wind Turbine Generators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sethuraman, Latha; Dykes, Katherine L

This report documents a set of analytical models employed by the optimization algorithms within the GeneratorSE framework. The initial values and boundary conditions employed for the generation of the various designs and initial estimates for basic design dimensions, masses, and efficiency for the four different models of generators are presented and compared with empirical data collected from previous studies and some existing commercial turbines. These models include designs applicable for variable-speed, high-torque application featuring direct-drive synchronous generators and low-torque application featuring induction generators. In all of the four models presented, the main focus of optimization is electromagnetic design with themore » exception of permanent-magnet and wire-wound synchronous generators, wherein the structural design is also optimized. Thermal design is accommodated in GeneratorSE as a secondary attribute by limiting the winding current densities to acceptable limits. A preliminary validation of electromagnetic design was carried out by comparing the optimized magnetic loading against those predicted by numerical simulation in FEMM4.2, a finite-element software for analyzing electromagnetic and thermal physics problems for electrical machines. For direct-drive synchronous generators, the analytical models for the structural design are validated by static structural analysis in ANSYS.« less

Expanded subgenomic mRNA transcriptome and coding capacity of a nidovirus

PubMed Central

Di, Han; Madden, Joseph C.; Morantz, Esther K.; Tang, Hsin-Yao; Graham, Rachel L.; Baric, Ralph S.

2017-01-01

Members of the order Nidovirales express their structural protein ORFs from a nested set of 3′ subgenomic mRNAs (sg mRNAs), and for most of these ORFs, a single genomic transcription regulatory sequence (TRS) was identified. Nine TRSs were previously reported for the arterivirus Simian hemorrhagic fever virus (SHFV). In the present study, which was facilitated by next-generation sequencing, 96 SHFV body TRSs were identified that were functional in both infected MA104 cells and macaque macrophages. The abundance of sg mRNAs produced from individual TRSs was consistent over time in the two different cell types. Most of the TRSs are located in the genomic 3′ region, but some are in the 5′ ORF1a/1b region and provide alternative sources of nonstructural proteins. Multiple functional TRSs were identified for the majority of the SHFV 3′ ORFs, and four previously identified TRSs were found not to be the predominant ones used. A third of the TRSs generated sg mRNAs with variant leader–body junction sequences. Sg mRNAs encoding E′, GP2, or ORF5a as their 5′ ORF as well as sg mRNAs encoding six previously unreported alternative frame ORFs or 14 previously unreported C-terminal ORFs of known proteins were also identified. Mutation of the start codon of two C-terminal ORFs in an infectious clone reduced virus yield. Mass spectrometry detected one previously unreported protein and suggested translation of some of the C-terminal ORFs. The results reveal the complexity of the transcriptional regulatory mechanism and expanded coding capacity for SHFV, which may also be characteristic of other nidoviruses. PMID:29073030

240 E Ontario St, September 2011, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Unshielded field gamma measurements within theexcavation and the spoil materials generated during the excavation process did not exceed the respectivethreshold values previously stated and ranged from a minimum of 7,500 cpm to a maximum of 8,100 cpm.

Dissociative Identity Disorder

ERIC Educational Resources Information Center

Schmidt, Tom

2007-01-01

Few psychological disorders in the Diagnostic Statistical Manual have generated as much controversy as Dissociative Identity Disorder (DID). For the past 35 years diagnoses of DID, previously referred to as Multiple Personality Disorder (MPD), have increased exponentially, causing various psychological researchers and clinicians to question the…

222 North Columbus Dr., August 2010, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation andthe spoil materials generated during the excavation process did not exceed the respective thresholdvalues previously stated and ranged from a minimum of 2,200 cpm to a maximum of 3,500 cpm.

425 E Randolph, August 2010, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation andthe spoil materials generated during the excavation process did not exceed the respective thresholdvalues previously stated and ranged from a minimum of 1,800 cpm to a maximum of 4,900 cpm.

248 E. South Water, August 2010, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation andthe spoil materials generated during the excavation process did not exceed the respective thresholdvalues previously stated and ranged from a minimum of 1,600 cpm to a maximum of 2,900 cpm.

200 N Columbus Dr, August 2010, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation andthe spoil materials generated during the excavation process did not exceed the respective thresholdvalues previously stated and ranged from a minimum of 2,500 cpm to a maximum of 3,300 cpm.

301 E South Water, August 2010, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation andthe spoil materials generated during the excavation process did not exceed the respective thresholdvalues previously stated and ranged from a minimum of 2,200 cpm to a maximum of 4,500 cpm.

151 N. Field Blvd., August 2010, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within theexcavation and the spoil materials generated during the excavation process did not exceed therespective threshold values previously stated and ranged from a minimum of 2,400 cpm to amaximum of 3,000 cpm.

426 East Grand Ave, October 2010, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation andthe spoil materials generated during the excavation process did not exceed the respective thresholdvalues previously stated and ranged from a minimum of 740 cpm to a maximum of 5,930 cpm.

400 E. Monroe, January 2011, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The fieldgamma measurements within the excavation and the spoil materials generated during the excavationprocess did not exceed the respective threshold values previously stated and ranged from a minimum of4,867 cpm to a maximum of 7,351 cpm.

641 N Michigan, September 2011, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The unshielded field gamma measurements within the spoil matehals generated during the drilling processdid not exceed the respective threshold values previously stated and ranged from background levels of 4,000cpm to a maximum of about 8,000 cpm.

Some Mid-Life Ruminations on the Human Capacity to Transcend One's Acculturation.

ERIC Educational Resources Information Center

Rousseve, Ronald J.

1983-01-01

The dialectical capacity of human consciousness enables us to generate alternatives in opposition to previous conditioning. Transcending one's acculturation need not leave one searching for gurus. Authentic personal meaning may be attained from an existential reawakening. (RM)

400 E Randolph, August 2010, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation andthe spoil materials generated during the excavation process did not exceed the respective thresholdvalues previously stated and ranged from a minimum of 1,600 cpm to a maximum of 4,200 cpm.

400 E North Water, August 2010, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurements within the excavation andthe spoil materials generated during the excavation process did not exceed the respective thresholdvalues previously stated and ranged from a minimum of 2,400 cpm to a maximum of 4,500 cpm.

512 N McClurg, August 2010, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The field gamma measurementswithin the excavation and the spoil materials generated during the excavation process did not exceed therespective threshold values previously stated and ranged from a minimum of 6,500 cpm to a maximum of9,500 cpm.

From prediction error to incentive salience: mesolimbic computation of reward motivation

PubMed Central

Berridge, Kent C.

2011-01-01

Reward contains separable psychological components of learning, incentive motivation and pleasure. Most computational models have focused only on the learning component of reward, but the motivational component is equally important in reward circuitry, and even more directly controls behavior. Modeling the motivational component requires recognition of additional control factors besides learning. Here I will discuss how mesocorticolimbic mechanisms generate the motivation component of incentive salience. Incentive salience takes Pavlovian learning and memory as one input and as an equally important input takes neurobiological state factors (e.g., drug states, appetite states, satiety states) that can vary independently of learning. Neurobiological state changes can produce unlearned fluctuations or even reversals in the ability of a previously-learned reward cue to trigger motivation. Such fluctuations in cue-triggered motivation can dramatically depart from all previously learned values about the associated reward outcome. Thus a consequence of the difference between incentive salience and learning can be to decouple cue-triggered motivation of the moment from previously learned values of how good the associated reward has been in the past. Another consequence can be to produce irrationally strong motivation urges that are not justified by any memories of previous reward values (and without distorting associative predictions of future reward value). Such irrationally strong motivation may be especially problematic in addiction. To comprehend these phenomena, future models of mesocorticolimbic reward function should address the neurobiological state factors that participate to control generation of incentive salience. PMID:22487042

Requirement for CD4 T Cell Help in Generating Functional CD8 T Cell Memory

NASA Astrophysics Data System (ADS)

Shedlock, Devon J.; Shen, Hao

2003-04-01

Although primary CD8 responses to acute infections are independent of CD4 help, it is unknown whether a similar situation applies to secondary responses. We show that depletion of CD4 cells during the recall response has minimal effect, whereas depletion during the priming phase leads to reduced responses by memory CD8 cells to reinfection. Memory CD8 cells generated in CD4+/+ mice responded normally when transferred into CD4-/- hosts, whereas memory CD8 cells generated in CD4-/- mice mounted defective recall responses in CD4+/+ adoptive hosts. These results demonstrate a previously undescribed role for CD4 help in the development of functional CD8 memory.

Communication enabled – fast acting imbalance reserve (CE-FAIR)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilches-Bernal, Felipe; Concepcion, Ricky; Neely, Jason C.

This letter presents a new frequency control strategy that takes advantage of communications and fast responding resources like PV generation, energy storage, wind generation, and demand response, termed collectively as converter interfaced generators (CIGs). The proposed approach uses an active monitoring of power imbalances to rapidly redispatch CIGs. This approach differs from previously proposed frequency control schemes in that it employs feed-forward control based on a measured power imbalance rather that relying on a frequency measurement. As a result, time-domain simulations of the full Western Electricity Coordinating Council (WECC) system are conducted to demonstrate the effectiveness of the proposed method,more » showing improved performance.« less

Numerical computation of complex multi-body Navier-Stokes flows with applications for the integrated Space Shuttle launch vehicle

NASA Technical Reports Server (NTRS)

Chan, William M.

1993-01-01

An enhanced grid system for the Space Shuttle Orbiter was built by integrating CAD definitions from several sources and then generating the surface and volume grids. The new grid system contains geometric components not modeled previously plus significant enhancements on geometry that has been modeled in the old grid system. The new orbiter grids were then integrated with new grids for the rest of the launch vehicle. Enhancements were made to the hyperbolic grid generator HYPGEN and new tools for grid projection, manipulation, and modification, Cartesian box grid and far field grid generation and post-processing of flow solver data were developed.

Interface Generation and Compositional Verification in JavaPathfinder

NASA Technical Reports Server (NTRS)

Giannakopoulou, Dimitra; Pasareanu, Corina

2009-01-01

We present a novel algorithm for interface generation of software components. Given a component, our algorithm uses learning techniques to compute a permissive interface representing legal usage of the component. Unlike our previous work, this algorithm does not require knowledge about the component s environment. Furthermore, in contrast to other related approaches, our algorithm computes permissive interfaces even in the presence of non-determinism in the component. Our algorithm is implemented in the JavaPathfinder model checking framework for UML statechart components. We have also added support for automated assume-guarantee style compositional verification in JavaPathfinder, using component interfaces. We report on the application of the presented approach to the generation of interfaces for flight software components.

Electrostatic micromembrane actuator arrays as motion generator

NASA Astrophysics Data System (ADS)

Wu, X. T.; Hui, J.; Young, M.; Kayatta, P.; Wong, J.; Kennith, D.; Zhe, J.; Warde, C.

2004-05-01

A rigid-body motion generator based on an array of micromembrane actuators is described. Unlike previous microelectromechanical systems (MEMS) techniques, the architecture employs a large number (typically greater than 1000) of micron-sized (10-200 μm) membrane actuators to simultaneously generate the displacement of a large rigid body, such as a conventional optical mirror. For optical applications, the approach provides optical design freedom of MEMS mirrors by enabling large-aperture mirrors to be driven electrostatically by MEMS actuators. The micromembrane actuator arrays have been built using a stacked architecture similar to that employed in the Multiuser MEMS Process (MUMPS), and the motion transfer from the arrayed micron-sized actuators to macro-sized components was demonstrated.

Application of a liquid crystal spatial light modulator to laser marking.

PubMed

Parry, Jonathan P; Beck, Rainer J; Shephard, Jonathan D; Hand, Duncan P

2011-04-20

Laser marking is demonstrated using a nanosecond (ns) pulse duration laser in combination with a liquid crystal spatial light modulator to generate two-dimensional patterns directly onto thin films and bulk metal surfaces. Previous demonstrations of laser marking with such devices have been limited to low average power lasers. Application in the ns regime enables more complex, larger scale marks to be generated with more widely available and industrially proven laser systems. The dynamic nature of the device is utilized to improve mark quality by reducing the impact of the inherently speckled intensity distribution across the generated image and reduce thermal effects in the marked surface. © 2011 Optical Society of America

A simplified analytic form for generation of axisymmetric plasma boundaries

DOE PAGES

Luce, Timothy C.

2017-02-23

An improved method has been formulated for generating analytic boundary shapes as input for axisymmetric MHD equilibria. This method uses the family of superellipses as the basis function, as previously introduced. The improvements are a simplified notation, reduction of the number of simultaneous nonlinear equations to be solved, and the realization that not all combinations of input parameters admit a solution to the nonlinear constraint equations. The method tests for the existence of a self-consistent solution and, when no solution exists, it uses a deterministic method to find a nearby solution. As a result, examples of generation of boundaries, includingmore » tests with an equilibrium solver, are given.« less

Novel foamy origin for singlet fermion masses

NASA Astrophysics Data System (ADS)

Ellis, John; Mavromatos, Nick E.; Nanopoulos, Dimitri V.

2017-10-01

We show how masses for singlet fermions can be generated by interactions with a D-particle model of space-time foam inspired by brane theory. It has been shown previously by one of the authors (N. E. M.) that such interactions may generate dynamically small masses for charged fermions via the recoils of D-particle defects interacting with photons. In this work we consider the direct interactions of D-particle with uncharged singlet fermions such as right-handed neutrinos. Quantum fluctuations of the lattice of D-particles have massless vector (spin-one) excitations that are analogues of phonons. These mediate forces with the singlet fermions, generating large dynamical masses that may be communicated to light neutrinos via the seesaw mechanism.

Focusing X-Ray Telescopes

NASA Technical Reports Server (NTRS)

O'Dell, Stephen; Brissenden, Roger; Davis, William; Elsner, Ronald; Elvis, Martin; Freeman, Mark; Gaetz, Terrance; Gorenstein, Paul; Gubarev, Mikhall; Jerlus, Diab;

Communication enabled – fast acting imbalance reserve (CE-FAIR)

DOE PAGES

Wilches-Bernal, Felipe; Concepcion, Ricky; Neely, Jason C.; ...

2017-06-08

This letter presents a new frequency control strategy that takes advantage of communications and fast responding resources like PV generation, energy storage, wind generation, and demand response, termed collectively as converter interfaced generators (CIGs). The proposed approach uses an active monitoring of power imbalances to rapidly redispatch CIGs. This approach differs from previously proposed frequency control schemes in that it employs feed-forward control based on a measured power imbalance rather that relying on a frequency measurement. As a result, time-domain simulations of the full Western Electricity Coordinating Council (WECC) system are conducted to demonstrate the effectiveness of the proposed method,more » showing improved performance.« less

A simplified analytic form for generation of axisymmetric plasma boundaries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luce, Timothy C.

An improved method has been formulated for generating analytic boundary shapes as input for axisymmetric MHD equilibria. This method uses the family of superellipses as the basis function, as previously introduced. The improvements are a simplified notation, reduction of the number of simultaneous nonlinear equations to be solved, and the realization that not all combinations of input parameters admit a solution to the nonlinear constraint equations. The method tests for the existence of a self-consistent solution and, when no solution exists, it uses a deterministic method to find a nearby solution. As a result, examples of generation of boundaries, includingmore » tests with an equilibrium solver, are given.« less

A 30-Year Study of 3 Generations at High Risk and Low Risk for Depression.

PubMed

Weissman, Myrna M; Berry, Obianuju O; Warner, Virginia; Gameroff, Marc J; Skipper, Jamie; Talati, Ardesheer; Pilowsky, Daniel J; Wickramaratne, Priya

2016-09-01

The increased risk of major depression in the offspring of depressed parents is well known. Whether the risk is transmitted beyond 2 generations is less well known. To our knowledge, no published study with direct interviews of family members and the generations in the age of risk for depression has evaluated beyond 2 generations. This information is important for detecting individuals at highest risk who may benefit from early intervention. To examine the familial aggregation of psychiatric disorder and functioning in grandchildren by their biological parents' and grandparents' depression status. Longitudinal retrospective cohort family study of 251 grandchildren (generation 3 [mean age, 18 years]) interviewed a mean of 2.0 times and their biological parents (generation 2) interviewed a mean of 4.6 times and grandparents (generation 1) interviewed up to 30 years. The study dates were January 1982 (wave 1) to June 2015 (wave 6). Cumulative rates of psychiatric disorders and functioning collected for all generations by clinically trained interviewers and best-estimate diagnosis made blind to diagnoses in members of previous generations. There were 91 families (G1) in the original sample, of whom 77 were eligible for inclusion (had a grandchild older than 5 years), and 80.5% (62 of 77) participated in the study. When first examining only 2 generations, the biological children (generation 3) of depressed compared with nondepressed parents (generation 2) had 2-fold increased risk for major depressive disorder (MDD) (hazard ratio [HR], 2.02; 95% CI, 1.08-3.79; P = .03), any disruptive disorder (HR, 1.70; 95% CI, 1.05-2.75; P = .03), substance dependence (HR, 2.96; 95% CI, 1.24-7.08; P = .01), any suicidal ideation or gesture (HR, 2.44; 95% CI, 1.28-4.66; P = .007), and poor functioning (F = 38.25, P < .001). When 3 generations were examined stratified by parental and grandparental depression status, association of a parent's MDD on the grandchild's MDD but not other disorders varied with the grandparent's depression status: grandchildren with both a depressed parent and grandparent (n = 38) were at highest risk for MDD. Among grandchildren without a depressed grandparent, those with (n = 14) vs without (n = 74) a depressed parent had overall poorer functioning (F = 6.31, P = .01) but not higher rates of any of the disorders. Potential confounding variables did not have a meaningful effect on the association between grandchild outcomes and parental or grandparental depression. In this study, biological offspring with 2 previous generations affected with major depression were at highest risk for major depression, suggesting the potential value of determining family history of depression in children and adolescents beyond 2 generations. Early intervention in offspring of 2 generations affected with moderate to severely impairing MDD seems warranted. The specificity of the transmission of depression across 3 generations may make this group a homogeneous sample for biological marker studies.

Cycle analysis of planar SOFC power generation with serial connection of low and high temperature SOFCs

NASA Astrophysics Data System (ADS)

Araki, Takuto; Ohba, Takahiro; Takezawa, Shinya; Onda, Kazuo; Sakaki, Yoshinori

Solid oxide fuel cells (SOFCs) can be composed of solid components for stable operation, and high power generation efficiency is obtained by using high temperature exhaust heat for fuel reforming and bottoming power generation by a gas turbine. Recently, low-temperature SOFCs, which run in the temperature range of around 600 °C or above and give high power generation efficiency, have been developed. On the other hand, a power generation system with multi-staged fuel cells has been proposed by the United States DOE to obtain high efficiency. In our present study, a power generation system consisting of two-staged SOFCs with serial connection of low and high temperature SOFCs was investigated. Overpotential data for the low-temperature SOFC used in this study are based on recently published data, while data for high-temperature SOFC are based on our previous study. The numerical results show that the power generation efficiency of the two-staged SOFCs is 50.3% and the total efficiency of power generation with gas turbine is 56.1% under standard operating conditions. These efficiencies are a little higher than those by high-temperature SOFC only.

Cross-generational THC exposure alters the developmental sensitivity of ventral and dorsal striatal gene expression in male and female offspring

PubMed Central

Szutorisz, Henrietta; Egervari, Gabor; Sperry, James; Carter, Jenna M.; Hurd, Yasmin L.

2016-01-01

Cannabis (Cannabis sativa, Cannabis indica) is the illicit drug most frequently abused by young men and women. The growing use of the drug has raised attention not only on the impact of direct exposure on the developing brain and behavior later in life, but also on potential cross-generational consequences. Our previous work demonstrated that adolescent exposure to Δ9-tetrahydrocannabinol (THC), the main psychoactive component of cannabis, affects reward-related behavior and striatal gene expression in male offspring that were unexposed to the drug during their own lifespan. The significant sex differences documented for most addiction and psychiatric disorders suggest that understanding the perturbation of the brain in the two sexes due to cannabis could provide insights about neuronal systems underpinning vulnerability to psychiatric illnesses. In the current study, we expanded our previous observations in males by analyzing the female brain for specific aberrations associated with cross-generational THC exposure. Based on the impact of adolescent development on subsequent adult behavioral pathology, we examined molecular patterns during both adolescence and adulthood. The results revealed a switch from the ventral striatum during adolescence to the dorsal striatum in adulthood in alterations of gene expression related to synaptic plasticity in both sexes. Females, however, exhibited stronger correlation patterns between genes and also showed locomotor disturbances not evident in males. Overall, the findings demonstrate cross-generational consequences of parental THC exposure in both male and female offspring. PMID:27221226

Sensitivity study of the Storegga Slide tsunami using retrogressive and visco-plastic rheology models

NASA Astrophysics Data System (ADS)

Kim, Jihwan; Løvholt, Finn

2016-04-01

Enormous submarine landslides having volumes up to thousands of km3 and long run-out may cause tsunamis with widespread effects. Clay-rich landslides, such as Trænadjupet and Storegga offshore Norway commonly involve retrogressive mass and momentum release mechanisms that affect the tsunami generation. As a consequence, the failure mechanisms, soil parameters, and release rate of the retrogression are of importance for the tsunami generation. Previous attempts to model the tsunami generation due to retrogressive landslides are few, and limited to idealized conditions. Here, a visco-plastic model including additional effects such as remolding, time dependent mass release, and hydrodynamic resistance, is employed for simulating the Storegga Slide. As landslide strength parameters and their evolution in time are uncertain, it is necessary to conduct a sensitivity study to shed light on the tsunamigenic processes. The induced tsunami is simulated using Geoclaw. We also compare our tsunami simulations with recent analysis conducted using a pure retrogressive model for the landslide, as well as previously published results using a block model. The availability of paleotsunami run-up data and detailed slide deposits provides a suitable background for improved understanding of the slide mechanics and tsunami generation. The research leading to these results has received funding from the Research Council of Norway under grant number 231252 (Project TsunamiLand) and the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement 603839 (Project ASTARTE).

CRISPR/Cas9-Mediated Genomic Deletion of the Beta-1, 4 N-acetylgalactosaminyltransferase 1 Gene in Murine P19 Embryonal Carcinoma Cells Results in Low Sensitivity to Botulinum Neurotoxin Type C.

PubMed

Tsukamoto, Kentaro; Ozeki, Chikako; Kohda, Tomoko; Tsuji, Takao

2015-01-01

Botulinum neurotoxins produced by Clostridium botulinum cause flaccid paralysis by inhibiting neurotransmitter release at peripheral nerve terminals. Previously, we found that neurons derived from the murine P19 embryonal carcinoma cell line exhibited high sensitivity to botulinum neurotoxin type C. In order to prove the utility of P19 cells for the study of the intracellular mechanism of botulinum neurotoxins, ganglioside-knockout neurons were generated by deletion of the gene encoding beta-1,4 N-acetylgalactosaminyltransferase 1 in P19 cells using the clustered regularly interspaced short palindromic repeats combined with Cas9 (CRISPR/Cas9) system. By using this system, knockout cells could be generated more easily than with previous methods. The sensitivity of the generated beta-1,4 N-acetylgalactosaminyltransferase 1-depleted P19 neurons to botulinum neurotoxin type C was decreased considerably, and the exogenous addition of the gangliosides GD1a, GD1b, and GT1b restored the susceptibility of P19 cells to botulinum neurotoxin type C. In particular, addition of a mixture of these three ganglioside more effectively recovered the sensitivity of knockout cells compared to independent addition of GD1a, GD1b, or GT1b. Consequently, the genome-edited P19 cells generated by the CRISPR/Cas9 system were useful for identifying and defining the intracellular molecules involved in the toxic action of botulinum neurotoxins.

Can virtual reality improve anatomy education? A randomised controlled study of a computer-generated three-dimensional anatomical ear model.

PubMed

Nicholson, Daren T; Chalk, Colin; Funnell, W Robert J; Daniel, Sam J

2006-11-01

The use of computer-generated 3-dimensional (3-D) anatomical models to teach anatomy has proliferated. However, there is little evidence that these models are educationally effective. The purpose of this study was to test the educational effectiveness of a computer-generated 3-D model of the middle and inner ear. We reconstructed a fully interactive model of the middle and inner ear from a magnetic resonance imaging scan of a human cadaver ear. To test the model's educational usefulness, we conducted a randomised controlled study in which 28 medical students completed a Web-based tutorial on ear anatomy that included the interactive model, while a control group of 29 students took the tutorial without exposure to the model. At the end of the tutorials, both groups were asked a series of 15 quiz questions to evaluate their knowledge of 3-D relationships within the ear. The intervention group's mean score on the quiz was 83%, while that of the control group was 65%. This difference in means was highly significant (P < 0.001). Our findings stand in contrast to the handful of previous randomised controlled trials that evaluated the effects of computer-generated 3-D anatomical models on learning. The equivocal and negative results of these previous studies may be due to the limitations of these studies (such as small sample size) as well as the limitations of the models that were studied (such as a lack of full interactivity). Given our positive results, we believe that further research is warranted concerning the educational effectiveness of computer-generated anatomical models.

Observations and modelling of a meteotsunami across the English Channel on 23rd June 2016

NASA Astrophysics Data System (ADS)

Williams, David; Horsburgh, Kevin; Schultz, David; Hughes, Chris

2017-04-01

Meteotsunami are shallow water waves in the tsunami frequency band, which are generated by sub-mesoscale pressure and wind velocity fluctuations. Whilst documented meteotsunami on the north-western European shelf have not been hazardous, around the world they have caused fatalities and significant economic losses. Previous observational studies suggest that across Western Europe strongly convective storms are meteotsunami-generating. We give evidence for a meteotsunami on 23rd June 2016 along the northern coastline of France, following strongly convective storms. This includes 1-minute temporal resolution tide gauge data, in situ pressure and wind velocities, and infrared satellite images. With an estimated wave height of 0.8 m at Boulogne, this meteotsunami is particularly large compared to previous observations in Western Europe. The tsunami travel times have been estimated using the wavefront method, showing that a single, instantaneous source for the waves is highly unlikely. Using the ocean model Telemac2D, idealised models of pressure and wind have been used to simulate the meteotsunami. The model supports that across the English Channel thunderstorms with north-easterly tracks, moving at the shallow water wave speed, can generate wave amplification through Proudman resonance. The Weather Research and Forecasting (WRF) model has been used to produce numerically simulated thunderstorms, which have been used to force the Telemac2D ocean model with idealised bathymetries. The WRF-Telemac2D model results also support meteotsunami generation by thunderstorms. To the author's knowledge this is the first time a thunderstorm simulation has been used to produce a meteotsunami-like wave, and indicates that non-hydrostatic, convective atmospheric processes are important for meteotsunami generation. This suggests that with combined high resolution observations and modelling, a meteotsunami forecasting system may become possible in Western Europe.

Development of Advanced Stirling Radioisotope Generator for Space Exploration

NASA Technical Reports Server (NTRS)

Chan, Jack; Wood, J. Gary; Schreiber, Jeffrey G.

2007-01-01

Under the joint sponsorship of the Department of Energy and NASA, a radioisotope power system utilizing Stirling power conversion technology is being developed for potential future space missions. The higher conversion efficiency of the Stirling cycle compared with that of Radioisotope Thermoelectric Generators (RTGs) used in previous missions (Viking, Pioneer, Voyager, Galileo, Ulysses, Cassini, and New Horizons) offers the advantage of a four-fold reduction in PuO2 fuel, thereby saving cost and reducing radiation exposure to support personnel. With the advancement of state-of-the-art Stirling technology development under the NASA Research Announcement (NRA) project, the Stirling Radioisotope Generator program has evolved to incorporate the advanced Stirling convertor (ASC), provided by Sunpower, into an engineering unit. Due to the reduced envelope and lighter mass of the ASC compared to the previous Stirling convertor, the specific power of the flight generator is projected to increase from 3.5 to 7 We/kg, along with a 25 percent reduction in generator length. Modifications are being made to the ASC design to incorporate features for thermal, mechanical, and electrical integration with the engineering unit. These include the heat collector for hot end interface, cold-side flange for waste heat removal and structural attachment, and piston position sensor for ASC control and power factor correction. A single-fault tolerant, active power factor correction controller is used to synchronize the Stirling convertors, condition the electrical power from AC to DC, and to control the ASCs to maintain operation within temperature and piston stroke limits. Development activities at Sunpower and NASA Glenn Research Center (GRC) are also being conducted on the ASC to demonstrate the capability for long life, high reliability, and flight qualification needed for use in future missions.

Improved object optimal synthetic description, modeling, learning, and discrimination by GEOGINE computational kernel

NASA Astrophysics Data System (ADS)

Fiorini, Rodolfo A.; Dacquino, Gianfranco

2005-03-01

GEOGINE (GEOmetrical enGINE), a state-of-the-art OMG (Ontological Model Generator) based on n-D Tensor Invariants for n-Dimensional shape/texture optimal synthetic representation, description and learning, was presented in previous conferences elsewhere recently. Improved computational algorithms based on the computational invariant theory of finite groups in Euclidean space and a demo application is presented. Progressive model automatic generation is discussed. GEOGINE can be used as an efficient computational kernel for fast reliable application development and delivery in advanced biomedical engineering, biometric, intelligent computing, target recognition, content image retrieval, data mining technological areas mainly. Ontology can be regarded as a logical theory accounting for the intended meaning of a formal dictionary, i.e., its ontological commitment to a particular conceptualization of the world object. According to this approach, "n-D Tensor Calculus" can be considered a "Formal Language" to reliably compute optimized "n-Dimensional Tensor Invariants" as specific object "invariant parameter and attribute words" for automated n-Dimensional shape/texture optimal synthetic object description by incremental model generation. The class of those "invariant parameter and attribute words" can be thought as a specific "Formal Vocabulary" learned from a "Generalized Formal Dictionary" of the "Computational Tensor Invariants" language. Even object chromatic attributes can be effectively and reliably computed from object geometric parameters into robust colour shape invariant characteristics. As a matter of fact, any highly sophisticated application needing effective, robust object geometric/colour invariant attribute capture and parameterization features, for reliable automated object learning and discrimination can deeply benefit from GEOGINE progressive automated model generation computational kernel performance. Main operational advantages over previous, similar approaches are: 1) Progressive Automated Invariant Model Generation, 2) Invariant Minimal Complete Description Set for computational efficiency, 3) Arbitrary Model Precision for robust object description and identification.

Few effects of multi-generational dietary exposure to genistein or nonylphenol on sodium solution intake in male and female Sprague-Dawley rats.

PubMed

Ferguson, Sherry A; Delclos, K Barry; Newbold, Retha R; Flynn, Katherine M

2009-01-01

Previous work in our laboratory indicated that lifelong dietary exposure to estrogen-like endocrine disrupters increased sodium solution intake in adult male and female rats. Here, we sought to discern the critical periods necessary for this alteration as well as establish the effects of lower dietary concentrations of genistein and nonylphenol. Male and female Sprague-Dawley rats (F0) consumed phytoestrogen-free chow containing 0, 5, 100, or 500 ppm genistein (approximately equal to 0.0, 0.4, 8.0, and 40.0 mg/kg/day) or 0, 25, 200, or 750 ppm nonylphenol (approximately equal to 0.0, 2.0, 16.0, and 60.0 mg/kg/day). Rats were mated within treatment groups and offspring (F1) maintained on the same diets. Mating for the F1, F2, and F3 (genistein only) was within treatment groups. At postnatal day (PND) 21, the F3 generation began to consume unadulterated phytoestrogen-free chow such that genistein exposure occurred only in utero and preweaning. The F4 generation was never directly exposed to genistein. On PNDs 65-68, intake of regular water and a 3.0% sodium chloride solution was measured for F1-F4 generations (genistein portion) or F1-F2 (nonylphenol portion). Although body weights were decreased by the highest dietary concentrations of genistein and nonylphenol, there were only minimal effects of exposure on sodium solution intake. As expected, intake was highest in female rats. With previous data, these results indicate that the dietary concentrations necessary to increase adult sodium solution intake in rats are greater than 500 ppm genistein and 750 ppm nonylphenol and such effects do not appear to increase across generations.

Analysis of low-frequency seismic signals generated during a multiple-iceberg calving event at Jakobshavn Isbræ, Greenland

USGS Publications Warehouse

Walter, Fabian; Amundson, Jason M.; O'Neel, Shad; Truffer, Martin; Fahnestock, Mark; Fricker, Helen A.

2012-01-01

We investigated seismic signals generated during a large-scale, multiple iceberg calving event that occurred at Jakobshavn Isbræ, Greenland, on 21 August 2009. The event was recorded by a high-rate time-lapse camera and five broadband seismic stations located within a few hundred kilometers of the terminus. During the event two full-glacier-thickness icebergs calved from the grounded (or nearly grounded) terminus and immediately capsized; the second iceberg to calve was two to three times smaller than the first. The individual calving and capsize events were well-correlated with the radiation of low-frequency seismic signals (<0.1 Hz) dominated by Love and Rayleigh waves. In agreement with regional records from previously published ‘glacial earthquakes’, these low-frequency seismic signals had maximum power and/or signal-to-noise ratios in the 0.05–0.1 Hz band. Similarly, full waveform inversions indicate that these signals were also generated by horizontal single forces acting at the glacier terminus. The signals therefore appear to be local manifestations of glacial earthquakes, although the magnitudes of the signals (twice-time integrated force histories) were considerably smaller than previously reported glacial earthquakes. We thus speculate that such earthquakes may be a common, if not pervasive, feature of all full-glacier-thickness calving events from grounded termini. Finally, a key result from our study is that waveform inversions performed on low-frequency, calving-generated seismic signals may have only limited ability to quantitatively estimate mass losses from calving. In particular, the choice of source time function has little impact on the inversion but dramatically changes the earthquake magnitude. Accordingly, in our analysis, it is unclear whether the smaller or larger of the two calving icebergs generated a larger seismic signal.

Development of cyclic shedding teeth from semi-shedding teeth: the inner dental arcade of the stem osteichthyan Lophosteus

NASA Astrophysics Data System (ADS)

Chen, Donglei; Blom, Henning; Sanchez, Sophie; Tafforeau, Paul; Märss, Tiiu; Ahlberg, Per E.

2017-05-01

The numerous cushion-shaped tooth-bearing plates attributed to the stem group osteichthyan Lophosteus superbus, which are argued here to represent an early form of the osteichthyan inner dental arcade, display a previously unknown and presumably primitive mode of tooth shedding by basal hard tissue resorption. They carry regularly spaced, recumbent, gently recurved teeth arranged in transverse tooth files that diverge towards the lingual margin of the cushion. Three-dimensional reconstruction from propagation phase-contrast synchrotron microtomography (PPC-SRµCT) reveals remnants of the first-generation teeth embedded in the basal plate, a feature never previously observed in any taxon. These teeth were shed by semi-basal resorption with the periphery of their bases retained as dentine rings. The rings are highly overlapped, which evidences tooth shedding prior to adding the next first-generation tooth at the growing edge of the plate. The first generation of teeth is thus diachronous. Successor teeth at the same sites underwent cyclical replacing and shedding through basal resorption, producing stacks of buried resorption surfaces separated by bone of attachment. The number and spatial arrangement of resorption surfaces elucidates that basal resorption of replacement teeth had taken place at the older tooth sites before the addition of the youngest first-generation teeth at the lingual margin. Thus, the replacement tooth buds cannot have been generated by a single permanent dental lamina at the lingual edge of the tooth cushion, but must have arisen either from successional dental laminae associated with the individual predecessor teeth, or directly from the dental epithelium of these teeth. The virtual histological dissection of these Late Silurian microfossils broadens our understanding of the development of the gnathostome dental systems and the acquisition of the osteichthyan-type of tooth replacement.

Perceptions of Successful Aging: Intergenerational Voices Value Well-Being.

PubMed

Kelly, Gina Aalgaard; Lazarus, Jennie

2015-03-01

This study explored the perceptions of successful aging from intergenerational perspectives. A total of 66 participants were interviewed from three different generations including college students, parents, and grandparents. After qualitative data collection and analyses were used, five conceptual categories emerged from the data that related to perceptions of successful aging. The five concepts include wisdom, health, financial stability, staying active, and well-being. Conceptual categories emerged from the participants of different generations, and some were interconnected across generations. Each category is representative of major thematic patterns. Well-being was the primary concept which emerged because all three generations perceived and explicitly discussed well-being as the most valued aspect of successful aging. Previous successful aging research informed the use of a bio-psycho-social theoretical lens to frame the study findings and discussion. © The Author(s) 2015.

Dynamic test input generation for multiple-fault isolation

NASA Technical Reports Server (NTRS)

Schaefer, Phil

1990-01-01

Recent work is Causal Reasoning has provided practical techniques for multiple fault diagnosis. These techniques provide a hypothesis/measurement diagnosis cycle. Using probabilistic methods, they choose the best measurements to make, then update fault hypotheses in response. For many applications such as computers and spacecraft, few measurement points may be accessible, or values may change quickly as the system under diagnosis operates. In these cases, a hypothesis/measurement cycle is insufficient. A technique is presented for a hypothesis/test-input/measurement diagnosis cycle. In contrast to generating tests a priori for determining device functionality, it dynamically generates tests in response to current knowledge about fault probabilities. It is shown how the mathematics previously used for measurement specification can be applied to the test input generation process. An example from an efficient implementation called Multi-Purpose Causal (MPC) is presented.

Diode-Laser Pumped Far-Infrared Local Oscillator Based on Semiconductor Quantum Wells

NASA Technical Reports Server (NTRS)

Kolokolov, K.; Li, J.; Ning, C. Z.; Larrabee, D. C.; Tang, J.; Khodaparast, G.; Kono, J.; Sasa, S.; Inoue, M.; Biegel, Bryan A. (Technical Monitor)

2002-01-01

The contents include: 1) Tetrahertz Field: A Technology Gap; 2) Existing THZ Sources and Shortcomings; 3) Applications of A THZ Laser; 4) Previous Optical Pumped LW Generations; 5) Optically Pumped Sb based Intersubband Generation Whys; 6) InGaAs/InP/AlAsSb QWs; 7) Raman Enhanced Optical Gain; 8) Pump Intensity Dependence of THZ Gain; 9) Pump-Probe Interaction Induced Raman Shift; 10) THZ Laser Gain in InGaAs/InP/AlAsSb QWs; 11) Diode-Laser Pumped Difference Frequency Generation (InGaAs/InP/AlAsSb QWs); 12) 6.1 Angstrom Semiconductor Quantum Wells; 13) InAs/GaSb/AlSb Nanostructures; 14) InAs/AlSb Double QWs: DFG Scheme; 15) Sb-Based Triple QWs: Laser Scheme; and 16) Exciton State Pumped THZ Generation. This paper is presented in viewgraph form.

Machine learning in the string landscape

NASA Astrophysics Data System (ADS)

Carifio, Jonathan; Halverson, James; Krioukov, Dmitri; Nelson, Brent D.

2017-09-01

We utilize machine learning to study the string landscape. Deep data dives and conjecture generation are proposed as useful frameworks for utilizing machine learning in the landscape, and examples of each are presented. A decision tree accurately predicts the number of weak Fano toric threefolds arising from reflexive polytopes, each of which determines a smooth F-theory compactification, and linear regression generates a previously proven conjecture for the gauge group rank in an ensemble of 4/3× 2.96× {10}^{755} F-theory compactifications. Logistic regression generates a new conjecture for when E 6 arises in the large ensemble of F-theory compactifications, which is then rigorously proven. This result may be relevant for the appearance of visible sectors in the ensemble. Through conjecture generation, machine learning is useful not only for numerics, but also for rigorous results.

The Effects of Crossflow on the Pressures and Lift Induced by the Fountain Generated Between Two Impinging Jets

NASA Technical Reports Server (NTRS)

Kuhn, Richard E.

1998-01-01

When a jet STOVL aircraft is hovering, or in a crossflow, while close to the ground wall jets flowing radially outward from the impingement points of the jets are generated. An upflow, or fountain, is generated where the wall jets from adjacent jets meet on the ground surface. The induced lift and suckdown generated by the impingement of the fountain on the lower surface of the configuration has been the subject of previous studies. This study analyzes the limited available pressure and force data on the effect of crossflow on the fountain induced lift and suckdown. The analysis includes the effects of jet spacing, height and operating conditions. However, it is limited to twin jet configurations of circular, vertical jets operating at subcritical nozzle pressure ratios over a fixed ground surface.

In situ experimental study of carbon monoxide generation by gasoline-powered electric generator in an enclosed space.

PubMed

Wang, Liangzhu; Emmerich, Steven J; Persily, Andrew K

2010-12-01

On the basis of currently available data, approximately 97% of generator-related carbon monoxide (CO) fatalities are caused by operating currently marketed, carbureted spark-ignited gasoline-powered generators (not equipped with emission controls) in enclosed spaces. To better understand and to reduce the occurrence of these fatalities, research is needed to quantify CO generation rates, develop and test CO emission control devices, and evaluate CO transport and exposure when operating a generator in an enclosed space. As a first step in these efforts, this paper presents measured CO generation rates from a generator without any emission control devices operating in an enclosed space under real weather conditions. This study expands on previously published information from the U.S. Consumer Product Safety Commission. Thirteen separate tests were conducted under different weather conditions at half and full generator load settings. It was found that the CO level in the shed reached a maximum value of 29,300 +/- 580 mg/m3, whereas the oxygen (O2) was depleted to a minimum level of 16.2 +/- 0.02% by volume. For the test conditions of real weather and generator operation, the CO generation and the O2 consumption could be expressed as time-averaged generation/consumption rates. It was also found that the CO generation and O2 consumption rates can be correlated to the O2 levels in the space and the actual load output from the generator. These correlations are shown to agree well with the measurements.

Employing online quantum random number generators for generating truly random quantum states in Mathematica

NASA Astrophysics Data System (ADS)

Miszczak, Jarosław Adam

2013-01-01

The presented package for the Mathematica computing system allows the harnessing of quantum random number generators (QRNG) for investigating the statistical properties of quantum states. The described package implements a number of functions for generating random states. The new version of the package adds the ability to use the on-line quantum random number generator service and implements new functions for retrieving lists of random numbers. Thanks to the introduced improvements, the new version provides faster access to high-quality sources of random numbers and can be used in simulations requiring large amount of random data. New version program summaryProgram title: TRQS Catalogue identifier: AEKA_v2_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEKA_v2_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 18 134 No. of bytes in distributed program, including test data, etc.: 2 520 49 Distribution format: tar.gz Programming language: Mathematica, C. Computer: Any supporting Mathematica in version 7 or higher. Operating system: Any platform supporting Mathematica; tested with GNU/Linux (32 and 64 bit). RAM: Case-dependent Supplementary material: Fig. 1 mentioned below can be downloaded. Classification: 4.15. External routines: Quantis software library (http://www.idquantique.com/support/quantis-trng.html) Catalogue identifier of previous version: AEKA_v1_0 Journal reference of previous version: Comput. Phys. Comm. 183(2012)118 Does the new version supersede the previous version?: Yes Nature of problem: Generation of random density matrices and utilization of high-quality random numbers for the purpose of computer simulation. Solution method: Use of a physical quantum random number generator and an on-line service providing access to the source of true random numbers generated by quantum real number generator. Reasons for new version: Added support for the high-speed on-line quantum random number generator and improved methods for retrieving lists of random numbers. Summary of revisions: The presented version provides two signicant improvements. The first one is the ability to use the on-line Quantum Random Number Generation service developed by PicoQuant GmbH and the Nano-Optics groups at the Department of Physics of Humboldt University. The on-line service supported in the version 2.0 of the TRQS package provides faster access to true randomness sources constructed using the laws of quantum physics. The service is freely available at https://qrng.physik.hu-berlin.de/. The use of this service allows using the presented package with the need of a physical quantum random number generator. The second improvement introduced in this version is the ability to retrieve arrays of random data directly for the used source. This increases the speed of the random number generation, especially in the case of an on-line service, where it reduces the time necessary to establish the connection. Thanks to the speed improvement of the presented version, the package can now be used in simulations requiring larger amounts of random data. Moreover, the functions for generating random numbers provided by the current version of the package more closely follow the pattern of functions for generating pseudo- random numbers provided in Mathematica. Additional comments: Speed comparison: The implementation of the support for the QRNG on-line service provides a noticeable improvement in the speed of random number generation. For the samples of real numbers of size 101; 102,…,107 the times required to generate these samples using Quantis USB device and QRNG service are compared in Fig. 1. The presented results show that the use of the on-line service provides faster access to random numbers. One should note, however, that the speed gain can increase or decrease depending on the connection speed between the computer and the server providing random numbers. Running time: Depends on the used source of randomness and the amount of random data used in the experiment. References: [1] M. Wahl, M. Leifgen, M. Berlin, T. Röhlicke, H.-J. Rahn, O. Benson., An ultrafast quantum random number generator with provably bounded output bias based on photon arrival time measurements, Applied Physics Letters, Vol. 098, 171105 (2011). http://dx.doi.org/10.1063/1.3578456.

INVESTIGATING THE EFFECT OF MICROBIAL GROWTH AND BIOFILM FORMATION ON SEISMIC WAVE PROPAGATION IN SEDIMENT

EPA Science Inventory

Previous laboratory investigations have demonstrated that the seismic methods are sensitive to microbially-induced changes in porous media through the generation of biogenic gases and biomineralization. The seismic signatures associated with microbial growth and biofilm formation...

PILOT-SCALE INCINERATION TEST BURN OF TCDD-CONTAMINATED TRICHLOROPHENOL PRODUCTION WASTE

EPA Science Inventory

A series of three tests directed at evaluating the incinerability of the toluene stillbottoms waste from trichlorophenol production previously generated by the Vertac Chemical Company were performed in the Combustion Research Facility (CRF) rotary kiln incineration system. This w...

200 E Illinois St, December 2011, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Field gamma measurements within the excavation and the spoil materials generated during the excavation process did not exceed the respective threshold value previously stated and ranged from a minimum of 7,100 cpm to amaximum of 9,400 cpm unshielded.

158 East Ontario, July 23, 2013, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Field gamma measurements within the excavation and the spoil materials generated during the excavationprocess did not exceed the respective threshold values previously stated and ranged from a minimum of6,700 cpm to a maximum of 8,700 cpm unshielded.